Traveling drive device for dump truck

A traveling drive device for a dump truck comprising:

• a tubular axle housing which is mounted to a vehicle body of the dump truck in a non-rotational state;
• a drive source provided in said axle housing;
• a rotational shaft which is provided so as to axially extend in said axle housing and is rotationally driven by said drive source;
• a wheel mounting tube which is rotatably provided on the axial outside of said axle housing and on the outer periphery side thereof via wheel support bearings and to which a wheel is mounted;
• a reduction mechanism which is provided between said wheel mounting tube and said axle housing to decelerate rotation of said rotational shaft for transmission to said wheel mounting tube;
• a tubular disk holding cylinder which is provided on the axial outside of said wheel mounting tube;
• an annular brake disk which is mounted to said disk holding cylinder and rotates together with said wheel mounting tube;
• and
• a brake device which applies braking to said wheel mounting tube by pressing a friction pad against said brake disk,
• wherein said disk holding cylinder is configured by a cylindrical body which is mounted to said wheel mounting tube and a plurality of disk mounting legs which are provided on said cylindrical body at intervals in a circumferential direction thereof and axially project outward from said cylindrical body,
• wherein a plurality of U-shaped projections, which are respectively disposed at positions corresponding to said respective disk mounting legs, are provided on an outer peripheral edge of a friction pad abutting ring which said friction pad of said brake disk abuts,
• wherein said U-shaped projections are each configured to have a recessed groove to engage with ones of said disk mounting legs so as to hold a distal end of ones of said disk mounting legs therein in the circumferential direction,
• wherein said disk mounting legs of said disk holding cylinder are each configured to have a platform which axially projects from said cylindrical body, a recessed groove fitting projection which is provided on the distal end side of said platform, and an arc-shaped curved-surface portion which is provided between said platform and said recessed groove fitting projection, where a circumferential dimension (A2) of said recessed groove fitting projection is less than a circumferential dimension (A1) of said platform,
• wherein ones of said recessed groove fitting projections fit into corresponding ones of said recessed grooves of said brake disk,
• wherein an axial thickness dimension (B2) of each of said U-shaped projections is greater than an axial thickness dimension (B3) of said friction pad abutting ring,
• wherein an arc-shaped curved-surface portion is provided between said platform and said recessed groove fitting projection to smoothly engage with each other,
• wherein a plurality of positioning members that axially position said brake disk relative to at least two of the disk mounting legs are provided between each of said at least two disk mounting legs and said U-shaped projections of said brake disk, and
• wherein said positioning members are each configured by a recessed groove engaging portion which engages with said recessed groove of one of said U-shaped projections, a leg mounting portion which is mounted to said recessed groove fitting projections of one of said disk mounting legs, and a disk abutting portion which positions said brake disk by abutting against one of said U-shaped projections of said brake disk.