Axial bearing and bearing arrangement comprising an axial bearing

Abstract

Axial bearing comprising at least one first axial bearing disk (2) and a rolling element cage (8) with several rolling elements (10) held in pockets (9), wherein the rolling element cage (8) has a double flange (11) located radially inside or outside with respect to the rolling elements (10) and with an annular flange section (12), characterized in that at least one flange opening (13) and an associated projection axially to the axial bearing disk (2), designed as a lubricant conveying element (14) for conveying a lubricant present from the side of the axial bearing disk (2) through the flange opening (13) are provided on the flange section (12).

Description

The invention relates to an axial bearing comprising at least one first axial bearing disk and a rolling element cage with several rolling elements held in pockets, wherein the rolling element cage has a double flange located radially inside or outside with respect to the rolling elements, with an annular flange section. An axial bearing is used wherever two components need to be rotatably mounted or supported relative to each other. An example is an automatic transmission, where transmission shafts or gears need to be supported accordingly. Generally, in such an automatic transmission, a high lubricant flow must be ensured to adequately lubricate the respective bearing point, i.e., the axial bearing, for its operation and to enable, for example, the actuation of hydraulic elements. However, sometimes it is very difficult to direct sufficient oil to individual bearing points, for example, within the transmission, not least due to the high power density and the increasingly compact, nested design of modern units such as automatic transmissions or step-down automatics. This is also because oil flow rates are sometimes reduced to minimize churning and drag losses. An example of such an axial bearing, as described above, can be found in DE 10 2020 121 938 A1. This axial bearing has one or more axial bearing discs with lubricant openings, which rest against a bearing component on which one or more lubricant supply channels are provided. These channels open into a recess provided in the axial bearing disc. The lubricant openings are formed in the recess, with the lubricant supply channel(s) opening into the area of ​​the recess, which serves as a collecting groove. The cage has a U-shaped double flange arrangement into which the lubricant openings open. This creates a lubricant reservoir, allowing the lubricant to reach the actual rolling area through the lubricant openings. The invention is based on the problem of specifying an axial bearing that allows sufficient lubricant supply to the actual rolling area. To solve the problem, in an axial bearing of the type mentioned above, the invention provides that at least one opening is provided on the flange section, as well as an axially projecting projection associated with it, which is designed as a lubricant conveying element for conveying a lubricant coming from the side of the axial bearing disc through the opening. In the installation situation where the axial bearing with its axial bearing disc rests against a corresponding component to be supported, a lubricant is present on this side, supplied, for example, from the component. This means that lubricant access to the axial bearing disc is provided. According to the invention, the rolling element cage is designed in a specific way such that it acts as a conveying medium, enabling the active delivery of the lubricant, such as oil, present on the side of the axial bearing disc into the rolling area. For this purpose, the annular rim section of the rolling element cage is provided with at least one rim opening, i.e., an axial opening that allows the lubricant to pass through this annular rim section.According to the invention, a lubricant conveying element is provided associated with or located in the area of ​​this flange opening. This element is implemented in the form of an axial projection extending towards the axial bearing disk and serves to actively convey the lubricant present on the side of the axial bearing disk through the flange opening. During operation, the rolling element cage rotates relative to the axial bearing disk. This causes the at least one lubricant conveying element to move through the oil reservoir present on the axial bearing side, thereby scooping up the lubricant and conveying it through the flange opening to the other side of the cage and into the adjacent rolling element area. The lubricant thus collects in the area of ​​the axial bearing disk and in the area of ​​the double flange, which is designed as a circumferential, annular groove.From there, the lubricant can be transported through the opening in the bearing surface by means of the lubricant delivery element. The rotational movement of the rolling element cage relative to the axial bearing disc creates a pumping or suction effect, which enhances the delivery action. This active lubricant delivery ensures that the lubricant is automatically and actively conveyed into the rolling area during operation, allowing for a sufficiently high flow rate and resulting in excellent lubrication of the rolling area. Preferably, several openings with associated lubricant conveying elements are provided, distributed around the circumference of the flange section. The openings are preferably arranged equidistantly around the circumference of the rolling element cage, as are the lubricant conveying elements. The lubricant conveying element(s) is preferably designed as a curved conveying vane. Such a conveying vane can be formed by embossing or notching during the manufacture of the rolling element cage, which is usually produced from a sheet metal part by stamping and forming. The conveying vane(s) preferably have a quasi-rectangular cross-section, thus possessing a correspondingly