Gearshift device and associated mobility device

Abstract

To provide a simplified transmission assembly for a mobility device.SOLUTION: A gear shifting device for a mobility device, comprising a selection shaft in which a shuttle and a worm are housed, three input pinions arranged to rotate freely around the selection shaft, three output pinions rotating integrally with a hollow shaft, a gear shift actuator arranged to displace the shuttle along the worm between three positions and to engage a selected gear ratio, the device comprising at least one set of three pawls positioned side by side along the longitudinal axis of the selection shaft; Each pawl is associated with a lifter device that allows the pawl to be lifted by the shuttle to engage the selected gear ratio via the input and output pinions.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to the field of gearshift devices, and more particularly to gearshift devices for mobility devices using at least electric propulsion, and for example electrically assisted bicycles. [Background technology]

[0002] When a mobility device is in operation, motive power is transmitted to the wheels via a crank system that rotates about the axis of a crankset, which typically drives the rear wheel via a chain.

[0003] Gearshift devices for mobility devices are already known from the prior art. These gearshift devices include a gearbox in which a shuttle is configured to position itself under the pinion of a selected gear ratio as it moves and engage this gear ratio via a pawl. Such devices require a large number of parts and are complex to manufacture and repair. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome one or more of the drawbacks of prior art devices by proposing a simplified transmission assembly for a mobility device. [Means for solving the problem]

[0005] For that reason, the present invention provides a gearshift device for a mobility device, comprising: a selection shaft in which the shuttle and the worm are housed; three input pinions configured to rotate freely about a selection shaft; -Three output pinions that rotate together with the hollow shaft; a gear shift actuator arranged to displace the shuttle along the worm between three positions and to engage a selected gear ratio; The device proposes a gearshift device including at least one set of three pawls positioned in line along the longitudinal axis of the selection shaft, each pawl being associated with a lifter device that enables the pawl to be lifted by a shuttle and engaged, via the input and output pinions, to the selected gear ratio.

[0006] Such multiple pawls allow the device to be optimized.

[0007] According to one embodiment of the invention, the gearshift device includes two sets of three pawls positioned side-by-side along the longitudinal axis of the selector shaft.

[0008] According to one embodiment of the invention, the sets of pawls are positioned 180 degrees from each other around the selection shaft.

[0009] According to one embodiment of the invention, the device includes a radial blocking system formed as a single piece to hold all of the pawls in place on the selection shaft.

[0010] According to one embodiment of the invention, the blocking system is formed by a longitudinal flat from which extend three tabs, each of the tabs being positioned on one of the pawls.

[0011] According to one embodiment of the present invention, the device includes three input and output pinions, three pawls, and three tabs.

[0012] According to one embodiment of the present invention, the radial blocking system includes a positioning tab.

[0013] The invention also relates to a mobility device, in particular an electrically assisted mobility device, comprising a gearshift device according to the invention.

[0014] According to one embodiment of the present invention, the device is an electrically assisted bicycle.

[0015] Further objects, features and advantages of the present invention will be better understood and will become more apparent from reading the description given below with reference to the accompanying drawings, given by way of example, in which: [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram of a mobility device according to one of the aspects of the present invention. [Figure 2] 2 illustrates a transmission assembly of the mobility device of FIG. 1. [Figure 3] 1 is a cross-sectional view of a portion of a transmission assembly according to one embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of another portion of a transmission assembly according to one embodiment of the present invention. [Figure 5] FIG. 1 is an elevational view of a pawl system according to the present invention; [Figure 6] FIG. 1 is a cross-sectional view of a pawl system according to the present invention. [Figure 7] 10 is an elevational view of a bung system for closing a housing of a gearshift device according to the invention, according to another embodiment of the invention; FIG. [Figure 8] FIG. 4 is a cross-sectional view of a portion of the output shaft. DETAILED DESCRIPTION OF THE INVENTION

[0017] 1 illustrates a mobility device 1 according to one of the embodiments of the present invention. Device 1, here, is an electric bicycle that includes an electric motor 2. Electric motor 2 is designed to provide some of the propulsion of the device.

[0018] The bicycle comprises at least two wheels 3, 3' to which motive power is supplied, in use, via two pedals which rotate around the axis of a crankset of axis Xp (FIG. 2) which drives the rear wheel, for example by a chain or any other transmission means.

[0019] The device 1 also includes a control unit 4 and a number of sensors 5, 5', 5'' located, for example, on the crankset, on the bicycle frame or on the wheels 3, 3'.

[0020] The device 1 shown here also includes an energy storage device in the form of a battery 6, a lighting system 7, a crankset 8 of axis Xp (FIG. 2), a location and / or navigation system 90, and a human-machine interface system 91 including, among other things, a touchscreen that can display information for the user and / or take into account the user's requirements. The human-machine interface system 91 is in particular connected to the location system 90 and serves as a navigation interface. The present invention is not limited to a particular human-machine interface system and may include any system known to those skilled in the art.

