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 orbit 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 orbit 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.
Functions: It is used for the storage, supply and recovery of hydraulic media, the connection between hydraulic components and the transmission of energy carrying hydraulic media, filtering impurities in the hydraulic media, keeping the media required for the normal operation of the system clean, heating or cooling the system, storing and releasing hydraulic energy or absorbing hydraulic pulsation and impact, and displaying the pressure and oil temperature of the system; Hydraulic working medium: various hydraulic oils (fluids), efficacy: as the energy carrying medium of the system, it plays the role of lubrication and cooling while transferring energy. Generally speaking, the hydraulic components that can complete certain specific functions are called hydraulic circuits. In order to meet the working requirements of certain machinery or equipment, the overall structure of several special basic functional circuits connected or combined together is called hydraulic system.
As far as energy conversion is concerned, the hydraulic pump and hydraulic motor are connected as reversible hydraulic components, and the working fluid can be input into any kind of hydraulic pump to make it become a hydraulic motor; On the contrary, when the main shaft of the hydraulic motor rotates under the action of external force orbit motor Price It can also become a hydraulic pump. Because they all have the same basic structural elements, namely sealed and recyclable volume and corresponding distribution mechanism. However, the working environment of hydraulic motor and hydraulic pump is different special-purpose orbit motor The performance requirements are also different. Therefore, there are many differences between the hydraulic motor and the hydraulic pump of the same model. The first hydraulic motor should be positive and negative, so its internal structure should be symmetrical; The speed range of the motor must be large enough, especially its minimum stable speed must have certain requirements.
Generally, rolling bearing or hydrostatic sliding bearing, hydraulic special-purpose orbit motor Since the pressure motor works under the condition of input pressure oil, it does not need to have self-priming capacity, but it needs to have a certain initial air tightness to provide the necessary starting torque. The existence of these differences makes the structure of the hydraulic motor and the hydraulic pump relatively close, but they cannot work reversibly. The classification of hydraulic motors can be divided into gear type, impeller type, plunger type and other types according to the structure type. According to the rated speed of the hydraulic motor, it can be divided into high speed and low speed. The rated speed exceeds 500r/min Hangzhou orbit motor High speed hydraulic motor, while the rated speed is lower than 500r/min, it belongs to low speed hydraulic motor.
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 orbit 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 Hangzhou 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.
