Its basic types are gear type, screw type, vane type and axial plunger type. Its main characteristics are high speed, small moment of inertia, convenient starting and braking, adjustment (speed adjustment and special-purpose Low speed high torque cycloidal hydraulic motor Reversing) High sensitivity. As the output torque of high-speed hydraulic motor is generally small, it is also called high-speed small torque hydraulic motor. Its basic type is radial plunger type, in addition, there are axial plunger, vane type, gear type and other structural types. Low speed hydraulic motors are mainly characterized by large displacement, large volume and low speed (sometimes Low speed high torque cycloidal hydraulic motor manufactor It can rotate a few revolutions per minute or even a few revolutions per minute), so it can be directly connected to the working mechanism; It does not need a speed reducer, greatly simplifying the transmission mechanism. Usually, the output torque of low-speed hydraulic motor is large, so it is also called low-speed high torque hydraulic motor.

The oil distribution sleeve is synchronized with the rotor, so that the rotor rotates once, and the seven oil distribution holes on the housing are closed 840 times by the twelve diaphragms of the oil distribution sleeve, while the rotor and stator form the largest and smallest closed cavities respectively 1420 times, collectively referred to as the seal cavity. In the circle of the oil distribution hole of the closed housing, the oil inlet and outlet of the rotor have three chambers respectively, one Beijing Low speed high torque cycloidal hydraulic motor The cavity is closed. When the rotor is transferred from the smallest enclosed cavity to the next largest enclosed cavity, before the rotor is transferred from the largest enclosed cavity to the next smallest enclosed cavity, oil is supplied to four cavities and three cavities special-purpose Low speed high torque cycloidal hydraulic motor Drain the oil.

The ignition time of internal combustion engines can be compared with this. It can be seen from the working principle of the cycloidal hydraulic motor that the oil sleeve and the rotor rotate synchronously, and the accuracy refers to the accuracy of the oil distribution link matching with the rotor to rotate the oil inlet, seal and discharge. There are many factors special-purpose Low speed high torque cycloidal hydraulic motor It will affect the oil distribution accuracy, such as the asymmetry of the rotor spline and cycloid tooth shape, the relative position accuracy of the stator sleeve needle hole and bolt hole, and the relative position asymmetry of the pin hole and spline on the output shaft and its internal spline, Low speed high torque cycloidal hydraulic motor manufactor The relative position accuracy of the longitudinal oil groove and the relative wedge groove of the coupling, and the asymmetry of splines at both ends of the coupling. As long as the above factors are controlled within the tolerance range, they will not have a great impact on the oil distribution accuracy, because all processing errors will not be offset.

After disassembling and inspecting the hydraulic motor installed on the drill, it was found that the friction surface of the valve disc and the port plate of the hydraulic motor was severely worn, and the deepest worn part was 0. 15mm; The output shaft oil seal is leaking. Cause analysis of oil leakage of output shaft oil seal. After disassembly inspection and test, the axial and radial clearances of the output shaft meet the standard requirements special-purpose Low speed high torque cycloidal hydraulic motor There is no obvious wear on the oil seal mating surface. However, it is found that the oil seal rubber has hardened and its elasticity has deteriorated. With the increase of sealing lip wear, the pre tightening capacity and sealing performance decrease, and the excessive oil temperature accelerates the wear of sealing lip; In addition, due to the liquid Beijing Low speed high torque cycloidal hydraulic motor The leakage of the pressure motor causes the back pressure in the housing to be too high, which further aggravates the wear and leakage of the sealing lip. The smaller the friction of the rotor in the stator sleeve, the higher the mechanical efficiency of the motor.