Patent Publication Number: US-2021170259-A1

Title: Motorized wheel assembly with quick release

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are incorporated by reference under 37 CFR 1.57 and made a part of this specification. This application is related to Patent Cooperation Treaty (PCT) Application No. PCT/IB2016/000536, filed Apr. 9, 2015, which is also incorporated herein by reference in its entirety for all purposes and made a part of this specification. 
    
    
     BACKGROUND 
     Field 
     This disclosure relates to electric vehicles. In particular, it relates to a motorized wheel assembly for a vehicle. 
     Description 
     Lightweight personal vehicles, such as skateboards, scooters, roller skates, and others are common for recreational use and transportation. These vehicles are commonly non-motorized, requiring the user to provide the power for motion. Several motorized personal vehicles have been developed. For example, some commercially available motorized skateboards use a motor and a toothed belt to drive one or two wheels. Additionally, motorized skateboards that include motorized wheels, such as hub mounted motors, are being developed. 
     SUMMARY 
     According to this disclosure, a motorized vehicle assembly includes one or more of the following: an axle comprising a channel extending along a central axis of the axle; a socket positioned within the channel of the axle; and/or a motorized wheel configured to be mounted on an end the axle. According to this disclosure, the motorized wheel includes one or more of the following: a boss configured to engage the end of the axle when the motorized wheel is mounted on the axle; an electric motor; a tire mounted on the rotor; and/or a plug positioned within the boss, the plug configured to engage with the socket when the motorized wheel is mounted on the axle. According to this disclosure, the electric motor includes one or more of the following: a stator fixed to the boss; and a rotor surrounding the stator, the rotor configured to rotate relative to the stator. The electric motor is configured to cause the rotor to rotate relative to the stator to cause the tire to rotate. 
     According to this disclosure, the assembly further comprises one or more of the following: the plug comprises prongs and the socket comprises receptacles, and/or wherein the prongs are configured to be received within the receptacles; a hanger, wherein the hanger supports the axle, and/or wherein the hanger comprises a channel formed therein, the channel of the hanger connected to the channel of the axle; the channel of the axle and the channel of the hanger form a continuous duct; a truck, the truck resiliently connected to the hanger by a kingpin; the truck comprising a surface configured to mount to the motorized vehicle, the surface including an opening formed therein, and/or a channel extending through the truck from the opening, wherein the channel of the truck is connected to the channel of the hanger; the channel of the axle, the channel of the hanger, and/or the channel of the truck form a continuous duct; wiring extending through the duct and connecting to the socket; the wiring is internally housed within the continuous duct of the axle, hanger, and/or the truck; the wiring is further connected to a battery in the motorized vehicle; the hanger further comprises a hollow pivot tube, and wherein the channel of the hanger extends through the hollow pivot tube; the truck further comprises a hollow pivot bushing, and wherein the channel of the truck extends through the hollow pivot bushing; a bore, a groove formed in an outer surface of the portion of the boss, and/or a pin configured in size and shape to be inserted into the bore, wherein, when the motorized wheel is mounted to the axle, the pin is inserted into the bore and is at least partially received within the groove; a receiving space formed in the truck, the receiving space positioned to receive a portion of the boss therein when the motorized wheel is mounted on the axle, a bore extending at least partially into the truck, the bore intersecting the receiving space, a groove formed in an outer surface of the portion of the boss, and/or a pin configured in size and shape to be inserted into bore, wherein, when the motorized wheel is mounted to the axle, the pin is inserted into the bore and is at least partially received within the groove; when the pin is at least partially received within the groove, the motorized wheel is retained on the axle; the motorized wheel further comprises an inner bearing positioned on the boss, an inner bell end positioned on the inner bearing, the inner bell end further connected to the rotor, wherein the portion of the boss extends outwardly away from the inner bearing and the inner bell end; a portion of the pin is threaded, a portion of the bore is threaded, and the threaded portion of the pin is configured to engage the threaded portion of the bore; the groove extends in a direction that is perpendicular to the central axis; a projection extending from an inner surface of the boss, and/or a slot formed in the end of the axle, wherein the slot is configured to receive the projection when the motorized wheel is mounted on the axle; the slot and projection are positioned to rotationally align the motorized wheel to axle around the central axis; the slot extends from an end of the axle along a direction parallel to the central axis; the projection comprises a grub screw extending through an opening in the axle; the projection extends from an inner surface of the portion of the boss; the motorized wheel further comprises an outer bell end connected to the rotor, the outer bell end including an opening, an outer bearing positioned on the boss, the outer bearing received with the opening of the outer bell end and/or a retainer configured to removably engage with the boss, the retainer including a flange that secures the outer bearing within the opening of the outer bell end; the retainer includes a threaded portion that engages with a threaded portion of the end of the boss; the outer bell end includes a flange surrounding the opening, and/or wherein the outer bearing is positioned between the flange of the outer bell end and the flange of the retainer; the motorized wheel further comprises a quick release mechanism configured for mounting the motorized wheel to the axle, the quick release mechanism comprising a single fastener actuable to mount the motorized wheel to the axle; the quick release mechanism further comprises a locking plate, the single fastener extending through the locking plate along the central axis, wherein advancing the single fastener causes displacement of a retaining ball in a direction perpendicular to the central axis; the end of the axle further comprises an opening through a wall of the axle, wherein advancing the single fastener causes displacement of the retaining ball at least partially into the opening in the axle; the locking plate comprises a cylindrical projection extending along the central axis and configured to be at least partially received within the boss or axle, wherein the retaining balls are disposed within the cylindrical projection and configured to be displaced radially outward by the fastener; the boss further comprises a divot that radially aligns with the opening through the wall of the axle, the divot positioned radially further from the central axis relative to the opening of wherein advancing the single fastener causes displacement of the retaining ball at least partially into the divot; the quick release mechanism further comprises a retainer, wherein the retainer is positioned between the locking plate and the tire, and/or wherein the retainer secures the tire onto the electric motor; the quick release mechanism further comprises a thrust bearing positioned between the locking plate and the retainer, and wherein the thrust bearing allows rotation of the retainer relative to the locking plate; the thrust bearing comprises a flat ring with roller bearings disposed thereon; the roller bearings contact a surface of the locking plate and a surface of the retainer when the thrust bearing is positioned therebetween; the locking plate comprises a channel, the retainer comprises a channel, and the thrust bearing is received within the channel of the locking plate and the channel of the retainer; and/or the motorized vehicle is a skateboard. 
     According to this disclosure, an axle assembly for a motorized wheel includes one or more of the following: a hanger having a channel formed there through; and/or an axle supported by the hanger, the axle having a channel formed therein. The channel of the hanger and the channel of the axle are connected to form a continuous duct. 
     According to this disclosure, an axle assembly further includes one or more of the following: a truck, the truck resiliently connected to the hanger by a kingpin; the truck including a surface configured to mount to a vehicle, the surface including an opening formed therein, and a channel extending through the truck from the opening, wherein the channel of the truck is connected to the channel of the hanger, and wherein the channel of the truck forms part of the continuous duct; the hanger further comprises a hollow pivot tube, wherein the channel of the hanger extends through the hollow pivot tube; the truck includes a hollow pivot bushing, wherein the channel of the truck extends through the hollow pivot bushing; at least a portion of the hollow pivot tube is received within the hollow pivot bushing; the duct forms a passageway for wiring between the vehicle and the axle; a socket positioned within the channel of the axle, wherein the wiring is connected to the socket, and wherein the socket is configured to connect to a motorized wheel to power the motorized wheel; and/or the socket comprises a receptacle configured to receive a prong of the motorized wheel to provide an electrical connection between the wiring and the motorized wheel. 
     According to this disclosure, a motorized wheel includes one or more of the following: a boss configured to engage an end of an axle when the motorized wheel is mounted on the axle; an electric motor; and/or a plug positioned within the boss, the plug in electrical communication with the electric motor, the plug configured to engage with a socket in the axle when the motorized wheel is mounted on the axle to provide electrical communication between the socket and the electric motor. 
     According to this disclosure, the motorized wheel of claim  45 , further includes one or more of the following: a portion of the boss configured to be received within a receiving space formed in a hanger when the motorized wheel is mounted on the axle; a groove formed in an outer surface of the portion of the boss; the grove is configured to at least partially engage a pin when the motorized wheel is mounted to the axle to retain the motorized wheel on the axle; when the pin is at least partially engaged within the groove, the pin extends through a bore that at least partially extends into the hanger; the motorized wheel further includes an inner bearing positioned on the boss, an inner bell end positioned on the inner bearing, the inner bell end further connected to the rotor, wherein the portion of the boss extends outwardly away from the inner bearing and the inner bell end; the groove extends in a direction that is perpendicular to the central axis; a projection extending from an inner surface of the boss, wherein the projection is configured to be received within a slot on the axle when the motorized wheel is mounted on the axle; the slot and projection are positioned to rotationally align the motorized wheel to axle around the central axis; the projection comprises a grub screw extending through an opening in the axle; the projection extends from an inner surface of the portion of the boss; a quick release mechanism, the quick release mechanism comprising a fastener actuable to mount the motorized wheel to the axle; the quick release mechanism further includes a locking plate, the fastener extending through the locking plate along an axis, wherein advancing the fastener causes displacement of retaining ball in a direction perpendicular to the axis, wherein the retaining ball is configured to engage with an opening through a wall in an end of the axle; the locking plate comprises a cylindrical projection extending along the central axis and configured to be at least partially received within the boss or axle, wherein the retaining balls are disposed within the cylindrical projection and configured to be displaced radially outward by the fastener; the boss further comprises a divot that radially aligns with the opening through the wall of the axle, the divot positioned radially further from the central axis relative to the opening of wherein advancing the single fastener causes displacement of the retaining ball at least partially into the divot; the quick release mechanism further comprises a retainer, wherein the retainer is positioned between the locking plate and the tire, and wherein the retainer secures the tire onto the electric motor; the quick release mechanism further comprises a thrust bearing positioned between the locking plate and the retainer, and wherein the thrust bearing allows rotation of the retainer relative to the locking plate; the thrust bearing comprises a flat ring with roller bearings disposed thereon; the roller bearings contact a surface of the locking plate and a surface of the retainer when the thrust bearing is positioned therebetween; the locking plate comprises a channel, the retainer comprises a channel, and the thrust bearing is received within the channel of the locking plate and the channel of the retainer; and/or the fastener comprises a single fastener. 
     According to this disclosure, a motorized wheel with a quick release mechanism includes one or more of the following: an electric motor; and/or a fastener actuable to mount the motorized wheel to the axle. 
     According to this disclosure the motorized wheel further includes one or more of the following: the axle is mounted on a hanger; the quick release mechanism further includes a bore extending into the hanger, and a groove on a boss of the electric motor, wherein the fastener comprises a pin configured to be received within the bore and at least partially within the groove; the quick release mechanism further includes a locking plate, the fastener extending through the locking plate along an axis, wherein advancing the fastener causes displacement of retaining ball in a direction perpendicular to the axis; a retainer, wherein the retainer is positioned between the locking plate and the tire, and wherein the retainer secures the tire onto the electric motor; and/or a thrust bearing positioned between the locking plate and the retainer, and wherein the thrust bearing allows rotation of the retainer relative to the locking plate. 
     According to this disclosure, a method for securing a motorized wheel to an axle mounted in a hanger includes one or more of the following: mounting a motorized wheel on an axle; and/or inserting a pin through a bore in a hanger such that the pin engages a groove on the motorized wheel. 
     According to this disclosure, the method further includes one or more of the following: aligning a projection on the motorized wheel with a slot on the axle; mounting the motorized wheel on the axle comprises sliding a boss of the motorized wheel on the axle such that the projection slides along the slot. 
     According to this disclosure, a method of manufacturing a motorized wheel assembly includes one or more of the following: positioning a socket within a channel of an axle; and/or routing wiring through the channel of the axle to the socket. 
