WO2021197995A1

WO2021197995A1 - Electric actuator

Info

Publication number: WO2021197995A1
Application number: PCT/EP2021/057687
Authority: WO
Inventors: Edouard DE WATTEVILLE; Jean-René PERNOT; Guillaume CALLERANT
Original assignee: Sonceboz Mechatronics Boncourt Sa
Priority date: 2020-04-03
Filing date: 2021-03-25
Publication date: 2021-10-07
Also published as: FR3109034A1; FR3109034B1; EP4128492A1

Abstract

The invention relates to an electric actuator comprising: - a stator assembly that is formed by a pack of metal sheets surrounded by windings and at least one connector, which is over-moulded with a material having a thermal conductivity greater than that of air, - a magnetised rotor assembly, - an electronic circuit which comprises the electronic power components for supplying the stator windings, - an at least partially metal casing through which an output of a drive shaft extends, the over-moulded stator assembly (30) coming into thermal contact with the casing, the electronic circuit being in contact with the over-moulded stator assembly, the over-moulded stator assembly having a housing for a first guiding bearing of the axle of the rotor, and having: - the casing forms a metal end plate, through which the output axle configured to receive the assembly formed by the electronic circuit attached to the over-moulded stator assembly extends, - the electronic power components of the electronic circuit being in direct or indirect thermal contact with the internal wall of the casing, - the electronic circuit being in thermal contact with the over-moulded stator assembly.

Description

Electric actuator

Field of the invention

The present invention relates to the field of mechatronics and more particularly to electric actuators, for example for automotive applications such as the rapid phase shift of the camshaft of internal combustion engines, over the entire operating range (including when the engine is off), to reduce emissions and fuel consumption while ensuring optimum vehicle performance; as well as the actuation of the water pump of the cooling circuit, to improve the fuel consumption of hybrid vehicles and increase the range of electric vehicles.

Such actuators can be placed near the component to be controlled and connected to the automobile battery which then constitutes the power source, a vehicle computer sending the requested steering and torque level information to an electronic circuit. power integrated in the actuator. Due to their level of integration on the heat engine, these actuators must be extremely compact, which requires optimizing both the engine part and the electronic circuit. More generally, it is possible to envisage, for such actuators, other applications where the mechatronics assembly must deliver a high torque with a high adjustment dynamic and a high precision.

One of the main issues with these actuators concerns the dissipation of the heat generated by the power components of the integrated control electronics, with regard to the usually high ambient temperature, the power densities involved as well as the extreme compactness. required which minimizes the exchange surfaces.

As a corollary, the reliability of the control electronics as well as its contribution to the reliability of the system controlled by the actuator constitute an additional issue. State of the art

Several examples of such actuators are known in the state of the art.

By way of example, patent application DE102018117987 describes another electric motor solution equipped with a basic motor module and a plug-in module which is electrically and mechanically connected to the basic motor module and is designed as an electronic module. The electronic module consists of the power electronics, the drive electronics and the control electronics, the electronics module and the base motor module each dissipating heat via a heat path (A, B), the heat paths (A, B) being separated from each other. This solution does not make it possible to optimize thermal control.

Patent application WO2015144156A1 is also known, which proposes an evacuation solution via the metal cover closing the rear of a mechatronic assembly. The actuator comprises an electric motor equipped with a stator, mounted and fixed in a first housing element, and an electronic module which is mounted and fixed in a second housing element which is itself connected to a stator winding by means of cables. passing through at least one housing element. The housing elements form a single unit heat conducting unit and the housing is designed as a heat sink for the stator and the electronic module.

Disadvantages of the prior art

The solutions of the prior art therefore do not allow the heat produced by the power components of the electronic circuit to be completely efficiently removed.

Indeed, the evacuation by the rear cover is not optimal because this part of the actuator is made of plastic material, having poor thermal conductivity, and its outer surface is exposed to the thermal environment which can be relatively high, in particular for applications concerning heat engines.

