TORQUE MOTOR COMPLETING A COIL HOLDER AND A MAGNETIC CORE INCLUDING A PERMANENT MAGNET

Description

1. Technical field of the invention

[0001] The invention relates to a torque motor, in particular a limited stroke torque motor for aeronautical applications. 2. Technological background

[0002] Torque motors are electric motors that aim to obtain torque by the circulation of an electric current of predetermined intensity in coils placed in a permanent magnetic field.

[0003] A torque motor comprises an armature, which is the part of the motor that carries the current-carrying coils, and an inductor, which is the complementary part of the motor that generates the permanent magnetic field.

[0004] This permanent magnetic field is generally generated by permanent magnets placed in the rotor or stator of the motor.

[0005] Torque motors are frequently used in the field of aeronautics, for example to equip pneumatic actuators of air bleed valves, cabin pressure regulating valves, fuel flow control systems, etc.

[0006] These aeronautical applications impose a plurality of constraints on torque engines, particularly in terms of mass, volume, temperature, vibration behavior, etc.

[0007] Therefore, the preferred architecture often includes a single-piece stator with at least one permanent magnet, stator windings, and a rotor forming the armature. This architecture results in motors that are compact and minimize rotor inertia.

[0008] This architecture imposes certain constraints during the manufacture of the motor, including the need to integrate the permanent magnets very early in the manufacturing process, and in particular upstream of the winding operations; the production of the stator electrical windings on specific tooling; the insulation of the windings prior to their integration into the motor; and the integration of the stator windings thus produced inside the monobloc stator magnetic circuit by delicate operations which consist of radially bringing the coils onto the magnetic circuit (from the inside or outside of the magnetic circuit, and which for some applications consists of manually shaping the stator coils and compacting them in order to be able to house them in the monobloc stator).

[0009] This manufacturing process is lengthy, tedious, and expensive. Furthermore, it presents risks of poor electrical insulation due to the handling of the stator coils during their integration into the stator magnetic circuit. Also, during the assembly of these torque motors, it is common to have to discard a significant number of manufactured parts due to damage to the stator coils during their integration into the stator circuit. In addition, this manufacturing process precludes the use of ceramic-coated wires.

[0010] The inventors therefore sought to improve torque motors, particularly those intended for aeronautical applications. Specifically, they aimed to propose a new torque motor structure that would facilitate assembly.A torque motor comprising a stator and a rotor extending along the same central axis, said stator further comprising a one-piece magnetic body, at least one pair of radial teeth extending along the central axis and defining slots for receiving stator coils and forming a radial air gap with said rotor, at least one permanent magnet carried by said one-piece magnetic body and comprising a stator coil winding support comprising a hollow body extending along the central axis and delimiting a receiving chamber for said rotor, said support further comprising housings for receiving said stator coils extending in planes parallel to the central axis, and having peripheral radial walls conforming to said receiving slots for said one-piece magnetic body, is also described in DE 19622186 A. Similar motors are described in EP 1583201 A and JP 2011-109785 A. 3. Objectives of the invention

[0011] The invention aims to provide a torque motor that overcomes at least some of the disadvantages of known torque motors.

[0012] The invention aims in particular to provide, in at least one embodiment, a torque motor which has a structure enabling assembly and manufacturing operations to be facilitated.

[0013] The invention aims in particular to provide, in at least one embodiment, a torque motor which has a structure which limits the scrapping of torque motors during assembly operations.

[0014] The invention also aims to provide, in at least one embodiment, a torque motor that exhibits improved electrical insulation performance compared to previous solutions.

[0015] The invention also aims to provide, in at least one embodiment, a torque motor whose structure makes it possible to substantially reduce the time and cost of manufacturing and assembly.

[0016] The invention also aims to provide a torque motor whose structure allows for particular adaptation to the automation of manufacturing, i.e. with reduced or even zero manual operations.

