2.5-way Solenoid Valve Operation Explanation

[5]Hydraulic pressure of return oil low-pressure circuit

Keep the hydraulic pressure of the return oil low-pressure circuit at 2.0 MPa or less in regard to the service life of the piston motor roller bearing and strength of other parts. Use beyond this pressure will shorten the piston motor life. Therefore, carefully consider the pressure strength when choosing pipe size, valves, etc.

[6]Pressure inside the 2nd-speed pilot pipe

To select the motor speed to high or low, the switchover pressure shown on Table 4 is required.

Table 4. Required Pilot Pressure for Selecting Motor Speed

To switch the speed from low to high, apply the 2nd-speed pilot pressure of 1.5 MPa or more. To switch the speed from high to low, apply a pilot pressure of 0.4 MPa or less. When running the motor at low speed in particular, the pressure leaks from the 2nd-speed control valve. This leak will flow into the 2nd-speed pilot pipe.

For this reason, design the circuit so as not to increase the pressure in the 2nd pilot pipe during low-speed rotation. Increasing the pressure inside the pilot pipe may cause motor malfunction and the motor speed may switch over from low to high.

[7]Installation of self-supplied circuit

The motor circuit and the pipe must be filled with oil before starting the motor. Install the self-supplied circuit on the hydraulic pressure circuit, based on careful consideration of the positional relationship of the motor and hydraulic tank. When the hydraulic motor is turned off, a trace of oil will leak from the piston motor, double counter balance valve and other valves. For this reason, if the motor is turned off for a long period of time, air will accumulate inside the motor circuit and pipe. This may cause aeration or cavitations directly after the motor starts, causing the motor to go out of control.

2nd-speed Pilot Pressure Low speed to high speed MPa 1.5 or more High speed to low speed MPa 0.4 or less

6.Components and Basic Functions

[1]Motor components and basic functions

The swash plate-type piston motor with case rotation type reduction gear for the open circuit comprises the following components: 1. The double counter balance valve for controlling the speed of the motor according to the feed flow 2. The crossover relief valve for determining the motor drive force and braking force 3. The 2nd-speed switching mechanism for switching the motor speed between 2 speeds, low speed and high speed 4. The parking brake function that locks the motor shaft with a mechanical brake when the motor is stopped. 5. The piston motor that converts the fluid energy of the pressurized oil sent from the hydraulic pump into mechanical energy and outputs high-speed, low-torque power. 6. The reduction gear that converts the high-speed, low-torque power output from the piston motor into lowspeed, high-torque power and outputs it.

The fluid energy of the pressurized oil sent from the hydraulic pump is converted into mechanical energy by the piston motor and the high-speed, low-torque rotation power is transmitted to the reduction gear.

At the reduction gear, the rotation power transmitted from the piston motor is converted into low-speed, hightorque rotation power and this power is transmitted to the devices that use the MAG-170VP-3800E series for open circuit.

[2]Component functions

Following describes the features of each component. 1. Double counter balance valve The purpose of this valve is to control the speed of the motor according to the feed flow. This valve prevents the motor rotation from running away when an external load is applied.

This motor cannot be used as a winch.

Important