Weight optimized high voltage contactor and method of manufacture

Abstract

In a particular embodiment, a contactor assembly is disclosed that includes a magnetic circuit defining a magnetic flux path extending between a top core and a bottom core through an outer core and a sleeve core, a solenoid coil arranged to generate magnetic flux along the magnetic flux path, and an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact. In this embodiment, at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material and interfaces between the outer core and the top core and between the outer core and the bottom core are permanently joined.

Description

WEIGHT OPTIMIZED HIGH VOLTAGE CONTACTORBACKGROUND

[0001] Electromechanical switching devices, such as contactors and relays, are commonly used to control the flow of electrical power in a wide range of electrical systems. In high-voltage applications, including electric vehicles (EVs), aerospace electrical systems, and energy storage systems, contactors are required to reliably switch large currents while meeting stringent requirements for safety, durability, and performance.

[0002] In many EV and industrial applications, contactors have traditionally been designed with an emphasis on cost, robustness, and electrical rating. As a result, such contactors often employ relatively large and heavy magnetic circuits, coils, and actuators to ensure sufficient contact force, travel, and response time under a wide range of operating conditions. While these designs are generally effective, they can impose significant penalties in terms of weight, power consumption, and thermal management.

[0003] Weight is an increasingly critical design constraint in certain markets, particularly in aerospace and advanced electrified vehicle applications, where reductions in component mass can yield substantial improvements in system efficiency, operating cost, and overall vehicle performance. In these environments, the cost associated with excess weight can far exceed the cost of the contactor itself. However, many existing high-voltage contactors available for such applications are derived from automotive or industrial designs that were not optimized for aggressive weight reduction, and instead retain excess mass in magnetic and structural components.

[0004] Efforts to reduce the size or mass of contactor components can introduce additional challenges. Reducing component mass or actuator size may adversely affect available actuation force, contact travel, response time, or resistance to shock and vibration. In addition, reduced-mass designs may be more sensitive to friction, misalignment, tolerance stack-up, and manufacturing variability7, potentially leading to degraded reliability7or inconsistent performance. As a result, conventional approaches to reducing contactor weight often involve unacceptable tradeoffs between mass reduction and functional performance.

[0005] Accordingly, there remains a need for improved high-voltage contactor designs that address the competing demands of weight reduction, performance, and reliability7in high-voltage electrical systems.SUMMARY

[0006] The following summary is meant to help one skilled in the art understand the various presently disclosed combinations of features. It is not meant to unduly limit the scope of any pending or future claims relating to the disclosure.

[0007] In accordance with at least one embodiment of the present disclosure, a weight optimized high voltage contactor is provided that includes a magnetic circuit and an actuator assembly configured to selectively engage and disengage electrical contacts. The magnetic circuit includes a plurality of core components and a solenoid coil arranged to generate magnetic flux that actuates a plunger to move a contact element between open and closed positions. One or more components of the magnetic circuit and actuator assembly may be formed of magnetically annealed ferromagnetic material and assembled to reduce losses associated with air gaps, thereby improving magnetic efficiency. By increasing the effectiveness of magnetic flux acting on the plunger, the contactor may achieve required actuation force and performance with reduced component mass, including reduced plunger and coil mass, relative to conventional high voltage contactors. In some embodiments, the contactor may be implemented as a conventional or latching contactor and may include guidance, clearance, and sealing features that support reliable operation while maintaining reduced weight.

[0008] In a particular embodiment, a contactor assembly is disclosed that includes a magnetic circuit having a top core, a bottom core, a cylindrical outer core extending between and secured to the top core and the bottom core, a cylindrical sleeve core secured to the bottom core, and a solenoid coil disposed between the cylindrical sleeve core and the cylindrical outer core. The assembly also includes an actuator assembly having a plunger disposed within the cylindrical sleeve core, a plunger shaft operatively coupled to the plunger, and a movable contact operatively coupled to the plunger shaft and configured to selectively engage one or more fixed contacts. In this embodiment, the plunger moves the plunger shaft in response to magnetic flux generated by the magnetic circuit. In addition, at least one of the top core, the bottom core, the cylindrical outer core, the cylindrical sleeve core is formed of a magnetically annealed ferromagnetic material and the cylindrical outer core is welded to the top core and to the bottom core.

[0009] In another embodiment, a contactor assembly is disclosed that includes a magnetic circuit defining a magnetic flux path extending betw een a top core and a bottom core through an outer core and a sleeve core, a solenoid coil arranged to generate magnetic flux along the magnetic flux path, and an actuator including a plunger movable within the sleeve core andoperatively coupled to a movable contact. In this embodiment, at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material and interfaces between the outer core and the top core and between the outer core and the bottom core are permanently j oined.

