Raceway element and method for its manufacture

Abstract

A sheet metal strip configured for use as an inner or outer raceway of a rolling-element bearing, and a method of forming the raceway by punching and/or laser cutting a strip of material from a metal sheet, bending the sheet into a ring and welding the ends of the strip together, and mounting the strip on a circular inner or outer surface to form an outer or inner raceway.

Claims

1. A raceway element for a bearing, wherein the raceway element is configured as an inner ring or as an outer ring of the bearing, or is configured to be attachable to an element serving as an inner ring or as an outer ring for the bearing, or to an inner ring or an outer ring of the bearing, wherein the raceway element comprises a strip having a substantially parallelogrammatic outer contour with two long sides connected by two short sides, wherein the two long sides and the two short sides are laser cut and/or punched from a sheet metal panel, and wherein the two short sides are joint edges configured to be connected to each other to form an annular raceway element.

2. The raceway element according to claim 1, wherein the two short sides are not perpendicular to the two long sides.

3. The raceway element according to claim 1, wherein the two short sides are connected via a material-bonded, interference-fit, or friction-fit connection.

4. The raceway element according to claim 1, wherein a surface of the raceway element has a profile in an axial direction that is concave or convex.

5. The raceway element according to claim 1, wherein the raceway element includes at least one bending facilitating recess for facilitating a bending of the raceway element into a ring shape, wherein the at least one bending facilitating recess is provided on a surface opposite a surface of the raceway element that is configured as raceway.

6. The raceway element according to claim 1, wherein the raceway element includes at least one chamfer formed along the joint edges.

7. The raceway element according to claim 1, wherein an outer contour of the raceway element includes at least one micro-connection point by which the raceway element is connected to the sheet metal panel from which the raceway element is manufactured.

8. A rolling-element bearing including at least one raceway element according to claim 1.

9. The raceway element according to claim 1, wherein the two short sides are perpendicular to the two long sides.

10. A method comprising: providing a sheet metal panel, forming one or more raceway elements from the sheet metal panel, the one or more raceway elements each having two parallel first sides having a first length and two second sides connecting the two parallel first sides, the second sides having a second length less than the first length and round bending the one or more raceway elements into a ring, wherein the first sides and the second sides are formed by laser cutting and/or punching.

11. The method according to claim 10, further including: applying a profile to the one or more raceway elements.

12. The method according to claim 10, further including: releasing the one or more raceway elements from the rest of the sheet metal panel by breaking micro-connection points via which the raceway element is connected to the rest of the sheet metal panel.

13. The method according to claim 10, wherein the first sides are formed by laser cutting and the second sides are formed by punching.

14. The method according to claim 13, including mounting the ring on a radial inner circumferential surface or on a radially outer circumferential surface to form a raceway, and mounting a plurality of rolling-elements on the raceway.

15. A method comprising: forming at least one pair of parallel laser cuts in a sheet metal panel, each of the laser cuts having a first end and a second end, a distance between the pair of laser cuts being less than a length of the laser cuts, the laser cuts including at least one interruption to create at least one micro-connection between the first ends and the second ends; and punching a pair of openings in the sheet metal panel, wherein the punched openings connect the first ends of the laser cuts and the second ends of the laser cuts.

16. The method according to claim 15, wherein the at least one pair of parallel laser cuts comprises a first cluster of the pairs of the laser cuts and a second cluster of the pairs of the laser cuts spaced from the first cluster.

17. The method according to claim 15, including: breaking the at least one micro-connection to remove one of the sheet metal strips; bending the removed strip and welding the first end of the removed strip to the second end of the removed strip to form a ring, mounting the ring on a radial inner circumferential surface or on a radially outer circumferential surface to form a raceway, and mounting a plurality of rolling-elements on the raceway.

18. The method according to claim 17, including applying a profile to a surface of each of the sheet metal strips before forming the laser cuts.

19. The method according to claim 17, wherein the punched openings are linear and the laser cuts are not perpendicular to the punched openings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic depiction of a sheet metal panel including a plurality of raceway elements according to a first exemplary embodiment of the disclosure.

