Differential Group
A differential divides the power that is sent to the wheels. A differential also causes a balance of power that is sent to the wheels. During a turn, the differential allows the inside wheel to rotate at a slower rate in relation to the outside wheel. The differential still sends the same amount of torque to each wheel.
Operation
Straight Forward or Reverse
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| Illustration 1 | g00660372 |
Standard Differential Group (1) Bevel pinion (2) Bevel gear (3) Side gears (4) Differential case (5) Shaft (6) Pinions (7) Sun gear | |
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 so the pinions do not turn on the spider. Bevel pinion (1) turns bevel gear (2). Bevel gear (2) turns case (4). Case (4) turns shaft (5). Shaft (5) turns side gears (3) through pinions (6). Pinions (6) do not turn on the shaft. The side gears turn final drive sun gears (7). The same amount of torque is sent through the final drives to each wheel.
Forward or Reverse Turn
When the machine is in a turn, the inside wheel is more resistant than the outside wheel to turn. This resistance causes different torques on the opposite sides of the differential. The outside wheel turns more easily than the inside wheel. The outside wheel starts to turn faster than the inside wheel.
Bevel pinion (1) turns bevel gear (2). Bevel gear (2) turns case (4). Case (4) turns shaft (5). Shaft (5) turns side gears (3) through pinions (6). Since more force is needed to turn one side gear more than the other side gear, the pinions (6) turn around the shaft (5). As the pinions turn, the pinions move around the side gears. The differential allows the inside wheel to turn at a slower rate than the outside wheel.
The same amount of torque is sent through the final drives to both the inside and outside wheels. This torque is only equal to the amount of torque that is necessary to turn the outside wheel.
Loss of Traction (Wheel Slippage)
When one wheel has more traction than the other wheel, 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 wheel with the least resistance.