Strut bearing unit for a motor vehicle

Abstract

Disclosed is a strut bearing unit (1) for a motor vehicle, comprising a lower cup (2) configured to support a suspension spring, an upper cup (3) configured to couple with a top mount which provides a connection to a chassis of the motor vehicle, a bearing (4, 5, 6) interposed between the upper cup (3) and the lower cup (2), wherein the strut bearing unit (1) comprises an inner sealing element (7) and an outer sealing element (8), which are separate from each other, wherein each sealing element (7, 8) is accommodated by a dedicated sealing seat provided by the upper cup (3) and / or the lower cup (2).

Description

[0001] 202400199

[0002] 1

[0003] Strut bearing unit for a motor vehicle

[0004] Technical field of the invention

[0005] The present invention relates to a strut bearing unit for a motor vehicle according to the generic term of patent claim 1.

[0006] Background of the invention

[0007] An automobile suspension system comprises a support strut supporting an axle and a wheel of a vehicle. A strut bearing unit or suspension bearing unit is disposed in the upper part of the support strut, opposite the wheel and the ground, between a suspension spring and an upper member, so called top mount, that is integral with the chassis of the vehicle or can be mounted to the chassis of the vehicle. Such a strut bearing unit is adapted for transmitting axial forces between the suspension spring and the chassis of the vehicle. The strut bearing unit consists of a lower cup and an upper cup, wherein a bearing is arranged between the lower and the upper cup.

[0008] In present suspension systems, the bearing must be sealed by a mostly complicated or delicate and therefore expensive sealing unit to provide an inwardly and outwardly sealed strut bearing unit.

[0009] It is therefore object of the present invention to provide a strut bearing unit which enables simplified and cost-effective sealing.

[0010] Summary of the invention

[0011] This object is solved by a strut bearing unit for a motor vehicle according to claim 1.

[0012] The strut bearing unit, also called suspension bearing unit, may particularly be of the MacPherson type (so called MacPherson suspension bearing unit). As described above, the strut bearing unit may be disposed in the upper part of the support strut, opposite the wheel and the ground, between a suspension spring and an upper member, in the following referred to as top mount. The top mount may either be integral with the chassis of the vehicle or may be mounted to the chassis of the vehicle. 202400199

[0013] 2

[0014] The strut bearing unit comprises a lower cup configured to support the suspension spring, an upper cup configured to couple with the top mount which provides a connection to a chassis of the motor vehicle, and a bearing interposed between the upper cup and the lower cup.

[0015] The strut bearing unit comprises an inner sealing element and an outer sealing element, which are separate from each other, wherein each sealing element is accommodated by a dedicated sealing seat provided by the upper cup and / or the lower cup. As the sealing elements can be inserted into the strut bearing unit separated from each other, handling and arranging the sealing elements is simplified compared to previous sealing elements which were large and thus complicated to be inserted. The here described sealing elements allow an easy and cheap way to create an inwardly and outwardly sealing of the strut bearing unit and can be easily applied in a corresponding manufacturing process.

[0016] According to an embodiment, the inner sealing element and the outer sealing element are provided as an axial seal and / or a radial seal. In the case of a radial seal, the sealing element is compressed mostly in a radial direction. When the sealing element is an axial seal, the compression of the sealing element is mostly in the direction of installation. This allows the seal to be customized to the respective requirements and conditions. The advantages of an axial seal are low friction, small installation width, long service life and favorable production costs. The advantages of a radial seal are reduced friction and therefore a long service life, good resistance to oils, lubricants, greases and hydraulic fluids and suitability for high pressures at low speeds. Depending on customer requirements, the kind of sealing element may be selected, providing a flexibility of adaptation to the specific requirements of the application. Further, also only one sealing element could be used or the sealing elements could be complemented by further additional sealing elements.

[0017] According to a further embodiment, one or more grooves are provided in the upper cup and / or the lower cup, in which the inner sealing element and / or the outer sealing element are arranged. The advantage of one or more grooves is that the inner and / or outer sealing element can easily be arranged and held at a certain position in the strut bearing unit.

