Patent Publication Number: US-2017350452-A1

Title: Bearing assembly with expanded outer diameter

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/344,658, filed Jun. 2, 2016, which application is incorporated in its entirety herein by reference. 
    
    
     FIELD 
     The present disclosure relates generally to bearing assemblies with an expanded outer diameter, for example, to fit into a housing designed for a larger bearing assembly. 
     BACKGROUND 
     Bearing assemblies generally include a plurality of rolling elements sandwiched between opposing raceways in bearing rings. The rolling elements may take many forms, such as spherical balls, rollers, tapered rollers, barrel-shaped spherical rollers, or others. Bearing assemblies are used in a wide range of applications. For example, in vehicles, bearing assemblies may be used for supporting an intermediate drive shaft (IDS) or a drive shaft (prop shaft). The IDS or prop shaft is typically supported by a bearing assembly, which is in turn supported on an outer housing. When used to support an IDS, the outer housing may be mounted to an engine block. When used to support prop shaft, the outer housing (e.g., a bracket with over-molded rubber) may be mounted to the vehicle chassis body. 
     BRIEF SUMMARY 
     In at least one embodiment, a bearing assembly is provided. The bearing assembly may include an inner bearing ring defining an inner race and a bore surface; an outer bearing ring having a first outer diameter and defining an outer race and a radially outer surface; a plurality of rolling elements supported between the inner race and the outer race; and a radial extension coupled to the radially outer surface of the outer bearing ring, the radial extension expanding an outer diameter of the bearing assembly from the first outer diameter to a larger second outer diameter; wherein the second outer diameter is configured to correspond to a diameter of a housing cavity that is larger than the first diameter such that the bearing assembly can be assembled with the housing. 
     The second outer diameter may be configured to match the diameter of the housing cavity such that the bearing assembly can be press fit into the housing cavity. The radial extension may have a density that is less than that of the outer bearing ring. In one embodiment, the radial extension is formed of a polymer or an elastomer. The radial extension may be over-molded or press fit onto the outer bearing ring. In one embodiment, the outer bearing ring has one or more grooves defined in the radially outer surface and the radial extension extends into the one or more grooves. In another embodiment, an outer surface of the radial extension has a textured surface profile including a plurality of raised portions and a plurality of depressed portions. An outer surface of the radial extension may have one or more grooves defined therein. 
     In at least one embodiment, a method is provided. The method may include applying a radial extension to a radially outer surface of an outer bearing ring of a bearing assembly; and the radial extension expanding an outer diameter of the bearing assembly from a first outer diameter to a larger second diameter that is configured to correspond to a diameter of a housing cavity that is larger than the first diameter such that the bearing assembly can be coupled to the housing. 
     The radial extension may be applied to the radially outer surface by over-molding. In another embodiment, the radial extension may be applied to the radially outer surface by press fitting the radial extension onto the radially outer surface. The radial extension may be formed of rubber and may be stretched onto the radially outer surface. Prior to applying the radial extension to the radially outer surface, the method may include increasing a surface area of the radially outer surface. Increasing the surface area may include roughening the radially outer surface and/or forming grooves in the radially outer surface. An outer surface of the radial extension may include at least one raised portion and at least one depressed portion. The method may further include press fitting the bearing assembly having the radial extension applied thereon into the housing cavity. 
     In at least one embodiment, a bearing and housing assembly is provided. The assembly may include a housing defining a cavity having a bearing diameter; and a bearing assembly comprising: an inner bearing ring defining an inner race and a bore surface; an outer bearing ring having a first outer diameter and defining an outer race and a radially outer surface; a plurality of roller elements supported between the inner race and the outer race; and a radial extension coupled to the radially outer surface of the outer bearing ring, the radial extension expanding an outer diameter of the bearing assembly from the first outer diameter to a larger second outer diameter; wherein the second outer diameter corresponds to the bearing diameter of the housing cavity and the bearing assembly is press fit into the housing cavity. 
