Abstract:
A bearing assembly, including a housing with a first circumferentially disposed groove; a bearing including an outer race with a second circumferentially disposed groove; and a retaining ring disposed within the first and second circumferentially disposed grooves. A method of retaining a bearing, including: locating a first portion of a ring within a groove in an outer race; installing a housing radially about the race to contact the race; locating a second portion of the ring within a groove in the housing; bringing temperature of the housing and the race to a first level; fixing, with contact between the race and the housing, the race with respect to the housing; increasing the temperature of the housing and race to a second higher level; creating a radial gap between the housing and the outer race; and fixing, with the retaining ring, a position of the race with respect to the housing.

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. 61/868,892, filed Aug. 22, 2013, which application is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a bearing assembly including a retaining ring disposed in respective grooves in a housing and an outer race for the bearing assembly and arranged to fix a position of the outer race with respect to the housing. The coefficient of thermal expansion of the retaining ring is at least equal to the coefficient of thermal expansion of the housing to ensure that the retaining ring remains in the groove in the housing when the bearing assembly is subjected to elevated temperatures. 
     BACKGROUND 
     Bearing assemblies, for example for internal combustion engines, are known to include a housing made of a first material and an outer race radially enclosed by the housing and made of a second material. For proper functioning of the bearing assembly, the outer race must be axially fixed with respect to the housing. Typically, the first material, such as aluminum or aluminum alloy, has a first coefficient of thermal expansion and the second material, such as steel, has a second coefficient of thermal expansion less than the first coefficient of thermal expansion. As a result, when the bearing assembly is subjected to elevated temperatures (for example, the internal combustion engine is operating), the housing expands radially outward more than the outer race, breaking contact between the housing and the outer race, which prevents axial fixing of the outer race with respect to the housing. 
     It is known to install the outer race in the housing with a tight interference or press fit that results in high compressive force between the outer race and housing. However, this tight fit increases the difficulty of installing the bearing assembly and causes distortion that interferes with operation of the bearing assembly. U.S. Patent Application Publication No. 2012/0304813 discloses the use of retaining clips that add a great deal of complexity to the bearing assembly as well as increasing the cost and dimensions of the bearing assembly. U.S. Patent Application Publication No. 2009/0080824 discloses a thermal compensating element that is in direct contact with a housing and the roller elements of the bearing assembly. The thermal compensating element compensates for thermal expansion by applying pressure directly to the roller elements, which can interfere with operation of the roller elements. U.S. Patent Application Publication No. 2006/0160651 discloses the use of a shim engaged with an axial surface of a bearing race to accommodate thermal expansion in a differential gear by axially expanding to compress the bearing race. U.S. Pat. No. 8,286,533 discloses the use of retaining clips that add a great deal of complexity to the bearing assembly as well as increasing the cost and dimensions of the bearing assembly. U.S. Pat. No. 4,549,823 discloses the use of an elastomeric ring between a housing and an outer race of a bearing assembly. 
     SUMMARY 
     According to aspects illustrated herein, there is provided a bearing assembly, including: a housing with a first circumferentially disposed groove; a bearing including an outer race with a second circumferentially disposed groove; and a retaining ring disposed within the first and second circumferentially disposed grooves. 
     According to aspects illustrated herein, there is provided a method of retaining a bearing, including: locating a first portion of an annular retaining ring within a first circumferentially disposed groove for an outer race of the bearing; installing a housing radially about the outer race such that the housing contacts the outer race; locating a second portion of the retaining ring within a second circumferentially disposed groove for the housing; bringing respective temperatures of the housing and the outer race to a first level; fixing, with contact between the outer race and the housing, axial and radial positions of the outer race with respect to the housing; increasing the respective temperatures of the housing and the outer race to a second level, higher than the first level; creating a radial gap between the housing and the outer race; and fixing, with the retaining ring, the axial and radial positions of the outer race with respect to the housing. 
