Activation system for pedal-activated electric vehicle

Abstract

To provide an activation system for a pedal-activated electric vehicle enabling: continuous variation other than discrete variation; automatic positioning on a gear ratio, which is easiest to use by a user, at a time of starting or traveling on a downhill; and energy recovery under braking.SOLUTION: An activation and traction system for a pedal-activated electric vehicle includes: an electric motor 30; a transmission that enables automatic positioning on a gear ratio and includes a planet device 102, an actuator 106 which discretizes a ratio, two extensible pulleys 108 and 110, and a variable speed drive 104 which includes a free wheel making it possible to recover energy during braking and operates independently of a pedal; and an integrated substrate 112 having devices for use in running control software which also performs sensor management.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to an actuation system for pedal-actuated electric vehicles, in particular in the field of pedal-assisted bicycles or e-bikes.

[0002] More particularly, a particularly advantageous application of the invention is in the field of pedal-assisted bicycles, which comprise an electric motor that can be operated to "assist" the pedaling of the user when required. The invention can also be used in pedal-operated electric three- or four-wheeled vehicles.

[0003] In particular, the invention relates to a solution for an actuation system for pedal-actuated electric vehicles of the type in which a motor acts on the pedal shaft and a chain actuated by the movement of the pedal or the motor acts on the rear wheel via a pinion.

[0004] Even more particularly, the present invention relates to a continuously variable pedal assist bicycle that also allows for energy recuperation during braking.

[0005] The present invention therefore relates to an actuation and traction system and a pedal-assisted three- or four-wheeled bicycle comprising an actuation and traction system. [Background technology]

[0006] E-bikes are pedal-assisted bicycles with an electric motor that can be operated to "assist" the user's pedaling when needed. This means that these bikes are equivalent in all respects to regular bicycles when the motor is not active. Conversely, when the user chooses to turn on the electric motor to help or assist pedaling, the bike becomes electric and requires only a small muscle effort to move.

[0007] Traffic regulations also recognise the difference between traditional bicycles and e-bikes, but consider them equal as neither exceed a speed of 25km / h, and therefore pedal-assisted bicycles do not require registration, license plates or insurance.

[0008] With pedal-assisted e-bikes, the electric motor starts automatically after the first few pedal strokes, allowing the e-bike to gain speed with minimal effort.

[0009] The electric motor operates based on signals sent by a sensor that detects the movement of the pedal. As the rotation of the pedal increases, the signals sent by the sensor become more frequent, so that the motor can gradually reach its maximum speed. The assistance makes pedaling smoother and easier. According to the regulations governing this type of vehicle, the motor is switched off when the maximum speed of 25 kilometers per hour is reached or when pedaling is stopped.

[0010] Two types of sensors are currently available on the market: motion sensors that can be activated by the first revolution of the pedal, and torque sensors, which are devices that can sense the force applied by the cyclist to the pedal, in which case the motor contribution is in fact modulated by the thrust that the cyclist applies to the bike with his legs.

[0011] The motor of an electric bicycle is powered by a rechargeable battery.

[0012] The same applies to pedal-operated electric vehicles, such as three- or four-wheelers.

[0013] If we ignore the electric motorized tricycle designed by Gustave Trouve as a demonstration in Paris in 1881, the electric bicycle is considered to have officially begun in 1895 with the filing of a patent application, U.S. Patent No. 552,271A, by American Ogden Bolton Jr. This solution involved the use of a motor located within the hub of the rear wheel.

[0014] Today, pedal-assisted electric bicycles are defined as hybrid vehicles that combine muscle power with the power of an electric motor.

[0015] The thrust of the electric motor is present simultaneously with the user's muscle pedaling, requiring less even effort from the user as he pedals, and is intended to support the user, for example, when climbing uphill or over uneven or rough terrain.

[0016] There are currently two types of solutions in the mounting techniques of e-bikes: in the first type, the motor is arranged directly in the hub of the front or rear wheel, while in the second type, the motor acts directly on the pedal axle, at the bottom bracket where the pinion with which the drive chain engages is located. The drive chain, driven by the pedaling movement of the user, acts on the rear wheel through the pinion.

[0017] The main difference between the two types of systems is the nature of the drive torque that the motor delivers to the wheels.

[0018] In the first type of solution, i.e. when the motor is in the front or rear wheel hub, the torque is strictly the torque delivered by the motor, and therefore the first type of solution cannot be applied to different use conditions where a greater or lesser intensity of pedaling assistance is required.

[0019] In the second type of solution, i.e. when the central motor is located on the pedal shaft, different gearbox-pinion reductions can be used, so that the torque transmitted to the ground can vary depending on the selected gear ratio and the conditions of use, i.e. starting, climbing, high or low speed.

[0020] Furthermore, the presence of a gearbox located on the hub of the driving wheel standardized the presence of a freewheel in the hub as a decoupling element, so that the pedals are not constantly moving even when traction energy is not required (downhill, braking).

