[0001] The invention relates generally to a stator centering plate, and more particularly to a stator centering plate for use with stamped torque converter stators.

BACKGROUND

[0002] Sheet metal stators are shown and described in commonly-owned United States

Patent Publication nos. 2007/0224042, 2007/0220877 and 2009/0232655.

BRIEF SUMMARY

[0003] Example aspects broadly comprise a stator assembly for a torque converter including first and second blade plates, a one-way clutch assembly disposed axially between the blade plates, and a centering plate. The one-way clutch assembly has an inner race with an outer circumferential surface, an outer race with an outer circumferential surface, and a plurality of blocking elements disposed radially between the inner race and the outer race. The centering plate has a ring portion grippingly engaged with the outer race outer circumferential surface and an annular portion with an inner circumferential surface arranged to radially position the inner race outer circumferential surface. In an example embodiment, at least one of the blade plates is made by stamping.

[0004] In some example embodiments, one of the blade plates has an aperture and the other blade plate has an axial protuberance disposed in the aperture. In an example embodiment, the protuberance has a deformed portion arranged to fix the blade plates together. In some example embodiments, the second blade plate has the aperture and a notch radially aligned with and circumferentially offset from the protuberance. The centering plate ring portion has a tab disposed in the notch. The outer race is disposed axially between the second blade plate and the centering plate annular portion. In an example embodiment, the first blade plate has a radially extending portion for axially retaining the centering plate.

[0005] In some example embodiments, the second blade plate has an inner circumferential surface. The outer race circumferential surface has a serrated portion and a non- serrated portion. The serrated portion is assembled with the second blade plate inner circumferential surface and the non-serrated portion is assembled with the centering plate annular portion inner circumferential surface. In an example embodiment, the serrated portion is press-fit into the second blade plate inner circumferential surface. [0006] In some example embodiments, the centering plate is made by stamping and the centering plate annular portion inner circumferential surface includes a shear length of at least seventy percent (70%). In an example embodiment, the centering plate is heat treated by ferritic nitrocarburizing, case hardending, or through hardening. In an example embodiment, the centering plate is made of aluminum or includes grooves. In an example embodiment, the first and/or second blade plate has at least a portion of a blade for guiding fluid in the torque converter. In an example embodiment, the first and/or second blade plate has an axially extending segment for positioning a bearing in the torque converter.

[0007] Other example aspects broadly comprise a stator assembly for a torque converter including a first stamped blade plate with a flow guiding portion, a second stamped blade plate having a flow guiding portion and a circumferential surface with a notch, a one-way clutch assembly and a stamped centering plate. The one-way clutch assembly is disposed axially between the blade plates and has an inner race with an outer circumferential surface, an outer race with an outer circumferential surface, and a plurality of blocking elements disposed radially between the inner race and the outer race. The outer race has a serrated portion pressed into the second blade plate circumferential surface, and a non-serrated portion. The stamped centering plate has a plurality of ring tabs grippingly engaged with the outer race smooth portion and extending into the notch, and an annular portion with a circumferential surface arranged to radially position the inner race circumferential surface.

[0008] In an example embodiment, the first blade plate has an aperture and the second blade plate has an axial protuberance extending from the circumferential surface and circumferentially offset from the notch. The protuberance is disposed in the aperture and includes a deformed portion arranged to fix the blade plates together.

[0009] Other example aspects broadly comprise a stator assembly for a torque converter including a first blade plate with a flow guiding portion and a potted portion, an outer race with an outer circumferential surface press-fitted into the potted portion, and a stamped centering plate at least partially disposed around the outer race outer circumferential surface. In an example embodiment, the first blade plate has a connecting portion with notches that connects the flow guiding portion and the potted portion. The centering plate includes tabs disposed around the outer race outer circumferential surface and extending into the notches. [0010] In some example embodiments, the stator assembly has an inner race with an outer circumferential surface and a plurality of blocking elements disposed radially between the outer race and the inner race. The centering plate has an annular portion with an inner circumferential surface proximate the inner race outer circumferential surface. In an example embodiment, the stator assembly has a second blade plate with a slot. The first blade has a connecting portion with a tab having an upset portion that connects the flow guiding portion and the potted portion. The tab extends through the slot and the first and second blade plates are at least partially fixed by the upset portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The nature and mode of operation of the present invention will now be more fully described in the following detailed description taken with the accompanying drawing figures, in which:

Figure 1A is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application;

Figure IB is a perspective view of an object in the cylindrical coordinate system of Figure 1 A demonstrating spatial terminology used in the present application;

Figure 2 is a perspective back view of a stator assembly according to an example aspect;

Figure 3 is a back view of the stator assembly of Figure 2;

Figure 4 is a section view of the stator assembly of Figure 2 taken generally along line 4- 4 in Figure 3;

Figure 5 is a front exploded view of the stator assembly of Figure 2;

Figure 6 is a back exploded view of the stator assembly of Figure 2.

