Stamped turbine hub with centering tabs for a torque converter

Abstract

Torque converter (10') comprising: a turbine with a turbine hub (32); a cover plate (14) attached to the turbine hub (32); a damper assembly including a damper flange (38) with an axially extending bushing portion (40) having an inner surface with a spline (42) or gear ring for engaging the input shaft of a transmission; a spring (16) arranged between the cover plate (14) and the damper flange (38); wherein the turbine hub (32) includes axially projecting tabs (44) in contact with an outer surface of the bushing part (40) to center the turbine hub (32) with respect to the bushing part (40), wherein the turbine hub (32) includes a radially inwardly extending portion (46) at least partially overlapping an axial end of the bushing part (40), and wherein the turbine hub (32) is a stamped sheet metal part that is connected to the turbine.

Description

[0001] The present invention relates to torque converters and, more particularly, to a turbine assembly for a torque converter.

[0002] Hydraulic torque converters, which are used in conjunction with internal combustion engines to transfer torque from the engine to a transmission, are known in the art.

[0003] Torque converters of the general type to which the present invention is applicable are shown in U.S. Patent No. 6,142,272 or U.S. Patent Application 2012 / 0266589, both assigned to the assignee of the present invention. In such torque converters, the converter housing is typically connected to the internal combustion engine for receiving torque and includes a pump having vanes on an inner surface thereof that can be hydraulically coupled to turbine vanes connected to an associated turbine disposed within the torque converter. The turbine is supported by a turbine hub, which may be an integral part of the turbine or a separately connected turbine hub, typically centered around the input shaft for the transmission.The turbine hub is connected to the drive shaft by a damper assembly including a damper flange having a bushing portion with an internal gear or spline for engaging the drive shaft. In US patent application 2012 / 0266589, the turbine hub is centered by seating on the bushing portion of the damper flange, and torque is transmitted from the turbine to the damper flange via damper springs disposed between a cover plate connected to the turbine hub and the damper flange. A bypass assembly may also be provided for directly transmitting torque to the damper flange through additional damper springs. In such arrangements, a stator is also typically disposed between the pump and turbine blades.

[0004] Other known torque converters are disclosed in the documents DE 10 2008 020 684 A1 and DE 10 2008 056 636 A1.

[0005] The Fig. 1 and Fig. 2 shows an enlarged view of a prior art torque converter 10 with the turbine hub 12, which is preferably connected to a turbine body 13 by fasteners 26 such as rivets. The turbine hub 12 is centered by sitting on the bushing portion 20 of the damper flange 18. Blades 15 are connected to the turbine body 13. In this case, the torque is transmitted from the turbine 13 via its hub 12 to a cover plate 14 connected to the turbine hub 12 and via a spring 16 of the damper assembly to the damper flange 18. In this case, to transmit axial loads from the turbine hub 12 to the damper flange 18, a bead or stop 24, shown, is required on the bushing portion 20, against which the turbine hub presses. However, this bead or stop 24 is usually formed by a die-stamping step, which increases the complexity of the manufacturing process.

[0006] Other arrangements for guiding and transmitting an axial load to the damper flange require additional stamped components or another feature in the damper flange. In the illustrated arrangement, the axial load contact surface of the hub 12 against the damper flange 18, as well as the receiving portion of the damper flange 18, generally require machining after the damper flange is formed due to tolerances and geometry. Additionally, stamping the stop 24 onto the bushing portion 20 of the damper flange has been found to adversely affect the inner diameter of the bushing portion, which is typically formed as an extruded bead during the stamping process for the damper flange 18.

[0007] Accordingly, the disadvantages of many of these known arrangements include more complex assembly and higher costs. Given further optimization efforts, it would also be desirable to achieve lower weight and fewer components, as well as simpler assembly of the torque converter.

[0008] It is the object of the present invention to provide a torque converter in which the aforementioned disadvantages are at least partially eliminated.

