Electric connector

Abstract

The invention relates to an electrical connector (103, 105) comprising a hollow cylinder extending about an axis of rotation (X), an electrical contact (107) and an annular insulator (111). The shape of the annular insulator (111) is complementary to the shape of the electrical contact (107), and the annular insulator is in contact with the outside of the surface of the electrical contact (107) over the entire longitudinal extent of the electrical contact other than a portion of the surface of the electrical contact (107), which portion of the surface of the electrical contact is intended to be in contact with a complementary electrical contact (107) of a complementary electrical connector (103, 105). Furthermore, the annular insulator (111) comprises a first annular insulator (111a), which covers the connection region (117) of the electrical contact (107) and is made of glass ceramic.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of electrical connection devices for high power transmission in an aircraft. In particular, the present invention relates to an electrical connector for establishing an electrical connection with a complementary electrical connector, and to an assembly comprising two complementary electrical connectors. BACKGROUND

[0002] The prior art includes documents WO-A1-2014183115, US-A-2824290, EP-A1-3364504 and FR-A1-3110781.

[0003] Current efforts to decarbonize aircraft are leading to an increasing integration of electrical systems into aircraft. The hybridization or electrification of aircraft is part of this trend and leads to new demands for high-power electrical connectors, i.e. electrical connectors capable of withstanding high voltages and high currents.

[0004] The preferred method for achieving high power levels mainly involves increasing the voltage level within the aircraft's onboard network, since increasing the current level would require greater conductor cross sections, leading to greater weight, which is contrary to the objectives pursued for use in aircraft.

[0005] The voltages currently envisaged for the aircraft's onboard network are therefore in the range of 800 to 1,000 volts (direct current (DC) voltage), but the voltage can eventually rise to 3,000 volts for a current of approximately 500 amperes.

[0006] At such high voltage and current values, combined with use in high altitude (e.g. 55,000 feet), which involves significant variations in temperature (e.g. ranging from -55°C to +250°C), pressure and humidity, rare or otherwise non-existent physical phenomena can appear.

[0007] One known phenomenon associated with such conditions of use is therefore partial discharge. This is a partial discharge of gas in an electrically insulating system due to temporary ionization, which occurs when the electrical stress (electric field) exceeds a critical value.

[0008] This phenomenon is crucial because it leads to a degradation and deterioration of the performance of the electrical system in which it appears.

[0009] In terms of electrical connectors, the occurrence of partial discharge within an electrical connector can damage the insulation contained within the connector (i.e. accelerate its aging), and even in the long term, can cause short circuits, rendering the connector inoperable.

[0010] In particular, when used in aircraft, electrical connectors are subjected to significant changes in temperature and pressure (caused by flight altitude), and partial discharge may cause insulation failure within the connector, resulting in the activation of protection devices and the disconnection of power supply to loads (engines, actuators, etc.) in the aircraft's electrical system.

[0011] For the reasons mentioned above, in the current technology, electrical connectors intended for use in the aerospace field are replaced by terminal blocks when used in high-power applications.

[0012] Furthermore, existing electrical connectors are limited to operating voltages between 28V DC and ±270V DC, and between 115V AC and 230V AC. These operating voltage values ​​will not cause partial discharge, even when used in aircraft at high altitudes.

[0013] In these electrical connectors, the electrical insulators used are in particular made of dielectric materials (i.e., materials that do not contain free charges capable of conducting electrons). Since current needs to transfer the charges that constitute itself to achieve conduction, these materials exhibit insulating properties because they prevent this conduction.

[0014] In addition, electrical connectors specifically designed for high-power transmission typically use elastomers, glass, air, or polymers as insulators.

[0015] However, while these materials are good electrical insulators, they have significant drawbacks for high-power applications.

[0016] In fact, elastomers and polymers have non-zero porosity, which is generated during their manufacturing process and reduces their insulating properties (and in some cases, such as when these materials are contaminated with impurities, it can even make them conductive).

