Cat CM235 Continuous Miner Operation and Maintenance Manual A6474X454 - PDF DOWNLOAD

BI001594 A6474X454 July 2012

Operation and Maintenance Manual CM235 Continuous Miner A6474X454 (Hydraulic & Oil Cooling System)

SAFETY.CAT.COM

__________________________________________________________ This manual is intended to provide GENERAL product information .

The illustrations, descriptions and procedures contained in this publication apply only to THIS machine. Caterpillar reserves the right to revise models and designs without prior notice.

This machine was manufactured under the guidelines, procedures and requirements of the appropriate government regulatory agencies.

At the completion of the manufacturing process, this unit was issued the appropriate approval numbers and nameplates indicating it met the technical requirements of these regulatory agencies. Any change to the design or structure of this unit, without the consent of Caterpillar and these regulatory agencies, or any repair or replacement of parts contrary to the instructions, may invalidate these approvals and render this unit unsafe to operate.

Strict compliance with all laws, regulations and practices regarding the safe operation and maintenance of underground mining equipment and strict adherence to the instructions in this manual is necessary for the personal safety of those working on or around this unit.

While this manual attempts to anticipate the most important operations and maintenance needs for this unit, unforeseen circumstances may arise that have not been addressed in this manual. If any concerns or questions arise, please contact your service representative immediately.

This work contains information protected under trade secret and other intellectual property laws, and is protected under the U. S. Copyright Act of 1976, as amended. This work is provided under license and the license is non-transferable. Distribution and access is limited only to authorized personnel. Disclosure, reproduction, distribution or unauthorized use may be a violation of federal and state laws and may subject the unauthorized user to criminal liability.

© CATERPILLAR 2012 ALL RIGHTS RESERVED

_________________________________________________Table of contents

Table of contents Safety Instructions............................................................................. 4 Introduction........................................................................................ 6 Cylinder locations .............................................................................. 7 Component locations......................................................................... 8 Main control valve ............................................................................. 10 Hydraulic schematics ........................................................................ 11 Hydraulic pump ......................................................................... 11 Main flow/primary pressure ....................................................... 12 Pilot pressure ............................................................................ 13 Cutter head ............................................................................... 14 Conveyor raise/lower ................................................................ 17 Conveyor swing......................................................................... 19 Gathering head ......................................................................... 21 Stabilizer shoe........................................................................... 24 Conveyor chain take-up ............................................................ 26 Oil cooling schematics....................................................................... 27 Oil system component location ................................................. 28 Oil supply circuit ........................................................................ 29 Left hand chassis cooling circuit ............................................... 30 Right hand chassis cooling circuit............................................. 31 Conveyor deck (center chassis) cooling circuit......................... 32 Thermal transfer circuit ............................................................. 33 Tram track oiler circuit............................................................... 34 Hydraulic pump ................................................................................. 35 Hydraulic pump motor ....................................................................... 39 Adjustment procedures ..................................................................... 43 Troubleshooting................................................................................. 50

________________________________________________________________ A6474X454

REV 2

Safety instructions _______________________________________________ Safety Precautions

!

WARNING Failure to maintain the hydraulic system will result in damage to its hydraulic components which will result in increased wear and premature failure.

IMPORTANT

!

The following safety precautions should be observed whenever operating or performing any maintenance, repair, or adjustment procedure on this machine.

Additional precautions may appear in each section of this book. All precautions listed applicable to this machine, as well as all applicable regulatory agency rules and regulations must be followed at all times.

WARNING

During disassembly of control valves, give particular attention to identification of parts for reassembly. Spools are selectively fitted to valve bodies and must be returned to the same bodies from which they were removed. Spools are NOT interchangeable between valve bodies.

Do not salvage spools or valve bodies for later use in “new” combinations. Damaged or improper components used during assembly may result in internal leakage or in “sticking" (hanging up) of the spool in the valve body. Incorrect component combinations may result in improper operation of the valve section, possibly causing unexpected machine operation that could result in machine damage or injury to personnel.

IMPORTANT

The two inch locking ball valve between the pump and main control valve must be locked open in normal operation.

!

DANGER

Never run the conveyor without the needle valve closed. Injury or death may occur.

!

DANGER

The area under and around the raised cutter head is dangerous. Securely block the head before performing maintenance on or below it. Failure to block the raised cutter head could result in serious injury or even death.

!

DANGER

Do not adjust, modify, or remove the load holding cartridge valve mounted in the cutter head cylinders. It is a safety feature to prevent accidental lowering of the cutter head.

!

DANGER

This load holding valve, like those on the stabilizer cylinders is preset. DO NOT ADJUST IT. If it malfunctions, replace it immediately.

!

WARNING

!

WARNING Use extreme caution when performing test procedures and making adjustments. Unless noted in the procedures, all controls are to be in the neutral position.

You could be seriously injured or killed by falling loads. Block the miner before performing maintenance and always observe the safe working load limits of all lifting and blocking devices.

IMPORTANT

Always use the proper tools when adjusting valve cartridges.

IMPORTANT

Do not start any motors - CLA, cutter head, pump, or traction motors - until all pressures are set. Start the pump motor as directed.

________________________________________________________________ 4 CM235 Hydraulics

______________________________________________ Safety instructions IMPORTANT

!

WARNING Two people are required to adjust pressure settings. One person will make the adjustments while the second person must remain at the machine stop at all times during the adjustment procedure. Failure to do so may result in serious injury or death.

IMPORTANT

!

Never rely on the load holding valve as a means of supporting the cutter or conveyor boom while making repairs. Severe injury or death could result.

Before making any further adjustments, verify that the hydraulic oil is at operating temperature.

WARNING Always allow cylinder functions to bottom out (stop moving) before adjusting any pressure. Pressure adjustments will only be accurate when the cylinder is in this condition.

IMPORTANT

The main relief is set higher than the port reliefs and will only relieve if a spike occurs in the system or if the port relief does not function properly. This provides protection of the main pump section.

!

DANGER

Do not adjust the main relief over 3,000 psi (207 bar). Destruction of the valve bank and the main pump could result.

!

DANGER

Always be alert for any unintended machine movement.

!

WARNING Keep body parts clear of machine while in raised position or serious injury could result.

!

WARNING Some procedures must be carried out with the cover of the electrical controller removed and some procedures require the controller to be energized during the tests. It is extremely important that you take all necessary precautions to prevent accidental electrical shock while working within the controller. An certified electrician must supervise and inspect all work performed.

!

WARNING Never disconnect a hydraulic hose if the circuit is pressurized or there is a load on the circuit. If a hose is disconnected while the cylinder is supporting a load, the load will fall.

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Hydraulic _______________________________________________________ Introduction

Hydraulic power for all hydraulically-actuated functions originates with the pump assembly. This includes power for cylinders, hydraulic motors, control valves, and pilot valves.

Fig. 1 gives an overview of hydraulic cylinders located on the CM235 Continuous Miner. Fig. 2 shows the location of other hydraulic components.

Schematics

This section gives general descriptions of the hydraulic components used on the miner along with typical schematics for hydraulic functions. The schematics in this section are general; always refer to the hydraulic schematic in your parts manual supplied with your machine.

Hydraulic Maintenance

In order for a hydraulic system to function correctly, it must be properly maintained. Maintenance of the hydraulic system includes: 1. maintaining atmospheric pressure in the tank by keeping the breather clean and free of obstructions; 2. maintaining a sufficient oil level in the tank; 3. maintaining tight, leak-proof pump suction lines to prohibit air being pumped through the system; and 4. changing filters and fluids at prescribed intervals.

For complete maintenance procedures, see the Maintenance Manual.

!

WARNING Failure to maintain the hydraulic system will result in damage to its hydraulic components which will result in increased wear and premature failure.

