Coupling assembly for a removable propeller

Disclosed is an aerial vehicle. The aerial vehicle may include a removable battery. Various embodiments of removable battery assemblies include a pull-bar battery assembly, a latch battery assembly, and a lever battery assembly. The aerial vehicle may also include a propeller locking mechanism to which propellers may be removably coupled. The propeller locking mechanism may obviate the need for tools for coupling or decoupling propellers to the aerial vehicle. Vents in the arm of the aerial vehicle may provide an air pathway, providing convective cooling for the electronics aerial vehicle.

TECHNICAL FIELD

The disclosure generally relates to the field of aerial vehicles and in particular to mechanical configurations for unmanned aerial vehicles.

BACKGROUND

Unmanned remote controlled aerial vehicles, such as quadcopters, continue to grow in popularity for both their commercial applications as well as recreational uses by hobbyists.

Another technology area with challenges has been power supply. Aerial vehicles are commonly powered by one or more batteries. After a battery loses its charge, a user may desire to swap out the battery, so that the aerial vehicle may continue to be flown without having to first recharge the battery. Consequently, a battery which can be removed quickly and easily is advantageous. Furthermore, some batteries swell or warp over time or when heated, which can make removal of a battery difficult.

As the popularity of aerial vehicles increases, an example area of technology that has been found susceptible to damage is assemblies for propeller blades. The propeller blades of an aerial vehicle may be susceptible to damage due to their light weight and high rate of rotation. Furthermore, due to their fragility, a user may wish to detach propellers prior to transporting the aerial vehicle. However, removing and attaching propeller blades may be time consuming or even impossible with existing aerial vehicles. Furthermore, many aerial vehicles require tools to remove propellers, which is inconvenient. Thus, it is advantageous to provide a propeller coupling assembly with easily replaceable propellers.

Additionally, during operation, processors, sensors, motors, and/or other electronics in aerial vehicles may overheat. Overheating may cause damage or cause electronics to behave sub-optimally. Aerial vehicles may need to carry heavy payloads or run computationally expensive image processing algorithms, exacerbating the overheating issue. Thus, a reliable means of cooling the aerial vehicle to offset the heat generated by the electronics may be advantageous.

DETAILED DESCRIPTION

Configuration Overview

Disclosed by way of example embodiments is a remote controlled unmanned aerial vehicle, or drone.

The aerial vehicle may include a removable battery. Various embodiments of removable battery assemblies may include a pull-bar battery assembly, a latch battery assembly, and a lever battery assembly. These various embodiments, may allow a user to attach and/or remove a battery quickly and easily. In some embodiments, the battery and/or the aerial vehicle include an element to assist a user in removing a battery that may have swollen or warped during operation of the aerial vehicle.

The aerial vehicle may include a propeller coupling assembly for coupling a propeller hub of a propeller to a propeller locking mechanism. The propeller locking mechanism may be rotated by a rotor of the aerial vehicle to rotate the propeller. The propeller locking mechanism may include a shaft, a plate, a spring, and one or more pins. The shaft may be coupled to a rotor. The plate may include an opening through which the shaft passes. The plate may have a toothed surface. The spring may encircle the shaft and may couple to the shaft and/or rotor at a first end and couple to the plate at a second end. The one or more pins may pins extend from the shaft.

The removable propeller may include a propeller hub coupled to one or more propeller blades. The propeller hub may include an aperture, one or more grooves, and one or more slots. The aperture may have a first opening at a first end of the propeller hub and a second opening at a second end of the propeller hub. The aperture may be cylindrical and the aperture may be coaxial with the shaft when the propeller locking mechanism couples to the propeller hub. The one or more grooves may each be formed in the aperture. Each groove may include a first opening at the first end of the propeller hub and a second opening at the second end of the propeller hub. The one or more grooves may be of sufficient size to allow the one or more pins of the propeller locking mechanism to pass through the grooves. The propeller hub may be a cylindrical shell, where the aperture is bounded by an internal surface of the cylindrical shell, and the one or more grooves are formed on the internal surface of the cylindrical shell. Each of the one or more grooves may rotate around an axis concentric with the aperture. The second opening of each of the one or more grooves may be directly opposite a respective one of the one or more slots. The one or more slots may be formed on the first end of the propeller hub. The propeller hub may also include a plurality of teeth extruding from the second end of the propeller hub. These teeth may reciprocally couple to the plate of the propeller locking mechanism.

When the propeller locking mechanism and the propeller hub are coupled together, each of the one or more pins of the propeller locking mechanism may fit into a corresponding slot of the one or more slots formed on the first end of the propeller hub, the aperture of the propeller hub may encircle the shaft, and the plate of the propeller locking mechanism and the second end of the second end of the propeller hub may mesh together. Also, the spring of the propeller locking mechanism may be compressed beyond its equilibrium when the propeller locking mechanism and the propeller hub are coupled together.

