Drone Propulsion System

Abstract

The propulsion system includes a motor disposed in a central portion of the propulsion system, the motor further including a rotor shaft. The system includes a splitter gearbox coupled to the rotor shaft, the splitter gearbox further including at least one splitter output shaft. The system includes at least one continuously variable transmission (CVT), the CVT coupled to the splitter output shaft, the CVT further including a drive shaft. The system includes at least one bevel gearbox, the bevel gearbox including a bevel gearbox input shaft and a bevel gearbox output shaft, the bevel gearbox input shaft disposed parallel to a horizontal plane and the bevel gearbox output shaft disposed at an angle relative to the bevel gearbox input shaft, the bevel gearbox input shaft coupled to the drive shaft. The system includes at least one propeller coupled to the bevel gearbox output shaft.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Patent Application No. 18 / 113,436, filed February 23, 2023. The entire teachings of the above application are incorporated herein by reference in their entirety.

[0002] The subject matter of this disclosure relates to a system for a propulsion system. In particular, the subject matter of this disclosure is directed to a propulsion system configured for use with a drone that utilizes a continuously variable transmission (CVT). [Background technology]

[0003] Generally, multi-rotor aircraft of any size, but primarily miniature or hobby aircraft, are unmanned aerial vehicles (UAVs) that use three or more rotors with fixed pitch rotors to generate lift. By varying the rotor speed so that the generated thrust is greater than, equal to, or less than the gravitational and drag forces acting on the aircraft, the drone (aircraft) can ascend, hover, or descend. A standard drone in a quadcopter configuration utilizes four motors (each with a propeller) mounted on an arm or pylon to generate thrust and provide lift for the aircraft. In this configuration, two motors rotate counterclockwise and two motors rotate clockwise. This configuration ensures that the torque from each motor cancels the corresponding counter-rotating propeller due to the conservation of angular momentum. Varying the speed of the counter-active rotors allows the quadcopter to rotate clockwise (CW) or counterclockwise (CCW) around its axis.

[0004] The maximum takeoff weight of an aircraft is limited by thrust capability, energy and power storage, and propulsion type / configuration. The goal of any aircraft is to be as light and powerful as possible. A CVT is a desirable transmission type because of the infinite ratio between minimum and maximum ranges required for smooth, precise control of propeller speed. Therefore, there remains a need for efficient and economical methods and systems for drone propulsion systems, such as those described herein. Summary of the Invention

[0005] The objects and advantages of the presently disclosed subject matter will be set forth in and apparent from the following description, and will be learned by practice of the presently disclosed subject matter. Additional advantages of the presently disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims thereof, as well as from the accompanying drawings.

[0006] To achieve these and other advantages and in accordance with the objects of the presently disclosed subject matter, as embodied and broadly described, the presently disclosed subject matter includes a propulsion system. The propulsion system includes a motor, the motor disposed in a central portion of the propulsion system, the motor further including a rotor shaft. The propulsion system includes a splitter gearbox coupled to the rotor shaft, the splitter gearbox further including at least one splitter output shaft. The propulsion system includes at least one continuously variable transmission (CVT), the CVT coupled to the splitter output shaft, the CVT further including a drive shaft. The propulsion system includes at least one bevel gearbox, the bevel gearbox having a bevel gearbox input shaft and a bevel gearbox output shaft, the bevel gearbox input shaft disposed parallel to a horizontal plane, the bevel gearbox output shaft disposed at an angle relative to the bevel gearbox input shaft, the bevel gearbox input shaft coupled to the drive shaft. The propulsion system includes at least one propeller, the propeller coupled to the bevel gearbox output shaft.

[0007] The subject matter of the present disclosure also includes a propulsion system. The propulsion system includes a motor disposed in a central portion of the propulsion system, the motor further including a rotor shaft. The propulsion system includes a splitter gearbox coupled to the rotor shaft, the splitter gearbox further including four splitter gearbox output shafts, the splitter gearbox output shafts extending radially at 90-degree intervals from the splitter gearbox, each of the splitter gearbox output shafts being disposed in a horizontal plane. The propulsion system includes four continuously variable transmissions (CVTs), each coupled to one of the splitter gearbox output shafts, each of the CVTs disposed proximate to the splitter gearbox, each CVT further including a drive shaft, each of the four drive shafts extending radially and colinearly with each of the splitter gearbox output shafts. The propulsion system includes four bevel gearboxes, each coupled to one of the drive shafts, the bevel gearboxes having a bevel gearbox input shaft and a bevel gearbox output shaft, the bevel gearbox input shaft being disposed coplanar with the splitter gearbox output shaft and the bevel gearbox output shaft being disposed perpendicular to the gearbox input shaft. The propulsion system includes at least four propellers, each coupled to one of the bevel gearbox output shafts, and configured to rotate parallel to a horizontal plane around each of the bevel gearbox output shafts.

[0008] It is to be understood that both the foregoing summary and the following detailed description are exemplary and are intended to provide further explanation of the subject matter of the present disclosure as claimed.

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to illustrate and provide a further understanding of the methods and systems of the disclosed subject matter and, together with the description, serve to explain the principles of the disclosed subject matter.

[0010] A detailed description of various aspects, features, and embodiments of the subject matter disclosed herein is provided with reference to the accompanying drawings, which are briefly described below. The drawings are illustrative and are not necessarily drawn to scale, and some components and features are exaggerated for clarity. The drawings illustrate various aspects and features of the inventive subject matter and may illustrate, in whole or in part, one or more embodiments or examples of the inventive subject matter. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a conceptual diagram of a drone propulsion system in accordance with the subject matter of the present disclosure.

[0012] [Figure 2] 1 is an exemplary embodiment of a propulsion system in a cross-sectional view in accordance with the subject matter of the present disclosure.

[0013] [Figure 3] 1 is a cross-sectional view of an embodiment of a CVT in accordance with the subject matter of the present disclosure.

[0014] [Figure 4A] FIG. 1 is a conceptual diagram of a drone propulsion system in accordance with the subject matter of the present disclosure. [Figure 4B] FIG. 1 is a conceptual diagram of a drone propulsion system in accordance with the subject matter of the present disclosure.

[0015] [Figure 5] FIG. 1 is a plan view of a multicopter drone in accordance with an aspect of the disclosed subject matter.

[0016] [Figure 6] 1A-C are front and rear isometric views of an embodiment of a CVT in accordance with the subject matter of this disclosure.

[0017] [Figure 7] FIG. 2 is a block diagram of a computing node in accordance with the subject matter of this disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] Reference will now be made in detail to exemplary embodiments of the presently disclosed subject matter, an example of which is illustrated in the accompanying drawings. The method and corresponding steps of the presently disclosed subject matter will be described in conjunction with a detailed description of the system.

[0019] The methods and systems presented herein may be used for propulsion. The subject matter of the present disclosure is particularly suitable for propulsion systems utilizing continuously variable transmissions configured for use in drones. For purposes of explanation and illustration, and not limitation, an exemplary embodiment of a system according to the subject matter of the present disclosure is shown in FIG. 1 and generally designated by the numeral 100. Similar numerals (distinguished by leading digits) may be provided among the various figures and drawings presented herein to indicate functionally corresponding, but not necessarily identical, structures.

[0020] 1, a schematic diagram of a propulsion system 100 is presented in block diagram form. Note that this schematic diagram is arranged utilizing dashed and solid lines. For purposes of this disclosure, some components may be connected mechanically, electrically, communicatively, or a combination thereof. Both mechanical and electrical or electromagnetic communication may be referenced in this disclosure, and any of the components described herein may be connected to any other component in a suitable arrangement.

[0021] With continued reference to FIG. 1 , system 100 includes motor 104. Motor 104 includes at least one rotor shaft. Motor 104 may be configured to generate one or more magnetic fields to rotate the rotor shaft disposed therein. For example, without limitation, motor 104 may include one or more windings wound on a stator, the windings configured to be an electromagnet or a plurality thereof. Motor 104 may alternate one or more magnetic fields to attract and / or repel one or more permanent magnets affixed to a portion of the rotor shaft. In various embodiments, motor 104 may include one or more permanent magnets disposed within the rotor shaft or forming a stator disposed around the rotor shaft. The permanent magnet stator may attract and repel a portion of the electromagnet (e.g., a winding of conductive material) around the rotor shaft. Those skilled in the art will understand that multiple configurations of electric motors may be utilized in accordance with the subject matter of this disclosure. The motor 104 may be configured to rotate the rotor shaft in both directions (clockwise and counterclockwise) about the axis of the rotor shaft (ie, reversible torque).

