TURBINE ASSEMBLY FOR A TORQUE CONVERTER INCLUDING A TAB PLATE AND TURBINE SHELL BRAZED TOGETHER AND METHOD OF FORMING

Abstract

A turbine assembly is provided. The turbine assembly includes a turbine shell and a tab plate connected to the turbine shell, the turbine shell and the tab plate being brazed together. A method of forming a turbine assembly impeller is also provided. The method includes aligning a tab plate with a turbine shell with a braze material therebetween and brazing the tab plate and turbine shell together by melting the braze material.

Description

BACKGROUND

U.S. Pat. No. 8,257,042 discloses a power transmitting member fastened to a turbine shell by a rivet.

U.S. Pat. No. 4,646,886 discloses a torque transmission member mounted on a turbine.

U.S. Publication No. 2007/0253823 discloses a spring retainer fixed to a turbine shell by folded blade tabs.

SUMMARY OF THE INVENTION

A turbine assembly is provided. The turbine assembly includes a turbine shell and a tab plate connected to the turbine shell, the turbine shell and the tab plate being brazed together.

Embodiments of the turbine assembly may also include one or more of the following advantageous features:

The turbine assembly may include elastic dampers and the tab plate may be arranged for driving the elastic dampers. The elastic dampers may be arc springs and the turbine assembly may include a retainer supporting the elastic dampers. The turbine shell and tab plate may be brazed together by a braze material, which extends between an outer surface of the turbine shell and an inner surface of the tab plate. The turbine shell may include at least one hole passing therethrough, the braze material surrounding the hole. The turbine assembly may include a turbine core ring, the at least one hole being radially outside of the turbine core ring.

A method of forming a turbine assembly impeller is also provided. The method includes aligning a tab plate with a turbine shell with a braze material therebetween and brazing the tab plate and turbine shell together by melting the braze material.

Embodiments of the method may also include one or more of the following advantageous features:

The turbine shell may include a hole extending between an inner surface and an outer surface thereof and the brazing may include applying the braze material into the hole. The brazing may further include heating the braze material such that a capillary action pulls the braze material away from the hole and in between an inner surface of the tab plate and the outer surface of the turbine shell. The capillary actions causes the braze material to flow radially outward with respect to an axis of the hole. The method may further include arranging tabs of the tab plate circumferentially between elastic dampers. The method may further include brazing the turbine shell and turbine blades together as the tab plate and the turbine shell are brazed together.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described below by reference to the following drawings, in which:

FIG. 1 shows a cross sectional view of a turbine assembly according to an embodiment of the present invention;

FIG. 2 shows a view of a section of the turbine assembly along A-A of FIG. 1;

FIGS. 3 a to 3c show a preferred embodiment of a method of forming the turbine assembly; and

FIG. 4 shows a torque converter including the turbine assembly.

DETAILED DESCRIPTION

FIG. 1 shows a cross sectional view of a turbine assembly 10 according to an embodiment of the present invention and FIG. 2 shows a view of a section of turbine assembly 10 along A-A of FIG. 1. Turbine assembly 10 includes a tab plate 12 brazed to a turbine shell 14. Tab plate 12 includes a base portion 16 extending along an outer surface 18 of turbine shell 14 and a tab portion 20 protruding away from base portion 16. In the cross sectional view show in FIG. 1, base portion 16 and tab portion 20 together have approximately an L-shape. At a rounded portion 19 of turbine shell 14, outer surface 18 of turbine shell 14 has a rounded shape and an inner surface 22 of base portion 16 is contoured to the shape of outer surface 18. An inner surface 24 of turbine shell 14 supports a plurality of turbine blades 26, which extend between inner surface 24 and a turbine core ring 28. Outer surface 18 of turbine shell 14 faces away from core ring 28. Radially inside of rounded portion 19 of turbine shell 14, turbine shell 14 includes a flat connecting portion 30, connectable to a turbine hub by a rivets passing through holes 36 in connecting portion 30. Turbine assembly is centered about an axis 38. Unless otherwise specified, the use of the terms radially, axially and circumferentially herein will be with respect to axis 38.

In this embodiment, tab plate 12 is used for circumferentially driving elastic dampers 40, which in this embodiment are arc spring 42 supported by a spring retainer 44 to form a damper assembly 32. Damper assembly 32 may be coupled to a clutch of the torque converter.

Rounded portion 19 of turbine shell 14 includes a brazing hole 46 passing through turbine shell 14 from outer surface 18 to inner surface 24. In this embodiment, brazing hole 46 is formed in turbine shell 14 radially outside of core ring 28. Brazing hole 46 is formed between two turbine blades 26, which may be connected to turbine shell 14 before or after turbine shell 14 and tab plate 12 are brazed together. Blades 26 may be connected to turbine shell 14 via blade tabs 48 that are inserted in slots passing through turbine shell 14 and bent to engage outer surface 18. Similarly, blades 26 may be connected to core ring 28 in the same manner, by engaging blade tabs 50 in slots 52 in core ring 28 and bending blade tabs 50. In a preferred embodiment, after blades 26 are connected to turbine shell 14 and core ring 18 by respective tabs 48, 50, blades 26 are brazed to both turbine shell 14 and core ring 18. The brazing may be accomplished as described in U.S. Pat. No. 7,918,645.

