Contactor with self-supporting coil

Abstract

An improved electrical device includes a high voltage switch device configured to selectively open / close a high voltage circuit. The device includes a self-supporting coil for driving an actuator assembly to open / close the high voltage circuit. The coil is free of a bobbin.

Description

Contactor with Self-Supporting CoilCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of United States Provisional Patent Application No. 63 / 678,360, filed August 1, 2024, and titled “Contactor with Self Supporting Coil,” the entirety of which is hereby incorporated by reference.FIELD OF THE TECHNOLOGY

[0002] The subject disclosure relates to electrical switching devices, such as contactor devices and electrical fuse devices, and more particularly to improved contactor devices with high voltage switching.BACKGROUND OF TECHNOLOGY

[0003] Many conventional devices are known to selectively power on or off electrical devices. For example, electrical contactors, e.g., high-voltage DC contactors, are conventionally available and used in electrical systems. Contactors may be configured to interrupt or complete a circuit to control electrical power to and from a device.

[0004] Conventional contactors may act as a switch, e.g., to selectively allow / disallow current flow. In examples, a contactor will have at least two discrete operating states, including a first, open state in which current does not flow through the device, and a second, closed state, in which current flows through the device. In some examples, a coil, e.g., an electromagnetic coil, may be energized / deenergized to cause movement of a movable contact between a first position associated with the fist operating state and a second position associated with the second operating state. In examples, the coil is required to provide sufficient force to reliably move the movablecontact. Accordingly, conventional coils often require relatively large amounts of copper or other conductive wire.

[0005] Accordingly, there is a need in the art for improved contactors having coils with one or more of reduced complexity, weight, and / or cost.SUMMARY OF THE TECHNOLOGY

[0006] The subject technology relates to improved electrical devices and methods of making and using those devices. In examples, aspects of this disclosure relate to improved switching devices that use a bobbinless coil to actuate aspects of such switching devices. For example, aspects of this disclosure may relate to contactors including a bobbinless coil to actuate a movable contact, e.g., via a shaft, for switching the contactor between open and closed operating states.

[0007] So that those having ordinary skill in the art to which the disclosed systems and techniques pertain will more readily understand how to make and use the same, reference may be had to the following drawings.

[0008] FIG. 1 is a perspective, cross-sectional view of a contactor, in accordance with aspects of this disclosure.

[0009] FIG. 2 is a cross-sectional view of aspects of the contactor of FIG. 1, in accordance with aspects of this disclosure.

[0010] FIG. 3 is a cross-sectional view of aspects of a conventional contactor, in accordance with aspects of this disclosure.DETAILED DESCRIPTION

[0011] The subject technology overcomes many of the prior art problems associated with electrical devices. In brief summary, the subject technology provides improved electrical devices including a contactor design that includes a bobbinless coil.

[0012] As noted above, conventional contactors open and close to allow or not allow current to pass through an electrical system. The contactor opening and closing motion is generally driven by an electromagnetic coil which drives a linear actuator, such as a shaft. Conventional coils generally include wire, e.g., copper wire, wound about a bobbin, as a spool, that produces a magnetic force when energized. The magnetic force drives the linear actuator to open or close the contactor.

[0013] In conventional arrangements, coils are wound on a bobbin. The bobbin may be used to house the coil and / or serve as a substrate for the coil winding. Conventional coils may also be covered in tape or overmolded in plastic.

[0014] When used in a contactor, the bobbin creates a gap between the coil and the moving elements of the actuator. The bobbin also comprises material disposed between the coil and the moving elements. Depending on the material used, the bobbin may interfere with the field generated by the coil. These and / or other factors lead to electromagnetic inefficiency, namely inadequate field strength. This inefficiency may result in reduced contactor performance, e.g., because a strong field is generally required to drive the linear actuator to open and close the contactor. To overcome such inefficiencies, conventional coils may use additional wire, e.g., as additional copper windings, to produce the necessary electromagnetic field and power to achieve the desired performance. This additional wire adds weight and cost.

[0015] Aspects of this disclosure relate to a contactor that includes a bobbinless or selfsupported coil. By eliminating the bobbin, the electromagnetic efficiency of the conventional coils discussed above can be reduced or eliminated. In some bobbinless coils described herein, windings in the bobbinless coil of this disclosure may be structurally supported via a thermobonded coating, varnish coating, overmold, or any other method or configuration that provides structural rigidity of the coils without a central bobbin.