[0022] With continued reference to FIG. 1 , motor 104 may be an electric motor. Motor 104 may be a direct current (DC) and / or alternating current (AC) electric motor. In various embodiments, motor 104 may be an induction motor, a synchronous motor, a commutator motor, a wound rotor motor, and / or a squirrel-cage motor. In various embodiments, motor 104 may be a shunt motor, a series motor, a permanent magnet DC (PMDC) motor, a compound motor, and / or a separately excited motor. In various embodiments, motor 104 may be a stepper motor, a brushless motor, a servo motor, a universal motor, and / or a reluctance motor. In various embodiments, motor 104 may be a brushless electric motor. Motor 104 may be any configuration of components configured to convert electrical energy into rotational or translational motion. In various embodiments, motor 104 may be a brushed motor, a single-phase, two-phase, three or more-phase, axial-flux, or radial-flux motor. In various embodiments, motor 104 may be air-cooled and / or liquid-cooled.

[0023] Continuing with reference to FIG. 1 , motor 104 may be an internal combustion engine. In various embodiments, motor 104 may be a piston-driven internal combustion engine. In various embodiments, motor 104 may be a Wenkel or rotary engine. In various embodiments, motor 104 may utilize the combustion of one or more liquid, vaporized, or gaseous fuels to move one or more components, such as a crankshaft. In various embodiments, motor 104 may be carbureted, fuel-injected, or variable valve fuel-injected. In various embodiments, motor 104 may be one, two, four, six, eight, ten, twelve, or more piston engines. In various embodiments, motor 104 may be a boxer engine, one-stroke, two-stroke, four-stroke, or other configuration engine. In various embodiments, motor 104 may be a circularly arranged piston-driven engine, where the pistons are radially arranged around a crankshaft and the combustion of fuel in the pistons cranks a centrally arranged shaft.

[0024] In various embodiments, multiple motors may be utilized, with the rotor shafts of each of these motors transmitting to a central output shaft for downstream actuation of components. In various embodiments, motor 104 may be disposed in a central portion of propulsion system 100. Motor 104 may be disposed at the relative center of a radially symmetric system (as can be easily seen with reference to FIG. 3 ). Motor 104 may be disposed such that the rotor shaft is disposed substantially vertically (perpendicular to the ground when the system is installed on the drone). In various embodiments, motor 104 may itself be radially symmetric, and the housing containing the stator, windings, magnets, and rotor shaft may comprise a substantially cylindrical shape. In various embodiments, the rotor shaft may be oriented parallel to the ground in a horizontal plane, with the rotor shaft mechanically coupled to one or more other components, as discussed below. In various embodiments, the rotor shaft may be disposed substantially vertically but oriented downward (facing the ground when installed on the drone). In various embodiments, the rotor shaft may be disposed about other angles relative to the vertical axis and horizontal, for example, at a 45 degree angle from vertical, and in several radial directions about the vertical axis. Those skilled in the art will recognize multiple configurations of motor 104 that may be configurable for use in the systems disclosed herein.

[0025] With continued reference to FIG. 1 , the system 100 includes a splitter gearbox 108. The splitter gearbox 108 may be centrally disposed within the system 100, such as above or below the motor 104 at the center of the radially symmetrical system. The splitter gearbox 108 is comprised of a single input shaft that is mechanically coupled to a rotor shaft of the motor 104. In various embodiments, the input shaft to the splitter gearbox may be coupled to a collective output shaft that transfers multiple motor output rotations to a single output shaft. The splitter gearbox input shaft may include splines, teeth, ridges, gears, or similar features configured to mechanically couple the shafts to one another. In various embodiments, the input shaft of the splitter gearbox 108 and the output shaft of the motor 104 are collinear. In various embodiments, the input shaft of the splitter gearbox 108 and the rotor shaft of the motor 104 are not collinear. In various embodiments, the input shaft of the splitter gearbox 108 and the rotor shaft of the motor 104 are disposed at an angle relative to one another and are mechanically coupled by a coupling, such as a universal joint. In various embodiments, the rotor shaft of the motor 104 and the input shaft of the splitter gearbox 108 are mechanically coupled to an intermediate component configured to transfer torque between the shafts, such as a gearbox configured to vary the torque transferred between the shafts or the orientation of the shafts relative to one another.

[0026] With further reference to FIG. 1 , the splitter gearbox 108 may be formed as a substantially cubic body. The input shaft may be disposed through a first face of the cube, and the output shaft may be disposed through at least one immediately adjacent side, thereby orthogonal to the input shaft. In various embodiments, the splitter gearbox input shaft and at least one splitter gearbox output shaft are disposed in different planes. In various embodiments, the splitter input shaft and the splitter output shaft are disposed in the same plane and perpendicular to each other. In various embodiments, the splitter input shaft and the splitter output shaft are disposed in the same plane at an acute angle to each other. In various embodiments, the splitter input shaft and the splitter output shaft are disposed in the same plane and at an obtuse angle to each other. In various embodiments, the splitter input shaft and the splitter output shaft are disposed in different planes and perpendicular to each other.

[0027] In various embodiments, the splitter input shaft and the splitter output shaft are disposed in different planes and at an acute angle relative to each other. In various embodiments, the splitter input shaft and the splitter output shaft are disposed in different planes and at an obtuse angle relative to each other. In various embodiments, there are multiple splitter output shafts, each equally spaced radially from each other, and the splitter input shaft intersects the radial center of the splitter output shaft. In various embodiments, the splitter output shafts are irregularly radially disposed around the splitter gearbox, and the splitter input shaft intersects the radial center of the splitter output shaft. In various embodiments, the splitter gearbox 108 is not radially symmetric, and the multiple splitter output shafts are disposed in substantially the same direction, which is different from the direction in which the splitter input shafts extend.

[0028] With continued reference to FIG. 1 , each of the splitter output shafts may include splines, ridges, teeth, or other features configured to assist in the mechanical coupling of the shaft to one or more other components. For example, without limitation, each of the multiple splitter output shafts may be configured as a splined shaft, where the shaft includes grooves cut along its length a predetermined distance along the shaft. For example, without limitation, the shaft may be connected to one or more shafts via a collar, where the collar includes features configured to couple to teeth on the splined shaft. The collar may then be further coupled to another shaft via the same or similar mechanism that mates with teeth around the exterior of the shaft and the interior of the collar.

[0029] 1 , the splitter gearbox may include multiple splitter output shafts, which may rotate in the same or different directions. For example, without limitation, each splitter output shaft may rotate in an alternating pattern, such as in an embodiment where there are four splitter output shafts, each rotating in the opposite direction of the two splitter output shafts immediately adjacent on either side. In such an embodiment, the four splitter output shafts are disposed perpendicular to one another at 90-degree intervals in the horizontal plane.

[0030] Continuing to refer to FIG. 1 , system 100 includes at least one continuously variable transmission (CVT) 112. CVT 112 is coupled to the splitter output shaft. In embodiments where multiple splitter output shafts are present, each splitter output shaft may be coupled to a separate CVT 112. For example, without limitation, the splitter output shafts may be relatively short such that each CVT 112 is closely coupled to the splitter gearbox 108. In various embodiments, CVT 112 may be fixed to a face of the splitter gearbox 108, and the coupling from the splitter output shaft to CVT 112 is not a load bearing and serves only to transfer torque between the shafts. In various embodiments, CVT 112 is configured with an input shaft and a drive shaft. The input shaft of CVT 112 is mechanically coupled to the splitter output shaft.

[0031] Continuing with reference to FIG. 1 , CVT 112 is configured to transmit torque from splitter gearbox 108 to bevel gearbox 116, as described in more detail below. CVT 112 is configured to adjust the continuously transmitted torque through multiple rotating bodies, which, when mechanically connected by roller components, include multiple surfaces capable of transmitting torque at a nearly infinite number of torque ratios. While a CVT may not itself use toothed gears, those skilled in the art will understand the term “gear ratio” to mean the ratio of the radii of the driving and driven rotating components. This ratio directly affects the transmission of torque between those rotating components. Those skilled in the art will also understand that a motor powering system 100, such as motor 104, may operate at a constant or nearly constant revolutions per minute (RPM) on its rotor shaft, with CVT 112 enabling an infinite number of gear ratios to thereby vary the speed and torque transmitted through the system to the final output component.