[0017] Using air as an insulator requires a large thickness to achieve effective electrical insulation. Furthermore, at high altitudes, the conductivity of water in the air increases to levels detrimental to the performance of the insulator.

[0018] On the other hand, glass has an excessively high dielectric constant compared to the other materials mentioned.

[0019] Generally speaking, these closed-cell materials cannot be used to quickly and non-destructively verify the porosity of the manufactured workpiece.

[0020] In addition, all of these materials have low thermal conductivity (for example, the thermal conductivity of elastomers is about 0.4 W / m•K and that of composites is about 0.3 W / m•K).

[0021] The low thermal conductivity of these materials has the disadvantage that their inclusion leads to a significant increase in temperature, especially for high-power applications. Furthermore, the poor heat dissipation (due to low thermal conductivity) can cause premature degradation of electrical connector components.

[0022] Finally, the porosity of these materials leads to the presence of partial discharges. Partial discharges can form within the cavities of porous materials, especially when used at high power, and can migrate from one cavity to another until electrical insulation is lost due to the presence of arc paths. For example, cavities larger than 17 micrometers are sufficient to cause premature aging of the electrical insulation through erosion.

[0023] Deterioration of insulation can cause carbon buildup (due to porosity) within the cavity. These deposits can gradually form conductive paths, generate arcs, and eventually lead to short circuits over time. Given the voltage and current levels applied to electrical connectors (for high-power applications), there is a significant risk of short circuits and even fires. Summary of the Invention

[0024] This invention proposes solutions to these shortcomings.

[0025] Therefore, one object of the present invention is to obtain an electrical connector using an insulator whose shape and material reduce the risk of partial discharge during high-power use, while enabling good heat dissipation.

[0026] Therefore, according to a first aspect, the present invention relates to an electrical connector for establishing an electrical connection with a complementary electrical connector, the electrical connector comprising: - A hollow cylinder that extends around a rotation axis; - At least one electrical contact, which is located inside the hollow cylinder and extends parallel to the axis of rotation; - At least one annular insulator, the at least one annular insulator extending parallel to the axis of rotation and positioned radially between the at least one electrical contact and the hollow cylinder. The electrical connector is characterized in that, throughout its entire longitudinal direction, the shape of the at least one annular insulator is complementary to the shape of the at least one electrical contact, and the at least one annular insulator covers, except for a portion of the surface of the at least one electrical contact, a portion of the surface of the at least one electrical contact configured to contact the electrical contact of the complementary electrical connector. The at least one annular insulator includes a first annular insulator made of glass-ceramic, which covers the connection area of ​​the at least one electrical contact.

[0027] The electrical connector according to the invention may include one or more of the following characteristics, which may be used separately or in combination with each other: - The at least one annular insulator further includes a second annular insulator made of an elastomer, preferably made of silicone resin, covering the conductive area of ​​the at least one electrical contact.

[0028] - The electrical connector is a socket-type electrical connector, and the at least one electrical contact is electrically connected to a busbar or cable, or the electrical connector is a plug-type electrical connector, and the at least one electrical contact is electrically connected to a cable or busbar.

[0029] - The at least one electrical contact is a male electrical contact.

[0030] - The at least one electrical contact is a female electrical contact.

[0031] - The electrical connector further includes at least one flat elastomer washer positioned on a second surface of the at least one radially extending electrical contact, the second surface being located at the interface between the at least one electrical contact and the at least one first annular insulator.

[0032] - The at least one first annular insulator further includes a layer of conductive material on all or part of the surface of the at least one first annular insulator located at the interface with the hollow cylinder.

[0033] - The glass ceramic used to make the first ring insulator is a zero-porosity ceramic.

[0034] According to a second aspect, the invention also relates to a component comprising two complementary electrical connectors according to the first aspect.

