BEARING ASSEMBLY

Abstract

A bearing assembly includes first and second raceways and balls between the raceways, and is conceptually divided into four quadrants by a ball rotational axis and an axis perpendicular to the ball rotational axis. The second raceway includes a first portion lying in the first quadrant and a second portion lying in the second quadrant, and the first raceway includes a first portion lying in the third quadrant and a second portion lying in the fourth quadrant. Each of the balls has a raceway contact point in each of the quadrants, and a center of curvature of each of the portion of the raceway in each quadrant is located in an opposite quadrant. The contact points are offset from the axis perpendicular to the ball axis of rotation and are arranged in a range of ±10°, around the axis perpendicular to the ball axis of rotation.

Claims

1-10. (canceled)

11. A bearing assembly comprising: a first raceway element having a first raceway, a second raceway element having a second raceway, and a plurality of balls disposed between the first raceway and the second raceway, wherein the bearing assembly is conceptually divided into four quadrants by a rotational axis of one of the plurality of balls and an axis perpendicular to the rotational axis of the one of the plurality of balls, wherein the second raceway includes a first portion lying in the first quadrant and a second portion lying in the second quadrant, and the first raceway includes a first portion lying in the third quadrant and a second portion lying in the fourth quadrant, wherein the one of the plurality of balls has a first contact point with the first portion of the second raceway and a second contact point with the second portion of the second raceway, and a third contact point with the first portion of the first raceway and a fourth contact point with the second portion of the first raceway, wherein a centerpoint of a radius of curvature of the first portion of the second raceway lies in the third quadrant and a centerpoint of a radius of curvature of the second portion of the second raceway lies in the fourth quadrant and a centerpoint of a radius of curvature the first portion of the first raceway lies in the first quadrant and a centerpoint of the radius of curvature of the second portion of the first raceway lies in the second quadrant, wherein the first, second, third and fourth contact points are offset from the axis perpendicular to the axis of rotation of the one of the plurality of balls, and wherein the first, second, third and fourth contact points are arranged in a range of ±10° around the axis perpendicular to the axis of rotation of the ball.

12. The bearing assembly according to claim 11, wherein an intersection point of the radius of curvature of the first portion of the second raceway and the radius of curvature of the second portion of the second raceway lies on the axis perpendicular to the rotational axis of the ball, and wherein an intersection point of the radius of curvature of the first portion of the first raceway and the radius of curvature of the second portion of the first raceway lies on the axis perpendicular to the rotational axis of the ball.

13. The bearing assembly according to claim 12, wherein the radius of curvature of the first portion of the second raceway and the radius of curvature of the second portion of the second raceway and the radius of curvature of the first portion of the first raceway and the radius of curvature of the second portion of the first raceway are identical.

14. The bearing assembly according to claim 13, wherein the radius of curvature of the first portion of the second raceway and/or the radius of curvature of the second portion of the second raceway and/or the radius of curvature of the first portion of the first raceway and/or the radius of curvature of the second portion of the first raceway is non-constant.

15. The bearing assembly according to claim 14, wherein the first raceway element and/or the second raceway element is a divided raceway element, and wherein the bearing assembly includes preload means for controlling locations of the first and second contact points and/or for controlling the locations of the third and fourth contact points.

16. The bearing assembly according to claim 14, wherein the first raceway element is an inner ring or a shaft disk, and wherein the second raceway element is an outer ring or a housing disk.

17. The bearing assembly according to claim 15, wherein the rotational axis of the one of the plurality of balls is perpendicular or parallel to a rotational axis of the ball bearing.

18. The bearing assembly according to claim 14, wherein the bearing assembly is a linear bearing, wherein the first raceway element is a rail, and wherein the second raceway element is a carriage.

19. The bearing assembly according to claim 11, wherein the radius of curvature of the first portion of the second raceway and the radius of curvature of the second portion of the second raceway and the radius of curvature of the first portion of the first raceway and the radius of curvature of the second portion of the first raceway are identical.

