| 摘要 |
PROBLEM TO BE SOLVED: To provide a power transmission device capable of changing a pressing force in an axial direction which is applied to a predetermined roller in a traction drive device when necessary.SOLUTION: A power transmission device includes a planetary roller transmission and a loading cam device 11. The loading cam device 11 has three cam mechanisms 114a-114c in a radial direction from a rotation center C of a cam ring 110. Then, by changing an engaging cam mechanism, the distance from a rotation center C to a rolling element and a cam surface engaged with each other is changed. A force in an axial direction applied to the rolling element and the cam surface engaged with each other, that is a pressing force applied to a sun roller of the planetary roller transmission, is in reverse proportion to the distance from the rotation center C to the rolling element and the cam surface engaged with each other. Therefore, the pressing force applied to the sun roller can be changed when necessary.SELECTED DRAWING: Figure 2 |
