Product Features

The YMS hydraulic motor is an internal-curve, multi-acting radial piston motor. Its main features are as follows:

Modular Design: The overall structure adopts a modular design with a chip-type stacking configuration. It is divided into four parts: the mechanical output module, hydraulic function module, flow distribution module, and mechanical braking module. This design facilitates compatibility with various mainstream optimized supporting systems.

High Efficiency: It adopts flat valve flow distribution technology, which has low sensitivity to pressure and temperature. This technology automatically compensates for wear between the flow distribution friction pairs, ensuring the motor maintains high volumetric efficiency for a long time. Meanwhile, the adoption of a roller-plunger structure simplifies the force transmission mechanism and improves mechanical efficiency.

High Operating Pressure and Excellent Low-Speed Performance: The stator curve design has been optimized to ensure output torque and stable rotational speed while reducing stator contact stress. Additionally, the stator is manufactured using new materials and advanced processes, significantly increasing the hydraulic motor’s operating pressure—with a maximum pressure of up to 40 MPa. Owing to the low inertia of the force transmission mechanism, the plunger pair equipped with a sealing piston ring, and the roller stopper made of anti-friction material, the motor achieves high starting efficiency and excellent low-speed performance.

Capability to Withstand Radial and Axial Loads: With an independently configured mechanical output module, as well as a large-diameter output shaft and bearings, the motor can withstand large axial and radial forces. It can be directly connected to a gear output or installed directly on the drive wheel of a vehicle.

Optional Mechanical Brake: It adopts a modular chip-type structure, allowing the integration of a mechanical braking device to achieve direct and safe service braking and parking braking of the output shaft.

Motor Displacement Control: Motors are available in two types: single-displacement motors and double-displacement motors. Single-displacement motors output full displacement, while double-displacement motors can switch between full-displacement and half-displacement output via control valve regulation to achieve speed control.

Vane Hydraulic Motor

Due to the action of pressure oil, the unbalanced force causes the rotor to generate torque. The output torque of a vane hydraulic motor is related to the motor’s displacement and the pressure difference between its oil inlet and outlet ports, while its rotational speed is determined by the flow rate of the oil input to the hydraulic motor.

Since hydraulic motors generally require the ability to rotate forward and reverse, the vanes of a vane hydraulic motor must be installed radially. To ensure that the roots of the vanes are always connected to pressure oil, a check valve should be installed in the channel that connects the return oil chamber and pressure oil chamber to the roots of the vanes (as applied in excavator travel motors). To ensure the vane hydraulic motor operates normally after pressure oil is introduced, the tips of the vanes must be in tight contact with the inner surface of the stator to guarantee good sealing performance; therefore, a torsion spring should be installed at the root of each vane.

Vane hydraulic motors feature a compact size, small moment of inertia, and sensitive action (suitable for variable-speed motors), making them applicable in scenarios requiring a high commutation frequency. However, they have relatively large oil leakage and unstable operation at low speeds. Consequently, vane hydraulic motors are generally used in applications that demand high rotational speed, low torque, and sensitive action.