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EP-4742514-A1 - AIRCRAFT WITH HIGH-PERFORMANCE PROPULSION UNIT

EP4742514A1EP 4742514 A1EP4742514 A1EP 4742514A1EP-4742514-A1

Abstract

The present invention relates to a drive unit 300 for a propeller 303 of an aircraft 307 suitable for vertical and horizontal flight. The drive unit 300 comprises a first electric motor 100 configured for rotating the propeller 303 and a first eccentric gear 104 for the operative connection between the propeller 303 and the first electric motor 100. The first electric motor 100 has a cylindrical rotor 1, wherein a surface of the rotor 1 has at least a first pair of recesses 200. According to the invention, a fixing unit 20 is arranged on a respective base surface 113 and/or a respective top surface 400 of the first rotor magnet 2 and the second rotor magnet 2, designed to fix the first rotor magnet 2 in the first recess 200 and the second rotor magnet 2 in the second recess 200, in particular by counteracting centrifugal forces acting on the first rotor magnet 2 and the second rotor magnet 2.

Inventors

  • EISENMANN, SIEGFRIED A.

Assignees

  • Eisenmann, Siegfried A.

Dates

Publication Date
20260513
Application Date
20250812

Claims (15)

  1. Drive unit (300) for a propeller (303) of an aircraft (307) suitable for vertical and horizontal flight, wherein the drive unit (300) comprises a first electric motor (100) configured for rotating the propeller (303) and a first eccentric gear (104) for operative connection between the propeller (303) and the first electric motor (100), wherein the first electric motor (100) comprises a cylindrical rotor (1), wherein a lateral surface of the rotor (1) has at least a first pair of recesses, wherein • a first and a second recess (200) of the first pair of recesses each extend from a top surface to a base surface of the rotor (1) parallel to a central axis (11) of the rotor (1); and • in the first recess (200) of the first pair of recesses a first rotor magnet (2) designed as a north pole is arranged precisely and in the second recess (200) of the first pair of recesses a second rotor magnet (2) designed as a south pole is arranged precisely, characterized by the fact that A fixing unit (20) is arranged on a respective base surface (113) and/or a respective top surface (400) of the first rotor magnet (2) and the second rotor magnet (2), designed to fix the first rotor magnet (2) in the first recess (200) and the second rotor magnet (2) in the second recess (200), in particular by counteracting centrifugal forces acting on the first rotor magnet (2) and the second rotor magnet (2).
  2. Drive unit (300) according to claim 1, wherein the electric motor (100) has a stator (110), wherein • the stator (110) has a first and a second stator magnet pair, wherein ∘ the stator magnets of the first stator magnet pair (15, 15') are arranged opposite each other on the rotor, and ∘ the stator magnets of the second stator magnet pair (16, 16') are arranged opposite each other on the rotor and offset by 90 degrees to the first stator magnet pair (15, 15'), • the respective stator magnets (15, 15', 16, 16') are U-shaped, • each leg (17) of a respective U-shaped stator magnet (15, 15', 16, 16') ∘ is integrally formed on the rotor (1), and ∘ has a coil (18) designed to be carried by electric current and thereby generate a magnetic field in the respective leg (17), • Each stator magnet (15, 15', 16, 16') is configured such that when an electric current flows through the two coils (18) of the respective stator magnet (15, 15', 16, 16'), one leg (17) of the respective stator magnet (15, 15', 16, 16') is configured as the north pole and the other leg (17) as the south pole, whereby a rotor magnet (2) configured as the north pole is attracted by the leg (17) configured as the south pole and a rotor magnet (2) configured as the south pole is attracted by the leg (17) configured as the north pole of the respective stator magnet (15, 15', 16, 16') such that the rotor (1) is rotated about a first axis of rotation (103) running coaxially to the central axis (11) of the rotor (1), • the coils (18) of the stator magnets of the first stator magnet pair (15, 15') are connected to each other via a first electrical or electronic circuit (14), and • the coils (18) of the stator magnets of the second stator magnet pair (16, 16') are connected to each other via a second electrical or electronic circuit (21).
  3. Drive unit (300) according to claim 2, wherein a first magnetic flux transmission unit (5), in particular a first soft iron bridge, is arranged such that when the first rotor magnet (2) and/or the second rotor magnet (2) is exposed to a magnetic field provided by the stator (110) of the electric motor (100), a magnetic flux is provided between the first rotor magnet (2) and the second rotor magnet (2).
  4. Drive unit (300) according to claim 2 or 3, wherein a first cooling unit (101), in particular having several cooling fins, is arranged on the stator magnets of the first stator magnet pair (15, 15') and/or the stator magnets of the second stator magnet pair (16, 16'), wherein the first cooling unit (101) is provided to • to dissipate frictional heat released during rotation of the rotor (1) – about a first axis of rotation coaxial to the central axis (11) of the rotor (1) – to the stator magnets of the first stator magnet pair (15, 15') and/or the stator magnets of the second stator magnet pair (16, 16'); and/or • to dissipate waste heat from the coils (18) of the stator magnets (15, 15', 16, 16').
