WO2004083664A1

WO2004083664A1 - Clutch control device

Info

Publication number: WO2004083664A1
Application number: PCT/FR2004/050097
Authority: WO
Inventors: Gilles Lebas
Original assignee: Valeo Embrayages
Priority date: 2003-03-11
Filing date: 2004-03-09
Publication date: 2004-09-30
Also published as: DE112004000398B4; FR2852370B1; FR2852370A1; DE112004000398T5

Abstract

The invention relates to a clutch control device (1), comprising a rotating motor shaft, provided with a threaded section, a clutch actuator (4), mounted in a casing (3), such as to slide relative to the casing and a coupling mechanism (13), for coupling the actuator (4) to the motor shaft, for transformation of the rotation thereof into a translation of the actuator (4). Said coupling mechanism (13) comprises a toothed wheel (14), mounted to rotate about a principal axis (15), fixed with relation to the casing (3) and engaging with the threaded section of the motor shaft. The coupling mechanism (13) comprises a torque limiter (16), connecting the toothed wheel (14) to the actuator (4).

Description

Clutch control device.

The present invention relates to the clutch control of a vehicle.

The clutch control can be entirely mechanical, that is to say it is effected by means of a cable connected to a pedal actuated at the foot by the driver of the vehicle. It can also be a hydraulic connection.

The clutch control can also be assisted, or even fully controlled.

To this end, the vehicle is fitted with an electrical or hydraulic control device which is interposed either between the actuating pedal and the clutch, or, in the case of an automatic transmission, downstream of a device also controlling the gearbox.

The invention relates to such a clutch control device, which comprises, on the one hand, a rotating drive shaft provided with a threaded portion, and on the other hand, in a casing, a clutch actuator, mounted sliding relative to the casing, as well as a mechanism for coupling the actuator to the motor shaft to transform the rotation of the latter into translation of the actuator, this coupling mechanism comprising a toothed wheel which, mounted for rotation around a main axis fixed relative to the housing, is meshed by the threaded portion of the motor shaft.

A device of this type is known from the French patent application published under the number FR-2 790 806 in the name of the applicant.

This device has already revealed its qualities.

However, in the event of a clutch failure, resulting in an increase or irregularity in the resistive torque applied to the control device, there is a risk of engine overheating and, more generally, damage to the control device.

The invention aims in particular to limit these risks while simplifying the design and manufacture of the control device.

To this end, the invention provides a control device of the aforementioned type, characterized in that the coupling mechanism comprises a torque limiter connecting the toothed wheel to the actuator.

Thus, the limiter couples the gear wheel in rotation to the actuator as long as the resistant force opposed by the actuator to the rotation of the wheel is less than a predetermined threshold.

Conversely, the limiter decouples the actuator from the toothed wheel as soon as this force is greater than the predetermined threshold. In this case, the toothed wheel, driven by the motor shaft, slips without driving the actuator. Consequently, the rotation of the motor shaft not being impeded, the risks of rupture of parts of the device are low, as are the risks of overheating of the motor.

According to one embodiment, the coupling mechanism comprises a crank pin mounted in rotation about the main axis, this crank pin being coupled, on the one hand to the actuator, and on the other hand to the toothed wheel via of the torque limiter.

The torque limiter may include a friction ring interposed between the crankpin and the toothed wheel, this friction ring having, for example, in section, a star shape. According to one embodiment, the crankpin is connected to the actuator by means of a secondary axis of rotation, parallel to the main axis and spaced from the latter.

The crank pin comprises for example a cylindrical sleeve coaxial with the toothed wheel and which extends axially at least partly in a coaxial bore formed therein, the torque limiter being interposed between said sleeve and said bore. As for the toothed wheel, it can be provided with a cylindrical jacket force-fitted into said bore, the torque limiter being interposed between the sleeve and the jacket.

According to one embodiment, the coupling mechanism is connected to a force compensation device capable of assisting the action of the motor shaft on the coupling mechanism.

This force compensation device comprises for example a compression spring interposed between the housing on the one hand, and the crank pin on the other hand, as well as, possibly, means for guiding the spring.

