Variable-speed actuator with inertial reduction system

Abstract

It is described a variable-speed actuator for controlling movement and for the precise regulation of movable members. The actuator comprises a motor connected to a speed reducer and an auxiliary energy management system connected to the speed reducer. The actuator is configured to allow operation of the auxiliary energy management system both when the motor is operative and when the motor is not operative. The actuator further comprises an anti-backdrive joint configured to engage when the motor is operative and to automatically disengage when the motor is not operative. The anti-backdrive joint comprises either a spring-biased movable element cooperating with a rotating element by means of teeth, contact elements, or friction surfaces, or an electromagnetic brake configured to lock the transmission when powered and to release automatically in the absence of power supply. Automatic disengagement reduces the moment of inertia to the active components of the speed reducer only.

Description

VARIABLE-SPEED ACTUATOR WITH INERTIAL REDUCTION SYSTEM

[0001] The present invention relates to a variable-speed actuator with an inertial reduction system.

[0002] In particular, the present invention concerns an actuator for HVAC systems provided with a high-efficiency speed reducer and designed for sustainable manufacturing.

[0003] The invention falls within the field of HVAC (Heating, Ventilation, and Air Conditioning) systems, providing an innovative solution for the actuation of components and dampers by means of an advanced actuator. The main objective is to optimize actuator performance through a speed reducer specifically designed to maximize efficiency and minimize environmental impact, while maintaining high levels of reliability and durability.

[0004] In general, the present invention relates to actuators for controlling movable members, particularly suitable for applications requiring precise regulation of position or movement, such as HVAC systems, including applications in explosive or potentially hazardous environments.

[0005] More specifically, the present invention relates to actuators integrating mechanical and electronic components, such as speed reducers and control systems.

[0006] The state of the art is represented by patent EP1632013B1, which relates to an electric actuator designed for controlling dampers and valves in potentially explosive environments. The actuator comprises two main housings.

[0007] A first explosion-proof housing accommodates components capable of generating sparks or heat, such as the electric motor and the control electronics, which could potentially trigger an explosion in hazardous atmospheres. This housing is designed to be flameproof, that is, capable of containing any internal explosion without allowing flames or sparks to propagate outside, thereby ensuring safety.

[0008] A second housing, which is not explosion-proof, contains mechanical components such as transmission gears and operating shafts, which do not represent an explosion risk and therefore do not require flameproof protection. The separation between electrical and electronic components and mechanical components allows a simpler design and reduces manufacturing costs, improving overall operational efficiency and safety.

[0009] Furthermore, the patent protects a key feature of the actuator, namely the ability to provide both the transmission shaft and the manual adjustment shaft with outputs on opposite sides of the external housing. This configuration is achieved by means of an external housing formed by two half shells which, once assembled, define a symmetrical and robust enclosure.

[0010] Specifically, the transmission shaft can extend from two opposite sides, allowing connection to external components from either side and facilitating installation in confined spaces, while increasing operational flexibility. Likewise, the manual adjustment shaft is accessible from both sides, improving accessibility and enabling rapid manual control in the event of an emergency or power failure. Openings for fastening means are also arranged on the same sides of the housing from which the transmission shaft and the manual adjustment shaft extend, further simplifying installation and increasing device stability.

[0011] This actuator configuration provides several advantages, including increased installation flexibility, ease of access for manual adjustment, and simplified assembly. The symmetrical arrangement and the separation of components into distinct housings represent an advanced solution that improves the safety and efficiency of the actuator in hazardous environments, such as petrochemical plants, refineries, and chemical production facilities.

[0012] The present invention falls within the field of actuators for controlling movement and for the precise regulation of movable members in industrial applications, with particular reference to HVAC systems and to harsh or potentially explosive environments. The invention aims to improve operational efficiency, safety, and stability of motion control by overcoming the technical and operational limitations encountered in known systems.

[0013] The prior art exhibits several limitations related to the precise and reliable control of actuators under critical operating conditions. In particular:

[0014] conventional actuators do not ensure adequate motion control when the motor is not operative, leaving the system exposed to instability or inefficiency;

[0015] the high moment of inertia of conventional speed reducers results in slow response times, increased energy losses, and difficulties in achieving rapid and controlled movements, as required in emergency situations;

[0016] the lack of integrated auxiliary energy management systems makes it difficult for the actuator to operate autonomously in the absence of motor-driven power supply;

[0017] the absence of modular or customizable configurations limits operational flexibility, particularly in applications with restricted installation spaces or specific functional requirements.

