Aircraft hybrid engine having gear ring encased fans

Abstract

A propulsion engine comprising at least a first propulsion unit including a first fan encased by a geared ring and a gas turbine engine driving a first shaft connected to the first fan, at least a second propulsion unit including a second fan encased by a geared ring connected to a second shaft operatively coupled to an electric machine and at least an electric storage device connected to the electric machine. The geared rings are configured to transmit torque between the fans so that they can rotate in conjunction (directly or through an intermediate gear) when they are driven by at least one of said first and second shafts. The propulsion engine is arranged for controlling the torque to be supplied to the assembly of the first and second fans by the gas turbine engine and/or by the electric machine acting as a motor or as a generator.

Claims

1. A propulsion engine comprising: a first propulsion unit including a first fan and a combustion engine driving a first shaft connected to the first fan; a second propulsion unit including a second fan connected to a second shaft operatively coupled to an electric machine; a electric storage device connected to the electric machine; the first and second fans of the first and second propulsion units being encased by geared rings configured to transmit torque between the first and second fans and being arranged to rotate in conjunction when the first and second fans are driven by at least one of said first and second shafts; the electric machine of the second propulsion unit being arranged for actuating, in combination with the electric storage device, as an electric motor extracting energy from the electric storage device to drive the second shaft and as an electric generator extracting the mechanical energy of the second shaft when the electric machine is driven by the second fan to charge the electric storage device; a controller connected to the combustion engine, to the electric machine and to the electric storage device and being configured and arranged to control a torque to be supplied to the first and second fans by at least one of the combustion engine and the electric machine acting as the electric motor, and to control a charge of the electric storage device by the electric machine acting as the electric generator.

2. A propulsion engine according to claim 1, further comprising an intermediate gear positioned between the first and second fans to transmit the torque between the first and second fans, said intermediate gear being connected to a linear actuator for engaging and disengaging a mechanical connection between the first and second fans formed by the intermediate gear.

3. A propulsion engine according to claim 1, further comprising a third propulsion unit including a third fan encased by a geared ring arranged to rotate in conjunction with the first and second fans of the first and second propulsion units.

4. A propulsion engine according to claim 3, further comprising an intermediate gear positioned between the third fan and one of the first and second fans to transmit torque between the third fan and the one of the first and second fans, said intermediate gear being connected to a linear actuator for engaging and disengaging a mechanical connection formed by the intermediate gear between the third fan and the one of the first and second fans.

5. A propulsion engine according to claim 3, wherein said third fan is arranged at one side of the first fan.

6. A propulsion engine according to claim 3, wherein said first, second and third fans each have an equal diameter.

7. An aircraft having at least one propulsion engine comprising: a first propulsion unit including a first fan and a combustion engine driving a first shaft connected to the first fan; a second propulsion unit including a second fan connected to a second shaft operatively coupled to an electric machine; an electric storage device connected to the electric machine; the first and second fans of the first and second propulsion units being encased by geared rings configured to transmit torque between the first and second fans and being arranged to rotate in conjunction when the first and second fans are driven by at least one of said first and second shafts; the electric machine of the second propulsion unit being arranged for actuating, in combination with the electric storage device, as an electric motor extracting energy from the electric storage device to drive the second shaft and as an electric generator extracting mechanical energy of the second shaft; when the electric machine is driven by the second fan to charge the electric storage device; a controller connected to the combustion engine, to the electric machine and to the electric storage device and being configured and arranged to control a torque to be supplied to the first and second fans by at least one of the combustion engine and the electric machine acting as the electric motor, and to control a charge of the electric storage device by the electric machine acting as the electric generator.

8. The aircraft according to claim 7, further comprising an intermediate gear positioned between the first and second fans to transmit the torque between the first and second fans, said intermediate gear being connected to a linear actuator for engaging and disengaging a mechanical connection between the first and second fans formed by the intermediate gear.

9. The aircraft according to claim 7, further comprising a third propulsion unit including a third fan encased by a geared ring arranged to rotate in conjunction with the first and second fans of the first and second propulsion units.

10. The aircraft according to claim 9, further comprising an intermediate gear positioned between the third fan and one of the first and second fans to transmit torque between the third fan and the one of the first and second fans, said intermediate gear being connected to a linear actuator for engaging and disengaging a mechanical connection formed by the intermediate gear between the third fan and the one of the first and second fans.

11. The aircraft according to claim 9, wherein said third fan is arranged at one side of the first fan.

12. The aircraft according to claim 9, wherein said first, second and third fans each have an equal diameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1a and 1b are, respectively, schematic plan and frontal views illustrating an embodiment of the hybrid engine of the invention with two propulsion units.

(2) FIG. 1c is a plan view illustrating an embodiment including intermediate gears for engaging/disengaging the two propulsion units.

