DE102021117390A1 - Working medium tank for a hydrodynamic retarder - Google Patents

Abstract

The proposed hydrodynamic retarder comprises a housing with a tank housing part and a tank cover, between which an enclosed tank is formed, which can be filled with a working medium and includes a fluid area (3). Furthermore, a tank ventilation system is provided, which on the one hand has a connection to the fluid area and on the other hand a connection to the environment, the tank ventilation system comprising a labyrinth and a valve which closes the connection to the environment in its closed position and the connection to the environment in the open position releases. To improve the retarder, it is proposed that the labyrinth of the tank ventilation system comprises several spaces and/or channels within the tank enclosed by the tank housing part and the tank cover, through which an air-working medium mixture can be routed to separate the working medium portion, with drip channels being provided through which are connected to the tank ventilation system with the fluid area, so that accumulations of working medium can be routed back into the fluid area from the tank ventilation system.

Description

The present invention relates to a working medium tank for a hydrodynamic retarder, in detail according to the preambles of the independent claims.

Hydrodynamic retarders are used, for example, as wear-free brakes in motor vehicle drive trains, in order to brake the motor vehicle, in particular a truck, bus or rail vehicle, by transmitting torque using a hydrodynamic circuit.

The retarder includes a toroidal working space formed by the rotor and stator, which is connected via a duct system to a working medium circuit with a working medium tank. The working area is ventilated via a profile ventilation system, via which air can be released by means of a connection between the working area and the environment. The air present in the working area in non-braking mode is routed out of the working area into the environment via the profile ventilation system when the retarder is switched to braking mode. An oil separator and a valve are provided to prevent the working medium, in particular oil, from getting into the environment.

Furthermore, a tank ventilation system is provided, via which air can be released by means of a connection between the working medium tank and the environment. The air that is pumped into the working medium tank to switch the retarder to braking mode is conveyed back out of the tank to the environment via the tank ventilation system when the retarder is switched back to non-braking mode. An oil separator system and a valve are provided to prevent the working medium, in particular oil, from getting into the environment with the air when the working medium tank is vented.

Both ventilation systems are, for example, from the DE 10 2013 207 004 A1 known. Special requirements are placed on the tank ventilation, since the working medium must be pressed from the working medium tank into the working chamber with the aid of compressed air in order to switch the retarder to braking mode. The filling level of the working space and thus the braking performance of the retarder depends on the air pressure, which is used to regulate the filling level. For switching to non-braking mode or when reducing the retarder braking torque, this means that compressed air must be released. In particular when the retarder is switched off, a relatively large amount of oil foam is formed, and the oil content of the oil foam must not be allowed to escape into the environment. In order to prevent this, different channel guides between the working medium tank and the environment are known. That's it CN 105 697 602 A a channel guide with a plurality of deposition chambers is known which have different structures.

The permitted oil ejection of modern retarders has been reduced in such a way that the known precautions for reducing the oil ejection when venting the working medium tank are no longer sufficient.

The object of the invention is to propose a working medium tank for a hydrodynamic retarder that ensures less oil ejection.

The object is achieved according to the invention by an embodiment corresponding to independent claim 1 . Further advantageous embodiments of the present invention can be found in the dependent claims.

The proposed hydrodynamic retarder comprises a housing with a tank housing part and a tank cover, between which an enclosed tank is formed, which can be filled with a working medium and includes a fluid area (3). Furthermore, a tank ventilation system is provided, which on the one hand has a connection to the fluid area and on the other hand a connection to the environment, the tank ventilation system comprising a labyrinth and a valve which closes the connection to the environment in its closed position and the connection to the environment in the open position releases.

In order to improve the retarder, it is proposed that the labyrinth of the tank ventilation system comprises several spaces and/or channels within the tank enclosed by the tank housing part and the tank cover, through which a mixture of air and working medium can be routed to separate the working medium portion, with drip channels being provided through which the Tank ventilation system are connected to the fluid area, so that working medium accumulations from the tank ventilation system can be routed back into the fluid area.

Drip ducts within the meaning of the invention are ducts at a working medium collection point that have a cross section that is large enough for the working medium, e.g. oil, to drip through them.

Furthermore, a separating element can be arranged between the tank housing part and the tank cover, through which individual spaces and/or channels of the labyrinth are arranged either between the tank housing part and the parting line or between the tank cap and the parting line.

In a preferred embodiment, the separating element can have sealing areas, by means of which the tank is sealed off from the environment. The seal can be designed as a bead seal, which has areas through which the tank can be divided into different areas, so that an improved structure of the labyrinth is made possible.