The aerial vehicle may also include vents in an arm of the aerial vehicle. The vents within the arm may capture airflow from around the aerial vehicle100and direct that airflow through one or more air pathways. The one or more air pathways may lead to components that benefit from cooling such as electrical motors, circuit boards and power sources. The cooling may allow for a decreased need in adding heat sinks to cool structures within the aerial vehicle. Moreover, this configuration also may help prolong operational use of the aerial vehicle100by obviating the need for additional weight from added heat sinks.

Example Aerial Vehicle Configuration

FIG. 1illustrates an example embodiment in which the aerial vehicle100is a quadcopter (i.e., a helicopter with four rotors). The aerial vehicle100in this example may include a housing130for payload (e.g., electronics, storage media, and/or camera), one or more arms135, one or more rotors140, and one or more propellers145. Each arm135may mechanically couple with a rotor140to create a rotary assembly. Each rotor140may be coupled to a respective propeller145. When the rotors140are operational, all the propellers145may spin at appropriate speeds to allow the aerial vehicle100to lift (take off), land, hover, and move (forward, backward) in flight. Modulation of the power supplied to each of the rotors140may control the trajectory and torque on the aerial vehicle100.

A gimbal110may be coupled to the housing130of the aerial vehicle100through a removable coupling mechanism that mates with a reciprocal mechanism on the aerial vehicle100having mechanical and communicative capabilities. The gimbal110may be removed from the aerial vehicle100. In some embodiments, the gimbal110may also be capable of being removably attached to a variety of other mount platforms, such as a handheld grip, a vehicle, and a generic mount, which can itself be attached to a variety of platforms. In some embodiments, the gimbal110may be attached or removed from a platform without the use of tools.

The gimbal110may be a 3-axis gimbal110with three motors, each corresponding to a respective axis. The gimbal110may be configured to allow for rotation of an object, such as a camera120, about an axis within an x-y-z Cartesian coordinate system. The gimbal110may couple to a camera frame150that couples to a camera120. The gimbal110and the camera frame150may form a mounting structure and when coupled together the entire assembly may be referenced as a gimbal110for ease of discussion. The camera frame150may be configured to allow the camera120to detachably couple (e.g., attach) to it and may include electrical connection points for the coupled camera120. The gimbal110may allow for the camera frame150to maintain a particular position and/or orientation so that the camera120mounted to it may remain steady as the aerial vehicle100is in flight. In some embodiments, the camera frame150may be integrated into the gimbal110as a camera mount. In some embodiments, the camera frame150may be omitted and the gimbal110may couple electronically and mechanically to the camera120.

Remote Controlled Aerial Vehicle

FIG. 2illustrates an aerial vehicle100, which communicates with a remote controller220via a wireless network225. The aerial vehicle100in this example is shown with a housing130and arms135of an arm assembly. In addition, this example embodiment shows a rotor140coupled with the end of each arm135of the arm assembly, a gimbal110, and a camera120.

The aerial vehicle100communicates with the remote controller220through the wireless network225. The remote controller220may be a dedicated remote controller or may be another computing device such as a laptop, smartphone, or tablet that is configured to wirelessly communicate with and control the aerial vehicle100. In one embodiment, the wireless network225may be a long range wireless communication system, for example, a long range Wi-Fi system. It also may include or be another wireless communication system, for example, one based on long term evolution (LTE), 3G, 4G, or 5G mobile communication standards. The wireless network225may include a unidirectional RC channel used for communication of controls from the remote controller220to the aerial vehicle100and a separate unidirectional channel used for video downlink from the aerial vehicle100to the remote controller220(or to a video receiver where direct video connection may be desired).

The remote controller220in this example includes a first control panel250and a second control panel255, an ignition button260, a return button265and a screen270. The first control panel, e.g., control panel250, may be used to control the vertical direction (e.g. lift and landing) of the aerial vehicle100. The second control panel, e.g., control panel255, may be used to control the horizontal direction of the aerial vehicle100. Each control panel250,255may be structurally configured as a joystick controller and/or touch pad controller. The ignition button260may be used to start the rotary assembly (e.g., start the propellers145). The return button265can be used to override the controls of the remote controller220and transmit instructions to the aerial vehicle100to return to a predefined location. The ignition button260and the return button265can be mechanical and/or solid state press sensitive buttons.