[0032] Various embodiments of the CVT 112 are described in more detail below, although there are multiple types of CVTs that the CVT 112 may embody. Those skilled in the art will understand, after reviewing this disclosure, that any transmission system may be configured for use with the system as described herein. For example, a standard transmission having separate sets of drive and driven gear ratios may be utilized without departing from the scope of this disclosure. In various embodiments, the CVT 112 may be replaced or used with any component configured to transfer power from one component to another. The transmission may use one or more intermeshing gears with multiple diameter ratios. The transmission may use one or more lubrication and control systems consistent with the entirety of this disclosure. Any number of transmissions may be deployed in the systems disclosed herein, including those configured for use with constant speed motors as described above.

[0033] In various embodiments, the CVT 112 may be a pulley-based CVT. A pulley-based CVT may use a belt, such as a V-belt, running between multiple (usually two) variable diameter pulleys. In embodiments, the pulleys may each be configured with two conical components, with the narrow end of each conical component disposed adjacent to the other, and the two conical components configured to be fixedly attached to a shaft disposed between them and passing through the center of each conical component. The space between the two conical components may act as a sheave. For purposes of this disclosure, a "sheave" is a pulley wheel used to hold a belt, wire, rope, wire rope, or other suitable component installed in the pulley. The sheave may have a grooved surface. The sheave may have a valley-shaped surface between the two conical halves. The sheave may also include an adjustable operating diameter (radius) for use with a belt, such as a V-belt.

[0034] The two conical components may be configured to move relative to each other, thereby varying the distance between them. In various embodiments, one of the two conical components is fixed in its position along the shaft, and the second conical component is configured to be passively or actively actuated along the shaft. In various embodiments, both conical components are configured to move along the shaft, thereby varying the distance between them. In various embodiments, the shaft itself may be configured to telescope or otherwise vary its length, thereby varying the relative distance of the conical components. In various embodiments, a V-belt runs between the conical components and contacts each so that the effective radius of the pulley is the distance between the V-belt and the center of the shaft, although there is not a pulley of that exact radius. A pulley-based CVT would include another half-conical pulley (because the V-belt has a fixed length) so that changing the radius of one of the two pulleys forces a change in the radius of the other pulley.

[0035] The belt's radial thickness is a compromise between maximum gear ratio and torque. Steel-reinforced V-belts are sufficient for low-mass, low-torque applications such as utility vehicles and snowmobiles, but chains are required for high-mass, high-torque applications such as automobiles. Each chain element must have conical sides that fit the pulley when the belt is running at its outermost radius. As the chain enters the pulley, the contact area decreases. Because the contact area is proportional to the number of elements, a chain belt requires many very small elements. Some CVTs transfer power to the output pulley through belt tension ("pulling" force), while others use compression of the chain elements (the input pulley "pushes" the belt, which in turn pushes the output pulley). Positive infinitely variable (PIV) chain drives are unique in that the chain engages positively with a conical pulley. This is achieved by having each chain link contain a stack of many small rectangular plates that can slide independently left and right. The conical pulley has radial grooves. Grooves on one side of the pulley correspond to ridges on the other, allowing the slide plate to be pushed back and forth along the pattern, effectively forming the correct pitch of teeth when sandwiched between the pulleys. Because of the mating surfaces, this type of drive is capable of transmitting large torques and is therefore widely used in industrial applications. One conical component may be fixed to the splitter output shaft, and the other conical component may be fixed to the drive shaft, thereby varying the gear ratio between the input and output shafts of the CVT 112.

[0036] In various embodiments, the CVT 112 may be a ratchet CVT. A ratchet CVT may use a series of one-way clutches, or ratchets, that commutate and sum only forward motion. While the on-off characteristics of typical ratchets mean that many of these designs are not continuous in operation (i.e., not technically CVTs), in practice, there are many similarities in operation, and a ratchet CVT can generate zero output speed from any given input speed (like an infinitely variable transmission). The drive ratio is adjusted by changing the linkage geometry within the oscillating elements so that the summed maximum linkage speed is adjusted even when the average linkage speed remains constant. Ratchet CVTs can transmit large torques because their static friction actually increases with torque throughput, and slippage is impossible in a properly designed system.

[0037] In various embodiments, the CVT 112 can be a hydrostatic and / or hydraulic CVT. In various embodiments, the CVT 112 can be an electric CVT. The electric CVT can include a power source, a generator, an electric motor, and a battery. The input shaft of the CVT can operate to drive an electric motor to drive an output shaft, such as a drive shaft, at a specific rpm, and excess energy can be stored by a battery. In various embodiments, the CVT 112 can be a cone CVT. A cone CVT can vary the drive (gear) ratio by moving one or more wheels or belts along the axis of rotation of one or more conical rollers. In various embodiments, there can be multiple input cones in contact with the output cone, and the multiple cones can be directly or indirectly fixed to the input shaft. In various embodiments, the CVT can be another type of CVT not described herein or a combination of CVTs as described herein. In various embodiments, the CVT 112 can be a toroidal CVT, an exemplary embodiment of which is shown in FIG. 3.

[0038] Continuing to refer to FIG. 1 , the system 100 includes at least one bevel gearbox 116. In some embodiments, the system 100 includes multiple bevel gearboxes 116. In various embodiments, there is a bevel gearbox 116 for each drive shaft extending from each CVT 112 disposed in the system 100. Each bevel gearbox 116 includes a bevel gearbox input shaft that is disposed parallel to the drive shaft to which it is mechanically coupled. In some embodiments, the bevel gearbox input shaft may be directly coupled to the drive shaft. In some embodiments, the drive shaft and the bevel gearbox input shaft are disposed in a horizontal plane. In some embodiments, the drive shaft and the bevel gearbox input shaft are mechanically coupled via an intermediate component, such as an intermediate gearbox, so that torque from the drive shaft is indirectly transmitted to the bevel gearbox input shaft. The bevel gearbox 116 may include one or more bevel gears fixedly attached at a terminal end to the bevel gearbox input shaft. In various embodiments, the bevel gearbox 116 includes a housing configured to encase the meshing gears and provide bearing locations for support within the bevel gearbox input shaft and the bevel gearbox output shaft. In various embodiments, the bevel gearbox 116 may include a substantially "L" shaped housing, with the bevel gearbox input shaft and the bevel gearbox output shaft disposed 90 degrees from each other in the same plane and terminating within the bevel gearbox 116 housing.

[0039] In various embodiments, the bevel gearbox 116 transmits torque from a bevel gearbox input shaft to a bevel gearbox output shaft, thereby rotating the output shaft and transmitting the direction of rotation. In various embodiments, the bevel gearbox 116 is configured to receive torque from a drive shaft to a bevel gearbox input shaft disposed in a substantially horizontal plane. The bevel gearbox output shaft transmits torque from the input shaft to the output shaft such that the bevel gearbox output shaft rotates about an axis disposed at an angle relative to the horizontal plane. In various embodiments, the bevel gearbox output shaft is disposed perpendicular to the horizontal plane. In various embodiments, the bevel gearbox output shaft is disposed at an acute angle relative to the horizontal plane. In various embodiments, the bevel gearbox output shaft is disposed at an obtuse angle relative to the horizontal plane.

[0040] A bevel gear is a gear in which the axes of two shafts intersect and the gear's teeth are conical in shape. Bevel gears are most often mounted on shafts that are 90 degrees apart, but they can be designed to operate at other angles. The pitch surface of a bevel gear is a cone-shaped surface known as the pitch cone. Bevel gears are very useful in machines because they transfer energy from linear to vertical power and are widely used in mechanical settings.

[0041] Two important concepts in gear design are the pitch surface and the pitch angle. The pitch surface of a gear is the imaginary toothless surface that would be obtained by averaging the peaks and valleys of the individual teeth. The pitch angle of a gear is the angle between the plane of the pitch surface and the axis.

