Retarder for high-temperature applications

Abstract

A braking system with a hydrodynamic retarder is proposed, coupled to the drive shaft of a system via a drive mechanism. The retarder comprises at least one rotor and one stator, both fixed to rotation on a shaft and arranged in a common housing, forming a torus-shaped working chamber, the shaft being driveable via a drive mechanism. According to the invention, it is proposed that the retarder comprises two sealing systems for separating two pressure areas, wherein a first shaft section of the shaft is arranged in the first pressure area and a second shaft section is arranged in the second pressure area, and a middle shaft section located between the shaft sections is not assigned to either of the pressure areas.

Description

[0001] The invention relates to a retarder for high-temperature applications according to the preamble of claim 1.

[0002] As known from DE 10 2020 125 509 B3, braking systems with hydrodynamic retarders are used in motor vehicles. The retarder comprises at least one rotor and one stator arranged on a shaft, which are arranged in a common housing and together form a torus-shaped working chamber. This chamber can be filled with a working medium from a working medium circuit via a working medium inlet for braking operation of the retarder and can be emptied back into the working medium circuit via a working medium outlet for non-braking operation of the retarder.

[0003] A retarder is also suitable for other applications, such as generating process heat in stationary or mobile systems. In this process, a rotary motion that needs to be slowed down (braking energy) is used to convert it into waste heat.

[0004] Different working fluids can be used in retarders. During braking, the retarder heats up due to the shear forces between the stator and rotor. This braking energy must be dissipated as heat. The ability to dissipate heat from the working fluid limits the retarder's braking performance to a certain extent.

[0005] The temperature range in which elastomer seals or mechanical seals and / or stationary elastomer seals can still be operated is limited, especially because the aging of the oil and the aging of the sealing elements pose the risk of premature failure.

[0006] From DE 10 2022 112 905 B3, for example, a sealing system is known with a seal that is movable in two functional positions and in which the diameter of the radial sealing surface is elastically adjustable.

[0007] With regard to the environment, it is particularly important that no oil or working fluid leaks from the retarder and enters the environment.

[0008] The object of the invention is to propose a braking system with a hydrodynamic retarder that remains reliable even at higher operating temperatures of the working medium in the working space.

[0009] The problem is solved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention are found in the dependent claims.

[0010] A braking system with a hydrodynamic retarder is proposed, coupled to the system's drive axle via a high-speed drive. The retarder comprises at least one rotor and one stator, both fixed to rotation on a shaft and arranged in a common housing, forming a torus-shaped working chamber, with the shaft being driveable via a high-speed drive.

[0011] The system can be any type of drivetrain, such as the drivetrain of a wind turbine or a vehicle. In the case of a wind turbine, the retarder is directly coupled to the rotor shaft to continuously convert wind energy into heat energy. Alternatively, the wind energy could then be converted into electrical energy via a generator or into heat energy via the retarder.

[0012] According to the invention, it is proposed that the retarder comprises two sealing systems for separating two pressure areas, wherein a first shaft section of the shaft is arranged in the first pressure area and a second shaft section is arranged in the second pressure area, and a middle shaft section located between the shaft sections is not assigned to either of the pressure areas.

[0013] The two sealing zones allow for functional separation between the areas, enabling the working fluid to be designed for higher operating temperatures. Higher operating temperatures offer the advantage that the converted heat can also be used to power processes requiring higher temperatures (process heat). Furthermore, the heat storage capacity is also better at higher temperatures.

[0014] The shaft is preferably supported in the area of ​​the first shaft section, the support comprising bearings arranged in a high-drive housing. The high-drive and the support can be connected to a separate lubrication system, through which they are supplied with oil, the first pressure area being sealed from the surrounding environment.

[0015] Preferably, the retarder housing can be a common housing formed by a rotor housing and a stator housing, which forms the second pressure area, wherein the second pressure area is sealed against the ambient area via gap seals.

[0016] Furthermore, the working chamber of the retarder can be connected to a working medium circuit via a feed channel and an outlet channel, so that it can be filled and emptied, the working medium being a high-temperature working medium.

