EP2872299A1 - Motion transmitting device with epicyclic reduction gearing, epicyclic reduction gearing and manipulating arm - Google Patents

Abstract

Device for transmitting motion between a motor (8, 8a) and a mobile member, comprising an epicyclic reduction gearing comprising a first sun wheel (2.1) and a second sun wheel (2.2) which are coaxial and are connected by means of transmission respectively to at least one first planet wheel (3.1) and one second planet wheel (3.2) which are borne coaxial with one another by a planet carrier (5) mounted to pivot eccentrically about the axis of the sun wheels, characterized in that the transmission means comprise flexible transmission members (6a, 7a) wound respectively around the first sun wheel and the first planet wheel and around the second sun wheel and the second planet wheel. Epicyclic reduction gearing and manipulation arm comprising such a device.

Description

 Planetary transmission device with epicyclic reduction gear, epicyclic reduction gear and manipulator arm.

The present invention relates to a reducing motion transmitting device epicyclic can be used on interfaces for more particuliè ^¬ surely in robotic applications, and cobotiques hap- ticks. The invention also relates to an epicyclic reduction gear and a manipulator arm for such applications.

Robots and haptic interfaces consist of poly-articulated mechanical chains and generally ac ^¬ tioned by electric motors. Their performances are directly related to the quality of the movement and effort transmission devices connecting in particular each actuated segment of the mechanical chain to the engine with which said segment is associated.

The transmission devices pose two ^¬ lems limiting their performance: in particular the energy of friction loss and the running clearance. In the transmission devices comprising a coupon ^¬ tor, these phenomena are more marked as the rap ^¬ reduction port is large so that more this reduction ratio is high and the yield is low.

In the field of industrial robots, there are quite satisfactory solutions for obtaining reduc ^¬ tors of great reduction ratio.

 These solutions include:

 belt reducers which, however, require several stages to achieve a large reduction ratio, their space requirement being very important;

- the gear teeth including those of planetary gearboxes that require however pleased ^¬ eral floors for large reduction ratios, such a reducing while having a relatively high inertia and important operation of games and / or harmful rubbing his performance ; - the wheel and screw allows very significant reduction in reports but is not réver ^¬ sible;

gearboxes in which an elliptical pivoting internal element comes into contact with a few teeth of a flexible ring gear with an external ring gear having a slightly different number of teeth. Thus, the flexible crown slightly rotated relative to the crown ex ^¬ dull as and measuring the rotation of the elliptic element tick, these gearboxes for large reports re ^¬ duction but with significant friction reducing performance.

If the drawbacks mentioned are annoying but acceptable in trielle industrial robotics applications, they become often extremely penali ^¬ sants in the case of haptic or cobotiques applications.

 Thus, on haptic interfaces and robots acting in cooperation with humans (commonly called cobots), an additional constraint is that the system is reversible (that is to say, it can be attacked as input, the motor then moving the actuated segment that is grasped by the user, or output, the user then moving the actuated segment which in turn drives the motor) and transparent (low friction and low play).

Most existing gearboxes used in industry do not have this feature so that they had to be adapted for applica tions cobotiques ^¬ haptic and without reaching the desired performance.

Specific reducers have therefore been developed for haptic interfaces and for co ^¬ botic applications.

The best known and most commonly used is the cable capstan. The reduction ratio is directly given by the ratio between the diameter of the driven pulley and that of the driving pulley, these diameters being calculated to the neutral fiber of the cable that connects them. However, the diameter of the driving pulley is limited by the winding capabilities of the cable and has a lower terminal typi ^¬ cally of the order of 10 mm for the most common cables. To obtain a high reduction ratio, it is necessary to increase the diameter of the driven pulley which quickly becomes bulky. Such a solution is no longer possible if we want to keep a compact system. This solution is therefore not suitable for obtaining a large reduction ratio.

Other systems are also used in cer ^¬ tain interfaces including:

 - Muffle reducers which, however, have a limited reduction ratio and are very complex and relatively bulky,

 ball screw reducers that implement complex parts.

 In order to obtain higher reduction ratios, it is therefore always necessary to use multi-stage gearboxes whose efficiency decreases.

Thus, there is no transmitted device ^¬ sion movements and effort with a high reduction ratio while being reversible, relatively compact and relatively simple construction.

 An object of the invention is to provide a motion transmission device capable of solving at least part of the aforementioned drawbacks.

For this purpose there is provided according to the invention, a movement transmission device between an engine and a movable member, comprising an epicyclic reducer COMPOR ^¬ as a first sun gear and a second sun gear coaxial connected by respective transmission means ^¬ at least a first satellite and a second satellite ^¬ lite which are carried coaxially to one another by a planet carrier mounted to pivot eccentrically about the axis of the planetaries, characterized in that the transmission means include flexible organs of transmission respectively wound around the first pla ^¬ nétaire and the first satellite and the second around pla ^¬ nétaire and the second satellite.

Thus, the epicyclic reduction gear of the invention is used in differential mode with a reduction ratio resulting from differences between the diameters of planetary and satellite. The reducer of the invention can thus be arranged to: allow with a single reduction stage to have a relatively high fixed reduction ratio; be reversible (the inlet and outlet of the gearbox can be reversed); have a high efficiency (typically of the order of 85% to 95% irrespective of the direction) which does not depend on the reduction ratio (low or even zero play and little friction); present a compact structure based on simple pieces to achieve. In addition, the apparent stiffness servo can be very important at the joint between two segments given the large reduction ratio. It is finally possible to deport the engine to operate the device remotely. In this case, it is the fast strand which ensures the transmission while the reduction is effected ni ^ni¬ or near the outlet and can be placed on the joint, which is favorable to performance.

 The invention also relates to an epicyclic reduction gear for such a device.

 The invention finally relates to an arm equipped with at least one such transmission device.

 Other features and advantages of the invention will emerge on reading the following description of particular non-limiting embodiments of the invention.

 Reference will be made to the appended drawings, among which:

 - Figure 1 is a schematic perspective view of a transmission device according to a first embodiment of the invention by means of cables;

FIG. 2 is a view similar to FIG. a device according to a variant of the first embodiment réa ^¬ lisation;

- Figure 3 is a schematic view in perspec tive ^¬ a transmission device according to a second embodiment cable;

- Figure 4 is a view similar to Figure 3 of a device according to a variant of the second embodiment réa ^¬ lisation;

 FIG. 5 is a schematic perspective view of a transmission device according to a third embodiment of cable;

- Figure 6 is a view in axial section of the operative part dispo ^¬ transmission of Figure 5;

 FIG. 7 is a schematic perspective view of a transmission device according to a fourth embodiment of cables;

- Figure 8 is a detailed perspective view of a particular implementation of the second Réali mode ^¬ tion cables;

 - Figure 9 is a view similar to Figure 8 of this device according to another angle of view;

 FIG. 10 is a perspective view of the planetary-satellite assembly of the device according to this implementation of the second embodiment;

 - Figure 11 is a view similar to Figure 8 of a device according to a first variant of this implementation of the second mode;