[0035] Finally, according to a third aspect, the present invention relates to an aircraft comprising an electrical connector assembly according to a second aspect. Attached Figure Description

[0036] The invention will be better understood through the following description, given by way of example only and with reference to the accompanying drawings, in which: Figure 1 This is a schematic representation of an embodiment of an assembly comprising two electrical connectors according to the present invention; Figure 2 This is an illustration of an embodiment of a ring insulator for an electrical connector according to the present invention; Figure 3 This is an illustration of an embodiment of a ring insulator for an electrical connector according to the present invention; Figure 4 This is an illustration of an embodiment of a ring-shaped insulator covering an electrical contact according to the present invention; Figure 5 This is a schematic representation of an embodiment of an assembly comprising two electrical connectors according to the present invention, wherein a leakage line is shown; Figure 6 This is a schematic representation of an embodiment of an assembly comprising two electrical connectors according to the present invention, wherein the positioning of at least one flat elastomer seal is shown; Figure 7 This is an illustration of an embodiment of an annular insulator covered by a conductive material layer for an electrical connector according to the present invention; Figure 8 This is an illustration of an embodiment of an annular insulator covered by a conductive material layer for an electrical connector according to the present invention; Figure 9 This is a cross-sectional view of an embodiment of an electrical connector assembly, wherein a hollow cylinder has a polymer layer covering all or part of its radially inner surface. Detailed Implementation

[0037] refer to Figures 1 to 4 We will now describe an embodiment of the assembly 101 according to the present invention, comprising two complementary electrical connectors 103 and 105.

[0038] More specifically, the examples shown in these figures relate to an assembly 101 comprising two complementary electrical connectors 103 and 105, which are respectively a plug including a male electrical contact 107 and a socket including a female electrical contact 107. Furthermore, in Figure 1 In the example shown, the two electrical connectors 103 and 105 have been assembled.

[0039] Here, the term "complementary" means that each electrical connector is complementary to another electrical connector because the electrical connector is configured to be mounted into the other electrical connector so as to be held together and form an electrical connection, for example, via a clamping device.

[0040] In addition to the non-limiting examples shown in these figures, the invention described below is generally applicable to socket-type electrical connectors and plug-type electrical connectors, wherein the electrical contacts are electrically connected to a busbar (e.g., by forming an integral part with the busbar) or a cable (e.g., by crimping the cable onto the electrical contacts).

[0041] Similarly, the present invention applies to electrical connectors in which the electrical contacts can be male or female. For example, male electrical contacts are typically shaped as studs, while female electrical contacts are typically shaped as holes, for example, complementary to the shape of studs, so that these conductive elements can be mounted together.

[0042] The electrical connectors described below can be, for example, so-called high-power electrical connectors (also referred to as power connectors), meaning that the electrical connectors are configured to withstand a DC voltage greater than or equal to 800 volts and a current greater than or equal to 500 amps. These electrical connectors may include those used for high-power transmission in aircraft.

[0043] therefore, Figure 1 The component 101 shown includes two connectors 103 and 105. Each electrical connector 103 or 105 is configured to establish an electrical connection with another electrical connector 105 or 103, referred to as a complementary electrical connector.

[0044] Each connector 103 and 105 includes a hollow cylinder 109 extending about the axis of rotation X. This hollow cylinder 109 is made of, for example, metal (e.g., stainless steel or aluminum) and is not... Figure 1 As shown in the text, but Figure 9 As shown in the image.

[0045] In the following description, the "longitudinal" and "radial" directions are defined with reference to the connector's axis of rotation.

[0046] Each connector 103 and 105 also includes an electrical contact 107, which is positioned within the hollow cylinder 109 and extends parallel to the axis of rotation X.

[0047] Finally, each connector 103 and 105 includes an annular insulator 111, which extends parallel to the axis of rotation X and is radially positioned between the electrical contact 107 and the hollow cylinder 109.

[0048] In the non-limiting example shown, each electrical connector 103 and 105 includes a single electrical contact 107. However, the invention is also applicable to electrical connectors that include one or more electrical contacts and one or more annular insulators surrounding these electrical contacts.