     In one embodiment, the housing includes a deformable element extending around the periphery of the cavity and an outer surface of the radial extension includes at least one raised portion and at least one depressed portion. When the bearing assembly is press fit into the housing cavity, the deformable element may be configured to extend into the at least one depressed portion in the outer surface of the radial extension. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The nature and mode of operation of the disclosure will now be more fully described in the following detailed description of the disclosure taken with the accompanying drawing figures, in which: 
         FIG. 1  illustrates a cross-section of a bearing assembly, according to an embodiment; 
         FIG. 2  illustrates a cross-section of the bearing assembly of  FIG. 1  inserted into a housing, according to an embodiment; 
         FIG. 3  illustrates a cross-section of a bearing assembly including a radial extension, according to an embodiment; 
         FIG. 4  illustrates a perspective view of a bearing assembly prior to the addition of a radial extension, according to an embodiment; 
         FIG. 5  illustrates a perspective view of the bearing assembly of  FIG. 4  with the radial extension applied, according to an embodiment; 
         FIG. 6  illustrates the bearing assembly of  FIG. 3  inserted into a housing, according to an embodiment; 
         FIG. 7A  illustrates a perspective view of a bearing assembly including a radial extension with a smooth surface, according to an embodiment; 
         FIG. 7B  illustrates a cross-section of the bearing assembly of  FIG. 7A ; 
         FIG. 8A  illustrates a perspective view of a bearing assembly including a radial extension with a textured surface, according to an embodiment; 
         FIG. 8B  illustrates a cross-section of the bearing assembly of  FIG. 8A ; 
         FIG. 9A  illustrates a perspective view of a bearing assembly including a radial extension with a ribbed surface, according to an embodiment; 
         FIG. 9B  illustrates a cross-section of the bearing assembly of  FIG. 9A ; 
         FIG. 10A  illustrates a perspective view of a bearing assembly including a radial extension with a grooved surface, according to an embodiment; and 
         FIG. 10B  illustrates a cross-section of the bearing assembly of  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION 
     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 disclosure is not limited only to the particular embodiments, methodology, materials and modifications described herein, and as such may, of course, vary. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. 
     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, which is limited only by the appended claims. It is to be understood that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. 
     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. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the following example methods, devices, and materials are now described. 
     With reference to  FIG. 1 , a bearing assembly  10  is shown. The bearing assembly  10  may include an inner bearing ring  12  and an outer bearing ring  14 . The inner bearing ring  12  may define an inner race  16  and the outer bearing ring  14  may define an outer race  18 . One or more (e.g., a plurality) of rolling elements  20  may be disposed and/or supported between the inner race  16  and the outer race  18  when the bearing assembly  10  is assembled. In the embodiment shown, the rolling elements  20  are spherical (e.g., ball bearings). However, any suitable type of rolling element may be used, such as roller bearings or others. Non-limiting examples of roller bearings may include cylindrical, cone-shaped/tapered, barrel shaped, or others. 
     The inner bearing ring  12  of the bearing assembly  10  may define a bore  22  having a bore size or diameter  24 . The bore size  24  may correspond to a size or diameter of a shaft, such as an IDS or prop shaft (not shown), to which the bearing assembly may be coupled. Non-limiting examples of bore sizes may include 30 mm, 35 mm, or 40 mm, however, the bearing assembly  10  may define any suitable bore size. In one embodiment, the bore size may be from 25 to 45 mm, or any sub-range therein, such as 30 to 40 mm. The outer bearing ring  14  may define an outer diameter (OD)  26  of the bearing assembly  10 . The bearing assembly  10  may also have a width  28 . In the embodiment shown, the bearing assembly  10  includes in-board seals  30  to reduce or mitigate the ingress of contaminants. However, in-board seals are not required, and the bearing assembly  10  may be an open bearing, have a separate shielding member, or any other configuration. 
