Thrust bearing, cage for the thrust bearing and method for producing the cage

Abstract

Axial bearing (1) with two rows of rolling elements (5, 6) aligned concentrically with respect to an axially extending rotational axis (7), and with a cage (2) formed from sheet metal. The rows of rolling elements are separated from one another by a central rib (12). The invention also relates to a cage for the axial bearing (1), in which the central rib (12) is formed by a doubling (17) of the sheet metal material of the cage (2). The invention further relates to a method for producing such a cage (2).

Description

Field of the invention

[0001] The invention relates to an axial bearing according to the preamble of claim 1. The invention also relates to a cage for the axial bearing according to claim 1 and according to the preamble of claim 4. Furthermore, the invention relates to a method for producing such a cage. Background of the invention

[0002] Such an axial bearing is known from JP 2007 145 843 A. Such a cage is known from JP 2010 007 745 A. Description of the invention

[0003] The object of the invention is to simplify the manufacture and assembly of an axial cage of this type.

[0004] The problem is solved by the subject matter of claims 1, 4 and 10.

[0005] The current single-piece, double-row axial cage design features two opposing profile shapes in the axial direction, with the rolling element rows defined by a central rib. This requires the cage to be turned during filling. The cage is very delicate. Furthermore, the tools for punching the pockets are very expensive and have short service life.

[0006] The advantage of the invention, however, lies in the fact that by replacing the single center bar with a double one, the profile shape can be produced in the same direction. This simplifies cage production. This eliminates the need to turn the cage when filling it with rolling elements. This simplifies the filling tools and simplifies cage assembly times.

[0007] According to the invention, the second rolling elements are at least partially separated from the first row of rolling elements by the first central rib sections or by second central rib sections of the central rib. At least some of the central rib sections are each formed by at least two directly adjacent wall sections of the central rib formed integrally with the sheet metal material of the cage, and the first wall sections are formed on the side of the first row of rolling elements and the second wall sections are formed on the side of the second row of rolling elements.

[0008] Furthermore, it is provided that each of the first pockets is delimited radially in the direction of the rotation axis by a first wall section of one of the first central rib sections. The second pockets are delimited radially in the direction of the first row of pockets by a second wall section of the first central rib sections or the second central rib sections. The wall sections are formed by a doubling of the sheet metal material of the cage. The doubling forms the central rib of the cage, which extends around an axis of symmetry.

[0009] The invention also provides a method for manufacturing such an axial cage. The cage is manufactured by cold forming sheet metal. The doubling is created by axial back pressing or through-pressing.

[0010] One embodiment of the invention provides that the wall sections between the rows of rolling elements are aligned in the axial direction and are in direct contact with one another radially, at least in sections.

[0011] The cage pockets are preferably filled with rollers or, alternatively, with balls. Each pocket can accommodate one or more rolling elements of the same or different design. The rolling element dimensions of the rolling elements inserted into the two rows of rolling elements are either identical or differ from pocket to pocket and / or from row to row.

[0012] Radial means perpendicular to the rotational axis, so that any radial plane is traversed perpendicularly by the rotational axis. Radial directions are therefore directions perpendicular to the rotational axis. The first row of rolling elements runs radially outward around the rotational axis in the cage, and the first rolling elements are correspondingly radially further away from the rotational axis than the second rolling elements. The second row of rolling elements runs radially inward in the cage, meaning the second rolling elements are closer to the rotational axis than the first rolling elements.

[0013] The rolling elements are preferably cylindrical or spherical rollers, but alternatively balls can also be used. The cage is a rotationally symmetrical component whose axis of symmetry corresponds to the axis of rotation.

[0014] Pockets are window-like openings in the cage in which the rolling elements are held and / or guided.

[0015] One-piece means made of the same sheet metal material as the cage and simultaneously in one piece with the cage. The cage, along with the ribs, pockets, and brackets, is cut from a single sheet material and preferably cold-pressed in a single manufacturing process.

