Differential locking mechanism for a drive axle assembly
View Patent ↗A drive axle assembly ( 10 ) includes a carrier ( 24 ) for supporting a differential case ( 22 ) with axle shafts ( 14, 16 ) extending therethrough and rotatable with the differential case ( 22 ) relative to the carrier ( 24 ). A plurality of friction discs ( 74, 76 ) are disposed within the differential case ( 22 ) and are alternatively connected to the differential case ( 22 ) and a drive hub ( 78 ), which is connected to one of the axle shafts ( 14 ). A sleeve ( 100 ) is operably connected to a piston ( 90 ) for generating a thrust force and for transmitting the thrust force through the sleeve ( 100 ) to move the friction discs ( 74, 76 ) closer together. A plurality of levers ( 104 ) are operably connected one with the other and disposed between the sleeve ( 100 ) and the friction discs ( 74, 76 ) to amplify the thrust force of the sleeve ( 100 ).
1. A drive axle assembly ( 10 ), comprising:
a carrier ( 24 );
a differential case ( 22 ) rotatably disposed in said carrier ( 24 );
a pair of axle shafts ( 14 , 16 ) disposed within said differential case ( 22 ) and rotatable relative to each other about an axis (A);
a drive hub ( 78 ) disposed about one of said axle shafts ( 14 , 16 );
a plurality of friction discs ( 74 , 76 ) adjacent one another in an alternating relationship defining a running clearance therebetween and disposed within and alternatively connected to said differential case ( 22 ) and said drive hub ( 78 );
a plate ( 102 ) defining a plurality of levers ( 104 ) each extending radially relative to said axis (A) between a radially inward end ( 114 ) to a radially outward end ( 116 ) and engaging said friction discs ( 74 , 76 ) and integrally interconnected by links ( 105 ) adjacent radially outward ends ( 116 );
an actuator assembly ( 84 ) disposed about one of said axle shafts ( 14 , 16 ) for engaging said levers ( 104 ) to force said levers ( 104 ) into engagement with said friction discs ( 74 , 76 ) for forcing said friction discs ( 74 , 76 ) into engagement with one another for transmitting torque between one of said axle shafts ( 14 , 16 ) and said differential case ( 22 ); and
said radially inward end ( 114 ) engaging said actuator assembly ( 84 ) and said radially outward end ( 116 ) engaging said differential case ( 22 ) having a disc engaging portion ( 118 ) between said radially inward ( 114 ) and outward ( 116 ) ends for engaging said friction discs ( 74 , 76 ) between said radially inward ( 114 ) and outward ( 116 ) ends thereof for amplifying a thrust force applied by said actuator assembly ( 84 ) by pivoting about the engagement of said radially outward end ( 116 ) with said differential case ( 22 ) in response to axial movement of said radially inward end ( 114 ) by said actuator assembly ( 84 ).
2. A drive axle assembly ( 10 ) as set forth in claim 1 wherein each of said levers ( 104 ) includes an elongated portion ( 120 ) extending from said radially inward end ( 114 ) to said disc engaging portion ( 118 ) and said links ( 105 ) adjacent thereto with a length of said elongated portion ( 120 ) defining a degree of amplification of the thrust force.
3. A drive axle assembly ( 10 ) as set forth in claim 2 wherein said disc engaging portion ( 118 ) is generally V-shaped.
4. A drive axle assembly ( 10 ) as set forth in claim 1 wherein said actuator assembly ( 84 ) includes a sleeve ( 100 ) movable axially and having first ( 106 ) and second ( 108 ) ends with said first end ( 106 ) defining a lip ( 110 ) and said second end ( 108 ) engaging said radially inward end ( 114 ) of said levers ( 104 ) with said sleeve ( 100 ) and said levers ( 104 ) rotatable about said axis (A) with said differential case ( 22 ) and at least one of said axle shafts ( 14 , 16 ).
5. A drive axle assembly ( 10 ) as set forth in claim 1 wherein said levers ( 104 ) of said plate ( 102 ) define a generally polygonal configuration.
