EP3784556A1

EP3784556A1 - Bicycle gearbox

Info

Publication number: EP3784556A1
Application number: EP19723323.2A
Authority: EP
Inventors: Martin SABAU; Marc Le Borgne
Original assignee: Kervelo
Current assignee: Kervelo
Priority date: 2018-04-27
Filing date: 2019-04-19
Publication date: 2021-03-03
Also published as: FR3080664A1; FR3080664B1; WO2019206836A1

Abstract

The present invention relates to a gearbox (1) for cycles (100) comprising: – at least a first (T1) and a second (T2) epicyclic geartrain, an epicyclic geartrain (T1, T2, T3) comprising: – a plurality of sun gears (11, 12, 17, 18, 22, 23) , and, a plurality of planet pinions (13, 14, 19, 20, 24, 25) associated with each sun gear (11, 12, 17, 18, 22, 23), said pluralities of planet pinions (13, 14, 19, 20, 24, 25) being mounted on a planet carrier (15, 26) and, - a peripheral annulus gear (16, 21, 27) configured to mesh with the planet pinions (13, 14, 19, 20, 24, 25) associated with a sun gear (11, 12, 17, 18, 22, 23), in which the gearbox (1) also comprises a clutch device (40) arranged between the first (T1) and the second (T2) epicyclic geartrains, in which a clutch pinion (41) is rotationally coupled to the planet carrier (15) and is configured to be able to move axially between a first position of engagement in which it is claw-coupled to a sun gear (12) of the first epicyclic geartrain (T1) and a second position of engagement in which it is claw-coupled to a sun gear (17) of the second epicyclic geartrain (T2), the clutch pinion (41) also being configured to be in a disengaged intermediate position.

Description

GEARBOX FOR CYCLES

The present invention relates to the field of cycles and the like, that is to say light vehicles with two or three wheels whose propulsion is at least partly achieved by human force.

It is known to use a gearbox on a cycle in order to allow the user to be able to choose different transmission ratios and thus be able to adapt his effort and pedaling rate to the terrain topology and environmental conditions in particular.

Gearboxes also allow, through the protection of their mechanism, to limit the maintenance required for their operation compared to derailleur systems.

However, known cycle gearboxes of the state of the art may have various drawbacks which tend to limit their use as a complexity and a large bulk inducing a high weight, a reduced speed range and a low linearity in the progression. reports that can create discomfort for the user as well as an architecture limiting the possibilities of integration on various types of cycles and making it difficult to combine with an electric motor.

Thus, the present invention aims to overcome these disadvantages by proposing a gearbox with a range of extended and relatively linear ratio and a simplified architecture.

For this purpose, the present invention relates to a gearbox for cycles comprising:

at least a first and a second epicyclic gear train, an epicyclic gear train comprising:

a plurality of planetary gears and,

a plurality of planet gears associated with each planet gear, said plurality of planet gears being mounted on a planet carrier and, a peripheral ring configured to mesh with the planet gears associated with a planetary gear,

wherein the planet gears can respectively be rotatably coupled to a transmission selector assembly via a set of pawls,

wherein the carrier is common to the first and second planetary gear trains, the gearbox further comprises a clutch device disposed between the first and second planetary gear trains in which a clutch gear is rotatably coupled to the carrier. satellite and is configured to be movable axially between a first engagement position in which it is linked by interconnection to a sun gear of the first epicyclic gear and a second engagement position in which it is linked by interconnection to a sun gear of the second epicyclic gear, the clutch gear being also configured to be in an intermediate position of disengagement.

According to another aspect of the present invention, the gearbox comprises a selector extending along a central axis of the gearbox, said selector comprising a set of cams configured to allow or not the engagement of the pawls with the planetary gears. .

According to another aspect of the present invention, the selector also comprises a guide groove in which is positioned a pin connected to the clutch device to allow the axial displacement of the clutch gear.

According to another aspect of the present invention, the selector is rotated via a device comprising a manual cable control or an electrically controlled device.

According to another aspect of the present invention, the selector is associated with an angular indexing device.

According to another aspect of the present invention, the gearbox comprises a third epicyclic gear train whose carrier corresponds to the peripheral ring of the second epicyclic gear train. According to another aspect of the present invention, the planetary gear trains each comprise two planetary gears.

According to another aspect of the present invention, the gearbox is configured to be arranged around a crank axle of a cycle, on a frame, the selector being concentric with said crank axle, the peripheral ring of the first epicyclic gear being integral in rotation of the pedal and the peripheral ring of the third epicyclic gear being rotationally secured to a transmission plate for propelling a driving wheel via a flexible connection (chain or belt) or rigid (shaft) transmission.

