Transmissions and related mobility vehicles

Abstract

The invention relates to a transmission comprising: a selection shaft (40) on which a shuttle (41) and a worm (21) are arranged; at least two input pinions (50, Fri) arranged to rotate freely about said selection shaft (40); at least two output pinions (60, Fi) rotationally connected to a hollow shaft (80); a speed change actuator (70) arranged to move said shuttle (41) along said worm (21) between at least two positions and to engage a selected gear ratio; and a speed change actuator (70) arranged on said selection shaft (40). and at least two pawls (42) arranged in a row and each associated with a lifting device (43) for lifting the pawls via the shuttle (41) to engage the selected gear ratio via the input pinion and the output pinion, the transmission (20) for a mobility vehicle (1) comprising a radial block system (44) formed as a single piece for maintaining all the pawls (42) in position on the selection shaft (40).

Description

[Technical field]

[0001] The present invention relates to the field of transmissions, and more specifically to transmissions for mobility vehicles utilizing at least electric propulsion, and for example power-assisted bicycles. [Background technology]

[0002] In operation of a mobility vehicle, power is transmitted to the wheels, typically via a chain, through a crank system that rotates about the axis of a crankset that drives the rear wheels.

[0003] Gearboxes for mobility vehicles are already known from the prior art. For example, patent application FR2975367 A1 discloses a transmission for a bicycle having a gearbox and a sliding shuttle for selecting the gears. The axial displacement of the shuttle is controlled via two cables that connect to a rotating hand grip arranged on the handlebar of the bicycle. The system requires many parts; its manufacture and maintenance are complex; in particular the cable control requires precise and regular adjustments. There is a need for a simplified and automated gearbox for cycles. Summary of the Invention

[0004] For this purpose, the present invention provides a selection shaft in which the shuttle and the worm are housed, at least two input pinions arranged to rotate freely about said selection shaft; at least two output pinions rotating integrally with the hollow shaft; a speed change actuator arranged to displace said shuttle along said worm between at least two positions to engage a selected gear; at least two pawls arranged on said selection shaft, each associated with a lifting device enabling said pawls to be lifted by said shuttle and to engage said selected gear via said input pinion and said output pinion; A transmission for a mobility vehicle, comprising: The transmission is further proposed to comprise a radial blocking system made in a single piece, which holds all said pawls in place on said selection shaft.

[0005] A radial block system formed in such a single piece is easier and less costly to manufacture and install.

[0006] According to one embodiment of the invention, the blocking system is formed from a longitudinal flat portion having at least two tabs extending therefrom, each of the tabs being positioned above one of the claws.

[0007] According to one embodiment of the invention, the tab originates from a first edge of the flat portion parallel to the axis of the blocking system and is oriented perpendicular to the axis of the blocking system.

[0008] According to one embodiment of the invention, the flat portion is inserted into a longitudinal slot formed in the selection shaft via a second edge opposite the edge on which the tab is located.

[0009] According to one embodiment of the present invention, the second edge is folded towards the shaft and inserted into the slot.

[0010] According to one embodiment of the invention, each pawl comprises a recess, the shape of said recess being complementary to the shape of said tab such that said tab is received in said recess.

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

[0012] According to one embodiment of the invention, the blocking system comprises positioning tabs.

[0013] The present invention also relates to a mobility vehicle, in particular an electrically assisted mobility vehicle, having a transmission according to the present invention.

[0014] According to one embodiment of the present invention, the vehicle is an electric-assisted bicycle.

