| 摘要 |
<p>A fixation portion of an attachment plate is fixed onto an upper surface of a flange portion of a housing. In a cylindrical retentive portion of the housing, there is formed an expanded diameter portion which is continuous to the flange portion. There is disposed a ball bearing in the expanded diameter portion. Formed integrally with the flange portion is a fitting portion such that the fitting portion is continuous to the expanded diameter portion.</p> |