DETAILED DESCRIPTION

[0012] At the outset, it should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Furthermore, it is understood that this invention is not limited only to the particular embodiments, methodology, materials and modifications described herein, and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. [0013] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the following example methods, devices, and materials are now described.

[0014] Figure 1A is a perspective view of cylindrical coordinate system 80 demonstrating spatial terminology used in the present application. The present invention is at least partially described within the context of a cylindrical coordinate system. System 80 has a longitudinal axis 81, used as the reference for the directional and spatial terms that follow. The adjectives "axial," "radial," and "circumferential" are with respect to an orientation parallel to axis 81, radius 82 (which is orthogonal to axis 81), and circumference 83, respectively. The adjectives "axial," "radial" and "circumferential" also are regarding orientation parallel to respective planes. To clarify the disposition of the various planes, objects 84, 85, and 86 are used. Surface 87 of object 84 forms an axial plane. That is, axis 81 forms a line along the surface. Surface 88 of object 85 forms a radial plane. That is, radius 82 forms a line along the surface. Surface 89 of object 86 forms a circumferential plane. That is, circumference 83 forms a line along the surface. As a further example, axial movement or disposition is parallel to axis 81, radial movement or disposition is parallel to radius 82, and circumferential movement or disposition is parallel to circumference 83. Rotation is with respect to axis 81.

[0015] The adverbs "axially," "radially," and "circumferentially" are with respect to an orientation parallel to axis 81, radius 82, or circumference 83, respectively. The adverbs "axially," "radially," and "circumferentially" also are regarding orientation parallel to respective planes.

[0016] Figure IB is a perspective view of object 90 in cylindrical coordinate system 80 of Figure 1A demonstrating spatial terminology used in the present application. Cylindrical object 90 is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present invention in any manner. Object 90 includes axial surface 91, radial surface 92, and circumferential surface 93. Surface 91 is part of an axial plane, surface 92 is part of a radial plane, and surface 93 is part of a circumferential plane.

[0017] The following description is made with reference to Figures 2-6. Figure 2 is a perspective back view of stator assembly 100 according to an example aspect. Figure 3 is a back view of stator assembly 100 of Figure 2. Figure 4 is a section view of stator assembly 100 of Figure 2 taken generally along line 4-4 in Figure 3. Figure 5 is a front exploded view of stator assembly 100 of Figure 2. Figure 6 is a back exploded view of stator assembly 100 of Figure 2.

[0018] Stator assembly 100 is a stator assembly for a torque converter. Assembly 100 includes blade plates 102 and 104 and one-way clutch assembly 106 disposed axially between the blade plates. In an example embodiment, at least one of the blade plates 102 and 104 is made by stamping. Plates 102 and 104 include respective flow guiding portions, or blade segments, 103 and 105 for redirecting fluid flow in the torque converter. Blade plates 102 and 104 include respective axially extending segments 107 and 109 for positioning bearings (not shown) in the torque converter.

[0019] One-way clutch assembly 106 includes inner race 108 with outer circumferential surface 110, outer race 112 with outer circumferential surface 114, and blocking elements disposed radially between the inner race and the outer race. In the embodiment shown, the blocking elements are springs 116 and rollers 118. In other embodiments (not shown), the blocking elements may be springs and sprag elements.

[0020] Stator 100 also includes centering plate 120 with ring portion 122 and annular portion 124 with inner circumferential surface 126. In an example embodiment, plate 120 is made by stamping and circumferential surface 126 includes a shear length of at least seventy percent (70%). In some embodiments, centering plate 120 may be heat treated by ferritic nitrocarburizing, case hardening, or through hardening for improved wear resistance and/or reduced friction. Plate 120 may be made from aluminum and/or include grooves (not shown) in surface 126 for reduced friction and/or improved oil flow.

[0021] As can best be seen in Figure 4, ring portion 122 is grippingly engaged with outer race circumferential surface 114. That is, portion 122 is tightly fit with surface 114 so that little or no radial movement is possible between portion 122 and surface 114. In other words, a radial position of outer race 112 is controlled by a precise fit between portion 122 and surface 114. Similarly, inner race outer circumferential surface 110 is arranged to radially position annular portion inner circumferential surface 126. That is, surface 110 is tightly fit with surface 126 so that little or no radial movement is possible between surface 110 and surface 126.