(2) FIG. 2A is a schematic detail view of a round-bent raceway element.

(3) FIG. 2B is a schematic detail view of a round-bent raceway element, wherein the joint edges are connected to each other.

(4) FIG. 3 is a further exemplary embodiment of a raceway element.

(5) FIG. 4A is a cross-section of a raceway element according to a further exemplary embodiment.

(6) FIG. 4B is a cross-section of a raceway element according to a further exemplary embodiment.

(7) FIG. 4C is a cross-section of a raceway element according to a further exemplary embodiment.

(8) FIG. 5A is a raceway element according to a further exemplary embodiment.

(9) FIG. 5B is a raceway element according to a further exemplary embodiment.

(10) FIG. 5C is a raceway element according to a further exemplary embodiment.

(11) FIG. 5D is a raceway element according to a further exemplary embodiment.

(12) FIG. 6A is a cross-section of a raceway element according to a further exemplary embodiment.

(13) FIG. 6B is a cross-section of a raceway element according to a further exemplary embodiment.

(14) FIG. 7A is a plan view of a raceway element according to a further exemplary embodiment in a first state.

(15) FIG. 7B is a plan view of the raceway element according to FIG. 7A in a second state.

(16) FIG. 7C is a perspective view of the raceway element from FIG. 7B.

(17) FIG. 8A is a plan view of a raceway element according to a further exemplary embodiment in a first state.

(18) FIG. 8B is a plan view of the raceway element according to FIG. 8A in a second state.

(19) FIG. 8C is a perspective view of the raceway element from FIG. 8B.

(20) FIG. 9A is a plan view of a raceway element according to a further exemplary embodiment in a first state.

(21) FIG. 9B is a plan view of the raceway element according to FIG. 9A in a second state.

(22) FIG. 9C is a perspective view of the raceway element from FIG. 9B.

(23) FIG. 10 is a schematic process diagram of a method for the manufacturing of a raceway element according to a further exemplary embodiment.

DETAILED DESCRIPTION

(24) In the following, identical or functionally equivalent elements are designated by the same reference numbers. The direction designations used in the following—axial, radial, circumferential—always refer to the finished raceway element.

(25) FIG. 1 shows a schematic depiction of a sheet metal panel 1 including a plurality of raceway elements 2 according to a first exemplary embodiment. Each of the raceway elements 1 has an outer contour 4. As is shown in FIG. 1, a plurality of raceway elements, even differently designed, can be formed from a sheet metal panel 1. Of course, it is also possible to form only one raceway element 2 from a sheet metal panel 1.

(26) As is schematically indicated in FIG. 1 by the line thickness, the outer contour 4 of a respective raceway element 2 is formed by laser cutting and/or punching, wherein the outer contour 4 in the exemplary embodiment shown in FIG. 1 has a rectangular shape.

(27) In particular, a first surface 5 of the raceway element 2 can be configured as a raceway that interacts with rolling elements rolling on it. Alternatively the first surface 5 of the raceway element 2 can be configured as a sliding surface that interacts with another sliding surface such that an element serving as inner ring and an element serving as outer ring for a bearing, or an inner ring and an outer ring of the bearing, are rotatable with respect to each other.

(28) In the exemplary embodiment shown in FIG. 1, in a first state on the sheet metal panel 1 the raceway element 2 has an outer contour 4 in the shape of an essentially rectangular strip having two long edges 7 and two short edges 6. Here the two short edges 6 are configured as so-called joint edges 6-1, 6-2 that are connected to each other in a second state in order to form the annular raceway element 2. Here the connecting of the joint edges 6-1, 6-2 can be effected in a material, friction-fit, or interference-fit manner, wherein a material connection is preferred, in particular by welding.

(29) The joint edges 6-1, 6-2 are preferably formed by punching. Here this punching of the joint edges 6-1, 6-2 can be effected after the laser cutting of the rest of the outer contour 4, i.e., of the two long edges 7. However, punching prior to the laser cutting is preferred since the metal plate still has greater stability here.