6. A drive axle assembly ( 10 ) as set forth in claim 2 wherein said radially outward end ( 116 ) slopes downwardly to said disc engaging portion ( 118 ) and then upwardly through a peak ( 124 ) to said elongated portion ( 120 ).
7. A drive axle assembly ( 10 ) as set forth in claim 4 , further including a pressure plate ( 80 ) disposed annularly about said axis (A) between said disc engaging portion ( 118 ) and said friction discs ( 74 , 76 ).
8. A drive axle assembly ( 10 ) as set forth in claim 1 including a piston housing ( 88 ) circumscribing at least one of said axle shafts ( 14 , 16 ) and supported by said carrier ( 24 ).
9. A drive axle assembly ( 10 ) as set forth in claim 8 including a piston ( 90 ) disposed in said piston housing ( 88 ) defining a cavity ( 92 ) therebetween.
10. A drive axle assembly ( 10 ) as set forth in claim 10 , wherein said piston ( 90 ) operably engages said sleeve ( 100 ) to provide the thrust force.
11. A drive axle assembly ( 10 ) as set forth in claim 10 wherein said actuator assembly ( 84 ) further includes a thrust bearing ( 112 ) coupled between said piston ( 90 ) and said sleeve ( 100 ) for isolating said piston ( 90 ) from said sleeve ( 100 ) such that any rotation of said sleeve ( 100 ) does not translate to said piston ( 90 ).
12. A drive axle assembly ( 10 ) as set forth in claim 11 including a hydraulic inlet ( 94 ) connected to said piston housing ( 88 ) for introducing a fluid into said cavity ( 92 ) for pressurizing said cavity ( 92 ) and forcing said piston ( 90 ) away from said piston housing ( 88 ).
13. A drive axle assembly ( 10 ) as set forth in claim 11 including an adjusting ring ( 86 ) operably connected to said carrier ( 24 ) and disposed annularly and stationary about one of said axle shafts ( 14 , 16 ).
14. A drive axle assembly ( 10 ) as set forth in claim 1 including a ring gear ( 20 ) operably connected to said differential case ( 22 ) and rotatable about said axis (A).
15. A drive axle assembly ( 10 ) as set forth in claim 14 wherein said differential assembly ( 18 ) further includes a differential spider ( 26 ) presenting four support shafts ( 62 , 64 ) orientated in the shape of a cross.
16. A drive axle assembly ( 10 ) as set forth in claim 15 wherein said differential assembly ( 18 ) further includes pinion gears ( 66 ) each supported for rotation on each of said support shafts ( 62 , 64 ).
17. A drive axle assembly ( 10 ) as set forth in claim 16 wherein said differential assembly ( 18 ) further includes a pair of side gears ( 28 , 30 ) presenting a meshing engagement with said pinion gears ( 66 ) and connected to each of said axle shafts ( 14 , 16 ).
18. A differential assembly ( 18 ), comprising:
a differential case ( 22 ) rotatable about an axis (A);
a drive hub ( 78 ) disposed about said axis (A);
a plurality of friction discs ( 74 , 76 ) adjacent one another in an alternating relationship defining a running clearance therebetween and disposed within and alternatively connected to said differential case ( 22 ) and said drive hub ( 78 );
a plate ( 102 ) defining a plurality of levers ( 104 ) each extending radially relative to said axis (A) between a radially inward end ( 114 ) to a radially outward end ( 116 ) and engaging said friction discs ( 74 , 76 ) and integrally interconnected by links ( 105 ) adjacent radially outward ends ( 116 );
an actuator assembly ( 84 ) disposed about one of said axle shafts ( 14 , 16 ) for engaging said levers ( 104 ) to force said levers ( 104 ) into engagement with said friction discs ( 74 , 76 ) for forcing said friction discs ( 74 , 76 ) into engagement with one another for transmitting torque between one of said axle shafts ( 14 , 16 ) and said differential case ( 22 ); and
said radially inward end ( 114 ) engaging said actuator assembly ( 84 ) and said radially outward end ( 116 ) engaging said differential case ( 22 ) having a disc engaging portion ( 118 ) between said radially inward ( 114 ) and outward ( 116 ) ends for engaging said friction discs ( 74 , 76 ) between said radially inward ( 114 ) and outward ( 116 ) ends thereof for amplifying a thrust force applied by said actuator assembly ( 84 ) by pivoting about the engagement of said radially outward end ( 116 ) with said differential case ( 22 ) in response to axial movement of said radially inward end ( 114 ) by said actuator assembly ( 84 ).
