阅读说明：本技术 直升机套件 (Helicopter kit ) 是由 路易吉·博塔索 阿蒂利奥·科隆博 皮耶安杰洛·马萨拉蒂 艾库特·塔梅尔 朱塞佩·夸兰塔 于 2019-06-28 设计创作，主要内容包括：描述了一种用于直升机(2)的套件(1),直升机(2)包括机身(3)和旋翼(4)；套件(1)包括适于衰减从旋翼(4)向机身(2)传递的振动并且插在机身(2)与旋翼(4)之间的至少一个装置(15)；装置(15)又包括：能操作地连接至旋翼(4)并且适于在使用中平行于第一轴线(B)振动的第一螺纹元件(21；20)；能操作地连接至机身(4)并且操作地连接至第一螺纹元件(21；20)从而在使用中围绕第一轴线(B)旋转振动的第二螺纹元件(20；21)；多个螺纹滚子(22),它们旋拧在第一和第二螺纹元件(21,20；20,21)上；滚子(22)能围绕其各自的第二轴线(C)相对于第一和第二螺纹元件(20,21)旋转,第二轴线平行于第一轴线并与第一轴线(B)是分离的；滚子(22)也能围绕第一轴线(B)相对于第一螺纹元件(21；20)和第二螺纹元件(20；21)旋转。(It is described a kit (1) for a helicopter (2), the helicopter (2) comprising a fuselage (3) and a rotor (4); the kit (1) comprises at least one device (15) suitable for attenuating the vibrations transmitted from the rotor (4) to the fuselage (2) and interposed between the fuselage (2) and the rotor (4); the device (15) in turn comprises: a first threaded element (21; 20) operatively connected to the rotor (4) and adapted to vibrate, in use, parallel to the first axis (B); a second threaded element (20; 21) operatively connected to the fuselage (4) and to the first threaded element (21; 20) so as to oscillate in rotation about a first axis (B) in use; a plurality of thread rollers (22) screwed on the first and second thread elements (21, 20; 20, 21); the rollers (22) being rotatable relative to the first and second threaded elements (20, 21) about their respective second axes (C), which are parallel to the first axes and are separate from the first axes (B); the roller (22) is also rotatable about the first axis (B) relative to the first threaded element (21; 20) and the second threaded element (20; 21).)

1. A kit (1) for a helicopter (2), said helicopter (2) comprising a fuselage (3) and a rotor (4); said kit (1) comprising at least one device (15) suitable for damping the vibrations transmitted from said rotor (4) to said fuselage (2) and interposed between said fuselage (2) and said rotor (4);

said device (15) in turn comprising:

-a first threaded element (21; 20) operatively connected to said rotor (4) and adapted to vibrate, in use, parallel to a first axis (B);

-a second threaded element (20; 21) operatively connected to said fuselage (4) and to said first threaded element (21; 20) so as to oscillate in rotation about said first axis (B) in use;

-a plurality of threading rollers (22) screwed on said first threading element (21; 20) and on said second threading element (20; 21);

said rollers (22) being rotatable with respect to said second threaded element (20; 21) about their respective second axes (C) parallel to and separate from said first axis (B);

said roller (22) being also rotatable about said axis (B) with respect to said first threaded element (21; 20) and said second threaded element (20; 21);

characterized in that said second threaded element (20; 21) is a screw (20) screwed on said roller (22) and said first threaded element (21; 20) is a female screw (21) screwed on said roller (22);

said female screw (21) defining a second thread, which is internal with respect to said first axis (B) and is screwed on said roller (22);

the screw (20) defines a third thread, external with respect to the first axis (B) and screwed on the roller (22).

2. Kit according to claim 1, characterized in that said roller (22) is movable in translation with said first threaded element (21; 20) in a direction parallel to said first axis (B).

3. Kit according to claim 1 or 2, characterized in that said device (15) is an inerter.

4. Kit according to any one of the preceding claims, characterized in that the roller (22) and the first threaded element (21; 20) have the same thread angle; and/or the roller (22) comprises a first single thread (23); and/or

The first threaded element (21; 20) and the second threaded element (20; 21) comprise a second and a third compound thread, respectively.

