| 摘要 |
PURPOSE:To prevent the abrasion occurring in the clattering of a drive gear of a speedometer with a differential gear case by forming a flange part engaging with the end face of the rotating differential gear case into one body over the entire circumference of the end face of said gear. CONSTITUTION:A drive gear 12 of a speedometer made of a synthetic resin such as nylon 66 is formed with a worm gear 12a intermeshing with a pinion gear for transmitting revolutions to the speedometer and has a flange part 13 overhanging to the inner side over the entire circumference on one end face. The gear 12 is fitted to the annular stepped part 3a of a rotating differential gear case 3 as its flange part 13 contacts with the end face 3b on the small diameter side. As a result, such a trouble that the gear rides on the edge part on the large diameter side of the part 3a on account of its thermal expansion or the thrust load to be exerted upon the same and is thereby generated a stepped abrasion is prevented. |