large surface area with which the lubricant can be scooped and conveyed. Since it is curved axially out of the plane of the annular disc-shaped flange section, with the bending angle being, for example, in the range between 10° and 60°, a ramp-like structure is consequently created, which facilitates the axial conveyance of the lubricant. According to one variant, the conveying blade(s) can be oriented circumferentially. Accordingly, the conveying blade(s) are oriented circumferentially, i.e., following the ring-shaped movement of the rolling element cage on the corresponding radius. If several conveying blades are used, they are all oriented in the same circumferential direction. This means that conveying only occurs when the rolling element cage rotates in one direction. Alternatively, if multiple conveying vanes are provided, a first part is oriented in one circumferential direction and a second part in an opposite circumferential direction. Accordingly, the conveying vanes are oriented differently. For example, if eight conveying vanes are distributed around the circumference, four conveying vanes can be oriented circumferentially and four other conveying vanes in the opposite direction, preferably alternating in this arrangement. This ensures that, regardless of the direction in which the rolling element cage rotates, lubricant conveyance is always possible, since one or the other part of the conveying vanes is always moving in a direction that facilitates lubricant conveyance. As explained, the lubricant is supplied from the side of the first axial bearing disk. This can be done in different ways. According to a first embodiment, the first axial bearing disk can have an L-shaped cross-section and a radial flange and an axial flange connected to it, wherein at least one lubricant opening is provided on the radial flange, forming the lubricant access point, and the double flange is arranged axially adjacent to this opening. In this embodiment, the radial flange of the first axial bearing disk is thus provided with one or more lubricant openings, preferably distributed equidistantly around the circumference, which, in the assembly position, communicate with corresponding lubricant supply channels provided on the component against which the first axial bearing disk rests.The radial flange can be flat in this area, but it can also, as described in DE 10 2020 121 938 A1, have a groove- or slot-shaped recess in which the lubricant openings are provided and which serves as a lubricant reservoir for the lubricant supplied from the component. It is sufficient if the axial bearing has only one axial bearing disk supported on the component. The rolling elements roll on this disk, while simultaneously rolling directly on the second component, which has a corresponding raceway. As described, one or more lubricant penetrations can be provided in the first axial bearing disk. Alternatively, lubricant can be supplied to the axial bearing disk by other means. Furthermore, as provided according to the invention, a second axial bearing disk can be provided, wherein the rolling element cage, including the rolling elements, is located between the two axial bearing disks, and wherein the flange section is axially spaced from the second axial bearing disk, such that the lubricant delivered by the lubricant supply element through the flange penetration reaches the area between the flange section and the second axial bearing disk.The bearing is therefore encapsulated, comprising two axial bearing discs. If such an axial bearing comprising two axial bearing discs is provided, a further development of the invention according to a second embodiment may provide that the first axial bearing disc has an L-shaped cross-section and a radial flange and an axial flange connected to it at its inner or outer circumference, and that the second axial bearing disc also has an L-shaped cross-section and a radial flange and an axial flange connected to it at its outer or inner circumference, wherein the radial flange of the first axial disc is radially spaced from the axial flange of the second axial disc by an annular gap. Accordingly, both axial bearing discs are L-shaped, the two radial flanges are parallel to each other, and the axial flange of the first axial bearing disc forms, for example, the outer circumference, and the axial flange of the second axial bearing disc forms the inner circumference of the axial bearing.Here too, as described, the radial flange of the first axial bearing disk can have corresponding lubricant supply openings, according to the first variant described above, through which the lubricant to be conveyed by the pumping element(s) is supplied from the side of the component being supported. Alternatively, in this two-disc design, according to a second variant, it is also conceivable that the radial flange of the first axial disk is radially spaced from the axial flange of the second axial disk by an annular gap. The lubricant access is formed via this annular flange, through which the lubricant is supplied from the side of the first axial bearing disk and brought into the area of ​​the double flange and thus of the spring element(s). In addition to the axial bearing itself, the invention further relates to a bearing arrangement comprising a bearing component with a bearing seat in which an axial bearing of the type described above is received with its first axial bearing disk, wherein one or more lubricant supply channels are provided on the bearing component through which lubricant can be supplied to the area of ​​the first axial bearing disk. Such a bearing arrangement can be implemented in a wide variety of assemblies or units. The invention is explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 a perspective schematic view, cutaway, of an axial bearing according to the invention, Fig. 2 a partial view of the rolling element cage together with the rolling elements