Crimped connection for a cover and impeller in a torque converter

The present invention broadly comprises a torque converter including a cover arranged to accept torque from a drive unit and an impeller. The cover and the impeller are joined by a crimped connection. In some aspects, the converter includes a sealing element disposed between the cover and the impeller and the sealing element is selected from the group consisting of an o-ring and a gasket. In some aspects, the cover is a cast piece. In some aspects, the cover is formed by a process selected from the group consisting of: molding, compression molding, and pressed metal forming. In some aspects, the cover is a stamped metal piece. The present invention also broadly comprises a torque converter including a cover, an impeller, and an induction brazed connection joining the cover and impeller. In some aspects, the cover further comprises axially disposed fingers engaged with the impeller.

FIELD OF THE INVENTION

The invention relates to improvements in apparatus for transmitting force between a rotary driving unit (such as the engine of a motor vehicle) and a rotary driven unit (such as the variable-speed transmission in the motor vehicle). In particular, the invention relates to a cover and an impeller for a torque converter joined by a crimped connection.

BACKGROUND OF THE INVENTION

A cover and an impeller for a torque converter are typically connected by welding. However, the heat associated with welding can cause distortion of the cover or impeller and can result in leaking at the joint between the cover and impeller.

Thus, there is a long-felt need for a means of connecting a torque converter cover and impeller without causing distortion of the cover and impeller or leaking between the cover and impeller.

BRIEF SUMMARY OF THE INVENTION

The present invention broadly comprises a torque converter including a cover and an impeller. The cover is arranged to accept torque from a drive unit. The cover and the impeller are joined by a crimped connection. In some aspects, the converter includes a sealing element disposed between the cover and the impeller and the sealing element is selected from the group consisting of an o-ring and a gasket. In some aspects, the cover is a cast piece. In some aspects, the cover is formed by a process selected from the group consisting of: molding, compression molding, and pressed metal forming. In some aspects, the cover is a stamped metal piece.

The present invention also broadly comprises a torque converter including a cover arranged to accept torque from a drive unit, an impeller, and an induction brazed connection joining the cover and impeller. In some aspects, the cover further comprises axially disposed fingers engaged with the impeller.

It is a general object of the present invention to provide a torque converter with a connection between a cover and an impeller that is free of distortion caused by welding and other joining means.

These and other objects and advantages of the present invention will be readily appreciable from the following description of preferred embodiments of the invention and from the accompanying drawings and claims.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a cross-sectional view of present invention torque converter100with cast cover102. Torque converter100also includes impeller104. Impeller104is formed by a metal fabricating process, such as stamping. Cover102is arranged to accept torque from a drive unit (not shown) and transfer the torque to impeller104. Impeller104radially overlaps cover102. Cover102and impeller104are joined by crimped connection106along joint108. Any crimped connection known in the art can be used for connection106. InFIG. 1, material forming impeller104has been manipulated to form the crimped connection. Connection106enables torque from the cover to be transferred to the impeller. That is, the connection fixedly secures the cover and the impeller, in particular, with respect to rotational movement.

In some aspects, converter100also includes sealing element110disposed between the cover and the impeller. Element110provides a liquid-tight seal between the cover and the impeller. Crimping the cover and the impeller at joint108maintains a compressive fit between element110and the cover/impeller. For example, connection106maintains radial force to compress inner face112of the impeller against element110. By radial, we mean orthogonal to axis116. Element110can be any sealing element known in the art, including, but not limited to an o-ring and a gasket.

Cover102inFIG. 1is formed by metal casting. However, in some aspects, cover102is formed by other processes including, but not limited to molding, compression molding, and pressed metal forming. Any material known in the art can be used to form cover102.

It should be understood that cast cover102, impeller104, and crimped connection106are not limited to any particular type, size, shape, or configuration. Further, the use of cover102, impeller104, and connection106with torque converters having sizes, shapes, configurations, and components different than those shown inFIG. 1is within the spirit and scope of the invention as claimed.