[0009] A torque converter is provided that includes a turbine with a turbine hub. A cover plate is attached to the turbine hub. Also provided is a damper assembly that includes a damper flange with an axially extending bushing portion having a geared or splined inner surface adapted to engage the transmission input shaft. A spring is disposed between the cover plate and the damper flange for transmitting torque from the turbine hub through the damper flange to the transmission input shaft. The turbine hub includes axially projecting tabs that contact an outer surface of the bushing portion to center the turbine hub with respect to the bushing portion. The turbine hub also includes a radially inwardly extending portion that at least partially overlaps an axial end of the bushing portion.

[0010] In another aspect, the radially inwardly extending portion includes a ring in contact with the axial end of the surface of the bushing portion to transfer axial loads from the turbine to the damper flange.

[0011] The turbine hub may be an integral part of the turbine or may be formed separately from the turbine hub, which is connected to the turbine body, for example, by fasteners, welding or soldering.

[0012] The turbine hub is a stamped sheet metal part. Furthermore, the tabs are preferably formed during the stamping process and extend axially from the turbine hub to at least partially surround the bushing portion of the damper flange, thereby centering the turbine relative to the damper.

[0013] Preferably, a clearance fit is provided between the radial inner surface of the axially projecting tongues and the outer surface of the bushing part.

[0014] According to a preferred embodiment, the radially inwardly extending part transfers axial loads arising during operation of the torque converter from the turbine to the damper flange.

[0015] A turbine assembly for a torque converter is also provided.

[0016] The above summary and the following detailed description will be better understood in conjunction with the accompanying drawings, which illustrate a preferred embodiment of the invention. In the drawings: Fig. 1 is a cross-sectional view of a portion of the torque converter according to a prior art. Fig. 2 an enlarged view of the turbine hub and the damper flange for the Fig. 1 shown torque converter according to the state of the art. Fig. 3 one of the Fig. 2 similar cross-sectional view showing the turbine hub and damper flange according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Certain terms used in the following description are for convenience only and are not to be construed as limiting. The terms "front", "rear", "upper", and "lower" refer to directions referred to in the drawings. The terms "inward" and "outward" refer to directions toward and away from the parts indicated in the drawings. The term "axial" refers to a direction along the axis of a shaft. When reference is made to a list of objects designated by "a, b, and / or c" (where a, b, and c represent the listed objects), this reference means each of objects a, b, or c, or combinations thereof. The terms used include the terms expressly stated above, derivatives thereof, and terms of similar import.

[0018] In the Fig. 1 and Fig. Figure 2 shows a cross-sectional view of a portion of a prior art torque converter 10. Shown is the turbine hub 12, which is connected to a turbine body 13 by fasteners 26. Likewise, the turbine blades 15 are preferably connected to the turbine body by brazing. The cover plate 14 is attached to the turbine hub 12 and transmits torque via springs 16 of the damper assembly to the damper flange 18. While the turbine hub 12 is shown as a separate piece connected to the turbine body, it will be apparent to those skilled in the art that the turbine hub 12 may be formed as an integral part of the turbine body. The damper flange 18 includes a bushing portion 20 having a ring gear or spline 22 on its inner surface for transmitting torque to the input shaft of the transmission (not shown).The figure illustrates only a partial view of the torque converter, with the axis of the drive shaft being designated by the reference number 26.

[0019] Fig. 3 shows one of the Fig. 2 similar partial view with the turbine hub 32 according to the invention for a torque converter 10', which is otherwise similar to the torque converter 10. The turbine hub 32 is also mounted either on a turbine body (reference number 13 in Fig. 1) to receive torque via a hydraulic coupling from the converter pump, which is attached to the torque converter housing. Also shown is the damper assembly portion with the damper flange 38 according to the invention, which includes the bushing portion 40 with a ring gear or spline 42 for engaging the transmission input shaft. In contrast to the prior art, the turbine hub 32 now includes axially projecting tabs 44 that contact an outer surface of the bushing portion 40 of the damper flange 38 to center the turbine hub 32 with respect to the bushing portion 40. Further, the turbine hub 32 includes a radially inwardly extending portion 46 that at least partially overlaps an axial end of the bushing portion 40.Preferably, these tongues 44 are stamped or cut out of the turbine hub 32, which itself is made of stamped sheet metal, and may be formed simultaneously with the formation of the turbine hub 32. According to a preferred embodiment, a plurality of equidistant tongues 44 are provided. For example, four tongues 44 may be provided, distributed equidistantly across the outer surface of the bushing part 40. Depending on the application, more or fewer tongues 44 may be provided.

