Cover plate sealed against a stator assembly

Abstract

Torque converter 10 for the powertrain of a motor vehicle, wherein the torque converter 10 comprises: a damper 12 comprising a first cover plate 42 and a drive flange 48; and a stator assembly 28, wherein the first cover plate 42 is rotatable at a sealed interface 102 with sealing against the stator assembly 28, the first cover plate 42 and the drive flange 48 form a flow gap 92 between them, a fluid flows through the flow gap 92 during operation of the torque converter 10 and the sealed interface 102 prevents the fluid from flowing through it, wherein the first cover plate 42 has an axially extending section 45 and one end of the axially extending section 45 forms the interface 102 sealed towards the stator assembly 28, wherein a radially inner surface 108 has a variable diameter, wherein the radially inner surface 108 has a plurality of projections 98 which abut the drive flange 48 and grooves 99, wherein each of the grooves 99 is formed between two of the projections 98 and the grooves 99 define channels which form the flow gap 92.

Description

[0001] The present disclosure relates generally to torque converters and, more particularly, to dampers and stator assemblies of torque converters. BACKGROUND OF THE INVENTION

[0002] US Patent No. 6,217,476 and US Patent Application 2013 / 056319 show turbine hubs sealed against stator shafts, and US Patent No. 7,926,635 B2 shows an inner race sealed against a stator shaft and a turbine hub. Publications DE 10 2004 024 004 A1, WO 2008 / 043331 A1, and DE 103 62 279 C5 show other prior art hydrodynamic torque converters.

[0003] The object of the invention is to further improve the known torque converters. SUMMARY OF THE INVENTION

[0004] A torque converter for the drivetrain of a motor vehicle is provided. The torque converter includes a damper having a first cover plate and a drive flange; and a stator assembly. The first cover plate is rotatable relative to the stator assembly at a sealed interface, and the first cover plate and the drive flange form a fluid gap therebetween. During operation of the torque converter, fluid flows through the flow gap. The sealed interface prevents the fluid from flowing therethrough.

[0005] A method for forming a torque converter is also provided. The method includes forming a first cover plate for a damper, a drive flange for a damper, and a stator assembly; and connecting the first cover plate, the drive flange, and the stator assembly together within the torque converter such that the first cover plate and the drive flange define a flow gap therebetween and the first cover plate and the stator assembly form a sealed interface that prevents fluid from flowing therethrough. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present invention will now be described with reference to the following drawings, in which: Fig. 1 shows a torque converter incorporating a damper according to an embodiment of the present invention; Fig. 2 schematically shows arrows indicating the flow of a cooling liquid through the Fig. 1 illustrate the torque converter shown; Fig. 3 a section of a cover plate and a drive flange 48 from the Fig. 1 and Fig. 2 shows the torque converter; and the Fig. 4a and Fig. 4b shows a method for forming a collar of an axially extending portion of the cover sheet. DETAILED DESCRIPTION

[0007] The present disclosure provides a method for manufacturing a cover plate that seals a stator shaft and allows fluid flow between the cover plate and a flange. This avoids complex hub designs with intersecting fluid paths.

[0008] Fig. 1 shows a torque converter 10 incorporating a damper 12 according to an embodiment of the present invention. The torque converter 10 includes a front cover 14 for connection to the crankshaft of a motor vehicle engine and a rear cover 16 forming a housing 18 for an impeller 20. The front cover 14 and the rear cover 16 are substantially cup-shaped and are connected to each other by providing an axial extension 22 of the rear cover 16 radially inward of an axial extension 25 of the front cover 14. The torque converter 10 also includes a turbine 26 opposite the impeller 20 and a stator assembly 28 disposed between the impeller 20 and the turbine 26. A damper 12 is disposed between the front cover 14 and the turbine 26 for transmitting torque from the turbine 26 to a shaft 38, which may be connected to a drive component such as a continuously variable transmission.The damper 12 includes damping components in the form of a radially inner set of springs 30, a radially outer set of springs 32, and a centrifugal damper 34. A lock-up clutch 40 is provided between the damper 12 and the front cover 14 to non-rotatably connect the turbine 26 and the impeller 20 via the damper 12 when the impeller 20 and the turbine 26 are at the same speed. When the turbine 26 is driven either by the engaged lock-up clutch 40 or by the fluid flow between the blades of the turbine 26 and the blades of the impeller 20, the turbine 26 transmits torque to the damper 12.