Furthermore, the assembly and manufacture of these solutions are relatively laborious. Finally, the mechanical and electrical robustness of the known solutions can be improved. Solution provided by the invention

In order to respond to the drawbacks of the prior art, the present invention relates in its most general sense to an actuator comprising: a stator assembly (30) formed by a pack of sheets (32) surrounded by coils (31) and at least one connector (35, 39), a magnetized rotor assembly (13), an electronic circuit (20) comprising the electronic power components (28, 29) for supplying said stator coils (31), a flange (1) being at least in metallic part, said stator assembly (30) coming into thermal contact with said flange (1), said stator assembly (30) having a housing of a first bearing (11, 12) for guiding a motor shaft (10), characterized in that the metal part of said flange (1) forms a front surface (2) traversed by said motor shaft (10) intended to be connected to the device to be controlled, the electronic power components (28, 29) of said circuit electronics (20) being in direct thermal contact o u indirect with the inner wall of said flange (1) in order to create thermal bridges between the electronic circuit and the metal part of the flange to evacuate heat through the front surface (2) on the output side of said motor shaft (10).

Advantageously, the stator assembly is in direct or indirect thermal contact with the front surface (2) to create thermal bridges in order to evacuate heat through the front surface on the output side of the motor shaft, said electronic circuit is in contact with said stator assembly to form a block, and that the front surface is configured to receive the block formed by said electronic circuit attached to said stator assembly, the stator assembly is overmolded in a material having a thermal conductivity greater than that of the air, or inserted into a metal casing, said flange comprises a second guide bearing for the motor shaft, said stator assembly ensures the rear closure of said flange, said magnetized rotor assembly comprises a magnet for encoding the position of the rotor capable of interacting magnetically with a magnetic sensor placed on said electronic circuit, the outer surface of said stator assembly exhibits timing elements of said electronic circuit, said coils are electrically connected to the electronic circuit by pressure connectors of the “pressfit” type or alternatively, via metal “leadframes” tracks, the electronic circuit has filtering components of reduced bulk and is positioned in front of the overmolded stator assembly, within the transverse annular flare of the flange, the electronic circuit is positioned at the rear of the overmolded stator assembly, and is in thermal contact with the flange by means of a metal part having axial protuberances housed in the recesses of the sheet metal bundle.

According to a variant, the actuator comprises intelligent electronics and at least two independently controllable three-phase windings, two microcontrollers or a dual microcontroller, the intelligent electronics being able to detect an internal fault by diagnosing the electronic and electrical elements, being able to control an exempt three-phase winding. of faults in order to offer at least half of the nominal torque at nominal current and able to inform the system via the communication channel.

The architecture of the actuator according to the invention has the effect that the electronics and the wound stator are placed in thermal contact with the flange, as close as possible to the customer interface, which promotes and simplifies the thermal exchanges with this last. At the same time, such an architecture makes it possible to simplify the overall structure of the actuator, for example by eliminating the rear cover and the associated ultrasonic welding operation or by any other equivalent solution such as gluing, laser welding, etc.

Detailed description of a non-limiting example of the invention The present invention will be better understood on reading the detailed description of a non-limiting example of application of the invention which follows, with reference to the appended drawings where

- Figure 1 shows a sectional view of a first variant embodiment more specifically intended for an application of an electronic camshaft phase shifter,

- Figure 2 shows a perspective view of an exploded partial section of the overmolded stator assembly according to the first variant embodiment,

- Figure 3 shows two perspective views from above of the stator assembly of the first variant embodiment before and after the engagement of the electronic circuit,

- Figure 4 shows a perspective view in partial section of the first embodiment showing the electronic circuit,

- Figure 5 shows a sectional view of a second variant embodiment,

- Figure 6 shows two perspective views from above of the stator assembly of the second variant embodiment before and after the engagement of the electronic circuit,

- Figure 7 shows a perspective view in partial section of the second embodiment showing the electronic circuit,

- Figure 8 shows a sectional view of a third variant embodiment,

- Figure 9 shows a perspective view from above in partial section and a perspective view from below of the stator assembly of the third variant embodiment and showing the electronic circuit,

