DE102022119916B4 - Multi-row axial bearing with curved axial bearing disk - Google Patents

Abstract

Axial bearing (1) with rolling elements (5, 6, 7) and at least one axial disk (8, 9), wherein the axial disk (8, 9) is provided with at least one rolling track (10, 11, 12) for the rolling elements (5, 6, 7), and wherein first rolling elements (5) designed as balls (13) and second rolling elements (6) designed as rollers (14) are provided, wherein the axial disk (8, 9) is provided with at least one curvature (15, 16, 17, 18), wherein the axial bearing is a multi-row axial bearing (1) with at least two rows (2, 3, 4) arranged concentrically to a central axis (19) and the rolling elements (5, 6, 7) arranged together in a first radial plane (L1), and wherein the axial disk (8, 9) is provided with at least one first rolling track (10) of the rolling raceways (10, 11, 12) of a first row (2) for rolling contacts with the balls (13) and a second rolling raceway (11) of the rolling raceways (10, 11, 12) of a second row (3) for rolling contacts of rolling elements (5, 6, 7) of the rolling elements (5, 6, 7), wherein the axial bearing (1) has a third row (4) with third rolling elements (7) arranged in the radial plane (L1), wherein a third rolling raceway (12) of the rolling raceways (10, 11, 12) of the third row (4) is assigned for rolling contacts with the third rolling elements (7), characterized in that the second rolling raceway (11) of the second row (3) for contacts with the second rolling elements designed as rollers (14) (6) and that the third rolling elements (7) of the third row (4) are designed as rollers (14), and that the first rolling track (10) and the second rolling track (11) differ geometrically from one another and that the third rolling track (12) differs geometrically from the first rolling track (10) and the second rolling track (11) and that the first axial disk (8) is provided with further curvatures (16, 17, 18), wherein a second curvature (16) of the curvatures (16, 17, 18) is formed at least on the first rolling track (10) and a third curvature (17) on the second rolling track (11) and a fourth curvature (18) on a third rolling track (12).

Description

Field of the invention

The invention relates to an axial bearing with rolling elements and with at least one axial disk, wherein the axial disk is provided with at least one rolling track for the rolling elements, and wherein first rolling elements designed as balls and second rolling elements designed as rollers are provided, wherein the axial disk is provided with at least one curvature.

Background of the invention

A combined axial-radial bearing, in which the axial bearing is provided by a series of rollers and the radial bearing is made up of a series of balls with corresponding angles of the axial-radial disks, is based on the DE 89 06 246 U1 out.

From the US 2016 / 0 010 688 A1 This is an axial bearing of the type that is formed from a single row of balls and needles. Furthermore, the US 2016 / 0 010 688 A1 a multi-row axial bearing with curved axial disks, the individual rows of which are fitted with balls. Two circumstances are exploited when such bearings are used. Firstly, the fact that rolling bearings with balls usually have low frictional resistance when operated under load compared to rolling bearings with needles is exploited. Secondly, the fact that rolling bearings with needles can absorb comparatively higher loads is exploited. Due to the curved raceways, the axial bearings mainly carry the load via the balls and a very small proportion of the length of the needles under lower loads, which means that the bearing runs with very little friction. Under load, the axial disks compress axially, i.e. the curvature is reduced and the line contact between the needles and the rolling raceways can be achieved up to the maximum. This improves the load-bearing capacity of the axial bearing. However, there are limits to the load-bearing capacity.

Description of the invention

The object of the invention is to provide an axial bearing with improved function, with which the load-bearing capacity can be increased and with which the friction can nevertheless be reduced.

The problem is solved by the subject matter of claim 1.

One feature of the invention provides that the axial bearing is a multi-row axial bearing with at least two rows arranged concentrically to a central axis. The axial disk has at least two geometrically different rolling raceways. Each rolling raceway is assigned a row of rolling elements. The rolling elements are arranged in a common first radial plane. This means that the rows of rolling elements support each other in parallel, at least when the axial bearing is subjected to maximum load. An essential feature is that the rolling raceways differ from one another in terms of their geometry and their position relative to the central axis. It is also conceivable that the rolling raceways differ from one another in terms of their alignment relative to the first radial plane. For the rolling elements, lying together in a radial plane means that the rolling element centers lie in the radial plane. For balls, the rolling element centers are the ball centers, and for rollers, these are the individual roller symmetry axes. In the latter case, it is sufficient if the roller axes intersect the first radial plane. In this case, the intersection points are the centers. The first radial plane is an imaginary plane penetrated perpendicularly by the central axis of the axial bearing.

