| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily set frictional force by making the outer diameter of an outer annular part corresponding to a plurality of cutout parts of a friction spring member, larger than the outer diameter corresponding to a connection part to an inner annular part, and making the diameter of an imaginary circle of a circular arc of the outer annular part, larger than the diameter of the internal wall surface of an outer ring member. SOLUTION: A friction spring member 4 comprises an outer annular part 4a, an inner annular part 4b and a connection part 4c formed of metallic material high in resilience and hardness, and the outer annular part 4a is cut out in two places. In the state of the friction spring member not being pressed into an engaging member 2, the diameter d1 of the outer annular part 4a is almost equal to or slightly smaller than the inner diamter d2 of the engaging member 2, but distance d3 between one tip and the other tip of two outer annular parts 4a is larger than the inner diameter d2. When the outer annular part 4a is pressed into the internal wall surface of the engaging part 2, specified frictional force therefore works between the external wall surface of the outer annular part 4a and the internal wall surface of the engaging member 2, and the frictional force is kept almost constant.</p> |
