TABLE OF CONTENTS Forces generated during grinding cause elastic deformation and deflection of the machine, the grinding wheel, and the workpiece. Grinding deflections lead to geometrical inaccuracies in the components being ground and should be carefully considered in the design of grinding cycles. The deflection between the wheel and the workpiece may greatly exceed the depth of cut taken by the wheel. Although this is usually recovered to a greater or lesser degree by spark-out at the end of the grinding cycle, non-symmetric machine defections cause shape inaccuracies and taper, and periodic deflections associated with machine-tool vibrations cause chatter, which reduces surface and geometrical quality and limits the production rate.
The present chapter is concerned with the role of deflections in grinding. To provide a basis for characterizing and controlling the grinding cycle, simplified linear analyses are presented which account for the difference between the machine infeed and actual stock removal in both continuous and discrete infeed operations. Some examples are presented which illustrate how deflections can lead to geometric inaccuracies. The chapter concludes with a brief description of forced and self-excited vibrations and their causes, and of methods for vibration suppression to enhance part quality and productivity.
Elastic deflection of the grinding system causes the actual stock removal to be less than the controlled infeed input to the machine. For analyzing this phenomenon, we begin with an idealized model as illustrated in Figure 12-1 for cylindrical plunge grinding. The machine structure supports the wheel with a...
