AU633072B2 - New and improved bearing assemblies - Google Patents

Description

AUSTRALIA

Patents Act COM LETE SPEC1ICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Cornp-tIv qneci 'kation Lodged: Accepted: Published: Priority Related Art: *41* 4 4 a a APPLICANT'S REF.: ~*Name(s) or Applic"...t(s): PLASTIC ;BEARING H0UPING-ALISTRALASIA PTY. LFD.

Addrcss(es) of Applicant(s): 0. 1 Doctors Gully Road Doreen 3754 Victoria, Australia Actual Inventor(s): Noel Francis Shoodcy Address for Serv ice is: P-ItLLlP ORM6jNDE AND FITZPATRICK Patent and Trade Mr rk Attorneys 367 Collins Street Nlelbourn,, Australia, 3000 Complete Specification for the invention ent'.Jed: NEW AND IMPROVED BEARING ASSenBLIEV.

Thle following statement is a full description of this invention, inluding the best method of performing it knowvn to applicant(s), P19 3 814 NEW AND IMPROVED BEARING ASSEMBLIES This application is a divisional application of Australian patent application 25410/88, the disclosure of which is incorporated herein by reference thereto.

The present invention relates generally to bearings and bearing assemblies. More particularly the present invention relates to bearings having complementary mating surfaces, such as for example a male and female arrangement for locating one bearing member with respect to an other bearing member, and which are a substitute for conventional ball or roller bearings.

Conventional ball or roller bearings in their many and varied forms usually consist of an innner race member which is fixedly located to a rotatable shaft, so as to rotate in accordance with corresponding rotation of the shaft, an outer S race member which is fixed to a stationary element, and balls or rollers held in position by a cage or flanges or the like located intermediate the inner and outer race members. The Sballs or rollers provide relative rotation of the inner and outer race members with respect to each other. Usually, the side of the ball bearin' -nr roller bearing presents cavities or depressions because of the wavy shape of the cage surrounding the balls or rollers.

It is an object of the invention to provide an improved bearing which at least partially overcomes problems with known bearings.

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1 *oo According to the present invention there is provided a member m untable on the shaft to be fixed thereto. An annular second beari member is rotatably mountable about and coaxial with the first 'b "-ing member to define at least two annular recesses. The two" r more annular recesses are at least partially separated by internal locating means projecting inwardly of tho second bearin member.

The second bearing member f the present invention is preferably an annular outer race. T- int.rnal locating means may be at least one radially inwardly di cted annular flange integral w 4 th the outer race. Alternative the internal locating means may be a discontinuo-s flange r med by a 39 -pluraliy o -gularl4y sa.-ld-absh.- or e-hp il Typ-i -2bearing for a shaft. The bearing includes a bearing comprising a first bearing member comprising an inner race and a thrust collar adapted to be connected to the inner race such that the thrust collar and inner race together define a continuous annular groove, and an annular second bearing member rotatably mountable about and coaxial with the first bearing member said annular second bearing member comprising an internal annular flange located in said annular groove.

The second bearing member of the present invention is preferably an annular outer race. The internal locating means may be at least one radially inwardly directed annular flange integral with the outer race. Alternatively, the internal locating means may be a discontinuous flange formed by a plurality of angularly spaced tabs or the like. Typically, t'.e 39 -2a- I ~R I -ars ~b~e--ekCC--Bl~qll%~ flange may be any of square, rectcingular, curved, dovetailed or the like in cross-section, or it may have any suitable desirable or convenient section or combination of sections.

Additionally, heat dissipation means may be provided on the flange, such as fins, flutes, threads, or the like. One form of heat dissipating means is a spiral or helical groove, or ridging in the side surfaces of the flange. The depth of the helical or spiral groove or ridging may be very small compared to the height of the flange.

In another form, there may b N two or more flanges defining a corresponding number of sses between the first and second bearing members. Where more ,nan a single flange is provided, the flanges may be of the same thickness and profile or may be of different thickness and different profiles.

Preferably, the flange is a paired or double flange, each flange being spaced apart from the other. Further, the flange may extend to any width relative the width of the outer race, from being almost the width of the outer race, to being a very thin lip.