The tank venting system is preferably arranged in the tank above the fluid area, wherein a defoaming space can be provided between the fluid area and the labyrinth, which is delimited from the fluid area by a web with a comb passage 11a. A web within the meaning of the invention can also be a rib of the cast part, with the comb passage having a plurality of openings through which the working medium, e.g. oil, can pass and oil-air bubbles are largely burst.

Furthermore, a second web with a second comb passage can be provided between the defoaming chamber and the labyrinth. It is advantageous if the second comb passage has passages that are 50% to 80% smaller than the passages of the first comb passage. In this way, even smaller oil-air bubbles are largely burst.

An advantageous structure of the labyrinth comprises a lower and an upper chamber space, which are arranged in the tank housing part and are connected via a connecting channel, a first passage channel through the separating element, into the tank cap and from there via a second connecting channel with a spiral channel in the tank cap.

Furthermore, a second through-channel can lead from the center of the spiral channel through the parting plane back into the tank housing part and the second through-channel can be connected to an inlet of the valve via a second transfer channel arranged in the tank housing part and a valve connection channel.

Before the de-oiled air gets into the environment, an outlet chamber can be connected to a valve outlet of the valve, wherein the outlet chamber can be an area that is formed by the tank housing part and the tank cover, which has an outlet opening for connection to the environment, the Outlet chamber can be connected to the fluid area via the valve and the labyrinth.

The outlet chamber acts as a silencer or can have additional elements in the outlet openings that enable rapid venting without excessive noise.

• 1 Zeigt den Retarder im Schnitt längs der Rotorachse
• 2 Schnitt A-A - Tank im Schnitt durch Kammerebene
• 3 Schnitt B-B - Tank im Schnitt durch Kammebene
• 4 Schnitt C-C - Tank im Schnitt durch Steigkanaldeckel
• 5 Schnitt D-D - Dichtungsebene
• 6 Schnitt E-E - Draufsicht mit erstem Dichtungsdurchgang und Ausganskammer
• 7 Schnitt F-F - Tankdeckel im Schnitt durch Spirale
• 8 Schnitt G-G - Draufsicht mit zweitem Dichtungsdurchgang und Ausgangskammer
• 9 Schnitt H-H - Draufsicht Auslasskanal

The invention is explained below with reference to figures. The figures show in detail:

• 1 Shows the retarder in section along the rotor axis
• 2 Section AA - Tank section through chamber plane
• 3 Section BB - Tank section through ridge plane
• 4 Section CC - Tank section through riser channel cover
• 5 Section DD - sealing plane
• 6 Section EE - Top view showing first seal passage and exit chamber
• 7 Section FF - Gas cap section through spiral
• 8th Section GG - top view with second sealing passage and exit chamber
• 9 Section HH - Top view of exhaust port

All figures show sectional views through a retarder. In order to simplify the representation, the cut component areas were not hatched. The sequence of the individual sectional views allows the flow of the air to be shown when the retarder is switched from braking mode to non-braking mode.

The position of the cuts in the longitudinal direction of the retarder 1 are all off 1 to see where 1 shows the retarder 1 in section along the rotor axis 2. The section planes AA to DD and FF can be seen from this view. The cutting planes for the top views, section EE and GG, are only in 5 and the location of the HH section is only in 4 drawn.

1 represents a section of the retarder 1, from which the three components of the retarder that are essential for the invention can be seen. The components include the tank housing part 6, the seal 7 and the tank cover 8, which enclose a fluid area. To delimit the chambers and channels, webs are provided in the cast parts, tank housing part 6 and tank cover 8, and in the seal 7 passages. Among the key areas in the 1 can be seen, belongs to the fluid area 3 and the defoaming chamber 9 arranged in the tank housing part 6. For the sake of simplicity, the fluid area 3 is only partially shown, the much larger volume range is in 1 not shown and is located in the lower part of the retarder. The entire fluid area 3 and the tank ventilation system 5 required for ventilation are enclosed and separated from one another by the tank housing part 6, the tank cover 8 and the seal 7 arranged between them. Furthermore, the riser channel 10 in the tank cap 8 can be seen, the general function of which is known from the StdT and is not explained further here.

In the non-braking mode, the working medium is stored in the fluid area 3 . The tank 23 enclosed by the parts 6, 7 and 8 can be pressurized with compressed air via a regulated compressed air connection, so that the oil or the working medium is conveyed into the working chamber 4 of the retarder, as a result of which the retarder 1 is switched to braking mode.

