SH240-5 Assembly and Disassembly of Swing Motor

Caution 1. Read and understand the contents of this Maintenance Manual before performing disassembly, reassembly, inspection, repair, or other such work of this product. 2. Handle this product according to the separate "Usage Cautions". 3. When removing this product from the equipment it is mounted on, stop that equipment system and wait for the surface temperature of this product to fall to about 40 ℃ or below before removing it. Working on this product while it is still hot can cause burns. Additionally, always bleed out the pressure before removing any line from this product. Removing a pressurized line can result in oil spraying out and causing burns and oil leaking. 4. Use the specialty tools and measurement instruments for disassembly, reassembly, inspection, and repair, etc. of this product. Using an inappropriate tool may result in injury or product damage. 5. Be careful of parts falling when performing disassembly, reassembly, inspection or repair, etc. of this product. This may result in injury or parts damage. 6. Do not directly touch with bare hands the machined edges or threaded sections of parts during disassembly, reassembly, inspection, or repair etc. of this product. This may result in injury. 7. Check performance after reassembly. Do not resume use unless performance is fully recovered. Using this product at a sub-par performance level may result in product damage. 8. The cautions (mark !) listed in this Maintenance Manual do not cover all possible dangers.

Always think of safety first during disassembly, inspection, reassembly, repair, or other such work.

1.Causes of Trouble and Solutions [1] General cautions This list consists of actions to be taken when an abnormality is sensed during use of the hydraulic motor. General cautions are listed below. 1) Think before attempting to fix a problem. Determine the nature of the abnormality before beginning work and think whether this same kind of problem has occurred before. Also, reconfirm whether the motor is the source of the problem. 2) Be careful about dust and dirt. The cause of wear is very often dust and dirt. So be careful that dust and dirt do not get into parts during disassembly. 3) Parts handling Parts are manufactured with a high degree of precision, so be careful not to scratch them during handling. 4) Do not damage O-rings or gasket surfaces while performing work. Also, it is recommended that O-rings are replaced for new ones during disassembly. [2] Investigating abnormalities in the motor main unit It is very difficult to search for the source of troubles in the hydraulic circuits. Inspect the following items and thoroughly investigate whether the motor is the source of troubles. 1) Inspecting oil within the casing Remove the drain plug and inspect the hydraulic oil within the casing. If a large amount of metal particles come out at the same time as oil, it is very likely that there is damage with parts within the motor. 2) Abnormal noise Check whether abnormal noise is coming from the motor main unit. 3) Measure pressure for each part. Do not perform disassembly inspection carelessly. Measure pressure for each part and look for abnormalities in each area. 4) Measure the amount of oil drained from the motor. 1.Operation is normal if about 30 L/min or less of oil drains from the motor when pressurized oil is applied after the swing is locked. 2.2 L/min or less of drained oil at constant swing is normal.

[3] Trouble conditions and countermeasures 1) Hydraulic motor does not rotate.

2) Rotation direction is reversed.

3) Motor speed is not reaching the set value.

4) Hydraulic motor does not rotate.

Symptom Cause

No pressure rise 1. Incorrect setting of the circuit safety valve 2. Operation problems with relief valve 1)Plunger sticking 2)Clogged plunger orifice 3. Plunger seating problem Pressure rises 1. Overload 2. Seizing of driving part 3. No release pressure acting on the brake 4. Piston sticking to the brake 5.Spool for brake release sticking 6. Friction plate seizing

Symptom Cause

Reversed rotation direction 1. Motor rotation direction reversed. 2. Input and output for line reversed.

Symptom Cause

Motor speed not reaching the set value 1. Insufficient oil flow amount 2. High temperature and severe leaking of oil 3. Wear or damage on each sliding section Solution

1. Reset safety valve correctly. 2.Disassemble and inspect. 1)Repair or replace sticking section(s). 2)Disassemble and clean. 3. Check seating sections and replace scratched part(s). 1.Eliminate load. 2. Inspect and repair piston/shoe, cylinder/ valve plate, etc. 3. Inspect and repair circuit. 4.Disassemble and inspect. 5.Disassemble and inspect. 6. Disassemble and inspect. Replace seizing part(s).

