Stator with improved robustness for electrical machines such as motors or generators, and electrical machines incorporating such a stator

Abstract

The invention relates to a stator (500) for an electric machine, such as an electric motor or electric generator, said stator (500) comprising: at least one face (106), called the air gap face, intended to be aligned with a rotor (104), or a translator, of said electric machine, and a winding (108) on said air gap face (106); said stator (500) being characterized in that it further comprises a protective layer (202) made of parylene covering said air gap face (106) and said electrical winding (108). It also relates to an electric machine, such as an electric motor or electric generator, comprising such a stator. See Figure 5a

Description

Title of the invention: Stator with improved robustness for an electric machine of the motor or generator type, and electric machine comprising such a stator

[0001] The present invention relates to a stator with improved robustness for an electric machine of the electric motor or electric generator type, and in particular for applications in which said electric machine is immersed in a dangerous fluid, and in particular a corrosive fluid or an inflammable product or even a fluid which participates / contributes / amplifies the ignition, for example liquid oxygen (LOx). It also relates to an electric machine, of the electric motor or electric generator type, comprising such a stator.

[0002] The field of the invention is generally the field of electrical machines, such as electric motors or electric generators, and in particular electrical machines immersed in a dangerous fluid, for example liquid oxygen or hydrogen. State of the art

[0003] Cryogenic engines used in rockets operate on the basis of a fuel / oxidizer mixture, for example comprising liquid oxygen LOx mixed with liquid hydrogen LH2 or liquid methane LCH4, generally called propellants. To transport these propellants from the tanks to the combustion chamber of the cryogenic engine, electric motors are used. To avoid having to manage dynamic seals, the electric motors used can be immersed in the propellants. Generally speaking, there are more and more fields in which an electric motor is immersed in a corrosive or flammable fluid, which is found between the stator and the rotor of said electric motor.

[0004] However, the various components of an electric motor are not compatible with such a fluid, which can present a risk of fire starting with serious consequences. One solution to this problem is to encapsulate the stator in a metal hoop: this solution leads to significant eddy current-induced losses, which become even more significant as the rotation speed increases, which reduces the performance of the electric motor. Another solution would be to deposit a PTFE coating on the stator: this solution requires a PTFE baking phase at too high a temperature, of the order of 350-400°C for example, which is not compatible with the various standard components of the stator and can lead to degradation of said stator.

[0005] An aim of the present invention is to remedy at least one of the drawbacks of the state of the art.

[0006] Another aim of the invention is to propose a solution for protecting an electrical machine immersed in a dangerous fluid, with a lower impact on the performance of said electrical machine.

[0007] Another aim of the invention is to propose a solution for protecting an electrical machine immersed in a dangerous fluid, presenting less risk of damage to said electrical machine.

[0008] It is also an aim of the invention to propose a solution for protecting an electrical machine immersed in a dangerous fluid, more effectively. Statement of the invention

[0009] The invention proposes to achieve at least one of the aforementioned aims by a stator for an electrical machine, of the electric motor or electric generator type, said stator comprising: - at least one face, called the air gap face, intended to face a rotor, or a translator, of said electrical machine, and - a winding on said air gap face; said stator being characterized in that it further comprises a protective layer made of parylene covering said air gap face and said electrical winding.

[0010] Thus, the invention proposes to deposit a protective layer of parylene at least on the side of the face of the stator facing the rotor, or the translator. Thus, when a machine comprising such a stator is immersed in a dangerous fluid, and said dangerous fluid is introduced into the air gap of said machine between the stator and the rotor, respectively the translator, the protective layer of parylene forms a barrier preventing said dangerous fluid from coming into contact with the stator. Thus, the stator is protected from the effects of the dangerous fluid by the protective layer of parylene.

[0011] The use of parylene to form the protective layer is advantageous for several reasons. On the one hand, parylene can be deposited without a high-temperature baking phase, unlike current solutions using a PTFE coating. Thus, the solution proposed by the invention is more respectful of the stator components and presents less risk of degradation of said stator and therefore of the electrical machine. On the other hand, parylene is a material resistant to dangerous fluids, and in particular to propellants, and even more particularly to LOx or liquid hydrogen LH2, which makes it possible to provide more effective protection against these dangerous fluids, while being a very good electrical insulator. In addition, this protection can be obtained with a thin layer of parylene which has no impact, or a limited impact, on the performance of the electric motor.