(30) The great advantage with combined laser cutting/punching or only with laser cutting is that, as shown by way of example in FIG. 1, the raceway element 2 can easily be cut-out from a large-surface sheet metal panel 1. Here a plurality of raceway elements 2 can be obtained from the sheet metal panel 1, which are dimensioned identically as shown in FIG. 1. However, it is also possible that these raceway elements 2 differ in their dimensions.

(31) In order to form a spatial fixing of the raceway element 2 or of the raceway elements 2 for steps, for example, occurring after the laser cutting, such as punching, bending, rolling, stamping, and to improve the manageability of the raceway element 2, the individual raceway elements 2 can preferably each be connected to the rest of the sheet metal panel 1 via micro-connection points 12 (FIG. 5). It can thereby also be made possible to support the plurality of raceway elements formed from the sheet metal panel 1 in a flat state, by the raceway elements 2 still remaining connected to the sheet metal panel 1 via the micro-connection points 12. These micro-connection points 12 may be released only when the respective raceway element 2 is required. The micro-connection points 12 are preferably configured such that releasing the raceway element 2 from the sheet metal panel 1 is possible by a simple manual breaking of the micro-connection points 12. Mechanical and/or machine breaking or removing is also possible.

(32) In order to also facilitate the storing and handling or the subsequent further processing, a plurality of raceway elements 2 can be grouped into a “Cluster” 14, wherein stabilizing metal-plate regions 16 are formed between the clusters 14. The stabilizing metal-plate regions 16 can thus prevent the unintentional release of the raceway elements 2 from the sheet metal panel 1. To provide one of the raceway elements 2 it can be provided that first the respective cluster 14 is completely released from the rest of the metal plate 1, and in a subsequent step the desired raceway element 2 is separated from the rest of the cluster 14.

(33) In order to form the finished raceway element 2, it must be brought into a desired shape (FIG. 2A), for example, by round bending, after it has been cut out from the sheet metal panel 1. The result of such a round bending is schematically shown in FIG. 2A, wherein for the sake of simplicity only a part of the round-bent raceway element 2 is shown.

(34) The two joint edges 6-1, 6-2 can be assembled via a connection, for example, a welded connection 8 as mentioned above, in order to form the finished annular raceway element 2. FIG. 2B shows the round-bent raceway element 2 after the two joint edges 6-1, 6-2 are connected to each other by the welded connection 8. In order to prevent excess material from protruding during connecting, in particular over the surface configured as raceway 5, as can be seen in the exemplary embodiment depicted of FIG. 2A or 2B, chamfers 10-1, 10-2, 10-3, 10-4 can be formed along the joint edges 6-1, 6-2. These chamfers serve for receiving excess material that arises during the welding without protrusions of the welding material impairing the raceway 5.

(35) FIG. 3 shows a further exemplary embodiment of a raceway element 2. The round bending of the strip-shaped raceway element 2 can be problematic in particular in the case of a sheet metal panel 1 having greater material thickness. Here the round bending of the raceway element 2 can be facilitated with the aid of bending facilitating recesses 19 that are present in the exemplary embodiment depicted in the form of a knurling 18. Here the knurling 18 is preferably provided on a side 9 opposite the surface 5 configured as a raceway. Furthermore, a rolling element 20 is depicted in FIG. 3, which rolling element 20 rolls on the raceway 5.

(36) The knurling 18 comprises a plurality of recesses that are distributed circumferentially over the raceway element 2 and extend perpendicular to the circumferential direction or perpendicular to a long edge 7 of the raceway element 2. The recesses 19 of the knurling 18 preferably extend continuously over an entire axial length of the finished, i.e., annular raceway element 2, but do not extend through the entire thickness 22 of the raceway element.

(37) FIGS. 4A, 4B, 4C each show a cross-section through a raceway element 2 according to further exemplary embodiments. Depending on the application, the raceway element 2 can be provided with a profile for the raceway 5. FIG. 4A shows a raceway element 2 having a straight raceway profile. FIG. 4B shows a cross-section of a raceway element 2 having a crowned or convex profile that is used, for example, in needle roller bearings. In contrast thereto, FIG. 4C shows a cross-section of a raceway element 2 having a hollow-shaped or concave profile that is used, for example, with toroidal rollers. The profile can be applied onto the sheet metal panel 1 prior to the cutting out or final releasing of the raceway element 2.