In addition, the ignition button260and the return button265may be illuminated with one or more light emitting diodes (LED) to provide additional details. For example the LED may switch from one visual state to another to indicate with respect to the ignition button260whether the aerial vehicle100is ready to fly (e.g., lit green) or not (e.g., lit red) or whether the aerial vehicle100is now in an override mode on a return path (e.g., lit yellow) or not (e.g., lit red). It also is noted that the remote controller220may include other dedicated hardware buttons and switches and those buttons and switches may be solid state buttons and switches. For example, a button or switch may be configured to allow for triggering a signal to the aerial vehicle100to immediately execute a landing operation and/or a return to designated location.

The remote controller220may also include hardware buttons or other controls that control the gimbal110. The remote controller220may allow it's user to change the preferred orientation of the camera120. In some embodiments, the preferred orientation of the camera120may be set relative to the angle of the aerial vehicle100. In another embodiment, the preferred orientation of the camera120may be set relative to the ground.

The remote controller220also may include a screen270(or display) which provides for visual display. The screen270may be a touch sensitive screen. The screen270also may be, for example, a liquid crystal display (LCD), an LED display, an organic LED (OLED) display, and/or a plasma screen. The screen270may allow for display of information related to the remote controller220, such as menus for configuring the remote controller220or remotely configuring the aerial vehicle100. The screen270also may display images or video captured from the camera120coupled with the aerial vehicle100, wherein the images and video are transmitted to the remote controller220via the wireless network225. The video content displayed on the screen270may be a live feed of the video or a portion of the video captured by the camera120. It is noted that the video content may be displayed on the screen270within a short time (e.g., fractions of a second) of being captured by the camera120.

The video may be overlaid and/or augmented with other data from the aerial vehicle100such as the telemetric data from a telemetric subsystem of the aerial vehicle100. The telemetric subsystem may include navigational components, such as a gyroscope, an accelerometer, a compass, a global positioning system (GPS), and/or a barometric sensor. In one example embodiment, the aerial vehicle100may incorporate the telemetric data with video that is transmitted back to the remote controller220in real time. The received telemetric data may be extracted from the video data stream and incorporate into predefine templates for display with the video on the screen270of the remote controller220. The telemetric data also may be transmitted separate from the video from the aerial vehicle100to the remote controller220. Synchronization methods such as time and/or location information may be used to synchronize the telemetric data with the video at the remote controller220. This example configuration may allow a user, e.g., operator, of the remote controller220to see where the aerial vehicle100is flying along with corresponding telemetric data associated with the aerial vehicle100at that point in the flight. Further, if the user is not interested in telemetric data being displayed real-time, the data may still be received and later applied for playback with the templates applied to the video.

The predefine templates may correspond with “gauges” that provide a visual representation of speed, altitude, and charts, e.g., as a speedometer, altitude chart, and a terrain map. The populated templates, which may appear as gauges on the screen270of the remote controller220, may further be shared, e.g., via social media, and or saved for later retrieval and use. For example, a user may share a gauge with another user by selecting a gauge (or a set of gauges) for export. Export may be initiated by clicking the appropriate export button, or a drag and drop of the gauge(s). A file with a predefined extension may be created at the desired location. The gauge may be selected and be structured with a runtime version of the gauge. The gauge may also be played back through software that can read the file extension.

Removable Battery

In some embodiments, the aerial vehicle100contains one or more removable batteries. A removable battery, as used herein, may refer to both the electrochemical device used to store chemical energy in one or more cells and to the mechanical structure, e.g., the housing surrounding the electrochemical device and/or an assembly to mechanically couple to the aerial vehicle100. In some embodiments, the battery may be rechargeable. The housing may include electrical contacts, which allows the aerial vehicle100to receive power from the battery. The housing may also include electrical contacts which allow for charging the battery. In some embodiments, the contacts used to discharge the battery during operation of the aerial vehicle100may be the same contacts used to recharge the battery. The electrical contacts may also be used to communicate with the aerial vehicle100. This communication may allow the aerial vehicle100to receive an indication of the current charge of the battery or allow the aerial vehicle100to authenticate the battery via an authentication protocol. The housing of the battery may also contain mechanisms for mechanically coupling to the aerial vehicle100and/or mechanisms for assisting the user in attaching or detaching the battery to or from the aerial vehicle100. Herein, three types of removable batteries are illustrated: a pull-bar battery, a lever assembly battery, and a latch battery.

FIGS. 3A-3Bdepict an example embodiment of a pull-bar battery300and the chassis310. The chassis310may be part of the aerial vehicle100and may provide a cavity within which the pull-bar battery mechanically couples. The pull-bar battery300may include a pull-bar301which may assist the user in removing the pull-bar battery300. The chassis310may be part of the housing130of the aerial vehicle100.FIG. 3Aillustrates a right side view of the pull-bar battery300partially removed from the chassis310with the pull-bar301contracted. The arrow320inFIG. 3Aillustrates the direction in which the user may push the pull-bar battery300when attaching the pull-bar battery300to the chassis310. In some example embodiments, the pull-bar301may be flush with the pull-bar battery300and/or the chassis310when contracted.

