Aircraft propulsion systems and aircraft including propulsion systems

Abstract

This application relates to a propulsion system for an aircraft. The propulsion system includes: an air duct having a first end and a second end, the air duct extending along a longitudinal axis from the first end to the second end; a fan; and a motor system configured to rotate the fan, the motor system including a first electric motor and a second electric motor, the fan and the motor system being located inside the air duct.

Description

Technical Field

[0001] The present disclosure relates to improvements related to propulsion systems for aircraft, particularly for unmanned aerial vehicles (UAVs), and to aircraft for manned or unmanned transportation, particularly drones, including the propulsion systems.

Background Art

[0002] Unmanned aerial vehicles (UAVs), also known as drones, are used in various fields such as civilian and military. UAVs may be used, for example, for transporting goods or for reconnaissance flights, but may also be used for transporting people such as medical transportation or passenger transportation.

[0003] A further development in UAV technology was the development of vertical take-off and landing (VTOL) UAVs. As the name suggests, these UAVs take off and land vertically, thereby requiring less landing space. These drones can also hover and maintain their position above a specific point.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The object of the present disclosure is to provide an improved propulsion system for aircraft, for example for UAVs. The improvements may also relate to aircraft for manned or unmanned transportation, particularly drones, including the propulsion system.

Means for Solving the Problems

[0005] As will become apparent from the following description, these and / or other objects are achieved by the subject matter disclosed herein and / or the subject matter recited in the appended independent claims. Advantageous embodiments and improvements are, inter alia, the subject of the dependent claims.

[0006] A first aspect of this disclosure relates to propulsion systems for aircraft, in particular for unmanned aerial vehicles, such as drones, such as vertical take-off and landing (VTOL) UAVs. Another aspect of this disclosure relates to aircraft, in particular for unmanned aerial vehicles (UAVs), such as drones, in particular for vertical take-off and landing (VTOL) UAVs, incorporating the propulsion system of the first aspect.

[0007] It should be noted that the configurations disclosed herein in relation to the first aspect of a propulsion system also apply to aircraft incorporating the first aspect of a propulsion system. In general, configurations disclosed in relation to different aspects, examples, or embodiments can be combined with each other, even if such combinations are not expressly described herein. Unless expressly stated otherwise, the configurations disclosed above and below herein apply to all aspects, examples, or embodiments of the disclosure, such as propulsion systems and aircraft. For example, where methodological configurations are described, they should be understood as also relating to propulsion systems and / or aircraft configured to perform or implement these configurations.

[0008] It should be noted that the advantages of the embodiments described herein relate to both the propulsion system and the aircraft containing the propulsion system. For example, a lighter propulsion system results in a lighter aircraft. A more energy-efficient propulsion system results in a more energy-efficient aircraft.

[0009] In some embodiments, the propulsion system includes an air duct, a motor system, and a fan. The air duct includes a first end and a second end. The air duct extends along its longitudinal axis from the first end to the second end. The fan and motor system are located inside the air duct. The motor system is configured to rotate the fan. The motor system includes a first electric motor and a second electric motor.

[0010] In the following, the propulsion system is described in relation to a motor system including a first electric motor and a second electric motor. However, the system is not limited to only two electric motors. The configuration for the first electric motor and / or the second electric motor may also apply to further motors, such as a third electric motor. However, the motor system may also include non-electric motors.

[0011] A propulsion system is defined as a machine that generates thrust to push an object, such as the propulsion system itself, forward. In the following application, the object is typically pushed through air. The thrust can be generated through the acceleration of gas, such as air, by an engine, such as a motor, such as an electric motor, thereby producing a force acting on the engine.

[0012] According to at least one embodiment, the air duct has a substantially cylindrical hollow shape extending along a longitudinal axis. According to at least one embodiment, the air duct includes a first end and a second end. The first end may be located on the opposite side of the second end along the longitudinal axis. The air duct extends from the first end to the second end.

[0013] The first end of the air duct defines the air inlet of the air duct, for example, the entrance to the air duct through which air can enter the air duct, for example, during the operation of the propulsion system. The second end of the air duct defines the air outlet of the air duct, for example, the exit to which air, for example, air that entered the air duct through the first end, for example, through the air inlet, can exit the air duct, for example, during the operation of the propulsion system. The air duct can define an airflow path from the first end of the air duct to the second end of the air duct.

[0014] In this specification, the direction toward the first end of the air duct may also be referred to as the “upward” direction, and the direction toward the second end of the air duct may also be referred to as the “downward” direction. Similarly, the “top” of the propulsion system may be defined as the section of the propulsion system adjacent to the first end of the air duct. The “bottom” of the propulsion system may be defined as the section of the propulsion system adjacent to the second end of the air duct. As will be discussed later, each applies to an aircraft including a propulsion system of the first embodiment.

[0015] According to at least one embodiment, the first end of the air duct defines a first circumferential plane. According to at least one embodiment, the second end of the air duct defines a second circumferential plane. The first circumferential plane and / or the second circumferential plane are substantially perpendicular to the longitudinal axis.

[0016] According to at least one embodiment, the air duct includes an inner surface and an outer surface. The inner surface of the air duct defines a substantially cylindrical shape having a first radius. The first radius corresponds to the inner radius of the air duct, for example, a hollow cylinder.

[0017] The outer surface of the air duct defines a substantially cylindrical shape having a second radius. The second radius corresponds to the outer radius of the air duct, for example, the outer radius of a hollow cylinder.

[0018] The difference between the second radius and the first radius, i.e., the difference between the outer radius and the inner radius, defines the thickness of the air duct, for example, the thickness of the air duct wall. The outer radius is larger than the inner radius.

[0019] According to at least one embodiment, the first radius can be between 10 cm and 1000 cm, 20 cm and 800 cm, 100 cm and 500 cm, for example, between 200 cm and 400 cm.

[0020] According to at least one embodiment, the first radius can be 10 cm, 20 cm, 50 cm, 80 cm, 150 cm, 250 cm, 350 cm, 450 cm, 550 cm, 650 cm, 750 cm, 850 cm, 950 cm or more.

[0021] According to at least one embodiment, the first radius can be 1000 cm, 900 cm, 800 cm, 700 cm, 600 cm, 500 cm, 400 cm, 300 cm, 200 cm, 100 cm, 70 cm, 40 cm, 15 cm or less.

[0022] According to at least one embodiment, the second radius can be between 20 cm and 1000 cm, 20 cm and 800 cm, 100 cm and 500 cm, for example, between 200 cm and 400 cm.

[0023] According to at least one embodiment, the second radius can be 20 cm, 50 cm, 80 cm, 150 cm, 250 cm, 350 cm, 450 cm, 550 cm, 650 cm, 750 cm, 850 cm, 950 cm or more.

[0024] According to at least one embodiment, the second radius can be 1000 cm, 900 cm, 800 cm, 700 cm, 600 cm, 500 cm, 400 cm, 300 cm, 200 cm, 100 cm, 70 cm, 40 cm, 30 cm or less.

[0025] However, the size of the air duct is not limited to the above values. The air duct can be arbitrarily scaled according to the required application.

[0026] According to at least one embodiment, the air duct defines an air flow path radially partitioned by the inner surface of the air duct. The air flow path can extend from a first end, for example, an air inlet, to a second end of the air duct, for example, an air outlet.

[0027] According to at least one embodiment, the first end of the air duct includes an inlet lip. The inlet lip may be an integral part of the air duct. The inlet lip may correspond to the curvature of the wall of the air duct. The inlet lip may be curved radially outwardly, for example, it may be a radially outwardly curved section of the wall of the air duct at the first end of the air duct. The inlet lip may be an additional element attached to the first end of the air duct.

[0028] According to at least one embodiment, the second end of the air duct includes an outlet lip. The outlet lip may be an integral part of the air duct. The outlet lip may correspond to the curvature of the wall of the air duct. The outlet lip may be curved radially outwardly, for example, it may be a radially outwardly curved section of the wall of the air duct at the second end of the air duct. The outlet lip may be an additional element attached to the second end of the air duct.

