TWI894362B - Device for winding/unwinding a link and winder of a link - Google Patents

Abstract

The invention describes a device for winding/unwinding a link, comprising: an input shaft and a hollow through output shaft, the two shafts being coaxial and movable in rotation about a longitudinal axis, a permanent magnet synchronous motor comprising a rotor integral in rotation with the input shaft, a cycloidal reducer comprising an eccentric cam mounted integral in rotation with the input shaft, and a cycloidal disc mounted integral in rotation with the cam, in such a way that a rotation of the cam about the longitudinal axis drives a rotation of the cycloidal disc in an eccentric and cycloidal movement, and a transmission member suitable for transmitting an angular displacement of the cycloidal disc to the output shaft.

Description

Device for winding/unwinding a chain element and chain element winder

The present invention relates to the field of devices for winding and/or unwinding links.

Devices for winding and/or unwinding links are used in many industrial applications. Specifically, a link must be deployed between two components that have a relative position that changes over time.

For example, the first element may be a support fixed to the ground, a robot frame, etc., and the second element may be a carrier or mobile stand on the ground, a robot arm, etc. The second element may be movable relative to the first element over a distance ranging from tens of meters to more than one kilometer.

The link is suitable for transmitting a fluid, energy and/or signal between the two components. The link can be a cable, an air or fluid tube, an optical fiber or a bundle of optical fibers, etc. The link is wound on a winding support, such as a winding reel.

A winding/unwinding device mounted on the first or second element is adapted to wind and/or unwind the link on a reel. The link thus extends between the reel provided on a first side of the winding/unwinding device and a swivel joint opposite the first side of the device.

The chain winding/unwinding device can be electrically activated and winds and/or unwinds the chain in synchronization with the displacement of the second element. Thus, as the second element approaches the first element, the device winds the chain onto the reel, reducing its length by the same amount, and unwinds a greater length of the chain as the second element moves away from the first element.

Document FR 2 335 754 discloses a chain link winding/unwinding device comprising a helical bevel gearbox. The gearbox comprises a plurality of small bevel gears, each of which is linked to a motor coupling assembly and engages with the same bevel gear. This device allows multiple motor coupling assemblies to be mounted on a common helical bevel gearbox. Thus, the torque can be tailored to the application in question, and the motor coupling assemblies can be manufactured in large quantities, thereby reducing manufacturing costs.

However, helical gearboxes lack tightness when significant speed reduction is sought. Furthermore, they cannot satisfactorily withstand brief and/or substantial vibrations. In fact, only a few of the gearbox's components are in contact with one another.

Other known devices for winding/unwinding a chain link include an asynchronous motor directly connected to the reel via a gearbox. However, an asynchronous motor only offers low accuracy for torque control. There can be a discrepancy of approximately 15% between the setpoint torque and the torque actually delivered by the asynchronous motor to the output shaft. In fact, in an asynchronous motor, the rotor does not rotate at the same speed as the magnetic field. This results in slip and magnetization of the rotor by the motor current, resulting in speed losses at the motor output and inaccuracies in the current/torque relationship. Consequently, part of the current input to the asynchronous motor is lost and not used to generate torque. Therefore, the discrepancy between the set-point torque and the torque actually supplied to the output shaft is significant, complicating control of the winding/unwinding device. Therefore, when high accuracy is required for torque control, asynchronous motors are completely unsatisfactory.

Furthermore, an asynchronous motor cannot exceed the torque for a short period of time and reach values as high as a synchronous motor. This can cause problems such as emergency stops or situations where the reel must pass over its feed point, requiring the reel to be braked and then driven in the opposite direction for a very short period of time.

Finally, these asynchronous motor winding/unwinding devices do not allow for satisfactory modularity. In fact, because these devices are controlled by a frequency converter and a control program that adjusts the torque setpoint according to the device's operating conditions, they require electronic regulation. However, controlling multiple asynchronous motors with a single frequency converter produces undesirable results in terms of the torque achieved relative to the setpoint. Therefore, when high accuracy in torque control is required, these electronically regulated asynchronous motor winding and/or unwinding devices cannot include multiple asynchronous motors.

Therefore, the power of the asynchronous motor must be tailored to each application to meet customer needs. Consequently, the size of the asynchronous motor driving the device becomes complex to accommodate various applications, particularly varying types of linkages, mounting heights, and the speed and acceleration of the winding/unwinding device. The torque cannot always be tailored to the specific needs of the application, and these devices for winding/unwinding linkages share a limited number of common components, increasing the cost of the device. Furthermore, a specific motor must often be purchased for a given application, further increasing costs and reducing the number of applicable applications.

Documents FR 2 607 333 A1 and FR 2 899 399 A1 disclose devices for winding/unwinding links that include a magnetic coupling with hysteresis. These devices require no electronic adjustment and are modular. In fact, the adjustment is performed by the magnetic coupling, which adjusts its speed to that of the reel, exerting a pure torque and thus a substantially constant pulling force on the link.

However, magnetic coupling devices used for winding/unwinding have a relatively low full output, making it impossible to control transients such as emergency stops or passing through a supply point. Furthermore, because it is difficult to assemble a large number of couplings on the same gearbox, the gearbox becomes very large, and increasing the size of the couplings is expensive, these devices become impractical above a certain power level.

One object of the present invention is to provide a tightening device for winding/unwinding a link having a large deceleration range.

Another object of the present invention is to provide a device for winding/unwinding a chain link, which has good accuracy for controlling the torque and allows a large torque increase in a short time.

Another object of the present invention is to provide a modular device for winding/unwinding a link so that the torque can be adapted to the desired application while still maintaining low manufacturing costs.

Another object of the present invention is to provide a device for winding/unwinding a chain element that can protect the chain element being wound/unwound.

According to a first aspect, the present invention relates to a device for winding/unwinding a chain member, comprising: an input shaft that is movable and rotatable around a longitudinal axis; an output shaft that is substantially coaxial with the input shaft, the output shaft being configured to allow the chain member to pass through a reel and a rotary joint. a hollow through shaft, the output shaft is suitable for driving the reel to rotate around the longitudinal axis; at least one permanent magnet synchronous motor, which includes a rotor configured to be arranged around a first portion of the output shaft, the rotor rotates integrally with the input shaft; a pendulum reducer, which is configured to be arranged around a first portion of the output shaft The oscillatory reducer comprises at least one inner cam, an outer crown, and at least one oscillatory plate disposed between each cam and the crown. Each cam is mounted to rotate integrally with the input shaft, and the at least one oscillatory plate is mounted to rotate integrally with each cam. Each cam is eccentric, so that rotation of each cam about the longitudinal axis drives the at least one oscillatory plate to rotate in an eccentric and oscillatory manner. Furthermore, a transmission member is configured to transmit an angular displacement of the at least one oscillatory plate to the output shaft, so that the eccentric and oscillatory rotation of the at least one oscillatory plate drives the output shaft to rotate about the longitudinal axis.

