阅读说明：本技术 用于航空发动机且配有滤气器及滤气器旁路管的进气单元 (Air intake unit for an aircraft engine, provided with an air filter and a bypass pipe for the air filter ) 是由 G·贝尔加米 于 2018-06-04 设计创作，主要内容包括：用于航空器(1)的发动机(2)的进气单元(5)具有：外壳(6),内部限定有气室(7),气室能连接至航空器(1)的发动机(2)；主进气口(8)；与主进气口(8)接合的滤气器(9)；旁路进气口(10)；开闭器装置(11),与旁路进气口(10)联接并具有两个分隔件(13、14),这两个分隔件被安装成适于绕彼此平行且间隔开的各自旋转轴线(15、16)旋转；以及致动器(12),使开闭器装置(11)在封闭位置与打开位置之间移动。在开闭器装置(11)的打开位置,上分隔件(13)被排布为横向于外壳(6)的壁(17)且处于旁路进气口(10)的中心区域,下分隔件(14)被排布为平行于外壳(6)的壁(17)且与壁(17)重叠。(An intake unit (5) for an engine (2) of an aircraft (1) comprises: a casing (6) internally defining a plenum (7) connectable to an engine (2) of the aircraft (1); a primary air inlet (8); an air filter (9) coupled to the primary air inlet (8); a bypass air inlet (10); a shutter device (11) coupled to the bypass air inlet (10) and having two partitions (13, 14) mounted so as to be suitable for rotating about respective axes of rotation (15, 16) parallel to and spaced apart from each other; and an actuator (12) that moves the shutter device (11) between the closed position and the open position. In the open position of the shutter device (11), the upper partition (13) is arranged transversely to the wall (17) of the casing (6) and in the central region of the bypass air intake (10), and the lower partition (14) is arranged parallel to the wall (17) of the casing (6) and overlapping the wall (17).)

1. air intake unit (5) for an engine (2) of an aircraft (1), the air intake unit (5) comprising:

A casing (6) inside which a plenum (7) is defined, which can be connected to the engine (2) of the aircraft (1);

A primary air inlet (8) obtained through a wall (17) of the casing (6) and through which external air required for the operation of the engine (2) can be drawn into the air chamber (7);

At least one air filter (9) supported by the housing (6) and engaged with the primary air inlet (8) to filter external air flowing through the primary air inlet (8);

At least one bypass air inlet (10) obtained through a wall (17) of the casing (6), separate and independent from the main air inlet (8) and the air filter (9), and through which external air required for the operation of the engine (2) can be sucked into the plenum (7);

A shutter device (11) coupled with the bypass air intake (10) and movable between a closed position, in which it closes the bypass air intake (10), and an open position, in which it sets the passage through the bypass air intake (10) free; and

an actuator (12) moving the shutter device (11) between the closed position and the open position;

wherein the shutter device (11) comprises two partitions (13, 14) mounted to rotate about respective axes of rotation (15, 16) parallel and spaced apart from each other and flush with the wall (17) of the casing (6) in the closed position to connect seamlessly the two ends of the wall (17) at the opposite sides of the bypass air inlet (10);

The intake unit (5) is characterized in that:

In the open position of the shutter device (11), an upper partition (13) is arranged transversely to the wall (17) of the casing (6) and in a central region of the bypass air intake (10); and is

in the open position of the shutter device (11), a lower partition (14) is arranged parallel to the wall (17) of the casing (6) and overlapping the wall (17).

2. An air inlet unit (5) according to claim 1, wherein the lower partition (14) is arranged on the inside of the air chamber (7) in the open position of the shutter means (11).

3. an air inlet unit (5) according to claim 1, wherein in the open position of the shutter device (11) the lower partition (14) is arranged facing an inner surface of the wall (17) of the housing (6).

4. an air inlet unit (5) according to claim 1, wherein in the open position of the shutter means (11) the lower partition (14) is located completely outside the bypass air inlet (10).

5. An air inlet unit (5) according to claim 1, wherein in the open position of the shutter means (11) the upper partition (13) is arranged in the middle of the bypass air inlet (10) and acts as a flow deflector, the upper partition directing air towards the air chamber (7).

6. An air inlet unit (5) according to claim 1, wherein in the closed position of the shutter device (11) the partitions (13, 14) are tangential to the wall (17) of the casing (6) and also to each other.

