Application of Lubrication Theory to Near-Dry Green Grinding – Feasibility Analysis

This paper describes an investigation about the grinding fluid optimization supply based on lubrication theory. The models for three-dimensional hydrodynamic flow pressure in contact zone between wheel and work are presented based on Navier-Stokes equation and continuous formulae. It is well known that hydrodynamic fluid pressure generates due to this fluid flux, and that it affects overall grinding resistance and machining accuracy. Moreover, conventional methods of delivering grinding fluid, i.e. flood delivery via a shoe or jet delivery tangential to the wheel via a nozzle, have been proved that they can not fully penetrate this boundary layer and thus, the majority of the cutting fluid is deflected away from the grinding zone. Therefore, in this paper, a new delivery method of grinding fluid, the minimum quantity lubricant (MQL)-near-dry green grinding is presented and analyzed for it not only reduces hydrodynamic lift force but also reduces grinding fluid cost to achieve green manufacturing. Experiments have been carried out to validate the performance of the MQL supply compared with conventional flood cooling. The experimental results have shown that the theoretical model is in agreement with experimental results and the model can well forecast hydrodynamic pressure distribution at contact zone between and workpiece and the MQL supply in grinding is feasible. Experiments have also been carried out to evaluate the performance of the MQL technology compared with conventional flood cooling. Experimental data indicate that the proposed method does not negatively affect to the surface integrity and the process validity has been verified.