BEARING UNIT AND SEPARATOR

Abstract

A bearing unit configured to support a first component for rotary movement with respect to a second component includes a first bearing having an inner ring and an outer ring and a second bearing having an inner ring and an outer ring and a separator axially disposed between and connecting the outer ring of the first bearing and the outer ring of the second bearing in an interference fit manner or in a friction fit manner to form a preassembled unit. The separator may be annular and have a plastic base body with axial openings in which metal spacers, cylindrical rods, for example, are mounted.

Claims

1. A bearing unit configured to support a first component for rotary movement with respect to a second component, the bearing unit comprising: a first bearing having an inner ring and an outer ring; a second bearing having an inner ring and an outer ring; and a separator axially disposed between and connecting the outer ring of the first bearing and the outer ring of the second bearing in an interference fit manner or in a friction fit manner to form a preassembled unit.

2. The bearing unit according to claim 1, wherein the separator connects the outer ring of the first bearing and the outer ring of the second bearing in an interference fit manner.

3. The bearing unit according to claim 2, wherein the separator comprises a base body made from a plastic and at least one spacer made from a metal.

4. The bearing unit according to claim 3, wherein the spacer has an extension in a circumferential direction that is less than 20°.

5. The bearing unit according to claim 3, wherein the spacer is cylindrical.

6. The bearing unit according to claim 3, wherein the base body is configured to position the at least one spacer in a circumferential direction and in a radial direction.

7. The bearing unit according to claim 3, wherein the separator includes at least two spacers spaced from each another in the circumferential direction.

8. The bearing unit according to claim 3, wherein the base body comprises a ring having a first axial side in contact with the outer ring of the first bearing and a second axial side in contact with the outer ring of the second bearing and a central hole and at least two openings radially spaced from the central hole and extending from the first axial side to the second axial side and a spacer in each of the at least two openings, each of the at least two spacers being in contact with the outer ring of the first bearing and the outer ring of the second bearing.

9. The bearing unit according to claim 8, further comprising at least one plastic seal receptacle configured to secure a seal outside a race surface in the axial direction.

10. The bearing unit according to claim 3, wherein the separator includes first and second radially inwardly projecting webs configured to prevent grease from the bearings from entering into an intermediate space axially between the bearings.

11. The bearing unit according to claim 10, wherein the first web projects toward the inner ring of the first bearing and is spaced from the inner ring of the first bearing by a first gap, wherein the second web projects toward the inner ring of the second bearing and is spaced from the inner ring of the second bearing by a second gap, and wherein a size of the first and second gaps is selected to interfere with movement of grease from the first bearing and from the second bearing to the intermediate space.

12. A separator configured to axially space an outer ring of a first bearing from an outer ring of a second bearing in a bearing unit and to connect to the outer ring of the first bearing to the outer ring of the second bearing in an interference-fit manner, comprising: an annular base body made of plastic and having a first axial side configured to contact the outer ring of the first bearing and a second axial side configured to contact the outer ring of the second bearing and a central hole and at least two openings radially spaced from the central hole and extending from the first axial side to the second axial side and a metal spacer in each of the at least two openings, each of the at least two spacers having an axial length equal to or greater than a distance between the first axial side and the second axial side.

13. The separator according to claim 12, including a first projection configured to engage a recess in the outer ring of the first bearing and a second projection configured to engage a recess in the outer ring of the second bearing.

14. The separator according to claim 13 including first and second radially inwardly projecting webs.

15. A bearing unit configured to support a first component for rotary movement with respect to a second component, the bearing unit comprising: a first bearing having an inner ring and an outer ring, the outer ring of the first bearing having a first axial side and having a radially outwardly facing annular groove; a second bearing having an inner ring and an outer ring, the outer ring of the second bearing having a first axial side configured to face the first axial side of the first bearing in the bearing unit and the outer ring of the second bearing having a radially outwardly facing annular groove; and a plastic annular separator having a first projection extending into the annular groove of the outer ring of the first bearing and a second projection extending into the annular groove of the outer ring of the second bearing and connecting the first bearing to the second bearing in an interference fit manner, the separator having a first annular surface facing the first axial side of the outer ring of the first bearing and a second annular surface facing the first axial side of the outer ring of the second bearing and a central hole and at least two openings radially spaced from the central hole and extending from the first annular surface to the second annular surface and a metal spacer in each of the at least two openings, each of the at least two spacers being in contact with the outer ring of the first bearing and the outer ring of the second bearing.

16. The bearing unit according to claim 15, wherein the metal spacer is cylindrical.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a schematic depiction of a sectional view of a bearing assembly including a separator according to an exemplary embodiment;

[0027] FIG. 2 is a schematic depiction of an enlarged section of FIG. 1;

[0028] FIG. 3 is a schematic depiction of a sectional view of a conventional bearing assembly.

