Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
  • B62M6/00—Rider propulsion of wheeled vehicles with additional source of power, e.g. combustion engine or electric motor
  • B62M6/40—Rider propelled cycles with auxiliary electric motor
  • B62M6/75—Rider propelled cycles with auxiliary electric motor power-driven by friction rollers or gears engaging the ground wheel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C13/00—Tyre sidewalls; Protecting, decorating, marking, or the like, thereof
  • B60C13/02—Arrangement of grooves or ribs

Definitions

• the present invention relates to electric assistance devices for bicycles and bicycles equipped with such devices.
• Some of these devices use an electric machine placed in the hub of one of the wheels of the bicycle. This electric machine drives the wheel directly or through a reduction system.
• This type of device has the disadvantage of a large mass, this mass being further located at the wheel which makes it very sensitive for the cyclist.
• disassembly of the wheel is complicated by the presence of electrical connections which are necessary for the power supply of the electric machine and hub-specific fasteners that are necessary for engine torque recovery.
• the document DE-20314210-U1 describes a principle of driving a bicycle by an electric motor in which a motor pinion meshes with a toothing integral with the circle of the front rim of the bicycle, said toothing being an internal toothing, that is, whose teeth point towards the wheel axle.
• a disadvantage of this system is that the teeth of the rim is likely to retain pebbles.
• the invention therefore aims to provide an electric assistance device for cycling and a bicycle equipped with said device that solve all or part of these difficulties.
• the invention proposes for this purpose an electric assistance device for a bicycle, said device comprising:
• fastening means able to fix the electric machine on the bicycle near a tire of a wheel of said bicycle
• the motor pinion comprises a toothing intended to mesh tangentially with a complementary toothing integral with said tire, the toothing of the motor pinion being a helical toothing.
• This type of gear and gear transmission is called “positive” transmission as opposed to friction transmission systems such as roller systems.
• a positive transmission is not dependent on the coefficient of friction and therefore for example insensitive to weathering or wear of the elements used.
• the electric machine is preferably a brushless three-phase synchronous motor with permanent magnets. More preferably the rotor is an external rotor.
• the toothing of the drive pinion is an asymmetric toothing whose teeth comprise driving faces and non-driving faces, the opening angle of the driving faces being smaller than the opening angle of the faces. non-motor.
• the drive pinion is driven by the electric machine via a freewheel mechanism so that the bandage does not drive the electric machine when the bike moves forward.
• said device further comprises a display unit and control connected to the control means of the electric machine and adapted to form an interface between the cyclist and the control means.
• said device further comprises a pedaling sensor connected to the control means of the electric machine.
• the fixing means comprise an oscillating arm articulated on a support, the support being intended to be secured to the bicycle and the oscillating arm carrying the electric machine so that the driving force transmitted to the tire by the drive pinion generates additional radial pressure in the meshing.
• a resilient means exerts prestressing on the orientation of the oscillating arm so that, in the absence of a driving force, the motor pinion is pressed radially against the bandage with a non-resting force. nothing.
• the fixing means define at least two positions of the electric machine relative to the tire, said at least two positions comprising a working position in which the motor pinion meshes with the bandage teeth and a position of fold in which the motor pinion is kept away from the bandage.
• the invention also relates to a bicycle electric assistance kit comprising the electric assistance device as described above, said electric assistance kit further comprising a tire, said tire being a tire comprising said complementary teeth.
• said complementary toothing is placed on a sidewall of the tire.
• said complementary toothing is an asymmetrical toothing whose teeth comprise driving faces and non-driving faces, the angle of opening of the driving faces being smaller than the opening angle of the non-driving faces. -motrices.
• the pitch of the complementary toothing is between 1.8 mm and 5.5 mm and more preferably between 1.8 mm and 2.5 mm.
• the invention also relates to an electric assistance bicycle comprising an electric assistance kit as described above.
• the electric assistance kit is installed on the rear wheel of the bicycle.