[0029] The inlet lip and / or the outlet lip provide a better shape for the inlet and / or outlet of air into and / or from the air duct. For example, the inlet lip increases the inlet surface for the air inlet of the air duct. For example, the outlet lip increases the outlet surface for the air outlet of the air duct. The inlet lip and / or the outlet lip have a curvature configured to improve the air flow through and / or around each respective inlet lip and / or outlet lip. Thereby, the air flow becomes more laminar when entering (in the case of the inlet lip) or exiting (in the case of the outlet lip) the air flow path of the air duct. Therefore, it significantly improves the efficiency and propulsion quality of the propulsion system.

[0030] According to at least one embodiment, the inlet lip has a shape that substantially corresponds to or mimics the NACA profile, thereby optimizing the air flow through the inlet lip, particularly around the inlet lip.

[0031] According to at least one embodiment, the outlet lip has a shape that substantially corresponds to or mimics a NACA profile, thereby optimizing the airflow through the outlet lip, and in particular, the airflow around the outlet lip.

[0032] According to at least one embodiment, the air duct is made from composite material and / or carbon fiber reinforced plastic.

[0033] According to at least one embodiment, the air duct includes a first reinforcing collar and / or a second reinforcing collar. The first reinforcing collar may be positioned at a first end of the air duct, for example, around the outer surface of the air duct at or near the first end of the air duct. The second reinforcing collar may be positioned at a second end of the air duct, for example, around the outer surface of the air duct at or near the second end of the air duct.

[0034] The first reinforcing collar and / or the second reinforcing collar have the function of reinforcing the air duct at their respective locations, for example, at the first end of the air duct and / or at the second end of the air duct. Such reinforcement improves the structural stability of the air duct, and therefore the propulsion system and the aircraft including the propulsion system.

[0035] The first and / or second reinforcing collars stabilize and reinforce the air duct. Furthermore, the first and / or second reinforcing collars may have the function of bearing and / or supporting heavier loads of the propulsion system, such as some of the heavier elements, as will be described later.

[0036] The first and second reinforcing collars can be connected to each other by at least one reinforcing strut, for example, four reinforcing struts, that extend longitudinally along the outer surface of the air duct. The propulsion system may include, for example, four reinforcing struts. The four reinforcing struts can be arranged radially symmetrically around the outer surface of the air duct.

[0037] The connection of the first and second reinforcing collars through the reinforcing strut provides better load distribution, resulting in the load of the propulsion system elements being distributed through the reinforcing strut from the first and / or second reinforcing collars to the second and / or first reinforcing collars.

[0038] The propulsion system may also include additional reinforcing collars, such as a third reinforcing collar. The third reinforcing collar may be positioned on the outer surface of the air duct, for example, along the longitudinal axis between the first and second reinforcing collars.

[0039] According to at least one embodiment, the propulsion system further includes at least two, for example, three, four, five, six or more radial guide vanes positioned at the first end of the air duct. The propulsion system may include, for example, four radial guide vanes.

[0040] According to at least one embodiment, at least two radial guide vanes extend from the inner surface of the air duct toward the central longitudinal axis of the air duct. The central longitudinal axis is parallel to the longitudinal axis of the extension of the air duct and can be an axis passing through the center point of the hollow cylinder defined by the air duct. In other words, the central longitudinal axis passes through the center points of the first circumferential plane and / or second circumferential plane defined by the first end and the second end of the air duct, respectively. The first and second circumferential planes are each perpendicular to the central longitudinal axis. Any element perpendicular to the longitudinal axis is perpendicular to the central longitudinal axis.

[0041] In other words, radial guide vanes extend radially inward toward the central longitudinal axis. In this application, the term “radially inward” describes the radial direction toward the hollow cylinder, for example toward the central longitudinal axis. “Radially outward” describes the radial direction toward the central longitudinal axis of the air duct. In aerospace engineering, “radial guide vanes” are sometimes also called “axial guide vanes” because the reference point is the axial extension of the guide vane, for example, the extension in the direction parallel to the longitudinal axis.

[0042] Each radial guide vane may have a first vane end connected to the inner surface of the air duct, for example, the inner surface of a hollow cylinder. Each radial guide vane may extend radially inward from the inner surface of the air duct toward the central longitudinal axis of the air duct. According to at least one embodiment, the radial guide vane may have a substantially linear shape, for example, an I-shape.

[0043] According to at least one embodiment, the radial guide vanes may have a Y-shape. The two arms of the "Y" may correspond to two first vane ends. The two first guide vane ends may be connected to the inner surface of an air duct. However, the radial guide vanes may also have an "X" shape or a similar different shape. According to at least one embodiment, the propulsion system includes a combination of radial guide vane shapes, for example, two Y-shaped radial guide vanes and two straight radial guide vanes.

[0044] According to at least one embodiment, the first reinforcing collar is positioned on a section of the outer surface of the air duct that corresponds to a section of the inner surface of the air duct to which radial guide vanes, for example, the ends of the first vanes, are connected. In other words, the first reinforcing collar on the outer surface of the air duct and the section of the inner surface of the air duct to which the radial guide vanes are connected are substantially on the same plane. The plane is perpendicular to the longitudinal axis.

[0045] As will be described later, the load supported by the radial guide vanes is therefore distributed not only to the air duct by the radial guide vanes, but also supported by and distributed to the first reinforcing collar. This is particularly advantageous in order to minimize the deformation tendency of the air duct and radial guide vanes. In particular, it significantly reduces the excessive stress on the radial guide vanes.

[0046] The load supported by the radial guide vanes can also be distributed to a second reinforcing collar through reinforcing struts in each embodiment, resulting in the overall load being distributed throughout the propulsion system, for example, through the first reinforcing collar and / or the second reinforcing collar and / or reinforcing struts. This load distribution reduces wear on functional parts, such as the radial guide vanes. It further stabilizes the overall architecture of the propulsion system during landing and in severe landing scenarios, such as in the event of unplanned malfunction.

[0047] According to at least one embodiment, at least two radial guide vanes extend along a first circumferential plane defined by a first end of the air duct. In other words, the radial guide vanes are perpendicular to the longitudinal axis, for example, the central longitudinal axis, and in particular extend along a plane along the first end of the air duct, for example, the first circumferential plane.

[0048] According to at least one embodiment, at least two radial guide vanes extend from the inner surface of the air duct toward the central longitudinal axis of the air duct and toward the second end of the air duct. In other words, the radial guide vanes in such an embodiment do not extend along a plane parallel to the first circumferential plane. To put it another way, the radial guide vanes extend along a plane that is not perpendicular to the longitudinal axis. In such an embodiment, the radial guide vanes form a first angle between the radial guide vanes and the first circumferential plane defined by the first end of the air duct.

[0049] Such embodiments improve aerodynamic inlet conditions at the first end, for example, at the air inlet, due to the effect of the extended inlet.

[0050] According to at least one embodiment, the first angle is between 0 and 45 degrees. The first angle may be, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, or 45 degrees.

[0051] According to at least one embodiment, the propulsion system may include one or more radial guide vanes extending along a plane that is not perpendicular to the longitudinal axis, and one or more radial guide vanes extending along a plane that is perpendicular to the longitudinal axis.

[0052] According to at least one embodiment, at least two radial guide vanes are arranged radially symmetrically with respect to the air duct on the inner surface of the air duct. The radial guide vanes can divide the first end of the air duct, for example, the air inlet, into subsections. In an embodiment having four radial guide vanes, the air inlet is divided into four subsections separated by the radial guide vanes.

[0053] Radial vane guides can also include or at least mimic a NACA profile, thereby improving airflow around the vanes, for example, to an air duct.

[0054] According to at least one embodiment, the propulsion system further includes a mounting platform to which radial guide vanes are connected. The mounting platform is formed of a hollow cylinder and can be positioned on a circumferential central section perpendicular to the longitudinal axis, for example, on the radial central section of the central longitudinal axis. The radial guide vanes may include a second vane end connected to the mounting platform. The second vane end may be positioned opposite the first vane end.