[0021] In this case, i.e. with the second type of solution, energy recovery is not possible, since under the aforementioned conditions of use and when braking or going downhill, it is clear that the motor located on the pedal shaft is stationary.

[0022] In current solutions on the market, the motor is powered by a lithium-ion battery, usually housed in such a way that it can be easily removed for charging.

[0023] Furthermore, an electric bike is equipped with an electrical system consisting of an electric motor, an effort sensor, a speed sensor, a cut-off sensor, and generally a display for controlling the riding, in addition to the electric motor and the battery.

[0024] In solutions of known type, a key element of the entire bicycle is the gearbox.

[0025] The gearbox allows shifting the gear ratio between the pinion on the pedal shaft and the pinion on the drive wheel shaft. This change in gear ratio is necessary to adjust the muscle effort applied to the gears and can vary according to different conditions of use, within the limits allowed by the user's capabilities.

[0026] The gearbox consists of a set of pinions located on the drive wheel axle and one or more crown wheels located on the pedal axle. The drive chain transfers the force applied to the pedals from the pinions to the selected pinion by a mechanism called a derailleur that slides the chain from one pinion to the other. This can only happen with a moving chain and therefore while the bicycle is moving.

[0027] Furthermore, during the transition from one pinion to another, the transmission of forces through the chain must be interrupted.

[0028] This type of operation presents several drawbacks.

[0029] For example, when there are obstacles, curves, gradient changes or unevenness, or suboptimal road or ground conditions, and at the same time require some traction that necessitates shifting gears, the user may very well find themselves in a situation where maintaining complete control of the vehicle is critical.

[0030] However, interruptions in power transmission during shifting can lead to erratic behavior of the bike, potentially resulting in skidding or the user losing control of the bike.

[0031] Therefore, in this case, the user would usually choose to stay in the wrong gear ratio rather than make a risky shift and encounter problems, which could equally result in either too much effort on the part of the user with excessive energy consumption by the motor, or an uncomfortable pedaling action by the user.

[0032] If the vehicle has to be stopped, the gearbox will, in known solutions of this type, be set to the gear ratio that was there before the stop, because when restarting, the gear ratio can only be shifted when the chain-pinion system is moving. However, the gear ratio is usually not the most suitable for starting. As a result of this limitation, i.e. the inability to shift gears when the bike is stationary, when starting, the effort exerted by the user is suboptimal due to excessive energy consumption by the motor. [Prior art documents] [Patent documents]

[0033] [Patent Document 1] U.S. Patent No. 552271A Summary of the Invention [Problem to be solved by the invention]

[0034] SUMMARY OF THE PRESENT EMBODIMENT It is therefore a primary object of the present invention to overcome or at least minimise the disadvantages outlined above and found in the prior art.

[0035] In particular, from this characterization, a first objective of the present invention is to improve upon several operational, performance, and efficiency characteristics typical of current e-bikes, or pedal-actuated electric vehicles such as three- or four-wheelers.

[0036] In the following description, reference will be made to electric bicycles or e-bikes, however the solution can also be applied to electric three-wheelers or pedal-operated electric four-wheelers, hereinafter referred to as "electric vehicles" for the sake of simplicity.

[0037] Therefore, the characteristic points of the proposed solution are listed below: ●Continuous fluctuations, not discrete ones Automatically adjusts to the gear ratio most convenient for the user, such as when starting or going downhill ●Energy recovery under braking

[0038] From the technical architecture selected to solve the identified critical factors, other possible sources of functional improvement also emerge, such as running the electric motor at higher RPMs to achieve better performance and increasing pedaling for quicker response.

[0039] A further object of the invention is to make available a solution that allows the system to be fitted to current frames without having to resort to shape and geometric modifications (compatibility). Thus, a modification kit is provided, in particular for current pedal-operated electric vehicles such as e-bikes or three- or four-wheelers.

[0040] Additionally, the use of an internal gearbox / pedals does not expose the system to impacts or dirt (mud, water, leaves, dust) and the lack of an external gearbox / pinion system gives the user the freedom to ride on potentially treacherous terrain.

[0041] The presence of a direct final ratio without a gearbox offers the possibility of using either a conventional chain or a maintenance-free (lubricant-free) toothed belt.

[0042] Finally, according to the present invention, the actuation system must be equally simple and cost-effective, in a manner that does not require substantial modifications to the structure, and characterized by manufacturing costs that are adapted to market needs, as well as small size, dimensions, and be applicable to electric vehicles such as e-bikes and known types of three- or four-wheeled vehicles. [Means for solving the problem]

[0043] In particular, the solution described in this specification relates to an actuation and traction system for a pedal-actuated electric vehicle comprising an electric motor, a planetary device, and a transmission having a variable speed drive that operates independently of the pedals, the variable speed drive comprising an actuator for discretizing the gear ratio and two extendable pulleys.

[0044] The actuation and traction system further comprises an integrated board provided with a device for operating control software with sensor management, said integrated board being adapted to control said electric motor based on signals received from the sensors.

