Bearing arrangement with inner ring with undercut groove to improve the flexibility of noses

Abstract

Bearing arrangement (10) for rotatably supporting a shaft element (12), wherein the bearing arrangement (10) comprises: an outer ring (18) which has a first bearing raceway (26); an inner ring (16) having a second bearing raceway (24), wherein the second bearing raceway (24) is spaced annularly opposite the first bearing raceway (26), wherein the inner ring (16) has a plurality of nose elements (32) extending in a projecting configuration from at least one end of the inner ring (16), wherein each of the plurality of nose elements (32) has a slot (34) formed between them; a plurality of bearing elements (20) positioned in a gap between and in engagement with the first bearing raceway (26) and the second bearing raceway (24); and a locking element (36) that engages in the plurality of nose elements (32) and exerts a pressure force on the plurality of nose elements (32) to couple the inner ring (16) with the shaft element (12), characterized by the fact that the bearing arrangement (10) has an undercut groove (40) which extends around its circumference extending along an inner surface (42) of the inner ring (16) and intersecting a proximal end (44) of each of the slots (34) formed between the plurality of nose elements (32), such that the undercut groove (40) increases an effective projection distance of the plurality of nose elements (32).

Description

AREA

[0001] The present disclosure relates to bearing arrangements and in particular to bearing arrangements having an inner ring with an undercut groove to provide improved nose flexibility. BACKGROUND AND SUMMARY

[0002] This section provides background information relating to the present disclosure that is not necessarily prior art. This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope of protection or all of its features.

[0003] Various arrangements are known in the art for securing the inner bearing ring of a bearing assembly to a rotating shaft. Such arrangements include shaft-contacting set screws and shaft-surrounding locking collars. Such locking collars have locking or tightening means, generally in the form of one or more locking screws. In the arrangement disclosed in generic US 4,537,519 A and US 6,908,230 B2, a bearing assembly is provided wherein the inner ring has equally spaced finger extensions or lugs of the inner ring which, when locked by a single screw locking collar, serve to grip a shaft and the inner ring and hold them tightly in position, thereby enabling improved concentricity of the inner ring with the shaft and higher shaft speeds.

[0004] The present teachings can be used in combination with any of a number of known force application arrangements for securing a bearing arrangement to a shaft and are particularly applicable to the compressible collars and finger extensions of the inner ring of the applicant's known SKWEZLOC® arrangement. adaptable, resulting in the previously mentioned advantages of improved shaft-ring concentricity and increased capacity for locking under high loads and high-speed shaft operations.

[0005] In general, these bearing assemblies are provided for use with a shaft passing through the assembly. Specifically, the bearing assembly may have an annular inner ring with a grooved raceway that is hardened to resist wear and extend the bearing life. An annular outer ring surrounds the annular inner ring at a spaced ratio, the outer ring having a grooved raceway arranged therein in the opposite direction to the raceway of the inner ring. The raceways are designed to receive, in a nested relationship, a plurality of spaced-apart ball or roller elements mounted in roller element pockets of a roller element cage. A lubrication passage is provided in the outer bearing ring, aligned with a passage in a housing of the bearing assembly or a bearing seat in which the bearing assembly is mounted.To seal the rolling element cage assembly, annular inner and outer fingers with annular seals between them are press-fitted onto the outer and inner bearing rings on each side of the loaded rolling element cage. In this way, the rolling elements can provide reduced frictional rotation of the shaft relative to the bearing assembly as they rotate in the hardened raceways of the inner and outer rings.

[0006] The inner ring may contain the previously mentioned finger extensions of the inner ring, or lugs that project from the inner ring and surround the shaft. These finger extensions or lugs are then folded to some extent around the shaft to define the concentricity of the now combined arrangement.

[0007] However, recent analyses have revealed that in some applications using commercially available shanks that lack the turned mass and polished finish of a higher-grade shank, this can result in eccentricity of the combined inner ring and shank assembly. This means that using lower-grade shanks with reduced tolerance requirements may necessitate that the inner ring finger extensions or lugs compensate for a greater degree of deflection and / or require that the inner ring finger extensions or lugs compensate for varying degrees of deflection from one extension to another.However, it was found that, as a result of at least some of this greater degree of deflection and the varying degree of deflection from one extension to another, the bearing raceway can be distorted when the locking collar is installed. This can further lead to inconsistent raceway dimensions between the inner and outer rings, causing reduced bearing performance and service life.

