A device for winding / unwinding a link.

Abstract

The present invention relates to a device for winding / unwinding a link adapted for transporting a fluid or transmitting energy and / or signals, the device comprising: a reel (2) adapted to receive said link in a wound form; a hollow through-shaft (3) adapted for the passage of said link or fluid between a rotary joint and the reel, the hollow through-shaft (3) being integrated with the reel (2) in order to drive said reel in rotation about the longitudinal axis (X) of said shaft; and at least one permanent magnet synchronous direct drive motor comprising a stator carrying windings (10) adapted to be electrically supplied in three phases, and a rotor carrying permanent magnets (11) facing the stator windings (10).

Description

Technical Field

[0001] The present invention relates to an apparatus for winding / unwinding a link adapted for fluid transport or energy and / or signal transmission.

Background Art

[0002] There are many industrial applications where it is necessary to transmit energy and / or signals (e.g., electric current, optical signals, mechanical tension, fluids, etc.) via a rotational connection between a first element and a second element movable relative to the first element. For example, the first element can be a cabinet fixed to the ground, a robot frame, etc., and the second element can be a carriage or traveling gantry on the ground, a robot arm, etc.

[0003] The aforementioned energy and / or signals are transmitted via an electric cable, an optical fiber or a bundle of optical fibers, a mechanical cable, a hydraulic or pneumatic conduit, or any other suitable means generally referred to herein as a "link".

[0004] To prevent the link from being deployed disorderly during the displacement of the second element relative to the first element, a link is disposed on a reel of a winder provided with a drive unit attached to the first element or the second element and adapted to rotationally drive the reel so as to wind back or wind up the link in synchronization with the displacement of the second element relative to the first element. Such a winding device is described, for example, in European Patent No. 3008005.

[0005] The winder must be adapted as much as possible to the application for which it is used, and the applications are very diverse. The size of the drive unit must be adapted according to the link, the height of the equipment, the speed and acceleration of the displacement of the second element relative to the first element.

[0006] The particularity of the winder is that it needs to supply a fairly large torque even if the rotational speed of the reel is low.

[0007] There are different types of drive units designed to address these technical constraints.

[0008] The first type of drive unit involves the association of a magnetic coupler with a motor, as described, for example, in French Patent Invention No. 2102600, French Patent Invention No. 2607333, and French Patent Invention No. 2899399. This concept recognizes a certain modularity from the same motor and coupler, in that several motor coupler sets can be mounted in the same gearbox to adjust the torque according to the application.

[0009] A second type of drive unit involves the association of a variable frequency motor with an electronic control unit. This type of drive unit does not benefit from the modularity of the first type in that a motor with the power required for the application must be selected. Another type of drive unit is an axial flux motor, as described, for example, in European Patent No. 3072220. [Overview of the project]

[0010] The objective of this invention is to design a new type of drive unit for a winder that can obtain high torque at low speeds.

[0011] In this regard, the present invention relates to a device for winding / unwinding a link adapted for the transport of fluids or the transmission of energy and / or signals: - A reel adapted to accept the above link in a wound form, - A hollow through shaft adapted for the passage of the link or fluid between the rotary joint and the reel, which is integrated with the reel to rotate the reel about the longitudinal axis of the shaft, - A permanent magnet synchronous direct drive motor comprising a stator supporting windings adapted to be electrically supplied in three phases, and a rotor supporting permanent magnets facing the windings of the stator. We propose a device equipped with the following features.

[0012] In some embodiments, the at least one motor and at least one rotor are formed by a central disk of the reel.

[0013] In other embodiments, at least one rotor of the at least one synchronous motor is rigidly integrated with the shaft. In some embodiments, permanent magnets are arranged through the at least one rotor such that each has a north face on one side of the rotor and a south face on the opposite side of the same rotor.

[0014] In some embodiments, each permanent magnet has a trapezoidal shape, and the height of each permanent magnet extends radially with respect to its longitudinal axis. Particularly advantageous, the magnets are arranged side by side to form a crown.

[0015] In some embodiments, the radial extension of the magnet crown is substantially equal to the height of the winding.

[0016] In a preferred embodiment, the motor has an axial magnetic flux.