 - Figure 12 is a view similar to Figure 11 of this device according to another angle of view;

 - Figures 13 and 14 are views respectively from above and in perspective of the set planetary - satellite carrier - satellite device according to this variant of this implementation of the second mode;

- Figures 15 and 16 are perspective views of details of one of the planets of this set hovered ^¬ tary - door -satellites satellites;

FIG. 17 is a sectional view of this assembly planetary - satellite carriers - satellites;

 FIG. 18 is a perspective view of the planetary-satellite carrier-satellite assembly of a device according to a second variant of this implementation of the second embodiment;

 FIG. 19 is a perspective view of the planetary-satellite carrier-satellite assembly of a device according to a third variant of this implementation of the second embodiment;

 - Figure 20 is a perspective view of a robotic arm according to a first application of the transmission device according to the invention;

 - Figure 21 is a perspective view of a robotic arm according to a second application of the transmission device according to the invention;

 FIG. 22 is a perspective view of a robotic arm according to a third application of the transmission device according to the invention;

- Figure 23 is a sectional view of the handle of the robotic arm of Figure 22, the handle incorporating a transmission device according to the third embodiment réa ^¬ lisation;

- Figure 24 is a sectional view of the handle of the robotic arm of Figure 22, the handle incorporating a transmission device according to a variant of realized ^¬;

FIG. 25 is a perspective view of a transmission dis ^¬ positive according to one embodiment of the invention by means of belts;

- Figure 26 is a sectional view of the provisions ^¬ tif transmission by belts.

Referring to the figures, the device ^¬ trans mission movement of the invention is intended to be my ^¬ ty between an engine and a movable member for transmitting movements and forces from one to the other.

The motor and / or the movable member are advantageously ^¬ provided with means of measuring position and / or de- placement such as encoders or other posi ^¬ tion sensors for measuring, in a manner known per se, the movements of the motor and / or the movable member.

On a robot, which makes it possible to perform tasks at least partially autonomously, this po ^¬ sition sensor will enslave the configuration of the robot and its trajectory in position or effort depending on the task to perform.

On a haptic interface, which allows an indi- of interacting with a virtual environment or comman der ^¬ a robot remotely, these sensors will mea ^¬ rer movements of the joints of the robot will be used to calculate the displacement the user, themselves used to control the remote robot or a virtual avatar, after possible filtering. The engines will be used to apply feedback to the user, for example by applying a strong ef ^¬ or resistance to its movements.

 Finally, on a cobot, motors and position sensors will be used to perform both functions.

 These measuring means are known in themselves and will not be detailed here.

The transmission device, generally designated 1, comprises a supporting frame 4 on which is mounted an epicyclic reduction gear, here the planetary type Workoutvia ^¬ external events, comprising a first sun gear coaxial 2.1 and a 2.2 second planetary one to other and re ^¬ linked by means of transmission respectively to at least a first satellite 3.1 and a second satellite 3.2 which are carried coaxially to each other by a planet carrier 5. The planet carrier 5 is mounted on the support frame 4 for driving the satellites 3.1, 3.2 in an eccentric rotation movement about the axis of the plan¬ ^¬ 2.1, 2.2.

According to the invention, the transmission means comprise flexible transmission members wound res ^¬ tively around the first planetary 2.1 and the first satellite 3.1 and around the second sun gear 2.2 and the second satellite 3.2.

In the embodiments shown in fi ^¬ Figures 1 to 24, the flexible transmission members are cables 6a (6Al ', 6a2', 6Al '', 6a2 '') each having at least one coiled portion around the sun gear 2.1, 2.2 and a portion wrapped around the satellite 3.1, 3.2.

 In the embodiment of Figures 25, 26, the flexible transmission members are belts 7a.

 Referring to Figures 1 and 2, and in accordance with the first embodiment of the transmission device according to the invention, the first sun gear 2.1 is fixed in rotation relative to the support frame 4 while the second sun gear 2.2 is connected to the mobile organ.

The planet carrier 5 is connected to a tie ^¬ sor shaft 8a of a motor to be driven in rotation by the latter about the axis of the planetary 2.1, 2.2. More pre ^¬ cisely, the planet carrier 5 is secured to a pulley 9 mounted to pivot about the planetary 2.1, 2.2, and connected to a pulley 10 integral with the motor output shaft 8a via a flexible transmission member, to know a cable 6b. The motor 8a is equipped with an encoder 8b which makes it possible to measure its rotation and to enslave the system accordingly. It is mounted on a plate 80. This plate could advantageously be mounted movably on the support frame 4 to be able to pivot about an axis parallel to the axis of the output shaft so as to make the distance between the shaft adjustable. motor output and the pulley 9 of the planet carrier. This would allow a tension of the cable 6b connecting the pulley 10 of the motor output shaft 8a to the pulley 9 of the planet carrier. Such a device is con ^¬ nu in itself to those skilled in the art and is not shown in Figures 1 and 2.

The satellites 3.1, 3.2 are integral with a shaft whose central portion is pivotally received in the pou ^¬ lie 9 of the planet carrier 5. The planet carrier 5 here comprises for each satellite 3.1, 3.2 a stem arm extending axially projecting from the pulley 9 to rece ^¬ to pivot the free end of the shaft carrying the satellites 3.1, 3.2 such that each satellite 3.1, 3.2 is received between a free end of the arm and the pulley 9 of the carrier and thus be guided at each of its ends to support the forces that apply to him, while extending between the arm and the corresponding sun gear.

To ensure good compactness to the transmission device, the pulley 10 is disposed adjacent imme ^¬ diate pulley 9 of the planet carrier 5 and satellites 3.1, 3.2 are arranged in the immediate vicinity of the planned ^¬ tary 2.1, 2.2.

In addition to their winding diameter is constant, cables 6b, 6a are advantageously ^¬ rolls helically on the pulleys 9, 10 on the planetary 2.1, 2.2 and 3.1 on the satellites, 3.2. At the function ^¬ ment of the device, the cables are advancing on these pulleys (the term "blocks" used here in a general sense without reference numeral denotes the pulleys 9, 10, the glide ^¬ tary 2.1, 2.2 and satellites 3.1, 3.2) that is to say that their distance to the end faces of these pulleys ^¬ ries. Consequently, these pulleys must have a length sufficient to ensure the device the desired deflection. The pitch of these propellers are also advantageously ^¬ depending on the diameters of these pulleys so that the advancement of the cables on each of the pulleys, facing one another, these pairs of pulleys is identical.

A numerical example is given below by way of indication. The satellites 3.1, 3.2 have radii

and the second sun gear 2.2 a radius R _p2 = 9.9mm. These rays are calculated considering that the cables 6 have a diameter of 0.57mm (unsheathed) and a diameter of 0.8mm (sheathed). The planet carrier pulley 9 has a radius R _ps = 30.4mm and the pulley 10 of the motor output shaft 8 has a radius R _m = 10.4mm. We then have a reduction ratio rl = 30, 4/10, 4 = 2, 92 and a total reduction of R = rlx1 / [1- (R _p i x R _s2 ) / (R _s i x R _P 2)] = 115, 75. the height of the pulley 10, the displacement at the engine 8a is of the order of 30 turns (± 15 turns) or 0.26 turns or almost 93.3 ° at the output (± 46.6 °) .

