192 clutches and power-stop control – Clutches – Automatic
Reexamination Certificate
2000-06-23
2001-11-20
Bonck, Rodney H (Department: 3681)
192 clutches and power-stop control
Clutches
Automatic
C192S1030FA, C180S249000
Reexamination Certificate
active
06318532
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to differential drives generally, and more particularly, relates to a hydraulically controlled torque transfer device for use with a differential drive in a vehicle.
2. Description of Related Art
The differential drive is well known in the motor vehicle industry. The differential drive is used in conjunction with the transmission and drive shaft or propeller shaft to turn the automotive vehicle wheels at different speeds when the vehicle is going around a curve, to differentiate the speed of each wheel individually and to provide the proper amount of torque to each wheel in slipping, turning, or other road to wheel conditions.
In a common all wheel drive power train layout of a motor vehicle there is a primary driven front/rear axle and a secondary driven hang on axle that is connected via a prop shaft or drive shaft and a torque transfer coupling to the primary driven axle. The torque transfer coupling is usually directly in front of the secondary driven axle. The axle differential creates the division of power or torque to each side shaft of the axle. The primary driven axle also includes a differential which divides necessary power to the side shaft of each axle and then the wheels. The division of torque between the front and rear axles is completed by the torque transfer coupling which is a separate unit on the drive train system and requires space for its housing and other related parts. There are many different ways to provide torque transfer between the primary driven and the secondary driven axles.
The current state of the art includes friction clutch pack systems that use ball ramp mechanisms and also hydraulic or pump systems. A state of the art pump system utilizes two gear pumps arranged in a static housing one is running with primary axle speed and the other with secondary axle speed in a closed hydraulic circuit wherein each of the gear pumps feed each other. Another state of the art gear rotor pump system is based on a single gear pump. The above mentioned two gear pumps and single gear pumps tend to have difficulties in feeding and externally controlling the rotating pump and they are very complex and expensive to manufacture and seal.
Therefore, there is a need in the art for a hydraulically controlled pump based system for torque transfer control between a primary driven axle and a secondary driven axle in an all wheel drive vehicle. This new hydraulic torque transfer device should combine the simplicity of a single gear rotary pump (gerotor pump) with the advantage of a more complex two pump system that has a stationary hydraulic circuit.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a new torque transfer device.
Another object of the present invention is to provide a torque transfer device that includes a hydraulic circuit that is stationary.
Yet another object of the present invention is to provide a torque transfer device that has easy access to control a hydraulic pressure for tuning characteristics of the torque transfer.
Yet a further object of the present invention is to provide a torque transfer device that has a quick response due to a high volume displacement pump.
Still a further object of the present invention is to provide a torque transfer device that has a reduced number of parts and is easier to manufacture.
Still another object of the present invention is to provide a torque transfer device that has a self-sealing pump arrangement.
A further object of the present invention is to provide a torque transfer device that has a large range of possible characteristics from degressive to progressive.
A further object of the present invention is to provide a torque transfer device that avoids complex valve schemes to separate pressure side from suction side in the hydraulic circuit.
Still a further object of the present invention is to provide a solenoid that acts as a switch or tuning feature to control the characteristics of the torque transfer device.
To achieve the foregoing objects the torque transfer device includes a differential housing. The torque transfer device further includes a clutch assembly, rotatably supported within the differential housing. A pump assembly is connected to the clutch housing on one side thereof. The torque transfer device includes a hydraulic assembly in contact with the pump on a side opposite of the clutch assembly. The torque transfer device also includes an axle housing which is rotatably fixed with respect to the differential housing. The hydraulic assembly is in constant contact with the axle housing. The hydraulic assembly is rotationally stationary with respect to the pump assembly.
One advantage of the present invention is that the torque transfer device has a hydraulic circuit that is stationary.
A further advantage of the present invention is that the torque transfer device has easy access control to the pressure characteristics and tuning of the torque transfer device.
Still a further advantage of the present invention is the quick response due to a high volume displacement pump in the torque transfer device.
Yet a further advantage of the present invention is the minimum number of parts and easier manufacturing of the torque transfer device.
A further advantage of the present invention is the self-sealing pump arrangement of the torque transfer device including the sealing disc, control disc, and pump housing.
Yet a further advantage of the present invention is the large range of possible characteristics and tuning from degressive to progressive of the torque transfer device.
Still a further advantage of the present invention is the nearly valveless scheme to separate the pressure side from suction side of the torque transfer hydraulic circuit.
Other objects, features, and advantages of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5405293 (1995-04-01), Severinsson
patent: 5687824 (1997-11-01), Hara et al.
patent: 0 570 841 A2 (1993-11-01), None
Bonck Rodney H
GKN Automotive Inc.
Nylander Mick A.
LandOfFree
Externally controlled hydraulic torque transfer device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Externally controlled hydraulic torque transfer device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Externally controlled hydraulic torque transfer device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2573312