[0020] The radially inwardly extending portion 46 of the turbine hub 32 is preferably in the form of a complete ring that contacts the axial end of the bushing portion 40 to transfer axial loads from the turbine to the damper flange 38. Alternatively, the axially inwardly extending portion 46 may be a series of segments separated by gaps at the locations of the tabs 44.

[0021] Preferably, there is a clearance fit between the radially inner surfaces of the axially projecting tongues 44 and the outer surface of the bushing part 40. This clearance fit generally has a clearance in the range of 0.3 to 0.6 mm, but may vary depending on manufacturing tolerances. These tolerances can be achieved during stamping of the turbine hub 32, thus eliminating the need for further machining.

[0022] Likewise, the bushing portion 40 of the damper flange 38 is preferably a stamped / extruded component, wherein the bushing portion is formed by stamping and extruding the damper flange from sheet metal during manufacture. The axial end surface of the bushing portion 40 that contacts the radially inwardly extending portion 46 of the turbine hub 32 is finished according to the typical manufacturing process, but does not require further machining, such as by swaging as in the prior art arrangement to form the Fig. 1 and Fig. 2 shown stop 24.

[0023] This design offers advantages by eliminating the need for an additional plate for pressing or guiding and / or eliminating additional manufacturing steps required after forming the flange due to tolerances and geometry. Furthermore, since no stamping step is required to form the stop 24, the adverse effects of this process step are also eliminated.

Claims

[1] Torque converter (10') comprising: a turbine with a turbine hub (32); a cover plate (14) attached to the turbine hub (32); a damper assembly including a damper flange (38) with an axially extending bushing portion (40) having an inner surface with a spline (42) or gear ring for engaging the input shaft of a transmission; a spring (16) arranged between the cover plate (14) and the damper flange (38); wherein the turbine hub (32) includes axially projecting tabs (44) in contact with an outer surface of the bushing part (40) to center the turbine hub (32) with respect to the bushing part (40), wherein the turbine hub (32) includes a radially inwardly extending portion (46) at least partially overlapping an axial end of the bushing part (40), and wherein the turbine hub (32) is a stamped sheet metal part that is connected to the turbine. [2] The torque converter (10') of claim 1, wherein the radially inwardly extending portion (46) comprises a ring in contact with the axial end surface of the sleeve portion (40). [3] Torque converter (10') according to claim 1, wherein there is a clearance fit between radially inner surfaces of the axially projecting tongues (44) and the outer surface of the bushing part (40). [4] The torque converter (10') of claim 1, wherein the radially inwardly extending portion (46) serves to transfer axial loads from the turbine to the damper flange (38). [5] Turbine assembly for a torque converter (10'), comprising: a turbine body (13); turbine blades (15) connected to the turbine body (13); a turbine hub (32) connected to the turbine body (13), the turbine hub (32) including axially projecting tongues (44) in contact with an outer surface of a bushing part (40) of a damper flange (38), to center the turbine hub (32) with respect to the bushing part (40), the turbine hub (32) including a radially inwardly extending part, which at least partially overlaps an axial end of the socket part (40), and wherein the turbine hub (32) is a separately stamped sheet metal part that is connected to the turbine body (13). [6] The turbine assembly of claim 5, wherein the inwardly extending portion (46) comprises a ring. [7] Turbine assembly according to claim 5, wherein the turbine body (13) is connected to the turbine hub (32) by fasteners, brazing and / or welding.

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