20. The bearing assembly according to claim 11, wherein the radius of curvature of the first portion of the second raceway and/or the radius of curvature of the second portion of the second raceway and/or the radius of curvature of the first portion of the first raceway and/or the radius of curvature of the second portion of the first raceway is non-constant.

21. The bearing assembly according to claim 11, wherein the first raceway element and/or the second raceway element is a divided raceway element, and wherein the bearing assembly includes preload means for controlling locations of the first and second contact points and/or for controlling the locations of the third and fourth contact points.

Description

[0025] In the following the invention is described in more detail using the exemplary embodiments depicted in the drawings. Here the exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the pending claims.

[0026] FIG. 1 shows a schematic cross-sectional view of a bearing assembly;

[0027] FIG. 2 shows a schematic cross-sectional view of the bearing assembly of FIG. 1 as a single row axial bearing;

[0028] FIG. 3 shows a schematic cross-sectional view of the bearing assembly of FIG. 1 as a single row radial bearing;

[0029] FIG. 4 shows a schematic cross-sectional view of the bearing assembly of FIG. 1 as a double row axial bearing;

[0030] FIG. 5 shows a schematic cross-sectional view of the bearing assembly of FIG. 1 as a double row radial bearing; and

[0031] FIG. 6 shows a schematic cross-sectional view of the bearing assembly of FIG. 1 as a linear bearing with divided raceway element.

[0032] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0033] FIG. 1 shows a bearing assembly 1 with a first raceway element 2 and a second raceway element 4. Balls 6 as rolling elements are arranged between the raceway elements 2, 4. The balls 6 roll on raceways 8 that are disposed on the raceway elements 2, 4.

[0034] The bearing assembly 1 can be configured as a ball bearing, in particular as a radial or axial bearing, or as a linear bearing. In the case of a radial bearing, the first raceway element 2 and the second raceway element 4 correspond to the inner ring and the outer ring. In the case of an axial bearing, the first raceway element 2 and the second raceway element 4 correspond to the shaft disk and the housing disk. In the case of a linear bearing, the first raceway element 2 and the second raceway element 4 correspond to the rail and the carriage.

[0035] In the bearing assembly 1 shown in FIG. 1, the raceways 8 can be conceptually divided into four quadrants I, II, III, IV. The division into the four quadrants I, II, III, IV is effected by the rotational axis A.sub.R of the ball and an axis A.sub.s that is perpendicular to the rotational axis A.sub.R. The raceway of the second raceway element 4 is formed by two segments 8-I, 8-II and lies in the first and second quadrants I, II, and the raceway of the first raceway element 2 is formed by two raceway segments 8-III and 8-IV and lies in the third and fourth quadrants III, IV.

[0036] The ball 6 comes in contact with the raceways 8-I, 8-II at two contact points P-I, P-II that are located in two contact zones 10-I and 10-II and with the raceways 8-III and 8-IV at two contact points P-III, P-IV that are located in the contact zones 10-III and 10-IV. In order to ensure that the ball 6 contacts the raceways 8 at the contact points P-I, P-II, P-IV, the raceways 8 have a special design: The centerpoint M-I of the radius of curvature R-I of the raceway segment 8-I lies in the third quadrant III, the centerpoint M-II of the radius of curvature R-II of the raceway segment 8-II lies in the fourth quadrant IV, the centerpoint M-III of the radius of curvature R-III of the raceway segment 8-III lies in the first quadrant I, and the centerpoint M-IV of the radius of curvature R-IV of the raceway segment 8-IV lies in the second quadrant II.

[0037] In the embodiment shown in FIG. 1, the intersection point of the radii of curvature R-I, R-II of the first and the second quadrants I, II lies on the axis A.sub.s, and the intersection point of the radii of curvature R-III, R-IV of the third and the fourth quadrant III, IV also lies on the axis A.sub.s. However, the intersection point can also not lie on the axis A.sub.s. Here the radius of curvature R is understood to mean the radius defining the curvature, i.e., the distance between the raceway 8 and the centerpoint M. In particular, as is shown in FIG. 1, the straight line through M-I and M-III intersects the straight line through M-II and M-IV at the intersection point S. In the case shown here, the intersection point S simultaneously lies on the intersection point of the rotational axis A.sub.R and the axis A.sub.s, but this is not absolutely necessary. Due to this specific design of the radii of curvature R of the raceways 8, it is ensured that the ball 6 contacts the raceways 8 at the contact points P-I, P-II, P-IV. The contact points P-I, P-II, P-IV lie in the contact zones 10 in a region of ±20°, in particular ±10°, about the axis A.sub.s.

