Pressure equalization reservoir for a gearbox and transmission

Abstract

Pressure equalization reservoir for a gearbox, wherein the pressure equalization vessel comprises a lid part (2) which has a continuous recess (20, 31, 32), wherein the recess (20, 31, 32) on the inside of the lid part (2) opens into a component (21) with variable internal volume, which is arranged in the pressure equalization vessel, wherein the component (21) with variable internal volume is a bellows (21), wherein the component (21) has a recess which is airtightly connected to the recess (20, 32, 31) in the lid part (2), wherein the lid part (2) is positively connected to a housing part (1) of the pressure equalization tank, characterized by the fact that a sealing plug (4, 30) is arranged at the outer end area of ​​the recess (20, 31, 32) of the cover part (2), which has a semipermeable membrane, wherein the lid part (2) is connected to the housing part (1) by means of locking clips (110) which engage in lugs (111) of the housing part (1), wherein a hood is provided on the outside of the sealing plug (4, 30) which has recesses.

Description

[0001] The invention relates to a pressure compensation tank for a transmission and a transmission.

[0002] It is well known that transmissions usually contain lubricating oil. Depending on the external ambient temperature and the load level of the transmission, the lubricating oil has different temperatures.

[0003] From US 4987 796 A, the closest prior art is a pressure compensation tank for a transmission.

[0004] From DE 101 22 993 A1 a device for closing an opening in a housing wall in a housing of a transmission is known.

[0005] The invention is therefore based on the object of developing a drive system comprising a transmission, wherein the service life and safety are to be increased.

[0006] According to the invention, the object is achieved in the pressure compensation tank for a transmission according to the features specified in claim 1 and in the transmission according to the features specified in claim 10.

[0007] Important features of the invention in the pressure compensation tank for a transmission are that the pressure compensation tank comprises a cover part which has a continuous recess, wherein the recess on the inside of the cover part opens into a component with a variable internal volume, which is arranged in the pressure compensation container, in particular wherein the component is elastically deformable such that the internal volume limited by the component can be changed accordingly, in particular wherein the deformation can be effected by pressure differences between the pressure in the internal volume delimited by the component and in the internal volume delimited by the pressure equalization vessel and the component.

[0008] The advantage here is that the lubricating oil takes up a different volume depending on the operating temperature. The pressure compensation tank is provided to accommodate this increase in volume. The space containing the lubricating oil and the space containing the air contained within the pressure compensation tank, which is connected to the ambient air via the recess, are separated by the elastic component. This prevents the lubricating oil from escaping into the environment, while still preventing dangerous overpressure in the gearbox, which could reduce the service life of the shaft seals or other seals and / or pose a safety risk.

[0009] According to the invention, the component with a variable internal volume is a bellows. This advantageously uses a particularly simple means whose volume can be changed without a significant pressure difference between the two spatial areas, i.e., the area containing the lubricating oil and the area connected to the ambient air via the recess.

[0010] In an advantageous embodiment, the component is made of an elastomer, in particular a lubricating oil-resistant elastomer. This allows for cost-effective production and the use of a cost-effective material.

[0011] According to the invention, the component has a recess that is hermetically connected to the recess in the cover part. Advantageously, the internal volume enclosed by the component is in communication with the ambient air, particularly via a sealing plug.

[0012] According to the invention, the cover part is positively connected to a housing part of the pressure equalization tank, in particular by means of a clip connection. This is advantageous in that a solid, airtight connection can be easily established and is detachable. This is particularly advantageous for maintenance and when refilling or topping up lubricating oil.

[0013] In an advantageous embodiment, the recess in the cover part is a continuous bore, in particular a longitudinal bore, or is composed of at least two bores that are not aligned parallel to one another, in particular two bores aligned perpendicular to one another. This is advantageous in that a connection between the ambient air and the internal volume of the component can be created through a simple and cost-effective bore or two such bores.

[0014] According to the invention, a sealing plug with a semipermeable membrane is arranged at the outer end of the recess in the lid part. This has the advantage of allowing air to be exchanged, thus allowing pressure to be equalized.

[0015] In an advantageous embodiment, the semipermeable membrane is permeable to air but impermeable to water and / or lubricating oil. This is advantageous because pressure equalization occurs without the lubricating oil escaping. The membrane prevents lubricating oil from passing through, but allows air exchange.

[0016] According to the invention, a cap with recesses is provided on the outside of the sealing plug. This advantageously provides mechanical protection, so that the membrane does not directly perform a housing-forming function, but rather the cap performs a mechanical protective function.