Certain preferred but non-limiting features of the winding/unwinding device are individually or in combination as follows: the input shaft is configured to encircle at least a portion of the output shaft; the winding/unwinding device further comprises a housing in which the at least one synchronous motor and the oscillating reducer are disposed, the output shaft passing through the housing from one end to the other end of the housing; the winding/unwinding device comprises between one and four synchronous motors mounted in series along the first portion of the output shaft; the at least one synchronous motor is an axial flux permanent magnet synchronous motor; the at least one cam and the input shaft are formed from a single piece, each cam comprising an outer surface having a radial dimension, each cam being mounted on the winding shaft. /The radial dimension changes according to the angular position around the longitudinal axis when the at least one pendulum is in the unwinding device; the at least one pendulum is a pendulum wheel; the transmission member includes a first portion and a second substantial radial portion suitable for connecting the first portion and the output shaft, the transmission member is configured so that an eccentric and pendulum rotation of the at least one pendulum drives the first portion of the transmission member to rotate around the longitudinal axis; the at least one pendulum includes at least one longitudinal hole, and the first portion of the transmission member forms at least one longitudinal finger suitable for extending in the at least one longitudinal hole of the at least one pendulum so as to transmit the angular displacement of the at least one pendulum to the at least one longitudinal finger of the transmission member The first part; the pendulum reducer comprises two substantially identical pendulum drums mounted in series along the longitudinal axis, the two pendulum drums being placed in the pendulum reducer with opposite eccentricities, wherein each pendulum drum comprises at least one longitudinal hole, the longitudinal holes of the two pendulum drums being arranged to face each other so that the pendulum drums are mounted on the winding/unwinding machine At least one pair of longitudinal holes is formed in the device, and the at least one finger of the transmission member extends in the at least one pair of longitudinal holes of the two pendulum drums; the winding/unwinding device includes a first pendulum drum and a second pendulum drum, the first pendulum drum is installed to rotate integrally with the at least one cam, and the second pendulum drum is installed to rotate with the first pendulum drum. A pendulum rotates integrally, wherein the first portion of the transmission member includes an internal tooth, which is arranged on the outer side of the second pendulum and is suitable for cooperating with an external pendulum tooth of the second pendulum so that an eccentric rotation of the second pendulum drives the first portion of the transmission member to rotate around the longitudinal axis; the first portion of the transmission member includes a rigid frame and a substantially cylindrical shaft assembly, the rigid frame includes a substantially cylindrical hole assembly distributed circumferentially around the longitudinal axis, wherein each shaft of the shaft assembly is inserted into each hole of the hole assembly of the frame of the first portion of the transmission member to form the internal tooth of the first portion of the transmission member.

According to a second aspect, the present invention relates to a chain winder comprising: a reel; a winding/unwinding device according to the first aspect; a rotary joint; and a control device, wherein the control device is adapted to control a set point and/or the synchronous motor so that the control device and the winding/unwinding device provide an appropriate winding/unwinding torque.

10: Input shaft

20:Output shaft

30: (Permanent Magnet) Synchronous Motor

31: Rotor

32: Stator

40: Shell

50: Swinging Speed Reducer

51: (internal) cam; camshaft

52: Thread reel

521,523: First pendulum

522,524: Second pendulum

53: (External) Crown

60: Transmission components

61: Part 1

62: Second part; second radial part

L: Longitudinal axis

Other features, objects and advantages of the present invention will become apparent upon reading the following detailed description, which is provided as a non-limiting example and is illustrated by the following figures: FIG1 shows a schematic side view of a winding/unwinding device according to an embodiment of the present invention.

Figures 2a and 2b show schematic perspective views as cross-sectional views of a portion of a winding/unwinding device according to an embodiment of the present invention.

Figure 3 shows a schematic side view of a winding/unwinding device according to an embodiment of the present invention.

Figure 4 shows a schematic side view of a winding/unwinding device according to an embodiment of the present invention.

Figures 5a and 5b show schematic perspective views as cross-sectional views of a portion of a winding/unwinding device according to an embodiment of the present invention.

A device for winding/unwinding a chain comprises: an input shaft 10 that is movable and rotates about a longitudinal axis L; an output shaft 20 that is substantially coaxial with the input shaft 10. The output shaft 20 is configured as a hollow through-shaft between a reel and a rotary joint for passing the chain. The output shaft 20 is adapted to drive the reel to rotate about the longitudinal axis L.

In the remainder of the application, the term "longitudinal axis L" refers to the axis around which the input shaft 10 and the output shaft 20 are arranged. A radial direction is a direction perpendicular to and passing through the longitudinal axis L. A longitudinal element is an element that extends primarily in the direction of the longitudinal axis L. A radial element is an element that extends primarily in the radial direction.

The terms inner and outer are used with reference to the radial direction such that a portion or inner surface of a component is closer to the longitudinal axis L than the portion or outer surface of the same component.

The terms upstream and downstream are used with reference to a position on the longitudinal axis L, respectively. The rotary joint is located upstream of the winding/unwinding device, and the reel is located downstream of the winding/unwinding device.

The term connector is used to refer to different types of connectors such as electrical cables, data cables, air or fluid tubes, etc.

The link is intended to be positioned between the reel and the swivel joint and to wind and/or unwind the reel. The swivel joint connects the reel, which is driven to rotate by the output shaft 20, to a winding/unwinding device that does not rotate about the longitudinal axis L. The swivel joint is mounted on the output shaft 20 and rotates integrally with the output shaft 20 about the longitudinal axis, allowing it to be driven by the output shaft 20 at the same rotational speed as the output shaft 20.

For example, in the case where power is transmitted by biasing the link, the rotary joint can be composed of a ring system made of an alloy with good electrical conductivity. Sintered brushes with a high conductive material content rub against the ring system, thus ensuring continuity. The link from the reel is connected to the rings. A link from the fixed part is connected to the brushes.