The first bearing member of the present invention preferably includes an inner race, and a thrust collar. The inner race may he annular and may define a bore fnr receiving a shaft or the like. Alternatively, the inner race may be an inner race stud to form a cam follower or the like. The inner race and the thrust collar together may define an inner race shoulder and a thrust collar shoulder respectively. The inner race is preferably locatable within the outer race so that the inner race shoulder is in face-to-face relationship with one I* side of the flange of the outer race to define one recess. The 3*8 thrust collar is preferably connectable to a part of the inner race which projects through the outer race, to be locatable so that the thrust collar shoulder is in face-to-face relationship with the other side of the flange to define a second recess.

Therefore, when located in place, the thrust collar and the inner L'ice together define an annular groove in which the flange of the outer race is received, The annular flange of the outer race may have a rectangular cross-section, and the shoulders of the thrust 39 Q.ollar and inner race are then correspondingly of a right-angle _Illllsll~llllllla~WR P. -~sl~Bl~sCl~a~ll~~iY~%%liBP~Jq~;l[eJID~ cross-section. The groove formed is complementary to the shape of the flange within fine tolerances since the flange must be capable of rotating in the r'nve. Therefore, the recesses formed may be of a size suitable to receive a lubricant or the like, or may be so small as to allow abutment while still providing a fine tolerance.

Further, the first bearing member may be axially split in some embodiments, such as for example to provide bearing shells. Thus, the inner race and the thrust collar may be annular, or may be semi-circular or the like.

The inner race may consist of three axially adjacent annular portions, where the first, and largest diameter portion defines the inner race shoulder, the second portion defines the bottom wall of the groove formed by the inner race and the thrust collar, and the third, and smallest diameter portion provides means to retain the bush members, and for connection of the inner race to the thrust collar.

Similarly, the bore of the inner race may also be of any cross-section, such as square, hexagonal, D-shaped, splined, or any combination of these, again depending on requirements. The bore may even be tapered axially. Of course, the bearing surfaces of the bearing must be circular such that rotation is allowed.

The means to retain the bush members and to connect the inner race to the thrust collar may be provided by a shallow annular groove about the external periphery of the third portion of the inner race. The groove is preferably located so that the third portion extends far enough to allow the part of the third portion beyond the groove to be flared over the outside of the tnrust collar, to hold the '.hrist collar in place. The flaring may be done by any suitable tool, and preferably the thrust collar has a slight chai fer on its external end surface over which the third portion of the inner race may be flared, so that the inner race does not project beyond that external surface. The internal end surface of the thrust collar may include a recess which at least partially receives a part of the second portion of the inner race to suitably define the thrust collar shoulder.

39 In another form, the means to rjtain the bush members JW -4-

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and to connect the inner race to the thrust collar may be a threaded third portion on the inner race which is suitable to engage a correspondingly threaded thrust collar. In this form, the thrust collar may also include an additional annular flange having a bore corresponding to the inner race bore, and having a threaded radial aperture therethrough to receive a grub screw or the like. Alternatively, the additional flange may engage an annular eccentric collar, itself having an aperture capable of receiving a grub screw or the like. The grub screw provides additional securement of the bearing of the present invention to a shaft or the like located in the bore thereof. In another alternative form, the inner race may comprise an integral fourth portion, adjacent to the first portion mentioned above and of a similar diameter to the third portion, in the form of an additional flange. This additional flange may also have an aperture therein suitable to receive a grub screw or the like, g* for securing the bearing of the present invention to a shaft or S the like.

S.This invention also relates generally to substitutes for or replacements for roller bearings and the like, which are adpated to replace, or are interchangeable with conventional steel-type track cam followers which use roller ,r needle type bearings. Therefore, a further modification to the bearing of the present invention is a cam follower wherein the first bearing means comprises an inner race stud together with a thrust collar. The inner race stud is similar to a •gee conventional bolt, having a head, an axially adjacent locating shaft portion, and a threaded shaft portion axially adjacent to the locating shaft. Those three parts conform to the three 3Q preferred portions of the inner race referred to above, in that the head defines the inner race stud shoulder, the locating shaft defines the bottom wall of the groove defined by the thrust collar and the head, while the threaded shaft is suitable for securing the bearing itself to a second member.

The thrust collar may take the form of an annular washer or the like, while still defining the thrust collar shoulder.

It will also be understood by a person skilled in the art that the external surface of the bearing, or more 39 particularly the external circumferential surface of the outer race, may be of any cross-section. The surface may be flat, convexly or concavely curved, conical or frustoconical, co any combinations of shapes, dependent upon specific requirements.