[0017] The invention also aims to provide, in at least one embodiment, a torque motor whose structure allows adaptation for use in frameless mode, better known by the English term " frameless "

[0018] The invention also aims to provide a torque motor whose structure allows, at a lower cost, a reduction in the radial distance between the stator teeth and the rotor teeth forming the air gap of the motor. 4. Description of the invention

[0019] To this end, the invention relates to a torque motor comprising a stator and a rotor extending along the same central axis, said stator further comprising a one-piece magnetic body, at least one pair of radial teeth extending along the central axis and defining slots for receiving stator coils and forming a radial air gap with said rotor, and at least one permanent magnet carried by said magnetic body.

[0020] A torque motor according to the invention comprises a stator and a rotor extending along the same central axis, said stator further comprising a monobloc magnetic body, at least one pair of radial teeth extending along the central axis and defining slots for receiving stator coils and forming a radial air gap with said rotor, at least one permanent magnet carried by said monobloc magnetic body, and comprising a winding support for the stator coils comprising a hollow body extending along the central axis and delimiting a receiving chamber for said rotor, said support further comprising receiving housings for said stator coils extending in planes parallel to the central axis, and having peripheral radial walls conforming to said receiving slots for said monobloc magnetic body,characterized in that the stator coils are housed in receiving housings before the assembly of said support in said monobloc magnetic body, said winding support is formed in one piece and furthermore having one axial end of the receiving housings more adjacent to the central axis than the other axial end having a diameter larger than the diameter of the rotor so that said rotor can be housed in said support by this axial end, so that the integration of the stator coils into said stator consists of inserting axially, into said monobloc magnetic body, said winding support equipped with said stator coils.

[0021] A torque motor according to the invention therefore comprises a winding support for the stator coils. This winding support is shaped to the one-piece stator magnetic core so that, once the coils are mounted in the receiving slots of the winding support, it is possible, during assembly, to simply slide the winding support axially into the one-piece magnetic core. This axial insertion of the winding support into the receiving slots of the one-piece magnetic core ensures the placement of the stator coils around the radial teeth. In other words, according to the invention, the stator coils are first mounted on the winding support in the coil receiving slots, and then integrated into the slots formed between the radial teeth by positioning the winding support in the slots thus formed in the one-piece stator magnetic core.Unlike previous solutions, the torque motor architecture according to the invention is not configured for radial integration of the stator coils around the radial teeth, but for axial integration via an additional component, namely the winding support. This additional component, instead of complicating manufacturing and assembly operations, actually facilitates assembly by allowing the axial insertion of the coils once they are mounted on the winding support.

[0022] In addition, the winding support is hollow and delimits a receiving chamber for the rotor so that it is easy to assemble a torque motor according to the invention, by axially inserting the rotor into the receiving chamber, in which the rotor can take place once the winding support equipped with the stator coils is axially inserted into the magnetic body of the stator, or before the winding support equipped with the stator coils is axially inserted into the magnetic body of the stator.

[0023] Advantageously and according to the invention, said winding support is electrically insulating, at least at the level of the housings receiving the stator coils.

[0024] According to this advantageous variant, this additional component (the winding support) provides electrical insulation between the magnetic circuit and the stator coils. The coil housings have peripheral radial walls shaped to match the stator slots, ensuring that the coils are completely electrically insulated from the magnetic circuit while minimizing the overall size once the winding support is inserted into the single-piece stator.

[0025] Advantageously and according to the invention, said stator coil winding support is non-magnetic.

[0026] A support according to this variant makes it possible not to disturb the magnetic field generated by the coils and magnets, in the air gap, that is to say in the space formed between the teeth of the stator and the rotor.

[0027] In other words, this additional part not only facilitates the assembly operations of a torque motor by axially inserting the stator coils, but also improves the performance of the motor.

[0028] Advantageously and according to the invention, said winding support is formed in one piece.

[0029] This variant allows for a single-piece winding support that can be inserted into the magnetic circuit in one movement. In other variants, the support can be made up of several parts, for example, one part for each coil receiving slot, which are assembled before axial insertion into the magnetic circuit. In yet another variant, the individual parts are inserted separately, axially, into the magnetic circuit.

