Electric drive for an aircraft and hybrid system for an aircraft

Abstract

The invention relates to an electric drive for an aircraft hybrid system. This electric drive comprises a rotor and a stator, wherein the stator may be connected to a structure of the aircraft and the rotor has an annular flange with a shaft through opening for mounting on a propeller flange, wherein the flange is formed of at least two parts, wherein each of these parts of the flange delimits a section of the shaft through opening.

Claims

1. An electric drive for an aircraft hybrid system comprising a rotor, a stator, wherein the stator connects to a structure of the aircraft and the rotor has an annular flange with a shaft through opening for mounting on a propeller flange, wherein one end face of the annular flange is described as a propeller side and another end face as a motor side, wherein a bearing housing section is formed on the motor side and a rotor bearing section is formed on the propeller side, and the stator has an annular bearing device and a torque support, wherein the bearing device is provided in the area of the bearing housing section of the annular flange and the rotor is fixed on the rotor bearing section of the annular flange, wherein reaction torque of the stator is delivered via the torque support to the structure of the aircraft, where the reaction torque is absorbed.

2. The electric drive according to claim 1, wherein the annular flange is formed of at least two parts, wherein each of the at least two parts of the annular flange delimits a section of the shaft through opening.

3. The electric drive according to claim 2, wherein a cup-shaped centering device is provided, which is designed for centering of the annular flange, and connects to a spigot of the propeller flange and a mounting section of the annular flange.

4. An aircraft hybrid system comprising a propeller shaft with the propeller flange, an electric drive according to claim 1, which is connected to the propeller flange, and an internal-combustion engine with crankshaft, wherein the propeller shaft is driven through the crankshaft.

5. The aircraft hybrid system according to claim 4, wherein the crankshaft of the internal-combustion engine connects to and disconnects from the propeller shaft via a clutch, wherein the clutch is in the form of a friction clutch.

6. The aircraft hybrid system according to claim 4, wherein a gearbox is provided between crankshaft and propeller shaft.

7. The electric drive according to claim 1, wherein the rotor has surrounding permanent magnets and is connected directly to the propeller flange, and thus transfers torque of an electric motor directly to a propeller.

8. The electric drive according to claim 1, wherein the bearing housing section and the rotor bearing section are roughly tubular in shape and the annular flange is roughly annular in shape.

9. The electric drive according to claim 1, wherein the structure of the aircraft is a static component of the aircraft.

10. The electric drive according to claim 1, wherein the structure of the aircraft is an engine housing, motor housing, gear housing, engine bearer, and/or engine mounting component of the aircraft.

11. The electric drive according to claim 1, wherein the annular bearing device of the stator is a roller bearing.

12. The electric drive according to claim 1, wherein the stator is rotatably mounted to the bearing housing section of the annular flange via the annular bearing device.

13. An electric drive for an aircraft hybrid system of an aircraft, the electric drive comprising: a flange comprising a shaft through opening for mounting on a propeller flange, a bearing housing section formed on a motor side end face of the flange, and a rotor bearing section formed on a propeller side end face of the flange; a rotor, which is mounted on a jacket wall of the rotor bearing section; and a stator comprising a bearing device and a torque support, wherein the bearing device is mounted on a jacket wall of the bearing housing section, and reaction torque is delivered to a structure of the aircraft via the torque support.

14. The electric drive according to claim 13, further comprising a centering device for centering the flange, wherein the centering device is connected to a spigot of the propeller flange and a mounting section of the flange.

15. The electric drive according to claim 13, wherein permanent magnets are arranged around the rotor, which is connected directly to the propeller flange and transfers torque of the electric driver directly to a propeller of the aircraft.

16. The electric drive according to claim 13, wherein the bearing housing section and the rotor bearing section are roughly tubular in shape and the flange is roughly annular in shape.

17. An electric drive for an aircraft hybrid system of an aircraft, the electric drive comprising: a flange comprising a shaft through opening for mounting on a propeller flange, a bearing housing section formed on a motor side end face of the flange, and a rotor bearing section formed on a propeller side end face of the flange; a rotor, which is mounted on a jacket wall of the rotor bearing section; and a stator comprising a bearing device and a torque support, wherein the bearing device is mounted on a jacket wall of the bearing housing section, and reaction torque is delivered to a structure of the aircraft via the torque support, wherein the flange comprises two parts, each of which delimits a section of the shaft through opening.

18. The electric drive according to claim 17, further comprising a centering device for centering the flange, wherein the centering device is connected to a spigot of the propeller flange and a mounting section of the flange.

