Abstract:
A sculptured bearing liner includes an inner surface defining a cavity configured to receive a bearing, an outer surface and a reduced thickness portion extending from one of the inner surface and the outer surface. A bearing assembly includes a bearing liner having an inner surface, an outer surface, and a reduced thickness portion extending between the inner surface and the outer surface, the inner surface defining a cavity. The bearing assembly further includes at least one bearing disposed in the cavity.

Description:
TECHNICAL FIELD 
     The present invention relates in general to the field of bearings. 
     DESCRIPTION OF THE PRIOR ART 
     Many machines incorporate rotating parts, such as shafts, gears, and the like. Most of these machines utilize bearings to support rotating members with respect to fixed members. The fixed members are, at times, made of softer materials, while the bearings comprise harder materials. If the bearings are retained directly against the softer, fixed member, the fixed member will likely be damaged when the bearing is replaced. Thus, it is often desirable to mount such bearings in bearing liners, which are then press-fit or otherwise retained in the fixed members. Moreover, fretting is less likely to occur between the bearing liner and the fixed member than if the bearing liner is omitted. 
     Many such machines are weight sensitive. In other words, it is important to design the machines so that their weight is kept to a minimum. Weight sensitivity is particularly important in aircraft. Helicopters, as well as other types of aircraft, utilize many bearings. For example, a typical helicopter gearbox contains six or more such bearings, which are typically mounted in bearing liners. Conventional bearing liners, however, have substantially consistent thicknesses. 
     There are many bearings and bearing liners well known in the art; however, considerable room for improvement remains. 
     SUMMARY OF THE INVENTION 
     There is a need for an improved bearing liner and bearing assembly. 
     Therefore, it is an object of the present invention to provide an improved bearing liner and bearing assembly. 
     This and other objects are achieved by providing a sculptured bearing liner. The sculptured bearing liner includes an inner surface defining a cavity configured to receive a bearing, an outer surface and a reduced thickness portion extending from one of the inner surface and the outer surface. 
     In another aspect of the present invention, a bearing assembly is provided. The bearing assembly includes a bearing liner having an inner surface, an outer surface, and a reduced thickness portion extending between the inner surface and the outer surface, the inner surface defining a cavity. The bearing assembly further includes at least one bearing disposed in the cavity. 
     The present invention provides significant advantages, including: (1) providing a means for reducing weight in assemblies that incorporate bearing liners; (2) providing a means for reducing weight in machines that are weight sensitive that incorporate bearing liners; and (3) providing a lighter-weight bearing liner. 
     Further objects and advantages of this invention will become apparent from a consideration of the drawings and ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which the leftmost significant digit(s) in the reference numerals denote(s) the first figure in which the respective reference numerals appear, wherein: 
         FIG. 1  is a stylized, perspective view of a first illustrative embodiment of a bearing liner according to the present invention; 
         FIG. 2  is a stylized, perspective view of a second illustrative embodiment of a bearing liner according to the present invention; 
         FIG. 3  is a stylized, cross-sectional view of a first illustrative embodiment of a bearing assembly including a plurality of bearings mounted in the bearing liner of  FIG. 1 , according to the present invention; and 
         FIG. 4  is a stylized, cross-sectional view of a second illustrative embodiment of a bearing assembly including a plurality of bearings mounted in the bearing liner of  FIG. 2 , according to the present invention. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer&#39;s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. 
     In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction. 
     The present invention represents sculptured bearing liner and a bearing assembly incorporating the sculptured bearing liner. The bearing liner includes a loaded portion and an unloaded or lightly loaded portion. The loaded portion and the unloaded or lightly loaded portion is determined by a load direction analysis. The unloaded or lightly loaded portion defines one or more recesses or openings that decrease the overall weight of the bearing liner. Because the one or more recesses or openings are defined in the unloaded or lightly loaded portion of the bearing liner, the overall suitability or strength of the bearing liner, and thus the bearing assembly incorporating the bearing liner, is not adversely impacted. 