The central axis of the axial bearing is defined as being axially aligned. Radial is therefore perpendicular to the roller axis. In connection with the arrangement according to the invention, radial planes are therefore penetrated perpendicularly by the central axis.

In their basic form, rollers are cylindrical, but also spherical or non-spherical rolling elements that rotate or roll around their own rolling axis. In this case, the term rollers also includes rollers defined as having a larger length-to-diameter ratio than needles.

The central axis of the axial bearing is a swivel axis or rotation axis around which the rows of the axial bearing arranged concentrically to this central axis swivel with swivel angles of up to 360° or rotate with rotation angles > 360° around the central axis of the axial bearing.

Both the front side of the axial disc and its rear side are directed away from the second radial plane when viewed from the second radial plane.

The advantage of the invention is that the axial bearing is designed in multiple rows in parallel arrangement. Parallel arrangement means that under the highest load the rolling elements of all Rows lying next to each other in the direction of the load. Each row is assigned a rolling raceway adapted to the loads, load sequence and the special geometry of the rolling elements used for this row. This allows optimal rolling conditions to be set for the operating and load conditions and reduces friction in the rolling bearing
This allows the efficiency and service life of such axial bearings to be optimized and, with a view to reducing friction, less energy is consumed, which improves the _CO2 balance.

The invention provides that the axial bearing has a third row with third rolling elements arranged in the same radial plane as the first and second rolling elements. This measure allows the axial bearing to be adapted to particularly high loads. The latter is particularly the case when, as the invention provides, the third rolling elements are designed as rollers.

The rollers in the third row can have the same length and shape as the rollers in the second row and be made of the same material, or they can differ from them in terms of these characteristics. Using identical rollers makes their production more economical because larger batch sizes can be produced and the costs for transport, handling and storage are comparatively lower than when using different rollers.

One embodiment of the invention provides that the rolling elements, both the balls and the rollers, all have the same diameter. The same diameter means that the rolling elements have the same nominal size, i.e. that the diameters can differ from one another within permissible tolerances. Alternatively, the balls can have a different diameter than the needles. It is also provided that the needles differ in diameter from row to row or even from one another in a row. The same applies to the balls. The diameters of the rolling elements, together with the geometry of the raceways, can be used to set certain special deflection and rolling characteristics that cannot be achieved with standard axial bearings.

The third rolling track for the third row provides another option for setting an adapted rolling behavior. The geometry of this third rolling track differs from the first rolling track and the second rolling track.

As already mentioned at the beginning, the three rows are arranged in a common radial plane. This results in a further embodiment of the invention, according to which the second row adjoins the first row in the first radial plane radially inward toward the central axis of the axial bearing and the third row adjoins the first row radially in the first radial plane outside away from the first radial plane.

A further embodiment of the invention provides that the first curvature, viewed in a longitudinal section along the central axis, rises above a second radial plane in an axially convex manner. The rolling raceways are formed on the outside of the convex surface of the curvature. The first rolling raceway is axially further away from this second radial plane than the second rolling raceway and/or the first rolling raceway. The first rolling raceway, which is the rolling raceway for the balls, is preferably formed at the turning point from rising to falling of the curved lines of the convex contour of the axial disk, which is furthest away from the second radial plane. The other two rolling raceways therefore run axially offset from the first rolling raceway in the direction of the second radial plane. The difference in the axial distances can either be compensated by larger rolling element diameters of the second and third rolling elements, or, as a preferred development provides, remains as an axial air gap at least in the unloaded state of the axial rolling bearing. In the lightly loaded state, the axial bearing runs only through the rolling contact of the balls, with very low frictional resistance and energy consumption. With higher loads and compression of the axial disc, the load share of the rollers will increase and the rollers will ultimately support the loads within the scope of their predetermined rolling contact, so that a high load capacity is ensured by two rows of rollers and one row of balls acting in parallel.

