INTERLOCKING RADIAL ROLLER BEARING ASSEMBLY

RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 60/724,826 filed October 7, 2005, and U.S. Provisional Patent Application No. 60/820,168 filed July 24, 2006. The entire contents of both applications are hereby incorporated by reference.

BACKGROUND

[0002] The present invention relates to radial roller bearing assemblies. More particularly, the present invention relates to a radial roller bearing assembly with synchronized races. [0003] Radial roller bearing assemblies typically comprise a plurality of rollers positioned between inner and outer races. A full complement of rollers may be positioned between the races or the rollers may be maintained by a bearing cage positioned between the races. The rollers serve to control friction between the two races. As one of the races moves relative to the other race, the rollers are free to roll between the races, thereby allowing the races to move independently of one another. ' ■ ^■ ': ' ^•

SUMMARY

[0004] In one embodiment, the invention provides a roller bearing assembly including first and second arcuate bearing races. The first and second arcuate bearing races each define ends and a central portion intermediate the ends. A plurality of rolling elements is positioned between the first and second bearing races. A unitizing member is positioned between the central portions of the first and second bearing races and is operable to retain the first and second bearing races together.

[0005] In another embodiment, the invention provides a roller bearing assembly comprising first and second bearing races with a plurality of rolling elements positioned therebetween. A first plurality of gear teeth are provided in the first bearing race. A second plurality of gear teeth are provided in the second bearing race in alignment with the first plurality of gear teeth. First and second gears are positioned between and interengage with the first and second pluralities of gear teeth. An insert is positioned between the first and second bearing races and between the gears. The insert defines an end of a first rolling element pocket

containing rolling elements positioned between the first gear and the insert, and defines an end of a second rolling element pocket containing rolling elements positioned between the second gear and the insert.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 is an isometric view, in partial section, of a roller bearing assembly in accordance with a first embodiment of the present invention.

[0007] Fig. 2 is an isometric view of a portion of the gear support utilized in the roller bearing assembly of Fig. 1.

[0008] Fig. 3 is an isometric view of a bearing assembly incorporating roller bearing assemblies in accordance with a second embodiment of the present invention. [0009] Fig. 4 is a top plan view of the bearing assembly of Fig. 3. [0010] Fig. 5 is a sectional view along the line 5-5 in Fig. 4.

[0011] Fig. 6 is an exploded isometric view of a bearing assembly that is an alternative embodiment of the present invention.

[0012] Fig. 7 is an isometric view of the bearing assembly of Fig. 6 after assembly. [0013] Fig. 8 is an isometric view, in partial section, of a roller bearing assembly in accordance with another embodiment of the invention.

[0014] Fig. 9A is an enlarged view of a portion of the bearing assembly of Fig. 8. [0015] Fig. 9B is a section view taken through line 9B— 9B of Fig. 8. [0016] Fig. 10 is an isometric view similar to Fig. 8 showing the inner race completely removed.

[0017] Fig. 11 is an isometric view of the bearing assembly of Fig. 8 shown fully assembled.

[0018] Fig. 12 is a top view of a roller bearing assembly in accordance with yet another embodiment of the invention.

[0019] Fig. 13 is a section view taken through line 13 — 13 of Fig. 12. [0020] Fig. 14 is a side view of the bearing assembly of Fig. 12. [0021] Fig. 15 is a section view taken through line 15 — 15 of Fig. 13. [0022] Figs. 16- 22 are various isometric views of the bearing assembly of Fig. 12.

[0023] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

DETAILED DESCRIPTION

[0024] The present invention will be described with reference to the accompanying drawing figures wherein like numbers represent like elements throughout. Certain terminology, for example, "top", "bottom", "right", "left", "front", "frontward", "forward", "back", "rear" and "rearward", is used in the following description for relative descriptive clarity only and is not intended to be limiting.

[0025] Referring to Figs. 1 and 2, a roller bearing assembly 10 that is a first embodiment of the present invention is shown. The roller bearing assembly 10 generally comprises a plurality of rollers 40 positioned between opposed races 20 and 30. In the present embodiment, each race 20, 30 extends over an arc of approximately 180° as the roller bearing assembly 10 is configured for use in an oscillating application. However, the races 20, 30 are not limited to such, but instead can be provided at any desired arc, including a complete circle of 360° for rotational applications. Alternatively, the races 20 and 30 may also be flat, as opposed to arcuate as shown.

