Vehicle with two wheels aligned one behind the other on a frame in which at least the front wheel is powered by an electric motor

Abstract

In a vehicle with two wheels aligned one behind the other on a frame, at least the front wheel, i.e. the steered one, is powered by its own electric motor, which is controlled by an electronic control unit (130) which distributes torque and power according to the dynamic situations encountered by the vehicle when ridden so that the peripheral speed of the front wheel (10) in contact with the ground does not result in skidding on the ground. In the event that each wheel is equipped with its own electric motor, the said electric motors are controlled by an electronic control unit (30) which distributes torque and power according to the dynamic situations encountered by the vehicle when ridden so that the peripheral speed of the wheels (10, 20) in contact with the ground does not result in skidding on the ground.

Description

[0001] VEHICLE WITH TWO WHEELS ALIGNED ONE BEHIND THE OTHER ON A FRAME IN WHICH AT LEAST THE FRONT WHEEL IS POWERED BY AN ELECTRIC MOTOR DESCRIPTION

[0002] The invention relates to a vehicle with two wheels aligned one behind the other on a frame in which at least the front wheel, the steered wheel, is driven by its own electric motor. The latter is controlled by an electronic control unit which distributes torque and power according to the dynamic situations encountered by the vehicle so that the peripheral speed of the front wheel in contact with the ground does not result in skidding on the ground.

[0003] More specifically, but not exclusively, the invention, which is also equipped with an accelerator, finds useful application in the electric micro-mobility sector.

[0004] The most commonly known solutions adopt a single electric motor positioned in the rear wheel hub.

[0005] With the positioning of the motor in the wheel hub, once the motor is activated, the torque is transferred directly to the wheel.

[0006] The electric motor is powered by a specific rechargeable battery.

[0007] However, the prior art embodiments pose a series of problems to which the present invention aims to provide an adequate solution.

[0008] A first problem is the possibility of the electric motors used overheating, essentially due to the compactness thereof, which is required because of the need to impact the overall vehicle weight in the least way possible. The effect is particularly noticeable in conditions in which particular effort is required, such as when riding uphill, where the motors tend to overheat and the consequent deterioration thereof quickly brings the said motors to the end of their life much earlier than would be natural.

[0009] If rear motors are used, with sufficient power to guarantee high torque values so as to enable the minimum user effort possible, problems may arise. In this case, in the presence of a considerable load condition with the possible addition of an external rear transported load (typical of cargo bikes), in uphill situations with slippery ground, rearing up or skidding may occur due to the transmission to the ground of an excess of torque by the rear wheel, which tends to skid over the ground.

[0010] Another problem is the difficulty that can be experienced in riding over small obstacles, even on flat ground. Electric vehicles are, indeed, heavier per se, as they comprise a greater number of heavy components (engine, battery, control electronics, brakes, and adequate oversized tyres). As a result, riding over small obstacles or even simply pushing the vehicle up steps to access upper floors becomes challenging, if not impossible, for the average user due to the weight thereof.

[0011] Another problem encountered in prior art embodiments is wear of the rear tyre (the one driven by the electric motor), which wears out much more quickly than the front tyre.

[0012] Finally, current commonly known electric vehicles are not devoid of difficulties when driving on sandy surfaces and uphill, which even limit their use in specific contexts despite the vehicle's environmental value (environmental compatibility). Electric traction is still limited in off-road riding, for example on mountain trails, in parks, and in nature reserves. In these contexts, in fact, current electric vehicles are still difficult to adopt as a usual means of transport, especially as they are generally used purely as a means of locomotion and, in the vast majority of cases, by "non-specialist" users. Among the advantages of the invention, safety when riding the vehicle is worthy of mention, with particular reference to rearing up or skidding on all types of terrain.

[0013] These objects and other advantages are achieved by the present invention which concerns a vehicle with two wheels aligned one behind the other on a frame, where each wheel is driven by its own electric motor as set out in the claims and as described and illustrated in the present description and in the appended figures.

[0014] Further characteristics and advantages of the invention will emerge more clearly from the figures appended to the following description of some preferred, but not exclusive, embodiments of the invention illustrated by way of a non-limiting example, in which:

[0015] Figure 1 shows a schematic side view in vertical elevation of a first embodiment;

[0016] Figure 2 shows a schematic side view in vertical elevation of a variant of the embodiment in Figure 1.

[0017] With reference to the aforesaid figures, 1 generally denotes a frame of a vehicle with two wheels 10 and 20 aligned one behind the other, where the front wheel 10 (i.e. the steered wheel) is supported and rotatably constrained to a fork 11 , which is in turn fixed to a handlebar 40, which is coupled, so as to be able to rotate, in a tube 41 which is integrally arranged so to "seal" the front part of the frame 1. A rear wheel 20 is rotatably supported by a rear fork 21 constituting the rear part of the frame 1 .

[0018] Both wheels 10 and 20 are provided with their own electric motors, respectively denoted 12 and 22. The electric motors are arranged and constrained coaxially to the hubs of the respective wheels 10 and 20 and are controlled by means of a control unit 30, which is equipped with a display 42 placed on the handlebar 40 in a position which is easily accessible by the user of the vehicle.

[0019] The electric motor 12 is fitted coaxially in the hub of the front wheel 10 (i.e. the steered wheel) so as to operate positioned between the said wheel and the front fork 11 to which the handlebar 40 is fastened.