7. Air inlet unit (5) according to claim 1, wherein for moving from the closed position to the open position or for moving from the open position to the closed position both partitions (13, 14) are rotated in the same direction.

8. Air inlet unit (5) according to claim 1, wherein the two partitions (13, 14) are angularly integral with each other to rotate together and in a synchronized manner about respective axes of rotation (15, 16).

9. an air inlet unit (5) according to claim 1, wherein one lower partition (14) is carried by at least one rocker arm (18) which is hinged to rotate about a first axis of rotation (16).

10. An intake unit (5) according to claim 9, wherein the rocker arm (18) comprises an outer arm (19) which is "V" -shaped and is rigidly connected to the lower partition (14), and an inner arm which is opposite to the outer arm (19) with respect to the first rotation axis (16) and is mechanically connected to the actuator (12).

11. The intake unit (5) according to claim 10, wherein the actuator (12) is a linear actuator and comprises a slider (21) that moves linearly and is articulated to one end of the inner arm (20) of the rocker arm (18).

12. An air inlet unit (5) according to claim 9, wherein the upper partition (13) is carried by at least one support arm (22) which is "V" -shaped and is hinged to rotate about a second axis of rotation (15).

13. An intake unit (5) according to claim 12, wherein an interconnection arm (23) is provided which connects the rocker arm (18) to the support arm (22) so that the rocker arm (18) is angularly integrated with the support arm (22) and thus transmits the rotary motion of the rocker arm (18) to the support arm (22).

14. An air inlet unit (5) according to claim 13, wherein the interconnecting arm (23) has an adjustable length.

Technical Field

The present invention relates to an air intake unit for the engine of an aircraft (aircraft), i.e. a man-made machine, which is self-supporting and movable in the air so as to allow the transport of people or objects in the earth's atmosphere.

The invention can be advantageously applied to helicopters, to which the following description refers in particular, without loss of generality.

background

Modern helicopters are equipped with at least one engine, the operation of which requires a continuous flow of fresh air; the term engine refers to both the main engine that operates the blade assembly and the auxiliary engine (also referred to as APU- "auxiliary power unit") that operates the auxiliary service equipment. In order to supply each engine with fresh air, the helicopter is equipped with at least one air intake, which may be provided with a filtering system and a duct (also called "plenum") arranged downstream of the filtering system and terminating in the engine.

When the dynamic pressure of air generated by helicopter motion is used to increase the intake static pressure and thus improve the volumetric efficiency of the engine, the air intake through the intake port may be dynamic (also referred to as "RAM"); in this case, the air inlet is (at least partially) oriented perpendicular to the direction of movement. Alternatively, when fresh air is drawn in due solely to the negative pressure effect generated by the engine, the air intake through the intake port may be static; in this case, the air intake is oriented laterally with respect to the direction of movement (and therefore on the side wall or the top wall of the fuselage).

Helicopters must be able to operate in a wide variety of environmental conditions, and therefore each engine of the helicopter must be protected in order to be able to operate even in extreme environmental conditions, for example in the presence of a large amount of dust, such as in sandy environments (beaches, deserts), or in the presence of many foreign bodies, such as dry leaves and the like.

The greatest risk of a helicopter engine is the ingestion of dust or other solid particles suspended in the atmosphere (due to the proper atmospheric movement and to the effect of the helicopter blades). In order to protect the engine from these risks, each intake unit may be equipped with at least one filtering system with its own air filter (air filter ) to block particles and thus protect the engine. The air filter may be of the barrier type (i.e. comprising one or more layers of porous material that trap particles) or of the centrifugal type (i.e. using centrifugal force to separate heavier solid particles from the incoming air stream).

The presence of a filtering system increases the service life of the engine, but at the same time constitutes a potential threat to flight operations, since the filtering system may be completely or partially clogged in the event of the amount of accumulated solid particles or the particle flow rate exceeding the capacity of the air filter or in the event of icing. If a complete or partial blockage of the filter system occurs, the respective engine may experience a significant (in the worst case even complete) power loss, leading to an accident. In order to always ensure a sufficient air flow towards the engine even if the filter is clogged, each filter system is equipped with an alternative or auxiliary intake path (also called bypass path) allowing the engine to be supplied with outside air that does not pass through the filter; in this way, safe and correct operation of the engine is ensured under all flight conditions.

