WO2017093746A1

WO2017093746A1 - Wheel connection arrangement

Info

Publication number: WO2017093746A1
Application number: PCT/GB2016/053788
Authority: WO
Inventors: Timur Artemev
Original assignee: Timur Artemev
Priority date: 2015-12-01
Filing date: 2016-12-01
Publication date: 2017-06-08
Also published as: GB2544987A; GB201521222D0

Abstract

A wheel connection arrangement (100) adapted to couple a wheel (105) to a chassis (110) is presented. The wheel connection arrangement (100) comprises at least one portion that is adapted to rotate about an axle (130) of the wheel connection arrangement (100), the axle (130) of the wheel connection arrangement (100) being offset from the axis (135) of rotation of the wheel (105). The wheel connection arrangement (100) is adapted to be movable between first and second positions so as to move the chassis (110) relative to the axis (135) of rotation of the wheel axle (105).

Description

WHEEL CONNECTION ARRANGEMENT

Field of Invention

The present invention relates to a wheel connection arrangement adapted to couple a wheel to a chassis and to powered transportation devices employing such an arrangement. Background to the Invention

Powered transportation devices for transporting loads, such as packages or individuals, are widely known. Such vehicles typically employ one or more wheels connected to chassis.

The market for powered transportation devices may be strongly dependent on factors such as weight, complexity, convenience, comfort of the device, and such factors may influence the cost of manufacturing of the device. There is therefore always a need to develop new and/or alternative features that may have an impact on one or more of the abovementioned factors. Further, it is preferable to develop such new and/or alternative features in a way that reduces production cost and/or complexity.

Summary of the invention

According to a first aspect of the invention, there is provided wheel connection arrangement adapted to couple a wheel to a chassis, wherein the wheel connection arrangement comprises at least one portion that is adapted to rotate about an axle of the wheel connection arrangement, the axle of the wheel connection arrangement being offset from the axis of rotation of the wheel, and wherein the wheel connection arrangement is adapted to be movable between first and second positions so as to move the chassis relative to the axis of rotation of the wheel axle. Thus, embodiments propose a simple wheel connection arrangement that may enable the chassis to be moved relative to the wheel axle. For example, this may enable the chassis to be raised or lowered relative to the wheel axle. Such movement of the chassis may provide a suspension arrangement that can be modified, controlled or altered according to requirements.

By way of example, embodiments may employ an actuator which is adapted to move the arrangement between the first and second positions. The actuator may therefore be used to actively alter or change a relative position of the chassis. In this way, the relative position of the wheel axle and chassis may be changed, and this may be done in a manner which is responsive to a control signal. The wheel connection arrangement may therefore be actively controlled or modified so as to maintain or achieve a desired characteristic or property. For example, a vertical position of the chassis may be maintained as the wheel goes over a bump, by moving the wheel connection arrangement to reduce a vertical distance between chassis and the wheel axle when the goes over the bump for example.

Operation of the actuator may, for example, be adapted to be in response to a control signal. The wheel connection arrangement may therefore be controlled by user or control system proving such a control signal. The control signal may therefore be provided by a user (via an input interface for example) or by a control system (which generates the control signal based on detected events, conditions, parameters, and/or values.

Embodiments may further comprise a control system adapted to generate the control signal, and the control signal may be adapted to control the actuator to maintain or manage an orientation or relative position of the chassis.

By way of example, the control system may comprise a processing unit adapted to process signals in accordance with a control algorithm to generate at least one of: the control signal and the drive signal. The control algorithm may be adapted to process signals from at least one of: a drive arrangement adapted to drive rotation of the wheel; an accelerometer system adapted to measure acceleration in at least one axis; a gyroscopic system; a speed sensing system adapted to detect a speed in at least one axis; a terrain sensing system adapted to detect one or more properties of a terrain; a sensing system adapted to detect a rotational parameter of the wheel, such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel; a yo-yo detection system adapted to detect the presence of a yo-yo-ing effect of the wheel; a load sensing system; an input interface adapted to receive an input from a user; a tyre pressure detection system.

Further, the control system may be adapted to generate a drive signal for controlling a rotational parameter of the wheel. The control system may comprise a processing unit adapted to process signals in accordance with a drive algorithm to generate the drive signal. For example, the drive algorithm may be adapted to process signals from at least one of: a drive arrangement adapted to drive rotation of the wheel; an accelerometer system adapted to measure acceleration in at least one axis; a gyroscopic system; a speed sensing system adapted to detect a speed in at least one axis; a terrain sensing system adapted to detect one or more properties of a terrain; a sensing system adapted to detect a rotational parameter of the wheel, such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel; a yo-yo detection system adapted to detect the presence of a yo-yo-ing effect of the wheel; a load sensing system; an input interface adapted to receive an input from a user; a tyre pressure detection system.

Embodiments may therefore leverage advantages provided by the development of micro-controller or processor-based system which provide for more complex or advanced control methodologies. By taking advantage of the capabilities of advanced electronic of computer-based control system, embodiments may enable the use of relatively simple (e.g. less complex) wheel connection/suspension arrangement, whilst still providing for complex control of the chassis position (relative to the wheel axle). For example, by controlling the position of the wheel connection arrangement (to control the relative position of the chassis) and by also controlling a wheel drive arrangement (to control a rotational parameter of the wheel for example), complex and/or accurate control of the wheel and/or chassis can be achieved. This may have significant and important benefits for factors of a wheeled device including weight, convenience, usability, complexity, cost, ride ability, or comfort for example.