(38) In order to ensure, for example, that the rolling elements 20 do not contact along the entire linear contact 21 of the connected joint edges 6-1, 6-2 in the case of rolling elements having a linear contact, i.e., a line-shaped abutment against the raceway 5, such as, for example, needle rollers, cylindrical rollers, tapered rollers, or the like, the connected joint edges 6-1, 6-2 in the exemplary embodiments that are shown in FIGS. 5A to 5D are disposed obliquely with respect to the linear contact 21 or obliquely with respect to the long edge 7 of the raceway element, which long edge 7 is parallel to the circumferential direction of the annular raceway element 2.

(39) FIG. 5A shows a raceway element 2 in a first state on the sheet metal panel 1, the one outer contour 4 in the shape of a parallelogram having two short sides 6 extending obliquely with respect to a circumferential direction; the short sides 6 are configured as joint edges 6-1, 6-2 that are connected to each other in a second state in order to form an annular raceway element.

(40) In the raceway elements 2 shown in FIGS. 5B to 5D, the joint edges are additionally configured as a first or second alignment element 26-1, 26-2, using which the first joint edge 6-1 is aligned radially, axially, and/or circumferentially with respect to the second joint edge 6-2, such that the joint edges 6-1, 6-2 to be connected are aligned precisely flush prior to the connection process. As is shown in FIGS. 5B to 5D, the first and the second joint edge 6-1, 6-2 preferably have mutually complementary alignment elements; here the alignment elements 26-1, 26-2 in FIG. 5B have a triangular shape, in FIG. 5C a semicircular shape, and in FIG. 5D a wave shape.

(41) As can be seen from the depicted exemplary embodiments, the alignment element 26-1, 26-2 can additionally serve to configure the course of the joint edges connected to each other such that a rolling element 20 having linear contact 21 does not roll over the connected joint edges 6-1, 6-2 along its entire linear contact 21, but rather only at partial points.

(42) For the case that the raceway element 2 forms a raceway 5 for rolling elements 20 in a rolling-element bearing including an inner ring, an outer ring, and the plurality of rolling elements that are disposed between the inner ring and the outer ring, a flange 28 for the rolling elements 20 is provided in the exemplary embodiments shown in FIGS. 6A and 6B, which flange 28 is formed from the same sheet metal panel 1 and is one-piece with the raceway element 2.

(43) The flange 28 is formed by bending, wherein a target bending point 24 is provided both in the exemplary embodiment in FIG. 6A and in the exemplary embodiment in FIG. 6B. In the exemplary embodiment in FIG. 6B, the target bending point is obtained such that a region 30 of the raceway element 2, which region 30 forms the flange, is rolled and/or milled such that a cross-section of this region 30 is flatter than a cross-section of the rest of the raceway element 32. The flange 24 is subsequently formed by folding, turning up, and/or bending of the region 30. FIG. 6A shows an alternative target bending point 24 in the form of a notch.

(44) Since depending on whether the raceway element 2 is used on an inner ring or on an outer ring, problems can arise during round bending of the raceway element 2 due to the compression or stretching of the flange 28, a knurling can also be provided on an outer edge 34 of the flange 28 in order to simplify the bending of the raceway element 2 even with an existing flange 28.

(45) FIGS. 7 to 9 show exemplary embodiments for a raceway element including at least one recess 40 that extends continuously through the surface of the raceway element 2, which surface is formed as raceway 5. Here FIGS. 7A, 8A, and 9A each show the raceway element 2 in a first state before the joint edges are connected to each other in order to form the annular raceway element 2. FIGS. 7B, 8B, and 9B show the respective exemplary embodiment of the annular raceway element 2 in a plan view, and FIGS. 7C, 8C, and 9C show the respective exemplary embodiment of the annular raceway element 2 in perspective view.