[0018] In addition to the solution described in patent EP1632013B1, several anti-backdrive mechanisms or holding devices used in actuators and transmission systems are known in the prior art.

[0019] Patent document EP 1 347 249 A1 discloses an actuator with manual override and locking features where mechanical and electrical components are separated for safety in hazardous environments. However, this document does not disclose an anti-backdrive joint configured to automatically disengage a speed reducer from a kinematic chain when a drive motor is not operative, nor does it address the reduction of effective inertia perceived during manual adjustment in the presence of irreversible or high-ratio reducers.

[0020] Patent document US 5 986 369 A describes a unidirectional transmission or locking arrangement intended to prevent backdriving under specific operating conditions. While the system controls motion direction, it does not include an elastically biased movable element configured for selective and automatic coupling and decoupling of a speed reducer in the absence of motor power, nor does it address inertial reduction during manual operation.

[0021] Patent document US 7 913 972 B2 discloses a valve actuator with a mechanical latch arrangement including a spring lever that permits manual setting and retention of a position against the force of a return spring. The described mechanism operates as a manual position hold but does not disclose a joint that automatically decouples a speed reducer from the drive when the motor ceases operation, nor is it integrated with an auxiliary energy management system aimed at reducing effective system inertia during manual adjustment.

[0022] In summary, the above-mentioned documents disclose various actuators, unidirectional devices, or holding mechanisms, but none disclose or suggest an anti-backdrive joint that automatically decouples a speed reducer when the motor is not operative, thereby reducing the effective inertial mass during manual adjustment in the presence of irreversible or high-ratio speed reducers.

[0023] The purpose of the present invention is to solve the above-mentioned problems of the prior art by providing a variable-speed actuator equipped with an inertial reduction system. This system enables:

[0024] a stable and efficient transmission of motion, even when the motor is not operative;

[0025] an inertially reduced configuration of the speed reducer, ensuring a rapid and precise response of the system;

[0026] the use of an auxiliary energy delivery system, such as a spiral spring, to drive autonomous movement of the reducer in the absence of motor-driven power supply;

[0027] the possibility of geometric and functional customization through additive manufacturing techniques, making the actuator compact and suitable for a wide range of applications.

[0028] The above and other purposes and advantages of the invention, as will become apparent from the following description, are achieved by a variable-speed actuator with an inertial reduction system, as defined in claim 1. Preferred embodiments and non-trivial variants of the present invention are the subject of the dependent claims.

[0029] It is understood that all the appended claims form an integral part of the present description. It will be immediately apparent that numerous variants and modifications (for example relating to shape, dimensions, arrangements, and parts having equivalent functions) may be made to what has been described without departing from the scope of protection of the invention as defined by the appended claims.

[0030] The invention described offers numerous advantages over the prior art, including:

[0031] the inertially reduced configuration enables rapid and precise movements, minimizing energy losses and response times, and ensuring stable motion control even in the absence of motor-driven power supply;

[0032] the modularity of the system, combined with the possibility of integrating additional transmissions and manual interfaces, makes the actuator adaptable to different industrial applications;

[0033] the use of additive manufacturing allows the implementation of a compact and customizable system, meeting specific application requirements;

[0034] the integration of auxiliary energy ensures continuous and controlled operation, even in emergency situations or critical environments.

[0035] The present invention will be better described with reference to some preferred embodiments, provided by way of example and not of limitation, with reference to the accompanying drawings, in which:Fig.1

[0036] shows a front view of an embodiment of a variable-speed actuator with an inertial reduction system according to the present invention.Fig.2a, Fig.2b

[0037] andshow an enlarged view of a portion II of the preceding figure.Fig.3

[0038] shows a front view of relevant elements of.Fig.4

[0039] shows a perspective view of the preceding figure.Fig.5

[0040] shows a relevant element of the preceding figure.Fig.6

[0041] shows a perspective view of relevant elements of.Fig.7

[0042] shows a front view of a further embodiment of the variable-speed actuator with an inertial reduction system according to the present invention.Fig.8

