MODULAR POWER PLANT FOR A ROTORCRAFT AND ASSOCIATED ROTORCRAFT

Abstract

A modular power plant for a rotorcraft comprising at least one lift rotor, the power plant comprising: at least one combustion or electric engine; a main gearbox, comprising a gearbox housing and a toothed wheel arranged in an internal space at least partially delimited by the gearbox housing, the toothed wheel having a degree of rotational freedom about a primary axis of rotation relative to the gearbox housing, the toothed wheel mechanically transmitting an engine torque generated by the at least one engine to the at least one lift rotor; and at least two mechanical connection interfaces, a first mechanical connection interface mechanically connecting the main gearbox to a first engine, and a second mechanical connection interface being left free or mechanically connecting the main gearbox to a second engine.

Claims

1. A modular power plant for a rotorcraft comprising at least one lift rotor, the power plant comprising: at least one engine chosen in the group comprising the combustion type engines and the electric type engines; a main gearbox, comprising a gearbox housing and a toothed wheel arranged in an internal space at least partially delimited by the gearbox housing, the toothed wheel having a degree of rotational freedom about a primary axis of rotation relative to the gearbox housing, the primary axis of rotation coinciding with or being parallel to a rotor axis of rotation of the at least one lift rotor, the toothed wheel mechanically transmitting an engine torque generated by the engine(s) to a rotor mast constrained to rotate with the at least one lift rotor; and at least two mechanical connection interfaces, a first mechanical connection interface mechanically connecting the main gearbox to a first engine of the at least one engine and a second mechanical connection interface being left free or mechanically connecting the main gearbox to a second engine of the at least one engine, wherein each mechanical connection interface comprises a pinion directly meshing with the toothed wheel, the pinions being distributed in azimuth around the primary axis of rotation, each pinion having a degree of rotational freedom about a secondary axis of rotation relative to the gearbox housing, each secondary axis of rotation being arranged parallel to the primary axis of rotation, and wherein each mechanical connection interface comprises an interface housing and reversible securing means for securing the interface housing with the gearbox housing and alternatively for releasing the interface housing from the gearbox housing.

2. The power plant according to claim 1, wherein at least one of the at least two mechanical connection interfaces comprises at least one rotation speed reduction stage.

3. The power plant according to claim 1, wherein at least one of the at least two mechanical connection interfaces comprises at least one angle gear.

4. The power plant according to claim 1, wherein one of the at least two mechanical connection interfaces comprises an output shaft constrained to rotate with the pinion, the output shaft mechanically transmitting an engine torque generated by the at least one engine to an auxiliary member of the rotorcraft.

5. The power plant according to claim 4, wherein the first mechanical connection interface comprises the output shaft.

6. The power plant according to claim 4, wherein the second mechanical connection interface comprises the output shaft.

7. The power plant according to claim 1, wherein the at least two mechanical connection interfaces comprise a third mechanical connection interface that is left free or mechanically connects the main gearbox to a third engine of the at least one engine.

8. The power plant according to claim 1, wherein the secondary axes of rotation are distributed in azimuth around the primary axis of rotation at an angle of between 20 degrees and 60 degrees.

9. A rotorcraft comprising at least one lift rotor rotated by at least one engine chosen in the group comprising the combustion type engines and the electric type engines, wherein the rotorcraft comprises the modular power plant according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The disclosure and its advantages appear in greater detail in the context of the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

[0069] FIG. 1 is a first partial three-dimensional view of a rotorcraft according to the disclosure;

[0070] FIG. 2 is a second partial three-dimensional view of the rotorcraft according to the disclosure;

[0071] FIG. 3 is a third partial three-dimensional view of the rotorcraft according to the disclosure;

[0072] FIG. 4 is a first partial schematic representation of a power plant according to the disclosure;

[0073] FIG. 5 is a second partial schematic representation of a power plant according to the disclosure;

[0074] FIG. 6 is a third partial schematic representation of a power plant according to the disclosure; and

[0075] FIG. 7 is a fourth partial schematic representation of a power plant according to the disclosure.

DETAILED DESCRIPTION

[0076] Elements that are present in more than one of the figures are given the same references in each of them.

[0077] As shown in FIGS. 1 to 3, the disclosure relates to a rotorcraft 1 provided with at least one lift rotor 2 comprising a plurality of blades. In order to rotate this or these rotors 2, such a rotorcraft 1 also comprises a power plant 10 having at least one combustion or electric engine 3, 13, 23.

[0078] According to FIG. 1, which partially represents such a power plant 10, a first engine 3 may be a combustion engine such as a piston engine or indeed a turboshaft engine.

[0079] According to FIG. 2, the power plant 10 may have at least one electric engine, for example a first engine 13 being an electric engine and a second engine 23 also being an electric engine.

[0080] According to FIG. 3, the power plant 10 may have at least a first electric engine 13, and indeed a second engine 23 that is also an electric engine, and a third combustion engine 3.

[0081] Furthermore, irrespective of the number of engines, the power plant 10 comprises a main gearbox 4, comprising a gearbox housing 5 and a toothed wheel 6 arranged in an internal space at least partially delimited by the gearbox housing 5.

[0082] Such a toothed wheel 6 has a degree of rotational freedom about a primary axis of rotation Z1 relative to the gearbox housing 5. This toothed wheel 6 allows an engine torque generated by the engine or engines 3, 13, 23 to be transmitted mechanically to said at least one lift rotor 2 via a mechanical link. Such a mechanical link may comprise a rotor mast, at least one speed reduction stage, for example an epicyclic speed reduction stage, etc.