Patent applications EP2282031a1, GB1201096A and EP3121416a1 describe air intake units for aircraft engines in which the air filter is mounted such that it can be moved (for example by rotational movement) when necessary to release the bypass path.

Patent applications EP3121415a1 and EP3121416a1 describe an air intake unit for an aircraft engine in which a main air intake is provided with a main air intake with which an air filter is permanently engaged, and a bypass air intake provided with a shutter device movable between a closed position, in which it closes the bypass air intake, and an open position, in which it allows free passage through the bypass air intake.

Disclosure of Invention

it is an object of the present invention to provide an air intake unit for an aircraft engine, which is provided with an air filter and an air filter bypass duct and which optimizes performance when the bypass duct is in use (i.e. when the bypass duct is opened to bypass the air filter).

According to the present invention, there is provided an air intake unit for an aircraft engine; the air intake unit includes:

A housing defining a plenum chamber within an interior of the housing, the plenum chamber being connectable to an engine of an aircraft;

A main intake port that is obtained through a wall of the housing and through which outside air required for the operation of the engine can be drawn into the air chamber;

at least one air filter supported by the housing and engaged with the primary air intake to filter outside air flowing through the primary air intake;

at least one bypass air inlet, obtained through a wall of the casing, separate and independent from the main air inlet and the air filter, and through which the external air required for the operation of the engine can be sucked into the air chamber;

A shutter device coupled to the bypass air inlet and movable between a closed position, in which it closes the bypass air inlet, and an open position, in which it sets a passage through the bypass air inlet free; and

An actuator that moves the shutter device between the closed position and the open position;

Wherein the shutter device comprises two partitions mounted to rotate about respective axes of rotation parallel to and spaced from each other and flush with the wall of the casing in the closed position, so as to connect seamlessly the two ends of the wall at opposite sides of the bypass air intake;

the air intake unit is characterized in that:

In the open position of the shutter device, the upper partition is arranged transversely to the wall of the casing and in a central region of the bypass air intake; and is

in the open position of the shutter device, the lower partition is arranged parallel to and overlapping the wall of the housing.

The claims describe preferred embodiments of the invention which form an integral part of the present description.

Drawings

The invention will now be described with reference to the accompanying drawings, which show non-limiting embodiments thereof, in which:

FIG. 1 is a schematic perspective view of a helicopter comprising a pair of twin turbine engines, each provided with an air intake unit made in accordance with the present invention;

FIG. 2 is a front view of one of the two intake units of FIG. 1 with the bypass duct in a closed configuration;

FIG. 3 is a cross-sectional view taken along line III-III of a portion of the intake unit of FIG. 2 with the bypass duct in a closed configuration;

FIG. 4 is a front view of the intake unit of FIG. 2 with the bypass duct in an open configuration; and

FIG. 5 is a cross-sectional view taken along line V-V of a portion of the intake unit in FIG. 2 with the bypass duct in a closed configuration.

List of reference numerals in the drawings

1 helicopter

2 turbine engine

3 inlet of the device

4 outlet port

5 air intake unit

6 outer cover

7 air chamber

8 Primary air intake

9 air filter

10 bypass air inlet

11 shutter device

12 actuator

13 upper partition

14 lower partition

15 axis of rotation

16 axis of rotation

17 wall

18 rocker arm

19 outer arm

20 inner arm

21 sliding block

22 support arm

23 interconnecting arm

Detailed Description

In fig. 1, numeral 1 generally designates a helicopter comprising two twin-turbine engines 2 (only one of which is visible in fig. 1) operating blade assemblies which allow the helicopter to be lifted vertically, to remain stationary in flight, and to be moved sideways, backwards or forwards.

Each turbine engine 2 comprises a tubular casing having, at the front, an air inlet 3 through which the turbine engine 2 draws in the external air required for its operation, i.e. the external air containing the oxygen required for combustion, and, at the rear, an air outlet 4 through which the turbine engine 2 discharges the exhaust gases resulting from the combustion. At the air inlet 3 of each turbine engine 2 there is provided an air intake unit 5, through which intake unit 5 the air taken in by said turbine engine 2 flows.