[0020] Similarly, the rear electric motor 22 is fitted coaxially in the hub of the rear wheel 20 so as to operate positioned between the said wheel and the rear fork 21 of the frame 1 .

[0021] In particular, the control unit 30 distributes the torque and power supplied by a battery 3, secured to the frame 1 , according to the dynamic situations encountered by the vehicle during motion. Specifically, the said unit operates by distributing power to the two motors so that the peripheral speeds of the wheels 10 and 20 in contact with the ground do not result in skidding on the ground.

[0022] The situation, which can, for brevity, be defined as dual traction, is managed by a system of sensors that measure the torques or speeds (number of revolutions per unit of time) of the motors coupled with the wheels 10 and 20. A sensor measuring torque or number of revolutions per unit of time is coupled with the electronic control unit 30, where, based on the outcome of the comparison with the numbers of revolutions of the front wheel and the rear wheel via the display 42, distribution of the power to motors 12 and 22 is controlled.

[0023] The distribution is controlled by the control unit 30 so that the peripheral speed of the wheels 10 and 20 in contact with the ground does not result in skidding on the ground.

[0024] Therefore, in the event of measurement of different numbers of revolutions in the unit of time between the rear wheel 20 and the front wheel 10 not due to different rolling diameters, which can occur in the event of one of the two wheels skidding, the control unit 30 intervenes, altering the power supplied to the individual motors so as to realign the peripheral speeds of the wheels and prevent skidding on the ground.

[0025] By means of the display 42, it is possible to choose and preset different levels of assistance and different methods for activating the dual traction.

[0026] The “dual traction” configuration automatically controlled by the control unit offers the advantages that motion is made possible and stable on practically any type of terrain and that the user can ride safely.

[0027] According to a further embodiment, the vehicle with two wheels aligned one behind the other is equipped with an electronic accelerator 60, which can be operated by the user (shown schematically as a control lever or knob 60) located on the handlebar 40 onto which a display 42 is applied, which acts on the control unit 30 to give clearance to start and to deliver power to the electric motors 12, 22 powering the two wheels 10 and 20, as well as to the distribution thereof thereto, in relation to a pre-selected value depending on the dynamic situations encountered by the vehicle when ridden, so that the peripheral speeds of the wheels 10 and 20 in contact with the ground do not cause skidding on the ground.

[0028] The vehicle is a moped / motorcycle, i.e. a vehicle with two wheels 10 and 20 with fully electric dual (front and rear) traction that uses the electricity supplied by the battery 3 via the control unit 30, which is activated in turn via the accelerator 60.

[0029] A variant of the embodiment just illustrated comprises an electronic accelerator 60, which can be activated by the user and acts on the control unit 30 to give clearance to start and deliver power to the electric motor 12 for the front wheel and an electric motor 22 for the rear wheel, as well as to the distribution thereof thereto, in relation to a pre-selected value depending on the dynamic situations encountered by the vehicle when ridden and the level of power selected by the user, so that the peripheral speeds of the wheels 10 and 20 in contact with the ground do not cause skidding on the ground.

Claims

CLAIMS1. A vehicle with two wheels aligned one behind the other on a frame characterised by the fact that: at least the front wheel, i.e. the steered one, is powered by its own electric motor, which is controlled by an electronic control unit (30; 130) which distributes torque and power according to the dynamic situations encountered by the vehicle so that the peripheral speed of the front wheel (10) in contact with the ground does not result in skidding on the ground; each wheel is driven by an electric motor, the said electric motors being controlled by an electronic control unit (130) which distributes torque and power according to the dynamic situations encountered by the vehicle so that the peripheral speed of the wheels in contact with the ground does not result in skidding on the ground; the said front electric motor (12) is fitted coaxially to the hub of the front wheel (10) so as to operate positioned between the said wheel and the front fork (11), it being envisaged that the rear electric motor (22) is fitted coaxially to the hub of the rear wheel (20) so as to operate positioned between the said wheel and the rear fork (21) which is part of the frame (1), and there being an electronic accelerator (60) envisaged, which can be activated by the user and acts on the control unit (130) to give clearance to start and to deliver power to the electric motors (110; 132) powering the two wheels (10) and (20) as well as to the distribution thereof thereto, in relation to a pre-selected valuedepending on the dynamic situations encountered by the vehicle, so that the peripheral speeds of the wheels (10) and (20) in contact with the ground do not cause skidding on the ground.

2. A vehicle according to Claim 1 characterised by the fact that each one of the said electric motors (12; 22) comprises a torque or cadence sensor coupled thereto to measure the torque level or the cadence, i.e. the number of revolutions per the unit of time, and transmit this measurement to the electronic control unit (30), whose task is to compare the said measurement against a pre-selected value in order to control power delivery.

3. A vehicle with two wheels aligned one behind the other according to Claim 2, characterised by the fact that the said vehicle comprises an electronic accelerator (60), which can be activated by the user and acts on the control unit (130) to give clearance to start and to deliver power to the electric motor (112) for the front wheel (10) and to an electric motor (132), as well as to the distribution thereof thereto, in relation to a preselected value depending on the dynamic situations encountered by the vehicle and the pre-selected assistance level value, so that the peripheral speeds of the wheels in contact with the ground do not cause skidding on the ground.

4. A vehicle with two wheels aligned one behind the other according to Claim 3, characterised by the fact that the said vehicle comprises an electronic accelerator (60), which can be activated by the user and acts on the control unit (130) to give clearance to start and to deliver power to the electric motor (110) for the front wheel (10).

Images