WHPM series is widely used in plant setting machine, tractors, harvesters, planters and other agricultural machinery. Its main structure is the integration of plunger hydraulic pump and plunger hydraulic motor. The power is input through the pump input shaft, and changes the Angle of the pump, so that the motor output shaft output different rotation direction and speed, so it can be very convenient to control the equipment forward, backward, neutral gear and corresponding speed.