Rotation of the reel in a first direction drives the link to wind around the reel, and rotation of the reel in a second direction opposite the first direction drives the link to unwind. The winding/unwinding device is operable in both the first and second rotational directions. Thus, the length of the link can be adjusted by the rotational bias of the reel.

The winding/unwinding device can protect the link by biasing the hollow shaft. In fact, the link can extend within the hollow shaft of the device between the reel and a swivel joint, with the reel being located on a first side of the winding/unwinding device and the swivel joint being located on a second side of the device, opposite the first side. The link is thus protected from potential degradation, for example, due to weather conditions, a restrictive external environment, corrosion from contact with the outside, or impact and friction with external components. Because the link is constrained to the output shaft 20, which rotates at substantially the same speed, the winding/unwinding device can also protect the link from being affected by the internal components of the winding/unwinding device.

The device for winding/unwinding the chain also includes: at least one permanent magnet synchronous motor 30, which includes a rotor 31 arranged to be encircled around a first portion of the output shaft 20, and the rotor 31 rotates integrally with the input shaft 10; a oscillating reducer 50, which is arranged to be encircled around a second portion of the output shaft 20, and the oscillating reducer 50 includes at least one inner cam 51, an outer crown 53, and at least one oscillating disc 52 arranged between each cam 51 and the crown 53, wherein each cam 51 is arranged The oscillating disc 52 is mounted to rotate integrally with the input shaft 10, and the cams 51 are mounted to rotate integrally with the cams 51. Each cam 51 is eccentric, so that rotation of the cam 51 about the longitudinal axis L drives the at least one oscillating disc 52 to rotate in an eccentric and oscillatory manner. A transmission member 60 is also provided, which is adapted to transmit an angular displacement of the at least one oscillating disc 52 to the output shaft 20, so that the eccentric and oscillatory rotation of the at least one oscillating disc 52 drives the output shaft 20 to rotate about the longitudinal axis L.

The term gearbox refers to a mechanism that is intended to reduce and increase torque, with the output shaft 20 rotating at a speed that is slower than the speed of the input shaft 10. Alternatively, the term gearbox may refer to any mechanism that is intended to modify the speed and torque of the output shaft 20 relative to the input shaft 10.

The oscillating reducer 50 can thus modify the speed of the output shaft 20 relative to the speed of the drive shaft by a certain ratio, known as the reduction ratio. The device for winding and/or unwinding the chain thus transmits the rotation of the input shaft 10 to the output shaft 20. The winding/unwinding device can thus drive the reel to rotate in response to the rotation of the rotor 31 of the synchronous motor(s) 30, thereby winding/unwinding the chain.

The term pendulum is used to denote a profile that corresponds substantially to a pendulum, i.e., to a trajectory corresponding to a point on a circle fixed to a generatrix that rolls but does not slide. The profile may vary from a purely theoretical pendulum profile. Typically, the pendulum drum 52 may have an outer pendulum surface.

A oscillating gear reducer 50 can compactly achieve a large reduction ratio, for example, up to approximately 1/120, such as 20, 40, or 90. Compared to other gearboxes, such as conventional helical helical gearboxes, the oscillating gear reducer 50 has a low probability of failure, low operating backlash, and high output. Compared to conventional helical helical gearboxes, the oscillating gear reducer 50 has a larger contact ratio, resulting in a greater number of contacting teeth. Therefore, the oscillating gear reducer 50 can better withstand brief and/or substantial vibrations.

A permanent magnet synchronous motor 30 (or synchronous motor 30) offers greater accuracy in torque control compared to an asynchronous motor. Because the magnetic field is generated by the permanent magnets, a synchronous motor does not cause slip or magnetization of the rotor 31 due to the motor current. Therefore, virtually all of the current input to the permanent magnet synchronous motor 30 is used to generate torque. This reduces the difference between the setpoint torque and the torque actually supplied to the output shaft 20. The mechanical torque thus directly reflects the current, which facilitates control of the winding/unwinding mechanism and provides more accurate control.

Furthermore, a synchronous motor 30 allows for a short-term and higher torque increase than an asynchronous motor. This makes emergency stop situations easier to control. The same applies to situations where the reel must pass over its feed point, requiring the reel to be braked and then quickly re-started in the opposite direction. Therefore, using a synchronous motor limits the power of the motor used for the same application.

Finally, the chain winding/unwinding device offers excellent modularity. In fact, several synchronous motors 30 can be controlled by the same inverter to electronically regulate the winding/unwinding device. This allows for the number of synchronous motors 30 in the winding/unwinding device to be varied. The size of the motor driving the device can thus be easily adapted to a variety of applications, particularly varying types of chains, mounting heights, and the speed and acceleration of the winding/unwinding device. Consequently, the chain winding/unwinding device shares a high number of common components, which reduces its cost.

For example, several identical or virtually identical synchronous motors 30 can be installed in series along the output shaft 20. Thus, the torque can be tailored to be as close as possible to the customer's needs. Furthermore, a larger number of identical permanent magnet synchronous motors 30 can be produced, which can reduce their cost.

The synchronous motor 30 is disposed upstream of the oscillating reducer 50. The input shaft 10 and the output shaft 20 extend substantially along the longitudinal axis L. The winding/unwinding device may have radial symmetry relative to the longitudinal axis L.

The input shaft 10 is a hollow shaft and may correspond to a drive shaft of the winding/unwinding device. The input shaft 10 may be configured to surround at least a portion of the output shaft 20, with the input shaft 10 being positioned further outward from the output shaft 20. Roller bearings may be provided between the input shaft 10 and the output shaft 20 to allow the input shaft 10 to rotate at a speed different from that of the output shaft 20.

The input shaft 10 may extend from the synchronous motor 30 and reach the oscillating reducer 50, particularly at least one cam 51 of the oscillating reducer 50. The input shaft 10 may have a first end adapted to extend from the side of the rotary joint and a second end opposite the first end.

The input shaft 10 receives the driving force to be transmitted from the synchronous motor(s) 30, which generates mechanical power to be transmitted via the rotor 31. The second end of the input shaft 10 may extend radially through the at least one cam 51 of the oscillating reducer 50. A cam 51 may be disposed around the second end of the input shaft 10, positioned further outward from the input shaft 10. A bearing may be disposed between the input shaft 10 and the output shaft 20 on the cam 51.

The at least one cam 51 and the input shaft 10 may be formed from a single piece. Alternatively, the cam 51 may be attached to the second end of the input shaft and fixed to the input shaft 10.