The elasticity or elastic behavior of the axial disk is optimally designed when the axial disk is hollow-curved on its rear side and at the same time elastically flexible. This allows the axial disk to elastically compress under load so that all rows come into play and to elastically rebound when the load is removed so that only the row of balls is again in play. In this case, the axial disk is curved in an arc shape when viewed in any longitudinal section along the central axis according to one embodiment of the invention. The first curvature of the first axial disk according to the definition of the patent claim is formed by a front side facing away from the second radial plane and axially spaced from a second radial plane with the at least one rolling track. and also by a rear side facing away from the front and facing the second radial plane at the same radial heights, such that both the front and the rear side have profiles that rise axially above the second radial plane and rise convexly away from the second radial plane in a common axial direction. The axial disk is preferably a component punched from sheet metal, preferably sheet steel, and embossed with the rolling raceways. The wall thickness of the axial disk can be the same in any longitudinal sections or, alternatively, the axial disk can have different thicknesses. The second radial plane is an imaginary plane in which the axial disk is supported. The axial disk is preferably supported via the circular line of a radially outer body edge of the axial disk or surface contact of a radially outer or the entire rear side of the axial disk. The latter preferably when the axial bearing is under maximum load. The rear side is the side of the axial disk facing away from the rolling raceways, which is supported on a component.

The invention provides further depressions or elevations, i.e. curvatures, on the first curvature, which are locally ring-shaped, preferably in the area of the rolling raceways. Such measures can be easily integrated into the punching or embossing process during the manufacture of the axial disc without additional or hardly noticeable additional effort. Such measures advantageously make it possible to set further specific special deflection and rolling characteristics. The local curvatures, which are preferably spherical circular surfaces and run concentrically around the central axis, can protrude from the first curvature in a spherical convex manner when viewed in any longitudinal section through the axial disc along the central axis, or can curve into the first curvature in a spherical concave manner. The latter is particularly advantageous on the rolling raceway for the balls, because it creates an osculation between the rolling raceway and the balls in the manner of a ball groove in a ball bearing, which reduces the surface pressure in the rolling contact and increases the load-bearing capacity of the row of balls.

The rolling and load-bearing behavior can also be positively influenced by providing the axial bearing with two of the axial disks. In the interest of economical batch sizes, the two axial disks are preferably designed as identical parts in terms of geometry and material. However, it is also conceivable to provide another axial disk with any other suitable geometry or on rolling track(s) formed directly on a component.

The rolling elements of the individual rows are preferably guided in a common cage. Alternatively, it is also conceivable to use two or three cages and/or several cage segments to guide the rolling elements.

Description of the drawings

• 1 zeigt einen Ausschnitt eines längs seiner Zentralachse 19 geschnittenen Axiallagers 1.
• 2 zeigt die untere Axialscheibe 8 der beiden Axialscheiben 8 und 9 des mit 1 dargestellten Axiallagers 1 als Einzelteil in der mit der Darstellung nach 1 vergleichbaren Ansicht.

The invention is explained in more detail below using an embodiment.

• 1 shows a section of an axial bearing 1 cut along its central axis 19.
• 2 shows the lower axial disc 8 of the two axial discs 8 and 9 of the 1 shown axial bearing 1 as a single part in the same manner as shown in 1 comparable view.

1 The axial bearing 1 is formed from a first axial disk 8, a second axial disk 9, first rolling elements 5, second rolling elements 6 and third rolling elements 7 and a cage 22. The first rolling elements 5 are designed as balls 13. The second rolling elements 6 and the third rolling elements 7 are each designed as rollers 14. The rollers 14 are identical parts. The diameters D of the balls 13 and the rollers 14 are all the same.

The balls 13 are guided together in a first row 2 in the cage 22. The axial bearing 1 has two rows 3 and 4 with the rollers 14. The rows 2, 3 and 4 or their rolling elements 5, 6 and 7 are arranged concentrically to the central axis 19. The ball centers 23 of the balls 13 and the roller axes 24 of the rollers 14 are ideally located in the first radial plane L1.

