Sealing arrangement with optimized sealing gap for dirt and oil sealing

Abstract

The invention relates to a sealing arrangement (1) for sealing a first component (2) against a second component (3) rotatably arranged relative to it about an axis of rotation (4), comprising a support ring (5) and a thrust ring (6) rotatable relative to the support ring, wherein two radially spaced sealing lips (7, 8) are arranged on the support ring (5), which bear against a side (9) of a U-shaped support area (10) of the thrust ring (6), and wherein an axially extending web area (11) of the thrust ring (6), projecting radially beyond the sealing lips (7, 8) from the outside, is provided with several circumferentially distributed drainage openings (12).

Description

[0001] The invention relates to a sealing arrangement for sealing a first component (preferably a housing) with respect to a second component (preferably a shaft) arranged so as to be rotatable about an axis of rotation relative to said first component, comprising a carrier ring and a thrust ring rotatable with respect to / relative to the carrier ring, wherein two radially spaced sealing lips are arranged on the carrier ring and bear against one (preferably axial) side of a support region of the thrust ring which is U-shaped in cross-section.

[0002] Sealing arrangements of this type are already well known in the art. For example, DE 10 2017 105 896 A1 discloses a bearing seal for sealing a bearing chamber.

[0003] However, it has been found that there is a fundamental risk that a relatively large amount of liquid and / or dirt can settle on the sealing lips during operation, thereby reducing the sealing effect.

[0004] It is therefore an object of the present invention to keep the sealing effect of the generic sealing arrangements as constant as possible, regardless of external influences.

[0005] This is achieved according to the invention in that an axially extending web region of the thrust ring, which extends radially beyond the sealing lips from the outside, is provided with several drainage openings distributed in the circumferential direction. The drainage openings are thus preferably implemented as through holes extending in the radial direction.

[0006] This ensures that any fluid accumulating on the sealing lips is directly drained away by the rotation. This keeps the sealing effect as constant as possible throughout the entire operation.

[0007] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0008] To achieve a suitable compromise between the necessary manufacturing effort and the required drainage effect, it has proven advantageous to incorporate a total of (exactly) six drainage openings in the web area. These drainage openings are preferably evenly distributed circumferentially.

[0009] Furthermore, it is advantageous if the sealing lips are designed as bent lips, thus having a bend / curvature at a specific point, and their free end areas are directed radially outward. This allows for the most effective seal possible.

[0010] In particular, it is advantageous if the two sealing lips are essentially identical in design and, more preferably, run partially or largely parallel to each other. It is also advantageous if the sealing lips rest with their free end areas on a common side of the thrust ring. This allows for the most compact design possible.

[0011] It is also advantageous for the carrier ring to have an axially extending sleeve section that radially covers the web area from the outside. This cleverly creates a space-saving labyrinth seal.

[0012] For optimal sealing, it is also advisable if an axial end area of ​​the sleeve area is (also) equipped with a seal / sealing contour.

[0013] If the sealing lips are part of a one-piece sealing body applied to a base body of the carrier ring, they can be easily manufactured / molded, for example by means of overmolding.

[0014] The sealing effect is further improved if the sealing body has a sealing section that protrudes axially outside the thrust ring, which sealing section is designed for direct contact with the second component.

[0015] Furthermore, the invention relates to a drive unit for a motor vehicle, comprising a housing, a shaft rotatably mounted in the housing and projecting into the housing through an opening, and a sealing arrangement according to the invention, acting between the housing and the shaft, according to at least one of the previously described embodiments.

[0016] The invention will now be explained in more detail below with reference to figures.

[0017] They show: Fig. 1 a longitudinal sectional view of a sealing arrangement according to the invention according to a preferred embodiment, Fig. 2 a perspective view of the longitudinally sectioned sealing arrangement according to Fig. 1, Fig. 3 a perspective view of a longitudinally sectioned thrust ring of the sealing arrangement, having a plurality of drainage openings, Fig. 4 a longitudinal sectional view of a drive unit comprising a sealing arrangement according to the invention, and Fig. 5 a detailed view of the drive unit in the area of ​​the sealing arrangement, illustrating its attachment to a shaft.

