1. The hydraulic system is characterized by high energy density. For motors with the same power, hydraulic motors are much smaller and lighter than motors. And it is easy to apply to mobile devices. 2. The hydraulic motor has convenient speed regulation, which can be adjusted infinitely from 0 to the maximum speed according to the adjustment of the hydraulic valve. The motor itself does not need special design and has low cost. This is much cheaper than motor+reducer, or variable frequency motor and servo motor. 3. The hydraulic motor is totally enclosed and can be safely used in dusty, wet (even underwater) and flammable environments, which is much more reliable than explosion-proof (flameproof) motors. 4. The hydraulic system has strong anti overload capacity, and it is protected by the overflow valve, allowing long (relatively) frequent overloads. It is easy to recover under overload conditions, without damaging the equipment or restarting the equipment. These unparalleled advantages of motors have made hydraulic motors and hydraulic technology rapidly spread and popularized all over the world in the past 20 years. People increasingly feel the importance of hydraulic motors in practice.

At present, the system used in series by multiple cycloidal motors (see Figure 1) is applied to sweepers, trenchless drills and airport luggage carts. The output shaft of the hydraulic motor often leaks oil during use, so it is useless to replace the dynamic seal of the output shaft. In series application, the problem of casing oil leakage pressure is ignored. The oil leakage pressure of the housing refers to the maximum pressure that the motor shaft seal can bear after the hydraulic motor is fully lubricated inside; If the hydraulic motor is applied customized M+S cycloidal motor Improper. After the machine has been working continuously for a period of time, due to various factors, the oil in the housing will not be released, resulting in higher and higher pressure in the housing of the hydraulic motor, which first leads to the failure of the shaft seal. The casing leakage pressure mentioned here is not the bursting pressure of the casing, but the pressure that the motor output shaft dynamic seal can bear. In the motor samples of some manufacturers, only the back pressure is mentioned. Actually, back pressure refers to electricity M+S cycloidal motor manufactor The return oil pressure of the engine, not the oil discharge pressure of the casing. During operation, the requirements for the oil discharge pressure of the cycloidal motor housing are as follows. Eaton is the world's first cycloid motor manufacturer. In China's domestic cycloidal motor manufacturing industry, Jining Jinjia Hydraulic Co., Ltd. uses Eaton technology to produce cycloidal motors. Its output shaft dynamic seal has better bearing capacity, that is, the unique internal oil circuit design of the company's products enables internal oil drainage not only to lubricate parts, but also to discharge excess oil while maintaining a certain housing oil drainage pressure.

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 customized M+S cycloidal 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 M+S cycloidal 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.

Cycloidal hydraulic motor structure: the internal meshing gear pair consisting of rotor and stator, cycloidal needle wheel, as the meshing pair, has a torque generating part. The stator, together with the spacer and the rear cover, is fixed on the housing to form seven cavities that are only connected with the oil holes on the housing one by one. A distribution mechanism consisting of an oil distribution sleeve and a housing. Two oil distribution sleeves Nanning M+S cycloidal motor The ring groove is respectively connected with the oil inlet and return ports of the housing, and its longitudinal groove has twelve oil ports, M+S cycloidal motor manufactor Six oil ports and the oil distribution hole of the housing form the oil distribution link. The splines at both ends of the linkage shaft are respectively connected with the rotor and the output shaft, which is used to transmit torque and ensure that the oil sleeve is synchronized with the output shaft. The function of the output shaft is to output the torque generated by the rotor through the linkage shaft and drive the oil distribution device to rotate synchronously.