Torsion spring assembly for switchgear

Abstract

The invention relates to a torsion spring assembly for a switching device (90, 80). The torsion spring assembly comprises at least one torsion spring (12a, 12b, 12c) configured to be arranged about a pivot axis (18, 20) for pivoting the at least one movable arm (60, 50) between a closed position, in which the current path is closed, and an open position, in which the current path is open. The at least one torsion spring (12a, 12b, 12c) is configured to be connected at a first end to the pivot shaft (18, 20) and at a second end to a base structure (22, 24) supporting the pivot shaft (18, 20).

Description

Technical Field

[0001] The present disclosure generally relates to switchgear for isolating an electrical device from a power line. More specifically, the present disclosure relates to providing a torsion spring assembly for switchgear. Background Art

[0002] Generally, switchgear is used to isolate an electrical device from a power line. Switchgear may include a disconnect switch (e.g., a vertical-break disconnect switch) and / or an earthing switch. A disconnect switch is a mechanical switch adapted to isolate an electrical device from a power line. Disconnect switches are typically used in high-voltage environments to create a visible break point to ensure reliable isolation of the electrical device from the power line, such that the electrical device can be safely operated or repaired without load. An earthing switch operates in conjunction with the disconnect switch to connect the isolated electrical device to ground, such that capacitive or inductive currents remaining on the isolated electrical device can be eliminated, and the isolated electrical device can be more safely operated or repaired.

[0003] Disconnect switches typically include a compression spring assembly that provides the torque required to operate the disconnect switch. Similarly, an earthing switch connected to the disconnect switch includes a dead weight assembly that provides the torque required to operate the earthing switch. However, such compression spring assemblies and dead weight assemblies according to the prior art include multiple components that can only be assembled using high skills. Such assembly results in higher costs for the compression spring assembly and the dead weight assembly, which ultimately results in higher costs for the disconnect switch and the earthing switch.

[0004] Furthermore, compression spring assemblies are typically provided for disconnect switches operating at higher voltage ratings, e.g., voltage ratings between 145 kV and 550 kV. Thus, a compression spring assembly may not be suitable for operating a disconnect switch at a lower voltage rating, as operating a disconnect switch at a lower voltage rating requires less torque.

[0005] Figure 1 An exemplary disconnect switch 90 including a compression spring assembly 10 according to the prior art is disclosed.

[0006] In this example, the disconnect switch 90 is a vertical-break disconnect switch and includes a movable arm 60 (also referred to as the disconnect switch movable arm 60), the movable arm 60 being connected to a pivot shaft 18 for pivoting the movable arm 60 between a closed position where the current path is closed and an open position where the current path is open. The vertical-break disconnect switch 90 includes a base structure 22 that supports the pivot shaft 18. The ends of the pivot shaft 18 are supported by both side portions 14a, 14b of the base structure 22, as Figure 1As shown. The pivot shaft 18 rotates or revolves about an axis to pivot the movable arm 60 to open or close the earthing switch. This axis can be the axis of a drive member (such as a drive insulator) (not shown) to which the pivot shaft 18 is connected.

[0007] The vertical-break disconnector 90 includes a compression spring assembly 10. The compression spring assembly 10 is configured to provide the torque required to operate the vertical-break disconnector 90. The compression spring assembly 10 is disposed on a side opposite to the connection point 16 of the pivot shaft 18 via a suitable connection mechanism such as a lever, a linkage, or the like.

[0008] The vertical-break disconnector 90 may also include an earthing switch having a movable arm (not shown), and additionally, a deadweight assembly is used to support the weight of the movable arm / aluminum conductor of the earthing switch by reducing the energy consumption from the operating drive. The deadweight assembly provides the torque required to operate the earthing switch. The deadweight assembly is fixed to the pivot shaft in a direction opposite to that of the aluminum conductor / movable arm of the earthing switch (e.g., at a 180-degree angle). However, the deadweight assembly is very heavy and bulky, as the deadweight assembly may have a weight of approximately 28 - 30 kilograms. Therefore, it is difficult to assemble the deadweight assembly in a proper position in a shorter time. Additionally, the transportation of the deadweight assembly requires separate packaging. SUMMARY OF THE INVENTION

[0009] The compression spring assembly and the deadweight assembly according to the prior art may not be suitable for the disconnector and the earthing switch respectively, because the compression spring assembly and the deadweight assembly are bulky and require high skills and careful assembly. In addition, the compression spring assembly may not be suitable for disconnectors operating at lower voltage ratings.