[0009] The lock-up clutch 40 includes a clutch disc 31 that circumferentially engages a disc 33 that circumferentially engages arc springs 32. A piston plate 35, provided axially within the front cover 14, is axially slidable toward and away from the front cover 14 to engage a friction surface on a first side of a clutch disc 31 and to press another friction surface of the clutch disc 31 on a second side of the clutch disc 31 opposite the first side against a clutch support disc 37. The clutch support disc 37 may be connected to the front cover 12 by a connecting element 39 rigidly attached to the front cover 14.The piston plate 35 is elastically connected to the front cover 14 by a leaf spring which extends axially between the front cover 14 and the piston plate 35 and causes the piston plate 35 to be radially fixed with respect to the front cover 14 but axially displaceable to engage the clutch disc 31.

[0010] The damper 12 includes a first cover plate 42 and a second cover plate 44, which support and circumferentially drive springs 30 during operation of the torque converter 10. The first cover plate 42 and the second cover plate 44 are riveted together to support the springs 30. The first cover plate 42 is also connected, in this example by a rivet 46, to the turbine 26 and is circumferentially driven by the turbine 26. The damper 12 also includes a drive flange 48 sandwiched between the cover plates 42, 44 for receiving torque transmitted from the turbine 26 to the cover plate 42 via the springs 30. The drive flange 48, in turn, transmits the torque to the shaft 38.The cover plate 42 has a radially extending portion 43 that extends radially outward from the shaft 38 beyond the springs 30, and an axially extending portion 45 that extends axially from a radially inner end of the radially extending portion 43. Likewise, the drive flange 48 has a radially extending portion 48 that extends radially outward from the shaft 38 beyond the springs 30, and an axially extending portion 49 that extends axially from a radially inner end of the radially extending portion 47. The axially extending portion 49 is toothed with the tooth profile of the shaft 38.

[0011] The stator assembly 28 includes a stator housing 50, a one-way clutch 52 supporting the stator housing 50, and a non-rotatable stator shaft 54. A radially outer surface of the stator shaft 54 ​​sealingly engages the impeller hub 55, which is rotatable relative to the stator shaft 54. The one-way clutch 52 includes an inner race 56 splined to the stator shaft 54, a rolling element 58, and an outer race 60. The stator shaft 54, the rolling element 58, and the outer race 60 are axially held in position between the retaining plate 62 and a stator hub 64. A radially inner surface of the inner race 56 sealingly engages a radially outer surface of an axial portion 45 of the flange 48.

[0012] Fig. 2 schematically shows arrows illustrating the flow path of a cooling fluid through the torque converter 10. The flow path of the cooling fluid begins in the region 70 between the stator shaft 54 ​​and the impeller hub 55, continues along a surface of the inner race 56 facing the impeller 20, and through a region 72 between the stator wheel 50 and the impeller 20. The cooling fluid then flows through a region 74 between the impeller 20 and the turbine 26 to a region 76 radially outside the turbine 26. The cooling fluid then flows radially outside the damper 12 to a region 78, more precisely, around the centrifugal damper 34 and then the arc springs 32. After flowing around the arc springs 32, the fluid enters a region 80 radially outside the lock-up clutch 40, passes through the lock-up clutch 40 and reaches a region 82 between the arc springs 30 and the front cover 14.To allow fluid to flow through the lock-up clutch 40, the connecting element 39 has a hole, slot, or gap to a portion of the support plate 37, and friction rings on the clutch plate 31 have flow grooves. The fluid then flows radially through a first flow gap 90 (Fig. Fig. 3) inwards, which is formed between the radially extending section 43 of the cover plate 42 and the radially extending section 47 of the drive flange 48, further axially to the stator shaft 54 ​​through a second flow gap 92 ( Fig. 3), which is formed between the axially extending portion 45 of the cover plate 42 and the axially extending portion 49 of the drive flange 48, up to a region 84.