[0012] In the present application, “dangerous” fluid means any fluid which has the effect of degrading the stator or which can cause inflammation. For example, the dangerous fluid may be a corrosive fluid, or a flammable fluid, or a fluid which participates in / contributes to / amplifies the inflammation.

[0013] According to non-limiting examples, the hazardous fluid may be a propellant. According to non-limiting examples, the hazardous fluid may be, or may comprise, liquid oxygen LOx and / or liquid hydrogen LH2 and / or liquid methane LCH4. For example, hydrogen is known to degrade material by embrittlement: it can therefore infiltrate the stator and degrade it by embrittlement. The hazardous fluid may also be pure oxygen, in the liquid or gaseous state.

[0014] The dangerous fluid can be liquid, gaseous or a mixture of liquid and gas.

[0015] It should be noted that parylene is also known as polyparaxylylene.

[0016] According to embodiments, the stator according to the invention may comprise a varnish, or a layer of varnish, deposited on part or all of said stator, in particular at least on the winding, the parylene protective layer being deposited on said varnish, or on said layer of varnish.

[0017] The use of a varnish, or a layer of varnish deposited, on said stator, or at least on the winding, makes it possible to obtain a surface allowing simpler and more effective deposition of the parylene protective layer.

[0018] In particular, the stator according to the invention may be entirely impregnated in varnish so that it comprises a layer of varnish on all its surfaces. Alternatively, the layer of varnish may be deposited only on a part of the stator, for example only on the winding or on the air gap face.

[0019] The varnish may be any type of varnish. In particular, the varnish may be polyester varnish, silicone-based, polyamide-imide, polyimide, etc.

[0020] According to embodiments, the stator according to the invention may comprise a resin deposited on part or all of the air gap face so as to cover the winding, the protective layer being deposited over said resin.

[0021] The use of a deposited resin, at least on the winding, makes it possible to obtain, at the level of said winding, a surface allowing a simpler and more effective deposition of the parylene protective layer. Indeed, the resin makes it possible to have a surface having fewer discontinuities, and fewer recesses, at the level of the winding, which makes it possible to ensure that the protective layer is deposited more effectively and continuously on the air gap face. In addition, the resin allows better adhesion of the parylene protective layer. Thus, the stator winding, and more generally the stator, can be better protected by the parylene protective layer.

[0022] The resin can be deposited by any known technique, for example by molding, by injection, by projection, etc. and the invention is not limited to a particular technique for depositing the resin.

[0023] According to embodiments, the air gap face may not include notches accommodating the winding. In this case, the winding is arranged around the air gap face.

[0024] According to embodiments, the air gap face may comprise notches accommodating the winding, each notch being delimited by two stator teeth. In this case, the winding is located in the notches provided on the air gap face.

[0025] In the case where the air gap face comprises notches accommodating the winding, according to non-limiting embodiments, the resin can be deposited in the notches, without covering the stator teeth.

[0026] In this case, the resin is deposited only in the notches and is not deposited on the stator teeth. In other words, the stator teeth remain visible after the resin has been deposited.

[0027] According to a non-limiting exemplary embodiment, the resin can be deposited flush with said stator teeth. Thus, a continuous surface is obtained at the air gap face on which the parylene protective layer is deposited.

[0028] According to a non-limiting exemplary embodiment, the resin can be deposited in the notches, while remaining set back from the stator teeth. In this case, each notch comprising the winding and the resin deposited in said notch forms a hollow relative to the stator teeth. In this case, each stator tooth projects relative to the notches comprising the resin.

[0029] According to embodiments, in the case where the air gap face comprises notches receiving the winding, the resin can be deposited over the entire air gap face, covering the winding and the stator teeth, in particular to form a continuous surface.