[0017] Preferably, the working medium is a high-temperature oil, a molten mineral salt or ionic liquid, or a metal with a low melting point. The working medium circuit includes, or is heatable, a heater to bring the working medium back to operating temperature after it has cooled down, in particular to liquefy it.

[0018] In a preferred embodiment, the surrounding area is formed by an intermediate housing, wherein both pressure zones are aligned relative to each other via the intermediate housing. According to the invention, the housings, i.e., the high-speed drive housing, intermediate housing, and retarder housing, are coupled to one another, thus enabling a floating bearing arrangement in the high-speed drive housing and allowing the shaft and rotor to be arranged in the retarder housing without contact and rotatably.

[0019] Furthermore, the surrounding area is designed in such a way that it is suitable for collecting working medium, and means, in particular a pump, are provided to pump the working medium back into the working medium circuit.

[0020] In a preferred embodiment, the stator can be clamped between the rotor housing and the stator housing, with a remaining clamping channel being connected to the surrounding area or the clamping channel being permanently closed to the surrounding area.

[0021] The invention will be explained below with the aid of figures. The figures show, in detail: Fig. 1 System section of a braking system with the retarder Fig. 2 a, b Examples of leakage drainage at clamping channels

[0022] Fig. Figure 1 shows a section of a braking system with a retarder 1 according to the invention. The essential structure of the retarder 1 is characterized by the fact that there are two pressure areas 15a and 15b and a shaft 12 that projects into both pressure areas 15a, b.

[0023] This design allows the retarder to be operated with a working fluid that can withstand high temperatures. A high-temperature working fluid such as...

[0024] High-temperature oils, molten mineral salts, other salts (ionic liquids), and metals with low melting points can be used here. To enable the use of these working fluids, a heating system may be provided to reheat the relevant components or the areas surrounding the working fluid after it has cooled down, re-heating it sufficiently to liquefy the fluid. Such working fluids must not enter the oil circuit, for example, for storage.

[0025] For the braking operation of the retarder 1, the working fluid from a working fluid circuit (not shown) is fed into the working chamber 13 via the supply channel 23 and pumped back out of the retarder into the working fluid circuit via the outlet channel 24. (general standard)

[0026] The shaft 11 is supported by bearings 18, which are arranged in the high-drive housing 22. The high-drive unit 17 comprises a high-drive gear 14, which is fixedly mounted on the shaft 1 and can be driven by a further drive gear.

[0027] The high-speed drive 17 and the bearings 18 are connected to a separate lubrication system (not shown) that supplies them with oil for lubrication and cooling. The first pressure zone 15a is sealed off from the ambient zone 19, outside the high-speed drive housing 22. The seal 26, e.g., a shaft seal, forms the first sealing system and is designed such that no oil can escape from the first pressure zone 15a during operation. The shaft 11 is cantilevered over the bearings 18 in the area of ​​the first shaft section 16a, the first shaft end.

[0028] The second shaft section 16b, the second shaft end, with the rotor (11) fixed to it, projects into the second pressure zone 15b, which is formed or enclosed by the rotor housing 2 and the stator housing 3. A sealing system 20, 21 is provided to seal the shaft passage; this system is adapted to the conditions of retarder operation, in particular high temperatures. The central shaft section 16c, located between the shaft sections 16a, 16b, is not assigned to either of the pressure zones 15a, b and passes through the ambient zone 19.

[0029] The second sealing system consists of a labyrinth seal 20 and a centrifugal disc 20, i.e., a non-contact sealing system in which leakage is unavoidable. The shaft passage is therefore only "sealed" with some leakage, and the remaining leakage must be collected, gathered, and fed back into the retarder at a suitable point or time.

[0030] The surrounding area 19 is formed by an intermediate housing 25, whereby both pressure zones 15a, b, or their housings 2, 3 and 22, are aligned with each other via the intermediate housing 25. The intermediate housing 25 forms a region in which working fluid can be collected, and means, in particular a pump, are provided to pump the working fluid back into the working fluid circuit.

[0031] In Fig. Figures 2a and 2b show examples of leakage drainage at clamping channels. For the purposes of the invention, leakage channels are gaps that form between two components of the retarder, e.g., rotor housing 2 and stator housing 3, at the contact point.

