DE102022200010A1 - Aviation engine for an aircraft, and aircraft with a corresponding aircraft engine and method for operating an aircraft engine - Google Patents

Abstract

The invention relates to an aircraft engine (3) for an aircraft (1), having: - a propeller (4) which is arranged on a drive shaft (5) of the aircraft engine (3) and rotated about an axis of rotation (6th axis) by means of the drive shaft (5). ) of the propeller (4) can be driven, - a propeller spinner (8) which is arranged in the front area (10) of the propeller (4) viewed in the direction (9) of the axis of rotation (6) of the aircraft engine (3), - a propeller spinner Adjusting device (12) for defined changing of the volume of the propeller spinner (8) in the radial direction (13) to the axis of rotation (6). The invention also relates to an aircraft (1) with at least one aircraft engine (3) and a method for operating one Aeronautical Engine (3).

Description

The invention relates to an aircraft engine for an aircraft, which has a propeller which is arranged on a drive shaft of the aircraft engine and can be driven about an axis of rotation of the propeller by means of the drive shaft. Furthermore, the aircraft engine has a propeller spinner, which is arranged in the front area of the propeller, viewed in the direction of the axis of rotation of the aircraft engine.

Furthermore, the invention relates to an aircraft with at least one aircraft engine. The invention also relates to a method for operating an aircraft engine of an aircraft, with a propeller of the aircraft engine, which is arranged on a drive shaft of the aircraft, being driven with the drive shaft about an axis of rotation of the propeller.

For example, "Personal Air Vehicles" (PAV) or aircraft that can take off and land vertically (eVTOL "electric Vertical Take-Off and Landing aircraft") are being developed for future mobility solutions. Such aircraft concepts can use a common propeller for the vertical take-off process as well as for cruising. For example, the "tilt wing concept" or "tilt rotor concept" can be used here. In contrast to "lift-and-cruise concepts", in these concepts separate motor-propeller units can be used both for starting and for cruising, so that the mass of the aircraft can be minimized.

The efficiency of the propeller has a significant influence on the electric range, in particular, of such aircraft. With these concepts, however, the propeller design often represents a compromise, since it must be coordinated with both hovering (hoovering or take-off) and cruising. For example, variable pitch propellers are used as standard in classic aircraft. With these, the individual propeller blades of the propeller are rotated synchronously around their longitudinal axis and thus adapted to the respective flight situation. A good level of efficiency can thus be achieved both during the take-off process (no inflow speed due to aircraft movement) and during cruising (inflow speed due to airspeed).

The prior art discloses, for example, variable propeller spinners for specifically influencing the cooling air flow for combustion engines arranged behind them, as well as propeller spinners optimized for aircraft with a “tilt rotor concept”.

For example, the U.S. 2020/0 223 552 A1 a rotor assembly for use in an aircraft. This includes a rotor hub, a spindle structure that includes a spinner opening, and a rotor blade. The rotor blade has a rotor root, which is found near the rotor hub. The rotor assembly also includes a moveable fairing surface that rests at least partially along the rotor hub.

One disadvantage is that the rotor blade in particular is rotated as a whole, but the inflow situation near the hub (small radius) and near the blade tip (large radius) is different. This represents a compromise that does not fully exploit the efficiency of a propeller. Also, the variation of engine speed and angle of attack provides only a limited possibility (degrees of freedom) to increase efficiency.

One object of the present invention is therefore to improve the efficiency of an aircraft drive, in particular a propeller.

This object is achieved by an aircraft engine, an aircraft and a method according to the independent patent claims. Useful further developments result from the dependent patent claims.

• - einen Propeller, welcher an einer Antriebswelle des Luftfahrtantriebs angeordnet ist und mittels der Antriebswelle um eine Rotationsachse des Propellers antreibbar ist,
• - einen Propellerspinner, welcher in Richtung der Rotationsachse des Luftfahrtantriebs betrachteten vorderen Bereich des Propellers angeordnet ist,
• - eine Propellerspinner-Verstelleinrichtung zum definierten Verändern des Volumens des Propellerspinners in radialer Richtung zur Rotationsachse.

One aspect of the invention relates to an aircraft engine for an aircraft, having:

• - a propeller, which is arranged on a drive shaft of the aircraft engine and can be driven by means of the drive shaft about an axis of rotation of the propeller,
• - a propeller spinner, which is arranged in the front area of the propeller viewed in the direction of the axis of rotation of the aircraft engine,
• - A propeller spinner adjustment device for defined changing the volume of the propeller spinner in the radial direction to the axis of rotation.

For example, an aircraft or an aircraft can be operated more efficiently with the aircraft drive according to the invention. The efficiency of the propeller can be increased by changing the volume of the propeller spinner in a defined manner using the propeller spinner adjustment device. For example, an increase in efficiency of 10%, in particular 20%, in particular 25%, compared to the propeller in the prior art can be achieved here.

The range of the aircraft when performing a cruising flight can be increased by the aircraft drive according to the invention. This is achieved through the improved efficiency of aircraft propulsion. For example, the more efficient aircraft propulsion means that the aircraft can take on more payload. In particular, with the aid of the aircraft drive according to the invention, the payload of the aircraft can be increased while the range remains the same.

In particular, a variable propeller spinner for aircraft can be provided with the help of the propeller spinner adjustment device. For example, with the propellers in the prior art, it can happen that when the aircraft is cruising, local downforce occurs, for example, in the vicinity of the hub of the propeller instead of lift (propeller thrust). Propeller blades near the hub, for example, therefore tend to brake the aircraft instead of propelling it. For example, averaged over a propeller radius, there is still a positive propeller thrust as lift, but with losses in efficiency. These disadvantages can occur, for example, by changing the volume of the propeller spinner in a defined manner according to the invention, so that, for example, such negative areas in the vicinity of the hub can be sealed off or covered. As a result, the efficiency of the propeller and in particular of the aircraft drive can be increased. In particular, the propeller spinner can be a propeller spinner whose size or volume can be dynamically adjusted and which can be changed or varied with the help of the propeller spinner adjustment device in such a way that, for example, areas of the propeller that are detrimental to efficiency can be covered or sealed off. The overall efficiency of a cruise flight of the aircraft can thus be increased.

In particular, the propeller spinner adjustment device can be used to change or adjust the volume or diameter of the propeller spinner in a defined manner, thereby increasing the efficiency of the aircraft drive and of the aircraft when cruising.

For example, the aircraft can be a convertible aircraft, which can be referred to as a vertical takeoff and vertical landing aircraft. In particular, convertible aircraft are capable of changing flight modes (flight states) during flight. For example, a hovering flight in helicopter mode, the subsequent transition from vertical to horizontal flight and horizontal flight as a fixed-wing aircraft are considered to be flight conditions relevant for a convertible aircraft.

For example, the aircraft drive can be a tilt rotor. For example, the aircraft can be designed as a tilt-wing aircraft.

In particular, the aircraft is a "vertical take-off and landing aircraft" (eVTOL). The aircraft engine can thus be used for an aircraft designed in this way. For example, the aircraft can be part of urban air mobility, such as air taxis.

In particular, the aircraft is able to carry out a vertical take-off and a vertical landing.