[0010] Therefore, there is a need to provide a simple and easily assembled spring assembly for switchgear operating at lower or higher voltage ratings, which alleviates at least some of the above problems.

[0011] Therefore, an object of the present disclosure is to provide a torsion spring assembly for switchgear to alleviate, reduce, or eliminate all or at least some of the above-mentioned drawbacks of the currently known solutions.

[0012] This object and other objects are achieved by a torsion spring assembly as defined in the appended claims. The term "exemplary" in this context is understood to be used as an instance, example, or illustration.

[0013] It should be understood that even though the exemplary prior art described herein relates to a vertical-break disconnector, the problems mentioned are relevant to other types of disconnectors and earthing switches. Therefore, the present invention disclosed herein is applicable to several types of disconnectors or earthing switches, especially disconnectors and earthing switches including a movable arm.

[0014] According to a first aspect of the present disclosure, there is provided a torsion spring assembly for a switching device. The torsion spring assembly includes at least one torsion spring configured to be arranged around a pivot axis for pivoting at least one movable arm between a closed position and an open position, where in the closed position, the current path is closed, and in the open position, the current path is open. The at least one torsion spring is configured to be connected to the pivot axis at a first end and to a base structure supporting the pivot axis at a second end.

[0015] The movable arm may include a movable contact. The at least one torsion spring may be directly connected to the pivot axis at a first end. The at least one torsion spring may be directly connected to the base structure at a second end.

[0016] Thus, compared with the compression spring assemblies and dead weight assemblies of the prior art, a simple torsion spring assembly including fewer components is provided. In addition, at least one torsion spring of the torsion spring assembly supports and balances any self-weight of the movable arm / current path conductor, and reduces the energy requirement of the operating driver for operating the switching device, because the at least one torsion spring is arranged around the pivot axis about which the movable arm / current path conductor rotates.

[0017] The second end of the at least one torsion spring may be configured to be held in a fixed position on the base structure. This enables the second end of the torsion spring to be firmly connected, thereby restricting the movement of the second end of the torsion spring, which helps the torsion spring to work.

[0018] The torsion spring assembly may further include a stop plate configured to be attached to the base structure for holding the second end of the at least one torsion spring in a fixed position. The stop plate may be a separate plate attached to the base structure for connecting the second end of the torsion spring. Thus, the stop plate is used to prevent the second end of the torsion spring from sliding, thereby restricting the movement of the second end of the torsion spring. The stop plate may be a bracket stop plate.

[0019] In some examples of the present disclosure, the second end of the at least one torsion spring includes an annular portion and is configured to be connected to the base structure by means of a fastener (such as a bolt) extending through the annular portion. The annular portion is a lateral annular extension of the torsion spring, and the annular portion is connected to the base structure. Thus, connecting the annular portion to the base structure by means of a fastener enables the second end of the torsion spring to be firmly fixed to the base structure, which prevents the second end of the torsion spring from sliding.

[0020] In some examples, the first end of the at least one torsion spring includes an annular portion and is configured to be connected to the pivot axis by means of a fastener (such as a bolt) extending through the annular portion.

[0021] Therefore, at least one torsion spring can be easily assembled without any high skills. Since assembling at least one torsion spring does not require high skills, the time required to assemble the torsion spring assembly can be reduced, and the torsion spring can also be easily transported.

[0022] In some examples, the torsion spring assembly includes two torsion springs configured to arrange one torsion spring at each end of the pivot shaft.

[0023] The design and configuration of the torsion spring can vary according to the application. As an example, the inner diameter of the torsion spring, the number of active body turns, and the wire diameter can depend on the switching device in which the torsion spring assembly should be used. In some examples, the torsion spring can be designed for different operating voltage ranges of disconnectors. In some examples, the torsion spring can be designed for earthing switches operating in different voltage ranges. Therefore, different designs of the torsion spring can be used for different operating voltage ranges of the switching device.