[0043] shows a perspective view of relevant elements of the preceding figure.Fig.9

[0044] shows the relevant elements of the preceding figure in a further perspective view.Fig.10

[0045] shows a perspective view of further relevant elements of.Figs.11-14

[0046] show relevant components of an embodiment of a speed reducer according to the present invention.Fig.15

[0047] shows a perspective view of a first embodiment of the speed reducer according to the present invention.Fig.16

[0048] shows a perspective view of a second embodiment of the speed reducer according to the present invention. AndFig.17

[0049] shows a perspective view of a housed embodiment of the variable-speed actuator with an inertial reduction system according to the present invention.

[0050] With reference toand, it can be noted that the actuator for controlling movement and for the precise regulation of movable members at variable speed comprises a motor 1 connected to a speed reducer 4, a manual control interface, where provided, configured to allow manual intervention on the actuator directly or indirectly on the movable member, and an auxiliary energy management system 3 connected to the speed reducer 4.

[0051] The actuator is configured to allow operation of the auxiliary energy management system 3 when the motor 1 is operative, and to allow operation of the manual control interface, where provided, and of the auxiliary energy management system 3 when the motor 1 is not operative.

[0052] Advantageously, the actuator comprises an anti-backdrive joint 7 configured to engage when the motor 1 is operative and to automatically disengage when the motor 1 is not operative. The anti-backdrive joint 7 comprises at least one of:– a movable element L configured to move between an engagement position and a disengagement position with respect to a rotating element D, the movable element L being biased by an elastic spring S, selective engagement occurring by means of teeth, complementary contact elements, or surfaces configured to generate friction;– an electromagnetic brake B, not illustrated, used to selectively lock the transmission when the motor 1 is powered and to automatically deactivate in the absence of power supply.

[0053] Automatic disengagement of the anti-backdrive joint 7 allows transmission of motion with a moment of inertia reduced to the active components of the speed reducer 4 only.

[0054] With reference to,, and, the movable element L is a sliding member 14 configured to move in a plane substantially parallel to the axis of rotation of the motor 1, guided along a guide 13 and biased by the elastic spring S toward the rotating element D.

[0055] The rotating element D is constituted by a disc 15, engagement occurring by means of connecting elements and / or teeth 17, 18, or by means of surfaces configured to generate friction.

[0056] With reference to, the movable element L is constituted by a movable lever 14′ configured to move in a plane substantially transverse to the axis of rotation of the motor 1, between an engagement position and a disengagement position with respect to the rotating element D.

[0057] The rotating element D is constituted by a disc 15′, engagement occurring by means of connecting elements and / or teeth 17′, 18′, or by means of surfaces configured to generate friction.

[0058] In a further embodiment, not illustrated, the movable element L is configured to perform a helical roto-translational movement with respect to the rotating element D, comprising a displacement component substantially parallel to and a displacement component substantially transverse to the axis of rotation of the motor 1, in order to selectively engage or disengage teeth or friction-generating surfaces.

[0059] The movable element L is provided with a further manipulator 19 configured to produce a forced disengagement from the rotating element D.

[0060] Alternatively, engagement between the movable element L and the rotating element D is achieved by means of surfaces configured to generate friction.

[0061] With reference to figures fromto, the speed reducer 4 comprises an eccentric pin 8 mounted on a fast rotating shaft 5, a first externally toothed wheel 9 mounted on the eccentric pin 8, an internally toothed wheel 10 meshing with the first wheel 9, a second externally toothed wheel 11 rigidly connected to the first wheel 9, and an output wheel 12 mounted coaxially on a slow rotating shaft 6.

[0062] The internally toothed wheel 10 is rigidly connected to the rotating element D.

[0063] The speed reducer 4 is of the irreversible type and comprises a hypocycloidal gear train which, when the motor 1 is not operative, behaves as a single body directly connected to the anti-backdrive joint 7.

[0064] The speed reducer 4 is an irreversible or semi-irreversible reducer comprising, by way of example, a worm gear reducer, a hypocycloidal reducer, a high-ratio epicyclic reducer, or a reducer having a geometry configured to prevent reverse transmission of motion.