According to another aspect of the present invention, the gearbox is configured to be disposed at a hub of a driving wheel of a cycle, the peripheral ring of the first epicyclic gear being rotatably connected to the pedal and the peripheral ring of the third epicyclic gear being coupled to the driving part of the front wheel via a freewheel device.

According to another aspect of the present invention, the gearbox is configured to be disposed about an axis of rotation of a rear wheel of a cycle, the selector being concentric with said axis of rotation of the rear wheel, the peripheral ring of the first epicyclic gear being rotationally secured to a transmission pinion connected by a chain to a transmission plate coupled in rotation to the pedal.

The present invention also relates to a cycle comprising a gearbox as described above.

According to another aspect of the present invention, the cycle also comprises an electric motor coupled to the gearbox at the peripheral ring of the third epicyclic gear.

According to another aspect of the present invention, the coupling between the electric motor and the peripheral ring of the third epicyclic gear is carried out via a return cone. angle.

According to another aspect of the present invention, the electric motor is arranged in a frame tube of the cycle, in particular a diagonal tube.

Other features and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the accompanying drawings in which:

FIG. 1 represents a schematic sectional view of a gearbox according to one embodiment of the present invention,

FIG. 2 represents an exploded schematic view of a gearbox according to one embodiment of the present invention,

FIG. 3 represents a schematic sectional and simplified view of the structure of the gearbox according to one embodiment of the present invention,

FIG. 4 represents a schematic sectional view along the axis A-A of FIG. 1,

FIG. 5 represents a schematic sectional view along the axis B-B of FIG. 1,

FIG. 6 represents a diagrammatic view in section along the D-D axis of FIG. 1;

FIG. 7 represents a schematic sectional view along the E-E axis of FIG. 1,

FIG. 8 represents a diagrammatic sectional view along the axis F-F of FIG. 1,

FIG. 9 represents a schematic sectional view along the axis G-G of FIG. 1,

FIG. 10 represents a schematic sectional view along the H-H axis of FIG. 1,

FIG. 11 represents a schematic sectional view along the axis I-I of FIG. 1,

FIG. 12 represents a schematic view of the clutch device,

FIG. 13 represents a diagrammatic view in section along the axis C-C of FIG. 1,

FIG. 14 represents a table of the engagement of the pawls and the clutch device as a function of the selected gear,

FIG. 15 represents a curve of the gear ratio obtained as a function of the speed engaged,

FIG. 16 represents a diagram of a cycle according to an embodiment of the present invention, FIG. 17 represents a partial diagram of an electric cycle comprising a gearbox according to a first embodiment of the present invention,

FIG. 18 represents a diagram of a gearbox according to a second embodiment of the present invention,

FIG. 19 represents a partial diagram of an electric cycle comprising a gearbox according to a second embodiment of the present invention,

FIG. 20 represents a partial diagram of an electric cycle comprising a gearbox according to a third embodiment of the present invention,

Fig. 21 is a schematic perspective view of a guide groove of a selector according to an embodiment of the present invention.

In all the figures, the identical elements bear the same reference numbers.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined or interchanged to provide other embodiments.

The present invention relates in particular to a gearbox for cycles comprising at least two epicyclic gear trains each comprising at least two planet gears (also called solar gears in some cases) of different size and a clutch device common to two planetary gear trains and configured to allow transmission with a unit ratio of one or the other planetary gear trains.

The present invention also relates to a transmission assembly comprising a gearbox coupled to an electric motor.

FIGS. 1 to 3 show an embodiment of a gearbox 1 comprising three epicyclic gear trains denoted T1, T2 and T3. The planetary gear trains are configured to be rotatable about a transmission selector assembly 3 which is concentric with an axis of rotation D corresponding for example to a crank axle 2 on which are mounted the cranks 4 as in Figures 1 and 2 or the axis of a rear wheel of a cycle. The axis of rotation D also corresponds to the central axis of the gearbox 1.