5. The kit of claim 4, wherein the kit comprises:

-a constraining element (31) for constraining said second threaded element (20; 21) to said fuselage (2);

-a bearing (41) interposed between said first threaded element (21; 20) and said constraint element (30) to relatively rotate said second threaded element (20; 21) with respect to said constraint element (30) about said first axis (B).

6. Kit according to any one of the preceding claims, characterized in that it comprises a flywheel (40) rotatable about said first axis (B) and operatively connected to said roller (22) and to said second threaded element (20; 21).

7. Kit according to claim 6, characterized in that said flywheel (40) is angularly integral with said second threaded element (20; 21).

8. Kit according to any one of the preceding claims, characterized in that it comprises at least one crown (47) fastened on said second threaded element (20; 21);

the crown (47) comprises gear teeth (49) facing the first axis (B) and meshing with a plurality of gear teeth (45, 46) carried by respective rollers (22).

9. A kit (1) for a helicopter (2), said helicopter (2) comprising a fuselage (3) and a rotor (4); the kit (1) comprises at least one device (15) suitable for damping the vibrations transmitted from the rotor (4) to the fuselage (2) and interposed between the fuselage (2) and the rotor (4);

said device (15) in turn comprising:

-a first threaded element (21; 20) operatively connected to said rotor (4) and adapted to vibrate, in use, parallel to a first axis (B);

-a second threaded element (20; 21) operatively connected to said fuselage (4) and to said first threaded element (21; 20) so as to oscillate in rotation about said first axis (B) in use;

-a plurality of threading rollers (22) screwed on said first threading element (21; 20) and on said second threading element (20; 21);

said rollers (22) being rotatable with respect to said second threaded element (20; 21) about their respective second axes (C) parallel to and separate from said first axis (B);

said roller (22) being also rotatable about said axis (B) with respect to said first threaded element (21; 20) and said second threaded element (20; 21);

characterized in that it comprises at least one crown (47) fastened to said second threaded element (20; 21);

the crown (47) comprises gear teeth (49) facing the first axis (B) and meshing with a plurality of gear teeth (45, 46) carried by respective rollers (22).

10. The kit according to any one of the preceding claims, comprising a support element (25), the support element (25) defining a plurality of seats (26), the plurality of seats (26) being in angularly fixed engagement with the respective roller (22);

the support element (25) is angularly movable about the first axis (B) with respect to the first threaded element (21; 20) and the second threaded element (20; 21).

11. A helicopter, comprising:

-said fuselage (2);

-said rotor (4);

-a support housing (5) of the rotor (4); and

-a plurality of connecting rods (7) interposed between said fuselage (2) and said support casing (5);

characterized in that it comprises, for each of said rods (7), a kit (1) according to any one of the preceding claims;

the damping device (15) is inserted between the housing (5) and the fuselage (2).

12. A helicopter according to claim 11, characterized in that said first (21; 20) and second (20; 21) threaded elements are constrained to the associated said rods (7).

13. A helicopter according to claim 11 or 12, characterized in that at least one of said rods (7) and said respective device (15) are hinged to said fuselage (2) about a third axis (D) coinciding with each other;

said at least one rod (7) and said respective device (15) are hinged to said rotor (4) about the same respective fourth axis (E) coinciding with each other.

14. A helicopter according to any one of claims 11 to 13, characterized in that one of said rod (7) and said device (15) is housed inside the other of said rod (7) and said device (15).

Technical Field

The present invention relates to a kit for a helicopter.

Background

Helicopters are known that basically comprise a fuselage, a main rotor located on top of the fuselage and rotating about its own axis, and a tail rotor located at the end of the fuselage.

In more detail, the rotor in turn substantially comprises:

-a support housing;

-a hub rotatable about said axis and equipped with a plurality of blades radially fastened to and projecting from said hub; and

-a main shaft connectable to the drive member and operatively connected to the hub to drive the hub in rotation.

The fuselage is usually constrained to the rotor by a plurality of connecting rods and anti-torque plates; in other words, the fuselage "hangs" on the support shell.

