Saddle-type vehicle with hybrid propulsion

Abstract

The present invention relates to a saddle-mounted vehicle for motorcycles or light motorcycles, the vehicle comprising a frame (2), at least one steering wheel (3) rotatably connected to the frame, and a single drive wheel (4). The vehicle also includes a motor assembly (10) and a transmission unit (T) mechanically connecting the motor assembly (10) to the drive wheel. The motor assembly includes a thermal engine (MT) having a crankshaft (11), an electric motor (E) having a stator (S) and a rotor (R), and a clutch (C) having a drive shaft (C1) and a driven shaft (C2). The motor assembly (10) also includes a gearbox (G) provided with an input shaft (111) and an output shaft (112). According to the present invention, the crankshaft (11) of the thermal engine (MT), the rotor (R) of the motor (E) and the two shafts (C1, C2) of the clutch are coaxial so as to rotate about a common axis of rotation (101), which is parallel to the longitudinal direction (Y) of the vehicle and parallel to the axis of rotation of the output shaft (112) of the gearbox (G).

Description

[0001] This invention pertains to the production of saddle-riding motorcycles with two or three wheels, wherein only one wheel is a drive wheel. In particular, this invention relates to saddle-riding vehicles with a hybrid propulsion system, i.e., vehicles comprising a motor assembly having a thermal engine and a reversible motor, the reversible motor serving either as an electric motor to increase the available torque at the drive wheel or as a generator to recharge a battery assembly connected to the same motor. Background Technology

[0002] In recent years, two-wheeled or three-wheeled motorcycles with hybrid propulsion systems have been proposed, in which an electric motor is added to a conventional internal combustion engine. The purpose of this propulsion system is essentially to utilize the internal combustion engine under efficient conditions and recover energy through the electric motor during deceleration or braking, and it is possible to use the electric motor alone as the propulsion unit. Generally speaking, the aim of hybrid propulsion systems is to reduce pollutant emissions generated by the operation of the internal combustion engine.

[0003] In hybrid propulsion systems, a first configuration, also known as a "series hybrid," is known, in which a heat engine drives the rotor of an electric generator to recharge a battery pack. The battery pack powers an electric motor, which in turn provides propulsion to the motorcycle's drive wheels. Therefore, in this configuration, the propulsion system is purely electric, and the heat engine is used solely for recharging the battery, thus allowing for optimal operation.

[0004] A configuration known as "parallel hybrid power" is also known, in which the drive wheels can be actuated by both a thermal engine and an electric motor.

[0005] Example of a hybrid motorcycle is described in WO 2004 / 054836, in which such a propulsion device is used in an open-frame motorcycle (small motorcycle). Specifically, the solution provides a propulsion assembly comprising a heat engine, an electric motor, and a generator. A centrifugal clutch is operatively arranged between the heat engine and the electric motor. The drive shaft of the centrifugal clutch is connected to the crankshaft of the heat engine via a continuously variable transmission (CVT), while the driven shaft of the centrifugal clutch is connected to the rotor of the electric motor. Finally, the rotor is connected to the drive wheel via a reduction gear.

[0006] In the propulsion assembly described in WO 2004 / 054836, propulsion is provided solely by the thermal engine when the electric motor is disconnected. Conversely, the propulsion system is purely electric when only the electric motor provides power and the thermal engine is disconnected. When the thermal engine and electric motor operate simultaneously, the propulsion assembly forms a parallel hybrid power system, wherein, in the low-speed range of the thermal engine, the propulsion of the drive wheels depends solely on the electric motor, while the thermal engine is used to recharge the battery via a generator.

[0007] Therefore, the above-described technical solution provides the transmission of motion (via CVT) from the drive shaft to the rotor on which the clutch and motor are mounted. In particular, the clutch and electric motor are arranged substantially close to the drive wheels.

[0008] Another example of a hybrid propulsion system is described in US 2013 / 00818985, in which the hybrid propulsion system is applied to a closed-frame motorcycle. According to this solution, the electric motor is mounted along an axis at a height lower than that of the heat engine's shaft relative to the ground. In this case, the propulsion assembly also includes a gearbox with an input shaft that rotates about an axis parallel to and spaced apart from the rotational axes of the heat engine and the electric motor's rotor. The gearbox also includes an output shaft connected to the drive wheel by means of a transmission unit. The motor assembly also includes a first clutch, the drive shaft of which is connected to the heat engine's shaft by means of a mechanical transmission, and the driven shaft of the clutch is integral with the gearbox's input shaft. A second clutch also includes a drive shaft connected to the electric motor's rotor by means of a second transmission, and the drive shaft is connected to the gearbox's input shaft.