[0030] Thus, the deposition of the protective layer can be carried out in a simpler and more efficient manner, to obtain more effective protection of the stator against dangerous fluids.

[0031] Regardless of the embodiment, preferably, the resin can be deposited sufficiently to cover the winding.

[0032] According to embodiments, the stator according to the invention may comprise resin on the edges of said stator, on either side of the air gap face, to cover, at least in part, the coil heads of the winding.

[0033] Thus, not only is the stator protected, but the winding is also protected, including the winding heads, which in certain applications may be immersed in the dangerous fluid. Indeed, in this case, the layer of parylene deposited at the air gap face can be extended to cover the edges of the stator and also cover the coil heads. Thus, a protective layer of parylene can be obtained, covering the air gap face but also the edges of the stator on either side of the air gap face.

[0034] According to embodiments, a protective layer of parylene can be deposited on the entire stator, directly or on a layer of resin previously deposited on the stator.

[0035] According to a particularly advantageous, but in no way limiting, embodiment, the stator according to the invention can be, at least in part, overmolded with the resin.

[0036] This embodiment makes it possible to facilitate the deposition of the resin on the stator, while making it possible to obtain a smooth surface at least on the air gap face, and preferably also on the edges of said stator on either side of said air gap face, and even more particularly on all the faces of the stator. Thus, a protective layer of parylene can be deposited simply and effectively on the air gap face, and preferably on the air gap face and on the edges of said stator on either side of said air gap face, and even more particularly on all the faces of the stator.

[0037] According to embodiments, the resin can be chosen from one of the following resins: - epoxy resin, - silicone resin, and - polyurethane resin.

[0038] Of course, other types of resins may be used depending on the application and / or the hazardous fluid to which the electrical machine according to the invention is subjected. The invention is not limited to a particular type of resin.

[0039] Stator according to any one of the preceding claims, characterized in that the parylene is, or comprises: - parylene N; - parylene C; - parylene D; and / or - parylene F, also called parylene HT by some manufacturers, and in particular parylene F-VT4 or parylene F-AT4.

[0040] The parylene protective layer can be deposited using any known technique, for example by vaporization, by spraying, etc.

[0041] According to embodiments, the parylene protective layer may have a thickness which is adapted to the application and / or to the nature of the dangerous fluid.

[0042] According to embodiments, the parylene protective layer may have a thickness of between 1 μm and 200 μm, and in particular of between a few 25 pm and 150 pm, and particularly a thickness of 100 pm. Such a thickness of the protective layer remains low and has a small, even negligible, influence on the performance of the electrical machine.

[0043] The stator according to the invention may be of any known shape and the invention is not limited to a particular shape of stator. Indeed, there are different known shapes of stator and the invention is applicable to all shapes of stator.

[0044] According to embodiments, the stator according to the invention may have a cylindrical shape.

[0045] In this case, the stator may comprise an internal bore provided to accommodate the rotor, or to translate it, the air gap face corresponding to the face of said bore.

[0046] Such a stator architecture is well known to those skilled in the art and will not be described in further detail here.

[0047] According to embodiments, the stator according to the invention may have a cylindrical shape and may be designed to be arranged in an external rotor, or in an external translator, the air gap face corresponding to the external face of said stator.

[0048] In this case, the external rotor / translator comprises a bore in which the stator according to the invention is arranged. This architecture in which the stator is arranged in the rotor / translator is also well known to those skilled in the art and it is not necessary to describe it in more detail here.

[0049] According to embodiments, the stator according to the invention may be in the form of a disc. In this case, the air gap face may correspond to one, and in particular to each, of the faces of said disc.

[0050] Of course, as indicated above, the stator may have other shapes, depending on the overall architecture of the electrical machine. For example, the stator according to the invention may have the shape of a flat stator or a tubular stator, etc.

[0051] According to another aspect of the present invention, there is provided an electrical machine comprising: - a stator according to the invention, and - a rotor, or translator, coupled to said stator such that the pyralene layer is located between said rotor and said stator.