     According to this disclosure the method further includes one or more of the following: attaching the axle to a hanger having a channel formed in the hanger, wherein the channel of the axle and the channel of the hanger are connected to form a continuous duct; routing the wiring through the channel of the hanger; attaching the hanger to a truck with a kingpin, the truck having a channel formed in the truck, wherein the continuous duct includes the channel of the truck; routing the wiring through the channel of the truck; attaching the truck to a vehicle; routing the wiring to a battery positioned on or within the vehicle; the vehicle is a skateboard and said attached the truck to the vehicle comprises attaching the truck to a deck of the skateboard; positioning a plug within a boss of a motorized wheel comprising an electric motor, the boss configured to be mounted, the plug connected to the electric motor; and/or mounting the boss on the axle such that the plug engages the socket to form an electrical connection between the electric motor and the wiring. 
     According to this disclosure, a method for manufacturing a motorized wheel includes one or more of the following: fixedly attaching a stator to a boss such that the stator surrounds the boss, the boss configured to mount to an axle of a vehicle; positioning a rotor around the stator, the rotor configured to rotate relative to the stator; and/or positioning a plug within the boss, the plug electrically connected to coils of the stator. 
     According to this disclosure the method further can further include mounting a tire onto the rotor. 
     According to this disclosure, a motorized skateboard includes one or more of the following: a deck; a truck connected to the deck; a hanger attached to the truck by a kingpin; an axle supported by the hanger; a wheel connected to the axle, the wheel including a tire mounted on an electric motor such that the electric motor drives the tire; a battery mounted proximal to the deck; and/or wiring connecting the battery to the electric motor, wherein the wiring is routed from the battery to the electric motor entirely inside the axle, hanger, truck, and deck. 
     According to this disclosure, the skateboard further includes one or more of the following: the hanger further comprises a hollow pivot tube, wherein the wiring is routed through the hollow pivot tube; the hanger further comprising one or more channels formed therein, the one or more channels functioning as cable ducts for routing the wiring; the axle further comprising one or more channels formed therein, the one or more channels functioning as cable ducts for routing the wiring; the truck further comprising one or more channels formed therein, the one or more channels functioning as cable ducts for routing the wiring; and/or the wiring is not externally visible. 
     According to this disclosure, an electric motorized skateboard includes one or more of the following a deck, truck, hanger, axle and/or a motorized wheel, wherein the wheel is removably mounted on the axle by a quick release mechanism. 
     According to this disclosure the skateboard further includes one or more of the following: the quick release mechanism comprises a single fastener; a thrust bearing and a retainer, wherein the retainer bears against the thrust bearing to retain the tire on the wheel; the fastener is selected from the set comprising bolts, thumbscrews, and grub screws; loosening of the fastener permits the quick and easy removal of the wheel from the skateboard without the use of other tools, nor the separate manual disconnection of any wiring connectors; the quick release mechanism comprises a retaining projection configured to extend radially toward the axle when the fastener is engaged with the wheel. 
     According to this disclosure, a hanger for an electric skateboard includes one or more of the following: a pivot tube; and/or a kingpin; the pivot tube and the hanger are both fitted with passages for the routing of services, the kingpin serves to carry at least a portion of the mechanical load, and the pivot tube serves to carry the services, and to restrict the locus of travel of the hanger around the kingpin, such that the hanger forms a steering mechanism for the skateboard. The hanger may further include the services comprise at least one of liquid coolant, air, or electrical cables. 
     According to this disclosure, a motorized vehicle assembly includes one or more of the following: a hanger; a wheel connected to the hanger via a fastener; and/or an electric motor connected to the wheel, the electric motor configured to turn the wheel relative to the hanger; the wheel can be disconnected from the hanger after disengaging the fastener. 
     According to this disclosure, the assembly may further include one or more of the following: the fastener comprises a pin, and wherein disengaging the fastener comprises removing the pin from a bore; disengaging the fastener comprises turning the fastener relative to the hanger; disengaging the fastener disengages connections axially securing the wheel to the hanger; an axle connecting the wheel to the hanger, wherein disengaging the fastener comprises disengaging the wheel from the axle. 
     According to this disclosure, a motorized wheel mounting assembly includes one or more of the following: a hanger comprising a conduit configured to accept an electrical wire; and/or the electrical wire is configured to power a motorized wheel configured to connect to the hanger. 
     According to this disclosure, the assembly may further include one or more of the following: a pivot connected to the hanger, the pivot comprising a conduit configured to accept the electrical wire, the conduit of the pivot connected to the conduit of the hanger; and/or a truck connected to the hanger, the truck configured to connect to a vehicle and comprising a conduit configured to accept the electrical wires, the conduit of the truck connected to the conduit of the hanger. 
     The foregoing is a summary and contains simplifications, generalization, and omissions of detail. Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, features, and advantages of the devices and/or processes and/or other subject matter described herein will become apparent in the teachings set forth herein. The summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of any subject matter described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features of the present disclosure will become more fully apparent from the following description, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not, therefore, to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. 
         FIG. 1  is a top perspective view of an embodiment of a motorized skateboard. 
         FIG. 2  is a bottom perspective view of the motorized skateboard of  FIG. 1 . 
         FIG. 3  is a perspective view of an embodiment of a motorized wheel assembly, including a truck, hanger, and two motorized wheels. 
         FIG. 4  is a longitudinal sectional view of the motorized wheel assembly of  FIG. 3 . 
         FIG. 5  is a transverse sectional view of the motorized wheel assembly of  FIG. 3 . 
         FIG. 6A  is a perspective view of an embodiment of the hanger of the motorized wheel assembly of  FIG. 3 . 
         FIG. 6B  is a transverse sectional perspective view of the hanger of  FIG. 6A . 
         FIG. 7A  is a perspective view of an embodiment of the truck of the motorized wheel assembly of  FIG. 3 . 
         FIG. 7B  is a longitudinal sectional perspective view of the truck of  FIG. 7A . 
         FIG. 8A  is a perspective view of an embodiment of a motorized wheel of the motorized wheel assembly of  FIG. 3 . 
         FIG. 8B  is a cross-sectional perspective view of the motorized wheel of  FIG. 8B . 
         FIG. 9A  is an exploded inside perspective view of an embodiment of a quick connect mechanism. 
         FIG. 9B  is an exploded outside perspective view of the quick connect mechanism of  FIG. 9A . 
         FIG. 10  is an exploded perspective view of an embodiment of a motorized wheel. 
         FIG. 11  is a sectional perspective view of an exemplary embodiment of a tire for the motorized wheel of  FIG. 10 . 
         FIG. 12  is a perspective view of an embodiment of a hanger that includes open channels. 
         FIG. 13  is a perspective view of an embodiment of a hanger that includes an open plenum. 
         FIG. 14  is a cross-sectional perspective view of another embodiment of a motorized wheel. 
         FIG. 15A  is an outside perspective view of another embodiment of a motorized wheel. 
         FIG. 15B  is an inside perspective view of the motorized wheel of  FIG. 15A . 
         FIG. 15C  is an exploded view of the motorized wheel of  FIG. 15A . 
         FIG. 16A  is an outside perspective view of an embodiment of an electric motor. 
         FIG. 16B  is an inside perspective view of the electric motor of  FIG. 16A . 
         FIG. 16C  is a cross-sectional perspective view of the electric motor of  FIG. 16A . 
         FIG. 17A  is a perspective view of an embodiment of a hanger and axle assembly. 
         FIG. 17B  is a cross-sectional perspective view of the hanger and axle assembly of  FIG. 17A . 
         FIG. 17C  is a detail view of one end of the hanger and axle assembly of  FIG. 17A . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description and the drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made a part of this disclosure. 
     This disclosure relates to motorized wheel assemblies, electric vehicles including the same, and associated methods of use and manufacture. Although described primarily in the context of a skateboard, the motorized wheel assemblies described herein can be used in many types of electric vehicles, including road luges, roller skates, inline skates, and small wheeled scooters, among many others. In some embodiments, the motorized wheel assemblies can include one or more motorized wheels. In some embodiments, the motorized wheel includes a tire mounted on an electric motor, such that the electric motor serves as the hub for the tire and drives the tire directly. 
     In some embodiments, the motorized wheel assemblies are configured for quick release and/or quick connect. As used herein, “quick release” and/or “quick connect” is intended to signify that a wheel of the motorized wheel assembly can be removed and/or replaced easily, such as, without tools, with commonly available tools (in other words, with non-specialized tools), with minimal tooling, by a user, without requiring substantial specialized knowledge, training, or instruction. In some embodiments, a quick release motorized wheel (having a quick release mechanism as discussed herein) can be removed and/or replaced by a user without requiring the vehicle to be shipped back to the manufacturer or a specialized repair shop. As used herein, the terms “quick release” and “quick connect” are each intended to refer to system for engaging and disengaging a wheel to a motorized wheel assembly. 
     As will be described in greater detail below, in some embodiments, a quick release motorized wheel can also include electrical connections (for example, between the electrical components of the wheel and other electrical components located elsewhere on the vehicle) that do not require direct handling. That is, in some embodiments, removal of a quick release motorized wheel can also disconnect an electrical connection between the motorized wheel and the vehicle without requiring a user to separately handle the electrical connection, and attachment of the motorized wheel to the vehicle (for example, replacement of the motorized wheel) can also connect the electrical connection between the motorized wheel and the vehicle without requiring the user to separately handle the electrical connection. In some embodiments, motorized wheel assemblies include an integral plug and socket. In some embodiments, the plug can be fitted coaxially in the motor&#39;s hollow shaft. When the motor is slid onto the axle, the plug can automatically engage with the socket fitted inside the hollow axle. Accordingly, in some embodiments, the user does not need to take special action to connect the electrical plug to the socket. 
     In some embodiments, the motorized wheel assemblies disclosed herein are configured to eliminate or minimize external wiring between a motorized wheel and an electric vehicle. For example, in some embodiments, wiring providing the electrical connection between electrical components of a motorized wheel and additional electrical components of an electric vehicle may be routed through the interior structures connecting the motorized wheel to the electric vehicle. In some embodiments where the vehicle is a skateboard, the wiring between electrical components stored in, on, or below the deck of the skateboard (or elsewhere) can be routed to a motorized wheel through ducts that extend through the interior of the truck, hanger, and axle connecting the motorized wheel to the deck. In some embodiments, the ducts are wholly internal. In some embodiments, the ducts are partially internal. In some embodiments, the ducts extend through the pivot tube of the hanger. As used herein ducts can refer to hollows, channels, conduits, passageways, pipes, pipelines, tubes, tunnels, grooves, etc. of any suitable shape and size to allow for passage and protection of electrical wiring. 
     Most existing electric skateboards have their motors supported from the hanger by a bracket and drive the wheels using a toothed belt. Some have the motors mounted inside the wheels as hub motors. Regardless of the type of drive system, most skateboards (including non-powered skateboards) have resiliently mounted hangers and trucks fixed to the deck. Because the hanger is resiliently mounted, this configuration allows steering of the skateboard by means of shifting the rider&#39;s weight laterally. Existing motorized skateboards traditionally use flying wiring (in other words, wiring that is routed at least partially through the air) to route the wires from the electric motors that power the wheels to the deck, where the electronic speed controllers (ESCs), batteries, and other electronics are normally located. Such flying wiring typically leaves the hanger or deck below the deck and is therefore exposed to road debris and potential damage. Such wiring typically is run in flexible cable, usually protected by a mesh sleeve. Such wiring can be subject to rapid flexing at a high cycle rate, due to the movement of the hanger relative to the deck when turning, wobbling in a straight line, or moving over uneven ground. Over time this can fatigue the wiring, causing failure. 
     Further, existing motorized skateboards do not have a quick release wheels, and therefore suffer from several disadvantages. For example, most existing motorized skateboards have to be returned to the dealer or manufacturer for even typically simple servicing. On most, a user cannot even change the bearings or wheels easily, without mechanical skills and/or special tools. This is in contrast to the easy bearing or wheel replacement possible on unpowered, conventional skateboards, which can be performed by even novice users. Existing motorized skateboards either do not allow for replacement or do not include the necessary tools to replace the bearings and wheels, since it is intended that the bearings and wheels be replaced by the vendor, not the user, unlike non-motorized skateboards that allow the user to change their own bearings and wheels. Additionally, for most existing motorized skateboards motor replacement is beyond the capability of most users. 
