Stator for torque converter with indentation

Abstract

Stator (82) for a torque converter (10), wherein the stator (82) comprises: a large number of shovels (86); a freewheel clutch (90); and a stator base body (88) for holding the blades (86), wherein the stator base body (88) accommodates the freewheel coupling (90) and the stator base body (88) has an indentation (132) radially outside the freewheel coupling (90) inside, wherein the stator base body (88) includes a radially outer, axially projecting ring (134) defining an outer circumferential surface (102) of the stator base body (88), and a radially inner, axially projecting ring (136) defining a circumferential surface (128) of a recess (112) in the stator base body (88), wherein the recess (112) accommodates the freewheel coupling (90) of the stator (82), the radially outer, axially projecting ring (134) and the radially inner, The axially protruding ring (136) defines the indentation (132) and the indentation (132) defines an annular groove (130) that surrounds the recess (112), wherein the radially inner, axially projecting ring (136) contains a plurality of notches (148) formed therein, which extend axially into the radially inner, axially projecting ring (136) on a radially extending surface (114) of the radially inner, axially projecting ring (136).

Description

[0001] The present disclosure relates generally to torque converters and, more particularly, to stators for torque converters. BACKGROUND OF THE INVENTION

[0002] Torque converter stators are often designed so that an outer race of a one-way clutch can slide axially within the stator body. Alternatively, a retractable outer race is disclosed in U.S. Patent No. 5,855,263.

[0003] The publications DE 11 2005 000 530 T5, DE 10 2013 213 183 A1, DE 11 2011 101 289 T5, DE 26 57 306 A1 and US 2013 / 0 126 290 A1 show stators of torque converters, wherein the stator comprises a plurality of blades, a one-way clutch and a base body for holding the blades, wherein the base body accommodates the one-way clutch and the base body contains an indentation in the interior radially outside the one-way clutch.

[0004] The object of the invention is to provide an improved stator of a torque converter. SUMMARY OF THE INVENTION

[0005] A stator for a torque converter is provided. The stator includes a plurality of blades, a one-way clutch, and a base body for supporting the blades. The base body receives the one-way clutch and includes an internally formed recess disposed radially outward of the one-way clutch. The base body includes a radially outer, axially projecting ring defining an outer peripheral surface of the base body and a radially inner, axially projecting ring defining a peripheral surface of a recess in the base body, the recess receiving the one-way clutch of the stator, the radially outer, axially projecting ring and the radially inner, axially projecting ring defining the recess, and the recess defining an annular groove surrounding the recess.In addition, the radially inner, axially projecting ring includes a plurality of notches formed therein that extend axially into the radially inner, axially projecting ring on a radially extending surface of the radially inner, axially projecting ring.

[0006] A torque converter is also provided. The torque converter includes a turbine, an impeller, and a stator axially between the turbine and the impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will now be described with reference to the following drawings, in which: Fig. 1 schematically shows a side cross-sectional view of a torque converter according to an embodiment of the present invention; Fig. 2 an enlarged side cross-sectional view of a stator of the Fig. 1 shown torque converter, which is compared to the view of the Fig. 1 shown stator is offset in the circumferential direction; and Fig. 3 schematically shows a perspective view of the stator. DETAILED DESCRIPTION

[0008] The disclosure provides a stator that minimizes deflection of an outer rim and a boss of the stator when an outer race is press-fitted into a stator by forming a recess in the base body of the stator casting in the area radially outside the outer race. By forming a recess, the design also reduces the weight and inertia of the torque converter.

[0009] Fig. 1 shows a side cross-sectional view of a torque converter 10 according to an embodiment of the present invention. The torque converter 10 includes a front cover 12 for connection to a crankshaft of an internal combustion engine and a rear cover 14 forming a housing 16 for an impeller or pump 18. The torque converter 10 also includes a turbine 20 formed as a piston to allow the turbine 20 to be axially displaceable toward and away from the impeller 18 to engage and disengage the impeller 18 and thus form a lock-up clutch. The turbine 20 includes a turbine housing 22 and an inner ring 24 for supporting a plurality of turbine blades 26 therebetween. The turbine housing 22 includes a rounded turbine support portion 28 for supporting the turbine blades 26 on a side of the blades 26 facing the front cover.Radially outward of the blade support portion 28, the turbine casing 22 includes a radial extension 30 that projects radially outward from an outer periphery of the blade support portion 28. Radially inward of the blade support portion 28, the turbine casing 22 includes a radial extension 31 connected at a radially inner end thereof to an axially extending inner peripheral portion 33, the inner peripheral surface of which is in contact with an outer peripheral surface of a hub 35. The impeller casing 16 includes a rounded blade support portion 32 that, together with a center ring 29, supports a plurality of impeller blades 34. Radially outward of the blade support portion 32, the impeller casing 16 includes a radially extending wall 36 that projects radially outward from an outer periphery of the rounded blade support portion 32.