The propeller can in particular be an air screw of the aircraft. With the help of the propeller, for example, a shaft power of an aircraft engine or a shaft turbine thrust or thrust can be generated.

In particular, the propeller can be designed as a variable-pitch propeller, with the angle of attack of the propeller blades being variable in the case of a variable-pitch propeller, as a result of which the angle of attack of the propeller blades can be adapted to different operating situations of the aircraft. With the help of the drive shaft, the propeller and the axis of rotation can be driven, so that the propeller can be brought to a predetermined speed. For example, the drive shaft can be configured parallel to the axis of rotation.

The propeller spinner can be an aeronautical spinner, which can be a streamlined fairing on an aircraft in front of the propeller at the center of the engine or on turbofan engines. The propeller spinner is used, for example, to reduce air resistance and thus ensure improved airflow to the aircraft engine.

For example, the aircraft engine can be referred to as the engine or engine unit of the aircraft.

For example, with the help of the propeller spinner, a propeller head of the propeller can be covered at least in areas, in particular completely. For example, the propeller spinner can reach up to the fairing of an aircraft engine or engine (“cowling”). Such a cladding of the aircraft engine can be referred to, for example, as a bonnet or engine nacelle.

Specifically, the propeller spinner adjustment device can be an electromechanical or mechanical device. For example, the propeller spinner adjustment device can be controlled and/or regulated with the aid of a control and/or regulation device in order to bring about the change in the volume of the propeller spinner. In particular, changing or adjusting or setting the volume of the propeller spinner takes place automatically.

In particular, the volume is changed as a function of a flight position of the aircraft operation or of the aircraft.

Optionally, the propeller spinner can be expanded radially with the help of the propeller spinner adjustment device in order to change its volume. In particular, a radial expansion or radial widening of the volume of the propeller spinner takes place here.

If necessary, the volume of the propeller spinner can be expanded in a defined manner using the propeller spinner adjustment device.

In particular, changing the volume of the propeller spinner is a deliberate adjustment or changing of the volume of the propeller spinner. The volume of the propeller spinner can be changed in particular by the system. Thus, changing the volume of the propeller spinner can be variably controlled.

The aircraft drive according to the invention can be used to minimize or counteract disadvantages when using one and the same propeller for vertical take-off or for hovering and cruising.

In one embodiment, it is provided that the propeller spinner adjustment device can be used to change the volume of the propeller spinner from a basic state to at least one expansion state in such a way that a propeller front surface of the propeller is covered at least in regions by the propeller spinner, which has changed in its volume, towards the front more than in the basic state , In particular the propeller spinner covers the propeller front surface at least in regions with a side of the propeller spinner facing the propeller. For example, the volume of the propeller spinner can be automatically changed from a basic state to at least one expansion state with the aid of the propeller spinner adjustment device as a function of a manipulated variable. For example, in the at least one expansion state, the volume of the propeller spinner is expanded or increased compared to the volume of the propeller spinner in the basic state. In particular, in the expansion state, the volume of the propeller spinner is expanded or enlarged compared to the volume of the propeller spinner in the basic state.

In particular, the volume of the propeller spinner can be variably changed starting from the basic state. In this case, in particular, the volume in the widened state can be expanded or widened or widened step by step.

In the basic state, the volume of the propeller spinner has not been changed by the propeller spinner adjustment device. In the basic state, the volume of the propeller spinner is not changed or influenced by the propeller spinner adjustment device.

For example, depending on a position of the aircraft engine or a flight phase of the aircraft, an expansion state adapted to the respective situation or circumstances can be set from a large number of possible expansion states of the volume. In particular, a wide variety of expansion states can be set, for example. In this way, the volume of the propeller spinner, starting from the basic state, can be converted into an expanded state that is adapted to the respective situation.

In the expanded state, the propeller front surface of the propeller can be covered or concealed or sealed off at least in regions, in particular partially, preferably completely, by means of the expanded propeller spinner. Due to the expanded or extended volume of the propeller spinner in the at least one expansion state compared to the basic state, the propeller front surface of the propeller can be covered more closely or further compared to the basic state. This can be done dynamically using the propeller spinner adjustment device.

For example, in the widened state, an inner propeller area of the propeller (relative to the axis of rotation) can be covered or sealed off at least in areas, so that any negative properties on the flight operation of the aircraft can be minimized in this area. In particular, can by sealing off or covering the propeller front surface, at least one flow speed can be slowed down in such a covered area, so that no or only a small braking effect occurs. As a result, the efficiency or overall efficiency of the propeller can be increased or increased when the aircraft is cruising.

In particular, the area or the side of the propeller which extends towards the propeller spinner can be covered at least in areas by the changed volume. The side or the area of the propeller spinner which faces the propeller or is directed towards the propeller can at least partially cover the propeller front surface. For example, the front propeller surface of the propeller can be the side of the propeller that faces forward in the longitudinal direction of the aircraft engine. In particular, the side of the propeller spinner that faces the propeller can be the side that bears against the propeller and in particular extends toward a center point of the propeller.

By covering the propeller front surface of the propeller at least in certain areas, unfavorable inflows during a cruising flight of the aircraft in the propeller area near the hub can be prevented or reduced. This can prevent that only a small propulsion or thrust, but a negative resistance (“drag”) is generated. In particular, in many operating situations of the aircraft, propulsion can even be negative at high flight speeds, so that the inner part of the propeller can slow down the air flow. This can also be minimized or reduced by the at least partially covered propeller front surface. This results in greater efficiency when the aircraft is cruising, since the energy consumption can be reduced and the range can be increased. Furthermore, there is less acoustic stress when cruising, both outside and inside the aircraft.

In a further exemplary embodiment, it is provided that at least one partial surface of the propeller front surface, which is radially inner with respect to the axis of rotation of the propeller and extends radially outwards from the axis of rotation, is covered by the propeller spinner in its radially widened state of expansion, in particular is covered more radially than in the ground state. Thus, an inner propeller area of the propeller is covered by the propeller spinner at least in areas in the widened state.

For example, the radially inner partial area of the propeller front area corresponds to 20%, in particular 30%, in particular 40% of a total area of the propeller front area.

In particular, for example, the inner partial area can correspond to one third of the total area of the propeller front area. In particular, the inner partial surface of the propeller front surface is arranged in the area of a propeller hub or rotor hub of the rotor.

With the aid of the propeller spinner, at least that partial area of the propeller front surface which is located directly in the area of the axis of rotation can be covered in the expanded state. Specifically, the inner patch is that surface area of the propeller front surface that extends remotely with respect to a distal end of the propeller. In particular, the proportion of the inner sub-area that is covered can vary depending on a set expansion state. In particular, as a function of an expansion state selected by the propeller spinner adjustment device, an area size can be determined which is covered within the inner partial area of the propeller front area.

In one exemplary embodiment it is further provided that a rear end of the propeller spinner facing the propeller is radially expanded in the expanded state compared to the basic state. Consequently, in particular the area or the side of the propeller spinner can be expanded radially, which or which extends towards the propeller. As a result, the propeller front surface, in particular the inner partial surface, can be covered or concealed at least in regions in an efficient manner.

