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| Illustration 1 | g00929791 |
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| Illustration 2 | g00929627 |
A differential divides the power that is sent to the wheels or a differential causes a balance of the power that is sent to the wheels. A differential allows one wheel to turn at a slower rate than the other wheel on an axle. For example, this occurs during a turn. During a turn, the differential allows the inside wheels to rotate at a slower rate in relation to the outside wheels. The differential still sends the same amount of torque to each wheel.
Straight Forward or Straight Reverse Operation
When the machine moves in a straight direction with the same amount of traction under each drive wheel, the same amount of torque on each axle holds the pinions. When the machine moves in a straight direction the pinions do not turn on the spider.
The drive shaft is connected to yoke (8). Yoke (8) is mounted on bevel pinion (1). The drive shaft will turn yoke (8). Yoke (8) will turn bevel pinion (1). Bevel pinion (1) turns bevel gear (16). Bevel gear (16) is mounted in case (18). Bevel gear (16) turns case (18). Case (18) turns spider (13). Spider (13) drives side gears (15) and pinions (14) together. Pinions (14) do not turn on the spider. Side gears (15) turn at the same speed as bevel gear (16) and case (18). Side gears (15) turn axle shafts (4) and (20). The same amount of torque is sent through the final drives to each wheel.
Operation during a Forward Turn or Operation during a Reverse Turn
When the machine is in a turn, the outside wheels turn faster than the inside wheels.
Bevel pinion (1) turns bevel gear (16). Bevel gear (16) turns case (18). Case (18) turns spider (13). Spider (13) drives side gears (15) and pinions (14) together. Side gears (15) turn axle shafts (4) and (20). Because the outside wheels turn faster than the inside wheels, the outside axle shaft turns pinions (14) on spider (13). As the pinions turn, the pinions move around the side gears. This allows the outside wheels to turn faster than the inside wheels.
The same amount of torque is sent through the final drives to both the inside wheels and to the outside wheels. This torque is only equal to the amount of torque that is necessary to turn the outside wheels.
Loss of Traction (Wheel Slippage)
When one bogie has more traction than the other bogie, the operation of the differential is identical to the operation of the differential during a turn. The same amount of torque is sent to both wheels. This torque is only equal to the amount of torque that is necessary to turn the wheels with the least resistance.
Differential Lock
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| Illustration 3 | g00871851 |
Location of Differential Lock Switch on the Left Joystick | |
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| Illustration 4 | g00929775 |
Differential Lock Valve | |
The differential is designed to deliver an equal amount of power to both bogies of an axle when the differential lock switch is activated.
The differential uses a hydraulically activated shifting piston (3) to lock axle shaft (4) and axle shaft (20) together. Shifting piston (3) is connected to a shaft inside the transmission gearbox. When the differential lock switch is activated, the front differential and the rear differential are locked at the same time.
When the differential lock switch is activated, the IQAN Monitoring and Control System sends a signal to the solenoid valve on the differential lock valve. This causes the solenoid to shift and this allows low pressure oil to flow to the differential. The differential lock switch is a momentary switch. In order to operate the differential lock switch, press the switch and hold the switch down.
Note: In order for the differential lock to engage, the machine speed must be below 2 km/h (1 mph). The IQAN Monitoring and Control System will disengage the differential lock when machine speed exceeds 5 km/h (3 mph) and the differential lock switch is pressed.
The low pressure oil flows through passage (B) to shifting piston (11). The low pressure oil extends shifting piston (11) which compresses spring (7). Shifting piston (11) will move downward. The shift rod will move down. This will cause spring (7) to compress. This shifts shifting fork (6) and shifting sleeve (3). Shifting sleeve (3) then engages coupling sleeve (5) .
When the shifting sleeve (3) is engaged with the coupling sleeve (5), side gears (15) are locked to differential case (18). Now, side gears (15) and pinions (14) cannot rotate. Differential case (18) and side gears (15) are locked together. Now, differential case (18) and side gears (15) rotate as one unit.
When the differential lock switch is turned off, pressure oil is cut off. The oil drains to the hydraulic tank. Spring (7) disengages shifting sleeve (3) from coupling sleeve (5). The differential lock is now disengaged.