In use, the operation of the rotor causes the generation of high and low frequency vibrations. More specifically, the low frequency vibrations are generated by the wash flow separated from the center of the blade and hub. This separation occurs at the center of the hub and affects the vertical and horizontal aerodynamic tail surfaces and tail rotors.

In use, the high angular velocity rotation of the blades causes the generation of additional high frequency vibrations which are transmitted to the main shaft and hence to the fuselage, thereby reducing the comfort of occupants within the fuselage.

It is well known in the industry that the vibratory loads acting on the rotor have pulses equal to N x Ω and multiples thereof in a frame of reference integral to the fuselage, where Ω is the rotational speed of the mast and N represents the number of rotor blades.

In other words, the hub and the main shaft transmit to them the pulses of the vibro-aerodynamic loads acting on the blade plane.

From the foregoing, there is clearly felt within the industry the need to limit the transmission of vibrations from the spindle to the fuselage with the above-mentioned pulse values equal to N x Ω and multiples thereof.

Passive and active damping devices are known for this purpose.

Passive damping devices basically comprise a mass body which is elastically suspended by a spring on a main shaft or hub. The vibrations of these suspended masses can at least partially absorb the vibrations on the main shaft and the hub.

The damping device converts kinetic energy in the elastic supporting motion of the mass body and applies a damping force proportional to the modulus of the spring and the displacement of the mass body.

Alternatively, the active damping means are essentially actuators which exert a sinusoidal damping force on the hub or spindle which counteracts the forces generated by the vibrations.

Damping devices that operate by absorbing vibrations through passive vibrating elements require the use of a combination of mass and spring in a standard layout and have minimal overall dimensions that limit flexibility of use.

Active damping devices are expensive and complex to manufacture.

Another solution recently developed is represented by the so-called "inertial" devices (called "inerters").

These devices are interposed between a first point and a second point and exert on them a force proportional to the difference in acceleration between the first point and the second point, the acceleration component along the line connecting these two points being expected.

By appropriate calibration of the inertia values, it can be ensured that the force reduces or eliminates the transmission of vibrations between the first point and the second point having a given frequency.

A first example of these inertial-type devices is described in EP-B-1402327, which essentially comprises:

-a rod connected to the first point;

-a housing connected to the second point, the rod being slidable relative to the housing; and

-a flywheel connected to the lever and able to rotate inside the housing due to the sliding of the lever caused by the vibrations on the first point.

US-A-2009/0108510 describes another inertial type damping device.

There is a recognized need in the industry for an inertial type damping device that can be easily integrated in helicopters of known type without altering the aerodynamic configuration of the helicopter.

There is also a recognized need in the industry for an inertial type damping device that is particularly compact, particularly accurate, and capable of damping large amplitude vibrations.

There is also a recognized need in the industry for a durable, inertia-type damping device with high load capacity and lowest possible friction.

JP- ｃA-S6078130 discloses ｃA kit according to the preamble of claims 1 and 9.

Disclosure of Invention

The object of the present invention is to provide a kit for a helicopter which is capable of meeting at least one of the above-mentioned needs in a simple and inexpensive manner.

The above mentioned objects are achieved by the present invention, as far as it relates to a kit for a helicopter according to claim 1.

The invention also relates to a kit for a helicopter according to claim 9.

Drawings

For a better understanding of the present invention, preferred embodiments are described below by way of non-limiting example only and with reference to the accompanying drawings, in which:

figure 1 is a perspective side view of a main rotor of a helicopter with a kit according to the present invention, with some parts removed for clarity;

figure 2 is an enlarged section along the axis II-II of figure 1 of the components of the kit of figure 1, with some parts removed for clarity;

fig. 3 is an enlarged section of the assembly of fig. 2 along the line III-III of fig. 2, with parts removed for clarity;

figure 4 is a section along the line IV-IV of figure 3; and

figure 5 is a highly enlarged perspective view of a helicopter comprising the kit of figures 1 to 4.

Detailed Description

With reference to fig. 1, reference numeral 1 denotes a kit for a helicopter 2.

With reference to fig. 5, helicopter 2 basically comprises a fuselage 3, a main rotor 4 positioned on top of fuselage 3 and rotating about axis a, and a tail rotor positioned at one end of fuselage 3 and rotating about its own axis transverse to axis a.

