The main parameters of bearing temperature rise and oil and gas lubrication

In high-speed machining, the thermal characteristics of the electric spindle are a major factor affecting the machining accuracy, and directly affect the increase of the rotational speed of the electric spindle. In the temperature rise of the electric spindle unit, the bearing temperature rise is an extremely important component. The temperature rise and temperature distribution of the bearing have a great influence on the performance of the bearing, which affects the assembly of the bearing, the working clearance of the bearing, and the performance of the lubricant. An increase in temperature deteriorates the lubrication state of the bearing, causing the bearing to fail prematurely. Therefore, thermal analysis of the bearing system can help us to rationally select and correctly use the bearing, which can provide a basis for fault and failure analysis of the bearing system.

 

    At present, the electric shaft shaft is usually a precision angular contact bearing that is adapted to high speed and can withstand both radial and axial loads. The test shows that the three main parameters of the oil and gas lubrication system (kinetic viscosity of the lubricating oil, compressed air pressure, compressed air flow) have the following conclusions on the temperature rise of the precision angular contact bearing:

 

    The viscosity of the lubricating oil is affected by the friction inside the bearing and affects the temperature rise of the bearing. As the viscosity increases, the temperature rise of the bearing will increase, and the trend in the high speed section is more obvious, but with the further increase of the viscosity, the bearing temperature The ascending gradient shows a decreasing trend. The flow and pressure of compressed air affect the temperature rise of the bearing by the convective heat of the compressed air and the bearing. In the range of compressed air pressure, the temperature rise of the bearing decreases with the increase of the air pressure, but the trend is not obvious. Increasing the flow of compressed air can reduce the temperature rise of the bearing, and as the speed increases, the effect of cooling will become more and more obvious.