     Most existing electric skateboards provide plugs and sockets for connecting the motor wiring. A user generally needs to handle these directly to connect and/or disconnect the electrical connections. This can expose the user to electric shock and can damage the electrical components if connected improperly. Some exiting electric skateboards solder the motor wires directly to the electronics in the deck, making motor replacement difficult and beyond capability of most users. 
     As noted previously, some embodiments of motorized wheel assemblies disclosed herein include quick release motorized wheels that reduce or eliminate the need for the user to own specialized tools and handle electrical connections in order to replace motors, tires, wheels, and bearings. For example, in some embodiments disclosed herein, a quick release motorized wheel is removable without tools, or with a single bolt or key. In some embodiments, components of the motorized wheel can also be relatively easily removed and replaced by the user, including the motor, both wheel bearings, and the tire. Further, in some embodiments, the motorized wheel assembly includes a captive plug and socket to provide the electrical connections, so that the user is not required to handle, align, and seat the plugs and sockets. 
     Thus, in some embodiments, the motorized wheel assemblies disclosed herein provide several notable advantages over existing motorized skateboards, some of which are described below. For example, in some embodiments, a quick release motorized wheel assembly reduces or eliminates the need for the user to own specialized tools and/or handle electrical connections, in order to, for example, replace motors, tires, wheels, and/or bearings or perform other maintenance. Further, in some embodiments, a motorized wheel assembly can hide and protect the wiring over a portion, substantially all, or all of the wiring&#39;s length, by using a hanger and truck with a hollow pivot tube and a hollow or recessed hanger to allow passage of the wiring. In some embodiments, a motorized wheel assembly does not require adding a separate conduit, which can mitigate the cost and weight. 
     In some embodiments, electric vehicles with other electrical components, such as LED lights on the wheels, electric brakes, cooling systems, etc., can also use features of embodiments disclosed herein. For example, wiring for these additional electrical components can be run through the truck, hanger, and axle as described herein. In some embodiments, skateboards that include motorized wheels with cooling systems can use the ducts through the truck, hanger, and axle for coolant hoses, in addition to electrical wiring. 
     In some embodiments, an advantage of routing the wiring through the pivot tube can be that the wires are then exposed to torsion, not bending. This can allow for the use of larger and stiffer wiring, which may not suffer from the limited number of bending cycles before cracking, as bending wiring does. 
     In some embodiments, another advantage of hiding the wiring over its entire or substantially entire length can be that the skateboard does not appear to be electrified or motorized, allowing the electric board to be mistaken for a non-electric board. Users may see this as an advantage. 
     In some embodiments, motorized wheel assemblies that include quick release features can easily and quickly allow a user to replace the motors (or motorized wheels) with higher or lower power motors (or motorized wheels), or with unpowered wheels, without having to change the hanger, truck, and/or board or ship the board to the dealer or manufacturer. For example, a motorized skateboard can be sold as a basic board with a cheaper or less powerful motors, and a user can change or upgrade motors if desired. This can allow the board to be easily upgraded. As another example, in the event of a motor or wheel failure of any kind, the user can easily remove the faulty wheel and mail it to the retailer for replacement or repair. Thus, advantageously, in some embodiments, there is no need to return the whole board in the event of a faulty motor or wheel. Further quick release replaceable wheels allow for the carrying of a spare wheel or motor, and changing in the field without any tools or with minimal tooling. 
     In some embodiments, an additional advantage can be that improper connection of the plug and socket is eliminated or minimized. For example, in some embodiments disclosed herein, there are no plugs to handle and get backwards and no live pins to accidentally touch, making the system simpler and safer. 
     In some embodiments, another advantage can be that the motor is secured to the axle when the plug and socket are fully or substantially fully engaged. Full engagement can help ensure a partly connected plug cannot arc and damage itself or cause the motor to stop. 
     These and other features and advantages present in some embodiments according to the present disclosure will become more apparent from the following description of certain non-limiting embodiments shown in the figures. 
       FIGS. 1 and 2  show top and bottom perspective views, respectively, of an embodiment of a motorized skateboard  100 , or other vehicles as discussed herein. In the illustrated embodiment, the motorized skateboard  100  includes a deck  110  and front and back motorized wheel assemblies  200 . Although illustrated with both front and back motorized wheel assemblies  200 , in some embodiments, either the front or back motorized wheel assembly  200  can be replaced with a non-motorized wheel assembly. In some embodiments, a non-motorized wheel assembly can be a wheel assembly (in other words, truck, hanger, axle, and wheels) as used in conventional non-powered skateboards. Accordingly, in some embodiments, the motorized skateboard  100  can be front-wheel drive, rear-wheel drive, or all-wheel drive. An embodiment of a motorized wheel assembly  200  is shown in greater detail in  FIGS. 4 and 5 , which are described below. 
     In the illustrated embodiment, the motorized wheel assemblies  200  each include a truck  210 , a hanger  240 , and two motorized wheels  300  mounted on an axle  260  (the axle  260  is shown, for example, in  FIG. 5 ). Although each wheel assembly  200  is illustrated as including two motorized wheels  300 , in some embodiments, one or both of the motorized wheels  300  can be replaced with non-motorized wheels. A non-motorized wheel can include a wheel as used in a conventional, non-powered skateboard or an idler wheel, which that does not include a rotor, stator, and/or magnets. Accordingly, in some embodiments, the motorized skateboard  100  includes one, two, three, or four motorized wheels  300 , depending on the user&#39;s requirements or desire for speed and acceleration versus battery and motor weight, and the remaining wheels may be non-motorized wheels. In some embodiments, a user may modify or alter the motorized skateboard  100  after purchase to include less or more motorized wheels  300 . In some embodiments, the motorized wheels  300  have substantially the same appearance as non-motorized wheels. Embodiments of motorized wheels  300  are shown in greater detail in  FIGS. 8A-11 and 14 , which are described below. 
     As shown in  FIGS. 1 and 2 , the motorized wheel assemblies  200 , including motorized wheels  300 , are mounted below the deck  110 . The trucks  210  are connected to the deck  110  by mounting hardware  205 . In the illustrated embodiment, the mounting hardware  205  includes four nuts and bolts for each motorized wheel assembly  200 , although other types of mounting fasteners may be used. In some embodiments, the mounting hardware  205  may be similar to or the same as hardware used to mount trucks in conventional skateboards. As best seen on the back motorized wheel assembly  200  in  FIG. 2 , the hangers  240  are connected to the trucks  210  by a kingpin  280 . In some embodiments, the hangers  240  are resiliently connected to the trucks  210  by the kingpin  280  such that the motorized wheel assemblies  200  are steerable in a manner similar to conventional skateboards (in other words, steerable by a user shifting his or her weight laterally). The axle  260  extends through the hanger  240  (see  FIG. 5 ) and the motorized wheels  300  are mounted on the axle  260  on opposite sides of the hanger  240 . In some embodiments, the motorized wheel assemblies  200  have an appearance substantially similar to the trucks, hangers, and wheels, used in conventional skateboards, such that the motorization of the motorized skateboard  100  is not readily apparent. 
     Various components  150  for the motorized skateboard can be mounted on, below, or within the deck  110 . In the illustrated embodiment, the components  150  are represented by the dashed lines shown on the bottom surface of the deck  110 . In some embodiments, the components  150  are positioned within the deck  110 . The components  150  can be accessible by one or more hatches in the top and/or bottom surfaces of the deck  110 . The components  150  may include batteries, electronic speed controllers (ESCs), a main controller, operator interfaces, radio interfaces, braking resistors, wiring harnesses, cooling system components, and/or other electronic components. As illustrated in  FIGS. 1 and 2 , the components  150  are housed inside the deck  110 , making their appearance non-obvious to a viewer. In some embodiments, the deck  110  comprises a tapered boat hull shape (for example, as shown in  FIG. 2 ). In some embodiments, a tapered boat hull shaped deck  110  can provide sufficient space within the deck  110  for the components  150 , while still having the appearance of a non-motorized skateboard. The shape of the deck  110  can take many other forms and is not limited to the shapes disclosed herein. 
     In the embodiment illustrated in  FIGS. 1 and 2 , wiring connecting the motorized wheels  300  to the components  150  is not visible because it is not external or substantially not external to the motorized skateboard. That is, the wiring connecting the motorized wheels  300  to the components  150  runs internal or substantially internal to the deck  110 , through the motorized wheel assemblies  200 , and into the motorized wheels  300 . Thus, in some embodiments, the motorized skateboard  100  does not include flying wiring that is exposed to road debris, damage, and substantial bending forces. Further, because the wiring is not external, it may not provide any indication that the motorized skateboard  100  is powered. 
     In some embodiments, the motorized wheel assemblies  200  are configured (as will be described below) such that the motorized wheels  300  offer quick release. That is, in some embodiments, the motorized wheels  300  can be removed and/or replaced easily, such as, without tools, with commonly available tools (in other words, with non-specialized tools), with minimal tooling, by a user, without requiring substantial specialized knowledge, training, or instruction. In some embodiments, the motorized wheel assemblies  200  are configured (as will be described below) to simplify the electrical connection (and/or connections to other services, such as cooling systems or hydraulic systems) between the motorized wheels  300  and the components  150 , for example, by including integral plugs and sockets that are connected or disconnected automatically when the motorized wheels  300  are attached or remoted to the motorized wheel assemblies  200 . 
       FIG. 3  is a perspective view of the motorized wheel assembly  200  of  FIG. 1 . As shown, the motorized wheel assembly  200  includes the truck  210 , the hanger  240 , and two motorized wheels  300 . The truck  210  is configured to mount to the underside of the deck  110 . In the illustrated embodiment, the truck  210  includes a baseplate  212  for mounting to the deck  110 . In some embodiments, the baseplate  212  is a flange having a substantially flat surface for interfacing with the deck  110 . The baseplate  212  includes holes through which the mounting hardware  205  (e.g., fasteners such as nut and bolt assemblies) is used to attach the hanger  240  to the deck. In  FIG. 3 , the mounting hardware  205  is illustrated positioned within the holes in the baseplate  212 . 
     The main body of the truck  210  extends away from the baseplate  212  and includes a pivot portion  214  and a kingpin portion  216  for interfacing with the hanger  240 . The pivot portion  214  is configured to receive a pivot portion  242  of the hanger  240 . The pivot portion  214  provides a pivot point for the pivot portion  242  of the hanger  240  such that the hanger  240  can pivot laterally to allow for steering. The kingpin portion  216  of the truck  210  is configured to receive the kingpin  280 , which extends through and connects the hanger  240  to the truck  210  (as shown in  FIG. 4 ). The kingpin  280  may be configured to provide a resilient connection between then truck  210  and the hanger  240  to allow for steering. For example, the kingpin  280  may include bushings  284 , as shown in  FIG. 4 . 
     As shown in the illustrated embodiment of  FIG. 3 , the truck  210  also includes an opening  222  that extends through the baseplate  212 . As will be described in greater detail below, the opening  222  allows for the passage of wiring through the motorized wheel assembly  200  to the motorized wheels  300 . The opening  222  may extend into the truck  210  from a side that, when mounted, contacts the deck  110 . When mounted, the opening  222  may be aligned with a corresponding opening into the deck  110 , thus allowing for passage of wiring between the deck  110  and the truck  210 . In some embodiments, the opening  222  is positioned below the pivot portion  214  of the truck  210 , such that the wiring can extend through the pivot portion  214  of the truck  210  and through the pivot portion  242  of the hanger  240  on route to the motorized wheels  300 . 
     As noted previously, the hanger  240  is connected to the truck  210  by the kingpin  280 . The kingpin  280  is secured by a kingpin nut  281  or other type of fastener. In the illustrated embodiment, the kingpin  280  extends through a central portion of the hanger  240 . Below the kingpin  280 , the pivot portion  242  of the hanger  240  pivotally engages the pivot portion  214  of the truck  210 . Above the kingpin  280 , the hanger  240  includes an axle portion  244 . An axle  260  extends through the axle portion  244  of the hanger  240  (see  FIGS. 4 and 5 ). In some embodiments, the axle  260  is pressed or glued into the axle portion  244  of the hanger  240 . The motorized wheels  300  are mounted on the axle  260 . The features of the motorized wheels  300  will be described below with reference to  FIGS. 8A-11 and 14 . 
