Hydrodynamic retarder comprising a working medium tank

Abstract

The invention relates to a retarder comprising a retarder chamber in which a rotatably mounted rotor and a stator are arranged which together form a working chamber that can be filled with and emptied of working medium. The retarder also comprises: a working medium tank which has a region for holding working medium that is not currently in the working chamber, and an expansion region; at least one filling channel for supplying working medium to the working chamber; and a return channel for discharging working medium from the working chamber, as well as a rotor housing, a stator housing, and a tank housing. According to the invention: the working medium tank comprises a storage region and a sump region; and a coupling plane is located on the tank housing below the sump region, through which cooling plane at least one second channel runs which is suitable for direct or indirect coupling with the outlet of the primary side of a heat exchanger.

Description

[0001] Hydrodynamic retarder with working medium tank

[0002] The invention relates to the structure of a hydrodynamic retarder for a motor vehicle, in particular the structure of the working medium tank of the retarder.

[0003] Hydrodynamic retarders have a working chamber that can be filled with a working fluid and emptied by it. The working fluid transfers torque from a bladed rotor to a bladed stator. When the working chamber is filled, the rotor and thus a shaft that is particularly fixed in rotation with the rotor, such as a propeller shaft or transmission output shaft indirectly connected to the wheels of a vehicle, are decelerated.

[0004] DE 10 2013 006 611A1 discloses a retarder and its working fluid circuit. The rotor and stator of the retarder form a toroidal working chamber, which is connected to a working fluid circuit with a working fluid tank via a duct system. The working chamber is vented via a venting system, through which air can escape into the environment through a connection between the working chamber and the environment. The working fluid tank can be connected to a compressed air connection or the environment via a valve, the MRCU.

[0005] To switch the retarder to braking mode, the working medium tank must be pressurized with compressed air via the MRCU, so that the working medium is pumped from the working medium tank into the working chamber via the filling channel. The filling channel is positioned in the working medium tank such that its inlet opening ends in the lower area of ​​the working medium tank, ensuring that the inlet opening of the filling channel is always below the working medium level, preventing air from entering the filling channel.

[0006] When the retarder is switched to non-braking mode, the working fluid tank must be vented and the working chamber ventilated. The working fluid is pumped from the retarder via the heat exchanger back into the working fluid tank.

[0007] The object of the invention is to propose a retarder with reduced manufacturing and assembly costs.

[0008] The object is achieved according to the invention by an embodiment according to the independent claim. Further advantageous embodiments of the present invention can be found in the subclaims.

[0009] A retarder is proposed, comprising a retarder chamber in which a rotatably mounted rotor and a stator are arranged, which together form a working chamber that can be filled with and emptied from the working chamber. The retarder further comprises a working-medium tank, which has a region for receiving working medium not currently present in the working chamber and an expansion region, at least one filling channel for supplying working medium into the working chamber and a return channel for discharging working medium from the working chamber, as well as a rotor housing, a stator housing, and a tank housing.

[0010] According to the invention, it is proposed that the working medium tank comprises a storage area and a sump area and that a coupling plane is arranged on the tank housing below the sump area, through which at least one second channel leads, which is suitable for direct or indirect coupling to the outlet of the primary side of a heat exchanger.

[0011] Furthermore, a first channel can be arranged in the tank housing, via which a direct or indirect connection to the inlet of the primary side of the heat exchanger can be established. In a preferred embodiment, the first channel can be arranged above the second channel. This arrangement enables a decoupling of the sealing planes. The sealing plane between the tank housing and the intermediate part can thus be made axially and radially, which simplifies production. Preferably, the filler pipe projects into the sump area, with the inlet opening into the filler pipe being covered by at least 20 mm to 50 mm of working medium in every operating state. The inlet opening of the filler pipe is thus sufficiently immersed in the working medium in all operating states so that no air can be sucked in via the filler pipe. It is also advantageous if the inlet opening of the filler pipe is arranged centrally above the second channel.

[0012] Furthermore, in one embodiment, an intermediate component can be provided between the tank housing and the heat exchanger, wherein channels are integrated in the intermediate component, via which the first channel is connected to the inlet and the second channel is connected to the outlet of the primary side of the heat exchanger.

[0013] Additional channels can also be integrated into the intermediate component, through which the secondary side of the heat exchanger can be connected to a cooling circuit. The intermediate component can be designed as a cast part with cast-in channels.

