Torque transmission unit of motor

#The present invention relates to a torque transmission unit of a motor incorporating a worm.

#In the torque transmission unit, in general, a torque generated in an armature of a motor is taken out through a worm, a worm wheel, a damper, a torque transmission disk and an output shaft.

#As described above, such a torque transmission unit incorporates therein many parts or elements. Therefore, it is hard to reduce the cost thereof and the weight thereof.

#FIG. 1 is a sectional view taken along the lines I--I in FIG. 2, showing a torque transmission unit according to an embodiment of the present invention;

#FIG. 2 is a longitudinal sectional view showing the torque transmission shown in FIG. 1;

#FIGS. 3 and 4 are exploded views showing a transmission mechanism shown in FIG. 1;

#Referring to FIGS. 1 and 2, a torque transmission unit 10 is mounted onto a motor 20. The motor 20 comprises an armature 21 provided on one end portion of an armature shaft 22, and a stator 23 surrounding the armature 21. The other end portion of the armature shaft 22 is formed with a worm 24.

#The torque transmission unit 10 comprises a gear casing 11 with an annular central boss 111, attached to a motor housing 25, and a worm wheel 12 with a central opening 121.

#The worm wheel 12 is meshed with the worm 24 of the armature shaft 22 and is rotatably supported at the central opening 121 by the boss 111 of the gear casing 11. The worm wheel 12 is provided at an inner end face with a plurality of radial ribs 122.