MECHANICAL ASSEMBLY INCLUDING A ROLLER BEARING

Abstract

The present document relates to a mechanical assembly, comprising: a first roller bearing including an inner race, an outer race and a plurality of rolling elements, wherein an axis of rotation of the first roller bearing defines a first axial direction oriented horizontally or inclined with respect to the vertical direction, a source of lubricant configured to deliver lubricant to the first roller bearing, and at least one movable element disposed adjacent to the first roller bearing on a first side of the first roller bearing in the first axial direction, wherein the rolling elements of the first roller bearing are tapered and their larger diameter ends point towards the at least one movable element, and/or wherein axes of rotation of the rolling elements of the first roller bearing are inclined with respect to the the first axial direction so that centrifugal forces generated inside the first roller bearing are configured to transport lubricant towards the at least one movable element.

Claims

1. A mechanical assembly, comprising: a first roller bearing including an inner race, an outer race and a plurality of rolling elements, wherein an axis of rotation of the first roller bearing defines a first axial direction oriented horizontally or inclined with respect to the vertical direction, a source of lubricant configured to deliver lubricant to the first roller bearing, and at least one movable element disposed adjacent to the first roller bearing on a first side of the first roller bearing in the first axial direction, wherein the rolling elements of the first roller bearing are tapered and their larger diameter ends point towards the at least one movable element, and/or wherein axes of rotation of the rolling elements of the first roller bearing are inclined with respect to the first axial direction so that centrifugal forces generated inside the first roller bearing are configured to transport lubricant towards the at least one movable element.

2. The mechanical assembly according to claim 1, wherein the source of lubricant is arranged to deliver lubricant to a lower half of the first roller bearing.

3. The mechanical assembly according to claim 1, wherein the source of lubricant includes a lubricant sump, wherein at least a portion of the first roller bearing is immersed in the lubricant sump.

4. The mechanical assembly according to claim 1, wherein the at least one movable element includes at least one further bearing.

5. The mechanical assembly according to claim 4, wherein the at least one further bearing includes at least one roller bearing including rolling elements.

6. The mechanical assembly according to claim 4, wherein an axis of rotation of the at least one further bearing is arranged in parallel to the first axial direction.

7. The mechanical assembly according to claim 6, wherein an axis of rotation of the at least one further bearing is disposed at a distance from the axis of rotation of the first roller bearing.

8. The mechanical assembly according to claim 4, wherein a projection of an annular space formed between the inner race and the outer race of the first roller bearing onto a plane perpendicular to the first axial direction overlaps with a projection of an annular space formed between an inner race and an outer race of the at least one further bearing onto said plane.

9. The mechanical assembly according to claim 1, further including a cover disposed on the first side of the first roller bearing, wherein the cover closes or at least partially closes an annular space formed between the inner race and the outer race of the first roller bearing on its first side.

10. The mechanical assembly according to claim 9, wherein the cover comprises at least one opening.

11. The mechanical assembly according to claim 10, wherein the at least one opening in the cover is disposed such that an annular space formed between an inner race and an outer race of the at least one further bearing intersects with a cone, the cone having an apex located at or within the at least one opening, the cone having a cone axis arranged in parallel to the first axial direction, and the cone having an opening angle of less than 70 degrees.

12. The mechanical assembly according to claim 10, wherein the at least one opening includes a plurality of openings having different sizes.

13. The mechanical assembly according to claim 10, wherein the at least one opening includes a first opening and a second opening, wherein the first opening is disposed above the second opening along the vertical direction and wherein a size of the first opening is larger than a size of the second opening.

14. The mechanical assembly according to claim 1, further including a first shaft and a first gear mounted on the first shaft, wherein the first shaft is supported by the first roller bearing.

15. The mechanical assembly according to claim 14, further including a second shaft and a second gear mounted on the second shaft, wherein the second gear is drivingly engaged with or in mesh with the first gear.

16. The mechanical assembly according to claim 15, wherein the first gear is disposed on the first side of the first roller bearing in the first axial direction.

17. The mechanical assembly according to claim 15, further including a terminal bearing disposed on the first side of the first roller bearing and arranged coaxially with the first roller bearing, wherein the at least movable element includes at least one further bearing disposed in between the first roller bearing and the terminal bearing along the first axial direction.