Solution

1. Check the rotation direction and assemble the motor correctly. 2. Correct line configurations.

Solution

1. Check the pump discharge volume and the circuit up to the motor. 2. Lower the temperature of the oil. 3. Replace part(s).

Symptom Cause

Insufficient braking torque 1. Wear on the friction plate 2. Brake piston sticking 3. Brake release pressure cannot be released. 4.Spool for brake release sticking 5. Damaged friction plate spline Solution

1. Disassemble and inspect. Replace parts worn beyond the limit. 2.Disassemble and inspect. 3. Inspect and repair circuit. 4.Disassemble and inspect. 5. Disassemble and inspect. Replace damaged part(s).

5) Severe hydraulic motor slipping

Investigate the amount of oil drained from the hydraulic motor. Motor operation is normal if the amount is 500 cc/min or less.

6) Oil leaking 1) Oil leaking from oil seal.

2) Oil leaking from matching surface

Symptom Slipping is severe when an external driving torque acts on the hydraulic motor. Cause

1. Operation problems with relief valve 1)Plunger sticking 2)Clogged plunger orifice 2. Plunger seating problem Solution

1.Disassemble and inspect. 1)Repair or replace sticking section(s). 2)Disassemble and clean. 2. Check seating sections and replace scratched part(s).

Symptom Oil leaking from oil seal Cause

1. Debris lodged in lip causing scratching. 2. Shaft scratched or worn 3. Pressure within the casing becoming abnormally high caused oil seal lip to turn up. 4. Shaft rusted. Solution

1. Replace oil seal(s). 2. Stagger the position(s) of the lip and shaft(s) or replace it (them). 3. Repair any clogged drain line(s). 4. Disassemble and repair.

Symptom Oil leaking from matching surface Cause

1. O-ring has not been inserted. 2. Scratched O-ring 3. Scratched seal surface 4.Loosened or damaged bolt Solution

1. Insert O-ring(s) and assemble. 2. Replace part(s). 3. Disassemble and repair. 4. Tighten to the specified torque or replace.

2.Maintenance Procedures [1] Replacement standards for worn parts If wear on any part exceeds the standard values below, replace or readjust that part. However, parts should be replaced regardless of these standards if it appear to be extremely worn based on appearance. Table 1. Part replacement standards

Item Standard dimensions (mm) Value at which replacement is recommended (mm) Solution

Clearances between piston and cylinder bore (D-d)

0.028 0.058 Replace the piston(s) or cylinder(s). Piston and shoe caulking section backlash (δ) 0 0.3 Replace the piston shoe assembly. Shoe thickness (t) 5.5 5.3 Replace the piston shoe assembly. Friction plate thickness 2.0 1.6 Replace the part(s).

Clearance (D-d)

Shoe thickness (t) Piston and shoe backlash (δ)

[2] Sliding surface repair standards

If the roughness of the sliding surface in any section exceeds the standard values below, repair or replace that part.

Table 2. Sliding surface repair standards

Note: 1) Using lapping, make the degree of surface roughness of each sliding surface equal to or lower than the standard value. 2) If the plate spring and cylinder spherical surface sliding section are rough, these should be replaced as a set.

Part name Standard surface roughness Surface roughness requiring repair

Shoe

0.8-Z (Ra=0.2) (Lapping) Shoe plate 0.4-Z (Ra=0.1) (Lapping) 3-Z (Ra=0.8)

3-Z (Ra=0.8)

Cylinder 1.6-Z (Ra=0.4) (Lapping) 12.5-Z (Ra=3.2)

Valve plate 0.8-Z (Ra=0.2) (Lapping) 6.3-Z (Ra=1.6)

3.Assembly and Disassembly [1] Bolt tightening torque Tightening torque values for bolts used in the motor are indicated in Table 3. When assembling, securely tighten bolts to these values. Table 3

If there is a variance with the part codes listed above, see the assembly cross-section diagram.