Description

(1) The apparatus according to the invention is explained in detail below with the aid of the Figures, which show in:

(2) FIG. 1 a propeller flange, a two-part annular flange, a stator with bearing device, in a perspective view

(3) FIG. 2 the view of FIG. 1 with two-part flange inserted in the bearing device of the stator, in a perspective view

(4) FIG. 3 the view of FIG. 2 with stator, bearing device and flange moved closer to the propeller flange

(5) FIG. 4 the view of FIG. 3 with centering device

(6) FIG. 5 the view of FIG. 4 with rotor

(7) FIG. 6 a side sectional view of a coupling element for a hybrid system

(8) FIG. 7 a schematic view of the structure of a power control according to the invention

(9) FIG. 8 a schematic view of the structure of a further embodiment of a power control according to the invention

(10) FIG. 9 a power lever device according to the invention in a schematic view in which the braking area lies behind a neutral position or a power section of the internal-combustion engine

(11) FIG. 10 a power lever device according to the invention in a schematic view, in which the braking area lies in the lower power section of the internal-combustion engine

(12) FIG. 11 a hybrid drive according to the invention in a side section view

(13) FIG. 12 a general view including the power lever device of FIG. 9, a power control system, a coupling element, a power lever side control connection, a motor side control connection and a throttle valve

(14) FIG. 13 a general view including the power lever device of FIG. 10, the power control system, the coupling element, the power lever side control connection, the motor side control connection and a throttle valve,

(15) FIG. 14 shows the general view of FIG. 13, in which the power requirement on the part of the power lever is withdrawn and the servo unit of the coupling element increases the power requirement at the internal-combustion engine through twisting of the lever.

(16) The structure of an electric drive 1 according to the invention for an aircraft hybrid system is described below (FIGS. 1 to 5 and FIGS. 6 and 11). This includes a flange 2, a stator 13 and a rotor 17.

(17) The flange 2 is at least two-part and annular. An end face of the flange 2 running transversely to the axial direction 3 is described as the propeller side 4, and another end face of the flange 2 is designated as the motor side 5.

(18) A tubular bearing housing section 6 is formed on a motor side 5 on the annular flange 2.

(19) Formed on the propeller side 4 is a roughly tubular rotor bearing section 7.

(20) A web extending radially outwards between bearing housing section 6 and rotor bearing section 7 forms a mounting section 9 and has radially continuous through holes 8, spaced equally apart from one another.

(21) A web which extends radially inwards forms a mounting section 11 and has similarly radially continuous through holes 10, spaced equally apart from one another. Through these through holes 10, the flange may be connected to a propeller flange 12 of an aircraft.

(22) The electric drive 1 also includes the stator 13. The stator 13, in which the electrical magnet windings are accommodated, has in the center an annular bearing device 14 with a shaft through opening 31, wherein the bearing device 14 is e.g. in the form of a roller bearing.

(23) A torque support 15 is also provided on the stator 13.

(24) The bearing device of the stator 13 may be mounted on a jacket wall 16 of the bearing housing section 6. In order to prevent slipping of the bearing device 14 on the bearing housing section 6, known means 38 for fixing components on shafts in the axial direction, such as a circlip or the like, are provided.

(25) FIG. 11 shows by way of example such an axial fixing device 38 using a ring flange 38, which fixes the bearing device 14 on the bearing housing section 6 in the axial direction. Alternatively, one or more ring segments may also be provided.

(26) The electric drive also has a rotor 17, which may be mounted on a jacket wall of the rotor bearing section 7.

(27) A cup-shaped centering device 18 is inserted in an annular gap 19 formed between rotor 17 and flange 2.

(28) Consequently, the flange 2 and the stator 13 are mounted on a motor side of the propeller flange 12.

(29) On a rotor side of the propeller flange 12, the rotor 17 and the centering device 18 are mounted.

(30) The rotor 17 is connected to the flange 2 via the through holes 10 formed in the mounting section 11.

(31) Propeller screws for fixing a propeller in suitable through holes 10 formed in the propeller flange 12 join a propeller (not shown) to the centering device 18, the propeller flange 12 and the flange 2.

(32) According to an alternative embodiment of the flange 2, the latter may also be formed in three, four or more parts. Advantageously the individual circular-segment-shaped sections of such a multi-part flange 2 are of equal size.

(33) An aircraft hybrid system according to the invention is described below.

(34) A drive of a known aircraft includes an internal-combustion engine with a crankshaft, wherein the crankshaft is connected to a propeller shaft via a propeller gearbox.

(35) The propeller shaft has on the free end a propeller flange, on which a propeller is mounted.

(36) An aircraft hybrid system according to the invention is formed by attaching to the propeller flange the electric drive 1 according to the invention as described above.

(37) According to an advantageous embodiment of the aircraft hybrid system, a clutch is provided between the propeller gearbox and the propeller shaft (FIG. 7).