       FIGS. 4 and 5  are cross-sectional views illustrating the internal features of the motorized wheel assembly  200  of  FIG. 3 .  FIG. 4  is a longitudinal sectional view of the motorized wheel assembly  200 .  FIG. 5  is a transverse sectional view of the motorized wheel assembly  200  with the motorized wheels  300  removed for illustration purposes. 
     The truck  210  is shown in  FIGS. 4 and 5  and includes the baseplate  212 , the pivot portion  214 , and the kingpin portion  216 . The baseplate  212  includes openings for mounting hardware  205 . The opening  222  is positioned on the baseplate  212  below the pivot portion  214 . A channel  223  extends from the opening  222  through the pivot portion  214 . 
     The kingpin  280  extends through the kingpin portion  216  of the truck  210 . A kingpin recess  217  is formed in the kingpin portion  216 . The kingpin recess  217  can extend partly into the kingpin portion  216  from a rear surface of the truck  210 . The kingpin recess  217  can be configured to receive a kingpin head  283  of kingpin  280 . In some embodiments, the kingpin recess  217  and the kingpin head  283  are configured in size and shape such that when the kingpin head  283  is received within the kingpin recess  217 , the kingpin  280  is substantially prevented or substantially inhibited from rotating. 
     The hanger  240  is attached to the truck  210  by kingpin  280 , which extends through central portion of hanger  240  as shown in  FIG. 4 . The kingpin  280  also extends through bushings  284  that are positioned on opposite sides of the hanger  240 . The bushings  284  are maintained in place by washers  285 , with one washer  285  positioned above the top bushing  284  and another washer  285  positioned below the bottom bushing  284 . In some embodiments, the washers  285  are curved. The bushings  284  may be similar to those used in conventional skateboards. In some embodiments, the bushings  284  and the kingpin  280  resiliently connect the hanger  240  to the truck  210  to allow for steering. 
     The pivot portion  242  of the hanger  240  also allows for resilient connection between the hanger  240  and the truck  210  to allow for steering. For example, the pivot portion  242  includes a pivot bushing  243 . The pivot bushing  243  provides a pivot point between the pivot portion  242  of the hanger  240  and the pivot portion  214  of the truck  210 . The pivot bushing  243  is received partially within a portion of the channel  223  of the truck  210 . A pivot tube  246  extends through the pivot portion  242  and the pivot bushing  243 . The pivot tube  246  is hollow. In some embodiments, the pivot tube  246  is rigid. In some embodiments, the pivot tube  246  is flexible. Openings  245  through the walls of the pivot tube  246  are connected to channels  247  (see  FIG. 5 ) that extend through the hanger  240 . In the illustrated embodiment, a first channel  247  extends through the hanger  240  on a first side of the kingpin  280 , and a second channel  247  extends through the hanger  240  on a second side of the kingpin  280 . In some embodiments, only a single channel  247  is included. The channels  247  extend through the hanger  240  between the pivot portion  242  and the axle portion  244 . 
     The axle  260  is received in the axle portion  244  of the hanger  240 . In some embodiments, the axle  260  may be pressed or glued into the axle portion  244 . In the illustrated embodiment, the axle  260  is hollow and includes a channel  268  formed therein. The axle  260  and the channel  268  can extend along a central axis or longitudinal axis  269 . A longitudinal axis can be an axis that extends along a greatest or longest dimension of a component. Axle openings  261  in the wall of the axle  260  are aligned with the hanger channels  247 . In the illustrated embodiment, two axle openings  261  are included that align with the two hanger channels  247 . In some embodiments, only a single channel  247  and a single axle opening  261  are included. In some embodiments, more than two channels  247  and axle openings  261  are included. 
     As shown, sockets  290  are positioned within the hollow channel  268  of the axle  260 . In some embodiments, the sockets  290  are pressed or glued into the axle  260 . In some embodiments, mechanical fasteners (e.g., bolts, screws, etc.) are used to fix the sockets  290  within the axle  260 . In some embodiments, the sockets  290  can be connected to the axle  260  any suitable or known process or processes, including permanent adhesive, thermal bonds, ultrasonic bonds, spot welds, i.e., thermal weld points, a stitch or stitches, strip welds, tacks formed by crimping, and/or press fit, shrink fit, sliding fit, interference fit, and/or snap fit mechanisms, including male and female parts (e.g., tongue-and-groove corresponding parts), and the like, including any combination thereof. As will be described below, the sockets  290  are configured to mate with plugs on the motorized wheels  300  to establish an electrical (and/or other type of) connection therebetween. The sockets  290  can be configured to allow for quick release of the motorized wheels  300 . The ends of the axle  260  can also include features for engaging the motorized wheels  300 . For example, in the illustrated embodiment, the ends of the axle  260  include openings  263  and slots  267 . The openings  263  and slots  267  can be configured to engage with corresponding features on the motorized wheels  300  to secure the motorized wheels  300  to the axle  260 . In some embodiments, the openings  263  and slots  267  engage with a quick release mechanism  390  that secures the motorized wheels  300  to the axle  260 . As will be discussed below, in some embodiments, the openings  263  engage with retaining balls, protrusions, projections, or bosses  334 . The slots  267  can engage with shoulders  336  of a quick release mechanism  390  of the motorized wheel  300  (see  FIGS. 8B-9B ). 
     As illustrated by the dashed lines in  FIGS. 4 and 5 , ducts  201  are formed through the motorized wheel assembly  200  between the opening  222  and the sockets  290 . The ducts  201  can be continuous. In the illustrated embodiment, the ducts  201  are formed by the opening  222 , channel  223 , pivot tube  246 , openings  245 , channels  247 , axle openings  261 , and axle  260 . The ducts  201  provide a continuous passageway through the motorized wheel assembly  200  through which services such as wiring, cooling air, hydraulic fluid, liquid coolant, etc., can be routed from the deck  110 , through motorized wheel assembly  200 , to the socket  290  for connection to the motorized wheel  300 . 
       FIGS. 6A and 6B  illustrate an embodiment of the hanger  240 .  FIG. 6A  is a perspective view, and  FIG. 6B  is a transverse sectional perspective view. As shown in  FIG. 6A , the body of the hanger  240  includes the axle portion  244  and the pivot portion  242 . The body of the hanger  240  also includes an opening  251  extending through a central portion thereof for receiving the kingpin  280 . A recess  253  is formed in each of the top and bottom surfaces of the central portion of the body of the hanger  240  for receiving the bushings  284  and washers  285 . 
     In the illustrated embodiment of  FIGS. 6A and 6B , a channel  249  extends through the axle portion  244 . The channel  249  is configured in size and shape to receive the axle  260 . A recess  255  is formed in the pivot portion  242  of the hanger  240 . The recess  255  is configured in size and shape to receive the pivot tube  246 . The recess  255  is connected to the channels  247 . The channels  247  are also connected to the channel  249 . The hanger  240  shown in  FIGS. 6A and 6B  is provided by way of example only, and other embodiments of hangers are possible, for example, as shown in  FIGS. 12 and 13  described below. 
       FIGS. 7A and 7B  illustrate an embodiment of the truck  210 .  FIG. 7A  is a perspective view, and  FIG. 7B  is a longitudinal sectional perspective view. The truck  210  includes a baseplate  212  for mounting the truck  210  to the deck  110 . In  FIG. 7A , mounting holes are shown, which extend through the baseplate  212  and are configured to receive mounting hardware  205 . A kingpin portion  216  and a pivot portion  214  extend away from the baseplate  212 . A channel  226  extends through the kingpin portion  216 . The channel  226  is configured to allow the kingpin  280  to extend therethrough. A kingpin recess  217  is formed in the rear of surface of the kingpin portion  216 . The kingpin recess  217  is configured to receive the head  283  of the kingpin  280  as described above. 
     A channel  223  extends through the pivot portion  214  of the truck  210  from the opening  222 . In the illustrated embodiment, the channel  223  includes a first portion  223   a  and a second portion  223   b . The first portion  223   a  may extend along an axis substantially orthogonal to the plane of the baseplate  212 . The second portion  223   b  may be configured to receive at least a portion of the pivot bushing  243  therein. The second portion  223   b  extends along an axis that is angled with respect to the axis of the first portion  223   a . In some embodiments, the angle between the axes is between about 15 degrees and about 75 degrees, about 30 degrees and about 60 degrees, between about 40 degrees and about 50 degrees, or about 45 degrees, although other angles are possible. In some embodiments, the axis of the second portion  223   b  is oriented at about 90 degrees from an axis of the channel  226  and the kingpin  280 . The illustrated embodiment of  FIGS. 7A and 7B  is provided by way of example only, and other embodiments of trucks are possible. 
     An embodiment of a motorized wheel  300  will now described with reference to  FIGS. 8A-11 .  FIG. 8A  is an inside perspective view of the motorized wheel  300 , shown removed from the axle  260 . As shown, the motorized wheel  300  includes a plug  305 . The plug  305  is configured and positioned to mate with the socket  290  (see  FIG. 5 ) when the motorized wheel  300  is installed on the axle  260 . In the illustrated embodiment, the plug  305  includes five pins, although other numbers of pins and other types of plugs  305  are possible. In some embodiments, the plug  305  and socket  290  establish an electrical connection. In some embodiments, the plug  305  and socket  290  may additionally or alternatively establish fluid connections, for example, for a cooling fluid or hydraulic fluid, or other types of connections. 
       FIG. 8B  is a cross-sectional perspective view of the motorized wheel  300 . The motorized wheel includes a tire  370  mounted on an electric motor  301 . The tire  370  and the electric motor  301  are shown separately in the exploded view of  FIG. 10 . The electric motor  301  serves as the hub for the tire  370  and can drive it directly as described below and as described in PCT Application No. PCT/IB2016/000536, which is incorporated herein by reference in its entirety for all purposes and made a part of this specification. 
     In some embodiments, the electric motor  301  is an outrunner motor. Outrunner motors are those that have an internal stator that is surrounded by an external rotor. The external rotor spins relative to the internal stator (e.g., about the central axis  269 ), which generally remains in a rotationally fixed orientation. In some embodiments, the electric motor may be brushless. In the illustrated embodiment, the electric motor  301  comprises an outer casing that is formed by an outer bell end  310 , an outer surface of a rotor  350 , and an inner bell end  320 . The outer casing surrounds a stator  340 . The stator  340  is mounted on a boss  355 . The boss  355  is configured to mount on an axle  260  (see for example,  FIG. 5 ). The boss  355  is further connected to the outer bell end  310  via a bearing  315 . Similarly, the boss  355  is further connected to the inner bell end  320  via a bearing  325 . The bearings  315 ,  325  allow the outer casing of the electric motor (in other words, the outer bell end  310 , the rotor  350 , and the inner bell end  320 ) to rotate relative to the boss  355  and the stator  340 . When the boss  355  is attached to the axle  260  of the motorized skateboard  100 , the electric motor  301  can drive the tire  370 , thus allowing the motorized wheel  300  to propel the motorized skateboard  100 . For example, the boss  355  and stator  340  can be substantially fixedly attached to the axle  260 . When the motorized wheel  300  is powered, the rotor  350  spins relative to the stator  340 . This rotation may be imparted to the tire  370 . 
     In the illustrated embodiment, the outer bell end  310  also includes cooling holes  311  (openings, cutouts, slots, apertures, etc.). The cooling holes  311  can allow cooling fluid (for example, air or water) to flow into and out of the interior of the electric motor  301 . On the opposite end of the electric motor  301  the inner bell end  320  can also include features similar to the outer bell end  310 , such as cooling holes  323 . 
     Each of the bearings  315 ,  325  may be ring bearings, including a central opening formed there through. The boss  355  is received within the central openings of the bearings  315 ,  325 . The bearings  315 ,  325  allow the outer bell end  310 , the rotor  350 , and the inner bell end  320  to rotate together relative to the boss  355 . The boss  355  may be configured as a substantially cylindrical tube. One or more of the ends of the boss  355  may be open. The boss  355  may be configured to receive or otherwise attach to an axle  260  of the motorized skateboard  100  to which the motorized wheel  300  is to be attached. In some embodiments, the boss  355  is rotationally fixed to the stator  340  such that the two rotate together. 
