Ball ramp clutch having force amplifying configuration

• US 20030094343A1
• Filed: 11/21/2001
• Published: 05/22/2003
• Est. Priority Date: 11/21/2001
• Status: Active Grant

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Showalter, Dan Joseph
• Granted Patent: US 6,691,845 B2
• Time in Patent Office: Days
• US Class Current: 192/35
• CPC Class Codes: F16D 11/10 with clutching members movable only axially
• CPC Class Codes: F16D 2011/004 using an internal or intermediate axially slidable sleeve, coupling both components together, whereby the intermediate sleeve is arranged internally at least with respect to one of the components
• CPC Class Codes: F16D 2023/123 Clutch actuation by cams, ramps or ball-screw mechanisms
• CPC Class Codes: F16D 23/12 Mechanical clutch-actuating mechanisms arranged outside the clutch as such specific for combined clutches F16D21/00; mechanisms specific for synchronisation F16D23/02
• CPC Class Codes: F16D 2300/0214 Oil or fluid cooling
• CPC Class Codes: F16D 25/02 with means for actuating or keeping engaged by a force derived at least partially from one of the shafts to be connected
• CPC Class Codes: F16D 25/0638 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 27/004 with permanent magnets combined with electromagnets
• CPC Class Codes: F16D 27/115 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 28/00 Electrically-actuated clutches arrangements for synchronisation F16D23/02; clutches actuated directly by means of an electromagnet F16D27/00; automatic clutches F16D43/00 - F16D45/00; external control F16D48/00
• CPC Class Codes: F16D 47/00 Systems of clutches, or clutches and couplings, comprising devices of types grouped under at least two of the preceding guide headings

Abstract

A preferred embodiment compound ball ramp clutch assembly for motor vehicle drive line components includes a force amplifying assembly having two ball ramp operators arranged in tandem. The clutch assembly includes a first ball ramp operator having opposed cam plates with load transferring balls, an electromagnetic coil, a rotor and an armature. When energized, the coil creates drag which causes separation of the plates of the first ball ramp operator which compresses a primary (pilot) clutch pack disposed in mechanical parallel with the cam plates and load transferring balls of a second ball ramp operator. A speed difference and drag across the second ball ramp operator compresses a secondary (main) clutch pack. Significantly increased torque carrying capacity is exhibited by such a compound or a tandem ball ramp clutch assembly.

Claims

1. A compound clutch assembly comprising, in combination,

a shaft having an axis,

a first axial force generating assembly disposed about said shaft and having at least one output feature translating parallel to said axis,

a second axial force generating assembly having a driven member acted upon by said output member and defining a plurality of ramped recesses, a drive member coupled for rotation with said shaft and defining a like plurality of ramped recesses and a plurality of load transferring balls disposed in said ramped recesses,

an output member,

a first friction clutch pack disposed between said drive member and said driven member and having a first plurality of clutch plates coupled for rotation with said driven member and a second, interleaved plurality of clutch plates coupled for rotation with said output member,

a second friction clutch pack disposed between said drive member and said output member and having a third plurality of clutch plates coupled for rotation with said shaft and a fourth plurality of clutch plates interleaved with said third plurality of clutch plates and coupled to said output member.

2. The clutch assembly of claim 1 wherein said first axial force generating assembly includes a plurality of hydraulic piston and cylinder assemblies.

3. The clutch assembly of claim 1 wherein said first axial force generating assembly includes a ball ramp operator assembly having two plates defining ramped, ball receiving recesses, balls disposed in solid recesses, a rotor, an electromagnetic coil and an armature.

4. The clutch assembly of claim 1 further including a chain drive sprocket coupled to said output member.

5. The clutch assembly of claim 1 wherein said second axial force generating assembly, said first friction clutch pack and said second friction clutch pack are disposed on a hub on said output member.

6. The clutch assembly of claim 1 further including a transfer case and wherein said clutch assembly selectively transfers energy from said shaft to a secondary output.

7. A compound clutch assembly comprising, in combination,

a shaft having an axis,

a first axial force generating assembly disposed about said shaft and having at least one first output member disposed for translation parallel to said axis,

a second axial force generating assembly having a first driven member acted upon by said output member and defining a plurality of ramped recesses, a drive member coupled for rotation with said shaft and defining a like plurality of ramped recesses and a plurality of load transferring balls disposed in said ramped recesses,

a second output member,

a first friction clutch pack disposed between said drive member and said driven member and having a first plurality of clutch plates coupled for rotation with said driven member and a second, interleaved plurality of clutch plates disposed for rotation with said output member,

a second friction clutch pack disposed between said drive member and said output member and having a third plurality of clutch plates coupled for rotation with said shaft and a fourth plurality of clutch plates interleaved with said third plurality of clutch plates and coupled to said output member.

8. The clutch assembly of claim 7 wherein said first axial force generating assembly includes a plurality of hydraulic piston and cylinder assemblies.

9. The clutch assembly of claim 7 wherein said first axial force generating assembly includes a ball ramp operator assembly having two plates defining a plurality of ramped, ball receiving recesses, a plurality of balls, a rotor, an electromagnetic coil and an armature.

10. The clutch assembly of claim 7 further including a chain drive sprocket coupled to said output member.

11. The clutch assembly of claim 7 further including a transfer case having a secondary output and wherein said clutch assembly selectively transfers energy from said shafts to said secondary output.

12. A compound clutch assembly comprising, in combination,

a first ball ramp operator assembly having a first pair of members defining opposed ramped recesses and load transferring members disposed in said recesses, a rotor, an electromagnetic coil, an armature and an apply plate,

a second ball ramp operator assembly having a second pair of members defining opposed ramped recesses and load transferring members disposed in said recesses, said apply plate axially engaging one of said members,

a first clutch pack disposed between said second pair of members of said second ball ramp operator assembly, and

a second clutch pack disposed adjacent another of said pair of members and adapted to transfer torque from an input member to an output member.

13. The clutch assembly of claim 12 wherein said first and second pair of members are circular plates.

14. The clutch assembly of claim 12 wherein said load transferring members are balls.

15. The clutch assembly of claim 12 wherein said first and second clutch packs include a first set of smaller diameter friction clutch plates and a second set of larger diameter clutch plates interleaved with said first set of clutch plates.

16. The clutch assembly of claim 12 further including a clutch hub disposed for rotation with said input member and wherein said output member associated with a plurality of plates of said second clutch pack.

17. A compound clutch assembly comprising, in combination,

an input member and an output member,

a hydraulic operator assembly having a plurality of piston and cylinder assemblies,

a ball ramp operator assembly having a pair of members defining opposed ramped recesses and load transferring members disposed in said recesses, said pistons axially engaging one of said pair of members,

a first clutch pack disposed between said second pair of members, and

a second clutch pack disposed adjacent another of said pair of members and adapted to transfer torque from said input member to said output member.

18. The clutch assembly of claim 17 wherein said first and second clutch packs include a first set of smaller diameter friction clutch plates and a second set of larger diameter clutch plates interleaved with said first set of clutch plates.

19. The clutch assembly of claim 17 wherein said pistons of said hydraulic operator include spring biasing means.

20. The clutch assembly of claim 17 further including a clutch hub disposed for rotation with said input shaft and wherein said output member is a housing having splines engaging a plurality of clutch plates in said second clutch pack.