| 摘要 |
The socket (10) has a concave coupling portion (20) to which a clutch is formed with a clutch ball. A convex counter-coupling portion of the clutch ball faces in an affecting region in a clutch state of the socket. A lubrication region is provided in the concave coupling portion. A lubricant portion receives lubricant i.e. grease. A solid body lubricant component (26) i.e. ball calotte surface, is received in the lubrication region. The solid body lubricant component loads air pressure of a draw bar (12) in a reference state with temperature of 20 degree Celsius. An independent claim is also included for a clutch ball. |
