Theoretical Analysis and Experimental Investigation into Hydrodynamic Pressure and Coolant Lift Force in Flood Delivery Grinding

Abstract

In the grinding process, conventional method of flood delivering coolant fluid by a nozzle in order to achieve high performance finishing. However, hydrodynamic fluid pressure can be generated ahead of the contact zone due to the wedge effect between wheel peripheral surface and work surface. In the paper, a theoretical hydrodynamic pressure modeling is presented for flow of coolant fluid through the grinding zone in flood delivery grinding. Moreover, coolant induced force can be calculated by integrate the hydrodynamic pressure distribution over the whole contact length. The theoretical results show that the hydrodynamic pressure was proportion to grinding wheel velocity, and inverse proportion to the minimum gap between wheel and work surface and the maximum pressure value was generated just in the minimum gap region in which higher fluid pressure gradient occuring. It can also be concluded the pressure distribution was uniform in the direction of width of wheel except at the edge of wheel because of the side-leakage. Furthermore, the hydrodynamic pressure and coolant induced force at wedge-like zone were also investigated experimentally. The experimental results show the theoretical model is agreement with experimental results and the model can well forecast hydrodynamic pressure distribution at contact zone between grinding wheel and workpiece.