[0010] In another embodiment, a method of constructing a contactor assembly is disclosed that includes forming a magnetic circuit including a top core, a bottom core, an outer core, and a sleeve core. In this embodiment, at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material. The method also includes welding the outer core to the top core and to the bottom core and positioning a solenoid coil between the outer core and the sleeve core. In addition, the method also includes assembling an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] One or more aspects of the present disclosure are discussed below with reference to the accompanying Figures. It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in one functional block or element.

[0012] Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. For purposes of clarity, however, not every' component may be labeled in every drawing. The Figures are provided for the purposes of illustration and explanation and are not intended to be limiting. In the Figures:

[0013] FIG. 1 is an exploded view of a magnetic circuit for a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0014] FIG. 2 is an exploded view of an actuator assembly for a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0015] FIG. 3 is an exploded view of an example of a w eight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0016] FIG. 4A is a sectional view' of an example of a non-latching w eight optimized high voltage contactor in accordance w ith at least one embodiment of the present disclosure.

[0017] FIG. 4B is a sectional view of an example of a latching weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0018] FIG. 4C is a sectional view of an example of an alternative weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0019] FIG. 5 A illustrates magnetic field saturation in a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0020] FIG. 5B illustrates magnetic field saturation in a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0021] FIG. 6A is a conventional plunger design.

[0022] FIG. 6B is an example plunger design for a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0023] FIG. 7 is a flowchart of an example method of constructing a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure.

[0024] FIG. 8 is a flowchart of an example method of constructing a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] Connecting and disconnecting electrical circuits is as old as electrical circuits themselves and is often utilized as a method of switching power to a connected electrical device between “on” and “off’ states. An example of one device commonly used to connect and disconnect circuits is a contactor, which is electrically connected to one or more devices or power sources. A contactor is configured such that it can change between “open” and “closed” states to interrupt or complete a circuit to control electrical power to and from a device.

[0026] Advances in technology7have led to the widespread adoption of electrical systems and electronic devices. A notable example is the evolution of electric vehicles (EVs), which are becoming the energy-efficient standard and are expected to replace most petroleum-powered vehicles. In high-value and frequently used electrical devices, overcurrent protection is essential to prevent malfunctions, permanent damage, and safety hazards such as electrical shock or fire. As electrical systems continue to evolve, improved solutions are needed to enhance the safety, reliability, and efficiency of mechanisms for triggering contactors.

[0027] Various embodiments of contact assemblies are described herein, featuring integrated components or portions designed to enhance operational performance, reliability, and safety. The present invention introduces new component features that improve functionality7, efficiency, and safety7. Additionally, embodiments of the invention relate to contactors — electrical switching devices — incorporating these advanced contact assemblies, as well as electrical circuits and systems that utilize these improved switching devices.

[0028] The terminology used herein for the purpose of describing particular examples is not intended to be limiting for further examples. Whenever a singular form such as '’a", “an” and “the” is used and using only a single element is neither explicitly nor implicitly defined as being mandatory, further examples may also use plural elements to implement the same functionality. Likewise, when a functionality is subsequently described as being implemented using multiple elements, further examples may implement the same functionality using a single element or processing entity. It will be further understood that the terms “comprises”, “comprising”, “includes” and / or “including”, when used, specify the presence of the stated features, integers, steps, operations, processes, acts, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, processes, acts, elements, components and / or any group thereof.

[0029] It will be understood that when an element is referred to as being “connected” or “coupled” to another element, the elements may be directly connected or coupled via one or more intervening elements. If two elements A and B are combined using an “or”, this is to be understood to disclose all possible combinations, i.e. only A, only B, as well as A and B. An alternative wording for the same combinations is “at least one of A and B”. The same applies for combinations of more than two elements.

[0030] Accordingly, while further examples are capable of various modifications and alternative forms, some particular examples thereof are shown in the figures and will subsequently be described in detail. However, this detailed description does not limit further examples to the particular forms described. Further examples may cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like numbers refer to like or similar elements throughout the description of the figures, which may be implemented identically or in modified form when compared to one another while providing for the same or a similar functionality.

[0031] The aerospace industry requires lightweight high-voltage contactors, but current options are limited to heavier, high-rated contactors designed primarily for cost efficiency in automotive EVs. In aerospace applications, the weight of these contactors significantly impacts both construction and operational costs. While weight reduction techniques exist, they are rarely implemented in automotive EVs, as the additional design complexities and manufacturing costs offer minimal benefits in that context.