[0055] In other words, the radial guide vanes extend radially inward toward the mounting platform and can connect to the mounting platform. The radial guide vanes extend radially inward from the inner surface of the air guide toward the mounting platform and can connect to the mounting platform.

[0056] The mounting platform can be held in place by connecting to the radial guide vanes.

[0057] According to at least one embodiment, the mounting platform is positioned on a first circumferential plane defined by the first end of the air duct. Alternatively, the mounting platform is positioned further, for example, downward toward the second end of the air duct with respect to the first circumferential plane defined by the first end of the air duct. In other words, the mounting platform may be longitudinally offset toward the second end of the air duct with respect to the first end, for example toward the first circumferential plane.

[0058] According to at least one embodiment, the radial guide vane has a wider section toward the inner surface of the air duct, for example toward the first vane end.

[0059] According to at least one embodiment, the radial guide vanes are made from the same material as the air duct, for example, carbon fiber reinforced plastic. Alternatively, the radial guide vanes may include or be made from different materials than those of the air duct.

[0060] According to at least one embodiment, the mounting platform is configured to allow the connection of a propulsion system and / or further elements of an aircraft to the mounting platform.

[0061] According to at least one embodiment, the mounting platform has a circular shape.

[0062] According to at least one embodiment, the mounting platform is configured to be connected to or releasably connected to a payload compartment.

[0063] The advantage of such a configuration is that the load of the payload compartment is distributed from the mounting platform to at least two radial guide vanes and further to the air duct. In embodiments having a first reinforcing collar, the load is further distributed to the first reinforcing collar and, in each embodiment, optionally to a second reinforcing collar through a reinforcing strut.

[0064] This results in better overall load distribution in the payload system, such as the payload compartment, and reduces stress on the propulsion system. This makes the propulsion system safer, reduces the structural load it carries, and thus allows for optimal aerodynamic and thermodynamic design.

[0065] According to at least one embodiment, the motor system of the propulsion system is connected to radial guide vanes. The motor system can be connected to a mounting platform. The motor system is located inside an air duct.

[0066] According to at least one embodiment, the motor system is positioned on the surface of a mounting platform facing, for example, downwards, which faces the second end of the air duct.

[0067] According to at least one embodiment, the motor system extends along the longitudinal axis toward the second end of the air duct. In particular, the motor system can be positioned along the central longitudinal axis toward the second end of the air duct. The motor system can be positioned to minimize turbulence with respect to the airflow path, i.e., the airflow from the first end to the second end.

[0068] According to at least one embodiment, the motor system is entirely located inside the air duct.

[0069] Placing the motor system inside the air duct, for example, entirely inside, has the advantage of centralizing the weight of the propulsion system, thereby improving the stability and predictability of the propulsion system and the aircraft while they are in operation, for example, while the propulsion system and the aircraft containing it are moving through the air.

[0070] By placing the motor system inside an air duct, the motor system is further automatically cooled, at least partially, through the airflow passing through the air duct. Therefore, the motor system requires fewer cooling means and is thus lighter. A motor system placed inside an air duct is also better protected from external influences (e.g., the environment). Therefore, the propulsion system and / or aircraft having such a propulsion system are more reliable and less susceptible to damage.

[0071] The placement of the motor system within the air duct and along the central longitudinal axis has the further advantage of improving stability due to its alignment along the axis.

[0072] Through its connection to the motor system mounting platform and / or radial guide vanes, the motor system's load is distributed to the radial guide vanes and air ducts, and optionally to the first reinforcing collar. This results in a better overall load distribution of the propulsion system, and thereby better propulsion quality. The motor system is a heavy element of the propulsion system and the aircraft. It is advantageous for its load to be distributed throughout the system, rather than being centrally supported by a single element, through the radial guide vanes, and / or the first and / or second reinforcing collars, and / or the reinforcing struts connecting the first and second reinforcing collars.

[0073] The motor system may have a substantially cylindrical shape and may be housed, for example, in a cylindrical housing or case. The motor system may have a radius smaller than or equal to the radius of the mounting platform. The motor system may have a radius larger than or equal to the radius of the mounting platform.

[0074] According to at least one embodiment, the motor system is positioned in a section of the air duct that extends along the longitudinal axis from between one-fifth and one-third of the longitudinal length of the inner duct, when viewed from a first end of the air duct toward a second end of the air duct.

[0075] According to at least one embodiment, the fan is mounted on a motor system. The fan is configured to be rotated by the motor system. The rotation of the fan creates a pressure difference that draws air in from an air inlet and moves it toward an air outlet. The movement of the fan generates an aerodynamic lift that can cause the aircraft to rise.

[0076] By mounting the fan to the motor system, the fan's load is also distributed through the motor system to the mounting platform and / or radial guide vanes, air ducts, and optionally the first and / or second reinforcing collars. Here again, this results in better load distribution in the propulsion system.

[0077] According to at least one embodiment, the fan is positioned further inside the air duct toward the second end of the air duct relative to the motor system.

[0078] According to at least one embodiment, the fan is positioned in the fan area of ​​the air duct. According to at least one embodiment, the fan area encompasses between one-fifth and one-third, for example, one-quarter, of the length of the air duct, viewed from a first end of the air duct toward a second end of the air duct.

[0079] According to at least one embodiment, the fan is positioned at a distance of one-quarter of the length of the air duct, viewed from a first end of the air duct toward a second end of the air duct.

[0080] The more the motor system is positioned longitudinally offset toward the second end of the air duct relative to the first end (e.g., the motor system is closer to the second end of the air duct), and the more the fan is positioned longitudinally offset toward the second end of the air duct relative to the first end (e.g., the fan is closer to the second end of the air duct), the better the aerodynamic conditions. The improved aerodynamic conditions result from the air duct reducing turbulence in the airflow through the airflow path, making the airflow more laminar. This improves the efficiency of the entire propulsion system and the aircraft. In at least one embodiment, the distance between the fan and the first end of the air duct, e.g., the air inlet, is between 10 percent and 30 percent of the total duct length. This has proven to be particularly energy efficient.

[0081] According to at least one embodiment, the fan is connected to a motor system via a shaft. According to at least one embodiment, the motor system is configured to rotate the shaft in order to rotate the fan.

[0082] According to at least one embodiment, the fan includes a plurality of fan blades. According to at least one embodiment, the fan blades extend radially from the axis toward the inner surface, for example radially outward.

[0083] According to at least one embodiment, the fan blades are of a length between 10cm and 1000cm, 20cm and 800cm, 100cm and 500cm, for example, between 200cm and 400cm.

[0084] According to at least one embodiment, the fan blades can be 10 cm, 20 cm, 50 cm, 80 cm, 150 cm, 250 cm, 350 cm, 450 cm, 550 cm, 650 cm, 750 cm, 850 cm, or 950 cm or longer.

[0085] According to at least one embodiment, the fan blades can be 1000cm, 900cm, 800cm, 700cm, 600cm, 500cm, 400cm, 300cm, 200cm, 100cm, 70cm, 40cm, or 15cm or less in length.

[0086] According to at least one embodiment, the fan blades have widths between 1 cm and 40 cm, 2 cm and 30 cm, 5 cm and 20 cm, for example, between 10 cm and 15 cm.

[0087] According to at least one embodiment, the fan blades can have a width of 1.5 cm, 3 cm, 4 cm, 7 cm, 12 cm, 17 cm, 25 cm, or 35 cm or more.

[0088] According to at least one embodiment, the fan blades can have a width of 32 cm, 22 cm, 18 cm, 14 cm, 11 cm, 8 cm, 5 cm, 4 cm, or 3 cm or less.

[0089] According to at least one embodiment, the fan blades are positioned at angles between 0 and 60 degrees with respect to a plane perpendicular to the longitudinal axis, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, and 55 degrees. According to at least one embodiment, the fan blades extend between 98 percent and 100 percent (e.g., 99 percent) of the radius of the circumference defined by the inner surface of the inner duct.