Embodiments may further comprise a locking arrangement adapted to lock the wheel connection arrangement in at least one position so as to substantially prevent movement of the chassis relative to the axis of rotation of the wheel axle. Relative movement of the chassis and the wheel axle may therefore be prevented unless deemed appropriate or allowable. User preference for ride height may therefore be catered for, for example.

The actuator may comprise a motor and gear, the motor being adapted to rotate the gear in response to the control signal, and the gear being adapted to translate rotation of the gear into movement of the arrangement between the first and second positions. The gear may comprise an arrangement of multiple gears, a gear train, or gear box for example.

The actuator may comprise a pneumatic or hydraulic actuator adapted to move between a contracted and extended configuration to move the arrangement between the first and second positions.

The actuator may comprise a rotary vane actuator, and the at least one portion may comprise, or may be coupled to, a rotary vane.

Thus, it will be understood that embodiments may further comprise an actuation arrangement that is adapt to alter a position of the wheel connection arrangement, and the actuation arrangement may, for example, operate in response to a control or activation signal. The activation signal may be based on one or more operating characteristics of a vehicle employing the wheel connection arrangement for example.

The wheel connection arrangement may be further adapted to maintain the chassis in a substantially constant orientation when the arrangement moves between the first and second position.

In embodiments, the wheel connection arrangement may be moved between two positions so as to alter a centre of gravity. Such movement of the wheel connection arrangement may be permitted when the coupled wheel(s) rapidly or suddenly accelerates or decelerates, for example due to the wheel(s) hitting a small bump or obstacle. Embodiments may therefore transfer a linear momentum (e.g. in the forward or backward direction) of the wheel(s) into movement of the chassis when the wheel hits a bump or obstacle. Thus, at least some of the forward running momentum of the wheel may be translated into relative movement of the chassis via the wheel connection arrangement so that the chassis moves away from a rest (e.g. first) position. Such movement may result in the chassis' centre of gravity moving. Movement of the centre of gravity may help, for example, towards propelling and/or lifting the chassis over an obstacle and thus reduce an amount of torque/power required of a drive arrangement. Embodiments may therefore reduce or alleviate power or torque requirements of a drive arrangement. Such reduction of required torque, for example, may enable a smaller, lighter and/or cheaper drive (e.g. motor) to be employed, thus reducing the cost and/or weight.

Embodiments may also help improve safety by reducing (e.g. damping) the effect of hitting a sudden acceleration or deceleration (caused by hitting a bump or obstacle for instance). For example, a sudden deceleration of the wheel may not be mirrored by the chassis. Instead, movement of the chassis relative to the rotational axis of the wheel may mean that a load or user supported by the chassis experiences more gradual acceleration/deceleration.

Embodiments may thus employ the realisation that traveling momentum of a load may be used to alter a centre of gravity, and the change of centre of gravity may help to pull a chassis forwards and upwards over a curb for example. It may be proposed to convert or translate linear momentum of the device/user into movement of a centre of gravity by moving the chassis relative to the rotational axis of the wheel axle when the wheel suddenly decelerates (for example, due to hitting a bump, small step, obstacle, etc.). The adjustment of the centre of gravity may help to overcome the bump or obstacle so that the amount of torque required by a drive arrangement may be reduced when compared to conventional devices hitting the same bump or obstacle. Embodiments may therefore provide a wheel connection arrangement that enables the use of a smaller, lighter and/or cheaper drive arrangement.

Movement of the chassis relative to the wheel axle may be used to alter or manipulate the centre of gravity of the loaded chassis, and the change of centre of gravity may help to pull the device forwards and upwards over a curb for example. In other embodiments, change of centre of gravity of the loaded chassis may help to balance the overall device. Adjustment of the centre of gravity of the loaded chassis may alter the centre of gravity of the overall loaded device (i.e. the centre of gravity of the device and its load) so that the stability of the device is improved.

Embodiments may comprise an orientation arrangement adapted to maintain the chassis in a substantially constant orientation when the wheel connection arrangement moves between the first and second position. Embodiments may therefore maintain an upper (user/load-supporting) surface of the chassis in a substantially horizontal configuration so that it does not tilt when moving relative to the wheel axle. This may help to prevent the chassis (or its load) from losing its balance, and may therefore improve the safety and/or usability of the device. By way of example, the orientation arrangement may comprise a rotatable mount (or secondary axle) upon which the chassis is supported such that the chassis is adapted to rotate relative to the wheel connection arrangement. Embodiments may therefore employ a simple and/or cheap arrangement for enabling the chassis to maintain a constant orientation.

Embodiments may be adapted to restrict or prevent movement of the wheel connection arrangement when the acceleration or deceleration of the wheel axle does not exceed a predetermined threshold value. In this way, embodiments may prevent the wheel connection arrangement from being free to move between different positions at all times. Instead, embodiments may be adapted such that only acceleration or deceleration of the coupled wheel axle or coupled chassis exceeding a certain threshold amount results in movement of the wheel connection arrangement between first and second positions. For such a purpose, a braking or movement-limiting arrangement may be employed. This may help to improve the stability, safety and/or usability of the wheel connection arrangement.

