In order to adapt to the requirements of forward and reverse rotation, the gear motor has equal oil inlet and outlet, symmetrical oil inlet and outlet, and a separate oil drain port to lead the leakage oil of bearing part out of the shell. Rolling bearings are used to reduce starting friction torque. In order to reduce the torque ripple, gear hydraulic motor has more teeth than the pump.

The gear hydraulic motor is made of poor tightness, low efficiency of capacity rent. The oil input pressure cannot be too high and can not produce large torque. The instantaneous speed and torque change with the position of the meshing point, so the gear hydraulic motor is only suitable for the situation of high-speed small torque. It is generally used in engineering machinery, agricultural machinery and machinery equipment which do not require high torque uniformity.