Ventilation valve for aero-engine gearbox

Abstract

The invention discloses a ventilation valve for an aero-engine gearbox, which comprises a valve body provided with an air passage in a penetrating manner, and a valve core and a return spring for pushing the valve core to move in the air passage are arranged in the valve body; wherein the return spring is positioned between the bottom of the valve body and the valve core; a driving assembly is further arranged in the valve body and located above the valve element, and in the normal posture, the driving assembly completely acts on the valve element and drives the valve element to compress the return spring, and the air channel is opened. In the inclined posture, the driving assembly partially acts on the valve element, and the return spring drives the valve element to abut against the air channel. In the normal posture, air circulation inside and outside the gearbox can be guaranteed, the problem that oil mist escapes due to the fact that the pressure intensity inside the gearbox is too large is solved, in the inclined posture, the interior and the exterior of the gearbox can be isolated, lubricating oil in the gearbox is prevented from leaking, and therefore the purposes of pressure relief and leakage prevention can be achieved at the same time.

Description

Technical Field

[0001] The invention relates to a pressure relief valve, in particular to a breathable valve used for an aircraft engine gear box. Background Art

[0002] The engine gearbox is a mechanical transmission device that changes the speed and torque through gear transmission, and is mainly used to achieve engine transmission and speed regulation. During the flight of the UAV engine gearbox, due to the large pressure difference between the inside and outside of the gearbox, the internal pressure will be much greater than the external pressure, and the oil mist inside the gearbox will escape and affect the lubrication effect of the gears. Therefore, in the prior art, a breathable valve is set to connect the inside and outside of the gearbox, so that the gas inside and outside the gearbox circulates, avoiding the problem of oil mist escaping due to excessive internal pressure.

[0003] The existing breathable valve includes a valve body, a valve core, and a spring, etc., which are fastened to the components through the front thread of the valve body. When the internal pressure is large, the gas pushes the valve core to move vertically to compress the spring, so that the internal gas flows out to reduce the pressure. For example, an improved breathable bolt disclosed in Chinese patent document CN209781636U includes a bolt body and an outer cover, the outer cover is detachably arranged on the head of the bolt body, the bolt body is provided with a breathable passage that penetrates the bolt body, the inner end of the breathable passage extends to the head of the bolt body and is located in the outer cover, the head of the bolt body or the outer cover is provided with a breathable port, and a one-way valve is provided between the outer cover and the head of the bolt body so that the breathable passage can only be opened in one direction. The utility model sets a one-way valve between the outer cover and the head of the bolt body, so that the one-way valve of the utility model can only be opened to exhaust when exhausting. When the utility model does not exhaust, the one-way valve seals the breathable passage, and water cannot pass through the breathable passage, thereby improving the waterproof performance of the breathable bolt and ultimately extending the service life of the gearbox.

[0004] In the prior art, when the pressure in the gearbox is greater than the elastic force of the return spring, the breathable cover will be pushed upward and the one-way valve will open, so that the gas inside and outside the gearbox can flow. Under normal circumstances, the gearbox needs to remain closed to prevent the lubricating oil from leaking. Therefore, it is necessary to select a return spring with appropriate elastic force to take into account the purpose of both pressure relief and leakage prevention. However, for the gearbox of an aviation drone, since it is mostly used in scenes with high altitude, low air pressure and large temperature difference, the pressure difference between the inside and outside of the gearbox varies, and the demand for the elastic force of the return spring also varies. In addition, since the flight posture of the drone varies during flight, during the flipping of the drone, the return spring will also be affected by the gravity of part of the lubricating oil in the gearbox, and the breathable cover is easier to open, resulting in the situation of lubricating oil leakage. If the elastic force of the return spring is increased in order to prevent the breathable cover from being easily opened, it is easy for the breathable cover to fail to open in time and fail to release pressure in time. Therefore, the breathable cover of the prior art will not be able to take into account the purpose of both pressure relief and leakage prevention when used in the gearbox of an aircraft engine. Summary of the invention

[0005] In order to solve the technical problem that the breather valve in the prior art cannot achieve both the purpose of pressure relief and leakage prevention, the present invention provides a breather valve for an aircraft engine gearbox, comprising a valve body with an airway running through it, a valve core and a return spring for pushing the valve core to move in the airway are arranged inside the valve body; wherein: the return spring is located between the bottom of the valve body and the valve core; a drive assembly is also provided in the valve body, and the drive assembly is located above the valve core. In the normal posture, the drive assembly acts entirely on the valve core, driving the valve core to compress the return spring, and the airway opens; in the tilted posture, the drive assembly partially acts on the valve core, and the return spring drives the valve core to press against the airway.

[0006] Note: In the present invention, the normal posture refers to when the left and right tilt angles of the vent valve are less than a fixed value, and when the left and right tilt angles of the vent valve are greater than a fixed value, it is a tilted posture. In the present invention, the fixed value is selected as a value within the range of 25° to 45°.

