| 摘要 |
PROBLEM TO BE SOLVED: To expand the adjusting range of backlash while the power transmission characteristics in normal and reverse directions are not changed in a worm gear device using a plural-lead worm. SOLUTION: The worm gear device includes a worm wheel 30 formed by a helical spur gear, and the plural-lead worm 20. The worm tooth part 21 of the worm and the wheel tooth part 31 of the worm wheel 31 are on the cylindrical surface including the center part of the meshing range of the worm tooth part and the wheel tooth part around the center axis of the worm, and adjusted and arranged so that the center line of the tooth space between the worm tooth parts in the center part is aligned with the center line of the wheel tooth part. This adjustment may be accomplished by making one of pitches of the respective tooth flanks of the worm tooth part smaller and the other larger, or by adjusting the intersecting angle of the worm and the worm wheel. |