[0052] According to advantageous embodiments of the machine according to the invention, the rotor, or the translator, can be encapsulated with a metallic material protecting said rotor, respectively said translator, against the dangerous fluid, in particular when the machine according to the invention is immersed in said dangerous fluid.

[0053] Alternatively, or in addition, the rotor, or the translator, may be covered with a protective layer made of parylene.

[0054] Such a layer of parylene covering the rotor can have the same characteristics characteristics than the parylene layer covering the stator, in particular in terms of thickness and / or composition. The parylene layer may be deposited on all or part of the rotor. Preferably, the parylene layer may be deposited on the entire surface of the rotor and completely cover the rotor.

[0055] According to embodiments, said electric machine according to the invention may be an electric motor.

[0056] According to embodiments, said electrical machine according to the invention may be an electrical generator.

[0057] According to another aspect of the present invention, there is provided a vehicle comprising an electric machine according to the invention.

[0058] In particular, the vehicle according to the invention may comprise an engine according to the invention. In the vehicle according to the invention, the engine according to the invention may in particular be used to transport propellants from a tank of said vehicle to a combustion chamber of a cryogenic engine of said vehicle.

[0059] In particular, the vehicle according to the invention may comprise an electric generator according to the invention.

[0060] The vehicle according to the invention can be any type of vehicle, namely a land vehicle, a flying vehicle, a maritime vehicle, etc.

[0061] According to a non-limiting exemplary embodiment, the vehicle according to the invention may be a vehicle running on hydrogen. Description of figures and embodiments

[0062] Other advantages and characteristics will appear on examining the detailed description of non-limiting embodiments, and the appended drawings in which: - FIGURES 1a and 1b are schematic representations of an exemplary embodiment of an electrical machine according to the state of the art; - FIGURES 2-4 are schematic representations of non-limiting exemplary embodiments of a stator according to the invention, in an axial sectional view; - FIGURES 5a and 5b are schematic representations of another non-limiting example embodiment of a stator according to the invention; and - FIGURES 6-7 are schematic representations of non-limiting exemplary embodiments of an electrical machine according to the invention.

[0063] It is understood that the embodiments which will be described below are in no way limiting. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described below isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection includes at least one preferably functional feature without structural details, or with only a part of the structural details if it is this part which is only sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.

[0064] In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

[0065] In the figures and in the remainder of the description, the elements common to several figures retain the same reference.

[0066] FIGURES 1a and 1b are schematic representations of an exemplary embodiment of an electrical machine according to the state of the art, respectively according to an axial sectional view and according to a radial sectional view.

[0067] The electric machine 100 of FIGURE 1 may be an electric motor or an electric generator.

[0068] The electrical machine 100 comprises a stator 102 and a rotor 104. In the following, in order not to complicate the description, it is considered without loss of generality that the electrical machine 100 comprises a rotor.

[0069] In the example shown, the electrical machine 100 comprises an external stator 102 in which the rotor 104 is arranged. In particular, the rotor 104 is arranged in a bore provided in the external stator 102. Of course, this example is given by way of illustration only and the invention is not limited to this electrical machine architecture.

[0070] The space between the stator 102 and the rotor 104 is called the air gap. In addition, in this document, the face 106 of the stator 102 facing the rotor 104 is called the air gap face 106 of the stator 102. In the example shown, the air gap face 106 of the stator 102 corresponds to the face of the internal bore of the stator 102.

[0071] The stator 102 further comprises a winding 108. This winding 108 receives an electrical power supply in the case where the electrical machine is an electric motor, or collects the current generated in the electrical machine 100, in the case where the electrical machine 100 is an electric generator.

[0072] In the example of FIGURES 1a and 1b, without loss of generality, the stator 102 comprises notches 110 provided on the air gap face 106. The winding 108 is arranged in the notches 110, and preferably does not extend beyond the notches 110. Each notch 110 is delimited on either side by two stator teeth 112 extending towards the rotor 104. Of course, this architecture is in no way limiting: indeed, in other embodiments, the stator 102 may not comprise notches 110, or stator teeth 112, and the winding 108 may be arranged directly on the air gap face 106.