[0032] In contrast, the aerospace industry prioritizes weight optimization over cost in high-voltage contactors. As disclosed herein, weight reduction is achieved through an efficient magnetic circuit that maximizes the magnetizing field (B-field) while requiring less magneto-motive force (MMF) from the coil compared to conventional contactors. This design enables the use of a substantially lighter coil while maintaining the same plunger force, enhancing overall efficiency and performance.

[0033] Embodiments described herein utilize magnetically annealed steel, precisely fitted to minimize gaps between core components and welded to enhance plunger force, shock resistance, and clear time performance through improved magnetic flux. Additionally, the design strategically identifies components within the complex magnetic circuit that contribute to magnetic flux and reduces or eliminates the mass of non-contributing parts to optimize efficiency and performance.

[0034] For further explanation, FIG. 1 sets forth an exploded view of a magnetic circuit assembly 100 for a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure. Magnetic circuit assembly 100 includes an outer core 101 and a bottom core 102. In some examples, outer core 101 and bottom core 101 are magnetically annealed. In some examples, outer core 101 and bottom core 102 are formed of an Iron-Cobalt-Vanadium soft magnetic alloy. Disposed inside outer core 101 is coil assembly 105, which includes the solenoid coil used for activating the contactor. Disposed within a center aperture defined by coil assembly 105 is sleeve core 103. In some examples, sleeve core 103 is magnetically annealed. In some examples, sleeve core 103 is formed of an Iron-Cobalt-Vanadium soft magnetic alloy. Sleeve core 103 further defines a center aperture in which the actuator assembly plunger will be located. In the example of FIG. 1, magnetic circuit assembly 100 also includes an optional bushing 104 that is seated over sleeve core 103 on a ledge with the center aperture of coil assembly 105.

[0035] In some examples, magnetic circuit assembly 100 is constructed by welding sleeve core 103 to bottom core 102. For example, sleeve core 103 may be welded to bottom core 102 via laser welding. After welding sleeve core 103 to bottom core 102, outer core 101 is welded to bottom core 102. For example, outer core 101 may be weld to bottom core 102 via laser welding. Coil assembly 105 is inserted between outer core 101 and sleeve core 103. However, it is contemplated that coil assembly 105 can be placed around sleeve core 103 prior to welding outer core 101 to bottom core 102. Bushing 104 is then seated over sleeve core 103 in the center aperture defined by coil assembly 105.

[0036] For further explanation, FIG. 2 sets forth an exploded view of actuator assembly 200 for weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure. Actuator assembly 200 includes plunger 203 defining a center aperture into which plunger spring 211 is disposed. Plunger spring 211 may be seated on aledge within the center aperture, or the center aperture may be narrower near the bottom of plunger 203, to prevent plunger spring 211 from falling through plunger 203. Disposed within plunger spring 211 is plunger spring guide 208, which provides support to plunger spring 211. Actuator assembly 200 also includes plunger shaft 201 passing through the center of plunger spring guide 208, plunger spring 211, and plunger 203. In some examples, plunger shaft 201 is magnetically annealed. In some examples, plunger shaft 201 is formed of an Iron-Cobalt-Vanadium soft magnetic alloy. Plunger shaft 201 is coupled to plunger 203 via a c-clip 202. In some examples, washer 204 is placed at the bottom of plunger 203 and c-clip 202 couples plunger shaft 201 to washer 204.

[0037] In FIG. 2, top core 205 is coupled to bottom envelope 206. In some examples, top core 205 is magnetically annealed. In some examples, top core 205 is formed of an Iron-Cobalt-Vanadium soft magnetic alloy. Plunger shaft 201 passes through top core 205 and bottom envelope 206 for interfacing with moveable contact 207. In some examples, plunger shaft 201 extends through an aperture in moveable contact 207, where the end of the plunger shaft 201 is coupled to a c-clip 213. Within an arc chamber defined by top envelope 123 and bottom envelope 206, plunger shaft 201 passes through contact spring 210 disposed between moveable contact 207 bottom envelope. In some examples, contact spring 210 is located around plunger shaft 201 between moveable contact 207 and washer 209. Contact spring 210 and c-clip 213 hold moveable contact 207 in a position around plunger shaft 201.

[0038] For further explanation, FIG. 3 sets forth an exploded view of a contactor assembly 300 for a weight optimized high voltage contactor in accordance with at least one embodiment of the present disclosure. Contactor assembly 300 utilizes magnetic circuit assembly 100. In the example contactor assembly 300 of FIG. 3, actuator assembly 200 is fitted over magnetic circuit assembly 100 such that the plunger 203 of actuator assembly 200 is fitted into the center aperture defined by sleeve core 103. In some examples, plunger 203 is magnetically annealed. In some examples, plunger 203 is formed of an Iron-Cobalt-Vanadium soft magnetic alloy. Top core 205 is fastened to outer core 101. Contactor assembly 300 includes atop envelope 123 that is fitted over actuator assembly 200. In some examples, ceramic magnet 125 is fitted between top envelope 123 and bottom envelope 206 of actuator assembly 200. Contactor assembly 300 also includes header assembly 126 including fixed contacts 131, 132. Header assembly 126 is fitted onto top envelope 123. O-rings 124 may be used to seat fixed contacts 131, 132 into contact apertures defined in top envelope 123.

