How does a gear motor work?

The working principle of the gear motor:
When the high-pressure oil enters the oil inlet cavity of the gear motor (composed of the surfaces of teeth 1, 2, 3 and 1', 2', 3', 4' and the relevant inner surfaces of the pump body and end cover), due to the meshing point The radii x and y are always smaller than the tip circle radius, so on the flanks of teeth 1 and 2', an unbalanced hydraulic pressure is created as indicated by the arrows. This hydraulic force then produces torque relative to axes O1 and O2. Under the action of this torque, the gear motor rotates in the direction of the arrow shown in the figure, dragging the external load to do work.
With the rotation of the gear, the volume swept by the teeth 1 and 1' is smaller than the volume swept by the teeth 3 and 4', so with the continuous change of the meshing teeth, the volume of the oil inlet cavity increases continuously, and the high-pressure oil Continuously entering, and at the same time being continuously brought into the oil return cavity and discharged. This is how the gear motor works according to the volume change.
When the displacement of the gear motor is constant, the output speed of the motor is only related to the input flow, and the output torque changes with the external load. With the rotation of the gear, the meshing point of the gear is constantly changing (that is, x and y are variables), which is the reason for the pulsation of the output speed and output torque of the gear motor even when the instantaneous flow of the input is constant. Therefore, the low-speed performance of the gear motor is not good.

Gear motors can be divided into two types: one is gear motor based on gear pump; the other is specially designed gear motor. The former is similar in structure to the gear pump, while the latter takes into account some special requirements of the motor: for example, the motor often starts with a load, the shock and vibration of the external load are serious, and it must be able to rotate in both positive and negative directions.