[0009] The heat engine and electric motor can be connected to or disconnected from the gearbox input shaft via two clutches. When both clutches are engaged, the propulsion assembly operates according to a parallel hybrid power scheme. When the first clutch is engaged and the second clutch is disengaged, the drive torque is generated solely by the heat engine. Conversely, when the first clutch is disengaged and the second clutch is engaged, the drive torque is generated solely by the electric motor. By disengaging the first clutch and simultaneously energizing the generator, operation according to a series hybrid power scheme is established.

[0010] The applicant has noted that the aforementioned technical solutions, as well as other conceptually similar solutions, have several drawbacks, particularly caused by the arrangement of the thermal engine and electric motor that constitute the hybrid propulsion system. Specifically, the current propulsion assembly configuration is exceptionally complex and bulky, making its manufacture and installation difficult. These aspects clearly impact the final manufacturing cost. Furthermore, the current propulsion assembly configuration may also be disadvantageous in terms of vehicle inspection and / or maintenance operations. Summary of the Invention

[0011] Therefore, the main objective of this invention is to provide a hybrid-propelled vehicle that is an effective alternative to known vehicles. A first objective of this objective is to provide a hybrid-propelled motorcycle whose motor assembly is particularly compact and can be easily mounted onto a frame. Another objective of this invention is to provide a reliable hybrid-propelled motorcycle that can be easily manufactured at a competitive cost.

[0012] The applicant has observed that the aforementioned tasks and objectives can be achieved by arranging a thermal engine such that its crankshaft rotates coaxially with the rotor of a reversible electric motor and coaxially with the (drive and driven) shaft of a clutch. In particular, the present invention relates to a saddle-type vehicle comprising a frame, at least one steering wheel rotatably connected to the frame, a single drive wheel, a motor assembly, and a transmission unit mechanically connecting the motor assembly to the drive wheel. The motor assembly includes:

[0013] - A heat engine, which includes a crankshaft;

[0014] - An electric motor, which includes a stator and a rotor;

[0015] - A clutch, comprising a drive shaft and a driven shaft; and

[0016] - Gearbox, which is equipped with an input shaft and an output shaft.

[0017] According to the invention, the crankshaft, the rotor, the drive shaft, and the driven shaft are coaxial so as to rotate about a common axis of rotation. Furthermore, this common axis of rotation is parallel to the axis of rotation of the output shaft of the gearbox and substantially parallel to the longitudinal direction of the vehicle frame.

[0018] According to the first embodiment, the crankshaft of the thermal engine is integrated with the rotor of the electric motor and the drive shaft of the clutch. Furthermore, the input shaft of the gearbox is connected to the driven element of the clutch, and the output shaft is connected to the drive wheel via a transmission unit.

[0019] According to one embodiment, the motor is arranged between the thermal engine and the clutch, such that the rotor is connected to the crankshaft on its first side and to the drive shaft of the clutch on its second side.

[0020] According to another embodiment that replaces the last mentioned embodiment, the thermal engine is arranged between the motor and the clutch, such that the crankshaft is connected to the rotor of the motor on its first side and to the drive shaft of the clutch on its second side.

[0021] According to another embodiment, the clutch is arranged between the heat engine and the electric motor, with the clutch's drive shaft integrated with the heat engine's crankshaft and the clutch's drive shaft integrated with the electric motor's rotor. In a possible modification, the gearbox's input shaft is connected to the electric motor's rotor, while its output shaft is connected to the drive wheel via a transmission unit.

[0022] In another implementation:

[0023] - The drive shaft of the clutch is integrated with the crankshaft of the thermal engine, and the driven shaft of the clutch is integrated with the input shaft of the gearbox.

[0024] - The output shaft of the gearbox is connected to the rotor of the motor, and

[0025] - The motor's rotor is connected to the drive wheel via a transmission unit.