[0016] For example, the omission of the bobbin may allow for the coil to be positioned more closely to the actuator and / or eliminate intervening (bobbin) material. According to aspects of this disclosure, the overall efficiency of the contactor may be improved with elimination of the bobbin and / or less material may be required for the coil, which may reduce one or more of size, weight, and / or cost.

[0017] Without limitation, the devices and techniques described herein may provide improved electrical devices, which may be less complex, may be cheaper to manufacture and / or use, and / or that may have improved safety and / or result in improved system protection, when compared to similar conventional systems. Moreover, while aspects of this disclosure may be particularly useful in certain application, like high voltage automotive systems, the systems and techniques described herein may be useful with many electrical systems.

[0018] Aspects of the disclosure will now be explained in more detail with reference to the Figures.

[0019] FIG. 1 is a perspective, cross-sectional view of an electrical device 100 according to aspects of this disclosure. In examples of this disclosure, the electrical device 100 may be a switch or contactor assembly, such as a DC contactor. In other examples, the electrical devicemay be a hybrid device, e.g., that includes a fuse or disconnect (such as a pyrotechnic disconnect). As will be appreciated from this disclosure, aspects of this disclosure may be incorporated into any electrical device that incorporates one or more movable contacts.

[0020] In the illustrated example, the electrical device 100 includes an electrical device housing 102. The housing 102 includes a housing base 104 disposed between an upper housing portion 106 and a lower housing portion 108. In the example of FIG. 1, the upper housing portion 106 is configured to cooperate with the housing base 104. In examples, the switch assembly housing base 104 and portions of the upper housing portion 106 may be metal parts, e.g., steel parts, welded to each other. In other examples, portions of the upper housing portion 106 can be ceramic, polymeric, or formed of other materials. The upper housing portion 106 defines, at least in part, an upper housing volume 110. In some examples, the upper housing volume 110 may be a hermetically-sealed volume. An electronegative gas may be contained in the upper housing volume 110. This hermetically sealed configuration can help mitigate or prevent electrical arcing between adjacent conductive elements, and in some embodiments, may help provide electrical isolation between conductive contacts, as detailed further herein. In some examples, the upper housing volume 110 can be under vacuum conditions, and can be hermetically sealed using known means of generating hermetically sealed electrical devices.

[0021] Features of the electrical device 100 are disposed in the upper housing volume 110.For example, the view of FIG. 1 shows two fixed contacts 112 coupled to the upper housing portion 106. The fixed contacts 112 are disposed partially in the upper housing volume 110 and are configured to electrically connect internal components (detailed further herein) of the electrical device 100 to external circuitry, for example, to an electrical system or device. For example, the fixed contacts 112 may be terminals configured to facilitate connection of first electrical leads (notshown) from a voltage source to second electrical leads (also not shown) associated with a load to be powered by the voltage source.

[0022] The electrical device 100 also includes a movable contact 114. The movable contact 114 is movable between a first position spaced from the fixed contacts 112 and a second position contacting the fixed contacts 112. The first position is shown in FIG. 1, and the movable contact 114 may be moved upward (in the orientation of FIG. 1) from the illustrated position to the second position. In the illustrated example, the movable contact 114 is a generally elongate member that, in the second position, not illustrated but just described, can simultaneously contact both of the fixed contacts 112. That is, a first end portion of the movable contact 114 can contact a first of the fixed contacts 112, and a second end portion of the movable contact 114 can contact a second of the fixed contacts 112. Accordingly, the movable contact 114 can selectively couple the two fixed contacts 112, to facilitate current flow between the fixed contacts 112, via the movable contact 114, and thus through the electrical device 100.

[0023] The electrical device 100 also includes an actuator assembly 116 configured to, among other functions, facilitate selective opening and closing of the electrical device 100, e.g., by facilitating selective movement of the movable contact 114 into and out of contact with the fixed contacts 112. In examples, the actuator assembly 116 can include the movable contact 114 and / or may be operatively coupled to the movable contact 114.

[0024] The actuator assembly 116 is illustrated as including a shaft 118, a carrier member 120, and a plunger 122. The carrier member facilitates attachment of an upper end of the shaft 118 to the movable contact 114 and a lower end of the shaft 118 is coupled to the plunger 122. The actuator assembly 116 is for example only; other types of actuator assemblies, includingdifferently configured shafts, carrier members, and / or plungers may be used. In some alternative examples, the shaft may be fixed directly to the movable contact 114, e.g., such that the carrier member 120 may not be included.

[0025] As also shown in FIG. 1, the shaft 118 extends through the base plate 104, such that the lower end of the shaft 118 is disposed in a lower volume 128 of the electrical device 100. The lower volume 128 is defined at least in part by the lower housing portion 108.