The input shaft 10 may have a device provided on the synchronous motor 30 for driving the rotor 31 of the synchronous motor 30. For example, complementary grooves on the input shaft 10 and the rotor 31 may rigidly connect the input shaft 10 and the rotor 31 of the synchronous motor 30 so that they rotate relative to each other.

When winding the link, the rotation of the rotor 31 is transmitted to the input shaft 10, and the rotor 31 drives the input shaft 10 to rotate around the longitudinal axis L. Therefore, the synchronous motor 30 or motors 30 are electric motors and drive the reel to rotate.

Conversely, when the link is unwound, the rotation of the input shaft 10 about the longitudinal axis L is transmitted to the rotor 31 of the synchronous motor 30 via the device for driving the rotor 31. Thus, the synchronous motor 30 acts as a generator and brakes the unwinding of the reel, preventing the reel from running out of control.

The output shaft 20 is a hollow, through-shaft. It can extend substantially the entire length of the winding/unwinding device between the rotary joint and the reel. The first portion of the output shaft 20 is positioned upstream of the second portion of the output shaft 20. Both the first and second portions of the output shaft 20 can be encompassed by the input shaft 10. Alternatively, only the first portion of the output shaft 20 can be encompassed by the input shaft 10.

The output shaft 20 may include a third portion downstream of the second portion, the third portion connecting the second portion and the end of the output shaft 20 at the reel. The transmission member 60 may be disposed between the second portion and the third portion of the output shaft 20.

The winding/unwinding device may include a housing 40 housing the at least one synchronous motor 30 and the oscillating reducer 50. The output shaft 20 passes through the housing 40 from one end to the other. Therefore, the link never comes into contact with the outside while passing between the rotary joint and the reel; the link remains housed within the output shaft 20. As a result, the link is better protected from potential degradation due to the external environment. It is also protected from the internal components of the winding/unwinding device.

In the case of a fluid, the output shaft 20 can be used as a conduit for transporting the fluid from one side of the winding/unwinding device to the other side. Therefore, there is no need to use another conduit for transporting the fluid through the winding/unwinding device.

The output shaft 20 may have a substantially constant radius along its entire length. Alternatively, the output shaft 20 may have a variable radius depending on its position along the longitudinal axis L. For example, within the range of the synchronous motor 30 and the oscillatory reducer 50, respectively, the first and second portions of the output shaft 20 may have a first radius. The third portion of the output shaft 20 may have a second radius. The first radius may be smaller than the second radius.

The winding/unwinding device may include between one and ten permanent magnet synchronous motors 30, for example, between one and four synchronous motors 30. The synchronous motors 30 may be mounted in series along the first portion of the output shaft 20. Thus, the synchronous motors 30 are arranged longitudinally from upstream to downstream.

Therefore, the number of permanent magnet synchronous motors 30 is adjusted based on customer needs and the intended application of the winding/unwinding device. Specifically, a small number of synchronous motors 30 with different power ratings, for example, two synchronous motors 30, can cover a known power range of 1.5 to 30 kW by using an appropriate pitch.

A permanent magnet synchronous motor 30 includes a rotor 31 and a stator 32. The rotor 31 includes a magnet assembly disposed substantially radially around the longitudinal axis L. The stator 32 is a magnet disposed substantially radially facing the rotor 31.

The permanent magnets can be trapezoidal magnets with reversed polarity between two consecutive magnets. Such trapezoidal magnets are shown, for example, in Figure 2b. The windings generate a magnetic flux, such as an axial flux, that alternates according to the frequency of the current passing through them. The opposing magnets are thus displaced to follow the rotating magnetic field, thereby generating torque.

By way of non-limiting example, FIG3 shows a winding/unwinding device comprising a single permanent magnet synchronous motor 30. The permanent magnets are disposed on an upstream surface of the rotor 31, and the stator 32 is disposed upstream of the rotor 31 such that a downstream surface of the stator 32 faces the upstream surface of the rotor 31.

A winding/unwinding device may include two or more synchronous motors 30. Each pair of synchronous motors 30 together form a motor assembly comprising a rotor 31 and a stator 32. The rotor 31 of a motor assembly includes two permanent magnet assemblies disposed on the other side of the rotor 31. Therefore, one of the two permanent magnet assemblies is disposed on an upstream side of the rotor 31, and the other of the two permanent magnet assemblies is disposed on a downstream side of the rotor 31.

The stator 32 can be positioned on either side of the rotor 31 such that each permanent magnet assembly of the rotor 31 faces one side of the stator 32. Advantageously, two opposing sides of the same permanent magnet can thus form the rotor 31 of a two-phase adjacent motor. Alternatively, the stator 32 can be positioned between two rotors 31, with the rotors 31 positioned on either side of the stator 32, and each winding configured to generate torque for the two different rotors.

As a non-limiting example, FIG1 shows a winding/unwinding device including four permanent magnet synchronous motors 30. These four synchronous motors 30 are combined into two motor assemblies, each including two synchronous motors 30.

The at least one permanent magnet synchronous motor 30 may be an axial flux permanent magnet synchronous motor 30. The axial flux synchronous motor 30 has better tightness in the longitudinal direction than a radial flux synchronous motor.

The oscillating reducer 50 may include a cam 51 or a plurality of cams 51 mounted in series along the longitudinal axis L. Each cam 51 of the device may have substantially the same cam geometry 51.

Each cam 51 may include an inner surface and an outer surface. The cam 51 is eccentric. Therefore, the at least one cam 51 may include an outer surface having a radial dimension that varies according to the angular position of the at least one cam 51 about the longitudinal axis L when the at least one cam 51 is installed in the winding/unwinding device, i.e., according to a radial direction. The variation in the radial dimension of the outer surface of the cam 51 defines the eccentricity of the cam 51.

The input shaft 10 may have a substantially fixed radius along the longitudinal axis L. Independently of its angular position about the longitudinal axis L, that is, regardless of its radial direction, the radius of the input shaft 10 may be smaller than a radial dimension of the outer surface of the cam 51. The interface between the second end of the input shaft 10 and the cam 51 thus forms a step of a staircase. The cam 51 is eccentric, and the step of the staircase varies depending on its angular position about the longitudinal axis L.

The inner surface of the cam 51 may have rotational symmetry with respect to the longitudinal axis L when the cam 51 is installed in the winding/unwinding device. The inner surface of the cam 51 may be substantially circular and centered on the longitudinal axis L, with one radius of the inner surface of the cam 51 substantially corresponding to a radius of the input shaft 10.