       FIG. 1  depicts a first illustrative embodiment of a sculptured bearing liner  101  according to the present invention. Bearing liner  101  comprises an inner surface  103  and an outer surface  105 , each extending between a first edge  107  and a second edge  109 . In the illustrated embodiment, an outer lip  111  extends radially outwardly from outer surface  105  at first edge  107  and an inner lip  113  extends radially inwardly from inner surface  103  at second edge  109 . It should be noted, however, that the present invention contemplates embodiments wherein one or both of outer lip  111  and inner lip  113  are omitted. Inner surface  103  and inner lip  113 , if present, define a cavity  115  in which one or more bearings, such as one or more of bearings  301 ,  303 , and  305  (not shown in  FIG. 1  but shown in  FIGS. 3 and 4 ) are received. Inner lip  113 , if present, retains the one or more bearings in cavity  115 , as the one or more bearings cannot move beyond inner lip  113  in a direction generally corresponding to an arrow  117 . 
     Generally, mechanical loads are transmitted through the one or more bearings, such as bearings  301 ,  303 , and  305 , to bearing liner  101  when the one or more bearings and bearing liner  101  are in service. In some implementations, however, loads are applied only to a portion of bearing liner  101 . Thus, bearing liner  101  includes a low-load zone  119 , indicated in  FIG. 1  as the portion within the phantom line. It should be noted that, for the purposes of this disclosure, loads ranging from substantially no loads to mechanically insignificant loads are imparted to low-load zone  119 . 
     Bearing liner  101 , therefore, defines a reduced thickness area  121  in low-load zone  119 , as low-load zone  119  does not require the mechanical properties required by other zone or zones of bearing line  101  require. Preferably, low-load zone  119  is 180° out of phase from a loaded zone of bearing liner  101 . In one particular preferred embodiment, reduced thickness area  121  is formed by a recess extending from inner surface  103  but not extending to outer surface  105 . It should be noted, however, that the present invention contemplates an embodiment wherein reduced thickness area  121  is formed by a recess extending from outer surface  103  but not extending to inner surface  105 . In another particular preferred embodiment, reduced thickness area  121  is formed by an opening extending from inner surface  103  to outer surface  105  but not extending to either first edge  107  or second edge  109 . It should be noted that one or more portions of reduced thickness area  121  may fully extend between inner surface  103  and outer surface  105 , while one or more other portions of reduced thickness area  121  may extend from inner surface  103  but not to outer surface  105  or may extend from outer surface  105  but not extend to inner surface  103 . 
     While reduced thickness area  121  is depicted in  FIG. 1  as having a particular size and shape, the scope of the present invention is not so limited. Rather, the scope of the present invention encompasses any bearing liner, such as bearing liner  101 , having a reduced thickness area, such as reduced thickness area  121 , of any suitable size and shape. The reduced thickness area, however, is confined within a low-load zone, such as low-load zone  119 , of the bearing liner. 
     Bearing liner  101  further comprises one or more clocking features  123  to aid in proper alignment of bearing liner  101  with respect to elements or components transmitting mechanical loads thereto. In the illustrated embodiment, clocking feature  123  is a mark that is substantially aligned with a corresponding mark on a structure in which bearing liner  101  is received. The present invention, however, contemplates clocking features other than a mark. 
       FIG. 2  depicts a second illustrative embodiment of a sculptured bearing liner  201  according to the present invention. Elements and features of bearing liner  201  correspond to elements and features of bearing liner  101 , except that reduced thickness area  121  is replaced by a plurality of reduced thickness areas  203 ,  205 , and  207 . One or more of reduced thickness areas  203 ,  205 , and  207 , in a preferred embodiment, extend from inner surface  103  but do not extend to outer surface  105 . In another preferred embodiment, one or more of reduced thickness areas  203 ,  205 , and  207  extend from inner surface  103  to outer surface  105 . The present invention, however, contemplates embodiments wherein one or more of reduced thickness areas  203 ,  205 , and  207  extend from outer surface  103  but do not extend to inner surface  103 . It should be noted that one or more portions of reduced thickness areas  203 ,  205 , or  207  may fully extend between inner surface  103  and outer surface  105 , while one or more other portions of reduced thickness areas  203 ,  205 , or  207  may extend from inner surface  103  but not to outer surface  105  or may extend from outer surface  105  but not extend to inner surface  103 . 