[0045] The actuation and traction system further includes a pinion for transmitting motion from the pedal or the electric motor to the wheels of the pedal-actuated electric vehicle. The pinion and the variable speed drive are coaxially positioned on the pedal shaft, and motion transmission is between the pedal and the wheels of the pedal-actuated electric vehicle via a kinematic chain with a planetary device and a variable speed drive.

[0046] The transmission of motion between the electric motor and the pinion is via a cascade of gears adapted to obtain the desired transformation ratio between the electric motor, which rotates at high speed, and the pinion, which actuates a motion transmission chain to the wheels of the electric vehicle.

[0047] The system further comprises a casing for housing the electric motor, the transmission, and the variable speed drive. Finally, a pinion gear is disposed outside the casing.

[0048] The present invention is based on the general consideration that it is possible to achieve the above mentioned objectives and in particular to meet the functional and reliability requirements by a solution involving a motion transmission via a kinematic chain comprising a planetary reducer, two extendable pulleys and a continuously variable reducer.

[0049] This solution applies to pedal-operated electric vehicles such as electric bikes and three- or four-wheeled vehicles.

[0050] Hereinafter, the present invention will be further described by the following detailed description of possible embodiments shown in the drawings, in which corresponding or equivalent features and / or components of the present invention are identified by the same reference numerals. It should be noted that the present invention is not limited to the embodiments described below and shown in the accompanying drawings, on the contrary, all variations and / or modifications to the embodiments described below and shown in the accompanying drawings that are obvious and immediately conceivable to those skilled in the art and are included within the scope of the present invention.

[0051] Embodiments of the systems disclosed herein are illustrated diagrammatically, given by way of non-limiting example. [Brief description of the drawings]

[0052] [Figure 1] 1A-1D are two perspective views of an actuation system for a pedal-actuated electric vehicle according to the present invention; [Diagram 2] FIG. 2 is a partially exploded view of a protective casing according to the present invention. [Diagram 3] FIG. 2 is an assembly diagram of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 4] FIG. 2 is an assembly diagram of an actuation system for the pedal-actuated electric vehicle of FIG. [Diagram 5] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 6] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 7] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 8] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 9] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 10] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 11] FIG. 2 is an exploded and partially assembled view of a portion of an actuation system for the pedal-actuated electric vehicle of FIG. [Figure 12] FIG. 1 shows a traction and actuation system according to the present invention in an assembled state but without the protective casing. [Figure 13] FIG. 2 is a top view of an assembled traction and actuation system according to the present invention, with particular emphasis on the expandable pulley mechanism. [Figure 14]1A-1C are schematic side, front and top views of a traction and actuation system according to the present invention with overall dimensions shown; [Figure 15] FIG. 1 is a perspective view of a traction and actuation system according to the invention in an assembled state, with particular emphasis on the transmission of motion, including a motor in operation; [Figure 16] FIG. 2 is a top perspective view of the assembled traction and actuation system according to the present invention, with particular emphasis on the transfer of motion during pedaling. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] The invention finds particular application in the field of electric bicycles or e-bikes.Furthermore, applications are in the field of pedal-operated electric vehicles such as three- or four-wheeled vehicles.

[0054] The solution proposed here has been made for application in the context of e-bikes, but it can also be transferred to other fields, such as that of pedal-operated electric vehicles, i.e. three- or four-wheeled vehicles.

[0055] Several intervention points for improving operational characteristics, performance, and efficiency emerge from the analysis of current e-bike characteristics.

[0056] First, after careful analysis and intensive research, it was concluded that a more appropriate choice would be continuous variation rather than discrete.

[0057] Additionally, it would be preferable to be able to have automatic alignment to the most convenient gear ratio, for example at start-up or under special circumstances while using the vehicle.

[0058] Finally, it would be advantageous to have braking energy recovery as well.

[0059] These are the three main objectives that the solution proposed here aims in particular to achieve.

[0060] From the technical architecture selected to address the identified critical factors, other possible drivers for functional improvement emerge.

[0061] In particular, provisions can be made to operate the electric motor at higher RPMs to achieve greater efficiency and increased pedaling ratios to achieve quicker response.

[0062] The principle of operation of the actuation system for a pedal-actuated electric vehicle according to the invention will now be described.

[0063] The need to achieve continuous rather than discrete variation is seen as having a natural consequence: the need to use variable speed drives instead of gearboxes with a series of discrete ratios.

[0064] By using a variable speed drive that operates independently of pedaling, automatic alignment to the most convenient gear ratio at start-up can also be achieved, thus solving start-up problems and avoiding the user exerting suboptimal effort and / or having excessive power consumption by the electric motor.

[0065] For energy recovery under braking, it is necessary to have a device that decouples the motor and wheels from the pedals, i.e., disconnects the motor and wheels from the pedals during the coasting step, so that the pedals can be stopped when the vehicle is moving forward (e.g., going downhill or decelerating) without requiring the use of muscle work to steer the e-bike or pedal-actuated electric vehicle.

