| 摘要 |
PURPOSE:To reduce gear noise of a helical spline while forming a total unit in small size by suppressing a valve timing adjusting device from extension of its axial direction length. CONSTITUTION:An internal helical spline 5a is formed in an internal surface of a sleeve 5 mounted on a sprocket 2 driven by a crankshaft of an internal combustion engine, and an external helical spline 3a is formed in an external surface of a sleeve 3 mounted on a cam shaft 1 fitted to float in the sprocket 2. A cylindrical gear collective unit 8 fitted to these splines is formed of a controlling member 6 and an arc-shaped gear, which are energized in the axial direction by a coil spring 27. By increasing a virtual tooth thickness with a tooth trace of these helical splines displaced in the axial direction, backlash is reduced, but since the arc-shaped gear is stored in space of notching in the axial direction the controlling member 6 partly in a circumferential direction, an axial direction length of the gear collective unit 8 can be suppressed from increasing. |
