WO2024187032A1

WO2024187032A1 - Electromechanical switching device with a shock resistance mechanism

Info

Publication number: WO2024187032A1
Application number: PCT/US2024/018943
Authority: WO
Inventors: Stefan Vasilev Metodiev; Nikolay Stoyanov CHEHLAROV
Original assignee: Sensata Technologies Inc.
Priority date: 2023-03-09
Filing date: 2024-03-07
Publication date: 2024-09-12

Abstract

Apparatuses, systems, devices, and methods for operating an electromechanical switching device with a shock resistance mechanism are disclosed. In an embodiment, an electromechanical switching device is disclosed that includes a moveable assembly having a plunger coupled to a plunger shaft. The electromechanical switching device also includes a flange coupled to an upper plate and a plunger spring coupled to the plunger and the flange. In this embodiment, the plunger and the flange have corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly. When application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange.

Description

ELECTROMECHANICAL SWITCHING DEVICE WITH A SHOCK RESISTANCE MECHANISM

FIELD OF THE TECHNOLOGY

[0001] The subject disclosure relates to an electromechanical switching device with a shock resistance mechanism.

BACKGROUND

[0002] Electromechanical switching devices, such as contactors and relays, are designed to carry a certain amount of electrical current for certain periods of time. The switching devices have a moveable assembly that closes the electrical circuit. Typically, the moveable assembly is actuated in linear fashion by a magnetic coil. The moveable assembly is prone to accidental movement by external acceleration, for example by mechanical shock. A shock could cause an unwanted closure of the high voltage contact that could result in a system short circuit.

SUMMARY

[0003] Apparatuses, systems, devices, and methods for operating an electromechanical switching device with a shock resistance mechanism are disclosed. In an embodiment, an electromechanical switching device is disclosed that includes a moveable assembly having a plunger coupled to a plunger shaft. The electromechanical switching device also includes a flange coupled to an upper plate and a plunger spring coupled to the plunger and the flange. In this embodiment, the plunger and the flange have corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly. When application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange .

[0004] In another embodiment, a method of operating an electromechanical switching device with a shock resistance mechanism is disclosed that includes applying a current to a coil in an electromechanical switching device. In this embodiment, the electromechanical switching device includes a moveable assembly including a plunger coupled to a plunger shaft. The electromechanical switching device also includes a flange coupled to an upper plate and a plunger spring coupled to the plunger and the flange. The plunger and the flange have corresponding multi -shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly. When application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange .

[0005] As described previously, unintended mechanical shocks may generate forces leading to the inadvertent activation of the electromechanical switching device. To mitigate these forces and minimize the unintended displacement of the movable assembly, the device employs a shock resistance mechanism. This mechanism comprises a plunger spring and magnetic attraction, interacting at the uniquely contoured interfaces of the plunger and flange. Further explanation will detail how limiting the accidental movement of the movable assembly can also decrease the likelihood of an unintentional closure of the high voltage contact, potentially preventing a system short circuit.

[0006] The foregoing and other objects, features and advantages of the invention will be apparent from the follow ing more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 A is a diagram illustrating a cross-sectional view of an example electromechanical switching device with a shock resistance mechanism according to at least one embodiment of the present disclosure.

[0008] FIG. IB is a diagram illustrating another cross-sectional view of the example electromechanical switching device of FIG. 1A.

[0009] FIG. 1 C is a diagram illustrating an isometric view of the example electromechanical switching device of FIG. 1A.

[0010] FIG. 2 is a diagram illustrating a method of operating an electromechanical switching device with a shock resistance mechanism according to at least one embodiment of the present disclosure.

DETAILED DESCRIPTION

[0011] The terminology⁷ 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 or implicitly defined as being mandatory, further examples may also use plural elements to implement the same functionality⁷. 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. [0012] 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 or 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.

[0013] 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.

[0014] As previously noted, the movable assembly within electromechanical switching devices, such as contactors or relays, is susceptible to unintended movements due to external forces like mechanical shocks. Traditional designs of these devices use linear springs to maintain the plunger in its initial position. To enhance the device's resistance to shock, one might consider increasing the initial force and stiffness of the spring. However, this adjustment necessitates stronger magnetic forces, which, in turn, require higher currents through the coil. Without employing pulse-width modulation (PWM) to limit power, this could lead to excessive energy loss and overheating in the device's coil, potentially reaching detrimental levels.

[0015] An alternative method involves introducing damping to the linear motion, which can be achieved through friction and/or air springs. While air springs demand dynamic sealing, their effectiveness diminishes over time due to wear, offering only a finite improvement in shock resistance. Mechanical locking mechanisms present another solution by enhancing shock resistance when the contactor is in the open position, albeit at the cost of added complexity, which may not be suitable for all applications.

[0016] This disclosure introduces an electromechanical switching device equipped with a specialized shock resistance mechanism. This mechanism is designed to prevent the unintentional activation of the device during events involving high shock, thereby ensuring its reliability and safety under such conditions. For further explanation, FIG. 1A is a diagram illustrating a cross-sectional view of an example electromechanical switching device (100) with a shock resistance mechanism according to at least one embodiment of the present disclosure. FIG. IB is a diagram illustrating another view of the switching device of FIG. 1A. FIG. 1C illustrates a side view of the switching device of FIG. 1A.