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_______________________________________________________Hydraulic Fig. 1: Cylinder locations

1

1

2

7

2 1

3

4

4

3

3

4

5 5

6

1. Cutter head raise cylinder 2. Gathering head raise cylinder 3. Conveyor lift cylinder

6

6

4. Stabilizer shoe cylinder 5. Conveyor swing cylinder 6. Conveyor chain take-up cylinder

______________________________________________________________ A6474X454 REV 2 7

_______________________________________________________Hydraulic Main Control Valve

The Main Control Valve (MCV) (Fig. 3), typically located on the right side of the machine, consists of a series of directional control valves assembled in a row.

Typically, there are (5) five working sections. The MCV directs fluid flow to perform a specific function of work that transforms hydraulic energy into mechanical energy. Control may be initiated manually or electrically (through the solenoid pilot valve).

If the valve sections are separated for any reason, make sure that all reassembled parts are in their proper location and that all mating surfaces are free of burrs and foreign items (paint, dirt, etc.). Assembly stud nuts or screws should be tightened to specified torques.

IMPORTANT

!

During disassembly of control valves, give particular attention to identification of parts for reassembly. Spools are selectively fitted to valve bodies and must be returned to the same bodies from which they were removed. Spools are NOT interchangeable between valve bodies.

Do not salvage spools or valve bodies for later use in “new” combinations. Damaged or WARNING improper components used during assembly may result in internal leakage or in "sticking" (hanging up) of the spool in the valve body. Incorrect component combinations may result in improper operation of the valve section, possibly causing unexpected machine operation that could result in machine damage or injury to personnel.

______________________________________________________________ A6474X454 REV 2 8

Hydraulic _______________________________________________________ Fig. 2: Hydraulic component location

1 2

11

1 4 3

5

8 6

9 10 7

1.

2.

3.

4.

5.

6.

Breather Tank magnet Oil level switch Gathering head float valve Conveyor chain take-up valve Relief valve, pilot pressure

7. Pilot pressure filter 8. Main pressure gauge 9. Hydraulic pump 10. Valve bank 11. Anti-chatter/maintenance valve

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Hydraulic _______________________________________________________ Fig. 3: Main control valve

2

1

3

8

9

10

11

12 7

6

4

1.

2.

3.

4.

Main inlet relief Pressure supply Tank return “A” port relief (typical)

5.

6.

7.

8.

“B” port relief (typical) “B” pressure solenoid (5 places) “A” pressure solenoid (5 places) Stabilizer shoe section

5

9. Conveyor swing section 10. Conveyor raise section 11. Gathering head section 12. Cutter raise section

________________________________________________________________ 10 CM235 Hydraulics

_______________________________________________________Hydraulic Hydraulic Pump Assembly

Hydraulic power for all of the hydraulically actuated functions originates with the pump assembly (Fig. 4). Always be sure the shut-off valve (if equipped) is turned to open and the locking device is replaced before starting the machine.

Hydraulic Pump On Circuit

This pump utilizes three working sections: main flow, cooling circuit and pilot flow. Oil is supplied from the oil reservoir through a suction line to the pump inlet ports. The main flow is monitored by a pressure gauge before entering the main control valve. After leaving the pump, the pilot flow enters a bypass filter, a relief valve set at 800 psi (55 bar) and a non-bypassing filter before continuing on to a pressure manifold which feeds the conveyor take-up circuit, tram oiler, gathering head circuit, tram breaker and main control valve.

IMPORTANT

The two inch locking ball valve must be locked open in normal operation.

Fig. 4: Hydraulic pump circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 11

Hydraulic _______________________________________________________ Main Flow Primary Pressure Circuit

The main flow-primary pressure circuit is powered by the hydraulic pump.

From the pump, oil enters the main control valve, whose relief is set at 3,000 psi (204 bar). The main control valve operates all cylinder functions.

Oil from both the primary circuit exits the main control valve and passes to a bypassing filter set at 40 psi (2.75 bar) and a temperature gauge and temperature control thermostat before passing to the oil reservoir. A hand pump, along with two check valves and a quick disconnect, is attached to the oil return line.

Fig. 5: Main flow-primary pressure circuit (pump running)

Pressure Return Suction

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_______________________________________________________Hydraulic Pilot Pressure Circuit

The pilot hydraulic section is a closed-center system powered by the hydraulic pump. It supplies oil flow to the following: 1. hydraulic tension conveyor chain take-up 2. gathering head float circuit, and 3. all solenoid valves, which control the tram breaker, shear down circuit and all main control valve functions.

From the pump, oil flows through a 5 micron oil pressure bypassing filter, a relief valve set at 600 psi (41 bar) and a non-bypassing filter before being distributed to the conveyor take-up, tram track oiler, tram breaker and main control valve.

Fig. 6: Pilot pressure circuit (pump running)

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 13

Hydraulic _______________________________________________________ !

DANGER

The area under and around the raised cutter head is dangerous. Securely block the head before performing maintenance on or below it. Failure to block the raised cutter head could result in serious injury or even death.

Cutter Head Cylinder

Circuit Operation - Raise

Circuit Operation - Lower

Oil is supplied from the hydraulic pump to the cutter head working section of the main control valve. By manual or remote solenoid control, the valve spool allows oil to enter the cutter head cylinder circuit.

Reference Fig. 8: To manually raise the cutter head (extend cylinders), pull the valve’s handle. Remote operation is achieved by energizing the cutter head raise solenoid (CHU). Oil goes to port “P2” and continues to the extend port of the cylinders, free flowing through the check valve of the load holding cartridge to extend the cylinders. The cutter head raise circuit is protected by a port relief that is set at 2,800 psi (193 bar).

Reference Fig. 9: To manually lower the cutter head (retract cylinders), push the valve’s handle. Remote operation is achieved by energizing the cutter head lower (CHD) solenoid. Oil goes to the retract port of the cylinders and also pilots open the load holding cartridge, allowing oil to exit through the extend ports on the cylinders. The extend port oil continues to the shear down relief valve block, where it passes through a counterbalance valve, which is set to relieve at 1,200 psi (83 bar), then through the main control valve and into the oil tank.

!

DANGER

Do not adjust, modify, or remove the load holding cartridge valve mounted in the cutter head cylinders. It is a safety feature to prevent accidental lowering of the cutter head.

!

DANGER

This load holding valve, like those on the stabilizer cylinders is preset. DO NOT ADJUST IT. If it malfunctions, replace it immediately.

!

WARNING

You could be seriously injured or killed by falling loads. Block the miner before performing maintenance and always observe the safe working load limits of all lifting and blocking devices.

________________________________________________________________ 14 CM235 Hydraulics

_______________________________________________________Hydraulic Fig. 8: Cutter head raise circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 15

Hydraulic _______________________________________________________ Fig. 9: Cutter head lower circuit

Pressure Return Suction

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_______________________________________________________Hydraulic conveyor Raise/Lower Circuit

Oil is supplied by the hydraulic pump to the conveyor raise/lower working section of the main valve control. By manual or remote solenoid control, the valve spool allows oil to enter the conveyor raise/lower cylinder circuit

Circuit Operation - Raise (extend)

Reference Fig. 10: To manually raise the conveyor (extend the cylinders), pull the valve’s handle. Remote operation is achieved by energizing the conveyor raise (CU) solenoid. Oil free flows through pilot operated check valves to the extend port of the cylinders. The conveyor raise circuit is protected by a port relief that is set at 2,200 psi (152 bar).

Circuit Operation Lower (retract)

Reference Fig. 11: To manually lower the conveyor (retract the cylinders), push the valve’s handle. Remote operation is achieved by energizing the conveyor lower (CD) solenoid. Oil is directed to the pilot port on the pilot operated check valve on the cylinders. This “pilots” the check valve open and allows oil to exit the cylinders through the main control valve and return to tank. The conveyor lower circuit is protected by a port relief that is set at 1,400 psi (97 bar).

