Abstract:
An assembly includes a rotatable member formed with a recess, a first component, a snap ring located in the recess for limiting axial displacement of the first component, and a bearing located between the first component and a second component, including a finger extending from a race of the bearing toward the bearing and able to limit radial movement of the snap ring.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an apparatus for retaining a snap ring in a groove formed in a rotating component having a speed that causes the snap ring to expand radially due to centrifugal force. 
     2. Description of the Prior Art 
     External snap rings attached to the exterior of rotating shafts and hubs tend to expand radially when rotating at high speeds, due to centrifugal force on the snap ring. 
     An easy way to hold snap rings in place is to have a step in the adjacent part that would wrap around the outer diameter of the snap ring, retaining it in place where the snap ring can&#39;t grow larger than the engagement groove when spinning fast. This approach requires that the part having the step can be pushed away from the snap ring so that the snap ring can be installed and retained part slid back. A clutch piston depressed against its return spring is an example of this approach. 
     When retaining a hub to a shaft, it normally will push against a hard stop, not a spring, thereby producing an installation problem when a snap ring is needed to hold the hub in place axially. 
     A potential solution, involves adding a second part, e.g., a loose L-shaped washer that gets pinched in place and has similar features to retain the snap ring, also requires ability to move the retained part beyond its normal location so that the snap ring can be installed. 
     SUMMARY OF THE INVENTION 
     An assembly includes a rotatable member formed with a recess, a first component, a snap ring located in the recess for limiting axial displacement of the first component, and a bearing located between the first component and a second component, including fingers extending from a race of the bearing toward the bearing and able to limit radial movement of the snap ring. 
     Little or no cost is added to the bearing due to the fingers being formed from material that would conventionally be scrapped after forming a bearing race without the fingers. The assembly includes no additional parts and no additional package space as compared to a conventional assembly. 
     The fingers key into the first component, assuring no relative motion between that bearing race and the first component, minimizing risk of wear between those parts when the bearing is not under axial load. As long as the fingers are asymmetric, they also provide the function of preventing the bearing from being installed upside down in the transmission. 
     The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The invention will be more readily understood by reference to the following description, taken with the accompanying drawings, in which: 
         FIG. 1  is a cross sectional side view of an assembly that includes a snap ring, thrust washer and thrust bearing; 
         FIG. 2  illustrates an alternate thrust bearing  40  in the assembly of  FIG. 1 ; 
         FIGS. 3A-3E  are each a side view of an alternate thrust bearing for the assembly; 
         FIG. 4A  is a side of the assembly having an alternate bearing; and 
         FIGS. 4B and 4C  are alternate views of the bearing of  FIGS. 4A and 3E . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to of  FIG. 1 , wherein an assembly  10  includes a thrust bearing  12 , a first component, such as a clutch hub  14 ; a shaft  16  supported for rotation about an axis  18 ; a snap ring  20 ; and a second component  22 , secured by a weld  24  to a second shaft  26 . Snap ring  20  is fitted in an annular recess  28  formed in the radial outer surface of shaft  16 . The thrust bearing  12  permits rotation of component  14  relative to component  22  and transmits axially-directed force between components  14  and  22 . Shaft  16  and snap ring  20  rotate about axis  18  at high speed, which may be about 7000 rpm. 
     Component  14  is formed with an axial extensions  30 , spaced mutually at equal angular intervals about axis  18 , the extensions  30  provides a radial pilot surface for locating the thrust bearing  12 . 
     Thrust bearing  12  preferably includes three tabs or fingers  32 , each finger spaced mutually at equal angular intervals about axis  18  and extending toward the snap ring  20 . The fingers are easy to make and use material of the bearing that would have been scrapped when forming this race if the tabs were not used in the assembly  10 . 
     Radial contact between the radial inner end of the fingers and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     Angular contact between the fingers  30  and the extensions  32  prevents rotation of the thrust bearing  12  relative to component  14 . 
       FIG. 2  illustrates an alternate thrust bearing  40 , which includes an L-shaped race  42  having legs  44  directed axially to provide greater axial length above the snap ring  20  to prevent the snap ring from moving radially outward from its recess  28  due to centrifugal force and retaining the snap ring in its correct location. 
       FIGS. 3A-3D  illustrate alternate thrust bearings for use in the assembly  10 . Bearing  46  includes races  48 ,  50 , surrounding cage members  52 ,  54 , which cage contains a series of annularly-spaced rotating members  56  supported for rotation about an axis  58 . Race  48  includes angularly-spaced fingers  62 , each finger is spaced mutually at equal angular intervals about axis  18 . Each finger  62  is formed with a radially-directed portion located at a different axial position from the position of fingers  30  of  FIG. 1 , and an axial portion  64 . 
     Radial contact between the radial surface  66  of fingers  62  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. Angular contact between fingers  62  and the extensions  32  prevents rotation of the thrust bearing  12  relative to component  14 . Furthermore, the axial location of radial portions  62  indicates to the installer that the bearing is correctly installed if its radial portions  62  key into component  14 . 
     Bearing  68  of  FIG. 3B  includes a race  70  formed with radial fingers  72 , each finger spaced mutually at equal angular intervals about axis  18 . Radial contact between the radial surface  74  of fingers  72  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     Bearing  76  of  FIG. 3C  includes a race  78  formed with L-shaped fingers  80 , each finger spaced mutually at equal angular intervals about axis  18 . Each finger  80  includes an axially-directed leg to provide greater axial length above the snap ring  20  to prevent the snap ring from moving radially outward from its recess  28 . Radial contact between the radial surface  84  of fingers  80  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     Bearing  86  of  FIG. 3D  includes a race  88  formed with fingers  90 , each finger spaced mutually at equal angular intervals about axis  18 . Each finger  90  includes an axially-directed portion  92  depending to a radially-directed portion  94 . Radial contact between the axial surface  96  of portion  92  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     Bearing  98  of  FIGS. 4A-4C  includes a race  100  formed with U-shaped fingers  102 , each finger spaced mutually at equal angular intervals about axis  18 . Each finger  102  includes a web  104  connecting axially-directed legs  106 ,  108  having concave outer surfaces. Bearing  98  provides extra length for retaining the snap ring  20  in its recess  28 . Radial contact between the radial surface  110  of fingers  102  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     Bearing  112  of  FIG. 3E  includes a race  114  formed with U-shaped fingers  116  folded in the opposite axial direction from the fingers  102  of  FIGS. 4A-4C . Each finger  116  is spaced mutually at equal angular intervals about axis  18 . Each finger  116  includes the web  104  connecting axially-directed legs  106 ,  108  having concave outer surfaces. Radial contact between the radial surface  118  of fingers  116  and the outer radial surface of the snap ring  20  prevents the snap ring from moving radially outward from its recess  28  due to centrifugal force. 
     In accordance with the provisions of the patent statutes, the preferred embodiment has been described. However, it should be noted that the alternate embodiments can be practiced otherwise than as specifically illustrated and described.