[0066] The above conditions define the architecture and the working principle of the actuation system for a pedal-operated electric vehicle according to the invention, which in particular: -Use of automatically operating variable speed drives; - Provides that under conditions where energy recovery is possible, the pedal system is disconnected or decoupled from the motor-wheel system.

[0067] In addition to these specific technical elements that regulate the operation of the system, there are also application specificities that allow a solution with maximum weight savings and lateral dimensions dictated by the normal alignment of the pedals. In particular, there are constraints on the maximum width of the pedal axle to ensure comfortable pedaling and correct leg positioning during pedaling. In this manner, standard structures and frames can be used, although there are some modifications to be made.

[0068] The steps that led to the solution proposed herein will now be described together with details of the project's evolution.

[0069] The first activity consists of evaluating possible alternatives and analyzing within each of them potential problems to be solved or elements to be further explored.

[0070] A literature survey on the design and use of variable speed drives led to the decision to implement an increase in the pedal rotation speed, since the relative movement of the pulley discs of a variable speed drive takes place faster the higher their rotation speed. An additional benefit of the increased rotation speed is the reduction in the instantaneous torque value transmitted by the variable speed drive. This increase in rotation speed was achieved by the use of a planetary device that acts as a speed increaser. Control of the position of the variable speed drive pulley is achieved by an actuator consisting of a small electric motor operating through a gear reduction.

[0071] The analysis continued by exploring the kinematics of the appropriate point of coupling of the electric motor with the variable speed drive to allow operation at high RPM.

[0072] High-speed technical solutions allow for a reduction in the size of both the variable speed drive and the motor, allowing the motor to operate under the best efficiency conditions, thus reducing the size and weight of the system as a whole.

[0073] A further element of the analysis and development was a system to decouple the pedals from the wheel-variable speed drive motor assembly under conditions where no muscle power is required for traction and vehicle deceleration energy can be recovered. In particular, a device was introduced to decouple the pedal box from the wheel-variable speed drive motor assembly. In particular, such a decoupling device is a free wheel positioned to decouple the pedals from the wheel-variable speed drive motor assembly.

[0074] In the solution embodied and proposed herein, the bicycle wheel drives the motor through the final transmission, thus making energy recovery feasible, and the pedals are kept stationary by the use of a freewheel mechanism that decouples the motor from the transmission system connected to the pedals.

[0075] The selection of the motor was based on torque / rpm characteristics, but also on an assessment that the motor was sized to match the application to meet the weight and size requirements of the particular intended application.

[0076] To make the device self-sufficient and minimize electrical connections to the vehicle, the electronics boards with variable speed drive actuation and motor control SW and associated sensor technology were planned to be mounted internally. Additionally, the containment casing was also sized and designed according to the heat dissipation capacity generated during operation.

[0077] Rough sizing of the various components allowing the definition of the overall architecture of the unit was followed by final validation and associated calculations, simulations, and strength and noise validation leading to the final design and drawings.

[0078] In particular, the present invention required the research and design of a planetary reducer and a variable speed drive with actuator to adapt the variable speed drive to a traction motor that can be used in e-bikes or pedal-operated electric vehicles. In particular, the motor / pinion coupling was also researched and designed to decouple the motion by the freewheel. In addition, a casing for heat dissipation was also researched and designed.

[0079] Finally, a control software implementation integrated with sensor management was developed.

[0080] Next, we will describe the overall system that has been studied and developed in accordance with the proposed objectives.

[0081] The solution proposed here relates to a gearbox for a pedal-assisted bicycle or pedal-operated electric vehicle, in particular the gearbox comprising a continuously variable reducer located on the pedal shaft and housed in a housing which would otherwise expose the reducer to shocks.

[0082] More specifically, the solution involves the use of a reducer with an extendable pulley, where the reducer is positioned on the pedal shaft and there is an actuator that discretizes the gear ratio. Finally, the system according to the invention allows energy recovery during braking, by means of a decoupling device, for example a free wheel.

[0083] 1 shows two perspective views of an actuation system for a pedal-operated electric vehicle in an installed state. The actuation system for a pedal-operated electric vehicle comprises a motor and a gearbox.

[0084] A right hand actuation cover or housing for a pedal actuated electric vehicle is indicated in the figures by reference numeral 1, while a left hand actuation cover or housing for a pedal actuated electric vehicle is indicated in the figures by reference numeral 7. The combination of the two housings, right 1 and left 7, provides a protective casing for housing the motor and gearbox for a pedal actuated electric vehicle. The casing has a structure designed to house the actuation system.

[0085] References 1a and 7a indicate the attachment points for connecting the two housing shells together and creating the structural casing, as well as for attaching the casing to the bicycle frame. Of course, the casing also has a protective function for the actuation system. On the left side there is the cover 1, reference 2 the stop ring, reference 3 the ball bearing, and symmetrically on the right cover side 7 there is a stop ring 8 and a ball bearing 9. These elements are used to support the pedal axle, allowing the rotation of the pedal during muscle or electric motor operation.