[0042] The bevel gearbox 116 may include two or more external bevel gears. This type of bevel gear is called external because the gear teeth face outward. The pitch surfaces of the meshed external bevel gears are coaxial with the gear shaft, and the apex of the two surfaces is at the intersection of the shaft axes and is disposed adjacent to the corner of the "L"-shaped bevel gearbox housing 116. In various embodiments, the bevel gearbox 116 includes a crown gear. The bevel gears, with a pitch angle of exactly 90 degrees, face outward parallel to the axis and have teeth resembling the protrusions of a crown. In various embodiments, the bevel gearbox 116 includes a miter gear. A miter gear is a special case of a bevel gear with an equal number of teeth. The shafts are positioned perpendicular to each other, and the gears have conical pitch surfaces with matching pitch surfaces and pitch angles. The tooth profile of a cylindrical gear corresponds to an involute (i.e., a triangular wave projected onto the circumference of a circle), while the tooth profile of a bevel gear is octagonal (i.e., a triangular wave projected onto the normal of the circle on a sphere). In various embodiments, the bevel gearbox 116 includes a spiral bevel gear. Spiral bevel gears have their teeth formed along a helical line. The advantage of spiral teeth over straight teeth is that they engage more gradually. Contact between the teeth begins at one end of the gear and spreads across the entire tooth. This reduces the sudden transfer of force when a new pair of teeth engages. With straight bevel gears, the sudden tooth engagement creates noise and impact stress on the teeth, especially at high speeds, and these bevel gears cannot withstand heavy loads at high speeds without breaking.

[0043] Continuing to refer to FIG. 1 , system 100 includes at least one propeller 120. In various embodiments, the propeller is coupled to a bevel gearbox output shaft. In various embodiments, system 100 includes three or more propellers. In various embodiments, system 100 includes four propellers, the four propellers being radially and equidistantly disposed around a central portion of the system. In various embodiments, the four propellers are disposed at the ends of a corresponding number of arms extending from the central portion of the system. Propeller 120 may be disposed substantially parallel to a horizontal plane. For purposes of this disclosure, a “propeller” is a component including a central hub with radially extending blades connected to the central hub, the propeller being configured, in embodiments, to generate linear lift when rotated through a fluid, such as air. Propeller 120 may be a fixed-pitch propeller. In various embodiments, propeller 120 may be a variable-pitch propeller.

[0044] With continued reference to FIG. 1 , the system 100 includes a flight controller 124. The flight controller 124 may be disposed proximate a central portion of the system 100. The flight controller may include a housing, which may be airtight and / or watertight. The housing may be sealable against dust or moisture intrusion. The flight controller 124 may be configured as the flight controller of FIG. 1 and / or FIG. 4. The flight controller 124 may be one or more printed circuit boards (PCBs). The flight controller 124 may be one or more computers running simultaneously onboard the system 100. In various embodiments, the flight controller 124 may be one or more single-board computers, such as Raspberry Pis®, Beagleboards®, Arduinos®, etc. The flight controller 124 may be communicatively connected to one or more sensors configured to detect aircraft, environmental, health, telemetry, and other data used to control the aircraft in which the system 100 is deployed.

[0045] For example, without limitation, the motor 104 may be disposed within a drone body, such as the drone body 128. The drone body 128 may be configured as a circular, elongated, rectangular, semi-rectangular, or otherwise three-dimensional polygonal body. The drone body 132 may be configured to house components of the system 100, such as the motor 104, and other centrally located or relatively heavy components, such as the splitter gearbox 108. The drone body 128 may be configured to house any electronics, such as flight control or other wiring, transceivers, sensors, etc. The drone body 128 may be configured to include legs for landing on flat or uneven surfaces. The drone body 128 may be configured to include wheels. The drone body 128 may be formed from one or more plastics, composites, metals, or combinations thereof.

[0046] The drone body 128 may include one or more arms. For purposes of this disclosure, "arm" refers to a radially extending spar to which a propeller is attached. The drone body 128 may include two arms 132, three, four, five, six, seven, eight, nine, ten, eleven, twelve, or more arms 132. Each arm 132 may include one or more propellers 120, as discussed further below.

[0047] Referring now to FIG. 2 , a portion of a multicopter drone 200 implemented with system 100 and an embodiment of system 100 are shown in cross section. Note that FIG. 2 is a cross section of a central portion of the drone and one arm of the drone. In various embodiments, drone 200 may include three, four, five, six, seven, eight, nine, ten, or more arms consistent with the description of one arm herein. Those skilled in the art will understand that multiple arms that may be present on drone 200 may be followed by a splitter gearbox 108. Additionally, the configuration, e.g., size and location, of various components within the arms can be rearranged as desired to reduce the thickness of the arms and provide a more aerodynamic profile. In various embodiments, splitter gearbox 108 may include one splitter output shaft for each arm. Those skilled in the art will also understand that while drone 200 may include only one motor 104 and one splitter gearbox 108, other arrangements of centrally located components may be appropriate. Multicopter drone 200 may include any of the components, systems, elements, and techniques described herein. For example, without limitation, drone 200 includes motor 104 as described herein. Motor 104 may be centrally disposed within drone body 132. Motor 104 may be a relatively heavy component, and to balance its weight within drone 200, motor 104 may be located at the radial center of drone 200.

[0048] Continuing to refer to FIG. 2 , the drone 200 includes a splitter gearbox 108. The splitter gearbox 108 may be disposed at the radial center of the drone 200 and above the motor 104, thereby evenly distributing the weight of the splitter gearbox 108's relatively large and complex gears. The splitter gearbox 108 may include one or more splitter gearbox input shafts 208 mechanically and rotatably coupled to the rotor shaft 204 of the motor 104. The splitter gearbox 108 may include as many splitter gearbox output shafts 212 as needed for the multiple arms present in the drone 200. The splitter gearbox output shafts 212 are mechanically and rotatably coupled to a CVT input shaft 216.

[0049] With continued reference to FIG. 2 , drone 200 includes CVT 112 as described herein. CVT 112 includes a drive shaft 220 rotatably coupled to CVT input shaft 216, as described with reference to FIGS. 1 , 3 , 6A-6B , or another CVT overall. In various embodiments, drive shaft 220 is disposed collinearly with splitter gearbox output shaft 212 and CVT input shaft 216. In various embodiments, drive shaft 220 is disposed non-collinearly with any other shaft herein. In various embodiments, drive shaft 220 is disposed radially from a central portion of drone 200. In various embodiments, drive shaft 220 is indirectly coupled to any other component herein, such as through the use of one or more intermediate gearboxes.

[0050] Continuing to refer to FIG. 2 , the drone 200 includes a bevel gearbox 116 as described herein. The bevel gearbox 116 includes a bevel gearbox input shaft 224 disposed parallel to the drive shaft 220. The bevel gearbox input shaft 224 is rotatably coupled, directly or indirectly, to the drive shaft 220. The bevel gearbox input shaft 224 may be configured to rotate about the same axis as or parallel to the drive shaft 220. The bevel gearbox 116 is configured to change the direction of rotation in a system as described herein. The bevel gearbox input shaft 224 may be fixed to a first bevel gear disposed within the bevel gearbox 116. The first bevel gear may mesh with a second bevel gear. The second bevel gear is fixed to a bevel gearbox output shaft 228, which is perpendicular to and collinear with the bevel gearbox input shaft 224. The bevel gearbox 116 may change its direction of rotation by 90 degrees, as illustrated in FIG. 2 . The bevel gearbox 116 may change its direction of rotation by less than 90 degrees, thereby tilting the bevel gearbox output shaft 228 toward the center of the drone 200. In various embodiments, the bevel gearbox 116 may change its direction of rotation by more than 90 degrees, thereby tilting the bevel gearbox output shaft 228 away from the center of the drone 200. The bevel gearbox 116 may include bevel gears appropriate for the desired change in shaft direction, such as bevel gears for larger angles and bevel gears for smaller angles, in accordance with the description associated with FIG. 1 .

[0051] 2, drone 200 includes at least one propeller 120. Propeller 120 may be rotatably coupled to a bevel gearbox output shaft 228. Propeller 120 may be configured to rotate about the output shaft axis and provide lift via at least one blade having an airfoil cross-section.