FIG. 3Billustrates a rear, top, and right view of the pull-bar battery300coupled to the chassis310with the pull-bar301extended. The arrow330inFIG. 3Billustrates the direction that a user may pull on the pull-bar301to first extend the pull-bar301and then to remove the pull-bar battery300from the chassis310. In some embodiments, the pull-bar battery300may be removed (or decoupled) in one continuous motion simply by pulling on the pull-bar301. In some example embodiments, the pull-bar battery300couples to the chassis310by friction. In other example embodiments, when inserted completely into the chassis310, the pull-bar battery300may be locked into place by a latch or a set of latches on the chassis310. The latch or latches may couple to corresponding hardware on the pull-bar battery300. In some embodiments, the pull-bar battery300may include a latch which couples with a corresponding mechanism in the chassis310. One or more latches on the pull-bar battery300and/or on the aerial vehicle100may be disengaged by extending the pull-bar301, thus enabling the pull-bar battery300to be removed. It will be apparent to one skilled in the art that alternate locking mechanism may be used in place of a latch. The pull-bar301may function to unlock the pull-bar battery300from the chassis310as well as a handle to make removal of the pull-bar battery300easy for a user. The pull-bar301may make removable of the pull-bar battery300easier by operating as a handle for the user to grab when removing the battery. This may assist the user in removing a depleted or partially-depleted pull-bar battery300that would otherwise be difficult to remove in cases in which the pull-bar battery300has swelled or warped while being discharged.

FIG. 4andFIG. 5illustrate a pull-bar battery300according to some example embodiments.FIG. 4illustrates a pull-bar battery300in isolation that includes the characteristic pull-bar301.FIG. 5illustrates an exploded view of the pull-bar battery300, partially inside the chassis310of the aerial vehicle100. InFIG. 5, the pull-bar301, a tab500, and a screw501are shown detached from the rest of the pull-bar battery300for illustrative purposes. The arrows520illustrate the way in which the pull-bar301, a tab500, and a screw may be assembled together. The arrow530illustrates how the pull-bar battery300may couple to the chassis310. Specifically, the pull-bar battery300may be inserted into the battery cavity formed by the chassis310to couple within the aerial vehicle100. In one example embodiment, the pull-bar301may be configured so that when it is pushed into the chassis310portion, a handle edge of the pull-bar battery300is substantially flush with a frame of the aerial vehicle100.

The chassis310may include a battery locking spring540which locks the pull-bar battery300in the chassis310. In some embodiments, when the pull-bar301is compressed, the battery locking spring540may prevent the pull-bar battery300from being removed. When the pull-bar301is compressed, a protruding element on the battery locking spring540may be adjacent to the tab500of the pull-bar battery300, thereby preventing the pull-bar battery300from being removed. That is, the contact between the tab500and the battery locking spring540may block the pull-bar battery300from being removed from the chassis310. When the pull-bar301is sufficiently extended away from the chassis310, the protruding element of the battery locking spring540may be pushed away from the tab500by a slanted surface on the pull-bar301, thus unlocking the pull-bar battery300from the chassis310. In this way, the pull-bar battery300may be locked into place by the battery locking spring540when the pull-bar301is compressed and may be unlocked (i.e., removable/decoupled) when the pull-bar301is extended. Similar locking mechanisms known to one skilled in the art which can be unlocked by extending the pull-bar301also may be used to couple the pull-bar battery300to the chassis310.

FIG. 6AandFIG. 6Billustrate an example embodiment of a removable battery that that may be coupled and removed, by a lever assembly, from the battery cavity formed by the chassis coupled with the aerial vehicle100.FIG. 6Aillustrates a right side view of a removable battery600and a chassis310with a lever610. The lever610is shown in an open position inFIG. 6A. The removable battery600couples with the chassis310.

In order to couple the removable battery600with the chassis310, a user may push the removable battery600into a cavity of the chassis310in the direction indicated by arrow620and then pull the lever610towards the underside of the chassis310in the direction indicated by arrow630. In some embodiments, the lever610may operate a locking mechanism, which locks the removable battery600into the chassis310of the aerial vehicle100. This locking mechanism may be such that the removable battery600is locked into the chassis310when the lever610is closed and unlocked from the chassis310(i.e., able to be removed) when the lever610is open. In some example embodiments, pushing the removable battery600into the cavity in the chassis310may cause the lever610to be closed. Thus, only a single action may be required by the user to insert the removable battery600and lock it into place. In an alternate embodiment, the user inserting the removable battery600into the corresponding cavity in the chassis310may not close the lever610, and the lever610may need to be closed by a separate action of the user.