[0026] The actuator assembly 116 is driven by a coil 130, e.g., a DC coil. In examples of this disclosure, the actuator assembly 116 and the coil 130 (along with, in some examples, other, associated components described herein), may comprise an actuator system for the electrical device 100. For example, and as shown in FIG. 3, the coil 130 is disposed proximate a plunger tube 132. In examples, the coil 130 is a cylindrical coil that is disposed around the plunger tube 132. The plunger 122 is disposed in the plunger tube 132, and the plunger 122 is movable relative to the plunger tube 132. In examples, the plunger tube 132 may be fixed relative to the coil 130, and the plunger 122 is free to move axially relative to the plunger tube 132 (and the coil 130) in response to activation / deactivation of the coil 130. The coil 130 may be selectively energized to cause movement of the plunger 122.

[0027] In examples of this disclosure, the coil 130 is a bobbinless or self-supporting coil. Specifically, the coil 130 is free of a bobbin or other central support around which the windings comprising the coil are disposed. In conventional contactors, an electromagnetic coil comprises a conductive wire wound about a bobbin. The bobbin is thus disposed between the coil and the plunger tube 132 (and the plunger 122). As noted above, the presence of the bobbin in the conventional devices creates a gap between the coil and the plunger tube and / or may interfere withthe field generated by the coil. In contrast, the coil 130 of this disclosure does not include such a bobbin.

[0028] In some examples, the coil 130 may be supported other than with a bobbin. For example, FIG. 1 shows that the coil 130 includes an overmold 134 formed on an outer, e.g., radially outward, portion of the coil 130. The overmold 134 may be a polymeric material that acts as a sleeve or the like formed around the coil 130. For example, during formation of the coil 130, wire may be wound around a post or other substrate, and the overmold 134 may be applied as a coating or the like on the wound wire. The post or other substrate may then be removed, e.g., such that the remaining coil 130, with the overmold 134, are self-supporting, e.g., without a bobbin. Moreover, and although not illustrated, the coil 130 may also or alternatively include a coating, e.g., a thermo-bonded coating, a varnish coating, or the like, which may provide some structural rigidity to the coil 130.

[0029] As also illustrated in FIG. 1, the coil 130 may have a stepped profile along its longitudinal direction. For example, the coil 130 is illustrated as being relatively thicker proximate an upper (in the orientation of FIG. 1) end and relatively thinner proximate an opposite (e.g., lower in the orientation of FIG. 1) end. In the illustrated example, the thinner portion may accommodate inclusion of a static core 136. For example, the static core 136 may be substantially cylindrical and made of a metallic, magnetic, and / or other material. In some examples, the static core 136 may assist in biasing the plunger 122 into the illustrated (open) position and / or the static core 136 may enhance a magnetic field generated by the coil 130.

[0030] FIG. 2 is an elevational, cross-sectional view of a coil assembly 200 showing aspects of the coil 130 in more detail. Specifically, FIG. 2 shows that the coil 130 is made of awire 202 generally formed (e.g., wound) around a longitudinal axis 204. The coil 130 defines a central opening 206, e.g., defining an inner diameter of the coil 130. As shown, the central opening 206 has a smaller diameter proximate the top of the coil 130 and a relatively larger diameter proximate the bottom of the coil 130. In the example, the static core 136 is positioned in the relatively larger diameter portion of the central opening 206.

[0031] FIG. 2 also shows the optional overmold 134 disposed around the wire 202 comprising the coil 130.

[0032] As also shown in FIG. 2, a terminal 208 (e.g., an electrical terminal) may be coupled to the coil 130. The terminal may be configured to couple the coil to a power source, such as a low voltage power source, to selectively energize the coil 130, as detailed herein. As will be appreciated from the arrangement of FIG. 2, because the central opening 206 is defined by the wire 202 comprising the coil 130, the coil 130 may be directly adjacent to the plunger (not shown in FIG. 2) to be moved by the coil 130.

[0033] As described above, the contactor or electrical device design according to aspects of this disclosure may differ from conventional contactors that require a bobbin. For example, FIG. 3 shows a coil assembly 300 having a conventional bobbin-type coil, in a view generally corresponding to the view of FIG. 2. In the example of FIG. 3, the coil assembly 300 includes coil windings 302 formed about a bobbin 304. The bobbin 304 comprises a substrate or spool about which the coil windings 302 are wrapped. Thus, in the example of FIG. 3, an inner diameter 306 of the bobbin 304 defines the surface of the coil assembly 300 closest to the plunger (not shown in FIG. 3). Unlike in the example of FIG. 2, the coil windings 302 are spaced from the plunger byat least the thickness of the bobbin 304. As noted above, this increased thickness or spacing may lead to inefficiencies in the coil.

