阅读说明：本技术 轴承保持架和滚动元件轴承 (Bearing cage and rolling element bearing ) 是由 M.卡尔森 H.林德格伦 于 2013-09-20 设计创作，主要内容包括：一种用于保持滚动元件轴承的滚动元件(14)的轴承保持架(24),所述轴承保持架(24)具有至少一个第一保持架杆(30)所连接到的至少一个第一环结构(18、34)。所述至少一个第一保持架杆(30)包括侧表面(44),该侧表面布置成在所述轴承保持架(24)处于使用中时沿着滚动元件(14)的外表面延伸,从而所述侧表面(44)包括径向外边缘(46)和径向内边缘(48)。在所述轴承保持架(24)处于使用中时滚动元件(14)位于其间的两个相邻的保持架杆(30)的径向外边缘(46)之间的距离大于所述两个相邻的保持架杆(30)的两个相邻的径向内边缘(48)之间的距离。(A bearing cage (24) for retaining rolling elements (14) of a rolling element bearing, the bearing cage (24) having at least one first ring structure (18, 34) to which at least one first cage bar (30) is connected. The at least one first cage bar (30) comprises a side surface (44) arranged to extend along an outer surface of the rolling elements (14) when the bearing cage (24) is in use, whereby the side surface (44) comprises a radially outer edge (46) and a radially inner edge (48). The distance between the radially outer edges (46) of two adjacent cage bars (30) between which the rolling elements (14) are located when the bearing cage (24) is in use is greater than the distance between two adjacent radially inner edges (48) of the two adjacent cage bars (30).)

1. A bearing cage (24) for retaining rolling elements (14) of a rolling element bearing, the bearing cage (24) has at least one first ring structure (18, 34) to which at least one first cage bar (30) is connected, characterized in that said at least one first cage bar (30) comprises a lateral surface (44), which is arranged to extend along the outer surface of the rolling elements (14) when said bearing cage (24) is in use, whereby the side surface (44) comprises a radially outer edge (46) and a radially inner edge (48), and the distance between the radially outer edges (46) of two adjacent cage bars (30) between which rolling elements (14) are located when the bearing cage (24) is in use is greater than the distance between two adjacent radially inner edges (48) of the two adjacent cage bars (30);

the bearing cage (24) comprises a second ring structure (36) to which at least one second cage bar (38) is connected, such that the at least one second ring structure (36) is arranged radially inside the at least one first ring structure (18, 34);

the at least one first cage bar (30) is configured such that the diameter of the bearing cage (24) is largest at a point/region (32) along the length of the at least one first cage bar (30) in order to improve lubricant flow towards the rotational centre of the rolling elements (14) when the bearing cage (24) is in use.

2. Bearing cage (24) according to claim 1, characterized in that said side surface (44) of said at least one first cage bar (30) comprises at least one chamfered edge (52).

3. Bearing cage (24) according to claim 2, characterized in that said at least one chamfered edge (52) is provided at said radially inner edge (48) of said first cage bar (30).

4. Bearing cage (24) according to claim 3, characterized in that said at least one second cage bar (38) is configured such that the diameter of said second ring structure (36) is largest at points/areas (40) along the length of said at least one second cage bar (38) in order to improve the lubricant flow towards the rotational centre of the rolling elements (14) when said bearing cage (24) is in use.

5. Bearing cage (24) according to claim 4, characterized in that said at least one second ring structure (36) is provided with at least one reservoir (42) for containing lubricant when said bearing cage (24) is in use.

6. Bearing cage (24) according to any of claims 4 to 5, characterized in that said at least one first ring structure (18, 34) is formed integrally with said at least one second ring structure (36).

7. Bearing cage (24) according to any of claims 4-5, characterized in that said at least one first ring structure (18, 34) is arranged to be connected to said at least one second ring structure (36).

8. Bearing cage (24) according to claim 1, characterized in that said at least one cage bar (30) comprises a point/area (32) arranged in a position above the centre of the rolling surface of each rolling element (14) when said bearing cage (24) is in use.