- Figure 10 shows a side sectional view of the fourth embodiment,

- Figure 11 shows a perspective view from above of the fourth embodiment, the flange being detached and seen in three-quarter section,

- Figure 12 shows a perspective view from above of the fourth variant embodiment without a flange and either without or with the electronic circuit,

FIG. 13a and FIG. 13b illustrate a comparison of the currents of the power bus and their harmonic decomposition in the case of a conventional architecture and of an architecture optimized to limit the oscillations thereof

- Figure 14 shows a block diagram of the control assembly of a mechatronic assembly according to the invention. General principle

The invention will be described below with reference to several non-limiting exemplary embodiments, each making it possible to respond to the same technical problem which is to improve the evacuation of the calories produced by the power components of the electronic control circuit of the coils. of the engine by creating thermal bridges between the electronic circuit, the metal part of the flange and the mass of the equipment to which the actuator is connected in order to exercise a function of angular displacement of an organ.

In order to limit the redundancies of the description, certain technical aspects common to the different embodiments and described for one of the variants will not be repeated for the other variants, without this being able to be interpreted as being limited to said variant.

Said variants relate to an application of the invention of the electric camshaft phase shifter or water pump type, these two applications differ only in the shape of the flange, which allows the actuator to be assembled for the application. The invention relates to the development of a novel optimized architecture, in particular from a thermal point of view. Indeed, such an actuator operates in a difficult environment corresponding to the engine compartment of the vehicle. In addition to vibration stresses, the actuator is subjected to high temperatures (> 120 ° C). However, the latter is said to be intelligent because it comprises complex on-board electronics, some of whose components have critical temperatures that must not be exceeded.

Therefore, it is necessary to set up an architecture making it possible to best meet this constraint by optimally dissipating the heat emitted by the electronic circuit. As indicated previously, the problem encountered is the heat emitted by the on-board electronics coupled with the high ambient temperature of the engine compartment, which can thus lead to the destruction of this same electronics if critical temperatures are reached and if a nominal operating speed is reached. preserved. In particular, the components which are particularly sensitive to these temperatures are the MOS type power switches participating in the control of the three phases of the motor. To increase the heat dissipation capacity, the invention aims to use the receiving interface of the actuator, that is to say the cylinder head of the internal combustion engine or the pump body, in order to dissipate the heat emitted by the actuator. the electronic circuit and thus drain the heat emitted by the electronic circuit to said cylinder head of the internal combustion engine or said pump body. Indeed, these elements are at a stable and regulated temperature. To achieve this heat drainage, it is necessary to create a thermal bridge between the electronic circuit and the metal flange which is in direct contact with an element of the component to be driven, for example the cylinder head of the internal combustion engine or the pump body. This flange is for example formed by an aluminum foundry part, a stamped part, or a sintered metal part and it has a large contact surface with the cylinder head or the pump body, in order to promote heat exchange.

Detailed description of embodiments more specifically dedicated to an electronic camshaft phase shifter

FIGS. 1 to 3 represent a first exemplary embodiment, more specifically intended for an application of an electronic camshaft phase shifter. The flange (1) forms a stamped solid block with a front face (2) traversed by the motor shaft (10) driving the member coupled to the actuator. The flange (1) defines a housing in which are positioned: the electronic circuit (20) an overmolded stator assembly (30).

The flange (1) has an annular transverse flare (3) complementary to an annular flare (33) of the overmolded stator assembly (30). The flange (1) and the overmolded stator assembly (30) are assembled by means of said annular flares (3, 33) and then held by screws inserted in hollow metal parts (4), allowing the actuator to be fixed on a member. complementary, for example an engine cylinder head. The transverse flare shape is not limited to annular. All the other shapes of the flares, which make it possible to assemble the flange and the stator assembly, can be used.

This embodiment also comprises a magnetic rotor assembly (13) comprising a rotor with magnets, a motor shaft (10) and optionally a positioning magnet (17). Said motor shaft (10) is linked to a rotor with permanent magnets made for example of sintered magnets. It is constituted in a known manner by a pack of sheets (16) in which pieces of magnets (15) are embedded. Of course, others solutions known in the state of the art, for example a rotor with surface magnets, can be implemented.