These guide means comprise for example two nestable complementary parts, capable of sliding relative to each other to adapt together to the length of the spring.

The force compensation device is preferably pivotally mounted relative to the casing, while it is rotatably mounted on the crankpin of the coupling mechanism. According to one embodiment, the clutch control device further comprises a device for measuring the angle of rotation of the coupling mechanism.

This measuring device comprises for example a linear sensor comprising a fixed element relative to the casing, and a movable element mounted to slide relative to the fixed element and connected to the coupling mechanism. As a variant, the angle measuring device comprises a rotary sensor comprising a fixed element relative to the casing, and a mobile element mounted in rotation around the main axis and placed opposite the fixed element.

This movable element is preferably mounted on the toothed wheel. It is for example a magnetic rib, projecting from the toothed wheel and having a decreasing height, while the fixed element of the sensor comprises a Hall effect probe which placed opposite the upper surface of said rib .

According to one embodiment, the actuator and the coupling mechanism of the control device are shaped so that they can be mounted in the casing in a single direction of assembly.

This results in a simplification of the assembly of the control device, which makes it possible to increase the automation of its manufacture.

The force compensation device and the sensor can also be arranged so that they can be mounted in the casing in the same assembly direction, which is for example parallel to the main axis.

The invention will be better understood on reading the following description of an embodiment proposed by way of nonlimiting example, made with reference to the appended drawings in which:

- Figure 1 is a perspective view of a clutch control device;

- Figure 2 is a perspective view, partially broken away, of the device of Figure 1, to see various components;

- Figure 3 is a view similar to Figure 2, taken at a different angle; - Figure 4 is a perspective view in section of the device of the preceding figures;

- Figures 5 and 6 are partial perspective views of the device of the preceding figures;

- Figure 6 is a perspective view of a set of components of the device of the previous figures;

- Figures 7 to 13 are perspective views illustrating the mounting of the device of the previous figures;

- Figure 14 is a perspective sectional view of the mounted device;

- Figure 15 is a perspective view of a clutch control device according to an alternative embodiment; - Figure 16 is a detailed perspective view, illustrating certain components of the device of Figure 15;

- Figures 17 to 20 are perspective views, from different angles and configurations, of a force compensation device for a device as illustrated in the previous figures.

FIG. 1 shows a device 1 according to the invention for the electrical control of an assisted (or controlled) clutch of a motor vehicle.

This device 1 comprises an electric motor 2 fixed on a casing 3 in which is slidably mounted an actuator 4 provided with a rod 5 partially received in a housing 6 placed inside the casing (FIG. 2).

A control unit (not shown) controls the engine 2 according to the gearbox ratio to be engaged, either under the action of the driver when the transmission is manually controlled, or according to a preset program when the transmission is automatic. The rod 5 has an inner end, received in the housing 6 and by means of which the rod 5 is subject to the latter, as well as an opposite outer end 7, which, projecting from the casing 3, is shaped as a ball joint for engage a clutch control lever (not shown).

The housing 6 is provided with an electrically controlled backlash mechanism 8 which acts on the rod 5 to make it undergo an irreversible movement of translation as the friction of the clutch wears off.

This backlash mechanism 8 will not be described in detail in the present application; it will suffice to refer to the aforementioned application FR-2 790 806.

The rod 5 protrudes from the casing 3 through an orifice 9 closed by a bellows seal 10 which, surrounding the rod 5, allows the latter to slide in leaktight manner while allowing it a certain angular movement.

The motor 2 comprises a rotating motor shaft 11 which extends partly in the internal space of the casing 3 and which has a threaded portion 12.

The control device 1 further comprises a coupling mechanism 13 of the actuator 4 to the motor shaft 11, to transform the rotation of the latter into translation of the actuator 4.

This mechanism 13 comprises a toothed wheel 14 mounted for rotation about an axis 15 known as the main axis, fixed relative to the casing 3 and perpendicular to the axis of the motor shaft 11. The toothed wheel 14 is tangent to the threaded portion 12 of the motor shaft 11 which meshes it in the manner of a wheel and worm gear pair. The coupling mechanism 13 also includes a torque limiter 16 connecting the toothed wheel 14 to the actuator 4.