[0090] According to at least one embodiment, the air duct includes further guide vanes positioned further toward the second end of the air duct than the fan, for example, further below the fan. The further guide vanes have the function of minimizing the rotation of the propulsion system.

[0091] The motor system of the propulsion system includes at least two electric motors, a first electric motor and a second electric motor. The first electric motor and the second electric motor are located inside an air duct, for example, entirely inside the air duct.

[0092] The first electric motor can be configured to operate the propulsion system, for example, by rotating a fan or by rotating a shaft. During normal operation of the propulsion system, the first electric motor is the motor that operates the fan. The first electric motor can also be the main electric motor of the propulsion system.

[0093] According to at least one embodiment, the second electric motor can be a motor-generator. The second electric motor can be configured to rotate a fan, for example, a shaft. The second electric motor can be configured as a backup electric motor configured to operate the propulsion system by rotating a fan when the first electric motor, for example the main electric motor, is malfunctioning, not functioning at all, or has no power. However, there are several other situations in which it may be advantageous to use the second electric motor during the normal operation of the propulsion system.

[0094] According to at least one embodiment, the second electric motor is configured to operate independently of the first electric motor. According to at least one embodiment, the first electric motor is configured to operate independently of the second electric motor.

[0095] According to at least one embodiment, the second electric motor is positioned further toward the second end of the air duct than the first electric motor, for example, further downward than the first electric motor. The second electric motor can be positioned between the fan and the first electric motor. Alternatively, the first electric motor can be positioned between the fan and the second electric motor. The first electric motor and / or the second electric motor can be positioned on the same axis, for example, or coupled together.

[0096] According to at least one embodiment, the propulsion system further includes a clutch. The clutch is coupled to both a first electric motor and a second electric motor and to a shaft.

[0097] The clutch can be configured to separate a first electric motor, such as a main motor, from its shaft.

[0098] According to at least one embodiment, the clutch is configured to allow a second electric motor to rotate the shaft without resistance from the first electric motor when the first electric motor is separated from the shaft.

[0099] The clutch can be configured to separate a second electric motor, such as a backup motor, from the shaft.

[0100] According to at least one embodiment, the clutch is configured to allow the first electric motor to rotate the shaft without resistance from the second electric motor when the second electric motor is separated from the shaft.

[0101] Providing a second electric motor, particularly as a backup motor, significantly improves the safety and reliability of the propulsion system. Especially when used in unmanned drones such as VTOL UAVs, the provision of a backup system is particularly useful in preventing uncontrollable dives by, for example, safely bringing the propulsion system back to the ground through the use of the second electric motor when the first electric motor malfunctions.

[0102] Using two electric motors, namely a first electric motor and a second electric motor, improves drivetrain efficiency and thereby provides a more energy-efficient propulsion system. The use of electric motors, such as a first electric motor and a second electric motor, also reduces the need for fossil fuels, thereby having a positive impact on the environment and measures against global warming.

[0103] The use of a clutch configured to allow either the first or second electric motor to rotate its shaft without the resistance of the other electric motor further reduces energy consumption and makes the propulsion system significantly more energy-efficient, especially during takeoff and landing.

[0104] According to at least one embodiment, the second electric motor is mounted on the shaft between the first electric motor and the fan. Alternatively, the first electric motor is mounted on the shaft between the second electric motor and the fan.

[0105] These alternative positionings have proven particularly advantageous in the overall shape of the propulsion system, especially the air duct. Placing the first and second electric motors on the same axis further improves the overall airflow quality of the air flowing through the airflow path of the air duct. In particular, it minimizes turbulence. Furthermore, mounting the first and second electric motors on the same axis minimizes the need for additional axes and the connection of the first and / or second electric motors to the fan. Thus, it leads to a more compact propulsion system, as well as minimizing the number of elements and weight.

[0106] The described arrangement of the first and second electric motors has the further advantage of improving the propulsion system and, consequently, the aircraft's center of gravity. Such an arrangement also requires less cable length when interconnecting functional components, for example, to a battery system. This results in an improved electrical wiring interconnection system (EWIS).

[0107] According to at least one embodiment, the first electric motor and / or the second electric motor is a brushless axial flux electric motor. However, the propulsion system is not limited to such brushless axial flux electric motors.

[0108] According to at least one embodiment, the first electric motor and / or the second electric motor can be configured so as not to require an engine control unit (ECU). This can be achieved, for example, through the use of a multi-level battery. However, the propulsion system is not limited to this embodiment.

[0109] According to at least one embodiment, the first electric motor and the second electric motor can be configured to rotate a fan, for example, an axis, simultaneously and / or independently. The first electric motor and the second electric motor can be configured to be used, for example, operated simultaneously during the takeoff and landing of an aircraft. During ground taxiing, the aircraft may use only one electric motor, for example, the first electric motor. Takeoff and landing are operations that require more power than normal ground taxiing. Therefore, it is advantageous to use both the first and second electric motors.

[0110] According to at least one embodiment, the first electric motor is an axial flux brushless DC or any other type of electric engine.

[0111] According to at least one embodiment, the propulsion system includes a battery system. The battery system may be configured to power a first electric motor and / or a second electric motor. The battery system may also be configured to power the propulsion system and / or any other elements of the aircraft that require power, such as a flight control system, navigation system, sensors, lights, etc.

[0112] The battery system may include at least one battery pack containing at least one battery. The battery system may include more than one battery pack, for example, two, three, four, five, six or more battery packs. According to at least one embodiment, the battery system includes four battery packs.

[0113] Each battery pack may contain one or more battery modules, for example, two, three, four, or more battery modules. Each battery module may contain one or more battery cells. One or more battery cells may be cylindrical cells, pouch cells, and / or prismatic cells. Different battery cells may be included in a battery module. Some battery modules in a battery system may have different battery cell types.

[0114] According to at least one embodiment, one or more or all of the battery packs and / or battery cells of a battery pack have different characteristics. These characteristics may be one or more or all of the following: energy, power, capacity, size, and shape. According to at least one embodiment, one or more battery packs and / or batteries of a battery pack have the same characteristics. These characteristics may be one or more or all of the following: energy, power, capacity, size, and shape. However, the characteristics of one or more battery packs are not limited to those mentioned.

[0115] According to at least one embodiment, the battery system can be a fail-safe energy storage system.

[0116] According to at least one embodiment, the battery system is positioned on the outer surface of the air duct. The battery system can be positioned in a region adjacent to the second end of the air duct. The battery system can be positioned on and / or mounted on a second reinforcing collar. Thus, the second reinforcing collar can bear and / or support the load of the battery system.

[0117] In certain embodiments, the load of the battery system can also be distributed to the first reinforcing collar through a reinforcing strut connecting the first reinforcing collar to the second reinforcing collar.

[0118] According to at least one embodiment, the battery system is located at a distance greater than 5 degrees based on the radial orientation of the fan. In particular, the axial distance of the battery system to the fan is between 5 and 30 degrees, between 10 and 20 degrees, for example, 15 degrees, based on the radial orientation of the fan.

[0119] According to at least one embodiment, the battery system is a rechargeable battery system.

[0120] According to at least one embodiment, the battery system is configured to be replaceable. Providing a replaceable battery system has the advantage of ensuring a propulsion system that can be used almost continuously. When the battery system is empty or nearly empty, it can be replaced without requiring battery charging time. Thus, the propulsion system can be used immediately again with a new, for example, fully charged battery system. An empty battery system can be charged independently.

[0121] According to at least one embodiment, the air duct includes a ventilation inlet and outlet configured to cool the battery system.

[0122] According to at least one embodiment, the propulsion system further includes a flap system. The flap system has the function of directing air passing through an airflow path in an air duct and exiting the air duct from a second end. Thereafter, the flap system provides means for yaw, roll, and pitch of the aircraft including the propulsion system.