For example, the axis of rotation of the propeller spinner corresponds to the axis of rotation of the propeller.

In one embodiment, it is also provided that the propeller has at least two propeller blades, which are each connected to the drive shaft at a connection point of the propeller, with a respective surface area of the at least two propeller blades, which extends towards the connection point and towards a respective radial end area which extends away from at least two propeller blades, is covered at the front at least in regions by the propeller spinner whose volume has been changed with the propeller spinner adjustment device. In particular, the respective surface area of the at least two propeller blades can be located within the radially inner part surface of the propeller front surface. In other words, the respective surface area of the at least two propeller blades, which extends within the radially inner partial surface of the propeller front surface, can be covered or sealed off at least partially, in particular completely, in the widened state by means of its propeller spinner with a changed volume.

In particular, the propeller can have at least two propeller blades, in particular a plurality of propeller blades. For example, the propeller blades may be referred to as blades or rotor blades.

The at least two propeller blades are each arranged at the connection point of the propeller and thus connected to the drive shaft, so that the propeller blades are moved or rotated about the axis of rotation by means of a rotational movement of the propeller at a predetermined speed. The connection point of the propeller is in particular the center of the propeller. In particular, the axis of rotation runs through the connection point. For example, the connection point can be referred to as a rotor hub or propeller hub or hub. The connection point serves to hold or fix the rotor blades of the rotor and to mechanically connect the rotor to the drive shaft, so that a force generated by the drive shaft can be transmitted to the rotor, in particular to the rotor blades . This serves in particular to drive the aircraft, in particular to move it.

The respective radial end area of the rotor blades can be a distal end of a respective rotor blade. In particular, the respective radial end area of the rotor blades is removed from the connection point.

In a further exemplary embodiment of the invention, it is provided that the respective surface area of the at least two propeller blades corresponds to at least 20%, in particular 30%, in particular 40%, of a respective propeller front surface of the at least two propeller blades. In other words, the respective surface area is the radially inner partial surface of the propeller front surface of the propeller, which is covered as a percentage depending on the set expansion state of the propeller spinner depending on the set expansion state. For example, one third of the respective propeller front surface of the at least two propeller blades can be covered with the help of the expanded propeller spinner. An inner propeller area, which extends in the area of the propeller hub, is thus covered at least in areas, in particular completely, in the expanded volume of the propeller spinner. For example, the respective surface area of the at least one propeller surface can correspond to any value between 15% and 45% of the respective propeller front surface of the at least two propeller blades. This respective percentage value is set as a function of a stage or category of the expansion state of the propeller spinner.

In one embodiment, it is provided that the propeller spinner is at least partially, in particular completely, made of a material which has anisotropic elasticity, in particular the propeller spinner has at least one stiffening element on an outer side in the circumferential direction. In particular, the material of the propeller spinner has at least partially, in particular completely, an anisotropic elasticity behavior. Anisotropic elasticity behavior means that a property, in particular a material property, is direction-dependent. Thus, for example, the material that is part of the propeller spinner can have a different elasticity behavior in a particular direction. For example, as a result, the propeller spinner can have high elasticity in the circumferential direction and a lower bending elasticity in the axial or radial direction. Due to the high elasticity in the circumferential direction, the volume of the propeller spinner can be expanded radially. Consequently, an increase in diameter can take place in the circumferential direction. Due to the lower bending elasticity in the axial or radial direction, the propeller spinner has a defined dimensional stability. This is particularly important when the aircraft is cruising, since high, in particular extreme, forces act on the propeller and in particular on the propeller spinner arranged in front of the propeller while the aircraft is flying.

In addition or instead, the propeller spinner can have at least one stiffening element or a plurality of stiffening elements on the outside of the propeller spinner in the circumferential direction. These are additional stiffening elements, so that the propeller spinner has a flight-stable shape both in its basic state and in its expanded expansion state, so that the aircraft can cruise efficiently. For example, the at least one stiffening element can consist of several partial elements. The at least one stiffening element is on the outside, in particular when viewed in the circumferential direction or outer shell of the propeller spinner arranged. For example, the material of the propeller spinner can be glass fiber reinforced polypropylene. In particular, this has different moduli of elasticity in two spatial directions of up to a factor of about 3.

Furthermore, the material can be polyurethane (TPU). This has a high elasticity and can be reinforced with carbon fibers (CF), for example.

For example, the propeller spinner can have a honeycomb structure, at least in some areas, which shows different elasticity behavior in different spatial directions. Such a structure can be realized, for example, using an anisotropic TPU-CF material.

In a further exemplary embodiment, it is provided that a shell of the propeller spinner is designed as a paraboloid, in particular the shell of the propeller spinner can be expanded radially in a rotationally symmetrical manner about the axis of rotation. The shell of the propeller spinner is, in particular, the outer jacket or outer jacket surface of the propeller spinner.

A paraboloid is a geometric shape of a second-order surface. In particular, the shell of the propeller spinner can be designed as an elliptical paraboloid. The casing of the propeller spinner can in particular be expanded radially in order to be able to change or expand the volume of the propeller spinner. The shell is designed or arranged rotationally symmetrically around the axis of rotation and can be widened or expanded radially. As a result, the volume of the propeller spinner can be changed or expanded to cover at least a partial area of the propeller front surface.

In particular, the shell can be a housing or a cover or a cladding of the propeller spinner.

In particular, the propeller spinner can be elastic.

In one exemplary embodiment, it is provided that the propeller spinner has, as an outer covering, a plurality of lamellae that can be adjusted by the propeller spinner adjustment device, the plurality of lamellae being arranged in a basic state of the volume of the propeller spinner in the direction of rotation about the axis of rotation so that they overlap with one another and are used to change the volume of the Propeller spinner the multiple slats are adjusted with the propeller spinner adjustment device in such a way that the multiple slats have a predetermined distance from one another.

In particular, the multiple slats can be controlled automatically for changing the volume with the help of the propeller spinner adjustment device and thus changed or varied. Thus, in one possible example, the propeller spinner can have a number of movable elements, such as the number of lamellae, as a shell or outer covering. Their position relative to one another can be changed in such a way that the volume of the propeller spinner can be changed.

In order to extend or broaden the volume of the propeller spinner, the position or arrangement of the plurality of lamellae is changed in such a way that the lamellae are at a greater distance from one another. This occurs in particular in the expansion state of the propeller spinner. In the basic state or initial state of the propeller spinner, the multiple lamellae are arranged so that they overlap one another. In order to change the volume of the propeller spinner into an expanded state, the lamellae are changed from their overlapping arrangement to an arrangement spaced apart from one another, so that the volume of the propeller spinner in particular expands. In particular, the arrangement of the lamellae can be varied depending on the type or status of the expansion state. This can be done in particular via a mechanical connection between the coupling of the slats to the propeller spinner adjustment device. In particular, the slats are adjusted automatically or automatically with the aid of the propeller spinner adjustment device.

