Hydrodynamic retarder with filling pipe

Abstract

The invention relates to a retarder, comprising a retarder chamber, in which a rotor and a stator which are rotatably mounted are arranged and which together form a working chamber which can be filled with a working medium and which can be emptied of the working medium. The retarder further comprises a working medium tank having a region for accommodating a working medium not currently in the working chamber and an expansion region. The invention further comprises at least one filling channel for feeding the working medium into the working chamber and a return channel for discharging the working medium from the working chamber, as well as a rotor housing, a stator housing and a tank housing. According to the invention, the filling channel is a tube having an inlet opening and an outlet opening, the inlet opening terminating in the working medium tank and the outlet opening terminating in an inlet chamber, the inlet chamber being formed by a stator housing and a stator.

Description

[0001] The present invention relates to a structure of a hydraulic retarder for a motor vehicle, in particular to a structure of a retarder filling channel.

[0002] A hydraulic retarder has a working chamber that can be filled with and emptied of a working medium. The working medium is used to transmit torque from a bladed rotor to a bladed stator. When the working chamber is filled, the rotor, and therefore, in particular, a shaft designed to be non-rotatably connected to the rotor, such as a cardan shaft or a transmission output shaft indirectly connected to the vehicle's wheels, is decelerated.

[0003] DE 10 2013 006 611 A1 discloses a retarder and its working medium circuit. The retarder's rotor and stator form an annular working chamber, which is connected to a working medium circuit having a working medium tank via a channel system. The working chamber is vented via an exhaust system, through which air can escape into the environment through a connection between the working chamber and the environment. The working medium tank can be connected to a compressed air connection or the environment via a valve, namely an MRCU.

[0004] To switch the retarder into braking operation, compressed air must be applied to the working medium tank via the MRCU, causing the working medium to be transported from the working medium tank through the filling channel into the working chamber. The filling channel is arranged in the working medium tank so that its inlet opening ends in the lower area of ​​the working medium tank. This ensures that the inlet opening of the filling channel is always below the working medium liquid level in all operating conditions, and air cannot enter the filling channel.

[0005] When the retarder is switched to non-braking operation, the working medium tank must be ventilated and the working chamber must be ventilated. The working medium is pumped back from the retarder to the working medium tank via a heat exchanger.

[0006] The object of the present invention is to propose a retarder with reduced manufacturing and assembly complexity.

[0007] The technical problem is solved by the embodiment according to the independent claim. Further advantageous embodiments of the invention are described in the dependent claims.

[0008] A retarder is proposed, comprising a retarder chamber, wherein a rotatably supported rotor and stator are disposed in the retarder chamber, the rotor and stator together forming a working chamber that can be filled with and emptied of a working medium. The retarder also comprises a working medium tank having an area for accommodating working medium not currently in the working chamber and an expansion area, 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.

[0009] According to the invention, it is proposed that the filling channel is a tube having an inlet opening and an outlet opening, wherein the inlet opening ends in the working medium tank and the outlet opening ends in an inlet chamber, wherein the inlet chamber is formed by the stator housing and the stator.

[0010] Preferably, the filling channel is led primarily through the working medium tank, which significantly simplifies production.

[0011] Furthermore, the working medium tank can comprise a trough region, wherein the inlet opening ends in said trough region. Within the scope of the present invention, a trough region is a region which can accommodate a small working medium volume relative to the volume of the working medium tank.

[0012] A coupling plane can be provided on the tank housing, through which the first and second channels are guided, wherein the coupling plane is arranged below the trough region and via these channels a flow-conducting connection to the primary side of the heat exchanger can be established. The connection to the heat exchanger can be realized directly or indirectly via a transition piece.

[0013] In a preferred embodiment, the outlet opening of the second channel is arranged so that it ends in the trough area. This allows the working medium pumped and cooled through the heat exchanger to first enter the working medium tank. Furthermore, it is provided that the working medium tank forms a fluid-conducting connection between the second channel and the filling channel. The gap formed between the outlet of the second channel and the inlet opening of the filling channel essentially performs three functions:

[0014] 1) When switching to braking mode:

[0015] Fill the working chamber through the filling tube;

[0016] 2) During braking operation:

[0017] The gap constitutes the channel section of the working medium circuit;

[0018] 3) When switching to non-braking operation:

[0019] Guide the working medium back into the working medium tank.