FIG. 6Billustrates a rear, bottom, and left view of an embodiment of the removable battery600shown inFIG. 6Ain which the lever610is nearly closed and where the removable battery600is fully inserted into the corresponding cavity in the chassis310of the aerial vehicle100. In order to remove (or decouple) the removable battery600from the chassis310, the lever610may be pulled away from underside of the chassis310in the direction indicated by the arrow640, which may unlock the removable battery600from the chassis310. The removable battery600may then be removed by pulling it the direction indicated by the second arrow650—down and away from a bottom of the chassis310. In some embodiments, pulling the lever610away from the underside of the chassis310when removing the removable battery600may also move the removable battery600in the direction indicated by the second arrow650. A user may subsequently remove the removable battery600by pulling in the direction of the second arrow650away from the chassis310. The mechanical advantage provided by the lever610may make removing the removable battery600significantly easier. This mechanical advantage may assist the user in removing a depleted or partially-depleted removable battery600that would otherwise be difficult to remove in cases in which the removable battery600has swelled or warped while being discharged.

FIG. 7AandFIG. 7Billustrate an embodiment of a removable battery that may be coupled and removed from the aerial vehicle100by a latch or “squeeze open” assembly.FIG. 7Aillustrates a left side view of the latch battery700and chassis310. In the embodiment illustrated inFIG. 7A, the latch battery700is shown partially inside the corresponding cavity of the chassis310.FIG. 7Billustrates a rear, top, and right view of the chassis310and latch battery700. The chassis310may be part of the aerial vehicle100. The chassis310may have a cavity within with the latch battery700may be mechanically inserted and couple with the aerial vehicle100to provide power to the aerial vehicle100.

The latch battery700may include buttons701which may be used to decouple the latch battery700and the chassis310. The latch battery700may be coupled to the chassis310by pushing the latch battery700in the direction indicated by the arrow710. Once the latch battery700, is fully inserted into the cavity in the chassis310, a locking mechanism may be triggered. The latch battery700may be removed by pressing on the buttons701as depicted by the arrow720while simultaneously pulling the latch battery700in the direction indicated by the arrow730.

These various embodiments of batteries may allow a battery to be quickly attached to and/or removed from an aerial vehicle100. The various embodiments described above may also securely attach the battery to the aerial vehicle100.

Detachable Propeller

The propeller blades of an aerial vehicle100, such as a quadcopter, are often susceptible to damage due to their light weight and high rate of rotation. Thus, it may be advantageous to provide for easily replaceable propellers.

FIG. 8,FIG. 9A,FIG. 9B, andFIG. 10illustrate example embodiments of removable propellers and corresponding propeller locking mechanisms which may allow for quick replacement of a propeller without the use of tools. A removable propeller and propeller locking mechanism may couple together as a propeller coupling assembly. The propeller coupling assembly may permit the propeller to be detached from and/or coupled to the aerial vehicle100without the use of tools. The propeller coupling assembly may lock the propeller into place and may be configured to prevent the propeller from accidently detaching from propeller locking mechanism.

FIG. 8illustrates an embodiment of a propeller locking mechanism800. The propeller locking mechanism800may include a base801, a shaft802, a spring803, a one or more pins804, and/or a toothed plate805. The base801may be rigidly coupled to the shaft802, which may in turn be rigidly coupled to the one or more pins804. One end of the spring803may be attached to the base801and/or the shaft802and the other end may be attached to the toothed plate805. The base801may be rigidly coupled to the shaft802so as to comprise a single shaft. The toothed plate805may include a plurality of teeth that provide adjacent ridges and valleys to which a reciprocal element of a propeller145may couple. The teeth of the toothed plate805may be located on the side of the toothed plate805opposite the base801(i.e., the teeth may face away from the base801). The shaft802may pass through the toothed plate805and the toothed plate805may be able to move up and down, along the axis of the shaft802. Vertical translation and/or rotation of the toothed plate805may cause the spring803to deform, e.g., compress, thus exerting an upward force on the toothed plate805. The shaft802and/or the base801may be coupled to a rotor (e.g., rotor140) of the aerial vehicle100. The rotor140may rotate a propeller by rotating the shaft802.

FIG. 9AandFIG. 9Billustrate example embodiments of a propeller900, which may couple to the propeller locking mechanism800illustrated inFIG. 8. The propeller900may be an embodiment of a propeller145. The propeller900may include a propeller hub910coupled to one or more propeller blades930. Only portions of the propeller blades930are shown inFIGS. 9A and 9B, as illustrated by the broken lines. The propeller hub910may include one or more locking slots940, one or more grooves920, and one or more lead-in chamfers960.

