Running device for dump truck

A travel assembly for a dump truck, said travel assembly comprising:

• a wheel on which a tire is to be mounted, a spindle inserted on a side of an inner periphery of the wheel,
• wheel bearings arranged between an outer peripheral wall of the spindle and an inner peripheral wall of the wheel to enable rotation of the wheel about the spindle,
• a motor arranged on a side of an axial end of the spindle,
• a drive shaft non-rotatably connected to an output shaft of the motor via a coupling, inserted on a side of an inner periphery of the spindle and extending out from an opposite axial end of the spindle,
• a reduction gear unit arranged on a side of the opposite axial end of the spindle and interposed between the drive shaft and the wheel to transmit power from the drive shaft to the wheel, and
• a support bearing arranged on the spindle and supporting the drive shaft thereon, wherein:
• the spindle is formed by a chassis-side member to be fixedly secured on a chassis of the dump truck and a reduction gear unit-side member located on a side closer to the reduction gear unit than the chassis-side member,
• the reduction gear unit is provided with a first planetary gear mechanism including a sun gear connected to the drive shaft and a second planetary gear mechanism for transmitting power transmitted from the first planetary gear mechanism to the wheel, which includes a carrier non-rotatably connected to the opposite axial end of the spindle,
• the first planetary gear mechanism and the second planetary gear mechanism are arranged in an order of the second planetary gear mechanism and the first planetary gear mechanism in an axial direction away from the spindle,
• a flange configured to accommodate thereupon the support bearing, the flange being integrally formed on the reduction gear unit-side member by casting on an inner periphery of the reduction gear unit-side member, the flange being positioned either:
• i) proximate to a midpoint of a length of the drive shaft, or ii) at the midpoint of the length of the drive shaft, and
• the support bearing supports the drive shaft at a portion thereof, the portion of the driveshaft being located between the coupling and the sun gear of the first planetary gear mechanism.