[0020] Especially during braking operation, it is advantageous if the inlet opening of the filling channel and the outlet opening of the second channel are aligned with each other. Furthermore, the distance (x) between the inlet and outlet openings is crucial for the function. A distance (x) of 1 mm to 15 mm is advantageous.

[0021] In particular, it can be provided that the inlet opening is designed in a funnel-shaped manner in order to further improve the flow process through the working medium tank during braking operation.

[0022] The present invention will be described in detail below with reference to the accompanying drawings:

[0023] Figure 1 A sketch of the retarder is shown in section,

[0024] Figure 2 The filling pipe in the operating medium tank is shown.

[0025] Figure 1 A sketch is shown, which illustrates the basic structure of the retarder 1. The housing of the retarder 1 consists essentially of two parts: a rotor housing 2 and a stator housing 3, which form half shells. The housing parts 2 and 3 enclose a cavity, which is divided into three areas: a cavity area 27, storage areas 26 and 25, and a retarder area 29.

[0026] The cavity area 27 , the storage area 26 and the tank area 25 together form the working medium tank 15 , wherein the working medium 9 collects in the storage area 26 and the tank area 25 when the retarder is switched into non-braking operation.

[0027] The cavity area 27 is essentially designed to ensure that no working medium can enter the space of the compressed air conditioning unit (also called MRCU) through the connection port 17. A working medium separator or oil separator 28 is arranged between the connection port 17 and the working medium tank 15. The separated oil can be returned to the working medium tank 15 through the drain port 30.

[0028] During braking operation, the compressed air control device adjusts the braking torque of the retarder 1. The higher the air pressure in the cavity region 27, the more working medium 9 is pressed from the working medium tank 15 into the retarder circuit.

[0029] 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 supported rotor shaft 8, and the channels for conducting the working medium are arranged in the retarder area 28. The rotor 6 can be arranged axially displaceably on the rotor shaft 8, as is known in the prior art.

[0030] A coupling plane 18 is provided on the tank housing 4, to which the 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 the stator 7 is connected to the upstream connection port 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. When switching to non-braking operation, i.e., when the pressure in the expansion region 27 drops, the cooled working medium 9 flows into the working medium tank 15 via the second channel 20.

[0031] Furthermore, a filling channel 12 is provided, which establishes a connection from the lower slot region 25 into the inlet chamber 23 , which in turn is connected to the working chamber 14 via a channel (not shown) in the stator 7 .

[0032] When the retarder is switched into braking operation, the air pressure in the expansion region 27 is increased via the connection 17, so that the working medium 9 enters the working chamber 14 via the filling channel 12, the inlet chamber 23, and the channel in the stator 7. The known pumping action of the retarder 1 causes the working medium 9 to be pumped back from the working chamber into the working medium tank 15 via the return channel 13, the first channel 19, the heat exchanger 11, and the second channel 20.

[0033] The filling channel 12 is arranged relative to the second channel 20 such that the working medium 9 flowing out of the second channel 20 can flow into the filling channel 12 through the inlet opening 21. During braking operation, this creates a circulating flow, in which the working medium 9 flows through the working medium tank 15 via a short section. The distance between the outlet of the second channel 20 and the inlet opening 21 can be selected to be between 1 mm and 15 mm, with mixing of the working medium 9 from the working medium tank and the working medium 9 from the circuit depending on this distance. Furthermore, a minimum working medium level in the working medium tank 15 must be above the inlet opening 21 to ensure that air cannot enter the filling channel 12.

[0034] The volume of the working medium in the circuit is regulated by the pressure of the regulating air in the expansion region 27, which in turn determines the braking torque of the retarder. This regulation of the braking torque is prior art and will not be explained in detail.

[0035] Figure 2 The arrangement of the filling pipe in the working medium tank 15 is shown. This view shows one possible design of the working medium tank 15 with a trough area 25. The trough area 25 is a small area located in the lower tank area that ensures that a certain volume of working medium always remains in the trough area 25, especially during braking operation of the retarder. Since the end of the filling pipe 12 with the inlet opening 21 ends in the trough area, it is ensured that no air can pass through the filling pipe 12 into the working chamber 14 or the working medium circuit.

