Cage for a bearing for a strut bearing unit

Abstract

A cage (1) for a bearing for a strut bearing unit is disclosed, characterized in that the cage (1) is formed as a ring comprising several recesses forming cage pockets (6), wherein the recesses are designed to accommodate rolling elements (7) and to keep the rolling elements (7) spaced apart from one another, wherein an outer circumferential surface (3) and / or an inner circumferential surface (2) of the cage is designed to provide a sliding functionality when in contact with a part of the strut bearing unit.

Description

Technical field of the invention

[0001] The present invention relates to a cage for a bearing of a strut mount unit according to claim 1. The present invention further relates to a corresponding strut mount unit for a motor vehicle according to claim 5. Background of the invention

[0002] In rolling bearings, cages are used to separate the rolling elements at equal distances, thereby reducing frictional heat generated by the rolling elements within the bearing. Cages keep the rolling elements spaced apart to ensure a uniform load distribution.

[0003] Rolling bearings, such as ball bearings, support and guide rotating or oscillating elements, such as shafts, axles, or wheels, and transmit loads between machine components, with the rolling elements transferring the load between an inner and an outer ring. Radial bearings accommodate loads that are predominantly perpendicular to the shaft. Some radial bearings can only accommodate purely radial loads, while most radial bearings can also accommodate axial loads.

[0004] Such rolling bearings can also be used in strut bearing units. A strut can be used in automotive suspension systems to support an axle and a wheel of a vehicle. A strut bearing unit, or suspension bearing unit, is located in the upper part of the strut, opposite the wheel and the ground, between a suspension spring and an upper element that is integrally connected to the vehicle chassis or can be attached to the vehicle chassis. Such a strut bearing unit is designed to transmit axial forces between the suspension spring and the vehicle chassis. The strut bearing unit consists of a lower shell and an upper shell, with a bearing located between the lower and upper shells. In such strut bearing units, a bearing is required to support axial and / or radial loads.

[0005] However, the bearings currently in use are primarily designed to support axial loads using rolling elements.

[0006] It is therefore an object of the present invention to provide a simple and cost-effective way to store radial loads and axial loads in a strut bearing unit. Summary of the invention

[0007] This problem is solved by a cage for a bearing for a strut bearing unit according to claim 1 and by a corresponding strut bearing unit according to claim 5.

[0008] The following describes a cage for a rolling bearing, in particular a ball bearing, for a strut bearing unit. The cage comprises several recesses that form cage pockets. The cage pockets are designed to receive rolling elements and keep them spaced apart from one another. The ring comprises an inner and an outer circumferential surface as well as two end faces, with the recesses formed in at least one of the end faces. Preferably, the recesses are designed as through-openings from one end face to the other, so that rolling elements received in the recesses can contact raceways that are arranged in contact with both end faces.

[0009] To provide a flexible and cost-effective method for supporting axial and radial loads, an outer and / or inner circumferential surface of the cage is designed to provide sliding functionality when in contact with a part of the strut bearing assembly. Thus, in addition to the rolling functionality provided by the rolling elements held in the pockets, the cage is designed to provide sliding functionality due to potential contact between the inner and / or outer circumferential surface and the strut bearing assembly. Therefore, when radial loads are applied to the rolling bearing, the outer and / or inner circumferential surface slides along a part of the strut bearing assembly.Thus, the cage provides a hybrid functionality by storing radial loads via the sliding functionality of the inner and / or outer circumferential surfaces and axial loads via the rolling functionality of the rolling elements in the pockets.

[0010] This has the advantage that the cage design improves the absorption of radial and / or axial loads, which is a requirement for a large number of vehicles. At the same time, the cage is flexible in its application, thus minimizing costs.

[0011] According to one embodiment, the cage further comprises a lubricant reservoir and through-holes provided in the outer circumferential surface, the inner circumferential surface, and / or the end faces of the cage, wherein the through-holes are designed to provide lubrication functionality by dispensing lubricant from the lubricant reservoir to the outside of the cage. The lubricant reservoir and the through-holes in the outer and / or inner circumferential surface and / or the end faces of the cage allow for a simple method of supplying a lubricant. The lubricant reservoir and the through-holes, which provide lubricant channels, are used to hold grease / oil and distribute it over the sliding surfaces.