In more detail, the rotor 4 is shown only in the following respects:

-a support housing 5;

a main shaft 6 rotating about an axis a, coupled in a manner not shown with a drive unit (for example, a turbine) carried by helicopter 1, and operatively connected to a hub (not shown) on which a plurality of blades (also not shown) are articulated.

Helicopter 2 also comprises a plurality of rods 7 extending along respective axes B inclined with respect to axis a and having respective ends 8 and 9 opposite each other, ends 8 and 9 being fastened to casing 5 and to top 10 of fuselage 3, respectively.

The bar 7 is hinged about axes D and E to anchors 12 and 13 carried by the top 10 and the casing 5, respectively.

Kit 1 comprises a plurality of devices 15 for damping the vibrations transmitted by rotor 4 to fuselage 3.

In the case shown, there are four devices 15 associated with the respective rods 7.

With reference to fig. 2 to 4, the means 15 extend along respective axes B, are hollow and house the associated rods 7.

Since the devices 15 are identical, only a single device 15 is described below.

Advantageously, the device 15 comprises (fig. 2 to 4):

a female screw 21 connected to rotor 4 and adapted to oscillate parallel to axis B;

a screw 20 connected to the fuselage 3, operatively connected to a female screw 21, so as to oscillate in rotation about an axis B; and

a plurality of threaded rollers 22 having threads 23 screwed onto the screw 20 and the female screw 21, able to rotate about their respective axes C, parallel to and separate from the axis B, and also able to rotate about the axis B with respect to the screw 20 and the female screw 21.

In this way, the device 15 realizes an inertial mass, i.e. a device capable of exerting on the fuselage 3 and the casing 5 a force proportional to the difference in acceleration between the fuselage 3 and the casing 5.

This force is able to damp the vibrations generated by the operation of the rotor 4 and to suppress their transmission to the fuselage 3.

In more detail, the device 15 comprises:

a tubular axial end projection 30, which is fastened to the housing 5; and

a tubular axial end projection 31 axially opposite projection 30 and fastened to top 10 of fuselage 2.

Projections 30 and 31 are hinged to respective anchors 12 and 13 about respective axes D and E.

Thus, the projection 30 is subjected to an alternating movement of axial vibrations parallel to the axis B, caused by the vibration load transmitted by the casing 5.

The device 15 further comprises, interposed between the projections 30 and 31:

a tubular body 32 fastened on the projection 30 and defining, on a portion axially opposite to the projection 30, the female screw 21; and

a tubular body 33 fastened on the projection 31 and defining the screw 20 on a portion axially opposite the projection 30.

In particular, the tubular body 32 comprises, in turn, at its axial ends opposite to each other:

a cup-shaped portion 35 connected to the projection 30; and

a cup-shaped portion 36 having a diameter greater than that of portion 35 and defining female screw 21.

Tubular body 33 in turn comprises:

a cup-shaped portion 37 connected to the projection 31; and

a portion 38 having a length longer than the portion 37 and a diameter smaller than the portion 37, and defining the screw 20.

The diameter of the portion 38 of the tubular body 33 is smaller than the diameter of the portion 36 of the tubular body 32.

Portion 38 of tubular body 33 is received within portion 36 of tubular body 32.

The screw 20 and the female screw 21 have a double-threaded screw.

The screw 20 and the female screw 21 are arranged radially facing each other and radially spaced apart from each other with respect to the axis B.

The rollers 22 are arranged in a position radially interposed between the screw 20 and the female screw 21 in the radial direction of the axis B.

The rollers 22 extend along their respective axes C and each have an external thread 23.

The thread 23 is screwed to both the female screw 21 and the screw 20.

The rollers 22 extend along respective axes C and are angularly equally spaced from one another about axis B, and in the case shown are nine in number.

The rollers 22 are:

-rotatable in a rotary motion about an axis C; and

simultaneously rotatable in a gyratory motion about axis B.

Preferably, the roller 22 is movable in translation with the female screw 21 in a direction parallel to the axis B.