  5. Drive unit (300) according to one of claims 2 to 4, wherein a respective leg (17) of a respective stator magnet (15, 15', 16, 16') is formed on the rotor (1) such that there is a distance between the respective leg (17) and the rotor (1) in the range of 10 µm to 300 µm, in particular in the range of 50 µm to 100 µm.
  6. Drive unit (300) according to one of the preceding claims, wherein mechanical retaining elements are arranged within a cavity of the rotor (1), which interact with matching retaining element counterparts of a rotation receiving unit (102) inserted into the cavity of the rotor (1) in such a way that when the rotor (1) is rotated about a first axis of rotation (103) running coaxially to the central axis (11) of the rotor (1), the rotation receiving unit (102) is rotated about the first axis of rotation (103).
  7. Drive unit (300) according to claim 6, wherein • the rotary receiving unit (102) is arranged on the first eccentric gear (104) such that when the rotary receiving unit (102) rotates, the first eccentric gear (104) rotates with it; and/or • a second cooling unit (105) is arranged on a side of the rotary receiving unit (102) opposite the first eccentric gear (104), designed to cool a first drive battery designed to supply the electric motor (100) with electrical energy, in particular wherein the second cooling unit (105) is designed as a cooling propeller, so that when the rotary receiving unit (102) rotates the cooling propeller (105) with it.
  8. Drive unit (300) according to one of the preceding claims, wherein the fixing unit (20) is ring-shaped and has a ring diameter such that the fixing unit (20) arranged on the respective base surface (113) and/or the respective top surface (400) of the first rotor magnet (2) and the second rotor magnet (2) can absorb centrifugal forces acting on the first rotor magnet and the second rotor magnet via respective axial extensions (50) of the first rotor magnet (2) and the second rotor magnet (2).
  9. drive unit (300) according to one of the preceding claims, wherein the fixing unit (20) is glued to the respective base surface (113) and/or the respective top surface (400) of the first rotor magnet (2) and the second rotor magnet (2).
  10. Drive unit (300) according to one of the preceding claims, wherein the fixing unit (20) is designed as an axial bearing for receiving forces acting coaxially and/or parallel to the central axis (11) on the rotor (1), in particular wherein the fixing unit (20) has a sliding layer on its side facing away from the respective base surface (113) and/or the respective top surface (400) of the first rotor magnet (2) and the second rotor magnet (2), in particular wherein the sliding layer comprises molybdenum disulfide.
  11. Drive unit (300) according to one of the preceding claims, wherein the rotor (1) has a potting compound, in particular a potting resin, in particular wherein the potting compound is cast between the first rotor magnet (2) and/or the second rotor magnet (2) and the first magnetic flux transmission unit (2).
  12. Drive unit (300) according to one of the preceding claims, wherein the first eccentric gear (104), in particular a cycloidal disk (119, 120) of the first eccentric gear (104), comprises a lightweight material, in particular carbon, preferably glass fiber reinforced carbon, Kevlar, titanium and/or aluminium.
  13. Aircraft (307) suitable for vertical and horizontal flight, wherein • the aircraft (307) has at least one wing (304); • comprising at least one airfoil (304) comprising at least one pivotable airfoil section (301, 302); and • the at least one pivotable airfoil section (301, 302) has a propeller (303) which is rotatably mounted on the airfoil section (301, 302) about an axis of rotation, characterized by the fact that comprising at least one pivotable wing part (301, 302) and a drive unit (300) according to one of claims 1 to 12.
  14. Aircraft (307) according to claim 13, wherein the aircraft (307) has a parachute deployment unit, wherein the parachute deployment unit is designed to deploy a parachute from the aircraft (307) in response to a control signal.
  15. Aircraft (307) according to claim 13 or 14, wherein the aircraft has at least one pivotable wing section (301, 302). • at least one first traction battery designed to supply the electric motor (100) with electrical energy, wherein the first traction battery is arranged in or on the wing part (301, 302) in such a way that it is replaceable and/or rechargeable there, • a communication unit designed to receive control signals, in particular control signals from an external transmitting source, • a control unit designed, depending on the control signals, to control a swivel angle of the airfoil section (301, 302) and to control the rotation of the propeller (303), and/or • at least one photovoltaic cell arranged on a surface of the wing part (301, 302), which is connected to the first traction battery and is designed to charge the first traction battery.

