LINEAR ACTUATOR SYSTEM WITH DECOUPLABLE AND CONTROLLABLE ACTUATOR

Abstract

LINEAR ACTUATOR SYSTEM WITH DECOUPLABLE AND CONTROLLABLE ACTUATOR The invention relates to a linear actuation system comprising an irreversible rotary actuator (102) driving a linear mechanical device (104), the actuator (102) comprising an electric motor, a reducer comprising a worm gear driving a wheel, an electrical and electronic control device configured to drive the rotation of the electric motor, to regulate the rotational speed and torque of the electric motor and to manage the position and number of revolutions of the electric motor, a sealing housing configured for sealing the electrical and electronic control device, and an output shaft driven in rotation by the reducer, the system also comprising a coupling and decoupling device (120) between the mechanical device (104) and the actuator (102), configured to transmit the torque of the output shaft to the mechanical device (104),said mechanical device (104) comprising at least one means for transforming torque into linear translational motion of a moving element. Figure for the abbreviation: Figure 1,

Description

Title of the invention: LINEAR ACTUATOR SYSTEM WITH DECOUPLABLE AND CONTROLLABLE ACTUATOR Technical field of the invention

[0001] The invention relates to an actuator system comprising an actuator and a linear mechanical device. In particular, the invention relates to an actuator system comprising an actuator that can be easily coupled to or decoupled from the linear mechanical device, the linear mechanical device being in particular a linear cylinder or a linear valve. The actuator system is particularly used in vehicles, especially aircraft. Technological background

[0002] Aircraft include a plurality of servovalves, which are motorized components that regulate the flow or pressure of a fluid. In an aircraft, these servovalves are used, in particular, for regulating the engine air intake flow and on distribution valves. Aircraft also include linear actuators, for example, for opening air intake flaps of air conditioning systems or air inlets of heat exchangers. These valves and actuators are controlled by integrated electric motors and are grouped under the name linear mechanical device, which may also include other types of devices.

[0003] Prior art linear mechanical devices are generally controlled and commanded by a centralized system controller, whose control instructions are received and processed by an electronic card integrated into the linear mechanical device.

[0004] In the event of maintenance or repair of a mechanical or electronic element, the linear mechanical device must be disassembled, and in the case of a valve the fluid must be drained before disassembly.

[0005] Electronic boards are also subject to stringent sealing requirements, either with respect to a fluid circulating in the linear mechanical device (particularly in the case of a valve), or with respect to a fluid in the environment in which the linear mechanical device is installed, for example, particularly in an aircraft, suspended lubricating oil, water vapor, etc. In particular, when the linear mechanical device is a linear actuator, surrounding water vapor can enter the actuator during its operation due to pressure changes during the actuator's movement or during altitude variations, and this water can condense inside the actuator.

[0006] Finally, the control of electronic boards by a centralized controller reduces the possibilities of precise and easily configurable control.

[0007] The inventors therefore sought an alternative solution enabling them to obtain a linear actuator system that meets the constraints of repairability and sealing, particularly in an aircraft. Objectives of the invention

[0008] The invention aims to provide a linear actuator system with a decoupling actuator, controllable and facilitating the implementation of a seal.

[0009] The invention aims in particular to provide, in at least one embodiment, a linear actuator system facilitating the maintenance and / or repair of the actuator or the linear mechanical device that it controls.

[0010] The invention also aims to provide, in at least one embodiment of the invention, a linear actuator system facilitating the control of the position of the linear mechanical device.