 It will be noted in these figures that the cables 6a and 6b are crossed for use in capstan (the adjacent pulleys turn in opposite directions). The cables 6a and / or 6b can also be used without crossing (contiguous pulleys rotating in the same direction), and this for all the embodiments.

 In the variant of Figure 2, the support frame 4 comprises two parts 4.1, 4.2 fixed to one another to form an L.

The motor 8a carrying the pulley 10 is mounted on the part 4.1 and the set planetary 2.1, 2.2, door satellite ^¬ lites 5 and pulley 9 of the planet carrier is mounted on the part 4.2 to extend laterally with respect to the mo ^¬ 8a and the pulley 10.

In addition, the planet carrier 5 comprises for each satellite a frame extending axially projecting from the pulley 9 of the planet carrier 5 so that each satellite is guided between the free end of the frame and the planet carrier pulley. 9 and that the sides of the frame extend laterally with respect to the planar pair ^¬ - satellite.

Specifically, the sides of the frame extend here opposite the sun gear and are joined by a yoke extending in a plane perpendicular to the axis of the sun gear to surround a portion of the circumference of the pla ^¬ nétaire and carrying a end of the satellite. The sides of the frame thus extend in an unobstructed portion of the pou ^¬ lie 9 of the planet carrier and the satellite may have its end opposite to the yoke received in the vicinity of the outer circuit of the planet carrier pulley. Each TELLITE his ^¬ 3.1, 3.2 and extends laterally relative to the planet carrier 5. This makes it possible to limit the radial dimensions of the planet carrier 5, thereby moving it away from the support frame 4, the motor 8a and the pulley 10. This makes it possible to limit the diameter of the pulley 9 of the planet carrier 5 and to expensive planet carrier assembly 5 and pulley 9 of the frame sup ^¬ port 4, the engine 8a and the pulley 10 in the same pro ^¬ portions without risk of creating collisions between these ^¬ sembles.

This arrangement and the L-shaped support frame 4 allow this variant of the first embodiment to be more compact than the first embodiment re ^¬ shown in Figure 1.

Referring to Figure 3, the trans ^¬ device assignment according to the second embodiment is distinguished from that of the variant of the first embodiment realized ^¬ shown in Figure 2 in that the planet carrier 5 and satellites 3.1, 3.2 are housed at least partially ^¬ inside the pulley 9 of the planet carrier 5.

 In the variant of FIG. 4, the motor 8a, its encoder 8b and the pulley 10 are offset relative to the planetary assembly - pulley 9 - planet carrier 5.

Note that regardless of the mode ^¬ realized, the motor can be positioned to have its output shaft is not parallel to that of the pulley 9 of the planet carrier: then using deflection pulleys for guiding inter ^¬ intermediaries the cable 6b of the pulley 10 to the pou ^¬ lie 9.

 In all cases, the transmission being performed on the fast strand before the reduction, the operation of the system is only slightly degraded.

Referring to Figures 5 and 6, and according to the three-layer ^¬ SIEME embodiment, the first planetary 2.1 serves as a base for fixing and supporting the motor 8a provided with its encoder 8b (hidden in Figure 5 by the planetary 2.1) and whose stator is here directly attached to the first glide ^¬ 2.1 silent.

In FIG. 6, the rotating guides are presented in a simplified way by radial clearances between the moving parts. These guides could of course be made by any appropriate means such as, for example and without limitation, plain bearings in bronze or polytetrafluoroethylene or ball bearings, needle or roller with straight or oblique contacts. In the same way, the parts integral in rotation are re ^¬ presented in a simplified manner by a lack of clearance ra ^¬ dial. It is understood that in practice these parts could be rendered integral in rotation by any appropriate means such as for example and in a nonlimiting manner by gluing, by keying or by pres ^¬ sion screw. These means are known to the skilled person and do ^¬ RONT not detailed here.

 The planet carrier 5 is here fixed directly to the end of the output shaft of the motor 8a so that the rotor directly drives the planet carrier 5 without the presence of the pulleys 9, 10 and the cable 6b. Thus, the system is radially much more compact.

This solution is particularly advantageous when one wants to drive a body aligned with the engine, here a button 30. Alternatively, the body may be for example the prono-supination axis of the wrist of a ro ^¬ botique arm.

The movable member could still have a tubular shape to surround the transmission device. This configuration is well adapted if the movable member is a handle grasped by the user in hand (we will choose in this case a small motor and size the system so that its outer diameter remains compatible with an intake by empaumement or pen taken, the mistletoe ^¬ dages can be performed with plain bearings, thin bearings or needle bearings for limi ^¬ ter the diameter of the assembly).

Referring to Figure 7, and in accordance with qua ^¬ trième embodiment of the transmission device according to the present invention, the movable member is mounted on the support frame 4 for sliding and is connected to an output of the epicyclic reduction gear by a crank pinion connection ^¬ lere. The rack and pinion connection comprises here and for example a cable having at least one end portion fixed to the movable member and a portion wound around a pinion connected in rotation to the second sun gear 2.2. This embodiment of the transformation of the rotational movement of the sun gear 2.2 into a translational movement of the movable member is given only by way of example and any other means for carrying out this transformation, for example and in a non-linear manner. limiting a pinion gear rack assembly or friction or crank link assembly is not beyond the scope of the invention.

 A detailed implementation of the transmission device of the second embodiment will now be described with reference to FIGS. 8 to 10 on which the cables are not shown to lighten the figures.

The general structure of this transmitted device ^¬ sion has already been described in relation to Figures 1 to 3.

The engine block 8 composed of the engine 8a and its co ^¬ 8b is mounted on a support plate 11 movable about an axis eccentric with respect to the axis of the engine so as to change the gap between the axes of the pulley 9 of the planet carrier 5 and the pulley 10 to tension the cable connecting them. The tension is obtained by a screw 12 (visible in Figure 9) engaged in the support plate 11 to have its free end bearing against the support frame 4. Two pressure screws 13 received in oblong openings 14 formed in an arc in the support frame 4 have their free end engaged in the support plate 11 to clamp the support plate 11 against the support frame 4 to block the rotation of the support plate 11 once the cable tensioned.

The planetary 2.1, 2.2 here have diameters substantially identical. The two satellites 3.1, 3.2 are so ^¬ lidaires rotating.

A first strand of secondary cable (not shown (a) a:

- a first end portion attached and ENROU ^¬ EAA on the first planetary 2.1;

- a central portion wound around the first satellite 3.1 on which it makes several turns (typical ^¬ five or six to work properly drives the satel ^¬ lite 3.1 by friction);

- a second end portion attached and ENROU ^¬ EAA on the first sun gear 2.1.