[0039] For further reference. FIG. 4A sets forth a sectional view of contactor assembly 300. Like numeral correspond to like component shown in FIGS. 1-3. In some examples, as shown in FIG. 4A, outer core 101 is welded to top core 205 at weld 401. These welds may be laser welds, for example. In some examples, outer core 101 is welded to bottom core 102 at weld 403. These welds may be laser welds, for example. In some examples, sleeve core 103 is welded to bottom core 102 at weld 405. These welds may be laser welds, for example. Further, in some examples, weld cup 127 may be welded to outer core 101 at weld 407. In some examples, weld cup 127 may be welded to header assembly at weld 409. These welds may be laser welds, for example.

[0040] As discussed above, in some examples, contactor assembly 300 is constructed, in part, by welding outer core 101 of the magnetic circuit assembly 100 to top core 205 and bottom core 102. In this way, there is no air gap between outer core 101 and top core 205 or between outer core 101 and bottom core 102. This increases the efficiency of the magnetic circuit in magnetic circuit assembly 100. The use of magnetically annealed material for construction of outer core 101. top core 205. bottom core 102, and / or sleeve core 103 further increases the efficiency of the magnetic circuit. For example, this material may be an Iron-Cobalt-Vanadium soft magnetic alloy. Likewise, plunger shaft 201 and / or plunger 203 may be constructed of the same magnetically annealed material, thus further increasing the efficiency of magnetic flux operating on plunger 203. Due to increased magnetic efficiency, the size of plunger 203 can be reduced. As such, less magneto-motive force is required from coil assembly 105 and the size of the coil can also be reduced. In this way, the weight of contactor assembly 300 is reduced while still achieving a similar plunger force as that of a comparably convention contactor assembly. In other words, more efficient core material, and changes to assembly methods in accordance with the present disclosure maximize plunger force while reducing the mass of certain components including the coil and plunger.

[0041] An important factor in meeting design requirements for travel time, clear time, and shock performance is the plunger force of the contactor. Embodiments herein achieve the same or similar plunger force of as that of a conventional contactor while achieving a reduction in weight (e.g., 40-60% reduction in weight compared to a conventional contactor with the same plunger force).

[0042] For further explanation, FIG. 4B illustrates a sectional view of a latching contactor 420 designed in accordance with at least one embodiment of the present disclosure. The latching contactor 420 is configured to selectively engage and disengage electrical contactswhile maintaining a closed or open state without requiring continuous energization of a solenoid coil, in contrast to conventional non-latching contactors.

[0043] In the illustrated embodiment, latching contactor 420 includes fixed contacts 421 supported by a header assembly 422, which is coupled to a weld cup 424 by weld 443. In some examples, weld cup 424 is hermetically sealed to header assembly 422 by the weld 443, such as a laser weld, TIG weld, resistance weld, or other suitable joining technique.

[0044] The latching contactor 420 further includes a bottom envelope 423 enclosing part of a magnetic circuit and actuator assembly. The magnetic circuit includes an outer core 426, a sleeve core 428, a bottom core 429, and a top core 445. In some embodiments, one or more of the outer core 426, sleeve core 428, bottom core 429, and top core 445 are composed of a magnetically annealed ferromagnetic material, such as an iron-cobalt-vanadium alloy, to enhance magnetic permeability and reduce hysteresis losses.

[0045] In the example of FIG. 4B, the outer core 426 is fastened to the top core 445 by a weld 425, and to the bottom core 429 by a weld 430, such that air gaps between the outer core 426 and the top and bottom cores are minimized or eliminated. The sleeve core 428 is fastened to the bottom core 429 by a weld 431. These welded interfaces improve magnetic flux continuity through the magnetic circuit and contribute to increased magnetic efficiency.

[0046] A coil assembly 427 is disposed between the outer core 426 and the sleeve core 428. Energization of the coil assembly 427 generates magnetic flux that acts on a plunger 444 disposed within the sleeve core 428. The plunger 444 is coupled to a shaft 440. which extends through the top core 445 and interfaces with amoveable contact 442 having a c-clip 213. In some embodiments, the moveable contact 442 is biased by a spring 441 toward an open or closed position.