[0011] The invention also aims to provide, in at least one embodiment of the invention, a linear actuator system facilitating the implementation of sealing of electronic elements. Description of the invention

[0012] To this end, the invention relates to a linear actuation system comprising an actuator and a linear mechanical device configured to be driven by the actuator, so as to cause a linear movement of a moving element in translation of the linear mechanical device,

[0013] characterized in that the actuator is an irreversible rotary actuator comprising: - an electric motor, - a reducer comprising a worm gear driven by the electric motor and a wheel driven by the worm gear, - an electrical and electronic control device, configured to control the rotation of the electric motor, to regulate the rotation speed of the electric motor, and to manage the position and number of revolutions of the electric motor, - a sealing housing configured to surround the electrical and electronic control device and to ensure the sealing of the electrical and electronic control device, - an output shaft, configured to be driven in rotation by the reducer,

[0014] and further comprising a coupling device between the mechanical device and the actuator, configured to allow coupling or decoupling of the actuator with the mechanical device and to transmit the torque supplied by the actuator via the output shaft to the mechanical device when the actuator and the mechanical device are coupled, said mechanical device comprising at least one means of transforming the torque into linear translational motion of the moving element.

[0015] A linear actuation system according to the invention thus provides, on the one hand, an actuator controllable by an electrical and electronic control device whose sealing is ensured by the sealing housing, and on the other hand, a linear mechanical device that does not require any electrical or electronic components requiring special sealing. The mechanical device therefore has a purely mechanical function, and the electrical and electronic management is centralized at the actuator. The coupling device allows for simplified coupling and decoupling of the actuator and the linear mechanical device, which simplifies the maintenance and / or repair of either one. In particular, the actuator can be quickly replaced by another identical, functional actuator during maintenance and / or repair, making it a line-replaceable unit (LRU).

[0016] The electrical and electronic control device can also be configured to regulate the torque of the electric motor.

[0017] Advantageously and according to the invention, the electrical and electronic control device includes means for receiving data representative of the electric current flowing through the electric motor, and means for receiving data representative of the number and direction of revolutions made by the output shaft and / or the electric motor when the actuator is in operation, and means for processing said data to estimate a position of the linear mechanical device.

[0018] According to this aspect of the invention, the actuator can estimate the position of the linear mechanical device from electrical (currents, voltages, power, etc.) and / or electronic (sensor data) information. This feature allows the actuator to easily adapt to different types of linear mechanical devices and to quickly configure a new actuator coupled to the linear mechanical device if the actuator is changed for maintenance and / or repair of the actuator system. Knowing the estimated position also allows for precise control of the linear mechanical device, enabling, for example, precise control of the opening of a flap or valve and thus control of the flow rate and / or pressure of the fluid passing through the flap or valve.The position of the linear mechanical device is an estimate because it is not based on a reading from a position sensor present in the linear mechanical device, but the accuracy and precision of the estimate can be equivalent to data from a position sensor. The resolution and sensitivity of the position estimate are also important factors. depend on the resolution and sensitivity of the motor and / or output shaft revolution counter.

[0019] The number and direction of the turns of the electric motor on the one hand and of the output shaft on the other hand are proportional and the measurement of the number and direction of the turns of the one makes it possible to calculate the number and direction of the turns of the other.

[0020] Advantageously and according to the invention, the linear actuation system is configured to perform an initialization step comprising: - sending a command to rotate the electric motor, - upon receiving data representing a strong increase in the electric current passing through the electric motor, a recording in a memory of initialization data representing a stop position of the linear mechanical device.

[0021] According to this aspect of the invention, this initialization step enables the configuration of the electrical and electronic control for position estimation. The sharp increase in the electric current flowing through the electric motor is representative of abnormal motor operation, which prevents the motor from rotating. This occurs when the linear mechanical device reaches a mechanical stop against an element of the actuator system. When the linear mechanical device reaches its stop, its position is therefore known.

[0022] Advantageously and according to the invention, the position of the linear mechanical device is estimated as a function of the number and direction of turns made by the output shaft and / or the electric motor from the stop position of the linear mechanical device.

[0023] According to this aspect of the invention, the number of motor revolutions achieved from the stop position allows the position of the linear mechanical device to be estimated, which can thus be precisely controlled.

[0024] Advantageously and according to the invention, the worm screw is configured to have a tooth inclination angle of less than or equal to 10°, preferably less than or equal to 5° so that the reducer is irreversible.

[0025] According to this aspect of the invention, the irreversibility of the actuator is made possible by the use of a worm screw whose angle of inclination of the teeth is less than 10°, preferably less than 5°.

