Abstract:
The present invention is an anti rotational creep bearing including a socket designed in the inner race of the bearing for partially receiving an anti creep ball therein, further including a shaft onto which the bearing is to be longitudinally mounted, including a channel defined along a longitudinal direction for receiving there along the anti creep ball projecting from its socket, wherein the depth of the socket plus the depth of the channel is at least equal to the diameter of the anti creep ball, such that when the bearing is installed on the shaft, the anti creep ball prevents creep in the rotational direction, however allows movement in the axial direction.

Description:
THE CROSS REFERENCE TO RELATED APPLICATIONS 
     The application is a division of U.S. Utility Patent Application No. 12/213,302, filed on Jun. 18, 2008, which is a National Stage filing based upon PCT Application No. PCT/CA2007/000008, filed on Jan. 4, 2007, which claims priority from previously filed U.S. Provisional Patent Application No. 60/766,600, titled “BEARING ANTI CREEP DEVICE &amp; METHOD”, filed on Jan. 31, 2006 by John Horvat. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to anti creep devices for ball bearings and more particularly relates to a bearing anti creep device, system and a method of employing the device. 
     BACKGROUND OF THE INVENTION 
     Typically a ball bearing, needle bearing or other types of bearings are mounted onto a shaft and also another object in order to permit rotation of the shaft relative to the object. Typically, the inner race of a bearing is pressed onto a shaft and the outer race of the bearing is pressed into a bearing seat defined within a housing. Due to longitudinal or axial thermal expansions and contractions of the shaft and/or the housing into which the bearing is seated, there must be made allowance for axial movement of the bearing relative to the shaft and/or relative to the housing. In order to provide for this longitudinal or axial movement, the bearing mounting must be loose enough to accommodate longitudinal or axial movement of the bearing. Upon rotation and loading of the bearing, the outer bearing and/or the inner bearing race may rotationally creep. For example the inner bearing race may creep (move) rotational on the outer diameter of the shaft causing abrasion, wear, distortion and/or fretting corrosion along the bearing seat contact surface. 
     This rotational creep is undesirable due to the damage that it can impart upon either the bearing, the housing that the bearing is mounted into and/or the shaft that the bearing is mounted onto. 
     The damage imparted by the rotational creep may become so extensive, that repair must be initiated which often can be expensive and require additional machining of housings and/or shafts and replacement of bearings which creates down time of the machine and therefore lost production to the manufacturing operation. 
     BRIEF SUMMARY OF THE INVENTION 
     Therefore, it is desirable to have a device and/or a method for prevention of rotational creep in order to ensure that the outer race and the inner race do not move rotationally relative to the bearing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example only with reference to the following drawings: 
         FIG. 1  a side elevational view of a ball bearing together with an anti creep ball mounted in the inner race. 
         FIG. 2  is a front perspective view of a ball bearing with an anti creep ball mounted in the inner race. 
         FIG. 3  is a top schematic perspective view of a shaft showing a channel defined therein. 
         FIG. 4  is a front elevational view of a ball bearing mounted on a shaft together with an anti creep ball mounted on the inner race. 
         FIG. 5  is a front perspective view of a shaft having a ball bearing mounted thereon on one end together with a channel defined in one end. 
         FIG. 6  is a schematic cross sectional view of the arrangement shown in  FIG. 5  showing a ball bearing mounted onto a shaft together with the anti creep ball. 
         FIG. 7  is a partial cut away schematic perspective view of the arrangement shown in  FIG. 5  showing a ball bearing mounted onto a shaft together with the anti creep ball. 
         FIG. 8  is a front perspective view of a ball bearing showing an anti creep ball mounted in the outer race. 
         FIG. 9  is a schematic perspective view of the bearing shown in  FIG. 8  with an anti creep ball shown mounted in the outer race. 
         FIG. 10  is a front perspective view of a housing showing a channel defined therein. 
         FIG. 11  is a front plan view of a bearing mounted into the bearing seat of a housing together with the anti creep ball mounted therein. 
         FIG. 12  is a front perspective view of the assembly shown in  FIG. 11 . 
         FIG. 13  is a cross sectional view of the assembly shown in  FIG. 12  in which a ball bearing is mounted onto a bearing seat defined in a housing together with a anti creep ball. 
         FIG. 14  is a front partial cut away perspective view of the arrangement shown in  FIG. 13 . 
         FIG. 15  is a front plan view of a ball bearing showing a socket defined in a bearing face. 
