The valve control system controls the flow by changing the opening of the valve throttle, thus controlling the speed of the actuator. Usually, the reason for low efficiency is the existence of throttling and overflow losses. Almost all mechanical equipment adopts valve control system. The pump control system can realize the stepless control of speed by changing the displacement of variable displacement pump, or control the flow through the combination of multiple constant displacement pumps to achieve the stepwise control of speed. The reason for high efficiency is that there is no throttling or overflow loss. It is widely used in high power hydraulic devices such as pressure processing machinery and plastic machinery. The actuator control system controls the flow by changing the variable hydraulic motor flow of the actuator, or through the joint work of multiple quantitative hydraulic motors, or by changing the action area of the composite hydraulic cylinder. Similar to the pump control system, this system has high efficiency because it has no throttling and overflow losses. It is suitable for traveling machinery, press and other hydraulic equipment.

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.

When the high-pressure oil enters the oil distribution shaft and enters each plunger cylinder hole of the working section through the oil distribution window, the corresponding plunger set is pushed against the curved surface of the cam ring L (housing), Huainan Cycloidal motor of overhead crane The cam ring surface gives a reaction force to the plunger at the contact position. This reaction force N acts on the common plane where the cam ring surface contacts the roller. This normal reaction force N can be decomposed into radial force PH and circumferential force T, which are balanced with the hydraulic pressure at the bottom of the plunger, while the circumferential force T overcomes the load torque, customized Cycloidal motor of overhead crane Drive cylinder 2 to rotate. Under this working condition, the cam ring and oil distribution shaft do not rotate. At this time, the plunger corresponding to the oil return section of the cam gear moves in the opposite direction, and the oil is discharged through the oil distribution shaft.

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 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.

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 Huainan Cycloidal motor of overhead crane 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 customized Cycloidal motor of overhead crane Large emissions, relatively small impact of leakage, large rotation inertia of the motor itself, easy to obtain good low-speed stability.