[0010] A friction material 40 is bonded to a surface of the radially outer extension 30 to engage the radially extending wall 36. According to other embodiments, the friction material may be bonded to the radially extending wall 36 instead of to the radially outer extension 30 or in addition to it. A damper assembly 42 is disposed between the front cover 12 and the turbine 20 and is configured to transmit torque from the turbine 20 to the input shaft of a transmission. The damper assembly 42 includes two discs—a first turbine-facing disc 44 riveted to the turbine 20 by rivets 46, and a second or front-cover-facing disc 48 connected to a hub 50 having an internal tooth profile 52 for connection to the input shaft of a transmission.

[0011] A first disc 44 includes a flat, annular main portion 54 provided with holes 56 extending axially therethrough for receiving rivets 46. Radially inward of the main portion 54, the first disc 44 is split at a radially inner end thereof into two sets of tabs 58, 60 that are axially and circumferentially offset from one another. At a radially outer end thereof, the first disc 44 includes a spring retainer 62 for retaining arc springs 64. According to this embodiment, a damper assembly 42 includes arcuate indentations 66, each receiving a arc spring 64, each arcuate indentation 66 having an inner surface that conforms to an outer surface of the corresponding arc spring 64. The radially outer end of the first disc 44 includes load limiting stops 68 circumferentially between the indentations 66.Each load limit stop 68 is designed to bear against a circumferential edge of two arc springs 64 and is axially and radially offset from the indentations 66.

[0012] A second disc 48 includes a flat, annular main portion 70 provided with holes 72 extending axially therethrough to receive a riveting tool for forming rivets 46, as well as pins 74 of an axial thrust disc 76 that limits the axial travel of the damper assembly 42 and the turbine 20 toward the cover 12 by abutting a radially extending inner surface 78 of the front cover 12. At a radially outer end thereof, the second disc 48 includes a plurality of circumferentially spaced drive tabs 80 that extend axially circumferentially into spaces between the springs 64. During operation of the torque converter 10, the first disc 44 transmits torque from the turbine 20 to the second disc 48 through contact between the circumferential edges of the tabs 80 and the circumferential edges of the springs 64.

[0013] A radially outer extension 30 of the turbine 20 engages the impeller 18 via a friction material 40 on a radially extending wall 36 to transmit torque supplied to the front cover 12 by the engine crankshaft to the input shaft of a transmission. By driving the turbine 20 through the impeller 18, either by contact via the friction material 40 with the impeller shell 16 when the lock-up clutch is engaged or by fluid flow between the blades 26, 34, the turbine transmits the torque via the rivet 46 to the damper assembly 42. The damper assembly 42, in turn, drives the input shaft of the transmission.

[0014] The torque converter 10 also includes a stator 82 axially between the turbine 20 and the impeller 18 to redirect fluid flowing from the turbine blades 26 before it reaches the impeller 18 to increase the efficiency of the torque converter 10. The stator 82 consists of a stator casting 84 containing a plurality of blades 86 and a stator base 88. The stator 82 also includes a one-way clutch 90 supported by a centering disc 92 within the stator base 88. An axial thrust disc 93, axially disposed between the stator 82 and the impeller 18, is attached to the stator 82 by a plurality of axially extending arms 93a that are circumferentially spaced apart from one another at an outer periphery of the centering disc 92.The one-way clutch 90 includes an inner race 94, an outer race 96, and rolling elements 98 and springs 100 arranged radially between the inner race 94 and the outer race 96. Fig. 3). The stator cast body 84 is non-rotatably connected to the outer race 96, and the inner race 94 and the outer race 96 are non-rotatably connected to each other or rotatable relative to each other, depending on the operating conditions of the torque converter 10. When the impeller 18 rotates faster than the turbine 20 and the stator 82 is stationary, the springs 100 ( Fig. 3) the rolling elements 98 into wedge-shaped surfaces to non-rotatably connect the inner and outer races 94, 96 to prevent rotation of the stator casting 84 and cause the stator 82 to divert the fluid flowing from the turbine 20 to the impeller 18. When the impeller 18 and the turbine 20 rotate at the same speed, the inner race 94 and the outer race 96 are rotatable with respect to each other, and the stator 82 rotates in the same direction as the impeller 18 and does not divert the fluid flowing from the turbine 20 to the impeller 18.

[0015] Fig. Figure 2 shows an enlarged side cross-sectional view of the stator 82, which is different from the view of the stator 82 of the Fig. 1. The stator 82 includes vanes 86 for deflecting the converter fluid, which are radially supported between an outer circumferential surface 102 of the stator base 88 and an inner circumferential surface 104 of an outer edge 106. On an outer circumferential surface 108 of the outer edge 106, the stator 82 includes a boss 110 that projects radially outward from the outer edge 106 and defines a radially outermost edge of the stator 82. The stator base 88 includes an annular recess 112 formed on a radially extending surface 114 thereof facing the impeller, which receives the one-way clutch 90. The annular recess 112 is defined by two stepped sections - a radially inner step 116 which receives the inner race 94 and a radially inner step 118 which receives the rolling elements 98 and the outer race 96.The radially inner step 116 includes a radially extending surface 120 extending radially outward from an innermost circumferential surface 122 of the stator casting 84, and an axially extending circumferential surface 124 extending from a radially outer edge of the radially extending surface 120. The radially outer step 118 includes a radially extending surface 126 extending radially outward from an axially extending circumferential surface 124 of the step 116, and an axially extending circumferential surface 128 extending from a radially outer edge of the radially extending surface 126.