[0013] Fig. 3 shows an enlarged section of the cover plate 42 and the drive flange 48 in the Fig. 1 and Fig. 2. As mentioned above, a radially extending gap 90 is formed between the radially extending portion 43 of the cover plate 42 and the radially extending portion 48 of the drive flange 48, and an axially extending gap 92 is formed between the axially extending portion 45 of the cover plate 42 and the axially extending portion 49 of the drive flange 48. In order to space the radially extending portion 43 a sufficient distance from the radially extending portion 47 to form the gap 90, the radially extending portion 43 is provided with a plurality of axially extending projections 94 extending axially from a wall 96 and circumferentially spaced from one another to allow fluid to flow radially along the radially extending portion 47 between the projections 94.In order to space the axially extending portion 45 a sufficient distance from the axially extending portion 49 to form the gap 92, the axially extending portion 47 is provided with a plurality of radially extending grooves 99 spaced circumferentially apart to allow fluid to flow axially between projections 98 along the axially extending portion 49. To prevent fluid from flowing between the stator assembly 28 and the cover plate 42 from the region 84 to the region 100, the cover plate 42 fits snugly against the stator assembly 28 to form a sealed interface 102. Accordingly, the fluid flow contacts the sealed interface 102 after passing through the flow gap 92.More specifically, a radially outer surface 104 of the collar 105 at the end of the axially extending portion 45 abuts a radially inner surface 106 of the inner race 56 to form the sealed interface 102. The first cover plate 42 is rotatable relative to the stator assembly 28 while sealing at the interface 102. Thanks to the sealed interface 102, a pressure differential can be advantageously created so that the cooling fluid does not seep past the inner race 56 through a flow path with lower flow resistance, but flows through the clutch 40.

[0014] The Fig. 4a and Fig. 4b show a method for forming the collar 105 of the axially extending portion 45 of the cover plate 42. Fig. Figure 4a shows the axially extending portion 45, which has a uniform thickness. The axially extending portion 45 is shaped to include radial projections 98 projecting from a radially inner surface 108 thereof with respect to grooves 99, and similarly shaped radially extending projections 110 projecting from a radially outer surface 112 thereof. Accordingly, Fig. 4a, that the axially extending portion 45 has a radially inner surface 108 with a variable diameter and a radially outer surface 112 with a variable diameter. Fig. Figure 4b shows the axially extending portion 45 after the end of the axially extending portion 45 has been modified to form the collar 105. The radially extending projections 110 on the outer surface 112 have been machined or coined to form an outer cylindrical surface 104 and thus form the interface 102 sealed against the radially inner surface 106 of the inner race 56. Accordingly, Fig. 4b, that the axially extending portion 45 has the radially inner surface 108 with a variable diameter and the radially outer surface 104 with a constant diameter, since the grooves 99 and the projections 98 have been removed from the radially outer surface by the machining. Fig.Figure 4b schematically shows that the projections 108 may abut the outer surface 101 of the axially extending portion 49 of the drive flange 48 to form a plurality of axially extending channels 114 defining the flow gap 92.

