NoSPIN Differential
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| Illustration 1 | g00281001 |
NoSPIN Differential Group Typical Illustration (1) Housing assembly. (2) NoSPIN differential and differential case. (3) Bevel pinion. (4) Bevel gear. | |
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| Illustration 2 | g00281002 |
NoSPIN Differential (5) Side gear. (6) Driven clutch. (7) Spring. (8) Holdout ring. (9) Holdout ring. (10) Spring. (11) Driven clutch. (12) Side gear. (13) Spring retainer. (14) Spring retainer. Center cam (15). (16) Snap ring. (17) Spider. | |
The NoSPIN differential is a locking type of differential. The NoSPIN differential is designed to deliver power to both wheels of an axle when ground slip conditions are encountered on one wheel. The NoSPIN differential is designed to disengage one axle when good traction conditions require overrun. The rotation of the outside wheel during a turn is an example of overrun. The NoSPIN differential group is a direct replacement for the standard differential. The NoSPIN differential is only available in the rear axle group.
When the speeds of the wheels are equal, the NoSPIN differential sends the same amount of torque to each wheel. When the speeds of the wheels are different, the NoSPIN differential sends torque to the slower turning wheel. A difference in the speeds of the wheels is caused by a turn.
The NoSPIN differential allows a wheel (axle) to turn faster than the speed of the bevel gear. The NoSPIN differential does not use the bevel gear in order to engage the wheel. For example, the outside wheel (axle) is not engaged with the bevel gear during a turn with power. The outside wheel turns faster than the bevel gear. The inside wheel (axle) is engaged with the bevel gear. The inside wheel turns at the same speed as the bevel gear. The inside wheel provides the power that moves the machine through the turn.
The NoSPIN differential is identical on both sides of spider (17). The NoSPIN differential has the following components: springs (7) and (10), side gears (5) and (12), driven clutches (6) and (11), holdout rings (8) and (9), center cam (15), snap ring (16) and spider (17) .
The inside splines of side gears (5) and (12) are connected to the sun gears for the final drives. The outside splines of the side gears are connected to the inside splines of drive clutches (6) and (11). The side gears send the power through the sun gears to the final drives.
Spider (17) is fastened to the differential case. Spider (17) turns at the speed of bevel gear (4). The spider has clutch teeth on both sides. The spider also has one long tooth. The long tooth is spider key (19). Center cam (15) fits inside the spider. Center cam (15) is held in position by snap ring (16). Center cam (15) is turned by spider key (19) which fits inside notch (18). Spider key (19) pushes on either side of notch (18). The direction of machine travel (forward or reverse) controls the turning direction of the spider and the side of notch (18) that will receive the force.
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| Illustration 3 | g00281011 |
NoSPIN differential Left Side (5) Side gear. (6) Driven clutch. (7) Spring. (13) Spring retainer. (17) Spider. | |
Springs (7) and (10) fit between the side gears (5) and (12) and spring retainers (13) and (14). The force of the springs holds the driven clutches against spider (17). The force of the springs holds the side gears against the differential case.
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| Illustration 4 | g00281012 |
Spider and Center Cam Center cam (15). (17) Spider. (18) Notch in center cam (15). (19) Spider key. | |
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| Illustration 5 | g00281013 |
Clutch and Holdout Ring (6) Driven clutch. (8) Holdout ring. (20) Notch in holdout ring. (21) Cam. | |
Driven clutch (6) and driven clutch (11) are identical. Each driven clutch has cam (21) which is part of the clutch. The teeth on the cam engage with the teeth of center cam (15). The teeth of the drive clutches engage with the teeth of spider (17). An annular groove in the shape of a circle is between the teeth of the driven clutches and the teeth of the cams.
Holdout ring (8) and holdout ring (9) are identical. Each holdout ring fits in the annular groove between the teeth of the driven clutches and the teeth of the cams. The teeth of the holdout rings engage with the notches in center cam (15). Notch (20) in the holdout ring engages with spider key (19). The spider key controls the movement of the holdout ring in relation to the spider. There is no connection between the holdout rings and the driven clutches except for friction.
NoSpin Differential Operation
The clutch action is the stopping of power that is going to the drive axle. When a wheel is turned faster than the speed of the bevel gear, the clutch action of the NoSPIN differential will allow the axle to turn faster than the bevel gear.
The clutch action of the NoSPIN differential is described in the following sequence.
If spider (17) turns, spider key (19) locates center cam (15). The spider and the center cam then turn at the speed of the bevel gear. The center cam turns holdout ring (8) and cam (21) at the speed of the bevel gear. The spider turns driven clutch (6) at the speed of the bevel gear. The driven clutch turns the side gear, the axle, and the wheel at the speed of the bevel gear.
When the wheel is turned faster than the speed of the bevel gear, the teeth of center cam (15) work similarly to ramps. The teeth of the cam (21) move up the teeth of the center cam (15). This action causes driven clutch (6) to disengage from the spider. The driven clutch pulls holdout ring (8) out of the grooves in the center cam (15). The friction between the holdout ring and the driven clutch turns the holdout ring until notch (20) in the holdout ring engages with spider key (19) .
The holdout ring is now turned by the spider key at the speed of the bevel gear. The teeth of the holdout ring are in a position that will not permit engagement with the notches in the center cam (15). The driven clutch and the cam move around the holdout ring at a speed faster than the speed of the bevel gear. The holdout ring keeps the driven clutch and the cam from being engaged with the center cam and the spider. The driven clutch, the cam, the axle shaft, and the wheel are now able to turn freely.