[0007] Compared with the prior art, in this solution, the return spring is located between the bottom of the valve body and the valve core, that is, the return spring is set below the valve core. Therefore, in the normal posture, the gravity of the drive assembly above the valve core acts on the valve core, which can compress the return spring to compress, and a gap appears between the valve core and the airway, and the air inside and outside the gearbox can flow through the gap. In the tilted posture, at this time, because the drive assembly partially acts on the valve core, that is, the gravity of the drive assembly acting on the valve core is reduced, and it is not enough to compress the return spring to contract, so the return spring is reset, thereby driving the valve core to move and press against the airway, and the airway is closed, avoiding the leakage of lubricating oil from the airway in the tilted posture.

[0008] Moreover, in the present solution, through the cooperation between the driving assembly and the return spring, as long as the gravity of the driving assembly is greater than the elastic force setting of the return spring, the compression of the return spring can be ensured in the normal posture, and the restoration of the return spring can also be ensured in the inclined posture, thus achieving the purpose of both pressure relief and leakage prevention, and having a simple structure.

[0009] Preferably, the driving assembly includes a driving member and a valve seat installed in the airway, the valve seat is provided with an airway matching the valve core, in a normal posture, the driving member presses the valve core, and in a tilted posture, the driving member partially presses the valve core. In this solution, the opening or closing of the airway is realized by utilizing the cooperation of the driving member and the valve seat to act on the valve core, and the structure is simple.

[0010] Preferably, the side wall of the airway in contact with the driving member is tilted outward. In this solution, the side wall of the airway is tilted, and in the tilted posture, the driving member will move along the tilted side wall, and after the movement, only part of the driving member will contact the valve core, so the driving member partially acts on the valve core, and the valve core closes the airway under the action of the return spring, and the structure is simple.

[0011] Preferably, the valve core includes a plunger body, and a plugging end matching the airway is provided on the upper portion of the plunger body. In this solution, the setting of the plugging end matching the airway can make the plugging end fit the airway to achieve a tighter plugging of the airway, which can further prevent the leakage of lubricating oil.

[0012] Preferably, an elastic ring is provided on the blocking end. The provision of the elastic ring in this solution can further enhance the tight blocking effect on the airway and further prevent the leakage of lubricating oil.

[0013] Preferably, an oil sealing assembly that allows air to flow is provided on the upper part of the valve body. In this solution, the provision of the oil sealing assembly can prevent the leakage of lubricating oil during the flow of air inside and outside the gearbox, thereby reducing the risk of lubricating oil leakage.

[0014] Preferably, the oil sealing assembly includes a water-gas separation membrane. In this solution, the water-gas separation membrane is used to separate air from lubricating oil, thereby reducing the risk of lubricating oil leakage.

[0015] Preferably, the oil sealing assembly further comprises a pressing plate provided with small holes, the pressing plate being located on the inner side of the water-gas separation membrane or the pressing plate being located on the inner side and the outer side of the water-gas separation membrane. In this solution, the setting of the pressing plate can protect the water-gas separation membrane and increase the service life of the water-gas separation membrane.

[0016] The present invention has the following beneficial effects: 1. The present invention can ensure gas circulation inside and outside the gear box in a normal posture, avoiding the problem of oil mist escaping due to excessive pressure inside the gear box. In an inclined posture, it can isolate the inside and outside of the gear box to prevent the lubricating oil in the gear box from leaking, thereby achieving the purpose of both pressure relief and leakage prevention.

[0017] 2. The present invention can prevent the leakage of lubricating oil during the flow of air inside and outside the gear box, thereby reducing the risk of lubricating oil leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of an embodiment of a breather valve for an aircraft engine gearbox according to the present invention; Figure 2 This is a schematic diagram of the air vent valve being tilted. DETAILED DESCRIPTION

[0019] The following is further described in detail through specific implementation methods: 1. Definition Water-gas separation membrane: a membrane material with selective permeability that allows air to pass normally but prevents liquid from passing.

[0020] 2. The reference numerals in the drawings of the specification include: pressure plate 1, water-gas separation membrane 2, valve body 3, drive member 4, valve seat 5, elastic ring 6, gasket 7, return spring 8, plunger body 9, oil sealing assembly 10.

[0021] The embodiment is basically as shown in the attached Figure 1 and Figure 2 As shown: a breathable valve for an aircraft engine gearbox, including a valve body 3 with an air passage running through it, a valve core and a return spring 8 for pushing the valve core to move in the air passage are arranged inside the valve body 3; the return spring 8 is located between the bottom of the valve body 3 and the valve core, specifically, the valve core includes a plunger body 9 and an elastic ring 6, a blocking end matching the air passage is arranged on the upper part of the plunger body 9, the elastic ring 6 is arranged on the blocking end, the return spring 8 is sleeved on the plunger body 9, and the elastic ring 6 is an O-ring.

