| 摘要 |
A reduction unit (B) that constitutes this in-wheel motor drive device (21) is equipped with a plurality of outer pins (27) (outer-periphery engagement members) that engage with the outer peripheries of curved plates (26a, 26b) to rotate the curved plates (26a, 26b). Each outer pin (27) is rotatably supported by needle roller bearings (61) positioned at both ends of each outer pin in the axial direction. A needle roller (65) that constitutes the needle roller bearing (61) includes a crowning (65c) at the outer diameter end. In the crowning (65c), the displacement amount (N) towards the diameter direction interior at a measuring point (M), which is a positioned 1.0mm towards the axial direction interior from a rolling end-face (65a), is 1-15μm. |