[0086] 2, which shows a partially exploded view, several fasteners can also be seen, by means of which the two covers, right 1 and left 7, can be connected together and fixed. The fasteners include in particular a fixing bush 4 and fixing screws, indicated with the reference numbers 5, 6, 10.

[0087] FIG. 1 also shows a pedal shaft A.

[0088] Finally, reference numeral 1b denotes cooling fins arranged on the right cover 1 to better dissipate the heat generated by the actuation system for a pedal-actuated electric vehicle.

[0089] Thus, all elements of the pedal operated electric vehicle actuation system are housed inside two covers, right 1 and left 7.

[0090] 3 and 4, there is a transmission with an electric motor or motor 30, a planetary reducer 102, an actuator 106 and a variable speed drive 104 with two extendable pulleys 108 and 110. The pedal operated electric vehicle actuation system further comprises a support 33 for an integrated board 112 with a device for operating the control software with sensor management.

[0091] A planetary device can be viewed as a speed reducer or speed increaser depending on the gear ratio introduced between the input and output speeds.

[0092] In particular, the effect of the planetary reducer and variable speed drive allows the device to provide a starting torque that can help the user overcome the initial launch, and the device can maintain a stable gear ratio on flat courses.

[0093] The electric motor 30 is mounted on a support plate 32 which is connected to the rest of the actuation system of the pedal operated electric vehicle by screws 31 (see FIG. 6). A plate 33 which supports the integration board 112 is mounted to the rear of the support plate 32. The electric motor 30 has a gear wheel 29 mounted on the motor shaft 30a.

[0094] The speed reducer or planetary speed increaser 102 will now be described with reference to FIGS.

[0095] Once the value of the pedal load was determined with the appropriate safety factor, the characteristics of the planetary mechanism made of steel and its design were calculated.

[0096] In particular, the actuation and traction system includes a primary transmission having a planetary gear 102 and a final transmission having a pinion 35.

[0097] 8, the reference number 65 denotes a shaft located on the pedal shaft A. The several elements forming the planetary mechanism 102 are mounted on the shaft 65 coaxial with the pedal shaft A.

[0098] In particular, there is a right planetary flange 60 and a left planetary flange 62 which together form a satellite carrier. A left sun gear 58, a roller bearing 61 and three externally toothed satellite gears 55 are interposed between the two planetary flanges 60 and 62. A pedal shaft swivel ring 59 is disposed between the left planetary flange 62 and the left sun gear 58. Furthermore, there are also several centering bushes 63 adapted to cooperate with pre-drilled holes on the planetary flanges 60 and 62 and to be fixed by screws 56.

[0099] Additionally, there are also several stop rings, indicated by the reference numerals 54 and 57. Finally, there is a fixed internally toothed crown gear 64. The fixed crown gear 64 is provided with a toothed internal profile capable of cooperating with a toothed external profile of the satellite gears 55.

[0100] The fixed crown gear 64 can mesh with the satellite gear 55 to define a gear ratio.

[0101] The planetary reducer 102 is a mechanical member that can alternate the speed ratio between the input shaft and the output shaft. The sun gear 58 as an input for the movement rotates the three satellite gears 55 that rotate inside the toothed ring gear 64. As a result, the axis of the satellite gears themselves 55, which are mounted on the satellite carriers 60, 62, moves along the periphery. Thus, the satellite carriers 60, 62 rotate at a reduced speed relative to the sun gear 58.

[0102] The mechanism of the actuator and the expandable pulleys will now be described with reference to Figure 9. In particular, there are two expandable pulleys, primary 110 and secondary 108, where the primary pulley 110 is a driven pulley connected to a pedal or motor and the secondary pulley 108 is a passive pulley.

[0103] Moreover, the two expandable pulleys, primary 110 and secondary 108, comprise two elements, one fixed and one movable, that function together to define an expandable pulley.

[0104] The actuator 106 includes an actuator body 24 connected to the movable primary pulley 18 by a main body 106c and a fork 106b.

[0105] The main body 106 c includes a through hole 106 d adapted to receive a portion of the moveable primary pulley 18 .

[0106] At the opposite end of the main body 106c from the fork 106b is a lever element 106a hinged to a pin restrained in the box c, which acts as a pivot pin for the lever on the box.

[0107] The primary pulley 110 comprises a movable primary pulley 18 cooperating with a fixed primary pulley 20. Thus, the primary driven pulley 110 is an expandable pulley. A toothed belt 19, designated by reference numeral 19, is used to transfer the motion from the driven primary pulley 110 to the passive secondary pulley 108. Symmetrically, the secondary pulley 108 comprises a movable secondary pulley 16 cooperating with a fixed secondary pulley 17.

