With the rapid development of China's economy, since the reform and opening up, the machinery industry has improved the advanced productivity in China by constantly introducing foreign technology. Especially after China's accession to the WTO, the machinery industry has accelerated scientific and technological innovation, and the annual export of equipment has continued to grow. With the continuous technological innovation of the hydraulic press industry in China, a number of high-tech industrial companies have emerged, and there are thousands of domestic production enterprises with a certain scale. Hydraulic press products are commonly used in stamping processing and stamping forming processes, such as forging, stamping, cold extrusion, straightening, bending, flanging, plate stretching, powder metallurgy, press fitting, etc. They are metal, plastic, rubber, wood, powder and other products. It can not only meet the functional diversification of electromechanical products to the maximum extent, but also is the basic guarantee for completing major projects and major technological transformation. Now the hydraulic press products have been widely used in automobile, engineering machinery, agricultural machinery, machine tools, plastic machinery, metallurgy and mining, power generation equipment, railway, ship, light industry, electronics, and defense industry products.

Along the revolution direction of the rotor, the volume of the tooth cavity at the front side of the connection between the rotor and the stator becomes smaller, which is an oil discharge cavity, and the volume at the rear side becomes larger. When the connecting line passes through the two tooth roots of the rotor, the oil inlet ends and the largest tooth cavity appears. When the connecting line passes through the two tooth tops of the rotor, the oil drainage ends and the smallest tooth cavity appears. In order to ensure the continuous rotation of the rotor, it is necessary to have the same regular oil distribution mechanism to cooperate with it, so that the tooth cavity at the front side of the connecting pipeline is always connected with the oil drain port, and the rear side is connected with the oil inlet port. As mentioned above, the oil distribution mechanism consists of a housing and an oil distribution sleeve. The 12 longitudinal grooves (x) on the oil distribution sleeve and the 12 intervals formed by the oil distribution groove face the root and top of the rotor through the positioning device, which proves that when the largest and smallest cavities occur, the oil distribution hole of the housing can be closed, thus separating the oil inlet groove and oil outlet groove of the oil distribution sleeve.

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 Cycloidal motor of overhead crane 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 Cycloidal motor of overhead crane 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.

The hydraulic motor has two circuits: the hydraulic motor series circuit and the hydraulic motor braking circuit. These two circuits can be classified into the next category. One of the series circuits of hydraulic motors: three hydraulic motors are connected in series with each other, and a reversing valve is used to control the start stop and steering. The flow through the three motors is basically the same. When the displacement is the same, the speed of each motor is basically the same. The oil supply pressure of the hydraulic pump Jiamusi manufactor High, small pump flow, generally used for light load and high speed. Serial circuit II of hydraulic motor: each reversing valve in this circuit controls one motor, each motor can work independently or simultaneously, and the rotation direction of each motor is also customized Cycloidal motor of overhead crane optional. The oil supply pressure of the hydraulic pump is the sum of the working pressure difference of each motor, which is applicable to the condition of high speed and small torque.