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.

Hydraulic transmission system, the hydraulic transmission system is generally an open loop system without feedback, which mainly transmits power, supplemented by information, and pursues the perfection of transmission characteristics. Hydraulic elements special-purpose High speed high torque cycloidal hydraulic motor The characteristics of components and their interactions determine the working characteristics of the system, and its working quality is greatly affected by the changes of working conditions. Hydraulic drive system is widely used. The hydraulic system of most industrial equipment belongs to this category. In the hydraulic control system, servo valves and other electrohydraulic devices are mostly used in the hydraulic control system High speed high torque cycloidal hydraulic motor Manufacturer The control valve constitutes a closed-loop system with feedback, which mainly transmits information, supplemented by power, and pursues the perfection of control performance. The system adds detection feedback, which can combine common components into an accurate control system, and its control quality is less affected by the change of working conditions. Hydraulic control system is widely used in high-precision CNC machine tools, metallurgy, aerospace and other industries.

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 High speed high torque 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 High speed high torque cycloidal hydraulic motor Manufacturer 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 manufacturer of the hydraulic motor has explained to us the relevant knowledge about the speed and low-speed stability of the hydraulic motor. The speed of the hydraulic motor depends on the flow of the supply fluid q and the discharge of the hydraulic motor itself v. The hydraulic motor has internal leakage. Not all the liquid entering the motor drives the hydraulic motor to work. Some of the liquid is lost due to leakage, and the actual speed of the motor is lower than the ideal situation. When the working speed of the hydraulic motor is too low, it cannot maintain a uniform speed, and it stops when entering Qingdao High speed high torque cycloidal hydraulic motor The unstable state is a creeping phenomenon. The high-speed hydraulic motor is required to work at a speed below 10r/min and the low-speed high torque hydraulic motor is required to work at a speed below 3r/min. All hydraulic motors can meet the requirements. Generally speaking, the low-speed stability of low-speed large torque hydraulic motors is better than that of high-speed motors. Due to the large emissions and size of the low-speed high torque motor, the sliding speed of the friction pair will not be too low even if the rotation speed is low special-purpose High speed high torque cycloidal hydraulic motor Large emissions, relatively small impact of leakage, large rotation inertia of the motor itself, easy to obtain good low-speed stability.

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 Qingdao Manufacturer 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 special-purpose High speed high torque cycloidal hydraulic motor 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.