[0022] Blade plate 102 includes aperture 128, and blade plate 104 includes axial protuberance, or tab, 130 extending from connection portion 131 and disposed in the aperture (ref. Figure 4). Although plate 102 includes the aperture and plate 104 includes the tab, other configurations of tabs and apertures are possible. For example, plate 102 may include the tab and plate 104 may include the aperture for receiving the tab. In an example embodiment, protuberance 130 includes deformed portion 132 arranged to fix the blade plates together. That is, after installing tab 130 into the aperture, portion 132 is deformed to prevent removal of tab 130 from aperture 128, thereby fixing plates 102 and 104 together.

[0023] In the embodiment shown in the figures, blade plate 104, and more specifically connection portion 131, includes notch 134 radially aligned and circumferentially offset from protuberance 130, and centering plate ring portion 122 includes tab 136 disposed in the notch. That is, because protuberance 130 and ring portion 122 share a common radius, portion 122 cannot be continuous because portions of the ring would interfere with the tab. In other embodiments (not shown), portion 122 and protuberance 130 may be disposed at different radii, and portion 122 may be a continous ring. As seen in Figure 4, outer race 112 is disposed axially between blade plate 104 and centering plate annular portion 124. Blade plate 102 includes radially extending portion 138, and centering plate annular portion 124 is axially retained by portion 138.

[0024] Blade plate 104 includes inner circumferential surface, or potted portion, 140.

Portion 140 is connected to flow guiding portion 105 by connecting portion 131. Outer race circumferential surface 114 includes serrated portion 142 and non-serrated portion 144. By serrated, I mean that portion 142 includes radial "teeth" or peaks for material displacement during assembly with a mating part. Portion 142 is assembled with inner circumferential surface 140. To be more specific, portion 142 is press fit into surface 140. In other words, serrated portion 142 must be forced into surface 140 so that the serrations displace material such that plate 104 and race 112 are tightly locked together and drivingly engaged. Portion 144 is assembled with centering plate ring portion 124. Portions 124 and 144 are grippingly engaged, as described above. That is, plate 120, and specifically ring portion 144, is at least partially disposed around outer race outer circumferential surface 114.

[0025] Centering Plate 120 is shown as a stamped steel part which has an inner diameter

126 and outer tabs 122 sized to provide for proper centering of one way clutch outer race 112. In other example embodiments (not shown), tabs 122 are a solid, annular ring. Outer race 112 is pressed into tabs 122 of the centering plate and is therefore centered by them. Tabs 122 are shown in this embodiment instead of a solid ring because there are connection tabs 130 for connecting the two stator halves located at the same diameter as the centering tabs 122.

[0026] In order to provide improved centering, inner diameter 126 of the centering plate may be stamped with a minimum sheer length of seventy percent (70%). A minimum shear length can provide the proper surface and size required for a centering feature, thereby eliminating a secondary machining process. To improve wear resistance, centering plate 120 may be heat treated by any method known in the art. For example, plate 120 may be heat treated by ferritic nitro carburizing, case hardening, or through hardening. The inner diameter may include optional grooves (not shown) for oil lubrication of the interface between centering plate 120 and inner race 108.

[0027] The one-way clutch may be a roller one-way clutch with conventional springs 116 and rollers 118. Although shown as a roller one-way clutch, other example embodiments (not shown) may include a sprag one-way clutch as is commonly known in the art. The outer race 112 is pressed into the turbine side blade plate 104. During operation of the torque converter, thrust acting on plate 104 urges plate 104 towards race 112, reducing the likelihood of axial separtion between plate 104 and race 112. That is, because the interface between plate 104 and race 112 is a press-fit connection without mechanical fasteners, race 112 is less likely to be "pressed out" of engagement with plate 104 in this configuration.

[0028] There are serrations 142 on the outside of the outer race which provide for torque transmission between the blade plate 104 and outer race 112. Blade plate 104 includes axial extensions 109 for centering a bearing (not shown) between a turbine (not shown) and stator 100, and blade plate 102 includes axial extension 107 for centering a bearing (not shown) between a pump (not shown) and stator 100. Pump side blade plate 102 is attached to turbine side blade plate 104 by tabs 130 which are formed out of the turbine side blade plate. These tabs are upset to fit tightly into slots 128 in the pump side blade plate. That is, the turbine side blade plate tabs are disposed in corresponding apertures in the pump side blade plate and expanded, similar to a conventional riveting operation. The resulting interface serves to radially position the plates relative to one another, and transmit torque between the plates. The two blade plates may also be joined by spot welds around the outer rims 146.

[0029] Of course, changes and modifications to the above examples of the invention should be readily apparent to those having ordinary skill in the art, without departing from the spirit or scope of the invention as claimed. Although the invention is described by reference to specific preferred and/or example embodiments, it is clear that variations can be made without departing from the scope or spirit of the invention as claimed.