Patent Description:
There are known electric vehicles with electric motor structures mounted on a wheel of the vehicle in such a way that the motor has its rotating rotor on the outer periphery and coupled directly to rotate the wheel without power transmission in between. A problem with the known solutions is the complexity thereof.

Document <CIT> presents an electric drive system for a vehicle. The drive system comprises a rotor which forms, at least in part, a rotatable wheel structure of the vehicle, said rotor including an inner surface that is coaxial with the axis of rotation of the wheel structure. The system also comprises a stator which forms, at least in part, a stationary axle structure of the vehicle and includes an outer surface encircled by the rotor and an electrical coil connectible to a source of electrical power to generate an electromagnetic force to rotate the rotor relative to the stator. Furthermore, the drive system comprises means for coupling the stator to the wheel structure such that the stator is at a location radially outwardly from the axis of rotation of the vehicle wheel.

Document <CIT> presents an electric drive system for a vehicle, on which a drive wheel is rotationally mounted on the frame of the vehicle in a direct or indirect manner. The system contains a force transmitting unit consisting of a wheel axle, wheel bearing, and wheel hub. The system also contains an electric drive equipped with an electric motor, and a control unit connected in an electrically conductive manner to the electric motor and having a connection to a power supply unit and to an actuator.

Document <CIT> presents a motor comprising a rotor assembly and a stator assembly to rotatably drive the rotor assembly. The stator assembly includes a body, a plurality of teeth extending radially from the body, and at least two winding sets, each winding set comprising coils wound on the teeth. The at least two winding sets includes a first set for driving the rotor assembly to a first variable operational range, and a second set for driving the rotor assembly to a second variable operational range different than the first.

Document <CIT> presents a potentiometer that detects a rotation amount of a throttle grip that is rotatably provided on a handle as a throttle opening, and controls an electric motor according to the throttle opening detected by the potentiometer.

The invention relates to an electric vehicle as defined in the independent claim <NUM> and to an electric motorcycle as defined in the independent claim <NUM>.

It is one objective of the invention to provide an electric vehicle and an electric motorcycle, which are simpler in construction than the known electric vehicles and electric motorcycles.

The objectives of the invention are attained with an electric vehicle and an electric motorcycle as set forth in the respective independent claims. A few preferred exemplary embodiments are presented in the dependent claims.

According to a first aspect, the invention is an electric vehicle which comprises an electric motor mounted on at least one wheel, said electric motor comprising a rotor fitted on the outer side and a stator fitted on the inner side. The electric motor's stator is arranged to function as an axle for said wheel in such a way that the stator is adapted to bear the loads between said wheel and the remaining structure of the electric vehicle. The electric vehicle comprises at least two wheels, and a body, wherein said wheel, on which the electric motor is provided, is arranged in attachment with the body by means of a support member.

The support member comprises a support member attachment portion adapted to be attached to the body by a bolt so that the support member attachment portion is between portions of the body in a direction of the rotational axis. The support member is configured so as to enable its disassembly into at least two separate pieces relative to a direction perpendicular to the rotational axis of said wheel, wherein the two separate pieces are further arranged to be attached to each other at portions of the pieces to be arranged between the body and said wheel. Furthermore, the support member is attached to the stator on both sides of said wheel in the direction of the rotational axis so that there are two attaching points on each of said sides. One of the attaching points on either of said sides is arranged on a first side of a first plane defined by the rotational axis and an imaginary line between the support member attachment portion and the rotational axis, and the other one of the attaching points on either of said sides is arranged on the opposite side of the first plane relative to the first side, wherein the attaching points are further arranged on a portion of the stator which is on a side of a second plane having the support member attachment portion, the second plane being perpendicular to the first plane and extending via the rotational axis.

Similar electric motors may have been included in more than one wheel, for example in two rear wheels, two front wheels, or all wheels of the vehicle. The wheels may have been made turnable or unturnable.