[0065] The auxiliary energy management system 3 comprises at least one spiral spring connected to the slow rotating shaft 6, configured to store elastic energy during operation of the motor 1 and to release it when the motor 1 is not operative.

[0066] The motor 1 is of the electric type.

[0067] The reducer 4 may constitute a first stage of a multi-stage speed reducer.Examples

[0068] The actuation system described is applicable in the HVAC field and in other industrial sectors, including areas classified in accordance with ATEX Directive 2014 / 34 / EU, and combines an electric motor, a hypocycloidal speed reducer, a helical spring connected to the slow shaft, and a unidirectional lever-type anti-backdrive joint. This configuration enables reliable operation both under normal conditions and under safety conditions, ensuring the ability to precisely position a valve or a damper and, at the same time, to automatically return it to a predetermined position in the absence of power supply. The numerical values relating to movement angles and mechanical torques are provided purely by way of example, for the sole purpose of illustrating the operating principle.

[0069] During motor-driven operation, the lever of the anti-backdrive joint keeps the internal ring gear of the reducer locked in the opening direction. The reducer therefore operates in a conventional configuration with a fixed ring gear, allowing the motor to determine the position of the slow shaft with high precision. In this condition, the slow shaft can be brought to a desired angle, for example 60°, during which the helical spring connected to the shaft is progressively loaded up to a torque proportional to the reached angle; for instance, a spring dimensioned to develop 0.5 Nm at a position of 90° may develop approximately 0.33 Nm at a position of 60°. These values are not limiting but illustrate the linear behavior of a torsion spring commonly used for elastic return.

[0070] When the motor remains powered and applies torque at the reached position, the actuator remains stable because the internal ring gear is held by the lever in its locking direction. If, instead, the motor were de-energized in this condition, the spring would tend to return the shaft toward the rest position, and since the return torque acts in the free direction of the anti-backdrive joint, the internal ring gear would be free to advance step by step and the reducer would assume a kinematic configuration with a movable ring gear, thereby allowing the spring to close the valve. Consequently, if it is desired to accurately maintain an intermediate position such as the example of 60°, the motor must remain powered and apply a torque sufficient to counterbalance that of the spring.

[0071] In the case in which the actuator is equipped with an electric motor of any type, controlled in position mode or torque mode so as to continuously apply an active torque during motion and during position holding, the system operates under a condition in which the driving torque is never zero as long as the drive is powered and active. In such a control mode, the motor does not merely impart motion but continuously generates a regulating torque intended to reduce the error between the actual position of the slow shaft and a reference position, or to maintain a set torque as a function of the load. This torque, transmitted through the hypocycloidal reducer, produces a reaction on the internal ring gear of the reducer that is oriented in the engagement direction of the lever of the anti-backdrive joint. Consequently, both during clockwise and counterclockwise movements, as well as during the holding of an intermediate position, the lever of the anti-backdrive joint remains engaged with the teeth of the ring gear, which is therefore fixed to the housing.

[0072] Under this condition, the hypocycloidal reducer operates in a fixed-ring configuration, maintaining the nominal reduction ratio and ensuring continuous transmission without jerks or kinematic discontinuities. The helical spring connected to the slow shaft may be loaded or unloaded depending on the reached angle, but it does not assume the role of a kinematically dominant element as long as the motor remains powered and controlled in position or torque. The operating mode with a movable ring gear and ratcheting action of the anti-backdrive joint occurs exclusively under conditions of absence of motor torque, for example in the event of power loss or intentional zero-torque command, in which the return spring becomes the main torque source and provides automatic repositioning of the slow shaft.

[0073] The actuator described comprises an advanced speed reducer (4), designed to ensure operational flexibility, energy efficiency, and safety, even in explosive environments or critical situations. The speed reducer (4) integrates an irreversibility system based on a hypocycloidal gear train and an anti-backdrive joint (7), optimizing system performance and ensuring stability under different operating conditions.

[0074] The speed reducer (4) integrates an irreversibility system based on a hypocycloidal gear train and a unidirectional joint (7), referred to as an “anti-backdrive joint”, which contributes to optimizing performance and ensuring system stability under various operating conditions.

