Sealing system

Abstract

The invention relates to a sealing system for isolating two pressure regions, comprising a sealing device arranged between a shaft and a component. According to the invention, the sealing device is arranged in a groove in an axially displaceable manner, the sealing device having a sealing surface and the groove having a groove sealing surface, the sealing device being displaceable into a first functional position or a second functional position depending on a pressure relationship in a pressure region.

Description

[0001] The invention relates to a sealing system for isolating two pressure areas, comprising two functional positions, and to application of the sealing system in a hydraulic retarder.

[0002] Technological progress has made it necessary to adapt the sealing system to the increased requirements. Special demands are placed on the sealing system if the system should have different properties, in particular sealing properties, for different operating conditions.

[0003] One area of ​​application of sealing systems with different functional positions is in hydraulic retarders. As is known, hydraulic retarders have a working chamber that can be filled with a working medium in order to transfer the torque of a driven rotor to a stator in a hydraulic manner.

[0004] The working chamber of the retarder is connected to the retarder working medium circulation circuit, in which a working medium such as oil or cooling water of a vehicle cooling circulation circuit can circulate. In order to seal the retarder circulation relative to the rotor shaft, radial shaft sealing rings and rectangular sealing rings are used. The rectangular sealing ring is an isolating element positioned between the working chamber and the shaft sealing ring. The rectangular sealing ring is used for the radial shaft sealing ring as a load-removing element so that no excessive pressure is applied to the radial shaft sealing ring from the working chamber, wherein a certain degree of leakiness is required depending on the pressure characteristics. The sealing effect of the rectangular sealing ring thus depends on the pressure applied during braking operation or non-braking operation. Since the rotor shaft rotates in both operating states, it is necessary in both operating states to lubricate and cool the sealing parts by oil flow.

[0005] Patent document DE 10 2020 107 729 A1 discloses a retarder with a cooling sealing system. The sealing system comprises a rectangular sealing ring arranged between a working chamber and a radial shaft sealing ring. The rectangular sealing ring is designed to enable a leakage flow that changes its direction depending on the operating state. However, due to the structural limitations, the leakage flow is only limited and depends essentially on the manufacturing tolerances.

[0006] EP 2 666 980 A1 discloses a sealing system which is movable in two functional positions.

[0007] Further sealing systems are known from DE 1 162 464 B and DE 6 929 111 U.

[0008] Patent document DE 10 242 735 A1 discloses a retarder having a sealing system.

[0009] The technical problem to be solved by the present invention is to provide a sealing system with improved properties.

[0010] This object is achieved according to the invention by the embodiments according to the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

[0011] The starting point is a sealing system for isolating two pressure areas, which comprises a sealing device arranged between a shaft and a component.

[0012] According to the invention, the seal is arranged axially displaceably in the groove, wherein the seal has a sealing surface and the groove has a groove sealing surface, wherein the seal can be moved into a first functional position or a second functional position depending on the pressure conditions in the pressure area. Within the scope of the invention, the seal is arranged axially displaceably in the groove. Different sealing properties can be achieved in the functional positions.

[0013] In a preferred embodiment, it can be provided that in the first functional position, isolation of the pressure areas is achieved and in the second functional position, pressure equalization between the pressure areas is achieved, in that at least one of the sealing surface and / or the groove sealing surface has a recess, so that a channel remains between the pressure areas in the second functional position.

[0014] Preferably, the channel is formed by providing a plurality of recesses which are implemented as pocket-shaped areas in the sealing surface of the seal and as depressions adjacent to the groove. The depressions can be implemented circumferentially on the shaft, for example, and at least one pocket-shaped area in the sealing surface can be formed by a partial area, so that when the sealing surface of the seal moves relative to the groove sealing surface to the second functional position, only a relatively small channel area is formed when viewed in the circumferential direction.

[0015] In a preferred embodiment, the sealing surface of the seal is symmetrically designed and the channel dimensions can be defined by the design or dimensioning of the recess. When installing the seal, it is not necessary to pay attention to the orientation of the seal.

[0016] Furthermore, it can be provided that the sealing device has a radial sealing surface, the diameter D of which can be elastically adjusted by the slide region. The slide region can also be designed so that the inner diameter can be enlarged, so that the sealing device can be mounted on the shaft.

[0017] Furthermore, a retarder is provided, which comprises the sealing system, wherein the first pressure region comprises a working chamber of the retarder, and wherein the sealing device can be moved into a first functional position or a second functional position depending on the pressure relationship between the pressure regions. In the event of an overpressure in the first pressure region, it is provided that the sealing device moves into the first functional position, in which the pressure regions are sealed from one another.

[0018] In addition, the sealing system in the retarder can be designed so that when there is overpressure in the second pressure area, the sealing device moves to the second functional position, thereby achieving pressure balance between the pressure areas, in which way at least one of the sealing surface and / or the groove sealing surface has a recess, so that in the second functional position a channel is retained between the pressure areas, which channel achieves pressure balance.

[0019] There are two main operating states in the retarder operation: braking operation and non-braking operation. It is advantageous here that the sealing system seals the circulation to the outside in braking operation and allows air or oil flow from the outside to the circulation in non-braking operation. The present invention achieves sealing of the circulation to the outside in braking operation and allows oil or air to enter the circulation in idling.

[0020] The present invention is explained below with reference to the accompanying drawings. In the accompanying drawings:

[0021] Figure 1 The sealing system is shown in a first functional position,

[0022] Figure 2 The sealing system is shown in a second functional position,

[0023] Figure 3 A view showing a sealing device.

