SPEED REDUCER

To reduce the size and weight of a speed reducer.SOLUTION: The speed reducer 100 includes: an internal gear 116 having a casing 122 encircling a main axis line 1La of the speed reducer and a plurality of outer pins 117 rotatably arranged in a pin groove 116b provided in the inner periphery of the casing; an external gear 114 meshing with the internal gear; an eccentric body 112 for oscillating the external gear; carriers 118, 120 to be rotated relative to the casing; and main bearings 124, 126 each having an inner periphery slide surface 148 to be rotated integrally with the casing and an outer periphery slide surface 149 to be rotated integrally with the carriers. One of the slide surfaces of the main bearings is made of resin, and the other is formed of a heat conductive material having higher wear resistance than the resin.SELECTED DRAWING: Figure 1 【課題】小型軽量化を図る。【解決手段】減速機１００の主軸線１Ｌａの周りを囲むケーシング１２２およびケーシングの内周に設けられたピン溝１１６ｂに回転可能に配置された複数の外ピン１１７を有する内歯歯車１１６と、内歯歯車と噛合う外歯歯車１１４と、外歯歯車を揺動させる偏心体１１２と、ケーシングと相対回転するキャリア１１８，１２０と、ケーシングと一体的に回転する内周すべり面１４８およびキャリアと一体的に回転する外周すべり面１４９を有する主軸受１２４，１２６と、を有し、主軸受におけるすべり面のうち、一方が樹脂により構成され、他方が樹脂よりも耐摩耗性が高い熱伝導材料により構成される。【選択図】図１