In particular, the lamellae are arranged or positioned in the direction of rotation or circumferential direction as an outer covering of the propeller spinner around the axis of rotation. In particular, the multiple lamellae are adjusted in the circumferential direction, so that the lamellae have a predetermined, in particular increased, distance from one another when viewed in the circumferential direction. For example, in the expanded state, the multiple lamellae can be arranged relative to one another in such a way that the multiple lamellae no longer overlap one another. In a possible state of widening, the multiple lamellae can be arranged at their outer edges so that they bear against one another at least in certain areas.

In particular, a cup-shaped outer covering or casing of the propeller spinner can be formed with the aid of the plurality of lamellae. In other words, the multiple lamellae can be fanned out for the expansion state of the propeller spinner.

In particular, the propeller spinner can consist of a plurality of lamellae on the outside, the volume or size of which can be varied by shifting the lamellae relative to one another.

In one embodiment, it is provided that the propeller spinner adjustment device is arranged in an interior area of the propeller spinner, with a movable adjustment element of the propeller spinner adjustment device being arranged in a front side of the propeller spinner facing away from the propeller, with the movable adjustment element being set up to use the propeller spinner Adjusting device for changing the volume of the propeller spinner to be moved within the inner area from the side facing away from the propeller towards the propeller. In particular, the volume of the propeller spinner can be changed by means of a mechanical mechanism.

For example, the movable adjustment element can be an adjustment cone. The interior of the propeller spinner is, for example, a cavity interior of the propeller spinner.

The movable adjustment element is arranged in particular within the interior of the propeller spinner and can be controlled for movement with the aid of the propeller spinner adjustment device. In the basic state of the propeller spinner, the movable adjusting element is located on the front side of the propeller spinner facing away from the propeller, ie in the area of the tip of the propeller spinner. For the expansion state of the propeller spinner, the movable adjusting element can be controlled and moved in such a way that it is moved, in particular pulled, from the front side of the propeller spinner facing away from the propeller towards the propeller, i.e. the side of the propeller spinner that extends towards the propeller. By moving the adjusting element from the front of the propeller spinner to the rear of the propeller spinner, a change in the volume of the propeller spinner can be brought about. Thus, with the help of a mechanical adjusting mechanism, the volume of the propeller spinner can be adjusted to cover at least one area of the propeller front surface.

One embodiment provides that the propeller spinner adjustment device has a pneumatic adjustment unit, wherein at least one inflatable element, which is arranged in an interior area of the propeller spinner, can be controlled by means of the pneumatic adjustment unit to change the volume of the propeller spinner. As a result, the volume of the propeller spinner can be adjusted in the simplest way by inflating or deflating the inflatable element again. In particular, in the home state of the propeller spinner, the inflatable elements are in a deflated or only partially inflated state.

In the expanded expansion state of the propeller spinner, the inflatable elements are in a partially, in particular fully, inflated state. The inflatable elements can be variably inflated depending on which expansion condition is provided and how much of the propeller front surface is to be covered. This can be done using the propeller spinner adjustment device. In particular, the at least one inflatable element or several inflatable elements can be arranged in the interior or interior area of the propeller spinner. In this way, the volume of the propeller spinner can be changed by means of a pneumatic mechanism.

In particular, the volume of the propeller spinner can be changed by adjusting it pneumatically or hydraulically.

For example, the inflatable elements can be designed as inflatable rings, which are arranged in the circumferential direction in the interior of the propeller spinner.

A further aspect of the invention relates to an aircraft with at least one aircraft engine according to the previous aspect or an advantageous development thereof. According to the invention, when the aircraft is hovering, the axis of rotation of the propeller is aligned to a longitudinal direction of the aircraft at a predetermined angle to the vertical and when the aircraft is cruising, the axis of rotation of the propeller is aligned to the longitudinal direction of the aircraft at a predetermined angle to the horizontal.

For example, in hovering flight, the axis of rotation of the propeller can be arranged in a value interval between ±10% to the vertical. During cruising flight, the axis of rotation of the propeller can be arranged in a value interval between ± 10% to the horizontal.

Optionally, the axis of rotation of the propeller can be arranged perpendicular to the longitudinal direction of the aircraft in the hover flight. Furthermore, when the aircraft is cruising, the axis of rotation of the propeller can optionally be aligned parallel to the longitudinal direction of the aircraft.

In particular, the orientation of the axis of rotation of the propeller can vary depending on the flight phase or flight condition of the aircraft.

For example, the aircraft can be a convertible aircraft that can take off vertically and land vertically. In particular, the aircraft can change flight modes or flight states during flight. For example, the aircraft can be a vertical take-off aircraft. In particular, the aircraft can be designed as an eVTOL (“vertical take-off and landing aircraft”). In particular, the aircraft can be referred to as an air taxi.

For example, the aircraft can be part of an aircraft fleet to provide an efficient mobility solution.

In particular, the aircraft can have at least one aircraft engine, in particular several aircraft engines, in particular engines. For example, the aircraft can have an aircraft drive according to the invention for each wing or wing. For example, two aircraft drives according to the invention can also be arranged per wing.

For example, the number of aircraft engines can be based on the respective area of application of the aircraft.

In particular, the compromise can be eliminated or minimized by means of the aircraft according to the invention and in particular by the aircraft drive according to the invention, with which the differences between the operating state "hovering", i.e. without control, and a forward flight, i.e. with onflow, are described. For example, when hovering, the propeller can generate useful lift near the hub, i.e. close to the propeller hub. When cruising it can happen that the propeller near the hub generates at least partially damaging downforce. This can also be the case with a controllable pitch propeller. For example, in the case of a controllable pitch propeller, the entire propeller blade can be pitched more strongly in accordance with the higher axial flow. In this case, an angle of attack can be varied. This can be solved with the present invention, for example.

A further aspect of the invention relates to a method for operating an aircraft engine of an aircraft, wherein a propeller of the aircraft engine, which is arranged on a drive shaft of the aircraft engine, is driven with the drive shaft about an axis of rotation of the propeller. According to the invention, the volume of a propeller spinner, which is arranged in the front area of the propeller viewed in the direction of the axis of rotation of the aircraft engine, is changed with a propeller spinner adjustment device depending on a position of the aircraft engine in the radial direction to the axis of rotation.

In particular, the method just described can be implemented with an aircraft engine or an aircraft according to the previous aspects or an advantageous development thereof. In particular, the aircraft engine and/or the aircraft can have means, in particular technical means, in order to carry out or execute the method just described.

In particular, the volume can be changed automatically as a function of the position of the aircraft drive or of the aircraft.

In particular, a flight phase or a flight mode or flight state of the aircraft can be characterized with the position of the aircraft drive. The aircraft can in particular perform a hover flight, for example in a helicopter mode. This takes place in particular during a take-off phase and/or a climb phase of the aircraft. The hovering flight also takes place during a descent and/or landing approach or landing of the aircraft. Hovering can be understood as a flight condition in which an aircraft is in the air in an unchanged position and unchanged altitude. Furthermore, when the aircraft is moving or when it is flying, a cruise flight can be carried out as a flight phase. For example, the air flight phase between the climb after reaching the planned cruising altitude and the beginning of the descent can be referred to as cruising flight. In particular, the aircraft and thus the aircraft engine are put into a cruising mode when, for example, a flight altitude for cruising is reached.

