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 special-purpose Low speed cycloidal hydraulic 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 Low speed cycloidal hydraulic 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.
1. Generally, the motor shall be able to run forward and backward. Therefore, the hydraulic motor is usually required to have structural symmetry in the design. 2. The actual working pressure difference of the hydraulic motor depends on the load torque. When the moment of inertia of the driven load is large and the speed is high, rapid braking or reverse rotation is required, high hydraulic impact will be generated. Therefore, the system should be equipped with necessary safety valves and buffer valves. 3. Under normal working conditions, the inlet and outlet pressure of the hydraulic motor is higher than the atmospheric pressure, so there is no suction performance problem like the hydraulic pump. However, if the hydraulic motor can work under pump conditions, its oil inlet should have a minimum pressure limit to avoid cavitation. 4. Some hydraulic motors must have sufficient back pressure at the oil return port to ensure normal operation. The higher the speed, the greater the back pressure, which indicates that the utilization rate of oil source pressure is not high and the system loss is increased. 5. Because the internal leakage of the motor is inevitable, there will be slow sliding when the hydraulic motor oil outlet is closed for braking. Therefore, when long-term accurate braking is required, a separate anti-skid brake shall be set.
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 Suzhou Low speed cycloidal hydraulic 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, Low speed cycloidal hydraulic 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.
BM cycloidal hydraulic motor is a small low-speed high torque hydraulic motor with single axis flow distribution and fixed rotor set. Its advantages are as follows: 1. It is small in size and light in weight, and its overall size is much smaller than other types of hydraulic motors with the same torque. 2. Wide speed range, stepless speed regulation, minimum stable speed up to 15 rpm, convenient installation and layout, low investment cost. 3. It can be used in series or parallel in the hydraulic system. 4. The moment of inertia is small, and it is easy to start under load. It can rotate in both forward and reverse directions, and it does not need to stop when reversing. BM cycloidal motor is widely used in agriculture, fishery, light industry Low speed cycloidal hydraulic motor manufactor The slewing mechanism of hoisting and transportation, mining, construction machinery and other machinery. Examples of BM cycloidal hydraulic motor used abroad; 1) Agricultural use: various combine harvesters, seeders, rotary tillers, lawn mowers, sprayers, feed mixers, ground drills. 2) Fishery use: net lifter. special-purpose Low speed cycloidal hydraulic motor 3) Light industry: commercial winding machines, textile machines, printing machines, washing machines. 4) For construction industry: road roller, cement mixer, sweeper.