As shown in fig. 2 to 5, each air intake unit 5 comprises a hollow casing 6 within which is defined a plenum 7 (i.e. an air intake chamber) in pneumatic communication with the turbine engine 2. Each casing 6 comprises a primary air inlet 8 through which external air required for the operation of the turbine engine 2 can be drawn; in other words, the outside air required for the operation of each turbine engine 2 may enter the plenum 7 by passing through the primary air inlet 8, and then pass from the plenum 7 to the turbine engine 2. In the embodiment shown in the figures, each casing 6 comprises a single primary air inlet 8, whereas according to other not shown and fully equivalent embodiments, each casing 6 comprises a plurality of primary air inlets 8 alongside one another.

Each air intake unit 5 comprises an air filter 9, which air filter 9 is supported by the casing 6 and engages the entire primary air intake 8 to filter the external air passing through said primary air intake 8 and entering the air chamber 7; in other words, the air filter 9 reproduces the shape of the main air inlet 8, engaging the main air inlet 8 in a gapless manner, then filtering all the air that passes through the main air inlet 8 and enters the air chamber 7. Preferably, each air filter 9 comprises a rectangular support frame (made of aluminium, plastic material or composite material) fixed to the outer wall of casing 6 and supporting one or more sheets of filtering material (for example made of cotton or other fibrous or non-woven fabric sandwiched between two layers of thin metal mesh, which provides shape and strength to the filtering material).

Each casing 6 also comprises a bypass air inlet 10, which bypass air inlet 10 is completely separate from the main air inlet 8 (and therefore from the air filter 9), is independent of one another, and is arranged alongside the main air inlet 8; in particular, in the embodiment shown in the figures, the bypass inlet 10 is arranged below the primary inlet 8. External air required for the operation of the turbine engine 2 may be drawn in through each bypass intake 10; in other words, the outside air required for the operation of each turbine engine 2 may enter the plenum 7 by passing through the bypass intake 10, and then reach the turbine engine 2 from the plenum 7. In the embodiment shown in the figures, each casing 6 comprises a single bypass air inlet 10, whereas according to other not shown and fully equivalent embodiments, each casing 6 comprises a plurality of bypass air inlets 10 alongside one another.

Each air intake unit 5 comprises a shutter device 11 coupled to the bypass air intake 10 and mounted movably so that it can move between a closed position (shown in fig. 2 and 3), in which it closes the bypass air intake 10 (to prevent the entry of air through the bypass air intake 10), and an open position (shown in fig. 4 and 5), in which it allows free passage of air through the bypass air intake 10 (to allow the entry of air through the bypass air intake 10).

finally, each intake unit 5 comprises an actuator 12 which moves the shutter means 11 between the closed position and the open position.

When each shutter device 11 is in the closed position (as shown in fig. 2 and 3), the external air can enter the plenum 7 (and therefore the turbine engine 2) only by passing through the main air inlet 8 and therefore through the air filter 9. Conversely, when each shutter device 11 is in the open position (as shown in fig. 4 and 5), the external air can enter the plenum 7 (and thus reach the turbine engine 2) both by passing through the primary air inlet 8 and therefore through the air filter 9, and by passing through the bypass air inlet 10 but therefore not through the air filter 9 (since the bypass air inlet 10 is free of filter material, it does not block the passage of air). It is clear that when each shutter device 11 is in the open position (as shown in fig. 4 and 5), almost all the air entering the plenum 7 to reach the turbine engine 2 passes through the bypass air inlet 10 instead of through the main air inlet 8 engaged with the air filter 9, due to the low load losses caused by the cross over (cross) of the bypass air inlet 10.

When each shutter device 11 is in the closed position (as shown in fig. 2 and 3), the incoming air must pass through the primary air intake 8 and through the air filter 9; thus, any impurities present in the air are blocked by the air filter 9, however, passage through the air filter 9 results in a loss of load in the incoming air, which compromises the performance of the turbine engine 2. On the other hand, when each shutter device 11 is in the open position (as shown in fig. 4 and 5), the incoming air passes mainly through the bypass air inlet 10 and any impurities present in the air are not blocked by the air filter 9; therefore, no load loss occurs to the intake air, however, the impurities present in the air are not blocked by the air filter 9.