[0016] The rolling elements of each row are arranged with even circumferential spacing or unevenly spaced around the axis of rotation. The circumferential spacing can be described as the length of imaginary arcs (radians) or as partial angles (pitch angles). The latter arise from the subdivision of a full circumferential angle of 360° viewed in any radial plane traversed perpendicularly by the axis of rotation, and their total is 360°. The term pitch therefore refers to both the pitch angles and the radians by which the pockets or rolling elements within a row are distributed / spaced from one another in the circumferential direction around the axis of rotation.

[0017] The central rib is divided into several circumferentially successive central rib sections, but formed as one piece with them. Each pocket is delimited in the direction of the other pocket row by a wall section of one of the central rib sections. Each sub-section of the wall sections runs circumferentially around the axis of rotation between two cage webs and delimits the pocket in the radial direction. The sub-sections form a radial run-up for the rolling elements - if rollers are preferably used, the respective central rib or the respective sub-section of the wall section on the central rib forms a radial run-up for the end face of the respective roller accommodated in the pocket. The pockets of the outer (first) pocket row are accordingly delimited radially in the direction of the rotation axis by sub-sections of the wall section of the central rib.In the direction radially away from the cage's rotation axis, the individual pockets of the outer (first) pocket row are delimited by outboard sections of an outboard. The pockets of the inner (second) cage row are each delimited radially outward toward the second pocket row, i.e., in the direction away from the rotation axis, by the sections of the second wall section. Radially inward, the cage pockets of the inner cage row are delimited by inboard sections of an inboard.

[0018] The pockets of the outer cage row are delimited in two mutually opposite circumferential directions by first cage webs. Each first cage web delimits one of the first pockets and another first cage pocket immediately adjacent to said first pocket in the circumferential direction. The respective partial section of the first wall section and the respective outboard section extend tangentially or circumferentially between the two first cage webs delimiting the respective first pocket and are radially opposite each other at the respective first cage pocket.

[0019] The pockets of the inner (second) cage row are delimited in two mutually opposite circumferential directions by second cage webs. Each second cage web delimits one of the second pockets as well as another second cage pocket immediately adjacent to said second pocket in the circumferential direction. The respective partial section of the second wall section and the respective inner rim section extend tangentially or circumferentially between the two second cage webs delimiting the respective second pocket and are radially opposite each other at the respective second cage pocket.

[0020] The first center rib sections and the second center rib sections are part of one center rib or together form one center rib. The center rib sections can be identical to one another, or they can differ from pitch to pitch. Alternatively, at least some of two radially adjacent pockets of the two rolling element rows can have a common center rib section. In the latter case, the two radially adjacent pockets are aligned radially in series with the rotational axis.

[0021] A doubling is a section of folded sheet metal of the cage where the two wall sections are pressed directly together so that they merge at a fold. Sheet material is equivalent to a sheet metal from which the cage is made and on which the shape of the cage with pockets and rims is produced without chipping by stamping, drawing, pressing, punching and embossing. Steels suitable for cold forming are preferably intended as the material for the sheet material. The doubling can therefore either have a partial section delimiting one of the pockets, at least two wall sections each at least partially delimiting another pocket, or merge into one of the webs of one of the rows of pockets in the cage at one or both wall sections.

[0022] Each row of pockets is characterized by adjacent pockets in the circumferential direction around the axis of symmetry, with each pocket being separated from the next neighboring pocket by a web. Each of the central rib sections delimits one of the pockets either in one radial direction or in both axial directions. If the central rib only borders a partial section of a wall section on one radial side, the central rib merges into a web on the opposite radial side. Optionally, central rib sections are also provided which merge into a web on one side and partially delimit one of the pockets on the same side. Central rib sections are also provided which merge into a web on each radial side, on one side into a web of the first row of pockets and on the other side into a web of the second row of pockets.In the latter case, it is also possible for the central board section to merge into a bridge on one side and also to define a pocket in part of a section.