[0073] The stator 102 comprises on either side of the air gap face 106, at its edges / ends, coil heads 114, visible in [Fig. 1a]. The winding 108 is electrically connected to the outside of the electrical machine 100 by a connection 116, visible in [Fig. 1a].

[0074] The assembly formed by the stator 102 and its elements as well as the rotor 104 is arranged in a casing 118, visible in [Fig.1a], closed on each side by flanges 120, visible in [Fig.1a]. The rotor 102 is connected to a drive shaft 122 passing through the or each flange 120.

[0075] When the electrical machine 100 is immersed in a dangerous fluid, in particular a corrosive or flammable fluid, said fluid is found between the stator 102 and the rotor 104. Such a dangerous fluid in contact with the stator 102 presents a risk of degradation of said stator 102 and / or a risk of ignition, in particular in contact with the winding 108.

[0076] The present invention makes it possible to protect the stator, and more generally the electrical machine, against such risks.

[0077] [Fig.2] is a schematic representation of an exemplary embodiment not limiting view of a stator according to the invention, according to a radial sectional view.

[0078] The stator 200 of [Fig.2] may be a stator of an electric motor or an electric generator.

[0079] The stator 200 of [Fig.2] comprises all the elements of the stator 102 of FIGURES 1a and 1b.

[0080] The stator 200 further comprises, on the side of the air gap face 106, a parylene protective layer 202. In the example of [Fig.2], the parylene protective layer 202 is deposited directly on the air gap face 106 of the stator 200, and covers the air gap face 106 and the winding 108 located in the notches 110, including the stator teeth 112.

[0081] Thus, when a machine comprising the stator 200 is immersed in a dangerous fluid, and said dangerous fluid enters the air gap of said machine and comes into contact with said stator 200, the parylene protective layer 202 forms a barrier preventing said dangerous fluid from coming into contact with the air gap face 106 of the stator 200 and the winding 108. Thus, the stator 200 is protected from the effects of the dangerous fluid by the parylene protective layer 202.

[0082] The parylene 202 protective layer can be produced by any deposition technique, for example by spraying or by PVD deposition.

[0083] The parylene protective layer 202 can be made using parylene N, parylene C, parylene D, or parylene F, and in particular parylene F-VT4 or parylene F-AT4.

[0084] The parylene protective layer 202 may have a thickness of 100 qm.

[0085] Optionally, the parylene layer 202 can be continued on either side of the air gap face and cover the coil heads 114 at the ends of the stator 200.

[0086] [Fig. 3] is a schematic representation of another non-limiting example of embodiment of a stator according to the invention, in a radial sectional view.

[0087] The stator 300 of [Fig.3] may be a stator of an electric motor or an electric generator.

[0088] The stator 300 of [Fig.3] comprises all the elements of the stator 200 of [Fig.2].

[0089] Furthermore, in the stator 300 of [Fig.3] and unlike the stator 200 of [Fig.2], a resin 302 is deposited in the notches 110 receiving the winding 108. The resin 302 is deposited so as to fill each notch 110 flush with the stator teeth 112 delimiting said notch 110. Thus, after depositing the resin 302 in the notches 110, a substantially flat and continuous surface is obtained at the level of the air gap face 106 of the stator 300.

[0090] The parylene protective layer 202 is deposited after deposition of the resin 302 in the notches 110 so that said protective layer 202 is deposited on the resin at the level of the notches 110. Like the example of [Fig.2], the parylene layer 202 covers the air gap face 106, the winding 108 being located in the notches 110 under the resin 302 and the stator teeth 112.

[0091] Optionally, the parylene layer 202 can be continued on either side of the air gap face 106 and cover the coil heads 114 at the ends of the stator 200.

[0092] Optionally, a layer of resin may be deposited on either side of the air gap face 106 to cover the coil heads 114. When the parylene layer 202 is continued on either side of the air gap face 106 to cover the coil heads 114, said parylene layer 202 may be deposited on the resin 302 covering the coil heads 114.

[0093] [Fig.4] is a schematic representation of another non-limiting example embodiment of a stator according to the invention, in a radial sectional view.