[0012] This can further improve the sliding functionality, as the lubricant can be directed to the contact surfaces of the sliding function, i.e., to the inner / outer circumferential surface and the corresponding parts or surfaces of the strut bearing unit. Furthermore, the functionality of the bearing can be improved, as the lubricant can be directed to the rolling contact surfaces, i.e., to the raceways for the rolling elements provided by the strut bearing unit.

[0013] Preferably, the lubricant can be filled into the cage once before installation in the strut bearing unit. This ensures that the cage, and therefore the bearing, is lubricated throughout the bearing's entire service life.

[0014] According to another embodiment, the lubricant is grease or oil. As explained above, the lubricant can facilitate the sliding function of the inner and / or outer circumferential surface of the cage interacting with a part of the strut bearing assembly.

[0015] According to another embodiment, the cage is made of low-friction material, in particular low-friction plastic material. For example, polymers with or without fillers (fibers) can be used, such as PEEK, POM, PA4.6, PA66, PA6-GF, or PA66-GF, or other polymers. The good sliding properties of polymer cages, which generate little friction and therefore allow for high speeds, are particularly advantageous here. For example, polymer cages with a carbon or glass fiber content of 15 to 30% can be manufactured. The use of (fiber) reinforcement can be advantageous and can provide a more stable material. Additionally, low-friction material can offer the advantage that, under poor lubrication conditions, the cage reduces the risk of seizing and consequential damage, as it can operate for a limited time with limited lubricant.

[0016] According to another aspect, a strut bearing assembly is provided. The strut bearing assembly, as further disclosed herein, also referred to as a suspension bearing assembly, may in particular be of the MacPherson type (so-called MacPherson suspension bearing assembly). The strut bearing assembly may be located in the upper part of the strut, opposite the wheel and the ground, between a suspension spring and an upper element. The upper element may either be integral with the vehicle chassis or may be attached to the vehicle chassis.

[0017] The strut bearing assembly comprises a lower shell designed to support the suspension spring, an upper shell designed to be coupled to the upper mounting which provides a connection to a vehicle chassis, and a bearing inserted between the upper shell and the lower shell.

[0018] The bearing of the strut bearing assembly, as described herein, may comprise an inner ring, an outer ring, and a cage as described above. The bearing may further comprise multiple rolling elements that can be inserted between the inner and outer rings and accommodated in the pockets provided by the cage. As described below, the bearing may contain no, some, or multiple rolling elements.

[0019] To provide a more cost-effective and simpler design, the bearing of the strut bearing unit, as described here, may comprise an inner ring formed by the lower shell of the strut bearing unit and / or an outer ring formed by the upper shell of the strut bearing unit.

[0020] The design of the strut mount unit described above results in a flexible design and reduced costs. In contrast to previously used strut mount units, the unit described here, due to the cage described above, facilitates the absorption of radial and / or axial loads for rolling bearings.

[0021] According to one embodiment, none of the cage pockets of the strut bearing unit accommodate rolling elements. Thus, the cage can be free of rolling elements. For example, all cage pockets of the strut bearing unit can be free of rolling elements if the strut bearing unit is subjected to low radial loads. In such a case, the strut bearing unit is required to primarily support radial loads. The cage design, which is capable of supporting radial loads due to its sliding functionality, allows for flexible application of the strut bearing unit. Low radial loads can, for example, be loads up to 8000 N, which can be supported by the sliding functionality. Higher loads, for example, loads above 8000 N, can additionally be supported by the rolling contact, as described above. It should be noted that the exact number of higher and / or lower loads can vary depending on the specific bearing and application.

[0022] According to another embodiment, some of the cage pockets accommodate rolling elements. For example, more than one of the cage pockets can accommodate rolling elements if the strut bearing assembly is subjected to radial and / or axial loads. The rolling elements can be evenly distributed around the circumference of the cage, thus providing a uniform distribution of the applied load.

