RADIAL BEARING ASSEMBLY HAVING SPRING RIM RETAINER

PRIORITY CLAIM

[0001] This application is based upon and claims priority to U.S. provisional application serial no. 63/415,113, filed October 11, 2022, which is incorporated herein by reference in its entirety for all purposes.

FIELD OF THE INVENTION

[0002] The present invention relates to the construction of bearings.

BACKGROUND OF THE INVENTION

[0003] Bearings are commonly used to facilitate rotation between connected parts, such as in automatic transmissions and planetary gear sets. A typical radial bearing has a plurality of bearing elements (e.g., rollers) located in respective pockets of an annular retainer (also referred to as a cage). In many bearing designs, the retainer is situated in a cup having a cylindrical portion with parallel radial flanges to yield a C-shaped profile. The inner surface of the cylindrical portion of the cup serves as the outer raceway of the bearing. The radial flanges maintain the retainer in the correct axial position.

[0004] During assembly, the cup is typically formed from a metal drawing process. After the cylindrical portion and one radial flange are formed, the cup may be heat-treated, leaving a portion that will become the second radial flange untreated. The cage, with or without the rollers in place, is then inserted into the cup. The second radial flange is then formed so as to retain the retainer in position. If the rollers are not already installed, they are inserted into respective pockets to complete the assembly. [0005] The present invention recognizes and addresses consideration of prior art constructions and methods.

SUMMARY OF THE INVENTION

[0006] According to one aspect, the present invention provides a bearing assembly comprising an outer cup having a cylindrical portion with first and second radial flanges at respective ends thereof. The cylindrical portion, the first radial flange, and the second radial flange of the outer cup may be hardened.

[0007] An annular bearing retainer is positioned in the outer cup so as to be located axially between the first and second radial flanges. The bearing retainer has first and second parallel rims between which a plurality of angularly spaced apart spanning members extend so as to define a plurality of bearing pockets. The bearing retainer further has a plurality of flex features defined in at least one of the rims, the flex features each including a reduced width connecting element. A plurality of bearing elements are respectively located in the bearing pockets.

[0008] According to some exemplary embodiments, the flex features may each be formed of first and second adjacent notches respectively extending from an inner circumference of a corresponding rim and an outer circumference of the corresponding rim to define the reduced width connecting element.

[0009] According to some exemplary embodiments, both the first rim and the second rim define a plurality of the flex features. For example, the first rim and the second rim may each have an equal number of the flex features. The respective flex features may alternate between the first rim and the second rim from one pocket to the next. A number of the flex features and a number of the pockets may be the same. [00010] According to some exemplary embodiments, the connecting element may have an S-shaped configuration.

[00011] According to some exemplary embodiments, the connecting element may extend straight in a radial direction such that the first and second notches and the connecting element define a Z- shaped configuration.

[00012] According to some exemplary embodiments, the connecting element may extend angularly.

[00013] Another aspect of the present invention provides a bearing retainer for a bearing assembly including rollers. The bearing retainer according to this aspect comprises an annular structure having first and second parallel rims between which a plurality of angularly spaced apart spanning members extend so as to define a plurality of roller pockets. A plurality of flex features are defined in at least one of the rims, the flex features formed of first and second adjacent notches respectively extending from an inner circumference of a corresponding rim and an outer circumference of the corresponding rim to define a reduced width connecting element. The annular structure may be urged to a reduced diameter but will thereafter spring back to a larger diameter.

[00014] A still further aspect of the present invention provides a method of producing a bearing assembly. One step of the method involves providing an outer cup having a cylindrical portion with first and second radial flanges at respective ends thereof, at least one of the first and second radial flanges defining a circular opening having a first radius. Another step involves providing an annular bearing retainer having an initial outer radius, the annular bearing retainer having first and second parallel rims between which a plurality of angularly spaced apart spanning members extend so as to define a plurality of bearing pockets, the bearing retainer further having a plurality of flex features each including a reduced width connecting element. A further step involves a plurality of bearing elements sized to be received in the pockets of the annular bearing retainer.

[00015] The bearing retainer is urged to have a reduced outer radius smaller than the initial outer radius and the first radius of the circular opening. The bearing retainer is moved axially into the outer cup so that the bearing retainer is positioned between the first and second radial flanges. The bearing retainer is released so that its outer radius expands to a radius greater than the first radius. Respective bearing elements may be positioned in respective pockets of the bearing retainer.

