CYLINDRICAL ROLLER BEARING AND METHOD FOR MANUFACTURING A CYLINDRICAL ROLLER BEARING

Abstract

Cylindrical roller bearings and methods for the production thereof are disclosed, wherein the cylindrical roller bearings can be manufactured inexpensively and with adequately high quality.

The cylindrical roller bearing may have an inner ring, an outer ring, and a multiplicity of cylindrical rollers, wherein the cylindrical rollers are arranged between the inner ring and the outer ring. The outer ring has an internal raceway for the cylindrical rollers, a fixed-rim portion, and a flanged-rim portion. The inner ring has an external raceway for the cylindrical rollers, and the internal raceway and/or the external raceway are/is formed into a final contour by extrusion.

Claims

1. A cylindrical roller bearing, comprising: an inner ring, an outer ring, and a multiplicity of cylindrical rollers, wherein the cylindrical rollers are arranged between the inner ring and the outer ring; wherein the outer ring has an internal raceway for the cylindrical rollers, has a fixed-rim portion and has a flanged-rim portion, and wherein the inner ring has an external raceway for the cylindrical rollers, the internal raceway and/or the external raceway having an extruded final contour.

2. The cylindrical roller bearing as claimed in claim 1, wherein the internal raceway and/or the external raceway has a convex curvature in a longitudinal section along a main axis of rotation (H) of the cylindrical roller bearing.

3. The cylindrical roller bearing as claimed in claim 2, wherein the convex curvature has deviation (h) of at least 2 m and less than 20 m in relation to a straight cylindrical shell surface.

4. The cylindrical roller bearing as claimed in claim 1, wherein the cylindrical rollers have a convex curvature in a longitudinal section along a main axis of rotation (H) of the cylindrical roller bearing.

5. The cylindrical roller bearing as claimed in claim 1, wherein the fixed-rim portion forms a toroidal fixed-rim abutment surface and/or a convex curvature of the fixed-rim abutment surface for the cylindrical rollers.

6. The cylindrical roller bearing as claimed in claim 1, wherein the flanged-rim portion forms an encircling contact line as a flanged-rim abutment region.

7. The cylindrical roller bearing as claimed in claim 1, wherein the fixed-rim portion has a securing contour, wherein the securing contour is formed into the fixed-rim portion by deformation by extrusion.

8. The cylindrical roller bearing as claimed in claim 1, wherein the fixed-rim portion has an encircling parting edge.

9. A method for manufacturing a cylindrical roller bearing as claimed in claim 1, wherein the external raceway of the inner ring is manufactured into the extruded final contour by extrusion from an inner-ring blank, and/or the internal raceway of the outer ring is manufactured into the extruded final contour by extrusion from an outer-ring blank.

10. The method as claimed in claim 9, wherein the method has at least one of the following steps: extrusion of an outer-ring blank from a round metal blank, wherein the outer-ring blank is formed as a cup; extrusion of the outer-ring blank to form an outer-ring intermediate product, wherein the internal raceway is formed into a final contour; or cutting a base out of the outer-ring intermediate product in order to form the inner ring.

11. A cylindrical roller bearing, comprising: an inner ring, an outer ring, and cylindrical rollers, wherein the cylindrical rollers are arranged between the inner ring and the outer ring; the outer ring having an internal raceway for the cylindrical rollers, a fixed-rim portion, and a flanged-rim portion; the inner ring having an external raceway for the cylindrical rollers; the internal raceway and the external raceway having an extruded final contour; and the internal raceway and the external raceway having a convex curvature in a longitudinal section along a main axis of rotation (H) of the cylindrical roller bearing.

12. The cylindrical roller bearing as claimed in claim 11, wherein the convex curvature has deviation (h) of at least 2 m and less than 20 m in relation to a straight cylindrical shell surface.

13. The cylindrical roller bearing as claimed in claim 11, wherein the cylindrical rollers have a convex curvature in a longitudinal section along a main axis of rotation (H) of the cylindrical roller bearing.

14. The cylindrical roller bearing as claimed in claim 11, wherein the fixed-rim portion forms a toroidal fixed-rim abutment surface and/or a convex curvature of the fixed-rim abutment surface for the cylindrical rollers.

15. The cylindrical roller bearing as claimed in claim 11, wherein the flanged-rim portion forms an encircling contact line as a flanged-rim abutment region.

16. The cylindrical roller bearing as claimed in claim 11, wherein the fixed-rim portion has a securing contour, wherein the securing contour is formed into the fixed-rim portion by deformation by extrusion.

