| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive device for reducing gear rattle generated by the collision of a driven gear against a drive gear when a contact point of a contact portion passes through a boundary portion between a gradual change portion and a pocket portion in response to the rotation of a drive cam.SOLUTION: In a second pocket boundary portion 542 that is a boundary portion between a first gradual change portion 531 of the drive cam and a second pocket portion 552, a normal-rotation-direction outline diameter change rate k2B+ that is an inclination of a line connecting a closest inflection point In to the gradual change portion 531 to a vertex S and a reverse-rotation-direction outline diameter change rate k2B- that is an inclination of a line connecting a closest inflection point Ip to the pocket portion 552 and the vertex S are defined. Each of the outline diameter change rates k2B+ and k2B- is set to be equal to or lower than a threshold K so that a boundary acoustic pressure generated by the collision of a driven gear against a drive gear when a contact point passes through the pocket boundary portion 542 falls in a reference acoustic pressure range that is a variation range of acoustic pressures generated when the contact point passes through the gradual change portions 531 and 532.SELECTED DRAWING: Figure 12 |