     While reduced thickness areas  203 ,  205 , and  207  are depicted in  FIG. 2  as having particular sizes and shapes, the scope of the present invention is not so limited. Rather, the scope of the present invention encompasses any bearing liner, such as bearing liner  101 , having a plurality of reduced thickness areas, such as reduced thickness areas  203 ,  205 , and  207 , of any suitable size and shape. The reduced thickness areas, however, are confined within a low-load zone, such as low-load zone  119 , of the bearing liner. 
       FIGS. 3 and 4  depict illustrative embodiments of bearing assemblies  307  and  401 , respectively. Referring in particular to  FIG. 3 , bearing assembly  307  comprises one or more bearings  301 ,  303 , and  305  received in a sculptured bearing liner  309 . Bearing liner  309  is retained in a structure  311 , preferably via a press fit. It should be noted that bearing assembly  307  may comprise other components or elements. In the illustrated embodiment, bearing liner  309  defines a reduced thickness area, indicated generally at  313 . Bearing liner  309  may define a single reduced thickness area  313 , corresponding to the embodiment of  FIG. 1 , or may define a plurality of reduced thickness areas  313 , corresponding to the embodiment of  FIG. 2 . In the illustrated embodiment, reduced thickness area  313  extends from an inner surface  315  of bearing liner  309  but does not extend to an outer surface  317  of bearing liner  309 . As discussed in reference to the embodiments of  FIGS. 1 and 2 , reduced thickness area  313  may, in an alternative embodiment, extend from outer surface  317  but not extend to inner surface  317 . In the illustrated embodiment, an outer lip  319  extends radially outwardly from outer surface  317  at a first edge  321  of bearing liner  309  and an inner lip  323  extends radially inwardly from inner surface  315  at a second edge  325  of bearing liner  309 . It should be noted, however, that the present invention contemplates embodiments wherein one or both of outer lip  319  and inner lip  323  are omitted. 
     Turning now to  FIG. 4 , bearing assembly  401  comprises one or more bearings  301 ,  303 , and  305  received in sculptured bearing liner  403 . Bearing liner  403  is retained in structure  311 , preferably by a press fit. Note that bearing assembly  401  may comprise other components or elements. In the illustrated embodiment, bearing liner  309  defines an opening  405  extending between an inner surface  407  and an outer surface  409  of bearing liner  403 . Opening  405  forms a reduced thickness area, i.e., a zero-thickness area, in bearing liner  403 . In the illustrated embodiment, an outer lip  411  extends radially outwardly from outer surface  409  at a first edge  413  of bearing liner  403  and an inner lip  415  extends radially inwardly from inner surface  407  at a second edge  417  of bearing liner  403 . It should be noted, however, that the present invention contemplates embodiments wherein one or both of outer lip  411  and inner lip  407  are omitted. 
     It should be noted that the bearing liner of the present invention, such as bearing liner  101 ,  201 ,  309 , and  403 , is a non-rotating element. In other words, bearing liners  101 ,  201 ,  309 , and  403  do not rotate with respect to a structure, such as structure  311  (shown in  FIG. 3 ), or with respect to a bearing, such as bearings  301 ,  303 , or  305  (shown in  FIGS. 3 and 4 ). Preferably, bearing liners  101 ,  201 ,  309 , and  403 , or their equivalents, comprise steel or a ceramic material. It should be noted that, in some embodiments, a portion of outer lip  111 ,  319 , or  411  and/or a portion of inner lip  113 ,  315 , or  407  may be removed, for example, to facilitate removal of bearing liners  101 ,  201 ,  309 , and  403  from a structure, to facilitate removal of a bearing from bearing liners  101 ,  201 ,  309 , and  403 , and/or to provide clearance for one or more other elements or components. It should also be noted that the bearing liner of the present invention, such as bearing liner  101 ,  201 ,  309 , and  403 , can take on any suitable size or shape. 
     The present invention has particular utility in machinery that is weight sensitive, such as helicopters, airplanes, aircraft, vehicles, and the like. Implementation of the bearing liner of the present invention can produce a weight savings, in one embodiment, of up to about 40% as compared to conventional bearing liners. 
     The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.