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US 6,626,787 B2Granted
On-demand all-wheel drive system
AssigneeNew Venture Gear, Inc.
InventorFred C. Porter
Life of this patent
Estimating the term…
Abstract
A drive axle assembly for use in an all-wheel drive vehicle having a first hydraulic coupling operable to automatically transfer drive torque to a secondary driveline in response to slip of the primary driveline and a second hydraulic coupling operable to bias torque and limit slip between the wheels of the secondary driveline.
Claims34
A drive axle assembly for use in a motor vehicle to transfer drive torque from a powertrain to a pair of wheels, comprising:
- a first hydromechanical coupling having an input shaft driven by the powertrain, a pinion shaft, a first transfer clutch operably disposed between said input shaft and said pinion shaft, a first piston disposed in a first piston chamber and actuatable to engage said first transfer clutch for transferring drive torque to said pinion shaft, a first fluid pump for pumping hydraulic fluid from a sump to said first piston chamber in response to relative rotation between said input shaft and said pinion shaft, and a control valve mounted to said first piston, said control valve operable to vent fluid from said first piston chamber to said sump in response to the occurrence of either of an over-pressure and an over-temperature condition;
- first and second output shafts adapted for connection to the pair of wheels;
- a differential assembly including a casing driven by said pinion shaft, and a gearset interconnecting said casing to said first and second output shafts;
- and
- a second hydromechanical coupling having a second transfer clutch operably disposed between said casing and said gearset of said differential assembly, a second piston disposed in a second piston chamber which is actuatable in response to fluid pressure in said second piston chamber to engage said second transfer clutch for biasing torque and limiting slip between said first and second output shafts, and a second pump for pumping fluid from said sump to said second piston chamber in response to relative rotation between said casing and one of said first and second output shafts.
2 more elements
A drive axle assembly for use in a motor vehicle to transfer drive torque from a powertrain to a pair of wheels, comprising:
- a first hydromechanical coupling having an input shaft driven by the powertrain, a pinion shaft, a first transfer clutch operably disposed between said input shaft and said pinion shaft, a first piston disposed in a first piston chamber and actuatable to engage said first transfer clutch for transferring drive torque to said pinion shaft, a first fluid pump for pumping hydraulic fluid from a sump to said first piston chamber in response to relative rotation between said input shaft and said pinion shaft, and a control valve mounted to said first piston, said control valve operable to vent fluid from said first piston chamber to said sump in response to the occurrence of either of an over-pressure and an over-temperature condition;
- first and second output shafts adapted for connection to the pair of wheels;
- a casing driven by said pinion shaft;
- a second hydromechanical coupling having a second transfer clutch operably disposed between said casing and first output shaft, a second piston disposed in a second piston chamber which is actuatable in response to fluid pressure in said second piston chamber to engage said second transfer clutch, and a second pump for pumping fluid from said sump to said second piston chamber in response to relative rotation between said casing and said first output shafts;
- and
- a third hydromechanical coupling having a third transfer clutch operably disposed between said casing and said second output shaft, a third piston disposed in a third piston chamber which is actuatable in response to fluid pressure in said third piston chamber to engage said third transfer clutch, and a third pump for pumping fluid from said sump to said third piston chamber in response to relative rotation between said casing and said second output shaft.
3 more elements
A drive axle for use in a motor vehicle to transfer drive torque from a powertrain to a pair of wheels, comprising:
- a housing;
- an input shaft rotatably supported within said housing and adapted to be driven by the powertrain;
- an interaxle portion supported by said housing and driven by said input shaft, comprising a first transfer clutch operably interconnecting said input shaft and a pinion shaft, a first clutch actuator comprising a first piston selectively operable to engage said first transfer clutch, a first pump for selectively pumping actuation fluid to said first piston for actuation thereof, and a first control valve operable for selectively disengaging said first transfer clutch in response to either of a first condition or a second condition;
- and
- a differential portion supported within said housing, comprising a drive case rotatably driven by said pinion shaft, first and second output shafts driven by said drive case adapted for connection to the wheels, a second transfer clutch operably disposed between said drive case and said first output shaft, a second clutch actuator operable to engage said second transfer clutch for limiting relative rotation between said drive case and said first output shaft, and a second pump for selectively pumping actuation fluid to said second clutch actuator for engaging said second clutch.
2 more elements
Dependencies are inferred from the claim text.