The outer surface of the cam 51 may have rotational symmetry about a camshaft 51 when the cam 51 is installed in the winding/unwinding device. The cam 51 is parallel to the longitudinal axis L but cannot be distinguished from the latter. The camshaft 51 is separated from the longitudinal axis L by a certain distance.

The outer surface of the cam 51 may be substantially circular and centered on the camshaft 51. In other words, when the cam 51 is installed in the winding/unwinding device, the center of the outer surface of the cam 51 is located on the camshaft 51 and is therefore not located on the longitudinal axis L.

The oscillating reducer 50 includes a oscillating drum 52 or a plurality of oscillating drums 52 mounted in series along the longitudinal axis L. The oscillating drums 52 of the oscillating reducer 50 may have substantially the same geometric shape or different geometric shapes.

One of the oscillating discs 52 of the oscillating reducer 50 may be a oscillating pulley. The oscillating disc 52 includes an inner surface and an outer surface. The outer surface of the oscillating disc 52 includes an outer oscillating tooth. The inner surface of the oscillating disc 52 has a shape and size that substantially corresponds to the shape and size of the outer surface of the cam 51. The outer surface of the cam 51 drives the inner surface of the oscillating disc 52 to rotate via a device that drives the oscillating disc 52. The device that drives the oscillating disc 52 may include a bearing disposed between the cam 51 and the oscillating disc 52, such as a needle or roller bearing. Alternatively, the device for driving the pendulum 52 may include a smooth bearing disposed between the cam 51 and the pendulum 52.

The pendulum 52 may have rotational symmetry about an axis of the pendulum 52 . When the pendulum 52 is installed in the winding/unwinding device, the axis of the pendulum 52 is parallel to, but not indistinguishable from, the longitudinal axis L. The pendulum 52 is spaced a certain distance from the longitudinal axis L. The axis of the pendulum 52 may correspond to the cam shaft 51 . Specifically, the inner surface of the pendulum 52 may be substantially circular, with one radius substantially corresponding to one radius of the outer surface of the cam 51 .

The outer pendulum teeth of the pendulum disc 52 may include circular teeth, each of which includes a base, a flank, and a top. The base of a tooth corresponds to the majority of the inner portion of the tooth, and the top of the tooth corresponds to the majority of the outer portion of the tooth. The flank of the tooth connects the base and the top of the tooth.

The outer teeth of the pendulum disc 52 can have a substantially pendulum profile. The generatrix of the pendulum of the pendulum tooth can substantially correspond to a circle inscribed in the base of the pendulum tooth, i.e., a circle tangent to the base of each tooth of the pendulum tooth. Alternatively, the outer teeth of the pendulum disc 52 can include a tooth offset to strengthen the teeth and increase their service life and performance. The generatrix of the pendulum thus has a generatrix offset relative to the tooth offset.

Alternatively, the outer teeth of the pendulum disc 52 may have a profile that is shifted away from a theoretical pendulum in order to reduce the constraints imposed on the teeth and facilitate assembly of the pendulum.

The outer crown 53 of the oscillating reducer 50 is fixed, meaning it cannot move and rotate about the longitudinal axis L. The crown 53 can be a wheel having rotational symmetry with respect to the longitudinal axis L. The crown 53 includes an internal tooth that engages the outer oscillating tooth of the oscillating disc 52.

The internal teeth of the crown 53 may comprise circular teeth, each comprising a base, a flank, and a apex. The base of a tooth corresponds to the majority of the outer portion of the tooth, and the apex of the tooth corresponds to the majority of the inner portion of the tooth. The flank of the tooth connects the base and the apex of the tooth. The teeth of the crown 53 may be distributed circumferentially around the longitudinal axis L, i.e., they are spaced apart by equal angular distances.

Each of the inner teeth of the crown 53 can have a substantially cylindrical profile. A generatrix of the rotating cylinder extends along the longitudinal axis L, and the cylinders are distributed substantially radially about the longitudinal axis L. Alternatively, each of the inner teeth of the crown 53 can have any shape suitable for cooperating with the oscillating teeth of the oscillating plate 52. For example, the teeth of the crown 53 can have a substantially annular shape to improve contact with the oscillating teeth of the oscillating plate 52. The annular shape of the teeth of the crown 53 can be suitable for use in an oscillating reducer 50 having a low reduction ratio. Alternatively, the inner teeth of the crown 53 can have an oscillating shape.

The crown 53 may have a number of teeth corresponding to one tooth plus one tooth on the bobbin 52. This single tooth deviation allows for a larger reduction ratio. Therefore, if the bobbin 52 has n teeth, the crown 53 has n+1 teeth. In the contact area between the bobbin 52 and the crown 53, at least one crest or one flank of a tooth on the bobbin 52 may contact at least one flank of a tooth on the crown 53. Multiple teeth on the bobbin 52 and/or the crown 53 may be in contact simultaneously.

The radius of a circle tangent to the top of each tooth of the outer pendulum teeth of the pendulum disc 52 can be smaller than the radius of a circle tangent to the bottom of each tooth of the inner teeth of the crown 53. Therefore, the pendulum disc 52 can rotate within the fixed crown 53 by following an eccentric pendulum movement.

In a first embodiment, the fixed crown 53 comprises a rigid frame and a shaft assembly. The rigid frame includes a hole assembly circumferentially distributed around the longitudinal axis L. The shafts of the shaft assembly are inserted into holes in the hole assembly of the crown 53 frame to form the internal teeth of the crown 53. This configuration of a rigid frame and a set of independent shafts rigidly assembled within the frame enables a high reduction ratio. The shafts of the shaft assembly can be substantially cylindrical, and the holes of the crown 53 frame can be substantially cylindrical, to produce teeth with a substantially cylindrical profile. Alternatively, the shafts and holes can have a substantially annular shape, or any other shape suitable for ensuring cooperation with the teeth of the pendulum disc 52.

In a second embodiment, the crown 53 is formed from a single piece and includes a plurality of protrusions suitable for forming the teeth of the crown 53. The protrusions may have a substantially cylindrical shape, an annular shape, or any other shape that allows for satisfactory contact with the pendulum teeth of the pendulum disc 52.