[0018] The figures are merely schematic in nature and therefore serve solely to clarify the invention. The same elements are designated by the same reference numerals.

[0019] In connection with the Fig. 4 and Fig. 5, the preferred application area of ​​the sealing arrangement 1 is firstly indicated. The sealing arrangement 1 is in Fig. 4 is inserted between a first component 2 in the form of a housing 21 and a second component 3 in the form of a shaft 22. The sealing arrangement 1 is arranged in the usual way in the region of an opening 23 in the housing 21, through which opening 23 the shaft 22 projects into the housing 21. The sealing arrangement 1 thus serves to seal the interior of the housing 21 from its surroundings in a dirt-tight and liquid-tight manner. The sealing arrangement 1 is arranged here in an axial direction (as seen from the shaft 22) directly next to a bearing 24 in the form of a rolling bearing (here a ball bearing) that supports the shaft 22 relative to the housing 21.

[0020] Furthermore, it should be noted that the drive unit 20 in which the sealing arrangement 1 is used is implemented in this exemplary embodiment as an electric drive unit 20 in the form of an electric axle / electric axle drive unit. However, it should be noted in this regard that the sealing arrangement 1 can also be used in any other application areas, in particular in other drive units.

[0021] In connection with the Fig. 1 to 3, the detailed structure of the sealing arrangement 1 according to the invention will now be described. The sealing arrangement 1 comprises, on the one hand, a support ring 5, which is typically attached to / supported on the first component 2 / the housing 21 during operation. The support ring 5, in turn, comprises a base body 17, typically made of a metal sheet, and a sealing body 18, which is preferably applied / sprayed onto the base body 17 in the form of a rubber coating.

[0022] The sealing body 18 has two sealing lips 7, 8 that protrude in the axial direction and are also arranged at a distance from one another in the radial direction. The sealing lips 7, 8 are designed as kinked lips and thus have a kink along their axial extension. The sealing lips 7, 8 are configured such that they extend / protrude radially outwards toward their free end / end region 13a, 13b. The respective sealing lips 7, 8 thus form a type of (radial) collecting tray that serves to collect any liquid, such as water or dirt, that accumulates during operation.

[0023] Furthermore, the sealing body 18 has a sealing section 19 which projects axially opposite to the sealing lips 7, 8 with respect to a radially extending disc region 25 of the carrier ring 5 / base body 17. This sealing section 19 serves, as for example in Fig. 5, for direct contact with a radial surface of the shaft 22.

[0024] The carrier ring 5 also has a radially outer sleeve region 14, which, in the preferred area of ​​use, rests against / is firmly held by the first component 2. At its axially free end / end region 15, the sleeve region 14 is equipped with a seal 16 in the form of a rubber coating. The seal 16 is also attached to a radially outer side of the end region 15 to seal a joint gap between the carrier ring 5 and the housing 21.

[0025] Between the sleeve region 14 and the disc region 25, the carrier ring 5 forms a groove which is open in the axial direction, wherein the thrust ring 6 projects in from one axial side, as described in more detail below, forming a labyrinth seal / a labyrinth-like gap 29.

[0026] During operation, the said thrust ring 6 is directly supported on the shaft 22 / connected to it in a rotationally fixed manner in the usual way.

[0027] The thrust ring 6 is simply a single piece formed from a sheet metal. The thrust ring 6 has a U-shaped cross-section. Thus, the thrust ring 6 directly forms a support area 10, which is U-shaped in cross-section. The thrust ring 6 thus forms an (axially open) interior space 26 / receiving chamber into which the sealing lips 7, 8 protrude and rest against the thrust ring 6 on one (axial) side 9. The sealing lips 7, 8 are typically pressed axially against the thrust ring 6 with a specific contact force.