For the invention, the further description only considers what happens when the retarder 1 is switched back to non-braking operation and the oil is pumped out of the working chamber 4 back into the fluid area 3 by the pumping action of the retarder 1 . During this work step, the compressed air must be able to escape from the tank into the environment. So that no oil gets into the environment, a tank ventilation system 5 is provided, which is arranged essentially above the fluid area 3 . The tank ventilation system 5 consists of several chambers and/or channels. through which the compressed air is conducted into the environment, each chamber and/or channel section being designed in such a way as to reduce the oil content of the compressed air or exhaust air.

It is essential to the invention that each chamber and/or each channel section of the tank ventilation system 5 has a connecting channel to the fluid area 3 via which separated oil can flow back into the fluid area 3 due to the force of gravity.

The individual chambers and / or channel sections are in the 2 until 9 shown in detail and described below.

2 sketches the section AA through the tank housing part 6, the plane of the section being referred to as the chamber plane, since the section clarifies the separation of the individual spatial regions 3, 9 and the labyrinth 10. In this intersection area, the fluid area 3 is separated by the web 25a from the defoaming chamber 9 arranged above it, which in turn is separated by the web 25b from the labyrinth 10 located above it.

3 sketches the section BB through the tank housing part 6, the plane of the section being referred to as the ridge plane, since the passages between the areas are represented by the section. The webs 25a, b have a comb structure in this plane, oil foam bubbles rising through these comb passages being caused to burst. The comb passages (webs 11a, b) have different cross sections.

The labyrinth 10 is divided into several sections, which are explained in more detail below. The seal 7 plays an important role for the labyrinth structure, since individual sections of the labyrinth are delimited by the seal 7 and the seal 7 enables a change between the sections. The labyrinth 10 thus includes areas that are only in the tank housing part 6 or only in the tank cover 7, and also through channels 17, 18, which connect sections in the tank housing part 6 with sections in the tank cover 8 through the seal 7.

During venting, the air-oil mixture passes through the comb (land 11b) into the first part of the labyrinth 10, the lower chamber space 12, which is delimited by the tank housing part 6 and the seal 7.

The air-oil mixture then passes through the connecting channel 13 into the upper chamber space 12b, which leads to the first through-channel 14.

4 and 5 sketch Section CC through the tank housing part 6 and section DD shows the view of the separating element 7. The separating element 7 is at the same time the seal between the tank housing part 6 and the tank cover 8 and was cut in section DD in such a way that the course of the seal between the separating element 7 and the tank cover 8 can be seen is.

The riser channel cover 27 is cut in the level of the riser channel ventilation 28 by the section CC. The riser channel cover 27 separates the riser channel 26 positioned in the tank cover 8 from the tank 23. The riser channel ventilation 28 is connected to the riser channel 26 only via openings in the seal 7, of which the upper one is in 5 can be seen, connected. The function of the riser channel 26 and its ventilation is sufficiently known from the StdT and is not described further here.

Furthermore are off 4 , section CC, the position of some drip channels 29a, b, c, .

the 6 , 8th and 9 outlines three top views of the tank 23 with the tank housing part 6, the seal 7 and the tank cap 8. From the top views, the sealing passages can be seen through which sections of the labyrinth 10 in the tank housing part 6 are connected to sections of the labyrinth 10 in the tank cap 8.

sketched in the process 6 the section DD, so that the first through channel 14 and the outlet chamber 21 can be seen. 8th , section GG, outlines the second through-channel 17 as an essential new detail.

7 sketches the section EE through the tank cap 8, the plane of the section being placed in such a way that the first transfer channel 15 and the spiral channel 16 are shown. Seen in the direction of flow, the air-oil mixture, which now has a lower oil content, flows through the second passage duct 17 into the first transfer duct 15 and from there into the spiral duct 16. The ducts are formed between the tank cap 8 and the seal 7, so that there is a separation from the fluid area 3 is present, there being a connection to the fluid area 3 via the drip channels 29a, b, c, d, so that separated oil can get back into the fluid area 3.

From the center of the spiral channel 16, see 8th , Leads a second through channel 17 through the seal 7 in a second transfer channel 18, the location of which is also from the 2 - 4 , The sections through the tank housing part 6 can be seen.

From the second transfer channel 17, the air mixture is passed on into the valve connection channel 19, the position of which can be seen from the top view 9 , section HH. In the closed position of the valve 20 there is no connection to the environment, so that compressed air can be introduced into the fluid area 3 so that the oil is conveyed from it into the working chamber of the retarder and the braking operation of the retarder is thus activated.

