Modular housing for vehicular power transfer devices

Details Modular housing for vehicular power transfer devices Modular housing for vehicular power transfer devices

2000-04-06

2001-09-04

Wright, Dirk (Department: 3681)

Planetary gear transmission systems or components

Planetary gearing or element

Nonplanetary gearing combined with planetary

C074S6650GA, C074S60600R

Reexamination Certificate

active

06283890

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a modular housing and assembly methods for power transfer devices of the type used in motor vehicles.
BACKGROUND OF THE INVENTION
As is widely known, automobile manufacturers desire the flexibility to offer a variety of drivetrain packages with different power transmission characteristics (i.e., number of gear ratios, torque capacity, 2WD/4WD, etc.) for each vehicle. This flexibility is limited, however, by the significant cost and leadtime required to design and validate a series of different power transfer devices (i.e., transfer cases, transmissions, transaxles, axle assemblies, etc.). This dilemma is further aggravated by the competitive need to develop lighter weight and higher efficiency power transfer devices at a reduced cost.
A significant amount of the weight and manufacturing cost associated with traditional power transfer devices is derived from the housing. Typically, the housing is assembled from two or more bell-shaped castings that are interconnected to form an enclosed chamber within which a geartrain is supported. Additionally, the various rotary components (i.e., shafts, gears, carriers, etc.) of the geartrain extend through and/or are rotatably supported by one or more of the castings. As such, each casting must be constructed from a material having sufficient strength and thickness to absorb the loads created during power transmission while providing acceptable noise isolation and heat transfer characteristics. Consequently, most housings are designed for use with a single power transfer device. Hence, increased costs are incurred when a variety of drivetrain packages are offered to the consumer.
Another disadvantage associated with conventional housings is the secondary machining required to permit the castings and the drive components of the geartrain to be properly aligned during assembly. For example, since threaded fasteners are used to rigidly connect the castings, the flatness of the mounting face on the rim of each casting and the location of threaded holes therein are critical to proper alignment and sealing of the power transfer device.
SUMMARY OF THE INVENTION
It is therefore desirable to provide a power transfer device with a modular housing assembly which, when compared to traditional housings, increases assembly precision while concomitantly decreasing cost and reducing sound transmission.
According to a first embodiment of the present invention, a power transfer device is provided with a modular housing assembly having a center case and a pair of cover plates which are secured to the center case to define an enclosed chamber. The center case includes a continuous sidewall which is open on two opposing sides to define a pair of openings. The cover plates are mounted to the center case and enclose its openings. Mounting shelves extend inwardly from the sidewall of the center case and are adapted to align and support mounting devices for carrying both the rotary and non-rotary components of a geartrain. The mounting shelves are designed to transfer the loads transmitted by the components of the geartrain to the sidewall of the center case. All of the mounting shelves may have a mounting surface located in a common plane. Such an arrangement simplifies the machining, inspection, and assembly time required to build a power transfer device. Moreover, the location of the mounting shelves may be commonized to permit different power transfer devices to be assembled using a single center case. As such, the modularity of the center case and the cover plates, in combination with the design flexibility afforded by the mounting shelves, will provide simplified assembly operations with higher precision alignment of the geartrain components.
According to another embodiment of the present invention, a power transfer device is provided with a modular housing assembly comprised of a box-like center case and a single cover plate. The center case includes a continuous sidewall segment and an integral base segment which together form an interior chamber which is enclosed by the cover plate.
In another embodiment of the present invention, a power transfer device is provided with a modular housing assembly having a center case and a cover plate. The center case includes a continuous sidewall segment and an integral base segment which together form an interior chamber which is enclosed by the cover plate. Mounting pads extend inwardly from the integral base and sidewall segments of the center case, and align and support mounting devices for carrying both the rotary and non-rotary components of a geartrain. The rotary and non-rotary components of the geartrain, along with an electric gearmotor, are entirely contained within the interior chamber of the center case. More specifically, the power transfer device in this instance includes a transfer case equipped with a torque transfer arrangement that is operable for automatically controlling the drive torque delivered to the front and rear drivelines of the vehicle to establish two-wheel, four-wheel high, neutral and four-wheel low drive modes.
In association with all of the embodiments, the cover plate includes a peripheral flange that is adapted to be mounted on a peripheral rim of the center case adjacent its opening. The cover plate contains an O-ring type seal adhered to its peripheral rim. Thereafter, the cover plate is secured to the center case by a set of spring clamps. The spring clamps are spaced for achieving a relatively constant load between the mating cover plate seal and the center case rim, thereby achieving a fluid-tight seal. The cover plates are not required to perform the traditional functions of locating and supporting the geartrain components or gearmotor and, as such, do not function to absorb or carry any loads from the geartrain or gearmotor. Instead, each cover plate encloses the opening of the center case for sealing a supply of lubricating fluid within the modular housing assembly. Preferably, the cover plates are manufactured from a stiff, yet lightweight material which, for example, can be a molded composite or stamped steel component.
Employing the above embodiments of the present invention, a power transfer device having a lightweight, yet robust, modular housing assembly can be used in a variety of power transmission applications. Additionally, the present invention reduces the manufacturing time and cost by improving tolerance capabilities for aligning the drive components of the power transfer device.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however 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 this detailed description.


REFERENCES:
patent: 4434606 (1984-03-01), Rhodes et al.
patent: 4782719 (1988-11-01), Yarnell
patent: 5146748 (1992-09-01), Okada
patent: 5156576 (1992-10-01), Johnson
patent: 5207121 (1993-05-01), Bien
patent: 5704863 (1998-01-01), Zalewski et al.
patent: 5836219 (1998-11-01), Klingler et al.
patent: 5960671 (1999-10-01), Nguyen
patent: 6053072 (2000-04-01), Schleuder
patent: 3815511 (1989-11-01), None
patent: 0543731 (1993-05-01), None

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