[0047] The actuator assembly further includes a plunger spring 437 and a plunger spring guard 438, which guide and bias the plunger 444 during actuation. The plunger 444 and shaft 440 may be retained relative to one another by a c-clip 432 and washer 435 arrangement. In some embodiments, one or more of the plunger 444, shaft 440, or associated components are composed of magnetically annealed material to further enhance magnetic response.

[0048] In the latching contactor 420, the magnetic circuit is configured such that magnetic flux generated during actuation establishes a holding force sufficient to maintain the plunger 444 and moveable contact 442 in a latched position after energization of the coil assembly 427 is discontinued. In this manner, the latching contactor 420 may remain in a closed or open state without continuous power consumption, while still benefiting from the weight-optimized magnetic circuit, reduced air gaps, and welded construction disclosed herein.

[0049] For further explanation, FIG. 4C illustrates a sectional view of an alternative conventional contactor 449 designed in accordance with the present disclosure. The contactor 449 represents an embodiment incorporating additional guidance, clearance, and manufacturability refinements while maintaining a non-latching actuation architecture.

[0050] The contactor 449 includes a weld cup 450 coupled to an outer core 459 by a weld 457, such as a laser weld. In some embodiments, the weld cup 450 is further coupled to a header assembly (not shown in FIG. 4C) to provide a hermetically sealed enclosure.

[0051] A bottom envelope 490 encloses part of the magnetic circuit and actuator assembly. The magnetic circuit includes the outer core 459, a sleeve core 464, a bottom core 466, and a top core 492. In some examples, one or more of these components are composed of magnetically annealed ferromagnetic material to improve magnetic efficiency and reduce required magneto-motive force.

[0052] A coil assembly 468 is disposed between the outer core 459 and the sleeve core 464. The sleeve core 464 defines a central aperture in which a plunger 469 is disposed. The plunger 469 is biased by a plunger spring 470 toward an open position and is coupled to a shaft 451 that extends through the top core 492 to actuate a moveable contact 452, which is configured to selectively engage one or more fixed contacts.

[0053] In the embodiment of FIG. 4C, the contactor 449 includes an added polytetrafluoroethylene (PTFE) bushing 456 positioned between the plunger 469 and an adjacent structure, providing a low-friction bearing surface. The PTFE bushing 456 allows the plunger 469 to float or slide with reduced friction, thereby improving reliability’, reducing stiction, and enhancing clear-time performance, particularly in embodiments employing reduced magnetic force margins.

[0054] The actuator assembly further includes a contact spring 453 and an additional spring 455, which cooperate to bias the moveable contact 452 and the shaft 451 during actuation and release. A spring guide 454 is provided to guide the contact spring 453 and the spring 455, and in some embodiments is configured to maintain axial alignment of the springs and the shaft 451 during operation.

[0055] The contactor 449 further includes a refined bobbin 458 having an optimized form and fit relative to the coil assembly 468, as well as a defined clearance 460 between the coil assembly 468 and adjacent insulation material, such as Kapton. These refinements accommodate manufacturing tolerances, thermal expansion, and electrical insulation requirements while maintaining compact size and reduced mass.

[0056] Arrows 462 schematically illustrate the direction of magnetic flux through the magnetic circuit when the coil assembly 468 is energized. In this embodiment, the magnetic circuit is configured to transmit magnetic flux through the outer core 459, sleeve core 464, bottom core 466, and top core 492, thereby generating sufficient force to actuate the plunger 469, the shaft 451, and the moveable contact 452.

[0057] The alternative conventional contactor 449 of FIG. 4C thus illustrates how the weight-optimized magnetic circuit disclosed herein may be combined with refined guidance structures, low-friction interfaces, spring-biased contact arrangements, and clearance management features to support reliable actuation, manufacturability, and reduced mass.

[0058] For further explanation, FIGS. 5A and 5B illustrate example magnetic field distributions within portions of the magnetic circuit of a contactor in accordance with the present disclosure. In particular, FIGS. 5A and 5B depict magnetic flux density’ and magnetic field intensity, respectively, within one or more ferromagnetic components of the magnetic circuit, including example saturation zones 501 and 503 formed in core material, such as within the sleeve core 103.

[0059] As shown in FIGS. 5A and 5B, magnetic flux is not uniformly distributed throughout the core material during actuation. Instead, localized regions of increased magnetic flux density and field intensity’ are formed along preferred flux paths, while other regions of the core material experience relatively lower magnetic utilization. The saturation zones 501, 503 correspond to regions of the core material that carry a significant portion of the magnetic flux during operation of the contactor, particularly when the solenoid coil is energized to actuate the plunger.