[0017] The apparatus may further include an electronic speed variator adapted to vary the supply current to the stator windings. The apparatus may also advantageously further include a rotary joint coupled to the end of a hollow shaft opposite the reel, and a control / command system comprising a processing unit coupled to or integrated with the electronic speed variator for controlling each motor, in particular, according to the position and operating stage of the winder. [Brief explanation of the drawing]

[0018] Other features and advantages of the present invention will be described in the following detailed description with reference to the accompanying drawings. [Figure 1] This is an overall view of a winding / unwinding device according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view of the winding / unwinding device of FIG. 1. [Figure 3] This is a perspective view of the winding / unwinding device of FIG. 1 having a partial cross-section of the motor according to a first embodiment of the motor. [Figure 4] This is a view similar to FIG. 3 having a second embodiment of the motor. [Figure 5] This is a view similar to FIGS. 3 and 4 having a third embodiment of the motor. [Figure 6] This is a cross-sectional view of a winding / unwinding device according to another embodiment of the present invention. [Figure 7] This is a perspective view of a winding / unwinding device according to another embodiment of the present invention having a partial cross-sectional view of the stator. [Figure 8] This is a view similar to FIG. 7 having two juxtaposed motors. [Figure 9] This is a view similar to FIGS. 7 and 8 having three juxtaposed motors. [Figure 10] This is a view similar to FIGS. 7 to 9 having four juxtaposed motors.

[0019] Only the elements necessary for the description of the winder are shown. The same reference numerals between the drawings indicate the same elements or elements performing the same function, and thus are not necessarily described in detail again.

Mode for Carrying Out the Invention

[0020] FIG. 1 is an overall view of a device for winding / unwinding a link according to an embodiment of the present invention.

[0021] The link can be an electric cable, an optical fiber or a bundle of optical fibers, a mechanical cable, a hydraulic or pneumatic conduit, or any other suitable means for transmitting energy and / or signals.

[0022] For the sake of clarity in the drawings, elements connected by rotary joints, control / command devices, and links are not shown.

[0023] One of these elements could be, in particular, but not limited to, a cabinet or robot frame fixed to the ground.

[0024] The other of these elements could, in particular, but not limited to, be a ground carriage or mobile gantry, or a robotic arm.

[0025] The winding / unwinding device (also referred to as the “winder” for the remainder of this specification) comprises a support adapted to be firmly integrated with one of the elements.

[0026] The winder also includes a reel 2 adapted to accept the link in a wound form.

[0027] The reel includes the following: - A mandrel 20 extending along the axis of rotation of the reel, and - Two sets of lateral arms 21a, 21b are fixed to both sides of the mandrel 20 and are adapted to accommodate the turns of the link laterally, defining the amount of winding of the link. Each set of arms forms a flange.

[0028] Alternatively (not shown), the flanges of the reel may be solid, and each set of arms may be replaced with discs of equivalent diameter.

[0029] The structure of the reel is rigidified by a ferrule, which can be an integral part of the mandrel or flange, i.e., the following: - An internal ferrule 22 located at a first distance from the mandrel, and - A pair of external ferrules 23a, 23b, where each ferrule is fixed to at least one arm of the respective flange at a second distance from the mandrel that is greater than a first distance.

[0030] The reel has a bearing surface adapted to receive the turn of the link, and the internal turn is in contact with the bearing surface. The bearing surface may, in particular, be part of a mandrel or an internal ferrule.

[0031] The space between flanges, i.e., the distance between two flanges, is defined according to the width of the link being wound onto the reel. To enable precise winding / unwinding of the link, especially in the case of single-turn reels, the space between flanges is adjusted so that the distance between flanges accommodates the link being wound at the proximal and distal ends of the arm. The space between flanges and the length of the arm, which define the reel's capacity, are selected according to the maximum length of link that can be easily wound onto the reel. Depending on the application, the outer diameter of the reel can typically be around 3–8 mm.

[0032] The reel 2 is rigidly integrated with the end of the shaft 3, which is rotatably mounted to the support via a bearing 30.

[0033] As can be seen better in Figure 2, shaft 3 is hollow to allow the passage of a link between reel 2 and a rotary joint (not shown) located on the side of the shaft opposite the reel. Thus, the link is protected from the elements surrounding the winder and is not at risk of being damaged by them.

[0034] When the link transports fluid, the hollow shaft itself can act as a conduit for the fluid, and the union with the link is located at the end of the shaft.

[0035] The end of the hollow shaft opposite the reel is connected to the hollow shaft of a coaxial rotary joint (not shown) that is aligned with the hollow shaft 3.

[0036] The shaft and reel are rotationally driven about the longitudinal axis X of the shaft 3 by at least one permanent magnet synchronous direct drive motor. This type of motor is also called a "direct drive motor".

[0037] The above-described motor comprises a stator 1 that is rigidly integrated with a support. In the figure, the stator 1 is formed integrally with the support, but it can also be formed from separate components that are rigidly connected to the support.