Transmission selector assembly 3

The transmission selector assembly 3 (see Fig. 2) comprises for example three concentric cylindrical parts therebetween. An internal portion called selector 31 comprising a set of cams 311 and a guide groove 313. The cams 311 are here represented by openings configured to receive the end of a pawl 331 but according to an alternative embodiment, the cams 311 may also be made by protuberances configured to press the end of a pawl 331. An intermediate portion 33 around which is disposed a set of pawls 331 for interacting respectively with the set of cams 311 and an outer portion 35 configured to maintain the intermediate portion 33 and the pawls 311 in position. The intermediate portion 33 comprises, for example, cutouts for forming resilient lamellae opposite the pawls 311. These resilient slats make it possible to create a spring effect and are configured to constrain the pawls 311 so as to bring their first end intended to interact with them closer together. the cams 311 of the selector 31. Such a configuration causes the pawl 311 to tilt when its first end is opposite a cam 311, the second end then coming into a housing of a pinion associated so as to lock said pinion in rotation as will be described in more detail in the following description. The outer portion 35 corresponds to a bottom bracket and is intended to be fixedly mounted relative to the frame of the cycle and to receive a pair of bearings 5 forming bearings configured to guide the crank axis 2 in rotation. The bearings 5 are for example ball bearings. The intermediate portion 33 can be made from a sheet or foil, in particular a flexible metal sheet, configured to be wound up and to be positioned inside the outer portion 35. The outer portion 35 comprises a set of openings 351 intended to receive respectively the ratchet assembly 331 of the intermediate portion 33. The intermediate portion 33 is intended to be fixed relative to the outer portion 35. The selector 31 is configured to be rotatable relative to the other two parts 33 and 35. The rotation of the selector 31 is for example controlled by a control device (not shown) comprising a manual control, such as a rotating handle, and a set of cables, for example a first cable configured to allow the rotation of the selector 31 in a first direction of rotation and a second cable configured to allow the rotation of the selector 31 in the opposite direction. Figure 4 shows a sectional view at the notch 315 for receiving the cables. However, other control devices including electrical can also be used. In addition, an angular indexing device 7 is also used to define a plurality of angular positions, twelve in this case, corresponding to the different gear ratios of the gearbox 1. This indexing device 7 is made for example by a grooved surface 71 formed on the selector 31 and a ball 9 (visible in Figure 5) intended to be positioned in the grooves of the fluted surface 71 to provide a haptic feedback to the user on the position of the selector 31. The device indexing device 7 also comprises a spring 10 (visible in FIG. 5) fixed on the outer part 35 and configured to constrain the ball 9 against the fluted surface 71 so that when the cables are actuated to cause the selector to rotate 31, the ball 9 is forced to pass from one groove to another and thus defines the indexing positions. Alternatively, the spring can be fixed on the selector 31 and the fluted surface formed in the outer portion 75. Thus, the transmission selector assembly 3 allows the selection of a speed (also called ratio) and the recovery of torque when a power transmission via the bottom bracket 2.

Tl, T2 and T3 epicvcloidal trains

The first epicyclic gear Tl includes a first sun gear 11 (also called sun gear in some cases), comprising a first predetermined number of teeth and a second sun gear 12 comprising a second predetermined number of teeth different from the first predetermined number of teeth. A first series of three first planet gears 13 (also called planetary gears when using the name solar gears) is associated with the first sun gear 11 and a second series of three second planet gears 14 is associated with the second sun gear 12. Figures 6 and 7 show sectional views respectively at the first pinion planetary gear 11 and the second sun gear 12 of this first epicyclic gear Tl (section DD and EE in FIG. 1). The first 13 and second 14 planet gears are rotatably mounted on a planet carrier 15 and are intended to be arranged around the associated planet gear 11, 12 so as to mesh with said associated planet gear 11, 12. satellites associated with different planetary gears of an epicyclic gear T1, T2, T3 are coupled in rotation in pairs (three pairs in this case). The two planet gears of a pair therefore have a number of different teeth and can be made in one piece. In addition, the number of planet gears associated with a planet gear can be different from three.

The first epicyclic gear train T1 also comprises a peripheral ring 16 called an inlet ring 16 corresponding to the input element of the gearbox 1, that is to say the element through which the torque supplied by the The user is transmitted to the gearbox 1. The peripheral ring 16 meshes with the first planet gears 13 associated with the first sun gear 11. The first epicyclic gear train T1 is also called the input gear.

The second epicyclic gear T2 comprises a first sun gear 17 comprising a third predetermined number of teeth and a second sun gear 18 comprising a fourth predetermined number of teeth different from the third predetermined number. A third series of three third planet gears 19 is associated with the first planet gear 17 and a fourth series of three fourth planet gears 20 is associated with the second planet gear 18. Figures 8 and 9 show sectional views respectively of the first pinion planetary gear 17 and the second sun gear 18 of this second epicyclic gear train T2 (section FF and GG in FIG. 1). The third 19 and fourth 20 planet gears are rotatably mounted on a planet carrier 15 and are arranged around the associated sun gear 17, 18 so as to be meshed with said associated sun gear 17, 18. In this case, the carriers Satellites 15 of the first T1 and second T2 epicyclic trains are made by a single piece.