Description

Field of invention The present invention relates to a drive unit for a propeller of an aircraft suitable for vertical and horizontal flight and a corresponding aircraft. Background of the invention Those in the revelations DE202017006138U1 , DE202019000936U1 , DE202019002731U1 and EP21210288.3 The aircraft shown have so-called "tilted wings" (i.e., wing sections that can be tilted) and "tiltrotors" (i.e., propellers) attached to each of these, thus enabling a meaningful separation of climb (vertical) and speed flight (horizontal). In state-of-the-art aircraft, for vertical flight (vertical takeoff), all wing sections are tilted from their horizontal position by approximately 90 degrees such that the propellers are located either above or below the wings. The airflow generated by the rotation of the propellers flows towards the ground, creating a lift force at each propeller that is directed vertically upwards, away from the ground. Because the wing section and propeller assembly in these aircraft is pivotally mounted relative to the rest of the wing, locating the motor responsible for propeller rotation in the remaining wing section or in the aircraft's interior is disadvantageous. This is partly because the kinetic energy provided by the motor would then have to be transferred to the propeller via the pivot axis of the respective wing section, which would significantly complicate the wing's construction. Consequently, these types of aircraft require propulsion units consisting of a propeller motor and a gearbox to transmit the kinetic energy provided by the propeller motor to the propeller. These units can be installed within a wing section. Due to the limited space available within each wing section, these propulsion units must be designed to be space-saving. Furthermore, these drive units must be lightweight yet capable of accelerating the propeller to high operating speeds, as the aircraft's own weight necessitates high propeller speeds to ensure safe and stable takeoff. Electric motors could be used as the power source for such drive units. Electric motors are used in a variety of applications, and therefore a wide range of designs exist. Particularly due to their high achievable power and torque, electric motors are in high demand in electromobility, among other fields. Switched reluctance motors have a different number of distinct poles on the rotor and stator. The rotor poles are often formed by permanent magnets made of a hard magnetic material, while the stator legs are magnetized by electrical coils. The stator legs, also called stator teeth, are alternately switched on and off. The magnetic field generated by the energized windings of the legs attracts the nearest rotor pole and is switched off as soon as (or shortly before) the rotor pole is opposite the attracting stator leg. In this position, another stator leg is energized, resulting in another interaction between a pole and the leg, and the rotor is attracted again in the same direction of rotation. Although reluctance motors are frequently designed with three or more phases, designs with two or only one phase also exist. However, a disadvantage of state-of-the-art electric motors is that, due to the heterogeneous design of the rotors, particularly the separate design of the rotor magnets, the rotor magnets can detach due to centrifugal force, especially at high speeds. Furthermore, the high power outputs and torques required for aircraft propulsion systems can only be achieved with state-of-the-art electric motors through large and therefore heavy designs. Object of the invention It is therefore an object of the invention to provide a drive unit for a propeller of an aircraft suitable for vertical and horizontal flight and to provide a suitable aircraft that overcomes the disadvantages of the state of the art. Another task is to provide a drive unit with an electric motor suitable for use at high speeds. Another task is to provide a drive unit that operates efficiently, powerfully and/or consistently. These problems are solved by realizing at least some of the characterizing features of the independent claims. Features that further develop the invention in an alternative or advantageous way can be found in some of the remaining features of the independent claims and in the dependent claims. Summary of the invention The present invention relates to a drive unit for a propeller of an aircraft suitable for vertical and horizontal flight. The drive unit comprises a first electric motor configured for rotating the propeller and a first eccentric gear for the operative connection between the propeller and the first electric motor. The first electric motor has a cylindrical rotor, wherein a surface of the rotor has at least a first pair of recesses. According to the invention, a first and a second recess of the first pair of recesses each extend from a top surface to a base surface of the rotor parallel to a central axis of the rotor. Furthermor