Electrical vehicle

Abstract

The invention relates to an electric motor vehicle, in particular an electrically driven motorcycle (1), of the type provided with: a chassis (2), a saddle (3), at least one front wheel (4) and one rear wheel (5),- an electric motor (6) arranged with its own rotor axis (6a) transversely with respect to 5 the chassis (2) and parallel to the rotation axis of the rear wheel (5), a control device (15) for said electric motor (6) comprising an inverter, a motion transmission system (7) interposed between an output drive wheel (9) of the electric motor (6) and the rear wheel (5), and comprising in turn a gear train (10) designed to achieve an overall gear ratio determined in the 10 torque transmission from the output wheel (9) of the electric motor (6) to the rear wheel (5), and at least one position transducer (16), in particular an encoder or a resolver, which is mounted on the drive system (7) downstream of the output drive wheel (9) of the electric motor (6) and connected to the inverter for transmitting to the inverter a signal indicative 15 of the angular position of the rotor of the electric motor (6) for controlling the latter, in particular its stator currents.

Description

[0001] DESCRIPTION ELECTRICAL VEHICLE

[0002] Technical field

[0003] The present invention relates to an electric motor vehicle.

[0004] Without thereby losing generality, reference will hereinafter be made to motor vehicles with two or more wheels provided with a saddle defining the rider's driving position, and more specifically to motorcycles, in which the saddle is intended to be mounted in a straddle position.

[0005] Background art

[0006] As known, conventional motorcycles are commonly equipped with a chassis, a saddle, a front driven wheel, a rear drive wheel, an internal combustion engine, and a motion transmission system, which is interposed between the engine and the rear drive wheel.

[0007] The transmission system is generally provided with a gear shifting member, which in turn may be provided with a pedal gear shifting lever. This latter, if present, is operable by the rider, through the foot, to control a selector drum with a sequential engagement cam for gear shifting.

[0008] In recent years, electrically powered motorcycles have been proposed, i.e., equipped with an electric motor in place of the internal combustion engine.

[0009] One of the technical problems tackled in the design of electrically powered motorcycles has been to redefine, in terms of space and weight, the position of the components mounted on the chassis so as not to compromise stability, size, and comfort of the motorcycle.

[0010] Particular attention has been focused on the housing of the batteries and of the electric motor to ensure proper weight balancing on the chassis.

[0011] In particular, to meet the aforementioned requirements, solutions have been proposed that provide for the electric motor with its rotor axis arranged transversely to the longitudinal axis of the motorcycle, i.e., parallel to the rotation axis of the rear drive wheel. Such a solution, however, involves dimensional problems in the positioning certain control components necessary for the electronic management of the motor, in particular according to the transverse dimension (width) of the motorcycle.

[0012] Object of the invention

[0013] The object of the present invention is to provide an electric motor vehicle allowing the housing of the control components necessary for the electronic management of the electric motor so as not to affect the overall dimensions of the motorcycle, and in particular not to affect the transverse dimension (width) of the motorcycle.

[0014] Said object is fully achieved by the electric motor vehicle which is the subject matter of the present invention and is characterized by the content of the claims set forth below.

[0015] Brief description of the drawings

[0016] The technical features of the invention and its advantages are highlighted in the following description of a preferred embodiment, illustrated merely by way of non-limiting example in the accompanying drawing tables, in which:

[0017] - Figure 1 shows in a diagrammatic manner an electric motor vehicle, in particular a motorcycle, in accordance with the present invention;

[0018] - Figure 2 shows in a diagrammatic manner a portion of the motorcycle of Figure 1 , which is the subject of the present invention;

[0019] - Figure 3 shows in detail the portion in Figure 2; and

[0020] - Figures 4 and 5 illustrate two possible embodiments of the present invention in relation to the portion in Figure 3.

[0021] With reference to Figure 1 , reference numeral 1 indicates an electric motor vehicle as a whole.

[0022] Detailed description of preferred embodiments of the invention In particular, the motor vehicle 1 is a motorcycle to which, for simplicity of discussion, reference numeral 1 will be assigned.

