Title: A new ball machining method by centreless grinding using a surface grinder
Authors: W. Xu; Y. Wu; M. Fujimoto; T. Tachibana
Addresses: School of Mechanical and Manufacturing Engineering, The University of New South Wales (UNSW), Kensington, Sydney, NSW 2052, Australia. ' Department of Machine Intelligence and Systems Engineering, Akita Prefectural University, 84-4 Tsuchiya-ebinokuchi, Yurihonjo, Akita 015-0055, Japan. ' Department of Machine Intelligence and Systems Engineering, Akita Prefectural University, 84-4 Tsuchiya-ebinokuchi, Yurihonjo, Akita 015-0055, Japan. ' Micron Machinery Co., Ltd., Zao-uwano 578-2, Yamagata 990-2303, Japan
Abstract: This paper proposes a novel centreless grinding method for machining ceramic balls using a surface grinder. In this method, a compact unit consisting of an ultrasonic shoe, an ultrasonic regulator, a relay controller, a blade, a stopper and their respective holders is installed on the worktable of a surface grinder to conduct centreless grinding operations. The grinding unit was actually constructed and it was experimentally confirmed that the rotational speeds of the ball around its own two axes, one is parallel to the wheel axis and another parallel to the wheel radius, can be controlled well, respectively, by the elliptic motions occurring on the shoe and regulator end-faces. Then, the grinding experiments validated the proposed technique and revealed that the grinding accuracy is significantly affected by the relay switch 'on' and 'off' times, and the ball cross-section roundness was improved from the initial value of 10.13 µm to the final one of 0.88 µm under the optimal grinding conditions.
Keywords: ceramic balls; ball machining; centreless grinding; surface grinders; ultrasonic vibration; grinding accuracy.
International Journal of Abrasive Technology, 2012 Vol.5 No.2, pp.107 - 118
Received: 19 Nov 2011
Accepted: 14 Feb 2012
Published online: 30 Jul 2014 *