Locking system for transmission assembly and associated mobility device.

Abstract

The invention relates to a transmission assembly (10) for a mobility device comprising a gear-changing device (20) and an electric motor (2) for providing part of the propulsion power of the device (1), the assembly being arranged in a housing 30 having at least one compartment for the electric motor (2), the compartment for the electric motor (2) having a closure system 90 with at least two covers (98, 92). Figure to be published with the abbreviation: 7

Description

Title of the invention: Closing system for transmission assembly and associated mobility device.

[0001] The present invention relates to the field of transmission assemblies, and more particularly a closing system for a transmission assembly for a mobility device using at least one electric propulsion, and for example an electrically assisted bicycle.

[0002] Gearboxes for mobility devices are already known in the prior art. For example, patent application FR2975367 A1 discloses a gear changing device for bicycles, the propulsion of which is provided by an electric motor. The assembly, gear changing device and electric motor, is arranged in a motor housing. The housing comprises several housings for each of the elements of the assembly. At least one closing system, of the cover or hood type, closes the housing containing the electric motor. The disadvantage of current closing systems comes from the fact that they do not allow the centering of the shaft of the electric motor and the circulation of the oil necessary for the operation of the electric motor without increasing the noise level of the assembly.

[0003] The present invention therefore aims to overcome one or more of the drawbacks of the devices of the prior art by proposing an improved transmission assembly for a mobility device.

[0004] For this purpose, the present invention proposes a transmission assembly for a mobility device comprising a gear change device and an electric motor for providing part of the propulsion power of the device, the assembly being arranged in a housing comprising at least one housing for the electric motor, the housing of the electric motor comprising a closing system with at least two covers.

[0005] According to one embodiment of the invention, the two covers are arranged one on top of the other, a sealing gasket being arranged between the two covers.

[0006] According to one embodiment of the invention, the first cover has an opening in its center allowing the insertion of bearings of a shaft of the electric motor.

[0007] According to one embodiment of the invention, the second cover covers the first cover.

[0008] According to one embodiment of the invention, the seal between the two covers is achieved with a circular seal arranged on the periphery.

[0009] According to one embodiment of the invention, the second cover is made of polymer.

[0010] The invention also relates to a mobility device, in particular an electrically assisted mobility device, comprising a transmission system according to the invention.

[0011] According to one embodiment of the invention, the machine is an electrically assisted bicycle.

[0012] Other aims, characteristics and advantages of the invention will be better understood and will appear more clearly on reading the description given below, with reference to the appended figures, given by way of example and in which: - [Fig.l] is a view of a mobility device according to one aspect of the invention, - [Fig.2] illustrates the transmission assembly of the mobility device of [Fig.l], - [Fig.3a] and [Fig.3b] illustrate a sectional view of a part of the transmission assembly a) and of the transmission assembly b), - [Fig.4] is a sectional view of a gear changing device according to the invention, - [Fig.5] is an elevation view along a first face of the interior of the housing of the transmission system according to the invention, - [Fig.6] is an elevation view along a second face of the housing of the closed transmission system according to the invention, - [Fig.7] is an elevation view of the electric motor housing closing system according to the invention, - [Fig.8] is a sectional view of the closure system according to the invention.

[0013] [Fig.l] illustrates a mobility device 1 according to one aspect of the invention. The device 1 is here an electrically assisted bicycle comprising an electric motor 2. The electric motor 2 is arranged to provide part of the propulsion of the device. It comprises at least one shaft and bearings 97 arranged at each end 96 of the shaft, as well as a rotor and stator.

[0014] The bicycle comprises at least two wheels 3, 3' to which a driving force is supplied, by means of two pedals rotating around a crankset axle of axis Xp [Fig.2] which drives the rear wheel for example by a chain, or any other means of transmission during its use.

[0015] The machine 1 also comprises a control unit 4 as well as several sensors 5, 5', 5”, located for example at the level of the pedals, on the frame of the bicycle or at the level of a wheel 3, 3'.

[0016] The machine 1 shown here also comprises an energy storage device in the form of a battery 6, a lighting system 7, a pedal assembly 8 with an Xp axis [Fig. 2], a location and / or navigation system 90 as well as a human-machine interface system 91 comprising in particular a touch screen capable of displaying information to and / or take into account the requests of said user. The human-machine interface system 91 is in particular connected to the location system 90 and serves as a navigation interface. The invention is not limited to a particular human-machine interface system, and may include any system known to those skilled in the art.

[0017] The wheels 3, 3' are equipped with a braking system 31, including in particular disc brakes 32.

[0018] The machine 1 comprises a transmission assembly 10 illustrated [Fig.2]. The transmission assembly 10 comprises a speed change device 20 according to the invention and the electric motor 2 to provide part of the power for the propulsion of the machine 1.

[0019] According to one embodiment of the invention, the transmission assembly 10 is at least partly housed in a housing 30 here positioned at the level of the crankset 8 whose axis Xp coincides with the output axis Xv of the gear change device 20.

[0020] According to one embodiment of the invention, the gear change device 20 illustrated [Fig.3a] and [Fig.3b]] comprises at least 2 ratios, and for example 3 or 7 ratios between a first ratio called ratio no. 1 and a higher ratio called ratio no. 3 or no. 7.

[0021] According to one embodiment of the invention, the speed change device 20 comprises a series of seven output pinions 60 of axis X of reference Fi to F3 or F7, integral in rotation with a hollow shaft 80 and a series of seven input pinions 50, of reference Fri to Fr3 or Fr7 arranged to rotate freely around the selection shaft 40.

[0022] According to one embodiment of the invention, the selection shaft 40 illustrated [Fig.4] houses a shuttle 41 surrounding a worm screw 21 of the speed change device 20.