[0024] According to a second aspect of the present disclosure, there is provided a switching device for a circuit. The switching device includes at least one movable arm connected to a pivot shaft for pivoting the at least one movable arm between a closed position and an open position, in the closed position, the current path is closed, and in the open position, the current path is open. The switching device further includes a base structure for supporting the pivot shaft. The switching device further includes a torsion spring assembly including at least one torsion spring arranged around the pivot shaft and connected to the pivot shaft at a first end and to the base structure at a second end. The advantage is that the torsion spring assembly provided herein can be simple and easy to assemble. Therefore, the cost of the torsion spring assembly can be reduced, which ultimately reduces the cost of the switching device. The switching device can be an earthing switch or a disconnector. The switching device can be an earthing switch or a disconnector of center-break type, double-break type, knee type, vertical-break type, etc.

[0025] In some embodiments, any of the above aspects may additionally have the same or corresponding features as any of the various features described above for any of the other aspects.

[0026] Any advantages associated with the torsion spring assembly disclosed herein can be used for any switching device operating at a lower voltage rating or a higher voltage rating by changing at least some of the parameters associated with the at least one torsion spring. Examples of these parameters can include the wire diameter of the torsion spring, the wire cross-section, the number of turns of the torsion spring, and the diameter of the torsion spring.

[0027] Other advantages will be apparent to those skilled in the art. Certain examples of the present disclosure may have some or all of the stated advantages. Description of the Drawings

[0028] The foregoing will become apparent from the following more particular description of example embodiments as illustrated in the accompanying drawings, in which like reference numerals refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis being placed upon illustrating example embodiments.

[0029] Figure 1 An exemplary vertical-break disconnect switch including a compression spring assembly according to the prior art is disclosed;

[0030] Figure 2 A circuit according to some examples of the present disclosure is disclosed;

[0031] Figure 3 A switching device of a circuit according to an example of the present disclosure, wherein the switching device includes a torsion spring assembly and the switching device is a vertical-break disconnect switch;

[0032] Figure 4A A vertical-break disconnect switch including a torsion spring assembly according to some examples of the present disclosure is disclosed;

[0033] Figure 4B A vertical-break disconnect switch including a torsion spring assembly according to some examples of the present disclosure is disclosed;

[0034] Figure 4C Another view of a vertical-break disconnect switch including a torsion spring assembly according to an example of the present disclosure is disclosed;

[0035] Figure 5A and Figure 5B An illustration of arranging two torsion springs according to an example of the present disclosure, wherein one torsion spring is arranged at each end of the pivot shaft of the vertical-break disconnect switch;

[0036] Figure 6A and Figure 6B An illustration of arranging a torsion spring at the end of the pivot shaft of a vertical-break disconnect switch according to some examples of the present disclosure;

[0037] Figure 7A and Figure 7B An illustration of arranging a torsion spring at the end of the pivot shaft of a vertical-break disconnect switch according to some examples of the present disclosure;

[0038] Figure 8 A switching device of a circuit according to an example of the present disclosure, wherein the switching device includes a torsion spring assembly and the switching device is an earthing switch;

[0039] Figure 9Disclosed is an earthing switch including a torsion spring according to an example of the present disclosure; and

[0040] Figure 10 Disclosed is an exemplary torsion spring provided for a switching device according to an example of the present disclosure, wherein the switching device is a vertical-break disconnector operating at a first voltage rating. Detailed Description

[0041] Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. However, the devices and methods disclosed herein may be implemented in many different forms and should not be construed as limited to the aspects set forth herein. Like numbers in the drawings always refer to like elements.

[0042] The terms used herein are for the purpose of describing particular aspects of the present disclosure only and are not intended to limit the invention. It should be emphasized that when used in this specification, the term "comprising / including" is used to specify the presence of the stated features, integers, steps or components, but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise.

[0043] Switching device: As used herein, a switching device refers to a disconnector or an earthing switch.

[0044] In the following detailed description, the switching device will be described as a vertical-break disconnector or an earthing switch. However, it should be understood that the switching device may be any other type of disconnector or earthing switch having a movable arm. The switching device may be center-break type, double-break type, knee type, etc.