[0034] For the sake of comparison, the example of FIG. 3 is illustrated as including a sleeve308, which may correspond in size and shape to the overmold 134, and a static core 310, which may generally correspond in size and shape to the static core 136 discussed above. For completeness, the coil assembly 300 also includes a terminal 312, which may generally correspond to the terminal 208 discussed above.

[0035] As will be appreciated from a comparison of FIG. 2 and FIG. 3, the inclusion of the bobbin 304 displaces the windings 302 further from the longitudinal axis. Moreover, because of the inclusion of the bobbin 304, the coil assembly 300 necessarily includes fewer windings to occupy the same volume.

[0036] As will be appreciated from the foregoing, the arrangements of FIGS. 1 and 2 may improve electromagnetic efficiency by removing the gap between the coil and movable elements in the space freed by removing the bobbin. Instead of the bobbin, aspects of this disclosure may present windings that may be structurally supported via a thermo-bonded coating, a varnish coating, an overmold, or any other method. Moreover, the coil 130, because of the omission of a bobbin, may be lighter and / or cheaper, e.g., due to smaller coil winding diameters allowing less copper.

[0037] In some examples, the coil 130 according to aspects of this disclosure may provide up to 30% copper savings with equivalent performance to existing designs. The devices according to this disclosure may also allow for higher power coils, more contact force (e.g., with similarcopper usage, and / or similar or lower power coils with similar or lower contact force (e.g., with reduced copper usage).

[0038] While the subject technology has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and / or modifications can be made to the subject technology without departing from the spirit or scope of the subject technology. For example, each claim may depend from any or all claims in a multiple dependent manner even though such has not been originally claimed.

Claims

WHAT IS CLAIMED IS:

1. An actuator system for an electrical device, the actuator system comprising: an actuator assembly configured to move a movable contact between a first position and a second position; and a self-supporting electromagnetic coil configured to be selectively energized to cause the actuator assembly to move the movable contact between the first position and the second position.

2. The actuator system of claim 1, wherein the self-supporting electromagnetic coil is free of a bobbin.

3. The actuator system of claim 1, further comprising an overmold disposed on an outer surface of the electromagnetic coil.

4. The actuator system of claim 3, wherein the overmold comprises a sleeve around the electromagnetic coil.

5. The actuator system of claim 1, further comprising at least one of a thermo-bonded coating or a varnish coating disposed at least partially on the self-supporting electromagnetic coil to provide stability to the electromagnetic coil.

6. The actuator system of claim 1, wherein the electromagnetic coil defines a central opening having a first diameter proximate a first end of the electromagnetic coil and a second diameter larger than the first diameter proximate a second end of the electromagnetic coil.

7. The actuator system of claim 6, further comprising a static core disposed in the central opening proximate the second end of the electromagnetic coil.

8. The actuator system of claim 1, wherein the self-supporting electromagnetic coil comprises a copper coil including a plurality of windings of a copper wire.

9. The actuator system of claim 1, wherein the actuator assembly comprises a shaft disposed at least partially in an opening defined by the self-supporting electromagnetic coil.

10. The actuator system of claim 9, further comprising: a plunger tube disposed in the opening defined by the self-supporting electromagnetic coil and fixed relative to the self-supporting electromagnetic coil; and a plunger coupled to the shaft and disposed in the plunger tube, the plunger being configured to move within the plunger tube and relative to the plunger tube.

11. An electrical device comprising: fixed contacts; a movable contact movable relative to the fixed contacts;an actuator assembly configured to move the movable contact between a first position spaced from the fixed contacts and a second position contacting the fixed contacts; and an electromagnetic coil selectively energized to move cause the actuator assembly to move the movable contact between the first position and the second position, wherein the electromagnetic coil is a self-supporting coil.

12. The electrical device of claim 11, wherein the self-supporting electromagnetic coil is free of a bobbin.

13. The electrical device of claim 11, further comprising an overmold disposed on an outer surface of the electromagnetic coil.

14. The electrical device of claim 13, wherein the overmold comprises a sleeve around the electromagnetic coil.

15. The electrical device of claim 11 , wherein the electromagnetic coil defines a central opening having a first diameter proximate a first end of the electromagnetic coil and a second diameter larger than the first diameter proximate a second end of the electromagnetic coil.

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