[0026] In a possible embodiment of the invention, the transmission unit includes a drive shaft connected to the output shaft of the gearbox and a transmission module that transmits the motion of the drive shaft to the drive wheel. Attached Figure Description

[0027] Other features and advantages of the invention will become more apparent from the following detailed description of some preferred but non-exclusive embodiments of the vehicle, provided for illustrative purposes and not for limitation, in which:

[0028] - Figure 1 This is a general schematic diagram of the vehicle according to the present invention;

[0029] - Figures 2 to 5 These are schematic diagrams relating to possible embodiments of the motor assembly of the saddle-type vehicle according to the present invention;

[0030] - Figure 6 This is a schematic diagram illustrating an embodiment of the vehicle according to the present invention.

[0031] In the accompanying drawings, the same reference numerals and characters denote the same elements or parts. Detailed Implementation

[0032] Referring to the accompanying drawings listed above, the present invention therefore relates to a saddle-mounted vehicle with a hybrid propulsion system. For the purposes of this invention, the term "saddle-mounted vehicle" should refer to any motorcycle or light motorcycle with two or three wheels.

[0033] Figure 1 This is a schematic diagram of a vehicle 1 according to the present invention. In any case, the vehicle 1 includes a frame 2 with a front frame portion 2A supporting one or two steering wheels 3. The frame 2 also includes a rear frame portion 2R specifically supporting drive wheels. Therefore, the term "drive" refers to the transmission of rotational torque generated by the motor assembly 10 to a single wheel of the vehicle 1.

[0034] The frame 2 of vehicle 1 is mechanically connected to the motor assembly 10 of drive wheels 4 via a transmission unit T. The transmission unit T can have different configurations and typically includes a series of motion transmission components that transmit all the torque generated by the motor assembly 10 to the drive wheels 4, causing the drive wheels 4 to rotate and ultimately move the vehicle forward. Vehicle 1 extends primarily along the longitudinal direction Y (or longitudinal axis Y), which is substantially aligned with the longitudinal direction of the vehicle itself, i.e., the fore-and-aft direction. In practice, the longitudinal direction is a fore-and-aft direction that is substantially perpendicular to the axis of rotation of the drive wheels 4.

[0035] Figures 2 to 5 This is a schematic diagram of a possible embodiment of the motor assembly 10 of the vehicle 1 according to the present invention. In any case, the motor assembly 10 includes a thermal engine MT and a reversible motor E, i.e., a motor that can operate as an electric motor or a current generator.

[0036] The thermal engine MT includes a crankshaft 11, which rotates based on principles known to those skilled in the art by means of a sliding crank mechanism to convert the translational motion of one or more pistons in a cylinder, the translational motion being caused by a combustion process occurring in the same cylinder.

[0037] The operation of the reversible motor E, operatively connected to the battery assembly B, is also known to those skilled in the art. In a first operating mode, the motor E operates as a "motor," converting input electrical energy supplied at the terminals of the stator S into mechanical power available at the rotor R. In a second operating mode, the motor E operates as an "alternator / generator," converting the rotational mechanical energy of the rotor R into electrical energy, which is preferably stored in the battery assembly B.

[0038] In the vehicle 1 according to the invention, the motor assembly 10 further includes a clutch C, which, as is known to those skilled in the art, is used to connect two shafts upon command, thereby allowing or potentially regulating the transmission of rotational motion from one shaft to another. In any case, for the purposes of the invention, the clutch C includes a drive shaft C1 and a driven shaft C2, the drive shaft C1 having at least one first connecting element C11 integrally connected thereto, and the driven shaft C2 having at least one second connecting element C12 integrally connected thereto. The clutch C includes an actuating device (not shown in the figures) for contacting the connecting elements C11, C12 with each other to transmit motion from the drive shaft C1 to the driven shaft C2. Still within the framework of the invention, the clutch C can be a "dry" type clutch or an "oil bath" type clutch, or it can be a centrifugal clutch. As mentioned above, torque converters commonly used in automatic gearboxes, and any other systems more generally suited to perform the functions of a "clutch" known to those skilled in the art, also fall within the definition of a clutch.

[0039] According to the present invention, in vehicle 1, motor assembly 10 is configured such that the crankshaft 11 of the heat engine MT, the rotor R of the motor E, and the two shafts of the clutch C (i.e., drive shaft C1 and driven shaft C2) all rotate about a common axis of rotation 101. In other words, the rotating elements (11, R, C1, C2) of motor assembly 10 are aligned, thereby forming a series of components (M, E, C) extending along the common axis.