[0026] Advantageously and according to the invention, the linear mechanical device is a linear actuator.

[0027] According to this aspect of the invention, the linear actuator can, for example, be used for opening or closing a flap, in particular an air inlet flap on an air conditioning unit or an air inlet flap of heat exchangers in liquid-loop systems. The arrangement of the electrical and electronic components in The rotary actuator eliminates the need for sealing. Specifically, when the cylinder is in operation, its movement can allow unwanted water vapor to enter and condense inside the cylinder. Without electrical or electronic components within the cylinder, this condensed water vapor poses fewer problems for the cylinder's operation.

[0028] Advantageously and according to the invention, the linear mechanical device is a needle valve in which the moving element in translation is a needle configured to regulate a flow and / or a pressure of a fluid passing through the valve.

[0029] According to this aspect of the invention, the needle valve can be particularly used in a steam cycle circuit as a regulating or bypass valve. In particular, the needle of the needle valve is generally immersed in the fluid it regulates (a liquid in the steam cycle circuit), and the linear actuation system thus allows simple decoupling of the actuator for maintenance and / or repair without the need to drain the mechanical part, in particular without the need to drain the liquid loop which, for example, requires a tightness of the order of 10⁵ Pa.

[0030] Advantageously and according to the invention, the coupling device comprises mechanical coupling means by tenon / mortise type coupling, configured to transmit the torque supplied by the actuator via the output shaft to the mechanical device when the actuator and the mechanical device are coupled.

[0031] According to this aspect of the invention, the mechanical coupling allows for a simple and inexpensive coupling for transmitting the actuator's torque. In this embodiment of the invention, the electrical and electronic control device is advantageously configured to regulate the electric motor's torque, so as to ensure that the torque capacity is not exceeded.

[0032] Advantageously and according to the invention, the coupling device includes magnetic coupling means configured to transmit the torque supplied by the actuator via the output shaft to the mechanical device when the actuator and the mechanical device are coupled.

[0033] According to this aspect of the invention, the magnetic coupling allows for a coupling that can be accompanied by a sealing cover to isolate a device through which a fluid flows with the actuator. This magnetic coupling is particularly useful for the variant in which the linear mechanical device is a needle valve.

[0034] Advantageously and according to the invention, the coupling device comprises two magnetic coupling portions separated by a sealing hood.

[0035] The invention also relates to a linear actuation system characterized in combination by all or part of the characteristics mentioned above or below. List of figures

[0036] 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:

[0037] [Fig-1] is a schematic perspective view of a linear actuation system according to a first embodiment of the invention.

[0038] [Fig.2] is a schematic perspective view of a linear actuation system according to a second embodiment of the invention.

[0039] [Fig.3] is a partial schematic cross-sectional view of the linear mechanical device and the coupling device of a linear actuation system according to the second embodiment of the invention.

[0040] [Fig.4] is a partial schematic perspective view of the inside of an actuator of a linear actuation system according to an embodiment of the invention.

[0041] Detailed description of an embodiment of the invention

[0042] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity.

[0043] In addition, identical, similar or analogous elements are designated by the same references in all figures.

[0044] Figure 1 schematically represents a linear actuation system 100 according to a first embodiment of the invention. The linear actuation system comprises an actuator 102 and a linear mechanical device, here a linear cylinder 104 configured to be driven by the actuator 102. The internal elements of the linear cylinder 104 are visible in the figure but are in practice completely enclosed by a housing 106, shown here partially. The linear cylinder includes, in particular, a reduction stage 108 for rotating a shaft 110. The rotation of the shaft 110 causes the translational movement of an assembly 112 consisting of a nut and a ball screw, which transmits the motion to a translationally movable element 116 comprising an end piece 114 that can, for example, be connected to a flap.

[0045] The linear cylinder 104 is connected to the actuator 102 via a coupling device 120 comprising a collar that clamps two conical counterforms for mechanically retaining the actuator 102 to the linear cylinder. The coupling device 120 transmits the torque via a direct or indirect coupling from the output shaft of the actuator 102 to the reduction stage 108, for example via a tenon / mortise coupling or other type.

