Torque transmitting structure and method of manufacture

• US 5,384,949 A
• Filed: 12/17/1993
• Issued: 01/31/1995
• Est. Priority Date: 01/05/1993
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Wodrich, Helmut A. H., Zanet, Mario S.
• Primary Examiner(s): Gorski, Joseph M.
• Application Number:
  US08/168,335
• Time in Patent Office: 410 Days
• Field of Search: 72/82, 72/83, 72/84, 72/208, 192/70.19, 192/70.2, 29/557
• US Class Current: 29/557
• CPC Class Codes: B21D 22/16 over shaping mandrels or formers
• CPC Class Codes: B21H 5/025 Internally geared wheels
• CPC Class Codes: Y10T 29/49471 Roll forming
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

A torque transmitting structure for an automatic transmission has an inner hub for rotating the structure and an outer annular shell. The annular shell has an internal radial spline portion, an external brake surface, a torque tube and an axially facing drive connecting surface. The annular shell is manufactured in a flow forming process, wherein a cup-shaped blank is secured on a mandrel which has a shape complementary to the internal shape of the shell. Forming rolls engage the outer surface and are moved axially relative to the mandrel in a manner to form the desired outer contour of the shell. After the flow forming operation, the shell is removed from the mandrel, the axial drive connection is formed by metal removal and the hub is bonded to the shell.

Claims

1. A method of manufacturing a torque transmitting housing, comprising the steps of:

providing a roller forming apparatus including at least one roller and a mandrel, the mandrel having a splined cylindrical portion of a first diameter, a smooth cylindrical portion of a second diameter greater than said first diameter, and a transition portion joining said splined cylindrical portion to said smooth cylindrical portion;

providing a cup shaped blank;

mounting said cup shaped blank on said mandrel adjacent said splined cylindrical portion;

then

rotating said at least one roller and said mandrel relative to each other about a longitudinal axis of said mandrel, while rotating said at least one roller about its longitudinal axis;

then

contacting said cup shaped blank with said at least one roller, while performing said rotating steps, and translating said at least one roller along said splined cylindrical portion with said at least one roller being radially spaced from said splined cylindrical portion a first distance, thereby forming said cup shaped blank into a first portion having a splined inner circumferential portion, a smooth outer circumferential portion, and a wall thickness corresponding to said first distance, while lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotating steps, and translating said at least one roller along said transition portion while increasing the radial spacing between said at least one roller and said transition portion to a second distance greater than said first distance, thereby forming said cup shaped blank into a second portion contiguous the first portion, having a smooth outer circumferential portion and a gradually thickening wall portion corresponding to said second distance while continually lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotation steps, and translating said at least one roller along pan of said smooth cylindrical portion with said at least one roller being radially spaced from said smooth cylindrical portion a third distance less than said first distance, thereby forming said cup shaped blank into a third portion, contiguous the second portion, having a smooth outer circumferential portion, a wall thickness corresponding to said third distance, and an outer diameter substantially equal to a terminus outer diameter of said second portion while continually lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotating steps, and translating said at least one roller along a second pan of said smooth cylindrical portion while increasing the radial spacing between said at least one roller and said smooth cylindrical portion to a fourth distance, thereby forming said cup shaped blank into a fourth portion, contiguous said third portion, having a smooth outer circumferential portion and gradually thickening wall portion corresponding to said fourth distance, while continually lengthening said cup shaped blank;

then

removing said at least one roller from contact with said cup shaped blank;

removing the formed cup shaped blank from said mandrel; and

forming axially extending drive tabs in said fourth portion.

2. A method of manufacturing a torque transmitting housing, comprising the steps of:

providing a roller forming apparatus including at least one roller and a mandrel, the mandrel having a splined cylindrical portion of a first diameter, a smooth cylindrical portion of a second diameter greater than said first diameter, and a transition portion joining said splined cylindrical portion to said smooth cylindrical portion;

providing a cup shaped blank;

mounting said cup shaped blank on said mandrel adjacent said splined cylindrical portion;

then

rotating said at least one roller and said mandrel relative to each other about a longitudinal axis of said mandrel, while rotating said at least one roller about its longitudinal axis;

then

contacting said cup shaped blank with said at least one roller, while performing said rotating steps, and translating said at least one roller along said splined cylindrical portion with said at least one roller being radially spaced from said splined cylindrical portion a first distance, thereby forming said cup shaped blank into a first portion having a splined inner circumferential portion, a smooth outer circumferential portion, and a wall thickness corresponding to said first distance, while lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotating steps, and translating said at least one roller along said transition portion while increasing the radial spacing between said at least one roller and said transition portion to a second distance greater than said first distance, thereby forming said cup shaped blank into a second portion contiguous the first portion, having a smooth outer circumferential portion and a gradually thickening wall portion corresponding to said second distance while continually lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotation steps, and translating said at least one roller along part of said smooth cylindrical portion with said at least one roller being radially spaced from said smooth cylindrical portion a third distance less than said first distance, thereby forming said cup shaped blank into a third portion, contiguous the second portion, having a smooth outer circumferential portion, a wall thickness corresponding to said third distance, and an outer diameter substantially equal to a terminus outer diameter of said second portion while continually lengthening said cup shaped blank;

maintaining contact between said at least one roller and said cup shaped blank while continually performing said rotating steps, and translating said at least one roller along a second part of said smooth cylindrical portion while increasing the radial spacing between said at least one roller and said smooth cylindrical portion to a fourth distance, thereby forming said cup shaped blank into a fourth portion, contiguous said third portion, having a smooth outer circumferential portion and gradually thickening wall portion corresponding to said fourth distance, while continually lengthening said cup shaped blank;

then

forming axially extending drive tabs in said fourth portion;

removing said at least one roller from contact with said cup shaped blank; and

removing the formed cup shaped blank from said mandrel.