9. Bearing cage (24) according to claim 8, characterized in that said bearing cage (24) comprises two axially opposite ring structures (26, 28) such that said at least one first cage bar (30) extends between said axially opposite ring structures (26, 28).

10. Bearing cage (24) according to claim 9, characterized in that said point/area (32) is arranged halfway between said two axially opposite ring structures (26, 28).

11. Bearing cage (24) according to the preceding claim 1, characterized in that said at least one first cage bar (30) of said at least one first ring structure (18, 34) comprises an end portion following the rolling element diameter profile.

12. Bearing cage (24) according to claim 11, characterized in that said end portions extend over 5-30%, preferably 10-20% of the length of said at least one first cage bar (30).

13. Rolling element bearing arrangement, characterized in that it comprises at least one bearing cage according to any of the preceding claims.

Technical Field

The present invention relates to a bearing cage for a rolling-element bearing and to a rolling-element bearing comprising at least one such bearing cage.

Background

A bearing cage is a spacer structure that holds the individual rolling elements of a rolling element bearing evenly spaced around a race.

Usually, the rolling element bearings are supplied with a certain amount of grease for lubrication purposes. Ideally, greases release their oil content gradually, thereby ensuring prolonged lubrication of the bearings. It is desirable to apply grease as close as possible to the surfaces of the parts to be lubricated, such as rolling elements. In particular, the amount of grease collected on the cage bars is beneficial. These quantities are close to the rolling elements and therefore the oil can be supplied directly thereto.

However, the centrifugal forces and the limited adhesion forces occurring when the rolling element bearing is in use have a negative influence on the grease retention capacity of the bearing cage. As a result, the grease on the cage bars may disappear and collect in other areas where lubricant may not be supplied to the center of the rolling elements or the raceways of the rings.

US patent US 6461048 relates to a cage for a rolling element bearing with improved grease retention. The cage comprises at least one annular body carrying regularly spaced cage bars, each pair of adjacent cage bars defining a cage pocket for housing rolling elements. At least one of the cage bars comprises an element radially on the outside and/or inside, said element defining at least one space for containing grease.

Disclosure of Invention

It is an object of the present invention to provide an improved bearing cage for retaining rolling elements of a rolling element bearing, which allows for better lubrication of the rolling element bearing and which facilitates assembly of the rolling element bearing.

This object is achieved by a bearing cage comprising a bearing cage for retaining rolling elements, said bearing cage having at least one first ring structure to which at least one first cage bar is connected. The at least one first cage bar comprises a side surface arranged to extend along an outer surface of the rolling elements when the bearing cage is in use, whereby the side surface comprises a radially outer edge and a radially inner edge. The distance between the radially outer edges of two adjacent cage bars between which rolling elements are accommodated is larger than the distance between the two adjacent radially inner edges of the two adjacent cage bars when the bearing cage is in use. The lubricant may thus be accommodated in the space between the outer surfaces of the rolling elements and the side edges of the cage bars.

Such a bearing cage allows more grease to attach itself to the cage bars when the bearing cage is in use, thereby obtaining an extended residence time of the grease in the rolling bearing, and a more reliable lubrication of the rolling element bearing. Furthermore, such a bearing cage enables the rolling elements of the rolling element bearing to be mounted in the rolling element bearing from above.

According to an embodiment of the invention, the side surface of the at least one cage bar may comprise at least one chamfered edge. For example, the chamfered edge may be provided at a radially inner edge of the first cage bar.

According to another embodiment of the invention, the bearing cage comprises a second ring structure to which at least one second cage bar is connected, whereby the at least one second ring structure is arranged radially inside the at least one first ring structure. The lubricant may thus be contained on the second ring structure when the bearing cage is in use.

According to an embodiment of the invention, said at least one second cage bar is configured such that the diameter of said bearing cage is largest at a point/area along the length of said at least one second cage bar, in order to improve the lubricant flow towards the rotational centre of the rolling elements when said bearing cage is in use.

According to another embodiment of the invention, the at least one second ring structure comprises at least one reservoir for containing lubricant when the bearing cage is in use.