19. A drive axle assembly ( 10 ) as set forth in claim 1 wherein each of said levers ( 104 ) includes an elongated portion ( 120 ) extending from said radially inward end ( 114 ) to said disc engaging portion ( 118 ) and said links ( 105 ) adjacent thereto with a length of said elongated portion ( 120 ) defining a degree of amplification of the thrust force.
20. A drive axle assembly ( 10 ) as set forth in claim 19 wherein said disc engaging portion ( 118 ) is generally V-shaped.
21. A differential assembly ( 18 ) as set forth in claim 18 wherein said actuator assembly ( 84 ) includes a sleeve ( 100 ) movable axially and having first ( 106 ) and second ( 108 ) ends with said first end ( 106 ) defining a lip ( 110 ) and said second end ( 108 ) engaging said radially inward end ( 114 ) of said levers ( 104 ) with said sleeve ( 100 ) and said levers ( 104 ) rotatable about said axis (A) with said differential case ( 22 ) and at least one of said axle shafts ( 14 , 16 ).
22. A differential assembly ( 18 ) as set forth in claim 21 wherein said radially outward end ( 116 ) slopes downwardly to said disc engaging portion ( 118 ) and then upwardly through a peak ( 124 ) to said elongated portion ( 120 ).
23. A differential assembly ( 18 ) as set forth in claim 18 further including a pressure plate ( 80 ) disposed annularly about said axis (A) between said disc engaging portion ( 118 ) and said friction discs ( 74 , 76 ).
24. A differential assembly ( 18 ) as set forth in claim 18 including a piston housing ( 88 ) and a piston ( 90 ) disposed in said piston housing ( 88 ) defining a cavity ( 92 ) therebetween.
25. A differential assembly ( 18 ) as set forth in claim 24 wherein said piston ( 90 ) operably engages said sleeve ( 100 ) to provide the thrust force.
26. A differential assembly ( 18 ) as set forth in claim 25 wherein said actuator assembly ( 84 ) further includes a thrust bearing ( 112 ) coupled between said piston ( 90 ) and said sleeve ( 100 ) for isolating said piston ( 90 ) from said sleeve ( 100 ).
27. A differential assembly ( 18 ) as set forth in claim 26 including a hydraulic inlet ( 94 ) connected to said piston housing ( 88 ) for introducing a fluid into said cavity ( 92 ) for pressurizing said cavity ( 92 ) and forcing said piston ( 90 ) away from said piston housing ( 88 ).
28. A differential assembly ( 18 ) as set forth in claim 18 further including a ring gear ( 20 ) operably connected to said differential case ( 22 ) and rotatable about said axis (A).
29. A differential assembly ( 18 ) as set forth in claim 28 further including a differential spider ( 26 ) presenting four support shafts ( 62 , 64 ) orientated in the shape of a cross.
30. A differential assembly ( 18 ) as set forth in claim 29 further including pinion gears ( 66 ) each supported for rotation on each of said support shafts ( 62 , 64 ).
31. A differential assembly ( 18 ) as set forth in claim 30 further including a pair of side gears ( 28 , 30 ) presenting a meshing engagement with said pinion gears ( 66 ) and connected to each of said first ( 14 ) and second ( 16 ) axle shafts.
32. A differential assembly ( 18 ) as set forth in claim 24 wherein said levers ( 104 ) of said plate ( 102 ) define a generally polygonal configuration.