At this stage, several orbit motor Serial application system. The motor output shaft often leaks oil in the application link, even if the dynamic seal ring of the output shaft is replaced, it will not help. This is the problem of ignoring the pressure of oil leakage in the case when selecting the cycloidal motor and applying it in series.

The pressure of case oil leakage refers to the greater pressure that the motor shaft seal ring can bear after getting sufficient lubrication in Madane; If the motor is not applied properly, the oil in the box will not be discharged due to various factors after the equipment continues to run for a certain period of time. As a result, the pressure of the motor box will become higher and higher, leading to the failure of the shaft seal ring earlier. The pressure of case oil drainage mentioned here is not the bursting pressure of the case, but the pressure that the dynamic seal ring of the motor output shaft can bear. In one point, the manufacturer's motor model only talks about the back pressure. In fact, the back pressure refers to the return oil pressure of the motor, not the pressure of the tank oil leakage. In operation, the pressure of the case oil drain of the cycloidal motor is described below.

Eaton is the earliest cycloid motor manufacturer in the world. In China's cycloidal motor manufacturing industry, Ningbo White Hydraulic Technology Co., Ltd. selects the cycloidal motor manufactured by Eaton Technology of the United States, and the pressure bearing level of the dynamic seal ring of its output shaft is better, that is, the company's products are designed with a unique internal main oil channel, so that the internal oil drain can not only lubricate parts, It can also drain off excessive oil while maintaining the pressure of oil drain in the stator case- Generally, the pressure of oil leakage in the case of the axial flow distribution motor in China is below 3.0Mpa, that of the disc flow distribution motor is below 5.0Mpa, while the pressure of oil leakage in the case of the axial flow distribution motor manufactured by Eaton Fluid Power (Jining) Co., Ltd. is 7.0-10.0Mpa, and that of the disc flow distribution motor is 7.0Mpa. Such statistics are clearly described in the motor model of the company. It must be noted that when the pressure of the motor case oil drain (internal drain) exceeds its reference value, the external drain port of the motor case must be connected to the oil tank, otherwise it will greatly interfere with the service life of the motor shaft seal ring, or even cause the shaft seal ring to fail, resulting in oil leakage at the output shaft.

In the specific work, it is not recommended that motors be used in series. On the contrary, in order to ensure the synchronization of many actuators, and at the same time, to control costs efficiently under the ring mirror that ensures the quality, the cycloidal motor manufactured by Eaton has greatly improved the pressure resistance level of the box. For example, the oil drainage pressure of the box of the h/s/t series axial flow distribution motor has reached 10.3Mpa, The case oil discharge pressure of 2000 series disc flow distribution motor is 14.0Mpa, which effectively improves the level of motor serial application, provides an improvement plan for the formulation of the machine, reduces the total flow of the pump source, and saves manufacturing costs. The oil drainage pressure of the motor box is also related to the motor's rotation speed n. Eaton has a clear diagram | solution to the relationship between the oil drainage pressure of the box and the motor's rotation speed in its product samples (Figure 2 shows the h/s/t series manufactured by Eaton.

The relationship between the case oil drainage pressure of the axial flow distribution motor and the motor rotation speed), H suggested the following formula to indicate how to estimate the case oil drainage pressure value of the motor in a system, that is, in which case the motor needs to be connected to leakage: case oil drainage pressure pc=0.6x (inlet pressure p1 - outlet pressure p2)+outlet pressure p2 According to the analytical calculation of specific application, If the pc value of - 1 motor is close to or meets the requirement of the manufacturer's product sample, the leakage port of the motor needs to be connected to the oil tank, otherwise the result will be unpredictable, which will not only endanger the operation, but also damage the ring mirror. However, the lower the oil drain pressure of the case, the better. First of all, the oil drain port of the motor should be located at a high place in the box, so that the motor is filled with hydraulic oil to lubricate the relative moving components; In addition, the pressure of oil drainage should be maintained above 0.35Mpa before adequate lubrication or) in the middle brush motor. The motor leakage port has three functions: damage control -- flushing the pollutants in the system (motor); System refrigeration - leaked oil will take away some heat from Madane; Increase the service life of the motor shaft seal - maintain a reasonable case oil drainage pressure. Although some manufacturers have indicated that the shaft seal of their own motors can withstand high pressure, the author believes that the dynamic seal of any hydraulic product is instantaneous, and generally speaking, it is an early part of the hydraulic components that is prone to failure. If it is disabled due to certain circumstances, high pressure oil will flow out from here, This is an uncertain risk for operators and field staff; Therefore, whether in the system design or in the field service, if there is a similar situation, in addition to the customer's understanding of the situation, the following is to deal with the problem, that is, the hydraulic seal should be removed and replaced before re testing.