Hitachi Construction Machinery Co., Ltd.

Takeshi Shibukawa

Takeshi Shinohara

Hayato Masuda

Naoyuki Inoue

Kyoko Tanaka

Shinichiro Hagihara

Tomoharu Morita

Yutaro Iwabuchi

Koki Sugiyama

Tomohiro Ueki

Taira Yamabuki

A traveling motor () of a reduction device () is mounted on a reduction gear () in a state protruding to an inner side in a left-and-right direction from a left side frame () and a right side frame () toward a center frame (). Moreover, a motor guard () provided on a rear side which is the other side in a front-and-rear direction of each of the side frames () and (), respectively, and covering the traveling motor () is constituted by an inner guard member () covering the traveling motor () and an outer guard member () covering the inner guard member () from an outer side.

Tracked vehicle

A reduction device () includes a fixed-side housing () accommodating a hydraulic motor () having an output shaft () and a rotating-side housing () rotated with respect to the fixed-side housing (), and a first-stage planetary gear reduction mechanism () having a first sun gear () and a second-stage planetary gear reduction mechanism () having a second sun gear () are provided in the rotating-side housing (). The first-stage planetary gear reduction mechanism () has a rotational shaft () having one side in an axial direction spline-connected with the output shaft (), while the first sun gear () is provided on the other side in the axial direction of the rotational shaft (). A small-diameter shaft (B) is provided on the rotational shaft (), and first and second half bushes () are fitted with the small-diameter shaft (B) from a radial direction. Thereby, the first sun gear () and a stepped part (A) of the second sun gear () are slidably brought into contact with flange parts (B,B) of the first and second half bushes ().

Reduction device

A wheel mounting cylinder () is rotatably provided on an outer peripheral side of an axle housing () through wheel support bearings (). A wet brake () is provided between the axle housing () and the wheel mounting cylinder () for applying a braking force to rotation of the wheel mounting cylinder (). A seal mechanism () is provided between the wet brake () and the wheel support bearing () for keeping a cooling liquid () of the wet brake () in a sealed state to lubricant oil () in the wheel mounting cylinder (). A foreign-object trapping portion () is provided between the wheel support bearing () and the seal mechanism () for trapping foreign objects flowing from the seal mechanism () toward the wheel support bearing ().

Travel drive device for dump truck

A dump truck has a flange on an inner peripheral wall of a spindle. The flange arranges a support bearing for supporting a shaft. The spindle is formed of a chassis-side member and a reduction gear unit-side member joined together by welding. The chassis-side member is fixed on a chassis of the dump truck, and the reduction gear unit-side member is located closer to a side of the reduction gear unit than the chassis-side member. The reduction gear unit-side member is located on a side of an outer periphery of the shaft portion, where a distance to a coupling between the motor and shaft and a distance to a first sun gear between the reduction gear unit and shaft are equal to each other. On an inner peripheral wall of the reduction gear unit-side member, the flange is cast together with the reduction gear unit-side member.

Running device for dump truck

There are provided an axle housing, a rotational shaft provided to axially extend in a spindle of the axle housing, a wheel mounting cylinder which is mounted on an outer peripheral side of the spindle through wheel support bearings and to which wheels are mounted, and a planetary gear reduction mechanism for decelerating rotation of the rotational shaft, which is transmitted to the wheel mounting cylinder. A carrier forming a part of the planetary gear reduction mechanism is mounted in a non-rotating state on an open end side of the spindle. A cylindrical coupling member is provided between the spindle and the carrier, and provided with an axial one side outer periphery splined-coupled to an open end inner peripheral side of the spindle and an axial other side outer periphery spline-coupled to an inner peripheral side of the carrier.

A travel assembly is provided with a cylindrical spindle for being fixed on a body of a working vehicle, a rotary shaft arranged extending in an axial direction through the spindle and rotationally drivable by a driving source, a rim rotatably arranged on a side of an outer periphery of the spindle to permit mounting of a wheel thereon, a planetary gear reduction mechanism for transmitting rotation of the rotary shaft to the rim at a reduced speed, a bearing rotatably supporting the rotary shaft via a sleeve integrally fitted on the rotary shaft, and a retainer holding the bearing in place. A lube oil pipe for feeding lube oil to the rotary shaft is held in place by the retainer. The lube oil pipe branches within the retainer to form an oil passage. The oil passage has an opening through which the lube oil can be fed to rolling elements in the bearing.

Travel assembly

A rotational shaft is provided in a spindle, a wheel mounting cylinder is provided which is mounted through wheel support bearings on an outer peripheral side of the spindle, and a planetary gear reduction mechanism is provided for decelerating rotation of the rotational shaft, which is transmitted to the wheel mounting cylinder. A carrier forming a part of the planetary gear reduction mechanism is mounted in a non-rotating state on an open end side of the spindle. A cylindrical coupling member is provided between an open side of the spindle and the carrier. An oil guide path is formed between a one-side end surface of each of planetary gears and an opposing surface portion of a cylindrical coupling member for guiding lubricant oil ejected from a meshing part therebetween to a planetary gear bearing.

A travel assembly, for example, suited for arrangement on a vehicle such as a mining dump truck, is provided with a travel motor, a planetary speed reduction mechanism for transmitting rotation of the travel motor at a lower rotational speed, a spindle forming an axle, and a wheel supported on the spindle via a tapered roller bearing and rotatable by the planetary speed reduction mechanism. The planetary speed reduction mechanism includes a sun gear rotatable by rotation of a shaft of the travel motor, planet gears for rotating the wheel in response to rotation of the sun gear, and a carrier for holding the planet gears. The travel assembly is provided with a spline connection connecting the spindle and the carrier with each other and an oil passage for guiding internal lube oil of the planetary speed reduction mechanism to the spline connection.

Wheels of a dump truck are each provided with a travel assembly for transmitting an output of an electric motor to the wheel via a reduction gear unit. The travel assembly is provided with a cooling circuit for cooling lube oil. The cooling circuit has an oil cooler and a recovery oil passage for guiding lube oil from a side of the gear unit to the cooler. The recovery oil passage has an intra-spindle recovery line inserted on a side of an inner periphery of a spindle, a suction pipe extending from the recovery line to a space surrounded by the spindle, the wheel and two spindle-supporting bearings, and communication holes formed in the wheel to communicate the side of the reduction gear unit with the space.

Travel assembly for dump truck

A travel assembly, for example, suited for arrangement on a vehicle such as a mining dump truck, is provided with a travel motor, a planetary speed reduction mechanism for transmitting rotation of the travel motor at a lower rotational speed, a spindle forming an axle, and a wheel supported on the spindle via a tapered roller bearing and rotatable by the planetary speed reduction mechanism. The planetary speed reduction mechanism includes a sun gear rotatable by rotation of a shaft of the travel motor, planet gears for rotating the wheel in response to rotation of the sun gear, stepped pins forming rotary shafts for the planet gears, a carrier for holding the stepped pins thereon, and bolts for fixedly securing the stepped pins on the carrier. The travel assembly is provided with a spline connection connecting the spindle and the carrier with each other and a limiting member for limiting movements of the bolts in a direction toward the tapered roller bearing.

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Tsuchiura, Japan

Takeshi Shibukawa