The at least one first ring structure may be integrally formed with the at least one second ring structure, or it may be arranged to be connected to the at least one second ring structure, for example by a snap-fit connection or welding.

The first ring structure and/or the second ring structure may comprise a metal such as steel or any other suitable material. The first ring structure and/or the second ring structure may comprise a metal plate, for example.

According to an embodiment of the invention, the at least one first cage bar is configured such that the diameter of the bearing cage is largest at a point/area along the length of the at least one first cage bar in order to improve the lubricant flow towards the rotational centre of the rolling elements when the bearing cage is in use. The expression "centre of rotation" refers to the centre of the rolling surface of the rolling element, which is located halfway between the ends of the rolling element.

The at least one cage bar may comprise raised points/regions at any position along its length, which will increase the surface area of the at least one cage bar and thus the amount of lubricant that may be contained thereon, and which will improve the lubricant flow towards the rotational centre of the rolling elements. More lubricant will thus collect on the at least one salient point/region and then fall onto the rolling surface of the rolling element in the vicinity of the at least one salient point/region. It should be noted that the at least one first cage bar may comprise a plurality of raised points/areas along its length in order to increase its surface area and improve lubricant flow towards the centre of rotation of the rolling elements when said bearing cage is in use.

According to an embodiment of the invention, the point/area is arranged to be located at a position above the centre of the rolling surface of each rolling element when the bearing cage is in use. The lubricant falling from said points/areas will thus be supplied to the centre of the rolling surface of the rolling elements, i.e. at a position halfway between the ends of each rolling element.

According to another embodiment of the invention, the bearing cage comprises two axially opposed ring structures, whereby the at least one cage bar extends between the axially opposed ring structures. The at least one first cage bar may comprise a point/region halfway between the two axially opposed ring structures.

According to a further embodiment of the invention, the at least one first cage bar of the at least one first ring structure comprises an end portion following a rolling element diameter profile. The end portion may extend over 5-30%, preferably 10-20% of the length of the at least one cage bar. The point/area may be arranged in a central portion of the at least one first cage bar, which central portion extends between the ends.

The bearing cage may be used for rolling element bearings such as ball or roller bearings, cylindrical roller bearings, toroidal roller bearings, tapered roller bearings or needle roller bearings.

The invention also relates to a rolling element bearing comprising at least one bearing cage according to any of the embodiments of the invention.

Drawings

The invention is further illustrated, by way of non-limiting example, with reference to the accompanying drawings, in which:

figures 1a-c show a bearing cage according to the prior art,

figures 2-4 show a rolling element bearing and a bearing cage according to an embodiment of the invention,

fig. 5a shows a cage bar of a bearing cage according to the prior art, an

Fig. 5b shows a cage bar of a bearing cage according to an embodiment of the invention.

It should be noted that the figures are not drawn to scale and that the dimensions of some of the features are exaggerated for clarity.

Detailed Description

Fig. 1a-c show a rolling bearing 10 according to the prior art. The rolling bearing comprises two bearing cages 12 for holding rolling elements 14. Each bearing cage 12 includes a ring structure 18 to which a plurality of cage bars 20 are connected. The cage bars 20 have a substantially flat outer surface following the diametrical profile of the rolling elements 14. The diameter of each bearing cage 12 is greatest at the ring of the ring structure 18 located between the two rows of rolling elements 14.

Fig. 2a-b show two bearing cages 24 for holding two rows of rolling elements 14 according to an embodiment of the invention. Each bearing cage 24 includes a pair of axially opposed rings 26, 28 such that a plurality of first cage bars 30 extend between the two axially opposed rings 26, 28. For example, all of the first cage bars 30 are configured such that the diameter of each bearing cage 24 is greatest at a point 32 midway along the length of the first cage bars 30, such that the point 32 will be located at a position above the center of the rolling surface of each rolling element 14, so as to improve lubricant flow towards the center of rotation of the rolling elements 14 when the bearing cage 24 is in use. In the embodiment shown, lubricant falling on the first cage bar 30 will flow towards the ends of the cylindrical rolling elements 14. The lubricant collected on said points 32 will fall onto the centre of the rolling surface of each rolling element 14. The lubricant reservoir is increased compared to the cage bars 20 of the bearing cage 12 according to the prior art, because the surface area of the first cage bars 30 of the bearing cage 24 according to an embodiment of the present invention is increased.

