| 摘要 |
PURPOSE:To reduce gearing noises in a system with a gear between a timing pulley and a cam shaft for the relative turn thereof through shifting in an axial direction, by using an elastic material such as rubber for giving no backlash at the gearing portion of the gear with said pulley and cam shaft. CONSTITUTION:The subject device has a constitution wherein a cylindrical gear 3 with helical teeth on the inner periphery thereof is fitted between a timing pulley 1 and a cam shaft 2, and the outer teeth 3a and the inner teeth 3b of said gear are respectively geared with the inner teeth 1a on the inner periphery of the pulley 1 and the outer teeth 2a on the outer periphery of the cam shaft 2. And the gear 3 is moved in an axial direction by a gear drive mechanism 4 and the cam shaft 2 is turned relatively to the pulley 1, thereby changing the operation cycle of a valve. In this case, said gear 3 comprises two gear components 3c and 3d, and an elastic member 3e such as rubber and plastics located between said components 3c and 3d for making the space thereof slightly out of alignment. |
