System for fixed equipment. This hydraulic system is mostly an open cycle system, including machine tools (workpiece clamping, worktable feeding, direction exchange, spindle drive), presses (pressing, blank holder, direction exchange, workpiece ejection), die-casting machines and injection molding machines (mold closing, demoulding, preforming, injection mechanisms), medical devices, garbage compression and other mechanical devices Jinzhou special-purpose System of standby and working devices. The hydraulic system for traveling equipment includes both open circulation system and closed circulation system, including vehicle driving (traveling drive, steering, braking and working equipment Cycloidal hydraulic motor with brake Manufacturer ), material conveying, loading, unloading and conveying equipment (conveying mechanism, transposition mechanism), various systems of aviation, space and navigation engineering.
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 Cycloidal hydraulic motor with brake 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 hydraulic motor with brake 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.
Its basic types are gear type, screw type, vane type and axial plunger type. Its main characteristics are high speed, small moment of inertia, convenient starting and braking, adjustment (speed adjustment and special-purpose Cycloidal hydraulic motor with brake Reversing) High sensitivity. As the output torque of high-speed hydraulic motor is generally small, it is also called high-speed small torque hydraulic motor. Its basic type is radial plunger type, in addition, there are axial plunger, vane type, gear type and other structural types. Low speed hydraulic motors are mainly characterized by large displacement, large volume and low speed (sometimes Cycloidal hydraulic motor with brake Manufacturer It can rotate a few revolutions per minute or even a few revolutions per minute), so it can be directly connected to the working mechanism; It does not need a speed reducer, greatly simplifying the transmission mechanism. Usually, the output torque of low-speed hydraulic motor is large, so it is also called low-speed high torque hydraulic motor.
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.
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.
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.