An embodiment may be adapted to restrict movement of the wheel connection arrangement to within a predetermined allowable range of positions (e.g. distances or angles from a rest position). For example, to restrict movement to within an allowable amount, the wheel connection arrangement may adapted to contact a stopper or arresting element when at an end of the allowable range of offset distances or angles. For instance, the wheel connection arrangement may comprise a stopper or brake that is adapted to restrict further movement by contacting (e.g. bearing against) a part of the wheel connection arrangement.

According to another aspect of the invention, there is provided a transportation device comprising: a wheel; a chassis for supporting a load for transportation; a drive arrangement adapted to drive rotation of the wheel; and a wheel connection arrangement according to any preceding claim, wherein the chassis is coupled to the wheel via the wheel connection arrangement.

The wheel connection arrangement may be adapted to move between the first and second positions in response to a control signal. The control signal may, for example, be based on at least one of: one or more operating characteristics of the transportation device; and a signal from an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the transportation device.

The transportation device may comprise a balance control system adapted to maintain balance of the transportation device in at least one axis (such as in the fore-aft direction, of in the lateral direction for example).

The load for transportation may comprise a package. Embodiments may therefore provide a powered transportation device for transporting package or items of stock in an automated manner.

Alternatively, the load for transportation may comprise a person. Embodiments may therefore provide a powered transportation device for transporting a person or individual.

The wheel may be hubless. Also the drive arrangement may comprise a direct drive motor. Alternatively, the drive arrangement may be positioned inside the void defined by the inner rim of the hubless wheel.

The transportation device may be a self-balancing unicycle device having a single primary wheel adapted to be driven by said motor. Embodiments may therefore provide a powered self-balancing unicycle device that employs a suspension arrangement that can be actively or dynamically controlled to alter the ride characteristics of the device. Such control may be complex in nature (via the use of a microprocessor for example) yet employ a relatively simple wheel connection arrangement. This may enable the device to employ a cheaper, smaller or more efficient drive arrangement compared to a convention device. Further, in an embodiment, the wheel may be hubless and the device may further comprise a direct drive motor. Other embodiments may comprise a drive arrangement which is positioned inside the void defined by the inner rim of the hubless wheel.

In another embodiment, the transportation device may comprise a pair of wheels. Also, the chassis may be positioned between the pair of wheels. For example, embodiments may include powered self-balancing two-wheeled transportation devices having a support platform on a chassis situated between the two wheels (so that a user or load is intended to be positioned between the two-wheels for example). In such embodiments, there may be provided a single support platform for supporting the user or load (between the wheels), and a control system may be provided which is adapted to control relative movement of the chassis and the wheel axle (via controlled movement of the wheel connection arrangement) and further adapted to control the drive arrangement in accordance with simultaneous control of the wheel connection arrangement.

Embodiments may therefore be adapted to cater for various configurations of support platforms, such as: single support platforms that extend through the device so as to protrude from either side; or separate support platforms (provided for each foot of a user, for example) situated on opposite sides of the device.

Embodiments may also help improve device safety by reducing (e.g. damping) the effect of hitting a sudden bump or obstacle, etc. For example, a sudden deceleration of the wheel (or wheel axle) may not be mirrored by the chassis. Instead, relative movement of the wheel axle to the chassis may mean that the transported load experiences less or more gradual deceleration.

For the avoidance of doubt, reference to a single, primary wheel should be taken to mean the generally circular unit that is adapted to rotate about a longitudinal axis of an axle to propel the device in a direction during use. The wheel axle may be adapted to be stationary while the wheel rotates about the wheel axle. Alternatively, the wheel axle may be adapted to rotate about its longitudinal axis to rotate a wheel about the same axis. The single wheel may be formed from one or more tyres and/or hubs that are coupled together (via a differential, for example). For example, an embodiment may comprise a single hubbed or hubless wheel having a single rim with a plurality of separate tyres fitted thereon. Alternatively, an embodiment may comprise a single hubbed or hubless wheel formed from a plurality of rims (each having a respective tyre fitted thereon), wherein the plurality of rims are coupled together via a differential bearing arrangement.

Embodiments may provide a controllable suspension arrangement or chassis to wheel coupling that can be actively or dynamically controlled to alter a relative positioning of a wheel and chassis. Such control of relative positioning of the wheel and chassis may enable controlled alteration of ride and/or driving characteristics. Also, control of the relative positioning may be implemented simultaneously and in conjunction with control of a drive arrangement of the wheel so as to enable complex, accurate and/or dynamic control of wheel rotational parameters (such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel. Also, a centre of gravity may be adjusted in a manner which helps to overcome a bump or obstacle for example.