18. The mechanical assembly according to claim 17, wherein the terminal bearing includes roller bearing including a plurality of rolling elements.

19. The mechanical assembly according to claim 18, wherein the rolling elements of the terminal bearing are tapered, wherein axes of rotation of the tapered rolling elements of the terminal bearing are inclined with respect to an axis of rotation of the terminal bearing.

20. The mechanical assembly according to claim 18, wherein the rolling elements of the terminal bearing are configured to transport lubricant from inside the terminal bearing towards the first roller bearing.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0026] FIG. 1 schematically shows a front view of elements of a mechanical assembly including three roller bearings.

[0027] FIG. 2 schematically shows a side view of the mechanical assembly of FIG. 1.

[0028] FIG. 3 schematically shows a perspective view of the mechanical assembly of FIGS. 1 and 2.

[0029] FIG. 4 schematically shows another front view of the mechanical assembly of FIGS. 1 to 3, further depicting shafts and gears mounted on the shafts.

[0030] FIG. 5 schematically shows another sectional view of the mechanical assembly of FIGS. 1 to 4.

[0031] FIG. 6 schematically shows another sectional view of the mechanical assembly of FIGS. 1 to 5.

DETAILED DESCRIPTION

[0032] FIG. 1 shows, in a schematic front view, a mechanical assembly 200 of the presently proposed type. The assembly 200 includes a first roller bearing 1 comprising an inner race 1b, an outer race 1a and a plurality of rolling elements 1c, 1d inside an annular space 1m extending between the inner race 1b and the outer race 1a. The first roller bearing 1 has an upper portion 1e and a lower portion 1f. The lower half 1f is immersed in a lubricant sump 3 formed in a lower part of a housing 100. The lubricant sump 3 may be filled or at least partially filled with a lubricant such as oil. In FIG. 1, the first roller bearing 1 is positioned in the foreground, as can be better observed FIG. 2. Here and in all of the following, recurring features depicted in different figures are designated with the same reference signs. An axis of rotation 2 of the first roller bearing 1 is oriented horizontally and perpendicular to the plane of projection of FIG. 1. The axis of rotation 2 of the first roller bearing 1 is more clearly illustrated in FIG. 2 and is represented by an arrow defining a first axial direction.

[0033] FIG. 1 further shows a second roller bearing 4 comprising an outer race 4a, an inner race 4b and a plurality of rolling elements 4c, and a third roller bearing 5 comprising an outer race 5a, an inner race 5b and a plurality of rolling elements 5c. FIG. 2 illustrates that rolling elements 1h and 1i of the first roller bearing 1 are formed by tapered or conical bodies with their larger diameter end oriented towards the first axial direction 2 and towards the second roller bearing 4 and toward the third roller bearing 5.

[0034] FIG. 1 illustrates that a lower lying portion of the first roller bearing 1 is submersed in the lubricant sump 3. Consequently, as the first roller bearing 1 rotates the rolling elements and the moving race pass through the lubricant sump 3, thereby transporting or lifting lubricant to the upper portion 1e of the first bearing 1. At the same time, as the tapered rolling elements 1c, 1d, 1h, 1i of the first roller bearing 1 rotate, centrifugal forces push lubricant disposed on or wetting the surface of the rolling elements 1c, 1d, 1h, 1i towards the larger diameter ends of the rolling elements 1c, 1d, 1h, 1i. In this way, lubricant is transported in the first axial direction 2 and from the first roller bearing 1 towards the second roller bearing 4 and the third roller bearing 5. Depending on the fill level of the lubricant sump 3, the second roller bearing 4 and the third roller bearing 5 may be disposed above the fill level of the lubricant sump 3, as indicated in FIG. 1, for example. In that case, lubricant from the lubricant sump 3 may be supplied to the second roller bearing 4 and to the third roller bearing 5 exclusively by the above-described pumping or transporting function effected by the rotating rolling elements 1c, 1d, 1h, 1i of the first roller bearing 1.

