| 摘要 |
A first rotary shaft (2) and a second rotary (3) are disposed such that they are rotatable around a rotation axis (L). The second rotary shaft (3) has a cylindrical supporting part (11) that covers the end section of the first rotary shaft (2). A case (4) supports the first rotary shaft (2) and the second rotary shaft (3). A first rolling bearing (5) is disposed between the first rotary shaft (2) and the case (4) and supports the first rotary shaft (2) such that it is rotatable. A second rolling bearing (6) is disposed between the supporting part (11) and the first rotary shaft (2) and supports the first rotary shaft (2) and the second rotary shaft (3) such that they are rotatable relative to each other. A transmission part (11A) of the second rotary shaft (3) transmits to the second rolling bearing (6) a preload force that pushes the second rotary shaft (3) to the first rotary shaft (2) side. A load-receiving part (31A) of the case (4) that receives the preload force transmitted from the second rolling bearing (6) to the first rolling bearing (5). |