[00016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the disclosure and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[00017] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which;

[00018] Figure 1 is an isometric view of a bearing assembly constructed in accordance with an embodiment of the present invention;

[00019] Figure 2 is a cross-sectional view of the bearing assembly taken along line 2-2 of Figure 1 ;

[00020] Figure 3A is an isometric view of a bearing cage that may be used with the bearing assembly of Figure 1, constructed according to an embodiment of the present invention; [00021] Figure 3B is an enlarged isometric view of a portion of the bearing cage of Figure 3A;

[00022] Figure 3C is an enlarged side view of a flex feature of the bearing cage of Figure 3B showing how the flex feature allows the diameter of the bearing cage to be temporarily reduced;

[00023] Figure 4 is a diagrammatic exploded view with the cup in cross-section showing one manner of producing the bearing assembly of Figure 1;

[00024] Figures 5A and 5B are isometric and partial isometric views of a bearing cage that may be used with the bearing assembly of Figure 1, constructed according to an embodiment of the present invention; and

[00025] Figures 6A and 6B are isometric and partial isometric views of a bearing cage that may be used with the bearing assembly of Figure 1, constructed according to an embodiment of the present invention.

[00026] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[00027] Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[00028] Furthermore, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

[00029] As used herein, terms referring to a direction or a position relative to the orientation of the bearing assembly, such as but not limited to “vertical,” “horizontal,” “top,” “bottom,” “above,” or “below,” refer to directions and relative positions with respect to the bearing assembly’s orientation as depicted in Figure 2. Further, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used herein should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form. In addition, the meaning of “in” may include “in” and “on.” The phrase “in one embodiment,” as used herein, does not necessarily refer to the same embodiment, although it may.

[00030] Embodiments of the present invention provide a roller cage design that allows for the diameter of the cage to be reduced so that the cage can be more easily assembled into a bearing cup. As a result, the assembly process of the bearing may be made simpler by reducing certain costly steps. The disclosed cage designs work on the principle of allowing the rim of the cage to flex such that the overall diameter of the cage is reduced to the desired size.

Embodiments of the present invention utilize a “spring rim” that allows the rim of the cage to maintain connection while being able to flex. The purpose of maintaining connection is to ensure that the cage springs back to the original pitch diameter once it is compressed and assembled into the bearing cup. The disclosed designs can be used for a new retainer type of a wide variety of standard bearings.

[0010] Figures 1 and 2 illustrate a bearing assembly 10 constructed in accordance with an embodiment of the present invention. Bearing assembly 10 includes an annular cup 12 having a cylindrical portion 14. Parallel radial flanges 16 and 18 are located at each end of the cylindrical portion 14. Cup 12 may be a drawn cup formed, for example, from an annular sleeve of low carbon steel. After cylindrical portion 14 and both flanges 16 and 18 are formed, the entirety of cup 12 may be hardened by heat treatment.

[0011] A retainer 20 is located in the axial region between flanges 16 and 18. Retainer 20, which may also be referred to as a cage, includes a plurality of pockets 22 (Figures 3 A and 3B) evenly spaced apart around its annular extent (i.e., they are spaced at the same angular increment). Each of the pockets contains a respective bearing element 24. It will be appreciated that each of the hearing elements 24 is capable of rotation with respect to the retainer 20. The inner surface of cylindrical portion 14 thus forms the outer raceway of bearing assembly 10. [0012] In this case, the bearing elements 24 are formed as cylindrical rollers. Moreover, the pockets 22 are configured so that the bearing elements 24 can be inserted after the retainer 20 is positioned in cup 12. Specifically, the pockets 22 arc configured to allow the bearing elements 24 to be inserted from the inner diameter of the retainer 20 past the retention features of the respective pocket 22, which will thereafter serve to keep the bearing elements 24 in the respective pockets 22.

[0013] Further details regarding the configuration of retainer 20 can be most easily explained with reference to Figures 3 A and 3B. As can be seen, retainer 20 has a pair of parallel side walls (“rims”) 26 and 28 between which spaced-apart spanning members 30 integrally extend. The pockets 22 are thus formed between adjacent pairs of the spanning members 22. The spanning members are configured with retention features that allow the bearing elements 24 to rotate while remaining in the pockets 22. The outer edges of the rims 26 and 28 may be chamfered, as indicated at 29.

[0014] Both rims 26 and 28 have flex features 32 which allow the overall diameter of retainer 20 to be temporarily reduced. Embodiments are contemplated having various numbers of such flex features, depending on the diameter reduction that is desired and/or other factors. For example, every other pocket may have one or more flex features, every third pocket may have one or more flex features, every fourth pocket may have one or more flex features, etc. In this embodiment, however, each of the pockets 24 has one such flex feature 32 at one of its two axial ends. As shown, the flex features 32 in this embodiment alternate between rim 26 and rim 28 from one pocket to the next around the annular extent of retainer 20. [0015] In this embodiment, adjacent notches 34a and 34b respectively extend radially outward from the inner circumference of the rims 26, 28 and radially inward from the outer circumference of rims 26, 28, as shown. In this case, the notches 34a and 34b are configured to form an S-shaped connecting element 36 of reduced width compared to the radial width of the rims 26, 28. Because notches 34a and 34b are arranged in opposite directions, connecting element 36 extends from the inner circumference of the corresponding rim 26, 28 at one end of connecting element 36 to the outer circumference of the corresponding rim 26, 28 at the other end of connecting element 36.

