Evaluation of grinding wheel wear in wet profile grinding for the groove of the ball bearing's inner ring by pneumatic probes

Wear is one of the most influential factors in profile grinding. The measuring of grinding wheel wear is costly and time consuming. We introduce a new online wear measuring method in a wet profile grinding for the inner ring groove of ball bearing. The advantage of this method is the reduction of electromagnetic influence of workpiece as well as the impact of grinding debris and cutting lubricant. Two pneumatic gauging probes are positioned at two different locations with the biggest gap in the wear value on the curved edge surface of the grind stone. When the compressed air flow is blown onto the working surface of the grinding wheel, the back pressure in the measuring chamber corresponding to the gap between the probe and the working surface of the grinding wheel can be measured. Therefore, the radial wear value of grinding wheel can be determined. Based on theoretical calculations and the establishment of its dynamic characteristic curve, it is demonstrated that the first probe measuring wear at the top of the curved edge surface of the grinding wheel with the parameters of the probe d(1) = 0.85; d(2) = 1.5; P = 4 Bar has a measurement range of 200 mu m, a maximum speed ratio of 0.01 Bar/mu m. The second probe used to capture wear at the margin of the curved edge surface of the grinding stone with the parameters of the probe d(1) = 0.65; d(2) = 1.6; P = 4 Bar has a measurement range of 140 mu m, a maximum speed ratio of 0.03 Bar/mu m. The experimental results show that the grinding wheel wear value varies at different points of the curved edge surface of the grinding wheel. In profile grinding for the inner ring groove of the 6208 ball bearing, the wear value at the edge of the curved edge surface of the grinding wheel is usually bigger than that at the top of the curved edge surface of the grinding wheel.