[2] Tools for assembly and disassembly

The necessary tools for assembly and disassembly are indicated in Tables 4 and 5. The bolts and plugs used vary for each type, so prepare tools based on examination beforehand.

Table 4 Wrenches

If there are variances with the plugs and bolts listed above, see the assembly cross-section diagram. Table 5 Other

Screw size Name Tightening torque N•m Applicable part code

M20 Hexagon socket head bolt 431 401 M33XP1.5 Relief valve 177 051 M36XP1.5 ROMH plug 539 469

PF1/4 ROH plug 36 467

Name Size Bolt width Applicable part code Tool Hexagon socket head bolt M20 17 401 Hexagon wrench

Relief valve M33XP1.5 41 051 Hexagon wrench, socket wrench

ROMH plug M36XP1.5 17 ROH plug PF1/4 6 469

467 Hexagon wrench Hexagon wrench

Tool Dimensions

Screwdriver

Steel rod Medium-sized flathead x 2

About size 10 x 8 x 200 x 1

Hammer Plastic hammer Metal hammer 1 each

Torque wrench Torque adjustment range ・ For 5 - 10 N•m ・ For 10 - 45 N•m ・ For 40 - 275 N•m ・ For 75 - 550 N•m

Slide hammer bearing puller Brake piston removal jig See the next page

Brake piston removal specialty tool

*1 Brake piston removal jig *2 Brake piston *3 Casing

[3] Disassembly procedure

When disassembling the motor, disassemble using the sequence indicated below. The numbers in parentheses after the part names are the codes used in the structure diagram.

1) Wrap the wire rope around the outer circumference of the motor, lift the motor with a crane, and clean with white kerosene. After cleaning, dry the motor using compressed air. •To prevent foreign matter from entering the motor, mask each port with tape, etc. before cleaning off adhered dirt and dust.

2) From the drain plug, drain the oil inside the casing (301).

3) Point the shaft end of the drive shaft (101) downwards and secure the motor on a surface which makes disassembly easy. At this time, place reference marks on the sections of the casing (301) and valve casing (303) that match with each other. •Select a clean location for disassembly.

Place a rubber plate or cloth on the platform so as not to damage the parts.

4) Loosen the relief valves (051) and remove them from the valve casing (303). •O-rings will be damaged when the relief valves are loosened, so be sure to replace the O-rings.

5) Remove the ROMH plugs (469) from the valve casing (303) and take out the springs (355) and plungers (351). •Be careful not to scratch the plunger seating sections.

6) Loosen the hexagon socket head bolts (401) and remove the valve casing (303) from the casing. (The valve casing will rise up from the casing when the bolts are removed due to the force of the brake springs (712).)

Additionally, remove the valve plate (131) from the valve casing. •Do this carefully so as not to let the valve plate fall from the valve casing. (The valve plate may be attached to the cylinder side.)

When prying open the matching surface with a screwdriver, etc., be careful not to scratch the surface.

7) Take out the brake springs (712) from the brake piston (702).

8) Use a jig and remove the brake piston (702) from the casing (301). •Apply the tips of the jig to the sides of the brake piston. Pull the brake piston out straight up.

9) Move the motor on its side so that it is horizontal with the ground and remove the cylinder (111) from the drive shaft (101).

Additionally, remove the pistons (121), holder plate (123), plate spring (114), and shoe plate (124). •Be careful not to scratch the sliding surfaces of the cylinder, shoe, etc.

If the shoe plate cannot be removed, proceed to 11) and remove.

10)Take out the friction plates (742) and separator plates (743) from the casing (301).

11)Take out the drive shaft (101) and shoe plate (124). •The spline will damage the oil seal (491) when the drive shaft is removed, so wrap the spline section of the drive shaft with vinyl tape, etc. (*1).