[0123] According to at least one embodiment, the flap system is positioned within the air duct, for example, close to a second end of the air duct. According to at least one embodiment, the distance between the flap system and the fan blades, viewed along the longitudinal axis, is between at least 20 percent and 50 percent of the air duct length, for example, 30 percent and 40 percent.

[0124] The propulsion system may also include a servo system, for example, connected to a flap system. The servo system is located outside the air duct, for example, on a second reinforcing collar.

[0125] According to a second aspect of this disclosure, an aircraft is provided which includes a propulsion system according to one or more of the embodiments described above. In particular, the propulsion system may be an aircraft. This means that the propulsion system may function as an independent aircraft, such as a drone. Thus, all configurations relating to the aircraft may also relating to the propulsion system, for example, if the aircraft includes a payload compartment, the propulsion system may include a payload compartment, and if the aircraft includes landing gear, the propulsion system may include landing gear.

[0126] The aircraft may be a drone, such as a VTOL, such as an eVTOL (electric VTOL), such as a ducted fan eVTOL UAV.

[0127] The propulsion system can be used by an aircraft as a primary propulsion system or as a single propulsion system. According to at least one embodiment, the aircraft includes one or more of the propulsion systems of the embodiments described above.

[0128] According to at least one embodiment, the aircraft includes a housing that at least partially radially surrounds an air duct of the propulsion system, for example, the outer surface of the air duct. The housing can be connected to a first end of the air duct, for example, to a first reinforcing collar. In particular, the housing can function as a skirt surrounding the air duct of the propulsion system, for example, the outer surface of the air duct, from the first end of the air duct toward a second end of the air duct. The housing can be formed integrally with the air duct, for example.

[0129] The housing can have an aerodynamic shape that facilitates the aircraft's airborne propulsion, thereby reducing turbulence and energy consumption. This results in more stable and predictable aircraft operation.

[0130] According to at least one embodiment, the housing includes a circular main body having four recesses. The recesses can extend from a second end of the air duct toward a first end of the air duct. The portion of the air duct is visible through the recesses of the housing. This shape of the aircraft, for example the shape of the housing, has proven to be particularly energy efficient while the aircraft is moving through the air. It also reduces the overall weight of the propulsion system and / or the aircraft.

[0131] According to at least one embodiment, the aircraft includes a landing gear, which is an element or so element of the aircraft that assists the aircraft in landing and is in contact with the ground when the aircraft is on the ground or landing.

[0132] Landing gear may have an aerodynamic shape. Such an aerodynamic shape may be useful for generating or assisting in the generation of lift, and for stabilizing the aircraft.

[0133] The landing gear may include landing struts extending from a first end of the air duct toward a second end of the air duct, for example, from a first reinforcing collar. The landing struts may extend, for example, downward from the first end of the air duct toward the second end of the air duct, and radially outward from the first end of the air duct. The landing struts may be long enough, for example, so that the air duct does not come into contact with the ground when the aircraft is in the landing position.

[0134] According to at least one embodiment, the landing strut can be configured such that, in the landing position, for example, when the aircraft is on the ground, the second end of the air duct is substantially 0 cm to 200 cm away from the ground, for example, 10 cm, 25 cm, 50 cm, 100 cm, or 150 cm.

[0135] The landing strut can be connected to a first reinforcing collar. The load supported by the first reinforcing collar, such as the motor system, fan, and / or payload compartment, is therefore distributed to the landing strut, which supports the weight supported by the first reinforcing collar. This is particularly useful when the aircraft, for example, the propulsion system, is on the ground. The weight of the motor system, fan, and / or payload compartment is distributed and supported by the landing strut, thus minimizing load spikes on a single element, such as radial guide vanes.

[0136] In embodiments where the propulsion system also includes a second reinforcing collar and a reinforcing strut connecting the first reinforcing collar to the second reinforcing collar, the load supported by the second reinforcing collar, such as the load of the battery system, is also distributed to the landing strut.

[0137] According to at least one embodiment, the four recesses define four elements of a housing configured to at least partially cover the landing strut.

[0138] According to at least one embodiment, the aircraft further includes a payload compartment configured to accommodate the cargo to be transported by the aircraft. The payload compartment may be releasably coupled to and / or releasably mounted to a mounting platform.

[0139] According to at least one embodiment, the payload compartment is releasably connected to the surface of a mounting platform facing the opposite side of the motor system. In other words, the payload compartment extends upward from the mounting platform. When mounted, the payload compartment can protrude from the first end of the air duct.

[0140] According to at least one embodiment, the payload compartment has connecting means for releasably connecting the payload compartment to a mounting platform. The mounting platform may have mounting means. The connecting means of the payload compartment may be connected to each mounting means on the mounting platform. The connecting means of the payload compartment may be located in the connecting section of the payload compartment. The payload compartment may have various shapes and configurations. It has been proven advantageous that the sides of the payload compartment converge with each other in the portion of the payload compartment facing the air duct when mounted. This improves the airflow around the payload compartment during the operation of the aircraft, for example, the propulsion system.

[0141] In its installed position, the payload compartment is centered with respect to the first circumferential plane. Therefore, when the propulsion system is operating and air flows into the air duct from the first end, the airflow must pass around the payload compartment.

[0142] The payload compartment is further configured to ensure efficient airflow to the first end of the air duct. This can be achieved through the aerodynamic shape of the payload compartment, for example, through the convergence section described above. The airflow may be substantially less turbulent and more laminar when it enters the air duct.

[0143] The payload compartment can be configured to accommodate lightweight elements, such as medical supplies. However, the payload compartment may also be configured as a cabin for transporting one or more people. Therefore, the entire aircraft and propulsion system are scalable.

[0144] According to at least one embodiment, the aircraft further includes a navigation system and / or a flight control system. In particular, the payload compartment may include a navigation system and / or a flight control system. The navigation system and / or a flight control system may be located in the upper section of the payload compartment, for example, in the section opposite the contact section of the payload compartment. Thus, the navigation system and / or a flight control system can be located at the highest point of the aircraft. This is beneficial because interference to the navigation system, for example by air ducts, is minimized.

[0145] According to at least one embodiment, the flight control system is located within the payload compartment.

[0146] According to at least one embodiment, the aircraft further includes a sensor system. In particular, the payload compartment may include a sensor system. According to at least one embodiment, the sensor system includes at least one of the following sensors: radar, lidar, RGB camera, antenna, camera, airflow velocity sensor, light, etc.

[0147] According to at least one embodiment, the aircraft may include fixed wings. Fixed wings can be attached to air ducts, for example, to a first reinforcing collar, or a second reinforcing collar, or a third reinforcing collar of the air duct, or to a payload compartment, or to an optional combination of the above.

[0148] Exemplary embodiments of this disclosure are described in detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in a variety of forms and is not limited to the embodiments described herein.

[0149] The drawings are not necessarily to scale. In certain cases, details that are not necessary for understanding the embodiment, or details that would make it difficult to recognize other details, may be omitted.

[0150] Elements that are identical or act equally are given the same reference numeral. [Brief explanation of the drawing]

[0151] [Figure 1] This is an isometric view of exemplary embodiments of a propulsion system and an aircraft. [Figure 2] This is a top view of an exemplary embodiment of a propulsion system and an aircraft. [Figure 3] This is a bottom view of an exemplary embodiment of a propulsion system and aircraft. [Figure 4] This is a schematic cross-sectional view of an exemplary embodiment of a propulsion system and an aircraft. [Figure 5]This is a schematic cross-sectional view of an exemplary embodiment of a propulsion system and an aircraft. [Figure 6] This is a simplified, schematic, and exemplary embodiment of the arrangement of a motor system within an air duct in an exemplary embodiment of a propulsion system. [Modes for carrying out the invention]

[0152] The reference numbers used in the descriptions of Figures 1 to 6 may be used in any of Figures 1 to 6.

