Ventilation and aeration arrangement for a motor vehicle transmission

Abstract

A ventilation and aeration arrangement for a motor vehicle transmission (2) with a housing arrangement (18) comprising a filter housing (20) and a cover arrangement (22), wherein the housing arrangement (18) encloses a filter chamber (24) and has at least one fluid inlet (6, 8) and at least one fluid outlet (26) in which at least one coalescing filter element (36) and at least one activated carbon arrangement (38, 42) are arranged, and wherein at least one pressure equalization element (54) designed as a hydrophobic membrane element (56) is provided, such that a fluid path (28) extending from the fluid inlet (6, 8) to the fluid outlet (26) is formed in the filter housing (20), wherein the at least one coalescing filter element (36) and the at least one activated carbon arrangement (38, 42) completely form the fluid path (28) in the filter chamber (24), wherein the coalescing filter element (36) directly connects to the at least one fluid inlet (6, 8), characterized in thatthat the filter housing (20) is essentially pot-shaped, such that the filter chamber (24) is cylindrical and the at least one fluid inlet (6, 8) is provided in the cylindrical part (32) of the filter housing (20), wherein the coalescing filter element (36) is tubular.

Description

[0001] The invention relates to a ventilation arrangement for a motor vehicle transmission with a housing arrangement comprising a filter housing and a cover arrangement, wherein the housing arrangement encloses a filter chamber and has at least one fluid inlet and at least one fluid outlet in which at least one coalescing filter element and at least one activated carbon arrangement are arranged, and wherein at least one pressure equalization element designed as a hydrophobic membrane material is provided, such that a fluid path extending from the fluid inlet to the fluid outlet is formed in the filter housing, wherein at least one coalescing filter element and the at least one activated carbon arrangement completely form the fluid path in the filter chamber, the coalescing filter element being directly connected to the at least one fluid inlet.

[0002] Such a venting and aeration arrangement is known from the prior art according to DE 10 2007 043 462 B3. This arrangement is intended to collect the oil that leaves the gearbox in hot, oil-enriched air during operation, in order to ensure compliance with environmental protection regulations. Simultaneously, such an arrangement serves to supply fresh air to the gearbox in case the gearbox cools down after operation and the pressure conditions in the overall system reverse. Furthermore, US 6 217 639 B1 discloses an arrangement with different filter elements whose fluid path in the filter chamber is completely filled, and wherein a coalescing filter element is directly connected to the at least one fluid inlet.Other filter arrangements are known, for example, from WO 2016 / 123 354 A1, WO 01 / 90 604 A1, US 4 811 571 A, DE 38 28 602 A1, US 2 325 657 A, DE 10 2007 043 462 B3 and US 3 744 976 A. However, such ventilation arrangements have the disadvantage that they require a relatively large installation space, which is not sufficiently available in modern vehicles.

[0003] The invention is therefore based on the objective of providing a ventilation arrangement that avoids the aforementioned disadvantage in a simple and cost-effective manner.

[0004] This problem is solved by designing the filter housing to be essentially pot-shaped, with a cylindrical filter chamber and at least one fluid inlet located in the cylindrical part of the filter housing. The coalescing filter element is tubular. This arrangement ensures a very compact design, as no installation space is required due to the fluid path being filterless. During transmission venting, the coalescing filter element, in direct contact with the at least one fluid inlet, captures oil aerosols and binds them within the matrix. Various forces, such as adhesonic and cohesive forces, as well as electrokinetics within the filter element, play a role in this process. Furthermore, this arrangement is particularly space-optimized and can be easily equipped with multiple fluid inlets.

[0005] In a particularly advantageous embodiment, at least two fluid inlets are provided, making it possible to ventilate or vent different gearbox compartments simultaneously using a ventilation arrangement.

[0006] Advantageously, the coalescence filter element is designed as a microglass fiber filter element.

[0007] In a particularly advantageous embodiment, it is especially advantageous if the coalescing filter element is installed under preload in the filter housing. This ensures that, in the event of ventilation, larger oil aerosol droplets are returned directly to the transmission via the fluid inlet. In a particularly advantageous embodiment, activated carbon, preferably coarse-grained, is provided as the first activated carbon arrangement in the coalescing filter element, wherein the coalescing filter element is closed off by a first nonwoven element in the direction of the fluid outlet. The coalescing filter element prevents abrasion of the activated carbon filling caused by vibrations on or in the vehicle from being introduced into the transmission. The nonwoven element prevents the activated carbon or its dust particles from being carried further into the fluid path.The preferably coarse-grained activated carbon ensures that, in the highly unlikely event of an overload of the coalescing filter element and a resulting saturation of this filter element, oil aerosols do not enter the further fluid path.

[0008] It is particularly advantageous if the filter chamber is divided into two parts by the first nonwoven element, wherein, starting from the first nonwoven element and extending towards the fluid outlet, the filter chamber is provided with activated carbon, preferably fine-grained, as an activated carbon arrangement, and wherein the filter chamber is closed off towards the fluid outlet by a second nonwoven element. This activated carbon, preferably fine-grained, is exclusively intended for the purpose of removing unpleasant odors. Here, too, a second nonwoven element is provided towards the fluid outlet to prevent activated carbon particles from being carried into the further fluid path. The first and second nonwoven elements are particularly advantageously designed as polyester nonwoven elements.