17. The cylindrical roller bearing as claimed in claim 11, wherein the fixed-rim portion has an encircling parting edge.

18. A method for manufacturing a cylindrical roller bearing as claimed in claim 11, wherein the external raceway of the inner ring is manufactured into the extruded final contour by extrusion from an inner-ring blank, and/or the internal raceway of the outer ring is manufactured into the extruded final contour by extrusion from an outer-ring blank.

19. The method as claimed in claim 18, wherein the method has at least one of the following steps: extrusion of an outer-ring blank from a round metal blank, wherein the outer-ring blank is formed as a cup; extrusion of the outer-ring blank to form an outer-ring intermediate product, wherein the internal raceway is formed into a final contour; or cutting a base out of the outer-ring intermediate product in order to form the inner ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further features, advantages and effects of the disclosure will emerge from the following description of a preferred exemplary embodiment of the disclosure and from the appended Figures, in which:

[0030] FIGS. 1a, 1b, 1c show an outer ring, an inner ring and a rolling body of a cylindrical roller bearing as an exemplary embodiment of the disclosure; and

[0031] FIG. 2 shows an illustration of the method according to the disclosure for manufacturing the cylindrical roller bearing with the components as per FIGS. 1a, 1b, 1c.

DETAILED DESCRIPTION

[0032] FIG. 1a shows, in a schematic longitudinal section, a first component of a cylindrical roller bearing 1 (see FIG. 2) in the form of an outer ring 2. FIG. 1b shows an inner ring 3 as a further component of the cylindrical roller bearing 1. FIG. 1c illustrates, in highly schematic form, as a further component of the cylindrical roller bearing 1, a rolling body in the form of a cylindrical roller 4. The three components are shown in each case in a schematic longitudinal section along a main axis of rotation H of the cylindrical roller bearing 1.

[0033] The outer ring 2 as per FIG. 1a has an internal raceway section 5 which, on the radially inner surface, bears an internal raceway 6. The internal raceway 6 is oriented coaxially and/or concentrically with respect to the main axis of rotation H and, in terms of approximate shape, is realized as a cylindrical shell surface.

[0034] At one axial end, a fixed-rim portion 7 is formed integrally on the internal raceway section 5, which fixed-rim portion, in the longitudinal section shown, protrudes at right angles from the internal raceway section 5. The fixed-rim portion 7 provides a fixed-rim abutment surface 8 for the cylindrical rollers 4.

[0035] On the opposite axial side, the outer ring 2 has a flanged-rim portion 9, which is likewise angled away from the internal raceway section 5 approximately at right angles. The flanged-rim portion 9 bears a flanged-rim abutment region 12. The outer ring 2 has, for installation purposes, an encircling outer cylindrical-shell-shaped contact surface.

[0036] The inner ring 3 is formed as a straight hollow cylinder which is oriented coaxially and/or concentrically with respect to the main axis of rotation H. On its radial outer side, the inner ring 3 bears an external raceway 10. The external raceway 10 is of approximately cylindrical-shell-shaped form. Furthermore, the inner ring 3 has a passage opening 11 for receiving a support structure, such as for example an axle or a shaft.

[0037] The cylindrical rollers 4 are arranged between the external raceway 10 and the internal raceway 6, and run or roll on said raceways. In the axial direction, the cylindrical rollers 4 are guided by the fixed-rim portion 7 and the flanged-rim portion 9, or the corresponding fixed-rim abutment surface 8 and the flanged-rim abutment region 12.

[0038] Considering the components more closely, the following form-related details are evident:

[0039] The internal raceway 6, which is of cylindrical-shell-shaped basic form, has a convex inward curvature in the longitudinal section shown. In FIG. 1a, the convex curvature 13 of the internal raceway 6 is illustrated on an exaggerated scale by means of a dashed line. In relation to a non-curved internal raceway, the convex curvature 13 of the internal raceway 6 has a height h of approximately ten micrometers. The convex curvature 13 of the internal raceway 6 is arranged centrally with respect to the internal raceway 6, such that the extreme of the convex curvature 13 of the internal raceway 6 is situated in the center of the internal raceway 6. The convex curvature 13 may also be referred to as a partially circular curvature.

[0040] On the fixed-rim section 7, the fixed-rim abutment surface 8 has a convex curvature 14 of the fixed-rim abutment surface 8, which is of toroidal form in the longitudinal section shown.

[0041] In the longitudinal section shown, the flanged-rim section 9 has a free end limb 15 which is oriented approximately perpendicular to the internal raceway section 5. In relation to a radial plane R perpendicular to the main axis of rotation H, the end limb 15 is inclined inwardly toward the internal raceway section 5. In this way, in the longitudinal section, as an abutment surface for the cylindrical rollers 4, there is only a punctiform region or, viewed overall, an encircling linear region as a flanged-rim abutment region 12.

