Limited slip differential
AssigneeClark Equipment Company
InventorGregory T. Dewald
Life of this patent
Estimating the term…
Abstract
A limited slip differential of the speed sensitive torque biasing type in which a plate type clutch between the case and a side gear is applied jointly by the force of a spring and by the thrust force on the side gear, when the differential is at the stall or low speed condition. As the differential begins to operate and its speed increases the clutch is gradually released by pressurized fluid which is responsive to the speed of rotation, and which releases the clutch by providing a hydrodynamic film on the friction surfaces of the clutch.
Claims18
A limited slip differential having a case rotatable about an axis, a ring gear on the case for rotating the case, the case having an internal cross-shaft, a bevel pinion gear rotatable about the cross-shaft, a pair of coaxial shafts extending inwardly into the opposite ends of the case respectively, and each shaft carrying a bevel side gear which is in mesh with the pinion gear, the differential comprising
- a friction clutch for clutching together one side gear and said case for limiting differential action between said axle shafts,
- a hydraulic pump operated by rotation of the differential case,
- said pump receiving hydraulic fluid through an antifriction bearing, and
- a conduit connecting said pump and said clutch for forcing fluid through the clutch thereby gradually releasing the clutch as the speed of said case increases.
A limited slip differential mechanism having two coaxial output shafts, differential gears between said shafts for connecting the shafts for joint operation, a rotatable case housing the differential gears, and a friction plate clutch for clutching one of said gears to the case for operating said shafts in unison, comprising
- a tapered roller bearing dynamically connected to said case,
- said bearing discharging fluid when said case is rotating,
- a plunger pump which receives the fluid discharged from said bearing,
- said plunger pump including a piston which reciprocates responsively to the rotation of said case,
- said pump discharging fluid through an outlet which directs said fluid onto a plate of said friction clutch,
- whereby said fluid provides a hydrodynamic film on said friction plate cluch mechanism,
- reducing the effectiveness of said clutch and the restriction on the slip of the differential.
A method for operating a limited slip differential having a case member rotatable about an axis, a ring gear on the case for rotating the case, the case having an internal cross-shaft, a bevel pinion gear rotatable on the cross-shaft, a pair of coaxial shafts extending inwardly into the opposite ends of the case respectively, and each coaxial shaft carrying a side gear which is in mesh with the pinion gear, the method comprising
- providing a clutch having at least one friction plate for clutching together one of said side gears and said case for restricting differential action between said coaxial shafts,
- providing a hydraulic pump operated by rotation of said case,
- providing an antifriction bearing connected to said case which acts to charge said pump,
- directing fluid from said bearing to said pump;
- and
- providing a conduit connecting said pump and said plate clutch for forcing fluid through the clutch and over said friction plate,
- thereby gradually releasing the clutch as the speed of said case increases.
Dependencies are inferred from the claim text.