[0023] The machine 1 according to the invention comprises a speed change actuator 70 arranged to move the shuttle 41 along the worm screw 21 by a helical kinematic connection, between at least 2 positions and for example between 3 or 7 positions from Pi to P3 or P7 and engage a selected gear.

[0024] According to one embodiment of the invention, the gear change actuator 70 comprises electrical means for moving the shuttle 41, in the form of a geared motor. This comprises a motor 81 and a reducer 82.

[0025] According to one embodiment of the invention, the geared motor also comprises a pinion 22 on the axis of the worm screw 21, an intermediate pinion 22' and a pinion 22'” on the axis Xm of the motor 81. The teeth of the pinions 22, 22', 22” can be straight as illustrated or helical in a variant not illustrated.

[0026] The rotational guidance of the worm screw 21 is for example ensured using bearings at each of its ends.

[0027] According to one embodiment of the invention, the shuttle 41 is configured to, during its movement, position itself under the pinion of the selected gear, and engage this gear.

[0028] Thus, during a gear change, the worm screw 21 is rotated by the gear change actuator 70 causing the axial movement of the nut 210 of the screw 21 which drives the shuttle 41, the selection means via a ball is positioned under a pawl 42 which allows the gear change.

[0029] According to an embodiment of the invention, illustrated [Fig.4], the gear change device 20 comprises at the level of the selection shaft 40 at least two pawls 42 and for example for a 3-speed engine, comprises three pawls 42, or 7 for a 7-speed engine.

[0030] According to one embodiment of the invention, the gear change device 20 comprises a series of three or seven pawls arranged one after the other along the longitudinal axis X2 of the selection shaft 40.

[0031] When the speed is selected, the shuttle 41 is positioned under the input pinion Fr, corresponding to the selected ratio i, which is then locked in rotation by one of the pawls 42, and meshes with the corresponding output pinion.

[0032] [Fig.5] [Fig.5] illustrates in detail on a first face 100 the casing 30 of the mobility device 1 of [Fig.1].

[0033] The housing 30 comprises a casing 301 delimiting a first housing 302 arranged to house the gears of the speed change device 20. The casing 301 also delimits several second housings, distinct from each other. The housings 303, 304, 305, and 306 are arranged to house respectively the electric motor 2, the reducer 82, the speed change actuator 70 and the control unit 4 of the mobility device. The second housings are preferably sealed, in particular the one arranged to contain the control unit 4. This first face 100 is closed by a cover not visible in these figures.

[0034] According to one embodiment of the invention, the second face 200 of the visible housing [Fig.6], that is to say the one opposite the first face 100, comprises at least one opening at the level of the housing 303 of the electric motor 2.

[0035] In the context of the invention, the opening at the level of the second face 200 of the housing 303 of the electric motor 2 is closed by a closing system 90 comprising at least two covers 98, 92.

[0036] According to one embodiment of the invention, the two covers 98, 92 are arranged one on top of the other, a sealing gasket 93 is arranged between the two covers 98, 92.

[0037] According to one embodiment of the invention, the first cover 98 is positioned so as to close the opening of the motor housing 303.

[0038] According to one embodiment of the invention, this first cover 98 has an opening 95 in its center. This opening 95 is adapted to the end of the shaft 96, of the electric motor 2, comprising bearings 97. That is to say that the bearings 97 arranged at the end 96 of the shaft can be inserted into the visible opening 95 [Fig.8]. Such an opening 95 makes it easier to center the bearings.

[0039] According to one embodiment of the invention, the second cover 92 is positioned above the first cover 98. This second cover 92 is solid, it does not have a central opening. It thus completely covers the first cover 98. This second cover 92 has a sealing role.

[0040] According to one embodiment of the invention, the second cover 92 is made of polymer.

[0041] According to one embodiment of the invention, the seal between the two covers is achieved with a circular seal 93 arranged on the periphery between the two covers 98, 92. This makes it possible to avoid leaks and to maintain good lubrication of the engine, without tightening.

[0042] Dissociating the bearing centering function from the lubrication function with a two-part protection system makes it possible to limit engine noise and vibrations.

[0043] According to one embodiment of the invention, the second cover 92 comprises at least two fixing systems 94, and for example three, formed by openings and arranged on the periphery of the cover 92. These openings allow the cover 92 to be fixed to the casing 30 of the mobility device 1.

[0044] The scope of the present invention is not limited to the details given above and allows embodiments in many other specific forms without departing from the scope of the invention. Therefore, the present embodiments should be considered by way of illustration, and may be modified without departing from the scope defined by the claims.

Claims

Claims

1. Transmission assembly (10) for a mobility device comprising a gear change device (20) and an electric motor (2) for providing part of the propulsion power of the device (1), the assembly being arranged in a housing (30) comprising at least one housing for the electric motor (2), characterized in that the housing of the electric motor (2) comprises a closing system (90) with at least two covers (98, 92).

2. A transmission assembly (10) according to claim 1, wherein the two covers (98, 92) are arranged one on top of the other, a sealing gasket (93) being arranged between the two covers (98, 92).

3. A transmission assembly (10) according to claim 1 or 2, wherein the first cover (98) has an opening (95) in its center allowing the insertion of bearings of a shaft of the electric motor (2).

4. Transmission assembly (10) according to one of claims 1 to 3, wherein the second cover (92) covers the first cover (91).

5. Transmission assembly (10) according to one of claims 1 to 4, in which the seal between the two covers is achieved with a circular seal (93) arranged on the periphery.

6. Transmission assembly (10) according to one of claims 1 to 5, in which the second cover (92) is made of polymer.

7. Mobility device (1), in particular electrically assisted mobility device, comprising a transmission assembly (10) according to any one of the preceding claims.

8. Mobility device according to claim 7, in which the device (1) is an electrically assisted bicycle.

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