[0042] The external raceway 10 of the inner ring 3 likewise has a convex curvature 17 (illustrated on an exaggerated scale by means of a dashed line) which has a height h of approximately ten micrometers in relation to a straight raceway.

[0043] As is illustrated very clearly in FIG. 1c, the raceway surface of the cylindrical roller 4 also has a convex curvature 18 of the raceway surface. It is optionally additionally possible for the cylindrical roller 4 to have toroidal encircling structures 16 on each of the face sides 19.

[0044] It must be emphasized that the convex curvatures 13, 14, 18 and/or the toroidal structure 16 are illustrated on a greatly exaggerated scale in the Figures, and have a height h of less than 20 micrometers.

[0045] By means of the described details, the friction in the cylindrical roller bearing 1 formed from the outer ring 2, the inner ring 3 and a multiplicity of cylindrical rollers 4 (cf. FIG. 2) can be considerably reduced. Specifically, the following improvements are obtained: as a result of the interaction between the internal raceway 6 with the convex curvature 13 and the raceway surface of the cylindrical roller 4, optionally with the convex curvature 18, the friction in the cylindrical roller bearing 1 is reduced. As a result of the interaction between the external raceway 10 with the convex curvature 17 and the raceway surface of the cylindrical roller 4, optionally with the convex curvature 18, the friction in the cylindrical roller bearing 1 is further reduced. The friction in the cylindrical roller bearing 1 is further reduced by the interaction between the convex curvature 14 of the fixed-rim abutment surface 8 and the toroidal structure 16 on the face sides 19 of the cylindrical rollers 4. The friction in the cylindrical roller bearing 1 is further reduced by the interaction between the flanged-rim abutment region 12 and the toroidal structure 16 on the face sides 19 of the cylindrical rollers 4.

[0046] FIG. 2 schematically illustrates a method for the manufacture of the cylindrical roller bearing 1 as an exemplary embodiment of the disclosure:

[0047] Proceeding from a round metal blank 20, in a preforming phase as per step I, an outer-ring blank 21 is produced. The outer-ring blank 21 has a base 22 and an encircling wall 23. The deformation may be realized for example as a deep-drawing process. It is evident that an encircling securing contour 24 is formed in in the region of the base 22 already in the preforming step. In a subsequent step II, the outer-ring blank 21 is made into an outer-ring intermediate product 25. The step II is also referred to as main deformation step. The base 22 is separated out, in particular punched out, along a parting edge 27. The base 22 or another circular-ring-shaped disk 26 forms a starting product for the inner ring 3. Said inner ring is formed from the circular-ring-shaped disk 26 by turning-down and flaring, as illustrated in the lower row of FIG. 2. In a final step, the outer ring 2 and the inner ring 3 are assembled, and the flanged-rim section 9 is bent.

[0048] The convex curvature 13 of the internal raceway 6 and the convex curvature 17 of the external raceway 10 result from an extrusion in the method according to the disclosure. In particular, the active surfaces of the tool for forming the internal raceway 6 and the external raceway 10 are formed as straight cylindrical shell surfaces. The convex curvature 14 of the fixed-rim abutment surface 8 is, by contrast, stamped in by means of a tool with an active surface complementary thereto.

LIST OF REFERENCE DESIGNATIONS

[0049] 1 Cylindrical roller bearing [0050] 2 Outer ring [0051] 3 Inner ring [0052] 4 Cylindrical roller [0053] 5 Internal raceway section [0054] 6 Internal raceway [0055] 7 Fixed-rim portion [0056] 8 Fixed-rim abutment surface [0057] 9 Flanged-rim portion [0058] 10 External raceway [0059] 11 Passage opening [0060] 12 Flanged-rim abutment region [0061] 13 Convex curvature of the internal raceway [0062] 14 Convex curvature of the fixed-rim abutment surface [0063] 15 End limb [0064] 16 Toroidal structure [0065] 17 Convex curvature of the external raceway [0066] 18 Convex curvature of the raceway surface of the cylindrical roller [0067] 19 Face side [0068] 20 Round metal blank [0069] 21 Outer ring blank [0070] 22 Base [0071] 23 Encircling wall [0072] 24 Securing contour [0073] 25 Outer ring intermediate product [0074] 26 Circular-ring-shaped disk [0075] 27 Parting edge [0076] H Main axis of rotation [0077] R Radial plane [0078] H Height (maximum deviation)