The motor shaft (10) is guided by a front bearing (11) crimped into the front face (2) of the flange (1) and by a rear bearing (12) integrated in the overmoulded stator assembly (30) . The motor shaft (10) being able to present at its front part a positioning magnet (17) interacting magnetically with Hall probes (26) mounted on the electronic circuit (20) to deliver information on the angular position of the rotor.

By convention, the term “front” will denote the side of the output of the motor shaft (10), this qualifier applying to all the components.

The overmolded stator assembly (30) incorporates a yoke formed by a bundle of sheets (32) surrounded by coils (31). The electrical connection between the coils and the electronic circuit (20) is made in a known manner by needle-eye connectors (27) (commonly described as of the “pressfit” type). The overmolding has, on its front end face, protuberances forming positioning pins (34) of the electronic circuit (20).

The overmolded stator assembly (30) also incorporates one or more overmolded connectors (35, 39). One of the connectors (35) receives the DC power supply current. The other connector (39) is intended for the input and output of low power control signals: input of the setpoint, preferably image of the torque and direction of rotation requested at the input, output of signals informing about the direction and the speed of rotation.

The connectors (35, 39) comprise metal tracks terminated by connectors (40, 41) of the pressfit type intended to ensure the arrival of the power supply and the control signals to the electronic card (20). The overmolded stator assembly (30) thus forms a monolithic block, of cylindrical shape extended by the connectors (35, 39), defining a central cavity for the insertion of the rotor. The disc-shaped electronic circuit (20) can be pushed against the front surface to allow engagement of the connectors (27) and locating pins (34) in the corresponding holes of the printed electronic circuit (20).

Optionally, a thermal paste or glue is deposited between the rear surface of the electronic circuit (20) and the front face of the stator assembly (30) overmolded to improve thermal conductivity between the electronic circuit (20) and the mass of the overmolded stator assembly (30).

This assembly is then slipped into the flange (1) before sealing by the peripheral links. A seal (38) positioned between the annular extensions of the flange (1) and of the overmolded stator assembly (30) seals the actuator.

This seal (38) may be of the “shape seal” type, that is to say a shaped seal, in order to ensure the seal between the overmolded stator assembly (30) and the flange (1), or an O-ring.

In the case of a shaped seal (38), the seal is effected on the flat face of the flange (1) and the groove housing the seal is circular. A shaped seal is suitable for this type of plane contact, and in addition, it has gadroons allowing it to be held in the groove provided for this purpose.

The electronic circuit (20) is thus positioned within the inner surface of the front face of the flange (1). A thermal paste or glue ensures thermal conduction between the power components, either the power electronic components (29) of the power bus filter, or the power electronic components (28) being MOS type power switches. , and the inner surface of the flange (1). A nominal distance is maintained between the bottom of the flange (1) and the surface of the electronic components of said electronic circuit (20), the entire electronic circuit (20) can then be in thermal contact with the flange (1) by the intermediate of thermal paste, a thermal adhesive, or possibly a foam with high thermal conductivity.

If implemented, the positioning magnet (17) magnetically interacts with Hall probes (26) mounted on the electronic circuit to provide information on the angular position of the rotor.

FIGS. 4 to 7 represent a second exemplary embodiment for an application of an electronic camshaft phase shifter. This differs from the previous one in that the coils (31) are no longer directly connected to the electronic circuit (20) by the “pressfit” connectors (27), but via metal tracks (21) or “leadframe”. In English in order to eliminate the routing of the coils on said electronic circuit (20) which makes it possible to increase the supply current of the coils. A metallic track (21) per electrical phase is used and makes it possible to ensure the distribution of the current to the coils associated with this phase. In order to keep a simple assembly process, said metal tracks (21) are assembled in a support part (22) allowing precise positioning and maintenance of the metal tracks (21) on the coiled sheet pack (32), before the overmolding operation, then integrating the overmolded stator assembly (30). The invention includes the use of insulation displacement connectors (not shown) to ensure the electrical connection of the metal tracks (21) to the coils (31) during the operation of positioning the support part (22) on the pack of sheets ( 32) wound. The connectors (24) terminate the metal tracks (21) at their second end and make it possible to ensure electrical contact with the electronic circuit (20). In the embodiment presented, they are of the “pressfit” type and the number of connectors per track is adjusted as a function of the maximum supply current of the electrical phases. Of course, this example is not limiting and any type of connection of the tracks to the electronic circuit that a person skilled in the art would consider is included in the invention.