of the axial bearing from Fig. 1, Fig. 3 a further partial view of the rolling element cage together with the rolling elements of the axial bearing from Fig. 1, and Fig. 4 a schematic schematic view, cutaway, of an axial bearing according to the invention of a second embodiment. Fig. 1 shows a sectional perspective view of an axial bearing 1 according to the invention, comprising a first axial bearing disk 2 and a second axial bearing disk 3. The first axial bearing disk 2 is L-shaped and has a radial flange 4 and an axial flange 5 forming the outer circumference of the axial bearing 1. The second axial bearing disk 3 is also L-shaped and has a radial flange 6 and an axial flange 7 forming the inner circumference of the axial bearing 1. A rolling element cage 8 is arranged between the two axial bearing disks 2 and 3, in which a plurality of pockets 9 are formed, each receiving a rolling element 10, as also shown, for example, in Figs. 2 and 3. The rolling element cage 8 has a double flange 11 formed on its inner circumference, which has a U-shaped cross-section, as illustrated in Fig. 1. This double flange 11 has an annular flange section 12 in which one or more flange openings 13 are formed, distributed around the circumference. Each flange opening 13 is associated with a lubricant conveying element 14, here in the form of a conveying vane 15, wherein the conveying vane 15 is formed as a projection by the material that was deformed by axial bending during the formation of the flange opening. In the example shown, the conveying vane 15 is rectangular, with the bending angle preferably in the range of 10° to 60°, preferably between 15° and 45°. The conveying vane 15 is projected towards the first axial bearing disk 2 by embossing or notching and is oriented circumferentially.Preferably, all conveying vanes 15 are distributed equidistantly around the circumference of the flange section 12 and oriented in the same direction; alternatively, some may be oriented in the direction shown in Fig. 1 and others in the opposite direction. Each conveying vane 15 serves to actively scoop up lubricant, i.e., oil, coming from or present on the side of the axial bearing disk 2, which is also present in the area of ​​the double flange 12, and to convey it through the respective flange opening 13 to the second axial bearing disk 6 and into the radially outwardly adjoining rolling area, in which the rolling elements 10 run on the corresponding raceways of the radial flanges 4, 6. To bring the lubricant into the actual conveying area, i.e., into the groove-shaped recess 16 of the double flange 12, the radial flange 4 of the first axial bearing disk 2 is spaced apart from the axial flange 7 of the second axial bearing disk 3 by a circumferential annular gap 17 in the example shown. Through this annular gap, a lubricant, which, as indicated by arrow P, is supplied from below the first axial bearing disk 2 via one or more lubricant supply channels located on the component on which the first axial bearing disk 2 is axially supported, can be transported into the area of ​​the conveying vanes 15, where the lubricant is then conveyed through the lubricant openings 13 via the conveying vanes 15. This promotion is possible because the rolling element cage 8 also rotates during operation when the two axial bearing discs 2, 3 rotate relative to each other, resulting from the rolling motion of the rolling elements 10.This results in the conveying blades 15 performing a relative movement with respect to the first axial bearing disk 2 and thus also with respect to the lubricant present in that area. Due to the quasi-ramp-like design of the conveying blades 15, the lubricant is actively scooped up by the rotation and conveyed axially via the conveying blades 15, transporting it in sufficient quantity to the actual rolling area. Fig. 4 shows a further embodiment of an axial bearing 1 according to the invention, again comprising a first axial bearing disk 2 and a second axial bearing disk 3, both of which have an L-shaped cross-section. In this embodiment, the arrangement is such that the first axial bearing disk 2 has a radial flange 4 and an axial flange 5 forming the inner circumference of the axial bearing 1, while the second axial bearing disk 3 has a radial flange 6 and an axial flange 7 forming the outer circumference. Here, too, a cage 8 is provided, which, like the cage 8 from the initial example in Figs. 1-3, is designed as a sigma cage. It has corresponding pockets in which the rolling elements 10 are again received. Here too, the cage 8 has a double rim 11 provided on its inner circumference, with an annular rim section 12, which in turn is provided with corresponding conveying elements 14, which are arranged adjacent to corresponding rim openings 13. In contrast to the embodiment shown in Figures 1-3, the radial flange 4 here has one or more lubricant openings 18, which in turn communicate with lubricant supply channels (not shown) of the component on which the first axial bearing disk 2 rests. Here, the lubricant is supplied via this lubricant opening 18, whereas in the embodiment shown in Figures 1-3, the lubricant was supplied via the annular gap 17. However, the function of the lubricant conveying elements 14 of the rolling element cage 8 is the same as in the embodiment shown in Figures 1-3; they also serve to actively convey the lubricant axially through the respective flange opening 13 into the actual rolling area and ensure a sufficient lubricant flow. Reference symbol list 1 Thrust bearing 2 Thrust bearing washer 3 Thrust bearing washer 3 4 Radial flange 5 Thrust flange 6 Radial flange 7 Thrust flange 8 Rolling element cage 9 Pockets 10 Rolling elements 11 Double flange 12 Flange section 13 Flange opening 14 Lubricant delivery element 15 Delivery vanes 16 Recess 17 Annular gap 18 Lubricant opening QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 10 2020 121 938 A1 [0003, 0011]