[0094] The stator 400 of [Fig.4] may be a stator of an electric motor or an electric generator.

[0095] The stator 400 of [Fig.4] comprises all the elements of the stator 300 of [Fig.3].

[0096] Furthermore, in the stator 400 of [Fig.4] and unlike the stator 300 of [Fig.3], the resin 302 is not only deposited in the notches 110 receiving the winding 108, but also on the stator teeth 112. In other words, the resin 302 is deposited over the entire air gap face 106 so as to fill all the notches 110 and cover all the stator teeth 112. Thus, a continuous layer of resin 302 is obtained on the air gap face 106 of the stator 102.

[0097] The parylene protective layer 202 is deposited after deposition of the resin 302 on the continuous and flat layer of resin previously obtained.

[0098] Optionally, the parylene layer can be continued on either side of the air gap face and cover the coil heads 114 at the ends of the stator 200.

[0099] FIGURES 5a and 5b are schematic representations of another non-limiting example embodiment of a stator according to the invention, respectively in a radial sectional view and in an axial sectional view.

[0100] The stator 500 of FIGURES 5a and 5b may be a stator of an electric motor or an electric generator.

[0101] The stator 500 of FIGURES 5a and 5b comprises all the elements of the stator 400 of [Fig.4],

[0102] Furthermore, in the stator 500 of FIGURES 5a and 5b and unlike the stator 400 of [Fig. 4], the resin 302 is not only deposited on the air gap face 106 of the stator 500, but it extends over the edges of the stator 500 on either side of said stator 500, as visible in [Fig. 5b]. In particular, the resin 302 covers the coil heads 114 of the winding 108 of the stator 500. Thus, a continuous layer of resin 302 is obtained, this continuous layer of resin extending over the entire air gap face 106 and over the edges of the stator 500 on either side of the air gap face 106.

[0103] Furthermore, in the stator 500 of FIGURE 5 and unlike the stator 400 of [Fig. 4], the parylene protective layer 202 is deposited over the entire resin layer 302 and extends, not only over the air gap face 106 of the stator 500, but it also extends over the edges of the stator 500 on either side of said stator 500, like the resin layer 302, as visible in [Fig. 5b].

[0104] In the example of FIGURES 5a and 5b, the stator 500 can be molded in the resin 302 and then the parylene protective layer 202 can be deposited on the resin 302.

[0105] [Fig.6] is a schematic representation of a non-limiting exemplary embodiment of an electrical machine according to the invention, in an axial sectional view.

[0106] The electric machine 600 of [Fig.6] may be an electric motor or an electric generator.

[0107] The machine 600 comprises a stator according to the invention, in particular the stator 500 of FIGURES 5a and 5b. Alternatively, the machine 600 may comprise any one of the stators 200, 300 or 400 of FIGURES 2-4.

[0108] In addition, the machine 600 includes the rotor 104 of FIGURE 1, as well as the housing 120 and the flanges 122 of FIGURE 1.

[0109] [Fig.7] is a schematic representation of another exemplary embodiment not limiting of an electric machine according to the invention, according to an axial sectional view.

[0110] The electric machine 700 of [Fig.7] may be an electric motor or an electric generator.

[0111] The machine 700 comprises all the elements of the machine 600 of [Fig.6].

[0112] Furthermore, in the machine 700, the rotor 104 is encapsulated in a casing 702 made with a metallic material protecting said rotor 104 against a dangerous fluid when the machine 700 is immersed in said dangerous fluid.

[0113] In the examples described, the electrical machine comprises a rotor 104. Of course, the invention is not limited to this characteristic. Alternatively, the rotor 104 can be replaced by a translator.

[0114] In the examples described, the stator comprises notches accommodating the winding. Of course, the invention is not limited to this characteristic. Alternatively, the stator may not comprise a notch accommodating the winding.

[0115] In the examples described, the stator is an external stator comprising a bore provided to accommodate a rotor, or a translator. Of course, the invention is not limited to this characteristic. Alternatively, the stator may be an internal stator intended to be arranged in a bore provided in a rotor / translator.