Claims

[1] Torque converter 10 for the drive train of a motor vehicle, the torque converter 10 comprising: a damper 12 including a first cover plate 42 and a drive flange 48; and a stator assembly 28, wherein the first cover plate 42 is rotatable at a sealed interface 102 while being sealed against the stator assembly 28, the first cover plate 42 and the drive flange 48 form a flow gap 92 between them, a fluid flows through the flow gap 92 during operation of the torque converter 10 and the sealed interface 102 prevents the fluid from flowing through it, wherein the first cover plate 42 has an axially extending portion 45 and one end of the axially extending portion 45 forms the interface 102 sealed towards the stator assembly 28, wherein a radially inner surface 108 has a variable diameter, wherein the radially inner surface 108 has a plurality of projections 98 abutting the drive flange 48 and grooves 99, each of the grooves 99 being formed between two of the projections 98 and the grooves 99 defining channels that form the flow gap 92. [2] The torque converter 10 of claim 1, wherein the radially inner surface 108 of the axially extending portion 45 is shaped to define the flow gap 92 toward the drive flange 48. [3] The torque converter 10 of claim 1, further comprising a turbine 26 and an impeller 20, wherein the stator assembly 28 is disposed between the turbine 26 and the impeller 20. [4] The torque converter 10 of claim 3 further comprising a lock-up clutch 40, wherein the fluid flows along a path from the space between the turbine 26 and the impeller 20, around the damper 12, through the lock-up clutch 40 and into the flow gap 92. [5] The torque converter 10 of claim 1, wherein the damper 12 further includes a second cover plate 44 and a plurality of springs 30, the first cover plate 42 and the second cover plate 44 supporting the springs 30 between both holders, and the drive flange 48 is disposed between the first cover plate 42 and the second cover plate 44 and drives the springs 30. [6] A method of forming a torque converter 10 for a motor vehicle, the method comprising: Forming a first cover plate 42 for a damper 12, a drive flange 48 for the damper 12 and a stator assembly 28 and Connecting the first cover plate 42, the drive flange 48 and the stator assembly 28 in the torque converter 10 such that the first cover plate 42 and the drive flange 48 form a flow gap 92 between them and the first cover plate 42 and the stator assembly 28 form a sealed interface 102 that prevents fluid from flowing therethrough, wherein forming the first cover sheet 42 includes: Forming the first cover plate 42 such that it has a radially extending portion 43 and an axially extending portion 45 extending from one end of the radially extending portion 43, wherein the axially extending portion 45 has a radially inner surface 108 with a variable diameter and a radially outer surface 112 with a variable diameter; machining the radially outer surface 112 such that the radially outer surface 104 has a constant diameter, wherein the radially outer surface 112 having the variable diameter has a plurality of axially extending grooves 99 and radial projections 98, each of the grooves 99 being arranged between two of the projections 98, and the machining removes the grooves 99 and projections 98 from the radially outer surface 112. [7] The method of claim 6, wherein forming the first cover plate 42 includes providing grooves 99 on a radially inner surface 108 of an axial extension 45 of the first cover plate 42, and the grooves 99 define the flow path toward the drive flange 48. [8] The method of claim 6, wherein forming the first cover plate 42 includes providing a radially outer surface 104 of an axial extension 45 of the first cover plate 42 having a constant diameter, the radially outer surface 104 defining the sealed interface 102 toward the stator assembly 28. [9] The method of claim 6, wherein the axially extending portion 45 has a constant thickness before machining and the axially extending portion 45 has a variable thickness after machining. [10] The method of claim 6, wherein joining the first cover plate 42, the drive flange 48, and the stator assembly 28 together in the torque converter 10 includes: Inserting the drive flange 48 and a plurality of springs 30 which are circumferentially spaced apart from one another within the drive flange 48 between the first cover plate 42 and a second cover plate 44, Riveting the first cover plate 42 and the second cover plate 44 together, and Sliding an inner race of the stator assembly 28 onto an axially extending portion 45 of the first cover plate 42 to form the sealed interface 102. [11] The method of claim 6, wherein after joining the first cover plate 42, the drive flange 48 and the stator assembly 28 together in the torque converter 10, a fluid flow is formed which extends from the space between a turbine 26 and a torque impeller 26, around the damper 12, through a lock-up clutch 40 of the torque converter 10 and into the flow gap 92. [12] The method of claim 11, wherein the liquid in the liquid flow path comes into contact with the sealed interface 102 after passing through the liquid flow gap 92.

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