[0026] The outer race 20 has a planar arced surface 22 extending between radially inward flanges 24 and 26. Similarly, the inner race 30 has a planar arced surface 32 extending between radially outward flanges 34 and 36. The rollers 40 are configured to be positioned between the races 20 and 30 and are retained by the flanges 24, 26 and 34, 36. In the present

embodiment, the rollers 40 are placed adjacent to one another without a cage positioned therebetween. However, a cage or the like can be provided if desired. [0027] A gear assembly 50 is provided between the races 20 and 30 to synchronize the relative movement of the races 20 and 30. The gear assembly 50 includes a toothed gear 54 positioned between gear teeth 52 extending from the interior surface of each race planar surface 22, 32. The race gear teeth 52 can be formed into the race material itself by any suitable manufacturing process or the race gear teeth 52 may be manufactured as a separate component and installed and attached on the respective race surfaces 22, 32, for example, retained in a cavity manufactured into the race surface 22, 32. It is preferable that an enlarged tooth 53 is provided at each end of the race gear teeth 52 to serve as a stop and limit the range of movement of the gear 54 relative to the race gear teeth 52.

[0028] The toothed gear 54 and the race gear teeth 52 are configured to intermesh such that movement of one of the races 20 will cause movement of the gear 54 which in turn will cause movement of the other race 30, in a direction opposite the movement of the first race 20. It is contemplated that multiple stacked gears (not shown) can be provided between the race teeth 52 to control relative movement direction and gear ratios.

[0029] The gear assembly 50 of the present embodiment also includes a support assembly 56. The support assembly 56 includes a contact roller 57 and a bridge member 58. The contact roller 57 has a diameter such that the contact roller 57 fits between the inward extending race gear teeth 52. The bridge member 58 bridges between the gear 54 and the contact roller 57. As such, as the races 20 and 30 move relative to one another, the contact roller 57 and the bridge 58 will move between the race gear teeth 52 while maintaining the configuration of the rollers 40 and preventing undesired roller 40 contact with the race gear teeth 52.

[0030] Referring to Fig. 2, the bridge 58 preferably also includes axial wings 59. The wings 59 are configured to be received in crimpings (not shown) of the flanges 24, 26 and 34, 36. The flanges 24,26 and 34, 36 may be crimped after the components are positioned in between the races 20, 30 or the flanges 24, 26 and 34, 36 may be snap fit about the wings 59. With the flanges 24, 26 and 34, 36 engaging the wings 59, the races 20 and 30 are retained together, forming a unitized roller bearing assembly 10. As can be seen in Fig. 1, a support assembly 56 may be provided at the opposite ends of the races 20 and 30 to unitize that end of

the races 20 and 30 and to provide added stability. A gear 54 may be provided at this end as well, but such is not required, as a single gear will synchronize the relative movement of the races 20 and 30.

[0031] The race gear teeth 52 are shown extending along only the end portions of the races 20, 30, however, it is understood that the race gear teeth 52 may be provided at various places along the entire arc of each race 20, 30. Additionally, multiple gears 54 may be provided in alignment with the race gear teeth 52 at various locations.

[0032] Referring to Figs. 3-5, a bearing assembly 100 incorporating a pair of spaced apart roller bearing assemblies 110 and 111 is shown. Each roller bearing assembly 110, 111 includes outer races 120, 121 and inner races 130, 131, respectively. A connection plate 102 extends between the respective outer races 120, 121 and a connection plate 104 extends between the respective inner races 130, 131 to form a single bearing assembly 100 incorporating two roller bearing assemblies 110, 111. The connection plate 102 may be formed integral with the inner flanges 126, 127 of the respective outer races 120, 121, as with the inner connection plate 104 and the races 130, 131. Alternatively, the races 120, 121 and 130, 131 may be formed separate and later interconnected.

[0033] The first roller bearing assembly 110 will be described with reference to Fig. 5. The outer race 120 includes a planar arced surface 122 positioned between radially inwardly extending flanges 124 and 126. Similarly, the inner race 130 has a planar arced surface 132 extending between radially outward flanges 134 and 136. The axially outer flanges 124 and 134 are each provided with a series of race gear teeth 152. The race gear teeth 152 are preferably formed integrally in the flanges 124 and 134, for example, by molding each race 120, 130 with the teeth 152 formed in the flanges 124 and 134. In the event the races 120, 130 are molded from a softer material, for example a polymer, it is preferable to position a hardened raceway 123, 133, respectively, within each race 120, 130. The hardened raceways 123, 133 can be assembled to the races 120, 130 or insert molded with the races 120, 130 at the time of manufacture thereof. The inner flanges 126 of the races 120, 130 can be provided with gear teeth, but such is not required.

