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US 2002/0173400 A1Published application
Locking differential with clutch activated by magnetorheological fluid
AssigneeSpicer Technology, Inc.
InventorWilliam Gordon Hunt
Life of this patent
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Abstract
A limited slip differential includes a friction clutch mechanism, an electromagnetic coupling, and a camming mechanism disposed between the friction clutch mechanism and the electromagnetic coupling. The camming mechanism converts shearing forces within the electromagnetic coupling to an axial force applied to engage the clutch mechanism. The camming mechanism includes annular discs having axially inclined ramps, and a roller bearing for movement along the ramps to provide for variable spacing between the annular discs, wherein increased spacing is used to apply the axial force.
Claims20
A limited slip differential assembly comprising:
- an input member;
- a first output shaft;
- a second output shaft coaxial with said first output shaft, said first and second output shafts rotating about an output drive axis;
- a differential interposed between said input member and said first and second output shafts, said differential transmitting rotation from said input member to said first and second output shafts and providing rotation of said first output shaft relative to said second output shaft;
- a clutch mechanism, said clutch mechanism providing resistance to relative rotation between said first output shaft and said second output shaft;
- an electromagnetic coupling having a first and second coupling members, said first and second coupling members defining a chamber having a magnetorheological fluid, said magnetorheological fluid increasing in density when charged by an electrical current, said magnetorheological fluid providing resistance to rotation of said first coupling member relative to said second coupling member;
- means for inducing said electrical current in said magnetorheological fluid;
- and
- a camming mechanism for engaging said clutch mechanism, said camming mechanism including a first disc associated with said coupling, and a second disc associated with said clutch mechanism, each of said first and said second discs having an inclined surface formed between said first and second discs, said inclined surfaces being axially inclined along a circumferential direction relative to said output drive axis, said means for inducing said electrical current being actuated in response to a predetermined amount of relative rotation between said first output shaft and said second output shaft, said coupling thereby creating a resistance to rotation of said first disc relative to said second disc, the resistance to rotation causing said first disc to rotate relative to said second disc, said inclined surfaces camming to result in an axial force actuating said clutch mechanism,
- wherein said electromagnetic coupling is disposed radially outside said camming mechanism.
7 more elements
A limited slip differential comprising:
- an input member;
- a first output shaft;
- a second output shaft;
- a differential interposed between said input member and said first and second output shafts, said differential transmitting rotation from said input member to said first and second output shafts and providing rotation of said first output shaft relative to said second output shaft;
- a clutch mechanism for directly connecting said first output shaft and said second output shaft to provide resistance to relative rotation between said first output shaft and said second output shaft;
- an electromagnetic coupling having first and second coupling members, said first and second coupling members defining an annular chamber having an magnetorheological fluid, said magnetorheological fluid increasing in density when charged by an electrical current, said magnetorheological fluid providing resistance to rotation of said first coupling member and said second coupling member;
- means for inducing said electrical current in said magnetorheological fluid, said means including a transformer adjacent one of said first and second coupling members, said transformer inducing said electrical current to charge said magnetorheological fluid;
- and
- a camming mechanism for engaging said clutch mechanism, said camming mechanism providing a force to engage said clutch mechanism, said camming mechanism being responsive to a resistance to rotation of said first coupling member relative to said second coupling member of said coupling;
- a sensor system monitor the relative rotation of said first output shaft and said second output shaft, said sensor system actuating said means for inducing said electrical current upon sensing relative rotation of said first output shaft and said second output shaft above a predetermined amount, said magnetorheological fluid thereby being charged to create the resistance to rotation of said first and second coupling members of said coupling,
- wherein said annular chamber circumscribes said camming mechanism.
8 more elements
Dependencies are inferred from the claim text.