Abstract: A hydraulic coupling for use in a vehicle drivetrain includes a housing and a pair of rotary members projecting therefrom. The hydraulic coupling also includes a hydraulic circuit defining a low-pressure portion wherein the hydraulic fluid is at a first, lower pressure and a high-pressure portion wherein the hydraulic fluid is in a second, elevated pressure relative to the first pressure. A hydraulic pump is operatively supported within the housing and located within the path of the hydraulic circuit between the low pressure and high-pressure portions. The hydraulic pump is operable to pump hydraulic fluid from the low-pressure portion to the high-pressure portion of the hydraulic circuit. In addition, a clutch is supported within the housing and located within the high-pressure portion of the hydraulic circuit. The clutch is actuable by hydraulic fluid that is pumped by the hydraulic pump at the second, elevated pressure to couple the pair of rotary members together.

Abstract: A limited slip differential for an automotive vehicle includes a torque input differential pinion carrier, two differential side gears and a pair of torque output axle half shafts. The differential also includes at least one friction clutch assembly having first friction clutch plates connected driveably to the differential pinion carrier and second friction clutch plates connected driveably to one of the side gears. An annular pressure chamber is defined in the carrier. An annular piston is movably supported within the pressure chamber and adjacent the friction plates of the friction clutch assembly. The limited slip differential further includes a positive displacement gear pump having pumping elements defining high pressure and low pressure ports whereby pressure in the pressure chamber creates a force on the piston that engages a clutch assembly to effect a friction torque bias in the differential through the friction clutch assembly.

Abstract: A control valve (80) of a hydraulic coupling (32) controls pumping from a casing inlet port (58) by a hydraulic pump (48) through a casing outlet port (78) to control coupling between two rotary members such as by operation of a clutch (68). The casing (34) is connected to one of the rotary members while a pumping component embodied by an impeller (50) is connected to the other rotary member and meshed with an internal ring gear (54) having one more tooth than the number of impeller teeth to provide sufficient pumping capacity so that the pump can act as a brake while still having relatively constant pumping pressure. The control valve (80) includes an elongated valve element (82) mounted within a recess (98) to provide accurate control of its closure when the pumped hydraulic fluid reaches a predetermined pressure corresponding to a predetermined extent of relative rotation between the two drivetrain members.

Abstract: A limited slip differential for use with an automotive vehicle comprising differential gearing including a pair of differential side gears, one side gear being connected to each of two axle shafts for vehicle traction wheels, a differential carrier housing supporting differential pinions engageable with the side gears, the differential carrier being connected drivably through a drive shaft to the vehicle engine, first and second clutches connecting the differential carrier with each side gear, a mechanical cam mechanism for transferring a clutch-engaging force from the carrier to each of the clutches, thereby establishing a mechanical torque bias in the differential mechanism, and a clutch spring acting on each clutch to partially engage the clutches whereby the clutch-engaging force increases as a function of engine throttle position at a first rate for low engine throttle settings and at a higher rate for advanced engine throttle settings.

Abstract: A speed-sensitive, limited-slip, geared differential mechanism for transferring driving torque to each of two torque output shafts. Side gears located in a planetary gear carrier housing, one side gear being drivably connected to one pump member of a positive displacement pump and the planetary gear carrier being connected to another pump member. The pump is supplied with silicone fluid from a fluid reservoir. The pump creates a hydrostatic torque bias when differential motion of the side gears occurs as silicone fluid circulates through the pump.

Abstract: A flow control valve for regulating the flow across an orifice to eliminate the effects of viscosity changes throughout a range of temperatures for the hydraulic fluid. The valve includes a base with an orifice and a slide valve element that registers with the orifice and that is movable by a double, helix-wound, bimetallic spring. The bimetallic spring extends linearly in the direction of motion of the slide valve element so that its effective length will change a predictable amount for a given temperature change, thereby progressively changing the size of the orifice as the spring moves the slide valve element to which it is connected.

Abstract: A check valve (12) includes a cage (14) having a tubular side wall (16) including outward and inward undulations (28,30) that provide fluid flow through the check valve and externally thereof as well as providing guiding of an associated valve element ball (36).

Abstract: A hydraulic coupling (38) for coupling a casing (46) and a pair of axle half shafts (40) of an auxiliary drive axle (36) of a vehicle drivetrain (22) includes a housing (44) for containing hydraulic fluid and the casing (44) rotatively mounted within the housing. A clutch (76) extends between the casing (46) and each of the axle half shafts (40) and is actuable to transfer torque therebetween by the operation of a pair of hydraulic pumps (90) that provide pumped hydraulic fluid to a pair of piston chambers (110) whose pistons (120) actuate the clutch. An outlet port (122) of each piston chamber (110) and an associated temperature compensated valve (124) and a pressure relief valve (126) of each piston chamber control the clutch actuation.