Patent ID: 8714656

Claim:
A travel drive device for a dump truck comprising: an axle housing mounted in a non-rotating state on a vehicle body of a dump truck and having an end side opened to form a cylindrical spindle; a rotational shaft provided to axially extend in said spindle of said axle housing and driven and rotated by a drive source; a wheel mounting cylinder which is rotatably provided on an outer peripheral side of said spindle through wheel support bearings and to which wheels are mounted; and a planetary gear reduction mechanism provided between said wheel mounting cylinder and said spindle to decelerate rotation of said rotational shaft, which is transmitted to said wheel mounting cylinder; wherein a carrier forming a part of said planetary gear reduction mechanism and rotatably supporting a plurality of planetary gears through support pins is mounted in a non-rotating state on an open end side of said spindle, wherein a cylindrical coupling member, which is formed as a cylindrical body made up of an independent member and in an inner peripheral side of which said rotational shaft is inserted, is provided between said spindle and said carrier, said cylindrical coupling member having an outer periphery of one side in an axial direction that is spline-coupled to an open end inner peripheral side of said spindle and having an outer periphery of another side in the axial direction opposite to said one side that is spline-coupled to an inner peripheral side of said carrier, wherein one female spline is provided on said open end inner peripheral side of said spindle and another female spline is provided on said inner peripheral side of said carrier, and a first male spline is provided in said outer periphery of said one side in the axial direction that is spline-coupled to said one female spline of said spindle and a second male spline is provided in said outer periphery of said another side in the axial direction that is spline-coupled to said another female spline of said carrier are provided in said cylindrical coupling member.