(38) By means of the clutch, the whole gearbox mechanism of the propeller gearbox of the internal-combustion engine may be decoupled from the propeller shaft, so that the propeller may be driven alone or via the electric drive according to the invention.

(39) Alternatively, the drive may also be designed without a propeller gearbox.

(40) In the case of such a direct drive of the propeller flange via the crankshaft, a clutch may be provided in the area of the connection between crankshaft and propeller flange.

(41) Located in the cockpit of known aircraft is a power lever, which the pilot is able to bring into a predetermined angular position, depending on the desired engine power. Such a power lever is connected via a control connection to a carburetor or to the injector (or throttle valve) of an internal-combustion engine.

(42) The control connection is so designed that, depending on the position of the power lever, the operation of the internal-combustion engine is controlled by control of the carburetor or the injector (or throttle valve).

(43) Activation of the control connection may also be assisted or controlled by a control unit.

(44) A connection between power lever and braking or carburetor setting or injector of the aircraft is therefore designed as the control connection 20.

(45) Described below is a power control system 21 for integration in the control connection 20 between a power lever 22 and the internal-combustion engine of an aircraft (FIGS. 7, 8, 10 and 11 to 14).

(46) The control connection 20 includes a power lever side control connection section 28 and a motor side control connection section 29.

(47) The power control system 21 provides a coupling element 23 to connect the power lever side and a motor side control connection 28, 29 between the power lever 22 and the internal-combustion engine.

(48) The coupling element 23 has a mechanical release device 24, which is in the form of a linear spring or a coil spring or similar. The release device 24 acts with a mechanical force on the power lever 22 of the control element 27 in such a way that the latter is pressed against a stop device 39.

(49) By means of the release device 24 it is ensured that, in the event of a fault, a direct connection between power lever and internal-combustion engine is always guaranteed i.e. that, in the event of a breakdown or with the hybrid system switched off, the power lever always has a direct link with the motor power control unit. The coupling element 23 includes a motion transmission device 32, 33, such as e.g. a sliding carriage 32 (FIG. 7) or a rotary disc 33 (FIG. 8), which is connected to the power lever side control connection and transmits its movement. In addition the coupling element 23 has a servo unit 27, e.g. a servomotor, which is connected to the motion transmission device 32, 33 and which actuates the motor side control connection 29.

(50) The servo unit 27 may also be in the form of a linear drive instead of a lever.

(51) Provided at the motor side control connection between coupling element 23 and internal-combustion engine is a motor sensor 26 to detect the position of the motor side control connection 29.

(52) Similarly, on the power lever side control connection between power lever 22 and coupling element 23 it is also possible to provide a power lever sensor 25 to detect the position of the power lever 22. However, this sensor is not absolutely essential.

(53) The servo unit 27 controls the motor side control connection 29 in such a way that the motor power may be controlled and in particular may be increased above the power requirement preset by the pilot through the power lever.

(54) The servo unit 27, e.g. a servomotor or a motor actuator, is provided for actuating the motor side control connection 29 and is positioned between coupling element 23 and motor.

(55) A power lever device 30 according to the invention will be described below.

(56) Also provided according to the invention is a power lever device 30. This includes a power lever which may be moved between a neutral position 35 and a full throttle setting 36 of the internal-combustion engine (FIGS. 9, 10). On reaching the full throttle position, the resistance of a release device 34 needs to be overcome so that, when the full throttle setting 36 of the internal-combustion engine is exceeded, the electric drive may be added up to the full power of the hybrid system 37.

(57) In the middle lever travel range, the power between neutral position 35 and full throttle setting 36 of the internal-combustion engine may be controlled and called up. After overcoming the resistance of the release device 34, in a lever travel range of the electric drive 36 to 37 before the lever travel range of the internal-combustion engine 35 to 36, the power of the electric motor may be called up additionally (FIGS. 9, 10, 12, 13, 14).

(58) Also provided is an activation device (not shown) for purely electric operation of the system. The activation device may be e.g. a suitable switch in the cockpit.

(59) For such purely electrical operation of the system, there may be provided in the lower power lever range a braking area 42 to 43 of the electric motor or a lever travel range for braking the propeller 42 to 43. Within this range, the electric motor may be activated in generator mode to brake the propeller in descent or landing approach. By this means, the kinetic energy of descent is absorbed and/or the aircraft is braked and/or a steeper descent may be made.

(60) In the lower power range, therefore, after overcoming a release device, the braking power of the electric motor may be accessed. The braking function of the electric motor may thus be used in addition to the braking power of the internal-combustion engine. The braking power is however obtained from the hybrid system in such a way that it does not result in stalling of the internal-combustion engine due to excessively strong braking.