[0034] A plurality of rollers 140 are positioned between the raceways 123, 133 of the races 120 and 130. In the present embodiment, the rollers 140 are retained within a cage 142. The

cage 142 includes a plurality of pockets 144 configured to receive and retain the rollers 140. The pockets 144 are defined by bars 146 extending between side rails 148. [0035] A gear 154 is positioned between race flanges 124, 134 and is aligned and interengaged with the race gear teeth 152. The gear 154 is preferably supported by a spindle 156 or the like extending from the cage rail 148. The toothed gear 154 and the race gear teeth 152 are configured to intermesh such that movement of one of the races 120 will cause movement of the gear 154 which in turn will cause movement of the other race 130, in a direction opposite the movement of the first race 120. It is contemplated that multiple stacked gears (not shown) can be provided, for example on multiple spindles, between the race teeth 152 to control relative movement direction and gear ratios.

[0036] The second roller bearing assembly 111 may be formed as a mirror image of roller bearing assembly 110 with a gear 154 provided between gear teeth 152 in its outer flanges 125 and 135 (not shown). However, since the upper races 120, 121 are interconnected, the lower races 130, 131 are interconnected, and the cages 142 are interconnected, synchronization caused by gear 154 provided with the first roller bearing assembly 110 will cause synchronization of both roller bearing assemblies 110 and 111.

[0037] The race gear teeth 152 are shown extending along only a portion of the races 120, 130, however, it is understood that the race gear teeth 152 may be provided along the entire arc of each race 120, 130. Alternatively, the gear teeth 152 may be provided in multiple segments along the arc of the races 120, 130. Additionally, multiple gears 154 may be provided in alignment with the race gear teeth 152 at various locations.

[0038] Referring to Figs. 6 and 7, a roller bearing assembly 200 that is an alternate embodiment of the present invention is shown. The bearing assembly 200 is similar to the bearing assembly 10 of the first embodiment and includes a plurality of rollers 240 positioned between opposed races 220 and 230. In the present embodiment, each race 220, 230 extends over an arc of approximately 180° as the roller bearing assembly 200 is configured for use in an oscillating application. However, the races 220, 230 are not limited to such, but instead can be provided at any desired arc, including a complete circle of 360° for rotational applications. Alternatively, the races 220 and 230 may also be flat, as opposed to arcuate as shown. [0039] The outer race 220 has a planar arced surface 222 extending between radially inward flanges 224 and 226. Similarly, the inner race 230 has a planar arced surface 232

extending between radially outward flanges 234 and 236. The rollers 240 are configured to be positioned between the races 220 and 230 and are retained by the flanges 224, 226 and 234, 236. In the present embodiment, the rollers 240 are placed adjacent to one another without a cage positioned therebetween, however, a cage or the like can be provided if desired. Each race 220, 230 is preferably formed with outwardly extending tabs 221, for example, during stamping of the races 220, 230. The tabs 221 provide assembly location and anti-rotation functions to both races 220, 230.

[0040] Gear assemblies 250 are provided between the races 220 and 230 to synchronize the relative movement of the races 220 and 230 and to prevent precessing of the rollers 240 out of the races 220, 230. Each gear assembly 250 of the present embodiment includes a toothed gear 254 aligned with a segment of gear teeth 252 in the planar surfaces 222, 232. In the present embodiment, the gear teeth 252 are pierced and coined into the race surfaces 222, 232 such that the gear teeth formed in the races 220, 230 do not extend above the raceway surfaces. This allows the rollers 240 to roll over the area of the gear teeth 252 without any interference. A smaller roller is not required in this embodiment. Additionally, the gear's root diameter can be made the same as the diameter of the rollers 240 such that the gear 254 extends from race surface 222 to race surface 232 and the gear 254 pilots on these surfaces 222, 232. The toothed gears 254 and the race gear teeth 252 are configured to intermesh such that movement of one of the races 220 will cause movement of the gear 254 which in turn will cause movement of the other race 230, in a direction opposite the movement of the first race 220. It is contemplated that multiple stacked gears (not shown) can be provided between the race teeth 252 to control relative movement direction and gear ratios.