[0153] As can be seen from Figure 1, the propulsion system 10 includes an air duct 12. The air duct 12 has a substantially cylindrical shape, particularly a hollow cylindrical shape. In this exemplary embodiment, the air duct 12 is made of carbon fiber reinforced plastic. The air duct 12 extends along the longitudinal axis L1 from a first end 13 to a second end 14. The first end 13 is on the opposite side of the second end 14. As can be seen from Figure 1, the first end 13 defines a first circumferential plane 62. The first circumferential plane 62 is substantially perpendicular to the longitudinal axis L1. The air duct further includes an inner surface 15 and an outer surface 16. The first end 13 defines an air inlet. The second end 14 defines an air outlet (see, for example, Figure 5).

[0154] The propulsion system 10 in Figure 1 also includes radial guide vanes 20, in particular four radial guide vanes 20 (only two are visible in Figure 1). The radial guide vanes 20 are positioned at the first end 13 of the air duct 12. The radial guide vanes 20 extend from the inner surface 15 of the air duct 12 toward the central longitudinal axis CL1. The central longitudinal axis CL1 is an axis that passes through the center point of the air duct 12 and is parallel to the longitudinal axis L1. Thus, the radial guide vanes 20 extend radially inward toward the central longitudinal axis CL1.

[0155] The propulsion system 10 and aircraft 100 in Figure 1 include a first reinforcing collar (not shown). The first reinforcing collar is positioned on a section of the outer surface 16 of the air duct 12 that corresponds to a section of the inner surface of the air duct 12 to which radial guide vanes 20, for example, first vane ends (not shown), are connected. In other words, the first reinforcing collar and the connection point of the first vane ends to the inner surface 15 of the air duct 12 may be substantially on the same plane, which is perpendicular to the longitudinal axis L1. Thus, the load on the radial guide vanes 20, for example the load of the payload compartment 400, is distributed to the first reinforcing collar.

[0156] The radial guide vanes 20 extend from the inner surface 15 of the air duct 12 toward the central longitudinal axis CL1 of the air duct 12 along a plane perpendicular to the central longitudinal axis CL1. In other embodiments, the radial guide vanes 20 may extend from the inner surface 15 of the air duct 12 toward the central longitudinal axis CL1 of the air duct 12 and toward the second end 14. In such embodiments, the radial guide vanes 20 form a first angle between the radial guide vanes 20 and a first circumferential plane defined by the first end 13 of the air duct 12. The angle may be 10 degrees. In other words, the radial guide vanes 20 in such embodiments do not extend along a plane parallel to the first circumferential plane 62.

[0157] In this exemplary embodiment, the radial guide vanes 20 are arranged radially symmetrically along the circumference of the air duct. Thereafter, the first end 13 is divided into subsections. In this exemplary embodiment, the radial guide vanes 20 have a profile that mimics a NACA profile to make the airflow through the first end 13, for example, the airflow entering the air duct 12, more laminar. The first vane end, and therefore the end of the radial guide vane connected to the inner surface of the air duct, may include a wider section than in other sections. In this exemplary embodiment, the radial guide vanes 20 are made from the same material as the air duct 12. However, the materials may differ.

[0158] The radial guide vanes 20 are connected to a mounting platform 22 (not shown in Figure 1). Specifically, each radial guide vane 20 includes a second vane end connected to the mounting platform 22 (not shown).

[0159] The mounting platform 22 is positioned more toward the second end 14 of the air duct 12 with respect to the first circumferential plane 62 defined by the first end 13. In other words, the mounting platform 22 is longitudinally offset from the first end 13 of the air duct 12 toward the second end 14 of the air duct 12.

[0160] However, in different embodiments, the mounting platform 22 may be positioned on a plane defined by the first circumferential plane 62.

[0161] In the exemplary embodiment shown in Figure 1, the propulsion system 10 also includes a fan 40, of which only one fan blade 42 is visible in the figure. The fan 40 is configured to be rotated by a motor system (not shown), as shown in more detail in Figures 5 and 6.

[0162] As can be seen in Figure 1, the air duct 12 also includes a second reinforcing collar 18b. The second reinforcing collar 18b is positioned around the outer surface 16 of the air duct 12 at the second end 14. The reinforcing collar serves to reinforce the air duct 12. Furthermore, the loads of elements directly or indirectly attached to the first reinforcing collar and / or the second reinforcing collar 18b are at least partially distributed through the first and second reinforcing collars 18b. The first and second reinforcing collars 18b are connected to each other by at least one reinforcing strut, for example, four reinforcing struts 19 (see Figure 5), which extend longitudinally along the outer surface 16 of the air duct 12. The air duct 12 may also include further reinforcing collars.

[0163] The first end 13 and second end 14 of the air duct 12 also include lips 17, specifically an inlet lip and an outlet lip (not shown in Figure 1). The lips 17 are curved lips 17 that curve radially outward, thereby increasing the area of ​​the air inlet and air outlet around the first end 13 and the second end 14. In this exemplary embodiment, the inlet lip and outlet lip are constructed integrally with the air duct 12. Both the inlet lip and outlet lip have a NACA profile or at least mimic a NACA profile.

[0164] As can be seen in Figure 1, the aircraft 100 includes (or is) a propulsion system 10, and further includes a housing 200 that at least partially radially surrounds an air duct 12, for example, the outer surface 16 of the air duct 12. The housing 200 is connected to a first reinforcing collar. In this exemplary embodiment, the housing 200 is formed integrally with the air duct 12. The housing 200 has an aerodynamic shape that facilitates the airborne propulsion of the aircraft 100.

[0165] In this exemplary embodiment, the housing 200 includes a substantially circular main body having four recesses 210 (only two are visible). The recesses 210 extend from the second end 14 of the air duct toward the first end 13. A portion of the air duct 12, for example, the outer surface 16 of the air duct 12, is visible through the recesses 210 of the housing 200. This shape of the housing 200, for example the shape of the aircraft 100, has proven to be particularly energy efficient while the aircraft 100 is moving through the air. It also minimizes the weight of the aircraft 100.

[0166] In this exemplary embodiment, the aircraft 100 also includes landing gear 300. The landing gear 300 is the element that contacts the ground when the aircraft 100 is landing or parked on the ground. The landing gear 300 includes landing struts 310. The landing struts 310 extend radially outward from the first end 13 of the air duct 12 toward the second end 14. The landing gear 300, for example, the landing struts 310, is configured to be long enough so that the air duct does not contact the ground in the landing position, for example, when the aircraft is on the ground. The air duct may be 10 cm from the ground. In other words, the landing struts 310 may be the only element that contacts the ground.

[0167] Landing gear may have an aerodynamic shape, as schematically shown in Figure 1, for example. Such an aerodynamic shape may be useful for generating or assisting in the generation of lift and for stabilizing the aircraft.

[0168] The four recesses in the housing 200 of the aircraft 100 define four elements of the housing 200 configured to at least partially cover the landing strut 310. In this exemplary embodiment, the landing strut 310 is substantially completely covered by the four landing elements of the housing 200, with only the end sections visible in the figure.

[0169] In this exemplary embodiment, the aircraft 100 also includes a mounted payload compartment 400. The payload compartment 400 extends upward from the mounting platform 22. The payload compartment 400 is detachable from the propulsion system 10, and in particular from the mounting platform 22 (not shown). The sides of the payload compartment 400 converge with each other in the portion 420 of the payload compartment 400 that faces the air duct 12 when viewed from the payload compartment 400 when mounted.

[0170] The aircraft 100 may also include fixed wings. The wings may be attached, for example, to an air duct 12.

[0171] Figure 2 shows a top view of an exemplary embodiment of the propulsion system 10 and the aircraft 100.

[0172] As can be seen in Figure 2, the first end 13 of the air duct 12 defines a first circumferential plane 62. The inner surface 15 of the air duct 12 defines an airflow path 60 from the first end 13 to the second end 14 of the air duct 12.