     The stator  340  can comprise a lamination stack with copper windings (in the figures, the copper windings are not shown for ease of illustration, although the windings or other suitable mechanisms can be included in use). The rotor  350  includes one or more magnets  354  mounted on an inner surface thereof. A wide variety of configurations for the stator  340  and the rotor  350  are possible, including various numbers of poles and magnets. The rotor  350  may comprise a mild steel cylinder fitted with neodymium boron permanent magnets on its inner surface. The stator  340  can be formed from laminated sheet steel, wound with copper wire. Other configurations and materials for the rotor  350  and/or the stator  340  are possible. A control board for the electric motor  301  may be included and may be housed within the outer casing of the electric motor or may be remotely located, for example, on or within the deck  110  of the motorized skateboard  100  (for example, among the components  150 ). 
     The motorized wheel  300  may be considered a direct drive system because power is transferred substantially directly from the electric motor  301  to the tire  370 . Other mechanical structures or linkages, including gears and/or belts are not necessary. Utilizing a motorized wheel  300  as discussed herein and also discussed in PCT Application No. PCT/IB2016/000536. which is incorporated by reference, can substantially mitigate or negate the need for a transmission (for example, a transmission including a gear box). This may provide several advantages. For example, without a gearbox with chain or belt means, maintenance of the vehicle can be substantially minimized or mitigated because, for example, there are minimal wearing parts other than the two inner and outer bearings  315 ,  325  per motorized wheel  300  (and the tire  370 ). Accordingly, where the motorized wheel  300  is included on the motorized skateboard  100 , the maintenance of the motorized skateboard  100  may be substantially the same as the maintenance on an unpowered board. Further, the bearings  315 ,  325  on the motorized wheel  300  may be larger than those of an unpowered board, so that the bearing maintenance is also significantly reduced. 
     Additionally, a motorized wheel  300  as discussed herein (without a transmission) can provide lower rolling drag or coasting losses in use. In vehicle designs that include a belt or gearbox transmission, by comparison, the transmission element typically loses energy, as well as all the bearings necessary to carry the various shafts. For example, in a typical belt driven skateboard, each motor will have one or two additional bearings to support the belt tension, so each driven wheel may have five, six, or more bearings in the power train. The losses in such a dual motor belt driven board may be about significantly higher than a board including the motorized wheel  300 . These losses make a notable difference in the ease with which the board can be pushed when the motor is not powered, for example, when the battery is dead (depleted of power). 
     Further, because the motorized wheel  300  does not have any belts or has minimal belts and transmission mechanisms, there is no belt tensioning required (or minimal/infrequent belt tensioning or transmission mechanism maintenance for any such mechanisms that may be present), and unskilled users can operate the board substantially without having to consider routine maintenance on the power transmission. No belt, chain, or gear transmission system means that there are no transmission losses while motoring, which can improve the battery range. Further, because the motorized wheel  300  does not have any belts it can be much simpler to remove and replace the motorized wheel  300 . 
     As illustrated in  FIG. 8B , the motorized wheel  300  can include a quick release mechanism  390 . In some embodiments, the quick release mechanism  390  allows for relatively simple mounting of the motorized wheel  300  on the axle  260 . For example, the quick release mechanism  390  can include a locking plate  331 , a fastener  333 , a thrust bearing  332 , and a retainer  330 . Embodiments of some of the components of the quick release mechanism  390  are shown in the exploded views of  FIGS. 9A and 9B , as described below. To mount the motorized wheel  300  on the axle  260 , the boss  355  can be slid onto the axle  260 . The quick release mechanism  390  can then be used to retain the motorized wheel  300  on the axle  260  by tightening the fastener  333 . 
     In some embodiments, the fastener  333  can be a grub screw, a thumbscrew, a bolt, or any other suitable fastener. In some embodiments, the fastener  333  is configured to be tightened by hand. In some embodiments, the fastener  333  is configured to be tightened with common tools (such as Allen wrenches or screwdrivers). In some embodiments, the fastener  333  is tightened with a single turn, half turn, or quarter turn of the fastener  333 . Advancing the fastener  333  can force retaining balls  334  in the locking plate  331  to move outwardly and engage with openings  263  (see  FIG. 5 ) in axle  260 . The boss  355  can include divots  356  formed on an inner surface the boss  355  that are configured in size and shape to radially align with the openings  263  of the axle  260  and the retaining balls  334 . When the fastener  333  is advanced, the retaining balls  334  can be forced outward, such that a portion of the retaining balls  334  extends through the openings  263  of the axle  260  and into the divots  356  of the boss  355 . 
     When the retaining balls  334  engage the openings  263  in the axle  260  and/or the divots  356  of the boss  355 , the locking plate  331  is held in a fixed relationship with the axle  260 . That is, the retaining balls  334  prevent the locking plate  331  from being removed from the axle  260 , until the fastener  333  is loosened such that the retaining balls  334  can recede into the locking plate  331 . In some embodiments, the retaining balls  334  further prevent the locking plate  331  from rotating relative to the axle  260 . When the locking plate  331  is thus secured to the axle  260 , the locking plate  331  is held against the thrust bearing  332 . The thrust bearing  332  then presses the retainer  330  against the tire  370  to hold the motorized wheel  300  in place on the axle  260 . The thrust bearing  332  allows the tire  370  and outer bell end  310  of the electric motor  301  to rotate relative to the locking plate  331 . 
     Thus, in some embodiments, tightening the single fastener  333  can secure the motorized wheel  300  to the axle  260 , and loosening the single fastener  333  can allow for quick release of the motorized wheel  300 . For example, the fastener  333  can be loosened such that retaining balls  334  withdraw from openings  263  of the axle  360 . The motorized wheel  300  can then slide off the axle  260 . Further, the tire  370  can also slide off the electric motor  301 . Thus, the tire  370 , the electric motor  301 , or the entire motorized wheel  300  can be easily replaced. In some embodiments, the fastener  333  cannot be fully seated unless the retaining balls  334  have been extended into the openings  263  in the axle  260 . In some embodiments, retaining balls  334  can be replaced by equivalent mechanisms, such as dogs or pawls of varying shapes. 
       FIGS. 9A and 9B  show inside and outside exploded perspective views of an embodiment of some of the components of a quick release mechanism  390  that can be used to secure the motorized wheel  300  to the axle  260  as described above. Embodiments of the locking plate  331 , the thrust bearing  332 , and the retainer  330  are shown. In the illustrated embodiment, the locking plate  331  comprises a circular disc  331   a  having a cylindrical projection  331   b  extending from and centered on an inner surface of the circular disc  331   a . The cylindrical projection  331   b  includes the retaining balls  334 . The retaining balls  334  can be loosely retained within the cylindrical projection  331   b  such that they can move backwards and forwards in a direction substantially orthogonal to a central axis of the cylindrical projection  331   b . The outward motion of the retaining balls  334  may be limited such that the in their outermost position a portion of the retaining balls  334  extends beyond the outer surface of the cylindrical projection  331   b . The cylindrical projection  331   b  is configured in size and shape to be at least partially received within channel  268  the axle  260 . As shown in  FIG. 9B , the fastener  333  extends into the outer surface of the circular disc  331   a  and into the cylindrical projection  331   b . As the fastener  333  is advanced into the cylindrical projection  331   b , it forces retaining balls  334  outwardly. In some embodiments, the cylindrical projection  331   b  includes shoulders  336  configured to substantially prevent or substantially inhibit the locking plate  331  from rotating as the fastener  333  is rotated. In some embodiments, the shoulders  336  engage with (for example, are received, or at least partially received, within) slots  267  in the ends of the axle  260 . When the shoulders  336  engage the slots  267 , the locking plate  331  is prevented (or substantially prevented) from rotating relative to the axle  260 . 
     In the illustrated embodiment, a trough  331   c  (e.g., groove, indentation, depression, etc.) is formed on the inner surface of the circular disc  331   a  of the locking plate  331  and configured to receive the thrust bearing  332 . In the illustrated embodiment, the thrust bearing  332  is a flat ring shape including bearings  332   a . In some embodiments, the bearings  332   a  are roller bearings, although other types of bearings are also possible. An outer surface of the retainer  330  also includes a trough  330   a  (e.g., groove, indentation, depression, etc.) that is configured to receive the thrust bearing  332 . When assembled, the thrust bearing  332  is positioned in the troughs  331   c ,  330   a  between the locking plate  331  and the retainer  330 . The thrust bearing  332  allows the retainer  330  to rotate relative to the locking plate  331  by, for example, bearings  332   a  rotating/spinning relative to or against the surfaces of the troughs  331   c ,  330   a . Accordingly, as bearings  332   a  rotate/spin relative to the troughs  331   c ,  330   a , the thrust bearing  332  may also rotate/spin about the central axis  269 . Thus, the retainer  330  is free to rotate with the tire  370  and outer casing (outer bell end  310 , rotor  350 , and inner bell end  320 ) of the electric motor  301 , while the locking plate  331 , axle  260 , the boss  355 , and stator  340  of the electric motor  301  remain fixed (do not rotate). 
     The retainer  330  can be configured to have ring shape. In some embodiments, holes  330   b  extend through the retainer  330 . The holes  330   b  can be configured to allow for cooling of the motorized wheel  300 , as described, for example, in PCT Application No. PCT/IB2016/000536, which is incorporated herein by reference in its entirety for all purposes and made a part of this specification. In the illustrated embodiment, a cylindrical flange  330   c  extends from the inner surface of the retainer  330 . When assembled, in some embodiments, the cylindrical flange  330   c  contacts the outer bearing  315  of the motorized wheel, in order to, for example, retain the outer bearing  315  in position between the retainer  330  and the outer bell end  310  or stator  340 . The retainer  330  also includes an outer lip  330   d . When assembled, in some embodiments, the outer lip  330   d  contacts a corresponding groove  376  (see  FIGS. 10 and 11 ) formed in the tire  370 , and thus holds the tire  370  in place on the electric motor  301 . 
     Returning to  FIGS. 8A and 8B , the plug  305  is positioned within the boss  355 . In some embodiments, the plug  305  is pressed or glued within the boss  355 . In some embodiments, mechanical fasteners (e.g., screws, bolts, etc.) can be used to retain the plug  305  within the boss  355 . In some embodiments, the plug  305  can be connected to the boss  355  by any suitable or known process or processes, including permanent adhesive, thermal bonds, ultrasonic bonds, spot welds, i.e., thermal weld points, a stitch or stitches, strip welds, tacks formed by crimping, and/or press fit, shrink fit, sliding fit, interference fit, and/or snap fit mechanisms, including male and female parts (e.g., tongue-and-groove corresponding parts), and the like, including any combination thereof. In some embodiments, the plug  305  includes cutouts  305   b  that are used to position the plug  305  within the boss  355 . In some embodiments, the cutouts  305   b  engage features on the locking plate  331 , or other parts of the motorized wheel  300 . As shown in  FIG. 5 , the corresponding socket  290  is positioned within the axle  260 . Thus, when the motorized wheel  300  is placed onto the axle  260 , the plug  305  can automatically engage the socket  290 . In the illustrated embodiment, the plug  305  includes prongs  305   a . Five prongs  305   a  are illustrated (see  FIG. 8A ). In some embodiments, plug  305  can have one, two, three, four, six, seven, eight, nine or more prongs  305   a.    