Fig. 10: Conveyor raise

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 17

Hydraulic _______________________________________________________ Fig. 11: Conveyor lower

Pressure Return Suction

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_______________________________________________________Hydraulic Conveyor Swing Cylinder

Oil is supplied by hydraulic pump to the conveyor swing working section on the main control valve. By manual or remote solenoid control, the spool allows oil to enter the swing circuit. The range on the cylinder will allow the conveyor tail to move 45 degrees off the centerline of machine in both directions.

Circuit Operation Right (extend)

Reference Fig. 12: To manually move the conveyor to the right (extend the cylinder), pull the valve’s handle. Remote operation is achieved by energizing the conveyor swing left (CSL) solenoid. Oil free flows to the extend port of the cylinder. The conveyor swing right circuit is protected by a port relief that is set at 1,800 psi (25 bar).

Circuit Operation Left (retract)

Reference Fig. 13: To manually move the conveyor to the left (retract the cylinder, push the valve’s handle. Remote operation is achieved by energizing the conveyor swing right (CSR) solenoid. Oil free flows to the retract port of the cylinder. The conveyor swing left circuit is protected by a port relief that is set at 1,800 psi (125 bar).

Fig. 12: Conveyor swing cylinder circuit - right

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 19

Hydraulic _______________________________________________________ Fig. 13: Conveyor swing cylinder circuit - left

Pressure Return Suction

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_______________________________________________________Hydraulic Gathering Head Raise/ Hold/Float/Lower Circuit

Circuit Operation Raise (extend)

Circuit Operation Lower (retract)

Oil is supplied by the hydraulic pump to the gathering head working section of the main control valve. By manual or remote solenoid control, the valve spool allows oil to enter the gathering head raise circuit.

Reference Fig. 14: To manually raise the gathering head pan (extend the cylinder), push the valve’s handle. Remote operation is achieved by energizing the gathering head up solenoid (GHU). Oil free flows through the check valve in counterbalance valve designated “VR” in the gathering head float valve block and is directed to both cylinder extend ports. At any time while raising the gathering head, the operator can stop the gathering head pan by centering the handle on the valve (or de-energizing the solenoid) and the pan will hold in position. The gathering head raise circuit is protected by a port relief that is set at 1,700 psi (117 bar).

Reference Fig. 15: To put the gathering head pan in the lower mode, pull the valve’s handle. Remote operation is achieved by energizing the gathering head down (GHD) solenoid. This vents the port labeled “V” on the gathering head float valve block to tank and allows control of the gathering head lower via the valves in the block. The counterbalance valve “VR” is set to relieve at 1,200 psi to allow the gathering head to drift down at a controlled rate of speed. This valve is adjustable and the rate of retract speed for the cylinders can be increased by decreasing the pressure setting of the valve.

Conversely, the retract speed for the cylinders can be decreased by increasing the pressure setting of the valve. When in the float condition, the cylinders carry some of the gathering head pan weight to prevent the gathering head leading edge from digging into the soft bottom of the mine and moves the machine’s center of gravity forward when mining. The gathering head lower circuit is protected by a port relief that is set at 1,700 psi (117 bar).

The counterbalance valve that is designated “CR” is set to relieve at 1,800 psi (124 bar). This setting will relieve pressure directly to the tank in the event of a forced movement of the gathering head.

The pilot pressure supply for the gathering head float comes from the hydraulic pump through a 2 micron non-bypass filter and a pressure reducing valve, to the pressure manifold and the gathering head float valve. The pilot pump provides make up oil for the gathering head cylinders. When the pan goes over uneven terrain, it may raise quickly and extend the gathering head cylinders at a rapid rate. This temporary condition can create high demand for pilot oil supply. In extreme cases, the pilot pressure may decrease to the point where the main control valve may not have sufficient pilot pressure to shift when the solenoids are engaged. It is, therefore, possible to experience a momentary loss of radio control of the machine.

To minimize the chance of the occurrence, a restrictor orifice is installed in the pilot supply for the valve block. This orifice is protected from contamination by an upstream filter. A downstream check valve keeps system pressure from entering the pilot pressure lines. An adjustable needle valve allows for the bleeding off of pressure for maintenance. This needle valve is to remain closed except for performing maintenance. A gauge port is incorporated into the valve block for maintenance and troubleshooting.

______________________________________________________________ A6474X454 REV 2 21

Hydraulic _______________________________________________________ Fig. 14: Gathering head raise circuit

Pressure Return Suction

________________________________________________________________ 22 CM235 Hydraulics

_______________________________________________________Hydraulic Fig. 15: Gathering head lower circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 23

Hydraulic _______________________________________________________ Stabilizer Shoe Cylinders

Oil is supplied by the hydraulic pump to the stabilizer shoe working section of the main control valve. By manual or remote solenoid control, the valve spool allows oil to enter the stabilizer shoe circuit.

Circuit Operation - Raise (retract)

Reference Fig. 16: To manually raise the stabilizer shoe (retract the cylinder), pull the valve’s handle. Oil free flows to the retracted port of the cylinder. The stabilizer raise circuit is protected by a port relief that is set at 1,150 psi (79 bar).

Circuit Operation - Lower (extend)

Reference Fig. 17: To manually lower the stabilizer shoe (extend the cylinders), push the valve’s handle.

Fig. 16: Stabilizer shoe circuit - raise (retract)

Pressure Return Suction

________________________________________________________________ 24 CM235 Hydraulics

_______________________________________________________Hydraulic Fig. 17: Stabilizer shoe circuit - lower (extend)

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 25

Hydraulic _______________________________________________________ Conveyor Chain TakeUp Circuit (optional)

Reference Fig. 18: The pilot-auxiliary hydraulic pressure circuit is powered by the hydraulic pump. From the pump, oil provides hydraulic power to the hydraulic tension conveyor chain take-up and to the four pilot pressure circuits.

The oil continues to the conveyor chain take-up valve where it passes thru a free flow check valve cartridge out to (2) two conveyor chain take-up cylinder assemblies. The conveyor chain take-up valve consist of a check valve to hold pressure in the circuit, a pressure reducing/relieving cartridge to reduce the pilot pressure to 200 psi for conveyor chain tension and relieves pressure build up above 200 psi. A needle valve cartridge relieves pressure from the circuit for maintenance.

!

DANGER

Never run the conveyor without the needle valve closed. Injury or death may occur.

Fig. 18: Conveyor chain take-up circuit

Pressure Return Suction

________________________________________________________________ 26 CM235 Hydraulics

______________________________________________ Oil Cooling System Introduction

An oil supply to the continuous miner is required for the following purposes: 1. cooling oil for all motors 2. cooling oil for the tram case 3. thermal transfer located on left and right ventilation ducts 4. tram track oiling

Schematics

The oil flow must meet the following requirement: 1. minimum flow rate per circuit of 5 gpm for cooling. Adjustments may be made as needed to achieve best cooling.

The oil system circuit in this manual is for a typical CM235 miner. The circuit for your machine may vary depending on your unique requirements. Always refer to the schematic in the parts book for your machine.

______________________________________________________________ A6474X454 REV 2 27

Oil Cooling System _______________________________________________ Fig. 22: Oil cooling system component locations

3 2 5 4

6 7 1

10 11

11

8

9

1. 3-unit oil cooling manifold 2. Thermal transfer - left hand ventilation duct 3. Thermal transfer - right hand ventilation duct 4. Thermal transfer - intermediate conveyor deck 5. Flow control cooling valve 6. Flow meter (3) 7. Flow control valve 8. Temperature gauge 9. Thermostat 10. Logic valve 11. Oilers (2)

________________________________________________________________ 28 CM235 Hydraulics

______________________________________________ Oil Cooling System Oil Supply Circuit

Cooling oil is supplied to the left, right and center cooling circuits from the pump typically located on the right hand side of the miner. The cooling oil supply to the miner is controlled through a 2 position, manually-operated ball valve.