     According to aspects illustrated herein, there is provided a bearing assembly, including: a bearing including an annular outer race constructed of a first material with a first coefficient of thermal expansion and including a radially outer circumferential surface and a first circumferentially disposed groove in the radially outer circumferential surface; an annular housing radially disposed about the bearing, constructed of a second material having a second coefficient of thermal expansion greater than the first coefficient of thermal expansion, and including a radially inner circumferential surface and a second circumferentially disposed groove in the radially inner circumferential surface; and an annular retaining ring including a first portion disposed within the first circumferentially disposed groove and a second portion disposed within the second circumferentially disposed groove. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application; 
         FIG. 1B  is a perspective view of an object in the cylindrical coordinate system of  FIG. 1A  demonstrating spatial terminology used in the present application; 
         FIG. 2  is a partial cross-sectional view of a bearing assembly with a retaining ring; 
         FIG. 3  is a perspective view of area  3  in  FIG. 2 ; 
         FIG. 4A  is a detail showing the housing and outer race of  FIG. 2  at a low temperature; 
         FIG. 4B  is a showing the housing and outer race of  FIG. 2  at a high temperature; 
         FIG. 5  is a schematic front view of a bearing assembly with a retaining ring showing a two-part housing; and, 
         FIG. 6  is a partial cross-sectional view of a bearing assembly with a retaining ring. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
       FIG. 1A  is a perspective view of cylindrical coordinate system  80  demonstrating spatial terminology used in the present disclosure. The present disclosure 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 . 
     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. 
       FIG. 1B  is a perspective view of object  90  in cylindrical coordinate system  80  of  FIG. 1A  demonstrating spatial terminology used in the present disclosure. Cylindrical object  90  is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present disclosure 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 a circumferential surface. 
       FIG. 2  is a partial cross-sectional view of bearing assembly  100  with a retaining ring. 
       FIG. 3  is a perspective view of area  3  in  FIG. 2 . The following should be viewed in light of  FIGS. 2 and 3 . Assembly  100  includes axis of rotation AR, annular housing  102 , annular outer race  104 , and annular retaining ring  106 . Housing  102  includes radially inner circumferential surface  108  with circumferentially disposed groove  110 . That is, groove  110  intersects surface  108 . Race  104  includes radially outer circumferential surface  112  with circumferentially disposed groove  114 . That is, groove  114  intersects surface  112 . Portion  112 A of surface  112  extends from groove  114  to axial end  115  of race  104  and portion  112 B of surface  112  extends from groove  114  to axial end  117  of race  104 . Ring  106  is disposed in grooves  110  and  112 . For example, radially outermost portion  106 A of ring  106  is disposed in groove  110  and radially innermost portion  106 B of ring  106  is disposed in groove  114 . Housing  102  is radially disposed about race  104 . As further described below, the retaining ring axially and/or radially restrains the outer race with respect to the housing. By “circumferentially disposed” we mean that the respective groove extends continuously about the housing or race in the circumferential direction defined above and has a depth in the radial direction as defined above and a width in the axial direction as defined above. In an example embodiment, one or both of grooves  110  and  114  extend 360 degrees in the circumferential direction. In an example embodiment, one or both of grooves  110  and  114  extend less than 360 degrees in the circumferential direction. For example, circumferential ends of groove  110  are separated by a portion of surface  108 . 
     In an example embodiment, housing  102  is constructed of a material, for example, aluminum or an aluminum alloy, with a particular coefficient of thermal expansion, and retaining ring  106  is constructed of a another material with a coefficient of thermal expansion equal to or greater than the coefficient of thermal expansion for housing  102 . In an example embodiment, housing  102  and ring  106  are constructed of the same material. In an example embodiment, race  104  is constructed of a material, for example, steel, having a coefficient of thermal expansion less than either of the respective coefficients of thermal expansion for the housing and the ring. 