The second epicyclic gear T2 also comprises a peripheral ring 21 called the intermediate ring 21. The intermediate ring 21 meshes with the fourth planet gears 20 associated with the fourth sun gear 18. The third epicyclic gear T3 comprises a first sun gear 22 comprising a fifth predetermined number of teeth and a second sun gear 23 comprising a sixth predetermined number of teeth. A fifth series of three fifth planet gears 24 is associated with the first planet gear 22 and a sixth series of three sixth planet gears 25 is associated with the second planet gear 23. Figures 10 and 11 show sectional views respectively of the first pinion planetary gear 22 and the second sun gear 23 of this third epicyclic gear T3 (section HH and II in FIG. 1). The fifth 24 and sixth 25 planet gears are rotatably mounted on a planet carrier 26 and are arranged around the associated sun gear 22, 23 so as to mesh with said associated sun gear 22, 23. In this case, the carrier satellite 26 of the third epicyclic gear T3 and the peripheral ring 21 of the second epicyclic gear T2, or intermediate ring 21, are made by a single piece.

The third epicyclic gear train T3 also comprises a peripheral ring 27 called an output ring 27. The output ring 27 meshes with the sixth planet gears 25 associated with the sixth planet gear 23. The output ring 27 is rotatably mounted relative to a housing 50 in the embodiment shown above, especially from Figures 1 to 3, the output ring 27 is coupled in rotation to a transmission plate 28 for receiving a chain configured to transmit the torque to a pinion disposed at the rear wheel. Alternatively, a transmission disk configured to receive a transmission belt can be used instead of the transmission plate. A protective cover 29 comprising at least one opening configured to pass the chain may be arranged around the transmission plate. The epicyclic train T3 is also called the output train.

In the case of a belt transmission, an opening or an opening device may be formed in the protective cover 29 to allow the passage of the belt. The gearbox 1 also comprises a protective casing 50 of cylindrical shape configured to be placed around the epicyclic gear trains T1, T2, T3. Clutch device 40

The gearbox 1 also comprises a clutch device 40 (better visible in FIG. 12 configured to block the rotation between a sun gear and its associated planet wheels, thereby producing a unit transmission ratio at the level of the epicyclic gear train. concerned.

In this case, the clutch device 40 is placed between the first T1 and the second T2 planetary gear trains and comprises a clutch gear 41 formed in particular by a first clutch half-gear 43 adjacent to the second sun gear 12 of the first epicyclic gear Tl and a second clutch half gear 45 adjacent to the first sun gear 17 of the second epicyclic gear. The two half-clutch gears 43 and 45 are rotatably coupled to the planet carrier 15 common to the first T1 and second T2 planetary gear trains. The two half-gears 43 and 45 are intended to be arranged in an annular groove of a central support 47, the two half-clutch gears 43 and 45 being rotatably mounted on said central support 47. An elastic washer 49 is disposed axially between the two half-gears 43 and 45 and is configured to move the two half-gears 43 and 45 away from each other. The central support 47 is mounted to move axially in translation relative to the transmission selector assembly 3. In addition, the clutch device 40 comprises a pin 51 (visible in FIG. 13) intended to be positioned in a radial housing. the central support 47 and configured to protrude into the guide groove 313 formed in the selector 31 of the transmission selector assembly 3. The displacement in axial translation along the axis of rotation D of the clutch gear 41 is thus guided by the shape of the guide groove 313 in which the pin 51 protrudes when the selector 31 is rotated. FIG. 21 shows a perspective view of the guide groove 313. The guide groove 313 has at least three zones. distinct zl, z2 and z3. The central zone z2 extends perpendicular to the rotation axis D of the selector 31 so that when the pin 51 is positioned in this central zone z2, the rotation of the selector 31 does not cause the pin 51 to move axially. a first side of the central zone z2 has a deflection angle (less than 90 °, for example 20 °) predefined with respect to the central zone z2 in a first direction so that when the pin 51 is positioned in this zone zl, the rotation of the selector 51 causes the axial displacement of the pin 51 in a first axial direction. The zone z3 located on a second side, opposite the first side, of the central zone z2 has a deflection angle (less than 90 °, for example 20 °) predefined with respect to the central zone z2 in a second direction so when the pin 51 is positioned in this zone z3, the rotation of the selector 51 causes the axial displacement of the pin 51 in the second axial direction opposite to the first axial direction. Zones z1 'and z3' parallel to the central zone z2 may be formed in the respective extension of the zones z1 and z3. Thus, the rotation of the selector 31 allows the passage from one position to another of the clutch gear 41 via the interaction between the guide groove 313 and the pin 51.