In an exemplary embodiment relating to the method described above, it is provided that the volume of the propeller spinner can be increased by one with the propeller spinner adjustment device Basic state is changed in at least one expansion state so that a propeller front surface of the propeller is at least partially covered by the propeller spinner, which has changed in volume, towards the front more than in the basic state. Depending on the position of the aircraft engine and/or a flight phase of the aircraft, for example, at least one of several expansion states for the propeller spinner can be set automatically, so that in particular the volume of the propeller spinner can be expanded in order to cover at least a partial area of the propeller front surface.

In a further exemplary embodiment of the method described above, provision is made for the volume of the propeller spinner to be changed automatically when the aircraft drive unit experiences a change in its position between a cruising position and a hovering position. Furthermore, the volume of the propeller spinner in the cruising position can be set to the expanded state and in the hover position to the basic state or changed or submitted. Depending on the position of the aircraft engine and/or an operating state of the aircraft, a point in time and/or a period of time for changing the volume of the propeller spinner and/or a volume size to which the volume of the propeller spinner is changed can be determined. For example, this can be done using an electronic evaluation unit of the propeller spinner adjustment device.

For example, the electronic evaluation unit can be used to determine or ascertain at what point in time and for what period of time the volume of the propeller spinner should be changed. This can, for example, be transmitted to the propeller spinner adjustment device, in particular a control unit. Furthermore, a volume size to which the volume of the propeller spinner will be brought or changed can be determined. A wide variety of information can be taken into account. For example, an operating state of the aircraft can be a flight phase. It is particularly important whether the aircraft is in a take-off phase or in a cruising phase.

In particular, advantageous embodiments of one aspect can be viewed as advantageous embodiments of another aspect and/or all aspects. In particular, advantageous exemplary embodiments of the aircraft engine can be regarded as advantageous exemplary embodiments of the aircraft and the method. Likewise, advantageous exemplary embodiments of the method can be regarded as advantageous exemplary embodiments of the aviation drive of the aircraft. This also applies in reverse.

The invention also includes developments of the aircraft according to the invention and of the method according to the invention, which have features as have already been described in connection with the developments of the aviation drive system according to the invention. For this reason, the corresponding developments of the aircraft according to the invention and the method according to the invention are not described again here.

The invention also includes the combinations of features of the described embodiments.

• 1 eine schematische Darstellung eines Luftfahrzeugs mit zumindest einem Luftfahrtantrieb in einer Reiseflug-Stellung;
• 2 eine weitere schematische Darstellung des Luftfahrzeugs aus 1 in einer Schwebeflug-Stellung;
• 3 eine schematische Darstellung des Luftfahrtantriebs aus 1, wobei sich das Volumen eines Propellerspinners des Luftfahrtantriebs in einem Grundzustand befindet;
• 4 eine weitere schematische Darstellung des Luftfahrtantriebs aus 1, wobei sich das Volumen des Propellerspinners des Luftfahrtantriebs in einem Aufweitungszustand befindet;
• 5 in einer beispielhaften Seiten-Schnittdarstellung des Propellerspinners einen Mechanismus, um das Volumen (hier im Grundzustand dargestelt) des Propellerspinners zu verändern;
• 6 in einer weiteren beispielhaften Seiten-Schnittdarstellung des Propellerspinners einen Mechanismus, um das Volumen (hier im Aufweitungszutand dargestellt) des Propellerspinners zu verändern;
• 7 eine weitere schematische Darstellung des Luftfahrtantriebs aus 1, wobei hier eine spezielle Ausführungsform einer Propellerspinner-Verstelleinrichtung dargestellt ist;
• 8 in einer beispielhaften Seiten-Schnittdarstellung des Propellerspinners einen Mechanismus, um das Volumen (hier im Grundzustand dargestellt) des Propellerspinners zu verändern;
• 9 in einer weiteren beispielhaften Seiten-Schnittdarstellung des Propellerspinners einen Mechanismus, um das Volumen (hier im Aufweitungszutand dargestellt) des Propellerspinners zu verändern;
• 10 eine beispielhafte Vorderansicht des Propellerspinners, wobei dieser als äußere Verkleidung mehrere verstellbare Lamellen (hier sind sie zueinander überlappend dargestellt) aufweist;
• 11 eine beispielhafte Seitenansicht des Propellerspinners aus 10;
• 12 eine beispielhafte Vorderansicht des Propellerspinners aus 10, wobei hier die Lamellen aufgefächert sind; und
• 13 eine beispielhafte Seitenansicht des Propellerspinners aus 12.

Exemplary embodiments of the invention are described below. For this shows:

• 1 a schematic representation of an aircraft with at least one aircraft engine in a cruise position;
• 2 Another schematic representation of the aircraft 1 in a hover attitude;
• 3 a schematic representation of the aircraft engine 1 , wherein the volume of a propeller spinner of the aircraft engine is in a ground state;
• 4 Another schematic representation of the aircraft engine 1 , wherein the volume of the propeller spinner of the aircraft engine is in a state of expansion;
• 5 in an exemplary side sectional view of the propeller spinner, a mechanism to change the volume (shown here in the basic state) of the propeller spinner;
• 6 in another exemplary side sectional view of the propeller spinner, a mechanism to change the volume (shown here in the expanded state) of the propeller spinner;
• 7 Another schematic representation of the aircraft engine 1 , wherein a special embodiment of a propeller spinner adjustment device is shown here;
• 8th in an exemplary side sectional view of the propeller spinner, a mechanism to change the volume (shown here in the basic state) of the propeller spinner;
• 9 in another exemplary side sectional view of the propeller spinner Mechanism to change the volume (shown here in the expanded state) of the propeller spinner;
• 10 an exemplary front view of the propeller spinner, this as the outer panel having a plurality of adjustable slats (here they are shown overlapping each other);
• 11 an exemplary side view of the propeller spinner 10 ;
• 12 an exemplary front view of the propeller spinner 10 , whereby here the lamellae are fanned out; and
• 13 an exemplary side view of the propeller spinner 12 .

The exemplary embodiments explained below are preferred exemplary embodiments of the invention. In the exemplary embodiments, the described components each represent individual features of the invention to be considered independently of one another, which also develop the invention independently of one another and are therefore also to be regarded as part of the invention individually or in a combination other than that shown. Furthermore, the exemplary embodiments described can also be supplemented by further features of the invention already described.

Elements with the same function are each provided with the same reference symbols in the figures.

The 1 1 shows, for example, a schematic representation of an aircraft 1. For example, the aircraft 1 can be a convertible aircraft or an eVTOL. In particular, the aircraft 1 serves as an urban air mobility vehicle. In particular, the aircraft 1 can take off and land vertically.

For example, the aircraft 1 can have two wings 2 or wings. So that the aircraft 1 can be operated and, in particular, moved, the aircraft 1 can have at least one aircraft engine 3 . For example, the aircraft engine 3 can be referred to as the engine or drive unit of the aircraft 1 . In this exemplary embodiment, the aircraft 1 has an aircraft engine 3 per wing 2 .