[0060] In some embodiments, the illustrated magnetic field distributions are obtained through finite element analysis (FEA) or other modeling techniques used to evaluate magnetic performance of the contactor. Such analysis may be used to identify regions of the magnetic circuit that contribute materially to magnetic force generation and regions that contribute less significantly. Based on this analysis, the geometry, thickness, or mass of one or more magnetic components may be selectively adjusted to reduce overall weight while maintaining sufficient magnetic flux to achieve desired plunger force, travel, clear time, and shock performance.

[0061] For example, in some embodiments, material may be reduced or removed from regions of the sleeve core 103 or other core components that are outside the saturation zones 501, 503. while material is retained or reinforced in regions that form part of the primary magnetic flux path. In this manner, the magnetic circuit may be optimized to improvemagnetic efficiency and reduce required magneto-motive force without adversely affecting actuator performance.

[0062] For further explanation, FIG. 6A sets forth a diagram of a conventional plunger 601 suitable for use in a contactor actuator. The conventional plunger 601 is generally cylindrical and includes a substantially solid body configured to be acted upon by magnetic flux generated by an associated magnetic circuit. In conventional designs, the plunger 601 is sized primarily to ensure sufficient magnetic coupling and mechanical robustness, often resulting in excess mass that does not materially contribute to force generation or actuation performance.

[0063] For further explanation, FIG. 6B sets forth a diagram of a plunger 603 designed in accordance with at least one embodiment of the present disclosure. In contrast to the conventional plunger 601, the plunger 603 includes a modified geometry in which one or more portions of the plunger body are removed, recessed, or otherwise reduced to decrease overall mass while maintaining functional engagement with the magnetic circuit. In some embodiments, the plunger 603 retains material in regions corresponding to primary magnetic flux paths, while material is reduced in regions that contribute less significantly to magnetic force generation.

[0064] As illustrated in FIG. 6B, the plunger 603 may include cutouts 650, reliefs, or reduced wall thicknesses that reduce mass without adversely affecting plunger travel, structural integrity, or magnetic performance. In some embodiments, the plunger 603 is formed of a magnetically annealed ferromagnetic material, such as an iron-cobalt-vanadium alloy, such that the reduced mass geometry continues to provide sufficient magnetic response when subjected to the magnetic field generated by the solenoid coil.

[0065] The reduction in plunger mass achieved by the geometry of plunger 603 may result in improved actuator performance, including reduced inertia, faster response time, improved clear time, and reduced required magneto-motive force from the coil. By reducing the mass of the plunger while preserving effective magnetic coupling, the overall weight of the contactor assembly may be reduced without compromising required plunger force or contact actuation performance.

[0066] Dimensions shown in FIGS. 6A and 6B are provided in millimeters for purposes of illustration and comparison only, and it will be understood that the specific dimensions, shapes, and proportions of the plunger may vary depending on application requirements, material selection, and desired performance characteristics.

[0067] For further explanation, FIG. 7 sets for an example method of constructing a contactor assembly in accordance with at least one embodiment of the present disclosure. In someexamples, assembling the magnetic circuit for the contactor assembly includes welding 702 a cylindrical sleeve core to a bottom core. For example, the sleeve core may be laser welded to the bottom core. The sleeve core may be composed of sheet stock of magnetically annealed material. The bottom core may be composed of bar stock of the magnetically annealed material. The method also includes welding 704 a cylindrical outer core to the bottom core. For example, the outer core may be laser welded to the bottom core. The outer core may be composed of sheet stock of magnetically annealed material. The method also includes inserting 706 a solenoid coil between the sleeve core and the outer core. The method also includes inserting 708 a plunger assembly into the sleeve core. For example, at least the plunger and plunger shaft coupled to the plunger are inserted into the sleeve core. The method also includes welding 710 a free end of the outer core to a top core. For example, the top core may be placed on the outer core such that the plunger shaft extends through an aperture in the top core. The top core may be laser welded to the outer core. In one example, the magnetic circuit, actuator assembly, and contactor assembly correspond to magnetic circuit assembly 100, contactor assembly 300. and actuator assembly 200 shown in of FIGs.1, 2, 3. and 4A-C.

[0068] For further explanation, FIG. 8 illustrates an alternative method 800 of manufacturing a contactor assembly in accordance with at least one embodiment of the present disclosure. The method 800 represents a manufacturing sequence that differs from other disclosed methods, such as the method illustrated in FIG. 7. while producing a contactor assembly having similar structural and functional characteristics.

[0069] The method 800 includes forming 802 a magnetic circuit including a top core, a bottom core, an outer core, and a sleeve core. In some embodiments, at least a portion of the magnetic circuit components are formed of a magnetically annealed ferromagnetic material, such as an iron-cobalt-vanadium alloy, to support efficient magnetic flux conduction. The magnetic circuit components may be formed by machining, forging, stamping, or other suitable manufacturing techniques prior to assembly.