This limiter 16, which acts by friction, is arranged to couple the toothed wheel 14 and the actuator 4 in rotation as long as the resistant force opposed by the actuator 4 to the rotation of the wheel 14 is less than a predetermined threshold. , and to decouple them as soon as this force is greater than said predetermined threshold.

As can be seen in FIGS. 5 and 6 in particular, the coupling mechanism 13 comprises a crank pin 17 mounted in rotation about the main axis 15.

This crank pin 17 is coupled, on the one hand to the actuator 4 at a distance from the main axis 15, and on the other hand to the toothed wheel 14 via the torque limiter 16.

It is also coupled to a device 18 for accumulating mechanical energy, arranged to assist the motor 2 in its action on the toothed wheel 14 and to at least partially compensate for the force that the actuator 4 opposes in reaction. the wheel 14, as will be explained later.

The crank pin 17 comprises a cylindrical sleeve 19, coaxial with the toothed wheel 14, and which extends axially at least in part in a coaxial bore 20 formed therein, the torque limiter 16 comprising meanwhile a friction ring 21 interposed and mounted tightly between the sleeve 19 and the bore 20. As can be seen in particular in FIG. 4, the crank pin 17 is composed of several separate parts assembled, namely, in addition to the sleeve 19, a support plate 22 and a bent lever 23 parallel, axially spaced from each other, which both extend radially with respect to the sleeve 19 and are axially force-fitted thereon. More specifically, the sleeve 19 has a cylindrical middle part 24 extended on either side by two cylindrical end parts whose diameter is less than that of the middle part 24, namely a lower end part 25, introduced in the bore 20 of the wheel 14, and an upper end part 26 which, with the middle part 24, extends in axial projection relative to the wheel 14 (FIG. 4). At its junction with the lower end 25 and upper end 26, the middle part 24 forms, respectively, a lower shoulder 27 and an upper shoulder 28.

The support plate 22 and the lever 23 are both supported, respectively, on the lower shoulder 27 and on the upper shoulder 28, the middle part 24 thus forming a spacer which maintains a minimum distance between them. The support plate 22 has an oblong shape and has two arms 29,

30 which extend radially opposite one another on either side of the main axis

15, the first 29 extending substantially opposite the point of contact between the drive shaft 11 and the toothed wheel 14, while the second 30 extends on the side of this point (Figure 5).

The lever 23 extends generally on one side only of the main axis 15. It has a proximal portion 31 which extends radially above the first arm 29 from the axis 15, extended by a portion distal 32 which forms with the proximal portion 31 an angle between 80 ° and 120 °, so that the lever 23 has, when viewed from above, a general L-shaped profile.

As can be seen in FIG. 4, the support plate 22 and the lever 23 are connected by a secondary axis 33 which extends parallel to the main axis 15 at a distance from the latter.

The secondary axis 33 is mounted for rotation relative to the plate 22 and to the lever 23, its ends being housed in two coaxial bores made respectively in the plate 22 at the end of its first arm 29, and in the lever 23 at the junction between its proximal 31 and distal 32 portions.

As can be seen in FIG. 14, the housing 6 of the actuator 4 is provided, on the side of the main axis, with a projecting finger 34 whose end is pierced with a hole through which the secondary axis 33, so that the actuator 4 is rotatably coupled to the crankpin around this axis 33.

As we have seen, the crank pin 17 is coupled to a force compensation device 18.

This device 18 comprises a compression spring 35 interposed between the casing 3 and the lever 23. More specifically, the spring 35 is mounted jointly on two interlocking guides, namely, on the one hand, a proximal guide 36 which is on the side of the lever 23 on which it is rotatably mounted about an axis 38 parallel to the main axis, and passing through a hole made in the lever 23 at the end of the distal portion 32 of the latter, and, on the other part, a distal guide 37 which is located on the side of the casing 3 on which it is mounted in rotation about an axis 39 also parallel to the main axis 15.