In this disclosure, the electric vehicle may refer for example to an electric automobile, an electric tractor, an electric motorcycle, an electric scooter, an electric moped, an electric bicycle, or a motorcycle resembling three-wheeled electric vehicle, or to any other vehicle which Is provided or can be provided with an electric motor according to one exemplary embodiment of the invention.

Said wheel may comprise a rim base, whose outer periphery is capable of being fitted with a tire, and in which the rotor is included in the rim base, preferably directly in the rim base.

The rotor can be fitted on the stator in a bearing-mounted manner, such as by means of a roller bearing, a needle bearing, a slide bearing, a magnetic bearing or a ball bearing or bearings. The rotor can be mounted on the stator with a roller bearing, the rotational axes of whose rollers are disposed in an unparallel manner with respect to the rotational axis of said wheel. According to one example, the roller bearing may have the rotational axes of its rollers set at an angle of <NUM> degrees with respect to the rotational axis of said wheel.

Between the rotor and the stator may have been fitted sealings so as to provide a sealed space for the rotor and stator's electromagnetic components. The sealings may have been arranged in such a way that the sealed space is provided both for the rotor and stator's electromagnetic components and for the bearing or bearings.

The stator comprises preferably a winding and the rotor comprises a magnet, such as a permanent magnet or electromagnet. The winding and the magnet may have been arranged peripherally in the stator and the rotor, enabling a magnetic force to be generated therebetween for rotating the rotor relative to the stator as the winding is supplied with electric current.

The widths of the stator's winding and the rotor's magnet in the direction of the wheel rotational axis can be substantially smaller than the width of the wheel.

The electric vehicle may comprise an electric motor control unit and a sensor arrangement, said sensor arrangement being adapted to generate a sensor signal and said control unit being adapted to control operation of the electric motor on the basis of the sensor signal. According to one working example, the sensor arrangement is included in a control element intended for controlling rotation speed of the electric motor, wherein the sensor signal is adapted to change in response to a change of position of the control element.

The control element may refer, among other things, to a steering wheel, a handle which can be squeezable handle or a rotatable handle, a touch screen, a control stick, or the like appropriate control element of a type usable in each exemplary embodiment.

According to a second aspect, the invention is an electric motorcycle which is an electric vehicle according to the first aspect.

The electric motorcycle control element can be a handle rotatable around its longitudinal axis, and the sensor arrangement can be fitted in said handle in such a way that the sensor signal is adapted to change in response to a change of position of the handle with respect to its rotational axis. The handle can be similar to a throttle handle included in conventional combustion engine-equipped motorcycles.

The invention provides benefits over the prior art. The electric vehicle and electric motorcycle of the invention are simpler in construction than the known solutions.

Several other benefits of the invention become clear for a skilled artisan on the basis a subsequent detailed description dealing with a few exemplary embodiments of the invention.

A few exemplary embodiments of the invention as described hereinafter may not be construed in a limited sense as it is obvious for a skilled artisan that the invention can also be implemented in ways other than those presented below.

A few exemplary embodiments of the invention will now be described in detail with reference to the accompanying figures.

<FIG> illustrate schematically an electric motor <NUM> for an electric vehicle <NUM> according to one exemplary embodiment of the invention: <FIG> in a cross-section view and <FIG> in a side view. Said electric motor <NUM> comprises a rotor <NUM> disposed on the outer side and an annular stator <NUM> disposed on the inner side. The electric motor <NUM> can be a type of brushless or brushed, alternating current or direct current motor.

According to the invention, the electric motor's stator <NUM> is arranged to function as an axle for a wheel <NUM> in such a way that the stator <NUM> is adapted to bear the loads between said wheel <NUM> and the remaining structure, such as a support member <NUM> and a body <NUM>, of an electric vehicle <NUM>. Hence, in the discussed wheel <NUM> there is no need for a separate hub, whereby the wheel <NUM> may have a middle part which comprises a void space <NUM> but which may also be provided as a solid structure. The stator <NUM> mountable with attaching means <NUM> to the remaining structure of the vehicle. The attaching means <NUM> is a per se known fastener which enables detachment and reattachment of the stator and the entire electric motor, such as for example a bolt. On the other hand, the attaching means <NUM> can be a welded joint or adhesive bonding which must be broken in order to detach the stator <NUM> and the electric motor.