     When engaged with the socket  290 , each prong  305   a  is received within a corresponding receptacle  290   a  (see  FIG. 5 ) of the socket  290 . The prongs  305   a  can be configured with a spring portion  390   b  (see  FIG. 8B ) that is configured to circumferentially expand to contact the walls of the receptacle  290   a . When the motorized wheel  300  is placed onto the axle  260 , the prongs  305   a  of the plug  305  are received within the receptacles  290   a  of the sockets  290 . The receptacles  290   a  slightly compress the spring portion  390   b  of the prongs  305   a , and the spring force of the spring portion  390   b  presses against the interior walls of the receptacles  290   a  to help ensure and maintain an electrical connection. Accordingly, manual and separate connection of the plug  305  and socket  290  may not be needed. This mitigates the need for unskilled users to handle electrical connections and reduce the total number of steps required to remove or replace the motorized wheel  300 . In some embodiments, the plug  305  and the socket  290  can be reversed, with the socket  290  positioned in the motorized wheel  300  and the plug  305  positioned in the axle  260 . Wiring  391  (illustrated by dashed lines) or other connection can be run between the plug  305  and the interior of the electric motor  301 . For example, as shown in  FIG. 8B , wiring  391  connects the prongs  305   a  of the plug  305  to the windings on the stator  340 . 
     Other types of plugs  305  and sockets  290  can also be used. In some embodiments, the plug  305  and socket  290  establish connections for other services (e.g., fluid connections for cooling fluids, lubricants, hydraulics, etc.) between the motorized wheel  300  and the axle  260 . Thus, is some embodiments, the plug  305  and socket  290  are configured to establish fluid connections between the axle  260  and the motorized wheel  300 . 
     In some embodiments, the motorized wheel  300  also includes a cooling system, for example, as described in Patent Cooperation Treaty (PCT) Application No. PCT/IB2016/000536, filed Apr. 9, 2015, which is incorporated herein by reference. Inclusion of a cooling system can increase the power to weight ratio and reduce the weight of the motorized wheel  300 . Because the electric motor is a substantial portion of the weight of a vehicle, reducing the weight of the motorized wheel may have a large impact on reducing the overall weight of the vehicle. 
       FIG. 10  is an exploded perspective view of some of the components of the motorized wheel  300 .  FIG. 10  illustrates the retainer  330 , the tire  370 , the outer bearing  315 , the electric motor (including the outer bell end  310 , the stator  340 , and the inner bell end  320 ), and the inner bearing  325 . In the assembled state, the outer lip  330   d  of the retainer  330  presses into the groove  376  of the tire  370  holding it onto the electric motor. Dogs  377  (or similar features, such as pawls, bosses, protrusions, etc.) on the tire  370  engage with corresponding cutouts  310   a  (or other similar features) on the outer bell end  310 . This ensures that rotation of the electric motor drives the tire  370 . The cylindrical flange  330   c  of the retainer holds the outer bearing  315  in place. The inner bell end  320  also holds the inner bearing  325  in place against the end of the hanger  240 . Thus, in some embodiments, when the motorized wheel  300  is removed, the inner and outer bearings  315 ,  325  are also easily replaceable. 
       FIG. 11  is a sectional perspective view of an exemplary embodiment of a tire  370  for the motorized wheel of  FIG. 10 . The groove  376  and dogs  377  are shown. 
       FIGS. 12 and 13  show perspective views of additional embodiments of hangers  240   a ,  240   b .  FIG. 12  illustrates a hanger  240   a  that includes open channels  241   a  in place of (or in addition to) the internal channels  247  shown in  FIG. 6B . The open channels  241   a  are open to one surface and/or to the environment for user access. Such an arrangement can allow for easier fitment of wiring or piping as discussed herein.  FIG. 13  is shows a hanger  240   b  that includes an open plenum  241   b  in place of (or in addition to) the internal channels  247  shown in  FIG. 6B . The open plenum  241   b  is open to one surface and/or to the environment for user access. Such an arrangement can allow for easier fitment of the wiring or piping as discussed herein. Further, in each of the embodiments of  FIGS. 12 and 13 , the wiring or piping, while not fully enclosed can still be protected by the hangers  240   a ,  240   b . In some embodiments, covers, lids, or other similar structures may be provide to at least partially enclose the wiring or piping positioned in the open channels  241   a  and/or open plenum  241   b.    
       FIG. 14  is a cross-sectional perspective view of another embodiment of a motorized wheel  300   a . In many respects, the motorized wheel  300   a  is similar to the motorized wheel  300  discussed above, and description of similar features will not be repeated here. The motorized wheel  300   a  includes an electric motor  301   a . The electric motor  301   a  includes an outer casing that is formed by an outer bell end  310 , an outer surface of a rotor  350 , and an inner bell end  320 . The outer casing surrounds a stator  340 . The stator  340  is mounted on a boss  355 . The boss  355  is hollow. A portion  3551  of the boss  355  extends beyond the inner bell end  320  away from the electric motor  301   a . The boss  355  is configured to mount on an axle  260  that is itself mounted to a hanger  240 . The boss  355  is connected to the outer bell end  310  by an outer bearing  315 . Similarly, the boss  355  is further connected to the inner bell end  320  by an inner bearing  325 . The bearings  315 ,  325  allow the outer casing of the electric motor  301   a  (in other words, the outer bell end  310 , the rotor  350 , and the inner bell end  320 ) to rotate relative to the boss  355  and the stator  340  (e.g., about the central axis  269 ). When the boss  355  is attached to the axle  260  of an electric vehicle, such as the motorized skateboard  100 , the electric motor  301   a  can drive the tire  370 , thus allowing the motorized wheel  300   a  to propel the motorized vehicle. 
     The outer bearing  315  is received within an opening in the outer bell end  310 . A flange  310   f  is formed on the outer bell end  310  and configured to limit inward motion of the outer bearing  315 . Thus, to install the outer bearing  315 , the outer bearing  315  can be pressed into the corresponding opening on the outer bell end  310  until it contacts the flange  310   f . A retainer  398  can be used to secure the outer bearing  315 . The retainer  398  can include a flange  398   f  that limits outward motion of the bearing  315 . Thus, when the retainer  398  is installed the outer bearing  315  is substantially constrained between the flange  398   f  of the retainer  398  and the flange  310   f  of the outer bell end  310 . A fastener  333  can extend through the retainer  398 . The fastener  333  can secure the retainer  398  in place. 
     The inner bearing  325  is received within an opening in the inner bell end  320 . A flange  320   f  formed on the inner bell end  320  and configured to limit inward motion of the inner bearing  325 . Thus, to install the inner bearing  325 , the inner bearing  325  can be pressed into the corresponding opening on the inner bell end  320  until it contacts the flange  320   f . When the motorized wheel  300   a  is installed on the axle  260 , the inner bearing  325  can contact the hanger  240 . The hanger  240  can thus limit outward motion of the inner bearing  325 . When installed, the inner bearing  325  is thus substantially constrained between the flange  320   f  of the inner bell end  320  and the hanger  240 . 
     A plug  305  is positioned within the boss  355 . The plug  305  is positioned to engage and form an electrical connection (and/or other types of connections as described above) with a socket  290  positioned within the axle  260 . In some embodiments, the plug  305  is pressed or glued within the boss  355 . In some embodiments, mechanical fasteners (e.g., screws, bolts, etc.) can be used to retain the plug  305  within the boss  355 . In some embodiments, the plug  305  can be connected to the boss  355  by any suitable or known process or processes, including permanent adhesive, thermal bonds, ultrasonic bonds, spot welds, i.e., thermal weld points, a stitch or stitches, strip welds, tacks formed by crimping, and/or press fit, shrink fit, sliding fit, interference fit, and/or snap fit mechanisms, including male and female parts (e.g., tongue-and-groove corresponding parts), and the like, including any combination thereof. 
     The boss  355  can be configured to receive the plug  305 . As shown, the boss  355  can be hollow, and the plug  305  can be positioned within the hollow of the boss  355 . In the illustrated embodiment, the boss  355  includes a flange  355   p  projecting inwardly from an inner surface of the boss  355 . The flange  355   p  contacts the plug  305 . An inside portion  305   i  of the plug  305  extends beyond the flange  355   p  toward the inner side of the electric motor  301   a  (toward the inner bell end  320 ). The inside portion  305   i  of the plug  305  is spaced apart from the inner surface of the boss  305 . A receiving space  355   s  is formed between the inner surface of the boss  355 , the flange  355   p , and the inside portion  305   i  of the plug  305 . When the motorized wheel  300   a  is installed onto the axle  260 , the end of the axle  260  is received within the receiving space  355   s . The flange  355   p  limits how far the motorized wheel  300   a  can be inserted onto the axle  260 . When the motorized wheel  300   a  is installed onto the axle  260 , the inside portion  305   i  of the plug  305  extends into the axle  260  such that the plug  305  can engage the socket  290 . An outside portion  305   o  of the plug  305  can contact the inside surface of the boss  355 . In some embodiments, an inner diameter of the boss  355  on the outside of the flange  355   p  is greater than an inner diameter of the boss  355  on the inside of the flange  355   p . In some embodiments, the inner diameter of the boss  355  is substantially equal on both sides of the flange  355   p.    
     As shown, the outside portion  305   o  of the plug  305  can include cutouts  305   b . The cutouts  305   b  align with cutouts in the boss  355  (not shown). The cutouts  305   b  in the plug  305  and the cutouts in the boss  355  allow passage of wiring  391 , tubing, or other structures between the plug  305  and the interior of the electric motor  301   a . For example, wiring  391  from windings on the stator  340  can be electrically connected to the plug  305  via the cutouts  305   b . In some embodiments, plug  305  can have one, two, three, four, six, seven, eight, nine or more prongs  305   a . The prongs  305   a  can include spring portions  390   b  as described above. 
     Other types of plugs  305  and sockets  290  can also be used. In some embodiments, the plug  305  and socket  290  establish connections for other services (e.g., fluid connections for cooling fluids, lubricants, hydraulics, etc.) between the motorized wheel  300  and the axle  260 . Thus, is some embodiments, the plug  305  and socket  290  are configured to establish fluid connections between the axle  260  and the electric motor  301   a.    
     A portion  3551  of the boss  355  extends from the inside of the electric motor  301   a  (in other words, extends away from the electric motor  301   a  from the inner bell end  320  and the inner bearing  325 ). The portion  3551  includes a groove  355   b  formed therein. As will be described below, the groove  355   b  can be used to retain the tire  370  onto the electric motor  301   a.    
     As shown, a tire  370  is mounted on the electric motor  301   a  such that the electric motor  301   a  drives the tire  370 . In the illustrated embodiment of  FIG. 14 , the tire  370  and electric motor  301   a  are configured such that the tire  370  mounts from the inside side of the motorized wheel  300   a  (in other words, from the same side as the connection to the axle). Accordingly, the inner bell end  320  can include cutouts that engage the dogs (similar to those shown in  FIGS. 10 and 11 ) on the tire  370 . The tire  370  can be configured as described above, and can include a groove  376  and a flange  376   a . The tire  370  is inserted onto the electric motor  301   a  until the flange  376   a  contacts the inner bell end  320 . A retainer  330  then holds the tire  370  in place. The retainer  330  can be configured as described above with reference to  FIGS. 9A and 9B , except that it is positioned on the inside of the motorized wheel  300   a.    
     The retainer  330  is held in place by a collar  337 , which presses a thrust bearing  332  into the retainer  330 . The thrust bearing  332  can be configured as described above with reference to  FIGS. 9A and 9B , except that it is positioned on the inside of the motorized wheel  300   a . The collar  337  includes a protrusion  337   p . The protrusion  337   p  engages the groove  355   b  on the boss  355  to retain the collar  337  in place. The thrust bearing  332  allows the retainer  330  to rotate with the tire  370 , while the collar  337  remains stationary. 
       FIGS. 15A and 15B  are outside and inside perspective views, respectively, of another embodiment of a motorized wheel  300   b .  FIG. 15C  is an exploded view of the motorized wheel  300   b . In some aspects, the motorized wheel  300   b  is similar to the motorized wheel  300  ( FIGS. 8A and 8B ) and the motorized wheel  300   a  ( FIG. 14 ) described above, with differences noted below. Description of some features of the motorized wheel  300   b  that are substantially similar to features of the motorized wheels  300 ,  300   a  will not be repeated here, with understanding that the previous description of those features with reference to the motorized wheels  300 ,  300   a  is applicable to the substantially similar features of the motorized wheel  300   b.    