Preferably, the thread angle of the thread 23 on the roller 22 is equal to the thread angle of the female screw 21.

Due to the coupling between the thread 23 and the screw 20, translation of the roller 22 along the axis B causes rotation of the tubular body 33 about the axis B.

Each roller 22 further comprises:

two axial ends 27 and 28 opposite each other; and

two gears 45 and 46, respectively, arranged adjacent to the ends 27 and 28.

The thread 23 of the roller 22 is a single thread.

It is important to underline that the angles of the threads 23 of the rollers 22, the threads of the screw 20 and the threads of the female screw 21 shown in the figures are merely symbolic.

The coupling between the thread 23 of the roller 22 and the screw 20 and the female screw 21 is reversible.

The device 15 further comprises a pair of crowns 47 and 48, respectively fastened to the female screw 21 and made integral with the female screw 21.

The crowns 47 and 48 are coaxial with and spaced apart along axis B.

Each crown 47 and 48 has internal gear teeth 49 which mesh with the respective gear 45 and 46 of each roller 22.

In this way, during rotation of the roller 22 about the axis B, the gears 45 and 46 mesh with the gear teeth 49 (fig. 4).

The device 15 also comprises two disc-shaped supports 25 on axis B, spaced from each other along axis B and rotatable with respect to the female screw 21 and to the screw 20.

Each support 25 defines a plurality of seats 26, which seats 26 are angularly equidistant from each other about the axis B and engage with the axial ends 27 of the respective rollers 22.

In the embodiment shown, there is a radial play between the support 25 and the portion 36.

In an alternative embodiment, an element with a low friction coefficient may be inserted between the support 25 and the portion 26 of the female screw 21.

The device 15 further comprises:

a flywheel 40 rotating about an axis B and angularly integral with the screw 20; and

two bearings 41 radially interposed between the portion 37 of the tubular body 33 and the projection 31.

In the case shown, the freewheel 40 is located at the shoulder defined by the portions 37 and 38 of the body 33.

As the tubular body 32 oscillates along the axis B, the freewheel 40 rotates with the screw 20.

The flyweight 40 is sized to achieve a desired value of rotational mass equal to the sum of the masses of the roller 22, the tubular body 32 and the flyweight 40. This value of the rotating mass adjusts the means 15 to a predetermined value of the vibration frequency of the housing 5, thanks to which the transmission to the fuselage 3 can be damped.

The bearing 41 enables the tubular body 33 to rotate relatively to the projection 31 about the axis B and supports the axial load transmitted by the screw 20.

The ends 8 and 9 of the rod 7 are received in the projections 30 and 31, respectively.

The rod 7 extends along the axis B starting from the end 8 towards the end 9 inside the projection 30, the tubular body 32, the tubular body 33 and the projection 31.

In particular, the diameter of the rod 7 is smaller than the inner diameter of the screw 23.

In use, the main shaft 6 drives the hub and blades in rotation about axis a.

The rotation of the hub and blades generates aerodynamic loads on the blades and hence vibrations, which are transmitted to the main shaft 6.

A rod 7 connects fuselage 3 to housing 5 of rotor 4.

In the following, the operation of helicopter 2 is illustrated with reference to a single rod 7 and a single device 15.

The operation of rotor 4 causes the generation of a vibration load.

The articulation of the projection 30 about the axis E prevents the rotation of the female screw 21 about the axis B.

The vibration load thus causes an alternating translational vibration of the projection 30, the tubular body 32 and the female screw 21 parallel to the axis B.

Due to the coupling between the thread 23 of the rollers 22 and the female screw 21, the alternate translation of the female screw 21 causes the alternate rotation of the support 25 about the axis B and of the rollers 22 about their respective axes C.

At the same time, the roller 22 describes an alternating revolving movement about the axis B, since the gears 45 and 46 mesh with the gear teeth 49 of the respective crowns 47 and 48, respectively.

Due to the coupling between the thread 23 of the roller 22 and the female screw 21, the rotation of the roller 22 about its respective axis C causes an alternating rotation of the screw 20, the tubular body 33 and the freewheel 40 about the axis B.