Cover102includes at least one connection point114for connecting cover102to the drive unit. In general, points114are distributed circumferentially about axis116. By circumferential, we mean at a certain radial distance from axis116. In some aspects, connection points114are lugs as shown inFIG. 1. In some aspects (not shown), the connection points form protrusions on surface118or surface118is formed with indents proximate the connection points. Further, impeller104is formed with at least one axial extension (not shown). By axial we mean substantially parallel to axis116. In general, the extensions are disposed about circumference120of the impeller. In some aspects, the extensions are in the form of fingers. The extensions extend beyond connection106toward axis116. The extensions and connection points are in axial alignment. For those connection points with proximate indents, part of the extension is in the indent. In both cases, the extensions are braced against the cover, strengthening the rotational connection of the cover and impeller.

FIG. 2is a cross-sectional view of present invention torque converter200with cover202. Torque converter200also includes impeller204. Cover202and impeller204are formed by metal fabricating processes such as stamping. Cover202is arranged to accept torque from a drive unit (not shown) and transfer the torque to impeller204. Cover202and impeller is204are joined by crimped connection206along joint208. Material from one or both of cover202and impeller204can be manipulated to form the connection. InFIG. 2, impeller204radially overlaps the cover and material from the impeller has been crimped to form the connection. In some aspects (not shown), the cover radially overlaps the impeller. Connection206enables torque from the cover to be transferred to the impeller. That is, the connection fixedly secures the cover and the impeller, in particular, with respect to rotational movement.

In some aspects, converter200also includes sealing element210disposed between the cover and the impeller. Element210provides a liquid-tight seal between the cover and the impeller. Crimping the cover and the impeller at joint208maintains radial force to compress inner face212of the impeller against element210. Element210can be any sealing element known in the art, including, but not limited to an o-ring and a gasket.

Any crimped connection known in the art can be used for connection206. It should be understood that stamped cover202, impeller204, and crimped connection206are not limited to any particular type, size, shape, or configuration. Further, the use of cover202, impeller204, and connection206with torque converters having sizes, shapes, configurations, and components different than those shown inFIG. 2is within the spirit and scope of the invention as claimed.

In some aspects (not shown), an impeller for a torque converter is formed by casting, a cover for the converter is formed by a metal fabricating process, such as stamping, and the cover and impeller are joined by a crimped connection. In these aspects, the material forming the cover is crimped. In some aspects, a sealing element is placed between the cover and impeller. In general, the descriptions forFIGS. 1 and 2are applicable to a torque converter with a cast impeller and fabricated metal cover.

In some aspects (not shown), at least one of the cover and impeller for a torque converter is formed by metal casting and the cover and impeller are joined by a brazed connection. That is, either or both of the cover and impeller are formed by casting. Returning toFIG. 1, the use of a brazed connection facilitates the positioning of the joint, between the cover and the impeller, closer to the impeller, reducing the axial length of segment122of the impeller. This is particularly advantageous when the impeller is stamped, as forming radial walls for stamped components increases the difficulty of the stamping process.

FIG. 3is a front view of present invention torque converter300with recesses and axial extensions. In some aspects, the cover or the impeller is formed with at least one axial extension and the other of the cover or impeller is formed with at least one recess. InFIG. 3, torque converter300is shown with cover302having recesses304and connection points306. The torque converter also includes impeller308having axial extensions310. Extensions310are in contact with points306and disposed in recesses304. An embodiment with the cover having the axial extensions and the impeller having the recesses is not shown. The extensions and recesses are complimentary such that respective extensions fit in or are disposed in respective recesses, for example, complimentary fingers and notches. The cover or impeller formed with the recesses is cast. The cover or impeller formed with the extensions can be cast or can be formed by another metal fabricating process, such as stamping. The joint formed between the cover and impeller is brazed. Any brazing means known in the art, including, but not limited to induction brazing can be used. The extensions and recesses serve to transfer rotational torque. The brazing provides an axial bond and serves to seal the connection between the cover and the impeller.