This embodiment also differs from the first in that said metal tracks extend axially above the coils (31), reducing the space allocated to the electronic circuit (20) on the outer periphery. Thus, in order to be able to house all the electronic components, said electronic circuit extends over its inner periphery and therefore requires placing the positioning magnet (17) axially facing the electronic circuit (20).

FIGS. 8 and 9 represent a third exemplary embodiment for an application of an electronic camshaft phase shifter. This embodiment differs from the previous two in that the electronic circuit (20) is not located inside the transverse annular flare (3), but attached to the rear part of the stator assembly (30). overmolded. This embodiment is preferred in the case where the electronic power components (29) associated with the electronic filter of the power supply are particularly bulky and cannot be advantageously installed inside the metal flange (1).

The installation of the electronic circuit (20) on the rear part of the overmolded stator assembly makes it possible to use the space located around the connectors (35, 39) for disposing said electronic power components (29) without increasing the overall dimensions of the electric actuator.

A leadframe type connection between the coils (31) and the electronic circuit (20) is used so as to limit the dimensions of said electronic circuit.

In order to efficiently drain the calories from the electronic circuit (20) to the component to be controlled, thermal bridges connect said electronic circuit (20) to the flange (1), these thermal bridges are produced using a metal part (37) showing axial growths (36). Said axial protuberances (36) are advantageously housed in clearances (320) of the pack of sheets (32) to provide a large contact surface with the pack of sheets (32) in order to ensure good evacuation of the heat produced by the losses. in the coils (31) and the sheet metal pack (32), but also so as not to impact on the radial size of the electric actuator. A nominal clearance between the electronic circuit (20) and the metal part (37) makes it possible to ensure good thermal contact by adding a paste, a foam, or a thermal adhesive filling said clearance. thermal contact between the metal part (37) and the flange (1) is provided on both sides by the axial protuberances (36) and the transverse annular flare (3). Finally, a nominal axial clearance between the overmolded stator assembly (30) and the flange (1) is ensured and can be filled with a thermal paste or a thermal foam in order to promote the evacuation of the calories. The annular shape of transverse flare has no limiting effect, but only illustrative. All other shapes of flares are possible.

Detailed description of an exemplary embodiment specifically dedicated to a water pump