(3) FIGS. 2a and 2b are, respectively, schematic plan and frontal views illustrating an embodiment of the hybrid engine of the invention with three propulsion units.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) In the embodiment shown in FIGS. 1a and 1b, the propulsion engine 10 is a multi-fan engine housed in a nacelle 20 comprising: A propulsion unit 11 in the right side having a first fan 13 encased by a geared ring 19 and a combustion engine 15 housed in a fairing 12 including at least a compressor, a combustion chamber and a turbine driving a first shaft 17 connected to the first fan 13. A second propulsion unit 21 in the left side having a second fan 23 encased by a geared ring 29 connected to a second shaft 27. The second shaft 27 is also coupled to an electric machine 25 housed in a fairing 22 and connected to an electric storage device 41, such as a battery, located externally to the fairing 22. A controller 30 for controlling the operation of the propulsion engine 10.

(5) As the first and second fans 13, 23 of the first and second propulsion units 11, 21 are coupled mechanically through the geared rings 19, 29 both fans 13, 23 provide thrust when the combustion engine 15 or the electric machine 25 or both are delivering power. No direct electric connection is required between the combustion engine 15 and the electric machine 25 and no specific generator is required in the combustion engine 15. The electric machine 25 can act in a reversible way as a motor to drive the second shaft 27 or as a generator to charge the electric storage device 41 driven by the power from the combustion engine or by the free rotation of the fans under aerodynamic forces in the descent phases of the flight.

(6) The electric storage device 41 may be also connected to the electric power system of the aircraft if it is envisaged that the production of electric power in the second propulsion unit 21 can be greater than the consumption. As is well known, there is an increased demand for electric power in aircraft as a consequence of substitutions of conventional equipment which depend on pneumatic, mechanic and hydraulic power by equipment that depend on electric power which provide a better system performance due to increase of reliability, less maintenance, and efficiency of energy.

(7) The controller 30 is configured and arranged for operating the propulsion engine 10 in one of the following operation modes.

(8) In a first mode of operation the propulsion engine 10 is actuated by the combustion engine 15 and the electric machine 25. The assembly of the first and second fans 13, 23 is driven by the torque provided by the first shaft 17 and the second shaft 27 to produce thrust. The electric machine 25 acts as an electric motor fed by the electric storage device 41 to drive the second shaft 27. This mode of operation would be used in all flight conditions requiring a high thrust.

(9) In a second mode of operation, the propulsion engine 10 is actuated by, only, the combustion engine 15. The assembly of the first and second fans 13, 23 is driven by the torque provided by the first shaft 17 to produce thrust. On the other hand the mechanical energy of the second shaft 27, driven by the second fan 23, is converted into electric energy by the electric machine 25, acting as an electric generator, and stored in the electric storage device 41. This mode of operation would be used when the electric storage device 41 needs to be charged and the flight conditions do not require an extra-thrust provided by the electric machine 25 acting as a motor.

(10) In a third mode of operation, the propulsion engine 10 is actuated by, only, the electric machine 25. The assembly of the first and second fans 13, 23 is driven by the torque provided by the second shaft 27 to produce thrust. The electric machine 25 acts as an electric motor fed by the electric storage device 41 to drive the second shaft 27. This mode of operation, which is also a more silent mode, would be used in those flight conditions not requiring the thrust provided by the combustion engine 15for example in cruise and final approach conditionsand when the electric storage device 41 has a suitable level of charge.

(11) In a fourth mode of operation the combustion engine 15 and the electric machine 25 are in power off mode, i.e., not delivering power to their respective fans 13, 23. The assembly of the first and second fans 13, 23 is driven by, only, the incoming air and the mechanical energy of the second shaft 27 driven by the second fan 23 is converted into electric energy by the electric machine 25, acting as an electric generator, and stored in the electric storage device 41. This mode of operation would be used to charge the electric storage device 41 in flight conditions not requiring the propulsion engine 10. In this mode of operation the propulsion engine 10 can therefore be used as a source of energy to perform the function of a Ram Air Turbine.

(12) The embodiment shown in FIG. 1c incorporates an intermediate gear 51 to connect the first and second fans 13, 23 encased by geared rings 19, 29. The intermediate gear 51 can be pulled back by means of a linear actuator 53 so that the power transmission between the first and second fans 13, 23 can be disengaged in cases, for example, of blade rupture, mechanical failure or any other reason.

(13) The first and second fans 13, 23 of the propulsion engine 10 can have the same size as represented in FIGS. 1a and 1b or a different size for meeting particular needs.

(14) In the embodiment shown in FIGS. 2a and 2b the propulsion engine 10 also includes a third propulsion unit 31 comprising a third fan 33 encased by a geared ring 39 arranged to rotate in conjunction with the first and second fans 13, 23 of the first and second propulsion units 11, 21. Intermediate gears between the first and second fans 13, 23 and between the first and third fans 13, 33 may be incorporated to the propulsion unit for allowing their engaging/disengaging. The control means are arranged for operating the propulsion engine in similar operation modes to those described above.

(15) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

(16) Although the present invention has been described in connection with various embodiments, it will be appreciated from the specification that various combinations of elements, variations or improvements therein may be made, and are within the scope of the invention as defined by the appended claims.