Coupling device comprising a coupling assembly with a coupling and a piston unit and a valve unit

Abstract

The invention relates to a coupling device comprising a coupling assembly with a coupling and a piston unit and a valve unit, wherein the valve unit is fluidically connected to the coupling assembly, in particular arranged on the coupling assembly, wherein the valve unit is configured to provide a pressure medium to the piston unit of the coupling assembly, wherein the piston unit comprises a pressure chamber, a sealing chamber and a piston arranged between the pressure chamber and the sealing chamber, wherein the valve unit has a first air inlet and a first air outlet, wherein the first air inlet enables air to be drawn from an environment into the pressure chamber and wherein the first air outlet enables air to be drawn from the pressure chamber into the environment.

Description

[0001] The invention relates to a coupling device comprising a coupling device with a clutch and a piston unit and a valve unit.

[0002] The invention further relates to a method for operating a coupling device.

[0003] Pneumatic clutches are particularly common in heavy commercial vehicles. They involve a piston with a clutch disc being moved by compressed air. The piston separates a pressure chamber, in which pressure can be generated to move the piston, from a sealing chamber that is sealed off from the pressure chamber.

[0004] Due to environmental influences and clutch wear, dirt can become trapped in the clutch, which can impair its function. Furthermore, as the piston moves toward the pressure chamber, a vacuum is created in the seal chamber. This vacuum can allow dirty air from the clutch environment to enter the seal chamber.

[0005] DE 10 2016 117 091 A1 discloses an arrangement for preventing the ingress of contaminated air into the seal chamber. The exhaust air from the pressure chamber is directed into the seal chamber, creating an overpressure in the seal chamber that prevents the ingress of contaminated air from the coupling environment.

[0006] The disadvantage of this arrangement is the high pressure that develops in the seal chamber. This pressure must be vented into the coupling environment, so a permeable connection with an air filter must be installed between the seal chamber and the coupling environment.

[0007] An object of the present invention is therefore to provide a coupling device and a method for operating a coupling device which can vent the pressure chamber and at the same time enables protection against contamination.

[0008] A further object of the present invention is to provide an alternative coupling device and an alternative method for operating a coupling device.

[0009] In one embodiment, the present invention achieves the above-mentioned objects in a coupling device comprising a valve unit and a coupling device with a coupling and a piston unit, wherein the valve unit is fluidically connected to the coupling device, in particular is arranged on the coupling device, wherein the valve unit is designed to provide a pressure medium to the piston unit of the coupling device, wherein the piston unit comprises a pressure chamber, a sealing chamber and a piston movably arranged between the pressure chamber and the sealing chamber, in that the valve unit has a first air inlet and a first air outlet, wherein the first air inlet is designed such that air can be guided from an environment into the pressure chamber and wherein the first air outlet is designed such that air can be guided from the pressure chamber into the environment.

[0010] In one embodiment, the present invention achieves the above-mentioned objects in a method for operating a coupling device according to one of claims 1 to 9, comprising the steps: - Moving the piston of the piston unit towards the pressure chamber, and - Discharge of exhaust air from the printing chamber into the environment through the first air outlet.

[0011] One advantage of this is that by arranging the valve unit on the coupling device, less installation space is required. Another advantage is that the air outlet in the valve unit allows the pressure chamber of the coupling device to be directly connected to the environment, preventing overpressure from being generated in the seal chamber. Another advantage is that by connecting the coupling device to the environment, the coupling device is fluidly connected to clean ambient air and not to potentially contaminated air from the coupling environment.

[0012] The term "environment" is to be understood in the broadest sense and, in the description, preferably in the claims, refers to an area outside the clutch device, in particular outside a clutch bell housing that surrounds the clutch device and a clutch disc. In particular, the environment can be the outside world.

[0013] It is possible that air from the environment is transported into the clutch environment via the first and / or the second air inlet.

[0014] It is conceivable that the first air inlet and the first air outlet are formed by a common duct.

[0015] Further features, advantages and further embodiments of the invention are described below or will become apparent thereby.

