192 clutches and power-stop control – Clutches – Automatic
Reexamination Certificate
2002-10-02
2004-08-24
Rodriguez, Saúl J. (Department: 3681)
192 clutches and power-stop control
Clutches
Automatic
C192S084600, C192S094000, C180S247000
Reexamination Certificate
active
06779641
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to power transfer systems for controlling the distribution of drive torque between front and rear wheels of a four-wheel drive vehicle and, more particularly, to a torque transfer coupling equipped with a ball-screw actuator.
BACKGROUND OF THE INVENTION
In view of increased consumer demand for four-wheel drive vehicles, a plethora of power transfer systems are currently being utilized in vehicular driveline applications for selectively directing power (i.e., drive torque) to the non-driven wheels of the vehicle. In many power transfer systems, a part-time transfer case is incorporated into the driveline and is normally operable in a two-wheel drive mode for delivering drive torque to the driven wheels. A mechanical “mode” shift mechanism can be selectively actuated by the vehicle operator for rigidly coupling the non-driven wheel to the driven wheels in order to establish a part-time four-wheel drive mode. As will be appreciated, a motor vehicle equipped with a part-time transfer case offers the vehicle operator the option of selectively shifting between the two-wheel drive mode during normal road conditions and the part-time four-wheel drive mode for operation under adverse road conditions.
Alternatively, it is known to use “on-demand” power transfer systems for automatically directing power to the non-driven wheels, without any input or action on the part of the vehicle operator, when traction is lost at the driven wheels. Modernly, it is known to incorporate the “on-demand” feature into a transfer case by replacing the mechanically-actuated mode shift mechanism with a clutch assembly that is interactively associated with an electronic control system and a sensor arrangement. During normal road conditions, the clutch assembly is maintained in a non-actuated condition such that the drive torque is only delivered to the driven wheels. However, when the sensors detect a low traction condition at the driven wheels, the clutch assembly is automatically actuated to deliver drive torque “on-demand” to the non-driven wheels. Moreover, the amount of drive torque transferred through the clutch assembly to the non-driven wheels can be varied as a function of specific vehicle dynamics, as detected by the sensor arrangement.
Conventional clutch assemblies, typically include a clutch pack operably connected between a drive member and a driven member, and a power-operated actuator for controlling engagement of the clutch pack. Specifically, torque is transferred from the drive member to the driven member by actuating the power-operated actuator for displacing an apply plate which acts on the clutch pack and increases the friction of engagement between the interleaved plates.
A variety of power-operated actuators have been used in the art with mixed results. Exemplary embodiments include those disclosed in U.S. Pat. No. 5,407,024 wherein a ball-ramp arrangement is used to displace the apply plate when a current is provided to an induction motor. Another example disclosed in U.S. Pat. No. 5,332,060, assigned to the assignee of the present application, which includes a linear actuator that displaces a pivoting lever arm to increase the friction forces in the clutch pack. While the above actuator devices have performed generally adequately for their intended purpose, a need exists for an improved actuator that is less complex, reduces the number of friction generating components which lead to inefficiencies and larger motor requirements, and an annular arrangement that provides operational simplicity and reduced space requirements.
SUMMARY OF THE INVENTION
In view of the above, the present invention is directed to a power transfer system for a four-wheel drive vehicle wherein the torque transfer coupling includes a clutch pack and a ball-screw actuator. The ball-screw actuator functions to axially translates an apply plate to operatively engage the clutch pack and vary the frictional engagement. This arrangement yields numerous operational advantages over the prior art including, but not limited to, establishing a direct drive between the motor output shaft and the apply plate, concentric mounting of the actuator elements with the motor output shaft, and a simplified mechanical arrangement that reduces the number of frictional elements increasing operational efficiency and decreasing motor requirements.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the following detailed description, attached drawings and claims.
REFERENCES:
patent: 2091268 (1937-08-01), Colman
patent: 3178958 (1965-04-01), Beck
patent: 3507374 (1970-04-01), Allaben, Jr.
patent: 4590816 (1986-05-01), Weyer
patent: 4635904 (1987-01-01), Whittingham
patent: 4718303 (1988-01-01), Fogelberg
patent: 4989686 (1991-02-01), Miller et al.
patent: 5199325 (1993-04-01), Reuter et al.
patent: 5332060 (1994-07-01), Sperduti et al.
patent: 5407024 (1995-04-01), Watson et al.
patent: 5462496 (1995-10-01), Dick et al.
patent: 5655618 (1997-08-01), Wilson et al.
patent: 5910061 (1999-06-01), Organek et al.
patent: 5943919 (1999-08-01), Babinski
patent: 6062330 (2000-05-01), Watson et al.
patent: 6167997 (2001-01-01), Keeney
patent: 6484857 (2002-11-01), Vonnegut et al.
www.powerjacks.com/Duff-Norton/Ball Screw Actuators / pp. 1-6.
www.powerjacks.com/Duff-Norton/Ball Screw Actuators / pp.1-2.
Bansbach Eric A.
Khazaee Mozaffar
Miller Daniel J.
Mohan Sankar K.
Vonnegut Carl H.
Harness & Dickey & Pierce P.L.C.
New Venture Gear Inc.
Rodriguez Saúl J.
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