The aircraft engine 3 can have a propeller 4 . For example, the propeller 4 can be referred to as an air screw. The propeller 4 is arranged, for example, on a drive shaft 5 of the aircraft engine 3 . The propeller 4 can be driven about an axis of rotation 6 of the propeller 4 with the aid of this drive shaft, which can in particular be referred to as a mechanical drive. The axis of rotation 6 is the axis about which the propeller 4 rotates. For example, the axis of rotation 6 can be aligned parallel to the drive shaft 5 .

In particular, the aircraft 1 can take on different flight phases. A flight phase can be a cruise flight or cruise flight phase of the aircraft 1, for example.

In particular, in the 1 the aircraft 1 shown in cruise flight. When cruising, the axis of rotation 6 of the propeller 4 is aligned with a longitudinal direction 7 or longitudinal axis (corresponds to the x-axis) of the aircraft 1 at a predetermined angle to the horizontal. For example, the axis of rotation 6 and the longitudinal direction 7 can be referred to as essentially parallel. The position of the aircraft engine 3 can be changed for landing or taking off. Mechanical adjusting devices can be provided for this purpose. Such an operation or state of the aircraft 1 is in the 2 shown. A hovering flight of the aircraft 1 is shown here. With the hover flight, the aircraft 1 can take off and land vertically (corresponding to the z-axis). In particular, when the aircraft 1 is hovering, the axis of rotation 6 of the propeller 4 is aligned with the longitudinal direction 7 of the aircraft 1 at a predetermined angle to the vertical. For example, as in the 2 shown, the axis of rotation 6 can be viewed essentially perpendicular to the longitudinal direction 7 .

Back to 1 . Furthermore, the aircraft engine 3 can have a propeller spinner or spinner 8, in particular as an aerodynamic measure. The propeller spinner 8 can be arranged in the front area 10 of the propeller 4 viewed in the direction 9 of the axis of rotation 6 of the aircraft engine 3 . In particular, the direction 9 of the axis of rotation 6 when the aircraft 1 is cruising can be the same as the direction 11 of the longitudinal direction 7 .

Thus, for example, the propeller spinner 8 can be referred to as the front cap or tip of the propeller 4 . In particular, as in the 1 to see the propeller spinner 8 at the foremost point of the aircraft engine 3 with respect to the direction 10 can be referred to.

In the hover of the aircraft 1 (cf 2 ) In turn, the direction 9 of the axis of rotation 6 and the direction 11 of the longitudinal direction 7 can be essentially vertical.

In the 3 a schematic representation of the aircraft engine 3 is shown.

Since negative properties can occur, particularly when the aircraft 1 is cruising, which can be caused by the propeller 4 , for example, the aircraft drive 3 can have a propeller spinner adjustment device 12 . This is an automatic, electromechanical adjustment device. In particular, this can be an electromechanical system. For example, a separate propeller spinner adjustment device 12 can be provided for each aircraft drive 3 . It is also conceivable that a central propeller spinner adjustment device is provided, with which all aircraft drives 3 of the aircraft 1 can be controlled and/or regulated. In particular, the propeller spinner adjustment device 12 can be referred to as a control unit.

In particular, the volume of the propeller spinner 8 can be changed in a defined manner in the radial direction 13 to the axis of rotation 6 with the aid of the propeller spinner adjustment device 12 . Thus, for example, the volume of the propeller spinner 8 can be reduced or increased. In particular, the propeller spinner adjustment device 12 can be used to automatically expand or widen the propeller spinner 8 radially. For example, the volume of the propeller spinner 8 can be changed or adapted or adjusted as a function of a position of the aircraft engine 3 and/or of a flight phase of the aircraft 1 .

For example, using the propeller spinner adjustment device 12, the volume of the propeller spinner 8 can be changed from a basic state (this is shown in 3 to see) in at least one expansion state (this is in the 4 to see) can be changed. In particular, the volume is in the expansion state (cf 4 ) expanded or enlarged compared to the ground state. In the 4 As already mentioned, one possible expansion state of different expansion states of the volume of the propeller spinner 8 is shown. In particular, the volume of the propeller spinner 8 can be changed in such a way that a propeller front of a propeller front surface 14 of the propeller 4 is covered at least in regions by the propeller spinner 8 whose volume has changed. The propeller 8 in particular is covered towards the front (viewed with respect to the direction 9 of the axis of rotation 6). In other words, the front area 10 of the propeller 4 can be covered at least in areas. In particular, areas of the propeller 8 that generate a negative thrust or an efficiency-reducing output can be covered by the changed volume 8 in the expansion state. As a result, a more efficient cruising flight can be achieved, so that in particular an increased range of the aircraft 1 can be achieved.

Furthermore, the propeller front surface 14 can be the entire surface of the propeller 4 with respect to the front area 10 of the propeller 4 .

In the upgraded state, the propeller spinner 8 can cover or shade the propeller front surface 14 at least in regions, in particular completely, with a side 15 of the propeller spinner 8 facing the propeller 4 . In particular, at least one partial surface 16 of the propeller front surface 14 that is radially inner with respect to the axis of rotation 6 of the propeller 4 and extends radially outwards from the axis of rotation 6 can be covered by the propeller spinner 8 in its radially widened state. In particular, the inner partial surface 16 extends from the axis of rotation 6 in the radial direction 13. In particular, in the expanded state, the inner partial surface 16 is in comparison to the basic state (cf 3 ) radially further covered. Furthermore, in 4 It can be seen that a rear end 17 of the propeller spinner 8 facing the propeller 4 is radially expanded in the expanded state compared to the basic state. In particular, this is widened or expanded further with respect to the radial direction 13 . In particular, the rear end 17 is at the opposite end of the propeller spinner 8 with respect to the direction 9.

For example, the propeller 4 has at least two propeller blades 19, 18. The propeller 4 can optionally have several propeller blades 18 , 19 . The propeller blades 18, 19 are connected or mechanically coupled to the drive shaft 5 at a connection point 20 of the propeller 4. The connection point 20 can in particular be the center of the propeller 4 . In particular, the connection point 20 is a propeller hub or rotor hub. For example, an axis of rotation 6 can run centrally through the connection point 20 so that the connection point 20 can also be rotated symmetrically about the axis of rotation 6 . For example, the connection point 20 can be connected to the drive shaft 5 along the axis of rotation 6 in order to rotate the propeller 4 and in particular the propeller blades 18, 19 as a function of a speed.

For example, a respective surface area 21, 22 of the at least two propeller blades 18, 19 can be covered at least in areas by the propeller spinner 8, whose volume has been changed by the propeller spinner adjustment device 12, on the front side with respect to the front area 10. For example, the two surface areas 21, 22 form the inner partial surface 16.

In particular, the respective surface area 21, 22 extends towards the connection point 20 and towards a respective radial end area 23, 24 of the at least two propeller blades 18, 19. Thus, the respective surface area 21, 22 can act near the center of the connection point 20 and in particular near the center of the center of the propeller 4.

In particular, the respective surface area 21, 22 can correspond to at least 20 percent, in particular 30 percent, in particular 40 percent of a respective propeller front surface 14 of the at least three propeller blades 18, 19. Thus, for example, the inner propeller area of the propeller 4 can be covered. For example, a respective surface area 21, 22 can correspond to a third, in particular a quarter, of a front surface of a respective propeller blade 18, 19.