     The motorized wheel  300   b  includes a tire  370 . The tire  370  is retained on an electric motor  301   b  (see the exploded view of  FIG. 3C ) by a cap  380 . An embodiment of the electric motor  301   b  is shown in greater detail in  FIGS. 16A-16C  and described below. The cap  380  can be a hubcap. The cap  380  can be secured to the electric motor  301   b  by fasteners  381 . The fasteners  381  can be mechanical fasteners, such as bolt fasteners, screw fasteners, clasps, locks, etc. In the illustrated embodiment, four bolts are shown, although other numbers and types of fasteners  381  are possible. The fasteners are inserted through corresponding openings  382  (see  FIG. 3C ) in the cap  380 . In some embodiments, the fasteners  381  are configured to be tightened or loosened with tool, such as a screw driver, Allen wrench, wrench, or socket. In some embodiments, the fasteners  381  are configured to be tightened or loosened by hand, such as thumb screws, for example. In some embodiments, the fasteners  381  are flush with an outside face of the cap  380  when tightened. For example, heads of the fasteners  381  can be countersunk into the outside face of the cap  380 . 
     The cap  380  can be a substantially flat disc shape as shown in  FIG. 15C , although other shapes are possible. The cap  380  includes an outside face, an inside face, and a peripheral edge  385 . The tire  370  can be configured as described above, and can include a groove  376  and a flange  376   a . When assembled, the cap  380  is received within the groove  376 . The peripheral edge  385  can contact the groove  376 . A portion of the inside face of the cap  380  contacts the flange  376   a  to retain the tire  370  onto the electric motor  301   b . The tire  370  includes dogs  377  (or similar features, such as pawls, bosses, protrusions, etc.). The dogs  377  on the tire  370  engage with corresponding cutouts  310   a  (or other similar features) on the outer bell end  310  of the electric motor  301   b . This ensures that rotation of the electric motor  301   b  drives the tire  370 . 
     In the illustrated embodiment of  FIGS. 15A-15C , the tire  370  is configured to mount onto the electric motor  301   b  from the outside side (in other words, from the side of motorized wheel  300   b  opposite the connection to the axle). In some embodiments, the tire  370  can be configured to mount from the inside side of the motorized wheel  300   b  (in other words, from the same side as the connection to the axle). In such embodiments, the cutouts  310   a  (that engage the dogs  377 ) and openings  310   b  (that receive the fasteners  381  as described below) can be formed in the inner bell end  320 . The cap  380  can include an opening configured to allow the axle to extend there through. In some embodiments, the cutouts  310   a  and openings  310   b  are included on both the inner bell end  320  and the outer bell end  310 , such that the tire  370  can be mounted from either side of the motorized wheel  300   b.    
     As seen in  FIG. 15C , the outer bell end  310  includes openings  310   b  that are configured to receive the fasteners  381 . The openings  310   b  can be aligned with the openings  382  on the cap  380 . In some embodiments, the openings  310   b  are threaded to receive a corresponding threaded portion on the fasteners  381 . Accordingly, the fasteners  381  extend through the openings  382  on the cap  380  and engage with the openings  310   b  on the outer bell end  310  to secure the cap  380  to the outer bell end  310 . The cap  380  engages the tire  370  to secure the tire  370  to the electric motor  301   b . Also shown in  FIG. 15C , the outer bearing  315  is received within a corresponding opening in the outer bell end  310  and retained by a retainer  398 . The retainer  398  can include an engagement structure  398   t  for engaging a tool useable to remove the retainer  398 . The engagement structure  398   t  can be a recess. The recess can be configured in size and shape to receive a portion of the tool. For example, as illustrated, the engagement structure  398   t  is a hex-shaped recess configured to receive an Allen wrench. 
     The inner bell end  320 , the inner bearing  325 , and a portion  3551  of the boss  355  of the electric motor  301   b  of the motorized wheel  300   b  are shown in  FIG. 15B . The inner bearing  325  and the boss  355  can be substantially similar to corresponding features of the motorized wheel  300   a , previously described. A portion  3551  of the boss  355  extends beyond the inner bell end  320  and the inner bearing  325  (away from the electric motor  301   b ). As shown, the boss  355  can include an open end. The open end of the boss  355  is configured to receive an axle  260  (shown, for example, in  FIGS. 17A-17C ) of a motorized vehicle, such that the motorized wheel  300   b  can be mounted on the axle  260 . The boss  355  will be described in more detail below with reference to  FIGS. 16A-16C  and  FIGS. 17A-17C . 
     As shown in  FIGS. 15B and 15C , bearing removal openings  310   c ,  320   c  are formed in the outer bell end  310  and inner bell end  320 , respectively, as described below, the bearing removal openings  310   c ,  320   c  are configured to facilitate removal of the bearings  315 ,  325 . 
     An embodiment of an electric motor  301   b  that can be used, for example, in the motorized wheel  300   b  described above (as well as with other motorized wheels described throughout this application or elsewhere), is shown in  FIGS. 16A-16C .  FIGS. 16A and 16B  are outside and inside perspective views, respectively, and  FIG. 16C  is a perspective cross-sectional view of the electric motor  301   b . In some aspects, the electric motor  301   b  is similar to the electric motor  301  ( FIGS. 8B and 10 ) described above, with differences noted below. Description of some features of the electric motor  301   b  that are substantially similar to features of the electric motor  301  will not be repeated here, with understanding that the previous description of those features with reference to the electric motor  301  is applicable to the substantially similar features of the electric motor  301   b.    
     With reference to  FIGS. 16A-16C , the electric motor  301   b  comprises an outer casing that is formed by an outer bell end  310 , an outer surface of a rotor  350 , and an inner bell end  320 . The outer casing surrounds a stator  340  ( FIG. 16C ). The stator  340  is mounted on a boss  355 . A portion  3551  of the boss  355  extends beyond the inner bell end  320  (away from the electric motor  301   b ). The boss  355  is configured to mount on an axle  260  that is itself mounted in a hanger  240  (see for example,  FIGS. 17A-17C ). As will be described below, the portion  3551  of the boss  355  may be received within a receiving space  258  of the hanger  240  (see  FIGS. 17A-17C ). The boss  355  is further connected to the outer bell end  310  by an outer bearing  315 . Similarly, the boss  355  is further connected to the inner bell end  320  by an inner bearing  325 . The bearings  315 ,  325  allow the outer casing of the electric motor  301   b  (in other words, the outer bell end  310 , the rotor  350 , and the inner bell end  320 ) to rotate relative to the boss  355  and the stator  340  (e.g., about the central axis  269 ). When the boss  355  is attached to the axle  260  of the motorized skateboard  100 , the electric motor  301   b  can drive the tire  370 , thus allowing the motorized wheel  300   b  to propel the motorized skateboard  100 . 
     As shown in  FIG. 16C , the outer bearing  315  is received within an opening in the outer bell end  310 . A flange  310   f  is formed on the outer bell end  310  and configured to limit inward motion of the outer bearing  315 . Thus, to install the outer bearing  315 , the outer bearing  315  can be pressed into the corresponding opening on the outer bell end  310  until it contacts the flange  310   f . A retainer  398  can be used to secure the outer bearing  315 . The retainer  398  can include a flange  398   f  that limits outward motion of the bearing  315 . Thus, when the retainer  398  is installed the bearing  315  is substantially constrained between the flange  398   f  of the retainer  398  and the flange  310   f  of the outer bell end  310 . The outer end of the boss  355  can include a threaded portion  355   e  configured to engage with a corresponding threaded portion  398   e  of the retainer  398  to secure the retainer  398  to the boss  355 . As noted previously, the retainer  398  also includes the engagement recess  398  configured to engage a tool. The tool can be used to tighten and loosen the retainer  398  to the boss  355 . In some embodiments, the retainer  398  can be tightened or loosened by hand. 
     The inner bearing  325  is received within an opening in the inner bell end  320 . A flange  320   f  is formed on the inner bell end  320  and configured to limit inward motion of the inner bearing  325 . Thus, to install the inner bearing  325 , the inner bearing  325  can be pressed into the corresponding opening on the inner bell end  320  until it contacts the flange  320   f . When the motorized wheel  300   a  is installed on the axle  260 , the inner bearing  325  can contact the hanger  240 . In some embodiments, the hanger  240  includes a flange  257  (see  FIG. 17C ) that contacts the inner bearing  325 . The hanger  240  thus limits outward motion of the inner bearing  325 . When installed, the inner bearing  325  is thus substantially constrained between the flange  320   f  of the inner bell end  320  and the flange  257  of the hanger  240 . 
     As shown in  FIGS. 16A and 16B , bearing removal openings  310   c ,  320   c  are formed in the outer bell end  310  and inner bell end  320 , respectively, as described below, the bearing removal openings  310   c ,  320   c  allow a tool to access and remove the bearings  315 ,  325 . For example, a tool can be inserted through the bearing removal openings  310   c ,  320   c  and hooked around an inside edge of the bearings  315 ,  325 . The tool can then be used to pull the bearings  315 ,  325  from their corresponding openings in the outer bell end  310  and the inner bell end  320 . In some embodiments, the outer bearing  315  can only be removed when the retainer  398  is removed. In some embodiments, the inner bearing  325  can only be removed when the motorized wheel  300   b  is removed from the axle  260 . These features allow a user to remove and replace the bearings  315 ,  325  without requiring substantial tooling, and can allow even novice users to perform the replacement themselves. 
     As shown in the cross-sectional view of  FIG. 16C , a plug  305  is positioned within the boss  355 . The plug  305  is positioned to engage and form an electrical connection (and/or other types of connections as described above) with a socket  290  positioned within the axle  260 . In some embodiments, the plug  305  is pressed or glued within the boss  355 . In some embodiments, mechanical fasteners (e.g., screws, bolts, etc.) can be used to retain the plug  305  within the boss  355 . In some embodiments, the plug  305  can be connected to the boss  355  by any suitable or known process or processes, including permanent adhesive, thermal bonds, ultrasonic bonds, spot welds, i.e., thermal weld points, a stitch or stitches, strip welds, tacks formed by crimping, and/or press fit, shrink fit, sliding fit, interference fit, and/or snap fit mechanisms, including male and female parts (e.g., tongue-and-groove corresponding parts), and the like, including any combination thereof. 
     The boss  355  can be configured to receive the plug  305 . As shown, the boss  355  can be hollow, and the plug  305  can be positioned within the hollow of the boss  355 . In the illustrated embodiment, the boss  355  includes a flange  355   p  projecting inwardly from an inner surface of the boss  355 . The flange  355   p  contacts the plug  305 . An inside portion  305   i  of the plug  305  extends beyond the flange  355   p  toward the inner side of the electric motor  301   b  (towards the inner bell end  320 ). The inside portion  305   i  of the plug  305  is spaced apart from the inner surface of the boss  355 . A receiving space  355   s  is formed between the inner surface of the boss  355 , the flange  355   p  and the inside portion  305   i  of the plug  305 . When the motorized wheel  300   b  is installed onto the axle  260 , the end of the axle  260  is received within the receiving space  355   s . The flange  355   p  limits how far the motorized wheel  300   b  can be inserted onto the axle  260 . When the motorized wheel  300   b  is installed onto the axle  260 , the inside portion  305   i  of the plug  305  extends into the axle  260  such that the plug  305  can engage the socket  290 . An outside portion  305   o  of the plug  305  can contact the inside surface of the boss  355 . In some embodiments, an inner diameter of the boss  355  on the outside of the flange  355   p  is greater than an inner diameter of the boss  355  on the inside of the flange  355   p . In some embodiments, the inner diameter of the boss  355  is substantially equal on both sides of the flange  355   p . In some embodiments, the flange  355   p  extends from the plug  305  rather than the boss  355 . 
     As shown, the outside portion  305   o  of the plug  305  can include cutouts  305   b . The cutouts  305   b  align with cutouts  355   o  in the boss  355 . The cutouts  305   b  in the plug  305  and the cutouts  355   o  in the boss  355  allow passage of wiring  391 , tubing, or other structures between the plug  305  and the interior of the electric motor  301   b . For example, wiring  391  from windings on the stator  340  can be electrically connected to the plug  305  via the cutouts  305   b ,  355   o . In some embodiments, plug  305  can have one, two, three, four, six, seven, eight, nine or more prongs  305   a . The prongs  305   a  can include spring portions  390   b  as described above. Wiring  391  (illustrated by dashed lines) or other connection can be run between the plug  305  and the interior of the electric motor  301   b . For example, as shown in  FIG. 16C , wiring  391  connects the prongs  305   a  of the plug  305  to the windings on the stator  340 . 
