| 摘要 |
PURPOSE:To enhance the wear resistance of a friction surface by giving high hardness to the cam surface of a cam member and weight and movable pulley plate. CONSTITUTION:A weight to push a movable pulley plate 6b with centrifugal force is formed from ceramic to increase the hardness of the weight at its peripheral surface to serve as the rolling and sliding face. Because cam surfaces 10, 11 are treated so as to have a hardness of 400-1,000Hv, the hardness of cam surfaces 10, 11 to contact the weight 8 can be increased. Accordingly the cam surfaces 10, 11 are free from risk of wear due to contact with the weight 8 made in ceramic as well as of mutual destructive abrasion with the weight 8. |