[0015] Further objects, features and advantages of the present invention will be better understood and will become more apparent from a reading of the following description, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram of a mobility vehicle according to one of the embodiments of the present invention. [Diagram 2] FIG. 2 illustrates a transmission assembly of the mobility vehicle of FIG. [Figure 3a] FIG. 3a shows a cross-sectional view of a portion of the transmission assembly. [Figure 3b] FIG. 4b shows a cross-sectional view of a portion of the transmission assembly. [Figure 4] FIG. 4 is a cross-sectional view of a transmission according to the present invention. [Diagram 5] FIG. 5 is a cross-sectional view of a part of a transmission having a blocking system according to the invention. [Figure 6] FIG. 6 is a cross-sectional view of a portion of a transmission having a blocking system according to the invention. [Figure 7] FIG. 7 is a cross-sectional view of the interior of a housing incorporating a portion of a transmission assembly according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Figure 1 shows a mobility vehicle 1 according to one of the embodiments of the present invention. The vehicle 1 here is a pedelec equipped with an electric motor 2. The electric motor 2 is designed to provide part of the propulsion power of the vehicle.

[0018] The bicycle comprises at least two wheels 3, 3' which are powered via two pedals rotating about the axis of a crankset having an axis Xp which, in use, drives the rear wheel, for example via a chain or other transmission means.

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

[0020] The vehicle 1 shown also comprises an energy storage device in the form of a battery 6, a lighting system 7, a crankset 8 having an axis Xp, a localization and / or navigation system 90, and a human-machine interface system 91. The human-machine interface system 91 comprises, among other things, a touch screen capable of displaying information to the user's requests and / or taking into account the user's requests. The human-machine interface system 91 in particular functions as a navigation interface in connection with the localization system 90. The invention is not limited to a particular human-machine interface system, which may comprise any system known to the person skilled in the art.

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

[0022] The vehicle 1 has a transmission assembly 10 shown in Figure 2. The transmission assembly 10 has a gearbox 20 according to the present invention and an electric motor 2 for supplying a portion of the power for propelling the vehicle 1.

[0023] According to one aspect of the invention, the transmission assembly 10 is at least partially housed in a housing 30 (shown in FIG. 7) disposed, here, on the crankset 8. The axis Xp of the crankset 8 is connected to the output axis Xp of the transmission 20. v Matches.

[0024] According to one embodiment of the present invention, the transmission 20 shown in Figures 3a and 3b has at least two gear ratios, for example seven gear ratios between a first ratio, referred to as 1st gear, and a higher gear ratio, referred to as 7th gear.

[0025] According to one embodiment of the present invention, the transmission 20 is configured to rotate around an axis X that rotates together with the hollow shaft 80. v and a series of seven input pinions 50, i.e., pinions having reference numbers Fr1 to Fr7, designed to rotate freely about the selection shaft 40.

[0026] According to one embodiment of the present invention, the selection shaft 40 shown in FIGS. 3 and 4 houses a shuttle 41 which surrounds the worm 21 of the transmission 20 .

[0027] According to one variant of the invention, the transmission 20 comprises an epicyclic gear set.

[0028] The vehicle 1 according to the invention is equipped with a gear change actuator 70 designed to move the shuttle 41 along the worm 21 by a helical kinematic connection between at least two positions, for example between seven positions P1 to P7, to engage a selected gear ratio.

[0029] According to one embodiment of the present invention, the selection shaft 40 is hollow.

[0030] According to one embodiment of the invention, the speed change actuator 70 comprises electrical means for moving the shuttle 41 in the form of a reduction gear set. This reduction gear set comprises: It is equipped with a motor 81 and a reducer 82.

[0031] According to one embodiment of the invention, the reduction gear set comprises a pinion 22 on the shaft of the worm 21, an intermediate pinion 22', and a pinion 22" on the shaft of the motor 81. The tooth sets of the pinions 22, 22', 22" may be straight cut teeth as shown, or in a variant not shown, may be helical teeth.

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

[0033] According to one embodiment of the present invention, the shuttle 41 is configured to be positioned under and engage the pinion of a selected gear ratio during its movement.

[0034] According to one embodiment of the present invention, the shuttle 41 is constructed similarly to that described in application FR2975367.

[0035] According to one embodiment of the present invention, the reduction gear set includes a pinion having a parallel or perpendicular axis as shown in FIG.