[0009] Preferably, the cover assembly includes at least one fluid outlet and the hydrophobic membrane element. For ease of assembly, the cover assembly comprises a base cover element. This base cover element can have a contact surface for the second nonwoven element to fix it in the predetermined position. Furthermore, the base cover element has an external and an internal thread, the external thread engaging with the filter housing and the internal thread engaging the pressure equalization element with the hydrophobic membrane element. Alternatively, the filter housing, the base cover element, and the pressure equalization element can be welded together. The at least one fluid outlet is advantageously designed as a partially annular opening.

[0010] Furthermore, the problem is solved by a motor vehicle transmission with such a ventilation arrangement, in which line elements are provided that fluidically connect one or more transmission interiors with the fluid inlets of the ventilation arrangement.

[0011] The invention is explained in more detail with reference to a drawing, which shows: Fig. 1 a perspective view of the motor vehicle transmission according to the invention with a ventilation arrangement according to the invention, and Fig. 2 a perspective sectional view of the ventilation arrangement according to the invention made of Fig. 1.

[0012] Fig. Figure 1 shows a perspective view of a motor vehicle transmission 2 according to the invention, which has a ventilation arrangement 4 according to the invention. The two fluid inlets 6, 8 of this arrangement are connected via conduit elements 10, 12 and corresponding connections 14, 16 to transmission interiors (not shown) for ventilation and venting, respectively. Connection 14 is connected to a gear set compartment filled with transmission oil, and connection 16 is connected to a clutch compartment filled with clutch oil. The ventilation arrangement 4 is designed such that no oil aerosols escape into the environment. During ventilation, when the transmission cools down, fresh air is introduced into the transmission, but no water aerosols are to enter the motor vehicle transmission 2 with this fresh air.

[0013] Fig. Figure 2 shows a perspective view of the ventilation arrangement 4 according to the invention. The ventilation arrangement 4 according to the invention has a housing arrangement 18, which includes a filter housing 20 and a cover arrangement 22. The filter housing 20 encloses a filter chamber 24 and has two fluid inlets 6, 8, of which only the fluid inlet 8 is shown here, and outlet openings 26 designed as semi-annular openings. The housing arrangement 18 is designed such that a fluid path 28 is shown from the fluid inlets 6, 8 to the fluid outlets 26.

[0014] The filter housing 20 is essentially pot-shaped, so that the filter chamber 24 is cylindrical. Flange elements 30 for mounting to the vehicle transmission 2 are provided on the outside of the filter housing 20. The fluid inlets 6, 8 are arranged in a particularly space-saving manner in the cylindrical part 32 of the filter housing 20. For easy connection with the in Fig. Connection pieces 34 are provided for the line elements 10, 12 shown in Figure 1. A tubular coalescing filter element 36 is inserted under preload in the lower part of the filter housing 20, in the area of ​​the fluid inlets 6, 8. The coalescing filter element 36 is designed as a microglass fiber filter element.

[0015] In the present embodiment, the tubular coalescing filter element 36 is filled with coarse-grained activated carbon 38, which serves as the first activated carbon arrangement. A first nonwoven element 40 is arranged towards the fluid outlets 26, separating the first activated carbon arrangement 38 from a second activated carbon arrangement 42. The second activated carbon arrangement 42 consists of fine-grained activated carbon, which fills the further filter chamber 24. The filter chamber 24 is closed by a second nonwoven element 44. In the present embodiment, both nonwoven elements 40 and 44 are made of polyester nonwoven material. The fluid path 28 in the filter chamber 24 is thus completely filled by the coalescing filter element 36 and the first and second droplet separator arrangements 38 and 42, resulting in an extremely compact venting arrangement 4.

[0016] The cover assembly 22 closes the filter housing 20 and has a base cover element 46 with an external thread 48 and an internal thread 50. The external thread 48 engages a corresponding thread 52 in the filter housing 20, while the internal thread 50 serves to receive a pressure equalization element 54. This pressure equalization element 54 has a hydrophobic membrane element 56, which is sealed by a sealing ring 58. The second fleece element 44 is held in position by a contact surface 60 of the base cover element 46. The filter housing 20, the base cover element 46, and the pressure equalization element 54 can also be welded together instead of being screwed together.