[0016] Radially outward of the annular recess 112, the stator casting 84 is provided with an indentation 132 that defines an annular groove 130 within the stator base body 88. More specifically, the indentation 132 is formed radially inward of the outer peripheral surface 102 of the stator base body 88 and radially outward of the axially extending peripheral surface 128 that defines an outermost peripheral surface of the annular recess 112. The groove 130 extends circumferentially around a central axis 133 of the stator 82 and axially from the radially extending surface 114 of the stator casting into the stator base body 88. The indentation 132 is formed by two axially projecting rings 134, 136 and includes an outer peripheral surface 138, an inner peripheral surface 140, and a radially extending surface 142 extending from the outer peripheral surface 138 to the inner peripheral surface 140.

[0017] During assembly of the stator 82, the outer race 96 is pressed axially into the annular recess 112, which can cause unexpected deflection of the outer rim 106 and the cap 110. The indentation 132 serves to reduce the axial deflection of the outer rim 106 and the cap 110 by diverting the deflection into the indentation 132, so that the outer rim 106 and the cap 110 cannot come into contact with the center ring 24 of the turbine 20 ( Fig. 1). According to another embodiment, the recess 112 may be arranged on the side of the stator 82 facing the turbine, and the indentation 132 is intended to prevent the outer edge 106 and the attachment 110 from coming into contact with the center ring 29 of the impeller 18 ( Fig. 1).

[0018] Fig. 3 shows a perspective view of the stator 82. Fig. 3 shows that the inner race 94 includes an inner tooth profile 144 for connection to a stator shaft and the outer race 96 includes an outer tooth profile 146 for connection to the peripheral surface 128 of the annular recess 112. Both the outer rim 106 and the cap 110 are formed as rings, with the outer rim supporting radially outer ends of the blades 86. The one-way clutch 90 radially between the races 94, 96 includes a plurality of pairs of rolling elements 98 and springs 100 to non-rotatably connect the races 94, 96 in the manner described above. Radially outward of the outer race 96 is the indentation 132 formed by a radially outer axially projecting ring 134 defining the outer peripheral surface 102 of the stator base 88 and being continuous, i.e.is not interrupted by gaps, and a radially inner, axially projecting ring 136 is defined which defines the circumferential surface 128 and is discontinuous at the radially extending surface 114, ie is interrupted by a plurality of notches 148 which extend partially axially into the ring 136 at the radially extending surface 114. . Fig. 1 provides a view along one of the notches 148, and the view of Fig. 2 shows a position along the circumference between two notches 148. The notches 148 serve to receive a respective arm 93a of the thrust washer 93 ( Fig. 1). The centering disc 92 ( Fig. 1, Fig.2) is provided radially inward of the axially projecting ring 136 which is in contact with the circumferential surface 128, and the centering disc is fixed to the stator by pressing stator material of the ring 136 over the centering disc 92 at a location 150, and then the thrust washer 93 is snapped over the centering disc 92.

Claims

[1] Stator (82) for a torque converter (10), the stator (82) comprising: a plurality of blades (86); a freewheel clutch (90); and a stator base body (88) for holding the blades (86), wherein the stator base body (88) accommodates the one-way clutch (90) and the stator base body (88) contains an indentation (132) radially outside the one-way clutch (90), wherein the stator base body (88) includes a radially outer, axially projecting ring (134) defining an outer peripheral surface (102) of the stator base body (88), and a radially inner, axially projecting ring (136) defining a peripheral surface (128) of a recess (112) in the stator base body (88), wherein the recess (112) receives the one-way clutch (90) of the stator (82), the radially outer, axially projecting ring (134) and the radially inner, axially projecting ring (136) defines the indentation (132) and the indentation (132) defines an annular groove (130) surrounding the recess (112), wherein the radially inner, axially projecting ring (136) includes a plurality of notches (148) formed therein that extend axially into the radially inner, axially projecting ring (136) on a radially extending surface (114) of the radially inner, axially projecting ring (136). [2] The stator (82) of claim 1, further comprising an outer rim (106) connected to radially outer ends of the blades (86) and a boss (110) projecting radially outward from the outer rim (106), the indentation (132) being configured to reduce axial deflection of the outer rim (106) and the boss (110) when an outer race of the one-way clutch (90) is pressed axially into the stator body (88). [3] Stator (82) according to claim 1 or 2, wherein the one-way clutch (90) includes an outer race (96) which is non-rotatably connected to the outer race (96) at the peripheral surface (128) of the recess (112). [4] The stator (82) of claim 3, further comprising a centering disc (92) that holds the one-way clutch (90) in the recess (112), the centering disc (92) being in contact with the peripheral surface (128) of the recess (112).

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