[0016] Referring now also to Figure 3C, flex feature 32 allows the retainer 20 to be urged to a smaller diameter during the assembly process. As shown by the arrows, connecting element 36 may deform as notches 34a and 34b become smaller. The overall reduction in the diameter of retainer 20 is due to the cumulative reduction in circumference achieved at each of the flex features 32 on both of the rims 26 and 28. Deformation of the connecting elements 36 stores energy that will subsequently cause retainer 20 to spring back to the original diameter.

[0017] Referring now to Figure 4, certain steps of producing bearing assembly 10 can be explained. Cup 12 is fully formed, having cylindrical portion 14 and both radial flanges 16 and 18. The inner circumference of flanges 16 and 18 defines an opening having a radius Rl. (While flanges 16 and 18 have the same opening diameter in this example, embodiments are contemplated in which the opening diameter of the two flanges is different, as necessary or desired.) The outer diameter of retainer 20 at rest is greater than Rl . Because of the flex features, retainer 20 can be urged to a reduced outer diameter R2 which is slightly less than Rl. As a result, retainer 20 can be moved into cup 12 through one of the flange openings. Once positioned in the cup 12, the force urging retainer 20 to the reduced diameter is removed, allowing it to spring back to the original diameter. Bearing elements 24 can then be inserted into the respective pockets 22.

[0018] Figures 5A and 5B show an alternative embodiment of a retainer in accordance with an embodiment of the present invention. Elements similar or analogous to those of the previous embodiment have a reference number augmented by one hundred. Thus, retainer 120 has a pair of parallel rims 126 and 128 between which spaced-apart spanning members 130 integrally extend. Pockets 122 are formed between adjacent pairs of the spanning members 130. The spanning members 130 are configured with retention features that allow the bearing elements 24 to rotate while remaining in the pockets 122. The outer edges of the rims 126 and 128 may be chamfered, as indicated at 129.

[0019] Both rims 126 and 128 have flex features 132 which allow the overall diameter of retainer 120 to be temporarily reduced. While embodiments are contemplated having various numbers of such flex features, each of the pockets 122 in this embodiment has one such flex feature 132 at one of its two axial ends. The flex features 132 alternate between rim 126 and rim 128 from one pocket to the next around the annular extent of retainer 120.

[0020] In this embodiment, the flex features 132 are formed as adjacent straight notches 134a and 134b which respectively extend radially outward from the inner circumference of the rims 126, 128 and radially inward from the outer circumference of rims 126, 128, as shown to yield a reduced width connecting element 136. In this case, the connecting element 136 extends straight in the radial direction such that the notches 134a, 134b and the connecting element 1 6 form a somewhat Z-shaped configuration. Retainer 120 can be urged to a smaller diameter in a similar manner to the previous embodiment but can thereafter spring back to its initial greater diameter. [0021] Figures 6 A and 6B show an alternative embodiment of a retainer in accordance with an embodiment of the present invention. Elements similar or analogous to those of the previous embodiment have a reference number augmented by two hundred. Thus, retainer 220 has a pair of parallel rims 226 and 228 between which spaced-apart spanning members 230 integrally extend. Pockets 222 are formed between adjacent pairs of the spanning members 230. The spanning members are configured with retention features that allow the bearing elements 24 to rotate while remaining in the pockets 222. The outer edges of the rims 226 and 228 may be chamfered, as indicated at 229.

[0022] Both rims 226 and 228 have flex features 232 which allow the overall diameter of retainer 220 to be temporarily reduced. While embodiments are contemplated having various numbers of such flex features, each of the pockets 222 in this embodiment has one such flex feature 232 at one of its two axial ends. The flex features 232 alternate between rim 226 and rim 228 from one pocket to the next around the annular extent of retainer 220.

[0023] In this embodiment, the flex features 232 are formed as adjacent triangular notches 234a and 234b which respectively extend radially outward from the inner circumference of the rims 226, 228 and radially inward from the outer circumference of rims 226, 228, as shown to yield a reduced width connecting element 236. In this case, the notches 234a and 234b are configured to form an angled connecting element 236 that extends from the inner circumference of the corresponding rim 226, 228 at one end of connecting element 236 to the outer circumference of the corresponding rim 226, 228 at the other end of connecting element 236. Retainer 220 can be urged to a smaller diameter in a similar manner to the previous embodiment but can thereafter spring back to its initial greater diameter. [0024] While one or more preferred embodiments of the invention are described above, it should be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope and spirit thereof. It is intended that the present invention cover such modifications and variations as come within the scope and spirit of the appended claims and their equivalents.