Analysis And Research Of Grinding Fluid For Ultra-high Speed Centrifugal Grinding Of Bearing Rings

Bearing is a vital part in the mechanical manufacturing area. As a key part of bearing, the manufacturing technical level of bearing rings can influence the development of the mechanical manufacturing industry deeply, especially in its machining accuracy and the surface quality. Ultra-high speed centrifugal grinding is an effective and advanced grinding technique in improving the surface quality of bearing rings, reducing its surface roughness and residual stress. In order to solve the problem of grinding burn under ultra-high speed centrifugal grinding, there are some analysis about the influence of extreme pressure agent to grinding fluid properties,which is based on abundant domestic and foreign research. It provides theory and practice for the formation of proper ultra-high speed centrifugal grinding fluid and creates a new type of T nozzle combined with air flow baffle and high pressure jet grouting method. There are some main contents and conclusions as follows:(1) A grinding fluid containing borate ester with nitrogen was compounded. It contains three kinds of grinding fluid, sulfide fat oil, chlorinated paraffin and zinc phosphate. We tested and analyzed by PH test and friction coefficient test. The result showed that the changes of the type and quantity of the extreme pressure agent will not alter its acid-base property. The effect of the extreme pressure agent with chlorine is better than sulfur series and phosphorus series on its friction and lubrication, and phosphorus series is worst. According to the analysis of results,its friction coefficient will be reduced with increasing the dosage of sulfur and chlorine in the grinding fluid under a certain range. However, its friction coefficient will be increased with increasing the dosage of extreme pressure agent with phosphorus.(2) The study consists of three kinds of extreme pressure agent. The test artifact is GCr15 bearing steel. The study compared and analyzed grinding force, surface micro topography and surface roughness. Experimental study shows that when using the same kind of grinding fluid, the grinding force will be decreased with the increaseof wheel speed, but increased with the increase of grinding depth. The surface roughness decreases with the increase of wheel speed, but increased with the increase of grinding depth. When using different grinding fluids, the grinding force and surface roughness reduced with the sulfur and chlorine agent obviously. The study of surface micro topography shows that sulfide fat oil and chlorinated paraffin can effectively improve the surface quality of grinding work piece under high speed or medium speed.In the ultra-high speed, only the effect of Sulfide fat oil is apparent.(3) Based on the combination of air flow baffle plate method and high pressure jet grouting method, a new type of T nozzle is designed by using SolidWorks software.It is suitable for the grinding fluid and the ultra high speed centrifugal grinding and the simulated analysis is carried out with ANSYS software.