[0023] A further embodiment of the invention provides that at least one of the pockets, either some of the pockets or all of the pockets of the cage, viewed in axial sectional planes in which the axis of symmetry also runs, are described by a bow-like profile. The webs begin on the left and right with a base. The base is essentially formed by a radially aligned section of the sheet metal material of the cage and is connected to one of the rims using a single material. A leg of the bow extends from the base and is either axially aligned or axially aligned but preferably slightly inclined “radially”. The leg then preferably merges at a bending radius into a bridge which runs essentially axially aligned to the other leg of the bow. The webs orThe sides of both rows of pockets are aligned in the same axial direction as the axially projecting wall sections of the central rim on one side and the outer or inner rim on the other side. This results in a W-shaped cross-sectional profile for each row of pockets in the axial section plane, in which the rims and webs merge into one another. Description of the drawings

[0024] The invention is explained in more detail below using an exemplary embodiment. Fig. Figure 1 shows a half-section through an axial bearing unit 34 with an exemplary embodiment of an axial bearing 1 according to the invention in an axial plane in which the rotational axis 7 of the axial bearing 1 is axially aligned. The axial plane thus corresponds to the image plane. The axial direction is indicated by a directional arrow and runs in the image plane. Fig. 2 shows the cage 2 of the Fig. 1 shown axial bearing 1 in an overall view, viewed from the front. Fig. 3 shows a half section of the cage 2 along the Fig. 2 in an axial plane in which the axis of symmetry 7 of the cage 2 is axially aligned. The axial plane thus corresponds to the image plane.

[0025] Fig. 1: An axial bearing unit 34 comprises an axial bearing 1 and a running disk 33. The axial bearing 1 is provided with two rows of rolling elements 5 and 6 aligned concentrically with respect to the axially extending axis of rotation 7. The first row of rolling elements 5 comprises first rolling elements 3 designed as rollers, which are arranged adjacent to one another in the circumferential direction. Due to the view, only one of the first rolling elements 3 is visible in the half-section. The first row of rolling elements 5 is located radially outward, so that it circumferentially surrounds the second row of rolling elements 6. The second row of rolling elements 6 comprises second rolling elements 4, which are also rollers. The radial distance of the second row of rolling elements 6 from the axis of rotation is smaller than that of the first row of rolling elements 5. The roller symmetry axes 36 are radially aligned, and their imaginary extensions V intersect the axis of rotation 7 in the illustrated rest position of the rollers.The cage 2, formed from a sheet metal material, is provided with a first row of pockets 8 and a second row of pockets 9. The first row of pockets 8 has a plurality of first pockets 10 distributed around the rotation axis 7, in each of which one of the first rolling elements 3 is received. Due to the manner of representation, in . Fig. 1 only one of the pockets 10 is visible. The pockets of the second row 9 are not visible in this illustration. In the illustrated embodiment, however, the pockets 10 and 11 of the cage 2 are assumed to be occupied by one roller each. The same rollers are used in both rows of rolling elements 5 and 6. Fig. 2 and Fig. 3, from which the arrangement of the pockets 10 and 11 can be seen. The pocket rows 8 and 9 are separated from one another in the radial direction by a central rib 12 which runs around the axis of rotation 7 and is formed integrally with the cage 2. The first rolling elements 3 are separated from the second rolling element row 6 by first central rib sections 13 of the central rib 12. The second rolling elements 4 are separated from the first rolling element row 5 by second central rib sections 14 of the central rib 12. In the illustration, only one central rib section 13 is visible in the foreground. The central rib 14 is hidden by the central rib 13 in this illustration but is assumed to follow behind it in the circumferential direction.

[0026] The central rib sections 13 and 14, specifically the central rib sections 13 or 14 directly radially adjoining one of the pockets 10 or 11, are each formed by two wall sections 15 and 16 of the central rib 12 that are directly adjacent to one another and formed integrally with the sheet metal material of the cage 2. The first wall section 15 is formed on the side of the first row of rolling elements 5, and the second wall section 16 is formed on the side of the second row of rolling elements 6.

[0027] The wall sections 15 and 16 extend between the rows of rolling elements 5 and 16 in an axial direction and are in direct contact with one another radially, at least in sections.