Brief description of the drawings

An example of the invention will now be described with reference to the accompanying diagrams, in which:

FIGS. 1 -3 show one embodiment of a wheel connection arrangement; FIG. 4 shows another embodiment of a wheel connection arrangement;

FIG. 5 shows another embodiment of a wheel connection arrangement; FIG. 6 shows another embodiment of a wheel connection arrangement; FIG. 7 shows another embodiment of a wheel connection arrangement; and

FIG 8 shows an embodiment of a drive arrangement. Detailed description

Proposed is a wheel connection arrangement for coupling a chassis to a wheel axle and for enabling movement of the chassis relative to the wheel axle. By allowing movement of the chassis relative to the wheel axle (which may normally be prevented in conventional transportation devices) whilst also controlling its degree, embodiments may enable active control of the relative position of the chassis, and such alteration may be implemented in response to user requirements and/or to maintain desired arrangement characteristics or properties. Such relative movement of the chassis may help, for example, towards propelling and/or lifting the chassis over an obstacle and thus reduce an amount of torque/power required of a drive arrangement.

The proposed concept(s) may thus be employed in various types of powered transportation devices that employ at least one wheel (rotating about or with an axle) driven by a drive arrangement. For instance, embodiments may provide a self-balancing transportation device having one, two, or more wheels. Further, such self-balancing transportation devices may be adapted to be automated (e.g. for transporting package or items in an automated manner).

The term vertical, as used herein, means substantially orthogonal to the generally horizontal ground surface upon which a transportation device may travel. The term lateral, as used herein, means substantially parallel to the generally horizontal ground surface. Also, terms describing positioning or location (such as above, below, top, bottom, etc.) are to be construed in conjunction with the orientation of the structures illustrated in the diagrams.

The diagrams are purely schematic and it should therefore be understood that the dimensions of features are not drawn to scale. Accordingly, the illustrated thickness of any of the components or features should not be taken as limiting. For example, a first component drawn as being thicker than a second component may, in practice, be thinner than the second component.

FIGS. 1 -3 show one embodiment of a wheel connection arrangement. FIGS. 1A and 1 B show the wheel connection arrangement in a first position, FIG. 1A being a side elevation and FIG. 1 B being a plan view. FIGS. 2A and 2B show the wheel connection arrangement in a second position, FIG. 2A being a side elevation and FIG. 2B being a plan view. FIGS. 3A and 3B show the wheel connection arrangement in a third position, FIG. 3A being a side elevation and FIG. 3B being a plan view. In the first to third positions a chassis coupled to the wheel connection arrangement has a different position relative to the axis of the wheel.

Referring to FIG. 1A, the wheel connection arrangement 100 is adapted to couple the wheel 105 to the chassis 1 10. Here, the wheel connection arrangement is coupled to the wheel axle 1 15 (about which the wheel rotates on bearings 120).

The wheel connection arrangement 100 comprises a rigid arm 125 that is adapted to rotate about a supplementary axle 130 of the wheel connection arrangement 100. The supplementary axle 130 of the wheel connection arrangement is offset (laterally and vertically) from the axis of rotation 135 of the wheel (and the wheel axle).

The wheel connection arrangement 100 is adapted to be movable between the first position (depicted in FIGS. 1A and 1 B), the second position (depicted in FIGS. 2A and 2B), and the third position (depicted in FIGS. 3A and 3B), so as to move the chassis 1 10 relative to the axis of rotation 135 of the wheel axle 1 15.

To move the arrangement 100 between the first, second and third positions, an actuator 140 is employed. Here, the actuator comprises a pneumatic or hydraulic actuator 140 which is adapted to move between a contracted configuration (depicted in FIGS. 3A and 3B) and an extended configuration (depicted in FIGS. 2A and 2B) so as to move the arrangement between the third and second positions, respectively. As can be seen from the illustrations of FIGS. 1 -3, movement of the arrangement between the first, second and third positions results in corresponding movement of the chassis 1 10 relative to the axis of rotation 135 of the wheel axle 1 15.

In this embodiment, the actuator 140 is adapted to operate in response to a control signal. A control system (such as microprocessor and associated sensor/detector arrangement) may be employed to generate the control signal. By way of example, the control signal may be generated by the control system so as to control the actuator to maintain or manage an orientation or position of the chassis. For instance, the control system of this embodiment may have a processing unit which is adapted to process signals in accordance with a control algorithm to generate the control signal. The signals processed may comprise signals from: a drive arrangement adapted to drive rotation of the wheel; an accelerometer system adapted to measure acceleration in at least one axis; a gyroscopic system; a speed sensing system adapted to detect a speed in at least one axis; a terrain sensing system adapted to detect one or more properties of a terrain; a sensing system adapted to detect a rotational parameter of the wheel, such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel; a yo-yo detection system adapted to detect the presence of a yo-yo-ing effect of the wheel; a load sensing system; an input interface adapted to receive an input from a user; and/or a tyre pressure detection system.

Also, the same, or another, control system may be employed to generate a drive signal for controlling a rotational parameter of the wheel. Such a control system may, for example, process signals in accordance with a drive algorithm to generate the drive signal. The drive algorithm may, for instance, process signals from: a drive arrangement adapted to drive rotation of the wheel; an accelerometer system adapted to measure acceleration in at least one axis; a gyroscopic system; a speed sensing system adapted to detect a speed in at least one axis; a terrain sensing system adapted to detect one or more properties of a terrain; a sensing system adapted to detect a rotational parameter of the wheel, such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel; a yo-yo detection system adapted to detect the presence of a yo-yo-ing effect of the wheel; a load sensing system; an input interface adapted to receive an input from a user; and/or a tyre pressure detection system.