[0049] Furthermore, in the non-limiting example shown, the electrical contact 107 of the electrical connector 103 is electrically connected to the cable 113 (in this case, the cable 113 is electrically connected to the cable 113 by crimping it into the electrical contact 107), while the electrical contact 107 of the electrical connector 105 is electrically connected to the busbar 115 (in this case, the busbar 115 is electrically connected to the busbar 115 by forming an integral part with the busbar 115).

[0050] The shape of the annular insulator 111 is complementary to the shape of the electrical contact 107, and covers the surface of the electrical contact 107 (i.e., the outer surface of the electrical contact) throughout its entire longitudinal extent (the longitudinal extent of the annular insulator), except for a portion 108 of the surface of the electrical contact 107. Figure 6Outside of the visible area, this portion 108 of the surface is configured to contact the electrical contacts of the complementary electrical connector.

[0051] In addition, the annular insulator 111 includes a first annular insulator 111a, which is made of glass ceramic and covers the connection area 117 of the electrical contact 107.

[0052] For each electrical connector 103 and 105, the connection area 117 refers to a portion of the longitudinal extension of the electrical contact 107, which, by extension, is itself designed to establish contact between the two electrical connectors, in particular by inserting the male electrical contact 107 into the female electrical contact 107.

[0053] Glass-ceramics can be, for example, zero-porosity ceramics, which are ceramics that possess high electrical insulation properties while having zero porosity due to their manufacturing process. One example is Macor. ® A ceramic composed of 55% fluorophlogopite and 45% borosilicate glass.

[0054] In addition, glass ceramics are known to have high dielectric strength and natural resistance to aging caused by partial discharge that may occur in air cavities (or bubbles).

[0055] In addition, glass ceramics also act as heat conductors because their thermal conductivity is higher than that of materials used in the prior art, thus preventing excessive temperature rise.

[0056] Finally, the glass ceramic itself can withstand temperatures exceeding 800°C.

[0057] In the non-limiting example shown, the annular insulator 111 further includes a second annular insulator 111b, which is made of an elastomer such as silicone resin and covers the conductive region 119 of the electrical contact 107.

[0058] For each electrical connector 103 and 105, the conductive region 119 refers to a portion of the longitudinal extension of the electrical contact 107, through which an electrical connection is established with a bus or cable in this portion of the longitudinal extension of the electrical connector, whether the electrical connector is a plug-type connector or a socket-type connector.

[0059] Therefore, the annular insulator 111, including the first annular insulator 111a and the second annular insulator 111b, covers the entire (radially outward) surface of the externally covering electrical contact 107, except for a portion 108 of said surface, which is intended to contact the complementary electrical contacts of the complementary electrical connector (especially as...). Figure 6 (As shown).

[0060] Elastomers possess high dielectric strength and high temperature resistance. The use of elastomeric insulators can limit the existence of air gaps that can lead to partial discharge.

[0061] Specifically, such elastomeric insulators can be compressed during the assembly of electrical connectors (e.g., by clamping devices included in the hollow cylinder 109 of the electrical connector) to achieve better sealing of the assembled electrical connector and reduce air gaps that may exist between the components of the electrical connector.

[0062] In addition, if it is possible Figure 1 As seen in the diagram, the second elastomeric insulator 111b rests on the first elastomeric insulator 111a, allowing the second elastomeric insulator 111a to compress the first elastomeric insulator 111a, particularly under the influence of thermal expansion, thereby reducing the presence of spaces (i.e. gaps) that may be filled with air.

[0063] More specifically, in the non-limiting example shown, the second annular insulator 111b is located behind the first annular insulator 111a (relative to the connection region 117) such that the radially extending plane contacts the complementary surface of the first annular insulator 111a.

[0064] This construction is particularly applicable to the non-limiting example described herein, in which the first annular insulator 111a includes two complementary and mating independent components 111aa and 111ab within the connection region 117.