 A second secondary cable strand (not shown) has:

- a first end portion attached and ENROU ^¬ EAA on the second planetary 2.2;

- a central portion wound around the second satellite 3.2 on which it makes several turns (typical ^¬ five or six to work properly drives the satel ^¬ lite 3.2 by friction);

- a second end portion attached and ENROU ^¬ EAA on the second planetary 2.2.

To improve the friction of the cable on its ^¬ tellites 3.1, 3.2, 3.1 satellites, 3.2 comprise a helical external groove 15 for receiving the coiled portion of cable. It is of course, however, that the ^¬ tellites 3.1, 3.2 could also be smooth.

As the cable is helically wound on the pou ^¬ lies and is therefore not perpendicular to the axis of the pulleys ("pulleys" used in a general sense without numerical reference means any pulley present in the epicyclic reducer and here in particular the planetary and satellite), it produces an axial force on satellites and planetary gears. Therefore, all the pulleys, except the fixed 2.1 sun gear, are mounted on bearings incorporating both axial and radial forces. Thus, in this example, the sun gear 2.2 and the satellites 3.1, 3.2 are rotatably mounted relative to the sun gear 2.1, respectively to the planet carrier 5, by means of needle bearings necessary for the recovery. radial forces that can be very important for a high effort capacity. These needle bearings are associated with thrust bearings containing the axial forces.

 The external helical grooves 15 of the satellites

3.1, 3.2 are here advantageously opposite directions for mi ^¬ nimise the axial forces.

Since the two strands of the secondary cable are fixed at their both ends on the planetary 2.1, 2.2, it is not necessary to provide external grooves heli ^¬ coïdales on global to improve the friction on the cable thereof. They are therefore smooth, which facilitates their machining at the same time as it facilitates the routing of the cables. It is understood, however, that the planetary 2.1, 2.2 could also be provided with external helical grooves.

 The distance between the axis of the planetary 2.1, 2.2 and that of the satellites 3.1, 3.2 is here fixed.

 Theoretically, it would be possible to calculate the exact length of the cables and fix them in a non-adjustable way on the 2.1, 2.2. Here, however, tensioners 40 are provided at both ends of each of the two cable strands of the epicyclic reduction gear. Two tensioners are arranged on the sun gear 2.1 and two other tensioners on the sun gear 2.2 (the second tensioner of the sun gear 2.1 is hidden by the end of the planet carrier 5 in FIGS. 8 to 10). They are movable in rotation about the axis of the planetary 2.1, 2.2 and can be moved and fixed by screws, which allows to stretch the cable strands and catch any soft strand.

The planet carrier 5 is made in three parts secured by screws and supports long pulleys 17 of great length intended to press the cables on the satellites 3.1, 3.2 along them at their entry and exit. The idle pulleys 17 maintain a winding angle of the cable around the satellites 3.1, 3.2. This ensures that any slack does not spread on the wound cable portion on satel ^¬ lites, which would be pre udiciable the friction of the cable and the drive of the satellites. It will be noted that the ends of the idle pulleys 17 are each rotatably mounted on a base 25 mounted on the planet carrier 5 to be adjustable in position relative to the satellites 3.1, 3.2, by means of a screw 26 passing through an oblong hole in the base. This makes it possible to retract the idle pulleys 17 for the assembly and / or possibly to apply the idle pulleys 17 on the cables to act as tensioners.

In this implementation, not ^¬ cable strands smells of 2.1 planets, satellites 2.2 3.1 3.2 2.1 then return to the planet, 2.2 after rain ^¬ eral rounds on satellites 3.1, 3.2. This results in a great length of the whole. To reduce this length, it is possible to separate the forward and return paths of the cable strands from the planetary gears 2.1, 2.2 to the satellites 3.1, 3.2 as shown in FIGS. 11 to 17.

 In the first variant of FIGS. 11 to 17, the device comprises a plurality of first satellites 3.1 and second satellites 3.2 mounted on the planet carrier 5 symmetrically about the axis of the planetary gears.

The device comprises more precisely two pairs of satellites 3.1, 3.2 arranged at 180 ° from one another and the device uses four cable strands ^¬ ondary 6Al '6Al'',6a2', 6a2 '', each of 'transform them putting the motion of a planet 2.1, 2.2 a satel ^¬ lite 3.1, 3.2 in one direction. Under these conditions, the two end portions of each of the cable strands 6Al '6Al'',6a2', 6a2 '' may be attached to the glide ^¬ tary 2.1, 2.2 and satellites 3.1, 3.2 and no enrou- It is not necessary to ensure that the cable adheres to them. As a result the length of the set is reduced. Thus, each planetary 2.1, 2.2 is connected to the satellite 3.1, 3.2 corresponding by two wire strands 6al ', 6al'',6a2', 6a2 '' fixed to the sun gear 2.1, 2.2 and the satellite 3.1, 3.2 so as to transmit the movement each in one direction.

The end portions of the cables are provided with splices (but this could also be nodes) represented by thicker portions of the cables. These splices are stopped by pins and tensioners fixed respectively on the satellites 3.1, 3.2 and on the planetary 2.1, 2.2. Planetary 2.1, 2.2 being more mas ^¬ sive than 3.1, 3.2 satellites, they are the ones which are provided tensioners consist of parts which are rotatable about the axis of the planetary and be secured by screws. It is understood that the tensioners could also be mounted on the satellites and pions on the planetaries. It would also be possible to equip both satellites and planetary tensioners.

Each tensioner here comprises a stirrup 18 for hooking the end portion. The stirrup 18 comprises an open end provided with hooks for retaining a rod 19 passed into the splice of the end portion and has an oblong opening for the step ^¬ wise of a screw 20 for fixing the stirrup 18 to the element around which the end portion is wound and on which it is fixed, here the sun gear 2.1, 2.2. The opening has longitudinal edges forming for the head of the screw 20 a range of increasing height along a longitudinal direction of the opening, the bearing having a lower part of the side of the hooks and a top part opposite . The tensioner thus has a wedge shape to remain effectively blocked when the screw is tightened. Any other type of tensioner could of course be used. Note that the hooks here also include a bearing heel against the surface of the sun gear beyond the rod 19 so as to oppose a deformation of the hooks (opening thereof) under a tensile force exerted on the stem 19. The tension of the cables is obtained in the following manner. The planet carrier 5 and the movable member are first immobilized in orientation by means of removable poles, not shown in the figures, being inserted into holes pierced opposite the fixed frame 4 and on the door -satellites 5 and the movable member for ^¬ sea for temporary rotational locking means. The tellites his ^¬ 3.1, 3.2 are then also blocked orien ^¬ tation using screw nipples 21a (shown in Figure 17). The first end portion of a first strand of a first cable 6a2 'is then fixed on the sun gear 2.2 and wound on it and then passed over the portion of the satellite 3.2 (shown at the top on fi ^¬ these figures) on which it is wound and on which the other end portion of the cable strand is fixed 6a2. Is li ^¬ Bère then this portion of 3.2 satellite by unscrewing the screw pin 21a and rotated slightly satellite 3.2 desired to tension the cable strand. If the cable strand was carefully prepared to length, the ROTA tion 3.2 satellite is zero or very low and the timing of the threads of various pulleys is not or little mo ^¬ Difie. We then reattached the orientation of this portion of the 3.2 satellite using a screw 21b (avanta ^¬ geusement cup point to improve the blocking ROTA tion) acting on the Satellite 3.1. Then attaching the first end of a second strand of the first cable 6al 'on the first threaded portion of the satellite 3.1, is wound on it, it is passed on the sun gear 2.1 on which it is wound. Finally, the second end of this second strand of the first cable 6al 'is fixed to the tensioner that can be rotated on the sun gear 2.1. This tensioner is then adjusted to ensure a cable tension and then blocked by tightening the screw 20. The principle is the same for the other two cable strands 6al '', 6a2 '' which wind on the other two portions of the satellites 3.1 and 3.2 shown at the bottom in the figures.

