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 plate-type stacking configuration. It is divided into four parts: the mechanical output module, hydraulic function module, oil distribution module, and mechanical braking module, facilitating compatibility with various mainstream optimized supporting systems.

High Efficiency: It adopts flat oil distribution technology, which has low sensitivity to pressure and temperature. This technology automatically compensates for wear between the oil 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 processes, significantly increasing the operating pressure of the hydraulic motor, with a maximum pressure of up to 40 MPa. Due to the low inertia of the force transmission mechanism, the plunger pair is equipped with a sealed piston ring, and the roller stopper is made of friction-reducing material, the motor achieves high starting efficiency and excellent low-speed performance.

Ability to Withstand Radial and Axial Loads: With an independently arranged 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 plate-type structure, which allows 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 categorized into single-displacement motors and dual-displacement motors. Single-displacement motors operate with full displacement output. Dual-displacement motors can realize both full-displacement and half-displacement output through control valve regulation, enabling speed control.

MCR安装尺寸_00.pdf

Generally, motors should be capable of forward and reverse operation; therefore, hydraulic motors are usually required to have structural symmetry in their design.

The actual working pressure difference of a hydraulic motor depends on the magnitude of the load torque. When the inertia of the driven load is large, the rotational speed is high, and rapid braking or reversal is required, high hydraulic impact will occur. Therefore, necessary valves and buffer valves should be installed in the system.

Under normal operating conditions, both the inlet and outlet pressures of a hydraulic motor need to be higher than atmospheric pressure, so there is no suction performance issue like that of a hydraulic pump. However, if the hydraulic motor may operate under pump conditions, its oil inlet should have a minimum pressure limit to prevent cavitation.

Some hydraulic motors must have sufficient back pressure at the oil return port to ensure normal operation, and the higher the rotational speed, the greater the required back pressure. An increase in back pressure means low pressure utilization efficiency of the oil source and increased system losses.

Since internal leakage of the motor is unavoidable, when the oil drain port of the hydraulic motor is closed for braking, there will still be slow inertial slippage. Therefore, for long-term precise braking, an additional brake to prevent slippage should be installed.