     With reference to  FIG. 2 , the outer bearing ring  14  of the bearing assembly is shown supported on a housing  40 . The housing  40  may include a wall  42  that defines a cavity or envelope  44 . The cavity  44  may be sized and shaped such that it matches or corresponds to the outer diameter  26  of the bearing assembly. The bearing assembly  10  may be inserted into the cavity  44  (e.g., by a press fit) such that a radially outer surface  46  of the bearing assembly  10  (e.g., the outer surface of the outer bearing ring  14 ) is in contact with the wall  42  of the housing  40 . As described above, the housing  40  may be mounted to another component, such as an engine block. 
     In general, when a bearing assembly is to be inserted into a housing, a bearing assembly is chosen or designed to fit a particular housing having pre-determined dimensions. Typically, a bearing assembly is chosen/designed that has the appropriate bore size for the application and an OD that matches the size of the cavity in the housing. However, it has been found that this may lead to using bearing assemblies that are larger than necessary. This may result in the use of bearing assemblies that are heavier and/or higher in cost than a smaller bearing assembly that also meets the load requirements for the application. 
     With reference to  FIG. 3 , an extended bearing assembly  50  is disclosed that has an expanded outer diameter. Accordingly, the extended bearing assembly  50  may be inserted into a housing that is designed and configured to receive a larger bearing assembly. This may allow a smaller bearing assembly, which may be lighter and/or lower cost, to be used in place of a larger bearing assembly. 
     The extended bearing assembly  50  may have the same or similar components to the bearing assembly  10 , and are identified with like numerals. However, the outer diameter (OD)  26  of the bearing assembly  50  is smaller than that of the bearing assembly  10 . In at least one embodiment, the extended bearing assembly  50  includes a radial extension  52 . The radial extension  52  may effectively increase the outer diameter of the bearing assembly from OD  26  to an expanded OD  54 . The expanded OD  54  may match or correspond to the size of a housing cavity (e.g., such as cavity  44  of housing  40 ), such that the bearing assembly  50  forms a press fit with the housing. 
     The radial extension  52  may be attached to or formed on the bearing (e.g., the outer bearing ring  14 ) during the production of the bearing assembly or in a separate step thereafter. In some embodiments, the radial extension  52  may be over-molded onto the bearing assembly, such as over the outer bearing ring  14 . In these embodiments, the radial extension  52  may be a plastic or polymer material. Non-limiting examples of polymers that may be used may include polyamides, such as nylon (e.g., PA6/PA66/PA46) or PPA, other thermoplastics, such as PPS or PAEK, thermoplastic elastomers (e.g., TPE or TPS), or others. The polymers may or may not include a reinforcing material, such as glass or carbon fibers. In another embodiment, the over-molded radial extension  52  may be formed of rubber or another elastomer. In other embodiments, the radial extension  52  may be press fit onto the outer bearing ring  14 , which may include stretching it over the outer bearing ring  14 . In these embodiments, the radial extension  52  may be formed of an elastic or flexible material, such as rubber or another elastomer. In addition to over-molding, press fitting, or stretching, any other technique to expand the diameter of the bearing assembly may be used for forming the radial extension  52 . For example, if only a small increase in OD is desired, a coating may be applied to the outer bearing ring  14 . In another example, a ring of material having the desired extra thickness may be attached or secured to the outer bearing ring  14 , for example, using an adhesive or fasteners. While the radial extension  52  has been described as a polymer, any other suitable material maybe use used, such as metals or ceramics. In one embodiment, the radial extension  52  may be formed of a material (or materials, if a composite) that is less dense than the outer bearing ring  14  (e.g., a metal, such as steel). Accordingly, the addition of the radial extension  52  may be lighter than a bearing assembly with a larger/thicker outer bearing ring. 