On a serial assembly, one could also pre- trim cable strands of the correct length and simply fix them without a tensioning system.

It will be noted that the diameters of the planetary gears and satellites (and consequently the pitch of the threads) are chosen close to one another. Indeed, this minimizes the length of planets and Satel lites ^¬. However, it would also be possible to choose ^heavier planes than satellites without departing from the scope of the invention, this solution making it possible to minimize the stresses in the cables.

Note also that the diameters of planned ^¬ tary and satellites are chosen lowest pos ^¬ sible. Therefore the rotating pairs of Satel lites ^¬ 3.1, 3.2 on the planet carrier 5 are provided by visible needle bearings on the 17 and not referenced. The rotation guide of the sun gear 2.2 with respect to the sun gear 2.1 is also ensured by needle ^roller bearings. The axial forces are in turn taken up by needle bearings also visible in Figure 17. The compactness constraints being less cri ^¬ ticks on the planet carrier 5, it is guided in ro ^¬ tation relative to planetary 2.1 and 2.2 by rou ^¬ ELEMENTS bearing with double row oblique contacts repre ^¬ sented in Figure 17 and which also show the axial ef- forts. It is understood that any other guide solution for retaining both ra ^¬ axial and axial forces could be used without departing from the scope of the invention.

A numerical example is given below by way of indication. The pulley 10 has for example an effective diameter of 26 mm and the pulley 9 of the planet carrier 5 a dia ^¬ useful meter 78 mm, which provides a first reduction ratio rl = 3. The cable connecting these two pou ^¬ lies is for example made of aramid fibers or type "micro-dyneema" and has a diameter of 0.42 mm. The two pulleys 9, 10 are provided with helical grooves to improve the adhesion and guidance of the cable. Not here is 0.5 mm on the pulley 10 and 1.5 mm on the pou ^¬ lie 9. This ratio of steps is chosen according to the reduction ratio for the system to work properly. Here the cable is almost six turns around the pulley 10, which corresponds to the smallest number ensuring both that the adhesion of the cable on the pulley is sufficient and that the cable falls in front of the grooves of the pulley 9 to the pulley. The cable could also have a different size and / or consist of a different material. In this case, the steps of the external grooves should be adapted. Again, the motor unit 8 is mounted on a support plate 16 movable about an axis eccentric with respect to the axis of the motor so as to be able to change the distance between the axes of the pulleys 9, 10 to tension the cable 6b . The voltage is obtained by a die ^¬ engine block of manual placement 8 which is then held in place using a screw press from the sup ^¬ harbor platinum 16 of the engine block 8 of the support frame 4.

In the second variant shown in FIG. 18 (in which the splices and cable stops are represented in a more schematic manner), the two satel ^¬ lites 3.1, 3.2 of each pair have the same diameter to facilitate their machining, the planetary diameters 2.1, 2.2 being different. Thus, the outer grooves 15 of the diameters 3.1, 3.2 are machined successively in one go. Under these conditions, it is not possible to change the winding direction between the two satellites 3.1, 3.2 and the voltage of the cables can not be done as before. Satellites 3.1, 3.2 are then mounted on axes centered former 22 associated with the crank pins 23 bearing on the engaged screw 24 in the planet carrier 5. This oven ^¬ nit an additional tensioning means of cables for ^¬ mant a distance adjustment member between the glide ^¬ tary and satellites. In addition to the 2.1 and 2.2 planetary tensioners, they ensure the tension of the 4 cable strands.

As a variant of the device of FIG. accordance to Figure 19 (wherein splices and stops cables are shown in a more schematic ^¬ tick and wherein the portions of the cables from the planetary satellites are not shown), the device is provided with three pairs of satellites 3.1 , 3.2 arranged at 120 ° from each other, two of them receiving only one strand of cable and the third two strands of cable. It is thus possible to fix all the ends of the cables by means of simple pins inserted into holes 27 and to tension them with eccentrics on the axes of the satellites 3.1, 3.2.

Note that the pins are advantageously enga ^¬ gés in flats 18 (shown in Figure 18) to prevent them from protruding cables wound on the satellites and do collide with each other or with other parts of the device. Advantageously Ega ^¬ LEMENT, external grooves 15 then connect progress ^¬ sively to the flat to avoid creating a stress concentration area in the cables or offensive to edges thereof.

 These flats are however not mandatory and the cable end fixing pins may be inserted on cylindrical portions 28 (shown in Figure 19) of the planetary and satellite.

 FIG. 20 represents a first application of the invention to a manipulation arm 100 intended to form a haptic interface and having for this purpose a handle as a terminal organ.

The arm 100 thus comprises a first base forming segment 101 on which is mounted, via a transmission device 1.1, a second trunk segment 102 for pivoting about a vertical axis. Third and fourth segments forming arm 103 and rod 104 are mounted, via transmission devices 1.2 and 1.3, on the second segment 102 to pivot about a sensi ^¬ horizontally horizontal axis. A fifth forearm segment 105 is mounted on the third segment 103 to pivot turn of a substantially horizontal axis. The forearm 105 is rotated by a sixth segment 106, forming an actuating rod, itself driven by the rod 104. The assembly consisting of the arm 103, the rod 104, the forearm 105 and the connecting rod 106 constitutes a parallelogram structure well known to those skilled in the art. The axes of rotation of the arm 103 and the link 104 relative to the trunk 102 could still not be aligned, the previous assembly then forming a bar mechanism structure.

A first wrist pad 107 to two articulated motorized axes ^¬ tions advantageously concurrent and per pendiculaires ^¬ is connected by one of its joints mo ^¬ torisées 107.1 segment 105 and the fifth by the other of its motorized articulations 107.2 a second wrist segment 108 on which is mounted a handle 109 via a motorized articulation 110.

 The first base segment 101 is the input of the transmission device 1.1 while the second trunk segment 102 is the output (or movable member) of the transmission device 1.1. The second segment 102 is also the input of the transmission devices 1.2 and 1.3 whose output is respectively formed by the third segment 103 and the fourth segment 104. The transmission devices 1.1, 1.2, 1.3 are, for example, of the type of transmission device. that of Figures 11 and 12.