[0028] Fig. 2: The cage 2 of the Fig. 1 is provided with a first row of pockets 8 and a second row of pockets 9. The first row of pockets 8 has a plurality of first pockets 10 distributed around the axis of symmetry 7 for receiving at least one of the first rolling elements 3 (in Fig. 1). The second pocket row 9 has a plurality of second pockets 11 distributed around the rotation axis 7 for receiving at least one of the second rolling elements 4 (shown in Fig. 1). The pocket rows 8, 9 are radially separated from one another by the central rib 12, which extends around an axis of symmetry 7 and is formed integrally with the cage 2. The first pockets 10 are separated from the second pocket row 9 by first central rib sections 13. The second pockets 11 are separated from the first pocket row 8 by second central rib sections 14 of the central rib 12.

[0029] The number Z1 of the first pockets 10 in the first pocket row 8 is greater than the number Z2 of the second pockets 11 in the second pocket row 9. This results in a different pitch T1 or T2 for the respective pocket row 8 or 9. The pitch T1 of the first pocket row 8 is smaller than the pitch T2 of the second pocket row 9. The pitches T1 and T2 are each specified as pitch angles α1 and α2, respectively, as partial angles of a full angle of 30°. In this case, the respective pitch T1 or T2 results from a quotient of the full angle of 360° by the number Z1 or Z2 of the pockets 10 or 11 in the respective rolling element row 5 or 6 (cf. Fig. 1) or the respective pocket row 8 or 9: (T1 or T2)=360°÷(Z1 or Z2)

[0030] In the example shown, the number Z1 of the first pockets is 10 = (Z1=22) and the number Z2 of the second pockets is 11 = (Z2=12)

[0031] It is possible (not shown) that the first pockets 10 are arranged with a uniform or uneven first pitch T1 to one another and distributed around the rotation axis 7, and the second pockets 11 are arranged with a uniform or uneven pitch T2 to one another distributed around the symmetry axis 7, wherein the first pitch T1 has a different value than the second pitch T2 or the same value as the second pitch T2.

[0032] The first pockets 10 of the first pocket row 8 are each delimited by cage webs 18 formed integrally with the cage 2. Each of the cage webs 18 delimits two circumferentially adjacent pockets 10. The second pockets 11 of the second pockets 12 of the pocket row 9 are each delimited by cage webs 19 formed integrally with the cage 2. Each of the cage webs 19 delimits two circumferentially adjacent pockets 11.

[0033] The cage 2 is provided with a radially outer rim 22 running around the axis of symmetry 7 and with a radially inner rim 25 running around the axis of symmetry 7.

[0034] Fig. 3: Each of the first pockets 10 is delimited radially in the direction of the axis of symmetry 7 by a first wall section 15 of a first central rib section 13. The second pockets 11 are delimited radially in the direction of the first row of pockets 8 by a second wall section 16 of the second central rib sections 14. The wall sections 15 and 16 are formed on a doubling 17 of the sheet material of the cage 2. The doubling 17 forms the central rib 12 of the cage 2, which extends around an axis of symmetry 7. The axis of symmetry 7 corresponds to the axis of rotation 7 of the Fig. 1 shown axial bearing 1.

[0035] The central rim 12 has a fold 20 at one end, at which the wall sections 15, 16 lie against one another with the sheet metal material of the cage 2 and merge into one another in a one-piece manner at the tip 35 of the fold 20. The tip 35 of the fold 20 is directed in an axial direction marked with the directional arrow. At the tip 35, the wall sections 15, 16 merge into one another in a one-piece, single-material manner. Axially below the tip 35, the wall sections 15 and 16 lie closely together. In a process not illustrated, one of the wall sections 15 or 16 is formed by cold forming in a direction opposite to the other of the wall sections 15 or 16, and both wall sections 15 and 16 are pressed radially against one another.