[0022] A driving assembly is also provided in the valve body 3. The driving assembly is located above the valve core. In the normal posture, the driving assembly acts entirely on the valve core, driving the valve core to compress the return spring 8, and the airway is opened. In the tilted posture, the driving assembly partially acts on the valve core, and the return spring 8 drives the valve core to press against the airway. Specifically, the driving assembly includes a driving member 4 and a valve seat 5 installed in the airway. The valve seat 5 is provided with an airway matching the valve core, and the upper side wall of the airway is tilted outward. In the normal posture, the driving member 4 compresses the valve core. In the tilted posture, the driving member 4 partially compresses the valve core. The driving member 4 is a steel ball, and the diameter of the steel ball is smaller than the aperture of the airway.

[0023] An oil sealing assembly 10 that allows air to flow is provided on the upper part of the valve body 3. The oil sealing assembly 10 includes a water-gas separation membrane 2 and a pressure plate 1 with small holes. The pressure plate 1 is located on the inner side of the water-gas separation membrane 2 or the pressure plate 1 is located on the inner side and the outer side of the water-gas separation membrane 2. In this embodiment, pressure plates 1 are provided on both sides of the water-gas separation membrane 2.

[0024] The specific implementation process is as follows: the vent valve in this embodiment is used in the gear box of an aerial drone as an example, the lower part of the valve body 3 is provided with threads, the valve body 3 is connected to the corresponding position on the gear box through threads, and a gasket 7 is also provided between the valve body 3 and the gear box. Figure 1 As shown, under normal conditions, that is, when the UAV is in normal flight, when the left and right inclination angles of the air valve are less than a fixed angle in the range of 25° to 45°, the driving member 4 falls into the air passage of the valve seat 5 and presses down the valve core. Even if the air valve is tilted, because the inclination angle of the air valve is less than the fixed angle, the force applied by the driving member 4 to the return spring 8 is greater than the restoring force of the return spring 8. Therefore, the return spring 8 is in a compressed state, and the valve core withdraws from the air passage of the valve seat 5. A gap appears between the valve core and the air passage, and the inside and outside of the gear box are connected through the gap. The air in the gear box can flow out normally to achieve pressure relief.

[0025] like Figure 2 As shown, when the UAV's flight posture tilts, the vent valve tilts, and the left and right tilt angles are greater than the fixed angle, the drive member 4 rolls along the side wall of the valve seat 5. At this time, the gravity applied to the valve core by the drive member 4 is reduced, and only part of the gravity is applied to the valve core, which cannot overcome the elastic force of the return spring 8, so the return spring 8 is reset, pushing the valve core upward, and the upward valve core abuts against and blocks the airway, and the inside and outside of the gear box are no longer connected, which can prevent the lubricating oil in the gear box from flowing out, avoiding the problem of lubricating oil leakage when the UAV posture tilts.

[0026] In the above process, the fixed angle of inclination of the vent valve is confirmed according to the actual factory conditions of the vent valve, that is, when different vent valves are used, the division of the left and right inclination angles of the vent valve corresponding to the state in which the driving member can maintain the downward pressure on the valve core during the tilting of the vent valve will be different. In this embodiment, the fixed angle is a value in the range of 25° to 45°.

[0027] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A breathable valve for an aircraft engine gearbox, comprising a valve body having an air passage running through it, a valve core and a return spring for pushing the valve core to move in the air passage being arranged inside the valve body; characterized in that: The return spring is located between the bottom of the valve body and the valve core; a drive assembly is also provided in the valve body, and the drive assembly is located above the valve core. In a normal posture, the drive assembly acts entirely on the valve core, driving the valve core to compress the return spring, and the airway is opened; In the tilted posture, the drive assembly partially acts on the valve core, and the return spring drives the valve core to press against the air passage.

2. The breather valve for an aircraft engine gearbox according to claim 1, characterized in that: The driving assembly includes a driving member and a valve seat installed in the airway, the valve seat is provided with an airway matching the valve core, in a normal posture, the driving member presses the valve core, and in a tilted posture, the driving member partially presses the valve core.

3. The breather valve for an aircraft engine gearbox according to claim 2, characterized in that: The side wall of the air passage in contact with the driving member is arranged to be inclined outward.

4. The breather valve for an aircraft engine gearbox according to claim 2 or 3, characterized in that: The valve core comprises a plunger body, and a blocking end matching the airway is provided on the upper part of the plunger body.

5. The breather valve for an aircraft engine gearbox according to claim 4, characterized in that: An elastic ring is arranged on the blocking end.

6. The breather valve for an aircraft engine gearbox according to claim 5, characterized in that: An oil sealing component allowing air to flow is arranged on the upper part of the valve body.

7. The breather valve for an aircraft engine gearbox according to claim 6, characterized in that: The oil sealing assembly includes a water-gas separation membrane.

8. The breather valve for an aircraft engine gearbox according to claim 7, characterized in that: The oil sealing assembly further comprises a pressing plate provided with small holes, wherein the pressing plate is located on the inner side of the water-gas separation membrane or the pressing plate is located on the inner side and the outer side of the water-gas separation membrane.

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