The first half-pinion 43 comprises a first series of teeth located on one side opposite the second sun gear 12 of the first epicyclic gear Tl and the second half-pinion 45 comprises a second series of teeth on the face opposite the first gear. planetary gear 17 of the second epicyclic gear T2. The first series of teeth is intended to be coupled in rotation by interconnection with a series of complementary teeth disposed on the second sun gear 12 of the first epicyclic gear T1. The second series of teeth is intended to be coupled in rotation by interconnection with a series of complementary teeth disposed on the first sun gear 17 of the second epicyclic T2. Thus, the clutch gear 41 formed by the central support 47, the two half-gears 43 and 45 and the spring washer 49 is movable in translation between a first engagement position in which the first half-pinion 43 is coupled in rotation by interconnection with the second sun gear 12 of the first epicyclic gear Tl and a second engagement position in which the second half-pinion 45 is rotatably coupled by interconnection with the first sun gear 17 of the second epicyclic gear T2. The clutch gear 41 may also be in an intermediate position in which it is disengaged, that is to say it is not coupled in rotation with any sun gear.

Operation The configuration of the gearbox 1 presented previously makes it possible to obtain twelve reports. These ratios are obtained by the engagement or not of the different pawls 331 at the cams 311 of the transmission selector assembly 3 and by the axial position of the clutch gear 41. These various ratios will now be described from the table. of Figure 14. The reference 331 designates a pawl in the general sense and references 331-1, 331-2 ... 331-6 designates a particular pawl among the six ratchets 331.

FIG. 14 represents a table comprising a first column indicating the different ratios, a second column indicating the position (engaged or not in a cam 311) of the first pawl 331-1 (the pawl 331 associated with the first sun gear 11 of the first epicyclic gear Tl) for the different ratios, a third column indicating the position of the second pawl 331-2 (the pawl 331 associated with the second sun gear 12 of the first epicyclic gear Tl) for the different ratios, a fourth column indicating the position of the pinion of clutch 41 relative to the second sun gear 12 of the first epicyclic gear Tl, a fifth column indicating the position of the clutch gear 41 relative to the first sun gear 17 of the second planetary gear T2, a sixth column indicating the position of the third pawl 331. -3 (the ratchet 331 associated with the first sun gear 17 of the second epicycloid gear l T2) for the different ratios, a seventh column indicating the position of the fourth pawl 331-4 (the pawl associated with the second sun gear 18 of the second epicyclic gear T2) for the different ratios, an eighth column indicating the position of the fifth pawl 331 5 (the pawl associated with the first sun gear 22 of the third epicyclic gear T3) for the different gears, a ninth column indicating the position of the sixth pawl 331-6 (the pawl associated with the second sun gear 23 of the third epicyclic gear T3) for the different ratios, a tenth column indicating the reduction ratio of the first epicyclic gear T1 for the different ratios, an eleventh column indicating the reduction ratio of the second epicyclic gear T2 for the different ratios, a twelfth column indicating the reduction ratio of the third. epicyclic train T3 for different ratios and a thirteenth column indicating the overall reduction ratio (by combining the ratios of the three planetary gear trains) for the different ratios.

The ratios of the last four columns correspond to ratios obtained with a first epicyclic gear T1 comprising a peripheral ring 16 of 100 teeth, a first planetary gear 11 of 79 teeth associated with planet gears 13 of 17 teeth, a second sun gear 12 of 83 teeth associated with planet gears 14 of 13 teeth, a second epicyclic gear T2 comprising a peripheral ring 21 of 113 teeth, a first planetary gear 17 of 72 teeth associated with planet gears 19 of 12 teeth, a second sun gear 18 of 59 teeth associated with planet gears 20 of 25 teeth and a third epicyclic gear T3 comprising a peripheral ring 27 of 109 teeth, a first sun gear 22 of 56 teeth associated with planet gears 24 of 22 teeth, a second sun gear 23 of 65 teeth associated with planet gears 25 of 13 teeth.

The different ratios of gearbox 1 will now be described in more detail

First

The first report is obtained by applying the following commands:

- The clutch gear 41 coupled by interconnection on the second sun gear 12 of the first epicyclic gear T1 leading to a unit ratio of the first epicyclic gear

Tl,

the third pawl 331-3 is engaged (in a cam 311) causing rotation locking of the first sun gear 17 of the second epicyclic gear T2 such that the ratio of the second epicyclic gear T2 is 0.42 and

- The sixth pawl 331-6 is engaged causing the rotational locking of the second sun gear 23 of the third epicyclic gear T3 so that the ratio of the third epicyclic gear T3 is 1.56.

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 331 in a first indexing position of the selector 31.

Second report:

The second report is obtained by applying the following commands: - The clutch gear 41 coupled by interconnection on the second sun gear 12 of the first epicyclic gear T1 leading to a unit ratio of the first epicyclic gear

Tl,

the third pawl 331-3 is engaged causing the rotational locking of the first sun gear 17 of the second epicyclic gear T2 such that the ratio of the second epicyclic gear T2 is 0.42 and

the fifth pawl 331-5 is engaged causing the rotational locking of the first sun gear 22 of the third epicyclic gear T3 so that the ratio of the third epicyclic gear is 2.1.