[0035] FIG. 2 further highlights that in addition to the tapered or conical shape of the rolling elements 1h, 1i of the first roller bearing 1 their axes of rotation 1k, 1l are inclined with respect to the first axial direction 2. More specifically, the axes 1k, 1l of the tapered or conical rolling elements 1h, 1i of the first roller bearing 1 are oriented in such a way that the axes of rotation of all rolling elements of the first roller bearing 1 form or are disposed on the surface of a cone whose diameter increases in the first axial direction 2. In this way, rotation of the first roller bearing 1 generates an additional centrifugal force acting on the lubricant disposed on or wetting the surfaces of the rolling elements of the first roller bearing 1. This additional force would be generated even in case the rolling elements of the first roller bearing 1 had a cylindrical shape rather than a tapered or conical shaped as in FIG. 2.

[0036] In FIG. 2, a first side 1g of the first roller bearing 1 faces the second bearing 4 and the third bearing 5. On the first side 1g of the first roller bearing, a cover 1q closes or at least partially closes the annular space 1m extending between the inner race 1b and the outer race 1a of the first roller bearing 1. For example, the cover 1q may be formed by a portion of the housing 100 schematically shown in FIG. 1. The cover 1q prevents lubricant from moving in the first axial direction 2 toward the second bearing 4 and/or toward the third bearing 5.

[0037] In order to guide lubricant out of the space 1m in the first axial direction 2 in a targeted manner, the cover 1q features openings 1n, 1p. The opening 1n is disposed or positioned in an area where a projection of the annular space 1m between the inner race 1b and the outer race 1a of the first roller bearing 1 onto a plane perpendicular to the first axial direction overlaps or intersects with a projection of an annular space formed or extending between the inner race 4b and the outer race 4a of the second bearing 4 onto the same plane. And the opening 1p is disposed or positioned in an area where a projection of the annular space 1m between the inner race 1b and the outer race 1a of the first roller bearing 1 onto a plane perpendicular to the first axial direction overlaps or intersects with a projection of an annular space formed or extending between the inner race 5b and the outer race 5a of the third bearing 5 onto the same plane. The openings 1n, 1p may have different sizes or cross sections. For instance, the opening 1n which is positioned above the opening 1p along the vertical direction may have a larger size or a larger cross section than the opening 1p. In this manner, the same or similar amounts of lubricant may be supplied from the first roller bearing 1 to the second bearing 4 and to the third bearing 5, for example.

[0038] Further, FIG. 2 illustrates axes of rotation 7, 8 of the second and third bearings 4, 5, respectively. The axes 7, 8 are arranged in parallel to the axis of rotation 2 of the first roller bearing 1. The bearings 1, 4, 5 each support a shaft 10, 12, 13, respectively. A perspective view of the shafts 10, 12, 13 is depicted in FIG. 3.

[0039] The mechanical assembly 200 further includes a terminal bearing 16. The terminal bearing 16 is disposed opposite the first roller bearing 1 and on the first side of the first roller bearing 1. The terminal bearing 16 is coaxially aligned with the first roller bearing 1, so that the axes of rotation 2, 17 of the first roller bearing 1 and of the terminal bearing 17 coincide. Along the axial direction 2, the bearings 4, 5 are located in between the first roller bearing 1 and the terminal bearing 16. The mechanical assembly 200 further includes a shaft 10 which is supported by the first roller bearing 1 and by the terminal bearing 16.

[0040] The rolling elements 16h, 16i of the terminal bearing 16 have a tapered or conical shape. The axes of rotation 16k, 16l of the rolling elements 16h, 16i of the terminal bearing 16 are inclined with respect to the axis of rotation 17 of the terminal bearing 16. The larger diameter ends of the tapered rolling elements 16h, 16i point towards the first roller bearing 1. Further, the axes of rotation 16k, 16l of the rolling elements of the terminal bearing 16 are oriented such that they are disposed on or form the surface of a cone, wherein the tip of the cone points in the first axial direction 2 and away from the first roller bearing 1. Consequently, when the terminal bearing 16 rotates and the terminal bearing 16 is at least partially immersed in the lubricant sump 3, axial forces generated by the terminal bearing 16 act on the lubricant disposed on or wetting the surface of the rolling elements 16h, 16i of the terminal bearing 16 in the same way as described above with reference to the rolling elements 1h, 1i of the first roller bearing 1. These forces acting on the lubricant inside the terminal bearing 16 are directed towards the first roller bearing 1 and force or push lubricant toward the first roller bearing 1.