The transmission member 60 is movable and rotatable about the longitudinal axis L. The transmission member 60 may include a first portion 61 and a second portion 62. The second portion 62 of the transmission member 60 may be substantially radial and may be adapted to connect the first portion 61 and the output shaft 20. The transmission member 60 may be configured such that an eccentric and oscillatory rotation of the at least one pendulum drum 52 drives the first portion 61 of the transmission member 60 to rotate about the longitudinal axis L. Thus, the eccentric and oscillatory rotation of the pendulum drum 52 is converted into rotation about the longitudinal axis L through cooperation between the pendulum drum 52 and the first portion 61 of the transmission member 60.

The first portion 61 of the transmission member 60 and the second portion 62 of the transmission member 60 may be formed from a single piece. The transmission member 60 and the output shaft 20 may also be formed from a single piece.

An outer surface of the crown 53 can be mounted flush with an outer surface of the housing 40, and/or an outer surface of the stator 32, and/or an outer surface of the first portion 61 of the transmission member 60. Thus, an outer surface of the assembly formed by the synchronous motor 30, the oscillating speed reducer 50, and the housing 40 can be substantially flat.

In a first embodiment, shown as a non-limiting example in Figures 4, 5a, and 5b, the oscillating reducer 50 has a single-stage architecture or a single-series architecture.

The at least one pendulum drum 52 thus includes at least one longitudinal hole. The first portion 61 of the transmission member 60 forms at least one longitudinal finger adapted to extend in the at least one longitudinal hole of the at least one pendulum drum 52 so as to transmit the angular displacement of the at least one pendulum drum 52 to the first portion 61 of the transmission member 60.

The first embodiment has the advantage of requiring only a single oscillating pulley 52 profile to convert the eccentric movement of the oscillating pulley 52 into a circular movement of the first portion 61 of the transmission member 60. Therefore, a single oscillating pulley can be sized for use with a single oscillating reducer 50.

The longitudinal fingers extend longitudinally and protrude from the second radial portion 62 of the transmission member 60. The longitudinal fingers may be substantially cylindrical.

The longitudinal hole may extend through the pendulum drum 52 or not, so that the longitudinal hole extends only in a downstream portion of the pendulum drum 52.

The longitudinal hole can be substantially cylindrical and have dimensions larger than those of the longitudinal finger. Therefore, when the pendulum 52 rotates, the longitudinal hole of the pendulum 52 circumscribes the longitudinal finger and rotates about the longitudinal axis L, thereby driving the longitudinal finger to rotate about the longitudinal axis L. In other words, the longitudinal hole of the at least one pendulum 52 is sized to absorb the radial motion component of the pendulum 52 that causes the pendulum 52 to rotate eccentrically, while still transmitting the rotational component about the longitudinal axis L.

More specifically, the oscillating disc 52 may include a plurality of longitudinal holes circumferentially distributed about the longitudinal axis L, and the first portion 61 of the transmission member 60 may form a plurality of longitudinal fingers circumferentially distributed about the longitudinal axis L. Each longitudinal finger is adapted to extend within a corresponding hole in the oscillating disc 52. This improves the mechanical resistance of the assembly, allowing the oscillating reducer 50 to withstand greater shock and pressure, and increase the reduction ratio.

In a first embodiment, the oscillating reducer 50 may include one or more oscillating spools 52 mounted in series along the second portion of the output shaft 20. For example, as shown in Figures 4, 5a, and 5b, the oscillating reducer 50 may include two substantially identical oscillating spools 523, 524 mounted in series along the longitudinal axis L, particularly along the second portion of the output shaft 20.

The two pendulum discs 523 and 524 are positioned in the pendulum reducer 50 at opposite eccentricities. In other words, the two pendulum discs 523 and 524 are positioned substantially angularly opposite each other, such that a bottom portion of a pendulum tooth of a first pendulum disc 523 is offset relative to a bottom portion of a pendulum tooth of a second pendulum disc 524, and vice versa. The eccentric position of the second pendulum disc 524 may be substantially 180° relative to the eccentric position of the first pendulum disc 523.

This configuration, with two pendulum pulleys 523 and 524 arranged with opposite eccentricities, allows for compensating for imbalances by rotating the two pulleys in opposite directions. Furthermore, this configuration distributes the contact pressure across different components and limits it to the individual teeth of the pendulum pulleys 523 and 524, with the pressure distributed across a number of teeth proportional to the number of pulleys. Furthermore, by favorably selecting the reduction ratio, particularly for odd-numbered reduction ratios, the two pendulum pulleys 523 and 524 are identical. Consequently, the same component is manufactured twice, resulting in manufacturing cost savings. Furthermore, this solution is limited to small reduction ratios, for example, below 20.

On the other hand, the reversibility of this structure is limited because the pendulum discs 523, 524 continue to move eccentrically with opposite eccentricities to return to a circular motion, generating friction on the fingers and producing this eccentric motion by rolling in a relatively large diameter hole. Therefore, the reversibility depends largely on the contact quality of these fingers.

The two oscillating discs 523, 524 can be identical and engage a common crown 53 and/or be mounted to rotate integrally with a common cam 51. When the wheels of the oscillating discs 523, 524 each have n teeth and the crown 53 has n+1 teeth, the reduction ratio is therefore directly equal to the number of teeth of the wheels of the oscillating discs 523, 524.

Alternatively, each of the pendulum drums 523 and 524 may be mounted on each fixed crown 53, and the two crowns 53 may be arranged in series along the longitudinal axis L. Alternatively or additionally, each of the pendulum drums 523 and 524 may be mounted to rotate integrally with each cam 51, and the two cams 51 may be arranged in series along the longitudinal axis L.

Each pendulum 523, 524 includes at least one longitudinal hole. The longitudinal holes of the two pendulums 523, 524 are arranged opposite each other so as to form at least one pair of longitudinal holes when the pendulums 523, 524 are installed in the winding/unwinding device. At least one finger of the transmission member 60 extends through the at least one pair of longitudinal holes of the pendulums 523, 524.

When the two pendulum coils 523 and 524 include a plurality of longitudinal holes distributed circumferentially around the longitudinal axis L, the longitudinal holes form a plurality of pairs of longitudinal holes distributed circumferentially around the longitudinal axis L. Each of the plurality of longitudinal fingers of the first portion 61 of the transmission member 60 extends into a pair of corresponding longitudinal holes.

The two pendulums 523 and 524 are integrated with each other so that they rotate at the same speed around the longitudinal axis L.

In a first embodiment, the oscillating reducer 50 may include two or more oscillating pulleys 52 mounted in series along the second portion of the output shaft 20. A larger number of oscillating pulleys 52 can limit the contact pressure on each tooth of the oscillating pulleys 52, and the pressure is distributed over a number of teeth proportional to the number of oscillating pulleys.