12)Perform the following as necessary. 1.Use a press (*1) to remove the inner race of the cylinder roller bearing (443) from the drive shaft (101). •It is acceptable to strike the inner race of the cylinder roller bearing using a steel rod, but be careful to strike the inner race evenly and to not damage the bearing. Do not reuse removed bearing. 2.Lightly strike the outer race of the cylinder roller bearing (443) from the oil seal (491) housing section side using a steel rod to remove the outer race from the casing (301). •Do not reuse removed bearing. 3.Use the slide hammer bearing puller (*1) to remove the cylinder roller bearing (444) from the valve casing (303). •Do not reuse removed bearing.

This completes the disassembly. Thoroughly inspect each section for abnormalities.

Swing motor internal structure diagram (SH240-5)

[4] Assembly procedure

The assembly procedure is the reverse of the disassembly procedure. However, follow the precautions below. 1) Be sure to repair any parts damaged during disassembly, and prepare replacement parts in advance. 2) Thoroughly clean all parts with cleaning fluid and dry with compressed air. 3) Be sure to apply clean hydraulic oil on sliding parts and bearings before assembling. 4) As a rule, replace all O-rings, oil seals, and other seal parts with new parts. 5) Use a torque wrench to tighten all installation bolts and plugs to the torque values specified in Table 3.

The assembly procedure is indicated below.

1) Place the casing (301) on an appropriate platform with the valve casing (303) side facing up.

2) (This section is only necessary when the cylinder roller bearing (443) is removed.)

Shrink fit the inner race of the cylinder roller bearing to the drive shaft (101). •Be careful with the direction of the collar of the cylinder roller bearing.

3) Use a jig to insert the oil seal (491) into the casing (301). •Be careful with the direction of the oil seal. (See the diagram below)

Apply a thin layer of grease to the oil seal lip section.

Evenly strike the oil seal and be careful not to scratch the outer circumference.

4) Install the outer race of the cylinder roller bearing (443) in the casing (301) by lightly striking it with a steel rod.

5) Mount the drive shaft (101) in the casing (301). •Carefully insert it so as not to scratch the lip section of the oil seal (491).

Wrapping vinyl tape, etc. around the shaft spline section to protect it is recommended.

6) Lay the casing (301) horizontal and insert the shoe plate (124). •Install with the larger chamfered side of the shoe plate on the casing side.

Apply a thin layer of grease to the matching surface to prevent it from falling out.

7) Set the holder plate (123) and plate spring (114) and also set the piston subassembly (10).

8) Install the piston subassembly (10) set in the holder plate (123) into the cylinder (111).

Then align the cylinder with the spline of the drive shaft (101) and insert it.

9) Set the casing (301) down with the oil seal (491) side facing downwards and alternately install separator plates (743) and friction plates (742) in that order.

Install the 4 separator plates and 3 friction plates.

10)Mount the O-rings (706) and (707) on the casing (301). •If a thin layer of grease is applied to the Orings, they will not break easily when inserting brake piston.

11)Install the brake piston (702) into the casing (301).

12)Install the brake springs (712) into the brake piston (702).

13)(This section is only necessary when the cylinder roller bearing (444) is removed.)

Install the outer race of the cylinder roller bearing into the valve casing (303) with a steel rod by lightly striking the rod with a hammer. •Evenly strike the outer circumference of the outer race completely in until it stops at the stepped section of the valve casing.

14)Install the valve plate (131) into the valve casing (303) and also mount the O-ring (472). •Apply a thin layer of grease to the valve plate matching surface. (To prevent falling off) (*1)

15)Install the valve casing (303) on the casing (301) and tighten with the hexagon socket head bolts (401).

Tightening torque: 430 N•m •Be careful with the installation direction of the valve casing.

Make sure that the valve plate (131) does not come off.

Make sure that the brake springs (712) do not fall over.

Tighten the hexagon socket head bolts equally.

16)Insert the plungers (351) and springs (355) into the valve casing (303) and tighten the

ROMH plugs (469) with the O-rings (488) mounted on them to the valve casing.

Tightening torque: 539 N•m •Check that the plungers move smoothly.

17)Mount the relief valves (051) on the valve casing (303) and tighten them.

Tightening torque: 177 N•m

This completes the assembly.