       FIG. 4A  is a detail showing the housing and outer race of  FIG. 2  at a low temperature. The following should be viewed in light of  FIGS. 2 through 4A . When housing  102  and outer race  104  are each substantially at a relatively low temperature, outer race  104  is axially and radially fixed, with respect to housing  102 , by contact between housing  102  and outer race  104 . For example, there is a compressive or frictional engagement between surfaces  108  and  112  which fixes the position of race  104  with respect to housing  102 . Thus, as shown in  FIG. 4A , there is no radial gap between surfaces  108  and  112 . For example, when assembly  100  is used in an internal combustion engine, the low temperature can be considered a non-operating temperature for the engine, for example, the engine is not operating and is at ambient temperature, or the engine has begun operation, but has not yet heated up. The non-operating temperature also can be defined as a temperature at which thermal expansion of housing  102  and outer race  104  has not occurred or at which the respective thermal expansions of housing  102  and outer race  104  are substantially equal. 
       FIG. 4B  is a detail showing the housing and outer race of  FIG. 2  at a high temperature. The following should be viewed in light of  FIGS. 2 through 4B . When housing  102  and outer race  104  are each substantially at a relatively high temperature, radial gap  116  is created between housing  102  and outer race  104  (between surfaces  108  and  112 ), and outer race  104  is axially and radially fixed, with respect to the housing  102 , by outer race  104 . For example, when assembly  100  is used in an internal combustion engine, the high temperature can be considered an operating temperature for the engine, for example, the engine is operating and the internal combustion process has raised the temperature of housing  102  and outer race  104  well above ambient temperature. The operating temperature also can be defined as a temperature at which thermal expansion of housing  102  has occurred or is occurring at a greater rate than the thermal expansion of outer race  104 . 
     As a result of the increase in temperature and differences between the respective coefficients of expansion for housing  102  and outer race  104  (coefficient is higher for housing  102 ), housing  102  expands at a greater rate than outer race  104 , creating gap  116 . Due to gap  116 , the compressive or frictional engagement of housing  102  and outer race  104  mentioned above is substantially nullified. Therefore, the engagement of housing  102  and outer race  104  is no longer sufficient to restrain outer race  104  with respect to housing  102  (fix axial and radial positions of outer race  104  with respect to housing  102 ). However, retaining ring  106  remains in contact with housing  102  and outer race  104  (disposed in grooves  108  and  112 ), to restrain outer race  104  with respect to housing  102 . 
     For example, as housing  102  expands to create gap  116 , portions  106 A and  106 B of remain in grooves  110  and  114 , respectively. Further, since the coefficient of thermal expansion for ring  106  is greater than the coefficient of thermal expansion for race  104 , portion  106 A expands within groove  114  to increase contact pressure (compressive or frictional) in axial and/or radial directions between portion  106 B and race  104 , which more firmly fixes ring  106  with respect to race  104 . Also, ring  106  expands radially outward, ensuring that portion  106 A remains disposed in groove  110 . In an example embodiment in which the coefficient of thermal expansion for ring  106  is greater than the coefficient of thermal expansion for housing  102 , portion  106 A expands within groove  110 , increasing contact pressure between portion  106 B and housing  102  in axial and/or radial directions. This increase in contact pressure further facilitates the fixing of ring  106  with respect to housing  102  and therefore, the fixing of race  104  with respect to housing  102 . 
       FIG. 5  is a schematic front view of bearing assembly  100  with a retaining ring showing a two-part housing. The following should be viewed in light of  FIGS. 2, 3, and 5 . In an example embodiment, housing  102  includes separate portions  102 A and  102 B fixedly connected to each other by any means known in the art. Portions  102 A and  102 B facilitate fabrication of assembly  100 . For example, ring  106  can be fabricated with a discontinuity to enable ring  106  to be radially expanded to pass over race  104  to slide into groove  114 . Portions  102 A and  102 B can then be placed together such that groove  110  encloses ring  106 . 
       FIG. 6  is a partial cross-sectional view of bearing assembly  100  with a retaining ring. In  FIG. 6 , assembly  100  is shown in an example configuration with inner race  118 , cage  120 , and roller element  122 . It should be understood that assembly  100  is not limited to use with the configuration of  FIG. 6 . 
     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.