[0032] Without a sealing element between two metal parts, it is very difficult to achieve a tight seal at the joint between two metal components that are clamped together by means of a screw connection.

[0033] To achieve a tight seal, the housing parts can be arranged as shown in Fig. 2a shows how the welds are welded. The welds are deliberately kept thin and unstable so that the operating forces are transmitted (almost) exclusively or essentially by the mechanical structure, screws, fits, etc., and only secondarily by the welds, so that the expected distortion of the weld seam can only cause subordinate forces compared to the structural operating forces.

[0034] In Fig. 2a The stator is clamped between the housing parts, and the clamping channel 6 opens into a collection chamber 9. Any leakage is discharged via the discharge channel 8. The discharge channel 8 can terminate in the intermediate housing 25 or be connected to it.

[0035] The second sealing system therefore does not include any seals that are elastomer seals at the points around which the working fluid flows. Reference symbol list 1 Retarder 2 rotor housings 3 Stator housings 4 Stator 5 Fasteners 6 clamping channel 7 Nut 8 Drainage channel 9 Collection room 10-channel 11 Rotor 12 wave 13 Workroom 14 High-speed drive wheel 15a, b Print areas 16a, b, c Wave segments 17 Upward drive 18 warehouses 19 Surrounding area 20 Labyrinth seal 21 Slingshot disc 22 High-speed drive housings 23 Feed channel 24 Exit channel 25 intermediate housings 26 Seal QUOTES INCLUDED IN THE DESCRIPTION

[0000] 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

[0000] DE 10 2020 125 509 B3

[0002] DE 10 2022 112 905 B3

[0006]

Claims

[1] Braking system with hydrodynamic retarder (1) which is coupled to the drive axle of a system via a high drive (17), comprising at least one rotor (11) arranged on a shaft (12) in a rotationally fixed manner and a stator (4), which are arranged in a common housing (2, 3) and together form a toroidal working space (13), wherein the shaft (12) can be driven via a high drive (17), characterized by in that the retarder comprises two sealing systems (20, 21, 26) for separating two pressure areas (15a, 15b), wherein a first shaft section (16a) of the shaft (12) is arranged in the first pressure area (15a) and a second shaft section (16b) is arranged in the second pressure area (15b), and a middle shaft section (16c) present between the shaft sections (16a, 16b) is not assigned to any of the pressure areas (15a, b). [2] Braking system according to claim 1 characterized bythat the bearing of the shaft (12) is arranged in the region of the first shaft section (16a), wherein the bearing comprises bearings (18) which are arranged in a high-drive housing (22). [3] Braking system according to claim 2 characterized by that the high drive (17) and the bearing are connected to a separate lubrication system via which they are supplied with oil, wherein the first pressure area is sealed from an ambient area (19). [4] Braking system according to claim 1 characterized by that the common housing, formed by a rotor housing (2) and a stator housing (3), forms the second pressure region (15b), wherein the second pressure region (15b) is sealed from the surrounding region (19) via gap seals (10, 20, 21). [5] Braking system according to claim 1 characterized bythat the working chamber (13) of the retarder (1) is connected to a working medium circuit via a supply channel (23) and an outlet channel (24) and can be filled and emptied via this, wherein the working medium is a high-temperature working medium. [6] Braking system according to claim 5 characterized by that the working medium is a high-temperature oil, a molten mineral salt or ionic liquid or a metal with a low melting temperature. [7] Braking system according to claim 5 characterized by that the working medium circuit includes a heater or is heatable. [8] Braking system according to claim 3 or 4 characterized by that the surrounding area (19) is formed by an intermediate housing (25), wherein both pressure areas (15a, b) are aligned with each other via the intermediate housing (25). [9] Braking system according to claim 5 characterized bythat the surrounding area (19) is suitable for collecting working medium, wherein means, in particular a pump, are provided for conveying the working medium back into the working medium circuit. [10] Braking system according to claim 4 characterized by , that the stator (4) is clamped between the rotor housing (2) and the stator housing (3), wherein a remaining clamping channel (6) is connected to the surrounding area (19) or the clamping channel (6) is permanently closed off from the surrounding area.

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