[0008] US Patent 3,397,021 A discloses a bearing unit with tapered roller bearings for a shaft, in which the position of a bearing cone is kept essentially constant by a receiving collar which is flexibly connected to the bearing cone by means of an inner and outer circumferential groove and is mounted on the shaft with a significantly stronger press fit than for the bearing cone.

[0009] From EP 0 348 365 A1, a device for fastening a machine element to a shaft is known, comprising a clamping sleeve and a clamping element interacting therewith, wherein the clamping sleeve and the clamping element have interacting threads or the like. The clamping sleeve is manufactured integrally with the machine element and is designed as at least one axially extended, sleeve-shaped, slotted section thereof. The sleeve-shaped section is designed such that it can be brought into radial engagement with the shaft during a relative rotation between the clamping element and the clamping sleeve.

[0008] The present teachings provide an improved configuration of an inner ring of a bearing arrangement, which is capable of compensating for a greater degree of shaft variation and furthermore prevents raceway deformation.Furthermore, the present teachings provide an improved inner ring configuration that is easy to manufacture, offering the benefits of improved concentricity for a wider range of shaft dimensions and conditions. Additionally, the present teachings provide an inner ring configuration capable of reducing ball path deformation of the bearing raceway for improved operation and wear.

[0010] Accordingly, according to the invention, a bearing arrangement with the features of claim 1 is provided, which rotatably supports a shaft element and has an advantageous design. The bearing arrangement comprises an outer ring having a first bearing raceway and an inner ring having a second bearing raceway. The raceways are spaced apart relative to each other. The inner ring has a plurality of lug elements extending in a projecting configuration from at least one end of the inner ring and having slots formed between them. Bearing elements are positioned in a gap between and in engagement with the first and second bearing raceways. An undercut groove extends circumferentially along an inner surface of the inner ring, generally adjacent to the plurality of lug elements.The undercut groove is functional for increasing the effective overhang distance of the majority of nose elements. The arrangement further features a locking element that engages with the majority of nose elements and exerts a compressive force on them to couple the inner ring to the shaft.

[0011] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are for illustrative purposes only and are not intended to limit the scope of protection afforded by this disclosure. DRAWINGS

[0012] The drawings described herein are provided for illustrative purposes only of selected embodiments and not of all possible implementations, and are not intended to limit the scope of protection of the present disclosure. Fig. Figure 1 is a perspective view that represents a storage arrangement according to the principles of the present teachings; Fig. Figure 2 is a cross-sectional view showing an inner ring having an undercut groove, in accordance with the principles of the present teachings; Fig. Figure 3 is a cross-sectional view in which some areas have been removed for clarity, showing the bearing arrangement according to the principles of the present teachings; Fig. Figure 4 is an enlarged cross-sectional view showing the inner ring, which has an undercut groove, according to the principles of the present teachings; Fig. Figure 5 is an enlarged cross-sectional view showing the wear-resistant hardened area of ​​the inner ring; Fig. Figure 6A is a cross-sectional view showing an inner ring having an undercut groove, according to some embodiments of the present teachings; and Fig. Figure 6B is a cross-sectional view showing an inner ring having an undercut groove, according to some embodiments of the present teachings.

[0013] Corresponding reference symbols indicate corresponding parts across the different views of the drawings. DETAILED DESCRIPTION

[0014] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings.

[0015] Exemplary embodiments are provided so that this disclosure is complete and fully communicates the scope of protection to the person skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be evident to the person skilled in the art that specific details need not be used, that exemplary embodiments can be embodied in many different forms, and that none should be designed to limit the scope of protection of the disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0016] The terminology used herein is intended solely for the purpose of describing certain exemplary embodiments and is not meant to be limiting. As used herein, the singular forms "one," "an," and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "exhibits," "show," "contain," and "have" are open and therefore specify the presence of said features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.The procedural steps, processes, and operations described herein should not be interpreted as necessarily requiring their execution in the specific order discussed or presented, unless specifically identified as such an order. It should also be understood that additional or alternative steps may be used.

[0017] When an element or layer is described as "on," "interacting with," "connected with," or "coupled with" another element or layer, it may be directly on, interfered with, connected, or coupled with the other element or layer, or intermediate elements or layers may be present. Conversely, no intermediate elements or layers may be present when an element is described as "directly on," "directly interacting with," "directly connected with," or "directly coupled with" another element or layer. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the related listed elements.

