| 摘要 |
A reduction gear (18) is provided with a fixed-side housing (19) in which a hydraulic motor (12) with an output shaft (16) is housed, and a rotating-side housing (21) that rotates with respect to the fixed-side housing. Inside the rotating-side housing (21), a first stage planetary gear reduction mechanism (24) with a first sun gear (28) and a second stage planetary gear reduction mechanism (32) with a second sun gear (33) are provided. The first stage planetary gear reduction mechanism (24) has a rotating shaft (25), of which one end in the axial direction is spline-coupled to the output shaft (16). The other end of the rotating shaft (25) in the axial direction is provided with the first sun gear (28). A small diameter shaft (27B) is provided on the rotating shaft (25), and first and second half bushes (40, 41) are fitted from the radial direction onto the small diameter shaft (27B). As a result, the first sun gear (28) and the step area (34A) of the second sun gear (33) slidably contact the flanges (40B, 41B) of the first and second half bushes (40, 41). |