Spring (7) engages the opposite side clutch, the opposite side cam, and the opposite side holdout ring with the center cam and with the spider. The engagement is maintained only while the driven wheel turns more slowly.
When the speed of the disengaged wheel slows to the lower speed of the bevel gear, the ground resistance creates a wheel torque which has a slight reverse direction. This causes the driven clutch and the cam to turn in a direction that is the opposite of the direction of rotation of the bevel gear. The friction between the holdout ring and the driven clutch causes the holdout ring to move in a direction that is opposite the direction of the bevel gear.
Notch (20) in the holdout ring moves away from spider key (19). When the teeth of the holdout ring are in a position to engage the notches in center cam (15), the force of the spring causes the driven clutch and the cam to move to the inside. The driven clutch pushes the holdout ring. The holdout ring now engages the center cam and the holdout ring is turned at the speed of the bevel gear. The teeth of cam (21) now engage the center cam and the teeth of the drive clutch engage the spider. Both wheels are now turned at the same speed.
Note: When both wheels are turned at the same speed, both wheels do not necessarily have the same torque. For example, when a wheel on ice is spinning at a faster rate than another wheel that is not on ice, both clutches engage. When both clutches engage, both wheels turn at the same speed. The wheel that is on ice will have less torque.
Straight Forward Operation
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| Illustration 6 | g00281018 |
Straight Forward Operation Typical Illustration (5) Side gear. (6) Driven clutch. (11) Driven clutch. (12) Side gear. (17) Spider. (22) Teeth of the spider. (23) Teeth of the driven clutches. | |
When the machine has straight forward movement, teeth (22) on both sides of spider (17) are fully engaged with teeth (23) of driven clutches (6) and (11). The teeth of cams (21) are engaged with the teeth of center cam (15). The following combination forces the differential together. The reverse angle of the teeth on the clutches and on the spider, the force of springs (7) and (10), cams (21) and center cam (15). This forces the engagement of the teeth of the clutches with the teeth of the spider.
In this condition, driven clutches (6) and (11) are fully engaged with spider (17). The driven clutches turn side gears (5) and (12) at the same speed as the bevel gear. The two side gears turn the axle shafts and the wheels at the same speed as the bevel gear.
Forward Turn with No Power
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| Illustration 7 | g00281019 |
Forward Right Turn with Power Typical Illustration (5) Side gear. (6) Driven clutch. (11) Driven clutch. (12) Side gear. (17) Spider. | |
During a turn, the outside wheel travels a longer distance than the inside wheel. When the machine turns with power, the NoSPIN differential allows the outside wheel to turn faster than the speed of the bevel gear. The NoSPIN differential does not allow the inside wheel to turn at a rate that is slower than the speed of the bevel gear. The inside wheel turns at the same speed as the bevel gear.
The teeth of the spider transfer the force to the inside driven clutch. The inside driven clutch turns the inside wheel at the same speed as the bevel gear. The inside driven clutch provides the power that is necessary to move the machine through the turn.
The traction of the road causes the outside wheel to turn at a speed that is faster than the speed of the bevel gear. This causes the driven clutch for the outside wheel to turn faster than the speed of the bevel gear. The movement of one wheel faster than the movement of another wheel begins the clutch action of the NoSPIN differential.
The cam for the driven clutch of the inside wheel has teeth. The teeth are engaged with the teeth of center cam (15). The teeth stay in the same position in relation to spider (17). The teeth of the inside drive clutch are engaged with the spider. The teeth on the other side of center cam (15) are used as ramps. The cam for the driven clutch of the outside wheel has teeth. The teeth move up the teeth of the center cam (15). This causes the outside driven clutch and the cam to move away from the spider and from the center cam (15). The outside driven clutch and the cam are not engaged with the spider or with the center cam.
The driven clutch for the outside wheel cannot be engaged with the spider until the speed of the outside wheel slows to the lower speed of the bevel gear. The holdout ring prevents the driven clutch and the cam from being engaged with the spider and with the center cam until the machine is moving in a straight direction. The operation of the differential is now identical to the operation of the differential while the machine is moving straight forward.
Straight Reverse Operation
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| Illustration 8 | g00281153 |
Straight Reverse Typical Illustration (5) Side gear. (6) Driven clutch. (11) Driven clutch. (12) Side gear. (17) Spider. (22) Teeth of the spider. (23) Teeth of the driven clutches. | |
When the machine moves in a straight reverse direction, teeth (22) on both sides of spider (17) are fully engaged with teeth (23) of driven clutches (6) and (11). During straight reverse operation, spider (17) rotates in a direction that is opposite the direction of rotation during straight forward operation. Because the spider turns in the opposite direction during straight reverse operation, teeth (22) of the spider press against the opposite face of teeth (23) of the driven clutches.
The action of the differential during straight reverse operation is identical to the action of the differential during straight forward operation.
Reverse Turn with Power
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| Illustration 9 | g00281154 |
Reverse Right Turn with Power Typical Illustration (5) Side gear. (6) Driven clutch. (11) Driven clutch. (12) Side gear. (17) Spider. | |
The action of the differential is identical to the action of the differential during a forward turn with power except for one conflict. During a reverse turn with power, spider (17) rotates in a direction that is opposite the direction of rotation during a forward turn with power.
Reverse Turn with No Power
The operation of the NoSPIN differential during a reverse turn with no power is identical to the operation of the NoSPIN differential during a reverse turn with power. The traction of the road causes the outside wheel to turn faster than the speed of the bevel gear. The inside wheel is turned at the speed of the bevel gear.