Patent ID: 7334943
Filing Date: 2008-02-26
Classification: C21D,C23C,F16C,F16H

Abstract:
1. A structure supporting a differential rotatably, comprising: an inner ring arranged at said differential; an outer ring arranged at an external peripheral portion formed to surround said differential; and a rolling element rolling between said inner ring and said outer ring, wherein at least one of said inner ring, said outer ring and said rolling element has a carbo-nitrided layer and has an austenite grain size number falling within a range exceeding 10, wherein steel is carbo-nitrided at a temperature higher than an A wherein at least one of the inner ring, the outer ring and the rolling element contains carbon in an amount of 0.95%-1.10%, silicon in an amount of 0.15%-0.35%, manganese in an amount of at most 0.5%, phosphorus in an amount of at most 0.025%, sulfur in an amount of at most 0.025%, chromium in an amount of 1.30%-1.60%, and molybdenum in an amount of less than 0.08%, with the remainder formed of Fe and an unavoidable impurity.