[0040] According to Figure 2 In the first embodiment of the motor assembly 10 schematically shown, the crankshaft 11 of the heat engine MT is integrated with the rotor R of the motor E and the drive shaft Cl of the clutch C. Therefore, the crankshaft 11, the rotor R, and the drive shaft Cl rotate at the same speed about a common axis of rotation 101.

[0041] In this embodiment, the motor assembly 10 further includes a gearbox G disposed between the clutch C and the transmission unit T. According to known principles, the gearbox G includes an input shaft 111 and an output shaft 112, as well as a plurality of gears (not shown in the figures), which can be actuated by a lever or by means of an electronic system and operatively positioned between the two shafts 111 and 112 to change the speed of the output shaft 112 relative to the speed of the input shaft 111. In this embodiment (… Figure 2 In the clutch, the input shaft 111 is connected to the driven shaft C2 of the clutch C, while the output shaft 112 is connected to the transmission unit T.

[0042] exist Figure 2 Schematic diagram and Figure 3 and Figure 4In the schematic diagram, the output shaft 112 of the gearbox G is coaxial with the input shaft 111. However, based on the configuration of the gearbox G, the two shafts 111 and 112 can also be arranged with different shafts.

[0043] exist Figure 3 In the second embodiment of the motor assembly 10 shown in the figure, the crankshaft 11, rotor R, and drive shaft C1 are still integral with each other, however... Figure 2 Compared to the diagram, the positions of the heat engine MT and the motor E are reversed. Specifically, the heat engine MT is operatively arranged between the motor E and the clutch C along the common axis of rotation 101. Therefore, the crankshaft 11 is connected to the rotor R on its first side and to the drive shaft C1 of the clutch C on its second side.

[0044] In the two configurations described ( Figure 2 and Figure 3 In this configuration, since the rotor R is integrated with the crankshaft 11, the motor E can be used as a "motor" for starting the thermal engine MT. Preferably, the thermal engine MT is equipped with a pressure reducing device to allow the cylinder to communicate with the external environment during the compression and expansion phases, thereby reducing the mechanical torque that must be provided by the motor for starting.

[0045] Still refer to Figure 2 and Figure 3 During the acceleration phase of vehicle 1, motor 10 can be advantageously used to increase the torque generated by the thermal engine MT. In this case, the windings of stator S are powered by battery assembly B.

[0046] Alternatively, during the acceleration phase, torque can be supplied to drive wheel 4 solely by the thermal engine MT. In this case, the stator S windings of motor E are not powered, and rotor R is driven to rotate only by crankshaft 11 of thermal engine 1, thus "idling" relative to stator S.

[0047] Still refer to Figure 2 and Figure 3 The diagram illustrates that during the constant-speed operation phase, motor E can operate as a "generator" to recharge battery module B. Alternatively, under operating conditions, the windings of the stator S of motor E can be de-energized, allowing the rotor R to rotate relative to the stator S without generating any electrical effect.

[0048] Finally, also during the vehicle's braking phase, motor E can remain disconnected, or alternatively, motor E can operate as a generator to recharge battery pack B. Typically, motor E can therefore be switched on or off during different vehicle operating phases (acceleration, constant speed, braking) based on the settings of its own control unit ECU. For simplicity, the control unit ECU only... Figure 2 As shown herein, but it should be understood that such a unit (ECU) may be present in any of the embodiments shown and described herein for allowing the motor to operate as an electric motor, a generator / alternator, or alternatively for allowing the motor to remain disconnected.

[0049] Figure 2 The schematically illustrated embodiment allows for better cooling of the heat engine MT because the motor assembly 10 is mounted such that the axis of rotation 101 is substantially parallel to the longitudinal axis of the vehicle 1 (see [link]). Figure 6 (See schematic diagram). In this configuration, the radiator can be easily mounted in front of the heat engine MT to cool the heat engine MT.

[0050] and Figure 2 Compared to the implementation method, Figure 3 The arrangement allows for simpler electrical connections and also takes into account the possible location of battery module B.