Claims

Axial bearing comprising at least one first axial bearing disk (2) and a rolling element cage (8) with several rolling elements (10) held in pockets (9), wherein the rolling element cage (8) has a double flange (11) located radially inside or outside with respect to the rolling elements (10) and having an annular flange section (12), characterized in that at least one flange opening (13) and an associated projection axially to the axial bearing disk (2), designed as a lubricant conveying element (14) for conveying a lubricant present from the side of the axial bearing disk (2) through the flange opening (13) are provided on the flange section (12). Axial bearing according to claim 1, characterized in that several openings (13) with associated lubricant conveying elements (14) are provided distributed around the circumference of the flange section (12). Axial bearing according to claim 1 or 2, characterized in that the lubricant conveying element or elements (14) is designed as a curved conveying vane (15). Axial bearing according to claim 3, characterized in that the or each conveying blade (15) is oriented in the circumferential direction. Axial bearing disc according to claim 3, characterized in that several conveying vanes (15) are provided, wherein a first part is directed in a first circumferential direction and a second part is directed in an opposite circumferential direction. Axial bearing according to one of the preceding claims, characterized in that the first axial bearing disk (2) has an L-shaped cross-section and a radial flange (4) and an axial flange (5) connected thereto, wherein at least one lubricant opening (18) forming a lubricant access is provided on the radial flange (4), axially adjacent to which the double rim (11) is arranged. Axial bearing according to one of the preceding claims, characterized by a second axial bearing disk (3), wherein the rolling element cage (8) together with the rolling elements (10) is received between the two axial bearing disks (2, 3), and wherein the flange section (12) is axially spaced from the second axial bearing disk (3) such that the lubricant conveyed by the lubricant conveying element (14) through the flange opening (13) enters the area between the flange section (12) and the second axial bearing disk (3). Axial bearing according to claim 7, characterized in that the first axial bearing disk (2) has an L-shaped cross-section and a radial flange (4) and an axial flange (5) connected thereto at the inner or outer circumference, and that the second axial bearing disk (3) also has an L-shaped cross-section and a radial flange (6) and an axial flange (7) connected thereto at the outer or inner circumference, wherein the radial flange (4) of the first axial disk (2) is spaced radially apart from the axial flange (7) of the second axial disk (3) by means of an annular gap (17) forming a lubricant access point. Bearing arrangement comprising a bearing component with a bearing seat in which an axial bearing (1) according to one of the preceding claims is received with its first axial bearing disk (2), wherein one or more lubricant supply channels are provided on the bearing component through which lubricant can be supplied to the area of ​​the first axial bearing disk (1).

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