[0017] In an advantageous embodiment, the interior space defined by the cover part and / or together with the housing part is connected to the interior space of a transmission by means of a pipeline, in particular, the pipeline leading from a recess in the housing part to a recess in the transmission. It is advantageous that the lubricating oil can be filled into the transmission by filling the housing part of the pressure compensation tank.

[0018] In an advantageous embodiment, the housing part has a screw thread for connecting to the cover part. This is advantageous because a positive, detachable connection can be easily established.

[0019] Important features of the gearbox include its equipping with a pressure compensation tank, with a pipeline connecting the pressure compensation tank and the gearbox. This is advantageous because the gearbox can be filled with lubricating oil from the open pressure compensation tank, especially when the cover is removed. When the cover is closed, the pressure compensation function can be performed safely, as the diaphragm prevents lubricating oil from escaping into the environment.

[0020] In an advantageous embodiment, the pressure compensation tank is arranged at a distance from the transmission, in particular with the pressure compensation tank being arranged at the same height as or higher than the top of the transmission. This is advantageous because it prevents the formation of air pockets in the pipe area, thus allowing uninterrupted flow of lubricating oil between the pressure compensation tank and the transmission.

[0021] The invention will now be explained in more detail with the aid of illustrations: In the Fig. 1 shows a pressure compensation tank not according to the invention in side view. In the Fig. 2 is a Fig. 1 corresponding cross section shown. In the Fig. 3 shows a further pressure compensation tank not according to the invention with a lateral closure plug in side view. In the Fig. 4 is a Fig. 3 corresponding cross section shown. In the Fig. 5 shows a further pressure equalization tank not according to the invention with sight glass 50 in side view. In the Fig. 6 is a Fig. 5 corresponding cross section shown. In the Fig. 7 shows a further pressure compensation tank with bayonet closure not according to the invention in an oblique view, wherein the lid is not yet closed. In the Fig. 8 is one to Fig. 7 corresponding side view shown. In the Fig. 9 the lid is secured by means of the bayonet lock Fig. 7 and Fig. 8 connected to the housing part 1. In the Fig. 10 is one to Fig. 9 corresponding side view shown. In the Fig. 11 is a Fig. 10 corresponding cross section shown. In the Fig. 12 shows a pressure compensation tank according to the invention in side view, the lid of which is closed by means of clips. In the Fig. 13 is a Fig. 12 corresponding cross section shown.

[0022] In the Fig. 1 shows a pressure equalization tank comprising a housing part 1, which can be closed by means of a cover part 2. Preferably, a seal is provided between the two parts.

[0023] For example, a screw thread is provided for closing, so that the cover part 2 can be screwed into the housing part 1 for closing.

[0024] The housing part 1 also has a connection area 3 for a pipe, with which the pressure compensation tank can be connected to a device containing a fluid. Preferably, the device is a gearbox that is to be filled with lubricating oil. With the cover part 2 removed, the lubricating oil can be poured into the housing part 1 and then flows into the gearbox.

[0025] With the exception of the air-filled undercuts inside the gearbox, the entire interior can be filled with lubricating oil. With further filling, the fill level rises to the level of the pressure equalization tank. The fill level in the pressure equalization tank is easily visible when the cover is open.

[0026] After closing the cover part, i.e., tightly connecting cover part 2 to housing part 1, a reduction in the fill level is to be expected during operation of the gearbox due to the increasing oil filling of the undercuts inside the gearbox. Furthermore, the fill level is subject to thermal fluctuations. Overpressure or underpressure in the air above the oil is avoided because the cover part 2 has a longitudinal bore 20 opening into a bellows 21 located in the interior of the pressure equalization tank. A sealing plug 4 is located at the outer end of the bore.

[0027] The sealing plug 4 comprises a semipermeable membrane that allows air to pass through but does not allow liquids such as water and / or lubricating oil to pass through. This ensures pressure equalization between the interior and exterior spaces. In further embodiments, the sealing plug 4 has a cap on its exterior that has recesses, such as slots or the like. This provides additional mechanical protection.

[0028] The execution according to Fig. 1 and Fig. 2 allows pressure equalization by extending or contracting the bellows. The bellows is preferably made of an elastic plastic, such as an elastomer or the like.

[0029] In Fig. 3 and Fig. 4, the sealing plug 30 is attached to the side of the pressure equalization tank. For this purpose, a transverse bore 31 is provided, which is located at the end area of ​​the pressure equalization tank facing away from the bellows 21. Fig. 3 and Fig. 4 non-continuous longitudinal bore 32. The transverse bore is also not continuous here and opens at its outwardly directed end region into the sealing plug 30. Preferably, the sealing plug 30 is identical in construction to the multi-part sealing plug 4 according to Fig. 1 and Fig. 2, so that it again encompasses the semipermeable membrane. In further embodiments, the transverse bore can also be continuous, and a closure plug can be provided at each of the two openings ending on the outside. Alternatively, one of the ends can be tightly closed with a simple, one-piece closure plug.

