On the Miniature Ball Bearing

On the effect of lap groove angle in lapping steel balls

Abstract

In lapping of steel balls, the ball motion mechanism is influenced by groove angle on lap disk. This also depends on kinds of lapping compound, lap materials and so on. But we investigated the effects of lapping quantity, sphericity of balls and cutting resistance caused by changing lap groove angle and lapping pressure and maintaining other conditions constant : that is definite lapping compound, its supplying method, lap material, etc.
Then we reached following conclusion by comparing theoretical analysis with experimental results.
(1) Lapping quantity varies considerably according to groove angle, and lapping quantity in the case of unsymmetry angle becomes larger than in the case of symmetry angle with same magnitude. Also, this tendency decreases under high lapping pressure (more than 100 gr./piece).
(2) In the case with symmetry groove angle, the ratio of lapping effect in each contact point between steel ball and lap disk is as follows.
A : B: C=1 : 1.7 : 1.5
(3) Smaller the magnitude of groove angle, the sphericity of balls becomes better, and the effect depending on symmetrization is more inconsiderable.