To provide a bearing arrangement for joints of a robot arm, which is employed for the inside chamber of a general industrial machinery or a spattering system or the like, prevents a misregistration of a work by damping the oscillation of the work at the time of transfer, and improves a conveyance speed.

The both inner rings of a combined bearing 30 are gripped with a pair of gripping members 41 and 42 from axial outer end surface, and are screwed with a fixing screw 46 in contact with each axial opposed surface simultaneously. Further, a wave washer 50 is inserted between the axial inner end surfaces of both the outer rings of the combined bearing 30, and next both the outer rings are attached at each axial direction outside in such a state that the axial opposite surfaces 47 and 48 of the pair of gripping members 41 and 42 are contacted together, and precompression is applied to each pair of rolling bearing 31 and 32 of the combined bearing 30.