[0173] The propulsion system 10 of this exemplary embodiment also includes radial guide vanes 20 (shown in diagonal lines), of which all four are at least partially visible. The radial guide vanes 20 extend from the inner surface 15 of the air duct 12 toward the center of the first circumferential plane 62, in particular toward the mounting platform 22 (not shown). The radial guide vanes 20 are connected to the mounting platform 22. In this exemplary embodiment, the payload compartment 400 is mounted on the mounting platform 22.

[0174] In this exemplary embodiment, the radial guide vane 20 is formed in a Y shape, with the two arms of the "Y" corresponding to two first vane ends 21a and 21b. The second vane end of the radial guide vane connects to the mounting platform and is not visible in the figure.

[0175] An exemplary embodiment of the propulsion system 10 further includes a first reinforcing collar 18a. The radial guide vanes 20 are connected to a section of the inner surface 15 that lies substantially in the same plane as the first reinforcing collar 18a.

[0176] In this exemplary embodiment, the section of the four fan blades 42 of the fan 40 is also visible. In this exemplary embodiment, they are represented aligned with the radial guide vanes 20, but the fan blades 40 are configured to be rotated by a motor system (not shown).

[0177] In this exemplary embodiment, a housing 200 extending radially outward from the first end 13 of the air duct 12 is also visible. The “corner” of the housing 200 represents the landing gear 300.

[0178] As can be seen in Figure 2, the payload compartment 400 is centrally located with respect to the first circumferential plane 62. The shape of the payload compartment 400 is such that less turbulence is generated and the airflow around the payload compartment 400 becomes more laminar when it enters the first end 13 of the air duct 12.

[0179] Figure 3 shows a schematic bottom view of an exemplary embodiment of the propulsion system 10 and the aircraft 100. Elements located inside or visible through the air duct 12 are not depicted in Figure 3.

[0180] As can be seen, the air duct 12 includes a second end 14 and a second reinforcing collar 18b positioned at the second end 14 in this exemplary embodiment. The second end 14 defines a second circumferential plane 64. At the corner of the housing 200, a landing strut 310 is visible. The landing strut 310 is mostly covered by the landing element of the housing 200.

[0181] The outer surface 16 of the air duct 12 defines a substantially cylindrical shape having a second radius. The second radius corresponds to the outer radius Or of the hollow cylinder, for example, the air duct 12. The difference between the outer radius Or and the inner radius Ir defines the thickness of the air duct 12.

[0182] In this exemplary embodiment, the inner radius Ir is 50 cm, while the outer radius Or is 60 cm. However, the propulsion system 10 is not limited to these radii.

[0183] In Figure 3, a servo system 460 for the flap system (not shown) is also visible.

[0184] Figure 4 shows a schematic cross-sectional view of an exemplary embodiment of the propulsion system 10 and the aircraft 100.

[0185] In this exemplary embodiment, the propulsion system 10 includes an air duct 12 and a housing 200 surrounding the air duct 12. The housing 200 includes a recess (not shown) that defines a landing element 300. The landing element 300 covers most of the landing strut 310.

[0186] As can be seen further in Figure 4, the propulsion system 10 includes a mounting platform 22. The mounting platform 22 is attached to the air duct 12 through radial guide vanes 20.

[0187] On the side of the mounting platform 22 facing the second end 14, the motor system 30 is mounted to the mounting platform 22. The motor system 30 is configured to rotate the fan 40. Both the motor system 30 and the fan 40 are located inside the air duct 12, for example, entirely inside. The fan 40 is located further inside the air duct 12 toward the second end 14 of the air duct 12 relative to the motor system 30.

[0188] The fan 40 is attached to the motor system 30. The rotation of the fan 40 creates a pressure difference that draws air in from the air inlet 12 and moves it toward the air outlet 14. The movement of the fan 40 generates propulsion for the propulsion system 10.

[0189] In particular, the fan 40 is positioned in the fan area of ​​the air duct 12, and the fan area is positioned over a quarter of the length of the air duct 12, viewed from the first end 13 of the air duct 12 toward the second end 14 of the air duct 12.

[0190] The fan 40 is connected to the motor system 30 through a shaft 36 (not shown). The fan blades 42 of the fan 40 extend radially from the shaft 36 toward the inner surface 15 of the air duct 12, for example radially outward. In this exemplary embodiment, the fan blades may be 490 cm long and 20 cm wide and are positioned at an angle of 30 degrees to a plane perpendicular to the central longitudinal axis CL1. The fan blades 42 extend about 99 percent of the radius of the circumference defined by the inner surface 15 of the air duct 12.

[0191] The air duct 12 may include additional guide vanes positioned further toward the second end 14 of the air duct 12 than the fan 40. Such additional guide vanes are not shown in this embodiment.

[0192] The motor system 30 of the propulsion system 10 includes a first electric motor 32 and a second electric motor 34 (not shown in detail). The first electric motor 32 is configured to operate the fan 40 independently of the second electric motor 34, and vice versa. However, the first electric motor 32 and the second electric motor 34 may also operate the fan 40 simultaneously, for example, during the takeoff and landing of the aircraft 100.

[0193] In this exemplary embodiment, the second electric motor 34 is a motor generator. The second electric motor 34 is also configured to rotate the fan 40. The second electric motor 34 is configured as a backup electric motor to operate the propulsion system 10 by rotating the fan 40, for example, in the event that the first electric motor 32, for example, the main electric motor, is malfunctioning.

[0194] On the opposite side of the mounting platform 22, for example, the side not facing the second end 14 of the air duct 12, the payload compartment 400 is attached to the mounting platform 22. The payload compartment 400 is releasably mountable to the mounting platform 22. The payload compartment 400 includes a navigation system 430 at its end opposite the mounting platform 22. The navigation system 430 is positioned at the highest point of the aircraft 100 and / or as far away as possible from the air duct 12. This improves the reachability and therefore accuracy of the navigation system.

[0195] The payload compartment 400 also includes a sensor system 440. In this exemplary embodiment, the sensor system 440 includes at least a camera 440.

[0196] The aircraft 100 also includes a flap system 450 and a servo system 460 connected to the flap system 450.

[0197] The flap system 450 has the function of directing the air passing through the airflow path within the air duct 12. The flap system 450 provides means for the yaw, roll, and pitch of the aircraft 100, including the propulsion system 10. The flap system 450 is positioned within the air duct 12, for example, in close proximity to the second end 14 of the air duct 12.

[0198] The distance between the flap system and the fan blades, viewed along the longitudinal axis, is 20 percent of the longitudinal length of the air duct 12.

[0199] Figure 5 shows a schematic cross-sectional view of an exemplary embodiment of Figure 4, with the propulsion system 10 and aircraft 100 rotated 90 degrees. Only additional visible functional parts are shown compared to Figure 4.

[0200] On the outer surface 16 of the air duct 12, the battery system 50 is attached to the propulsion system 10 toward the second end 14. The battery system 50 is configured to supply power to the motor system 30, for example, a first electric motor 32 and a second electric motor 34 (not shown), as well as to further systems such as a flight control system, a navigation system, sensors, and servos.

[0201] In this exemplary embodiment, the battery system 50 includes four battery packs 52 (only two are visible). The two visible battery packs are arranged radially opposite to each other on the outer surface 16 of the air duct 12. The other two battery packs are rotated 90 degrees relative to the two visible battery packs in the figure and are arranged radially opposite to each other on the outer surface 16 of the air duct. In this exemplary embodiment, the battery packs 52 of the battery system 50 have the same characteristics, e.g., size. In other embodiments, they may have different characteristics, e.g., size and different quantities. Each battery pack may include a plurality of battery modules, for example, in this configuration each battery pack includes three battery modules. Each battery module includes a plurality of battery cells. The battery cells may be cylindrical, pouched, and / or prismatic, e.g., cylindrical cells, pouched cells, and / or prismatic cells.

[0202] In the exemplary embodiment shown in Figure 5, the propulsion system 10 further includes a strut 19 connecting a first reinforcing collar and a second reinforcing collar (not shown). The strut 19 extends longitudinally along the outer surface 16 of the air duct 12 from the first reinforcing collar to the second reinforcing collar.

