Analysis Of High Speed Light Load Sliding Bearing Temperatuer Rise Characteristic

With the development of modern industry, hydrodynamic lubrication sliding bearing now has been widely applied to various rotating machin ery, the dynamic pressure bearing has a high precision operation, good shock resisistance, large bearing capacity, low power consumption, and can be used in heavy load and high presicion. The lubricating oil into the bearing chamber, separated from the jou rnal and bearing surface, prevent the friction of solid surface, due to the rotation of the journal, the dynamic pressure effect in the bearing and journal at minimum clearance, oil friction generates heat, the viscous disspation of the lubricating oil also generates heat, and the viscosity-temperature effect will affect the lubricating oil flow in the bearing chamber and bearing capacity of the bearing, because most of heat produced by the lubricating oil away, the other part of the bearig structure of the heat transfer away, it can be known that the temperature rise of the bearing will directly affect the normal operation of the system, in this paper, we mainly study in considerations of cavitation effect, bearing length, radius clearance changes and groove on the bearing the influence law of temperature, and in consideration of temperation field based on the analysis of the variation of the dynamic characteristic parameters. The specific research contents and results are as follows:First flow field are presented, basic equations and cavitation equation by equation of discrete and lay a foundation for the analysis theory, three-dimensional flow field caculation model is established, analysis of the bearing temperature rise using CFX software, the grid independent of the verification and the previous model to verify the accuracy of the analysis method in this paper.Then under different cavitation pressure bearing produced the change rule of law of cavitation and the bearing temperature, with increse of cavit ation pressure and bearing produce cavitation region and gas phase volum fraction increases, has little effect on the oil film temperature are analyzed. The influence of the change of bearing bearing length and radius of bearing on temperature rise of the bearing is analyzed. With the increase of the bearing length and radius gap, the maximum oil film temperature and the maximum oil film pressure are all lower, and the phase volum fraction value is increased.Secondly, the influence of oil groove on tempeture rise of bearing is analyzed. Comparing the calculation results without oil groove and upper and lower bearing oil groove are provided, and verify the importance of set oil groove bearing. Then respectively analyzes the upper bearing oil groove angle, wi dth and lower bearing oil groove angle,width changes of bearing temperature rise effect. And analyzes the change under the influence of the bearing oil groove depth on the bearing temperature rise. With the calculation result shows that the upper bearing oil groove angle 45~180 degrees, the highest oil film temperature values changed little, bearing the maximum oil film pressure value increased by about 16%, when the bearing oil groove angle is 0~135 degrees, maximum gas phase volum fraction value around 0.99, and when the oil groove angle is 180 degrees, the gas phase volume fraction values decreased to 0.8. With the upper bearing oil groove width in 15mm~20mm, the oil temperature gradually decreased and maximum oil film temperature value reduced by about 4%, the maximum oil film pressure value increased by about 14%, the maximum gas phase volume fraction values decreases by about 13%. With the angle of the low oil groove at 45~180 degrees, the maximum oil film temperature value reduced by about 3%, the bearing oil film pressure distribution shape change, the maximum oil film pressure value is reduced by about 65%, the bearing oil groov angle is 0~135 degrees, generate cavitation region is basically the same,when the oil groove angle of 180 degrees, reducing in cavitation region decreased, the maximum gas phase volum fraction slightly lower. With the lower bearing oil groove width in 15mm~20mm. the temperature of the maximum oil film bearing value changed little, pressure values decreased about 2%, maximum g as phase volum fraction values were 0.8. Current bearing oil groove depth in 0.mm~2mm changes, the value of the maximum pressure of oil film bearing, maximal oil film temperature value and the maximum gas phase volume fraction values is gradually reduced.Then analyzes the lower bearing oil groove width changes corresponding to the bearing temperature rise under the conditions of different eccentricity. The maximum oil film temperature increased by about 0.7% in the bearing, and the maximum oil film pressure in the bearing increased by about 13%, and the maximum gas phase volum fraction value increased by about 5%.Finally, in the condition of considering the cavitation effect and the temperature field, the use of harmonic excitation thoery and computational fluid mechanics grid technonolgy to solve the move with the speed under the same frequency dynamic characteristics of journal bearing coefficient are analysed.