It will therefore be appreciated that the wheel connection arrangement

1 10 may provide a controllable chassis to wheel coupling arrangement that can be actively or dynamically controlled (using the actuator 140) to alter a relative positioning of the wheel 105 and chassis 1 10. Such control of relative positioning of the wheel and chassis may enable controlled alteration of ride and/or driving characteristics of the wheel 105. Also, control of the relative positioning may be implemented simultaneously and in conjunction with control of a drive arrangement of the wheel 105 so as to enable complex, accurate and/or dynamic control of wheel rotational parameters (such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel).

It is also noted that the actuator 140 is rotatably (or pivotally) coupled to the chassis 1 10 so that the chassis 1 10 may be maintained in a substantially constant orientation (e.g. horizontal) when the wheel connection arrangement moves between the first, second and third positions.

FIG. 4 shows another embodiment of a wheel connection arrangement. FIG. 4A shows the wheel connection arrangement in a first position. FIG. 4B shows the wheel connection arrangement in a second position. FIG. 4C shows the wheel connection arrangement in a third position. In the first to third positions, a chassis coupled to the wheel connection arrangement has a different position relative to the rotational axis 25 of the wheel.

The wheel connection arrangement 200 is adapted to couple the wheel 205 to a chassis (not shown). Here, the wheel connection arrangement is coupled to the inner rim of a hollow wheel axle 215 (about which the wheel 205 rotates on bearings 220).

The wheel connection arrangement 200 comprises a rigid arm 225 that is pivotally coupled to the inner rim of the wheel axle 215. Thus, the rigid arm 225 is pivotally coupled to the inner rim of the wheel axle 215 at a coupling position that is offset from the rotational axis 25 of the wheel 205.

The wheel connection arrangement 200 is adapted to be movable between the first position (depicted in FIG. 4A), the second position (depicted in FIG. 4B), and the third position (depicted in FIG. 4C), so as to move the chassis relative to the axis of rotation 25 of the wheel axle 215.

To move the arrangement 200 between the first, second and third positions, an electromagnetic actuator 240 is employed. Here, the actuator 240 comprises a curved array 240A of magnets situated adjacent a set of coils/windings 240B provide at the distal end of the rigid arm 225. Controlled application of electrical current in the coils/windings is adapted to cause movement of the distal end of the rigid arm 225 along the curved array 240A of magnets so as to result in movement of the rigid arm relative to the the axis of rotation 25 of the wheel axle 215 which, in turn, moves the arrangement between the first, second and third positions. As can be seen from the illustrations of FIGS. 4A-4C, movement of the arrangement between the first, second and third positions results in corresponding movement of the chassis (which is coupled to the rigid arm) relative to the axis of rotation 25 of the wheel axle 215.

Thus, the wheel connection arrangement 200 may be for altering a position of the wheel axle 215 relative to a chassis. The wheel connection arrangement of FIG. 4 comprises a rigid bar (which is adapted to support the chassis) movably coupled to the wheel axle 215 at an axle coupling position. Here, the axle coupling position is offset from the axis 25 of rotation of the wheel axle 215. The wheel connection arrangement of FIG. 4 also comprises an actuator adapted to move the rigid bar relative to the wheel axle 215 so as to move the coupled chassis relative to the axis 25 of rotation of the wheel axle 215.

Here, the wheel axle 215 comprises a hollow cylinder and the rigid bar 225 is movably (e.g. pivotally) coupled to the inner rim of the hollow cylinder such that the axle coupling position is positioned inside the hollow cylinder (e.g. on or adjacent the inner rim of the hollow cylinder).

Thus, in this embodiment, the wheel connection arrangement is adapted to fit inside the wheel axle 215. The actuator 240 is thus contained within the wheel axle 215. The actuator 240 may then rotate the rigid bar 225 relative to the wheel axle 215, and this may be done in response to a control signal.

Also, from FIGS. 4A-4C, it will be seen that the rigid bar is adapted to substantially maintain a predetermined (e.g. substantially horizontal) orientation when moved relative to the wheel axle 215 by the actuator 240.

FIGS. 5 shows another embodiment of a wheel connection arrangement. FIG. 5A shows the wheel connection arrangement in a first position. FIG. 5B shows the wheel connection arrangement in a second position. FIG. 5C shows the wheel connection arrangement in a third position. In the first to third positions, a chassis coupled to the wheel connection arrangement has a different position relative to the rotational axis 25 of the wheel 305. The wheel connection arrangement 300 is adapted to couple the wheel 305 to a chassis (not shown). Here, the wheel connection arrangement is coupled to the inner rim of a hollow wheel axle 315 (about which the wheel 305 rotates on bearings 320).

The wheel connection arrangement 300 comprises a rotary vane actuator 340 and wherein a chassis is coupled to a rotary vane 340A of the rotary vane actuator 340. Thus, the rotary vane 340A is pivotally coupled to the inside of the rotary vane actuator 340. The rotary vane actuator 340 is fixed to the inner surface of the wheel axle 315 at a coupling position that is offset from the rotational axis 25 of the wheel 305.

The wheel connection arrangement 300 is adapted to be movable between the first position (depicted in FIG. 5A), the second position (depicted in FIG. 5B), and the third position (depicted in FIG. 5C), so as to move the chassis relative to the axis of rotation 25 of the wheel axle 315.