Oil then flows through a relief valve set at 250 psi (17 bar) and a flow control valve to a 3-unit flow control cooling valve. Oil then flows to 10 gpm flow meters before supplying oil to the left, right and center cooling circuits.

Fig. 21: Oil supply circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 29

Oil Cooling System _______________________________________________ Left Hand Chassis Cooling Circuit

Cooling oil is supplied to the left chassis cooling circuit from the pump typically located on the right hand side of the miner. Oil then flows through a relief valve set at 250 psi (17 bar) and a flow control valve to a 3-unit flow control cooling valve. Oil then flows to a 10 gpm flow meter before supplying oil to the left hand chassis cooling circuit which includes the left tram motor, CLA motor, and cutter motor. Oil then flows to a 5-port pressure manifold.

Fig. 22: Left hand chassis cooling circuit

Pressure Return Suction

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______________________________________________ Oil Cooling System Right Hand Chassis Cooling Circuit

Cooling oil is supplied to the right chassis cooling circuit from the pump typically located on the right hand side of the miner. Oil then flows through a relief valve set at 250 psi (17 bar) and a flow control valve to a 3-unit flow control cooling valve. Oil then flows to a 10 gpm flow meter before supplying oil to the right hand chassis cooling circuit which includes the pump motor, and right tram, CLA and cutter motors. Oil then flows to a 5-port pressure manifold.

Fig. 22: Right hand chassis cooling circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 31

Oil Cooling System _______________________________________________ Conveyor Deck (Center Chassis) Cooling Circuit

Cooling oil is supplied to the intermediate conveyor deck (center chassis) cooling circuit from the pump typically located on the right hand side of the miner.

Oil then flows through a relief valve set at 250 psi (17 bar) and a flow control valve to a 3-unit flow control cooling valve. Oil then flows to a 10 gpm flow meter before supplying oil to the center chassis cooling circuit which includes the intermediate conveyor deck thermal transfer and the tram case. Oil then flows to a 5-port pressure manifold.

Fig. 22: Conveyor deck (center chassis) cooling circuit

Pressure Return Suction

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______________________________________________ Oil Cooling System Thermal Transfer Cooling Circuit

After cooling all motors and the tram case located on the left, right and center circuits, oil then flows to a 5-port pressure manifold. From the manifold, cooling oil also passes through left and right hand thermal transfer ventilation ducts monitored by check valves on both sides of the miner. A temperature gauge, located on the right hand side of the miner, measures the temperature of the oil.

Oil temperature is controlled by a temperature control thermostat before returning to tank.

Fig. 25: Thermal transfer cooling circuit

Pressure Return Suction

______________________________________________________________ A6474X454 REV 2 33

Oil Cooling System _______________________________________________ Tram Oiler Circuit

Oil feeds from a pilot supply and the cutter head lower circuit into a logic valve before passing through a flow control valve and either flowing to tank or to two “lube minder” adjustable oilers which supply oil to left and right tram tracks. A used oil tank is located on the circuit between the two oilers.

Fig. 25: Tram oiler circuit

Pressure Return Suction

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_________________________________________________ Hydraulic Pump Introduction

The following procedure is for the removal and installation of the hydraulic pump.

Tool Set

Basic Tool Set

Safety

When removing or installing the hydraulic pump, observe the following safety precautions:

Blocking

!

WARNING You could be seriously injured or killed by falling loads. Observe the safe working load limits of all lifting and blocking devices and keep a safe distance from suspended loads.

!

WARNING Failure to follow all applicable lockout/tagout procedures may result in machine damage or serious injury or death of personnel.

______________________________________________________________ A6474X454 REV 2 35

Hydraulic Pump __________________________________________________ Hydraulic Pump Removal

To remove the hydraulic pump (Fig. 204): 1. Lower the conveyor tail section until it is level with the floor.

2. Lower the gathering head and cutter head assemblies until they rest on the floor.

3. Disconnect the trailing cable to de-energize the miner. Follow all Federal and mine regulations for lockout/tagout.

4. Locate the rub rail directly behind the tram case on the operator’s side of the miner. Remove the two rub rail pins that secure the rub rail to the two rub rail sections adjacent to it and remove the rub rail.

5. Swing the operator’s case outward and locate the hydraulic pump and motor assembly.

6. Using the adjustable wrench, disconnect the inlet hose from the pump. Plug the hose end to keep it clean.

7. Using the adjustable wrench, disconnect the pilot and valve hoses from the pump fittings. Plug the hose ends to keep them clean.

Fig. 204: Hydraulic pump

Rub rail Operator’s case

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_________________________________________________ Hydraulic Pump Fig. 205: Hydraulic pump installation

Motor

Pump

Lockwasher Hex head capscrew

______________________________________________________________ A6474X454 REV 2 37

Hydraulic Pump __________________________________________________ Hydraulic Pump Installation

To install the hydraulic pump: 1. Slide the pump assembly into the pump motor (Fig. 205).

2. Insert and tighten, hex head capscrews and lockwashers to secure the pump assembly to the motor.

3. Insert the hydraulic hose fittings into the pump assembly and tighten.

4. Attach and tighten the exit pilot and valve hoses to the pump fittings.

5. Attach the inlet hose to the pump.

6. Replace the rub rail between the two adjacent rub rails and secure it with the two rub rail pins.

7. Check the hydraulic fluid level.

8. Jog pump motor on and off a few times to prime the pump before starting.

________________________________________________________________ 38 CM235 Hydraulics

___________________________________________ Hydraulic Pump Motor Introduction

The following procedure is for the removal and installation of the hydraulic pump motor.

Tool Set

Basic Tool Set

Safety

When removing or installing the hydraulic pump motor, observe the following safety precautions:

!

WARNING Failure to follow all applicable lockout/tagout procedures may result in machine damage or serious injury or death of personnel.

!

WARNING The hydraulic pump motor is extremely heavy. Prepare to support its weight before removing it from the tractor frame.

______________________________________________________________ A6474X454 REV 2 39

Hydraulic Pump Motor _____________________________________________ Hydraulic Pump Motor Removal

To remove the hydraulic pump motor (Fig. 206): 1. Lower the conveyor tail section it is level with the floor.

2. Lower the gathering head and cutter head until they touch the floor.

3. Disconnect the trailing cable to de-energize the miner.

4. Remove the hydraulic pump (see Hydraulic pump removal procedure in this chapter).

5. Remove the four (4) 3/4 X 1 1/2” hex head capscrews that secure the motor to the pump stand.

6. Remove the two (2) 1/2 X 1 1/2” hex head capscrews and lockwashers that secure the pump stand to the tractor frame and remove the pump stand.

Fig. 206: Hydraulic pump stand removal

Hex head capscrew

Motor

Pump stand Lockwashers Hex head capscrew

________________________________________________________________ 40 CM235 Hydraulics

___________________________________________ Hydraulic Pump Motor 7. Remove the cover and its o-ring from the motor’s junction box by removing four hex head capscrews and lockwashers.

8. Locate the three taped power connections inside the junction box.

9. Strip off the three layers of tape covering each of the three lug connections inside the junction box.

10. Tag the three lugs to facilitate reconnection during motor installation.

11. Remove the hex head capscrew, flat washer, lockwasher, and hex head nut that secures the three power cable lugs to the three motor lugs.

12. Remove the two socket head capscrews and lockwashers that secure the stuffing box’s half-moon clamp to the junction box.