[0016] According to an advantageous development of the invention, the valve unit has a second air inlet and a second air outlet, wherein the second air inlet is designed to allow air to be guided from the environment into the sealing chamber, and wherein the second air outlet is designed to allow air to be guided from the sealing chamber into the environment. This prevents a negative pressure from developing in the sealing chamber when the piston moves toward the pressure chamber, since the pressure chamber is fluidly connected to the environment. One advantage of this is that dirty air from the clutch environment is not drawn into the sealing chamber.

[0017] According to a further advantageous development of the invention, the valve unit comprises an air return, wherein the air return fluidically connects the first air outlet to the second air inlet. The air return thus enables a fluidic connection between the pressure chamber and the sealing chamber via the valve unit. This allows exhaust air from the pressure chamber to be directed into the sealing chamber, creating an overpressure in the sealing chamber. One advantage of this is that the overpressure prevents the penetration of contaminated air from the clutch environment.

[0018] According to a further advantageous development of the invention, the air return and the first air outlet are designed such that, when air flows from the pressure chamber into the first air outlet, between 5% and 50%, preferably between 15% and 45%, in particular between 25% and 35% of the air flowing from the pressure chamber into the first air outlet is directed into the second air inlet. One advantage of this is that not all of the air from the pressure chamber is directed into the sealing chamber, so that only a slight overpressure is generated in the sealing chamber. The pressure in the sealing chamber can thus be adjusted. One advantage of this is that a slight overpressure can be provided, which can prevent the penetration of dirty air from the environment, but does not need to be vented through additional ventilation channels.

[0019] According to a further advantageous development of the invention, the first air outlet has a constriction, wherein the constriction is fluidically connected to a clutch chamber of the clutch. The clutch chamber is in particular the space that surrounds a clutch disc of the clutch device. The clutch chamber can be fluidically separated from the outside world by a clutch bell housing. When the air from the pressure chamber is passed through a constriction at high pressure, the Venturi effect creates a negative pressure that can suck air out of the clutch chamber. One advantage of this is that air in the clutch chamber, which may be contaminated by clutch wear, for example, can be removed from the clutch chamber. A further advantage is that warm air in the clutch chamber can be removed and replaced with cold air from the environment, so that the temperature in the clutch chamber can be reduced.

[0020] According to a further advantageous development of the invention, an air filter is arranged at an interface between the environment and the first and / or second air inlet and / or the first and / or second air outlet. One advantage of this is that the air flowing into the pressure chamber and / or the sealing chamber is purified from the environment.

[0021] According to a further advantageous development of the invention, a filter is arranged at an interface between the constriction and the environment. When air flows through the constriction, air can be drawn out of the clutch chamber by the Venturi effect. This creates a negative pressure in the clutch chamber. Since the clutch chamber is fluidly connected to the environment via the constriction, air from the environment can flow into the clutch chamber. This air is cleaned by the filter, preventing the clutch device from becoming contaminated. One advantage of this is that the clutch device is protected from penetrating dirt.

[0022] According to a further advantageous development of the invention, the first and / or second air inlet and / or the first and / or second air outlet have a linear bore between the pressure chamber and / or the sealing chamber and the environment. An advantage of this is that the fluidic connection between the environment and the pressure chamber or the sealing chamber can be established in a simple manner.

[0023] According to a further advantageous development of the invention, at least two, preferably at least three, in particular at least four valves are arranged on a straight bore. By arranging multiple valves on a straight bore, they can be connected in series. This eliminates the need for complex cross-bores between valves. One advantage of this is that the manufacture of the valve unit is simplified. A further advantage is that the fluidic connection between the pressure chamber and / or sealing chamber with the environment can be easily provided with valves.

[0024] According to a further advantageous development of the invention, between 5% and 50%, preferably between 15% and 45%, in particular between 25% and 35%, of the exhaust air from the pressure chamber is directed into the sealing chamber. One advantage of this is that a slight overpressure can be generated in the sealing chamber, which keeps out dirty air from the coupling environment, but does not require venting through dedicated ventilation ducts.