In a second embodiment, shown as a non-limiting example in Figures 1, 2a, 2b, and 3, the oscillating reducer 50 comprises a two-stage or two-series architecture. The oscillating reducer 50 thus comprises two oscillating drums 521, 522 having different profiles, mounted in series along the longitudinal axis L.

The oscillating speed reducer 50 includes a first oscillating drum 521 and a second oscillating drum 522. The first oscillating drum 521 is mounted to rotate integrally with the at least one cam 51. The second oscillating drum 522 is mounted to rotate integrally with the first oscillating drum 521.

The first portion 61 of the transmission member 60 may include an internal tooth disposed outside the second oscillating disc 522 and adapted to cooperate with an external oscillating tooth of the second oscillating disc 522 so that the eccentric rotation of the second oscillating disc 522 drives the first portion 61 of the transmission member 60 to rotate about the longitudinal axis L.

The first oscillating plate 521 engages with the internal teeth of the fixed crown 53 in a manner similar to that described above with reference to the at least one oscillating plate 52 of the oscillating reducer 50. If the first oscillating plate 521 has n teeth, the crown 53 may advantageously have n+1 teeth.

The eccentric rotation of the first pendulum 521 drives a corresponding eccentric rotation of the second pendulum 522. The second pendulum 522 engages the inner teeth of the first portion 61 of the transmission member 60. The inner teeth of the first portion 61 of the transmission member 60 cooperate with the outer pendulum teeth of the second pendulum 522 to transmit the angular displacement of the second pendulum 522 to the first portion 61 of the transmission member 60. This displacement is thus received by the first portion 61 of the transmission member 60 outside the second pendulum 522 for transmission to the output shaft 20 of the winding/unwinding device. The first portion 61 of the transmission member 60 is guided to rotate by the bias of the output shaft 20 and is thus constrained to rotate about the longitudinal axis L and angularly deflect.

The second embodiment has the advantage of not requiring fingers to convert the eccentric movement of the pendulum into circular movement. Thus, the reversibility of the assembly is improved.

The first portion 61 of the transmission member 60 can be a wheel having rotational symmetry about the longitudinal axis L. The first portion 61 of the transmission member 60 includes an inner tooth that engages the outer tooth of the second pendulum disc 522. The geometry of the first portion 61 of the transmission member 60 can be similar to the geometry of the crown 53.

The internal teeth of the first portion 61 of the transmission member 60 may comprise circular teeth, each tooth comprising a base, a flank, and a apex. The base of a tooth corresponds to the majority of the outer portion of the tooth, and the apex corresponds to the majority of the inner portion of the tooth. The flank of the tooth connects the base and the apex. The teeth of the first portion 61 of the transmission member 60 may be circumferentially distributed around the longitudinal axis L, i.e., they are spaced apart by equal angular distances.

Each of the internal teeth of the first portion 61 of the transmission member 60 can have a substantially cylindrical profile. A generatrix of the rotating cylinder extends substantially along the longitudinal axis L, and the cylinders form teeth distributed substantially radially about the longitudinal axis L. Alternatively, each of the internal teeth of the first portion 61 of the transmission member 60 can have any shape suitable for cooperating with the oscillating teeth of the second oscillating disc 522. For example, the teeth of the first portion 61 of the transmission member 60 can have a substantially annular shape to improve contact with the oscillating teeth of the second oscillating disc 522. The contact is thus achieved at the center of the tooth and extends from the center of the tooth over the life of the gearbox.

The first portion 61 of the transmission member 60 may have a number of teeth corresponding to one tooth plus one tooth on the second oscillating pulley 522. This single tooth deviation allows for a greater reduction ratio. Therefore, if the second oscillating pulley 522 has N teeth, the first portion 61 of the transmission member 60 has N+1 teeth.

In the contact area between the second pendulum 522 and the first portion 61 of the transmission member 60, a top or a flank of a tooth of the second pendulum 522 may contact at least one flank of a tooth of the first portion 61 of the transmission member 60. Several teeth of the second pendulum 522 and/or the first portion 61 of the transmission member 60 may be in contact simultaneously. The rotation of the second pendulum 522 within the first portion 61 of the transmission member 60, through the bias of the tooth-to-tooth contact, pushes back on the first portion 61 of the transmission member 60, causing it to rotate about the longitudinal axis L.

In a first embodiment, the first portion 61 of the transmission member 60 comprises a rigid frame and a shaft assembly. The rigid frame includes a hole assembly circumferentially distributed around the longitudinal axis L. The shafts of the shaft assembly are inserted into holes in the hole assembly of the frame of the first portion 61 of the transmission member 60, thereby forming the gears of the first portion 61 of the transmission member 60. This configuration of a rigid frame and an independent shaft assembly rigidly assembled within the frame enables a high reduction ratio. The shafts of the shaft assembly may be substantially cylindrical and the holes of the frame of the first portion 61 of the transmission member 60 may be substantially cylindrical, so as to produce a substantially cylindrical profile, a substantially annular shape or any shape of teeth suitable for ensuring cooperation with the teeth of the second spool 522.

In a second embodiment, the first portion 61 of the transmission member 60 is formed from a single piece and includes a plurality of protrusions adapted to form the teeth of the first portion 61 of the transmission member 60. The protrusions may have a substantially cylindrical shape, an annular shape, or any other shape that allows for satisfactory contact with the pendulum teeth of the second pendulum disc 522.

The reduction ratio of the two-stage oscillating reducer 50 is available when the first oscillating plate 521 includes n teeth, the crown 53 includes n+1 teeth, the second oscillating plate 522 includes N teeth, and the first portion 61 of the transmission member 60 includes N+1 teeth. or For example, when N=8 and n=10, the reduction ratio of the oscillating reducer is R=45.

The winding/unwinding device can be integrated into a chain reel. The chain reel comprises a reel, a winding/unwinding device as described above, a rotary joint, and a control device. The output shaft 20 is configured to allow the chain to pass between the reel and the rotary joint, and the output shaft 20 is adapted to drive the reel to rotate about the longitudinal axis L.

The control device is adapted to control a set point and/or control the synchronous motor(s) 30 so that the control device and the winding/unwinding device provide an appropriate winding/unwinding torque.

The winding/unwinding torque can vary depending on the degree of winding of the link. In fact, for example, when two elements of the link are displaced to unwind the link, the winding radius varies depending on the amount of link wound on the reel. Therefore, the control device and the winding/unwinding device can be adapted to provide a winding/unwinding torque that is modified according to the degree of winding of the link.