[0017] The function of the ventilation arrangement 4 can now be described as follows: As soon as the vehicle transmission 2 is operated, the oil temperature and thus the air pressure in the vehicle transmission 2 begin to rise. Due to the higher air pressure, the air containing oil aerosols must leave the vehicle transmission 2 via the venting arrangement 4. For this purpose, the air enters, for example, the line element 12 and is guided via the fluid inlet 8 into the filter housing 20 and thus into the filter chamber 24, where it first encounters the microglass fiber filter element 36, which binds the oil aerosols. The fluid inlet 8 also defines the beginning of the fluid path 28, which, following the microglass fiber filter element 36, leads through a first activated carbon arrangement 38, which is designed as coarse-grained activated carbon. The coarse-grained activated carbon 38 is particularly suitable for capturing further oil aerosols from the exhaust air in the unlikely event of overloading the microglass fiber filter element 36.The coarse-grained activated carbon 38 is separated from the second activated carbon arrangement 42 in the fluid path 28 by a first polyester nonwoven fabric 40. This separating layer prevents mixing of the two different activated carbon arrangements 38 and 42. The second activated carbon arrangement 42 also consists of activated carbon, but this is fine-grained. This fine-grained activated carbon 42 is exclusively intended to absorb unpleasant odors. Further along the fluid path 28, a second polyester nonwoven fabric 44 is provided to ensure that carbon dust, generated, for example, by vibrations in the vehicle, is not carried along the fluid path towards the fluid outlet 26. The air, purified in this way, can then exit the arrangement 4 via the fluid outlet 26 after passing through the hydrophobic membrane element 56. In the case of ventilation, fresh air can enter the assembly 4 through the outlet opening 26 and travels through the fluid path 28 in the reverse direction to be guided into the gearbox interior (not shown) via the fluid inlets 6, 8. During this process, oil aerosol droplets can dissolve in the coalescing filter element 36 and also be guided into the gearbox interior.

Claims

[1] Ventilation and de-aeration arrangement for a motor vehicle transmission (2) with a housing arrangement (18) which has a filter housing (20) and a cover arrangement (22), wherein the housing arrangement (18) encloses a filter chamber (24) and has at least one fluid inlet (6, 8) and at least one fluid outlet (26) in which at least one coalescing filter element (36) and at least one activated carbon arrangement (38, 42) are arranged and wherein at least one pressure compensation element (54) designed as a hydrophobic membrane element (56) is provided, such that a fluid path (28) extending from the fluid inlet (6, 8) to the fluid outlet (26) is formed in the filter housing (20), wherein the at least one coalescing filter element (36) and the at least one activated carbon arrangement (38, 42) completely form the fluid path (28) in the filter chamber (24), wherein the coalescence filter element (36) is directly connected to the at least one fluid inlet (6, 8), characterized bythat the filter housing (20) is substantially pot-shaped, such that the filter chamber (24) is cylindrical and the at least one fluid inlet (6, 8) is provided in the cylindrical part (32) of the filter housing (20), wherein the coalescence filter element (36) is tubular. [2] Ventilation arrangement according to claim 1, characterized by that at least two fluid inlets (6, 8) are provided. [3] Ventilation arrangement according to claim 1 or 2, characterized by that the coalescence filter element (36) is designed as a micro glass fiber filter element. [4] Ventilation arrangement according to one of the preceding claims, characterized by that the coalescing filter element (36) is inserted under pre-tension in the filter housing (20). [5] Ventilation arrangement according to one of the preceding claims, characterized bythat activated carbon (38), preferably coarse-grained, is provided in the coalescence filter element (36) as the first activated carbon arrangement, wherein the coalescence filter element (36) is closed off by a first fleece element (40) as seen in the direction of the fluid outlet (26). [6] Ventilation arrangement according to claim 5, characterized by that the filter chamber (24) is divided into two parts by the first fleece element (40), wherein, starting from the first fleece element (40) in the direction of the fluid outlet (26), the filter chamber (24) is provided with activated carbon (42), preferably fine-grained, as a second activated carbon arrangement, and wherein the filter chamber (24) is closed off by a second fleece element (44) in the direction of the fluid outlet (26). [7] Ventilation arrangement according to claim 5 or 6, characterized by that the first and second nonwoven elements (40, 44) are designed as polyester nonwoven elements. [8] Ventilation arrangement according to one of the preceding claims, characterized by that the at least one fluid outlet (26) and the hydrophobic membrane element (56) are provided in the cover arrangement (22). [9] Ventilation arrangement according to one of the preceding claims, characterized by that the cover assembly (22) has a base cover element (46). [10] Ventilation arrangement according to claim 9, characterized by that the base cover element (46) has a contact surface (60) for the second fleece element (44). [11] Ventilation arrangement according to claim 9 or 10, characterized by that the base cover element (46) has an external and an internal thread (48, 50), wherein the external thread (48) engages in the filter housing (20) and wherein the pressure compensation element (54) with the hydrophobic membrane element (56) engages in the internal thread (50). [12] Ventilation arrangement according to claim 9 or 10, characterized bythat the filter housing (20), the base cover element (46) and the pressure compensation element (54) are welded together. [13] Ventilation arrangement according to one of the preceding claims, characterized by that the at least one fluid outlet (26) is designed as a partially annular opening. [14] Motor vehicle transmission with a ventilation arrangement (4) according to one of the preceding claims, characterized by that line elements (10, 12) are provided which fluidically connect one or more transmission interior spaces with the fluid inlets (6, 8) of the ventilation and venting arrangement (4).

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