In the ventilation position of the valve 20, the compressed air can escape from the tank via the tank ventilation system 5 and via the valve outlet channel 19 into the outlet chamber 21 and from there via silencers or filter elements 22 through the outlet openings 24 as de-oiled air into the environment. The filter element 22 can comprise a fleece, which filters the last oil aerosols from the air/working medium mixture.

Further details can be seen in all sketches, which are not discussed in connection with this invention and which are therefore also not explained in more detail. Areas above the fluid area 3, which are shown in the tank housing part 6 or in the tank cover 8 around the ventilation system 5, belong to the fluid area 3 and are connected to it via drain openings, even if the drain openings are not shown.

reference list

1

retarders

2

rotor axis

3

fluid area

4

working space

5

tank ventilation system

6

tank housing part

7

poetry

8th

gas cap

9

defoaming room

10

labyrinth

11a, b

Bridge with ridge passage

12a,b

lower/upper chamber space

13

connecting channel

14

first through channel

15

first transfer channel

16

spiral canal

17

second through channel

18

second transfer channel

19

valve connection channel

20

Valve

21

outlet chamber

22

filter element

23

tank

24

exit openings

25a, b

web

26

riser channel

27

riser channel cover

28

riser vent

29a,b,c..

drip channel

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102013207004 A1 [0005]
• CN105697602A [0005]

Claims (10)

Hydrodynamic retarder (1), with a housing comprising a tank housing part (6) and a tank cover (8), between which an enclosed tank (23) is formed, which can be filled with a working medium and includes a fluid area (3) with a Tank ventilation system (5), which has a connection to the fluid area (3) on the one hand and a connection to the environment on the other hand, the tank ventilation system (5) comprising a labyrinth (10) and a valve (20) which, in its closed position, forms the connection to the closes the environment and in the open position releases the connection to the environment, characterized in that the labyrinth (10) of the tank ventilation system (5) has several spaces (9, 12a, b) and/or channels (11a, b, 13, 14, 15, 16, 17, 18, 19) within the tank (23) enclosed by the tank housing part (6) and the tank cover (8), through which a mixture of air and working medium can be conducted in order to separate the working medium portion, drip channels (29a, b, ....) featured are seen, through which the tank ventilation system (5) with the fluid area (3) in connection, so that working medium accumulations from the tank ventilation system (5) back into the fluid area (3) can be routed. Hydrodynamic retarder (1) after claim 1 , characterized in that a separating element (7) is arranged between the tank housing part (6) and the tank cover (8), through which the individual spaces (9, 12a, b) and/or channels (11 a, b, 13, 15 , 16, 18, 19) of the labyrinth (10) are separated either between the tank housing part (6) and the parting plane (7) or between the tank cover (8) and the parting plane (7). Hydrodynamic retarder (1) after claim 2 , characterized in that the separating element (7) has sealing areas, by means of which the tank is sealed off from the environment. Hydrodynamic retarder (1) after claim 1 , characterized in that the tank ventilation system (5) is arranged in the tank (23) above the fluid area (3), with a defoaming space (9) being provided between the fluid area (3) and the labyrinth (10) which extends towards the fluid area (3). is delimited by a ridge having a comb passage 11a. Hydrodynamic retarder (1) after claim 4 , characterized in that between the defoaming chamber (9) and labyrinth (10) a second web with a second comb passage (11b) is provided. Hydrodynamic retarder (1) after claim 4 and 5 , characterized in that the second comb pass (11b) has passes which are 50% to 80% smaller than the passes of the first comb pass (11a). Hydrodynamic retarder (1) after claim 1 , characterized in that a lower and upper chamber space (12a, b) of the labyrinth (10) are arranged in the tank housing part (6) and via a connecting channel (13), a first through-channel (14) through the separating element (7), into the Tank cap (8) and from there via a second connecting channel (14) with a spiral channel (16) in the tank cap (8). Hydrodynamic retarder (1) after claim 7 , characterized in that from the center of the spiral channel (16) a second through channel (17) through the parting plane (7) back into the tank housing part (6). Hydrodynamic retarder (1) after claim 7 , characterized in that the second through channel (17) via a tank housing part (6) arranged second transfer channel (18) and a valve connection channel (19) is connected to an input of the valve (20). Hydrodynamic retarder (1) after claim 1 , characterized in that an outlet chamber (22) is connected to a valve outlet of the valve (20), the outlet chamber (21) being an area formed by the tank housing part (6) and the tank cover (8), which has an outlet opening (24) for connection to the environment, wherein the outlet chamber (21) can be connected to the fluid region (3) via the valve (20) and the labyrinth (10).

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