The second bearing member of the present invention is preferably fabricated from a thermoplastic polyester resin, and the inner and outer races are preferably made from a corrosion proof metal such as stainless steel or the like and more preferably coated with a hard material such as a titanium nitride ceramic coating or the like. Additionally, all of the components may be made of plastics material, such as the outer race, the inner race, and the thrust collar.

The members may also be fabricated or moulded from a synthetic polymeric material or materials, such as an unreinforced, partially crystalline, thermoplastic polyester, for example polyethylene terephthalate. However, materials g from which the components of the present invention may be made include plastics, ceramics, glass, pure carbons, carbon fibres, Sgraphite impregnated materials, kevlar, phosphorous bronze or the like, and may include combinations thereof. It will be understood by a person skilled in the art that the selection of a particular material will be dependent upon the particular application required of the bearing. For instance, where the bearing is being used in a corrosive atmosphere due to the •nee presence of a particular type of chemical, a material would be selected that was resistant to that type of corrosion.

Similarly, if metals are used in the bearing, then the same *999 considerations would apply. For instance, if rusting was not perceived to be a problem, mild steel may be used.

Alternatively, 316 stainless steel may be used, or for light 3 weight applications 410 stainless steel may be used. As discussed earlier, any combination of metal and plastics etc.

may be used, or entirely plastics may be used with there preferably being no metal-to-metal contact by the bearing surfaces.

Some examples of practical arrangements of the invention will now be described with reference to the accompanying drawings. However, it is tcn be understood that the following description in no way limits the generality of the invention as 39 described above.

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In the drawings: Tigure la is a partial perspective view of the components of a first embodiment of the bearing of the present invention; Figure lb is a cross-sectional view of the embodiment of Figure la; Figure ?a is a perspective view of the embodiment of Figures la and lb in use.

Illustrated in Figures la and lb are the components of a bearing according to the present invention shown both separated and together when in use. Illustrated is an annular second bearing member 10, and an annular first bearing member 12.

First bearing member 12 comprises an inner race 18 and a thrust S collar 20. Inner race 18 has a first portion 22 defining a shoulder, a second portion 24, and a third portion 26. Third S portion 26 includes an annular groove 28 so that when third W portion 26 is received within thrust collar 20 the par' 29 beyond groove 28 may be forcibly flared over (not shown) the chamfer 30 of thrust collar 20 to retain the thrust collar in place. Thrust collar 20 also defines a shoulder 32, and an extended flange portion 33. Inner race 18 also defines a hexagonal shaped recess 35 suitable for receiving the head of the correspondingly shaped bolt. Of course, such a recess is preferred only, and is beneficial when a flush fit is required when a bolt or the like is the shaft to which the bearing is to be attached.

Second bearing member 10 is an outer race having a flange 34 with a generally rectangular cross-section. As shown in Figure lb, shoulders 32 and 22 together define a groove 39 which receives flange 34. Bearing surfaces are provided between shoulder 22 and flange 34 and member 10, a4nd-be- weetn- -flantg -1A- and- bu-s-h--44- 1-4 bsh a-Ind -&hault-1-e--- 32.

Each or the components of the bearing are machined or formed to very close tolerances. However, due to imperfections in machining and other methods of formation it may be preferred to apply a lubricant between each of the bearing surfaces, to additionally ease the effects of friction. Gaps 36 are 39 provided as reservoirs for excess or run-off lubricant. Any -7r asem~ aP~'rBF~s~3~T~ 1 Brll%~BB~Cl~i~B41~i

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suitable lubricant may be used. Alternatively, a coating of a material such as a titanium nitride ceramic may be applied, to increase the surface hardness of the metal components. Gold has also been succi .?sfully used.

Illustrated by broken lines 38 and 40 are possib alternative configurations for the external circumferenti' surface of member 10. As described earlier a range of surface configurations may be used as required.