[0030] Advantageously and according to the invention, said winding support is formed of ceramic.

[0031] This advantageous variant allows the use of torque motors in extreme temperature environments.

[0032] Advantageously, and according to the invention, said stator coils are formed of wires coated with brittle insulation, that is to say, particularly susceptible to deterioration during their shaping (plasticity). Examples of such insulation include mineral-based insulators, such as ceramics.

[0033] Prior art torque motors without winding supports do not allow the use of coils made from ceramic-insulated wires due to the fragility of such coils and the risk of damage during radial insertion. A torque motor according to this embodiment of the invention, on the other hand, allows the use of coils made from ceramic-insulated wires, thus opening up new applications for this torque motor, particularly in terms of temperature resistance.

[0034] Advantageously and according to the invention, said stator comprises two permanent magnets arranged opposite each other, a pair of radial teeth defining two slots for receiving two stator coils and said non-magnetic support comprises two housings for receiving said stator coils.

[0035] This advantageous variant allows for a torque motor with low manufacturing costs while offering performance compatible with various aeronautical applications, particularly for pneumatic actuator control systems for air sampling valves or cabin pressure regulation.

[0036] Advantageously and according to the invention, said winding support carries bearings for said rotor.

[0037] This advantageous variant gives the winding support not only a function of supporting the coils, facilitating the axial insertion of the coils into the magnetic circuit, but also a mechanical function of supporting the rotating guide elements and axially stopping the rotor.

[0038] Alternatively or in combination, said support includes stops extending radially and forming angular stops for the rotor.

[0039] This variant provides an additional functionality to the winding support, which is to limit the angular displacement of the rotor in the rotor receiving chamber by the presence of radial stops that protrude into the receiving chamber.

[0040] Advantageously and according to the invention, said stator coil winding support further comprises a peripheral compartment for connecting the stator windings with a power supply wire for said torque motor.

[0041] This peripheral compartment facilitates the electrical connection between an external power supply wire and the stator windings. If the winding support is insulating, this connection compartment also provides electrical insulation due to the characteristics of the winding support.

[0042] Advantageously and according to the invention, the winding support for the stator coils further comprises at least one notch configured to guide and retain at least one power supply wire for said torque motor.

[0043] These guide notches can, for example, be provided at the level of a base of the winding support to guide the power supply wire towards the electrical connection compartment, for example.

[0044] The invention also relates to a method for assembling a torque motor comprising a stator and a rotor extending along the same central axis, said stator further comprising a one-piece magnetic body, at least one pair of radial teeth extending along the central axis and defining slots for receiving stator coils and forming a radial air gap with said rotor, at least one permanent magnet carried by said one-piece magnetic body, a winding support being formed in one piece, stator coils comprising a hollow body extending along the central axis and delimiting a receiving chamber for said rotor, said support further comprising receiving housings for said stator coils extending in planes parallel to the central axis, and having peripheral radial walls conforming to said receiving slots for said one-piece magnetic body,said support further having an axial end of the receiving housings more adjacent to the central axis than the other axial end having a diameter larger than the diameter of the rotor, characterized in that it comprises the following steps: , mounting of the stator coils on the winding support, axial insertion of the winding support fitted with the stator coils into the one-piece magnetic body of the stator, axial insertion of the rotor into the hollow body of the winding support.

[0045] An assembly method according to the invention thus makes it possible to assemble a motor according to the invention by first mounting the stator coils on the winding support, and then axially inserting the winding support fitted with the coils into the motor stator. The insertion of the rotor can be carried out either simultaneously with the insertion of the winding support or subsequently.

[0046] According to an advantageous variant of the assembly process, the coils are impregnated after mounting on the coil winding support.

[0047] The coils can be mounted on the winding support either by holding the winding support in a fixed position and rotating a winding wire in the receiving slots of the winding support, or by holding the winding wire in a fixed position and rotating the winding support around the winding wire.