[0051] According to Figure 2 and Figure 3 Both embodiments shown are valid possible configurations in which the thermal engine MT and the electric motor E can be arranged in a common housing, and the clutch C can also optionally be arranged in the housing to form a single component that can be more easily mounted onto the frame 2 of the vehicle 1.

[0052] according to Figure 4 In another embodiment of the motor assembly 10 shown, a clutch C is operatively arranged between the heat engine MT and the motor E along the common axis of rotation 101. Specifically, the drive shaft C1 of the clutch C is integrated with the crankshaft 11 of the heat engine MT, while the driven shaft C2 is integrated with the rotor of the motor E. Also in this embodiment, the motor assembly 10 includes a gearbox G, the input shaft 111 of which is integrated with the rotor R, and the output shaft 112 of the gearbox G is connected to the transmission unit T.

[0053] When clutch C is engaged, i.e., when the connecting elements C1 and C12 of clutch C are connected, the crankshaft 11 of the thermal engine MT is rotatably integrated with the rotor R of the electric motor E. The torque generated by the thermal engine MT is thus transmitted to the drive wheel 4. This torque can be provided alone, or alternatively, it can be supplemented by engaging the electric motor E in "motor" operation mode to increase thrust (boost).

[0054] Conversely, when clutch C is disengaged, i.e., when the two connecting elements C11 and C12 are disconnected, the thermal engine MT no longer provides driving power. The propulsion force of drive wheel 4 can therefore be provided solely by motor E through gearbox G and transmission unit T.

[0055] Therefore, in this embodiment, vehicle 1 can have a pure electric propulsion system (clutch C disengaged) or a hybrid propulsion system (clutch C engaged and the motor activated). In the case of pure electric propulsion, the gears of gearbox G can be advantageously used for climbing hills.

[0056] and Figure 4 Compared to the diagram, in Figure 5 In the schematically illustrated embodiment, the motor E is operatively arranged along the common axis of rotation 101 between the transmission unit T and the gearbox G, which in turn is positioned between the clutch C and the motor E. Specifically, the input shaft 111 of the gearbox G is connected to the driven shaft C2 of the clutch C, while the output shaft 112 is connected to one side of the rotor R of the motor E. The transmission unit T is connected to the other side of the rotor R. Therefore, in this embodiment, the gear G is only activated when the clutch C is engaged, i.e., when the propulsion force is fully or partially provided by the thermal engine MT. Thus, when the propulsion device is purely electric, the gears of the gearbox G are not used.

[0057] Advantageously, Figure 4 and Figure 5 The schematically illustrated possible implementation allows the thermal engine MT to use the electric motor E as a "motor" for inertial starting. This starting requires the clutch connecting elements C11 and C12 to be initially disengaged. In this case, the vehicle 1 moves by a purely electric propulsion system. When the vehicle 1 reaches a predetermined speed, the friction device C closes, i.e., is activated, to connect the two connecting elements C11 and C12, and thus drive the crankshaft 11 to rotate, thereby starting the thermal engine MT. In a possible operating mode, when the clutch C is engaged, the electric motor E can advantageously be accelerated by means of a control unit to compensate for the deceleration of the rotor R due to the increased load on it.

[0058] Reference Figure 4 , Figure 5 In the schematic embodiment shown, during the acceleration phase of vehicle 1, motor E can therefore be engaged in "motor" mode to increase thrust, or alternatively, motor E can remain disconnected, thus not contributing to the thrust provided solely by the thermal engine MT. Figure 6 In the implementation, the switching on of the motor E, which is the "motor", is instead used to supplement the acceleration phase, as mentioned above.

[0059] Still refer to Figure 4 and Figure 5The schematically illustrated implementation allows for the recharging of battery pack B by engaging motor E in "generator" mode during the vehicle's constant speed operation or braking phases. In any case, motor E can be disconnected during one or both of these phases.

[0060] exist Figure 6 In the embodiment shown, the common axis of rotation 101 defined by the motor assembly 10 is oriented substantially parallel to the longitudinal axis Y.

[0061] In terms of vehicle stability, Figure 6 The arrangement shown has also proven particularly advantageous, especially in terms of rolling motion. In fact, the plane containing the axis of rotation of the heat engine MT, and therefore the plane containing the axis of rotation of the rotor R of the motor E, does not change during vehicle rolling. In practice, this configuration avoids or at least greatly reduces the potential for rotational opening effects, which could amplify similar effects caused by the wheels.