[0036] The cage webs 18 or 19 are curved in such a way that, in imaginary axial planes in which the axis of symmetry 7 of the cage 2 also runs axially, they have a course described by a bracket 26 or 27. The axial plane is the image plane. The respective cage web 18 runs radially in the axial plane between the central rim 12 and an outer rim section 21 of the outer rim 22, with the respective bracket 26 extending from a base 28 formed on the central rim 12 on one side and from a further base 29 formed on one of the rim sections 21. The bracket 26 protrudes from the bases 28 and 29 in an axial direction aligned with the axis of symmetry 7 and the doubling 17. The respective cage webs 19 extend radially in the or another axial plane between the central rim 12 and an inner rim section 24 of the inner rim 25.The respective bracket 27 extends from a base 30 formed on the central rim 12 on one side and from a further base 31 formed on one of the rim sections 24 and protrudes from the bases 30 and 31 in an axial direction aligned with the axis of symmetry 7 and the doubling 17. The legs 37 of each bracket 26 or 27, which extend slightly towards one another but are essentially axially aligned, merge into a bridge 38. Mounts 39 for holding or guiding the rolling elements (not shown) are optionally formed on the bases 28, 29, 30, 31, legs 37, or bridges 38.

[0037] The outer rim 22 and the inner rim 25 are sheet metal strips which encircle the axis of symmetry 7 and are formed of a single material with the cage webs 18 and 19, which are aligned in the same axial direction indicated by the directional arrow as the central rim 12 and the axis of symmetry 7. List of reference symbols 1 thrust bearing 2 cages 3 first rolling elements 4 second rolling elements 5 first row of rolling elements with the first rolling elements 6 second row of rolling elements with the second rolling elements 7 Axis of rotation of the axial bearing, axis of symmetry of the cage 8 first row of pockets 9 second row of pockets 10 first bags 11 second pockets 12 centerboard 13 first midboard sections of the midboard 14 second midboard section of the midboard 15 first wall sections of the central board 16 second wall sections of the central board 17 Duplication 18 first cage bar 19 second cage bar 20 folds 21 radial outer rim section 22 radial outer rim 24 radial inner rim section 25 radial inner rim 26 first bracket 27 second bracket 28 Base of the bridge 29 Base of the bridge 30 Base of the bridge 31 Base of the bridge 32 Roll symmetry axis 33 Running disc 34 Axial bearing unit 35 Tip of the fold 36 Roll symmetry axis 37 legs 38 Bridge 39 brackets T1 first division T2 second division V Extension of the roll symmetry axis Z1 Number of first pockets Z2 Number of second pockets QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2007 145 843 A

[0002] JP 2010 007 745 A

[0002]