[0038] According to a preferred embodiment, the stator 1 supports a plurality of windings 10 having three-phase power arranged around axis X to create a magnetic field along axis X in which the polarity alternates according to the direction of the current passing through the windings. More precisely, the stator 1 comprises a plurality of oriented electrical sheets 100 separated from each other by radial notches, and each winding consists of a set of turns 101 of conductive wires slid into the notches.

[0039] The motor also includes a rotor that is rotatably movable relative to the stator 1. The rotor supports a plurality of permanent magnets 11.

[0040] The turns of the winding 10 are arranged substantially radially so as to create an axial magnetic field facing the rotor's permanent magnet 11.

[0041] In some embodiments, referring to Figures 2 to 5, the rotor consists of a disk 24 integrated with a reel on which permanent magnets are fixed. Advantageously, the disk can be matched with a mandrel 20.

[0042] To optimize the surface covered by the magnets, the magnets advantageously have a substantially trapezoidal shape with heights oriented radially with respect to the axis X, and the narrowest base is positioned closer to the axis X than the widest base. The base of the magnets may be straight or curved. Thus, permanent magnets can be juxtaposed facing the windings to form a crown coaxial with the axis X. Thus, as shown in Figures 3 to 5, the stator 1 includes windings 10 of different heights, and the rotor includes trapezoidal permanent magnets 11 arranged according to a crown whose width, corresponding to the height of the magnets, is preferably less than or equal to the height of the windings (the height of the windings is measured radially with respect to the axis X).

[0043] In other embodiments, referring to Figures 6 to 10, the rotors 41, 42 comprise disks on which permanent magnets 11 are fixed, and the disks are not part of the reel 2 but are firmly integrated with the hollow shaft 3. In particular, the rotors may be formed integrally with the hollow shaft or may be firmly fastened to the hollow shaft by, for example, grooves, pins, or other arbitrary fastening means. The stator 1 is arranged around the rotors 41, 42 and the hollow shaft 3 via bearings 30 that allow the rotors 41, 42 and the hollow shaft to rotate relative to the stator 1. The stator 1 comprises a surface facing the rotor surface that carries the permanent magnets, the surface supporting a plurality of windings 101 to 104 having three-phase power arranged around axis X, and creating a magnetic field along axis X whose polarity alternates according to the direction of the current passing through the windings.

[0044] More precisely, the stator 1 comprises a plurality of electrical steel plates separated from each other by radial notches, and each winding 101-104 consists of a set of turns of conductive wires slid into the notches.

[0045] Particularly advantageous is that this rotor and stator arrangement allows several motors to be placed side by side along axis X, with each motor relating a rotor surface carrying permanent magnets to a stator surface facing the windings and supporting the windings. Thus, each rotor can be common to two adjacent motors, with the first surface carrying permanent magnets belonging to the first motor, and the second surface, opposite to the first surface, similarly carrying permanent magnets belonging to the second motor. According to this principle, additional rotors can be added, each combined with a surface of the stator, each contributing to two additional motors.

[0046] Accordingly, Figure 6 shows an embodiment having four motors 51-54, each comprising two rotors 41, 42 supporting permanent magnets 111-114 on two surfaces, with each surface of the rotor facing the respective surface of the stator containing windings 101-104.

[0047] The architecture in Figure 6 allows the number of motors to be varied between 1 and 4, depending on the number of rotor surfaces 41 and 42 equipped with permanent magnets and the number of stator surfaces equipped with windings. Naturally, additional motors can be added by providing one or more additional rotors coaxial with rotors 41 and 42, and their respective additional stator surfaces.

[0048] Figure 7 shows an embodiment in which the rotor 41 is equipped with magnets 111 on a surface facing the surface of the stator 1, which includes the windings 101, thereby forming a motor 51. The rotor 41 is rigidly integrated with the shaft 3 and is coaxial with the reel.

[0049] Figure 8 shows an embodiment in which the rotor 41 is equipped with magnets 111 on the surface facing the stator 1 which includes the windings 101 to form a motor 51, and magnets 112 are equipped on the opposite side of the rotor 41 which faces the second surface of the stator 1 which includes the windings 102 to form a second motor 52.

[0050] The magnet can be attached, for example, to the surface of the rotor 41.

[0051] Alternatively, a single set of magnets can be used for two adjacent motors. In this case, the magnets are arranged within the rotor 41 such that each magnet has its north face on the first side of the rotor 41 and its south face on the other side of the same rotor 41, and adjacent magnets have their south face on the first side of the rotor 41 and their north face on the other side of the rotor 41. In other words, the north and south faces alternate on both sides of the rotor 41.