FIGS. 10 to 12 represent a fourth exemplary embodiment for a water pump application. This embodiment differs from the first embodiment in that the overmolded stator with its electric coils is inserted into a metal casing (5) in order to constitute the stator assembly. It also differs in that the transverse flaring (33) is not produced in the overmolding of the stator, but in the metal casing (5) and in that it does not have a magnet (17) to determine the angular position of the motor shaft (10), this not being particularly desired in the context of a pump. Also, the flange (1) has in its front part a chamber (18), thus forming part of the chamber of the pump body in which the fluid is pumped, this chamber (18) being connected to a duct (25) conveying the pumped fluid. In the embodiment shown, the rear guide (12) of the rotor assembly (13) is a sliding bearing fixed in a flare of the metal casing (5). It can be noted that in the embodiment presented, the front guide (11) is not present, this second guide being produced by the pump to which the actuator is assembled, nevertheless the motor shaft (10) of the rotor is partially guided by an axial annular protuberance (8) of the overmolding of the stator. Said axial annular protuberance (8) opens onto the chamber (18) of the flange (1), and has a diameter slightly greater than the motor shaft (10) so as to let the fluid to be pumped into an internal cavity of the 'stator assembly (30), the fluid then being able to be as close as possible to the packets of sheets (16, 32) of the rotor and of the stator. The actuator is assembled by inserting the rotor assembly into the metal casing (5) at the level of the first bearing (12), then the overmolded stator is driven into the metal casing (5) by guiding partially the motor shaft (10) of the rotor. The electronic card is then assembled on the overmolding of the stator and the flange (1) inserted and held to the stator assembly (30) by fixing screws. Finally, this embodiment differs in that it has a single overmolded connector (35) making it possible both to transmit the power supply and the control signals. This embodiment is not, however, limiting of the invention in the context of a pump because the possibility of optimizing the cooling by letting the pumped fluid flow within the magnetic actuator brings additional constraints, such as the management of the tightness which must be done through the addition of multiple gaskets (58, 68) in order to avoid any contact of the fluid with the electronic card, or even by overmolding (6) of the inner surface of the stator sheets and a shrink wrap (14) of the rotor so as to prevent corrosion of the sheets, the latter elements increasing the magnetic air gap reducing the performance of the actuator. In addition, this construction does not overcome the evacuation of heat by placing the stator assembly (30) and the electronic card (20) in direct thermal contact with the flange (1), which remains the dissipation means. privileged, this flange (1) allowing better heat exchanges with the circulating fluid. In fact, in the configuration presented, the fluid entering the internal cavity of the stator is not constrained to a flow and the drainage of the calories is then done more by conduction.

Thus we can quite imagine other means of producing pump actuators, closer to the first embodiment for which the fluid pumped does not enter the actuator, or even for which the flange (1) does not form part of the pump body, but is in direct contact with the latter.

Optimization of electronic architecture

For embodiments 1, 2 and 4, a significant gain in axial size results from the integration of the electronics directly into the flange (1). This integration is only made possible by reducing the dimensions of the components of the power supply filter, namely capacitors and inductors. To obtain this dimensional reduction, two strategies can be implemented. The first results directly from the technological evolution of power electronics, which makes it possible to obtain much smaller dimensions at iso-power, typically a volume reduction by a factor of 2 or 3. An alternative that we are considering is to adapt the motor control, preferably in block switching (BCC - Block Commutation Control) but potentially in vector control (FOC - Field Oriented Control), to limit the current oscillations that the power supply filter will have to absorb. This alternative results from a finer discretization of the electrical space with the control of more than 3 electrical phases. Figure 13a illustrates a comparison of the current oscillations of the power supply at the head of the inverter, said inverter feeding the BLDC motor through block switching (BCC), between a conventional 3-phase configuration ( 61), a non-optimized configuration involving more than 3 phases (62) and an optimized configuration involving more than 3 phases (63). Figure 13b illustrates a comparison of the harmonic decomposition of the power supply current at the level of the inverter head, the latter supplying the BLDC motor thanks to a so-called block switching (BCC), between a conventional configuration at 3 phases (70) and an optimized configuration involving more than 3 phases (80) and showing the reduction of 45% of the harmonics associated with the fundamental chopping frequency of the inverter (71) as well as the reduction of the spectral content of more low frequency (72). The characteristic of these currents allows us to use filtering components of lower capacity in alternating current (known as current ripple) and therefore of lower volume, and in the ideal even allows us to eliminate the mode filtering inductor. differential or common mode mounted in series on the supply line. In the case where the reduction in size of these components is not allowed, either for technological reasons or for economic reasons, an alternative presented by the third embodiment makes it possible to efficiently transfer the calories from the electronic circuit to the metal cover by the use of thermal bridges.

This alternative embodiment exploits the space located on the opposite side of the metal flange, the radial size of which is less restricted, it is then possible to advantageously arrange the filtering components around the stator overmolding in order to limit the axial size while controlling the pressure. radial bulk.

Description of electronic control and fault mode strategies

As we have already mentioned, in addition to the optimization of the actuator and in particular of the control electronics with a view to better heat dissipation, another challenge of the invention relates to improving the reliability of this electronics and by extension of the system controlled by the actuator. To this end, FIG. 14 represents a block diagram of the control assembly of a mechatronic assembly according to the invention.