[0025] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures with reference to the drawings.

[0026] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0027] Preferred embodiments and embodiments of the present invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components or elements.

[0028] This shows Fig. 1 shows a coupling device according to an embodiment of the present invention; Fig. 2 shows a contact area between the coupling device and the valve unit according to an embodiment of the present invention; Fig. 3 shows a coupling device with a cable guide according to an embodiment of the present invention; Fig. 4 a valve unit according to an embodiment of the present invention; and Fig. 5 steps of a method according to an embodiment of the present invention.

[0029] Fig. 1 shows in schematic form a coupling device according to an embodiment of the present invention.

[0030] The coupling device 1 comprises a coupling device 2 and a valve unit 3. The valve unit 3 is designed to provide the coupling device 2 with a pressure medium, in particular compressed air. By means of the compressed air, a piston 4 of the coupling device 2 can be displaced so that a clutch disc 5 is moved. The coupling device 2 can in particular be arranged within a clutch bell 6 and thus be shielded from other components. The clutch bell surrounds a clutch chamber 24. The piston 4 is sealed by a seal 7 and separates a pressure chamber 8 from a sealing chamber 9. The piston 4, the pressure chamber 8 and the sealing chamber 9 are part of a piston unit 23. By introducing compressed air into the pressure chamber 8, the piston 4 is moved in the direction of the sealing chamber 9 and moves the clutch disc 5. When the piston 4 moves, a negative pressure can arise in the pressure chamber 8 and / or the sealing chamber 9.In this case, it is possible for the negative pressure to be compensated by providing, in particular by suction, air from the clutch bell housing 6. Due to clutch wear or lubricating oil, the air in the clutch bell housing 6 may contain dirt particles, which can thus enter the clutch device 2 and impair the function of the clutch device 2.

[0031] A first air inlet 10 and a first air outlet 11 are provided in the valve unit 3. The first air inlet 10 and the first air outlet 11 connect the pressure chamber 8 to a space outside the clutch bell housing 6, in particular to an environment, for example, the outside world. In this way, fresh air from the environment can enter the pressure chamber. Since the fresh air from the environment usually contains no or negligible amounts of dirt particles, less dirt enters the pressure chamber.

[0032] Similarly, a second air inlet 12 and a second air outlet 13 can be provided in the valve unit 3, which connects the space outside the clutch bell housing 6, in particular the environment, with the sealing chamber 9. In this way, a negative pressure in the sealing chamber 9 can also be reduced by air from the environment, so that fewer dirt particles from the clutch bell housing 6 enter the piston unit 23. At the same time, overpressures in the pressure chamber 8 and the sealing chamber 9 can be reduced through the first and second air outlets 11, 13. In particular, air from the pressure chamber 8 and the sealing chamber 9 can be guided into the environment.

[0033] The first air inlet 10 and the first air outlet 11 can be configured as two separate lines within the valve unit 3. It is also conceivable for the first air inlet 10 and the first air outlet 11 to be configured as a single line, enabling bidirectional air flow. Similarly, the second air inlet 12 and the second air outlet 13 can also be configured as two separate lines or as a common line within the valve unit 3.

[0034] Fig. 2 shows a coupling device according to an embodiment of the present invention.

[0035] The coupling device 1 according to Fig. 2 essentially corresponds to the coupling device 1 according to Fig. 1. The difference to the coupling device 1 according to Fig. 1 is that in the coupling device 1 according to Fig. 2 an air return 14 is arranged in the valve unit 3.

[0036] The air return 14 connects the first air outlet 11 to the second air inlet 12. The air return thus allows the air to be blown out of the pressure chamber 8 into the sealing chamber 9. This allows pressure equalization between the pressure chamber 8 and the sealing chamber 9. Not all of the air that is fed from the pressure chamber 8 into the first air outlet 11 is fed into the sealing chamber 9, but only a portion of the air. In particular, between 10% and 30% of the air that is fed from the pressure chamber 8 into the first air outlet 11 is fed into the sealing chamber 9 via the air return 14. This allows a slight overpressure to be generated in the sealing chamber 9, which prevents dirty air from the clutch bell 6 from entering. At the same time, some of the air can be diverted into the environment so that the overpressure in the sealing chamber 9 does not unintentionally become high.A high overpressure in the sealing chamber 9 could lead to an unintentionally strong air flow from the sealing chamber 9 into the clutch bell 6, which could cause air turbulence of the dirty air in the clutch bell 6.

