| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce abnormal wear and noise by reducing frictional resistance between a worm wheel provided to a gear body and an output gear. <P>SOLUTION: First and second worms 32a with opposite torsional directions are formed on the peripheral surface of an armature shaft 25, and the first and second gear bodies 33 provided with a first or second worm wheel 33a and a first or second pinion gear 33b are rotatably stored in a gear case 26. Each worm wheel 33a is meshed with the corresponding worm 32a, and the first and second pinion gears 33b are meshed with the output gear 35. The output gear 35 is brought into sliding contact with the first and second worm wheels 33a from an axial direction to restrict the axial movement of the first and second gear bodies 33, and also an oil sump groove 51 is formed in a sliding surface brought into sliding contact with the first and second worm wheels 33a of the output gear 35, thereby a sliding contact part between the output gear 35 and the first and second worm wheels 33a is lubricated with a lubricating oil stored in the oil sump groove 51. <P>COPYRIGHT: (C)2008,JPO&INPIT |