[0052] Therefore, the first motor formed by the rotor 41 has magnets on its crowns that alternately have north and south faces. On the opposite side of the same rotor 41 is a crown of magnets with the opposite polarity. By offsetting the stator windings located on both sides of the rotor by the pitch of the magnets, twice the torque is generated for the crown of magnets used on one side.

[0053] Therefore, each magnet has a side used by the first motor 51, and the opposite side is used by the second motor 52. For example, the rotor 41 can be made from a metal plate having a reservation in the form of magnets, and the magnets 111-114 are arranged to penetrate the rotor 41.

[0054] In the embodiments shown in Figures 7 and 8, the rotor 42 is not used to form a motor and therefore does not support permanent magnets. It is certainly possible to reduce the size of this rotor 42 in order to increase the compactness of the device.

[0055] Figure 9 shows an embodiment in which, in addition to motors 51 and 52, a second rotor 42 is equipped with magnets 113 on a surface facing the surface of the stator 1, which includes windings 103, thereby forming a third motor 53.

[0056] Figure 10 shows an embodiment in which, in addition to motors 51 and 52, a second rotor 42 is provided with magnets 113 on the surface facing the third surface of the stator 1 which includes the windings 103 to form a third motor 53, and magnets 114 on the opposite surface facing the fourth surface of the stator 1 which includes the windings 104 to form a fourth motor 54.

[0057] Alternatively, motors 53 and 54 can be formed by the same set of magnets arranged through the rotor 42, such that each has a north face on one side of the rotor 42 and a south face on the other side of the same rotor 42, by alternating the north and south faces of adjacent magnets on each side of the rotor.

[0058] The number of rotors is purely illustrative and not limiting; those skilled in the art will understand how to adapt it depending on the parameters of the winding device and the required torque.

[0059] In embodiments comprising one or more rotors 41-42 supporting permanent magnets 111-114, the permanent magnets 111-114 have, advantageously, a substantially trapezoidal shape with heights radially oriented with respect to the axis X, where the narrowest base is positioned closer to the axis X than the widest base. The bases of the magnets may be straight or curved. Thus, the permanent magnets can be juxtaposed facing the windings to form a crown coaxial with the axis X.

[0060] Each motor is controlled by an electronic speed variator (not shown) adapted to vary the voltage, frequency, and supply current of the windings of the stator 1. The windings create a magnetic field that rotates at a speed proportional to the supply frequency, generating the rotation of one or more rotors, which are magnetic fields created by permanent magnets. Advantageously, the current supplied to the windings can be controlled to vary the magnetic field and thus adapt the torque generated by the motor.

[0061] The electronic speed variator is part of the winder's control / command system, and further comprises a processing unit coupled to or integrated with the variator for controlling the motor, in particular, according to the winder's position and operating stage.

[0062] The above control / command system further includes sensors adapted to measure the current flowing through the motor windings.

[0063] The processing unit comprises at least one processor configured to perform a computational algorithm taking into account input data supplied by a sensor, and a memory in which parameters necessary for the execution of the algorithm are recorded.

[0064] In some embodiments, the processing unit is integrated directly into the variator, while in other embodiments, the processing unit is integrated into an external programmable logic controller (e.g., one of the machine to which the winder is connected) outside the variator.

[0065] The processing unit and variator may be located inside a cabinet situated near the winder.

[0066] The advantage of such a direct drive motor or a set of direct drive motors is that it allows for the avoidance of the use of any transmission element such as a gearbox, and thus overcomes all the problems that arise with such gearboxes, particularly any failures and operating clearances of the gearbox, as well as losses caused by its yield.

[0067] Furthermore, in such a motor, the rotor and stator do not come into contact. Therefore, there is no mechanical wear, resulting in excellent reliability and a long service life.

[0068] On the other hand, such a motor or set of motors would enable the generation of torque with a substantially shorter duration than current asynchronous motor technology, which is important for reducing the braking duration of the winder in emergencies (given the motor's constant power) or for allowing the winder to pass over the feed point more quickly. This requires a strong over-torque for a short period (typically less than 5 seconds) compared to the torque generated in normal use.

[0069] Furthermore, by increasing the size of the reel, the winder according to the present invention can accommodate a large number of permanent magnets and position these magnets at a considerable distance from the axis X, thereby generating the desired torque.

[0070] For example, typically, a diameter of about 1.5 m is available for arranging the magnets. The rotational speed of the reel is typically about 30 rpm, but more commonly, it may be substantially between 0 and 100 rpm. The torque generated by the motor can reach 8000 Nm.

[0071] As can be seen in Figures 3 to 10, the winder architecture according to the present invention is suitable for specific modularity with respect to the size and / or number of windings and the size of the permanent magnets.