DETAILED DESCRIPTION

[0029] In the following description of the accompanying depictions, identical reference numbers designate identical or comparable components. Furthermore, summarizing reference numbers are used for components and objects that appear multiple times in an exemplary embodiment or in an illustration, but that are described together in terms of one or more common features. Components or objects that are described with identical or summarizing reference numbers can be identical with respect to individual, multiple, or all features, for example their dimensions, but possibly also embodied differently provided the description does not explicitly or implicitly indicate otherwise.

[0030] FIGS. 1 and 2 shows a schematic sectional depiction of a bearing unit 10. The bearing unit 10 comprises a first bearing 11 as well as a second bearing 12 and a separator 13. The separator 13 is disposed in axial direction (the direction of axis M) between a first outer ring 14 of the first bearing 11 and a second outer ring 15 of the second bearing 12. The separator 13 is configured to connect the two outer rings 14 and 15 to each other as a preassembled unit. Of course the separator 13 is also configured to hold the two outer rings 14 and 15 at a defined axial distance to each other in the axial direction. In some exemplary embodiments this distance be set with a precision of between 5 μm and 20 μm.

[0031] In the exemplary embodiment of FIGS. 1 and 2 the bearings 11 and 12 are each a tapered roller bearing that are installed in a back-to-back arrangement with respect to each other, i.e., such that their rolling elements 16 and 17 are facing one another with their smaller diameters. Each of the outer rings 14 and 15 respectively includes a race surface 18 for the rolling elements 16 and 17 on a radially inwardly facing side. An inner race surface of the bearing 14 and of the bearing 15 is located respectively on an inner ring 20 of the second bearing 12 and an inner ring 21 of the first bearing 11. The two inner rings 21 and 20 abut on each other in the axial direction on their inwardly directed end surfaces 22 and 23. Radially inwardly the two inner rings 20 and 21 are connected to each other in the region of their end surfaces 22 and 23 via a connecting ring 24. The inner rings 20 and 21 include recesses 25 on their radially inwardly directed sides that serve for the receiving of the connecting ring 24.

[0032] The rolling elements 17 and 16 are respectively retained in a rolling-element bearing cage 26. In some further, not-depicted exemplary embodiments the bearing can have a different shape and/or arrangement. For example, the rolling elements can be omitted. It can be an X-arrangement or bearings with different rolling elements, for example, ball roller bearings, cylindrical roller bearings, needle roller bearings, or the like.

[0033] The separator 13 comprises a base body 26 as well as at least one spacer 27. In the exemplary embodiment of the Figures the separator 13 comprises three spacers that are disposed spaced from each other in the circumferential direction. Directly adjacent spacers each have a spacing of 120° to one another. In FIG. 1 only one of the spacers 27 can be seen. The spacer 27 and also the not-depicted spacers serve to space the two outer rings 14 and 15 from each other in the axial direction M. The spacer 27 includes a harder and more stable material than the base body 26, for example, the same material as the outer rings 14 and 15 or a different metallic material, for example, steel.

[0034] The base body 26 includes a lighter material, for example, a plastic or a ceramic. The base body 26 is configured as an annular component that includes at least one opening 28 in which the spacer 27 can be disposed. The base body 26 also includes two further, not-depicted openings for the two not-depicted spacers.

[0035] Via the opening 28 the spacer 27 is positioned radially inward and radially outward as well as in the circumferential direction. The spacer 27 can, for example, be configured as a needle roller or cylindrical roller, but does not serve as a rotating rolling element. In other words the spacer 27 does not perform any rotational movement about its own center axis m. The opening 28 has a shape and size that is configured such that the spacer 27 is received therein. Just like the spacer 27, the opening 28 has a circular cross-section. The spacer 27 and the opening 28 are related in size such that the spacer 27 can be easily pushed into the opening 28 but cannot fall out by itself. In other exemplary embodiments the openings and the spacers can also have other fits or no fit with respect to each other. In some further, not-depicted exemplary embodiments the spacers can also have a different shape, for example, an angular cross-section, and/or be provided in a different number.

[0036] The axis m of the opening 28 is disposed parallel to the center axis M of the bearing unit and radially outside it. In the installed state the opening 28 is located at a radial height at which the inwardly facing end sides 29 and 30 of the outer rings 15 and 14 are also located. A diameter of the opening 28 here is at least 10%, 20%, 25%, 30%, 40%, 50%, 60%, 70% of a maximum radial extension r of the outer rings 14 or 15. However, the diameter of the opening 28 or of the spacer 27 here can be less than 80%, 70%, 60%, 50% of the maximum radial extension r of the outer rings 14 and 15.

[0037] In a region radially outside the bore 28 the separator includes a connecting structure 31 and 32 on both sides. This can be seen better in the enlarged depiction of FIG. 2. The connecting structures 31 and 32 extend here farther in the axial direction than a region of the base body 26 wherein the bore or opening 28 is disposed. At the end of the axial region a lug 33 is formed that points in the radial direction. Both sides are symmetrically configured, therefore only the side of the outer ring 15 is representatively described.

