Patent ID: 7648283
Filing Date: 2010-01-19
Classification: B60B,F16C

Abstract:
1. A vehicle wheel bearing apparatus comprising: an outer member with double row outer raceway surfaces formed on its inner circumferential surface with double row outer raceway surfaces; inner members each formed with an inner raceway surface on its outer circumferential surface, said inner raceway surfaces facing opposite to the double row outer raceway surfaces, double row balls are freely rollably contained between the outer raceway surfaces and inner raceway surfaces; a counter portion is formed near the bottom of each inner raceway surface, said counter portion has an outer diameter larger than, by a predetermined run-over height, an inscribed circle diameter of balls under a supposed condition where the balls are perfectly held within the outer raceway surface as if they would be contacted with the bottom the outer raceway surface, said counter portion is formed by a cylindrical portion axially extending from each inner raceway surface; a tapered portion converges toward the end face of each inner members, a smaller cylindrical portion extends from the tapered portion in a direction away from said counter portion, said raceway surfaces is a ground surface, said cylindrical portion is a ground surface and said tapered portion is a ground surface; and transitions between the counter portion and the inner raceway surface as well as between the cylindrical portion and the tapered portion are rounded and smoothly continuous to effectively prevent the generation of scratches onto the balls during assembly of said wheel bearing.