[0075] The anti-backdrive joint (7) may be identified and described by different technical terms, depending on the functional and application context. Such synonyms or alternative descriptions include:one-way joint, emphasizing the ability of the mechanism to allow motion in only one direction;freewheel joint, commonly used to indicate a mechanism that allows free motion in one direction and blocks motion in the opposite direction;directional locking joint, highlighting the capability of the joint to actively block motion in a single direction;unidirectional clutch joint, integrating a clutch to allow more precise motion control;unidirectional ratchet joint, designed to allow stepwise motion in only one direction;ratchet mechanism, a generic term describing devices capable of preventing reverse motion, adaptable to different types of joints;unidirectional transmission device, emphasizing the role of the joint in transmitting motion in a single direction;limited-rotation joint, which restricts motion to the desired rotational direction;joint with monodirectional locking function, technically describing the one-direction blocking function, ensuring stability and efficiency.

[0076] The terminology used is selected according to the specificity of the technical or patent context, without prejudice to the essential function of the anti-backdrive joint (7), which is to prevent reverse motion and to ensure stable and efficient transmission of motion.

[0077] The speed reducer (4) includes an eccentric pin (8) mounted on a fast rotating shaft (5), directly connected to the motor shaft (1). Rotation of the eccentric pin generates an orbital motion, transmitted to a first externally toothed wheel (9), which meshes with a fixed internally toothed wheel (10). The fixed wheel (10), mounted on the anti-backdrive joint (7), transmits motion to a second externally toothed wheel (11), rigidly connected to the first wheel (9), and subsequently to an internally toothed output wheel (12), mounted coaxially on the slow rotating shaft (6). This system enables a significant speed reduction and torque amplification, required for precise and reliable control of movable members.

[0078] The anti-backdrive joint (7) plays a key role by ensuring locking of the fixed wheel (10) during operation of the motor (1), while allowing unlocking when the motor (1) is not operative. This enables autonomous operation of the system, which can be supported by the auxiliary energy management means (3) or by the manipulator (2), not illustrated, both configured to drive motion of the speed reducer (4) when the motor (1) is inactive.

[0079] In a further embodiment, as an alternative to the anti-backdrive joint, the function of controlling motion transmission in the absence of motor power supply (1) may be performed by an electromagnetic brake (B). Such brake is configured to keep the transmission locked when powered together with the motor (1) and to automatically deactivate when the electrical supply is interrupted. In this manner, upon loss of motor power, the electromagnetic brake is released, allowing movement of the movable member under the action of the auxiliary energy management means (3). Although the electromagnetic brake locks the transmission in both directions of rotation when active, it achieves the same technical function as the anti-backdrive joint, enabling functional separation between the motor-driven operating phase and the auxiliary-energy-assisted movement phase in the absence of power supply.

[0080] The auxiliary energy management means (3), such as a spiral spring connected to the slow rotating shaft (6), store elastic energy during operation of the motor (1) and release it to ensure rapid and precise movement. The manipulator (2), connected at strategic points of the system (for example to the fixed wheel (10), to the slow shaft (6), or downstream of the speed reducer (4)), provides an additional manual actuation mode.

[0081] This advanced configuration ensures a moment of inertia reduced to the active components only, improving efficiency and minimizing losses. The system is capable of managing rapid and precise movements, such as a quarter turn in fractions of a second, making the actuator particularly suitable for high-precision industrial applications.

[0082] The speed reducer (4) may be combined with an additional reducer (20), not illustrated, to increase output torque or to offset the output axis, improving versatility and adaptability of the system to operational requirements.

[0083] Manufactured by additive manufacturing, the actuator is customizable, compact, and resistant to wear, ensuring long operational life even in harsh or hazardous environments. These features make it particularly suitable for HVAC systems in explosive or critical environments, where reliability, robustness, and precision are essential.

[0084] In mechanical systems for actuating movable members, speed reducers characterized by irreversible behavior are widely used, that is, reducers in which a torque applied to the slow shaft is not capable of driving the fast shaft in the reverse direction. This condition occurs when reverse transmission of motion is prevented or strongly hindered by the set of structural characteristics of the reducer.

[0085] Irreversibility may derive from multiple factors, including high transmission ratios, meshing geometries with dedicated kinematics (for example worm gear reducers or hypocycloidal reducers with high eccentricity), significant internal friction, or contact conditions in which the pressure angle is greater than the friction angle. Under such circumstances, the return force applied to the slow shaft is insufficient to overcome the internal resistances of the mechanism, effectively preventing backdriving toward the fast shaft.