(61) FIG. 10 shows a hybrid power lever according to the invention in which, in the lower control range, the braking function already lies in the lever range of the internal-combustion engine. This is possible because, in this variant, the braking function of the electric motor is activated only with the internal-combustion engine switched off. The neutral position for the internal combustion engine 35 here corresponds to a full braking power position 43 of the electric drive 1 in generator mode. In the area between neutral position 35 and full throttle setting 36 of the internal-combustion engine, a lever position zero braking power 42 is provided.

(62) This braking area may therefore be provided in the area of the lower internal-combustion engine control range (FIG. 10) or alternatively below the neutral point 35 of the internal-combustion engine (FIG. 9). Here the neutral position of the internal-combustion engine 35 corresponds to a zero braking power 42 of the electric drive 1 in generator mode. Located in the area behind the full throttle setting 36 of the internal-combustion engine is a new lever position, namely full braking power 43.

(63) In combined internal-combustion engine/electric motor operation, the internal-combustion engine power may be controlled in a lower section of the power lever between idling internal combustion engine 35 and internal-combustion engine full throttle setting 36. In an upper power lever area between neutral electric drive 36 and full throttle electric drive 37, the electric motor power which is also available may be accessed and controlled.

(64) To switch over from combined electric motor/internal-combustion engine operation to purely electric operation, the activation device is actuated by the pilot. The ignition of the internal-combustion engine together with the injection is then switched off. The clutch is then opened, which separates the connection between the internal-combustion engine and the propeller. The internal-combustion engine is then switched off.

(65) In this purely electric motor operation, in the front power range between neutral electric drive 36 and full throttle electric drive 37, the power of the electric motor may be set by the position of the power lever 22.

(66) In the middle power lever range 35 to 36 (normally provided for the internal-combustion engine), no power is available from the internal-combustion engine, since it is switched off.

(67) In the braking area 42 to 43 or in the lower power lever range, the braking power of the electric motor may be activated by pulling back the power lever 22. The further back the power lever 22 is pulled, the higher the braking power of the electric motor.

(68) To go around with an aircraft, a changeover is made back from purely electric operation to combined electric/internal-combustion engine operation.

(69) In order to switch to combined electric/internal-combustion engine operation on the ground or in flight, two options are provided for starting the internal-combustion engine: 1. by activating a switch provided for this purpose, e.g. a “fly-with-fuel” button in the area of the engine control on the cockpit panel; 2. by a start switch 40 on the power lever as described below.

(70) A switch 40 may be provided on the front stop of the power lever 22. If the power lever is pressed against this switch, against resistance, or if the pilot operates the switch provided for this purpose in the area of the engine control, then the system triggers start-up of the internal-combustion engine.

(71) The clutch which is held open in electric motor operation is closed, causing the internal-combustion engine to be turned by the electric motor and the propeller. Ignition and injection are then activated. This starts the internal-combustion engine, so that the power of the latter is now available in addition to that of the already running electric motor.

(72) If in the landing approach or on touching the landing strip, it is necessary to go around, then the power lever may be pushed completely forwards on to the upper stop of the power control of the electric motor, where the starting of the internal-combustion engine is activated. By this means, in addition to the full power of the electric motor, the power of the internal-combustion engine is also available for going around.

(73) FIGS. 12 to 14 show an overview comprising the power lever and the power control system and the coupling element with a power lever side control connection, a motor side control connection and a throttle valve 41.

(74) FIGS. 12 and 13 show the differently arranged braking areas, wherein the braking area may also be between these two areas.

(75) In FIG. 14, the power requirement on the part of the power lever 22 is withdrawn, and the servo unit of the coupling element increases the power requirement at the actual power lever position of the internal-combustion engine.

(76) Also provided are methods according to the invention for mounting the electric motor and for operation of the power control system in accordance with the remarks made above.

LIST OF REFERENCE NUMBERS

(77) 1 electric drive 2 flange 3 axial direction 4 propeller side 5 motor side 6 bearing housing section 7 rotor bearing section 8 through hole 9 mounting section 10 through hole 11 mounting section 12 propeller flange 13 stator 14 bearing device 15 torque support 16 jacket wall 17 rotor 18 centering device 19 annular gap 20 control connection power control system power lever 23 coupling element 24 release device 25 power lever sensor 26 motor sensor 27 servo unit 28 power lever side control connection section 29 motor side control connection section 30 power lever device 31 shaft through opening 32 sliding carriage 33 rotary disc 34 release device 35 idling internal combustion engine 36 full throttle setting internal-combustion engine/idling electric drive 37 full throttle hybrid drive 38 axial fixing device 39 stop device 40 switch 41 throttle valve 42 full braking power 43 zero braking power