[0014] In a further embodiment, a drain can be provided in the intermediate component through which the working medium can be drained from the working medium tank and the primary circuit of the heat exchanger. Preferably, a second drain is provided on the intermediate component through which the cooling medium can be drained from the secondary circuit of the heat exchanger.

[0015] The invention is explained below with reference to the figures. The figures show in detail:

[0016] Fig.1 Sketch of a retarder in section

[0017] Fig.2 Oil tank with sump and intermediate component

[0018] Figure 1 shows a sketch illustrating the basic structure of the retarder 1. The outer shell of the retarder 1 essentially consists of two parts: the rotor housing 2 and the stator housing 3, each of which forms a half-shell of the housing. The housing parts 2 and 3 enclose a cavity, which is divided into three sections. A cavity section 27, a storage section 26, and a retarder section 29 are provided.

[0019] The cavity area 27, the storage area 26 and the sump area 25 together form the working medium tank 15, wherein the working medium 9 collects in the storage area 26 and sump area 25 when the retarder is switched to non-braking mode.

[0020] The cavity area 27 is a space essentially designed to ensure that no working fluid can enter the compressed air control unit, also known as the MRCU, via port 17. A working fluid separator or oil separator 28 is provided between port 17 and the working fluid tank 15. Separating oil can flow back into the working fluid tank 15 via the drain 30.

[0021] During braking, the compressed air control regulates the braking torque of the retarder 1 . The higher the air pressure in the cavity area 27, the more working medium 9 is pressed from the working medium tank 15 into the retarder circuit.

[0022] The area between the rotor housing 2 and the stator housing 3 is referred to as the retarder area 29. The rotor 6, the stator 7, the bearing-mounted rotor shaft 8, and channels for conveying the working fluid are located in the retarder area 29. The rotor 6 can be arranged axially displaceably on the rotor shaft 8, as is known from the prior art.

[0023] A coupling plane 18 is provided on the tank housing 4, to which a heat exchanger 11 can be attached directly or indirectly, wherein a first channel 19 and a second channel 20 are provided in the coupling plane 18. The working chamber 14, between the rotor 6 and stator 7, is connected to the flow connection of the heat exchanger 11 via the first channel 19, and the outlet of the heat exchanger 11 is connected to the working medium tank 15 via the second channel 20. The cooled working medium 9 enters the working medium tank 15 via the second channel 20 when switching to non-braking mode, i.e. when the pressure in the expansion region 27 drops. Furthermore, a filling channel 12 is provided, which establishes a connection from the lower sump region 25 to the inlet chamber 23, which in turn is connected to the working chamber 14 via channels in the stator 7, not shown.

[0024] When the retarder is switched to braking mode, the air pressure in the expansion area 27 is increased via connection 17, causing the working fluid 9 to flow into the working chamber 14 via the filling channel 12, the inlet chamber 23, and the channels in the stator 7. The known pumping action of the retarder 1 causes the working fluid 9 to be pumped back from the working chamber via the return channel 13, the first channel 19, the heat exchanger 11, and the second channel 20 into the working fluid tank 15.

[0025] The filling channel 12 is arranged relative to the second channel 20 such that working medium 9 flowing out of the second channel 20 can flow into the filling channel 12 via the inlet opening 21. During braking, this creates a circular flow, with the working medium 9 flowing through the working medium tank 15 over a short section. The distance between the outlet from the second channel 20 and the inlet opening 21 can be selected between 1 mm and 15 mm, with the mixing of working medium 9 from the tank and working medium 9 from the circuit depending on the distance. Furthermore, the minimum working medium level in the working medium tank 15 must be above the inlet opening 21 to ensure that no air enters the filling channel 12.

[0026] The pressure of the control air in expansion zone 27 regulates the working fluid volume in the circuit, which in turn determines the retarder's braking torque. This braking torque control is standard and will therefore not be described in detail.

[0027] Figure 2 shows an alternative design of the lower part of the oil tank with sump and intermediate component 33. This design differs essentially from the illustration in Figure 1 in that the first channel 19 is arranged higher than the second channel 20. When switching to braking mode, the working medium 9 enters the retarder circuit via the filler pipe 12 and in braking mode a working medium flow emerges from the second channel 20 after passing through the heat exchanger 11, flows briefly through the working medium tank 15 and enters the filler pipe 12 via the inlet opening 21.