[0065] exist Figure 1 Especially Figure 5 and Figure 6 In the non-limiting example shown, with respect to electrical connector 103, the first part 111aa of the first annular insulator 111a has an annular shape, while the second part 111ab of the first annular insulator 111a has a sleeve shape that is complementary to the shape of the first part 111aa on one hand (and thus covers the first part 111aa of the first annular insulator 111a of electrical connector 103) and complementary to the shape of the second part 111ab of the first annular insulator 111a of electrical connector 105 on the other hand (and thus also covers the second part 111ab of the first annular insulator 111a of electrical connector 105).

[0066] Furthermore, in the case of electrical connector 105, the first part 111aa of the first annular insulator 111a is also annular, with its inner diameter varying once (i.e., varying once at a single location along the longitudinal range of the part) to form support for the complementary shoulder formed in the second part 111ab of the first annular insulator 111a.

[0067] In any case, when assembling electrical connectors 103 or 105, the pressure exerted by the second annular insulator 111b on the first annular insulator 111a tends to keep the components 111aa and 111ab of the first annular insulator 111a close together.

[0068] Figure 2 Components 111aa and 111ab of the first annular insulator 111a for the male electrical contact 107 are shown prior to assembly of the electrical connector. Figure 3 Components 111aa and 111ab, which are also used for the first annular insulator 111a of the female electrical contact 107 before assembling the electrical connector, are shown. Figure 4 A male electrical contact 107 covered by its respective annular insulator is shown (in Figure 4 (in the left part) and female electrical contact 107 (in Figure 4 (in the right part).

[0069] Dividing the first annular insulator 111a into several parts 111aa and 111ab facilitates the manufacture of the first annular insulator 111a and the positioning of the insulator parts during the assembly of the electrical connector. Specifically, before tightening the assembly, the annular insulator parts can be positioned on both sides of the shoulder of the electrical contact (e.g., Figure 1 (as shown in the example) and the component is positioned.

[0070] The electrical contact 107 may have a shoulder, i.e., a partial modification of its cross-section. Since the first annular insulator 111a has a complementary shape, the first annular insulator can rest on the shoulder, thereby preventing the electrical contact 107 from translating along the X-axis.

[0071] In this case, when assembling electrical connector 103 or electrical connector 105, the different components of the first annular insulator 111a contact on both sides of the shoulder.

[0072] In all cases, for each annular insulator, those skilled in the art can adjust the shape and number of these components, particularly according to the required shape of the electrical contacts and hollow cylinders, to facilitate the manufacture and assembly of the electrical connector.

[0073] Furthermore, the shape and arrangement of the various components constituting the first annular insulator 111a can be optimized to reduce the risk of partial discharge, particularly by extending the creepage distance at the interfaces between these components (by...). Figure 5 The lines 123 in the diagram represent the risk of partial discharge.

[0074] In practice, at the operating voltage, these wires must be long enough to prevent partial discharge from causing a short circuit in the insulation gap used to separate the electrical contact 107 from the hollow cylinder 109.

[0075] Figure 6 A specific embodiment is shown in which each electrical connector 103 and 105 of component 101 further includes a flat washer 125, which is also made of an elastomer and is positioned on the surface of electrical contact 107 that extends radially at the interface between electrical contact 107 and first annular insulator 111a.

[0076] In other embodiments, the number and location of the flat joints may vary, but the purpose is to extend the current creepage distance in all cases, while further limiting the presence of air gaps at the interfaces between the various components included in the electrical connector.

[0077] Figure 7 and Figure 8 Another embodiment is shown, wherein the first annular insulator 111a includes an additional conductive material layer 127 on all or part of the surface of the first annular insulator 111a located at the interface with the hollow cylinder 109.

[0078] More specifically, Figure 7 Components 111aa and 111ab are shown, which are suitable for a male electrical contact and are partially covered by a conductive material layer 127, while Figure 8 Components 111aa and 111ab are shown for a first annular insulator 111a suitable for a female electrical contact and partially covered by a conductive material layer 127.