[0018] Preferably the one or more grooves have a rectangular and / or trapezoidal cross-sectional shape. This allows to optimally adapt the one or more grooves to the inner and / or outer 202400199

[0019] 3 sealing element, or the type of seal used. Further, such a form of grooves can be easily manufactured.

[0020] According to a further embodiment, centering diameters are provided in the upper cup and / or lower cup, which provide a chamber for the inner sealing element and / or the outer sealing element. In particular, the inner and / or the outer sealing element may be clamped or pressed between the centering diameters of the upper cup and / or lower cup. Such an arrangement provides the advantage of an easy manufacturing as the upper and / or lower cup may be formed accordingly during the manufacturing and no additional step of making grooves or other sealing seats is necessary.

[0021] According to a further embodiment, the inner sealing element and / or the outer sealing element interferes with the upper cup and / or the lower cup. This ensures a reliable and stable connection between the sealing element(s) and the contact surfaces of the upper cup and / or the lower cup and thus ensures an optimum seal between the sealing element and the lower or upper cup.

[0022] According to a further embodiment, the inner sealing element and / or the outer sealing element comprises a lubricant that reduces the frictional torque, or the inner sealing element and / or the outer sealing element are made of a material with reduced frictional torque. The advantage thereof is to ensure a long-lasting seal. For example, the inner and / or the outer sealing element may be made of fluororubber or polytetrafluoroethylene. The lubricant may be based on silicon and / or may be grease or oil.

[0023] According to a further embodiment, the inner sealing element and / or the outer sealing element is made in the form of a ring, for example an O-ring or any other shape such as a quatrefoil ring, or an injected seal. The configuration of the inner and / or outer sealing element in the form of a ring or injection seal provides the advantage that for example one single O-ring can replace a radial and axial lip seal system. Thus, the configuration of the inner and / or outer sealing element may be simplified compared to existing sealing elements which have a more complex structure and configuration. Further, there is a direct link between seal compression and friction torque, which can be easily adjusted and controlled. 202400199

[0024] 4

[0025] The inner sealing element and / or the outer sealing element may be made of nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, fluororubber, ethylene propylene, butyl, silicone, fluorosilicone, fluorocarbon, nitril, chloroprene, polyacrylic, polytetrafluoroethylene, or any other kind of polymer or rubber for example.

[0026] The ring can be a standard fully (O-)ring or a (O-)ring coil cut, where the ring is cut to size and assembled during the manufacturing process of the strut bearing unit. Furthermore, the injected seal can be injected during the manufacturing process of before. The injected seal can be made for example of polyurethane or self-lubricating material or can be made of TPS- SEBS (thermoplastic elastomer styrene-ethylene-butylene copolymer).

[0027] According to a further embodiment, the upper cup and / or the lower cup have a protrusion that extends in the direction of and is arranged opposite to the inner sealing element and / or the outer sealing element. The protrusion may be of a triangular shape. The protrusion may extend completely or in sections along the area to be sealed. The protrusion, which is preferably in direct contact with the inner and / or outer sealing element, may ensure a reliable seat and arrangement of the respective sealing element. This may be done for example by pressing the respective sealing element onto the corresponding contact surface (i.e., the lower and / or the upper cup or the groove provided in the lower and / or upper cup) by means of the protrusion. This may additionally improve the sealing function so that nothing can penetrate from the outside into the strut bearing unit or escape from the inside from the strut bearing unit, for instance lubricant from the sealing or from the bearing.

[0028] Further preferred embodiments are defined in the dependent claims as well as in the description and the figures. Thereby, elements described or shown in combination with other elements may be present alone or in combination with other elements without departing from the scope of protection.

[0029] Brief description of the drawings

[0030] In the following, preferred embodiments of the invention are described in relation to the drawings, wherein the drawings are exemplarily only, and are not intended to limit the scope of protection. The scope of protection is defined by the accompanied claims, only.

[0031] The figures show: 202400199

[0032] 5

[0033] Fig. 1 : a first embodiment of a strut bearing unit in a side sectional view,

[0034] Fig. 2: a second embodiment of the strut bearing unit in a side sectional view, Fig. 3: a third embodiment of the strut bearing unit in a side sectional view, and Fig. 4: a fourth embodiment of the strut bearing unit in a side sectional view

[0035] Detailed description of the invention

[0036] In the following same or similar functioning elements are indicated with the same reference numerals.