[0037] Fig. 3 shows a coupling device according to an embodiment of the present invention.

[0038] The coupling device 1 according to Fig. 3 essentially corresponds to the coupling device 1 according to Fig. 1. The difference to the coupling device 1 according to Fig. 1 is that in the coupling device 1 according to Fig. 3 a constriction 15 is arranged in the first air outlet 11 in the valve unit 3.

[0039] The constriction 15 is fluidically connected to the clutch bell 6. The constriction 15 increases the speed of the air as it exits the first air outlet 11, thereby reducing the static pressure in the constriction. Since the constriction 15 is fluidically connected to the clutch bell 6, a negative pressure is created which draws air out of the clutch bell 6. In other words, air can be discharged from the clutch bell 6 into the environment via the constriction 15 with the help of the Venturi effect. This can be used to remove dirty air from the clutch bell 6. It is conceivable to then direct the air from the pressure chamber 8 into the environment via the constriction 15 if a sufficiently large volume of air is available in the pressure chamber 8.This allows a cleaning process to be carried out in which a larger amount of air can be removed from the clutch bell 6 than if air is removed from the pressure chamber 8 at regular intervals.

[0040] The removal of air from the clutch bell housing 6 can also be used to cool the clutch device 2, since warm air can be removed from the clutch bell housing 6, and the resulting negative pressure draws cool air from the environment into the clutch bell housing 6 and the sealing chamber 9. A filter 16 can be arranged between the environment and the constriction 15 so that air flowing into the pressure chamber 8, the sealing chamber 9, and / or the clutch bell housing 6 is cleaned.

[0041] Fig. 4 shows a valve unit according to an embodiment of the present invention.

[0042] The valve unit 3 comprises an air inlet 17, an air outlet 18 and an outlet 19 for a transmission brake. It is possible that the air inlet 17 is connected to the first air inlet 10 according to Fig. 1 and it is possible that the air outlet 18 corresponds to the first air outlet 11 according to Fig. 1. Air can be directed from the air inlet 17 to a clutch device line 22 via two inlet valves 20a, 20b. The clutch device line 22 can direct air to the clutch device 2. Furthermore, air can be directed to a transmission brake (not shown) via another inlet valve 20c. By means of the two closing valves 21a, 21b, air can be directed from the clutch device line 22 to the air outlet 18, and by means of another closing valve 21c, air can be directed from the transmission brake 19 to the air outlet 18.

[0043] It is conceivable that two, three, or four of the valves 20a, 20b, 20c, 21a, 21b, 21c are connected in series. For example, the intake valves 20a, 20b and the closing valves 21a, 21b could be connected in series. In particular, the intake valves 20a, 20b and the closing valves 21a, 21b could each be arranged on a common straight line, so that only a few straight holes are required to connect all four valves.

[0044] Fig. 5 shows steps of a method according to an embodiment of the present invention.

[0045] Fig. 5 shows steps of a method for operating a coupling device. The coupling device can be operated in particular according to one of the Fig. 1 to 3 must be trained.

[0046] In step S1, the piston of the piston unit is moved toward the pressure chamber. This reduces the volume of the pressure chamber, and the air in the pressure chamber must be removed.

[0047] In a further step S2, exhaust air from the pressure chamber is led into the environment through the first air outlet.

[0048] In particular, only a portion of the exhaust air, for example, 40% to 60% of the exhaust air, is discharged into the environment through the first air outlet. The remaining 60% to 40% of the exhaust air can be directed into the sealing chamber of the coupling device via an air return.