The propeller hub910may include an aperture with a first opening at a first end (e.g., the top of the propeller hub910) and a second opening at the second end (e.g., the bottom of the propeller hub910). The first opening and the second opening may be connected by an internal surface. The internal surface may be an open cylinder in which the openings of the cylinder are the first and second openings of the propeller hub910. The one or more grooves920may be on the internal surface. The one or more grooves920may each include a first groove opening922at the first end of the propeller hub910and a second groove opening924at the second end of the propeller hub910. The first groove openings922of the one or more grooves920may be part of the first opening of the aperture of the propeller hub910. Similarly, the second groove openings924of the one or more grooves920may be part of the opening of the second opening of the aperture of the propeller hub910. In some example embodiments, a second groove opening924is formed in a lead-in chamfer960formed on the second end of the propeller hub910. The lead-in chamfer960may include two slanted edges that form an indent in the second end of the propeller hub910. The peak of the lead-in chamfer960may be co-located with the opening of the second opening924of a respective groove920.

The one or more locking slots940and the one or more grooves920may be formed as indents in the propeller hub910(e.g., on the first end of the propeller hub910). In some example embodiments, the one or more locking slots940form a chamfered edge with the first end of the propeller hub910as illustrated inFIG. 9A. The one or more grooves920may be on the interior of the propeller hub910(e.g., the grooves920may run along the internal surface of the propeller hub910). In some example embodiments, the grooves920may rotate around an axis concentric with the internal surface of the propeller hub910, as illustrated inFIG. 9A. In some embodiments, the grooves920may be parallel with the axis of the internal surface in the propeller hub910, as illustrated inFIG. 9B. The propeller hub910may be in the shape of a cylindrical shell as illustrated inFIGS. 9A and 9B. The propeller hub910may be rigidly attached to the one or more propeller blades930. The propeller hub910and the propeller blades930may be elements of the same material body. The propeller hub910may have a toothed bottom950that includes a plurality of teeth that provide adjacent ridges and valleys that may reciprocally couple to (and decouple from) the toothed plate805of the propeller locking mechanism800.

The propeller hub910may fit around the shaft802of the propeller locking mechanism800. In order to lock the propeller900to the propeller locking mechanism800, a user may place the propeller hub910of the propeller900over the shaft802so that the shaft802is aligned with the aperture of the propeller hub910. The pins804on the shaft802may block the propeller hub910from being pressed down unless the second groove openings924at the second end (e.g., the bottom) of the propeller hub910corresponding to the bottom ends of the grooves920are properly aligned with the pins804. The pins804may fit into the grooves920. By pressing down on the propeller900and rotating it, the propeller hub910may be moved past the pins804by running the pins804through the grooves920on the interior of the propeller hub910. In example embodiments in which the second groove openings924of the propeller hub910are formed in lead-in chamfers960, the lead-in chamfers960may make the user's task of aligning the second groove openings924with the pins804easier.

In some example embodiments, while the pins804enter the second openings924of the grooves920and/or enter the lead-in chamfer960, the toothed bottom950of the propeller hub910may come into contact with the toothed plate805. In alternate example embodiments, the toothed bottom950of the propeller hub910may come into contact with the toothed plate805, while the pins804are being passed through the grooves920. The toothed bottom950of the propeller hub910and the teeth on the top of the toothed plate805may reciprocally mesh together. As the propeller900is pressed down and rotated, the toothed plate805that is meshed to it may move down and rotate as well. Accordingly, as the propeller900is pushed down by the user, the spring803may cause the toothed plate805to exert a vertical restoring force on the propeller900. The teeth of the toothed plate805may mesh with those on the propeller hub910forming a Hirth joint.

Once the pins804have passed completely through the grooves920by passing through the first groove openings922of the grooves920, the user may maneuver the pins out of the grooves920so that the pins804are above the propeller900. The user may align the locking slots940on the propeller900with the pins804. The one or more locking slots940may have the same widths as the one or more grooves920, because the one or more locking slots940couple with the one or more pins which pass through the one or more grooves920. In some embodiments, torsion on the spring803may cause the locking slots940to align with the pins804, mitigating the need for the user to align the pins804and locking slots940. In some example embodiments, once the pins804have passed completely through the grooves920by passing through the first groove openings922, the spring803may exert a rotational restoring force on the propeller hub910causing the propeller hub910to rotate so that the pins804align with the locking slots940. In this way, the locking slots940of the propeller hub910may align with the pins804and the propeller hub910may lock into place when a user releases the propeller900. The vertical force exerted by the spring803may hold the propeller900in place by pushing the locking slots940into the pins804. Thus, when the pins804are in the locking slots940of the propeller900, the propeller900may be locked to the propeller locking mechanism800.

