| 摘要 |
PURPOSE:To improve seizure-resisting property by providing a bearing case, the inner base of which is cut to be triangular to improve the initial fitting performance of the end surface of a cross pin to the inner base of the beaing case when a yoke is deformed and to prevent a local contact therebetween. CONSTITUTION:l is a feed for one rotation at the time of cutting with a single point tool, that is, a pitch of a triangular spiral groove of the inner base of a bearing case 31, (h) is a depth of the groove, and R is a nose radius. In the case where the triangular spiral groove is thus formed on the inner base of the bearing case 31 by cutting, when the end surface of a cross pin 2 and the inner base of the bearing case 31 locally contact on a point of the periphery of a contact surface, the top 11 of the triangular section is worn away rapidly to be flat 12, so that the initial fitting performance is improved at a contact surface of both to prevent a local contact. Thus, the initial fitting performance is improved to enhance seizure-resisting property at the time of high-speed rotation. |