[0028] As in the Fig. 2 and Fig.3, an axially projecting web region 11 of the thrust ring 6, which projects axially into the groove region 27 of the carrier ring 5 and determines the course of the gap 29, is equipped according to the invention with a plurality of drainage openings 12 in the form of radial through holes distributed in the circumferential direction.

[0029] It can be seen that a total of six drainage openings 12 are incorporated into the web area 11. The drainage openings 12 are evenly distributed in the circumferential direction. The drainage openings 12 are designed as bores.

[0030] This makes it possible for any fluid / dirt accumulating during operation on the side of the sealing lips 7, 8, particularly on the side of the first (i.e., radially outer) sealing lip 7, to be directly discharged radially (via a shortcut) and to flow out of the sealing arrangement 1 via the shortest possible path via the radial space 28 radially between the sleeve region 14 and the web region 11. This significantly reduces the stress on the sealing lips 7, 8 caused by accumulating water, oil, or dirt.

[0031] For the sake of completeness, it should be noted that the directional terms used herein, axial / axial direction, radial / radial direction, and circumferential direction, are to be understood with reference to a rotational axis 4 of the rotating component of the sealing arrangement 1 / the shaft 22 of the drive unit 20. An axial direction is thus understood to be a direction along / parallel to the rotational axis 4, a radial direction is understood to be a direction perpendicular to the rotational axis 4, and a circumferential direction is understood to be a direction along a circular line coaxial with the rotational axis 4. List of reference symbols 1 Sealing arrangement 2 first component 3 second component 4 axis of rotation 5 carrier ring 6 thrust ring 7 first sealing lip 8 second sealing lip 9 Page 10 Support area 11 Bridge area 12 Drain opening 13a free end area of ​​the first sealing lip 13b free end area of ​​the second sealing lip 14 Sleeve area 15 End area of ​​the sleeve area 16 Seal 17 basic bodies 18 sealing bodies 19 Sealing section 20 drive unit 21 housings 22 Wave 23 Opening 24 warehouses 25 disc area 26 Interior 27 Gutter area 28 Radial space 29 gap QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2017 105 896 A1

[0002]

Claims

[1] Sealing arrangement (1) for sealing a first component (2) with respect to a second component (3) arranged to be rotatable relative to the first component about an axis of rotation (4), comprising a carrier ring (5) and a thrust ring (6) which is rotatable relative to the carrier ring, wherein two radially spaced sealing lips (7, 8) are arranged on the carrier ring (5) and bear against one side (9) of a support region (10) of the thrust ring (6) which is U-shaped in cross section, characterized by that an axially extending web region (11) of the thrust ring (6) projecting radially from the outside beyond the sealing lips (7, 8) is provided with a plurality of drainage openings (12) distributed in the circumferential direction. [2] Sealing arrangement (1) according to claim 1, characterized by that six drainage openings (12) are introduced into the web area (11). [3] Sealing arrangement (1) according to claim 1 or 2, characterized bythat the sealing lips (7, 8) are designed as kinked lips and their free end regions (13a, 13b) are directed radially outwards. [4] Sealing arrangement (1) according to one of claims 1 to 3, characterized by that the carrier ring (5) has an axially extending sleeve region (14) which radially covers the web region (11) from the outside. [5] Sealing arrangement (1) according to claim 4, characterized by that an axial end region (15) of the sleeve region (14) is equipped with a seal (16). [6] Sealing arrangement (1) according to one of claims 1 to 5, characterized by that the sealing lips (7, 8) are part of a one-piece sealing body (18) applied to a base body (17) of the carrier ring (5). [7] Sealing arrangement (1) according to claim 6, characterized bythat the sealing body (18) has a sealing section (19) projecting axially outside the thrust ring (6), which sealing section (19) is designed to bear directly against the second component (3). [8] Drive unit (20) for a motor vehicle, comprising a housing (21), a shaft (22) rotatably mounted in the housing (21) and projecting into the housing (21) through an opening (23), and a sealing arrangement (1) according to one of claims 1 to 7, inserted between the housing (21) and the shaft (22).

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