Furthermore, the winding/unwinding torque can vary depending on an operating state of the winder. This state can be characterized by parameters such as a speed, an acceleration, or a predetermined speed in the first or second rotational direction. Therefore, the control device and the winding/unwinding device can be adapted to provide a winding/unwinding torque that is modified depending on an operating state of the winder.

Alternatively or additionally, the control device and the winding/unwinding device may therefore be adapted to provide a predetermined winding/unwinding torque.

Alternatively or additionally, the control device and the winding/unwinding device may be adapted to provide a winding/unwinding torque that is regulated as a function of a measurement of the winding and/or unwinding effect on the link. The torque regulation is thus controlled and carried out in a closed loop.

10: Input shaft 20: Output shaft 30: (Permanent magnet) synchronous motor 31: Rotor 32: Stator 40: Housing 50: Oscillating reducer 51: (Inner) cam; camshaft 52: Oscillating bobbin 521: First oscillating bobbin 522: Second oscillating bobbin 53: (Outer) crown 60: Transmission member 61: First section 62: Second section; second radial section L: Longitudinal axis

Claims (12)

A device for winding/unwinding a chain member, comprising: an input shaft (10) movable to rotate around a longitudinal axis (L); an output shaft (20) substantially coaxial with the input shaft (10), the output shaft (20) being configured to allow the chain member to pass through a hollow through-shaft between a reel and a rotary joint, the output shaft (20) being adapted to drive the reel to rotate around the longitudinal axis (L); At least one permanent magnet synchronous motor (30) comprising a rotor (31) arranged to surround a first portion of the output shaft (20), the rotor (31) rotating integrally with the input shaft (10); A oscillating reducer (50) is configured to surround a second portion of the output shaft (20), the oscillating reducer (50) comprising at least one inner cam (51), an outer crown (53), and at least one oscillating disc (52) disposed between each cam (51) and the crown (53), wherein each cam (51) is mounted to rotate integrally with the input shaft (10), the at least one oscillating disc (52) is mounted to rotate integrally with each cam (51), and wherein each cam (51) is eccentric so that a rotation of each cam (51) around the longitudinal axis (L) drives the at least one oscillating disc (52) to rotate in an eccentric and oscillating manner; and A transmission member (60) is adapted to transmit an angular displacement of the at least one pendulum disc (52) to the output shaft (20), so that an eccentric and pendulum rotation of the at least one pendulum disc (52) drives the output shaft (20) to rotate around the longitudinal axis (L). A device for winding/unwinding a link as claimed in claim 1, wherein the input shaft (10) is configured to surround at least a portion of the output shaft (20). The device for winding/unwinding a chain as claimed in claim 1 or 2 further comprises a housing (40) equipped with the at least one synchronous motor (30) and the pendulum reducer (50), wherein the output shaft (20) passes through the housing (40) from one end to the other end of the housing (40). A device for winding/unwinding a chain as claimed in claim 1 or 2, comprising between one and four synchronous motors (30) mounted in series along the first portion of the output shaft (20). A device for winding/unwinding a link as claimed in claim 1 or 2, wherein the at least one synchronous motor (30) is an axial flux permanent magnet synchronous motor. A device for winding/unwinding a link as claimed in claim 1 or 2, wherein the at least one cam (51) and the input shaft (10) are formed from a single piece, and wherein each cam (51) comprises an outer surface having a radial dimension, the radial dimension varying according to the angular position about the longitudinal axis (L) of each cam (51) when mounted in the winding/unwinding device. A device for winding/unwinding a chain as claimed in claim 1 or 2, wherein the transmission member (60) includes a first portion (61) and a second substantial radial portion (62) suitable for connecting the first portion (61) and the output shaft (20), and the transmission member (60) is configured so that an eccentric and pendulum rotation of the at least one pendulum drum (52) drives the first portion (61) of the transmission member (60) to rotate around the longitudinal axis (L). A device for winding/unwinding a link as claimed in claim 7, wherein the at least one pendulum (52) includes at least one longitudinal hole, and wherein the first portion (61) of the transmission member (60) forms at least one longitudinal finger adapted to extend in the at least one longitudinal hole of the at least one pendulum (52) so as to transmit the angular displacement of the at least one pendulum (52) to the first portion (61) of the transmission member (60). A device for winding/unwinding a chain as claimed in claim 8, wherein the pendulum reducer (50) comprises two substantially identical pendulum drums (523, 524) mounted in series along the longitudinal axis (L), the two pendulum drums (523, 524) being placed in the pendulum reducer (50) with opposite eccentricities, wherein each pendulum drum (523, 524) comprises at least one longitudinal hole, the longitudinal holes of the two pendulum drums (523, 524) being arranged to face each other so that the pendulum drums (523, When the two pendulums (523, 524) are installed in the winding/unwinding device, at least one pair of longitudinal holes is formed, and the at least one finger (61) of the transmission member (60) extends in the at least one pair of longitudinal holes of the two pendulums (523, 524). A device for winding/unwinding a chain member as claimed in claim 7, wherein the oscillating cable reducer (50) includes a first oscillating cable drum (521) and a second oscillating cable drum (522), the first oscillating cable drum (521) being mounted to rotate integrally with the at least one cam (51), and the second oscillating cable drum (522) being mounted to rotate integrally with the first oscillating cable drum (521). The first part (61) of the transmission member (60) includes an inner tooth, which is arranged on the outer side of the second pendulum disc (522) and is suitable for cooperating with an outer pendulum tooth of the second pendulum disc (522) so that the eccentric rotation of the second pendulum disc (522) drives the first part (61) of the transmission member (60) to rotate around the longitudinal axis (L). A device for winding/unwinding a link as claimed in claim 10, wherein the first part (61) of the transmission member (60) includes a rigid frame and a substantially cylindrical shaft assembly, the rigid frame includes a substantially cylindrical hole assembly distributed circumferentially around the longitudinal axis (L), wherein each shaft of the shaft assembly is inserted into each hole of the hole assembly of the rigid frame of the first part (61) of the transmission member (60) to form the inner tooth of the first part (61) of the transmission member (60). A winder for a link element, comprising: a reel; a device as claimed in any one of claims 1 to 11, which is a winding/unwinding device; a rotary joint; and a control device, wherein the control device is suitable for controlling the synchronous motor (30) so that the control device and the winding/unwinding device provide an appropriate winding/unwinding torque.