[0046] Figure 2 schematically represents a linear actuation system 200 according to a second embodiment of the invention. Figure 3 shows a partial view and a cross-section of a linear mechanical device and a coupling device of a linear actuation system according to the second embodiment of the invention.

[0047] The linear actuation system includes an actuator 202 substantially identical to the actuator of the first embodiment and a linear mechanical device, here a needle valve 204 configured to be driven by the actuator 202. The needle valve 204 and the actuator are connected by a coupling device 220.

[0048] As shown in [Fig. 3], an output shaft 206 of the actuator 202, shown partially, drives, via a tenon / mortise coupling, a first magnetic coupling portion 220a of the coupling device 220, which is a magnetic coupling device. The coupling device 220 includes a second magnetic coupling portion 220b arranged on the side of the needle valve 204. The two magnetic coupling portions 220a and 220b are separated by a sealing cover 220c, ensuring a completely leak-proof connection, particularly to prevent the fluid flowing through the valve 204 from escaping at the coupling with the actuator 202.

[0049] Magnetic coupling is for example achieved by a set of three pairs of magnetic poles without a magnetic yoke, forming a coupling by Halbach effect.

[0050] The second portion 220b of the magnetic coupling drives a worm screw 208 via a tenon / mortise coupling 210. The rotation of the worm screw 208 causes a translational movement of a movable element 210 comprising a nut and whose end includes a needle valve 212, allowing the regulation of the flow and / or pressure of a fluid from an inlet 214 to an outlet 216. The needle valve 204 is arranged here in the closed position.

[0051] Figure 4 schematically represents, in perspective and partial view, the interior of an actuator 302 according to one embodiment of the invention. This actuator 302 can be used in linear actuation systems according to the first and second embodiments of the invention, as well as in other undescribed embodiments.

[0052] The actuator comprises an electric motor 330 controlled by an integrated, non-visible electrical and electronic control device 332, configured to control the rotation of the electric motor 330, to regulate the rotational speed of the electric motor 330, and to manage the position and number of revolutions of the electric motor 330. Furthermore, the electronic control allows for the management of the motor's torque to ensure that the torque capacity is not exceeded when a magnetic coupling is implemented.

[0053] The electric motor drives a reduction gear comprising, in particular, a first toothed wheel 334 attached to a worm gear 336. The worm gear 336 drives a second toothed wheel 338, here fully toothed so as to be able to control several revolutions of the output shaft. The teeth of the worm gear 336 and the second wheel The toothed gear 338 has an angle of inclination less than or equal to 10°, preferably less than or equal to 5°, so as to guarantee the irreversibility of the mechanical transmission. The second toothed gear 338 directly drives an output shaft 340, enabling the actuating of the linear mechanical device to which it is coupled. In another representation, the second toothed gear may be partial if the desired range of motion is limited.

[0054] The electrical and electronic control device 332 also includes means for receiving data representative of the electric current flowing through the electric motor, and means for receiving data representative of the number and direction of revolutions made by the output shaft and / or the electric motor 330 when the actuator 302 is in operation, and means for processing said data to estimate a position of the linear mechanical device

[0055] Electrical and electronic control thus makes it possible, in particular, to estimate the position of the linear mechanical device by placing this device in a stop position (detected by an increase in the current flowing in the electric motor), for example, the position shown in [Fig. 1] where the electric actuator is in its closed stop position or in [Fig. 3] where the needle valve is in its stop position with the valve closed. From this known position, counting the number of revolutions of the electric motor 330 and / or the output shaft 340 of the actuator makes it possible to estimate the position of the linear mechanical device such as the linear actuator or the needle valve needle. This estimation may be the subject of an initialization step comprising: - sending a command to rotate the 330 electric motor, - upon receipt of data indicating a sharp increase in electric current passing through the electric motor, a recording in a memory of an initialization data representative of a stop position of the linear mechanical device.