[0021] The wheels 3 , 3 ′ are equipped with a braking system 31 , which includes, inter alia, a disc brake 32 .

[0022] The device 1 has a transmission assembly 10 illustrated in Figure 2. The transmission assembly 10 includes an automatic gearshift device 20 according to the present invention and an electric motor 2 for providing some of the power to propel the device 1.

[0023] According to a first variant of the invention, the device has three gears.

[0024] According to one embodiment of the present invention, the transmission assembly 10 is at least partially housed within a housing 30 located here at the crankset 8, the axis Xp of which is connected to the output axis X of the gearshift device 20.v matches.

[0025] In the context of the present invention, the gearshift device 20 illustrated in Figures 2-4 includes three gear ratios.

[0026] According to one embodiment of the present invention, the gearshift device 20 illustrated in Figures 3 and 4 has three gear ratios ranging from a first gear ratio referred to as 1st gear to a higher gear ratio referred to as 3rd gear.

[0027] According to one embodiment of this first variant, the gearshift device 20 comprises a set of three output pinions 60 of axis X, in particular pinions referenced F1 to F3, which rotate integrally with a hollow shaft 80 (FIG. 8), and a set of three input pinions 50 of axis X, referenced FR1 to FR3, which are arranged to rotate freely around the selector shaft 40.

[0028] According to one embodiment of the invention, the selector shaft 40 illustrated in FIGS. 3 to 6 houses a shuttle 41 which surrounds the worm 21 of the gearshift device 20 .

[0029] The device 1 according to the invention includes a gear shift actuator 70 configured to move the shuttle 41 along the worm 21 by a spiral motion connection between three positions P1 to P3 and to engage a selected gear ratio.

[0030] According to one embodiment of the present invention, the gearshift actuator 70 includes electrical means for moving the shuttle 41 in the form of a reduction gear set, which includes a motor 81 and a reduction gear 82.

[0031] According to one embodiment of the invention, the reduction gear set also includes a pinion 22 on the axis of the worm 21, an intermediate pinion 22', and a pinion 22''' on the axis Xm of the motor 81. The tooth sets of the pinions 22, 22', 22'' can be straight cut teeth as illustrated, or in a variant not illustrated, helical teeth.

[0032] The rotational guidance of the worm 21 is ensured, for example, by means of rolling bearings at each of its ends.

[0033] According to one embodiment of the invention, the shuttle 41 is configured to be positioned under and engage the pinion of the selected gear ratio as it moves. According to one embodiment of the invention, the gearshift device 20 includes a set of three pawls positioned in line along the longitudinal axis X2 of the selector shaft 40.

[0034] According to one embodiment of the present invention, the gearshift device 20 includes at least one set of three pawls positioned in line along the longitudinal axis X2 of the selector shaft 40.

[0035] According to one embodiment of the present invention, the gearshift device 20 includes two sets of three pawls positioned side-by-side along the longitudinal axis X2 of the selector shaft 40.

[0036] According to one embodiment of the invention, the sets are arranged 180 degrees from each other around the selection shaft 40. This limits the number of parts compared to the prior art. The pawls 42 have a shape configured to cooperate with the input pinions FRi. The pawls 42 are housed in recesses 420 formed on the selection shaft 40. Each pawl 42 is housed in a drilled hole 430 in the inner shaft and is associated with a lifter device, and ball 43 visible, for example, in FIGS. 5 and 6, that protrudes into the interior of the inner shaft and is positioned directly below each pawl 42 so that each pawl 42 can be lifted via the shuttle 41.

[0037] Thus, during a gear shift, the worm 21 is rotated by the gear shift actuator 70 which causes axial movement of the nut 210 of the worm 21 which drives the shuttle 41, which in turn rotates the input pinion FR corresponding to the selected gear ratio i which is subsequently blocked against rotation by one of the pawls 42. iand meshes with the corresponding output pinion.

[0038] In the context of the present invention, to hold the pawls 42 in place within their housings, the gearshift system includes at least one radial blocking system 44 formed as a single piece. That means a system 44 that keeps the pawls 42 pressed into their housings while allowing them to be lifted by the ball 43 and shuttle 41. The radial blocking system 44 is formed in one piece, which makes it easier to fit or manufacture and limits costs.

[0039] According to one embodiment of the present invention, the blocking system 44 includes a longitudinal flat 440 .

[0040] According to one embodiment of the present invention, the system 44 includes three tabs 441 for a three-gear arrangement.

[0041] According to one embodiment of the invention, the tabs 441 are formed starting from a first edge 442 of the flat portion 440 that is parallel to the axis Xb of the blocking system 44 and is oriented perpendicular to the axis Xb of the blocking system 44. The rotating blocking system 44 thus forms a comb with flat and separate teeth.

[0042] According to one embodiment of the present invention, the flat portion 440 is inserted into a longitudinal slot 45 formed in the selection shaft 40 and parallel to the axis of the shaft via a second edge 443 opposite the edge 442 on which the tab 441 is located.