[0023] The motorcycle 1 comprises a chassis 2 and a saddle 3 to be straddled, which is fastened to the chassis 2 and defines the driving position of the rider.

[0024] The motorcycle 1 further comprises a front driven wheel 4, a rear drive wheel 5, an electric motor 6 for operating the same motorcycle 1 , and a motion transmission system 7, which is interposed between the electric motor 6 and the rear drive wheel 5.

[0025] The electric motor 6 of the motorcycle 1 is mounted on the chassis 2 with its own rotor axis 6a transverse to the prevalent extension longitudinal direction D of the chassis 2 and of the motorcycle 1 itself.

[0026] The rotor axis 6a of the motor 6 coincides with the axis of the output shaft of the motor 6, i.e., with the axis of the motor shaft 8 illustrated in Figures 2 to 5, and is parallel to the rotation axis 5a of the rear drive wheel 5.

[0027] A toothed wheel 9, defining an output drive wheel of the electric motor 6, is keyed onto the shaft 8, the function of which is to transmit torque and power to the transmission system 7.

[0028] Therefore, the motion transmission system 7 is interposed between the output drive wheel 9 of the electric motor 6 and the rear drive wheel 5 of the motorcycle 1 .

[0029] The transmission system 7 comprises a gear train (or cascade) 10 (toothed wheels 10), which are designed to obtain a particular overall transmission ratio.

[0030] Each gear 10 is mounted on a respective rotating shaft 11 , parallel to the shaft 8, to transmit torque and power from the output drive wheel 9 of the electric motor 6 to a pinion 12 of the transmission system 7, which, in turn, is connected to the rear drive wheel 5 by means of a chain 13.

[0031] In more detail, the pinion 12 is keyed onto the shaft 11 of the terminal gear 10 of the gear train 10, i.e., it is integral with the gear 10 arranged at the rear with respect to the head gear 10, which is instead meshed with the toothed wheel 9.

[0032] The transmission chain 13 is closed in a loop around the pinion 12 and a toothed wheel 14, which is mounted integral on the hub of the rear drive wheel 5 (Figure 2).

[0033] The chain wheel 13 and the toothed wheel 14 define the terminal part of the transmission system 7.

[0034] The final transmission of the motorcycle 1 is therefore of chain-type, and the gear train 10 defines a speed reducer arranged and shaped to reduce the rotation speed at the wheel with respect to the rotor of the electric motor 6 so as to increase the torque.

[0035] In particular, the electric motor 6 is selected with a rotor rotation speed, and therefore of the shaft 8, comprised between 17,000 rpm and 20,000 rpm, preferably equal to 18,500 rpm.

[0036] The motorcycle 1 further comprises a control device 15, in turn provided with an inverter (not shown) that supplies the electric motor 6 on the basis of the (current) angular position of its rotor so as to ensure correct and efficient dispensing of the drive torque. In particular, the inverter receives the signal on the angular position of the rotor from at least one sensor defined by a position transducer 16 associated with the transmission system 7 and connected to the inverter of the control device 15.

[0037] The position transducer 16 is advantageously mounted on the transmission system 7, downstream of the output drive wheel 9 of the electric motor 6.

[0038] It should be noted that the term “mounted” mentioned above, and hereinafter, means that the position transducer 16 is at least in part integral with a corresponding part of the transmission system 7 to detect the (current) position of such a part, from which the (current) angular position of the rotor of the electric motor 6 is derived.

[0039] Depending on the type of signal (mechanical, electromagnetic, optical, etc.) and the type of information (absolute or relative), the position transducer 16 may be analog (resolver) or digital (encoder). In particular, the position transducer is associated with one of the wheels of the gear train 10.

[0040] The position transducer 16 is advantageously mounted on the aforementioned shaft 11 , i.e., on a reduced shaft with respect to the rotor of the electric motor 6.

[0041] The position transducer 16 comprises a rotatable component and a fixed one.

[0042] The rotatable component is integrally connected to the respective gear 10 for transmitting as output to the fixed component a signal containing information relating to the angular position of the rotor of the electric motor 6.