[0056] The position of the linear mechanical device is thus estimated as a function of the number and direction of revolutions made by the output shaft 340 and / or the electric motor 330 from the stop position of the linear mechanical device.

[0057] The actuator 302 thus comprises the electronic and electrical components necessary for the operation of the linear actuation system. Sealing can be ensured by a sealing housing 342 surrounding the electrical and electronic control device 332. The sealing of the linear mechanical devices can therefore be reduced, or even eliminated, depending on the configuration of the linear actuation system or the type of valve.

[0058] The sealing housing 342 can also surround part or all of the other actuator components, in particular the electric motor.

Claims

Demands

1. A linear actuation system comprising an actuator (102, 202, 302) and a linear mechanical device (104, 204) configured to be driven by the actuator (102, 202, 302), so as to cause linear motion of a movable element (116, 212) in translation of the linear mechanical device, characterized in that the actuator (102, 202, 302) is an irreversible rotary actuator comprising: - an electric motor (330), - a gearbox comprising a worm gear (336) rotated by the electric motor (330) and a wheel (338) rotated by the worm gear (336), - an electrical and electronic control device (332) configured to control the rotation of the electric motor (330), to regulate the rotational speed of the electric motor (330), and to manage the position and number of revolutions of the electric motor (330),- a sealing housing (342) configured to surround the electrical and electronic control device (332) and to ensure the sealing of the electrical and electronic control device (332), - an output shaft (340), configured to be driven in rotation by the reducer, and further comprising a coupling device (120, 220) between the mechanical device (104, 204) and the actuator (102, 202, 302), configured to allow coupling or decoupling of the actuator (102, 202, 302) with the mechanical device (104, 204) and to transmit the torque supplied by the actuator (102, 202, 302) via the output shaft (340) to the mechanical device (104, 204) when the actuator (102, 202, 302) and the device (104, 204) mechanical are coupled, said device (104, 204) mechanical comprising at least one means of transforming the torque into linear translational motion of the moving element.

2. A linear actuation system according to claim 1, characterized in that the electrical and electronic control device (332) comprises means for receiving data representative of the electric current flowing through the electric motor (330), and means for receiving data representative of the number and direction of revolutions made by the output shaft (340) and / or the motor (330) electrical when the actuator is in operation, and means of processing said data to estimate a position of the linear mechanical device.

3. Linear actuation system according to claim 2, characterized in that it is configured to perform an initialization step comprising: - sending a rotation command to the electric motor (330), - upon receiving data representing a strong increase in the electric current through the electric motor (330), recording in a memory initialization data representing a stop position of the linear mechanical device.

4. Linear actuation system according to claim 3, characterized in that the position of the linear mechanical device is estimated as a function of the number and direction of revolutions made by the output shaft (340) and / or the electric motor (330) from the stop position of the linear mechanical device.

5. Linear actuation system according to any one of claims 1 to 4, characterized in that the worm (336) is configured to have a tooth inclination angle less than or equal to 10°, preferably less than or equal to 5° so that the reducer is irreversible.

6. Linear actuation system according to any one of claims 1 to 5, characterized in that the linear mechanical device is a linear cylinder (104).

7. Linear actuation system according to any one of claims 1 to 5, characterized in that the linear mechanical device is a needle valve (204) in which the translationally moving element is a needle (212) configured to regulate a flow and / or pressure of a fluid passing through the valve.

8. Linear actuation system according to any one of claims 1 to 7, characterized in that the coupling device comprises mechanical coupling means (120) by tenon / mortise type coupling, configured to transmit the torque supplied by the actuator via the output shaft to the mechanical device when the actuator and the mechanical device are coupled.

9. A linear actuation system according to any one of claims 1 to 7, characterized in that the coupling device comprises means

10. (220a, 220b) magnetic couplings configured to transmit the torque supplied by the actuator via the output shaft to the mechanical device when the actuator and the mechanical device are coupled. Linear actuation system according to claim 9, characterized in that the coupling device comprises two magnetic coupling portions (220a, 220b) separated by a sealing hood (220c).

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