Drive assembly with drive tongues attached to the turbine housing and manufacturing process

Abstract

Drive assembly for a torque converter (10), comprising: a turbine housing (22) including a rounded portion (24) and a radially outward projection (28) on an outer periphery of the rounded portion (24); and a driver tongue (42) which is attached to the radially outer projection (28) of the turbine housing (22) by means of an adhesive, which comprises an impeller (18) and wherein the radially outer projection (28) of the turbine housing (22) is designed to engage and disengage the impeller (18), which further comprises a damper (48) driven by the driver tongue (42), wherein the damper (48) includes a spring holder (52) for holding a plurality of springs (50) and the driver tongue (42) is non-rotatably connected to the plurality of springs (50).

Description

[0001] The present disclosure relates to drive assemblies for torque converters and, more particularly, to drive tabs attached to turbine housings of torque converters. BACKGROUND

[0002] Patent specification US 8 257 042 B2 discloses a welded drive plate or power transmission component.

[0003] Further drive assemblies for torque converters are known from the publications DE 11 2011 101 289 T5, KR 10 2013 0 045 719 A, JP 2003 - 21 219 A and DE 101 19 915 A1.

[0004] It is an object of the invention to provide an improved drive assembly for a torque converter, in particular with regard to the attachment of a plate with a spring drive tab to a turbine. SUMMARY OF THE INVENTION

[0005] A drive assembly for a torque converter is provided. The drive assembly includes a turbine housing having a rounded portion and a radially outward projection on an outer periphery of the rounded portion; and a tongue plate adhesively bonded to the radially outward projection of the turbine housing. An impeller is further provided, wherein the radially outward projection of the turbine housing is configured to engage and disengage the impeller. The drive assembly further includes a damper driven by the drive tongue, the damper including a spring retainer for supporting a plurality of springs, and the drive tongue is rotationally connected to the plurality of springs.

[0006] Embodiments of the torque converter may also have one or more of the following advantageous features: The torque converter may further include a friction surface on a side of the radially outer projection opposite the tongue plate, wherein the impeller is driven in and out by the radially outer projection over the friction surface. is disengaged. The friction surface can be attached to the radially outer projection by means of an adhesive. The tongue plate and the friction surface can be attached to the radially outer projection by means of the same adhesive. The turbine housing may be axially displaceable so that the radially outer projection engages and disengages the impeller. The turbine housing may have a radially inner projection on an inner periphery of the rounded portion, with the damper being attached to the radially inner projection. The damper may include a cover plate with a thrust surface that slides along a cover of the torque converter.

[0007] A method for forming a drive assembly for a torque converter is also provided. The method includes attaching a drive tab to a turbine housing using an adhesive and stamping the drive tab from an outer diameter of a damper cover plate. The method further includes providing an abutment surface on the cover plate that slides along a cover of the torque converter, and engaging an impeller through the radial projection.

[0008] Embodiments of the method may also have one or more of the following advantageous features: The method may further include thermally curing the cam follower and cover plate together before attaching the cam follower to the turbine housing. The method may further include non-rotatably connecting the damper to the cam follower. The turbine housing may include a rounded portion and a radially outward projection on an outer periphery of the rounded portion, with the cam follower attached to the radially outward projection. The method may further include attaching a friction material using an adhesive to a side of the radially outward projection opposite the cam follower. The cam follower plate and the friction material may be attached to the radially outward projection using the same adhesive. The method may further include attaching a damper to a radially inward projection of the turbine housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be described with reference to the following drawing, in which: Fig. 1 shows a torque converter incorporating a drive assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0010] Fig.1 shows a torque converter 10 according to an embodiment of the present invention. The torque converter 10 includes a cover 12 having a front portion 14 for connection to a crankshaft of an internal combustion engine and a rear portion 16 for forming a housing 17 of an impeller or pump 18. Both the front portion 14 and the rear portion 16 are substantially cup-shaped and are connected to each other by providing an axial projection of the rear portion 16 radially inward of an axial projection of the front portion 14. The axial projection of the front portion 14 can then be welded to an outer surface of the axial projection of the rear portion 16 by forming a weld 19.

[0011] A turbine 20 is enclosed by a cover 12 and includes a turbine casing 22 having a rounded portion 24 supporting a plurality of turbine blades 26 on a surface of the turbine casing 22 facing the impeller 18. The turbine 20 includes a radially outward projection 28 extending radially outward from an outer periphery of the rounded portion 24 and a radially inward projection 30 extending radially inward from an inner periphery of the rounded portion 24. The impeller casing 17 includes a rounded portion 32 supporting a plurality of impeller blades 34 and a radially outward portion 36 extending radially outward from an outer periphery of the rounded portion 32.

[0012] The turbine 20 is configured to be axially movable toward and away from the impeller 18 to engage and disengage the impeller 18. A friction material 38 is affixed to a surface of the radially outer projection 28 of the turbine housing 22 facing the impeller 18 to form a friction surface on the radially outer projection 28 to engage the radially outer portion 36 of the aft portion 16. A force generated by hydraulic pressure in a hydraulic pressure region 40 can urge the turbine housing 22 toward the impeller 18 such that the friction material 38 engages the radially outer portion 36 and the turbine 20 rotates together with the impeller 18 and the cover 12 at the same speed about axis A.

