| 摘要 |
<p>The disclosed free ball bearing comprises: a main body that has a ball cup in which a ball-containing recess is formed, the inside surface of said ball-containing recess being a concave hemispherical surface; a plurality of support balls distributed along the aforementioned concave hemispherical surface in the main body; a main ball that is larger in diameter than the support balls and is rotatably supported on the aforementioned concave hemispherical surface with the support balls interposed therebetween; and a covering housing provided so as to enclose the ball cup in the main body. An opening through which part of the aforementioned main ball protrudes is formed in the covering housing. The covering housing has a retaining prong that is inserted between the concave hemispherical surface in the main body and the main ball and restricts the movement of the support balls, thereby increasing the rotational resistance of the main ball. The main body can move, with respect to the covering housing, in the height direction of the ball cup, which is the same as the depth direction of the ball-containing recess. As a result of said movement of the main body, the retaining prong can switch between a position in which the movement of the support balls is restricted and a position, away from the support balls, in which the aforementioned restriction is released.</p> |
