Bearing anti creep device and method

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.

THE CROSS REFERENCE TO RELATED APPLICATIONS

The application claims priority from previously filed U.S. Provisional Patent Application No: 60/766,600, titled “BEARING ANTI CREEP DEVICE & 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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The first embodiment of the present invention is depicted inFIGS. 1 through 7inclusively.FIG. 1shows a ball bearing102which includes an outer race104and inner race106, bearing cage108having ball bearings110therein. Ball bearing102also includes an anti creep ball100shown mounted in the inner diameter111of the inner race106of ball bearing102.FIG. 2a perspective schematic view of ball bearing102shows anti creep ball100, located roughly mid way across the width of the inner diameter111of the inner race106.

FIG. 3shows a shaft112having a channel114defined therein.FIGS. 4 and 5show a ball bearing102mounted on shaft112. Typically a bearing such as ball bearing102is either slideably received onto shaft112in the longitudinal direction122and/or is pressed onto the end of shaft112in the longitudinal direction122due to a friction fit between the inner race106and the outer diameter113of shaft112. Anti creep ball100registers with longitudinal channel114as ball bearing102is pushed longitudinally over shaft112into the installed position as shown inFIG. 5. Referring now toFIGS. 6 and 7which schematically show in cross section along the longitudinal direction122, ball bearing102mounted onto shaft112. Anti creep ball100is preferably a small ball bearing which is seated in a socket120defined in inner race106of ball bearing102. Socket120is also referred to as first socket through out this specification. A second socket123is preferably a channel114which is preferably a semi circular shaped groove adapted to receive therein substantially one half of the anti creep ball. The depth of socket120is approximately ½ of the diameter of anti creep ball100and therefore the depth of channel114is also approximately ½ the diameter of anti creep ball100. In order to assemble ball bearing102onto shaft112, anti creep ball100is mounted into socket120and held in place with a small amount of grease for example. Thereafter, ball bearing102with anti creep ball100mounted in socket120can be slideably fit over the end of shaft112provided that anti creep ball100registers and travels along channel114during the assembly procedure along longitudinal direction122. Person skilled in the art will recognize that there must be sufficient clearance between anti creep ball100and channel114to allow assembly. A person skilled in the art will note that the inclusion of anti creep ball100will prevent rotation of the inner race106in rotational direction124relative to shaft112due to the locking function of anti creep ball100which is simultaneously mounted in socket120and also channel114. The use of anti creep ball100allows ball bearing102to move in the longitudinal direction122, however prevents bearing creep in the rotational direction124shown inFIG. 4.

FIGS. 8 through 14show a second embodiment of the present invention. Ball bearing103depicted inFIGS. 8 and 9shows a anti creep ball100mounted in the outer diameter115of the outer race104of ball bearing103. In this application, ball bearing103is mounted into a housing140having a bearing seat142, a shoulder144and a channel114. Shown in assembled position inFIGS. 11 and 12, ball bearing103is slideably mounted onto bearing seat142by slideably urging ball bearing103in the longitudinal direction122onto bearing seat142until it is flush with shoulder144defined in housing140.FIGS. 13 and 14show schematically in partial cross section view the mounting of ball bearing103into housing140. Ball Bearing103is slideably urged in longitudinal direction122into bearing seat142by aligning and registering anti creep ball100with channel114in order to install ball bearing103into housing140. In similar fashion as the previous embodiment, anti creep ball100is located simultaneously in a socket120and also in a channel114. Socket120has a depth approximately ½ the diameter of anti creep ball100and channel114has a depth again of approximately ½ the diameter of anti creep ball100. Therefore, ball bearing103is free to move in the longitudinal direction122, however will prevent rotational creep in rotation direction124.

The third embodiment of the present invention is depicted inFIGS. 15 through 21in which ball bearing105includes a socket120defined in the bearing face131of the outer race104. A housing141having a shoulder144and a bearing seat142has defined on the shoulder144a socket120. Socket120is a spherical dome adapted to receive up to one half of the anti creep ball. As best shown in cross sectional view as inFIGS. 20 and 21, the depth of socket120defined in shoulder144is approximately ½ of the diameter of anti creep ball100and the socket120defined in the outer race104of bearing105, also has a depth of approximately ½ of anti creep ball100. Therefore, bearing105can move freely in the longitudinal direction122for installation purposes. To install ball bearing105is urged longitudinally along bearing seat142until outer race104of ball bearing105abuts with shoulder144of bearing seat142. In order for outer face131of outer race104of ball bearing105to make contact with shoulder144, socket120defined in shoulder144and socket120defined in outer race104must align and register in order to accommodate therein anti creep ball100. Additionally a retaining device is used to fix ball bearing105into bearing seat142thereby minimizing longitudinal movement of ball bearing105. The retaining device not shown could be a circlip, retaining plate, or any other means to fix ball bearing105into bearing seat142. A person skilled in the art will recognize that a shaft passing through inner race106can move longitudinally relative to ball bearing105.

Inner diameter111, outer diameter115, and bearing face131are examples of bearing mounting surfaces. A mounting surface may be any surface of a bearing used to hold the bearing in place. Shoulder144, bearing seat142shaft outer diameter113, 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 bearing102and103are 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 direction122, however prevents movement of the bearing in the rotational direction124, namely rotational creep relative to the bearing seat and/or the shaft.

Therefore, a person skilled in the art will note that ball bearing102and103is free to move in the longitudinal direction122; however the presence of anti creep ball100and the socket120will prevent rotational creep.

Referring now toFIGS. 22 and 23which depict ball bearing201having three distinct sockets defined at different locations of the bearing namely, socket220on outer diameter230, socket222defined on the inner radial face236of inner race206and socket224defined in inner diameter232of inner race206. This particular ball bearing201is shown with a dust cover208which covers up the bearing cage and the ball bearings which are located under the dust cover208. Ball bearing201includes an outer race204, having an outer diameter230and an outer radial face238. Socket220is defined in the outer diameter230of outer race204. Ball bearing201further includes an inner race206which has an inner radial face236and also an inner diameter232. Socket222is defined in inner radial face236of inner race206. Socket224is defined in inner diameter232of inner race206.

A person skilled in the art will note that sockets220,222and224are dimensioned to accept approximately ½ of anti creep ball250therein.

Ball bearing201is 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 ball250with 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 ball250.