[0052] Referring now to FIG. 3 , an embodiment of the CVT 112 is shown in a schematic cross-sectional view. Those skilled in the art will understand that the CVT 112 may be any suitable type of CVT, such as those described herein, or another type of CVT not described. FIG. 3 illustrates a cross-sectional view of a toroidal-type CVT. The toroidal CVT 300 includes an input shaft 304. The input shaft 304 may be coupled to a rotor shaft of a motor, not shown for clarity. The input shaft 304 may be directly or indirectly coupled to the rotor shaft of the motor 104. The input shaft 304 may be rotatably coupled to the rotor shaft of the motor 104. The input shaft 304 includes a first conical surface 308. The first conical surface 308 is disposed collinearly and radially symmetrically about the input shaft 304. The first conical surface 308 includes a concave conical shape such that the surface of the first conical surface is curved and radially symmetric about the input shaft 304.

[0053] Continuing with reference to FIG. 3 , CVT 300 includes a drive shaft 312. According to an embodiment, the drive shaft extends collinearly with the input shaft. In various embodiments, input shaft 304 and drive shaft 312 are disposed in a non-collinear arrangement. Drive shaft 312 includes a second conical surface 316. Second conical surface 316 is disposed opposite first conical surface 308, with the apexes of the conical surfaces disposed proximate to one another. First conical surface 308 and second conical surface 316 are symmetrically disposed and, in embodiments, rotate about the same axis extending therebetween. In various embodiments, first conical surface 308 and second conical surface 316 include a gap therebetween. Second curved surface 316 includes a concave conical shape with the same or similar curvature as first conical surface 308. In various embodiments, the first conical surface 308 and the second conical surface 316 include different curved profiles.

[0054] Continuing to refer to FIG. 3, CVT 300 includes at least one power roller 320. Power roller 320 includes a circular surface that includes a curved edge portion configured to simultaneously contact both first conical surface 308 and second conical surface 316. Power roller 320 is configured to turn when input shaft 308 turns first conical surface 308. Power roller 320, in turn, rotates second conical surface 316 and drive shaft 312. Power roller 320 is configured to contact both first conical surface 308 and second conical surface 316, contacting first and second peripheries around the conical surfaces, respectively. For example, in FIG. 3, power roller 320 is angled such that the periphery encompassed by the contact portion on first conical surface 308 is smaller than the second periphery encompassed by power roller 320 on second conical surface 316. The first and second circumferences can be varied by tilting the power rollers 320, thus changing the "gear ratio" between the input shaft 304 and the drive shaft 312. The power rollers 320 can be tilted to contact the third and fourth circumferences, thereby stepping up or down the infinite "gear ratio" between the input shaft 304 and the drive shaft 312. The infinite steps in gear ratio achievable by the CVT 300 allow the motor 104 to output the same RPM at the rotor shaft, but effectively control the RPM of the drive shaft 312.

[0055] Power roller 320 may be tilted by an actuator, such as actuator 324. Actuator 324 may be a stepper motor, a servo motor, or the like. Actuator 324 is configured to be controlled according to at least one of a number of manners. In various embodiments, actuator 324 may be controlled via electronic signals provided by one or more flight controllers. Actuator 324 may be configured such that the flight controller controls the angular position of a servo (actuator 324), which changes the specific contact point (i.e., the circumference of first conical surface 308 and second conical surface 316 of the CVT, and therefore its output speed).

[0056] In various embodiments, the actuator 324 may be controlled utilizing one or more encoders, such as mechanical, optical, magnetic, electromagnetic induction, or other types of encoders. The actuator 324 is configured to rotate the power roller 320 relative to the first conical surface 308 and the second conical surface 316, thereby changing the gear ratio between the input shaft 304 and the drive shaft 316 via the periphery of the conical surfaces that contact the power roller. The power roller 320 may include one or more tensioning components configured to maintain contact with the first conical surface 308 and the second conical surface 316 during rotation. For example, without limitation, the power roller 320 may include one or more biasing devices, such as leaf springs, helical springs, etc., to urge the power roller 320 against the first conical surface 308 and the second conical surface 316, respectively and simultaneously. Power roller 320 may be formed from one or more high friction materials to reduce or eliminate slippage against first conical surface 308 and second conical surface 316 .

[0057] Continuing with reference to FIG. 3 , the CVT 300 may include a second power roller 328. The power roller 328 may be disposed opposite the power roller 320. The power rollers 320, 328 may be configured to mirror the rotation of the other, thereby contacting the same circumference on the counter-rotating first and second conical surfaces 308, 316, thereby transmitting the rotation of the input shaft 304 to the drive shaft 312. The second power roller 328 may tilt via an actuator 332. The actuator 332 may be a servo motor. The actuator 332 may be controlled via the same or similar command signals originating from a flight controller, as described herein. The actuator 332 may be controlled via one or more on-board computers, as described herein.

[0058] 4A, there is shown in block diagram form an embodiment of a propulsion system 400. Those skilled in the art will appreciate that components present in this system may be the same as or similar to individual components as described with reference to other figures of this disclosure, namely, FIG.

[0059] 4A , system 400 includes motor 104. Motor 104 may be any motor as described herein. Motor 104 may be an electric motor, an internal combustion engine, a combination thereof, or another undescribed motor suitable for application of system 400. Motor 104 may include a rotor shaft, such as rotor shaft 204. Rotor shaft 204 may be configured to transmit rotation generated by the motor to splitter gearbox 108.

[0060] Continuing with reference to FIG. 4A , the system 400 includes a splitter gearbox 108. The splitter gearbox 108 may include one or more splitter gearbox input shafts, such as gearbox splitter input shaft 208. The splitter gearbox input shaft may be rotatably coupled to the rotor shaft 204. The splitter gearbox 108 includes four splitter gearbox output shafts that are the same as or similar to the splitter gearbox output shaft 212. The splitter gearbox 108 may include four output shafts that are radially disposed at 90 degrees and coplanar with one another, as shown in FIG. 5 . The splitter gearbox output 108 may include four or more intermediate gearboxes or components configured to transmit rotation from the rotor shaft, through the splitter gearbox input shafts, to the splitter gearbox output shafts and divide the rotation evenly among the output shafts. Each splitter output shaft is rotatably coupled to one of the four CVTs 112a-d. Each splitter gearbox output shaft (212) may be rotatably coupled to the input shaft of a single CVT 112a-d. Each of the CVTs 112a-d may be mounted on the splitter gearbox 108. Each of the CVTs 112a-d may be mounted on a separate face of the housing of the splitter gearbox 108. In various embodiments, the CVTs 112a-d may each include a housing configured to enclose the gearbox and provide one or more mounting portions, such as through holes, threaded holes, hooks, protrusions, etc.

[0061] Continuing with reference to FIG. 4A, the CVTs 112a-d may be configured to adjustably transmit rotation from the splitter gearbox output shaft to the drive shaft, as described herein. The adjustable transmission of rotation is achieved by varying the contact points of one or more power rollers disposed between input and output conical surfaces attached to the input and output shafts, respectively. Each of the CVTs 112a-d may be rotatably connected to one or more servo motors (servos) 142a-d. The servos 142a-d may be configured to be independently controlled via the flight controller 124. The flight controller 124 is communicatively connected to each of the servos 142a-d and to at least one command signal 136. The command signal 136 may be generated by one or more users, a computer, or a combination thereof. The command signal 136 may be transmitted by one or more wireless transceivers. The command signal 136 may be received by one or more remotely located receivers communicatively coupled to the flight controller 124. Each of the CVTs 112a-d includes at least one drive shaft extending radially therefrom, each of which is configured to variably transfer rotation from the rotor shaft 204 of the motor 104 to the bevel gearboxes 116a-d.