• Figure 1 is a schematic side view of an electric bicycle according to a first embodiment of the invention.
• Figure 2 is a more detailed schematic view of a second embodiment of an electric bicycle according to the invention.
• Figure 3 schematic sectional view showing the cooperation of the electric machine with the bandage of an electric bicycle according to the invention.
• Figure 4 is a detailed sectional view of the meshing of the drive pinion with the toothing of the bandage according to a preferred embodiment of the invention.
• FIG. 5 is a diagrammatic sectional view of the detail of the toothing of the driving pinion of FIG. 4.
• Figure 6 is a schematic sectional view of the detail of a toothing of a preferred embodiment of a bandage according to the invention.
• Figure 7 is a side view of a helical gear pinion according to a preferred embodiment of the device of the invention.
• FIG. 8 sectional view in perspective of a tire on a bicycle according to the invention.
• Figure 9 is a schematic perspective view of a detail of a preferred embodiment of the electric assist device according to the invention.
• Figure 10 is a schematic perspective view of the embodiment of Figure 9 from a different point of view.
• FIG. 1 we see the main elements of an electric bicycle according to the invention.
• An electric machine 2 is fixed to the frame 1 1 of the bicycle 1 near a tire 5, here in the vicinity of the tire of the rear wheel 61.
• a source of electrical energy in this case a battery 7, supplies the electric machine with electricity.
• intermediate control means 8 The motor pinion 3 meshes tangentially with a toothing 51 of the bandage 5 and can thus transmit a driving force that assists the cyclist.
• FIG. 2 shows another embodiment in which the electric assistance device is intended to cooperate with the tire of the front wheel 62 of the bicycle.
• the fixing means 4 of the electric machine 2 are better seen in this figure.
• the fixing means preferably comprise an oscillating arm 41 articulated with respect to a fixed support 42 along an axis 43 substantially parallel to the shaft of the electric machine. .
• the support 42 is secured to the bike, here the front fork 12 of the bike.
• the motor pinion 3 meshes with the toothing 51 which is integral with the sidewall of the tire 5.
• the fixing means are configured as here so that the transmission of a driving force by the driving pinion generates an additional dynamic force. support of the pinion on the tire and therefore additional radial pressure in the meshing. This effect is for example obtained if the pivot axis 43 is as here spaced from the plane of the meshing (spread outward of the bandage in this configuration).
• an elastic means exerts prestressing on the orientation of the oscillating arm so that the driving pinion 3, in the absence of a driving force, comes to rest radially against the bandage with a non-zero bearing force.
• the elastic means may be, for example, a torsion spring acting around the axis of rotation 43 of the oscillating arm or a simple tension or compression spring acting directly between the oscillating arm 41 and the support 42.
• Figure 3 there is shown in view according to the plane of the wheel a preferred embodiment of the cooperation between the electric machine 2 and the tire 5.
• the electric machine is inclined at an angle ⁇ relative to the plane 61 1 of the wheel 61.
• the angle ⁇ may vary but it is preferably between -10 ° and + 30 °.
• a is about 25 °
• the toothing 51 is integral with a flank 52 of the tire and is located radially below the equator 54.
• the tire may be a tire or non-pneumatic or even a solid tire.
• the electric machine directly drives the motor pinion, that is to say without any intermediate reduction means, the pinion being carried by the shaft of the electric machine.
• a freewheeling mechanism is interposed between the shaft and the pinion so that the bandage does not drive the electric machine when the bicycle is moving forward. In the event that the device does not include a free wheel, electric energy recovery can be achieved when the cyclist brakes.
• the electric machine 2 is preferably placed radially outside the motor pinion 3 relative to the axis of the bicycle wheel, that is to say above the pinion motor 3 in this configuration.
• FIG 4 shows in detail the meshing of the motor pinion 3 on the bandage.
• the pinion transmits to the bandage a driving force FM.
• FM driving force
• the teeth 32 of the pinion are asymmetrical and configured so that the opening angle of their driving faces 33 is smaller than the opening angle of their non-driving faces 34
• the shape of the complementary toothing 51 integral with the tire is naturally adapted accordingly. This arrangement makes it possible to appreciably improve the efficiency of the meshing as well as to increase the maximum value of the transmissive FM driving force.
• the line Dl is the line perpendicular to the tangent of the teeth at the point of contact at mid-height of the teeth (see also Figure 6).