[0041] A pair of gear holders 260 are provided to support the gears 254. Each gear holder 260 includes a body 262 with spaced apart shaft retainers 264. A shaft 266 is passed through a respective gear 254 and secured in the shaft retainers 264. Preferably, the gear holders 260 also serve to retain the opposed races 220, 230 together. Each race 220, 230 is formed with retention slots 270 adjacent the gear tooth areas at the junctures of the race surfaces 222, 232 and the respective flanges 224, 226 and 234, 236. The retention slots 270 are configured to receive retention tabs 272 extending axially from the ends of the gear holder body 262. The gear holder body 262 preferably has a slot 263 adjacent each retention tab 272 to provide for deflection of the tabs 272 past the race flanges 224, 226, 234, 236 during assembly. Use of the

retention tabs 272 and retention slots 270 eliminates the need for a secondary crimping operation and also allows for maximization of the roller 240 length between the flanges 224, 226 and 234, 236, thereby increasing the bearing's capacity.

[0042] Figs. 8-11 illustrate another embodiment of a bearing assembly 300 of the present invention that helps prevent roller precession. The components of the bearing assembly 300 are similar to the components of the bearing assemblies 10, 110, and 200, with like parts designated with three-hundred seribs numerals. Differences between the bearing assembly 300 and the bearing assemblies 10, 110, 200 are discussed in detail.

[0043] The bearing assembly 300 includes only a single gear 354 housed between the races 320, 330 to synchronize the races 320, 330. The single gear 354 cooperates with race gear teeth 352 formed substantially at the central portion of the arcuate races 320, 330. The rollers 340 are positioned between the races 320, 330 on both sides of the gear 354 as shown in Figs. 8 and 10. Positioning the gear 354 centrally and the rollers 340 on opposite sides of the gear 354 enables the rollers 340 to better support loads that are concentrated non-centrally relative to the races 320, 330, of the bearing assembly 300, i.e., load zones that are concentrated on either or both sides of the bearing assembly 300 and not in the central location where the gear 354 is positioned.

[0044] Additionally, the use of only a single gear 354 and only one set of race gear teeth 352 provides added room for additional rollers 340 to support the loading of the bearing assembly 300, thereby increasing the load capacity of the bearing assembly 300. The single gear 354 also can eliminate difficulties encountered when attempting to synchronize bearing assemblies incorporating two gears. Specifically, the single set of race gear teeth 352 can be located with less precision than would otherwise be required in embodiments requiring two sets of race gear teeth for two separate gears.

[0045] The single gear 354 is supported by a gear carrier 360 having two carrier clips 362. The gear 354 is supported on a shaft 366 that is rotatably supported between the two carrier clips 362. As best seen in Fig. 9B, each carrier clip 362 includes a plurality of retention tabs 372 configured to engage and ride in grooves or slots 370 formed (e.g., coined) in the flanges 324, 326, 334, 336 of the races 320, 330. The gear carrier 360 thereby defines a unitizing member positioned between the central portions of the races 320, 330. The clips 362 hold or retain the components of the bearing assembly 300 together to provide a unitized bearing

assembly 300. The central location of the clips 362 relative to the races 320, 330 can improve the assembly retention/unitization of the bearing assembly 300 over designs where retention occurs at locations spaced from the central portions of the races 320, 330 (e.g., at the ends of the races). The clips 362 and their retention tabs 372 are resilient and can deflect to facilitate assembly. In other embodiments, the tabs or projections 372 can be formed on the flanges 324, 326, 334, 336 to be received in apertures in the carrier clips 362.

[0046] The rollers 340 on each side of the gear 354 are retained and captured by respective wire retainers 380. In the illustrated embodiment, the wire retainers 380 are formed from a length of material having a substantially constant cross-section that is formed into a generally U-shaped member. The retainers 380 each include arcuate arm portions 382 that extend along the arcuate races 320, 330 adjacent the axial ends of the rollers 340 and between the flanges 324, 326, 334, 336. As shown in Figs. 8, 10, and 11, the contour of the arcuate arm portions 382 is substantially the same as the contour of the flanges 324, 326, 334, 336. Each arm portion 382 includes an end portion 384 configured to be received into a respective aperture 386 in the carrier clips 362, thereby securing the retainers 380 to the gear carrier 360. Of course, other methods and configurations for securing the retainers 380 to the clips 362 can also be used. The ends of the arm portions 382 opposite the end portions 384 are interconnected by a base portion 388 that extends axially adjacent the roller 340 spaced furthest from the gear 354 and closest to the respective ends of the bearing races 320, 330. The rollers 340 are thereby retained within a roller pocket defined on one end by the carrier clips 362 and on the other end by the base portion 388.