     Other types of plugs  305  and sockets  290  can also be used. In some embodiments, the plug  305  and socket  290  establish connections for other services (e.g., fluid connections for cooling fluids, lubricants, hydraulics, etc.) between the motorized wheel  300   b  and the axle  260 . Thus, is some embodiments, the plug  305  and socket  290  are configured to establish fluid connections between the axle  260  and the electric motor  301   b.    
     As shown in  FIGS. 16B and 16C , a portion  3551  of the boss  355  extends from the inside of the electric motor  301   b  (in other words, extends away from the electric motor  301   b  from the inner bell end  320  and the inner bearing  325 ). As shown, the portion  3551  of the boss  355  can include a groove  355   b  formed in an outside or outer surface of the portion  3551 . In some embodiments, the groove  355   b  extends in a direction perpendicular to the longitudinal axis of the boss  355 . The portion  3551  can also include a projection  355   a . The projection  355   a  extends from the inner surface of the boss  355 . In some embodiments, the projection  355   a  can be a pin, guide, boss, etc. In some embodiments, the projection  355   a  is a grub screw engaged with a hole in the boss  355 . The grub screw can be advanced such that a portion of the grub screw extends into the hollow of the boss  355 . The portion  3551  of the boss  355 , the groove  355   b , and the projection  355   a  can form a part of a quick connect system for the motorized wheel  300   b  as will be described below. 
       FIG. 17A  is a perspective view of an embodiment of a hanger and axle assembly  400 .  FIG. 17B  is a cross-sectional perspective view of the hanger and axle assembly  400 , and  FIG. 17C  is a detail view of one end of the hanger and axle assembly  400 . In some embodiments, the hanger and axle assembly  400  is configured for use with the motorized wheel  300   b  (including the electric motor  301   b ) described above ( FIGS. 15A-16C ), although use with other motorized wheels (or non-motorized wheels) is possible. The hanger and axle assembly  400  includes a hanger  240  and an axle  260 . 
     In some aspects, the hanger  240  and axle  260  of the assembly  400  are similar to the hangers  240  and axles  260  described above, with differences noted below. Description of some features of the hanger  240  and axle  260  of the assembly  400  that are substantially similar to features described above may not be repeated here, with understanding that the previous description of those features is applicable to the features of the hanger  240  and axle  260  of the assembly  400 . 
     The axle  260  is mounted to the hanger  240 . The axle  260  is received in an axle portion  244  of the hanger  240 . In some embodiments, the axle  260  may be pressed or glued into the axle portion  244 . In the illustrated embodiment, the axle  260  is hollow and includes a channel  268  formed therein. The axle  260  and the channel  268  can extend along a central axis (similar to the axis  269  shown in  FIG. 5 ). Axle openings  261  in the wall of the axle  260  are aligned with channels  247  in the hanger  240 . In the illustrated embodiment, two axle openings  261  are included that align with the two hanger channels  247 . In some embodiments, only a single channel  247  and a single axle opening  261  are included. In some embodiments, more than two channels  247  and axle openings  261  are included. 
     A pivot portion  242  of the hanger  240  allows for resilient connection between the hanger  240  and a truck  210  (for example, as shown in  FIGS. 7A and 7B ) to allow for steering, as described above. For example, the pivot portion  242  includes a pivot bushing  243 . The pivot bushing  243  provides a pivot point between the pivot portion  242  of the hanger  240  and the truck  210 . A pivot tube  246  extends through the pivot portion  242  and the pivot bushing  243 . The pivot tube  246  is hollow. In some embodiments, the pivot tube  246  is rigid. In some embodiments, the pivot tube  246  is flexible. Openings through the walls of the pivot tube  246  are connected to channels  247  that extend through the hanger  240 . In the illustrated embodiment, a first channel  247  extends through the hanger  240  on a first side of a kingpin opening  251 , and a second channel  247  extends through the hanger  240  on a second side of the kingpin opening  251 . A recess  253  may extend into the hanger  240  around the kingpin opening  251 . 
     Similar to the hangers  240  and axles  260  previously described (for example, with reference to  FIGS. 3-6A ), the hanger  240  and axle  260  of the assembly  400  are configured with a duct or passageway  201  (illustrated with dashed lines in  FIG. 17B ) for routing wiring, tubing, or other structures between an electric vehicle and sockets  290  positioned within the hollow channel  268  of the axle  260 . The duct or passageway  201  can be formed by the pivot tube  246 , channels  247  of the hanger  240 , and channel  268  of the axle  260 . 
     In some embodiments, the sockets  290  are pressed or glued into the axle  260 . In some embodiments, mechanical fasteners (e.g., bolts, screws, etc.) are used to fix the sockets  290  within the axle  260 . In some embodiments, the sockets  290  can be connected to the axle  260  by any suitable or known process or processes, including permanent adhesive, thermal bonds, ultrasonic bonds, spot welds, i.e., thermal weld points, a stitch or stitches, strip welds, tacks formed by crimping, and/or press fit, shrink fit, sliding fit, interference fit, and/or snap fit mechanisms, including male and female parts (e.g., tongue-and-groove corresponding parts), and the like, including any combination thereof. The sockets  290  are configured to mate with plugs  305  on the motorized wheels  300   b  to establish an electrical (and/or other type of) connection therebetween. The sockets  290  can be configured to allow for quick release of the motorized wheels  300   b  such that the connection between plug  305  and socket  290  is automatically made when the motorized wheels  300   b  are installed on the axle  260 . 
     The hanger and axle assembly  400  can include features for a quick connect system for installing the motorized wheels  300   b  on the axle  260 . For example, as best seen in  FIG. 17B , the hanger  240  includes a receiving space  258  surrounding the axle  260  at the locations where the axle  260  extends outwardly from the hanger  240 . The receiving space  258  is configured to receive the portion  3551  of the boss  355  when the motorized wheel  300   b  is installed onto the axle  260 , that is, when the axle  260  is inserted into the hollow of the boss  355 . A flange  257  may surround the receiving space  258 . The flange  257  can contact the inner bearing  325  when the motorized wheel  300   b  is installed on the axle  260 . The hanger  240  also includes bores  259  extending therethrough. The bores  259  partially intersect the receiving space  258 . The bores  259  are configured to receive pins  405  (rods, screws, bolts, etc.). When each pin  405  is inserted into the channels  268 , a portion  405   b  of the pin  405  is positioned within the receiving space  258  (see  FIG. 17C ). When the motorized wheel  300   b  is installed on the axle  260 , the portion  405   b  of the pin  405  is partially received within the groove  355   b  in the portion  3551  of the boss  355 . Engagement between the pin  405   b  and the groove  355   b  prevents the motorized wheel  300   b  from being removed from the axle  260  until the pin  405   b  is removed. 
     In some embodiments a portion of the bores  259  and a portion of the pins  405  are threaded, such that the pins  405  can be screwed into the bores  259 . The pins  405  can include a head portion  405   a . The head portion  405   a  can include features for engaging a tool (such as a screw driver, Allen wrench, wrench, or socket) for tightening and loosening the pins  405 . In some embodiments, the pins  405  are configured to be tightened and loosened by hand (for example, thumb screws or similar). 
     In the illustrated embodiment, each end of the axle  260  also includes a slot  267 . The slot  267  can be configured to engage with the projection  355   a  of the portion  3551  of the boss  355 . In some embodiments, engagement of the projection  355   a  with the slot  267  can ensure proper alignment between the plug  305  and the socket  290 , by, for example, ensuring alignment between the prongs  305   a  and the receptacles  290   a . This can prevent an improper connection between the plug  305  and the socket  290 . Further, engagement of the projection  355   a  with the slot  267  can ensure proper alignment between the groove  355   b  and the pin  405 . 
     Thus, the motorized wheel  300   b  can be retained on the axle  260  using the quick connect system. For example, the end of the axle  260  is inserted into the hollow of the boss  355 . To insert the axle  260  into the hollow of the boss  355 , the user can align the projection  355   a  with the slot  267 . Once aligned, the axle  260  can be slid within the hollow of the boss  355 , with the projection  355   a  sliding along the slot  267 . As the axle  260  is inserted into the boss  355 , prongs  305   a  of the plug  305  enter and establish a connection with the receptacles  290   a  of the socket. Engagement between the projection  305   a  and the slot  267  ensures that the plug  305  and socket  290  are properly aligned. As the axle  260  slides into the boss  355 , the portion  3551  of the boss  355  is received within the receiving space  258 . At the same time, the end of the axle  260  is received within receiving space  355   s  within the boss  355 . To retain the motorized wheel  300   b  on the axle  260 , the pin  405  is inserted into the bore  259 . The pin  405  engages the groove  355   b . Engagement between the projection  355   a  and the slot  267  ensures that the pin  405  and the groove  355   b  are properly aligned. The pin  405  can be tightened to secure the pin  405 , thus retaining the motorized wheel  300   b  on the axle. 
     To remove the motorized wheel  300   b , the pin  405  is loosened and removed. The motorized wheel  300   b  can then slide off the axle  260 . 
     The color, embellishments, and exterior decoration of the motorized wheel assemblies and motorized wheels are not relevant to the function, and may be of any style the market desires. 
     Although, shown with the example of the skateboard  100 , the motorized wheel assemblies and motorized wheels described herein can be also useful for other weight and/or space sensitive wheeled sports applications, including road luge, roller skates, inline skates, grass skiing, and small wheeled scooters, among others types of vehicles. As used herein, a vehicle is a platform which may be used for the transport of goods and/or people. Small wheeled vehicles can include electric warehouse and factory cars, buggies, autonomous vehicles, skateboards, scooters, roller skates and street luge. Vehicles may be unpowered, for example, as in the case of most skateboards, roller skates and street luge, or may have one or more wheels driven by electric motors. Powered vehicles can include electric vehicles, where the power supply is usually a battery, and can also include vehicles such as slot cars, dodgem cars, tracked vehicles and trams, where a sliding contact, often a pantograph, is used to connect the vehicle to a fixed power supply such as overhead electrified mesh, wire or rails. The motorized skateboard  100  and/or motorized wheel assemblies and motorized wheels may have beneficial application in last leg commuting vehicles because it is both powered and lightweight. A last leg commuting vehicle is one that can be hand carried, or slung from a backpack, then used to transport the user from a train, plane, tram, or other public transport system, to their final destination. 
     It is contemplated that various combinations or sub combinations of the specific features and aspects of the embodiments disclosed above may be made and still fall within one or more of the inventions. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an embodiment can be used in all other embodiments set forth herein. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above. Moreover, while the inventions are susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the inventions are not to be limited to the particular forms or methods disclosed, but to the contrary, the inventions are to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various embodiments described and the appended claims. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “passing a suspension line through the base of the tongue” include “instructing the passing of a suspension line through the base of the tongue.” It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like includes the number recited. Numbers preceded by a term such as “approximately,” “about,” and “substantially” as used herein include the recited numbers, and also represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. Features of embodiments disclosed herein preceded by a term such as “approximately,” “about,” and “substantially” as used herein represent the feature with some variability that still performs a desired function or achieves a desired result for that feature. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein, are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced embodiment recitation is intended, such an intent will be explicitly recited in the embodiment, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the disclosure may contain usage of the introductory phrases “at least one” and “one or more” to introduce embodiment recitations. However, the use of such phrases should not be construed to imply that the introduction of an embodiment recitation by the indefinite articles “a” or “an” limits any particular embodiment containing such introduced embodiment recitation to embodiments containing only one such recitation, even when the same embodiment includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce embodiment recitations. In addition, even if a specific number of an introduced embodiment recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, embodiments, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     Although the present subject matter has been described herein in terms of certain embodiments, and certain exemplary methods, it is to be understood that the scope of the subject matter is not to be limited thereby. Instead, the Applicant intends that variations on the methods and materials disclosed herein which are apparent to those of skill in the art will fall within the scope of the disclosed subject matter.