Motorized joints 107.1, 107.2, 110 ^¬ little wind for example be formed by conventional electric motors or gearmotors, the driven element is re- connected to the output shaft of the motor or gearbox, or transmission devices the type of fi ^¬ Figures 5 and 6.

Fig. 21 shows a second application of the invention to a manipulator arm 100 for forming a robot. The manipulation arm 100 of FIG. 21 is identical to that of FIG. 20 except that the handle has been replaced by a clamp. This clip advantageously includes an additional motor to control the closing of the clamp.

 It is understood that the invention could easily be applied to a collaborative robot, for example by adding a tool to the haptic interface of FIG. 20 and using it as a cobot or by adding at the end robot of Figure 21 a handle allowing the user to easily move directly to the clamp or close to it.

 FIG. 22 represents a third application of the invention to a manipulation arm 200 intended to form a haptic interface and having for this purpose an end member provided with a handle.

The arm comprises a fixed base 201, two trunks 202a and 202b and a plurality of segments 203a, 204a, 205a and 203b, 204b, 205b mounted to pivot in pairs relative to each other, two first wrist segments 206a and 206b, a second wrist segment 207, a handle holder 208 and a handle 209. The trunks 202a and 202b are rotatable relative to the base 201 about two axes 301a and 301b advantageously parallel and here horizontal. These rotational movements are measured and pi ^¬ LOTES using blocks 401a and 401b motors each consisting of a motor and an angular position sensor fixed on the base 201. The segments 203a, 203b, respec tively ^¬ 204a, 204b and 205a, 205b are rotatable about axes 302a, 302b, respectively 303a, 303b and 304a, 304b relative to the trunks 202a, 202b respectively ^¬ ment segments 203a, 203b and 204a, 204b. The axes 302a, 303a and 304a, respectively 302b, 303b and 304b are advan ^¬ tageusement mutually parallel and perpendicular to the axis 301a, respectively 301b. Engine blocks 402 (of which only the one referenced 402a mounted on the trunk 202a is visible in the figure) are mounted on the trunks 202a and 202b and are used to measure and control the MOTION ^¬ elements 203a and 203b of the segments. Other engine blocks 403 (of which only the one referenced 403a mounted on the trunk 202a is visible in the figure) are still mounted on the trunks 202a and 202b. The engines of the engine blocks 403 are ^¬ seen driving pulleys which drive through the cable winches secondary pulleys 210a and 210b (or more precisely sectors of pulley). Of course, any other type of gearbox could be used between the engine blocks 403 and the parts 210a, 210b, such as for example and without limitation friction reducers or gears. The engine blocks 403 are used to measure and control the movements of the segments 204a and 204b by means of the pulleys 210a and 210b serving as connecting rods on the one hand, and connecting rods 211a and 211b, on the other hand, within seg ^¬ elements 203a and 203b and form with the segments 203a and 203b, 204a and 204b and the pulleys 210a and 210b structures parallelograms. Finally, devices in double parallelogram, whose first links (not ^¬ in the segments 203a and 203b parallel biel ^¬ letters 211a and 211b and not visible in the figure) are fixed on the trunks 202a and 202b and the second biel ^¬ lates (passing in the segments 204a and 204b and of which only the end is visible in Figure 22) are fixed on the segments 205a and 205b, ensure that the axes 305a and 305b of rotation between the segments 205a and 205b and the first wrist segments 206a and 206b are paral ^¬ Lele to axes 301a and 301b regardless of the movements of the robot. The second wrist segment 207 is rotatable relative to the first wrist segments 206a and 206b about two axes 306a and 306b advantageously parallel to each other. The handle door 208 is rotatable relative to the second segment 207 about an axis 307 parallel to the axes 306a and 306b. A motion amplifying device is introduced here is between ^¬ cond segment 207 and the door handle 208. The rotation of the handle 208 about the axis 307 is directly com ^¬ mended by the segment of the movement 207 around the axis 306a and 306b and amplified with respect to these rotations. Finally, The handle 209 is movable in rotation about an axis 308 advantageously perpendicular to the axis 307. The presence of the handle holder 208 is not essential and the handle could also be directly rotatably mounted relative to the second segment. 207 which should ^¬ all times be angled so that the axes 308 of one hand, and 306a and 306b on the other hand are advantageously ^¬ perpendi cular. An epicyclic reduction gear of the type of that of FIGS. 5 and 6 and incorporating a seventh motor unit is housed in the handle 209.

The handle 209 is best seen in the sectional view of Figure 23. The handle includes a tubu- lar body 212 surrounding the transmitting device 1 and for ^¬ mant the output thereof, the input of the transmission device being the handle holder 208 on which is fixed the engine block 8 incorporating a motor 8a and an angular position sensor 8b.

 The transmission device is similar to that of Figures 5 and 6.

The sun gear 2.1 is fixed relative to the handle holder 208 and serves as a support for the engine block 8 which directly drives the planet carrier 5 via a shaft 213 passing through the sun gear 2.1. The planet carrier 5 is guided in rotation relative to the base (that is to say to the sun gear 2.1) by two angular contact ball bearings which ensure its guidance even in the presence of remote forces generated at the satellite interfaces. 3.1, 3.2 and planetary 2.1, 2.2 and / or by the user when manipulating the handle. Finally, the 2.2 nétaire ceiling is integral with the tubular body 212 of the poi ^¬ panied 209 and is guided in rotation on the planetary holder 5 by two angular contact ball bearings assu ^¬ also rent its guide in the presence of efforts deported. Note that an additional ball bearing could be integrated at the other end of the tubular body 212 to ensure its guidance on the planet carrier 5 on the side of the engine block 8. The tension of the ball bearings (which are maintained remotely using a rappor ^¬ tée spacer) is adjusted by a fine-pitched nut with notches 214 on the side of the sun gear 2.1 and by a screw 215 largely dimensioned on the side of the sun gear 2.2.

 An example of sizing is given below purely for illustrative purposes. The sun gear 2.1 has a diameter of 7.50 mm, the sun gear 2.2 has a diameter of 6.72 mm, the satellite 3.1 has a diameter of 8.50 mm and the satellite 3.2 has a diameter of 7.50 mm, which leads to a reduction ratio of 66 (diameters are given to the neutral fiber of the cables). Associated with a motor whose torque capacity is about 5.5 mNm continuously and 16.4 mNm peak, this device develops a maximum torque of about 1 Nm, which is well suited for a handful of torque. haptic interface.

It has been provided that a single strand of cable drives between the sun gear 2.1 and the satellite 3.1 and a single strand of cable ensures the drive between the sun gear 2.2 and the satellite 3.2. The diameter of the cable used here is 0.56 mm. A first strand of cable is inserted at one of its ends in a hole of the satellite 3.1 and stopped by a node or crimping. It is then wound on the satellite 3.1 and then passes on the sun gear 2.1. After a sufficient number of turns to ensure good adhesion, it goes back to the satellite 3.1 on which it is wound before being fixed at its other end, for example with a screw and a pressure washer . The principle is the same on global 2.2 and Satel lite ^¬ 3.2. Note that the number of winding turns on the planetary must also be compatible with the steps of different pulleys. Here the pitch is 0.67 mm on global 2.1 and 3.2 satellite, 0.60 mm on the pla ^¬ nétaire 2.2 and 0.76 mm on the 3.1 Satellite. Under these conditions, the cable is about eight turns on the plan¬ ^¬ so that the length of the seven free nets in the windings is close to the length of the eight winding turns. The number of winding turns is therefore greater than the number strictly necessary to ensure rer adhesion of the cable on the planetary and is ty ^¬ cally five or six rounds. The pulleys are not low, it does however not lead to increased number ^¬ table length of the device remains compact.