The present invention finds particular application in indoor conveyor systems in industries such as the food industry. For example, in an indoor conveyor system designed to transfer chickens from one work station to another for various processing requirements, each roller of the system has at least two bearings. Such a roller is illustrated in Figure 2.

o Figure 2 shows a roller 50 having two longitudinally extending parallel arms 52 and 54. Each arm 52 and 54 has secured thereto a bearing 53 according to the present invention. A rail or the like (not shown) passes through opening 56 to support the roller, and a chicken (also not shown) may be suspended from the bottom end 58 of the roller The roller 50 may then travel along the rail by the free rotation of the bearings, and may be movable by attachment to a conveying means such as a chain or the like through connection point 60. Bearings 53 are shown bolted to the respective arms by a hexagonal headed bolt, which head fits into correspondingly shaped aperture The bearing according to the present invention here substitutes the conventional ball bearings, which have been 3 0 found to easily break, and thus require complete replacement, sometimes allowing ball beari.\gs to fall into food processing stations, Problems are also evident with ball bearings wearing on each other, and allowing minute metal shavings to also fall into food processing stations.

Another advantage of the bearing of the present invention is that the bearing runs quieter than conventional all metal bearings. The reduction in noise is particularly apparent in situations where a large number of bearings are 39 used, such as for example in indoor conveyor systems where each -8roller of the conveyor system has at least two bearings. The overall reduction in noise in enclosed environments is desirable because of the health and safety problems encountered when using lErge numbers of all metal bearings in confined spaces.

A further advantage resides in tb- male/female matingly lo-L- e engaging means of the bearing, which is used to locate thek btrs members with respect to each other, and to provide an increase in bearing surface without increasing the external dimensions of the bearing assembly. Also, tlhe bearing is resistent to corrosion, rust, contamination and the like because the external surfaces are relatively smooth and the internal locating means and bearing surfaces, being located internally within the bearing, are not exposed to the outside environment.

A further advantage that arises is the ease with which the bearirg of the present invention may be taken apart. This *is due to the ability to apply a force to the thrust collar to 6* Sbend back the flared-over lip of the inner race, and then replace, for example, the thrust collar, while merely re-flaring the inner race to reconnect. However, the embodiments of the present invention having the threaded thrust collar and inner race are clearly more preferred if ease of removal is considered particularly advantageous and desirous, Yet another advantage lies in the ease of production of the bearing of the present invention. There are no small working parts which require detailed production, and each piece required can be readily mass produced, with a subsequent saving in cost.

Those skilled in the art will appreciate that there may be many variations and modifications of the configuration described herein which are within the scope of the present invention.

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Claims (9)

1. A bearing comprising a first bearing member comprising an ii.iier race and a thrust collar adapted to be connected to the inner race such that the thrust collar and inner race together define a continuous annular groove, and an annular second bearing member rotatably mountable about and coaxial with the first bearing member said annular second bearing member comprising an internal annular flange located in said annular groove.

2. A bearing according to claim 1 wherein the internal flange is continuous. -hkv

3. A bearing according to claim 1 wherein the i-t-hr-s-t- collar is adapted to be received on the inner race and fixed thereto.

4. A bearing according to claim 1 wherein the thrust collar is adapted to be removably fastened to the inner race. -thrust C.c

5. A bearing according to claim 4 wherein the; be-4ajg- and inner race comprise complimentary threaded portions. 6 A bearing according to any one of claims 1 to wherein the inner race is formed of metal and the cuter race is of a plastics material. 7, A bearing according to claim 3 wherein the inner race includes a deformable end portion which is capable of being S flared over a corresponding chamfered end portion of said thrust collar, to secure the inner race to said thrust collar, 8 A bearing according to any one of claims 1 to 7 wherein the inner race is annular defining a bore for receiving a shaft or the like.

9. A bearing according to claim 8 wherein th be -ing adapted to be fixed to the shaft when the shaft is located in the bore, A bearing according to any one of claims 1 to 7 wherein the inner race is an inner race stud having a head and shaft portion.

11. A bearing according to any one of claims 1 to wherein the annular second bearing member comprises portions on the inner circumference thereof which are disposed on either side of the flange and which bear upon portions of the 39 outer circumference of the inner bearing member which are disposed on either side of the groove.

12. A bearing according to claim 1 Sbatantially as herein described with reference to Figures la and lb.

13. A roller for a conveyor system, said roller including a body portion having two extending elongate arms each rotatably secured to a bearing according to any one of claims 1 to 11, said body portion capable of being attached to an article to be transported and to a conveying means, said bearings capable of abutting and moving along a support means. 14, A roller according to claim 13 substantially as herein described with reference to Figure 2. DATED: 6 October 1992 PHILLIPS ORMONDE FITZPATRICK Attorneys for: PLASTIC BEARINGS HOUSINGS AUSTRALASIA PTY LTD 1326S Si 39 -11-