The radial piston hydraulic motor uses a cam ring with a special curve to make each plunger reciprocate several times within one cycle of cylinder block rotation, which is called multi action special-purpose OM cycloidal motor Internal curve radial plunger hydraulic motor (referred to as internal curve motor) is used. The internal curve motor has the advantages of small size, light weight, radial force balance, small torque ripple, high starting efficiency, stable operation at very low speed, etc. It has been widely used OM cycloidal motor Price In marine machinery. Working principle of inner curve motor: the inner wall of the cam ring (housing) is composed of x evenly distributed curved surfaces with the same shape. Each curved surface with the same shape can be divided into two symmetrical sides. The side that allows the plunger set to extend outward is the working section (oil inlet section), and the opposite side is called the oil return section. The number of reciprocating times of each plunger per revolution of the hydraulic motor is equal to the number of curved surfaces of the cam ring x (x is called the number of times of action of the motor).

Most of its hydraulic system uses working medium, such as hydraulic oil with continuous fluidity, which converts the mechanical energy of the prime mover driving the pump into the pressure energy of the liquid through the hydraulic pump, and sends it to the actuator (hydraulic cylinder, hydraulic motor or swing hydraulic motor) through various control valves, such as pressure, flow, direction, etc., to convert it into mechanical energy to drive the load. This hydraulic system is generally composed of the following parts: power source, actuator, control valve, hydraulic auxiliary device and hydraulic working medium, which play their respective roles: power source: prime mover (motor or internal combustion engine) and hydraulic pump, whose role is to convert the mechanical energy generated by the prime mover into the pressure energy of liquid, and output oil with a certain pressure;

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.

In the middle opening system, the main reversing valve of the middle opening system is in the middle position, through which the hydraulic pump is unloaded, and the liquid returns to the oil tank under low pressure. This kind of system generally uses constant displacement pump as oil source; When the reversing valve is in the middle position, the energy transmission starts with a low value that is basically zero, and the energy rises after changing, so that the pressure liquid enters special-purpose OM cycloidal motor The actuator acts on the load; When the reversing valve is in the middle position, the internal leakage is very small. Generally, when the same function is achieved, the energy consumption of the intermediate open circuit is smaller. in Guangdong special-purpose Open system is mostly used for working conditions requiring intermittent movement or supporting load, such as prime movers that do not want to start and stop frequently. The system has high efficiency, and needs to use makeup oil pump and flushing valve for oil makeup and heat exchange.

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 OM 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 OM cycloidal motor Price 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.