• the half-lines D2 and D3 are separated from D1 by an angle ⁇ .
• Sector A corresponds to the area between the line D1 and the right half D2.
• Sector B corresponds to the area between the line D1 and the right half D3.
• the angle ⁇ does not exceed 60 °.
• One way to ensure that the driving force generates an additional dynamic support force is to verify that the position of the intersection of the axis 43 with the median plane of the pinion meets one of the following conditions: If the axis 43 is located at the front of the pinion relative to the direction of travel of the bicycle (as shown in Figure 1), the intersection must be located in the sector A shown in Figure 4.
• the teeth 51 of the bandage there is shown on a larger scale the teeth 51 of the bandage to better view a preferred embodiment.
• the teeth 51 1 of the set of teeth of the bandage have driving faces 512 and non-driving faces 513. It can be seen that the opening angle B1 of the driving faces 512 is substantially lower. that the opening angle B2 of the non-driving faces 513.
• the toothing has a pitch P and a height H.
• the pitch of the toothing is preferably between 1.8 mm and 5.5 mm and preferably between 1, 8 mm and 2.5 mm in order to minimize the noise emitted by the meshing.
• This figure also shows the straight line D1 mentioned above with reference to FIG. 4.
• Figures 5 and 6 illustrate teeth having rectilinear faces.
• the angles described above shall be measured by considering the tangent at the point corresponding to the half-height of the tooth (see the mean radius Rm in Figure 5 and the half height H / 2 on the Figure 6).
• Figure 7 is shown on a larger scale the motor pinion 3 and an essential feature of the invention according to which the toothing is a helical toothing.
• the axis of the teeth 32 is inclined at an angle ⁇ relative to the axis 35 of the pinion and therefore relative to the shaft of the electric machine.
• the angle ⁇ illustrated here is about 15 °, but it may for example be between 4 and 40 ° and preferably between 15 ° and 30 ° to minimize noise without greatly degrading the maximum value of the driving force FM transferable.
• the motor pinion 3 is made of metal, for example steel. If necessary, the freewheel mentioned above can be integrated inside the pinion.
• FIG 8 we see a preferred embodiment of the tire 5. This is a tire comprising in known manner flanks 52, a tread 53 and rods 54 for its anchoring on a bike rim not shown. It can also be seen that the teeth of the toothing 51 integral with the sidewall are inclined relative to the radial direction of the tire by an angle corresponding to the helix angle ⁇ described for the driving pinion with reference to FIG.
• the set of teeth of the tire consists mainly of rubber with a Shore A hardness preferably between 55 and 85 and preferably between 75 and 85 to promote the maximum value of the transmissive FM driving force.
• the toothing is preferably molded at the same time as the tire but it can also be attached to a conventional tire molded previously.
• a textile reinforcement may be associated with the surface of the toothing to limit abrasive wear and toothing noise. It is advantageous to use polyamide-type textile reinforcing fabrics woven so as to be extensible during the molding of the toothing.
• FIGS. 9 and 10 show an embodiment of the invention in which the electric machine can be held in the folded position, ie away from the bandage by an electric actuator 44.
• the actuator comprises a cam 45 bearing against the oscillating arm 41. The rotation of the cam causes the spacing of the motor pinion relative to the tire and thus the disengagement of the device.
• the actuator may for example be a servomotor or an electromagnet. The fallback position allows a perfectly quiet operation of the bike in non-assisted mode.
• the actuator can be controlled automatically according to different parameters such as the speed of the bike, the pedaling, the state of charge of the battery.
• the actuator can also be controlled by the cyclist, for example via the display and control unit.
• disengagement of the pinion can also be achieved manually directly at the swingarm or via a cable connected to a control available to the cyclist.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Transportation (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
• Tires In General (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=47714334

Family Applications (1)

Country Status (5)

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Family Cites Families (49)

• 2012
  • 2012-12-05 FR FR1261632A patent/FR2998859B1/fr not_active Expired - Fee Related
• 2013
  • 2013-12-02 EP EP13799050.3A patent/EP2928765A1/de not_active Withdrawn
  • 2013-12-02 CN CN201380063110.6A patent/CN104853981A/zh active Pending
  • 2013-12-02 WO PCT/EP2013/075278 patent/WO2014086728A1/fr not_active Ceased
  • 2013-12-02 US US14/649,960 patent/US9475546B2/en active Active

Non-Patent Citations (2)

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