[0036] According to one embodiment of the present invention, the variable speed actuator 70 comprises a bevel gear set, a straight cut spur gear set, or a helical gear set and / or has one or more stages.

[0037] According to an alternative embodiment of the invention, the speed change actuator 70 comprises a belt, or a chain, or a universal joint.

[0038] According to an embodiment of the present invention shown in Figures 5 and 6, the transmission 20 is provided with at least two pawls 42 on the selection shaft 40. For example, in a vehicle with 1 to 7 speeds, seven pawls 42 are provided.

[0039] According to one embodiment of the invention, the transmission 20 comprises a series of seven pawls arranged consecutively along the longitudinal axis X2 of the selection shaft 40.

[0040] According to one embodiment of the present invention, the transmission 20 comprises at least a series of at least seven pawls arranged consecutively along the longitudinal axis X2 of the selection shaft 40.

[0041] According to one embodiment of the present invention, the transmission 20 comprises three series of at least seven pawls arranged consecutively along the longitudinal axis X2 of the selection shaft 40. The series of pawls are spaced 120 degrees apart from one another about the selection shaft 40.

[0042] The pawls 42 have a shape adapted to cooperate with the input pinion Fri. The pawls 42 are housed in recesses 420 formed in the selection shaft 40. Each pawl 42 is associated with a lifting device, for example a ball 43 visible in Figs. 4 and 6, housed in a bore 430 of the inner shaft and projecting into the interior of the inner shaft, arranged below each pawl 42 and capable of lifting it via the shuttle 41.

[0043] Once a gear is selected, the shuttle 41 is positioned under the input pinion Fri corresponding to the selected gear ratio i, and is prevented from rotating by one of the pawls 42 so as to mesh with the corresponding output pinion.

[0044] In the context of the present invention, the transmission system comprises at least one radial blocking system 44 made as a single piece, so as to hold the pawls 42 in position in their housing 420. What is meant by this is a system 44 which keeps the pawls 42 pressed into their housing while at the same time allowing them to be lifted by the ball 43 and the shuttle 41. The radial blocking system 44 is made in one piece, which allows easy installation and manufacturing and limits costs.

[0045] According to one embodiment of the present invention, the block system 44 includes a longitudinal flat 440 .

[0046] According to one embodiment of the present invention, the system 44 includes at least two tabs 441, for example seven tabs 441 for a seven-speed vehicle.

[0047] According to one embodiment of the invention, the tabs 441 originate from a first edge 442 of the flat portion 440 that is parallel to the axis Xb of the block system 44 and is oriented perpendicular to the axis Xb of the block system 44. The rotating block system 44 thus forms a comb with separate flattened teeth.

[0048] 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 parallel to the axis of the shaft via a second edge 443 opposite the edge 442 on which the tab 441 is located.

[0049] According to one embodiment of the present invention, the second edge 443 is bent towards the shaft 40 and inserted into the slot 45 .

[0050] The blocking system 44 is arranged on the selection shaft 40 such that each tab 441 is located on a pawl 42 .

[0051] According to one embodiment of the present invention, each pawl 42 includes a recess 421. The shape of the recess 421 is complementary to the shape of the tab 441 such that the tab 441 does not move when the tab is received in the recess 421 and the pawl is secured.

[0052] According to an embodiment of the invention, the rotation block system 44 comprises a positioning tab 446, which is arranged on a second edge 443 inserted in the slot 45. This tab 444 cooperates with a further housing 445, which has a shape complementary to that of the positioning tab 446 and is formed on the selection shaft 40. By means of this positioning tab 446 the tab 441 of the device can be centered on the claw 42.

[0053] Thus, the rotational block system 44 exerts sufficient pressure or pushing force on each pawl 42 to block the pawl 42 within the housing 421 while still allowing the pawl 42 to be lifted by the shuttle 41 .

[0054] According to one embodiment of the present invention, the transmission system includes at least three rotation blocking systems 44 arranged to block three series of pawls.