To move the arrangement 300 between the first, second and third positions, a hydraulic or pneumatic rotary vane actuator 340 is employed. Here, the rotary vane actuator 340 comprises a rotary vane 340A situated inside a sealed chamber 350. Controlled application of hydraulic or pneumatic forces to either side of the rotary vane 340A is adapted to cause rotational movement of the rotary vane 340A about its axis of rotation 360 so as to result in movement of the rotary vane 340A relative to the axis of rotation 25 of the wheel axle 315 which, in turn, moves the arrangement between the first, second and third positions. As can be seen from the illustrations of FIGS. 5A-5C, movement of the arrangement between the first, second and third positions results in corresponding movement of the chassis (which is coupled to the rotary vane actuator) relative to the axis of rotation 25 of the wheel axle 315.

Thus, the wheel connection arrangement 300 may be for altering a position of the wheel axle 315 relative to a chassis (coupled to the rotary vane).

Again, in this embodiment, the wheel connection arrangement is adapted to fit inside the wheel axle 315. The actuator 340 is thus contained within the wheel axle 315. The actuator 340 may then cause movement of a coupled chassis relative to the wheel axle 315, and this may be done in response to a control signal.

FIG. 6 shows yet another embodiment of a wheel connection arrangement. FIG. 6A shows the wheel connection arrangement in a first position. FIG. 6B shows the wheel connection arrangement in a second position. FIG. 6C shows the wheel connection arrangement in a third position. In the first to third positions, a chassis coupled to the wheel connection arrangement has a different position relative to the rotational axis 25 of the wheel 405.

The wheel connection arrangement 400 is adapted to couple the wheel

405 to a chassis (not shown). Here, the wheel connection arrangement is coupled to the inner rim of a hollow wheel axle 415 (about which the wheel 405 rotates on bearings 420).

The wheel connection arrangement 400 comprises a pneumatic or hydraulic actuator 440 adapted to move between a contracted and extended configuration, wherein the pneumatic or hydraulic actuator 440 is coupled to the wheel axle 415. Here, the pneumatic or hydraulic actuator 440 is pivotally coupled to the inner rim of the hollow cylindrical wheel axle 415. The actuator 440 is fixed to the inner surface of the wheel axle 415 at a coupling position that is offset from the rotational axis 25 of the wheel 405.

The wheel connection arrangement 400 is adapted to be movable between the first position (depicted in FIG. 6A), the second position (depicted in FIG. 6B), and the third position (depicted in FIG. 6C), so as to move the chassis relative to the axis of rotation 25 of the wheel axle 415.

To move the arrangement 400 between the first, second and third positions, a hydraulic or pneumatic actuator 440 is employed. Controlled application of hydraulic or pneumatic forces either expands or contracts the actuator 440 to cause rotational movement of the actuator 440 relative to the axis of rotation 25 of the wheel axle 415 which, in turn, moves the arrangement between the first, second and third positions. As can be seen from the illustrations of FIGS. 6A-6C, movement of the arrangement between the first, second and third positions may result in corresponding movement of the chassis relative to the axis of rotation 25 of the wheel axle 415. Thus, the wheel connection arrangement 400 may be for altering a position of the wheel axle 415 relative to a chassis (coupled to the actuator 440).

Again, in this embodiment, the wheel connection arrangement is adapted to fit inside the wheel axle 415. The actuator 440 is thus contained within the wheel axle 415. The actuator 440 may then cause movement of a coupled chassis relative to the wheel axle 415, and this may be implemented in response to a control signal.

FIG. 7 shows yet another embodiment of a wheel connection arrangement. FIG. 7A shows the wheel connection arrangement in a first position. FIG. 7B shows the wheel connection arrangement in a second position. FIG. 7C shows the wheel connection arrangement in a third position. In the first to third positions, a chassis coupled to the wheel connection arrangement has a different position relative to the rotational axis 25 of the wheel 505.

The wheel connection arrangement 500 is adapted to couple the wheel 505 to a chassis (not shown). Here, the wheel connection arrangement is coupled to the inner rim of a hollow wheel axle 515 (about which the wheel 505 rotates on bearings 520).

The wheel connection arrangement 500 comprises the actuator comprises a motor 540 and gear 545, the motor 540 being adapted to rotate the gear 545, and the gear 545 being adapted to mesh with a portion 560 of the wheel axle 515 such that rotation of the gear is translated to movement of the wheel axle 515. Here, the motor 540 and gear 545 are pivotally coupled to the inner rim of the hollow cylindrical wheel axle 515 via a rigid connecting rod 570. The rigid connecting rod 570 is pivotally mounted to the inner surface of the wheel axle 515 at a coupling position that is offset from the rotational axis 25 of the wheel 505. The motor 540 and gear 545 are provided on the distal end of the rigid connecting rod 570 so that they are provided a position that is offset from the rotational axis 25 of the wheel 505

The wheel connection arrangement 500 is adapted to be movable between the first position (depicted in FIG. 7A), the second position (depicted in FIG. 7B), and the third position (depicted in FIG. 7C), so as to move the chassis relative to the axis of rotation 25 of the wheel axle 515. To move the arrangement 500 between the first, second and third positions, a motor 540 and gear 545 is employed. Controlled rotation of the gear 545, combined with the meshing of the gear 545 with a portion 560 of the wheel axle 515 cause rotational movement of the rigid connecting rod 570 relative to the wheel axle 515 which, in turn, moves the arrangement between the first, second and third positions. As can be seen from the illustrations of FIGS. 7A-7C, movement of the arrangement between the first, second and third positions may result in corresponding movement of the chassis relative to the axis of rotation 25 of the wheel axle 515.