In some example embodiments, each of the pins804may be held at a first position by springs which are internal to the shaft802so that the pins804extend a first distance from the shaft802. When a force is applied to the pins804, such as when a user presses down on the pins804, the pins804may be pushed into the shaft802by compressing and/or extending the springs attached to the pins804. In some example embodiments, the groove920in the propeller900may be shallower at the top of the propeller900than at the bottom.

A groove920may be deep enough at the base of the propeller900so that a pin804can fit into the groove920without being pushed down, but may be too shallow at the top of the propeller for a pin804to fit into the groove without the pin804being pressed down. In such an embodiment, the user may not need to press down the pins804in order to attach the propeller900to the propeller locking mechanism800—the pins804may be pressed down as the propeller900is twisted onto the propeller locking mechanism800and the grooves920becomes gradually shallower. However, the pins804may need to be pressed down in order to remove the propeller900. This example embodiment may help prevent the propeller900from being inadvertently removed from the propeller locking mechanism800even if the pins804fall out of the locking slots940. In other example embodiments, the grooves920may be of uniform depth. In those example embodiments, the pins804may need to be pressed down in order to attach and to remove the propeller900. In some example embodiments the pins804are fixed (e.g., the pins804are not attached to springs and cannot be pushed down and thus the pins804extend a set length from the shaft802). It is not required that the propeller locking mechanism800includes only two pins804—any number of pins804may be used. Also, the propeller locking mechanism800may include an element of any shape that extends from the shaft802in place of a pin804. Furthermore, in some example embodiments, the propeller900may include one or more pins on the internal surface of the cylindrical shell and the propeller locking mechanism800may include corresponding grooves on the shaft802.

FIG. 10illustrates an example embodiment of a propeller coupling assembly including a propeller900locked into a propeller locking mechanism800. The embodiment shown inFIG. 10is similar to the embodiments shown inFIG. 8,FIG. 9A, andFIG. 9B, in that attaching the propeller900to the propeller locking mechanism800may involve manipulating the propeller900so that the pins804pass through the grooves920of the propeller900and then rotating the propeller900so that pins804couple into the locking slots940. The spring803may push the propeller900upward so that it stays locked in place. In the embodiment illustrated inFIG. 10, the interconnecting teeth on the propeller hub910of the propeller900and the toothed plate805of the propeller locking mechanism800are different than those illustrated inFIGS. 8,9A, and9B. The example embodiment ofFIG. 10is illustrated with two teeth (only the first tooth can be seen inFIG. 10), where each tooth is reciprocal with a respective lead-in chamfer960of the propeller hub910. It will be apparent to one skilled in the art that any number and/or manner of teeth or keying mechanisms may be used to connect the propeller hub910to the propeller locking mechanism800and to transfer torque from the propeller locking mechanism800to the propeller900during operation of the rotor140. The interconnecting teeth or keying mechanism may be such that when the propeller900is locked into the propeller locking mechanism800, the spring803exerts no torque on the propeller900(i.e., the deforming forces on the spring803exerted by the attachments of the spring803to the toothed plate805and the base801are purely compressive and produce no torque), when the rotor140is not in operation. In some embodiments, a sleeve coupling assembly, a key and keyset pair, a spline coupling assembly, and/or some other type of coupling assembly may be used in place of the toothed bottom950of the propeller hub910and the toothed plate805.

In some example embodiments, the toothed plate805may be held at an equilibrium position when the propeller900is not attached. During the process of attaching the propeller900, while the pins804are in the grooves920, the toothed plate805may come into contact with the toothed bottom950of the propeller hub910. The equilibrium position of the toothed plate805may be such that the rotation of the propeller900with the respect of the shaft802when this contact occurs will be the same relative rotation at which the propeller900is locked into the propeller locking mechanism800. For example, in the embodiment illustrated inFIG. 9A, the bottom of each groove920is directly opposite a respective locking slots940. That is, the bottom of each groove920is directly under a respective locking slot940. Thus, if the spring803holds the toothed plate805at an equilibrium position so that the propeller900and the toothed plate805make contact when the pins804are near the bottom of the grooves920, then when the pins804are in the locking slots940, the propeller900will be at roughly the same orientation as when the toothed plate805first came into contact with the teeth of the propeller hub910. Because the spring803may be free of torsion when the toothed plate805is held at an equilibrium position, the spring803likewise may be free of torsion when the propeller900and the propeller locking mechanism800are locked together. Furthermore, because the position of the locking slots940correspond the position at which the spring803is free of torsion, the spring803may align the pins804and the locking slots940once the pins804have passed through the grooves920, which may make the action of locking the propeller900into place easier for a user.