[0036] The heat exchanger 11 is shown here only schematically, with an intermediate component 32 being provided, which connects the heat exchanger to the tank housing 4 via the connecting plane 18. In this embodiment, the second channel 20 is integrated into this intermediate component 33. Furthermore, channels are integrated into the intermediate component 33, via which the heat exchanger 11 is connected to the working medium circuit.

[0037] The inlet opening 21 of the filling channel 12 and the outlet opening 22 of the second channel 20 are aligned with each other and arranged opposite each other at a distance x, as described previously. In order to achieve a flow of the working medium 9 through the working medium tank 15 which is as laminar as possible, the inlet opening 21 is also designed funnel-shaped, in order to achieve a flow of the working medium through the working medium tank 15 which is as laminar as possible in the braking operation.

[0038] List of reference signs

[0039] 1 retarder

[0040] 2 rotor housing

[0041] 3 stator housing

[0042] 4 tank housing

[0043] 5a, b bearing

[0044] 6 rotor

[0045] 7 stator

[0046] 8 rotor shaft

[0047] 9 working medium

[0048] 10 seal

[0049] 11 heat exchanger

[0050] 12 filling channel

[0051] 13 return channel

[0052] 14 working chamber

[0053] 15 working medium tank

[0054] 16 coupling plane

[0055] 17 connection interface

[0056] 18 connection plane

[0057] 19 first channel

[0058] 20 second channel

[0059] 21 inlet opening

[0060] 22 outlet opening

[0061] 23 entry chamber

[0062] 24a, b coupling plane

[0063] 25 slot region

[0064] 26 storage region

[0065] 27 expansion region

[0066] 28 oil separator

[0067] 29 retarder chamber

[0068] 30 discharge opening

[0069] 31 structural element

[0070] 32 air channel

[0071] 33 intermediate member

[0072] X distance

Claims

1. A hydraulic retarder (1), comprising a retarder chamber (29) in which a rotatably mounted rotor (6) and a stator (7) are arranged, said rotor and stator together forming a working chamber (14) which can be filled with and emptied of a working medium, a working medium tank (15) having areas (25, 26) for accommodating working medium not currently in the working chamber (14) and an expansion area (27), at least one filling channel (12) for feeding a working medium into the working chamber (14), and a return channel (13) for discharging the working medium from the working chamber (14), and rotor housing (2), stator housing (3) and box housing (4), It is characterized in that The filling channel (12) is a tube with an inlet opening (21) and an outlet opening (22), wherein the inlet opening ends in the working medium tank (15) and the outlet opening (22) ends in an inlet chamber (23), wherein the inlet chamber (23) is formed by the stator housing (3) and the stator (7).

2. The hydraulic retarder (1) according to claim 1, characterized in that The filling channel (12) is essentially guided through the working medium tank (15).

3. The hydraulic retarder (1) according to claim 1, characterized in that: The working medium tank (15) comprises a trough region (25), wherein the inlet opening (21) ends in the trough region (25).

4. The hydraulic retarder (1) according to claim 1, characterized in that A coupling plane (18) is provided on the tank housing (4), through which a first channel (19) and a second channel (20) are guided, wherein the coupling plane is arranged below the groove region (25) and a flow-conducting connection to the primary side of the heat exchanger (11) can be established via the channels (19, 20).

5. The hydraulic retarder (1) according to claim 3, characterized in that: The second channel (20) has an outlet opening (22) which ends in a trough region (25).

6. The hydraulic retarder (1) according to claim 3, characterized in that: The working medium tank (15) provides, at least in sections, a fluid-conducting connection between the second channel (20) and the filling channel (12).

7. The hydraulic retarder (1) according to claim 4 or 5, characterized in that: The inlet opening (21) of the filling channel (12) and the outlet opening (22) of the second channel (20) are aligned with each other.

8. The hydraulic retarder (1) according to claim 6, characterized in that The distance (x) between the inlet opening (21) and the outlet opening (22) is 1 mm to 15 mm.

9. The hydraulic retarder (1) according to claim 4, characterized in that: The inlet opening (21) is designed in a funnel shape.

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