All wheel drive system for a motor vehicle

• US 20030146034A1
• Filed: 07/25/2002
• Published: 08/07/2003
• Est. Priority Date: 03/18/1999
• Status: Active Grant

• Current Assignee: GKN Driveline North America Incorporated (Melrose Industries Plc)
• Original Assignee: GKN Automotive, Inc. (Melrose Industries Plc)
• Inventors: Gassmann, Theodore, Peura, Brent
• Granted Patent: US 6,769,506 B2
• Time in Patent Office: Days
• US Class Current: 180/248
• CPC Class Codes: B60K 17/00 Arrangement or mounting of transmissions in vehicles clutches per se, e.g. construction thereof, F16D; gearing per se, e.g. construction thereof, F16H
• CPC Class Codes: B60K 17/22 characterised by arrangement, location, or type of main drive shafting, e.g. cardan shaft
• CPC Class Codes: B60K 17/344 having a transfer gear
• CPC Class Codes: B60K 17/351 comprising a viscous clutch
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: F16D 2200/006 containing fibres or particles
• CPC Class Codes: F16D 25/0638 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 3/845 allowing relative movement of joint parts due to the flexing of the cover
• CPC Class Codes: F16D 35/02 with rotary working chambers and rotary reservoirs, e.g. in one coupling part
• CPC Class Codes: F16D 43/284 controlled by angular speed

Abstract

“An all wheel drive system for a motor vehicle having a front differential and rear differential, a pair of front and rear halfshaft assemblies, a power takeoff unit, a constant velocity joint connected to the power takeoff unit, a first propshaft, a plunging constant velocity joint, a second propshaft, a flexible coupling, a self contained speed sensing torque transfer assembly connected to the flexible coupling wherein torque is selectively transferrable when the self contained speed sensing torque transfer assembly is engaged, and a torque arm assembly.”

Claims

1. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint;

a flexible coupling having a first end and a second end, said first end of said flexible coupling connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said flexible coupling such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said flexible coupling, and connected at the other end to a viscous coupling;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

2. The all wheel drive system of claim 1 further comprising:

a torque arm connected to said rear differential and to said motor vehicle to support said rear differential and to reduce the torque reaction of said rear differential.

3. The all wheel drive system of claim 1 further comprising:

a torque arm assembly comprising a torque arm having an elongate body for protecting said speed sensing torque transfer device from heat radiated from said motor vehicle, said torque arm having an asymmetric configuration including an upper section and a side section, each section affixed to said rear differential and also to said motor vehicle to reduce the torque reaction load of said rear differential and a compliant mount affixable to said torque arm and a bracket affixable to said compliant mount and said motor vehicle.

4. An all wheel drive system as in claim 3 wherein said compliant mount includes at least one dampening cavity for absorbing reaction forces on said compliant mount.

9. The all wheel drive system of claim 1 further comprising:

a torque arm connected to said rear differential and to said motor vehicle to support said rear differential and to reduce the torque reaction of said rear differential.

10. The all wheel drive system of claim 1 further comprising:

a torque arm assembly, said torque arm assembly comprising a torque arm having an elongate body for protecting said speed sensing torque transfer device from heat radiated from said motor vehicle, said torque arm having an asymmetric configuration including an upper section and a side section, each section affixed to said rear differential and also to said motor vehicle to reduce the torque reaction load of said rear differential; and

a torque arm mount affixable to said torque arm allowing positional adjustment of the torque arm in relation to said torque arm mount.

5. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint, said second propshaft manufactured from a carbon fiber reinforced plastic material having a longitudinal stiffness to density ratio in a range from 3 to 9, a fiber by volume ratio greater that 50% and a winding angle of 600 of less;

a flexible coupling having a first end and a second end, said first end of said flexible coupling connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said flexible coupling such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said flexible coupling, and connected at the other end to a viscous coupling;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

6. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint, said second propshaft manufactured from a carbon fiber reinforced plastic material having a torsional stiffness to density ratio in a range from 1 to 2.2, a fiber by volume ratio greater that 50% and a winding angle of 60°

of less;

a flexible coupling leaving a first end and a second end, said first end of said flexible coupling connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said flexible coupling such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said flexible coupling;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

7. A rear module for an all wheel drive vehicle, said all wheel drive vehicle having a frame, and a torque output member, said rear module comprising:

a rear differential having at least one output member, an input member and an interface section;

a self contained speed sensing torque transfer assembly connected to said torque output member of said all wheel drive vehicle whereby torque is selectively transferrable to at least one output member of said differential when said self contained speed sensing torque transfer assembly detects a speed difference between said torque output member and said input member of said differential; and

said self contained speed sensory torque transfer assembly comprising a bi-directional overrunning clutch and a viscous coupling; and

a torque arm connected to said interface section of said differential and said frame to support said rear differential.

8. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint;

a universal joint having a first end and a second end, said first end of said universal joint connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said universal joint such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said universal joint, and connected at the other end to a viscous coupling;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

11. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint, said second propshaft manufactured from a carbon fiber reinforced plastic material having a longitudinal stiffness to density ratio in a range from 3 to 9, a fiber by volume ratio greater that 50% and a winding angle of 60°

of less;

a universal joint having a first end and a second end, said first end of said universal joint connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said universal joint such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said universal joint, and connected at the other end to a viscous coupling;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

12. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint, said second propshaft manufactured from a carbon fiber reinforced plastic material having a torsional stiffness to density ratio in a range from 1 to 2.2, a fiber by volume ratio greater that 50% and a winding angle of 60°

of less;

a universal joint having a first end and a second end, said first end of said universal joint connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said universal joint such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said universal joint;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheel.

13. A rear module for an all wheel drive vehicle, said all wheel drive vehicle having a frame, and a torque output member, said rear module comprising:

a rear differential having at least one output member, an input member and an interface section;

a self contained speed sensing torque transfer assembly connected to said torque output member of said all wheel drive vehicle whereby torque is selectively transferrable to said at least one output member of said differential when said self contained speed sensing torque transfer assembly detects a speed difference between said torque output member and said input member of said differential; and

a torque arm connected to said interface section of said differential and said frame to support said rear differential.

14. A speed sensing torque transfer system for use with motor vehicle having a first torque transmitting member and a second torque transmitting member comprising:

a bi-directional overrunning clutch connected to a first torque transmitting member; and

a viscous coupling operatively connected to said bi-directional overrunning clutch, said viscous coupling connected to a second torque transmitting member whereby when said first torque transmitting member rotates faster than said second torque transmitting member, torque is transferred through said bi-directional overrunning clutch to said viscous coupling thereby providing torque to said second torque transmitting member.

15. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint;

a flexible coupling having a first end and a second end, said first end of said flexible coupling connected to said second end of said second propshaft;

a bi-directional overrunning clutch connected to said second end of said flexible coupling;

a viscous coupling operatively connected to said bi-directional overrunning clutch;

a rear differential connected to said viscous coupling; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear differential and said viscous coupling engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.

16. An all wheel drive system for a motor vehicle comprising:

a front differential for providing driving torque to said motor vehicle, said front differential having a front differential gear ratio;

a power takeoff unit operatively connected to said front differential;

a propshaft assembly operatively connected to said power takeoff unit;

A bi-directional overrunning clutch connected to said propshaft assembly;

a viscous coupling connected to said bi-directional overrunning clutch;

a rear differential connected to said viscous coupling, said real differential having a rear gear ratio greater than said front differential by a range from 0.08% to 5% allowing said rear differential to overrun said front differential in normal operating conditions, and whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when said front differential begins to rotate faster than said rear differential the bi-directional clutch engages and passes driving torque to said viscous coupling and said viscous coupling progressively engages and provides driving torque to said rear differential until said slip condition is resolved.

17. The all wheel drive system of claim 16, where said range is from 0.2% to 5%.

18. The all wheel drive system of claim 16, where said range is from 0.75% to 2%.

19. An all wheel drive system for a motor vehicle comprising:

a front differential;

a pair of front halfshaft assemblies operatively connected to said front differential whereby said front differential supplies torque to said pair of front half shaft assemblies, each of said pair of front half shaft assemblies connected to a respective front wheel;

a power takeoff unit operatively connected to said front differential;

a constant velocity joint connected to said power takeoff unit whereby said front differential supplies torque to said constant velocity joint through said power takeoff unit;

a first propshaft having a first end and a second end, said first end connected to said constant velocity joint;

a plunging constant velocity joint connected to said second end of said first propshaft;

a second propshaft having a first end and a second end, said first end connected to said plunging constant velocity joint;

a flexible coupling having a first end and a second end, said first end of said flexible coupling connected to said second end of said second propshaft;

a self contained speed sensing torque transfer assembly connected to said second end of said flexible coupling such that torque is selectively transferrable when said self contained speed sensing torque transfer assembly is engaged, said self contained speed sensing torque transfer assembly including;

a bi-directional overrunning clutch connected at one end to said second end of said flexible coupling, and connected at the other end to a viscous coupling;

a rear differential having an overrunning gear ratio offset connected to said viscous coupling and including a rear axle pinion; and

a pair of rear halfshaft assemblies operatively connected to said rear differential for transferring torque to said rear halfshaft assemblies, each of said rear halfshaft assemblies connected to a respective rear wheel whereby under normal operating conditions said all wheel drive system provides substantially all torque to said front differential, and in a slip condition when either of said front wheels begins to slip said front differential rotates at a higher speed than said rear axle pinion and said self contained speed sensing torque transfer assembly engages thereby providing torque to said rear differential until said slip condition is resolved whereupon substantially all torque is transferred back to the front wheels.