[0017] The switching device (100) includes fixed contacts (not pictured) and a moveable contact (not pictured). In the open state, no current flows between the fixed contacts. In the closed state, where the moveable contact makes contact with the fixed contacts, current flows between the fixed contacts through the moveable contact. The movable contact is moved by an actuation assembly that includes a plunger (101), a plunger shaft (102), a plunger spring (104). When a coil (105), such as a solenoid actuator, is energized, a magnetic field is created and concentrated by steel parts - the plunger (101), the flange (103), a steel frame (106), a flux tube (107), and an upper plate (108). The magnetic field forces the plunger (101) with upper direction. If the force is bigger than the pre-load force from the plunger spring (104). the plunger (101) begins to move towards the flange (103). The plunger (101) and the actuator shaft (102) drive the moveable contact toward the fixed contacts until the moveable contact is in a closed position in which contact is established between the moveable contact and the fixed contacts, thus transitioning the switching device (100) from the open state to the closed state. Movement of the plunger (101) compresses the plunger spring (104). When the coil ( 105) is de-energized, the plunger (101 ) is driven downward from the force of the energy stored in the compressed plunger spring (104), and the actuator assembly pulls the moveable contact downward until the moveable contact is in an open position, thus breaking contact between the moveable contact and the fixed contacts. In this example, the plunger spring (104) provides sufficient force load that prevents all movable parts from moving during a 90G shock (e.g., a shock with peak acceleration of 882.9m/s²). The high holding force is needed to achieve high shock resistance in the closed state. In a particular embodiment, the contactor achieves power consumption below 30W for pick-up and approximately 3W for holding.

[0018] Beyond the stabilizing effect of the plunger spring, the innovative design of this electromechanical switching device is further enhanced through the integration of uniquely corresponding multi-shaped interfaces between the plunger (101) and the flange (103). According to various embodiments disclosed herein, the geometry of these interfaces can be chosen and optimized to achieve maximum magnetic attraction at both the start and end of the plunger's travel. This optimization process includes tailoring various parameters, shapes, and configurations to suit specific needs. In certain designs, the interfaces are specifically engineered to minimize the air gap between the plunger and the flange in the open state, thereby reducing the magnetic resistance. This minimal air gap allows for the reduction of holding current via pulse-width modulation (PWM) to levels that ensure adequate force while preventing the plunger (101) from reverting to its original position.

[0019] In one specific embodiment, the flange and the plunger feature corresponding conical interfaces, which serve to amplify the initial magnetic force in the open state. Another embodiment showcases a combination of multi-shaped interfaces between the flange and the plunger. For instance, as depicted in Figures 1A-B, the flange incorporates both a flat interface (120) and a conical interface (122), while the plunger is designed with matching flat (130) and conical (132) interfaces. It is important to note that the dimensions, shapes, and overall configuration of the contactor can be customized and scaled to meet evolving requirements. A further example includes the adoption of corresponding parabolic interfaces between the flange and the plunger, illustrating the versatile design possibilities inherent in this design.

[0020] As explained above, users of a switching device do not want unintended closing of the electromechanical switching device. For example, some electric vehicle (EV) systems divide a battery pack in two halves. In this example, both halves can be switched in parallel or in series. This is required to be able to charge on older stations with 400V and at the same time run a motor with 800V. During driving, two contactors must remain open If accidentally closed by mechanical shock (i.e. crash), a short circuit in the battery will be created. High shock resistance is needed to ensure safe driving even during high shock events. Typical shock resistance levels are up to 10-50g 11ms half sine. The shock resistance of the disclosed switching device is above 10-50g 11 ms half sine. Using the shock resistant mechanism described in embodiments of the present disclosure, high shock resistance may be created and the chance of accidental closure of the contractor is reduced.

[0021] For further explanation, FIG. 2 sets forth a diagram illustrating a method of operating an electromechanical switching device with a shock resistance mechanism according to at least one embodiment of the present disclosure. The method of FIG. 2 includes applying (202) a current to a coil in an electromechanical switching device that includes a moveable assembly having a plunger coupled to a plunger shaft. The electromechanical switching device also includes a flange coupled to an upper plate and a plunger spring coupled to the plunger and the flange. In this embodiment, the plunger and the flange have corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly. When application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange .

[0022] Advantages and features of the present disclosure can be further described by the following statements:

[0023] 1. An electromechanical switching device comprising: a moveable assembly including a plunger coupled to a plunger shaft; a flange coupled to an upper plate; a plunger spring coupled to the plunger and the flange; the plunger and the flange having corresponding multishaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly; when application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange .

[0024] 2. The electromechanical switching device of statement 1, wherein the multi-shaped interfaces include corresponding conical interfaces.

[0025] 3. The electromechanical switching device of statement 1 or 2, wherein the multishaped interfaces include corresponding flat interfaces.

[0026] 4. The electromechanical switching device of any of statements 1-3, wherein the multi-shaped interfaces include corresponding flat interfaces and corresponding conical interfaces.

