Abstract:
An angular contact ball bearing, and a method for lubricating the same, has multiple ball pockets connected to an annulus channel via at least one hole that allows a fluid to flow from the annulus channel to the ball pockets.

Description:
BACKGROUND 
     The present disclosure relates generally to bearing assemblies and more particularly, to a bearing cage for an angular contact ball bearing assembly. 
     Bearing assemblies are often used in engines to facilitate rotational movement of engine components. In particular, angular contact ball bearings are frequently used in gas turbine engines to support rotating engine components. The high speed rolling element bearings include multiple rolling elements contained within a bearing cage. The rotation of the rolling elements within the bearing cage causes friction between the rolling elements and any bearing components contacting the rolling elements. In order to reduce the effects of friction, and to remove heat generated by friction, the rotating components within the bearings are lubricated and cooled by injecting oil or another coolant into the portion of the bearing cage holding the rotating element. 
     Current bearing cage designs utilize channels etched into a bearing cage land surface that simultaneously provide lubricant to the bearing cage land surface and to the rotating elements of the bearing assembly. 
     SUMMARY 
     Disclosed is an angular contact ball bearing having a bearing cage. The bearing cage has a plurality of ball pockets, an annulus channel running circumferentially through the bearing cage relative to an axis defined by the bearing cage, and at least one hole connecting one of the plurality of ball pockets to the annulus channel. 
     Also disclosed is a method for lubricating an angular contact ball bearing including the steps of injecting oil into an annulus channel, and passing oil from the annulus channel into a ball pocket through a hole connecting the annulus channel to a ball pocket, thereby lubricating the ball pocket. 
     Also disclosed is a ball bearing cage having an annulus channel, a plurality of ball pockets for holding ball bearing elements, and a plurality of holes. Each of the ball pockets is connected to the annulus channel via at least one of the holes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example view of a rolling element bearing. 
         FIG. 2  illustrates a flattened view of the bearing cage of the rolling element bearing of  FIG. 1 . 
         FIG. 3  illustrates a cutout end view of the bearing cage of the rolling element bearing of  FIG. 1 . 
         FIG. 4  illustrates a cutout end view of an alternative embodiment of the bearing cage of the rolling element bearing of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates an example ball bearing assembly  10  that has a bearing cage  20 . The bearing cage  20  includes multiple ball pockets  30  each of which contains a ball bearing element  32 . The bearing cage  20  is cylindrical and defines an axis A. The bearing cage  20  also includes an annulus channel  40  running circumferentially through the bearing cage  20  relative to the axis A. The annulus channel  40  is connected to each ball pocket  30  by a hole  50 . An outer bearing ring  70  surrounds the exterior of the bearing cage  20  and an interior bearing ring  80  is positioned inside the bearing cage  20 . Each of the outer bearing ring  70  and the inner bearing ring  80  includes a raceway  34  to allow rotation of the inner and outer bearing rings  70 ,  80  about the axis A. The rotation of the inner and outer bearing rings  70  causes the ball bearing element  32  to also rotate.  FIG. 1  is not drawn to scale, and certain features such as the gaps between the bearing cage  20  and the inner and outer bearing rings  70 ,  80  are exaggerated for explanatory purposes. 
     Lubricant or oil can be injected into the annulus channel  40  and centrifugal force due to the rotation of the bearing elements  20 ,  70 ,  80 , forces the lubricant or oil through the holes  50  connecting the annulus channel  40  to each ball pocket  30  and into the ball pockets  30 . Once the lubricant or oil reaches the ball pocket  30 , the rotation of the ball bearing element  32  spreads the lubricant or oil across the ball bearing element  32  surface, thereby lubricating the bearing assembly  10 . 
     A flattened internal view of the bearing cage  20  is illustrated as bearing cage  120  in  FIG. 2 . The view of  FIG. 2  illustrates the interior surface of the bearing cage  120 , the multiple ball pockets  130 , and the annulus channel  140 . The holes  150  connecting the annulus channel  140  to each of the ball pockets  130  are illustrated using hidden lines, as the holes  150  pass through the bearing cage  120  rather than intersecting either the inner or outer surface of the bearing cage  120 . 
     By passing the holes  150  through the bearing cage  120 , lubricant or cooling oil can be delivered to the ball pocket  130  from the annulus channel  140  without causing additional breaks in the surface area of the bearing cage lands  122 . Breaks in the surface area of the bearing cage lands  122 , such as would be present with surface channels instead of holes  150 , adds the possibility of wear, when the bearing cage  120  contacts the inner ring  80 . The additional wear can cause the bearing to fail prematurely. 
       FIGS. 3 and 4  illustrate a cutout side view of two example bearing cages  120 , illustrated as bearing cages  210  and  310 . The example bearing cages  210 ,  310  can each be used as the bearing cage  20  in the example of  FIG. 1 . The bearing cages  210 ,  310  include cylindrical hole shaped ball pockets  230 ,  330 , with each of the ball pockets  230 ,  330  defining an axis B. Each bearing cage  210 ,  310  additionally includes an annulus channel  240 ,  340  and a hole  250 ,  350  connecting the annulus channel  240 ,  340  to the illustrated ball pocket  230 ,  330 . An interior cage land surface  222 ,  322 , is illustrated as the bottom surface. The interior cage land surface  222 ,  322  faces the inner bearing ring  80  in the assembly of  FIG. 1 , and can incidentally contact the inner bearing ring  80  (illustrated in  FIG. 1 ) during standard use. As illustrated in  FIGS. 3 and 4 , each of the annulus channels  240 ,  340  includes a far wall  242 ,  342  on the edge of the annulus channel  240 ,  340  farthest away from the ball pocket  230 ,  330  and a base wall  244 ,  344  approximately parallel to the cage land surface  222 ,  322 . 
     The third annulus channel wall  246  illustrated in  FIG. 3  is angled away from the ball pocket  230  interior wall  232  such that the third annulus channel wall  246  provides an angled surface for intersecting with the hole  250 . As an alternate embodiment, the third annulus channel wall  346  is approximately parallel to the axis B defined by the ball pocket  330  as is illustrated in  FIG. 4 . Additional alternative annulus channel shapes could also be used depending on manufacturing concerns and still fall within the above disclosure. 
     Additionally, the hole  250 ,  350  connecting the annulus channel  240 ,  340  to the ball pocket  230 ,  330  is angled relative to both the interior cage land surface  222 ,  322  and the axis B. The particular angle of the hole  250 ,  350  can be varied depending on manufacturing concerns, provided neither the ball pocket  230 ,  330  intersection nor the annulus channel  240 ,  340  intersection intersects with the interior cage land surface  222 ,  322  or the exterior cage land surface. Furthermore, the hole  250 ,  350  connecting the annulus channel  240 ,  340  to the ball pocket  230 ,  330  could alternatively be approximately parallel to the interior cage land surface  222 ,  322 . 
     Although embodiments of this invention have been disclosed, a worker of ordinary skill would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.