Rotating shaft and motor with reduction mechanism using the same

摘要

PROBLEM TO BE SOLVED: To make a revolving shaft more compact and lightweight while suppressing a decrease in function of a driving system without increasing the weight nor mass of the revolving shaft.SOLUTION: A diameter d2 of a worm 24a is set to be larger than a diameter d3 of a bearing member mount part 24c, and a diameter d4 of a rotor mount part 24d is set to be smaller than a diameter d3 of the bearing member mount part 24c, so an armature shaft 24 increases in neither weight nor mass on the whole and a tooth height of the worm 24a can be made high without varying a diameter d1 of a worm part 24b. Consequently, a worm wheel can be made small in a state in which the function of a driving system is suppressed from decreasing while bending strength of the worm part 24b and engagement strength between the worm 24a and a worm wheel are made sufficient. A wiper motor provided with the armature shaft 24 can be thereby made more compact and lightweight.