In particular, a third, in particular a quarter, of the propeller front surface 14 can be covered with the help of the propeller spinner 8 whose volume has been changed in a widened state.

For example, the propeller spinner 8 can be formed at least partially, in particular completely, from a material that has anisotropic elasticity. The propeller spinner 8 can, for example, have at least one stiffening element 26 on an outer side 27 in the circumferential direction 25 (cf 8th ) exhibit. In particular, the at least one stiffening element 26 is a stabilizing element in order to improve the stability of the propeller spinner 8, in particular during cruising flight. In particular, the propeller spinner 8 can have a plurality of stiffening elements 26 .

For example, the propeller spinner 8 can have a sleeve 28 (cf 1 ) exhibit. This shell 28 can be referred to as a jacket or outer shell, for example. In particular, the shell 28 can be designed as a paraboloid. Thus, the shell 28 and in particular the propeller spinner 8 has a parabola-like shape. In particular, the sleeve 28 can be expanded radially in a rotationally symmetrical manner about the axis of rotation 6, so that the volume of the propeller spinner 8 can be changed.

In particular, the 5 a possible embodiment or mechanism to change the volume of the propeller spinner 8. For this purpose, for example, the propeller spinner adjustment device 12 can be arranged in an interior area 29 or cavity of the propeller spinner 8 . A movable adjustment element 30 of the propeller spinner adjustment device can be arranged in a front side 31 facing away from the propeller 4 (with respect to the direction 9 of the axis of rotation 6). In the 5 In particular, the basic state of the propeller spinner 8 and in particular of the movable adjusting element 30 is again shown. In the 6 at least one expansion state of the propeller spinner 8 is now shown. The basic state is again visualized with the dashed lines 32 . The movable adjustment element 30 is now moved from the front side 31 towards the propeller 4 by means of the propeller spinner adjustment device 12 in order to change the volume within the inner area 29 . For this purpose, the movable adjusting element 30 can be moved in the direction (opposite to the direction 9) of the propeller 4 by means of a spindle 33, for example. In this case, in particular the adjustment element 30 is moved towards a counter-element 34 . This movement within the propeller spinner 8 can cause an expansion or change in volume.

In the 7 Another possibility for changing the volume is shown. In this case, for example, the propeller spinner adjustment device 12 can be arranged outside of the propeller spinner 8 . This can be done, for example, in a region of the propeller 4 that faces away from the direction 9 . Here, however, in contrast to the version in 6 the spindle 33 or threaded spindle is arranged outside, in particular completely outside, of the propeller spinner 8 . For this purpose, for example, the propeller spinner adjustment device 12 can have an electric motor 35 . The electric motor 35 can have a housing 36, a stator 37, a rotor 38 and a hollow shaft 39, for example. Furthermore, shaft bearings 40 can be provided. An adjustment actuator 41 can in turn be provided for adjusting the movable adjustment element 30 . This can be operated using the electric motor 35 . In particular, the adjusting actuator 41 can be arranged within the propeller spinner 8 . Cable guides can be provided for this purpose, for example. In particular, the electric motor 35 has a cooling air duct 42 .

In particular, it can be in the 7 propeller spinner 8 shown is a non-rotatable spinner.

In the 8th Another possibility for changing the volume is shown. The propeller spinner adjustment device 12 can have a pneumatic or hydraulic adjustment unit 43 . This adjusting unit 43 can be arranged in particular in the inner area 29 of the propeller spinner 8 . At least one inflatable element 44, which is arranged in the interior area 29, can be controlled with the aid of the pneumatic adjustment unit 43, which can be controlled and/or regulated by the adjuster spinner adjustment device 12. The inflatable elements can be inflated to change the volume, in particular to expand the volume. In particular, in the 8th turn the basic state of the propeller spinner 8 is shown.

In the 9 an expansion state is again shown. In the process 9 the at least one inflatable element 44, for example an inflatable ring, is inflated, in particular filled with air or a gas, so that the volume of the propeller spinner 8 expands. In particular, the inflatable element 44 can be controlled using the pneumatic adjustment unit 43 . On the one hand, this can be inflated or deflated again, depending on the volume requirements of the propeller spinner 8.

In the following 10 until 13 Another possibility for changing the volume of the propeller spinner 8 is shown.

For example, the 10 a front view of the propeller spinner 8 viewed from the front area 10.

In this case, for example, the propeller spinner 8 can have a plurality of slats 46 adjustable by the propeller spinner adjustment device 12 as an outer covering 45 . Here is in the 10 again the initial state 32 of the propeller spinner 8 is shown. In the basic state or initial state 32 , the lamellae 46 are arranged so that they overlap one another in the circumferential direction 25 or the circumferential direction about the axis of rotation 6 . For this purpose, for example, in 11 a side view shown.

To change the volume 8, the lamellae 46 can be adjusted or changed, so that the lamellae 46 in particular are fanned out. This is now in the 12 shown. In this case, the lamellae 46 are controlled in particular with the aid of the propeller spinner adjustment device 12 such that they are fanned out. The volume is thus expanded radially. This is in the 12 between the comparison to the ground state 32 can be seen. The multiple lamellae 46 are controlled or adjusted in such a way that the multiple lamellae 46 are at a predetermined distance 47 from one another. For example, this is in 13 to see. The volume of the, in particular elastic, propeller spinner 8 can thus be widened or increased by the lamellae 46 which are now spaced apart.

In one embodiment of the invention, the volume of the propeller spinner 8 can be changed automatically with the propeller spinner adjustment device 12 depending on a position of the aircraft engine 3 and/or a flight phase of the aircraft 1 in the radial direction 13 to the axis of rotation 6. Thus, the volume of the propeller can be adjusted on the system side by electro-mechanical systems.

Furthermore, with the help of the propeller spinner adjustment device 12, for example, the volume of the propeller spinner 8 can be changed from the basic state 32 to at least one expansion state in such a way that the propeller front surface 14 of the propeller 4, at least in some areas, can be extended forwards more than in the ground state 32 is covered. This can also be done by an automated system, in particular a control and/or regulating device.

Furthermore, for example, the volume of the propeller spinner 8 can be changed automatically if the aircraft engine 3 changes its position between a cruising position (cf 1 ) and a hover position (compare 2 ) learns. For example, the propeller spinner adjustment device 12 can be an electronic evaluation unit (cf 3 ) exhibit. In particular, the volume of the propeller spinner 8 can be set to the expanded state in the cruise position and to the ground state in the hover position. Depending on the respective position of the aircraft engine and/or the operating state of the aircraft 1, a point in time and/or a period of time for changing the volume of the propeller spinner 8 and/or a volume variable by which the volume of the propeller spinner 8 is changed can be determined become. This can be determined using the electronic evaluation unit or computing unit 48 and transmitted to the respective units.

For example, the propeller spinner 8 can have a shape memory alloy with which the shape of the propeller spinner 8 can be changed. For example, the control or controls for changing the volume of the propeller spinner 8 by means of piezo electrical controls or centrifugally controlled controls.

