Worm reducer and method of assembling worm reducer

A method of assembling a worm reducer which includes:

• a housing including a wheel accommodation part, and a worm accommodation part provided in a skew position with respect to the wheel accommodation part and having a part continued to the wheel accommodation part;
• a worm wheel rotatably supported in the wheel accommodation part;
• and
• a worm including worm teeth provided on an axially intermediate portion of a worm shaft and rotatably supported in the worm accommodation part at two axial positions which interpose the worm teeth therebetween by a pair of bearings at a state where the worm teeth are meshed with the worm wheel,
• the method comprising:
• causing the worm wheel to be rotatably supported in the wheel accommodation part;
• externally fitting the pair of bearings at the two axial positions which interpose the worm teeth therebetween;
• inserting the worm into the worm accommodation part from an opening side of the worm accommodation part at a state where the worm is offset outward in a radial direction of the worm wheel such that the worm teeth and the worm wheel do not interfere with each other;
• causing one of the pair of bearings which is externally fitted to a leading side in an insertion direction of the worm to pass an outer diameter-side of a part of an outer peripheral edge of the worm wheel, which protrudes most into the worm accommodation part;
• displacing the worm inward in the radial direction of the worm wheel such that the worm teeth mesh with the worm wheel;
• further inserting the worm to a predetermined position in the worm accommodation part while the worm teeth and the worm wheel are meshed with each other, so that the worm is rotatably supported in the worm accommodation part by the pair of bearings.