The propeller coupling assembly allows the propeller900to removably couple to the propeller locking mechanism800. The propeller900may be quickly and easily attached to or removed from the aerial vehicle100without the use of the tools. The force of the toothed plate805on the propeller900resulting from the compressed spring803may keep the one or more pins804of the propeller locking mechanism800inside the locking slots940propeller hub910. The one or more pins804and/or the toothed plate805intermeshed with the toothed bottom950of propeller hub910may transfer a rotational load from the shaft802to the propeller900.

Thermal Vents

FIGS. 11 and 12illustrate two example embodiments in which the arms135on the aerial vehicle100include vents. The vents may allow for airflow through the arms135for cooling of electronics within the aerial vehicle100. The electronics cooled by the airflow may be the motors that power the propellers, computer processors, and/or a power source for the aerial vehicle100; e.g., battery or batteries. In some embodiments, the electronics may be near the airflow. In some example embodiments, the electronics may be connected to thermally conductive material, such as a metal wire, and the thermally conductive material may be convectively cooled by the airflow, which, in turn, cools the electronics. In some embodiments, the thermal vents may be coupled with, or integrated with, channels that direct received air to particular portions of the aerial vehicle100, e.g., where the electronics or power sources are located.

By way of example, inFIGS. 11 and 12the vents are on the top of the arm135underneath the propeller. When the propellers are active, this configuration may increase the airflow1103into the vents which may enhance the cooling.

FIG. 11illustrates an example embodiment with one or more vents1100, an air pathway1101(or channel), and an outlet vent1102. The embodiment ofFIG. 11may allow for airflow1103through the air pathway1101. The airflow1103is illustrated by a dashed-line indicating an air flow path within the air pathway1101. This airflow1103may be used to cool electronics in the arm135or in the housing130of the aerial vehicle100. Wires used to transfer power and/or control signals between the housing130and the motors in the rotors140may be in thermal contact with the airflow1103. This may allow heat generated by the motor to flow along the wire and be absorbed by the airflow1103, thus cooling the motor. The airflow1103also may be in thermal contact with electronics in the housing such as computer processors, sensors, communication circuits, and/or one or more battery. Thermal contact may comprise direct convective cooling of the electronics and/or convective cooling of a conductor that is in thermal contact with the electronics.

The airflow1103of each arm135may flow out of a single outlet vent1102or out of a plurality of outlet vents1102. The outlet vent1102is depicted inFIG. 11as being oriented upwards, but in alternate embodiments the outlet vent1102may be oriented in some other direction. It is noted that there may be one or more outlet vents1102and one or more outlet vents may be directed towards specific components in the housing for which cooling airflow may be desired. The air pathway1101may be a connected cavity in the arm135and the housing130, or may be a tube that runs from the vents1100to the outlet vent1102. InFIG. 11, three thin rectangular vents1100are depicted, but in alternate embodiments the vents1100may vary in number, size, shape, and position.

FIG. 12illustrates an alternate example embodiment of vents which may allow for airflow through the arms135of the aerial vehicle100. The illustrated embodiment includes three vents1200, an air pathway1201, and an outlet vent1202, the combination of which may allow for airflow1203through the air pathway1201. The airflow1103is illustrated by three dashed lines which depict air flow paths. InFIG. 12, only one air pathway1201and outlet vent1202are illustrated, however it is understood the remaining two vents1200likewise may have corresponding air pathways and output vents. The airflow1203may cool electronics in the arm and/or electrical components in the rest of the aerial vehicle, if the electrical components are in thermal contact with the airflow1203(e.g., through a wire which is convectively cooled by the airflow1203and which is connected to the electrical component). Some example embodiments may include a single air pathway1201to which every vent1200and output vent1202is connected. In some example embodiments the arm135may be hollow, and the air pathway1201is the hollow cavity of the arm135. In some example embodiments, the arm135may include a different number of vents1200than is depicted inFIG. 12.

Vents in the arm135of an aerial vehicle100may provide a reliable means of cooling the aerial vehicle100to offset the heat generated by the electronics. Cooling the components of the aerial vehicle100may obviate the overheating of processors, sensors, motors, and/or other electronics in the aerial vehicle100. Placing the vents (e.g., vents1100or vents1200) underneath a propeller145may produce greater airflow through air pathways (e.g., air pathway1101or air pathway1201) resulting in active cooling of the aerial vehicle100without the need for additional fans and/or heat sinks. In this way, this configuration may help prolong operational use of the aerial vehicle100by obviating the need for additional weight from cooling components, such as heat sinks and/or cooling fans.

Additional Considerations