[0086] In the actuator of the present invention, use of a hypocycloidal reducer may lead to conditions of irreversibility, especially in the presence of high reduction ratios and reduced contact tolerances. When the motor (1) is not operative, the reducer tends to behave as a single body rigidly connected to the internal members, making manual adjustment of the actuator by means of the manipulator (2) difficult.

[0087] To overcome this functional limitation, the actuator integrates an anti-backdrive joint (7) configured to automatically decouple the speed reducer (4) from the slow shaft (6) when the motor is not powered, drastically reducing the inertial mass perceived by the operator. Such decoupling enables safe manual adjustment even in the presence of irreversible or semi-irreversible reducers, avoiding the efforts and resistances normally associated with conventional systems.

[0088] The integration between the hypocycloidal reducer and the anti-backdrive joint therefore produces a particularly advantageous combined effect:it ensures stable transmission of motion during motor-driven operation;it ensures controlled backdriving or complete release during manual adjustment;it provides an optimal balance between efficiency, precision, and operational safety.

[0089] By virtue of these characteristics, the actuator is suitable for a wide range of industrial applications requiring irreversible or high-ratio reducers, while maintaining the possibility of rapid and safe manual adjustment when the motor is not operative. The combination of the speed reducer (4) with the anti-backdrive joint (7) thus allows extension of the actuator’s use to demanding contexts, such as HVAC installations, dampers, and valves in hazardous or critical environments, where reliability, precision, and operational continuity are required.

[0090] The invention is susceptible of industrial application in that it can be manufactured and used in the production of mechanical and electromechanical actuators intended for controlling movable members, in particular in the HVAC sector and in industrial applications characterized by high safety and reliability requirements.

[0091] In particular, the architecture of the reducer according to the invention is suitable for use in environments subject to stringent regulations, such as potentially explosive environments, in which containment of moving masses, reduction of kinetic energy associated with rotating members, and control of mechanical stresses during operation and return under safety conditions are required.

[0092] The kinematic and structural configuration of the reducer enables achievement of favorable dynamic behavior, characterized by reduced inertias and reliable operation even under critical operating conditions, making the invention particularly suitable for actuation systems with intrinsic safety functions.

[0093] The invention may be manufactured using different industrial production technologies. In particular, additive manufacturing represents a particularly suitable manufacturing method for enhancing the characteristics of the reducer architecture, allowing functional integration of multiple elements, optimization of internal geometries, reduction of masses, and simplification of the assembly. Such advantages are difficult to achieve with traditional manufacturing technologies, while the latter nevertheless remain compatible with implementation of the invention.

[0094] Additive manufacturing does not constitute the subject matter of the patent protection, but rather a preferred technological solution for industrialization of the reducer, as it allows full exploitation of the structural and functional benefits derived from the inventive architecture described.

[0095] The invention is therefore industrially applicable to mass production or small-batch production of reducers and actuators intended for HVAC systems, automated industrial systems, and applications in environments characterized by high requirements of safety, reliability, and risk containment.

[0096] With regard to applicability in ATEX environments, the system complies with the technical principles set forth in Directive 2014 / 34 / EU and in standards EN ISO 80079-36 and 80079-37. Spring-return actuators are widely used also in ATEX execution, and the kinetic energy associated with the stepping of the ring gear in the free direction is very low due to the reduction ratio and the limited mass of the movable member; this effectively prevents the occurrence of mechanical ignition sources. Such characteristics fall within protection type “c” (constructional safety) and are compatible with use in potentially explosive atmospheres, a condition also documented by analogous commercial products.

[0097] Finally, the choice of the number of teeth of the ring gear of the anti-backdrive joint affects the frequency and energy of the steps in the free direction. A ring gear with twelve teeth represents a particularly favorable balance, as it provides structurally robust teeth, sufficiently small steps to reduce impacts, and a not excessive frequency that limits overall friction. Values, by way of example, between ten and sixteen teeth are equally suitable, while much higher numbers may excessively reduce tooth cross-section and increase wear. In any case, the system maintains its functionality regardless of the exact number of teeth, which may be adapted according to mechanical dimensioning and application requirements, provided that the operating principle of the lever-type joint is satisfied.