[0023] In another embodiment, all cage pockets accommodate rolling elements. This can be particularly useful when high radial and axial loads are applied to the strut bearing unit. This improves the bearing capacity of the strut bearing unit for radial and / or axial loads.

[0024] For example, the cage can be formed as a solid ring that provides sufficient stability to provide primary contact with the strut bearing unit in the case of low loads and can be flexible enough to allow rolling element contact in the case of high loads.

[0025] According to a preferred embodiment, the strut bearing unit comprises an inner and / or an outer raceway, which is formed as a separate annular raceway element arranged on the inner and / or outer ring, respectively. The raceway element can be arranged as a separate component on the inner and / or outer ring, for example, by injection molding or similar methods known in the art. This results in improved sliding and rolling contact of the rolling bearing. In particular, the separate raceway elements can be formed from different materials than the upper and / or lower shell of the strut bearing unit. Thus, the raceway elements can be formed using a material that improves the properties and functions of the rolling elements and rolling bearings.In contrast, the material of the upper and / or lower shell of the strut bearing unit can be chosen to improve, for example, the stability and service life of the strut bearing unit itself.

[0026] In alternative embodiments, the inner and / or outer ring does not include an inner and / or outer raceway formed by separate elements. In this case, the raceways can be formed directly by the upper and / or lower shell.

[0027] According to another embodiment, the raceway is made of a low-friction material. This low-friction material can be a polymer such as PEEK, PA4.6, PA6.6, PA6-GF, or PA66-GF. Such a material can, in particular, improve the functionality of the rolling bearing and reduce wear on the rolling elements. The raceway elements can also be made of sheet metal.

[0028] Further preferred embodiments are defined in the dependent claims, the description, and the figures. Elements described or shown in combination with other elements may be present alone or in combination with other elements without leaving the scope of protection. Brief character description

[0029] Preferred embodiments of the invention are described below with reference to the drawings, which are only exemplary and are not intended to limit the scope of protection. The scope of protection is defined exclusively by the accompanying claims.

[0030] The figures show: Fig. 1: A perspective view of an exemplary cage for a strut bearing unit; Fig. 2A: a sectional view of a cage pocket of the cage made of Fig. 1; Fig. 2B: a sectional view of the cage made of Fig. 1; Fig. 3A: a sectional view of the cage pocket together with a rolling element of a rolling bearing in a strut bearing unit; Fig. 3B: a sectional view of the cage of a rolling bearing in a strut bearing unit; Fig. 3C: a sectional view of the cage together with a lubricant reservoir of a rolling bearing in a strut bearing unit; and Fig. 4: A perspective view of a strut bearing unit. Detailed description of the invention

[0031] In the following, identical or similarly functioning elements are marked with the same reference symbols.

[0032] Fig. Figure 1 shows a cage 1 for a bearing 10 for a strut bearing unit 20, which is formed as a ring. The ring includes several recesses that form cage pockets 6. The recesses are designed to receive rolling elements 7 and to keep the rolling elements 7 spaced apart from one another. The cage 1 comprises an outer circumferential surface 3 and an inner circumferential surface 2. At least one of the circumferential surfaces 2, 3 is designed to provide a sliding function when it comes into contact with a part of the strut bearing unit (in Fig. (1 not shown) is in contact.

[0033] As in Fig. 2A in a sectional view of Fig. As shown in Figure 1, the cage pocket 6 can contain a rolling element 7 for transmitting loads. As can be further seen, in addition to the inner circumferential surface 2 and the outer circumferential surface 3, the cage also includes the end faces 4. Fig. 2B shows another, different sectional view of Fig. 1 the inner circumferential surface 2, the outer circumferential surface 3 and the end faces 4.

[0034] Next to cage 1, they show Fig. 2A and Fig. 2B the outer raceway 5a and the inner raceway 5b, which are not part of the cage 1, but are elements of the rolling bearing. The inner raceway 5b and / or the outer raceway 5a can preferably be arranged as a separate element on the inner ring, which is formed by a lower shell 21 of the strut bearing unit 20, and / or on the outer ring, which is formed by an upper shell 22 of the strut bearing unit 20 (as shown in the Fig. 3A, Fig. 3B, Fig. 3C and Fig. 4 is shown and further explained). This arrangement achieves improved sliding and rolling contact of the rolling bearing 10.