[0062] exist Figure 6 In the middle, the motor assembly 10 has a connection with Figure 2 The configuration shown schematically corresponds to the configuration illustrated in the diagram. However, the motor assembly 10 can also be configured as follows: Figure 3 and Figure 4 The configuration shown is an embodiment in which the gearbox G has an output shaft 112 connected to the transmission unit T.

[0063] exist Figure 6 In the transmission unit T, there is a transmission shaft T1 (e.g., by means of a universal joint or constant velocity joint) connected to the output shaft 112 of the gearbox G and the transmission module (e.g., a quasi-hyperboloid) T2, which transmits the rotational motion of the shaft T1 to the drive wheel 4.

[0064] The above-described technical solution allows the outlined tasks and objectives to be fully achieved. In particular, the arrangement of the components (thermal engine MT, electric motor E, and clutch C) along the same axis facilitates assembly and makes it easier to mount these components onto the vehicle frame, thereby reducing final manufacturing time and cost.

Claims

1. A saddle-mounted vehicle (1), the vehicle (1) comprising a frame (2), at least one steering wheel (3) rotatably connected to the frame, a single drive wheel (4), a motor assembly (10), and a transmission unit (T) mechanically connecting the motor assembly (10) to the drive wheel (4), in, The motor assembly (10) includes: - A heat engine (MT), the heat engine (MT) including a crankshaft (11); - An electric motor (E), the electric motor (E) comprising a stator (S) and a rotor (R); - Clutch (C), the clutch (C) including a drive shaft (C1) and a driven shaft (C2); - A gearbox (G) having an input shaft (111) and an output shaft (112) and a plurality of gears, which are actuated by a lever or by means of an electronic system and operatively positioned between the input shaft (111) and the output shaft (112) so as to change the speed of the output shaft (112) relative to the speed of the input shaft (111). The crankshaft (11), the rotor (R), the drive shaft (C1), and the driven shaft (C2) are coaxial so as to rotate about a common axis of rotation (101). The frame (2) of the vehicle (1) defines the longitudinal direction (Y). The common axis of rotation (101) is parallel to the axis of rotation of the output shaft (112) of the gearbox (G) and substantially parallel to the longitudinal direction (Y). The thermal engine (MT), the electric motor (E), the clutch (C), and the gearbox (G) are arranged in a configuration selected from the group consisting of: - First configuration, in which the motor (E) is arranged between the thermal engine (MT) and the clutch (C) such that the rotor (R) is connected to the crankshaft (11) on a first side of the rotor (R) and to the drive shaft (C1) of the clutch (C) on a second side of the rotor (R); - A second configuration in which the clutch (C) is arranged between the thermal engine (MT) and the electric motor (E), and wherein the drive shaft (C1) of the clutch (C) is integral with the crankshaft (11) of the thermal engine (MT), and the driven shaft (C2) of the clutch (C) is integral with the rotor (R) of the electric motor (E); - A third configuration in which the drive shaft (C1) of the clutch (C) is integrated with the crankshaft (11) of the thermal engine (MT), and the driven shaft (C2) of the clutch (C) is integrated with the input shaft (111) of the gearbox (G); the output shaft (112) of the gearbox (G) is connected to the rotor (R) of the motor (E), and wherein the rotor (R) of the motor (E) is connected to the drive wheel (4) via the transmission unit (T).

2. The vehicle (1) according to claim 1, wherein, The crankshaft (11) of the thermal engine (MT) is integrated with the rotor (R) of the motor (E) and the drive shaft (C1) of the clutch (C), wherein the input shaft (111) is connected to the driven shaft (C2) of the clutch (C), and wherein the output shaft (112) is connected to the drive wheel (4) via the transmission unit (T).

3. The vehicle (1) according to claim 1, wherein, The input shaft (111) of the gearbox (G) is connected to the rotor (R) of the motor (E), and the output shaft (112) is connected to the drive wheel (4) via the transmission unit (T).

4. The vehicle (1) according to claim 1, wherein, The transmission unit (T) includes a transmission shaft (T1) connected to the output shaft (112) of the gearbox (G) and a transmission module (T2) that transmits the motion of the transmission shaft (T1) to the drive wheel (4).

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