[0079] Advantageously, this type of deposit reduces the occurrence of partial discharge by placing the first annular insulator 111a and the hollow cylinder 109 at the same potential. In fact, equipotentiality is achieved by providing a conductive coating 127 on the outer surfaces of components 111aa and 111ab, thereby reducing the risk of electric shock.

[0080] at last, Figure 9One embodiment is shown (the upper part is for a socket-type electrical connector, and the lower part is for a plug-type electrical connector), wherein the hollow cylinder 109 of the electrical connector (not shown) includes a polymer layer 129 on a portion of its radially inner surface. For example, the polymer layer 129 may be a fluoropolymer material, such as perfluoroalkoxy (PFA). Here, the advantage of this deposit is that it reduces the presence of air gaps, which can be a cause of partial discharge.

[0081] Finally, the arrangement and materials used for the ring insulator, especially the first ring insulator, can significantly reduce the presence of air regions (cavitation), increase the dielectric constant of the insulator, and improve the overall high-temperature resistance of the electrical connector.

Claims

1. An electrical connector (103, 105) for establishing an electrical connection with a complementary electrical connector (103, 105), said electrical connector (103, 105) comprising: - A hollow cylinder (109) extending about a rotation axis (X); - At least one electrical contact (107), said at least one electrical contact being positioned inside the hollow cylinder (109) and extending parallel to the axis of rotation (X); - At least one annular insulator (111), the at least one annular insulator extending parallel to the axis of rotation (X) and radially positioned between the at least one electrical contact (107) and the hollow cylinder (109), The electrical connectors (103, 105) are characterized in that the shape of the at least one annular insulator (111) is complementary to the shape of the at least one electrical contact (107), and the at least one annular insulator covers the surface of the at least one electrical contact (107) externally, except for a portion (108) of the surface of the at least one electrical contact (107), wherein the portion of the surface of the at least one electrical contact is configured to contact the complementary electrical contact (107) of the complementary electrical connectors (103, 105). The at least one annular insulator includes a first annular insulator (111a) made of glass-ceramic, which covers the connection region (117) of the at least one electrical contact (107), and The at least one annular insulator (111) further includes a second annular insulator (111b) made of an elastomer, preferably made of silicone resin, covering the conductive region (119) of the at least one electrical contact (107).

2. The electrical connector (103, 105) according to claim 1, wherein, The electrical connectors (103, 105) are socket-type electrical connectors, and the at least one electrical contact (107) is electrically connected to the bus (115) or the cable (113), or the electrical connectors (103, 105) are plug-type electrical connectors, and the at least one electrical contact (107) is electrically connected to the cable (113) or the bus (115).

3. The electrical connector (103, 105) according to claim 1 or 2, wherein, The at least one electrical contact (107) is a male electrical contact.

4. The electrical connector (103, 105) according to claim 1 or 2, wherein, The at least one electrical contact (107) is a female electrical contact.

5. The electrical connector (103, 105) according to any one of claims 1 to 4, wherein, The electrical connector (103, 105) further includes at least one flat elastomer washer (125) positioned on a second surface of the at least one electrical contact (107) extending radially at the interface between the at least one electrical contact (107) and the at least one first annular insulator (111).

6. The electrical connector (103, 105) according to any one of claims 1 to 5, wherein, The at least one first annular insulator (111a) further includes a layer of conductive material (127) on all or part of the surface of the at least one first annular insulator located at the interface with the hollow cylinder (109).

7. The electrical connector (103, 105) according to any one of claims 1 to 6, wherein, The glass ceramic used to make the first annular insulator (111a) is a zero-porosity ceramic.

8. A component (101) comprising two complementary electrical connectors (103, 105) according to any one of claims 1 to 7.

9. An aircraft comprising a set of electrical connectors as claimed in claim 8.

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