[0048] The invention also relates to a torque motor and a method of assembling a torque motor characterized in combination by all or part of the characteristics mentioned above or below. 5. List of figures

[0049] Other objects, features and advantages of the invention will become apparent from the following description, given by way of non-limiting example only, and which refers to the accompanying figures in which: there figure 1 is a schematic exploded perspective view of a torque motor according to an embodiment of the invention, the figure 2 is a schematic perspective view of a winding support for a torque motor according to an embodiment of the invention, the figures 3a to 3d are schematic perspective views of the different stages of axial insertion of a winding support into a stator of a torque motor according to an embodiment of the invention, the figure 4 is a schematic perspective view of a stator of a torque motor according to an embodiment of the invention, the figure 5 is a schematic perspective view of a winding support equipped with stator coils of a torque motor according to an embodiment. 6. Detailed description of an embodiment of the invention

[0050] In the figures, scale and proportion are not strictly to scale for illustrative and clarity purposes. In all the detailed descriptions that follow with reference to the figures, unless otherwise indicated, each component of the torque motor is described as it is arranged when the torque motor is assembled. Furthermore, identical, similar, or analogous components are designated by the same reference numerals in all figures. The terms axial and radial are used without limitation with reference to the principal axis Z along which the torque motor extends, shown in particular in the figure. figure 1 Finally, for a given element, the terms interior and exterior or peripheral are used to designate respectively the parts of the element close to the main Z axis or far from the main Z axis.

[0051] A torque motor according to the invention comprises, as shown in the figure 1, a stator 10 and a rotor 20 extending along the same central axis Z.

[0052] The stator 10, according to the embodiment shown in the figures, comprises, as represented in particular on the figure 4 , a single-piece magnetic body 11, a pair of radial teeth 12 extending along the central axis Z and defining between them two slots 15, 16 for receiving stator coils, and two permanent magnets 13, 14 carried laterally by the single-piece magnetic body 11.

[0053] The torque motor according to the invention further comprises a winding support 30 for the stator coils 32, 33 comprising a hollow body 34 which extends along the central axis Z.

[0054] According to the embodiment shown in the figures, this support 30 is formed in one piece. However, according to other embodiments, the support 30 may be formed of one or more pieces assembled together by means of assembly.

[0055] According to the embodiment shown in the figures, the hollow body 34 defines in its center a housing 35 for receiving the rotor 20. This housing 35 opens at each axial end of the hollow body 34 so that the rotor 20 can be housed in the housing by an axial end of the hollow body during the assembly operations of the torque motor.

[0056] Support 30 includes, as shown on the figure 2 , housings 41, 42 for receiving the stator coils 32, 33. These coils 32, 33 extend in planes parallel to the central axis Z.

[0057] There figure 2 illustrates the support 30 free of all stator coils 32, 33 and the figure 5 illustrates the support 30 equipped with the stator coils 32, 33.

[0058] The support 30, once equipped with the stator coils 32, 33 is conformed to the receiving notches 15, 16 of the magnetic body 11 of the stator, formed between the radial teeth of the magnetic body 11 of the stator.

[0059] Thus, the integration of the stator coils 32, 33 into the stator 10 consists of inserting axially, into said monobloc magnetic body 11 of the stator, the support 30 equipped with said stator coils 32, 33.

[0060] The various steps implemented by a method for assembling a torque motor according to the invention are schematically represented by the figures 3a to 3d . In these figures, the one-piece magnetic body 11 is already inserted into a housing 51.

[0061] On the figure 3a , the winding support 30 equipped with the stator coils 32, 33 enters the monobloc magnetic body 11.

[0062] On the figure 3b , the winding support 30 is partially inserted into the one-piece magnetic body 11.

[0063] On the figure 3cThe winding support is fully inserted into the one-piece magnetic body 11. The stator coils 32, 33 are therefore positioned between the radial teeth of the stator. This positioning of the stator coils 32, 33 was achieved solely by an axial displacement of the winding support.

[0064] On the figure 3d The rotor 20 was inserted axially into the housing 35 of the winding support 30. The final assembly step, not shown in the figures, consists of fitting the motor with a power supply wire and screwing a base 52 onto the motor housing 51.