         FIG. 16  is a schematic perspective view of a ball bearing shown with a socket defined in a bearing face. 
         FIG. 17  is a front schematic perspective view of a housing shown together with a socket defined in a shoulder of the housing. 
         FIG. 18  is a front elevational view of the assembled bearing and housing: 
         FIG. 19  is a front perspective view of the device shown in  FIG. 18 . 
         FIG. 20  is a cross sectional view of the assembly shown in  FIGS. 18 and 19  in which a ball bearing is shown mounted in a bearing seat abutting a shoulder shown together with an anti creep ball. 
         FIG. 21  is a partial cut away perspective view of the arrangement shown in  FIG. 20 . 
         FIG. 22  is a schematic top perspective view of yet alternate ball bearing showing three different socket locations. 
         FIG. 23  is a schematic top perspective view of the ball bearing shown in  FIG. 22  with the anti creep balls shown in stalled in the sockets. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The first embodiment of the present invention is depicted in  FIGS. 1 through 7  inclusively.  FIG. 1  shows a ball bearing  102  which includes an outer race  104  and inner race  106 , bearing cage  108  having ball bearings  110  therein. Ball bearing  102  also includes an anti creep ball  100  shown mounted in the inner diameter  111  of the inner race  106  of ball bearing  102 .  FIG. 2  a perspective schematic view of ball bearing  102  shows anti creep ball  100 , located roughly mid way across the width of the inner diameter  111  of the inner race  106 . 
       FIG. 3  shows a shaft  112  having a channel  114  defined therein. Figuresr 4  and  5  show a ball bearing  102  mounted on shaft  112 . Typically a bearing such as ball bearing  102  is either slideably received onto shaft  112  in the longitudinal direction  122  and/or is pressed onto the end of shaft  112  in the longitudinal direction  122  due to a friction fit between the inner race  106  and the outer diameter  113  of shaft  112 . Anti creep ball  100  registers with longitudinal channel  114  as ball bearing  102  is pushed longitudinally over shaft  112  into the installed position as shown in  FIG. 5 . Referring now to  FIGS. 6 and 7  which schematically show in cross section along the longitudinal direction  122 , ball bearing  102  mounted onto shaft  112 . Anti creep ball  100  is preferably a small ball bearing which is seated in a socket  120  defined in inner race  106  of ball bearing  102 . Socket  120  is also referred to as first socket through out this specification. A second socket  123  is preferably a channel  114  which is preferably a semi circular shaped groove adapted to receive therein substantially one half of the anti creep ball. The depth of socket  120  is approximately ½ of the diameter of anti creep ball  100  and therefore the depth of channel  114  is also approximately ½ the diameter of anti creep ball  100 . In order to assemble ball bearing  102  onto shaft  112 , anti creep ball  100  is mounted into socket  120  and held in place with a small amount of grease for example. Thereafter, ball bearing  102  with anti creep ball  100  mounted in socket  120  can be slideably fit over the end of shaft  112  provided that anti creep ball  100  registers and travels along channel  114  during the assembly procedure along longitudinal direction  122 . Person skilled in the art will recognize that there must be sufficient clearance between anti creep ball  100  and channel  114  to allow assembly. A person skilled in the art will note that the inclusion of anti creep ball  100  will prevent rotation of the inner race  106  in rotational direction  124  relative to shaft  112  due to the locking function of anti creep ball  100  which is simultaneously mounted in socket  120  and also channel  114 . The use of anti creep ball  100  allows ball bearing  102  to move in the longitudinal direction  122 , however prevents bearing creep in the rotational direction  124  shown in  FIG. 4 . 
       FIGS. 8 through 14  show a second embodiment of the present invention. Ball bearing  103  depicted in  FIGS. 8 and 9  shows a anti creep ball  100  mounted in the outer diameter  115  of the outer race  104  of ball bearing  103 . In this application, ball bearing  103  is mounted into a housing  140  having a bearing seat  142 , a shoulder  144  and a channel  114 . Shown in assembled position in  FIGS. 11 and 12 , ball bearing  103  is slideably mounted onto bearing seat  142  by slideably urging ball bearing  103  in the longitudinal direction  122  onto bearing seat  142  until it is flush with shoulder  144  defined in housing  140 .  FIGS. 13 and 14  show schematically in partial cross section view the mounting of ball bearing  103  into housing  140 . Ball Bearing  103  is slideably urged in longitudinal direction  122  into bearing seat  142  by aligning and registering anti creep ball  100  with channel  114  in order to install ball bearing  103  into housing  140 . In similar fashion as the previous embodiment, anti creep ball  100  is located simultaneously in a socket  120  and also in a channel  114 . Socket  120  has a depth approximately ½ the diameter of anti creep ball  100  and channel  114  has a depth again of approximately ½ the diameter of anti creep ball  100 . Therefore, ball bearing  103  is free to move in the longitudinal direction  122 , however will prevent rotational creep in rotation direction  124 . 