Each air intake unit 5 comprises an electronic control unit which drives an actuator 12 to move the shutter device 11 between the closed position (as shown in figures 2 and 3) and the open position (as shown in figures 4 and 5). In particular, when helicopter 1 is close to the ground (during take-off or landing or when stationary at low altitude), the incoming air may (likely) contain impurities, so each shutter device 11 is set by the electronic control unit and kept in a closed position to filter the incoming air; in contrast, when helicopter 1 is higher than the ground (i.e. far from the ground, for example at a height of tens of meters), the intake air is less likely to contain impurities, so each shutter device 11 is set and kept in the open position by the electronic control unit, to avoid (unnecessary) compromise of the performance of turbine engine 2.

In addition, each electronic control unit is connected to a pressure sensor which is arranged in the air chamber 7 and measures the pressure of the inlet air after it has passed through the air filter 9; when the incoming air pressure measured by the pressure sensor is below a threshold value, the corresponding shutter device 11 is set and held in the open position (as shown in fig. 4 and 5) by the electronic control unit, regardless of whether the helicopter 1 is close to the ground or not. In other words, the inlet air pressure measured by each pressure sensor indicates the degree of clogging of the corresponding air filter 9, since the more clogged the air filter 9, the less the inlet air pressure measured by the pressure sensor; therefore, when the air filter 9 is too clogged, i.e. when the incoming air pressure measured by the pressure sensor is below a threshold value, each shutter device 11 is set and kept in the open position (as shown in fig. 4 and 5) by the electronic control unit, so as to avoid excessively compromising the performance of the turbine engine 2.

Each shutter device 11 comprises an upper partition 13 and a lower partition 14, which are arranged side by side in the closed position (as shown in figures 2 and 3) to completely cover the bypass air intake 10. In each shutter device 11, the upper partition 13 is rotatably mounted so as to rotate about a rotation axis 15 between a closed position (shown in fig. 2 and 3) and an open position (shown in fig. 4 and 5), and the lower partition 14 is rotatably mounted so as to rotate about a rotation axis 17 between a closed position (shown in fig. 2 and 3) and an open position (shown in fig. 4 and 5), the rotation axis 17 being parallel to and spaced apart from the rotation axis 16. Preferably, in each shutter device 11, in order to move from the closed position (shown in figures 2 and 3) to the open position (shown in figures 4 and 5), both partitions 13 and 14 rotate in the same direction (anticlockwise as seen in the figures); and accordingly, in order to move from the open position (as shown in fig. 4 and 5) to the closed position (as shown in fig. 2 and 3), the two partitions 13 and 14 are rotated in the same direction (clockwise as shown in the drawings).

According to the preferred embodiment shown in the figures, in the closed position (shown in figures 2 and 3), the upper partition 13 and the lower partition 14 of each shutter device 11 are flush with the wall 17 of the casing 6, so as to seamlessly connect the two ends of the wall 17 at the opposite sides of the bypass air intake 10; in other words, in the closed position (as shown in fig. 2 and 3), the partitions 13 and 14 of each shutter device 11 are tangent to the wall 17 of the casing 6 and also to each other. In order to ensure good airtightness in the closed position (shown in fig. 2 and 3), in each shutter device 11, at the bypass air inlet 10, the edges of the partitions 13 and 14 and/or the edge 10 of the wall 17 of the casing 6 have respective elastic gaskets.

According to the preferred embodiment shown in the figures, in the open position (as shown in fig. 4 and 5), in each shutter device 11, the upper partition 13 is arranged transversely to the wall 17 of the casing 6 and in the central region of the bypass air intake 10, and the lower partition 14 is arranged parallel to the wall 17 of the casing 6 and overlapping said wall 17 (in particular inside the air chamber 7, i.e. facing the inner surface of the wall 17). In other words, in the open position (as shown in fig. 4 and 5), in each shutter device 11, the upper partition 13 is arranged in the middle of the bypass air inlet 10 and acts as a deflector which directs the air towards the air chamber 7, while the lower partition 14 is located entirely on the outside of the bypass air inlet 10.