[0013] On a surface of the outboard projection 28 opposite the friction material 38, a drive tongue 42 is attached to the radially outboard projection 28. According to a preferred embodiment, both the friction material 38 and the drive tongue 42 are attached to the radially outboard projection 28 with the same adhesive, which may be, for example, a thermosetting phenolic resin such as Arofene 295-E-50 or MACtac IF-4023A. The drive tongue 42 includes a radial portion 44 for flush attachment to the radially outboard projection 28 and an axial projection 46 for driving a damper 48. More specifically, the drive tongue 42 drives a plurality of radially outboard arc springs 50 of the damper 48, which are supported by a spring retainer 52. Within the projection 46, free spaces are formed on its circumference in order to accommodate arc springs 50 over its circumference.The spring retainer 52 includes a rounded portion extending around an outer periphery of the arc springs 50 and a radially extending portion extending from the rounded portion toward axis A to form a first cover plate 54 which, together with a second cover plate 56, supports inboard arc springs 50 of the damper 48. The first cover plate 54 is secured by rivets 58 to the radially inboard projection 30 of the turbine housing 22 and a retaining flange 57. The radially inboard projection 30 is slidable along an outer surface of a stop 59 against which the retaining flange 57 abuts to limit movement of the radially inboard projection 30 away from the impeller 18. The damper 48 also includes a damper hub 51 between the cover plates 54, 56 for transmitting torque from the damper 48 to a subsequent drive component such as a continuously variable transmission.When the turbine 20 is driven by the impeller 18, either by coupling via the contact between the friction material 38 and the impeller shell 17 or by the fluid flowing between the blades 24, 34, the turbine 20 transmits torque to the damper 48 via the drive tongue 42, which in turn transmits torque to the downstream drive component via the damper hub 51.

[0014] The second cover plate 56 includes a contact surface 60 formed by a low-friction material provided on a surface of the cover plate 56 near the front portion 14 of the cover 12. To limit or prevent wear of the contact surface 60, this portion of the cover plate 56 is modified to have a low coefficient of friction, so that the contact surface 60 slides along the inner surface of the front portion 14 of the cover 12. The contact surface 60 can, for example, consist of a Teflon coating, a layer of low-friction material, a plastic disc, or be formed as a bearing. The contact surface 60 allows the cover plate 56 to slide along the front portion 14 of the cover when the damper 48 is caused to rotate about axis A by the turbine 20.

[0015] According to a preferred embodiment of the present invention, the driver tab 42 and the cover plate 56 are cut from the same sheet metal. In particular, the driver tab 42 may be cut from a radially outer end 62 of the cover plate 56 to define an end 64 of the axial portion 46 of the driver tab 42 and then further machined to form clearances for receiving the arc springs 50 along the circumference. The driver tab 42 is then bent to form the radial portion 44 and the axial portion 46 and then subjected to a heat treatment together with the cover plate 56 to harden the driver tab 42 and the cover plate 56. After hardening, the driver tab 42 may be attached to the turbine housing 22 using an adhesive.Unlike other designs in which drive tabs or plates are first bonded to a turbine housing by inserting the tabs of a drive tab or plate into slots in the turbine housing and brazing them to the turbine housing, the drive tab 42 is bonded to the turbine housing 22 using an adhesive at a lower temperature than brazing. Due to the lower temperature involved in bonding using an adhesive, the drive tab 42 can be pre-cured prior to bonding. This means that since the part must be heated to a high temperature during brazing, a pre-cured part would soften again in the brazing furnace. In contrast, although a thermosetting adhesive can be used to bond the drive tab to the turbine housing, the bonding temperature is low enough that the hardness of a pre-cured part is not affected by the bonding process.

Claims

[1] Drive assembly for a torque converter (10), comprising: a turbine housing (22) including a rounded portion (24) and a radially outward projection (28) on an outer periphery of the rounded portion (24); and a driver tongue (42) which is attached to the radially outer projection (28) of the turbine housing (22) by means of an adhesive, which comprises an impeller (18) and wherein the radially outer projection (28) of the turbine housing (22) is designed to engage and disengage the impeller (18), which further comprises a damper (48) driven by the driver tongue (42), wherein the damper (48) includes a spring holder (52) for holding a plurality of springs (50) and the driver tongue (42) is non-rotatably connected to the plurality of springs (50). [2] The drive assembly of claim 1, further comprising a friction surface on a side of the radially outer projection (28) opposite the drive tongue (42), the radially outer projection (28) engaging and disengaging the impeller (18) through the friction surface. [3] Drive assembly according to claim 2, wherein the friction surface is attached to the radially outer projection (28) by an adhesive. [4] Drive assembly according to claim 3, wherein the driver tongue (42) and the friction surface are attached to the radially outer projection (28) by means of the same adhesive. [5] Drive assembly according to claim 1, wherein the turbine housing (22) is axially displaceable so that the radially outer projection (28) engages and disengages the impeller (18). [6] The drive assembly of claim 1, wherein the damper (48) includes a cover plate (54) having a contact surface (60) that slides along an inner surface of a cover (12) of the torque converter (10). [7] A method of forming a drive assembly for a torque converter (10), comprising: Attaching a driver tongue (42) to a turbine housing (22) by means of an adhesive, Punching the driver tongue (42) from an outer diameter of a cover plate (54) of a damper (48), Providing a pressure surface (60) on the cover plate (54) which slides along a cover (12) of the torque converter (10), wherein the turbine housing (22) includes a rounded part (24) and a radially outer projection (28) on an outer circumference of the rounded part (24), and the driving tongue (42) is attached to the radially outer projection (28), the coupling of an impeller (18) of the torque converter (10) with the radial projection (28). [8] The method of claim 7, further comprising thermally treating the driver tongue (42) and the cover plate (54) prior to attaching the driver tongue (42) to the turbine housing (22). [9] The method of claim 7, further comprising non-rotatably connecting the damper (48) to the driver tongue (42). [10] The method of claim 7, further comprising securing a friction material (38) to a side of the radially outer projection (28) opposite the drive tongue (42) by an adhesive. [11] The method of claim 10, wherein the driver tongue (42) and the friction material (38) are secured to the radially outer projection (28) by the same adhesive.

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