[0035] Other arrangements are also possible; for example, the inner ring formed by the lower shell 21 of the strut bearing unit 20 and the outer ring formed by the upper shell 22 of the strut bearing unit 20 may not include an inner raceway 5b and / or outer raceway 5a formed by separate elements. In this case, the raceways may be formed directly by the lower shell 21 of the strut bearing unit 20 and / or the upper shell 22 of the strut bearing unit 20.

[0036] As in the Fig. 3A, Fig. 3B and Fig. As can be seen in Figure 3C, the strut bearing unit 20 comprises a bearing 10 arranged between the upper shell 22 and the lower shell 21. In the illustrated embodiment, the inner ring of the bearing 10 is formed by the lower shell 21 of the strut bearing unit 20, and the outer ring of the bearing 10 is formed by the upper shell 22 of the strut bearing unit 20. Alternatively, the inner ring and / or the outer ring could also be formed by separate elements inserted into the upper shell 22 or the lower shell 21. The cage 1, with the inner circumferential surface 2, the outer circumferential surface 3, and the end faces 4, is arranged between the inner ring and the outer ring.

[0037] The strut bearing unit 20 can comprise the inner raceway 5b and the outer raceway 5a, which are formed by separate elements. In a preferred arrangement, the raceways 5a and 5b are arranged as separate elements on the inner ring formed by the lower shell 21 of the strut bearing unit 20 and / or on the outer ring formed by the upper shell 22 of the strut bearing unit 20. In another possible arrangement, the strut bearing unit 20 may not comprise separate elements for the inner raceway 5b and / or the outer raceway 5a.

[0038] With reference to Fig. Figure 3A shows the rolling element 7, which is arranged in the cage pocket 6 of the cage 1 of the rolling bearing 10. In the illustrated embodiment, the strut bearing unit 20 comprises the inner raceway 5b and the outer raceway 5a, which are formed by separate elements arranged on the inner ring formed by the lower shell 21 of the strut bearing unit 20, and / or the outer ring formed by the upper shell 22 of the strut bearing unit 20. The raceway 5a, 5b ensures improved sliding and rolling contact of the rolling bearing 10. The raceway 5a, 5b can be made of a material that improves the properties and functions of the rolling elements 7 and the rolling bearing 10, such as a low-friction material. The low-friction material can be polyamide, such as... B. PEEK, PA4.6, PA6.6, PA6-GF or PA66-GF, which can particularly improve the functionality of the rolling bearing 10 and reduce the wear of the rolling elements 7.

[0039] As in Fig. As can be seen in Figure 3B, the inner circumferential surface 2 and the outer circumferential surface 3 of the cage 1 are designed to provide a sliding function 11 when in contact with a part of the strut bearing unit 20. The sliding function 11 absorbs radial forces. When the bearing 10 is subjected to radial loads, the inner circumferential surface 2 and / or the outer circumferential surface 3 can slide along a part of the strut bearing unit 20, transferring the radial loads from the cage 1 to the upper and / or lower shell 21, 22 of the strut bearing unit 20 and vice versa.

[0040] Fig. Figure 3C shows a possible arrangement of the lubrication reservoir 9 and the through-openings 12, which are provided in the inner circumferential surface 2 and the outer circumferential surface 3 and / or the end faces 4. The openings allow the supply of lubricant to the sliding contact surfaces, i.e., the circumferential surfaces and the corresponding surfaces of the strut bearing unit 20, as well as to the rolling contact surfaces, i.e., the raceways 5a, 5b and the rolling elements 7. Other arrangements are also possible; for example, at least one through-opening can be designed as a refill opening for introducing lubricant into the lubricant reservoir of the cage (in Fig. 3C not shown).

[0041] With reference to Fig. Section 4 describes the arrangement of the strut bearing unit 20 in more detail.