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 331 in a second indexing position of the selector 31.

Third

The third report is obtained by applying the following commands:

- A clutch gear 41 coupled by interconnection on the second sun gear 12 of the first epicyclic gear T1 leading to a unit ratio of the first epicyclic gear

Tl,

the fourth pawl 331-4 is engaged causing the rotation locking of the second sun gear 18 of the second epicyclic gear train T2 so that the ratio of the second epicyclic gear T2 is 0.65 and

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 331 in a third indexing position of the selector 31. Fourth report:

The fourth report is obtained by applying the following commands:

the first pawl 331-1 is engaged causing the rotational locking of the first sun gear 11 of the first epicyclic gear Tl so that the ratio of the first epicyclic gear Tl is 1.7,

- The sixth pawl 331-6 is engaged causing the rotation locking of the second sun gear 23 of the third epicyclic gear T, 3 so that the ratio of the third epicyclic gear T3 is 1.56.

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a fourth indexing position of the selector 31.

Fifth report:

The fifth report is obtained by applying the following commands:

the second pawl 331-2 is engaged, causing the second sun gear 11 of the first epicyclic gear T 1 to lock in rotation so that the ratio of the first epicyclic gear T 1 is 1.96,

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a fifth indexing position of the selector 31. Sixth report:

The sixth report is obtained by applying the following commands:

the third pawl 331-3 is engaged causing the rotational locking of the first sun gear 17 of the second epicyclic gear T2 so that the ratio of the second epicyclic gear is 0.42 and

the fifth pawl 331-5 is engaged causing the rotational locking of the first sun gear 22 of the third epicyclic gear T3 so that the ratio of the third epicyclic gear T3 is 2.1.

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a sixth indexing position of the selector 31.

Seventh report:

The seventh report is obtained by applying the following commands:

the second pawl 331-2 is engaged causing the rotational locking of the second sun gear 12 of the first epicyclic gear Tl so that the ratio of the first epicyclic gear is 1.96,

the fifth pawl 331-5 is engaged causing the rotational locking of the first sun gear 22 of the third epicyclic gear T3 so that the ratio of the third epicyclic gear T3 is 2.1. The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a seventh indexing position of the selector 31.

Eighth report:

The eighth report is obtained by applying the following commands:

the second pawl 331-2 is engaged causing the rotational locking of the second sun gear 12 of the first epicyclic gear Tl so that the ratio of the first epicyclic gear Tl is 1.96,

the fourth pawl 331-4 is engaged causing the rotation locking of the second sun gear 18 of the second epicyclic gear T2 such that the ratio of the second epicyclic gear is 0.65 and

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in an eighth indexing position of the selector 31.

Ninth report:

The ninth report is obtained by applying the following commands:

the fourth pawl 331-4 is engaged causing the rotation locking of the second sun gear 18 of the second epicyclic gear train T2 so that the ratio of the second epicyclic gear T2 is 0.65 and the fifth pawl 331-5 is engaged causing the rotational locking of the first sun gear 22 of the third epicyclic gear T3 so that the ratio of the third epicyclic gear T3 is 2.1.

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a ninth indexing position of the selector 31.

Tenth report:

The tenth report is obtained by applying the following commands:

The cams 311 and the groove 313 of the selector 31 are therefore configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a tenth indexing position of the selector 31.

Eleventh

The eighth report is obtained by applying the following commands:

- A clutch gear 41 coupled by interconnection on the first sun gear 17 of the second epicyclic gear T2 leading to a unit ratio of the second planetary gear T2, the second pawl 331-2 is engaged causing the rotational locking of the second sun gear 12 of the first epicyclic gear Tl so that the ratio of the first epicyclic gear Tl is 1.96,

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in an eleventh indexing position of the selector 31.

Twelfth report:

The twelfth report is obtained by applying the following commands:

- A clutch gear 41 coupled by interconnection on the first sun gear 17 of the second epicyclic gear T2 leading to a unit ratio of the second planetary gear T2,

The cams 311 and the groove 313 of the selector 31 are thus configured to obtain these conditions of placement of the clutch gear 41 and engagement of the pawls 311 in a twelfth indexing position of the selector 31.

These different ratios make it possible to obtain the following gear ratios: 0.66-0.88-1.01-1.12-1.29-1.5-1.73-1.98-2.32-2 , 67-3,06-3,57.