As can be seen in FIG. 2, the compensation device 18 is housed in an appendage 40 of the casing 3, in which it can be angularly debated around the axis 39 according to an angular opening of a few degrees - from 2 ° to 10 ° for example. Each guide 37, 38 comprises a circular plate 41, 42 centered on the geometric axis of the spring 35, an axis which extends in a plane perpendicular to the main axis 15.

The plates 41, 42 are extended, in the direction of one another, by complementary rods 43, 44 of which a first 43 has in section a solid cross-shaped profile of which one of the branches 43a is wider than the other 43b, and of which the second 44, which has a hollow profile in section, has an imprint 45 complementary to the first rod 43, so that the rods 43 and 44 can be fitted and slide one inside the other parallel to the geometric axis of the spring 35, while retaining their mutual orientation.

The spring 35 is mounted jointly on the rods 43, 44 and comes at its two ends to bear against the plates 41, 42 between which it is compressed, the guides 37 and 38 sliding relative to each other for s 'Adapt jointly to the length of the spring 35 when it compresses or, on the contrary relaxes. The widest branch 43a of the first rod 43 has a width slightly less than the internal diameter of the spring 35. The same applies to the dimension of the second rod 44, measured perpendicular to the width of the branch

43a. In this way, the spring 35 is always guided precisely, without risk of sagging, whatever its length. The rotation of the wheel 14 and of the crank pin 17 is guided by two bearings, namely a lower bearing 46 and an upper bearing 47, which each have an axial portion 48 fitted on the main axis 15 and interposed between the latter and the muff

19, extended by a flange 49 bearing, for the lower bearing 46, on the lower end 25 of the sleeve 19 and, for the upper bearing 47, on its upper end 26.

The pads 46 and 47 are preferably self-lubricating, so as to facilitate the rotation of the crank pin 17 around the main axis 15.

As can be seen in FIG. 4, the lower pad 46 is directly in abutment against a lower wall 50 of the casing 3, in which is formed a cylindrical housing 51 for a lower end 52 of the main axis 15.

On the other hand, the upper cushion 47 is in indirect support against an upper wall 53 of the casing 3, by means of a spacer 54 in which the upper end 55 of the main axis 15 is housed.

According to one embodiment, the toothed wheel 14 is made of a thermoplastic material which, relative to steel, has the advantage of being able to be easily and inexpensively shaped while having reduced inertia, which increases the reactivity of the control device 1.

In this case, the friction ring 21 is not in direct contact with the bore 20 formed in the toothed wheel 14, a metal jacket 56 force-fitted into the bore 20 being interposed between the latter and the ring 21. This jacket 56 considerably reduces the wear of the toothed wheel 14.

As for the friction ring 21, it is made of a metallic material and preferably has, in section, a star profile which gives it a certain radial elasticity (FIG. 8). The ring 21 is prestressed before being mounted between the axle 15 and the wheel 14, so as to couple them in rotation under normal conditions of use, that is to say as long as the resistant force opposed by the actuator 4 is below the predetermined threshold.

As can be seen in particular in FIG. 5, the control device 1 is also equipped with a device 57 for measuring the angle of rotation of the wheel 14. This device 57 includes a linear Hall effect sensor 58 provided with 'a housing

59 fixed to the casing 3 and in which a rod 60 is slidably mounted.

This rod 60 is provided at its free end with a U-shaped fork 61 having a sliding engagement with a pin 62 which, at a distance from the main axis 15 to which it is parallel, projects from the second arm 30 of the support plate 22 The rest position of the control device 1 is illustrated in FIG. 5.

In this position, the crank pin 17, which is integral in rotation with the toothed wheel 14, and the compensation device 18, are placed in such a way that the geometric axis of the spring 35 intersects the main axis 15.

Consequently, the torque exerted by the compensation device 18 under the thrust of the spring 35 is zero. The system is therefore in equilibrium, as long as no rotation is imparted to the toothed wheel 14.