[0108] Reference numeral 21 denotes a primary pulley spring, reference numeral 22 is an elastic stop ring or circlip, and reference numeral 23 is a spring casing.

[0109] Referring again to FIG. 9, there is the free wheel 11, the support element 12 for the secondary driven pulley 108, and the roller bearing 13.

[0110] Reference number 15 designates balls on primary pulleys 17 and 20. These balls 15 are adapted to cooperate with corresponding grooves 16a and 18a made in the inner parts of the movable secondary pulley 16 and the movable primary pulley 18, respectively.

[0111] Reference numeral 106b denotes an actuator fork having a pin, the fork actuation system being integrated with a linear motor.

[0112] Figure 10 shows two external toothed wheels 49 which realize the transmission of motion from the pedal axle A to the wheels. Reference 38 denotes a wheel support on the pedal axle A and reference 53 denotes a secondary pulley wheel support adapted to receive inside it a decoupling device, for example a free wheel 43. The free wheel 43 ensures that the pedals do not move at all times, even when traction energy is not required (such as when braking or going downhill or during deceleration). In particular, the presence of the decoupling device allows the wheels to rotate and the bicycle to move while the pedals remain stationary.

[0113] The elements forming the final transmission will now be described with reference to figure 11. The final transmission comprises a cascade of gears, allowing the transfer of motion from the pedals or motor to the wheels of the bicycle.

[0114] Reference numeral 52 denotes a lock ring (e.g., a Bosch lock ring) and a grooved pinion 35 is mounted to the lock ring. The pinion 35 engages a chain that actuates the bicycle wheel. The pedals, chain, wheel, and bike frame are not illustrated for ease of illustration in the drawings.

[0115] The pinion spacer 47 is on the opposite side of the pinion 35 with respect to the ring nut 52. The pinion spacer 47 is connected to a Corteco seal ring 36 which is connected to a washer 40 which is held in place by a stop ring 50. Reference numeral 44 denotes a roller bearing housed in the pinion carrier 51. Reference numeral 34 denotes a number of primary pulley balls disposed on the pinion carrier 51. Additionally, there is a resilient stop ring or circlip 39 positioned between the pinion carrier 51 and the wheel support on the pedal axle 38.

[0116] The transmission is provided with two intermediate wheels 42, of the externally toothed type, mounted on roller bearings 41. The intermediate toothed wheels 42 are intended to interact with two wheels 49.

[0117] Elements 37 and 45 represent the support for the intermediate gear 42. Elements 41, 42, 45 and 37 are held together by screws 48 and an outer pin 46.

[0118] As will be appreciated above, a variable speed drive with an actuator that operates autonomously relative to pedaling can also address the need to have automatic alignment to the most usable gear ratio at start-up.

[0119] Thus, instead of having a conventional centrifugally actuated actuator, a belt actuated variable speed drive was designed with motor actuation by an electric motor. The magnitude of the change in the variable speed drive ratio was based on an evaluation of the change obtained with discrete gears, which is summarized in the table below showing possible solutions. [Table 1]

[0120] Additionally, the table below shows the different ratios that can be obtained with three pinions, 22, 32, and 44, and nine pinions, 11, 12, 14, 16, 18, 21, 24, 28, and 32. Typically, the crown is forward on the pedal axle and the pinion is backward on the rear wheel axle. [Table 2]

[0121] Correct alignment of the driven pulley 110 and the passive pulley 108 to achieve the desired gear ratio 108 is achieved by an electric motor 30 which operates reversibly and is controllable to several revolutions such that correct alignment is always achieved. The motor 30 was selected from current commercial products with special attention to the characteristics of weight, size, and reliability, but furthermore reliability was achieved through potential under-utilization of the electric motor 30, both in terms of usage time and required performance.

[0122] A commercially available product, selected not only for proper sizing but also for its oil and heat resistance and the requisite anti-static properties, was used for the drive belt 19.

[0123] FIG. 12 shows a traction and actuation system according to the present invention in an assembled state, but without the protective casing.

[0124] In a preferred embodiment, a permanent magnet type electric traction motor 30 (see FIG. 13) offering optimum performance at speeds between 1500 and 4000 RPM and a torque of 120 N / m is available from a specialist supplier.

[0125] 13A shows the driven primary pulley 110 at its maximum opening and the passive secondary pulley 108 at its minimum opening. When the driven primary pulley 110 is at its maximum opening, the moveable primary pulley 18 is at its maximum distance from the fixed primary pulley 20. Similarly, when the passive secondary pulley 108 is at its minimum opening, the moveable secondary pulley 16 is at its minimum distance from the fixed secondary pulley 17. In this state, the belt 19 is at its lowest position at the primary pulley 110 and its highest position at the secondary pulley 108.