[0037] Fig. 1 to 4 show each a different embodiment of a strut bearing unit 1 in a side sectional view having a lower cup 2 and an upper cup 3. Each cup 2, 3 may have the general form of a cylindrical ring. Between the lower cup 2 and the upper cup 3, a bearing is arranged, which comprises an inner ring 4, an outer ring 5 and rolling elements 6 inserted between the inner ring 4 and the outer ring 5. The bearing may be a rolling bearing, for example a ball bearing, but may also be any other kind of bearing such as a plain bearing or a roller bearing. The strut bearing unit 1 as shown in Figs. 1 to 4 comprises an inner sealing element 7 and an outer sealing element 8. The upper cup 3 may be coupled with the chassis of a motor vehicle (not shown) and the lower cup 4 comprises a connection part 12 to couple with the suspension spring of the motor vehicle (not shown).

[0038] Fig. 1 shows a first embodiment of the strut bearing unit 1 in a side sectional view wherein the inner sealing element 7 and the outer sealing element 8 are provided each as a radial seal. In the upper cup 3 and lower cup 2, centering diameters 10 are provided, which form each a chamber for the inner sealing element 7 and the outer sealing element 8. These chambers function as sealing seats holding the inner sealing element 7 and the outer sealing element 8 in a predetermined position between the lower cup 2 and upper cup 3, wherein the position is defined by the centering diameters 10 provided in the lower cup 2 and upper cup 3. The inner sealing element 7 and the outer sealing element 8 are made hereby in the form of an O-Ring.

[0039] Fig. 2 shows a second embodiment of the strut bearing unit 1 in a side sectional view wherein the inner sealing element 7 and the outer sealing element 8 are provided each as an axial seal. In the lower cup 2 grooves 9 as sealing seats are provided, in which the inner sealing element 7 and the outer sealing element 8 are arranged. The inner sealing element 7 and the outer sealing element 8 are made hereby also in the form of an O-Ring. Alternatively, the sealing 202400199

[0040] 6 elements 7, 8 or one of the sealing elements 7, 8 could be formed using injection molding, forming an injected seal. In this case, the material of the sealing element(s) 7, 8 could be injected directly into the respective groove 9.

[0041] Furthermore, the upper cup 3 comprises two protrusions 13, wherein each extends in the direction of and is arranged opposite to the inner sealing element 7 and outer sealing element 8. In the herein shown example, the protrusions 13 are of a triangular shape in cross-section. However, it should be noted that the protrusions 13 may have any suitable shape, for example a rectangular shape. Further, it should be noted that the protrusions 13 may extend continuously in the circumferential direction or may consist of several distinct elements in the circumferential direction.

[0042] Fig. 3 shows a third embodiment of the strut bearing unit 1 in a side sectional view wherein the inner sealing element 7 is provided as a radial seal and the outer sealing element 8 is provided as an axial seal. In the upper cup 3 and lower cup 2, centering diameters 10 are provided, which form a chamber for the inner sealing element 7. These chambers function as sealing seats holding the inner sealing element 7 in a predetermined position between the lower cup 2 and upper cup 3, wherein the position is defined by the centering diameters 10 provided in the lower cup 2 and upper cup 3. In the lower cup 2, grooves 9 as sealing seats are provided, in which the outer sealing element 8 are arranged. In the herein shown example, the protrusions 13 are of a triangular shape in cross-section. However, it should be noted that the protrusions 13 may have any suitable shape, for example a rectangular shape. The inner sealing element 7 and the outer sealing element 8 are made hereby also in the form of an Ci- Ring.

