| 摘要 |
PURPOSE:To shorten the total width of a differential gear by installing a gear revolution suppressing part and an axial directional shift regulating part, within the width of the engagement teeth part of a worm gear for speedometer, thus reducing the width of the above-described gear. CONSTITUTION:A worm gear 10 for speedometer has an annular body 21 having an engagement teeth part 20 on the outer peripheral surface and has the folding- fan-shaped projecting stripes 22 which protrude inwardly at the positions symmetrical to the center of the circle of the annular body 21. The folding-fan- shaped projections 25 which project inwardly are formed at the symmetrical positions crossing at right angles to the line connecting two stripes 22 on the inner peripheral surface of the annular body 21. A revolution suppressing part where the both edge surfaces in the circumferential direction of the projections 25 are engaged with the edge part of a concaved part 16 for suppressing revolution is constituted, and an axial directinal shift regulating part 14 is constituted from the inside edge surfaces of the projecting stripes 22 and the outside edge surfaces 26 of the projecting stripes 25, and the both parts are accommodated within the width of the engagement teeth part 20.
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