[0116] In the examples described, the stator has a cylindrical shape. Of course, the invention is not limited to this characteristic. Alternatively, the stator may have any other shape depending on the architecture of the electrical machine, such as for example a discoid shape, a planar shape, a tubular shape, etc. In all cases, the stator comprises an air gap face facing the rotor / translator, said air gap face comprising a winding, arranged or not in notches provided on said air gap face.

[0117] Generally, the invention is not limited to the examples which have just been described which are given by way of illustration only.

Claims

Claims

1. Stator (200;300;400;500) for an electric machine (600;700), of the electric motor or electric generator type, said stator (200;300;400;500) comprising: - at least one face (106), called the air gap face, intended to face a rotor (104), or a translator, of said electric machine (600;700), and - a winding (108) on said air gap face (106); said stator (200;300;400;500) being characterized in that it further comprises a protective layer (202) made of parylene covering said air gap face (106) and said electric winding (108).

2. Stator according to the preceding claim, characterized in that it comprises a varnish, or a layer of varnish, deposited on part or all of said stator, the protective layer (202) of parylene being deposited on said varnish, or on said layer of varnish.

3. Stator (300;400;500) according to any one of the preceding claims, characterized in that it comprises a resin (302) deposited on part or all of the air gap face (106) so as to cover the winding (108), the protective layer (202) being deposited over said resin (302).

4. Stator (200;300;400;500) according to any one of the preceding claims, characterized in that the air gap face (106) comprises notches (110) receiving the winding (108), each notch (110) being delimited by two stator teeth (112).

5. Stator (300) according to claims 3 and 4, characterized in that the resin is deposited in the notches (110) without covering the stator teeth (112), and in particular flush with said stator teeth (112).

6. Stator (400;500) according to claims 3 and 4, characterized in that the resin (302) is deposited over the entire air gap face (106) covering the winding (108) and the stator teeth (112), in particular to form a continuous surface.

7. Stator (500) according to any one of claims 3 to 6, characterized in that it comprises resin (302) on the edges of said stator (500), on either side of the air gap face (106), to cover, at least in part, the coil heads of the winding (108).

8. Stator (500) according to claim 3, characterized in that it is, at least in part, overmolded with the resin (302).

9. Stator (300;400;500) according to any one of claims 3 to 8, characterized in that the resin (302) is chosen from one of the following resins: - epoxy resin, - silicone resin, - polyurethane resin.

10. Stator (200;300;400;500) according to any one of the preceding claims, characterized in that the parylene is, or comprises: - parylene N; - parylene C; - parylene D; and / or - parylene F, and in particular parylene F-VT4 or parylene F-AT4.

11. Stator (200;300;400;500) according to any one of the preceding claims, characterized in that the parylene protective layer (202) has a thickness of between 1 pm and 200 pm, and in particular of between some 25 pm and 150 pm, and in particular 100 pm.

12. Stator (200;300;400;500) according to any one of the preceding claims, characterized in that it is of cylindrical shape and comprises an internal bore provided to accommodate the rotor (104), or to translate it, the air gap face (106) corresponding to the face of said bore.

13. Stator according to any one of claims 1 to 11, characterized in that it is of cylindrical shape and is intended to be arranged in an external rotor, or an external translator, the air gap face corresponding to the external face of said stator.

14. Stator according to any one of claims 1 to 11, characterized in that it is in the form of a disc, the air gap face corresponding to one of the faces of said disc.

15. Electrical machine (600;700) comprising: - a stator (200;300;400;500) according to any one of the re- preceding indications, and - a rotor (104), or translator, coupled to said stator (200;300;400;500) so that the layer (202) of pyralene is located between said rotor (104) and said stator (200;300;400;500).

16. Machine (700) according to the preceding claim, characterized in that the rotor (104), or the translator, is encapsulated with a metallic material (702).

17. Electric machine (600;700) according to any one of claims 15 or 16, characterized in that said machine is: - an electric motor, or - an electric generator.

18. Vehicle comprising an electric machine (600;700) according to any one of claims 15 to 17.

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