| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a speed reducer having a lightweight aluminum housing, which reduces an unfavorable change of a distance between the centers of gears. <P>SOLUTION: The speed reducer 21 comprises: a driving gear 23 and a driven gear 24 which are received in a housing 25; a first bearing 29 which supports the driving gear 23; and a second bearing 33 which supports the driven gear 24. The housing 25 includes a main housing 37 containing aluminum and a sub housing 38 supported by the main housing 37. The sub housing 38 includes a first portion 38a which supports the first bearing 29, a second portion 38b which supports the second bearing 33, and a connecting portion 38c which connects the first and second portions 38a, 38b to each other. The sub housing 38 is formed of a material which has a coefficient of thermal expansion lower than aluminum. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