[0047] Figs. 12-22 illustrate yet another embodiment of a bearing assembly 400 of the present invention that helps prevent roller precession. The components of the bearing assembly 400 are similar to the components of the bearing assemblies 10, 110, 200, and 300 with like parts designated with four-hundred and five-hundred series numerals. Differences between the bearing assembly 400 and the bearing assemblies 10, 110, 200, and 300 are discussed in detail below.

[0048] The bearing assembly 400 includes two gears 454 housed between the races 420, 430 to synchronize the races 420, 430. The gears 454 cooperate with race gear teeth 452 formed substantially at the end portions of the arcuate races 420, 430. The gears 454 are each supported by a gear support or carrier 460 having two carrier sidewalls 462 (see Figs. 16, 17,

and 19-22 - gear carriers 460 removed in Figs. 12 and 13 for clarity). The gears 454 are each supported on a respective shaft 466 that is rotatably supported between the two carrier sidewalls 462. Unlike the gear carrier construction of the bearing assemblies 200 and 300 discussed above, the illustrated gear carriers 460 do not include any retention tabs or projections configured to engage and ride in any apertures formed in the flanges 424, 426, 434, 436 of the races 420, 430 to unitize the bearing assembly 400 (i.e., hold all the bearing assembly components together as a single unit).

[0049] Instead, and as illustrated in Figs. 13, 15, 17, and 18, the bearing assembly 400 includes an insert or spacer 500 that is generally centrally positioned between the gears 454 and between the races 420, 430. The insert 500 includes retention tabs or projections 572 located and configured to be received in corresponding grooves, slots, or other apertures 470 formed (e.g., coined) in the flanges 424, 426, 434, 436 of the races 420, 430, in areas adjacent to the range of relative travel of the insert 500, to unitize the bearing assembly 400. The insert 500 thereby operates as a unitizing member positioned between the central portions of the races 420, 430. The centralized location of the insert 500 relative to the arc length of the races 420, 430 can improve the retention/unitization of the bearing assembly 500 over designs where retention/unitization occurs at locations spaced from the central portions of the races 420, 430 (e.g., near the ends of the races 420, 430). In another embodiment, two or more inserts 500 could be positioned between the gears 454 to facilitate unitizing the bearing assembly 400. In yet other embodiments, the gear carriers 460 could also include retention features, such as those illustrated in the bearing assemblies 200 and 300, to be received in apertures in the races to further improve bearing unitization.

[0050] The insert 500 is resilient so that the retention projections 572 can deflect to facilitate assembly into the apertures 470 in the races 420, 430. The illustrated insert 500 includes a body portion 504 and oppositely-extending arm portions 508 (see Figs. 15 and 18). The arm portions 508, due to their wave-like or multiple-bend geometry (e.g., two or more bends per arm portion 508), provide the resiliency to deflect (inwardly toward the body portion 504 and outwardly away from the body portion 504) in order to facilitate insertion of the projections 572 into the apertures 470 as discussed above. In an alternative construction, the projections 572 could be formed in the flanges 424, 426, 434, 436 and the apertures 470 could be formed in the insert. The illustrated insert 500 is a plastic member formed by molding or

other suitable techniques, however, other materials (e.g., metals, etc.) and configurations can also be used to form the insert 500.

[0051] In addition to unitizing the bearing assembly 400, the insert 500 further defines an end of the two roller pockets formed on opposite sides of the insert 500. As best seen in Figs. 13 and 17, a first roller pocket containing a first complement of rollers 440 is positioned between one of the gears carriers 460 of a gear 454 and one side of the insert 500. A second roller pocket containing a second complement of rollers 440 is positioned between the other of the gears carriers 460 and the other side of the insert 500. Both the gear carriers 460 and the insert 500 are configured to abut the adjacent roller 440, and act as an end stop or support for the abutting roller 440. The gear carriers 460 prevent roller precession, or the tendency for the rollers 440 to move toward the ends of the races 420, 430. In other constructions, separate abutment members could be inserted between the gear carriers 460 and the adjacent rollers 440, and the insert 500 and the adjacent rollers 440. As with all embodiments discussed herein, the rollers could be replaced with other rolling elements (e.g., balls, needles, etc.) depending upon the particular application. [0052] Various features of the invention are set forth in the following claims.