In the late 1850s, the initial low-speed large-torque hydraulic motor was developed from a fixed rotor component of an oil pump. This component consists of an internal ring gear and a matching gear or rotor. The inner ring gear is fixedly connected to the housing, and the oil entering from the oil port pushes the rotor to revolve around a point. This slowly rotating rotor is driven by a spline shaft into a cycloidal hydraulic motor.

After the advent of this initial cycloidal motor, after decades of evolution, another concept of motor began to take shape. This motor is equipped with rollers in the built-in ring gear. A motor with rollers can provide higher starting and running torque. The rollers reduce friction and thus improve efficiency, even at low speeds. Can produce stable output. By changing the direction of the input and output flow, the motor is quickly reversed, and equivalent torque is generated in both directions. Each series of motors has a choice of various displacements to meet various speed and torque requirements.