According to one exemplary embodiment of the invention, the stator <NUM> can be irremovably attached to a body of the vehicle <NUM> at least from what is the other side of the stator <NUM> with respect to a lateral direction X of the wheel <NUM>.

In the embodiment shown in <FIG>, the stator <NUM> comprises a winding <NUM> formed with winding wires, while the rotor <NUM> comprises magnets <NUM>, preferably permanent magnets or electromagnets. In the embodiment shown in <FIG>, the widths of the stator winding <NUM> and the rotor magnet <NUM> in the direction of a rotational axis X of the wheel are substantially smaller than the width of the wheel.

In the exemplary embodiment shown in <FIG>, the wheel <NUM> comprises a rim base <NUM> and a tire <NUM> (presented with dashed lines) disposed thereon, and the rotor <NUM> is attached directly to the rim base <NUM>. Attachment of the rotor <NUM> to the rim base <NUM> can be effected by using conventional attachment methods and fasteners.

In another embodiment there are one or more structural layers between the rotor <NUM> and the rim base <NUM>. Such a structural layer can be functional, whereby it may for example dampen vibrations between the rotor and the rim base or serve as an element to assist attachment between the rotor <NUM> and the rim base <NUM>, or as the like element.

The tire <NUM>, which is provided or capable of being provided on the wheel <NUM>, can be a per se known tire: an air-filled, solid, foam-filled tire, or the like. Neither is a separate tire <NUM> necessary but, instead, the rim base <NUM> may constitute a tread surface upon which the wheel <NUM> rotates on a driving surface.

The rotor <NUM> is preferably adapted to be rotatable relative to the stator <NUM>, specifically rotatable around an outer periphery of the stator <NUM>. The rotor <NUM> can be arranged on the stator <NUM> in a bearing-mounted fashion, such as by means of a roller bearing <NUM>, a needle bearing <NUM>, a slide bearing <NUM>, a magnetic bearing <NUM> or bearings <NUM>.

The bearing assembly can be dimensioned preferably in such a way that the stator <NUM> functions as an axle for the wheel <NUM>, which is capable of bearing the entire load transmitted by way of the wheel <NUM> of an electric vehicle <NUM> to the driving surface. In other words, the bearing assembly between the rotor <NUM> and the stator <NUM> works as a sole wheel bearing for the wheel <NUM>. In the embodiment shown in fig. 3A, between the rotor <NUM> and the stator <NUM> are disposed sealings <NUM> so as to generate a sealed space for electromagnetic components of the rotor <NUM> and the stator <NUM>. The sealings <NUM> may have been arranged so as to provide a sealed space for the bearing <NUM> or bearings <NUM>. Alternatively, the sealings <NUM> may have been arranged so as to provide a sealed space both for electromagnetic components of the rotor <NUM> and the stator <NUM> and for the bearing <NUM> or bearings <NUM>.

In the embodiment shown in <FIG>, the rotor <NUM> is bearing-mounted to the stator <NUM> with a roller bearing <NUM>, having rotational axes Y of its bearing rollers <NUM> disposed to be divergent with respect to a rotational axis X o the wheel. The benefit is that the bearing assembly is supported both in the direction of the rotational axis X of the wheel <NUM> and in a direction perpendicular thereto. In the present case, said angle is <NUM> degrees, but may of course be other than that.

<FIG> illustrate schematically some electric vehicles according to a few exemplary embodiments of the invention. <FIG> depicts an electric passenger car. According to a few exemplary embodiments of the invention, the electric vehicle may also be a van, a bus, a truck, or a trailer truck. <FIG> depicts an electric tractor. According to a few exemplary embodiments of the invention, the electric vehicle may also be another type of working machine, such as a forklift, a combine harvester, or an excavator. <FIG> depicts an electric motorcycle according to one exemplary embodiment of the invention. <FIG> depicts an electric bicycle according to one exemplary embodiment of the invention, which comprises an electric energy storage <NUM> such as a battery or a battery bank.