[0062] Continuing with reference to FIG. 4A , the system 400 includes four bevel gearboxes 116a-d. Each of the four bevel gearboxes 116a-d is rotatably coupled to one of four drive shafts extending from the CVTs 112a-d, respectively. Each of the bevel gearboxes 116a-d includes a bevel gearbox input shaft as described herein. The input shaft is disposed in a horizontal plane or parallel thereto. The input shaft may be disposed collinearly with the drive shaft. The bevel gearboxes 116a-d may include a bevel gearbox output shaft disposed perpendicular and coplanar with the input shaft, thereby changing the shaft orientation from substantially horizontal to substantially vertical. The bevel gearboxes 116a-d may be configured to transmit rotation from a horizontal plane to a vertical orientation within the drive shaft extending radially from the CVTs 112a-d, thereby rotating one of the fourth propellers 120a-d. In various embodiments, a first portion of bevel gearboxes 116a-d is configured to rotate a first portion of propellers 120a-d in a first direction, and a second portion of gearboxes 116a-d is configured to rotate a second portion of propellers 120a-d in a second direction, the second direction being different from the first direction. In various embodiments, propellers 120a, 120c are configured to rotate clockwise via gearboxes 116a, 116c, and propellers 120b, 120d are configured to rotate counterclockwise via gearboxes 116b, 116d, as shown in FIG. 5 . The sequential rotation of the propellers in four-propeller system 400 serves to prevent rotation of drone 200 as a whole due to conservation of angular momentum. For example, without limitation, if all propellers rotate in the same direction, such as clockwise, the entire drone 200 will rotate. It will be noted by those skilled in the art that the system disclosed herein allows for individual control of the four propellers individually, and therefore, an infinite arrangement of propellers rotating at a particular RPM can be used to control the movement of the drone 200.

[0063] 4B, an exemplary schematic embodiment of a propulsion system is shown. Those skilled in the art will recognize that the representation of components shown in FIG. 4B is for illustrative purposes only, and that the relative placement, number of each type of component, and connections between components do not limit possible embodiments of system 400.

[0064] 4B, system 400 includes motor 104, shown here as an electric motor disposed in a central portion of the system, with motor 104 exhibiting conductive windings running through the housing. Motor 104 may be centrally located within system 400 for weight distribution purposes, but in various embodiments may be located elsewhere within the system. For example, motor 104 may be disposed on its own arm or within the arm of a propeller.

[0065] 4B, system 400 includes splitter gearbox 108, which is shown with one input shaft and four total output shafts (three visible shafts) as described herein. Rotation of the input shaft transmits torque to each of the four output shafts. In various embodiments, rotation of the input shaft may transmit torque to one or more output shafts in one or both possible rotational directions.

[0066] 4B, system 400 includes four CVTs 112. The four CVTs 112 may correspond to any of CVTs 112a-d, as shown in FIG. 4A. Although the four CVTs 112 are shown as toroidal CVTs as described herein, this does not limit the type of CVT that may be used in system 400. CVT 112 may include an input shaft and an output shaft, which are rotatably coupled by a torque transmission element configured to rotate with the input shaft and impart its torque to the output shaft, the angle of the torque transmission element creating a gear ratio between the input shaft and the output shaft, as described herein.

[0067] 4B, the system 400 includes four bevel gearboxes 116 disposed on each arm of the propulsion system 400. The bevel gearboxes 116 may be configured to transmit torque from the CVT output shaft upward at 90 degrees toward the propellers 120. The bevel gearboxes 116 may include different angles, such as oblique angles, acute angles, or a series of direction changes configured to dispose each of the propellers 120 at an angle other than the input shaft of the bevel gearboxes 116.

[0068] Continuing with reference to FIG. 4B , the system 400 includes four propellers 120 secured to the output shafts of each of the bevel gearboxes 120. Each of the propellers may be configured to rotate in a first direction or a second direction. For example, without limitation, two of the four propellers 120 may be configured to rotate in a first direction and the other two may be configured to rotate in a second direction. In various embodiments, the propellers 120 may be configured in a co-directional arrangement adjacent to each other or across the arrangement, as shown in FIG. 5 . Each of the propellers 120 may be a counter-rotating propeller, as described herein, such that one propeller secured to the output shaft of the bevel gearbox rotates in a first direction and a second propeller secured to the same output shaft and disposed concentrically with the first propeller rotates in a second direction. In various embodiments, each bevel gearbox may include multiple propellers 120 affixed to one or more output shafts, such as one propeller disposed on a first side of the bevel gearbox and a second propeller disposed on a second side of the bevel gearbox, with each propeller driven by the bevel gearbox via one or more output shafts. The propellers of the preceding embodiments may be, for example, but not limited to, contra-rotating propellers or may rotate in the same direction. This serves to cancel the rotational momentum of the propellers. In this manner, contra-rotating propellers may be disposed on each of the arms of the system 400. In various embodiments, contra-rotating propellers may be disposed on one or more arms of the system 400.

[0069] 6A-6C, a CVT 600 is shown in a front isometric view. The CVT 600 may operate similarly to the CVT 300 and / or any of the CVTs 112, as described herein. The CVT 600 includes a CVT input shaft 604. The CVT input shaft 604 may be rotatably coupled to one of the individual splitter gearbox output shafts. The CVT input shaft 604 may be coupled to the respective shafts by one or more mating features, such as a slot and tang, a key slot, and a slotted protrusion. In various embodiments, the CVT input shaft 604 may be coupled to the splitter gearbox output shafts via splines disposed along one or both shafts and a toothed collar that securely couples the shafts together. The CVT input shaft 604 may be disposed colinearly with one or more shafts to which it is directly or indirectly coupled. The CVT input shaft 604 is coupled to an input wheel 608. The input wheel 608 may be fixedly coupled to the CVT input shaft 604 and configured to rigidly rotate therewith. The input wheel 608 may be fixed to the CVT input shaft 604 via one or more bearings, such as a ball bearing, a sleeve bearing, or the like. The CVT input shaft 604 may include one or more notches with circumferentially arranged teeth configured to mate with a plurality of splines disposed on the CVT input shaft 604. In various embodiments, the input wheel 608 may be formed from a metal, a composite material, a plastic, or the like. For example, the input wheel may be formed from a plurality of steel alloys. For example, the input wheel 608 may be formed from aluminum. For example, the input wheel 608 may be formed from an additive manufacturing technique such as 3D printing. In various embodiments, the input wheel 608 may be substantially formed from a first material, such as machined aluminum, and the outermost edge of the input wheel 608 may be formed from rubber or may include rubber applied thereto. Rubber disposed on the end of the input wheel 608 may be configured to prevent slippage between the wheel and any rotating components that contact it.

[0070] 6A-6C , the CVT 600 includes a drive shaft 612. The drive shaft 612 may be the same as or similar to any drive shaft described herein. The drive shaft 612 may be fixedly coupled to an output wheel 616. The drive shaft 612 and the output wheel 616 may be configured to rotate at the same speed. In various embodiments, the drive shaft 612 may be configured to rotate at a different speed than the output wheel 616, with the two components indirectly linked by an intermediate gearbox, as described herein. The output wheel 616 is disposed opposite and facing the input wheel 608, and the input shaft 604 and the drive shaft 612 may be disposed collinearly. The output wheel 616 may be formed in the same or similar manner as the input wheel 608. The output wheel 616 may be fixed to the drive shaft 612 in the same or similar manner as the input wheel 608 to the input shaft 604. The output wheel 616 and the input wheel 608 may be substantially parallel and configured to rotate in parallel planes relative to one another. The output wheel 616 and the input wheel 608 define a space between them, the space spanning a distance from the outermost edges of the input wheel 608 and the output wheel 616. In various embodiments, the input wheel 608 and the output wheel 616 each include at least one tensioning component (not shown). The tensioning component may be configured to align and support one or both of the input wheel 608 and the output wheel 616 during their rotation and / or against possible deflection from forces exerted on the wheels from the TTC 620. The one or more tensioning components may be configured to maintain proper spacing between the input wheel 608 and the output wheel 616. The one or more tensioning components may include one or more springs, such as a helical spring, a leaf spring, a radial spring, or a combination thereof. The one or more tension components may include one or more bearings such as ball bearings, sleeve bearings, torsion bearings, deep groove bearings, angular contact bearings, self-aligning bearings, cylindrical bearings, full complement cylindrical roller bearings, needle roller bearings, tapered bearings, etc.

[0071] 6A-6C , the CVT 600 includes a torque transfer component (TTC) 620. The TTC 620 is at least partially rotatably disposed between the input wheel 608 and the output wheel 616. The TTC 620 may be disposed proximate the ends of the input wheel 608 and the output wheel 616. In various embodiments, the TTC 620 may be disposed proximate the rotational axis of one or both of the input wheel 608 and the output wheel 616. In various embodiments, the TTC 620 may be disposed at the outermost edges of the input wheel 608 and the output wheel 616. The TTC 620 is configured to simultaneously contact portions of the input wheel 608 and the output wheel 616. The TTC 620 may be configured to simultaneously contact equal-sized portions of the input wheel 608 and the output wheel 616. The TTC 620 may be configured to separately and simultaneously contact different-sized portions of the input wheel 608 and the output wheel 616. The TTC 620 may be configured to contact different portions of each of the input wheel 608 and the output wheel 616 over time. The TTC 620 may be formed from metal, composite material, plastic, or a combination thereof, in various embodiments.