[0038] In order to ensure that the ball bearing 1 can support not only axial or radial loads, the contact points P-I, P-II, P-IV are always offset with respect to the axis A.sub.s. In this way the ball 6 always has four contact points P-I, P-II, P-IV with the raceways 8 that each are located in the contact zones 10-I, 10-II, 10-III and 10-IV, whereby a good radial load rigidity and a good load and pressure distribution, and thus a low-wear behavior, are achieved.

[0039] The bearing assembly 1 can be used in different configurations, as is shown in FIGS. 2 to 6.

[0040] As is shown in FIG. 2, the bearing assembly can be used as a single row axial ball bearing, wherein in this case the rotational axis A.sub.R is perpendicular to the bearing rotational axis A.sub.L. Here the axis A.sub.s about which the contact zones 10-I, 10-II, 10-III, 10-Iv are arranged lies parallel to the rotational axis A.sub.L of the bearing.

[0041] Alternatively the bearing assembly 1 can be used as a single row radial bearing as is shown in FIG. 3. In this case the rotational axis A.sub.R is parallel to the rotational axis A.sub.L of the bearing 1. The axis A.sub.s, about which the contact zones 10-I, 10-II, 10-III and 10-Iv are arranged is in this case perpendicular to the bearing rotational axis A.sub.L.

[0042] The bearing assembly 1 can also be used as a double row axial ball bearing (FIG. 4) or as a double row radial ball bearing (FIG. 5). In the case of a double row axial ball bearing, the rotational axis A.sub.R is perpendicular to the bearing rotational axis A.sub.L, and in the case of a double row radial ball bearing, the rotational axis A.sub.R is parallel to the bearing axis A.sub.L.

[0043] In the case of such a double row axial or radial ball bearing, the inner or outer rings 2, 4 can be configured as divided rings (not shown). In this case, a preload mechanism, for example, a screw connection, can be used in order to control the contact points P-I, P-II, P-IV or contact zones 10 between the ball 6 and the raceways 8. Due to the preloading of the respective ring 2, 4, the preload of the contact points P-I, P-II, P-IV can be adjusted by an adjusting of the clearance between the parts of the divided ring 2, 4. Single row axial or radial ball bearings can also be realized with divided rings 2, 4 and preload mechanisms.

[0044] The bearing assembly 1 can also be used as a linear bearing as is shown in FIG. 6. In this case the first raceway element 2 is formed by a rail and the second raceway element by a carriage 12 and an element 4′ separated therefrom. Also in this case the second raceway element 4′ can be adjusted in its preload or its clearance by a preload element 14 in order to correspondingly adjust the contact points P-I, P-II, P-IV or the contact zones 10-I, 10-II, 10-III, 10-IV. In the case of the linear bearing 1 of FIG. 6, the ball rotational axis A.sub.R is perpendicular to the direction of movement of the bearing 1 in the carriage 12.

[0045] Due to the ball bearing described here, a good radial and axial load rigidity and a low-wear behavior due to a lower friction can be achieved.

REFERENCE NUMBER LIST

[0046] 1 Bearing assembly [0047] 2 First raceway element [0048] 4 Second raceway element [0049] 6 Balls [0050] 8 Raceways [0051] Contact zones [0052] 12 Carriage [0053] 14 Preload mechanism [0054] I, II, III, IV Quadrants [0055] A.sub.L Bearing rotational axis [0056] A.sub.R Ball rotational axis [0057] A.sub.S Axis perpendicular to the ball rotational axis [0058] M Centerpoint of the radius of curvature [0059] P Contact points [0060] R Radius of curvature [0061] S Intersection point