(46) FIG. 7 shows a raceway element 2 in which the recess 40 is formed as a lubricant reservoir in order, for example, to improve the lubrication conditions for the rolling elements 20 and achieve a weight reduction by material saving. Here the recess 40 is formed in the region of the connected joint edges 6-1, 6-2, wherein the first and second joint edge 6-1, 6-2 each include a first section 42 and a second section 44. The first section 42 and the second section 44 are defined by the recess 40 and are configured such that in the annular state of the raceway element 2 (FIGS. 7B, 7C), the first section 42 and the second section 44 are disposed circumferentially offset with respect to each other.

(47) Furthermore, the at least one recess also makes it possible to reduce material, which can on the one hand reduce the costs of the raceway element, and on the other hand reduces the weight of the raceway element.

(48) FIG. 8 shows a raceway element 2, wherein the recess 40 is disposed on an edge region of the raceway element 2 along the circumferential direction, whereby, for example, a material saving can be achieved in a part of the raceway 5 that supports no loads, such as, for example, with a balance shaft. Furthermore, FIG. 8 in turn shows an oblique course of the connected joint edge 6-1, 6-2, which minimizes the contact between rolling elements having linear contact and joint edges 6-1, 6-2.

(49) Similar to FIG. 7, FIG. 9 shows a raceway element 2, wherein the recess 40 is formed in the region of the connected joint edges 6-1, 6-2 and defines a first section 42 and a second section 44 of the first and second joint edge 6-1, 6-2, wherein in the annular state of the raceway element 2 (FIGS. 9B, 9C) the first and second section 42, 44 are disposed circumferentially offset with respect to each other.

(50) Also in the exemplary embodiments shown in FIG. 7 and FIG. 9, in addition to minimizing the length of the joint edges, an oblique positioning of the joint edges can also be provided in order to further reduce the contact between rolling elements having linear contact and connected joint edges.

(51) FIG. 10 shows a schematic diagram of a method 100 for manufacturing a raceway element 2 described above. Here the method comprises a step S1, in which a sheet metal panel 1 is provided. Subsequently in a step S2, one or more raceway elements 2 are formed from the sheet metal panel 1 by laser cutting and/or punching. A plurality of elements 2 are preferably formed simultaneously, whereby the manufacturing of the raceway elements 2 can be more efficient, which consequently reduces the manufacturing costs of each individual raceway element 2, so that even small quantities can be cost-effective.

(52) Depending on the raceway element 2 required, the method 100 can include a step S3, in which at least one recess 40 is formed in a surface configured as raceway 5. Furthermore, in a step S4 a profile can be applied onto the raceway element 2, wherein the profile is in particular concave, convex, or straight. Provided the raceway element 2 is still connected to the sheet metal panel 1 by micro-connection points 12, in a step S5 these micro-connection points 12 can be released by breaking. However, step S5 can also take place at another point during the method.

(53) Furthermore, the method 100 can include a step S6, in which a flange 28 for the rolling elements is formed from the same sheet metal panel, and one-piece with the raceway element, by folding or bending. In order to finally complete the raceway element 2, in a step S7 the raceway element 2 is formed by round bending, and completed in a step S8 by connecting of the joint edges 6-1, 6-2.

(54) In summary a raceway element can be manufactured particularly economically by the raceway element being formed by laser cutting and/or punching, whereby an individual manufacturing is possible without tools that are specifically matched to the dimensions of the raceway element. The raceway element can advantageously be manufactured from a metal plate, wherein during manufacturing the raceway element is still connected to the rest of the metal plate via micro-connection points.

(55) 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 raceway elements.

(56) 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.

(57) 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

(58) 1 Sheet metal panel 2 Raceway element 3 Outer contour 4 Surface 6-1, 6-2 Joint edge 7 Long edge 8 Connection 9 Surface 10-1-10-4 Chamfer 12 Micro-connection point 14 Cluster 16 Metal-plate regions 18 Knurling 19 Bending facilitating recess 20 Rolling element 21 Linear contact 22 Thickness 24 Target bending point 26-1, 26-2 Alignment element 28 Flange 30, 32 Region 34 Edge 40 Recess 42 First section 44 Second section 100 Method S1-S8 Method steps