     With reference to  FIGS. 4 and 5 , perspective views are shown of a bearing assembly before ( FIG. 4 ) and after ( FIG. 5 ) the addition of the radial extension  52 . In  FIG. 4 , the radially outer surface  46  of the outer bearing ring  14  forms the outermost surface of the bearing assembly. As described above, the OD of the bearing assembly (prior to adding the radial extension  52 ) may be smaller than the diameter of a housing cavity for a certain application, but the bearing assembly may be otherwise capable for the application (e.g., sufficient load and longevity/fatigue properties). It has been discovered that by adding a radial extension  52  to the bearing assembly, an extended bearing assembly  50  may be formed that will fit the diameter of the housing but also reduce weight and/or cost. The extended bearing assembly  50  may also allow for more standardization of bearing assemblies. For example, one bearing assembly design may be implemented in multiple applications by adjusting the radial extension dimensions instead of redesigning the bearing assembly itself. This may reduce the amount of resources, such as time, cost, and testing, that are associated with developing a new bearing design for each application. 
     In the embodiments shown in  FIGS. 3 and 5 , channels or grooves  56  are formed in the radially outer surface  46  of the outer bearing ring  14 . These grooves  56  may be referred to as retaining features, and may increase the bonding or adhesion between the radial extension  52  and the outer bearing ring  14 . There are two grooves  56  shown in the illustrated embodiments, however, there may be a single groove  56  or there may be multiple grooves  56  (e.g., two or more). In addition, while the grooves are shown as rectangular, they may have any suitable shape, such as triangular or truncated triangular. Grooves are merely an example of a retaining feature, and other types of retaining features may be used, in addition to or instead of grooves. For example, the radially outer surface  46  may be roughened to increase the surface area for the radial extension  52  to adhere to. One example of roughening may be knurling. In one embodiment, the groove(s)  56  may be roughened (e.g., knurled) to further amplify their surface area increase. The retaining features (e.g., grooves) may be formed in the outer bearing ring  14  during its production or as an intermediate step before applying the radial extension  52 . The retaining features may be formed in any suitable way, such as machining (e.g., turning). 
     With reference to  FIG. 6 , the extended bearing assembly  50  is shown inserted into the housing  40 . As described above, the housing  40  includes a peripheral wall  42  that defines a cavity  44  that corresponds to an outer diameter of the bearing assembly  10 . The OD of the bearing assembly  50  (e.g., without the radial extension) is smaller than the OD of bearing assembly  10 . But, the radial extension  52  expands the diameter of the bearing assembly  50  to an OD  54  that is the same or substantially the same as that of bearing assembly  10 . Accordingly, the bearing assembly  50  may be inserted (e.g., by press fit) into the cavity  44  of the housing  40  in the same manner as bearing assembly  10 . However, bearing assembly  50  may be lighter and/or less costly than bearing assembly  10  due to the use of less dense and/or lower cost materials (e.g., polymers) to increase the outer diameter. 
     With reference to  FIGS. 7A-10B , several examples are shown of different radial extension configurations. The radial extensions may have different surface configurations or profiles. In these embodiments, the expanded OD (e.g., OD  54 ) may refer to the largest diameter of the radial extension. For example, for a ribbed surface profile, the OD may be measured at the peaks rather than the valleys. While several examples of surface profiles are shown, the illustrated examples are not intended to be limiting. One of ordinary skill in the art will understand, based on the present disclosure, that other profiles may be used or the profiles shown may be modified. 
     With reference to  FIGS. 7A and 7B , a bearing assembly  100  is shown. The bearing assembly  100  includes a radial extension  102  having a smooth or flat surface profile  104 . Accordingly, the surface profile  104  of the radial extension  102  may be configured as a cylinder, for example, having substantially no projections or depressions in the surface. The selection of the surface profile may depend on the application and/or the particular housing into which the bearing assembly will be inserted. For example, some housings may have a deformable element, such as a rubber portion or rubber insert (e.g. a seal or gasket) positioned around a periphery or circumference of the cavity that will receive the bearing assembly. As described above, the radial extensions may be formed of an elastomeric material, such as rubber. In these embodiments, it may be possible to eliminate the rubber lip or rim of the housing (for housings that include such rubber lips/rims). In embodiments where a deformable rubber lip/rim is present, press fitting a bearing assembly having a smooth or flat profile into a housing with a rubber rim or lip may be difficult. 
