The present disclosure relates to methods of fabricating a housing for a stator for a torque converter. The method reduces the operational steps need for the fabrication while producing better quality surface finishes. The present disclosure also relates to a housing for a stator for a torque converter with a surface with an advantageous radial extent that requires fewer or simpler processing steps.
It is known to use an end mill with diameter DM2 less than DM1 to remove the button by displacing the end mill in a circular or other pattern(s) within the pocket such that a rotating portion of the end mill contacts point 216. However, the preceding process requires a more complicated control scheme and more complicated movement by the end mill. Further, because of the intermittent contact between the side of the end mill and the side of the pocket, the finish of the side wall is degraded.
According to aspects illustrated herein, there is provided a method for fabricating a stator for a torque converter, including: positioning, with respect to each pocket in a plurality of pockets in the first side of a housing for the stator, a cylindrically-shaped cutting device with an outer diameter equal to a desired diameter for said each pocket; rotating the cylindrically-shaped cutting device about a longitudinal axis for the cylindrically-shaped cutting device; axially displacing the rotating cylindrically-shaped cutting device in a first axial direction to contact a respective cylindrical wall for said each pocket; removing, with the cylindrically-shaped cutting device, respective material from the respective side wall; removing, with the cylindrically-shaped cutting device, respective material from a respective ring-shaped surface forming a portion of a respective end wall for said each pocket. The end wall includes a respective indentation: in contact with the respective ring-shaped surface; substantially centered with respect to the respective ring-shaped surface; and extending further than the respective ring-shaped surface in the first axial direction. The method includes: forming a respective diameter of the respective side wall for said each pocket equal to the desired diameter; forming a respective length, in the first axial direction, of the respective side wall for said each pocket equal to a desired length; and leaving a portion of the respective indentation in place. The housing includes a radially inner circumference and a plurality of blades circumferentially spaced in a radially outermost portion of the housing. Each pocket in the plurality of pockets is arranged to receive a respective engagement assembly for a one-way clutch for the stator and is disposed in a region radially between the inner circumference and the plurality of blades. Each pocket in the plurality of pockets includes a respective first opening facing in a second axial direction opposite the first axial direction and a respective second opening in communication with the respective first opening and at least partially facing in a circumferential direction. The first side faces in the second axial direction and the respective cylindrically-shaped side wall is in communication with the respective first and second openings.
According to aspects illustrated herein, there is provided a method for fabricating a housing for a stator for a torque converter, including: forming of metallic material, in a space formed between first and second molds, the housing, wherein the housing includes: a central opening through which an axis of rotation for the housing passes; a radially inner circumference; and a plurality of blades circumferentially spaced in a radially outermost portion of the housing. The method includes forming with the first mold, a first side of the housing facing in a first axial direction; forming, using a plurality of protrusions on the first mold, a plurality of recesses in the first side, wherein: each pocket includes a respective side wall and a respective end wall formed by the housing; and the plurality of protrusions extends into the space. The method includes forming, using a first protrusion on the first mold extending into the space, a notch passing completely through the inner circumference; selecting a location of the first protrusion on the first mold such that the location has a predetermined spatial relationship with at least one protrusion from the plurality of protrusions; forming with the second mold, a second side for the housing facing in a second axial direction, opposite the first axial direction; placing the housing on a surface including a second protrusion; facing the second side to the surface; disposing the second protrusion in the notch, wherein the second protrusion has a known spatial relationship with the plurality of pockets; for said each pocket, selecting a respective radial and circumferential location of a cutting device according to the known relationship of the second protrusion with the plurality of pockets; while in the respective radial and circumferential location, axially displacing the cutting device to contact the respective side wall of said each pocket; and shaping, using the cutting device, the respective side wall and the respective end wall for said each pocket.
According to aspects illustrated herein, there is provided a housing for a stator for a torque converter, including: a plurality of blades circumferentially spaced in a radially outermost portion of the housing; a first side facing in a first axial direction and including a first planar surface orthogonal to an axis of rotation for the stator and including a circumferentially continuous radially outermost portion, a second surface radially inward of the first planar surface and offset from the first planar surface in a second axial direction, opposite the first axial direction; a plurality of at least partially axially extending surfaces connecting radially innermost edges of the first planar surface to the second surface; and a plurality of pockets in the first side, each pocket arranged to receive a respective engagement assembly for a one-way clutch and including a respective first opening facing in the first axial direction. The respective first opening includes a respective first boundary formed by the first planar surface and a respective second boundary formed by the second surface. The housing includes a respective second opening in communication with the respective first opening and at least partially facing in a circumferential direction; a respective cylindrically-shaped side wall parallel to an axis of rotation for the stator; and a respective diameter formed by the respective cylindrically-shaped side wall. A radial distance from a radially outermost edge of the circumferentially continuous radially outermost portion of the first planar surface to a radially innermost edge of the first planar surface is less than the respective diameter.
Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which:
At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the disclosure. It is to be understood that the disclosure as claimed is not limited to the disclosed aspects.
Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described 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 disclosure.
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 disclosure belongs. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure.
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.
As shown in
In an example embodiment, an eighth step injects molten metallic material into cavity 142 formed by molds 102 and 104 to form the housing. Axially displacing the rotating cylindrically-shaped cutting device in direction AD1 includes displacing the rotating cylindrically-shaped cutting device one only once in direction AD1 for each pocket to remove the material from the side wall and the end wall. As shown in
In an example embodiment, for each pocket, an eleventh step: locates at least a part of body 144 for strut 146 for assembly 132 in space 148 in wall 106, at least a part of engagement portion 150 of the strut in opening 138, and locates at least a part of resilient element 152 of assembly 132 in space 148 or opening 138. In a twelfth step, the resilient element urges the engagement portion radially inward.
In an example embodiment, a thirteenth step locates inner race 154 radially inward of the inner circumference of the housing such that portions 150 engage the inner race, and secures end plate 156 to housing 100 such that the struts and resilient elements are axially sandwiched between the housing and the end plate.
As described above, prior art cast stator housing include a button at the end wall of a pocket for a rocker/strut assembly for a one-way-clutch. Also as described above, an end mill cannot remove material at a point through which the axis of rotation for the end mill passes. Advantageously, the above method overcomes the problems of the prior art by casting indentation 120 in the end wall of the pocket. The location of the indentation coincides with the orientation of the axis of rotation of an end mill used to remove material from the pocket to form the final diameter and length of the pocket. Thus, there is no need for the end mill to remove material from the end wall at the location aligned with the axis of rotation, since the indentation is in this location. Therefore, the further operations, described above, needed to remove the button are eliminated.
As noted above, an end mill with an outside diameter less than the desired diameter for a pocket can be used to remove the button by displacing the diameter within the pocket such that a rotation portion of the end mill contact the center of the end wall. Advantageously, the method described above eliminates the need for the preceding procedure which adds complication to reaming operations and degrades the final surface finish of the side walls of the pockets. Specifically, the only motion required for the end mill, other than rotation, is one “pass” in direction AD1.
The following should be viewed in light of
As noted above, in prior art casting operations, there are no benchmarks on the side of the housing analogous to side 106 which can be correlated to a jig or other positioning device against which a side analogous to side 166 must be laid in order to access features such as pockets for a one-way-clutch. Thus, the dimensional tolerance error between the two sides of the stator housing, inherent in the casting process, are transferred to positioning of the operations, for example positioning an end mill, on the features.
Advantageously, notch 164 passes through the inner circumference of the housing, connecting sides 106 and 166, and accepts protrusion 168. The position of protrusion 168 is known within the frame of reference of the jig or positioning device. As noted above, the positioning of the end mill is in the frame of reference of the jig or positioning device. Thus, protrusion 168 functions as a benchmark with respect to the jig or positioning device. Further, since protrusion 168 is accessible from side 106, protrusion 168 can be used, in conjunction with the known spatial relationship of notch 164, as a bench mark for determining desired locations of features such as pockets 108 on side 106. Thus, the error inherent in the dimensional tolerances noted above is avoided, resulting in more accurate positions of tools operating on side 106, for example, more accurate positioning of the end mill to machine the pockets to the desired dimensions and finishes.
The following should be viewed in light of
As noted above, an end mill is used to finish the side and end walls of the pockets. Also as noted above, diameter 112 of the end mill can be advantageously sized to equal a desired diameter 122 of the pockets. As part of the fabricating process for housing 100, surface 170 must be machined to create the desired characteristics of the surface. Machining on surface 170 creates a flat surface for proper positioning of end plate 156, for example. Advantageously, the same end mill used to machine the pockets can be used to finish surface 170. Even more advantageously, since diameters 112 and 122 are greater than radial distance 184, only a single circumferential pass of the end mill around surface 170 is required. That is, since diameter 112 is greater than distance 184, the radial extent of the end mill completely covers surface 170 as the end mill is revolved about AR. Thus, additional finishing steps for surface 170 are eliminated, decreasing the complexity and cost for fabrication housing 100.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/740,049, filed Dec. 20, 2012, which application is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61740049 | Dec 2012 | US |