 FIG. 24 illustrates an alternative embodiment of the handle of FIG. 23.

According to this variant, the motor 8 is used to drive not the planet carrier 5 but directly the satellites 3.1, 3.2. For this, an additional primary pulley 29 is fixed in rotation on the shaft 213 itself fixed to the motor shaft. It rotates satellites 3.1, 3.2 via a further pulley 30 inse ^¬ SOE between satellites 3.1, 3.2 and integral with satel ^¬ lites 3.1, 3.2 rotated. The reduction ratio here is 1 (the satellites rotate at the same speed as the mo ^¬ tor, here in opposite direction) but could be different (satellites could also rotate in the same direction as the motor with the cable winding without crosses ^¬). Otherwise, operation is similar to that described in relation to Figure 23, the ratio of reduction ^¬ however being different in that the planet carrier 5 does not necessarily rotate at the same speed as satellites.

 It is understood that one could also use transmission devices according to this embodiment of the invention on all or part of the other axes of the robot of Figure 22 and all or part of the axes of the robots of Figures 20 and 21.

Figures 25 and 26 show a transmission device according to the first embodiment wherein the cables 6a, 6b have been replaced by ^¬ rings 7a, 7b.

The belts 7a, 7b not advancing on the pulleys (pulley 10, pulleys 9 of the planet carrier, planetary 2.1, 2.2 and satellites 3.1, 3.2), the device is much more compact. For the sake of clarity of these figures, the pou ^¬ lie are represented smooth but it is possible, even It is advantageous to use profiled and / or notched belts and pulleys having a negative impression of the belts.

 Of course, the invention is not limited to the embodiments described but encompasses any variant within the scope of the invention as defined by the claims.

In particular, although, for the sake of simplicity of the figures, the pivot links are represented by an axis (or shaft) and a bore having a small clearance, it is understood that, in practice, this function is ens ^¬ rered by the necessary guide elements such as, for example, straight or oblique ball bearings, roller bearings, needle bearings, thrust ball or roller thrust bearings, or plain bearings made of bronze or polytetrafluoroethylene. In the same way, the parts are machined to ^¬ surer the resistance of the guiding elements in rotation and in translation. These solutions are known to those skilled in the art and are therefore not shown in detail.

It is understood also that the orientation of the rotation axes as shown in the figures is by no means limited to, the axes represented verti cally ^¬ could be horizontal and vice versa following the disposal of the structure, or inclined at an certain angle.

In addition, the device movement measurement means and / or haptic interfaces, robots and co-bots integrating it are not necessarily integrated on or only on the engines as described above. Thus these sensors, which can be of any suitable type, such as for example and not limited to optical encoders, hall effect sensors or magné sensors ^¬ to-optics, can be placed on the engines, on joints or to be deported. They can be used as means for detecting movements and for measuring the angular positions of the output sun gear with respect to the frame support, the engine relative to the support frame or segments relative to each other. They can still be doubled by placing for example a sensor on the mo ^¬ tor and another sensor on the joint. This redundancy brings greater reliability to the device.

The motor itself may be of any type, in par ticular ^¬ an electric DC motor, a brushless motor, a synchronous motor autopilot, an async ^¬ chronous motor, a piezoelectric actuator, an actuator based alloys shape memory, or even a thermal, pneumatic or hydraulic actuator. On a haptic interface or cobot, one can also use a wholesaler ^¬ brake operative part to oppose the user's movements and the guide, in particular a brake magnetically tick, a powder brake or a device using fluid magneto-rheological or electrorheological. Engines can also be combined with the brakes on the various axes of the robot. This type of association is known to those skilled in the art and will not be detailed here. Several motors, for example two, can still be used as input to a transmission device according to the present invention, these motors being then controlled so coor ^¬ data, reproducing for example an agonist and antagonist behavior in a bio-inspired approach two engines of similar capacity. Two motors of different sizes can also be used to implement a macro-micro type control. The actuators can still be associated with flexible elements, for example and not exhaustively in series or in parallel, according to an "Elastic Actuators Series" or "Parallel Elastic Actuators" type diagram. All these provisions ^¬ tive are known to the skilled person and will not be die cut ^¬ here.

The cables may be made, for example and non-exhaustively, of steel, aramid, Kevlar, "dyneema" or "micro-dyneema" type, polypropylene or any other material capable of offering the mechanical strengths sought for such a device. They can be formed by an assembly of strands, the strands can themselves be wrapped around a soul.

Finally, the terminal member of the interface, the robot or the cobot can take several forms. On a haptic inter ^¬ , it usually takes the form of a handle taken in hand by the user. This handle may be for example and non-exhaustively a pen, a joystick, for example of the joystick type, a ball, a clamp, etc. according to the envisaged applications, which include games, simulation devices, in particular ^¬ assembly, maintenance or technical training gesture or workstation, remote handling, remote operation or remote displacement for example in the nuclear field, the aerospace field or the medical field. On a robot, it generally takes the form of a gripping means, such as for example a clamp with two or more jaws or a suction cup. It can still be a dextral gripper of which there is a large variety well known to those skilled in the art. Finally, in the case of a cobot, it can for example take the form of the combination of a handling handle and a gripper or an active tool or not.

Finally, it is understood that even if the device according to the present invention is reversible and has a good efficiency, it can be associated with one or more force sensors mounted for example and not exhaustively at the output of each motor, at the joints of the robot or at the end thereof at the terminal body, the additional force signals being utili ^¬ SSS together with those for the position control of the robot.

 Alternatively, the transmission device of the invention may comprise a second reducer in series with the first reducer. The second reducer is for example an epicyclic reducer.

In another variant: - the planetary carrier may serve as supports for ^¬ mo tor;

 the satellites can be connected to the planet carrier by a pivoting shaft connected to the motor to be rotated by it;

 each cable comprises two end portions wound and fixed respectively on the sun gear and on the satellite;

 different diameters of planet wheels and satellites are usable, the sum of the radii of the first sun gear and the first satellite being preferably substantially equal to the sum of the radii of the second sun gear and the second satellite;

 the outer grooves may have a triangular, trapezoidal or U-shaped profile that is crushed or not;

- The pulleys can be mounted or not on adjustable supports between a close position of the adjacent pou ^¬ lie allowing the cable to leave or rejoin the pulleys extending tangentially to them and a position away from the adjoining pulley to facilitate mounting.