[0030] In Fig. 5 and Fig. Figure 6 shows a further embodiment, wherein, in contrast to the described embodiments, a sight glass 50 is additionally arranged on the outside of the housing part 1 of the pressure equalization tank. Thus, the fill level of the pressure equalization tank can be observed even when the cover part 2 is closed. The sight glass is tightly connected to the housing part 1.

[0031] In the Fig. 7 to 11 shows a version with a bayonet lock as a connection between cover part 2 and housing part 1. Fig. 7 and Fig. 8 the pressure compensation tank with the cover part 2 lifted off and not yet closed. The cover part has bayonet pins 70 projecting towards the housing part 1, which can engage in bayonet recesses 71 of the housing part 1.

[0032] In the Fig. 9, Fig. 10 and Fig. Figure 11 shows the closed state of the pressure compensation tank. The bayonet pins 70 engage the bayonet recesses 71 and, together with a seal, particularly an O-ring, arranged between the cover part 2 and the housing part 1, create a tight connection.

[0033] In the Fig. 12 and Fig. 13 shows an embodiment according to the invention in which the cover part 2 is connected to the housing part 1 by means of locking clips 110, which engage in lugs 111 of the housing part 1, instead of by means of the screw cap or the bayonet closure. List of reference symbols 1 housing part 2 lid part 3 Connection area for pipeline 4 sealing plugs 20 Longitudinal bore 21 Bellows 30 sealing plugs 31 Cross hole, not through 32 Longitudinal bore, not through 50 sight glass 70 bayonet pins 71 Bayonet recess 110 closure clips 111 Nose

Claims

[1] Pressure compensation tank for a gearbox, wherein the pressure compensation container comprises a cover part (2) which has a continuous recess (20, 31, 32), wherein the recess (20, 31, 32) on the inside of the cover part (2) opens into a component (21) with a variable internal volume, which is arranged in the pressure compensation container, wherein the component (21) with variable internal volume is a bellows (21), wherein the component (21) has a recess which is hermetically connected to the recess (20, 32, 31) in the cover part (2), wherein the cover part (2) is positively connected to a housing part (1) of the pressure compensation tank, characterized by , that a sealing plug (4, 30) having a semi-permeable membrane is arranged at the outer end region of the recess (20, 31, 32) of the cover part (2), wherein the cover part (2) is connected to the housing part (1) by means of locking clips (110) which engage in lugs (111) of the housing part (1), wherein a hood having recesses is provided on the outside of the closure plug (4, 30). [2] Pressure compensation tank according to claim 1, characterized by that the component (21) is elastically deformable such that the internal volume delimited by the component (21) can be changed accordingly. [3] Pressure compensation tank according to at least one of the preceding claims, characterized by that the component (21) is made of an elastomer, in particular of a lubricating oil-resistant elastomer. [4] Pressure compensation tank according to at least one of the preceding claims, characterized bythat the deformation can be effected by pressure differences between the pressure in the internal volume delimited by the component (21) and in the internal volume delimited by the pressure equalization vessel and component (21). [5] Pressure compensation tank according to at least one of the preceding claims, characterized by that the recess in the cover part (2) is a continuous longitudinal bore (20) or is composed of at least two bores (31, 32) which are not aligned parallel to one another. [6] Pressure compensation tank according to claim 5, characterized by that the recess in the cover part (2) is composed of at least two bores (31, 32) aligned perpendicular to each other. [7] Pressure compensation tank according to one of the preceding claims, characterized by that the semipermeable membrane is permeable to air but impermeable to water and / or lubricating oil. [8] Pressure compensation tank according to one of the preceding claims, characterized bythat the interior space delimited by the cover part (2) and / or together with the housing part is connected to the interior space of a transmission by means of a pipeline, in particular wherein the pipeline leads from a recess in the housing part (1) to a recess in the transmission. [9] Pressure compensation tank according to one of the preceding claims, characterized by that a sight glass (50) is arranged on the housing part (1). [10] Transmission with a pressure compensation tank according to at least one of the preceding claims, characterized by that a pipeline is provided between the pressure equalization tank and the gearbox. [11] Transmission according to claim 10, characterized by that the pressure compensation tank is arranged at a distance from the gearbox. [12] Transmission according to claim 11, characterized by that the pressure equalizing tank is positioned at the same height as or higher than the top of the gearbox.

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