[0028] The position of the first channel 19 can be chosen arbitrarily, since the return channel 13 is connected here, which establishes a direct connection to the working chamber 14. The return channel 13 can be a channel cast into one or more of the following parts: the rotor housing 2, the stator housing 3, and / or the tank housing 4. Alternatively, the return channel can also be designed as a pipe. The arrangement on a different level enables, among other things, different sealing concepts so that tolerances can be better compensated. Here, one axially in the connection level 18 and one radially by inserting nozzles into the second channel 20 on the intermediate component 33.

[0029] The cross-sectional view of the intermediate component 33 also shows an example of the layout of the channels 34a, 34b for the working medium 9 and the channels 35a, 35b for the cooling water. An outlet 30a, 30b is provided for each of the working medium circuit and the cooling water circuit. In particular, the working medium can drain completely from the retarder's working medium circuit via the working medium outlet 30a.

[0030] List of reference symbols

[0031] 1 retarder

[0032] 2 rotor housings

[0033] 3 starter housings

[0034] 4 tank housings

[0035] 5a, b camp

[0036] 6 Rotor

[0037] 7 Stator

[0038] 8 Rotor shaft

[0039] 9 Working medium

[0040] 10 Seal

[0041] 11 heat exchangers

[0042] 12 filling channel

[0043] 13 Return channel

[0044] 14 Workspace

[0045] 15 Working medium tank

[0046] 16 coupling level

[0047] 17 Connection

[0048] 18 connection level

[0049] 19 first channel

[0050] 20 second channel

[0051] 21 Entrance opening

[0052] 22 Exit opening

[0053] 23 Inlet chamber

[0054] 24a, b coupling level

[0055] 25 Swamp area

[0056] 26 Storage area

[0057] 27 Expansion area

[0058] 29 Retarder room

[0059] 30a, b Expiry

[0060] 33 Intermediate component

[0061] 34a, b canal

[0062] 35a, b canal

[0063] Distance

Claims

Patent claims 1. Hydrodynamic retarder (1), comprising a retarder chamber (29) in which a rotatably mounted rotor (6) and a stator (7) are arranged, which together form a working chamber (14) that can be filled with and emptied from the working chamber; a working medium tank (15) that has an area (25, 26) for receiving working medium not currently in the working chamber (14) and an expansion area (27); at least one filling channel (12) for supplying working medium into the working chamber (14); and a return channel (13) for discharging working medium from the working chamber (14);and a rotor housing (2), a stator housing (3) and a tank housing (4), characterized in that the working medium tank (15) comprises a storage area (24) and a sump area (25) and that a coupling plane (18, 18,a) is arranged on the tank housing (4) below the sump area (25), through which at least one second channel (20) leads, which is suitable for direct or indirect coupling to the outlet of the primary side of a heat exchanger (11); 2. Hydrodynamic retarder (1) according to claim 1, characterized in that a first channel (19) is arranged in the tank housing (4), via which a direct or indirect coupling with the inlet of the primary side of the heat exchanger (11) can be established.

3. Hydrodynamic retarder (1) according to claim 2, characterized in that the first channel (19) is arranged above the second channel (20).

4. Hydrodynamic retarder (1) according to claim 1, characterized in that the filling pipe (12) projects into the sump area (25), wherein the inlet opening (21) into the filling pipe (12) is covered by at least 20 mm to 50 mm of working medium (9) in every operating state.

5. Hydrodynamic retarder (1) according to claim 4, characterized in that the inlet opening (21) of the filling pipe (12) is arranged centrally above the second channel (20).

6. Hydrodynamic retarder (1) according to claim 2, characterized in that an intermediate component (33) is provided between the tank housing (4) and the heat exchanger (11), wherein channels (34a, 34b) are integrated in the intermediate part (33), via which channels the first channel (19) is connected to the inlet and the second channel (20) is connected to the outlet of the primary side of the heat exchanger (11).

7. Hydrodynamic retarder (1) according to claim 6, characterized in that further channels (35a, 35b) are integrated in the intermediate component (33), via which channels the secondary side of the heat exchanger (11) can be connected to a cooling circuit.

8. Hydrodynamic retarder (1) according to claim 6, characterized in that the intermediate component (33) is a cast part with cast-in channels.

9. Hydrodynamic retarder (1) according to claim 6, characterized in that an outlet (30a) is provided on the intermediate component (33), via which the working medium (9) can be drained from the working medium tank (15) and the primary circuit of the heat exchanger (11).

10. Hydrodynamic retarder (1) according to claim 6, characterized in that an outlet (30b) is provided on the intermediate component (33), via which Cooling medium can be drained from the secondary circuit of the heat exchanger (11).

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