The system described by the invention proposes to use an intelligent electronic architecture in order to mitigate the degradation of one or more electronic or electrical elements constituting said system.

In the event of an internal failure, the control electronics can detect it by diagnosing the electronic elements, namely said at least one microcontroller (52), said power switches (28), said module (51) and the electrical elements. , or said motor architecture (100), making up the system, then check at least one of the fault-free assemblies including one of the two three-phase windings in order to offer at least half of the nominal torque at nominal current in said three-phase winding and finally inform the ECU by the communication channel (112) using a defined communication protocol. The fault-free assembly including one of the two three-phase windings can transiently offer an emergency mode with more than half of the nominal torque (Tsecours> 50% Tnominai) by increasing the current in the power switches (28) and therefore the three-phase winding.

Claims

1 - Electric actuator for controlling a member comprising: a stator assembly (30) formed by a pack of sheets (32) surrounded by coils (31) and at least one connector (35, 39), a magnetic rotor assembly (13), an electronic circuit (20) comprising the electronic power components (28, 29) for powering said stator coils (31), a flange (1) being at least partly metallic, said stator assembly (30) coming into thermal contact with said flange (1), said stator assembly (30) having a housing of a first bearing (11, 12) for guiding a motor shaft (10), characterized in that the metal part of said flange (1) forms a surface front end (2) through which said motor shaft (10) intended to be connected to the device to be controlled, the electronic power components (28, 29) of said electronic circuit (20) being in direct or indirect thermal contact with the inner wall of said flange (1) in order to create thermal bridges es between the electronic circuit and the metal part of the flange to remove heat through the front surface (2) on the output side of said motor shaft (10).

2 - Actuator according to claim 1, characterized in that the stator assembly (30) is in direct or indirect thermal contact with the front surface (2) to create thermal bridges in order to remove heat through the front surface on the side of the output of the motor shaft (10).

3 - Actuator according to claim 1, characterized in that said electronic circuit (20) is in contact with said stator assembly (30) to form a block, and that the front surface (2) is configured to receive the block formed by said electronic circuit (20) attached to said stator assembly (30). 4 - Actuator according to claim 1 characterized in that the stator assembly (30) is molded in a material having a thermal conductivity greater than that of air, or inserted into a metal casing (5).

5 - Actuator according to claim 1 characterized in that said flange (1) comprises a second bearing (11, 12) for guiding the motor shaft (10).

6 - Actuator according to claim 1 characterized in that said stator assembly (30) ensures the rear closure of said flange (1).

7 - Actuator according to claim 1 characterized in that said magnetized rotor assembly (13) comprises a magnet (17) for encoding the position of the rotor capable of interacting magnetically with a magnetic sensor (26) placed on said electronic circuit (20) .

8 - Actuator according to claim 1 characterized in that the outer surface of said stator assembly (30) has wedging elements (34) of said electronic circuit (20).

9 - Actuator according to claim 1 characterized in that said coils (31) are electrically connected to the electronic circuit (20) by connectors (27) of the "pressfit" type.

10 - Actuator according to claim 1 characterized in that the coils (31) are electrically connected to the electronic circuit (20) via metal tracks (21) "leadframes".

11 - Actuator according to claim 1 characterized in that the electronic circuit (20) has filtering components of reduced size and is positioned in front of the stator assembly (30), within a transverse flare (3 ) of the flange (1).

12 - Actuator according to claim 1 characterized in that the electronic circuit (20) is positioned at the rear of the stator assembly (30) and is in thermal contact with the flange (1) via a metal part (37) having axial protuberances (36) housed in recesses (320) of the sheet metal package (32). 13 - Actuator according to one of the preceding claims characterized in that it comprises intelligent electronics and at least two independently controllable three-phase windings, two microcontrollers or a dual microcontroller (52), the intelligent electronics being able to detect an internal fault by diagnosing the electronic and electrical elements, which can control a three-phase winding free from faults in order to provide at least half of the nominal torque at nominal current and which can inform the system through the communication channel (112).