Electrolytic in-process dressing superfinishing of spherical bearings usingmetal-resin bond ultra-fine CBN wheels

摘要

The use of electrolytic in-process dressing (ELID) superfinishing has beeninvestigated with the aim of substantially improving surface finish on sphericalbearing balls as well as reducing process times. Using ELID in a superfinishingconfiguration is substantially different from the more conventional precisiongrinding set-up. With this ELID superfinishing system, metal-resin bonded (MRB)wheels containing very small superabrasives (30 to 0.12 μm) were employed.Surface finishes of 2 nm Ra were achieved with a #12 000 wheel, an order ofmagnitude better than balls produced using the conventional productiontechniques of barrelling or polishing. Consistently sub-10 nm Ra finishes wereachieved with a #2000 wheel. Different ways of using the ELID system, includingELID 1, ELID 2, and ELID 3, were studied to examine how the different typescontrol the cutting condition at the wheel's surface. It is the ability tocontrol easily the cutting condition of superabrasives of this size that allowsmirror surface finishes to be efficiently produced. Monitoring of wheel spindleand ELID power usage was found to provide useful information in assessing thewheel c