[0055] The shuttle 41 is capable of selecting a selected gear ratio, which can engage the input pinion Fri via a pawl 42 and can be prevented from rotating by a rotation blocking system 44 .

[0056] The input pinion Fri then meshes with the output pinion Fi.

[0057] When the vehicle 1 is running at gear ratio i without changing gears, the worm 21 does not rotate.

[0058] When changing the gear ratio, the worm 21 is rotationally driven by the speed change actuator 70, causing an axial movement of the nut 210 of the worm 21. This drives the shuttle 41, making it possible to change the speed. The pivot connection thus implemented converts the rotational movement of the worm 21 into a translational movement of the shuttle 41.

[0059] 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.

[0060] In an embodiment not shown, the shuttle 41 can take a position referred to as neutral position P0, in which no gear ratio is engaged.

[0061] FIG. 7 shows the casing 30 of the mobility vehicle 1 of FIG. 1 in more detail.

[0062] The casing 30 has a case 310 defining a first housing 311 arranged to house the gear set of the transmission 20. The casing 310 also defines at least two second housings 312, 313, 314, 315 separate from one another, which together are adapted to house respectively the electric motor 2, the reduction gear set 11, the transmission actuator 70 and the control unit 4 of the mobility vehicle. According to an embodiment of the invention, at least the second housing is fluid-tight and is intended for example to house the control unit 4.

[0063] According to one embodiment of the invention, the casing 310 housing the transmission 20 is closed by two lateral flanges 317, only one of which is shown in Figure 4. The first housing 311 has two facing holes in the lateral flanges 317 to receive the crankset spindles of the mobility vehicle 1.

[0064] The scope of the present invention is not limited to the detailed description given above, as it is possible to embody it in many other specific forms without departing from the field of application of the present invention. The present embodiment is therefore to be considered as illustrative, and can be modified without departing from the scope defined by the claims.

Claims

1. - a selection shaft (40) on which the shuttle (41) and the worm (21) are housed; at least two input pinions (50, Fri) arranged to rotate freely about said selection shaft (40); at least two output pinions (60, Fi) rotating integrally with the hollow shaft (80); a speed change actuator (70) arranged to displace said shuttle (41) along said worm (21) between at least two positions to engage a selected gear; at least two pawls (42) arranged on said selection shaft (40), each associated with a lifting device (43) enabling said pawls to be lifted by said shuttle (41) and to engage said selected gear via said input pinion and said output pinion; A transmission (20) for a mobility vehicle (1), comprising: a radial block system (44) formed as a single piece, the radial block system (44) holding all of the pawls (42) in place on the selection shaft (40); The block system (44) is formed from a longitudinal flat (440), At least two tabs (441) extend from said longitudinal flat (440); Each of the tabs (441) is disposed above one of the claws (42); A transmission (20) characterized in that the flat portion (440) is inserted into a longitudinal slot (45) formed in the selection shaft (40) via a second edge (443) opposite to a first edge (442) on which the tab (441) is arranged.

2. the tab (441) originates from a first edge (442) of the flat portion (440) parallel to the axis (Xb) of the block system (44) and is oriented perpendicular to the axis (Xb) of the block system (44); The transmission (20) of claim 1.

3. The second edge (443) is folded toward the selection shaft (40) and inserted into the slot (45); The transmission (20) of claim 1.

4. Each claw (42) is provided with a recess (421); the shape of said recess (421) is complementary to the shape of said tab (441) such that said tab (441) is received in said recess (421); A transmission (20) according to one of claims 1 to 3.

5. Seven input pinions (50) and output pinions (70), seven pawls (42), and seven tabs (441). A transmission (20) according to one of the preceding claims.

6. The radial block system (44) includes a positioning tab (446). A transmission (20) according to one of the preceding claims.

7. A mobility vehicle (1) comprising a transmission (20) according to any one of claims 1 to 6.

8. The vehicle (1) is an electric assist bicycle. The mobility vehicle of claim 7.

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