[0126] 13B shows a state in which the primary pulley 110 is at its minimum opening and the secondary pulley 108 is at its maximum opening. When the primary pulley 110 is at its minimum opening, the moveable primary pulley 18 is at its minimum distance from the fixed primary pulley 20. Similarly, when the secondary pulley 108 is at its maximum opening, the moveable secondary pulley 16 is at its maximum distance from the fixed secondary pulley 17. In this state, the belt 19 is at its highest position at the primary pulley 110 and its lowest position at the secondary pulley 108.

[0127] FIG. 14 shows the maximum overall dimensions of the actuation and traction system. In particular, the maximum dimension is 174 cm in height, the maximum dimension is 150 cm in width, and the maximum dimension is 205 cm in length. These dimensions are shown as non-limiting examples and were specified taking into account various construction constraints as well as general indications for proper setup of position and pedaling.

[0128] 15 and 16, the actuation and traction system is shown in operation. The arrows indicate the direction of rotation of the various elements of the actuation and traction system.

[0129] The electric motor 30 is coupled to the pinion 35 via a cascade of gears adapted to obtain the desired gear ratio between the motor 30, which rotates at high speed, and the pinion 35, which actuates the transmission chain of the pedal-operated electric vehicle.

[0130] During pedaling, the planetary gearbox 102 actuates a driven primary pulley 110, coaxial with the pedal axis A, by which a belt is driven. The belt 19 transmits the movement, by a cascade of gears, to a passive secondary pulley 108 acting on the final drive (pinion 35 meshing with the drive chain at the wheel), the gear connected to which also meshes with a gear to which the electric motor 30 is pinned, thereby assisting the pedaling according to the required torque. The motor 30 is always active during the pedaling step.

[0131] During active pedalling, the pedal shaft A is connected to the planetary gearbox to actuate the satellite carrier 60 / 62 by means of the satellite gear 55 engaged in the crown gear 64 housed in the casing, which in turn actuates the sun gear 58. The sun gear 58 transmits the active rotation to the primary pulley 110 by means of the free wheel 11.

[0132] The primary pulley 110 by belt 19 drives the secondary pulley 108 which is connected to gear 49 by a free wheel 43. The free wheel 43 locks the gear 49 to the secondary pulley 108 when motion comes from the secondary pulley 108 (16 / 17).

[0133] Gear 49 is connected to motor 30 by gear 29 and to equivalent gear 49 by gear 42 , which is connected to pinion 35 .

[0134] Thus, in the case of active pedaling, effort is transferred from pedal shaft A via satellite gear 55 transmission to pinion 35 > sun gear 58 > primary pulley 110 > secondary pulley 108 > gear 49 > gear 42 > gear 49 > pinion 35.

[0135] The operation of the motor 30, which is coupled to gears 49 to support pedalling, depends on the settings selected by the supervisor SW and the user.

[0136] During the coasting step, when the motion comes from the wheels and the pedals are stationary, the pinion 35 drives the gears 49>42>49>29 (motor) by the effect of a fixed linkage with some regenerative capability due to the setting. Thanks to the presence of a decoupling device, i.e. the free wheel 43, the secondary pulley is not fed and therefore remains stationary, as do the primary pulley, the sun gear, the satellite gear and the pedal shaft.

[0137] In the case of reverse pedaling (when you have to pedal backwards for some reason), if the pedal shaft was fixedly connected to the primary pulley, the entire pulley assembly would be set in motion. The presence of the free wheel 11 between the pedal shaft and the primary pulley 110 also eliminates coasting in this direction of rotation.

[0138] During operation, no matter how efficient the motor 30 is, heat is produced both by the motor 30 itself and by the electronic board 112. To dissipate it, taking into account the high thermal conductivity properties of the container casing, the latter is provided with a series of fins 1b that increase the heat dissipation. The electronic board 112 is placed in contact with the surface of the container by means of a highly conductive mat (not shown).

[0139] A system of kinetic energy recovery during braking, achieved by the rotation of a motor obtained from a cascade of gears connected to a pinion, makes it possible to recover energy from the speed of the bike and convert it into electrical energy, which recharges the battery so that it can be used again for pedal assistance.

[0140] The sensors integrated into the system are The speed sensor is mounted directly on the electronic board 112 and receives a signal from a nearby rotating gear. ●The torque sensor is mounted near the pedal shaft and receives its signal via the sun gear of a planetary gear that is controlled by the pedal shaft itself.

[0141] An electronic board 112 containing the management SW is arranged in contact with the outer wall of the casing 1 to facilitate its cooling, which is facilitated by laying a thermally conductive mat. The development of the device management SW is the subject of various projects.

[0142] Of course, the solution can also be applied to electric three- or four-wheeled vehicles.

[0143] While the present invention has been described above by a detailed description of embodiments thereof as illustrated in the drawings, the present invention is obviously not limited to the embodiments as described above and as illustrated in the drawings, but on the contrary, all variations and / or modifications to the embodiments as described and as illustrated in the accompanying drawings are within the scope of the present invention and will be apparent and directly relevant to those skilled in the art.

[0144] Therefore, the scope of protection of the present invention is defined by the following claims.