Thus, the wheel connection arrangement 500 may be for altering a position of the wheel axle 515 relative to a chassis (coupled to the rigid connecting rod 570 for example).

Again, in this embodiment, the wheel connection arrangement is adapted to fit inside the wheel axle 515. The motor 540 and gear 545 are thus contained within the wheel axle 515.

Figures 8A and 8B illustrate an operation of a drive arrangement according to an embodiment. Here, a first gearing portion 820 of the wheel 810 is coupled to a second gearing portion 830 of a drive arrangement, the second gearing portion being a complimentary shape to the first gearing portion 820. Thus rotation of the second gearing portion 830 causes a rotation of the first gearing portion 820 (and thereby the wheel 810).

By way of example, the gearing ratio of the second portion 830 to the first portion 820 may be 30: 1 , 20: 1 or 5: 1 .

A connection portion 835 of the drive arrangement may connect a motor 850 (e.g. an electric motor) to the second gearing portion 830 of the drive arrangement, to thereby enable the motor 850 to control rotation of the second gearing portion. The connection portion 835 may be comprised as an aspect of the motor 850. In this way, the motor may thereby provide an individual drive to the wheel 810, via the first 820 and second 830 gearing portions.

Thus the connection portion 835 and the second gearing portion 830 may together act as a drive shaft for the wheel 810.

Thus, rather than a drive arrangement comprising a direct drive motor wholly positioned within the void defined by an inner rim, a drive arrangement may be positioned externally to the wheel, and be adapted to drive the wheel via a gearing arrangement. Other examples may include a belt or other coupling connection.

A gearing arrangement 840 may be provided to couple the output of the motor 850 (e.g. an output pin of the motor 850) to the connection portion 835 of the drive arrangement. By way of example only, the gearing arrangement 840 may comprise a transmission adapted to selectably provide different gearing ratios between the motor 850 and the connection portion 835.

Such an embodiment of a drive arrangement provides a high degree of control over the driving of the wheel 810, with an optimal level of torque. Such embodiments also reduce the weight of the wheel, as the drive arrangement need not be positioned within the wheel.

The embodiment may comprise a wheel connection arrangement (not shown) such as those previously described. In at least one embodiment, the position of the second gearing portion 830 relative to the first gearing portion 820 may be altered, for example, based on a position of a chassis coupled to the wheel 810.

In at least one embodiment, the wheel connection arrangement comprises the drive arrangement illustrated by Figures 8A and 8B, such that a position of the second gearing portion 830 relative to the wheel 810 defines a position of the chassis (not shown) relative to the wheel.

In at least one example, illustrated in Figures 8C and 8D, the drive arrangement may be provided through the wheel connection arrangement 100, previously described with reference to at least Figures 1 -3. For example, the connection member 835 may be threaded through a connecting leg 880 of the wheel connection arrangement to connect to the second gearing portion 830. Thus, the connection member 835 may be moved by an actuator 140 of the wheel connection arrangement.

This enables the position of the connection member 835 to move as the position of the wheel connection arrangement is moved. This may simplify a construction of the drive arrangement and wheel 810.

It will be understood that embodiments thereby enable a drive arrangement for a wheel may be positioned externally to the wheel, for example, on the chassis of the transportation device. Such a drive arrangement may be adapted to drive one or more wheels using a belt 890, chain or other flexible member. In particular, the connection member 835 may be driven by the belt 890, chain or other flexible member. In particular, the belt may be coupled to the connection member 835 via a pulley 895.

Positioning the drive arrangement on the chassis of the transportation device reduces the weight of the wheel (as the drive arrangement is advantageously not positioned within the wheel). Thus, a weight of an unsuspended portion of the wheel, for example passing through bumps or holes, may be reduced, improving a ride stability.

In particular, this may decrease the weight and complexity of an actuator 140 of the wheel connection arrangement. Furthermore, controlling a lighter wheel using a same actuator results in a more efficient suspension system with reduced power requirements to alter the position of the wheel relative to the chassis. Thus less power may be used in providing a suspension system.

Furthermore, a shaking or vibration of the drive arrangement is reduced, as the wheel connection arrangement may act as a suspension system, thereby increasing the longevity and reliability of the drive arrangement.

Embodiments may be employed in a powered transportation device to alleviate power or torque requirements on the drive arrangement. Such reduction of required torque, for example, may enable a smaller, lighter and/or cheaper motor to be employed, thus reducing the cost and/or weight of the device. It may also improve device safety by reducing (e.g. damping) the effect of hitting a sudden bump, obstacle, etc. and/or improving stability of the device. Thus, the wheel arrangement may act as a suspension arrangement.