<FIG> presents schematically an electric vehicle <NUM> according to one exemplary embodiment of the invention, specifically an electric motorcycle <NUM>. The electric motorcycle may comprise an electric motor <NUM>, which is included in at least one wheel <NUM> and comprises a rotor <NUM> disposed on the outer side and a stator <NUM> disposed on the inner side. The electric motor <NUM> has its stator <NUM> preferably arranged to function as an axle for the wheel <NUM> in such a way that the stator <NUM> is adapted to bear the loads between said wheel <NUM> and the remaining structure of the electric motorcycle <NUM>. Therefore, the discussed wheel <NUM> does not require a separate hub.

According to one exemplary embodiment of the invention, the electric vehicle <NUM> or the electric motorcycle <NUM> may comprise a control unit <NUM> for the electric motor <NUM>. The electric motorcycle <NUM> may comprise a sensor arrangement <NUM> adapted to produce a sensor signal <NUM>. The control unit <NUM> may have been adapted to control operation of the electric motor <NUM> on the basis of the sensor signal <NUM>. The sensor arrangement <NUM> may have been arranged in a control element <NUM>, intended for controlling rotation speed of the electric motor <NUM>, in such a way that the sensor signal <NUM> is adapted to change as the position of the control element <NUM> changes with respect to its rotational axis. The change of position of a control element <NUM> according to one exemplary embodiment has been denoted with reference numeral <NUM>. The control element <NUM> can be a steering wheel, a stick, a touch screen, or for example similar to a throttle handle included in prior known combustion engine-equipped motorcycles. The sensor arrangement <NUM> can be based on measuring a force applied to the control element <NUM> or it can be a position sensor.

According to one exemplary embodiment of the invention, the electric motorcycle's <NUM> control element <NUM> is a handle <NUM> rotatable around its longitudinal axis, and wherein sensor arrangement <NUM> is adapted to change in response to a change of position of the handle <NUM> with respect to its rotational axis.

According to one exemplary embodiment of the invention, the electric vehicle or the electric motorcycle can be without a sensor arrangement.

According to several exemplary embodiments of the invention, control unit <NUM> for the electric motor <NUM> is electrically connected <NUM> to the electric motor <NUM> for controlling operation of the electric motor <NUM>.

The electric vehicle <NUM> or the electric motorcycle <NUM> may comprise an electric energy storage <NUM> such as a battery or a battery bank.

The control unit <NUM> for the electric motor <NUM> of the electric vehicle <NUM> or the electric motorcycle <NUM> may comprise a computing unit such as a microcontroller or a processor. The control unit <NUM> may further comprise memory capable of being stored with some program code which can be executed with the computing unit. According to several exemplary embodiments of the invention, the control unit <NUM> comprises a frequency converter or an inverter for modifying electric power to be delivered to the electric motor <NUM>. The electric power can be preferably supplied from the electric energy storage <NUM>. In addition, the electric motor <NUM> may have been provided with sensors such as speed or position sensors and, optionally, among other things, with temperature sensors and sensors measuring other parameters of the electric motor. The control unit <NUM> is preferably adapted to measure a current supplied to the electric motor <NUM> and a voltage connected to the poles of the electric motor <NUM>. In addition, the control unit <NUM> may be adapted to measure the current and/or voltage and/or output of the electric energy storage <NUM>.

The electric vehicle <NUM> or the electric motorcycle <NUM> has its wheel <NUM> mounted to a body <NUM> of the vehicle <NUM> or the electric motorcycle <NUM> by means of a support member <NUM>. The support member <NUM> may comprise, among other things, a suspension <NUM> and/or shock absorption <NUM>.

The stator <NUM> is attached to the remaining structure of an electric vehicle <NUM> or an electric motorcycle <NUM> from both sides thereof (as presented in <FIG>, <FIG>), or from the direction of a void space <NUM> created by an inner periphery of the annular stator <NUM>, or by a combination of these. The attaching means <NUM> can be disposed on just a certain part or sector of the stator <NUM>.