[0018] Although the terms first, second, third, etc., may be used herein to describe different elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be restricted by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another. Terms such as "first," "second," and other numerical terms, when used herein, do not imply any sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0019] Spatially relative terms, such as "inner," "outer," "below," "underneath," "lower," "above," "upper," and the like, may be used herein to simplify the description and to describe the relationship of one element or feature to another element(s) or feature(s), as depicted in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures were reversed, elements described as "below" or "underneath" other elements or features would then be oriented as "above" the other elements or features. Thus, the exemplary term "below" can encompass an orientation as both above and below.The device may be oriented differently (rotated by 90° or other orientations) and the spatially relative describers used herein may be interpreted accordingly.

[0020] In accordance with the principles of the present teachings, a bearing arrangement 10 is shown in the accompanying figures and described herein, which has an advantageous design. In particular with reference to Fig. 1 to 3 is the bearing arrangement 10 for use with a shaft element 12 ( Fig. 3) configured. In particular, the bearing arrangement 10 can have a bearing housing 14 having an annular inner ring 16 rotatably arranged within an outer ring 18 inside the bearing housing 14. The inner ring 16 can be supported, at least indirectly, for rotation with the shaft element 12 by a plurality of bearing elements or other anti-friction elements 20 positioned around an outer side of the inner ring 16 and an inner side of the outer ring 18. In this way, the plurality of bearing elements 20 can be positioned within a circumferential raceway 22 extending between the inner ring 16 and the outer ring 18. In particular, the raceway 22 can have a grooved raceway 24 formed circumferentially along an outer surface of the inner ring 16 and a counter-grooved raceway 26 formed circumferentially along an inner surface of the outer ring 18.The grooved raceway 24 of the inner ring 16 and the grooved raceway 26 of the outer ring 18 are spaced apart from each other to define the raceway 22. In some embodiments, the grooved raceway 24 and / or the grooved raceway 26 are hardened against wear to improve bearing life and operation. In some embodiments, the majority of bearing elements 20 can be enclosed within a bearing cage 25.

[0021] In some embodiments, one or more sealing elements 28 can be used to engage opposite ends of the inner ring 16, the outer ring 18, the bearing elements 20, and / or the bearing housing 14 to retain a lubricant (e.g., grease) within a volume containing the bearing elements 20. The lubricant can be supplied with this volume via a grease fitting 30 ( Fig. 3) be introduced.

[0022] With particular reference to Fig. In sections 1 to 4, the inner ring 16 has a plurality of nose elements 32 extending from it in an annular projection to surround the shaft element 12. The nose elements 32 are provided with a plurality of slots 34 parallel to the axis of shaft rotation to allow radial compression by a surrounding slotted locking collar 36. However, it should be understood that alternative locking force arrangements can be used in addition to the collar 36.

[0023] With further reference to Fig. In embodiments 1 to 4 of the invention, the inner ring 16 has an undercut groove 40 extending along an inner surface 42 of the inner ring 16. The undercut groove 40 extends circumferentially around the inner surface 42 of the inner ring 16 to define a complete and continuous groove. The undercut groove 40 is arranged to intersect the proximal end 44 of the slots 34. The undercut groove 40 can at least partially serve to extend the effective length of the cantilever beam of the nose element 32, thereby providing an improved deflection range of the beam without increasing the width of the inner ring 16 or encountering a hardened area of ​​the grooved raceway 24 of the inner ring 16, as discussed in more detail herein.

[0024] As background, with specific reference to Fig. It can be understood that existing designs of an inner ring that have finger extensions or noses have an effective nose length X, extending from a support surface or shoulder 46 of the inner ring 16 to a distal end 48 of the nose. As can be recognized, this reduced effective nose length X results in a minimal deflection capability of the nose, which directly limits the ability of the majority of noses to compensate for varying dimensions of the shaft element, as discussed herein. However, in accordance with the present teachings, the addition of the undercut groove 40 increases the effective nose length Y, extending from the distal end 48 of the nose 32 to an inner or proximal end 50 of the undercut groove 40. This increased effective nose length Y provides an improved ability of the noses 32 to compensate for varying dimensions of the shaft element and runout conditions.