Claims

An actuator for controlling movement and for the precise regulation of movable members at variable speed, comprising a motor (1) connected to a speed reducer (4), a manual control interface, where provided, configured to allow manual intervention on the actuator directly or indirectly on the movable member, and an auxiliary energy management system (3) connected to the speed reducer (4), the actuator being configured to allow operation of the auxiliary energy management system (3) when the motor (1) is operative and operation of the manual control interface, where provided, and of the auxiliary energy management system (3) when the motor (1) is not operative, characterized in that it comprises an anti-backdrive joint (7) configured to engage when the motor (1) is operative and to automatically disengage when the motor (1) is not operative, the anti-backdrive joint (7) comprising at least one of:– a movable element (L) configured to move between an engagement position and a disengagement position with respect to a rotating element (D), the movable element (L) being biased by an elastic spring (S), selective engagement occurring by means of teeth, complementary contact elements, or surfaces configured to generate friction;– an electromagnetic brake (B) configured to selectively lock the transmission when the motor (1) is powered and to automatically deactivate in the absence of power supply;wherein automatic disengagement of the anti-backdrive joint (7) allows transmission of motion with a moment of inertia reduced to the active components of the speed reducer (4) only.The actuator according to claim 1, characterized in that the movable element (L) is a sliding member (14) configured to move in a plane substantially parallel to the axis of rotation of the motor (1), guided along a guide (13) and biased by the elastic spring (S) toward the rotating element (D), the rotating element (D) being constituted by a disc (15), engagement occurring by means of connecting elements and / or teeth (17), (18), or by means of surfaces configured to generate friction.The actuator according to claim 1, characterized in that the movable element (L) is constituted by a movable lever (14′) configured to move in a plane substantially transverse to the axis of rotation of the motor (1), between an engagement position and a disengagement position with respect to the rotating element (D), the rotating element (D) being constituted by a disc (15′), engagement occurring by means of connecting elements and / or teeth (17′), (18′), or by means of surfaces configured to generate friction.The actuator according to any one of claims 1–3, characterized in that the movable element (L) is configured to perform a helical roto-translational movement with respect to the rotating element (D), comprising a displacement component substantially parallel to and a displacement component substantially transverse to the axis of rotation of the motor (1), in order to selectively engage or disengage teeth or surfaces configured to generate friction.The actuator according to any one of the preceding claims, characterized in that the movable element (L) is provided with an additional manipulator (19) configured to produce a forced disengagement from the rotating element (D).The actuator according to any one of the preceding claims, characterized in that engagement between the movable element (L) and the rotating element (D) is achieved by means of surfaces configured to generate friction.The actuator according to any one of the preceding claims, characterized in that the speed reducer (4) comprises an eccentric pin (8) mounted on a fast rotating shaft (5), a first externally toothed wheel (9) mounted on the eccentric pin (8), an internally toothed wheel (10) meshing with the first wheel (9), a second externally toothed wheel (11) rigidly connected to the first wheel (9), and an output wheel (12) mounted coaxially on a slow rotating shaft (6), the internally toothed wheel (10) being rigidly connected to the rotating element (D).The actuator according to any one of the preceding claims, characterized in that the speed reducer (4) is of the irreversible type and comprises a hypocycloidal gear train which, when the motor (1) is not operative, behaves as a single body directly connected to the anti-backdrive joint (7).The actuator according to any one of the preceding claims, characterized in that the speed reducer (4) is an irreversible or semi-irreversible reducer comprising, by way of example, a worm gear reducer, a hypocycloidal reducer, a high-ratio epicyclic reducer, or a reducer having a geometry configured to prevent reverse transmission of motion.The actuator according to any one of the preceding claims, characterized in that the auxiliary energy management system (3) comprises at least one spiral spring connected to the slow rotating shaft (6), configured to store elastic energy during operation of the motor (1) and to release it when the motor (1) is not operative.The actuator according to any one of the preceding claims, characterized in that the motor (1) is of the electric type.The actuator according to any one of the preceding claims, characterized in that the speed reducer (4) constitutes a first stage of a multi-stage speed reducer.

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