It is of course also understood that the devices of FIGS. 20 to 22 are only given by way of examples. This would use a following or trans mission systems of the present invention, for example and my ^¬ not limited Niere on all types of robots, and in cobots ^¬ terfaces haptic architecture series of three or six ^¬ operated freedom sandstone , on all types of robots, cobots and haptic interfaces with mixed architecture with six degrees of freedom, using for example two branches made with a pivot and a parallelogram and a serial axis, on all types of robots, cobots and interfaces hap ^¬ parallel architecture ticks with six degrees of freedom ac ^¬ tioned, for example using three branches with two or three engines each, on exoskeletons of legs, trunk, arms and hands or on humanoid robots, in particular their legs, arms and hands.

Claims

1. A device for transmitting motion between a motor (8, 8a) and a movable member, comprising an epicyclic reduction gear comprising a first sun gear (2.1) and a second sun gear (2.2) coaxial connected by transmission means respectively to at least one first satellite (3.1) and a second satellite (3.2) which are carried coaxially to one another by a planet carrier (5) mounted to pivot eccentrically about the axis of the planetaries, characterized in that the transmitted ^¬ sion means comprise flexible transmission members (6a, 7a) respectively wound around the first sun gear and the first satellite and around the second sun gear and the second satellite.

2. Device according to claim 1, wherein the flexible transmission members are cables (6a) each having at least one portion wrapped around the plane ^¬ taire (2.1, 2.2) and a portion wound around the satellite (3.1, 3.2).

3. Device according to claim 2, wherein the planetaries (2.1, 2.2) and / or the satellites (3.1, 3.2) comprise an outer helical groove (15) for ré ^¬ cevoir the coiled cable portion.

 4. Device according to claim 3, wherein the helical outer grooves (15) of the satellites (3.1, 3.2) are in opposite directions.

 5. Device according to claim 2, wherein each cable (6a) comprises two end portions wound and fixed to the sun gear (2.1, 2.2) and a central portion wound around the satellite (3.1, 3.2).

6. Device according to claim 2, wherein each cable (6a) comprises two strands, the two end ^por¬¬ tions are wound and fixed respectively on the sun gear (2.1, 2.2) and on the satellite (3.1, 3.2).

7. Device according to claim 5 or claim 6, comprising a tensioner (40; 18, 19, 20; 22, 23, 24) of at least one of the end portions wound and fixed.

8. Device according to claim 7, wherein the wound and fixed end portion is connected direc ^¬ ment to the tensioner (40; 18, 19, 20).

9. Device according to claim 8, wherein the tensioner comprises a stirrup (18) and a rod (19) for hooking the end portion, the stirrup having an oblong opening for the passage of a screw (20). ) fixing the stirrup to the element around which the end portion is wound and fixed, the opening having longitudinal edges forming for the head of the screw a por ^¬ tee of increasing height along a direction of the aperture, the span having a bottom portion on the end portion side and a top portion opposite.

10. Device according to claim 7, wherein ^¬ the tensioner (22, 23, 24) comprises a member for adjusting an angular position of the element on which is enrou ^¬ lée and fixed the end portion of cable .

11. Device according to claim 2, in the ^¬ which the planet carrier (5) also carries at least one idler pulley (17) for maintaining a winding angle of the cable about at least one of satellites (3.1 , 3.2).

 12. Device according to claim 2, wherein each sun gear (2.1, 2.2) is connected to the corresponding satellite (3.1, 3.2) by two cables (6a) with two strands each fixed to the sun gear and the satellite so as to transmit the movement each in a sense.

 13. Device according to claim 2, comprising means for temporarily locking in rotation of at least one of the planetaries (2.1, 2.2) and satellites (3.1, 3.2).

14. Device according to claim 1, wherein the flexible transmission members are belts (7a).

15. Device according to claim 1, in ^¬ which the movable member is mounted to slide in transla ^¬ and is connected to an output of the epicyclic reduction gear by a ROTA tion of motion transforming device in translation.

16. Apparatus according to claim 15, in which ^¬ a rotational translational translation device ^¬ translation is a pinion rack connection.

17. Device according to claim 16, in which the rack and pinion le link comprises a cable having at least one end portion fixed to the movable member and a portion wound around an output gear of the epicyclic reduction ^¬ tor.

 18. Device according to claim 1, in which the epicyclic reduction gear is of the planetary type with external drives.

19. Device according to claim 1, in which the first planetary ^¬ (2.1) is fixed and the second sun gear (2.2) is pivotable.

20. Apparatus according to claim 19, in which the first planetary ^¬ (2.1) serves as a fixing base and supporting the motor (8, 8a).

21. Apparatus according to claim 19, in ^¬ which the planet carrier (5) serves to support the motor (8, 8a).

22. Apparatus according to claim 19, in ^¬ which the planet carrier (5) is connected to the motor (8, 8a) to be rotated by the latter around the planetary axis (2.1, 2.2).

23. Apparatus according to claim 22, in ^¬ which the planet carrier (5) is integral with a pulley (9) connected to a pulley (10) integral with the motor shaft by a flexible transmission member (6b , 7b).

24. Device according to claim 23, wherein the motor (8, 8a) is mounted on a support (11, 16) adjustable in position relative to the pulley of the planet carrier (9).

25. Apparatus according to claim 23, in which ^¬ satellites (3.1, 3.2) are arranged in the pulley (9) of the planet carrier (5).

 26. Device according to claim 19, in which the satellites (3.1, 3.2) are connected to the planet carrier (5) by a pivoting shaft connected to the motor (8, 8a) to be rotated by the latter. .

27. Apparatus according to claim 19, in ^¬ which the planet carrier (5) is integral with an output shaft of the motor (8, 8a).

28. Apparatus according to claim 19, in which the engine ^¬ (8, 8a) is supported by a support (4) and the planet carrier (5) is disposed laterally rap ^¬ port support.

29. Apparatus according to claim 19, in which ^¬ satellites (3.1, 3.2) are arranged laterally with respect to the planet carrier (5).

30. Apparatus according to claim 19, in which the ^¬ planetary gearbox comprises a plurality of first planet wheels (3.1) and second satellites (3.2) mounted on the planet carrier (5) symmetrically about the planetary axis (2.1 , 2.2).

31. Apparatus according to claim 19, in which ^¬ satellites (3.1, 3.2) have diameters appreciably identical.

32. Apparatus according to claim 19, in which ^¬ the sum of the first planetary radii (2.1) and the first carrier (3.1) is substantially equal to the sum of the second planetary radii (2.2) and the second satellite ( 3.2).

 33. Device according to claim 1, comprising a second reducer in series with the first reducer.

34. Device according to claim 33, in which the second ^¬ reducer is an epicyclic reduction gear.

 35. Epicyclic gear reducer for a device according to any one of the preceding claims.

36. Manipulation arm having at least one first segment and a second segment connected to each other by a hinge, and an actuator according to any one of claims 1 to 34 mounted between the two segments for moving the second segment relative to the first segment; segment.

37. The arm of claim 36, wherein the second segment is a handle and planetary reduction ^¬ tor is housed in said handle.