[0025] As with reference to Fig. 4, Fig. 6A and Fig. As can be recognized in 6B, the undercut groove 4 can have any number of cross-sectional configurations when viewed along a plane parallel to the axis of rotation of the shaft element 12. In particular, in some embodiments, the undercut groove 40 can have a generally arcuate groove shape with generally parallel edges—namely, the proximal side 50 and the distal side 52. The sides 50 and 52 can extend from the inner surface 42 to a terminal arcuate surface 54 within the undercut groove 40. Alternatively, in some embodiments, as in Fig. Figure 6A shows that the sides 50 and 52 extend from the inner surface 42 to the inner chamfers 56 and an inner flat surface 58. The inner flat surface 58 can generally be flat. Similarly, in some embodiments, as in Fig. Figure 6B shows that sides 50 and 52 extend from the inner surface 42 to an inner planar surface 58 (excluding internal chamfers 56). Furthermore, it should be noted that the specific size and dimensions may vary depending on the operation and intended conditions. For example, as shown in Fig. 6B shows that the width and depth of the undercut groove 40 vary.

[0026] It should be understood that the undercut groove 40 can have any cross-sectional geometry, such as rectangular, semicircular or trapezoidal, provided that the property removes material from the inner ring and isolates the nose area.

[0027] However, in some embodiments, different dimensional relationships result in an advantageous compromise and improved operation. This is particularly true with regard to... Fig. In some embodiments, it was found that the following dimensional relationships result in relieved stresses in the region of the nose 32. This means that dimension A, which is the minimum thickness extending between the undercut groove 40 and a support surface 46, can generally be equal to dimension B, which is the minimum thickness of the nose 32 along a direction orthogonal to the axis of rotation of the shaft element 12, generally a section with reduced thickness of the nose 32. By ensuring that dimensions A and B are generally equal to each other, the depth F of the undercut groove 40 is fixed, leading to relieved stresses in the nose 32.

[0028] Furthermore, in some embodiments it has been found that the following dimensional relationship results in improved operation of the undercut groove 40 without negatively affecting the reliability of the wear-hardened bearing raceway 24 of the inner ring 16. As discussed herein, it is desirable to wear-harden the bearing raceway 24 of the inner ring 16 to improve bearing life and operation. Wear-hardening the bearing raceway 24 results in a region 60 of hardened material, which is generally defined by transverse hatching in the Fig. 4 and Fig. 5 is designated. The hardened area 60 can have an edge-to-edge width along an outer surface of the inner ring 16 of dimension Z ( Fig. 5) define. The hardened area 60 can further define an edge-to-edge width along an inner surface 42 of the inner ring 16 that is less than dimension Z, generally resulting in an inwardly tapered cross-section. With reference to Fig. 4. A width E of the undercut groove 40 can be determined in conjunction with the dimension Z of the hardened area 60 and an offset distance C between a distal point 62 of the hardened area 60 and a proximal side 50 of the undercut groove 40 (it should be noted that the distance C is measured along a single axis parallel to the axis of rotation of the shaft element 12 (for example, axial direction)). In particular, the dimension C can be greater than or equal to a constant K times dimension E. The dimension C thus represents a minimum offset distance in front of the proximal side 50 of the undercut groove 40 and the hardened area 60, which in turn limits the width E of the undercut groove 40. This arrangement prevents or at least reduces the negative effect on the raceway 24 of the inner ring 16 that results from the application of the locking collar 36 around the nose 32.Thus, the raceway 24 can maintain a precise cross-sectional shape and spacing from the opposing raceway 26, thereby providing improved bearing life and operation. In some embodiments, the constant K can be approximately 0.6 for smaller applications.

[0029] It should be understood that the cross-sectional shape of the undercut groove 40 can influence the heat treatment process of the inner ring 16, which follows the initial machining. In some cases, improper dimensioning of the inner ring 16 can result in internal cracks within the inner ring. Therefore, it has been found that in applications using heat treatment, dimension C should also be at least half the dimension Z to provide sufficient spacing to ensure accurate heat treatment.

[0030] Referring again to Fig.In some embodiments, the width of the collar 36 is essentially equal to the length X of the nose element 32, which simplifies the assembly of the collar during assembly to ensure an aligned fit or to compensate for the collar 36. However, it should be understood that the collar 36 can have a larger or smaller width dimension.

[0031] In some embodiments, the nose elements 32 may have a circumferential groove or recess 64 extending circumferentially around the outer surface of the nose elements 32 at a distance from the distal end 48. In some embodiments, the width of the recess 64 is approximately half the width of the locking collar 36.

[0032] According to the principles of the present teachings, the bearing arrangement, and in particular the inner ring, allows for increased deflection of the nose elements and is thus capable of accommodating a wider tolerance range of shaft elements without negatively affecting the roundness of the bearing raceway. This provides a larger range of acceptable shaft element dimensions while maintaining reliable and efficient bearing operation. This configuration results in improved bearing life and performance.