[0049] In summary, at least one of the embodiments of the present invention may have at least one of the following features and / or realize at least one of the following advantages: - Protection from dirty air in the clutch environment, - Fluidic connection of the coupling with clean ambient air, - Providing at least a slight overpressure in the pressure chamber.

[0050] Although the present invention has been described using preferred embodiments, it is not limited thereto but can be modified in many ways. Reference symbol 1 coupling device 2 Coupling device 3 valve unit 4 pistons 5 clutch disc 6 clutch bell 7 Seal 8 Printing room 9 Sealing chamber 10 first air intake 11 first air outlet 12 second air inlet 13 second air outlet 14 Air return 15 bottleneck 16 filters 17 Air intake 18 Air outlet 19 Transmission brake air outlet 20a Inlet valve 20b Inlet valve 20c additional inlet valve 21a Closing valve 21b Closing valve 21c additional closing valve 22 Coupling device line 23 Piston unit 24 Clutch chamber QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 117 091 A1

[0005]

Claims

[1] Coupling device (1), comprising a valve unit (3) and a coupling device (2) with a coupling and a piston unit (23), wherein the valve unit (3) is fluidically connected to the coupling device (2), in particular is arranged on the coupling device (2), wherein the valve unit (3) is designed to provide a pressure medium to the piston unit (23) of the coupling device (2), wherein the piston unit (23) comprises a pressure chamber (8), a sealing chamber (9) and a piston (4) movably arranged between the pressure chamber (8) and the sealing chamber (9), characterized by in that the valve unit (3) has a first air inlet (10) and a first air outlet (11), wherein the first air inlet (10) is designed such that air can be guided from an environment into the pressure chamber (8) and wherein the first air outlet (11) is designed such that air can be guided from the pressure chamber (8) into the environment. [2] Coupling device (1) according to claim 1, characterized by in that the valve unit (3) has a second air inlet (12) and a second air outlet (13), wherein the second air inlet (12) is designed such that air can be guided from the environment into the sealing space (9) and wherein the second air outlet (13) is designed such that air can be guided from the sealing space (9) into the environment. [3] Coupling device (1) according to claim 2, characterized by that the valve unit (3) comprises an air return (14), wherein the air return (14) fluidly connects the first air outlet (11) to the second air inlet (12). [4] Coupling device (1) according to claim 3, characterized bythat the air return (14) and the first air outlet (11) are designed such that when air flows from the pressure chamber (8) into the first air outlet (11), between 5% and 50%, preferably between 15% and 45%, in particular between 25% and 35% of the air flowing from the pressure chamber (8) into the first air outlet (11) is directed into the second air inlet (12). [5] Coupling device (1) according to one of claims 1 to 3, characterized by that the first air outlet (11) has a constriction (15), wherein the constriction (15) is fluidically connected to a coupling chamber of the coupling. [6] Coupling device (1) according to one of claims 1 to 4, characterized by that an air filter (16) is arranged at an interface between the environment and the first (10) and / or second air inlet (12) and / or the first (11) and / or the second air outlet (12). [7] Coupling device (1) according to claim 5, characterized bythat a filter (16) is arranged at an interface between the constriction (15) and the environment. [8] Coupling device (1) according to one of claims 1 to 7, characterized by that the first (10) and / or the second air inlet (12) and / or the first (11) and / or the second air outlet (13) has a straight bore between the pressure chamber (8) and / or the sealing chamber (9) and the environment. [9] Coupling device (1) according to claim 8, characterized by that at least two, preferably at least three, in particular at least four valves (20a, 20b, 21a, 21b) are arranged on a straight bore. [10] Method for operating a coupling device (1) according to one of claims 1 to 9, comprising the steps: - moving (S1) the piston (4) of the piston unit (23) in the direction of the pressure chamber (8), and - Discharge (S2) of exhaust air from the pressure chamber (8) into the environment through the first air outlet (11). [11] Method according to claim 10, characterized by that between 5% and 50%, preferably between 15% and 45%, in particular between 25% and 35% of the exhaust air from the pressure chamber (8) is directed into the sealing chamber (9).

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