<FIG> shows schematically a part of the electric vehicle <NUM> or the electric motorcycle <NUM> according to one exemplary embodiment of the invention. In <FIG> is depicted a support member <NUM> provided for the attachment of a wheel <NUM> to the body <NUM>. As can be observed from <FIG>, the stator <NUM> mounted on the wheel <NUM> can have the support member <NUM> attached thereto from both sides of the stator <NUM> in a lateral direction of the wheel <NUM>. According to a few exemplary embodiments of the invention, the support member <NUM> can be constructed from several pieces, whereby it can be opened up or taken apart, enabling thereby an easier removal of the wheel <NUM>. In <FIG> is optionally presented a dashed line, indicating a part at which the two-piece support member <NUM> can be opened up or taken apart. The discussed pieces can be attached or attachable to each other with fasteners such as bolts and, if necessary, nuts.

The stator <NUM> is attached to the support member <NUM>, which is intended for the wheel <NUM> of an electric vehicle <NUM> or an electric motorcycle <NUM>, and which is suspended and/or shock absorbed <NUM> relative to the remaining body <NUM> of the electric vehicle <NUM> or the electric motorcycle <NUM>.

<FIG> illustrate schematically a support member <NUM> for the wheel <NUM> of an electric vehicle <NUM> or an electric motorcycle <NUM> according to one exemplary embodiment of the invention. <FIG> present a support member <NUM> according to one exemplary embodiment of the invention, which is constructed from at least two pieces detachable from each other. The support member <NUM> is provided, among other things, with a suspension <NUM> and/or shock absorption <NUM>, by means of which the support member <NUM> can be additionally or optionally attached to the body <NUM> of the electric motorcycle <NUM>.

Claim 1:
An electric vehicle (<NUM>) which comprises an electric motor (<NUM>) mounted on at least one wheel (<NUM>) of the electric vehicle, said electric motor (<NUM>) comprising a rotor (<NUM>) fitted on the outer side and a stator (<NUM>) fitted on the inner side, wherein the electric motor's (<NUM>) stator (<NUM>) is arranged to function as an axle for said wheel (<NUM>) in such a way that the stator (<NUM>) is adapted to bear the loads between said wheel (<NUM>) and the remaining structure of the vehicle (<NUM>), which the electric vehicle (<NUM>) comprises at least two wheels (<NUM>), and a body (<NUM>), wherein said wheel (<NUM>), on which the electric motor (<NUM>) is provided, is arranged in attachment with the body (<NUM>) by means of a support member (<NUM>), characterized in that the support member (<NUM>) comprises a suspension (<NUM>) and/or a shock absorption (<NUM>) attached between the body (<NUM>) and a portion of the support member (<NUM>) between the body (<NUM>) and said wheel (<NUM>), and a support member attachment portion adapted to be attached to the body (<NUM>) by a bolt so that the support member attachment portion is between portions of the body (<NUM>) in a direction of the rotational axis (X), and wherein the support member (<NUM>) is:
- configured so as to enable its disassembly into at least two separate pieces relative to a direction perpendicular to the rotational axis (X) of said wheel (<NUM>), wherein the two separate pieces are further arranged to be attached to each other at portions of the pieces to be arranged between the body (<NUM>) and said wheel (<NUM>), and
- attached to the stator (<NUM>) on both sides of said wheel (<NUM>) in the direction of the rotational axis (X) so that there are two attaching points on each of said sides, wherein one of the attaching points on either of said sides is arranged on a first side of a first plane defined by the rotational axis and an imaginary line between the support member attachment portion and the rotational axis (X), and the other one of the attaching points on either of said sides is arranged on the opposite side of the first plane relative to the first side, wherein the attaching points are further arranged on a portion of the stator (<NUM>) which is on a side of a second plane having the support member attachment portion, the second plane being perpendicular to the first plane and extending via the rotational axis (X).