     With reference to  FIGS. 8A-10B , several examples of bearing assemblies are shown having non-flat surface profiles that may facilitate insertion of the bearing assemblies into a housing, for example, a housing with a rubber rim or lip. By having a non-flat surface (e.g., at least one raised portion and one depressed portion), there may be gaps or depressions in the surface that may allow the rubber to deform into, thereby providing a seal and easing the insertion of the bearing assembly into the housing. 
     With reference to  FIGS. 8A and 8B , a bearing assembly  200  is shown. The bearing assembly  200  includes a radial extension  202  having a textured surface profile  204 . As used herein, a textured surface profile may be one that includes a plurality of raised portions and a plurality of depressed portions. In the embodiment shown, the edges  206  of the radial extension  202  (e.g., on either side of the width) may be raised and a plurality of spaced apart raised slats or strips  208  may extend between the edges  206 . The slats  208  may extend parallel to the width of the bearing assembly (e.g., as shown) or they may be oblique to the width direction. In one embodiment, the edges  206  and the slats  208  may be co-planar. Between the spaced apart slats  208  there may be depressions or valleys  210 . The cross-section of  FIG. 8B  is taken across a depression  210  and shows the raised edges  206  on either side thereof. When the bearing assembly  200  is inserted into a housing having a rubber (or other elastomer) rim or lip, the rubber may deform and extend into or fill the depressions  210 . This may facilitate a good seal between the housing and the bearing assembly, as well as ease insertion of the bearing assembly and improve the mechanical locking between the bearing assembly and the housing. 
     With reference to  FIGS. 9A and 9B , a bearing assembly  300  is shown. The bearing assembly  300  includes a radial extension  302  having a textured surface profile  304 . In the embodiment shown, the surface profile  304  includes a plurality of alternating ridges or ribs  306  and valleys or depressions  308  extending parallel to the width of the bearing assembly. However, in some embodiments, the ridges  306  and valleys  308  may be oblique to the width direction. In one embodiment, both the ridges  306  and the valleys  308  may extend a full width of the radial extension  302 , from one edge  310  to the other. The ridges  306  and valleys  308  may have any suitable shape in side profile, for example, they may be formed as a square wave, triangular wave, sin wave, scalloped, or others. When the bearing assembly  300  is inserted into a housing having a rubber (or other elastomer) rim or lip, the rubber may deform and extend into or fill the valleys  308 . This may facilitate a good seal between the housing and the bearing assembly, as well as ease insertion of the bearing assembly and improve the mechanical locking between the bearing assembly and the housing. 
     With reference to  FIGS. 10A and 10B , a bearing assembly  400  is shown. The bearing assembly  400  includes a radial extension  402  having a grooved surface profile  404 . The surface profile  404  may be flat or smooth, such as in  FIGS. 7A and 7B , except that one or more grooves or channels  406  may be defined therein. The groove or grooves  406  may extend around a circumference of the radial extension  402 , as shown. The illustrated embodiment has a single groove  406 , which is optionally centered along the width of the bearing assembly. However, there may be multiple grooves  406  (e.g., two or more), which may be spaced along the width of the bearing assembly. The groove(s)  406  may extend around an entire circumference of the radial extension  402  or only a portion thereof. In one embodiment, the groove(s)  406  may be intermittent such that there are periodic gaps between grooved portions (e.g., resembling a dotted/dashed line). The groove(s)  406  may have any suitable shape, for example, it/they may be a triangular grove, square/rectangular groove, rounded/scalloped groove, truncated triangle groove, etc., or a combination thereof. When the bearing assembly  400  is inserted into a housing having a rubber (or other elastomer) rim or lip, the rubber may deform and extend into or fill the groove(s)  406 . This may facilitate a good seal between the housing and the bearing assembly, as well as ease insertion of the bearing assembly and improve the mechanical locking between the bearing assembly and the housing. 