In a preferred embodiment of the method of the present invention, which is shown schematically in FIGS. 3a to 3c, tab plate 12 is placed down on a support surface and turbine shell 14 is placed on top of tab plate 12. Tab plate 12 may be formed as a single ring-shaped integral piece with a plurality of axially extending tabs 54 protruding downward away from turbine shell 14. In this embodiment, tabs 54 are circumferentially spaced apart from each other by gaps 56 for receiving elastic dampers 40, i.e., arc springs 42. After turbine shell 14 is placed on top of tab plate 12 and appropriately aligned such that brazing holes 46 are all centered around a center axis of tab plate 12 and outer surface 18 of turbine shell 14 is in close contact with inner surface 22 of tab plate 12, a braze material 62 is placed in each of brazing holes 46. Then, braze material 62 is heated such that braze material 62 is liquefied and a capillary action pulls the braze material 62 radially away from each respective hole 46, with respect to an axis of the respective hole 46, in between inner surface 22 of the tab plate 12 and outer surface 18 of turbine shell 14. Braze material 62 is then cooled to permanently connect tab plate 12 and turbine shell 14.

In a preferred embodiment of the present invention, turbine shell 14 and core ring 28 are connected together by tabs 48, 50 of blades 26 before tab plate 12 and turbine shell 14 are brazed together. This allows blades 26 to be brazed to turbine shell 14 and core ring 28 at the same time that turbine shell 14 and tab plate 12 are brazed together. For example, braze material 62 may be placed in holes 46 and into brazing locations between blades 26 and core ring 28 and brazing locations between blades 26 and turbine shell 14. Then, tab plate 12, turbine shell 14, blades 26 and core ring 28 may be passed through a brazing furnace together to melt the braze material 62, which permanently connects tab plate 12, turbine shell 14, blades 26 and core ring 28 together at the same time after the braze material 62 is cooled.

In an alternative embodiment, instead of tab plate 12 being formed as a single integral ring-shaped piece, tab plate 12 may be formed as a plurality of separate tab plates spaced circumferentially from each other on turbine shell 14. For example, each separate tab plate may include a tab 54 and may be individually brazed to turbine shell 14 by braze material 62. In such embodiments, it may be helpful to first fasten each separate tab plate to turbine shell 14 before brazing. For example, each separate tab plate may include a tab similar to tab 50 of blade 26 and may be inserted into slots in turbine shell 14 similar to slots 52 in core ring 28 to fasten the individual pieces to turbine shell 14. Other fasteners may also be used in other embodiments, such as hooks for example.

After turbine shell 14 and tab plate 12 are brazed together, tab plate 12 may be engaged with a driven component, which in this embodiment is damper assembly 32. Tab plate 12 and spring retainer 44, which retains arc springs 42, may be meshed together, by aligning tabs 54 of tab plate 12 between springs 42 of spring retainer 44 as shown in FIG. 3c. Arc springs 42 may be positioned in gaps 56 between tabs 54. Turbine assembly 10 may be then used in a torque converter of a motor vehicle, which transfers power from a crankshaft of an engine to a transmission.

A schematic of a torque converter 110 including turbine assembly 10 is shown in FIG. 4. Tab plate 12 brazed to turbine shell 14 is arranged for circumferentially driving damper assembly 32 by extending into circumferential gaps between dampers 40. Spring retainer 44 may be coupled to a clutch plate 114 which includes a friction surface 112 for engaging a cover 116 of torque converter 110, which connects to an engine crankshaft. Torque converter 110 also includes an impeller or pump 118 opposite turbine assembly 10. In other embodiments, turbine assembly 10 may be used in a torque converter in other arrangements and tab plate 12 may be used to drive a component other than damper assembly 32.

In an alternative embodiment, instead of turbine shell 14 including brazing holes 46, brazing holes may be included in tab plate 12. Braze material 62 may then be melted into the brazing holes in tab plate 12 to permanently connect tab plate 12 to turbine shell 14. In this case, the part may be brazed with the tab plate resting on top of the shell.

In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.

Claims

1. A turbine assembly comprising: a turbine shell; anda tab plate connected to the turbine shell, the turbine shell and the tab plate being brazed together.

2. The turbine assembly as recited in claim 1 further comprising elastic dampers, the tab plate arranged for driving the elastic dampers.

3. The turbine assembly as recited in claim 2 wherein the elastic dampers are arc springs.

4. The turbine assembly as recited in claim 2 further comprising a retainer supporting the elastic dampers.

5. The turbine assembly as recited in claim 1 wherein the turbine shell and tab plate are brazed together by a braze material, the braze material extending between an outer surface of the turbine shell and an inner surface of the tab plate.

6. The turbine assembly as recited in claim 5 wherein the turbine shell includes at least one hole passing therethrough, the braze material surrounding the hole.

7. The turbine assembly as recited in claim 6 further comprising a turbine core ring, the at least one hole being radially outside of the turbine core ring.

8. The turbine assembly as recited in claim 1 further comprising a driven component, the tab plate arranged for circumferentially driving the driven component.

9. A torque converter comprising the turbine assembly as recited in claim 1.

10. A method of forming a turbine assembly impeller comprising: aligning a tab plate with a turbine shell with a braze material therebetween; andbrazing the tab plate and the turbine shell together by melting the braze material.

11. The method as recited in claim 10 wherein the turbine shell includes a hole extending between an inner surface and an outer surface thereof, the brazing including applying the braze material into the hole.

12. The method as recited in claim 11 wherein the brazing further includes heating the braze material such that a capillary action pulls the braze material away from the hole and in between an inner surface of the tab plate and the outer surface of the turbine shell.

13. The method as recited in claim 12 wherein the capillary actions causes the braze material to flow radially outward with respect to an axis of the hole.

14. The method as recited in claim 10 further comprising arranging tabs of the tab plate circumferentially between elastic dampers.

15. The method as recited in claim 14 wherein the elastic dampers are arc springs.

16. The method as recited in claim 15 wherein the arc spring are supported by a spring retainer.

17. The method as recited in claim 10 further comprising brazing the turbine shell and turbine blades together as the tab plate and the turbine shell are brazed together.