[0042] The strut bearing unit 20 comprises the cage 1, which is formed as a ring for the bearing 10 with an inner circumferential surface 2, an outer circumferential surface 3, and an end face 4. The cage 1 is arranged between the inner ring of the bearing 10, which is formed by the lower shell 21 of the strut bearing unit 20, and the outer ring of the bearing 10, which is formed by the upper shell 22 of the strut bearing unit 20.

[0043] The strut bearing unit 20 provides the outer raceway 5a and the inner raceway 5b. The raceway 5a, 5b can preferably be arranged as a separate element on the inner ring formed by the lower shell 21 of the strut bearing unit 20, and / or on the outer ring formed by the upper shell 22 of the strut bearing unit 20. As shown in Fig.As can be seen in Figure 4, the outer raceway 5a and the inner raceway 5b are designed as ring-shaped raceway elements that can be easily inserted into the upper shell 22 and / or the lower shell 21. Alternatively, the raceway elements 5a, 5b can also be formed by injection molding or similar processes.

[0044] In other arrangements, the strut bearing unit 20 may not include separate elements such as the outer raceway 5a and / or the inner raceway 5b, and the raceways 5a, 5b may be provided directly by the inner ring and / or outer ring.

[0045] According to the arrangement of the strut bearing unit 20, the outer circumferential surface 3 and the inner circumferential surface 2 of the cage 1 provide a sliding functionality 11 when they are in contact with a part of the strut bearing unit 20.

[0046] In summary, the cage described here for a bearing and the associated strut bearing unit provides a flexible design with reduced costs and improves the absorption of radial and / or axial loads. Reference symbol list 1 cage 2 inner circumferential surface 3 outer circumferential surface 4 Front surface 5a outer track 5b inner track 6 cage pockets 7 rolling elements 9 lubrication containers 10 warehouses 11 Gliding functionality 12 passageways 20 Strut bearing unit 21 lower bowl 22 upper bowl

Claims

Cage (1) for a bearing for a strut bearing unit, characterized in that the cage (1) is formed as a ring comprising several recesses forming cage pockets (6), wherein the recesses are designed to accommodate rolling elements (7) and to keep the rolling elements (7) spaced apart from one another, wherein an outer circumferential surface (3) and / or an inner circumferential surface (2) of the cage is designed to provide a sliding functionality when in contact with a part of the strut bearing unit. Cage (1) according to claim 1, further comprising a lubrication reservoir (9) and through-openings (12) provided in the outer circumferential surface (3), the inner circumferential surface (2) and / or the end faces of the cage, wherein the through-openings (12) are designed to provide a lubrication functionality by dispensing lubricant from the lubrication reservoir (9) to the outside of the cage. Cage (1) according to claim 2, wherein the lubricant is grease or oil. Cage (1) according to one of the preceding claims, wherein the cage (1) is made of a low-friction material, in particular of low-friction plastic material. Strut bearing unit (20) for a motor vehicle, comprising a lower shell (21) designed to support a suspension spring, an upper shell (22) designed to be connected to a chassis of the motor vehicle, and a bearing (10) inserted between the upper shell (22) and the lower shell (21), characterized in that the bearing (10) comprises an inner ring, an outer ring, and a cage (1) according to any one of claims 1 to 4, wherein several rolling elements (7) can be inserted between the inner ring and the outer ring and can be received in the pockets (6) provided by the cage. Strut bearing unit (20) according to claim 5, wherein the inner ring is formed by the lower shell (21) and / or wherein the outer ring is formed by the upper shell (22). Strut bearing unit (20) according to claim 5 or 6, wherein the cage pockets (6) are free of rolling elements (7). Strut bearing unit (20) according to claim 5 or 6, i) wherein some of the cage pockets (6) are filled with rolling elements (7), or ii) wherein all cage pockets (6) are filled with rolling elements (7). Strut bearing unit (20) according to one of claims 5 to 8, comprising an outer raceway (5a) and / or an inner raceway (5b) formed as a separate annular raceway element (23) arranged on the inner and / or outer ring, respectively. Strut bearing unit (20) according to claim 9, wherein the outer and / or the inner raceway (5a, 5b) is made of low-friction material.

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