[0072] Therefore, in the embodiment shown in Figure 3, the stator 1 includes a winding 10 having a height h1, the upper part of the radial winding being at a distance d from the axis X, the height of the magnet 11 being substantially equal to the total thickness of the winding, and the magnet being positioned facing the winding.

[0073] In the embodiment shown in Figure 4, the stator 1 includes a winding 10 having a height h2 less than h1. Preferably, the top of the winding in the radial direction is at a distance d from the axis X, as with the winding in Figure 3, and the broad bottom of the magnet 11 is located at the same distance from the axis X as the magnet of the rotor in Figure 3 to maximize the torque generated.

[0074] In the embodiment shown in Figure 5, the stator 1 includes a winding 10 having a height h3 less than h2. Preferably, the top of the winding in the radial direction is at a distance d from the axis X, as with the winding in Figures 3 and 4, and the wide bottom of the magnet 11 is located at the same distance from the axis X as the magnet of the rotor in Figures 3 and 4 to maximize the torque generated.

[0075] Depending on the available space, particularly the dimensions of the reel, the position of the magnet and winding relative to the axis X can be adjusted.

[0076] Optionally, a specific modularity can be achieved by forming each magnet in the form of two or more trapezoidal sections juxtaposed radially, such that the sum of their heights forms the total height of the magnet.

[0077] Depending on the application, it is possible to form magnets of maximum height by using the trapezoidal assembly, or to form magnets of minimum or intermediate height by using only a portion of the trapezoidal section and placing them on the crown.

[0078] Naturally, the illustrated embodiments are given for illustrative purposes only, and those skilled in the art can use any other turns for the windings, thereby determining the size and number of magnets according to the application, torque, and required speed. Those skilled in the art can further adapt the turns for the windings 101-104 and determine the size and number of magnets 111-114, as in embodiments where one or more rotors 41, 42 are integrated with the shaft 3, as shown in Figures 6-10. Furthermore, in such embodiments, the size and number of turns for the windings 101-104 and the number of magnets 111-114 may differ or be the same for several motors 51-54 formed by the surfaces of the rotor and stator 1.

[0079] Furthermore, although the axial flux motor has been described with reference, the motor may, according to an alternative embodiment, be a radial flux motor. In this embodiment, the rotor comprises a drum integrated with a mandrel 20 supporting permanent magnets, and the stator 1 supports windings having three-phase power that radially orients the magnetic field. The magnets can be positioned inside or outside the windings.

Claims

1. A device for winding up / unwinding a link adapted for the transport of fluids or the transmission of energy and / or signals, - A reel (2) adapted to receive the link in a wound form, - A hollow through shaft (3) is integrated with the reel (2) to rotate the reel (2) about the longitudinal axis (X) of the hollow through shaft (3), the end of the hollow through shaft (3) opposite to the reel (2) is coupled to a rotary joint, and the hollow through shaft (3) allows the passage of the link between the reel (2) and the rotary joint. - A permanent magnet synchronous direct drive motor comprising: a stator supporting windings (10) adapted to be electrically supplied in three phases; and a rotor supporting permanent magnets (11) facing the windings (10) of the stator, At least one rotor of the at least one permanent magnet synchronous direct drive motor is formed by the central disk (24) of the reel (2) or is firmly integrated with the hollow through shaft (3). Device.

2. The apparatus according to claim 1, wherein at least one rotor of the at least one permanent magnet synchronous direct drive motor is rigidly integrated with the hollow through shaft (3), and the permanent magnets are arranged through the at least one rotor (41) such that each has a north face on one side of the rotor (41, 42) and a south face on the opposite side of the same rotor (41, 42).

3. The apparatus according to claim 1 or claim 2, wherein each permanent magnet (11) has a trapezoidal shape, and the height of each permanent magnet extends radially with respect to the longitudinal axis (X).

4. The apparatus according to claim 3, wherein the permanent magnets (11) are arranged side by side to form a crown.

5. The apparatus according to claim 4, wherein the radial extension of the crown of the permanent magnet (11) is substantially equal to the height of the winding (10).

6. The apparatus according to any one of claims 1 to 5, wherein the permanent magnet synchronous direct drive motor is an axial magnetic flux motor.

7. The apparatus according to any one of claims 1 to 6, further comprising an electronic velocity variator adapted to change the supply current of the windings of the stator.

8. The apparatus according to claim 7, further comprising: a rotary joint coupled to the end of the hollow through shaft (3) opposite to the reel (2); and a control / command system including a processing unit coupled to or integrated with the electronic speed variator for controlling each permanent magnet synchronous direct drive motor according to the position and operating stage of the winder.

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