     Accordingly, bearing assemblies having an expanded or extended outer diameter are disclosed, as well as methods of forming the expanded diameter portion. These bearing assemblies may have numerous advantages or benefits over the traditional approach of selecting or designing a new bearing assembly for each particular housing based on the outer diameter of the outer bearing ring. The disclosed approach may allow for a single bearing assembly with a certain shaft/bore size to be used with a large variety of housings because the size/thickness of the radial extension may be changed without any changes to the bearing assembly itself. Therefore, a “custom” bearing assembly can be produced for each housing by tailoring the thickness of the radial extension, all while using s standardized bearing assembly design. 
     Such standardization may reduce the time and cost associated with designing a new bearing assembly from scratch. Instead, only the radial extension may need to be adjusted, for example, by changing an over-molding tool. This may be substantially easier and more cost effective than changing the design of the bearing assembly itself. In addition to cost and time savings, the use of the radial extension may also provide a significant weight reduction compared to using a larger bearing assembly. This may be particularly true when a relatively light duty bearing assembly can be used in a relatively large housing. For example, bearings used with intermediate drive shafts and propeller shafts may not require high-load bearing assemblies. Accordingly, a relatively light-load or light-duty bearing assembly may have a radial extension added (e.g., by over-molding) to increase the OD of the bearing assembly to fit a relatively large housing. If the radial extension is formed of a light weight material, such as a polymer, then significant weight reduction may be achieved. 
     Another benefit of the disclosed radial extensions may be an improvement in noise, vibration, and harshness (NVH). The material used for the radial extension may provide a damping effect that may reduce noise or vibration in the bearing assembly. This may be particularly true if the radial extension is formed of an elastomeric material, such as rubber. Accordingly, the disclosed expanded diameter bearing assemblies may provide streamlined engineering, cost reduction, and/or weight reduction, all without compromising the fit or function of the bearing assembly. 
     Examples 
     In one example, a bearing assembly is being selected based on a particular housing design. The housing has a bore dimension of 40 mm, a width of 22 mm, and is configured to receive a bearing assembly with an OD of 72 mm. Conventionally, a bearing assembly would be chosen (or designed from scratch) to have a matching 40 mm bore dimension and a 72 mm OD. However, according to the present disclosure, an existing bearing assembly design may be used that has a bore dimension of 40 mm, a width of 17 mm, and an OD of 68 mm. A radial extension having a thickness of 2 mm may be applied to the bearing assembly (e.g., by over-molding) to increase the OD of the bearing assembly by 4 mm to the 72 mm required by the housing. Accordingly, a smaller bearing assembly may be used, which will reduce the bearing OD by 4 mm and width by 5 mm. In many applications, the width dimension is not a critical one, therefore a smaller width may be used without compromising the safety or performance of the bearing assembly. 
     In another example, a bearing assembly is being selected based on a different housing design. The housing has a bore dimension of 35 mm, a width of 18 mm, and is configured to receive a bearing assembly with an OD of 62 mm. Again, conventionally, a bearing assembly would be chosen (or designed from scratch) to have a matching 35 mm bore dimension and a 62 mm OD. However, according to the present disclosure, an existing bearing assembly design may be used that has a bore dimension of 35 mm, a width of 16.6 mm, and an OD of 55 mm. A radial extension having a thickness of 3.5 mm may be applied to the bearing assembly (e.g., by over-molding) to increase the OD of the bearing assembly by 7 mm to the 62 mm required by the housing. Accordingly, a smaller bearing assembly may be used, which will reduce the bearing OD by 7 mm and width by 1.4 mm. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.