13. Remove the clamp and slide the stuffing box out of the junction box.

The power cable should be completely disconnected from the motor.

14. To prevent damage to the power cable lugs and gland assembly, cover the power cable and secure it to the miner in a safe location.

15. To protect the motor’s electrical connections, replace the motor junction box cover and secure it using four hex head capscrews and lockwashers.

16. Carefully slide the hydraulic pump motor out of the tractor frame.

______________________________________________________________ A6474X454 REV 2 41

Hydraulic Pump Motor _____________________________________________ Hydraulic Pump Motor Installation

To install the hydraulic pump motor (Fig. 202): 1. Slide the hydraulic pump motor into position in the tractor frame.

2. Remove the four hex head capscrews and lockwashers that secure the junction box cover and remove the cover and its o-ring.

3. Insert the three lugs of the power cable (with gland and stuffing box already installed) into the motor’s junction box.

4. Replace the stuffing box’s half-moon clamp in its channel to secure the stuffing box in the junction box.

5. Tighten the two socket head capscrews to secure the clamp to the junction box.

6. Inside the junction box, locate the motor’s lug connections. Match the motor lug connections to the corresponding power cable lugs (refer to the wiring diagram supplied in your parts manual).

7. Attach the first motor lug to its corresponding power cable lug by inserting a hex head capscrew through the motor lug, through the power cable lug, through a flat washer, and through a lockwasher. Secure the capscrew with a hex nut. Repeat this step for the other two lugged connections.

8. When all three connections have been secured, wrap the first connection with a layer of glass tape, the second connection with a layer of rubber tape and the third with a layer of plastic tape.

9. Replace the junction box o-ring and cover.

10. Insert the four hex head capscrews and lockwashers to secure the junction box cover and tighten.

11. Position the pump stand against the motor and attach to the motor with four (4) 3/4 X 1 1/2” hex head capscrews.

12. Insert and tighten the two (2) 1/2 X 1 1/2” hex head capscrews and lockwashers to secure the pump stand to the tractor frame.

13. Install the hydraulic pump (see hydraulic pump installation procedure in this chapter).

________________________________________________________________ 42 CM235 Hydraulics

___________________________________________ Adjustment procedures Introduction

1. Always refer to the hydraulic schematic in the parts book supplied with your miner.

2. Most relief valves are set to factory specifications and should require no further adjustment.

3. Generally speaking, when adjusting relief valves, turning the adjusting screw in (clockwise) will increase the pressure setting.

4. If the valve pressure setting is unknown, always adjust the valve fully counterclockwise prior to initiating any action that will create flow and prove the potential for pressure.

!

WARNING Use extreme caution when performing test procedures and making adjustments.

Unless noted in the procedures, all controls are to be in the neutral position.

Gauges

The miner is equipped with an isolator hydraulic pressure gauge to aid in setting relief pressures. The gauge measures the following pressures: 1. main pressure (all functions of the MCV) 2. pilot pressure (regulated 500 psi) 3. pilot pressure (regulated 1800 psi) 4. conveyor chain take-up pressure 5. gathering head float/relief pressure 6. pan assist pressure

Setting Relief Valves

Setting relief valve pressure is necessary when a relief valve is replaced with a new unit or when an existing relief valve needs to be adjusted. To properly adjust a relief valve, the circuit must be “dead-headed”.

Setting Hydraulic Pressures

The adjustment procedure should start with the pilot pressure circuit. This system will build pressure as soon as the pump is started. The main relief valve on the main control valve (MCV) and the pilot pressure relief valve should be adjusted to their lowest setting prior to initial start up and adjustment. Reference circuit descriptions, abbreviations, and terms in the Hydraulic Components section of this chapter.

Flow Control Cooling Valve

The flow control cooling valve should be adjusted to have approximately 5 gpm on each circuit. Adjustments may be made as needed to achieve best cooling. Reference the oil supply circuit in the Hydraulic Schematics section of this manual.

______________________________________________________________ A6474X454 REV 2 43

Adjustment procedures ___________________________________________ Tram Track Oiler

Adjustments to the tram track oilers can be made to increase or decrease the amount of oil being sprayed per cycle. The following procedures will help achieve desired results.

Prior to startup, the oilers must be primed. Follow these steps to prime the oilers: 1. Remove the oiler lines that feed the track spray including the check valves.

2. Leave the lines open for a few minutes of or until oil starts dripping.

3. Re-install the lines with the check valves (check valves must be present in order for the oilers to work).

To adjust the amount of oil sprayed per cycle on the tram tracks:

1. Locate the adjustment nuts and screws on the bottom of each oiler.

2. Loosen the nut and screw IN the stem to DECREASE the amount of oil being sprayed. Screw OUT the stem the INCREASE the amount of oil being sprayed. Reseat the nut once the desired spray is achieved.

IMPORTANT

Do not start any motors - CLA, cutter head, pump, or traction motors - until all pressures are set. Start the pump motor as directed.

Load Holding Valve Adjustment

IMPORTANT

The load holding valve is factory preset and should not be field adjusted.

Never rely on the load holding valve as a means of supporting the cutter or conveyor boom while making repairs. Severe injury or death could result.

Adjustment procedure should start with the pilot/auxiliary pressure circuit, which will build pressure as soon as the pump is started.

________________________________________________________________ 44 CM235 Hydraulics

___________________________________________ Adjustment procedures Pilot Pump Circuit Relief Valve Adjustments !

The following procedure is for start up of new and rebuilt machines:

WARNING Two people are required to adjust pressure settings. One person will make the adjustments while the second person must remain at the machine stop at all times during the adjustment procedure. Failure to do so may result in serious injury or death.

1. Reduced pilot pressure circuit: loosen the nut on the pressure reducing valve cartridge and turn the screw out (counter-clockwise) using an Allen wrench to prevent over pressuring the gauge on this circuit.

2. Start the pump motor and adjust the pilot pressure relief valve. a. Loosen the nut on the valve cartridge and, using an Allen wrench, turn the screw in (clockwise) to increase pressure or out (counter-c lockwise) to decrease pressure. Refer to the hydraulic schematic for pressure setting.

3. Adjust the reduced pilot pressure valve. b. Turn the cartridge in (clockwise) until the pressure reading is 350 psi. c. While holding the cartridge in place, tighten the nut to lock the spool in place. Double check the pressure reading to ensure that the cartridge was not turned while tightening the nut.

4. Readjust the pilot pressure relief valve, is necessary, to 600 psi.

Relief valve replacement Pilot relief valve replacement: Set the pilot relief to 600 psi, per Step 3, making sure that the conveyor chain take-up knob is closed (turn clockwise to IMPORTANT Before making any further adjustments, verify that the hydraulic oil is at operating

temperature.

______________________________________________________________ A6474X454 REV 2 45

Adjustment procedures ___________________________________________ Conveyor Chain Take-Up Valve Replacement:

Set the pilot relief to 200 psi (14 bar), per step 4 of the Pilot/auxiliary pump circuit relief valve adjustments procedure, making sure the conveyor chain takeup needle valve is closed (turn clockwise to close).

Main Control Valve Working Port Relief Adjustment

Each valve bank section, with the exception of the gathering head, stabilizer shoe and cutter head, has two (2) working port reliefs (Fig 25). When the handle is pulled (spool in), oil is directed to the work port and relief closest to the handle; this is “A” port. When the handle is pushed in (spool out), oil is directed to the work port and relief farthest from the handle; this is ‘B” port.

Fig. 25: Main control valve Port reliefs

“A” port relief !

“B” port relief

WARNING Always allow cylinder functions to bottom out (stop moving) before adjusting any pressure. Pressure adjustments will only be accurate when the cylinder is in this condition.

IMPORTANT The main relief is set higher than the port reliefs and will only relieve if a spike occurs in

the system or if the port relief does not function properly. This provides protection of the main pump section.