[0070] The method 800 further includes welding 804 the outer core to the top core and to the bottom core. In some embodiments, the outer core is welded to the top core by a first weld and to the bottom core by a second weld. The welding operations may include laser welding, TIG welding, resistance welding, or other suitable welding techniques. Welding the outer core to the top and bottom cores may reduce magnetic air gaps at the interfaces between these components and provide a rigid magnetic structure.

[0071] In the method 800 of FIG. 8, the sleeve core is welded 805 to the bottom core prior to positioning the solenoid coil. By welding the sleeve core to the bottom core at this stage, alignment between the sleeve core and the bottom core may be established before insertion of the solenoid coil, thereby facilitating subsequent assembly steps and reducing the likelihood of coil damage during welding.

[0072] After welding the sleeve core to the bottom core, the method 800 includes positioning 806 a solenoid coil between the outer core and the sleeve core. The solenoid coil may be inserted radially or axially depending on the configuration of the magnetic circuit and may be supported by a bobbin or other insulating structure. In some embodiments, the solenoid coil is positioned such that it is electrically isolated from the magnetic circuit components by insulation material.

[0073] The method 800 further includes assembling 808 an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact. The plunger may be inserted into a central bore of the sleeve core and coupled to a shaft or other transmission element that actuates the movable contact. Additional actuator components, such as guides or retainers, may also be assembled at this stage.

[0074] The method 800 additionally includes inserting 810 a biasing spring into the sleeve core to urge the plunger toward an open-contact position. The biasing spring may be positioned to act directly on the plunger or indirectly through a shaft or intermediate component. In some embodiments, the biasing spring is inserted after the plunger is positioned within the sleeve core, although alternative insertion sequences may also be used.

[0075] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, apparatuses, and methods, according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

[0076] Advantages and features of the present disclosure can be further described by the following statements:

[0077] 1. A contactor assembly comprising: a magnetic circuit including: a top core; a bottom core; a cylindrical outer core extending between and secured to the top core and the bottomcore; a cylindrical sleeve core secured to the bottom core; and a solenoid coil disposed between the cylindrical sleeve core and the cylindrical outer core; and an actuator assembly including: a plunger disposed within the cylindrical sleeve core; a plunger shaft operatively coupled to the plunger; and a movable contact operatively coupled to the plunger shaft and configured to selectively engage one or more fixed contacts; wherein the plunger moves the plunger shaft in response to magnetic flux generated by the magnetic circuit, wherein at least one of the top core, the bottom core, the cylindrical outer core, the cylindrical sleeve core is formed of a magnetically annealed ferromagnetic material, and wherein the cylindrical outer core is welded to the top core and to the bottom core.

[0078] 2. The contactor assembly of statement 1, wherein the top core, the bottom core, the cylindrical outer core, and the cylindrical sleeve core are each formed of the magnetically annealed ferromagnetic material.

[0079] 3. The contactor assembly of statement 1 or 2, wherein the plunger is formed of the magnetically annealed ferromagnetic material.

[0080] 4. The contactor assembly of any of statements 1-3, wherein the magnetically annealed ferromagnetic material comprises an iron-cobalt-vanadium alloy.

[0081] 5. The contactor assembly of any of statements 1-4, wherein the cylindrical outer core is welded to the top core by a first weld and welded to the bottom core by a second weld.

[0082] 6. The contactor assembly of any of statements 1-5, wherein the first weld and the second weld comprise laser welds.

[0083] 7. The contactor assembly of any of statements 1-6, wherein the cylindrical sleeve core is welded to the bottom core.

[0084] 8. The contactor assembly of any of statements 1-7, wherein the contactor assembly is configured as a non-latching contactor.

[0085] 9. The contactor assembly of any of statements 1-8, wherein the contactor assembly is configured as a latching contactor.

[0086] 10. The contactor assembly of any of statements 1-9, wherein the cylindrical sleeve core defines a central bore that guides axial movement of the plunger during actuation.

[0087] 11. The contactor assembly of any of statements 1-10, wherein the actuator assembly further includes a spring biasing the plunger toward an open-contact position.

[0088] 12. A contactor assembly comprising: a magnetic circuit defining a magnetic flux path extending between a top core and a bottom core through an outer core and a sleeve core; a solenoid coil arranged to generate magnetic flux along the magnetic flux path; and an actuator including a plunger movable within the sleeve core and operatively coupled to amovable contact; wherein at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material, and wherein interfaces between the outer core and the top core and between the outer core and the bottom core are permanently joined.

[0089] 13. The contactor assembly of statement 12, wherein the interfaces are permanently joined by welding.