     The third embodiment of the present invention is depicted in  FIGS. 15 through 21  in which ball bearing  105  includes a socket  120  defined in the bearing face  131  of the outer race  104 . A housing  141  having a shoulder  144  and a bearing seat  142  has defined on the shoulder  144  a first socket  121 . First socket  121  is a spherical dome adapted to receive up to one half of the anti creep ball. As best shown in cross sectional view as in  FIGS. 20 and 21 , the depth of second socket  123  defined in shoulder  144  is approximately ½ of the diameter of anti creep ball  100  and the first socket  121  defined in the outer race  104  of bearing  105 , also has a depth of approximately ½ of anti creep ball  100 . Therefore, bearing  105  can move freely in the longitudinal direction  122  for installation purposes. To install ball bearing  105  is urged longitudinally along bearing seat  142  until outer race  104  of ball bearing  105  abuts with shoulder  144  of bearing seat  142 . In order for outer face  131  of outer race  104  of ball bearing  105  to make contact with shoulder  144 , second socket  123  defined in shoulder  144  and first socket  121  defined in outer race  104  must align and register in order to accommodate therein anti creep ball  100 . Additionally a retaining device is used to fix ball bearing  105  into bearing seat  142  thereby minimizing longitudinal movement of ball bearing  105 . The retaining device not shown could be a circlip, retaining plate, or any other means to fix ball bearing  105  into bearing seat  142 . A person skilled in the art will recognize that a shaft passing through inner race  106  can move longitudinally relative to ball bearing  105 . 
     Inner diameter  111 , outer diameter  115 , and bearing face  131  are examples of bearing mounting surfaces. A mounting surface may be any surface of a bearing used to hold the bearing in place. Shoulder  144 , bearing seat  142  shaft outer diameter  113 , are examples of mating surfaces used to mate with a mounting surface to hold a bearing in place. 
     A person skilled in the art will note that ball bearing  102  and  103  are examples of how the anti creep ball could be installed in typical installations. The reader will note that the anti creep ball and this method of preventing rotation of creep can be applied to needle bearings, thrust bearings, roller bearings and/or any other type of bearing which is subject to rotational creep. The reader will also note that this method and device for preventing rotational creep allows for movement of the bearing in the longitudinal direction  122 , however prevents movement of the bearing in the rotational direction  124 , namely rotational creep relative to the bearing seat and/or the shaft. 
     Therefore, a person skilled in the art will note that ball bearing  102  and  103  is free to move in the longitudinal direction  122 ; however the presence of anti creep ball  100  and the first and second sockets  121  and  123  will prevent rotational creep. 
     Referring now to  FIGS. 22 and 23  which depict ball bearing  201  having three distinct sockets defined at different locations of the bearing namely, socket  220  on outer diameter  230 , socket  222  defined on the inner radial face  236  of inner race  206  and socket  224  defined in inner diameter  232  of inner race  206 . This particular ball bearing  201  is shown with a dust cover  208  which covers up the bearing cage and the ball bearings which are located under the dust cover  208 . Ball bearing  201  includes an outer race  204 , having an outer diameter  230  and an outer radial face  238 . Socket  220  is defined in the outer diameter  230  of outer race  204 . Ball bearing  201  further includes an inner race  206  which has an inner radial face  236  and also an inner diameter  232 . Socket  222  is defined in inner radial face  236  of inner race  206 . Socket  224  is defined in inner diameter  232  of inner race  206 . 
     A person skilled in the art will note that sockets  220 ,  222  and  224  are dimensioned to accept approximately ½ of anti creep ball  250  therein. 
     Ball bearing  201  is an example of how a bearing could be arranged to include sockets in various locations of the bearing in order that one is able to use an anti creep ball  250  with the ball bearing in any one of the configurations as shown in the previous embodiments. 
     The reader will also note that a ball bearing could be manufactured with no sockets from the original equipment manufacturer, in which case one would have to retrofit the existing bearing with a socket. One could also manufacture the ball bearings with one and/or more sockets already in place from the manufacturer thereby making it simpler to take advantage of the use of anti creep ball  250 .