!

DANGER

Do not adjust the main relief over 3,000 psi (207 bar). Destruction of the valve bank and the main pump could result.

!

DANGER

Always be alert for any unintended machine movement.

IMPORTANT Reference the Hydraulic section in this chapter for individual circuit information. Al-

ways refer to the hydraulic schematic in your parts manual for your miner.

Always allow cylinder Two people functions are required to bottom to adjust out (stop pressure moving) settings. before adjusting One person anywill pressure. make the Pressure adjustWARNING ! ! WARNING ments adjustments while the will second only be person accurate must when remain the at cylinder the machine is in this stop condition. at all times during the adjustment procedure. Failure to do so may result in serious injury or death.

________________________________________________________________ 46 CM235 Hydraulics

___________________________________________ Adjustment procedures Main Control Valve Adjustment

To properly adjust any relief valve, the hydraulic system must be “dead headed”. Dead heading is achieved by actuating a cylinder function and allowing it to travel to its full stroke position (either extended or retracted). To set the main system relief, it is recommended that the stabilizer shoe cylinder be extended until it is dead headed.

1. Remove the protective cap on the front port relief of the cutter head working section and loosen the nut on the adjusting screw. Turn the adjusting screw in all the way.

2. Loosen the nut on the main relief cartridge. Turn the main relief adjusting screw two turns clockwise.

!

WARNING Keep body parts clear of machine while in raised position or serious injury could result.

______________________________________________________________ A6474X454 REV 2 47

Adjustment procedures ___________________________________________ Port Relief Valve Adjustment If the correct pressure reading is not obtained as noted in Items 1 through 5 below, the port relief (Fig 26) for that function must be adjusted. The port reliefs shown are typical for each section of the valve. The adjustment procedure for each port relief is the same and is: 1. Remove the protective cap on the port relief and loosen the nut on the adjusting screw.

2. Turn the port relief screw in (clockwise) to increase pressure and out (counter-clockwise) to decrease pressure.

3. Once the correct pressure reading is obtained, return the function to the neutral position, hold the screw in place, and tighten the lock nut. Check the pressure reading to ensure that the screw did not turn while the lock nut was being tightened.

Fig. 26: Main control valve - port reliefs

“A” port relief

“B” port relief

Stabilizer Conveyor swing Conveyor raise Gathering head

Cutter raise

________________________________________________________________ 48 CM235 Hydraulics

___________________________________________ Adjustment procedures Pressure readings 1. Cutter Head

1. Activate the cutter head raise circuit to fully raise the cutter head. The main control pressure gauge should read 2,800 psi (193 bar).

2. Activate the cutter head lower circuit to fully lower the cutter head and raise the front of the machine off the ground. The main control pressure gauge should read 3,000 psi (207 bar).

2. Conveyor Raise/Lower

1. Activate the conveyor raise circuit to fully raise the conveyor. The main control valve pressure gauge should read 2,300 psi (159 bar).

2. Activate the conveyor lower circuit to fully lower the conveyor. The main control valve pressure gauge should read 1,400 psi (96 bar).

Note: Be sure that the ball valve is closed on the tank oil fill part of this circuit.

3. Conveyor Swing

1. Activate the conveyor swing left circuit to fully swing the conveyor to the left.

The main control valve pressure gauge should read 1,800 psi (124 bar).

2. Activate the conveyor swing right circuit to fully swing the conveyor to the right. The main control valve pressure gauge should read 1,800 psi (124 bar).

4. Gathering Head

1. Activate the gathering head raise circuit to fully raise the gathering head.

The main control valve pressure gauge should read 1,700 psi (117 bar).

2. If 1,700 psi (117 bar) is not obtainable, check that the relief in the gathering head float valve that is stamped “CR” is set to 1,800 psi (124 bar) (see Gathering head raise/hold/float-lower circuit in the Hydraulic section of this chapter).

5. Stabilizer Shoe

1. Activate the stabilizer shoe raise circuit to fully raise the stabilizer shoe.

The main control valve pressure gauge should read 1,150 psi (79 bar).

2. Activate the stabilizer shoe lower circuit allow to fully lower the stabilizer shoe.

______________________________________________________________ A6474X454 REV 2 49

Troubleshooting _________________________________________________

Introduction

!

The following section lists possible problems encountered when servicing the Continuous Miner and can aid in locating and correcting these problems. This section covers basic components, with each listed in a trouble-cause-remedy format.

WARNING Some procedures must be carried out with the cover of the electrical controller removed and some procedures require the controller to be energized during the tests. It is extremely important that you take all necessary precautions to prevent accidental electrical shock while working within the controller. An certified electrician must supervise and inspect all work performed.

Hydraulic Troubleshooting Procedures

For maintenance procedures and tests that DO NOT require the controller to be energized, precautions include: 1. Before removing the controller covers, remove power from the system by disconnecting the trailing cable.

2. Use insulated gloves and tools where possible.

3. All connections must be tight and care must be taken to prevent bolts, nuts, washers and other small metal fasteners from being dropped or lost inside the controller. These lost fasteners could cause electrical shorts inside the controller.

For procedures that DO require that the controller be energized while the cover is off: 1. At no time should you reach inside the controller while it is energized. If it becomes necessary to make adjustments or to replace parts inside the controller, the power should be disconnected, locked and tagged out.

2. Use insulated gloves and tools where possible.

3. All connections must be tight and care must be taken to prevent bolts, nuts, washers and other small metal fasteners from being dropped or lost inside the controller. These lost fasteners could cause electrical shorts inside the controller.

________________________________________________________________ 50 CM235 Hydraulics

_________________________________________________Troubleshooting Typical Hydraulic Problems

The most common causes for improper function are: 1. contaminated oil or poor oil quality; 2. low or insufficient oil in the system; 3. using the wrong type of oil or wrong viscosity grade; 4. air in the hydraulic system; 5. internal or external leakage of the hydraulic system; 6. improper mechanical adjustments, such as reliefs; 7. mechanical or structural damage leading to component failure; and 8. components by-passing (internal leaking or inability to hold pressure) which leads to erosion of bushings, valve spools, and other costly, critical components.

The construction and operating characteristics of each of these components should be clearly understood before attempting to troubleshoot the machine.

Please familiarize yourself with the operational descriptions of the hydraulic circuits given in the Hydraulics section of this chapter.

Each component in the system has a maximum rated speed, flow, torque, or pressure. The correct operating pressures of a system must be known and must always be checked and set with a pressure gauge.

______________________________________________________________ A6474X454 REV 2 51

Troubleshooting _________________________________________________ The ability to recognize trouble indicators in a specific system is usually acquired with experience. the gaining of this experience can be greatly enhanced by developing a logical sequence for determining the cause of a hydraulic problem and implementing the proper remedy. Refer to the general troubleshooting charts in this section that illustrate the logical sequence for shutdown, troubleshooting, and restarting the machine. The charts cover: 1.

general safety procedure for shutting down the machine;

2.

troubleshooting excessive noise;

3.

troubleshooting excessive heat;

4.

troubleshooting incorrect flow;

5.

troubleshooting incorrect pressure;

6.

troubleshooting faulty movement/operation; and

7.

general restart checklist and procedure

This general information is intended to enhance the understanding of basic hydraulic principles which will lead to the development of a logical troubleshooting procedure. Specific troubleshooting checklists for each hydraulic circuit are given directly after the very important “Contaminants in hydraulic systems” section.

Contamination

Cleanliness must be a high priority when servicing the hydraulic system. Ensure that bulk oils are at acceptable cleanliness levels.

