摘要 |
A vehicle drive and work performing system including a rotary output, variable displacement, hydraulic drive motor (22) adapted to drive a vehicle, at least one hydraulic implement motor (14, 16 and 18) adapted to power a work performing implement, a hydraulic pump (10) providing hydraulic fluid under pressure to the motors, a flow control valve (12) for controlling the fluid flow from the pump to at least the drive motor, and a pressure control valve (30) for controlling the displacement of the drive motor to achieve a desired fluid pressure level at the drive motor, and including the improvement wherein a load sensor (60, 62) is connected to the implement motor for providing a signal representing the load thereon and a piston (54) is responsive to the signal for causing the pressure control valve to change the displacement of the drive motor to thereby change the fluid pressure level thereat to a value different from the desired fluid pressure level. |