[0203] In Figure 5, the airflow through the air duct 12, for example, the airflow during takeoff, is indicated by arrow 60. Air enters the air duct from the first end 13. This is achieved through the operation of the fan 40. In this exemplary embodiment, an inlet lip 17, which is an integral part of the air duct 12 and curves radially outward, increases the inflow of air through the first end 13 of the air duct 12. The airflow passes through the air duct 12 and exits the air duct 12 from the second end 14. The flap system 450 may give the airflow a different direction. In the simplified schematic diagram of Figure 5, the air is pushed straight downward.

[0204] Figure 6 shows a simplified schematic exemplary embodiment of the arrangement of the motor system within the air duct in an exemplary embodiment of the propulsion system 10.

[0205] In this figure, the air duct 12 is shown only partially and schematically through dashed lines. The air duct has an inner surface 15, of which only a portion is shown. The propulsion system 10 in this exemplary embodiment includes four radial guide vanes 20 (only three are visible) positioned at the first end 13 of the air duct 12. The radial guide vanes 20 are attached to the inner surface 15 of the air duct 12. The radial guide vanes 20 extend radially inward from the inner surface 15 toward the mounting platform 22. The radial guide vanes 20 are connected to the mounting platform 22. The mounting platform 22 in this exemplary embodiment has a circular shape.

[0206] The motor system 30 is mounted on one side of the mounting platform 22, for example, the side facing the second end 14 of the air duct 12. The motor system 30 is located inside the air duct, for example, entirely inside. The motor system 30 includes a first electric motor 32 and a second electric motor 34. The first electric motor 32 and the second electric motor 34 are housed in a cylindrical housing. In this exemplary embodiment, the cylindrical housing has a diameter smaller than the diameter of the mounting platform 22. However, a larger cylindrical housing may be envisioned.

[0207] The propulsion system 10 further includes a fan 40 inside the air duct 12. The motor system is configured to rotate the fan 40. The fan 40 is attached to the motor system, for example, a first electric motor 32 and a second electric motor 34, through a shaft 36. The motor system 30, for example, the first electric motor 32 and the second electric motor 34, is configured to rotate the shaft 36 in order to rotate the fan 40.

[0208] The propulsion system 10 further includes a clutch (not shown). The clutch connects both the first electric motor 32 and the second electric motor 34 to the shaft 36. The clutch is configured to separate the first electric motor 32 from the shaft 36. When the first electric motor 32 is separated from the shaft 36, the clutch is configured to allow the second electric motor 34 to rotate the shaft 36 without resistance from the first electric motor 32.

[0209] In this exemplary embodiment, the clutch is also configured to isolate a second electric motor 34, for example, a backup motor, from the shaft 36. The clutch is configured to allow the first electric motor 32 to rotate the shaft 36 without resistance from the second electric motor 34 when the second electric motor 34 is isolated from the shaft 36. Both the first and second electric motors can operate the fan simultaneously. This may be used, for example, during takeoff.

[0210] The second electric motor 34 is mounted on a shaft 36 between the fan 40 and the first electric motor 32. In this figure, the shaft 36 is shown as particularly long simply for clarity and to understand its structure. However, the size and distance are not representative in this figure or any other figure. [Explanation of Symbols]

[0211] 10. Propulsion System 12 Air duct 13 First end 14. Second end 15. Inner self 16 Exterior 17 Lip 18a First reinforcement collar 18b Second reinforcement collar 19 Reinforcement strut 20 Radial guide vanes 21, 21a, 21b First guide vane ends 22 Mounting Platform 30 Motor Systems 32 First electric motor 34. Second electric motor 36 axes 40 Fans 42 Fan Blades 50 Battery System 52 Battery Packs 60 Airflow path 62 First circumferential plane 64 Second circumferential plane 100 aircraft 200 Housing 210 recess 300 Landing Gear 310 Landing Strut 400 Payload Compartment 420 Convergence Section 430 Navigation System 440 Sensor System 450 Flap System 460 Servo System Ir Air duct inner radius Or outer radius L1 Longitudinal axis CL1 Center longitudinal axis

Claims

1. A propulsion system (10) for an aircraft (100): An air duct (12) including a first end (13) and a second end (14), the air duct (12) extending along a longitudinal axis (L1) from the first end (13) to the second end (14), Fan (40) A motor system (30) configured to rotate the fan (40), the motor system (30) includes a first electric motor (32) and a second electric motor (34), Includes, Here, the fan (40) and motor system (30) are located inside the air duct (12) of the propulsion system.

2. The propulsion system (10) according to claim 1, further comprising at least two radial guide vanes (20) positioned at a first end (13) of an air duct (12), wherein the at least two radial guide vanes (20) extend radially inward from the inner surface (15) of the air duct (12).

3. The propulsion system (10) according to claim 1 or 2, further comprising a mounting platform (22) to which a motor system (30) is mounted and / or at least two radial guide vanes (20) are connected to the mounting platform (22).

4. The propulsion system (10) according to claim 3, wherein the mounting platform (22) is longitudinally offset with respect to the first end (13) toward the second end (14) of the air duct (12).

5. The air duct (12) includes a first reinforcing collar (18a) and / or a second reinforcing collar (18b), the first reinforcing collar (18a) and / or the second reinforcing collar (18b) are positioned on the outer surface (16) of the air duct (12). A propulsion system (10) according to any one of claims 1 to 4, wherein a first reinforcing collar (18a) is positioned at a first end (13) of the air duct (12), and / or a second reinforcing collar (18b) is positioned at a second end (14) of the air duct (12).

6. The propulsion system (10) according to claim 5, as dependent on claim 2, wherein the first reinforcing collar (18a) on the outer surface (16) of the air duct (12) and the section of the inner surface (15) of the air duct (12) to which the radial guide vanes (20) are connected are substantially on the same plane, and the plane is perpendicular to the longitudinal axis.

7. The propulsion system (10) according to claim 5 or 6, further comprising a landing gear (300), the landing gear (300) comprising a landing strut (310) extending from a first end (13) of the air duct (12) toward a second end (14) of the air duct (12), wherein the landing strut (310) is connected to a first reinforcing collar (18a).

8. The propulsion system (10) according to claim 7, wherein the landing gear (300) has an aerodynamic shape configured to generate lift and / or to balance the propulsion system (10).

9. A propulsion system (10) according to any one of claims 1 to 8, wherein a fan (40) is connected to a motor system (30) via a shaft (36), and a first electric motor (32) and a second electric motor (34) are configured to rotate the shaft (36) in order to rotate the fan (40).

10. The propulsion system (10) according to claim 9, further comprising a clutch, wherein the clutch is configured to separate a first electric motor (32) and / or a second electric motor (34) from a shaft (36), and / or the second electric motor (34) is mounted on the shaft between the first electric motor (32) and a fan (40).

11. The propulsion system (10) according to any one of claims 1 to 10, wherein the fan (40) is further positioned inside the air duct (12) toward the second end (14) of the air duct (12) relative to the motor system (30).

12. The propulsion system (10) according to any one of claims 1 to 11, further comprising a battery system (50) configured to supply power to a first electric motor (32) and / or a second electric motor (34).

13. The propulsion system (10) according to claim 12, wherein the battery system (50) is located on the outer surface of the air duct (12) adjacent to the second end (14) of the air duct (12).

14. The propulsion system (10) according to claim 12 or 13, as dependent on claim 5, wherein the battery system (50) is attached to the second reinforcing collar (18b).

15. The propulsion system (10) according to any one of claims 1 to 14, wherein the first electric motor (32) and the second electric motor (34) are configured to rotate a fan (40) simultaneously.

16. An aircraft (100), comprising a propulsion system (10) according to any one of claims 1 to 15.

17. The aircraft (100) according to claim 16, further comprising a payload compartment (400) configured to accommodate cargo to be transported by the aircraft (100).

Images