1 and 2 The respective axial disk 8 or 9 is provided with at least the rolling tracks 10, 11 and 12 for the rolling elements 5, 6 and 7. The respective first rolling track 10 is intended for rolling contacts of the balls 13 of the first row 2 with the respective axial disk 8 or 9. The respective second rolling track 11 is intended for rolling contacts with the rollers 14 of the second row 3. The respective third rolling track 12 is assigned to rolling contacts of the rollers 14 of the third row 4 with the axial disks 8 and 9. The axial disks 8 and 9 are identical parts.

1 In the illustration, the axial bearing 1 is not loaded or is only slightly loaded, so that only the balls 13 carry the load. An air gap 26 running around the central axis and narrowing radially in the direction of the central axis or an air gap 27 widening axially in the direction of the central axis 19 is formed between the rollers 14 and the respective opposing rolling raceways 11 and 11 of the second row 3.

The ideal case is shown in which, as already mentioned, the ball centers 23 of the balls 13 and the roller axes 24 of the rollers 14 lie in the first radial plane L1. Possible displacements of the rolling elements 5, 6, 7 relative to one another or axial sagging and tilting of the rolling elements 6 or 7 in the cage 22 and possibly one-sided contact of the rollers 14 without load with one of the rolling tracks 11 and 12 are conceivable in practice, so that air gaps can also be formed on one side between only one rolling track 11 or 12 and the respective roller 14 with a value twice the value of both air gaps 26 and 27, while on the other side the rollers 14 sag in one direction, for example under the effect of gravity, and contact rolling tracks 11 or 12 in this direction.

2 Both the first rolling track 10 and the second rolling track 11 and the first rolling track 10 and the third rolling track 12 and the second rolling track 11 and the third rolling track 12 differ geometrically from one another. The radius R3 of the third rolling track 12 is larger than the radius R1 of the first rolling track 10 and the radius R1 of the first rolling track 10 is larger than the radius R2 of the second rolling track 11. The axial distance A1 of the first rolling track 10 from the second radial plane L2 is the largest of the distances A1, A2 and A3 and larger than the axial distances A2 and A3 of the second rolling track 11 and the third rolling track 12 from the second radial plane L2. The distances A2 and A3 of the second rolling track 11 and the third rolling track 12 are the same. The axial disk 8 is curved in the longitudinal section such that its first curvature 15 in a longitudinal section rises axially bulging with the axial direction of the arrow convexly curved away from this radial plane L2 over a second radial plane L2. The second radial plane L2 is a plane parallel to the first radial plane L1. In this radial plane L2, the axial disk 8 is supported during installation with a body edge 25 running around the central axis 19, for example against a component not shown. It is also shown and possible that the radially inner body edge 28 of the axial disk 8 lies or is supported in the same radial plane L2 or alternatively in another radial plane (not shown). The first curvature 15 is characterized by a front side 20 facing away from the second radial plane L2 and axially spaced from the second radial plane L2 and also by a rear side 21 facing away from the front side 20 and facing the second radial plane L2 such that both the front side 20 and the rear side 21 have profiles that rise axially above the second radial plane L2 and run convexly away from the second radial plane L2 and are parallel to one another. The distance between the front side 20 and the rear side 21 is defined by a constant sheet thickness of the punched and embossed axial disk 8. The front side 20 has the rolling raceways 10, 11 and 12. The axial disk 8 is provided with further curvatures 16, 17 and 18, which are partially formed on the first curvature 15. The third curvature 17 is convexly curved from the first curvature 15 on the second rolling track 11 from the perspective of the radial plane L2. A second curvature 16 is concave on the first rolling track 10 from the perspective of the radial plane L2 and a fourth curvature 18 on the third rolling track 12 is again convexly curved. Due to its concave design, the second curvature 16 forms a ball groove in which the balls 13 run in rolling contact under osculation ( 1 ). Alternatively, the third curvature is convex and the second and/or fourth curvature are concave (not shown).

