| 摘要 |
PROBLEM TO BE SOLVED: To provide a power transmission device for suitably varying the rotation of a driven-side rotor.SOLUTION: A water pump 1 includes a pulley 5, inner plate 6, ball 7, lever 8, cam 10a and stator 11. The cam 10a has a first section R1 where the amount acting on the lever 8 is set relatively small and a second section R2 where the amount is set relatively large. The lever 8 is configured so that it comes into a first state engageable with the ball 7 when the cam 10a abuts on the lever 8 in the first section R1 and it comes into a second state where it does not engage with the ball 7 when the cam 10a abuts on the lever 8 in the second section R2. The water pump 1 has first to third control modes for controlling a relative phase of the cam 10a to the inner plate 6. |