Claims

1. An actuation and traction system for a pedal-operated electric vehicle, comprising an electric motor (30), a planetary device (102), and a transmission having a continuously variable speed drive (104) that operates independently of the pedals, wherein the continuously variable speed drive (104) includes an actuator (106) for discretizing a ratio and two expandable pulleys (108, 110), the actuation and traction system further comprises an integrated board (112) having a device for operating control software with sensor management, the integrated board (112) is adapted to control the electric motor (30) based on signals received from the sensors, and the actuation and traction system operates independently of the pedals or the electric An actuation and traction system further comprising a pinion (35) for transmitting motion from a motor (30) to the wheels of the electric vehicle, wherein the pinion (35) and the continuously variable speed drive (104) are coaxially positioned on a pedal shaft (A), motion transmission between the pedal and the wheels of the electric vehicle is performed via a kinematic chain comprising the planetary device (102) and the variable speed drive (104), and motion transmission between the electric motor (30) and the pinion (35) is performed via a cascade of gears adapted to obtain a desired conversion ratio between the electric motor (30) rotating at high speed and the pinion (35) actinguating the chain for transmitting motion to the wheels of the electric vehicle.

2. The operating and traction system according to claim 1, wherein the planetary device (102) is mounted on a shaft (65) positioned on the pedal shaft (A) of the electric vehicle and comprises a satellite carrier formed by a right planetary flange (60) and a left planetary flange (62), the satellite carrier (60, 62) comprising a left sun gear (58), a roller bearing (61), three outer toothed satellite gears (55), and an inner toothed fixed crown gear (64) having an inner toothed shape that can cooperate with the outer toothed shape of the satellite gears (55), and the planetary device (102) can define the transmission ratio.

3. The actuation and traction system according to claim 1, wherein the continuously variable speed drive (104) comprises an actuator (106) and an expandable pulley mechanism (108, 110) including a driven primary pulley (110) and a passive secondary pulley (108) connected to the pedal or motor (30), the pulleys being connected to each other by a toothed belt (19) for transmitting motion from the driven primary pulley (110) to the passive secondary pulley (108).

4. The operating and traction system according to claim 3, wherein the primary pulley (110) comprises a movable primary pulley (18) that cooperates with a fixed primary pulley (20), and the secondary pulley (108) comprises a movable secondary pulley (16) that cooperates with a fixed secondary pulley (17).

5. The actuation and traction system according to claim 4, wherein the actuator (106) comprises an actuator body (24) connected to the movable primary pulley (18) by a main body (106c) and a fork (106b), and the main body (106c) provides a lever element (106a) that constitutes a lever pin at the opposite end of the main body (106c) to the fork (106b).

6. The operating and traction system according to claim 5, wherein the continuously variable speed drive (104) comprises a free wheel (11), a support element (12) for the secondary driven pulley (108), and a roller bearing (13).

7. The operation and traction system according to claim 1, wherein the transmission of movement from the pedal shaft (A) to the wheels of the electric vehicle is performed by two outer toothed wheels (49): a first outer toothed wheel (49) mounted on a wheel support (38) on the pedal shaft (A) and a second outer toothed wheel (49) on the wheel support (53) of the secondary pulley (108).

8. The actuation and traction system according to claim 7, wherein the second outer toothed wheel (49) is adapted to house a decoupling device (43) therein, the decoupling device causing the pedal to decouple from the wheel of the electric vehicle.

9. The operating and traction system according to claim 8, wherein the decoupling device (43) is a free wheel for decoupling the pedal from the wheel in order to achieve energy recovery under braking.

10. The actuation and traction system according to claim 8, wherein the kinematic chain for transmitting motion from the pedal shaft (A) to the wheel comprises a second decoupling device (11) between the pedal shaft and a primary pulley (110) to eliminate feeding during reverse pedaling.

11. The operating and traction system according to claim 1, comprising a casing (1, 7) for housing the electric motor (30), the transmission having the planetary device (102) and the variable speed drive (104), wherein the pinion (35) is positioned outside the casing (1, 7), and the casing (1, 7) is configured to dissipate heat.

12. The actuation and traction system according to claim 11, wherein the casing (1, 7) is formed by two housings, a right housing (1) and a left housing (7), and the two housings have a plurality of mounting points (1a, 7a) on which the casing can be fixed to the frame of the electric vehicle, and a stop ring (2) and a ball bearing (3) are located inside the right housing (1) and a stop ring (8) and a ball bearing (9) are located symmetrically on the right cover (7) side, supporting the pedal shaft and allowing the pedal to rotate during muscle actuation or electric motor actuation (30).

13. The actuation and traction system according to claim 12, wherein the right housing (1) has cooling fins (1b) for more effectively dissipating the heat generated by the actuation system of the electric vehicle.

14. An electric bicycle comprising the operating and traction system described in claim 1.

15. An electric tricycle or electric quadruple-wheeled vehicle comprising the operating and traction system described in claim 1.

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