Reference List

1

aircraft

2

wing

3

aeronautical propulsion

4

propeller

5

drive shaft

6

axis of rotation

7

longitudinal direction

8th

propeller spinner

9

direction of the axis of rotation

10

front section of the propeller

11

Direction of the longitudinal direction of the aircraft

12

Propeller spinner adjustment device

13

radial direction

14

propeller face

15

side of the propeller spinner facing the propeller

16

inner surface of the propeller front surface

17

rear end of propeller spinner

18, 19

propeller blades

20

connection point

21, 22

surface areas

23, 24

radial end areas

25

circumferential direction

26

stiffening element

27

outside

28

Covering

29

interior

30

adjustment element

31

Front of propeller spinner

32

ground state

33

spindle

34

counter element

35

electric motor

36

housing of the electric motor

37

Electric motor stator

38

Rotor of the electric motor

39

hollow shaft

40

shaft bearing

41

adjustment actuator

42

cooling air duct

43

pneumatic adjustment unit

44

inflatable element

45

outer fairing

46

several slats

47

distance between the slats

48

electronic evaluation unit

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US20200223552A1 [0006]

Claims (15)

Aviation engine (3) for an aircraft (1), having: - a propeller (4) which is arranged on a drive shaft (5) of the aircraft engine (3) and can be driven by means of the drive shaft (5) about an axis of rotation (6) of the propeller (4), - a propeller spinner (8) which is arranged in the direction (9) of the axis of rotation (6) of the aircraft engine (3) considered front region (10) of the propeller (4), characterized by - A propeller spinner adjustment device (12) for defined changing of the volume of the propeller spinner (8) in the radial direction (13) to the axis of rotation (6). Aviation propulsion (3) after claim 1 , characterized in that the propeller spinner adjustment device (12) can be used to change the volume of the propeller spinner (8) from a basic state to at least one expansion state in such a way that a propeller front surface (14) of the propeller (4) is changed at least in regions by the volume of the propeller spinner Propeller spinner (8) is covered towards the front more than in the basic state, in particular the propeller spinner (8) covers the propeller front surface (14) at least in regions with a side (15) of the propeller spinner (8) facing the propeller (4). Aviation propulsion (3) after claim 2 , characterized in that at least one partial surface (16) of the propeller front surface (14), which is radially inner with respect to the axis of rotation (6) of the propeller (4) and extends radially outwards from the axis of rotation (6), is separated from the propeller spinner (8) in is covered in its radially widened expansion state, in particular is covered further radially than in the basic state. Aviation propulsion (3) after claim 2 or 3 , characterized in that a rear end (17) of the propeller spinner (8) facing the propeller (4) is radially expanded in the expanded state compared to the basic state. Aircraft drive (3) according to one of the preceding claims, characterized in that the propeller (4) has at least two propeller blades (18, 19), which are each connected to the drive shaft (5) at a connection point (20) of the propeller (4). , wherein a respective surface area (21, 22) of the at least two propeller blades (18, 19) which extends towards the connection point (20) and towards a respective radial end area (23, 24) of the at least two propeller blades (18, 19). extends, is covered at the front at least in regions by the propeller spinner (8) whose volume has been changed by means of the propeller spinner adjustment device (12). Aviation propulsion (3) after claim 5 , characterized in that the respective surface area (21, 22) of the at least two propeller blades (18, 19) corresponds to at least 20%, in particular 30%, in particular 40%, of a respective propeller front surface (14) of the at least two propeller blades (18, 19). . Aircraft engine (3) according to one of the preceding claims, characterized in that the propeller spinner (8) is formed at least partially, in particular completely, from a material which has anisotropic elasticity, in particular the propeller spinner (8) in the circumferential direction (25) at least one Having stiffening element (26) on an outer side (27). Aircraft engine (3) according to one of the preceding claims, characterized in that a sleeve (28) of the propeller spinner (8) is designed as a paraboloid, in particular the sleeve (28) of the propeller spinner (8) can be radially expanded rotationally symmetrically about the axis of rotation (6). . Aviation drive (3) according to one of the preceding claims, characterized in that the propeller spinner (8) has a plurality of lamellae (46) adjustable by the propeller spinner adjustment device (12) as an outer covering (45), the plurality of lamellae (46) in a basic state of the volume of the propeller spinner (8) in the circumferential direction (25) around the axis of rotation (6) are arranged overlapping each other and for changing the volume of the propeller spinner (8) the plurality of lamellae (46) with the propeller spinner adjustment device (12) in such a way are adjusted so that the plurality of slats (46) have a predetermined spacing (47) from one another. Aviation drive (3) according to one of the preceding claims, characterized in that the propeller spinner adjustment device (12) is arranged in an inner region (29) of the propeller spinner (8), a movable adjustment element (30) of the propeller spinner adjustment device (12) being in on a front side (31) of the propeller spinner (8) facing away from the propeller (4), the movable adjustment element (30) being set up to change the volume of the propeller spinner (8) within the interior area by means of the propeller spinner adjustment device (12). (29) to be moved from the side (31) facing away from the propeller (4) towards the propeller (4). Aircraft engine (3) according to one of the preceding Claims 1 until 9 , characterized in that the propeller spinner adjusting device Device (12) has a pneumatic adjustment unit (43), at least one inflatable element (44) which is arranged in an inner area (29) of the propeller spinner (8) being arranged by means of the pneumatic adjustment unit (43) for changing the volume of the propeller spinner ( 8) is controllable. Aircraft (1) with at least one aircraft engine (3) according to one of the preceding Claims 1 until 11 , characterized in that in a hovering flight of the aircraft (1) the axis of rotation (6) of the propeller (6) to a longitudinal direction (7) of the aircraft (1) at a predetermined angle to the vertical and in a cruising flight of the aircraft (1) the The axis of rotation (6) of the propeller (4) is aligned with the longitudinal direction (7) of the aircraft (1) at a predetermined angle to the horizontal. Method for operating an aircraft engine (3) of an aircraft (1), wherein a propeller (4) of the aircraft engine (3), which is arranged on a drive shaft (5) of the aircraft engine (3), with the drive shaft (5) about an axis of rotation (6) of the propeller (4), characterized in that - the volume of a propeller spinner (8) which, viewed in the direction (9) of the axis of rotation (6) of the aircraft engine (3), is the front region (10) of the propeller (4 ) is arranged, with a propeller spinner adjustment device (12) depending on a position of the aircraft engine (3) in the radial direction (13) to the axis of rotation (6) is changed. procedure after Claim 13 , characterized in that the propeller spinner adjustment device (12) changes the volume of the propeller spinner (8) from a basic state to at least one expansion state in such a way that a propeller front surface (14) of the propeller (4) is changed at least in regions by the volume of the propeller spinner Propeller spinner (8) is covered more towards the front than in the basic state. procedure after Claim 14 , characterized in that the volume of the propeller spinner (8) is changed automatically when the aircraft engine (3) undergoes a change in its position between a cruise position and a hover position, in particular the volume of the propeller spinner (8) in the cruise flight position in the expanded state and in the hovering position in the basic state, in particular depending on the position of the aircraft engine (3) and/or an operating state of the aircraft (1), a point in time and/or a period of time for changing the volume of the propeller spinner (8) and/or a volume size to which the volume of the propeller spinner (8) is changed is determined.

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