The bearing 41 prevents this rotation from being transmitted to the body 3 through the projection 31, and supports the axial load transmitted by the screw 20.

The device 15 therefore generates an inertial vibration torque on the flywheel 40, deriving from the translational vibration motion transmitted from the casing 5 to the tubular body 32.

More specifically, the inertial vibration torque is caused by the alternate rotation of the rollers 22, the screw 20, and the flywheel 40.

Due to the alternating rotation of the roller 22, the tubular body 33, the screw 20 and the freewheel 40, the device 15 exerts two equal forces on the constraint points of the projections 30 and 31, respectively with the shell 5 and the fuselage 3, these forces being opposite each other and proportional to the relative acceleration between the above mentioned constraint points.

These torque forces dampen the vibrations transmitted to fuselage 3, since they tend to cancel the vibration forces transmitted by internal rod 7, thereby increasing the comfort of the occupants of helicopter 2.

In other words, the device 15 implements an inertial mass.

By examining the cartridge 1 according to the invention, the advantages that can be achieved thereby are evident.

In particular, the kit 1 comprises a plurality of inertial-type damping devices 15. The devices 15 each comprise a plurality of rollers 22, these rollers 22 being screwed on the associated screw 20 and female screw 21 and rotating about respective axes B and C as a result of the axial vibrations transmitted from the casing 5 to the tubular body 32 and female screw 21.

The device 15 is therefore able to convert the axial vibrations of the tubular body 30 into an alternating rotation of the rollers 22 about the axes B and C and of the screw 20 and of the flywheel 40 about the associated axis B.

This alternating rotation produces a force on anchors 12 and 13 that is proportional to the relative acceleration of anchors 12 and 13.

This force suppresses the transmission of vibrations to anchor 13 and therefore to fuselage 3, thus improving the perceived comfort inside helicopter 2.

The device 15 of the kit 1 has low friction, high capacity and is durable with respect to inertial devices of known type and described in the background of the present description, thanks to the presence of the rollers 22 interposed between the respective screws 20 and female screws 21.

In addition, the presence of the rollers 22 interposed between the screw 20 and the female screw 21 makes the device 15 particularly compact and precise.

This makes the application to helicopter 2 particularly advantageous.

Each device 15 houses a rod 7 and is hinged to the associated anchor 12 and 13 about the same hinge axis D and E of the associated rod 7 to the anchor 12 and 13.

The device 15 therefore does not require any substantial redesign of the helicopter 1 and makes use of the already provided anchors 12 and 13 for fixing the mast 7 between the housing 5 and the top 10 of the fuselage 3.

Furthermore, this enables the kit 1 to be retrofitted in a particularly simple and inexpensive manner to an already existing helicopter 2 equipped with a rod 7.

For this purpose, it is sufficient to hinge the device 15 about the axes D and E to the already existing anchors 12 and 13.

The flywheel 40 is able to adjust the force generated by the associated device 15 to a particular value of the vibration frequency to be damped. In fact, increasing or decreasing the rotational moment of inertia of flywheel 40 is sufficient to change the frequency of vibration that is primarily damped by the associated device 15.

The crowns 47 and 48 enable the rollers 22 to rotate about the associated common axis B by virtue of the meshing between the respective gear teeth 49 and the gears 45 and 46 of the rollers 22.

The supports 25 of each device 1 hold the respective rollers 22 angularly spaced about the axis B.

Finally, it is clear that modifications and variants can be made to the kit 1 described and illustrated herein, without thereby departing from the scope defined by the claims.

In particular, female screw 21 may be connected to fuselage 3 by means of a protrusion 31, and screw 20 may be connected to casing 5 by means of a protrusion 30.

Furthermore, in addition to revolving about axis B with respect to screw 20, roller 22 is also free to translate axially parallel to axis B with respect to female screw 21.

In addition, the means 15 can be housed inside the respective rods 7 or connected to further respective structural elements interposed between the top 10 of the fuselage 3 and the shell 5.

Furthermore, the cartridge 1 may comprise only one support 25 and only one crown 47 or 48.

Finally, the tubular elements 32 and 33 of each device 15 can be fastened directly to the associated rod 7.