[0072] Still referring to FIGS. 6A-6C , the TTC 620 can form at least a portion of a spherical profile. In various embodiments, the TTC 620 is a hemisphere, with the apex of the hemisphere disposed toward the space between the input wheel 608 and the output wheel 616. In various embodiments, the TTC 620 comprises a complete or partially complete sphere, with the equidistant radii defining the sphere extending beyond the midpoint where the hemispheres would terminate. In various embodiments, the TTC 620 is an elongated, curved shape that is radially symmetric about a vertical axis running through its center in FIG. 6A (shown for orientation only; the axis is not included for clarity). In various embodiments, the TTC 620 is a three-dimensional shape that includes multiple arcs, not just a continuous arcuate surface as found on a sphere. In various embodiments, the TTC 620 is another radially symmetric shape with a substantially circular cross-section configured to rotate due to friction from the input wheel 608. In various embodiments, the TTV 620 is formed from rubber or another non-skid material, which in turn is configured to provide adequate friction between the input wheel 608, the TTC 620, and the output wheel 616.

[0073] 6A-6C, the TTC 620 is configured to tilt in an arcuate path within the space between the input wheel 608 and the output wheel 616. The TTC 620 may be configured to tilt in a direction parallel to the input shaft 604 and the drive shaft 612. Tilting the TTC 620 then changes the perimeter of the profile that contacts both the input wheel 608 and the output wheel 616. For example, without limitation, when the TTC 620 is in a "direct drive" position, the TTC 620 is substantially parallel to the wheel orientation. Thus, the perimeter of the spherical profile of the TTC 620 that contacts both the input wheel 608 and the output wheel 616 will be the same length. As the TTC 620 tilts toward one of the wheels, the perimeter in the direction of the tilt increases, and the perimeter that contacts the wheel on the opposite side of the tilt decreases. Because the input wheel 608 rotates the TTC 620, which in turn rotates the output wheel 616, the effective gear ratio between the input and output wheels changes due to the different circumferences circumscribed by each of the wheels on the TTC 620. In various embodiments, the profile of the TTC 620 can be configured so that the circumference contacting the wheel decreases in the direction of tilt of the TTC 620 and the circumference contacting the wheel on the opposite side increases. Those skilled in the art will understand that the profile of the TTC 620 and the shape and size of each of the input wheel 608 and output wheel 616 can be configured to manipulate the effective gear ratio as a function of the tilt of the TTC 620.

[0074] With continued reference to FIGS. 6A-6C , the TTC 620 may be mounted on a rotatable mounting arm (RTA) 624. The RTA 624 may be disposed generally around the periphery of and on the sides of the input wheel 608 and the output wheel 616, as shown in FIGS. 6A-6B . The RTA 624 may be configured to suspend the TTC 620 in an optimal position relative to the wheels. The RTA 624 may rotate as an assembly, thereby tilting the spherical portion of the TTC 620 relative to the edges of the input wheel 608 and the output wheel 616. The RTA 624 may be coupled to an actuator, such as actuator 628. The actuator 628 may be a servo motor, as shown in FIGS. 6A-6B . The actuator 628 may be a stepper motor. The actuator 628 may be controlled via one or more computers, such as a flight controller consistent with the description herein. In various embodiments, the actuator 628, and any actuators as described herein, are controlled by a flight controller via pulse-width modulation (PWM) signals.

[0075] 6B , the CVT 600 may include a tensioning component 632 configured to simultaneously urge the TTC 620 against the input wheel 608 and the output wheel 616. The tensioning component 632 may be internal to a column connecting the spherical portion of the TTC 620 and the RTA 624. The tensioning component 632 may be a helical spring, with a first end of the spring disposed internal to the spherical component and a second end of the spring disposed in the RTA 624, such that tension in the spring serves to stretch the spherical portion away from the RTA 624, thereby simultaneously pressing the spherical portion against the wheels. As the RTA 624 rotates, the tensioning component 632 may expand or contract to contact the input wheel 608 and the output wheel 616 throughout the arc of rotation of the RTA 624, specifically, throughout the rotation of the spherical portion of the TTC 620.

[0076] 6C , the CVT 600 includes a CVT housing 636. The CVT housing 636 may be formed from plastic, metal, composite materials, etc. The housing 636 may be configured to prevent the ingress of dust and contaminants to the contact surfaces of the components of the CVT 600. The CVT housing 636 may be fastened closed via one or more mechanical fasteners, such as screws, nails, pegs, and necessary holes appropriate for their use. The CVT housing 636 may include hardware configured to attach the CVT 600 to one or more portions of the system 400, such as one or more portions of the splitter gearbox 108, such as its housing.

[0077] 7, a schematic diagram of an example computing node is shown. Computing node 710 is merely one example of a suitable computing node and is not intended to suggest any limitation as to the scope of use or functionality of the embodiments described herein. In any event, computing node 710 is capable of implementing and / or performing any of the functions described herein above.

[0078] In computing node 710, computer system / server 712 may exist that operates in conjunction with many other general purpose or special purpose computing system environments or configurations. Examples of known computing systems, environments, and / or configurations that may be suitable for use with computer system / server 712 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable appliances, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices.

[0079] The computer system / server 712 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, etc. that perform particular tasks or implement particular abstract data types. The computer system / server 712 may also be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media, including memory storage devices.

[0080] 7, the computer system / server 712 in the computing node 710 is shown in the form of a general-purpose computing device. Components of the computer system / server 712 may include, but are not limited to, one or more processors or processing units 716, a system memory 728, and a bus 718 that couples various system components including the system memory 728 to the processor 716.

[0081] Bus 718 represents any one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures, such as, by way of example only, but not limited to, an Industry Standard Architecture (ISA) bus, a MicroChannel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, a Video Electronics Standards Association (VESA) local bus, a Peripheral Component Interconnect (PCI) bus, a Peripheral Component Interconnect Express (Pie), and an Advanced Microcontroller Bus Architecture (AMBA).

[0082] Computer system / server 712 typically includes a variety of computer system-readable media. Such media can be any available media that can be accessed by computer system / server 712 and includes both volatile and nonvolatile media, removable and non-removable media.

[0083] The system memory 728 may include computer system-readable media in the form of volatile memory, such as random access memory (RAM) 730 and / or cache memory 732. The computer system / server 712 may also include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example, the storage system 734 may provide for reading from and writing to a non-removable, non-volatile magnetic medium (not shown, typically referred to as a "hard drive"). Although not shown, a magnetic disk drive may be provided for reading from and writing to a removable, non-volatile magnetic disk (e.g., a "floppy disk"), and an optical disk drive may be provided for reading from or writing to a removable, non-volatile optical disk, such as a CD-ROM, DVD-ROM, or other optical medium. In such cases, each may be connected to the bus 718 by one or more data media interfaces. As further shown and described below, the memory 728 may include at least one program product including a set (e.g., at least one) of program modules configured to perform the functions of embodiments of the present disclosure.

[0084] The programs / utilities 740 have a set (at least one) of program modules 742, which may be stored in memory 728 along with, by way of example and not limitation, an operating system, one or more application programs, other program modules, and program data. Each operating system, one or more application programs, other program modules, program data, or combinations thereof may include an implementation of a network environment. The program modules 742 generally perform the functions and / or techniques of the embodiments described herein.

[0085] The computer system / server 712 may also communicate with one or more external devices 714, such as a keyboard, pointing device, display 724, one or more devices that allow a user to interact with the computer system / server 712, and / or any device (e.g., a network card, a modem, etc.) that allows the computer system / server 712 to communicate with one or more other computing devices. Such communication may occur via an input / output (I / O) interface This may be done via bus 722. Additionally, computer system / server 712 may communicate with one or more networks, such as a local area network (LAN), a general wide area network (WAN), and / or a public network (e.g., the Internet), via network adapter 720. As shown, network adapter 720 communicates with other components of computer system / server 712 via bus 718. It should be understood that other hardware and / or software components, not shown, may be used in combination with computer system / server 712. Examples include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, data archive storage systems, etc.