[0090] 14. The contactor assembly of any of statements 12-13, wherein the magnetically annealed ferromagnetic material comprises an iron-cobalt-vanadium alloy.

[0091] 15. The contactor assembly of any of statements 12-14, wherein the outer core is welded to the top core and the bottom core.

[0092] 16. The contactor assembly of any of statements 12-15, wherein the sleeve core is secured to the bottom core by welding.

[0093] 17. The contactor assembly of any of statements 12-16, wherein the magnetic circuit is enclosed within a hermetically sealed weld cup.

[0094] 18. A method of constructing a contactor assembly, the method comprising: forming a magnetic circuit including a top core, a bottom core, an outer core, and a sleeve core, wherein at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material; welding the outer core to the top core and to the bottom core; positioning a solenoid coil between the outer core and the sleeve core; and assembling an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact.

[0095] 19. The method of statement 18, further comprising welding the sleeve core to the bottom core prior to positioning the solenoid coil.

[0096] 20. The method of statement 18 or 19, further comprising inserting a biasing spring into the sleeve core to urge the plunger toward an open-contact position.

[0097] It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present disclosure without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present disclosure is limited only by the language of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A contactor assembly comprising:a magnetic circuit including:a top core;a bottom core;a cylindrical outer core extending between and secured to the top core and the bottom core;a cylindrical sleeve core secured to the bottom core; anda solenoid coil disposed between the cylindrical sleeve core and the cylindrical outer core; andan actuator assembly including:a plunger disposed within the cylindrical sleeve core;a plunger shaft operatively coupled to the plunger; anda movable contact operatively coupled to the plunger shaft and configured to selectively engage one or more fixed contacts;wherein the plunger moves the plunger shaft in response to magnetic flux generated by the magnetic circuit,wherein at least one of the top core, the bottom core, the cylindrical outer core, the cylindrical sleeve core is formed of a magnetically annealed ferromagnetic material, andwherein the cylindrical outer core is welded to the top core and to the bottom core.

2. The contactor assembly of claim 1, wherein the top core, the bottom core, the cylindrical outer core, and the cylindrical sleeve core are each formed of the magnetically annealed ferromagnetic material.

3. The contactor assembly of claim 1, wherein the plunger is formed of the magnetically annealed ferromagnetic material.

4. The contactor assembly of claim 1, wherein the magnetically annealed ferromagnetic material comprises an iron-cobalt-vanadium alloy.

5. The contactor assembly of claim 1, wherein the cylindrical outer core is welded to the top core by a first weld and welded to the bottom core by a second weld.

6. The contactor assembly of claim 5, wherein the first weld and the second weld comprise laser welds.

7. The contactor assembly of claim 1, wherein the cylindrical sleeve core is welded to the bottom core.

8. The contactor assembly of claim 1, wherein the contactor assembly is configured as a non-latching contactor.

9. The contactor assembly of claim 1, wherein the contactor assembly is configured as a latching contactor.

10. The contactor assembly of claim 1, wherein the cylindrical sleeve core defines a central bore that guides axial movement of the plunger during actuation.

11. The contactor assembly of claim 1, wherein the actuator assembly further includes a spring biasing the plunger toward an open-contact position.

12. A contactor assembly comprising:a magnetic circuit defining a magnetic flux path extending between a top core and a bottom core through an outer core and a sleeve core;a solenoid coil arranged to generate magnetic flux along the magnetic flux path; and an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact;wherein at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material, andwherein interfaces between the outer core and the top core and between the outer core and the bottom core are permanently joined.

13. The contactor assembly of claim 12, wherein the interfaces are permanently joined by welding.

14. The contactor assembly of claim 12, wherein the magnetically annealed ferromagnetic material comprises an iron-cobalt-vanadium alloy.

15. The contactor assembly of claim 12, wherein the outer core is w elded to the top core and the bottom core.

16. The contactor assembly of claim 12, wherein the sleeve core is secured to the bottom core by w elding.

17. The contactor assembly of claim 12, wherein the magnetic circuit is enclosed within a hermetically sealed weld cup.

18. A method of constructing a contactor assembly, the method comprising:forming a magnetic circuit including a top core, a bottom core, an outer core, and a sleeve core, wherein at least a portion of the magnetic circuit is formed of a magnetically annealed ferromagnetic material;welding the outer core to the top core and to the bottom core;positioning a solenoid coil between the outer core and the sleeve core; and assembling an actuator including a plunger movable within the sleeve core and operatively coupled to a movable contact.

19. The method of claim 18, further comprising welding the sleeve core to the bottom core prior to positioning the solenoid coil.

20. The method of claim 18, further comprising inserting a biasing spring into the sleeve core to urge the plunger toward an open-contact position.

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