Areas where customers have made improvements in the past include: 1.

implementing ISO Cleanliness Code standards for bulk hydraulic oils;

2.

evaluating bulk oil shipments for cleanliness by conducting particle counts and maintain records;

3.

minimizing drum usage by utilizing tote tanks and five gallon pails;

4.

utilizing plastic versus steel storage tanks, if possible;

5.

installing desiccant breathers on all bulk tanks;

6.

using sealed plastic containers for adding oil to small sumps;

7.

locating bulk tanks near equipment and pump directly to reservoirs;

________________________________________________________________ 52 CM235 Hydraulics

_________________________________________________Troubleshooting 8.

utilizing filter carts to maintain oil cleanliness standards;

9.

properly training personnel on the importance of clean oil and best practices for storage and handling; and

10.

monitoring the program closely and looking for continuous improvement.

Eliminate contamination source through “clean” maintenance practices best achieved by maintenance and troubleshooting given below:

Multi-Function Failure

1.

always clean the area around the component that is to be removed and inspected;

2.

store components in a plastic bag after inspection and prior to replacement on machine;

3.

cap off all open hoses/fittings;

4.

never touch a filter with bare hands when installing it back onto the machine; and

5.

pay close attention to the filler/breather cap and replace it when damaged or in the recommended time frame.

If more than one function fails to operate on the machine, check the output of the pumps. Since this is an “open center” circuit, the normal pressure (with all directional control valves in the center position) should be less than 100 psi.

This pressure reading illustrates the necessary pressure to circulate the oil through the system. If the pressure reading under these conditions is significantly greater than 100 psi, it is likely that one of the control valves is trying to direct oil to one (or more) of the circuits on the machine.

The next step in troubleshooting a multi-function failure is to check the pilot pressure on the main control valve manifold. This pressure should be between 400 500 psi. If the pilot pressure is significantly below 350 psi, start with the General Troubleshooting Flow Chart IV - Incorrect Pressure. Another step to resolve multifunction failure is to have an electrician check for power to the solenoid circuits.

Check for correct pump rotation if electrical work has been performed (such as trailing cable replacement).

______________________________________________________________ A6474X454 REV 2 53

Troubleshooting _________________________________________________ Cutter Head Raise Failure

1. Check pilot supply pressure.

2. Check pilot pressure at the raise pilot cylinder on the cutter head directional control valve when the valve is in the Raise position.

3

Check the directional control valve for proper operation.

4. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

5. Check that the "in-line" counterbalance holding valve is piloted and shifting to direct retract port cylinder oil flow back to tank.

6. Check to see that there is no mechanical bind.

7. Check cylinders for bypassing.

8. Check for pilot pressure on the cutter head cylinder’s holding valves. Also check that the valves are shifting to send oil back to the tank. (Note: cylinder removal will be required to safely achieve this)

Cutter Head Lower Failure

1. Check pilot supply pressure at remote control valves.

2. Check pilot pressure at the Lower pilot cylinder on the cutter head directional control valve when the remote control valve is in the Lower position.

3. Check the direction control valve for proper operation.

4. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

5. Check to see that there is no mechanical bind or hydraulic block.

6. Check flow control valve cartridge.

7. Check cylinders for bypassing.

8. Check for pilot pressure on the cutter head cylinder's holding valves. Also check that the valves are shifting to send (extend port) oil back to the tank.

Note: cylinder removal will be required to safely achieve this.

________________________________________________________________ 54 CM235 Hydraulics

_________________________________________________Troubleshooting

Gathering Head Raise Failure

1. Check the directional control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Check to see that there is no mechanical bind.

4. Check cylinders for bypassing (they will leak out the top).

5. Check needle valve on pilot circuit to verify that it is not open or leaking off.

6. Check in-line counterbalance valve for proper operation or blockage.

Gathering Head Float Failure

1. Check the control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Check to see that there is no mechanical bind.

4. Check cylinders for bypassing (they will leak out the top).

5. Check needle valve on pilot circuit to verify that it is not open or leaking off.

Conveyor Raise Failure

1. Check the directional control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Be sure that the built-in atmospheric-vented reliefs on the cylinders are not dumping oil.

4. Check to see that there is no mechanical bind.

5. Verify that cylinders are not bypassing.

______________________________________________________________ A6474X454 REV 2 55

Troubleshooting _________________________________________________ Conveyor Lower Failure

1. Check the directional control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Verify that pilot pressure is being applied to open the piloted built-in checks.

4. Verify that cylinders are not bypassing.

5. Ensure the flow control valve is not closed

Conveyor Swing Failure

1. Check the directional control valve for proper operation.

2. Check for any mechanical bind or any obstruction blocking movement, either to the cylinder itself, the main pivot area, or to some point along or under the discharge conveyor itself. Also check to ensure that the pivot bushings have not frozen up from lack of lubrication.

3. Verify that the cylinder is not bypassing.

Stabilizer Raise Failure

1. Check the directional control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Check the lubrication network for bound bushings.

4. Check for any mechanical bind or any obstruction blocking movement.

5. Check cylinder for bypassing.

Stabilizer Lower Failure

1. Check the control valve for proper operation.

2. Check to see that piping has not been crossed, especially if the problem occurs after maintenance or repair work.

3. Check the lubrication network for bound bushings.

4. Check for any mechanical bind or any obstruction blocking movement.

5. Check cylinder for bypassing.

________________________________________________________________ 56 CM235 Hydraulics

_________________________________________________Troubleshooting Table 7: Flow chart I for troubleshooting excessive noise Pump Noisy Cause

Motor Noisy Remedy

Cause

Cavitation

A

Coupling misaligned

Air in fluid

B

Motor or coupling worn or damaged

Coupling misaligned

C

Pump worn or damaged

E

Relief/Counterbalance Valve Noisy Remedy

Cause

Remedy

C

Setting too low or too close to another valve setting

D

Worn poppet and seat

E

Remedies A. Any or all of the following: 1. replace dirty filters 2. wash strainers in solvent compatible with system fluid 3. clean clogged inlet line 4. clean reservoir breather vent 5. change system fluid 6. change to proper pump drive motor speed 7. check fluid temperature B. Any or all of the following: 1. tighten leaky inlet connections 2. fill reservoir to proper levels: with few exceptions, all return lines should be below fluid level in the reservoir 3. bleed air from system 4. replace pump shaft seal; also replace shaft if worn at seal journal C. All of the following: 1. align unit 2. check condition of seals, bearings, and coupling D. Install and/or adjust pressure gauge E. Overhaul or replace defective parts

______________________________________________________________ A6474X454 REV 2 57

Troubleshooting _________________________________________________ Table 8: Flow chart II for troubleshooting excessive heat Pump Heated

Motor Heated Cause

Fluid Heated

Cause

Remedy

Cause

Remedy

See Fluid Heated

System pressure too high

D

Cause

Remedy

Fluid heated

See Fluid Heated

Cavitation

A

Relief or unloading valve set too high

D

Valve setting incorrect

D

Unloading valve set too high

D

Air in fluid

B

Excessive load

C

Worn or damaged valve

E

Fluid dirty or low supply

F

Relief or unloading valve set too high

D

Worn or damaged motor

E

Incorrect fluid viscosity

F

Excessive load

C

Oil cooling

H

Faulty fluid cooling system

G

Worn or damaged pump

E

Worn pump, valve motor, cylinder, or other component

E

Fluid heated

Remedy

Relief Valve Heated

See Fluid Heated

Fluid heated

Remedies 3. locate and correct mechanical binding A. Any or all of the following: 4. check for workload in excess of circuit design 1. replace dirty filters D. Install and/or adjust pressure gauge 2. clean clogged inlet line E. Overhaul or replace defective parts 3. clean reservoir breather vent F. 1. change filters 4. change system fluid 5. change to proper pump drive motor speed B. Any or all of the following: 1. tighten leaky inlet connections