[0038] Viewed from its end side 30, the outer ring 15 has a smaller diameter on its radially outwardly directed surface than in a region of the outer ring 15 that connects to a shoulder 34. Viewed from the shoulder 34, a groove 35 is disposed on a side facing the end side 30. The groove 35 is disposed encircling in the circumferential direction. The lug 33 engages into this groove 35. The groove 35 and the lug 33 are configured here such that they abut on each other in an interference-fit manner. The outer ring 15 thus includes a receiving structure (e.g., the groove 35), which is configured, together with the connecting structure 31 of the separator 13, to connect the outer ring 15 to the separator 13. The outer ring 14 also has such a not-further-specified receiving structure. In some further, not-depicted exemplary embodiments the connecting structure can also have a different shape or function, for example, the groove and the lug can be in contact with each other in a friction-fit manner.

[0039] Radially inside the opening 28 the separator 13 includes radially inwardly projecting sections 37 and 38. The sections 37 and 38 are spaced from each other in the axial direction. The sections 37 and 38 have a relatively thin extension in the axial direction, almost only web- or leaf-shaped. The sections 37 and 38 project radially inwardly almost up to the inner rings 20 and 21, but they are spaced by a gap by at least 0.01 mm, 0.05 mm, 0.1 mm, 0.5 mm, or 1 mm. The sections 37 and 38 serve to actually retain grease from the bearings 11 and 12 in them and to prevent, or at least reduce, a risk that the grease flows into an intermediate space 39 that is located between the bearings 11 and 12 in the axial direction. The separator 13 can be referred to, for example, as a distance ring.

[0040] The bearing 12 is closed axially outward via a seal 40. The seal 40 is retained in a seal receptacle 41. The seal receptacle 41 also includes a connecting structure 42 that engages into a corresponding groove 43 of the outer ring 15. The seal receptacle 41 can be manufactured, for example, from a plastic. In some further, not-depicted exemplary embodiments the seals can be omitted, have another shape, and/or the seal receptacles can be omitted.

[0041] In an analogous manner a cover disc 44 made from a plastic is provided on the other bearing 11. This terminates the bearing 11. In some further, not-depicted exemplary embodiments, instead of the cover disc 44 a similar arrangement of the seal receptacle 41 and the seal 40 can be provided.

[0042] In the exemplary embodiment of the figures the bearing unit 10 is a truck hub unit (truck hub unit, THU) including an outer ring in a component structure. The bearing assembly has a diameter that falls in a range between 70 mm and 90 mm. Under certain circumstances the bearing can also have a diameter that is greater than 50 mm and smaller than 150 or 250 mm. The outer ring can be composed of various components. The steel parts in the rolling element region, i.e., those that form the race surfaces, can be connected to one another or held at a spacing by plastic parts, namely the separator. Here an inner plastic ring, i.e., the base body, is embodied such that it can retain standard parts, such as, for example, balls, rollers, needles, in position axially between the two outer-ring shoulders and thus as spacer can generate a precise spacing.

[0043] Via lateral end caps the cover disc 44 or the seal receptacle 41, for example, can be clipped into the outer rings and serve as gap seal and/or receive additional seals. In some exemplary embodiments a manufacturing complexity can be reduced by the bearing assemblies or the outer ring. Cost advantages can thereby arise. Furthermore, a significant weight saving compared to conventional bearings can possibly be achieved.

[0044] The exemplary embodiments and their individual features disclosed in the above description, the following claims, and the accompanying Figures can be meaningful and implemented both individually and in any combination for the realization of an exemplary embodiment in its various designs.

[0045] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved bearing units with separators.

[0046] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0047] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0048] 1 Bearing unit [0049] 2 Outer ring [0050] 3 Rolling-element row [0051] 4 Rolling-element row [0052] 5 Inner ring [0053] 6 Inner ring [0054] 7 Region [0055] 8 Seal [0056] 9 Seal [0057] 10 Bearing unit [0058] 11 Bearing [0059] 12 Bearing [0060] 13 Separator [0061] 14 Outer ring [0062] 15 Outer ring [0063] 16 Rolling element [0064] 17 Rolling element [0065] 18 Race surface [0066] 19 Inner race surface [0067] 20 Inner ring [0068] 21 Inner ring [0069] 22 End surface [0070] 23 End surface [0071] 24 Connecting ring [0072] 25 Recess [0073] 26 Base body [0074] 27 Spacer [0075] 28 Opening [0076] 29 End side [0077] 30 End side [0078] 31 Connecting structure [0079] 32 Connecting structure [0080] 33 Lug [0081] 34 Shoulder [0082] 35 Groove [0083] 37 Section [0084] 38 Section [0085] 39 Intermediate space [0086] 40 Seal [0087] 41 Seal receptacle [0088] 42 Connecting structure [0089] 43 Groove [0090] 44 Cover disc [0091] M Axial direction [0092] r Radial extension