What are the life analysis of Sauer hydraulic pumps?

Sao hydraulic pump is a small precision mechanical tribology system. The main factors affecting the life of the hydraulic pump (motor) are the fatigue strength of the structural parts and the friction and wear of the sports pair, especially the latter. There are various bearing pairs used in the pump, piston and rotor motion pairs, rotor and oil distribution plate motion pairs, plunger and wear plate motion pairs, valve core and valve sleeve motion pairs.
Regarding the fatigue life of the bearing: According to the structural requirements of the pump, the initial life expectancy of the bearing is carried out. The influence of additional lateral force caused by temperature and mechanical error, runout at high speed, impact and other factors are not considered. The axial equivalent dynamic load, the bearing life used in the pump is usually 8 000 to 90 00 h. If the influence of temperature, deformation, lateral force and other factors are taken into account, the calculated life of the bearing needs to be further revised. The revised data shows that the life of the bearing in the pump is about 5 000 to 7 000 h.
　　In order to solve the bearing life problem, it is necessary to select long-life bearings and take advantage of bearing expertise to jointly carry out hydraulic pump bearing optimization work. Make the bearing life can meet the host index requirements.

Through the motion calculation of several pairs of motion pairs in the pump, the necessary solid modeling and motion analysis are carried out using relevant software tools. Obtain more accurate motion relations and motion parameters, so as to make the design of the specific pressure, specific speed and specific power of each friction pair and motion pair more reasonable and improve reliability.
　　 At present, the wear life of domestic hydraulic pumps is much lower than the fatigue life. Excessive wear of key friction pairs in the pump restricts the life of the pump. The friction and wear of the friction pair in the pump is a very complicated phenomenon, but the wear is phased. After the friction pair is running in, the stable wear stage (that is, the flat straight section of the wear bathtub curve) has a certain regularity. In the scope of engineering application, the wear speed is expressed as r=kpmVn (where r is the wear speed; k is the wear resistance coefficient under certain working conditions; p and V are the pressure on the friction surface and the relative linear velocity; m is the coefficient 1～ 3; n is a coefficient, generally = 1). Therefore, increasing the outlet pressure and speed of the pump will accelerate the wear and reduce the life of the pump, which shows that there is an inverse relationship between the wear life and the accelerating stress. The stress of accelerating wear in the pump also includes working conditions such as temperature, pollution degree, and working frequency.