Since, under the control of the control unit - under the action of the driver or automatically - the drive shaft 11 rotates (counterclockwise in FIG. 5) the toothed wheel 14, this in turn drives the pin 17 which, pivoting about the main axis 15, angularly moves the compensation device 18 from its equilibrium position as defined above.

Under the thrust of the spring 35 exerted on the lever 23, the compensation device 18 applies to the crank pin 17 a torque which is added to that applied by the drive shaft 11 via the toothed wheel 14. The sum of these torques being greater than the resistive torque opposed by the actuator 4 under the thrust of the elastic members of the clutch, the crank pin 17 pushes the actuator 4 outwards from the casing 3 in the manner of a connecting rod-crank system, the movement undergone by the actuator 4 being a combination of a translation, and of a rotation centered on the gasket bellows seal 10.

The rod 60 of the sensor 58, initially taken out of the housing 59, is pushed back inside the latter under the thrust of the pin 62 which accompanies the rotation of the crank pin 17 while sliding in the fork 61.

The rod 60 is for example provided with a magnetic multipolar plate formed of a plurality of contiguous domains with reverse magnetization direction of a given domain with respect to the two domains which are contiguous to it, while the sensor 58 is provided with a Hall effect probe which, placed in the housing 59 in line with the retracted part of the rod 60, detects the successive reversals of polarity of the multipole plate to provide a signal proportional to the displacement of the rod 60.

A simple signal processing, for example within the control unit of the control device 1, makes it possible to measure the angular displacement of the crank pin 17 and to compare it with the desired theoretical displacement, as a function of the rotation of the motor shaft 11.

When the actual angular displacement of the crank pin 17 is equal to or substantially equal to its theoretical displacement, this means that the crank pin 17 and the wheel 14 are suitably coupled, and that the device 1 encounters no difficulty in controlling the clutch.

When the gear change has been recorded, the control device 1 acts in reverse of what has just been described, the drive shaft 11 driving the wheel 14 in the opposite direction (that is to say in clockwise in Figure 5) until the device 1 is again in its rest position. As soon as the resistance opposed by the actuator 4 is greater than the predetermined threshold, that is to say that the resistive torque applied by the actuator 4 to the crank pin 17 is greater than the sum of the torques applied by the motor shaft 11 and the compensating device 18, the friction ring 21, calibrated as a function of said threshold, separates from the crank pin 17 or from the wheel 14, so that the latter, still driven by the motor shaft 11, starts to skate without being able to drive the crank pin 17 from which it is thus decoupled.

As the wheel 14 rotates freely despite the friction caused by the friction ring 21, the motor 2 undergoes only minimal heating, or even no heating. No constraint appears in the parts of the device 1, and in particular in the parts making up the coupling mechanism 13.

This results in increased reliability and longevity of the control device 1. The control unit, connected to the angle measuring device 57, is informed by the latter that the rotation of the crank pin 17 is blocked. In this case, it can be programmed to stop engine 2 in order to avoid any unnecessary consumption of energy. It can also be programmed to warn the driver of a system failure, for example by controlling the lighting of a warning light on the vehicle dashboard.

The assembly of the control device 1 is carried out as follows, starting from the empty casing 3, to which only the motor 2 is fixed.

We start by fitting the lower end 52 of the main axis 15 into the corresponding cylindrical housing 51 formed in the lower wall 50 of the casing 3 (FIG. 7).

A first sub-assembly 63 is then formed comprising the lower bearing 46, the toothed wheel 14, the jacket 56, the friction ring 21, the support plate 22, the sleeve 19, the secondary axis 33 and the pin 62. These parts are assembled in a single direction parallel to the axis of the toothed wheel 14 (Figure 8).

The jacket 56 is first force-fitted into the bore 20 of the wheel 14. The friction ring is then fitted into the jacket 56. The support plate 22 is force-fitted onto the lower end part 25 of the sleeve 19, until it comes to bear against the lower shoulder 27. The lower end part 25 of the sleeve 19 is then introduced into the friction ring until the support plate 22 comes to bear against the toothed wheel 14. The secondary axis 33 and the pin 62 are introduced into the corresponding holes made respectively in the first and in the second arm 29, 30 of the support plate 22, the lower pad 46 being inserted in the lower end part 25 of the sleeve 19. This sub-assembly 63 is then fitted onto the main axis 15 (FIG. 9).