[0065] The assembly of a torque motor according to the invention is thus simplified by allowing the mounting of the stator coils 32, 33 onto the support 30, and then the insertion of the support equipped with coils into the stator. The mounting of the stator coils 32, 33 into the receiving slots 41, 42 can be carried out using an automated assembly line, which simplifies and accelerates the assembly operations compared to manual operations. Similarly, the axial insertion of the winding support into the one-piece magnetic body of the stator and the axial insertion of the rotor can be automated.

[0066] Furthermore, the winding support equipped with the coils being conformed to the notches 15, 16 of the stator, the dielectric performance of the torque motor according to the invention is improved compared to the torque motors of the prior art.

[0067] The use of a winding support also minimizes the radial distance between the stator and rotor teeth, which forms the motor's air gap. This optimized air gap allows for a torque motor with improved electromechanical performance compared to previous solutions.

[0068] Preferably, the winding support is non-magnetic and electrically insulating. For example, it is made of ceramic.

[0069] Such a ceramic support makes it possible not to disturb the magnetic field generated by the coils and magnets in the air gap of the motor, which helps to improve the performance of a torque motor according to this embodiment.

[0070] According to one embodiment of the invention, the stator coils 32, 33 are formed from ceramic-insulated wires. Since the torque motor according to the invention is no longer subject to the risk of coil damage due to complex coil insertion procedures in the stator, a torque motor can, in an advantageous embodiment, comprise ceramic-coated wires.

[0071] This allows the torque motor according to this embodiment of the invention to be used in motor environments (which can have temperatures of around 450°C) without requiring the addition of a specific ventilation means for the torque motor.

[0072] The torque motor according to the embodiment shown in the figures also includes a housing 51 and a base 52. The housing 51 and the base 52 are configured to be joined together to enclose the various components of the torque motor. To this end, the housing 51 may include, according to an embodiment not shown in the figures, radial tabs in which holes are provided for the passage of screws opposite corresponding holes formed in the base 52. Of course, other means of assembly between the housing 51 and the base 52 may be provided without modifying the object of the invention. These may consist of threads formed on the peripheral wall of the housing 51 and corresponding to threads formed on the base 52. They may also consist of snap-fit ​​means or any equivalent means.

[0073] The torque motor also includes rotor bearings 61, 62. According to one embodiment of the invention, these bearings 61, 62 are directly supported by the winding support 30, which limits the number of parts of the torque motor and facilitates its assembly.

[0074] The winding support also includes and is shown on the figures 2 And 5 , a compartment 68 peripheral connection of the stator windings with a power supply wire from the torque motor.

[0075] This peripheral compartment 68 is formed, according to the embodiment shown in the figures, in a lateral wing of the winding support that extends along the central axis between the stator coil receiving recesses 41, 42. This compartment 68 has at least one opening configured to receive a power supply wire from the torque motor and a second opening configured to receive one end of the stator coil wires. This second opening for receiving the stator coil wire is, for example, formed in an internal wall of the compartment, and the first opening is, for example, formed in an external wall of the compartment.According to one embodiment, this peripheral compartment 68 is configured to receive a power supply plug shaped like a winding plug configured to receive one end of the wires of the stator coils such that the insertion of the power supply plug into the compartment spontaneously ensures the electrical connection with the wires of the stator coils connected to the winding plug.

[0076] The winding support also includes and is shown on the figures 2 And 5 Two orifices 64 are provided in close proximity to each other in the peripheral wall of the winding support, forming means for guiding and retaining a power supply wire for the torque motor. According to another embodiment, the means for guiding and retaining the power supply wire are formed by a notch provided at the base of the winding support.

[0077] A motor coupled according to the embodiment shown in the figures makes it possible both to facilitate the assembly operations of the motor and to improve the dielectric strength characteristics.

[0078] The invention is not limited to the embodiment shown in the figures. In particular, the winding support can have other shapes as long as it is conformed to the monobloc stator to allow axial insertion of the winding support fitted with the stator coils.

