Front Hub
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| Illustration 1 | g01194794 |
(1) Planetary drive (2) Fill port (3) Drain port | |
The machine is equipped with a planetary final drive at each front wheel. Planetary drive (1) is a gear reducer with a fixed spindle and a rotating hub. The front hydraulic motor provides the power which drives an internal coupler. The internal coupler drives the planetary gear train. The parking brake disks are splined to the rotating coupler. The parking brake plates are splined to the stationary spindle. The drive wheel is bolted to the outer perimeter of the planetary drive hub.
Planetary drive (1) is a three-stage reducer that contains three planetary gear trains. The spindle and the hub are sealed with a duo-cone seal gp. The wheel rolls on a large double row ball bearing which connects the hub and the spindle. The internal machinery of the planetary reducer is splash lubricated. Fill port (2) and drain port (3) are labelled on the face of the hub cap by an impression in the casting.
Planetary Operation
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| Illustration 2 | g01194800 |
The front propulsion motor is bolted to the spindle. The spindle is stationary, and the motor is stationary. The motor output shaft is splined to the coupler. The sun gear of the first planetary gear train is integral to the shaft which enters the coupler from the right.
As the coupler turns in the direction of the motor, the first planetary gears rotate in the opposite direction. The first planetary gears drive the first planetary carrier in the direction of the motor rotation, at a reduced speed.
The first planetary carrier is splined to the right end of the intermediate sun gear. The intermediate planetary gears are driven by the intermediate sun gear. The intermediate planetary gears rotate in the opposite direction of the motor rotation. The intermediate planetary gears drive the intermediate planetary carrier in the direction of the motor rotation at a second reduction of speed.
The intermediate planetary carrier is splined to the right end of the final sun gear. The final planetary gear set is driven by the final sun gear. The final planetary gears rotate in the opposite direction of the motor rotation. The final planetary gears drive the outer hub in the opposite direction of the motor rotation, at a third and final speed reduction. The front wheel bolts to the outer hub.
The parking brake springs occupy cavities around the left perimeter of the parking brake piston. These springs provide clamping force against the stacked disks and plates. The disks and plates are splined to the spindle and to the coupler. In order to release the brakes, hydraulic pressure is directed into the parking brake oil passage. This oil acts against the right side of the parking brake piston. The oil pressure drives the piston to the left. This releases the parking brakes.