[0041] FIG. 3 shows a perspective view of the assembly 200, wherein the first roller bearing 1 supports a first shaft 10, the second bearing 4 supports a second shaft 12, and the third bearing 5 supports a third shaft 13. A first gear 11 is mounted on the first shaft 10, a second gear 14 is mounted on the second shaft 12, and a third gear 15 is mounted on the third shaft 13. The two gears 14, 15 are in mesh with one another, and one of the gears 14, 15 is in mesh with the first gear 11 mounted on the first shaft 10. As before, the arrow 2 represents the first axial direction. FIG. 4 shows a front view of the assembly 200 depicting the three bearings 1, 4, 5 and the gears 14, 15 disposed.

[0042] FIG. 5 shows a sectional view of the mechanical assembly 200 including the first roller bearing 1 and the second roller bearing 4, wherein the plane of projection includes an axis of rotation of the bearings 1 and 4. Again, the first axial direction is represented by the arrow 2. With the viewing direction pointing in the first axial direction 2, the second bearing 4 is positioned behind the first roller bearing 1. The assembly 200 includes a metallic block which forms a channel or chamber 26 disposed in between the first roller bearing 1 and the second bearing 4. In a region where projections of the bearings 1 and 4 onto a plane perpendicular to the first axial direction 2 overlap, lubricant can flow from the first roller bearing 1 to the second bearing 4 via the channel or chamber 26 in a direction represented by an arrow 22. Here, the direction 22 and the first axial direction 2 enclose an angle of less than 30 degrees.

[0043] FIG. 6 schematically shows another sectional view including details of the mechanical assembly 200 including the first roller bearing 1, the second bearing 4 and the third bearing 5, wherein the second and third bearings 4, 5 are positioned behind the first roller bearing 1 along the first axial direction 2.

[0044] Connection channels 24, 26 fluidly connect the space 1m formed between the inner race and the outer race of the first roller bearing 1 and accommodating the rolling elements of the first roller bearing 1 with a space 4x formed between an inner race and an outer race of the second bearing 4 and accommodating rolling elements of the second bearing 4, and with a space 5x formed between an inner race and an outer race of the third bearing 5 and accommodating rolling elements of the third bearing 5, respectively. In this manner, the rolling elements of the first roller bearing 1 may transport and/or distribute lubricant from disposed on or wetting a surface of the rolling elements of the first roller bearing to the second and third roller bearings 4, 5 via the connection channels 24, 26. As indicated in FIG. 6, the connection channels 24, 26 may be formed within or may be shaped by the housing 100. The housing 100 closes the space 1m on a side of the first roller bearing facing the second and third bearings 4, 5. Openings 1n and 1p in the portion of the housing 100 closing the space 1m provide fluid communication between the space 1m and the connection channels 24, 26.

[0045] The opening 1n and the second bearing 4 are disposed and arranged in such a way that the space 4x formed between the races of the second bearing 4 intersects with a first cone whose apex is located at or within the opening 1n, whose cone axis is arranged in parallel to the rotation axis 2 of the first roller bearing 1, and which has an opening angle of at most 40 degrees, as indicated by a longitudinal axis 22 of the channel 26 and an angle 20 between the longitudinal axis 22 and the rotation axis 2 of the first roller bearing 1, wherein the angle 20 amounts to one half of the opening angle of the first cone. Similarly, the opening 1p and the third bearing 5 are disposed and arranged in such a way that the space 5x formed between the races of the third bearing 5 intersects with a second cone whose apex is located at or within the opening 1p, whose cone axis is arranged in parallel to the rotation axis 2 of the first roller bearing 1, and which has an opening angle of at most 70 degrees, as indicated by a longitudinal axis 23 of the channel 24 and an angle 10 between the longitudinal axis 23 and the rotation axis 2 of the first roller bearing 1, wherein the angle 21 amounts to one half of the opening angle of the second cone. FIGS. 3-5 are drawn to scale, although other relative dimensions may be used if desired.