TM 5-2410-240-23-1
0010
ELECTRO-HYDRAULIC CONTROLS CONTINUED
5. Forward Travel Continued
As a result of the duty cycle settings, inside each hydrostatic pump (Figure 10, Item 1), the proportional solenoid
valve (Figure 10, Item 5) shifts to the left. Pilot oil flows from the line (Figure 10, Item 4) through the proportional
solenoid valve (Figure 10, Item 5) into the passage (Figure 10, Item 6) and then into the chamber of the actuator
piston (Figure 10, Item 7). Inside the chamber, the oil overcomes the force of the opposite spring and the actuator
piston shifts to the left.
As the actuator piston (Figure 10, Item 7) shifts to the left, oil flows from the chamber of the actuator piston into
passage (Figure 10, Item 2), and then through the proportional solenoid valve (Figure 10, Item 5) and the passage
(Figure 10, Item 3) to the pump case drain.
In turn, the displacements of the left and right side hydrostatic pumps increase, and oil flows from the pumps to the
left and right hydrostatic drive motors, respectively. As the oil flows through the motors, the motors rotate and move
the machine forward.
Figure 10. Hydraulic Oil Flow for Forward Travel.
0010
6. Reverse Travel
The ECM (Figure 11, Item 2) interprets two signals and determines that the joystick (Figure 11, Item 1) is in the
REVERSE position. The machine ECM sets the duty cycle for the motor displacement control solenoids (Figure 11,
Items 7 and 8) between 33% and 70%. These solenoids are located in the left and right hydrostatic drive motors,
respectively.
The machine ECM (Figure 11, Item 2) also sets the duty cycle for the reverse solenoids (Figure 11, Items 5 and 6)
between 23.5% and 86% and the duty cycle for the forward solenoids (Figure 11, Items 3 and 4) at less than 26%.
These solenoids adjust the proportional solenoid valves in the left and right side hydrostatic pumps, respectively.