[0033] Furthermore, the principles of the present teachings offer a number of advantages over the prior art, such as, but not limited to, increased nose deformation, improved stock retention capacity, and reduced runout due to the locking mechanism. This results in reduced vibration and noise generated by the bearing arrangement. It also allows the use of commercially available stock components that have not been turned, ground, and / or polished, thus reducing manufacturing and assembly costs.

[0034] The principles of the present teaching can be used in all collar locking applications where raceway roundness is a key parameter and in applications requiring an increased effective nose length without the need to physically increase the overall length of the inner ring.

[0035] The preceding description of the embodiments has been provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment but are, where applicable, interchangeable and may be used in a selected embodiment, even if not specifically shown or described. The same may also vary in different ways. Such variations should not be considered a departure from the disclosure, and all such modifications are intended to be contained within the scope of protection of the disclosure.

Claims

[1] Bearing arrangement (10) for rotatably supporting a shaft element (12), wherein the bearing arrangement (10) comprises: an outer ring (18) which has a first bearing raceway (26); an inner ring (16) having a second bearing raceway (24), wherein the second bearing raceway (24) is spaced annularly opposite the first bearing raceway (26), wherein the inner ring (16) has a plurality of nose elements (32) extending in a projecting configuration from at least one end of the inner ring (16), wherein each of the plurality of nose elements (32) has a slot (34) formed between them; a plurality of bearing elements (20) positioned in a gap between and in engagement with the first bearing raceway (26) and the second bearing raceway (24); and a locking element (36) that engages in the plurality of nose elements (32) and exerts a pressure force on the plurality of nose elements (32) to couple the inner ring (16) with the shaft element (12), characterized by , that the bearing arrangement (10) has an undercut groove (40) which extends around its circumference extending along an inner surface (42) of the inner ring (16) and intersecting a proximal end (44) of each of the slots (34) formed between the plurality of nose elements (32), such that the undercut groove (40) increases an effective projection distance of the plurality of nose elements (32). [2] Bearing arrangement (10) according to claim 1, wherein the undercut groove (40) extending circumferentially along the inner surface (42) of the inner ring (16) extends continuously along the inner surface (42) of the inner ring (16). [3] Bearing arrangement (10) according to claim 1, wherein each of the plurality of nose elements (32) has an upper surface and a lower surface, defining a minimum thickness, wherein the minimum thickness of each of the plurality of nose elements (32) is equal to a minimum wall thickness between the upper surface of the nose elements (32) and the undercut groove (40). [4] Bearing arrangement (10) according to claim 1, wherein the effective cantilever distance of the plurality of nose elements (32) is greater than an actual cantilever distance of each of the plurality of nose elements (32), wherein the effective cantilever distance is measured from a distal end (48) of each of the plurality of nose elements (32) to a proximal side (50) of the undercut groove (40). [5] Bearing arrangement (10) according to claim 1, wherein the second bearing raceway (24) is wear-hardened to define a wear-hardened area (60) of hardened material, wherein the wear-hardened area (60) has a width (Z) measured along an outer surface of the inner ring (16), wherein the width (Z) is at least twice the distance (C) between a distal point (62) of the wear-hardened area (60) and a proximal side (50) of the undercut groove (40). [6] Bearing arrangement (10) according to claim 1, wherein the second bearing raceway (24) is wear-hardened to define a wear-hardened area (60) of hardened material having a distal point (62) along an outer surface of the inner ring (16), wherein an axial distance (C) between the distal point (62) and a proximal side (50) of the undercut groove (40) is greater than or equal to a width (E) of the undercut groove (40) multiplied by a predetermined constant (K). [7] Bearing arrangement (10) according to claim 6, wherein the predetermined constant (K) is 0.

6. [8] Bearing arrangement (10) according to claim 1, wherein the effective cantilever distance of the nose elements (32) extends from a distal end (48) of each of the nose elements (32) to a proximal side (50) of the undercut groove (40). [9] Bearing arrangement (10) according to claim 1, wherein the undercut groove (40) has opposite parallel sides (50, 52) which terminate at an arc-shaped surface (54). [10] Bearing arrangement (10) according to claim 1, wherein the undercut groove (40) has opposite parallel sides (50, 52) which terminate at a flat surface (58). [11] Bearing arrangement (10) according to claim 10, which further comprises a chamfer (56) formed between at least one of the parallel sides (50, 52) and the flat surface (58).

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