[0043] Fig. 4 shows a fourth embodiment of strut bearing unit 1 in a side sectional view wherein the inner sealing element 7 is provided as an axial seal and the outer sealing element 8 is provided as a radial seal. Thus, it shows the third embodiment of the strut bearing unit according to Fig. 3 in an opposite arrangement. Therefore, in the upper cup 3 and lower cup 2 centering diameters 10 are provided, which form a chamber for the outer sealing element 8. These chambers function as sealing seats holding the outer sealing element 8 in a predetermined position between the lower cup 2 and upper cup 3, wherein the position is defined by the centering diameters 10 provided in the lower cup 2 and upper cup 3. For the axial seal, a groove 9 is provided in the lower cup 2 serving as sealing seat, in which the outer sealing 202400199

[0044] 7 element 8 is arranged. The inner sealing element 7 and the outer sealing element 8 are made hereby also in the form of an O-Ring. Alternatively, the sealing elements 7, 8 or one of the sealing elements 7, 8 could be formed using injection molding, forming an injected seal. In this case, the material of the sealing element(s) 7, 8 could be injected directly into the respective groove 9.

[0045] Furthermore, the upper cup 3 comprises a protrusion 13, extending in the direction of and is arranged opposite to the outer sealing element 8. In the herein shown example, the protrusion 13 is of a triangular shape in cross-section. However, it should be noted that the protrusion 13 may have any suitable shape, for example a rectangular shape.

[0046] In summary, a strut bearing unit with an inner sealing element and an outer sealing element is provided, which are separate from each other, wherein each sealing element is accommodated by a dedicated sealing seat provided by the upper cup and / or the lower cup, which allows a simplified and cost-effective sealing for a strut bearing unit for a motor vehicle.

[0047] 202400199

[0048] Reference numerals

[0049] 1 Strut bearing unit

[0050] 2 Lower cup

[0051] 3 Upper cup

[0052] 4 Inner ring

[0053] 5 Outer ring

[0054] 6 Rolling element

[0055] 7 Inner sealing element

[0056] 8 Outer sealing element

[0057] 9 Groove

[0058] 10 Centering diameters

[0059] 12 Connection part lower cup

[0060] 13 Protrusion

Claims

2024001999C l a i m sStrut bearing unit for a motor vehicle1. A strut bearing unit (1) for a motor vehicle, comprising a lower cup (2) configured to support a suspension spring, an upper cup (3) configured to couple with a top mount which provides a connection to a chassis of the motor vehicle, a bearing (4, 5, 6) interposed between the upper cup (3) and the lower cup (2), characterized in that the strut bearing unit (1) comprises an inner sealing element (7) and an outer sealing element (8), which are separate from each other, wherein each sealing element (7, 8) is accommodated by a dedicated sealing seat provided by the upper cup (3) and / or the lower cup (2).

2. The strut bearing unit according to claim 1, wherein inner sealing element (7) and the outer sealing element (8) are provided as an axial seal and / or a radial seal.

3. The strut bearing unit according to claim 1 or 2, wherein one or more grooves (9) are provided in the upper cup (3) and / or the lower cup (2), in which the inner sealing element (7) and / or the outer sealing element (8) are arranged.

4. The strut bearing unit according to claim 3, wherein the one or more grooves (9) have a rectangular and / or trapezoidal cross-sectional shape.

5. The strut bearing unit according to claim 1 or 2, wherein centering diameters (10) are provided in the upper cup (3) and / or lower cup (2), which provide a chamber for the inner sealing element (7) and / or the outer sealing element (8).

6. The strut bearing unit according to any one of the preceding claims, wherein the inner sealing element (7) and / or the outer sealing element (8) interferes with the upper cup (3) and / or the lower cup (2).202400199107. The strut bearing unit according to any one of the preceding claims, wherein the inner sealing element (7) and / or the outer sealing element (8) comprises a lubricant for reducing the frictional torque.

8. The strut bearing unit according to any one of the preceding claims, wherein the inner sealing element (7) and / or the outer sealing element (8) are made of a material having a reduced frictional torque.

9. The strut bearing unit according to any one of the preceding claims, wherein the inner sealing element (7) and / or the outer sealing element (8) is made in the form of an O-ring or an injected seal, preferably made of nitrile butadiene rubber, hydrogenated nitrile butadiene rubber, fluororubber or polytetrafluoroethylene.

10. The strut bearing unit according to any one of the preceding claims, wherein the upper cup (3) and / or the lower cup (2) have a protrusion (13) that extends in the direction of and is arranged opposite to the inner sealing element (7) and / or the outer sealing element (8).

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