[0083] Such a power plant 10 is said to be modular because it comprises at least two mechanical connection interfaces 7, 17, 27, a first mechanical connection interface 7, 17, 27 mechanically connecting the main gearbox 4 to a first engine 3, 13, 23 and a second mechanical connection interface 7, 17, 27 being left free or mechanically connecting the main gearbox 4 to a second engine 3, 13, 23.

[0084] In order to keep the space requirement of this power plant 10 small, each mechanical connection interface 7, 17, 27 comprises a pinion 8, 18, 28 meshing directly with the toothed wheel 6. These pinions 8, 18, 28 are distributed in azimuth around the primary axis of rotation Z1, possibly but not necessarily at equal distances.

[0085] Furthermore, the respective pinions 8, 18, 28 of each mechanical connection interface 7, 17, 27 have a degree of rotational freedom around respective secondary axes of rotation Z2, Z2′, Z2″ relative to the gearbox housing 5. Such secondary axes of rotation Z2, Z2′, Z2″ are thus arranged respectively parallel to the primary axis of rotation Z1.

[0086] Moreover, such secondary axes of rotation Z2, Z2′, Z2″ are distributed in azimuth around the primary axis of rotation Z1 at an angle of between 20 degrees and 60 degrees.

[0087] As shown in FIG. 4, the respective pinions 8, 18, 28 of each mechanical connection interface 7, 17, 27 may be carried by input shafts guided directly in rotation by the gearbox housing 5.

[0088] However, according to other examples shown in FIGS. 5 to 7, the different mechanical connection interfaces 7, 17, 27 may also respectively comprise an interface housing 9, 19, 29 and reversible securing means 30 for securing this interface housing 9, 19, 29 with the gearbox housing 5 and alternatively releasing or removing it therefrom.

[0089] Advantageously, each of the mechanical connection interfaces 7, 17, 27 may in this case be removed from the main gearbox 4 and optionally replaced, for example, by another mechanical connection interface corresponding to another engine.

[0090] These reversible securing means 30 may, for example, have screws cooperating with matching nuts or tappings or even studs cooperating with nuts in order to reversibly secure each interface housing 9, 19, 29 with the gearbox housing 5 by tightening screws and/or nuts.

[0091] Furthermore, as shown in FIG. 6, the mechanical connection interfaces 7, 17, 27 may comprise at least one rotation speed reduction stage 31. This rotation speed reduction stage 31 may be limited to the pairing formed by the toothed wheel 6 with the pinions 8, 18, 28 or may indeed have one or more other gears.

[0092] This rotation speed reduction stage 31 makes it possible to reduce the speed of rotation of the input shaft and to rotate the toothed wheel 6 at a speed of rotation slower than the speed of rotation of the engine 3, 13, 23.

[0093] Similarly, as shown in FIG. 7, a mechanical connection interface 7, 17, 27 may comprise at least one angle gear 32.

[0094] Such an angle gear 32 may comprise, for example, two bevel pinions with helical teeth, and then allows an input shaft corresponding to an engine 3, 13, 23 to be arranged perpendicular to the secondary axis of rotation Z2, Z2′, Z2″ of the pinion 8, 18, 28 with which the angle gear 32 cooperates.

[0095] Advantageously, one of the mechanical connection interfaces 7, 17, 27 may comprise an output shaft 33 constrained to rotate with a pinion 8, 18, 28. Such an output shaft 33 mechanically transmits an engine torque generated by an engine 3, 13, 23 to an auxiliary member 12 such as a rear rotor of the rotorcraft 1. Such a rear rotor is generally arranged at a tail boom and makes it possible, in particular, to control the yawing motion of the rotorcraft 1.

[0096] The first mechanical connection interface 7, 17, 27 may comprise the output shaft 33.

[0097] In this case, the first mechanical connection interface 7, 17, 27 is connected both to the first engine 3, 13, 23 by an input shaft, to the toothed wheel 6 by the pinion 8, 18, 28 and to the auxiliary member 12 by the output shaft 33.

[0098] Alternatively, the second mechanical connection interface 7, 17, 27 may comprise the output shaft 33.

[0099] In this case, the second mechanical connection interface 7, 17, 27 may be connected both to the second engine 3, 13, 23 by an input shaft, to the toothed wheel 6 by the pinion 8, 18, 28 and to the auxiliary member 12 by the output shaft 33. However, if the second mechanical connection interface 7, 17, 27 is left free, the pinion 8, 18, 28 of this second mechanical connection interface 7, 17, 27 is then rotated by the toothed wheel 6.

[0100] The pinion 8, 18, 28 may then transmit an engine torque to the output shaft 33, and consequently to the auxiliary member 12.

[0101] In practice, and as shown in FIGS. 4 and 7, the at least two mechanical connection interfaces 7, 17, 27 may comprise a third mechanical connection interface 27 that may be left free or indeed mechanically connect the main gearbox 4 to a third engine 23.

[0102] Furthermore, the auxiliary member 12 may also be formed by one or more pusher or tractor propeller or indeed alternatively by an electric machine operating in generator mode.

[0103] Naturally, the present disclosure is subject to numerous variations as regards its implementation. Although several embodiments are described above, it should readily be understood that it is not conceivable to identify exhaustively all the possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present disclosure.