[0043] According to one embodiment of the present invention, this second edge 443 is bent towards the shaft 40 so as to be inserted into the slot 45 .

[0044] The blocking system 44 is arranged on the selection shaft 40 in such a way that each tab 441 is positioned above a pawl 42 .

[0045] According to one embodiment of the present invention, each pawl 42 includes a recess 421 whose shape complements the shape of tab 441 so that tab 441 is received within recess 421 and does not move when the pawl is immobilized.

[0046] According to one embodiment of the invention, the rotation blocking system 44 includes a positioning tab 446. This positioning tab 446 is located on a second edge 443 that is inserted into the slot 45. This tab 446 cooperates with an additional housing 445 whose shape complements the shape of the positioning tab 446 and is formed in the selection shaft 40. This positioning tab 446 allows the tab 441 of the device to be centered relative to the pawl 42.

[0047] The rotational blocking system 44 thus applies a pressure, or force, to each pawl 42 that is sufficient to block the pawl 42 within the housing 421 while allowing the pawl 42 to be lifted by the shuttle 41 .

[0048] According to one embodiment of the present invention, the gearshift system includes at least two rotation blocking systems 44 positioned in such a way as to block two sets of pawls.

[0049] Thus, when the mobility device is in operation, the shuttle 41 can select a selected gear ratio, which engages the input pinion FRi via the pawl 42 and is blocked from rotation due to the rotation blocking system 44.

[0050] The input pinion FRi in turn meshes with the output pinion Fi.

[0051] When the device 1 is running at gear ratio i without a gear change, the worm 21 does not rotate.

[0052] During a change of gear ratio, the worm 21 is driven in rotation by a gearshift actuator 70 which causes an axial movement of the nut 210 of the worm 21 which drives the shuttle 41 and thus enables the gearshift. The pivot connection thus implemented converts the rotational movement of the worm 21 into a translational movement of the shuttle 41.

[0053] According to one embodiment of the invention, limit stops 211, 211' limit the movement of the shuttle 41 at each end. According to another embodiment of the invention, the movement of the shuttle is controlled by position sensors.

[0054] In a non-illustrated embodiment, the shuttle 41 can introduce a position referred to as neutral position P0 in which no gear ratio is engaged.

[0055] The assembly is placed in a casing, a first face 100 of which is illustrated in FIG.

[0056] The casing 30 has a case 301 that defines a first housing 302 arranged to house the gear set of the gearshift device 20. The case 301 also defines a plurality of second housings that are separate from one another. The housings 303, 304, 305, and 306 are configured to house the electric motor 2, the reduction gear 82, the gearshift actuator 70, and the control unit 4 of the mobility device, respectively. The second housings are preferably sealed and are particularly configured to contain the control unit 4. This first face 100 is closed by a cap or cover type bung system.

[0057] The scope of the present invention is not limited to the details given above, but allows for embodiments in many other specific forms without departing from the field of application of the present invention. Consequently, the embodiments of the present invention should be considered as illustrative, but can be modified without departing from the scope defined by the claims.

Claims

1. A gearshift device (20) for a mobility device (1), comprising: - a selection shaft (40) on which the shuttle (41) and the worm (21) are housed; - three input pinions (50, FRi) arranged to rotate freely around said selection shaft (40); - three output pinions (60, Fi) rotating integrally with the hollow shaft (80); a gearshift actuator (70) arranged to displace said shuttle (41) along said worm (21) between three positions and to engage a selected gear ratio; The gear shift device (20) includes at least one set of three pawls positioned in a line along the longitudinal axis (X2) of the selection shaft (40), each pawl (42) being associated with a lifter device (43) that enables the pawl to be lifted by the shuttle (41) and to engage the selected gear ratio via the input pinion and output pinion.

2. 2. The gearshift device (20) of claim 1, wherein the gearshift device (20) includes two sets of three pawls positioned side-by-side along the longitudinal axis (X2) of the selector shaft (40).

3. 3. The gearshift device (20) of claim 2, wherein the sets of pawls are positioned 180 degrees from each other around the selector shaft (40).

4. 4. A gearshift device (20) according to any one of claims 1 to 3, comprising a radial blocking system (44) formed as a single piece to hold all of said pawls (42) in place on said selector shaft (40).

5. 5. A gear shift device (20) according to claim 4, wherein the blocking system (44) is formed by a longitudinal flat (440) from which extend three tabs (441), each of the tabs (441) being positioned on one of the pawls (42).

6. A gearshift device (20) according to any one of claims 1 to 5, comprising three input and output pinions (50, 70), three pawls (42), and three tabs (441).

7. A gearshift device (20) according to any one of claims 1 to 6, wherein the radial blocking system (44) comprises a positioning tab (446).

8. A mobility device (1), in particular an electrically assisted mobility device, comprising a gearshift device (20) according to any one of claims 1 to 7.

9. Mobility device according to claim 8, wherein the device (1) is an electrically assisted bicycle.

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