[0086] The present disclosure may be embodied as a system, method, and / or computer program product. The computer program product may include a computer-readable storage medium (or media) having computer-readable program instructions thereon for causing a processor to perform aspects of the present disclosure.

[0087] A computer-readable storage medium may be a tangible device capable of retaining and storing instructions for use by an instruction execution device. The computer-readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer-readable storage media includes the following: portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disk read-only memory (CD-ROM), digital versatile disks (DVD), memory sticks, floppy disks, mechanically encoded devices such as punch cards or raised structures in grooves having instructions recorded thereon, and any suitable combination of the foregoing. As used herein, computer-readable storage media should not be construed as being, per se, transitory signals, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., light pulses passing through a fiber optic cable), or electrical signals transmitted over a wire.

[0088] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device or to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium within the respective computing / processing device.

[0089] The computer-readable program instructions for carrying out the operations of the present disclosure may be either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and traditional procedural programming languages ​​such as the "C" programming language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or a connection may be made to an external computer (e.g., through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA) may execute computer-readable program instructions by utilizing state information of the computer-readable program instructions to individualize the electronic circuitry to perform aspects of the present disclosure.

[0090] Aspects of the present disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, are implemented by computer-readable program instructions.

[0091] These computer-readable program instructions may be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, executed by the processor of the computer or other programmable data processing apparatus, produce means for implementing the functions / acts specified in the flowchart and / or block diagram blocks. These computer-readable program instructions may also be stored on a computer-readable storage medium that can cause a computer, programmable data processing apparatus, and / or other device to function in a particular manner, such that the computer-readable storage medium having instructions stored therein comprises an article of manufacture containing instructions that implement aspects of the functions / acts specified in the flowchart and / or block diagram blocks.

[0092] The computer-readable program instructions may also be loaded into a computer, other programmable data processing apparatus, or other device such that a series of operational steps are executed on the computer, other programmable apparatus, or other device to generate a computer-implemented process, whereby the instructions executing on the computer, other programmable apparatus, or other device implement the function / act specified in the block(s) of the flowcharts and / or block diagrams.

[0093] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of instructions, including one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block in the block diagrams and / or flowchart diagrams, and combinations of blocks in the block diagrams and / or flowchart diagrams, may be implemented by a special-purpose hardware-based system that performs the specified functions or actions or executes a combination of special-purpose hardware and computer instructions.

[0094] The description of various embodiments of the present disclosure has been presented for purposes of illustration, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used herein were selected to best express the principles of the embodiments, practical applications or technical improvements to technology found in the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

Claims

1. 1. A propulsion system, comprising: a motor disposed in a first portion of the propulsion system, the motor further comprising a rotor shaft; and a splitter gearbox coupled to the rotor shaft, the splitter gearbox further comprising at least one splitter output shaft; and at least one continuously variable transmission (CVT), the CVT coupled to the splitter output shaft, the CVT further comprising a drive shaft; at least one bevel gearbox comprising a bevel gearbox input shaft and a bevel gearbox output shaft, the bevel gearbox input shaft being disposed parallel to a horizontal plane and the bevel gearbox output shaft being disposed at an angle relative to the bevel gearbox input shaft; the bevel gearbox input shaft is coupled to the drive shaft; at least one bevel gearbox; at least one propeller, said propeller coupled to said bevel gearbox output shaft; A propulsion system comprising:

2. The CVT is an input shaft coupled to the output shaft of the motor, the input shaft including a first conical surface, the first conical surface including a concave conical shape collinear with the input shaft; a second conical surface coupled to the drive shaft, the second conical surface including a concave conical shape collinear with the drive shaft, the second conical surface disposed opposite the first conical surface; at least one power roller including a circular surface rotatably disposed between the first conical surface and the second conical surface, the power roller configured to contact the first conical surface and the second conical surface at a first outer periphery and a second outer periphery, respectively; at least one power roller configured to rotate while contacting the first conical surface and the second conical surface at the first outer periphery and the second outer periphery, respectively; The propulsion system of claim 1 , comprising:

3. 3. The propulsion system of claim 2, wherein the power roller is rotatably disposed between the first conical surface and the second conical surface and configured to rotate thereby contacting a third outer periphery and a fourth outer periphery, respectively.

4. 3. The propulsion system of claim 2, wherein the power roller is coupled to an actuator, the actuator configured to rotate the power roller between the first outer periphery and the second outer periphery and between a third outer periphery and a fourth outer periphery.

5. The propulsion system of claim 4 , wherein the actuator is a servo motor.

6. The CVT is an input shaft coupled to an input wheel, the input wheel configured to rotate with the input shaft; an output wheel coupled to the drive shaft, the output wheel configured to rotate with the drive shaft, the output wheel disposed parallel to and facing the input wheel, defining a space therebetween; and a torque transmission component rotatably disposed between the input wheel and the output wheel, the torque transmission component including at least a portion of a spherical profile configured to simultaneously tangentially contact the input wheel and the output wheel; a torque transfer component configured to tilt in an arcuate path within the spacing between the input wheel and the output wheel; The propulsion system of claim 1 , comprising:

7. 7. The propulsion system of claim 6, wherein the torque transfer component is coupled to a rotatable mounting arm, the rotatable mounting arm further coupled to an actuator, the actuator configured to tilt the rotatable mounting arm.

8. The propulsion system of claim 7 , wherein the rotatable mounting arm comprises a tension component configured to simultaneously bias the torque transfer component against the input wheel and the output wheel.

9. The propulsion system of claim 8 , wherein the actuator is a servo motor.

10. 7. The propulsion system of claim 6, wherein the input wheel and the output wheel each include a wheel tensioner component, the wheel tensioner component configured to maintain the spacing between the input wheel and the output wheel.

11. The propulsion system of claim 1 , wherein the motor is an electric motor.

12. The propulsion system of claim 1 , wherein the motor is an internal combustion engine.

13. The propulsion system of claim 1 , wherein the propulsion system comprises three or more propellers.

14. 14. The propulsion system of claim 13, wherein the propulsion system comprises four propellers, the four propellers being radially and equally spaced about a central portion of the propulsion system.

15. 10. The propulsion system of claim 9, wherein the servo motor is controlled by a flight controller via a pulse width modulated (PWM) signal.

16. The propulsion system of claim 8 , wherein the tension component is a spring.

17. 1. A propulsion system, comprising: a motor disposed in a central portion of the propulsion system, the motor further comprising a rotor shaft; and a splitter gearbox coupled to the rotor shaft, the splitter gearbox comprising: four splitter gearbox output shafts, the splitter gearbox output shafts extending radially at 90 degree intervals from the splitter gearbox; further comprising four splitter gearbox output shafts, each of the splitter gearbox output shafts being disposed in a horizontal plane; Splitter gearbox; four continuously variable transmissions (CVTs), each CVT coupled to one of the splitter gearbox output shafts; Each of the CVTs is disposed adjacent to the splitter gearbox, and each CVT further includes a drive shaft; each of the four drive shafts extends radially and co-linearly with each of the splitter gearbox output shafts; Four CVTs and four bevel gearboxes, each bevel gearbox coupled to one of the drive shafts, the bevel gearboxes including a bevel gearbox input shaft and a bevel gearbox output shaft, the bevel gearbox input shaft being disposed coplanar with the splitter gearbox output shaft and the bevel gearbox output shaft being disposed at right angles to the gearbox input shaft; at least four propellers, each of the propellers coupled to one of the bevel gearbox output shafts, each propeller configured to rotate parallel to the horizontal plane around each of the bevel gearbox output shafts; A propulsion system comprising:

18. 18. The propulsion system of claim 17, wherein a first portion of a bevel gearbox is configured to rotate a first portion of a propeller in a first direction, and a second portion of the bevel gearbox is configured to rotate a second portion of the propeller in a second direction, the second direction being different from the first direction.

19. 20. The propulsion system of claim 17, wherein each CVT is coupled to a separate servo motor.

20. 20. The propulsion system of claim 17, wherein each servo motor is configured to be independently controlled.

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