| 摘要 |
PROBLEM TO BE SOLVED: To favorably suppress the backlash quantity of an engagement part without selectively assembling a dimension-controlled worm, etc., and to suppress the backlash quantity even if abrasion of teeth increases. SOLUTION: A worm wheel 4 is relatively movably divided in an intermediate position in the tooth width direction, a ring spring 43 relatively rotating the divided bodies 4a and 4b is provided, and the teeth 30a of the worm 3 are clamped between the teeth of the divided bodies 4a and 4b so that the backlash quantity can be suppressed. |
