When the working load changes from low speed to high speed in a wide range, the hydraulic motor is also required to be able to drive and regulate speed in the corresponding wide range, which requires the motor to have good low-speed stability and high speed performance. The speed regulation range K of the hydraulic motor is usually expressed by the ratio of the allowable maximum speed to the minimum speed. special-purpose Cycloid hydraulic motor It is the highest operating speed of hydraulic motor, but it is limited by many factors, mainly including: 1. Service life. After the speed increases, each pair is worn Xuchang manufactor The service life is shortened. 2、 Mechanical efficiency limits. At high speed, the hydraulic motor needs to input large flow, accordingly, the hydraulic loss of each circulating component increases, reducing the mechanical efficiency.
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 Cycloid 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 Cycloid hydraulic motor 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.
Of course, you can increase the traffic special-purpose Cycloid hydraulic motor Increase the speed, but how much will affect the service life. As long as it is within the rated power range, there is no problem. If the oil pressure reaches the rated pressure and the speed increases, it will exceed the power range it can withstand. Of course, it will damage the service life of the cycloidal hydraulic motor. Just like not eating so much hard food, it will damage the stomach. Increasing the flow can only increase the speed in a limited way, from 500 to 900, change the model of the motor, increase the flow of the cycloidal motor, increase the speed without control, increase the internal oil pressure, increase the internal leakage, directly reduce the efficiency, and damage the motor. Above Xuchang manufactor Ming can try, and consult the cycloid hydraulic motor expert if he thinks the error is found.
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 Cycloid hydraulic 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 Xuchang 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.
What is the oil supply mode of the hydraulic pump? The straight shaft swashplate plunger pump can be divided into two types: self suction type and pressurized type. Most high-pressure oil supply hydraulic pumps use pneumatic oil tank, and some hydraulic pumps are also equipped with oil make-up slave pump to deliver pressure oil to the oil inlet of the hydraulic pump. The self-priming pump has the characteristics of strong self-priming ability and no need for external oil supply special-purpose Cycloid hydraulic motor 。 Bearings for hydraulic pumps. The most important part of the plunger pump is the bearing. If the bearing has clearance, the normal clearance of the three pairs of friction pairs inside the hydraulic pump cannot be guaranteed. At the same time, the hydrostatic support oil film thickness of each friction pair will be damaged, thus reducing the service life of the plunger pump bearing. According to the data provided by the manufacturer of the hydraulic pump, the average service life of the bearing is 10000 hours. If the service life exceeds this value, a new port shall be replaced. 3、 Conclusion. The service life of the piston pump is related to the maintenance at ordinary times, the quantity and quality of the hydraulic oil, and the cleanliness of the oil. At the same time, avoid Cycloid hydraulic motor manufactor The particles in the oil will wear the friction pair of the plunger pump, which is also an effective method to extend its service life.