This makes it possible to obtain a ratio of 540% between the first and last gear as well as a good linearity in the progression between the ratios as represented in FIG. represents a curve of the evolution of the reports according to the number of the engaged report. This linearity provides increased comfort for the user.

The present invention is not limited to the embodiment described above but extends to other variants. The variants concern in particular a number of planetary gears other than two for the planetary gear trains, a different number of planetary gears between the different planetary gear trains, a different number of epicyclic gear trains, for example only two epicyclic gear trains, an associated additional clutch device. to the third epicyclic train, etc. In addition, the number of gears of the gearbox 1 may be different from 12.

In addition, according to a second embodiment, the gearbox 1 can be disposed at an axis of rotation of a rear wheel. In this case, the gearbox 1 also comprises a freewheel device as shown in FIG. 18. In this case, the input ring 16 is rotatably coupled to a transmission pinion intended to be coupled with a transmission plate. transmission located at the level of the pedals via a chain or a belt. In addition, the protective casing 50 is rotatably mounted relative to the frame of the bicycle and performs the function of flanges of the hub so that the spokes of the wheel are fixed on said casing 50 and allow the rotational drive of the wheel. The protective case is then rotatably coupled to the output ring 27.

According to a third embodiment, the gearbox 1 can be disposed at a front axle wheel axis which is also the crank axle 2 (the crankset being intended to be mounted on the axis of rotation of the front wheel). In this case, as for the second embodiment, the protective housing 50 is rotatably mounted relative to the frame of the bicycle and performs the function of the hub flanges so that the spokes of the wheel are fixed on said housing. protection 50 and allow the drive in rotation of the wheel. The protective case is then rotatably coupled to the output ring 27. In addition, the gearbox comprises a freewheel device. The present invention also relates to a cycle 100 comprising a gearbox 1 according to one of the embodiments presented above.

The present invention also relates to a transmission assembly 200 comprising a gearbox 1, coupled to an electric motor 110 as shown in FIGS. 17, 19 and 20. The gearbox 1 comprises at least one first epicyclic gear train corresponding to the input train and a second epicyclic gear corresponding to the output gear. Thus, the gearbox 1 can correspond to a gearbox 1 as previously described as shown in FIGS. 17 and 19, but can also be a gearbox 1 without a clutch device 40 as represented in FIG. the coupling between the output shaft of the electric motor 110 and the gearbox 1 is made at the peripheral ring of the output gear. The gearbox 1 is for example arranged at the calf of the crank axle of a cycle 100.

According to a first embodiment of the transmission assembly 200 shown in FIG. 17, the electric motor 110 is arranged so that the output shaft 112 of the electric motor 110 extends perpendicular to the axis D of the gearbox 1.

The electric motor 110 may be disposed in a tube of the frame of the cycle, for example the down tube 111 as shown in Figure 16 or the seat tube. The coupling between the output shaft 112 of the electric motor 110 and the gearbox 1 can be achieved by an angular return cone 116 for transferring the torque between the output shaft 112 and the output ring 27 of In addition, a freewheel 118 may also be disposed between the output shaft 112 and the output ring 27. The electric motor 110 may also include a reducing device 120 at its output shaft 112. The reduction mechanism 120 makes it possible to adapt the operating range of the electric motor 110. A battery 114 associated with the electric motor 110 may also be arranged in a tube of the frame of the cycle such as the down tube 111 as shown in FIG. The battery 114 may be fixed or removable. According to a second embodiment of the transmission assembly 200 shown in FIG. 19, the electric motor 110 is arranged so that the output shaft 112 of the electric motor 110 extends parallel to the axis D of the gearbox 1. The coupling between the output shaft 112 of the electric motor 110 is for example made by a reduction mechanism 120 '. The reduction mechanism 120 'is, for example, a two-stage gearbox (the first stage being geared to a pinion gear rotatably coupled to the output shaft 112 of the electric motor 110 and the second stage being geared to the output ring 27) and can include a free wheel. In addition, in this embodiment the electric motor 110 may be disposed in a housing 50 'which is common with the gearbox 1. The other aspects of the transmission assembly 200 are similar to the first embodiment shown in FIG. figure 17.

According to a third embodiment of the transmission assembly 200 shown in Figure 20, the gearbox 1 is a gearbox G without clutch device 40. The operation remains otherwise similar to the embodiment presented above. The gearbox G comprises for example a first epicyclic train TG said input train and a second epicyclic train T2 'said output train. The first train TG includes for example 4 planetary gears and the second train T2 'comprises for example 2 planetary gears. In addition, the transmission selector assembly 3 of the gearbox G may be configured to provide a 7-speed gearbox G corresponding to the ratios 4 to 10 shown previously (i.e. gearbox ratios). gearbox 1 in which the clutch is not engaged). A number of different planetary gear trains and a number of different planetary gears for each of the planetary gear trains are conceivable. In addition, the number of gears of gearbox G may be different from 7.