Reference symbols

1

Axial bearing

2

first row

3

second row

4

third row

5

first rolling elements

6

second rolling elements

7

third rolling elements

8th

first axial disc

9

second axial disc

10

first rolling track

11

second rolling track

12

third rolling track

13

Bullet

14

role

15

first curvature

16

second curvature

17

third curvature

18

fourth curvature

19

Central axis of the thrust bearing

20

Front of the first axial disc

21

Back of the first axial disc

22

Cage

23

Sphere center

24

Roller axle

25

Body edge

26

Air gap

27

Air gap

28

Body edge

A1

axial distance of the first rolling raceway

A2

axial distance of the second rolling raceway

A3

axial distance of the third rolling raceway

D

diameter

L1

first radial plane

L2

second radial plane

R1

first radius

R2

first radius

Claims (9)

Axial bearing (1) with rolling elements (5, 6, 7) and at least one axial disk (8, 9), wherein the axial disk (8, 9) is provided with at least one rolling track (10, 11, 12) for the rolling elements (5, 6, 7), and wherein first rolling elements (5) designed as balls (13) and second rolling elements (6) designed as rollers (14) are provided, wherein the axial disk (8, 9) is provided with at least one curvature (15, 16, 17, 18), wherein the axial bearing is a multi-row axial bearing (1) with at least two rows (2, 3, 4) arranged concentrically to a central axis (19) and the rolling elements (5, 6, 7) arranged together in a first radial plane (L1), and wherein the axial disk (8, 9) is provided with at least one first rolling track (10) of the rolling raceways (10, 11, 12) of a first row (2) for rolling contacts with the balls (13) and a second rolling raceway (11) of the rolling raceways (10, 11, 12) of a second row (3) for rolling contacts of rolling elements (5, 6, 7) of the rolling elements (5, 6, 7), wherein the axial bearing (1) has a third row (4) with third rolling elements (7) arranged in the radial plane (L1), wherein a third rolling raceway (12) of the rolling raceways (10, 11, 12) of the third row (4) is assigned for rolling contacts with the third rolling elements (7), characterized in that the second rolling raceway (11) of the second row (3) is designed for contacts with the second rolling elements (6) and that the third rolling elements (7) of the third row (4) are designed as rollers (14), and that the first rolling track (10) and the second rolling track (11) differ geometrically from one another and that the third rolling track (12) differs geometrically from the first rolling track (10) and the second rolling track (11) and that the first axial disk (8) is provided with further curvatures (16, 17, 18), wherein a second curvature (16) of the curvatures (16, 17, 18) is formed at least on the first rolling track (10) and a third curvature (17) on the second rolling track (11) and a fourth curvature (18) on a third rolling track (12). Axial bearings according to Claim 1 , characterized in that the first rolling elements (5) and the second rolling elements (6) and the third rolling elements (7) have the same diameter (D). Axial bearings according to Claim 1 or 2 , characterized in that the second rolling elements (6) and the third rolling elements (7) are geometrically identical. Axial bearing (1) according to one of the preceding Claims 1 until 3 , characterized in that the second row (3) adjoins the central axis (19) of the axial bearing (1) radially inward in the first radial plane (L1) and the third row (4) adjoins the first row (2) radially in the first radial plane (L1) away from the central axis (19). Axial bearing (1) according to one of the preceding claims, characterized in that the first curvature (15), viewed in a longitudinal section along the central axis (19), rises axially convexly above a second radial plane (L2) and is designed to be elastically flexible in the direction of the second radial plane (L2), wherein the first rolling raceway (10) is axially further away from the second radial plane (L2) than the second rolling raceway (11) and/or the first rolling raceway (10) is axially further away from the second radial plane (L2) than the third rolling raceway (12). Axial bearing (1) after Claim 5 , characterized in that the first curvature (15) is characterized by a front side (20) facing away from the second radial plane (L2) and axially spaced from the second radial plane (L2) with the at least one rolling raceway (10, 11, 12) and also by a rear side (21) facing away from the front side (20) and facing the second radial plane (L2) such that both the front side (20) and the rear side (21) have a course which rises axially above the second radial plane (L2) and rises convexly away from the second radial plane (L2). Axial bearing (1) according to one of the preceding claims, characterized in that the axial bearing (1) has the first axial disc (8) and at least one second axial disc (9), wherein at least one row (2, 3, 4) of the rolling elements (5, 6, 7) are arranged axially between the axially opposite axial discs (8, 9). Axial bearing (1) after Claim 7 , characterized in that the first axial disc (8) and the second axial disc (9) are geometrically identical to one another. Axial bearings according to Claim 2 , characterized in that all of the rolling elements (5, 6, 7) are arranged in a common cage (22).