It is noted that embodiments of the transportation device may employ one or more wheels. Also, while specific embodiments have been described with reference to a powered self-balancing unicycles having one or more foot platforms, it is to be understood that embodiments need not be restricted to powered self-balancing unicycles, but may instead be employed in transportation devices having more than one wheel and/or a supporting platform for supporting a user (such as a seat for example). By way of example, embodiments may include powered two-wheeled transportation devices.

Also, the load for transportation may comprise a package rather than a person or human. Embodiments may therefore provide a powered transportation device for transporting package or items of stock in an automated manner for example.

Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Accordingly, while specific embodiments have been described herein for purposes of illustration, various modifications will be apparent to a person skilled in the art and may be made without departing from the scope of the invention.

Claims

1 . A wheel connection arrangement adapted to couple a wheel to a chassis,

wherein the wheel connection arrangement comprises at least one portion that is adapted to rotate about an axle of the wheel connection arrangement, the axle of the wheel connection arrangement being offset from the axis of rotation of the wheel,

and wherein the wheel connection arrangement is adapted to be movable between first and second positions so as to move the chassis relative to the axis of rotation of the wheel axle.

2. The arrangement of claim 1 , further comprising an actuator which is adapted to move the arrangement between the first and second positions.

3. The arrangement of claim 2, wherein the actuator is adapted to operate in response to a control signal.

4. The arrangement of claim 3, further comprising a control system adapted to generate the control signal, wherein the control signal is adapted to control the actuator to maintain or manage an orientation or relative position of the chassis.

5. The arrangement of claim 3 or 4, wherein the control system is adapted to generate a drive signal for controlling a rotational parameter of the wheel.

6. The arrangement of claim 4 or 5, wherein the control system comprises a processing unit adapted to process signals in accordance with a control algorithm to generate the control signal, and wherein the control algorithm is adapted to process signals from at least one of:

a drive arrangement adapted to drive rotation of the wheel;

an accelerometer system adapted to measure acceleration in at least one axis;

a gyroscopic system; a speed sensing system adapted to detect a speed in at least one axis; a terrain sensing system adapted to detect one or more properties of a terrain;

a sensing system adapted to detect a rotational parameter of the wheel, such as a rotational speed of the wheel, a rotational acceleration or deceleration of the wheel, an angular velocity of the wheel, an angle or rotation of the wheel;

a yo-yo detection system adapted to detect the presence of a yo-yo-ing effect of the wheel;

a load sensing system;

an input interface adapted to receive an input from a user; and a tyre pressure detection system.

7. The arrangement of claim 5 or 6, wherein the control system comprises a processing unit adapted to process signals in accordance with a drive algorithm to generate the drive signal, and wherein the drive algorithm is adapted to process signals from at least one of:

a drive arrangement adapted to drive rotation of the wheel;

an accelerometer system adapted to measure acceleration in at least one axis;

a gyroscopic system;

a speed sensing system adapted to detect a speed in at least one axis; terrain sensing system adapted to detect one or more properties of a terrain;

a load sensing system;

8. The arrangement of any preceding claim, further comprising a locking arrangement adapted to lock the wheel connection arrangement in at least one position so as to substantially prevent movement of the chassis relative to the axis of rotation of the wheel axle.

9. The arrangement of any of claims 2 to 8, wherein the actuator comprises a motor and gear, the motor being adapted to rotate the gear in response to the control signal, and the gear being adapted to translate rotation of the gear into movement of the arrangement between the first and second positions.

10. The arrangement of any of claims 2 to 8, wherein the actuator comprises a pneumatic or hydraulic actuator adapted to move between a contracted and extended configuration to move the arrangement between the first and second positions.

1 1 . The arrangement of any of claims 2 to 8, wherein the actuator comprises a rotary vane actuator, and wherein the at least one portion comprises, or is coupled to, a rotary vane.

12. The arrangement of any preceding claim, wherein the arrangement is further adapted to maintain the chassis in a substantially constant orientation when the arrangement moves between the first and second position.

13. A transportation device comprising:

a wheel;

a chassis for supporting a load for transportation;

a drive arrangement adapted to drive rotation of the wheel; and

a wheel connection arrangement according to any preceding claim, wherein the chassis is coupled to the wheel via the wheel connection arrangement.

14. The transportation device of claim 13, wherein the wheel connection arrangement is adapted to move between the first and second positions in response to a control signal, and wherein the control signal is based on at least one of:

one or more operating characteristics of the transportation device; and a signal from an entity presence detection system adapted to detect the presence of an entity on, at or near a part of, the transportation device.

15. The transportation device of claim 13 or 14, wherein the transportation device comprises a balance control system adapted to maintain balance of the transportation device in at least one axis.

16. The transportation device of any of claims 13 to 15, wherein the load for transportation comprises a person.

17. The transportation device of any of claims 13 to 15, wherein the load for transportation comprises a package or item for delivery.

18. The transportation device of any of claims 13 to 17, wherein the drive arrangement is adapted for automated control.

19. The transportation device of any of claims 13 to 18, wherein the wheel is hubless.

20. The transportation device of claim 19, wherein the drive arrangement is a direct drive motor or is positioned inside the void defined by the inner rim of the hubless wheel.

21 . A wheel connection arrangement substantially as herein described above with reference to the accompanying figures.

22. A powered transportation device substantially as herein described above with reference to the accompanying figures.