[0043] The fixed component of the position transducer 16, consequently to the signal coming from the rotating component, transmits a signal indicative of the angular position of the rotor of the electric motor 6 to said inverter, which processes the received data and, consequently, supplies the electric motor 6 correctly and efficiently on the basis of the angular position of its rotor.

[0044] The behavior of the electric motor in terms of speed and torque is in particular controlled using high-performance control techniques, for example, FOC (Field Oriented Control), which consists of controlling the stator currents on the basis of the detected present (current) angular position of the rotor.

[0045] The mounting of the position transducer 16 on the transmission system 7, downstream of the output drive wheel 9 of the electric motor 6, is particularly advantageous as it does not affect the overall size of the motorcycle 1 , and in particular it does not affect the transverse dimension (width) of the same motorcycle 1 .

[0046] So as to further reduce the transverse bulk of the transmission system 7, and therefore the bulk (width) of the motorcycle 1 in the direction transverse to the predominant extension longitudinal direction D of the chassis 2 and of the same motorcycle 1 , the gears 10 lie distributed on two planes parallel to each other (Figures 3, 4, and 5). Therefore, one or more gears 10 lie on one plane, and the remaining gears 10 lie on the other parallel plane.

[0047] According to variants not illustrated, having a different number of gears 10, the aforementioned lying planes may be greater in number than two.

[0048] Independently of the number of lying planes, the mounting of the position transducer 16 close to the respective gear 10 (wheel 10), in a position facing towards the inside of the motorcycle 1 , proves to be particularly advantageous.

[0049] Figures 4 and 5 show two possible positions of the position transducer 16 according to what is stated above.

[0050] According to a variant not shown, equally falling within the present invention, the transducer 16 may be mounted on a reduced shaft of the transmission system 7, which may have a variable speed ratio with respect to the rotor of the electric motor 6.

[0051] The invention thus conceived is susceptible to evident industrial application and may be the subject of numerous modifications and variants, all falling within the scope of the same inventive concept. Furthermore, all the details may be replaced by technically equivalent elements.

Claims

CLAIMS1 . An electric motor vehicle comprising:- a chassis (2),- a saddle (3),- at least one front wheel (4) and one rear wheel (5),- an electric motor (6) arranged with its own rotor axis (6a) transversely to said chassis (2) and parallel to the rotation axis of the rear wheel (5),- a device (15) for controlling said electric motor (6) comprising an inverter, and- a motion transmission system (7) interposed between an output drive wheel (9) of the electric motor (6) and the rear wheel (5), and comprising a gear train (10) designed to achieve an overall gear ratio determined in the torque transmission from the output wheel (9) of the electric motor (6) to the rear wheel (5); the motor vehicle (1 ) being characterized in that it further comprises at least one position transducer (16), in particular an encoder or a resolver, which is mounted on the drive system (7) downstream of the output drive wheel (9) of the electric motor (6) and connected to said inverter for transmitting thereto a signal indicative of the angular position of the rotor of the electric motor (6) for controlling said electric motor (6), in particular its stator currents.

2. A motor vehicle according to claim 1 , characterized in that the position transducer (16) is mounted on a shaft (11 ) of the transmission system (7), reduced with respect to the rotor of the electric motor (6).

3. A motor vehicle according to claim 1 or 2, characterized in that the position transducer (16) is mounted close to a respective gear (10) of said gear train (10), positioned facing inward of the motor vehicle (1 ).

4. A motor vehicle according to any one of claims 1 to 3, characterized inthat the position transducer (16) comprises a rotatable component and a fixed one, said rotatable component being connected to at least one of said gears (10) for transmitting as output to the fixed component a signal containing information relating to the angular position of the rotor of the electric motor (6).

5. An electric motor vehicle according to claim 4, characterized in that said fixed component of the position transducer (16), consequently to the signal coming from said rotating component, transmits a signal indicative of the angular position of the rotor of the electric motor (6) to said inverter, which processes the received data and, consequently, supplies the electric motor (6) correctly and efficiently on the basis of the angular position of the rotor.

6. An electric motor vehicle according to any one of the preceding claims 1 to 5, characterized in that the gears (10) of said gear train (10) lie distributed on at least two planes parallel to each other.

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