Claims

[1] Axial bearing (1) with two rows of rolling elements (5, 6) aligned concentrically to an axially extending axis of rotation (7) and with a cage (2) formed from sheet metal material, wherein - a first rolling element row (5) of the rolling element rows (5, 6) several first rolling elements (3) distributed in the circumferential direction around the rotation axis (7) - and a second rolling element row (6) of the rolling element rows (5, 6) has a plurality of second rolling elements (4) distributed in the circumferential direction around the rotation axis (7), - the rows of rolling elements (5, 6) are radially adjacent to one another, i.e. aligned transversely to the axis of rotation (7), in such a way that the first row of rolling elements (5) extends radially outward around the second row of rolling elements (6), - the rows of rolling elements (8, 9) are separated from one another in the radial direction by a central rib (12) extending around the axis of rotation (7) and formed integrally with the cage (2), - the first rolling elements (3) are separated from the second row of rolling elements (6) by first central rib sections (13) of the central rib (12), characterized by , that - the second rolling elements (4) are at least partially separated from the first row of rolling elements (5) by the first central rib sections (13) or by second central rib sections (14) of the central rib (12), - at least some of the central rim sections (13, 14) are each formed by at least two wall sections (15, 16) of the central rim (12) which are directly adjacent to one another and are formed in one piece with the sheet metal material of the cage (2), the first wall section (15) being formed on the side of the first row of rolling elements (5) and the second wall sections (16) being formed on the side of the second row of rolling elements (6). [2] Axial bearing (1) according to claim 1, characterized bythat the wall sections (15, 16) between the rows of rolling elements (5, 6) are aligned in the axial direction and lie radially against one another in direct contact with one another at least in sections. [3] Axial bearing according to claim 1, characterized by that the first rolling elements (3) are arranged with a uniform or uneven first pitch (T1) to one another and the rotation axis (7) and the second rolling elements (4) are arranged with a uniform or uneven pitch (T2) to one another distributed around the rotation axis (7), wherein the first pitch (T1) has a different value than the second pitch (T2) or the same value as the second pitch (T2). [4] Cage (2) of an axial bearing according to the preceding claims, wherein - the cage (2) is provided with a first row of pockets (8) and a second row of pockets (9), - the first row of pockets (8) has a plurality of first pockets (10) distributed around the axis of symmetry (7) for receiving at least one of the first rolling elements (3), wherein the axis of symmetry (7) of the cage (2) corresponds to the axis of rotation (7), - the second row of pockets (9) has a plurality of second pockets (11) distributed around the axis of rotation (7) for receiving at least one of the second rolling elements (4), - the rows of pockets (8, 9) are separated from one another in the radial direction by a central rim (12) extending around an axis of symmetry (7) and formed integrally with the cage (2), - the first pockets (10) are separated from the second row of pockets (9) by first central rim sections (13) of the central rim (12) - the second pockets (11) are separated from the first row of pockets (8) by second central rim sections (14) of the central rim (12) characterized by , that - each of the first pockets (10) is delimited radially in the direction of the rotation axis (7) by a first wall section (15) of one of the first central rim sections (13), - the second pockets (11) are delimited radially in the direction of the first row of pockets (8) by a second wall section (16) of the first central rim sections (13) or the second central rim sections (14), - the wall sections (15, 16) are formed on a doubling (17) of the sheet material of the cage (2), wherein the doubling (17) forms the central rim (12) of the cage (2) extending around an axis of symmetry (7), wherein the axis of symmetry (7) corresponds to the axis of rotation (7). [5] Cage (2) according to claim 1, 2 or 4, characterized by that at least the central rim sections (13, 14) or the central rim (12) have a fold (20) at one end, at which the wall sections (15, 16) lie against one another with the sheet metal material of the cage (2) and merge into one another in one piece. [6] Cage (2) according to claim 4 or 5, characterized bythat at least one of the pockets (10, 11), either the first pockets (11) or the second pockets (12), of one row of pockets (8) or the other of the other row of pockets (9) orat least one of the pockets (11, 12) of each of the two rows is delimited by cage webs (18, 19) formed in one piece with the cage (2), wherein the cage webs (18, 19) have a course described by a bracket (26, 27) in imaginary axial planes, in which the axis of symmetry (7) of the cage (2) also runs axially aligned, wherein the respective cage webs (18, 19) extends radially in the axial plane between the central rim (12) and either an outer rim section (21) of an outer rim (22) or between the central rim (12) and an inner rim section (24) of an inner rim (25), and wherein the respective bracket (26, 27) extends from a base (28, 30) formed on the central rim (12) on one side and from a further base (29, 31) protrudes in an axial direction aligned with the axis of symmetry (7) and the doubling (17). [7] Cage according to claim 6, characterized by that the outer rim (22) and the inner rim (25) are sheet metal strips which encircle the axis of symmetry (7) and are formed from a single material with the cage webs (18, 19), and which are aligned in the same axial direction as the central rim (12) and the axis of symmetry (7). [8] Cage according to one of the preceding claims 4 to 7, characterized by that central rim sections (13, 14) adjacent to one another in the circumferential direction differ geometrically from one another and that the central rim sections (13, 14) following one another in the circumferential direction around the axis of symmetry 7 together form the central rim (12) encircling the axis of symmetry (7). [9] Cage (2) according to the preceding claims 4 to 8, characterized bythat the first pockets (10) of the first row of pockets (8) are arranged with a uniform or uneven first pitch (T1) to one another and the rotation axis (7) and the second pockets (11) of the second row of pockets (9) are arranged with a uniform or uneven second pitch (T2) to one another around the rotation axis (7), wherein the first pitch (T1) has a different value than the second pitch (T2). [10] Method for producing an axial cage (2) according to one of the preceding claims 4 to 9, characterized by that the cage (2) is produced by cold forming of sheet metal, the doubling (17) being produced by axial backward pressing or pushing through.

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