2. check system fluid viscosity; change if necessary 3. fill reservoir to proper level G. 1. clean cooler and/or strainer

2. fill reservoir to proper levels: with few excep2. replace cooler control valve tions, all return lines should be below fluid level in the reservoir H. 1. Check oil supply to motor 3. bleed air from system 4. replace pump shaft seal; also replace shaft if worn at seal journal C. All of the following: 1. align unit 2. check condition of seals, bearings, and coupling

________________________________________________________________ 58 CM235 Hydraulics

_________________________________________________Troubleshooting Table 9: Flow chart III for troubleshooting incorrect flow No Flow Cause

Low Flow Remedy

Excessive Flow

Cause

Remedy

Cause

Remedy

Pump not receiving fluid

A

Flow control set too low

D

Flow control set too high

D

Pump drive motor not operating

E

Relief or unloading valve set too low

D

RPM of pump drive motor incorrect

H

Pump to drive coupling sheared

C

Flow by-passing thru partially open valve

E of F

Improper size pump used for replacement

H

Pump drive motor turning in wrong direction

G

External leak in system

B

Directional control set in wrong position

F

RPM of pump drive motor incorrect

H

Entire flow passing over relief valve

D

Worn pump, valve, motor, cylinder, or other component

E

Damaged pump

C

Pilot filter clogged

A

Improperly assembled pump

E

Pilot filter clogged

A

Remedies A. Any or all of the following:

F. Any or all of the following

1. replace dirty filters

1. check position of manually operated controls

2. clean clogged inlet line

2. check electrical circuit on solenoid operated controls

3. clean reservoir breather vent 3. repair or replace pilot pressure pump 4. fill reservoir to proper level G. Reverse rotation B. Any or all of the following: H. Replace with correct unit 1. tighten leaky inlet connections 2. bleed air from system C. All of the following: 1. check for damaged pump or pump drive 2. replace and align coupling D. Adjust setting on valve E. Overhaul or replace part

______________________________________________________________ A6474X454 REV 2 59

Troubleshooting _________________________________________________

Table 10: Flow chart IV for troubleshooting incorrect pressure No Pressure

Low Pressure

Cause

Remedy

Cause

No flow

See Table 5 Pressure relief path exists

Erratic Pressure

Remedy See Table 5

Cause

Excessive Pressure

Remedy

Cause

Remedy

Air in fluid

B

Pressure reducing, relief, or unloading valve misadjusted

D

Pressure recuing, relief, or unloading valve worn or damaged

E

Pressure reducing valve set too low

D

Worn relief valve

E

Pressure reducing valve damaged

E

Contamination in fluid

A

Damaged pump, motor, or cylinder

E

Accumulator defective or has lost charge

C

Worn pump, motor, or cylinder

E

Remedies A. Replace dirty filters and system fluid B. 1. tighten leaky connections 2. fill reservoir to proper level and bleed air from system C. 1. gas valve for leakage 2. charge to correct pressure 3. overhaul if defective D. Adjust valve E. Overhaul or replace part

________________________________________________________________ 60 CM235 Hydraulics

_________________________________________________Troubleshooting Table 11: Flow chart V for troubleshooting faulty operation No Movement Cause No flow or pressure

Slow Movement

Remedy

Cause

See Table Low flow 5

Erratic Movement Remedy

Excessive Speed or Movement

Remedy

Cause

Cause

Remedy

See Table 5

Erratic pressure

See Table Excessive flow 6

See Table 5

Air in fluid

See Table Feedback 3 transducer malfunctioning

E

Limit or sequence device (mechanical, electrical, or hydraulic) inoperative or misadjusted

E

Fluid viscosity too high

A

Mechanical bind

B

Insufficient control pressure for valves

See Table 6

No lubrication of machine ways or linkage

G

Misadjusted or malfunctioning valve amplifier

C

No lubrication of machine ways or linkage

G

Erratic command signal

F

Overriding work load

H

Misadjusted or malfunctioning valve amplifier

C

Misadjusted or malfunctioning valve amplifier

C

Inoperative solenoid or proportional valve

E

Sticking valve

D

Malfunctioning feedback transducer

E

worn or damaged cylinder or motor

E

Worn or damaged cylinder or motor

E

Sticking valve

D

Pilot filter clogged

See Table 5

Worn or damaged cylinder or motor

E

Remedies A. 1. check fluid temperature 2. check system fluid viscosity; change if necessary B. Locate bind and repair C. Adjust, repair, or replace part D. 1. clean and adjust or replace part 2. check condition of system fluid and filters E. Overhaul or replace part F. Repair command console or interconnecting wires G. Lubricated H. Adjust, repair, or replace counterbalance valve

______________________________________________________________ A6474X454 REV 2 61

Troubleshooting _________________________________________________ Table 12: Restarting checklist Has the cause of the failure been remedied?

No

Carry out further investigation.

Yes

Clean or flush the system as required.

Yes Can dirt have entered the system by the unit failure or during replacement?

No Is the unit the correct one?

No

Modify or replace with correct unit.

No

Remedy installation.

No

Remedy installation.

Yes

Is the unit adjusted to a safe condition for start up?

Yes Are all hydraulic connections correct?

Yes Are all electrical connections correct?

Yes Is the unit adjustable?

No

Adjust to a safe condition.

Yes No Have the cases of pumps and motors been filled?

No

Fill case.

Yes

Bleed or prime as necessary.

No

Remove safety interlocks.

No

Sound alarm or inform personnel.

Yes Will the system require bleeding or priming?

No Have all safety interlocks been removed

Yes Are all personnel aware the machine is restarting?

Yes Start machine (see Startup procedure in this chapter).

________________________________________________________________ 62 CM235 Hydraulics

_________________________________________________Troubleshooting Bearings Table 13: Bearing troubleshooting Trouble, symptom or cause

Probable cause

overheating bearing 1.

Test, check and/or remedy

Wrong type of grease or oil.

1.

Consult the lubrication chart for the proper lubricant.

2.

Low oil level; loss of lubricant through seal; excessive grease.

2.

Oil level should normally be at the center of lowest ball or roller in bearing; check seals for signs of leaking.

3.

Insufficient clearance in bearing.

3.

Replacement bearing should be identical to original equipment to ensure proper internal clearance.

4.

Housing bore out of round; housing warped; excessive distortion of housing; undersized housing bore.

4.

Check and scrape housing bore to relieve pinching of bearing; be sure pedestal surface is flat and shims cover entire area of pillow block base when applicable.

5.

Shaft out of line.

5.

Correct alignment and be sure shafts are coupled in a straight line.

Insufficient clearance in bearing.

1.

Replacement bearing should be identical to original equipment to ensure proper internal clearance.

2.

Foreign matter acting as abrasive.

2.

Clean bearing housing and replace worn seals.

3.

Housing bore out of round; housing warped; excessive distortion of housing; undersized housing bore.

3.

Check and scrape housing bore to relieve pinching of bearing; be sure pedestal surface is flat and shims cover entire area of pillow block base when applicable.

4.

Shaft and other parts of bearing assembly distorted.

4.

Replace bearing, shaft and other parts as needed.

Enlarged housing bore causing spinning of outer ring in housing.

1.

Re-bore housing and press steel bushing in bore, then machine bore to correct size.

2.

Foreign matter acting as abrasive.

2.

Clean bearing housing and replace worn seals.

3.

Unbalanced loading.

3.

Check balance of rotating parts and rebalance as needed.

Chip in bearing housing; insufficient clearance in bearing; Ball or roller dented from extreme loading.

1.

Replace with OEM bearing; do not hammer on any part of bearing; clean housing and use fresh lube.

noisy bearing 1.

vibrating bearing 1.

unsatisfactory 1. performance

______________________________________________________________ A6474X454 REV 2 63

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