[0024] Figure 1 The sealing system 1 is shown in a first functional position. The sealing ring 4 is arranged in the groove 11 of the shaft 3. The sealing device 4 moves axially depending on the pressure relationship in the pressure areas 5.1, 5.2, so that the first sealing surface 7.1 of the sealing device 4 presses against the groove sealing surface 12.1. In the sealing plane 6, a complete seal is achieved with respect to the second pressure area 5.2.

[0025] The sealing device 4 is implemented as a sealing ring or a rectangular sealing ring. The end faces of the sealing device 4, namely the first sealing surface 7.1 and the second sealing surface 7.2, form a continuous surface, wherein the surface has recesses 13.1 and 13.2, and also as shown in FIG. Figure 3 As shown, the sealing surfaces 7.1 and 7.2 are reduced in the radial direction. The effective diameter for sealing is thus changed by the recesses 13.1 and 13.2. However, in the first functional position, it is still ensured that the first sealing surface 7.1 and the groove sealing surface 12.1 are in full contact with each other in the sealing plane 6. As a result, the sealing device 4 can be implemented symmetrically.

[0026] A further recess is arranged adjacent to the groove 11, which is designed here as a depression 14. The combination of the pocket region 13.2 and the depression 14 forms a channel 10 between the shaft 3 and the seal 4.

[0027] exist Figure 21 and 2 show a second functional position in which pressure compensation between the pressure regions 5.1, 5.2 can be achieved via the channel 10. In the retarder, the illustrated position of the sealing device 4 corresponds to a non-braking operation, wherein air and / or oil volume flows or leakage flows can enter the downstream components via the channel 10.

[0028] The hollow can also be formed by perforations or openings within the scope of the invention. The use of elastic elements is also conceivable. The desired air and / or oil volume flow can be adjusted by the size of the hollow 13.2 and / or the depression 14.

[0029] To simplify the installation of the seal 4 , the seal 4 has a slide region 16 , by means of which the diameter D1 of the seal can be varied, so that installation on the shaft can be easily achieved.

[0030] Figure 3 For easier understanding, the seal 4 is shown in a perspective view. This view shows the slide region 16, which allows the inner diameter D1 of the seal 4 to be changed. As a result, the seal can be widened on the shaft 3 and moved to the groove. It is clearly shown that a recess 13.2 and a sealing surface 7.2 form a continuous surface that is not significantly interrupted by the design of the slide region 16.

[0031] List of Reference Numerals

[0032] 1 Sealing system

[0033] 2 Housing

[0034] 3 Axis

[0035] 4 Sealing device

[0036] 5.1 First pressure area

[0037] 5.2 Second pressure zone

[0038] 6 Sealing plane

[0039] 7.1 First sealing surface

[0040] 7.2 Second sealing surface

[0041] 8.1 Working medium

[0042] 9 Volumetric tributaries

[0043] 10 channels

[0044] 11 slots

[0045] 12.1, 12.2 Groove sealing surface

[0046] 13.1, 13.2 Hollow

[0047] 14 Depression

[0048] 15 Radial sealing surface

[0049] 16 Slider Area

[0050] D1 inner diameter

Claims

1. A sealing system (1) for isolating two pressure areas (5.1, 5.2), the sealing system comprising a sealing device (4) arranged between a shaft (3) and a component (2), wherein: The sealing device (4) is arranged in a groove (11) so as to be axially movable, wherein the sealing device (4) has sealing surfaces (7.1, 7.2) and the groove (11) has groove sealing surfaces (12.1, 12.2), wherein the sealing device (4) can be moved into a first functional position or a second functional position according to the pressure relationship in the pressure area (5.1, 5.2), and is characterized in that the sealing device (4) has a radial sealing surface (15), the diameter D of which can be elastically adjusted via a slider area (16).

2. The sealing system (1) according to claim 1, characterized in that In the first functional position, the pressure areas (5.1, 5.2) are isolated and in the second functional position, pressure equalization is achieved between the pressure areas (5.1, 5.2) in that at least one of the sealing surfaces (7.1, 7.2) and / or the groove sealing surfaces (12a, b) has a recess (13.1, 13.2, 14), so that in the second functional position a channel (10) is retained between the pressure areas.

3. The sealing system (1) according to claim 2, characterized in that The channel (10) is formed by providing a plurality of recesses (13.1, 13.2, 14) which are designed as pocket-shaped areas (13.1, 13.2) in the sealing surface (7.1) of the seal (4) and as depressions (14) adjacent to the groove (11).

4. The sealing system (1) according to claim 1, characterized in that The sealing surfaces (7.1, 7.2) of the sealing device (4) are symmetrically designed.

5. A retarder comprising a sealing system (1) according to any one of claims 1 to 4, characterized in that: The first pressure region (5.1) comprises a working chamber of the retarder, wherein the sealing device (4) can be moved to a first functional position or a second functional position depending on the pressure relationship between the pressure regions (5.1, 5.2), wherein when there is an overpressure in the first pressure region (5.1), the sealing device (4) moves to the first functional position in which the sealing regions are sealed from each other.

6. The retarder according to claim 5, characterized in that: When there is overpressure in the second pressure area, the sealing device (4) moves to a second functional position, thereby achieving pressure balance between the pressure areas (5.1, 5.2), in that at least one of the sealing surfaces (7.1, 7.2) and / or the groove sealing surfaces (12a, b) has a recess (13.1, 13.2, 14), so that in the second functional position a channel (10) remains between the pressure areas (5.1, 5.2), which channel achieves pressure balance.

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