Dynamic analysis and grinding tracks in the magnetic fluid grinding system: Part I. Effects of load and speed

The differential equations of ball and float motions in the magnetic fluid grinding system are formulated. In this dynamic model, depending on the magnitudes of the contact loads, the ball will either contact or separate from the shaft and/or the float during the grinding process. Using the steady-state solutions as the initial conditions, the differential equations of motion are solved. Numerical results show that in contact cases, the effects of variable shaft speed and variable contact load on the ball-spin angle and the resultant area covered by the grinding tracks are small. However, when the ball separates from the shaft, the ball-spin angle varies with time because the ball has lost the driving force from the shaft, and thus the area covered by the grinding tracks on the ball surface increases. Furthermore, the combined effect of variable shaft speed and variable contact load on the appearance of grinding tracks is different from that of variable contact load alone, and this difference provides the ergodic possibility to grind a ball with high roundness using the magnetic fluid grinding method.