The sensor 58 is placed parallel to the main axis 15 so that the fork 61 comes to fit on the pin 62 (Figures 9 and 10).

The actuator 4 also deposited parallel to the main axis 15, so that its finger 34 comes to fit on the secondary axis 33 (Figures 10 and 11), while the rod 5 passes through the orifice 9 in which arranged the bellows 10.

A second sub-assembly 64 is formed comprising the compensation device 18 and the lever 23 which is fixed to it for rotation about the axis 38 of the proximal guide 36.

This second sub-assembly 64 is deposited parallel to the main axis 15, so that the lever 23 comes to fit together on the main axis 15 and on the secondary axis 33 until the lever 23 is rests against the shoulder upper 28, while the axis of rotation 39 of the distal guide 37 is housed in a cylindrical reserve 65 formed hollow in the casing 3 at the end of its appendage 40 (Figures 11 and 12).

Then the upper pad 47, still parallel to the main axis 15, is introduced into the upper end part 26 of the sleeve 19 (FIG. 12). Then the spacer 54 is fitted onto the upper end 55 of the axis 15.

We can then close the casing 3, the upper wall 53 of which is applied against the spacer 54 while ensuring the maintenance of the coupling mechanism 13 (FIG. 14).

The assembly which has just been described is particularly simple, in particular because the internal components of the control device 1 are successively mounted in a single direction, parallel in this case to the main axis 15. This assembly is enabled by the configuration and arrangement of the components, in particular the actuation mechanism 13, the actuator 4, the compensation device 18 and the sensor 58. It is thus possible to automate, at least in part, the assembly of the device 1.

An alternative embodiment of the clutch control device 1 is illustrated in FIGS. 15 and 16.

The elements common to the embodiment described above retain their numerical references, while the numerical references of the modified elements are preserved by being decorated with the sign "'".

This variant differs from the embodiment which has just been described essentially by the production of the toothed wheel 14 'and the sensor 58'.

As can be seen in FIG. 15, the toothed wheel 14 ′ does not form a solid disc as described above, but it is perforated to form an angular sector centered on the main axis 15, which extends over an angular opening of Approximately 120 ° around the axis 15. This results in a substantial gain in space.

As for the sensor 58 ′, it comprises a housing 59 ′ split at 66, fixed to the housing 3 and disposed directly above the toothed wheel 14 ′, which is provided with a magnetized rib 67 which extends along an arc of circle and whose height is uniformly decreasing.

The sensor 58 'comprises a Hall effect probe, the sensitive part of which is at the bottom of the slot 66. The sensor 58' is mounted in such a way that it overlaps the rib 67, the Hall effect probe thus being at the plumb with the upper surface of the rib 67. In this way, when the toothed wheel 14 'is rotated, the sensor 58' measures the variation of the magnetic field detected by the probe as a function of the angular position of the rib 67.

One of the advantages of this sensor structure 58 ′ is that the housing 59 ′ and the rib 67 are mounted directly on the fixed (in this case the housing 3) and mobile (the toothed wheel 14 ′) functional parts of the device. 1.

As no intermediate articulation is provided, capable of introducing a functional clearance, the sensor 58 'makes it possible to measure with great precision the relative displacement of the parts of the device 1, in this case the toothed wheel 14' relative to the housing 3.

For the rest, the general structure of the device 1 is unchanged. As for its mounting, it conforms to the method described above.

Claims

1. A clutch control device (1) comprising, on the one hand, a rotating motor shaft (11) provided with a threaded portion (12), and on the other hand, in a casing (3), a clutch actuator (4), slidably mounted relative to the casing (3), as well as a mechanism (13) for coupling the actuator (4) to the motor shaft (11) to transform the rotation of the latter ci in translation of the actuator (4), this coupling mechanism (13) comprising a toothed wheel (14) which, mounted for rotation about a main axis (15) fixed relative to the casing (3), is meshed by the threaded portion (12) of the motor shaft (11), device characterized in that the coupling mechanism (13) comprises a torque limiter (16) connecting the toothed wheel (14) to the actuator (4) , as well as a crank pin (17) rotatably mounted around the main axis (15) and coupled to the actuator (4), this crank pin (17) being also coupled to the toothed wheel (14) by the torque limiter intermediate (16) .

