| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive unit capable of preventing tooth surface interference by limiting an output shaft tilt angle when a shaft is greatly inclined due to abnormal bearing conditions, and alarming the abnormal conditions by motor output decline. <P>SOLUTION: When a bearing part 18 is abnormal, since the output shaft 9 is greatly inclined around it and an input shaft 8 is also greatly inclined linked with it, and thus gears of a reduction gear set 5 (a sun gear 11 and a pinion large diameter gear part 13a) interfere with each other. Before the interference, a radial gap is set so that a rotor 7 is brought into frictional contact with the inner periphery of a stator 6 as indicated in a B part. By the contact, the maximum tilt angle of the output shaft 9 is limited to the tilt angle shown in the figure, the tooth surface interference of the gear set 5 is prevented, and sudden deceleration by it is prevented. Also, frictional heat generated when the rotor 7 comes in contact with the inner periphery of the stator 6 elevates the temperature of a motor 4 to an irreversible demagnetization zone, and by the automatic decline of motor output, the abnormal conditions of the bearing part 18 is reported. <P>COPYRIGHT: (C)2013,JPO&INPIT |
