| 摘要 |
<p>This invention provides a technique that, even when fabrication with a large machining allowance is carried out after heat treatment, can ensure necessary heat treatment hardened case depth and surface hardness, can prevent strength lowering and can reduce heat treatment cost. A cage (40) is in a short cylindrical form, a plurality of pockets (41), which are disposed between an internal ball face in an outer ring and an external ball face in an inner ring in a constant velocity universal joint, for housing balls provided in a ball track between the outer ring and the inner ring, are provided at equal intervals in the circumferential direction. A heat treatment hardened case (M) is formed by induction hardening at a site including the peripheral part of the pockets (41) and a columnar part (42) between the pockets (41) and excluding both end face parts (43) over the whole area in the thickness-wise direction.</p> |