[0027] 5. The electromechanical switching device of any of statements 1 -4, wherein the multi-shaped interfaces include corresponding parabolic interfaces.

[0028] 6. The electromechanical switching device of any of statements 1-5, wherein the coil is a solenoid actuator.

[0029] 7. The electromechanical switching device of any of statements 1-6, wherein the plunger spring is configured to apply a preload force on the plunger to prevent the moveable assembly from moving to a closed position.

[0030] 8. The electromechanical switching device of any of statements 1-7, wherein the moveable assembly is surrounded by a steel frame.

[0031] 9. The electromechanical switching device of any of statements 1-8 further comprising: a plurality of stationary contacts; and a moveable contact coupled to the plunger shaft and configured to engage with the plurality of stationary contacts in a closed position. [0032] 10. A method of operating an electromechanical switching device with a shock resistance mechanism, the method comprising: applying a current to a coil in an electromechanical switching device that includes: a moveable assembly including a plunger coupled to a plunger shaft; a flange coupled to an upper plate; a plunger spring coupled to the plunger and the flange; the plunger and the flange having corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly; when application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange.

[0033] 11. The method of statement 10, wherein the multi-shaped interfaces include corresponding conical interfaces.

[0034] 12. The method of statement 10 or 11, wherein the multi-shaped interfaces include corresponding flat interfaces.

[0035] 13. The method of any of statements 10-12, wherein the multi-shaped interfaces include corresponding flat interfaces and corresponding conical interfaces.

[0036] 14. The method of any of statements 10-13, wherein the multi-shaped interfaces include corresponding parabolic interfaces.

[0037] 15. The method of any of statements 10-14, wherein the coil is a solenoid actuator. [0038] 16. The method of any of statements 10-15, wherein the plunger spring is configured to apply a preload force on the plunger to prevent the moveable assembly from moving to a closed position.

[0039] 17. The method of any of statements 10-16, wherein the moveable assembly is surrounded by a steel frame.

[0040] 18. The method of any of statements 10-17, wherein the electromechanical switching device further comprises: a plurality of stationary contacts; and a moveable contact coupled to the plunger shaft and configured to engage with the plurality of stationary contacts in a closed position.

[0041] 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

CLAIMS What is claimed is:

1. An electromechanical switching device comprising: a moveable assembly including a plunger coupled to a plunger shaft; a flange coupled to an upper plate; a plunger spring coupled to the plunger and the flange; the plunger and the flange having corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly; when application of the electric current to the coil is removed, the force of the energy- stored in the plunger spring drives the plunger away from the flange.

2. The electromechanical switching device of claim 1 wherein the corresponding multishaped interfaces include corresponding conical interfaces.

3. The electromechanical switching device of claim 1 wherein the corresponding multishaped interfaces include corresponding flat interfaces.

4. The electromechanical switching device of claim 1. wherein the corresponding multishaped interfaces include corresponding flat interfaces and corresponding conical interfaces.

5. The electromechanical switching device of claim 1, wherein the corresponding multishaped interfaces include corresponding parabolic interfaces.

6. The electromechanical switching device of claim 1, wherein the coil is a solenoid actuator.

7. The electromechanical switching device of claim 1, wherein the plunger spring is configured to apply a preload force on the plunger to prevent the moveable assembly from moving to a closed position.

8. The electromechanical switching device of claim 1, wherein the moveable assembly is surrounded by a steel frame.

9. The electromechanical switching device of claim 1 further comprising: a plurality of stationary contacts: and a moveable contact coupled to the plunger shaft and configured to engage with the plurality⁷ of stationary⁷ contacts in a closed position.

10. A method of operating an electromechanical switching device with a shock resistance mechanism, the method comprising: applying a current to a coil in an electromechanical switching device that includes: a moveable assembly including a plunger coupled to a plunger shaft; a flange coupled to an upper plate; a plunger spring coupled to the plunger and the flange; the plunger and the flange having corresponding multi-shaped interfaces configured for magnetically attracting the flange and the plunger in response to application of an electric current to a coil surrounding the moveable assembly; when application of the electric current to the coil is removed, the force of the energy stored in the plunger spring drives the plunger away from the flange .

11. The method of claim 10 wherein the corresponding multi-shaped interfaces include corresponding conical interfaces.

12. The method of claim 10 wherein the corresponding multi-shaped interfaces include corresponding flat interfaces.

13. The method of claim 10, wherein the corresponding multi-shaped interfaces include corresponding flat interfaces and corresponding conical interfaces.

14. The method of claim 10, wherein the corresponding multi-shaped interfaces include corresponding parabolic interfaces.

15. The method of claim 10, wherein the coil is a solenoid actuator.

16. The method of claim 10, wherein the plunger spring is configured to apply a preload force on the plunger to prevent the moveable assembly from moving to a closed position.

17. The method of claim 10, wherein the moveable assembly is surrounded by a steel frame.

18. The method of claim 10, wherein the electromechanical switching device includes: a plurality of stationary contacts: and a moveable contact coupled to the plunger shaft and configured to engage with the plurality of stationary contacts in a closed position.