Forced vibrations during grinding and their effect on surface quality

[摘要] Two types of vibration, i.e. forced and self-excited, are generated during the grinding process. The forced vibration is mainly introduced due to the wheel unbalance and the self-excited vibration due to the machining process itself. An attempt has been made to analyse the forced vibration in order to help with the formulation of a basis for the dynamic acceptance test of a grinding machine. A systematic analysis of the effects of the wheel unbalance on the dynamic system of the grinding machine, grinding forces, macro and micro geometrical workpiece parameters and wheel wear has been made by conducting a series of grinding tests. A new approach has been made to study the motion of the wheelspindle in its bearings. A theoretical expression relating the wheel unbalance and workpiece waviness has also been derived. A Churchill plain hydraulic cylindrical grinding machine was adapted for the present investigation. Three wheels of grades K, M and 0 were employed. A suitable experimental set up was developed to measure the various parameters involved. The two most important conclusions which emerged from the present investigation are as follows: 1. With increase in wheel unbalance an increase in the wheelhead and wheelspindle vibration are noticed. The relative motion between the wheel and the workpiece, the variation in the grinding forces and the workpiece waviness are also increased with the increase in the wheel unbalance. 2. The wheel unbalance does not affect the temperature in the bearings, the grinding ratio, the average grinding forces and longitudinal surface roughness parameters. Some improvement in bearing area, however, was observed with the increase of wheel unbalance.

[发布机构] University:University of Birmingham;Department:Mechanical Engineering Department

[关键词] T Technology;TJ Mechanical engineering and machinery