Claims

1. Torque motor comprising a stator (10) and a rotor (20) extending along the same central axis (Z), said stator (10) further comprising a single-piece magnetic body (11), at least one pair of radial teeth (12) extending along the central axis (Z) and defining notches (15, 16) for receiving stator coils (32, 33) and forming a radial air-gap with said rotor, at least one permanent magnet (13, 14) borne by said single-piece magnetic body (11), and comprising a winding support (39) for the stator coils (32, 33) comprising a hollow body (34) extending along the central axis (Z) and delimiting an enclosure (35) for receiving said rotor (20), said support (30) further comprising housings (41, 42) for receiving said stator coils (32, 33) extending in planes in parallel with the central axis (Z) and having peripheral radial walls shaped to match said notches (15, 16) for receiving said single-piece magnetic body (11), characterised in that said stator coils (32, 33) are housed in the receiving housings (41, 42) prior to assembly of said support (30) in said single-piece magnetic body (11), said support is formed from a single part and further having an axial end of the receiving housings (41, 42) more closely adjacent to the central axis (Z) than the other axial end having a diameter larger than the diameter of the rotor such that said rotor can be housed in said support via this axial end.

2. Torque motor as claimed in claim 1, characterised in that said winding support (30) is electrically insulating, at least at the housings for receiving the stator coils (32, 33).

3. Torque motor as claimed in any one of claims 1 to 2, characterised in that said winding support (30) is non-magnetic.

4. Torque motor as claimed in any one of claims 1 to 3, characterised in that said winding support (30) is made of a ceramic material.

5. Torque motor as claimed in any one of claims 1 to 4, characterised in that said stator (10) comprises two permanent magnets (13, 14) arranged facing one another, one pair of radial teeth (12) defining two notches (15, 16) for receiving two stator coils (32, 33), and in that said support (30) comprises two housings (41, 42) for receiving said stator coils (32, 33).

6. Torque motor as claimed in any one of claims 1 to 5, characterised in that said stator coils (32, 33) are formed from leads coated with an insulator of mineral origin, such as ceramic material.

7. Torque motor as claimed in any one of claims 1 to 6, characterised in that said support (30) bears bearings of said rotor (20).

8. Torque motor as claimed in any one of claims 1 to 7, characterised in that said support (30) comprises stops extending radially and forming angular stops for the rotor.

9. Torque motor as claimed in any one of claims 1 to 8, characterised in that said support (30) further comprises a peripheral compartment for connecting the stator coils with a power supply lead for said torque motor.

10. Torque motor as claimed in any one of claims 1 to 9, characterised in that said support (30) further comprises a guide notch configured to be able to guide and hold at least one power supply lead for said torque motor.

11. Method for assembling a torque motor comprising a stator (10) and a rotor (20) extending along the same central axis (Z), said stator (10) further comprising a single-piece magnetic body (11), at least one pair of radial teeth (12) extending along the central axis (Z) and defining notches (15, 16) for receiving stator coils (32, 33) and forming a radial air-gap with said rotor, at least one permanent magnet (13, 14) borne by said single-piece magnetic body (11), a winding support (30), being formed from a single part, for the stator coils (32, 33) comprising a hollow body (34) extending along the central axis (Z) and delimiting an enclosure (35) for receiving said rotor (20), said support (30) further comprising housings (41, 42) for receiving said stator coils (32, 33) extending in planes in parallel with the central axis (Z) and having peripheral radial walls shaped to match said notches (15, 16) for receiving said single-piece magnetic body (11), said support further having an axial end of the receiving housings (41, 42) more closely adjacent to the central axis (Z) than the other axial end having a diameter larger than the diameter of the rotor (20), characterised in that it comprises the following steps: - mounting the stator coils (32, 33) on the winding support (30), - axially inserting the winding support (30) fitted with the stator coils (32, 33) in the single-piece magnetic body (11) of the stator, - axially inserting the rotor (20) in the body (34) of the winding support (30).