2. Device according to claim 1, characterized in that the torque limiter (16) comprises a friction ring (21) interposed between the crankpin (17) and the toothed wheel (14).

3. Device according to claim 2, characterized in that the friction ring (21) has in section a star shape.

4. Device according to one of claims 1 to 3, characterized in that the crank pin (17) is connected to the actuator (4) by means of a secondary axis of rotation (33), parallel to the main axis (15) and removed from it.

5. Device according to one of claims 1 to 4, characterized in that the crank pin (17) comprises a cylindrical sleeve (19) coaxial with the toothed wheel (14) and which extends axially at least partly in a bore (20) coaxial formed therein, the torque limiter (16) being interposed between said sleeve (19) and said bore (20).

6. Device according to claim 5, characterized in that the toothed wheel (14) is provided with a cylindrical jacket (56) force-fitted into said bore (20) and in that the torque limiter (16) is interposed between the sleeve (19) and the shirt (56).

7. Device according to one of claims 1 to 6, characterized in that the toothed wheel (14) is made of a plastic material.

8. Device according to one of claims 1 to 7, characterized in that the coupling mechanism (13) is connected to a device (18) of force compensation capable of assisting the action of the motor shaft (11 ) on the coupling mechanism (13).

9. Device according to claims 1 and 8, taken together, characterized in that the force compensation device (18) comprises a compression spring (35) interposed between the casing (3) on the one hand, and the crankpin (17) on the other hand.

10. Device according to claim 9, characterized in that the force compensation device (18) comprises means for guiding the spring (35).

11. Device according to claim 10, characterized in that the guide means comprise two complementary parts (36, 37) nestable, capable of sliding relative to each other to adapt together to the length of the spring ( 35).

12. Device according to one of claims 8 to 11, characterized in that the force compensation device (18) is pivotally mounted relative to the casing (3).

13. Device according to one of claims 8 to 12, taken together with one of claims 5 to 7, characterized in that the force compensation device (18) is rotatably mounted on the crankpin (17).

14. Device according to one of claims 1 to 13, characterized in that it comprises a device (57) for measuring the angle of rotation of the coupling mechanism

(13).

15. Device according to claim 14, characterized in that the angle measuring device (57) comprises a linear sensor (58) comprising an element (59) fixed relative to the casing (3), and an element (60) mobile mounted sliding with respect to the fixed element (59) and connected to the coupling mechanism (13).

16. Device according to claim 14, characterized in that the angle measuring device comprises a rotary sensor (58 ') comprising an element (59') fixed relative to the casing (3), and a mobile element (67) mounted in rotation around the main axis (15), opposite the fixed element (59 ').

17. Device according to claim 16, characterized in that the movable element

(67) is mounted on the toothed wheel (14 ').

18. Device according to claim 17, characterized in that the mobile element (67) is in the form of a magnetic rib, projecting from the toothed wheel (14 ') and which has a decreasing height, and in that the fixed element (59 ') of the sensor (58') comprises a Hall effect probe which is located opposite the upper surface of said rib.

19. Device (1) according to one of claims 1 to 18, characterized in that the actuator (4) and the coupling mechanism (13) are shaped to be able to be mounted in the housing (3) in a single direction assembly.

20. Device (1) according to claims 8 and 19, taken together, characterized in that the force compensation device (18) is arranged to be able to be mounted in the casing (3) in said direction of assembly.

21. Device (1) according to claim 19 or 20, taken together with claim 16 or 17, characterized in that the sensor (58, 58 ') is arranged to be able to be mounted in the casing (3) in said direction d 'assembly.

22. Device (1) according to one of claims 19 to 21, characterized in that the assembly direction is parallel to the main axis (15).