In each shutter device 11, the lower partition 14 is carried by at least one rocker 18 hinged to a wall 17 of the casing 6 so as to rotate about the rotation axis 16 (in practice, two rockers 18 are preferably arranged at opposite sides of the lower partition 14); the rocker 18 has an outer arm 19, which is "V" shaped and rigidly connected to the lower partition 14, and an inner arm 20, which is opposite the outer arm 19 with respect to the rotation axis 16 and is mechanically connected to the actuator 12. In particular, the actuator 12 is a linear (pneumatic, hydraulic or electric) actuator comprising a slider 21, which moves linearly and is hinged to one end of the inner arm 20 of the rocker 18; in this way, the linear movement of the slider 21 of the actuator 12 causes a rotation of the rocker 18 about the rotation axis 16 and, consequently, a subsequent rotation of the lower partition 14 about the rotation axis 16.

In each shutter device 11, the upper partition 13 is carried by at least one supporting arm 22, which is "V" -shaped and is hinged to the wall 17 of the casing 6 so as to rotate about the rotation axis 15 (in practice, two supporting arms 22 are preferably arranged at opposite sides of the upper partition 13). An interconnection arm 23 is provided which connects the rocker arm 18, in particular the outer arm 19 of the rocker arm 18, to the support arm 22, so that the rocker arm 18 is formed angularly integrally with the support arm 22 and, thus, the rotary movement of the rocker arm 18 is transmitted to the support arm 22. According to a preferred embodiment, the interconnection arm 23 has a length that is adjustable (i.e. editable), for example by means of a screw system, to allow, in use, the transmission of the rotational movement of the rocker arm 18 to the support arm 22 to be adjusted.

In summary, each actuator 12 simultaneously moves both partitions 13 and 14 of the shutter device 11, thanks to the presence of the interconnection arm 23 which makes the two partitions 13 and 14 angularly integral with each other.

According to a possible (but non-limiting) embodiment, at each air inlet 9 or 10, a metal grid with a relatively large mesh (in the size range of one or two centimeters) can be arranged, which has the function of preventing birds from entering.

The embodiment shown as an example in the illustrated figures relates to a turbine engine 2, but the invention may find advantageous application in any type of engine for aircraft.

it is important to note that each intake unit 5 described above may be coupled to the main engine of helicopter 1 or to an auxiliary engine of an Auxiliary Power Unit (APU); in other words, each intake unit 5 described above may be used in any case in which fresh air must be taken in from the external environment for the operation of the (main or auxiliary) engine of helicopter 1.

the embodiment shown by way of example in the figures shown relates to a helicopter 1, but the invention may find advantageous application in any type of aircraft (and thus also in an airplane).

The embodiments described herein may be combined with each other without departing from the scope of the invention.

The above-described air intake unit 5 has many advantages.

The above-described air intake unit 5 allows the aircraft 1 to operate safely in areas where dust is flying (and therefore areas where the air close to the ground is filled with impurities raised by natural wind and by the thrust of the aircraft 1), thanks to the presence of the air filter 9, which operates (by arranging the shutter means 11 in the closed position) if necessary to filter in advance the air taken in by the turbine engine 2.

Furthermore, the air inlet unit 5 described above is able to operate without any performance compromise for most flights, since the air filter 9 is bypassed by the bypass air inlet 10 (by arranging the shutter device 11 in the open position) when the aircraft is high above (i.e. far from) the ground.

The shape of the shutter means 11 of the air intake unit 5 described above allows the aerodynamic break (i.e. the aerodynamic resistance that increases during the forward movement) to be zero when the shutter means 11 are in the closed position, and to be minimal when the shutter means 11 are in the open position. In fact, in the closed position, the two partitions 13 and 14 of the shutter device 11 seamlessly complete the wall 17 of the casing 6 (i.e. the "body" of the helicopter 1), while in the open position, the lower partition 14 "disappears" completely in the air chamber 7, while the upper partition 13 becomes a deflector, which allows the air to flow smoothly into the air chamber 7, and the upper partition protrudes very little beyond the dimensions of the casing 6.

Furthermore, the shape of the shutter means 11 makes it possible to minimize the force that must be exerted by the actuator means 12 to move the partitions 13 and 14 between the closed position and the open position.

The air intake unit 5 described above is suitable for any type of helicopter, has a reduced overall size and can be installed relatively simply even in existing helicopters that have not been previously arranged for this solution (i.e. it is suitable for use as a retrofit solution to add new functions to the old system).