The first cage bar 30 may include an end that follows the rolling element diameter profile. Such end portions may extend over 5-30%, preferably 10-20% of the length of the first cage bar 30, such that at least part of the central portion between said end portions is configured to maximize the diameter of each bearing cage 24 at the point/area therebetween, in order to improve lubricant flow towards the rotational centre of the rolling elements 14 when the bearing cage 24 is in use. For example, at least part of the central portion between the end portions may be raised relative to the end portions to form such a point/region of maximum diameter.

Fig. 3a-b illustrate a bearing retainer comprising a first ring structure 34 including a pair of axially opposed rings 26, 28, such that a plurality of first retainer bars 30 extend between the two axially opposed rings 26, 28. The bearing cage 24 further comprises a second ring structure 36 to which a plurality of second cage bars 38 are connected, such that the second ring structure 38 is arranged to be radially inward of the at least one first ring structure 34 when the bearing cage 24 is in use. The second cage bars 38 are configured such that the diameter of the second ring structure 36 is largest at a point 40 along the length of the second cage bars 38 in order to improve lubricant flow towards the centre of rotation of the rolling elements 14 when the bearing cage 24 is in use.

The "length" of the first or second cage bars 30, 38 refers to the distance from the first ring 26 of the ring structure to the end of the first or second cage bar 30, 38 or to the second ring 28 of the ring structure, measured along the outer surface of the first or second cage bar 30, 38.

The at least one first cage bar 30 and/or the at least one second cage bar 38 may comprise at least one channel to improve lubricant flow towards the rotational center of the rolling elements 14 when the bearing cage 24 is in use.

The second ring structure 38 may include at least one reservoir 42 for containing lubricant when the bearing cage 24 is in use.

Fig. 4a-b show the first ring structure 34 arranged to be connected to the second ring structure 36, for example by a snap fit connection or welding. Alternatively, the first ring structure 34 may be integrally formed with the second ring structure 36.

Fig. 5a shows two adjacent cage bars 20 of a bearing cage according to the prior art. Fig. 5b shows two adjacent first cage bars 30 of a bearing cage according to an embodiment of the invention. The first cage bar 30 comprises a side surface 44 arranged to extend along an outer surface of the rolling elements 14 when the bearing cage is in use. The side surface 44 comprises a radially outer edge 46 and a radially inner edge 48, and the distance between the radially outer edges 46 of two adjacent cage bars 30, which accommodate the rolling elements 14 therebetween when the bearing cage is in use, is larger than the distance between the radially inner edges 48 of two adjacent cage bars 30. In this way, lubricant can be accommodated in the space between the outer surface of the rolling elements 14 and the side edges 44 of the cage bars 30.

The side surface 44 of the at least one first cage bar 30 includes at least one chamfered edge 52. At least one chamfered edge 52 may be provided at the radially inner edge 52 of the first cage bar 30 as shown in the illustrated embodiment.

In the prior art cage bars according to fig. 5a, each cage bar 20 comprises a lug 50 which limits the amount of lubricant that can be accommodated in the space between the surface of the rolling elements 14 and the side edges of the cage bar 20. The cage bars 30 of the bearing cage according to an embodiment of the present invention do not comprise such lugs 50.

Since the side surfaces 44 of the cage bars 30 do not follow the curvature of the rolling elements 14, i.e. the side surfaces 44 of the cage bars 30 do not extend in a direction along the circumference of the rolling elements 14, the bearing elements 14 can be placed into the bearing cage from above, which facilitates the assembly of the rolling element bearing.

It will be obvious to a person skilled in the art that the invention can be further modified within the scope of the claims. For example, the bearing cage may be formed from a plurality of separate components, such as a pair of bearing cage halves.