The other aspects of the G gearbox are similar to the gearbox 1.

The transmission assembly 200 also comprises an electric motor 110 coupled to the gearbox G at the peripheral ring 27 of the output gear T2. The coupling between the electric motor 110 and the output ring 27 may be similar to the first embodiment (axis of the electric motor 110 perpendicular to the axis of the gearbox G) as shown in FIG. 20 but may also be similar at second embodiment (axis of the electric motor 110 parallel to the axis of the gearbox G). The other aspects are similar to the first two embodiments described above from FIGS. 17 and 19.

The present invention also relates to a cycle 100 as shown in FIG.

16 comprising a set 200 as described above. The electric motor 110 and the battery 114 are for example arranged in the diagonal tube 111 of the cycle 100.

The different embodiments of the gearbox 1 and the transmission assembly 200 can also be mounted on recumbent cycles or tricycles.

Claims

A gearbox (1) for cycles (100) comprising:

at least a first (T1) and a second (T2) epicyclic gear train, an epicyclic gear train (T1, T2, T3) comprising:

a plurality of planet gears (11, 12, 17, 18, 22, 23) and,

a plurality of planet gears (13, 14, 19, 20, 24, 25) associated with each planet gear (11, 12, 17, 18, 22, 23), said plurality of planet gears (13, 14, 19, 20, 24, 25) being mounted on a carrier (15, 26) and,

- a peripheral ring (16, 21, 27) configured to mesh with the planet gears (13, 14, 19, 20, 24, 25) associated with a sun gear (11, 12, 17, 18, 22, 23),

wherein the planet gears (11, 12, 17, 18, 22, 23) can respectively be rotatably coupled to a transmission selector assembly (3) via a set of pawls (331),

characterized in that the planet carrier (15) is common to the first and second planetary gear trains (T1 and T2) and in that the gearbox (1) also comprises a clutch device (40) arranged between the first gearbox (T1) and the second (T2) epicyclic gear train in which a clutch gear (41) is rotatably coupled to the planet carrier (15) and is configured to be movable axially between a first engagement position in which it is linked by interconnection to a sun gear (12) of the first epicyclic gear (Tl) and a second engagement position in which it is linked by interconnection to a sun gear (17) of the second epicyclic gear (T2), the pinion of clutch (41) being also configured to be in an intermediate disengagement position.

2. Transmission (1) according to claim 1 comprising a selector (31) extending along a central axis of the gearbox (1), said selector (31) comprising a set of cams (311) configured to allow or not engagement of the pawls (331) with the planet gears (11, 12, 17, 18, 22, 23).

3. Transmission (1) according to claim 2 wherein the selector (31) also comprises a guide groove (313) in which is positioned a pin (51) connected to the clutch device (40) to allow the axial displacement of the clutch gear (41).

4. Gearbox (1) according to claim 2 or 3 wherein the selector (31) is rotated via a cable device comprising a manual control.

5. Gearbox (1) according to one of claims 2 to 4 wherein the selector (31) is associated with an angular indexing device (7).

6. Gearbox (1) according to one of the preceding claims comprising a third epicyclic gear (T3) whose carrier (26) corresponds to the peripheral ring (21) of the second epicyclic gear (T2).

7. Transmission (1) according to one of the preceding claims wherein the epicyclic trains (T1, T2, T3) each comprise two planetary gears (11, 12, 17, 18, 22, 23).

8. Transmission (1) according to one of the preceding claims configured to be arranged around a crank axis (2) of a cycle (100), the selector (31) being concentric with said bottom bracket ( 2), the peripheral ring (16) of the first epicyclic gear (Tl) being integral in rotation with the pedal.

9. Gearbox (1) according to one of claims 1 to 7 configured to be disposed about an axis of rotation of a rear wheel of a cycle (100), the selector (31) being concentric with said axis of rotation of the rear wheel, the peripheral ring (16) of the first epicyclic gear (Tl) being rotationally integral with a transmission pinion.

10. Cycle (100) comprising a gearbox (1) according to one of the preceding claims.

The cycle (100) according to claim 10 in combination with claim 8 further comprising an electric motor (110) and wherein the electric motor (110) is coupled to the gearbox (1) at the peripheral ring ( 27) of the third epicyclic gear (T3).

12. Cycle (100) according to claim 11 wherein the coupling between the electric motor (110) and the peripheral ring (27) of the third epicyclic gear (T3) is formed via a cone angle.

13. Cycle (100) according to claim 11 or 12 wherein the electric motor is disposed in a ring frame tube (100), including a diagonal tube.