[0045] Figure 2 An example circuit 100 is disclosed. The circuit 100 mentioned herein includes switching devices 90, 80. In some examples, the switching devices 90, 80 may be disconnectors, for example, the vertical-break disconnector 90. It should be noted that any other type of disconnector may be considered herein, such as a horizontal knee-break disconnector, a side-break disconnector, etc. In some examples, the switching devices 90, 80 may be an earthing switch 80. In some examples, the earthing switch 80 may be operated by being connected to the vertical-break disconnector 90. In this document, it should be understood that the vertical-break disconnector 90 and the earthing switch 80 may be arranged together to form the circuit 100.

[0046] A vertical-break disconnect switch 90 (also referred to as an isolator, switchgear, disconnect switch, etc.) can be a mechanical switch for isolating an electrical installation from a power line. The vertical-break disconnect switch 90 can include a movable contact and a fixed contact (described in a later part of the specification in connection with the accompanying drawings). As Figure 2 shown, the movable contact can be pivotally supported on a first mounting post 66 and insulated from the first mounting post 66 by an insulating member 58a and an insulating member 58b. In some examples, the insulating members 58a and 58b can be ceramic insulating members. The fixed contact can be mounted on a second mounting post 68 and insulated from the second mounting post 68 by an insulating member 56. The movable contact and the fixed contact of the vertical-break disconnect switch 90 are electrically connected to opposite ends of a power line (e.g., a bus bar in a high-voltage system). The movable contact and the fixed contact of the vertical-break disconnect switch 90 can be respectively used to visibly isolate one end of the corresponding power line from the other end after a circuit breaker in the power line has been opened.

[0047] The vertical-break disconnect switch 90 includes a movable arm 60 connected to a pivot axis (described in a later part of the specification in connection with the accompanying drawings), the pivot axis being for pivoting the movable arm 60 between a closed position in which the current path is closed and an open position in which the current path is open.

[0048] In some embodiments, the vertical-break disconnect switch 90 can operate with one or more earthing switches. For simplicity, Figure 2 operation of the vertical-break disconnect switch 90 with two earthing switches 80a and 80b is disclosed. The earthing switches 80a and 80b can be operable to connect the isolated electrical installation to earth so that capacitive or inductive currents remaining on the isolated electrical installation can be dissipated. Thus, the isolated electrical installation can be operated or repaired more safely. The first earthing switch 80a and the second earthing switch 80b include movable contacts and fixed contacts. The movable contact of the first earthing switch 80a can be pivotally supported to the first mounting post 66. The fixed contacts of the first earthing switch 80a and the second earthing switch 80b are arranged directly above the pivot axes of the respective movable contacts of the first earthing switch 80a and the second earthing switch 80b ( Figure 3 not shown in the figure). The first earthing switch 80a is electrically connected between one end of the power line and earth, and the movable contact of the vertical-break disconnect switch 90 is connected to the aforementioned one end of the power line. The second earthing switch 80b is electrically connected between the other end of the power line and earth, and the fixed contact of the vertical-break disconnect switch 90 is connected to the aforementioned other end of the power line.

[0049] Each of the earthing switches 80a / 80b includes a movable arm 50a / 50b (collectively referred to as the movable arm 50) connected to a pivot shaft for pivoting the movable arms 50a / 50b between a closed position where the earthing switch is closed and an open position where the earthing switch is open.

[0050] As Figure 2 shown, when the movable arm 60 of the vertical-break disconnector 90 is in a horizontal position, the movable arm 60 of the vertical-break disconnector 90 is in a closed state to close the power line. In this case, the movable arms 50a of the first earthing switch 80a and 50b of the second earthing switch 80b must be placed in an almost horizontal position to keep away from the corresponding fixed contacts of the first earthing switch 80a and the second earthing switch 80b. Conversely, when the movable arms 50a of the first earthing switch 80a and 50b of the second earthing switch 80b are in a vertical position, the first earthing switch 80a and the second earthing switch 80b are in a closed state to connect both ends of the power line to the ground. In this case, it is prohibited to close the vertical-break disconnector 90 while the earthing switches 80a and 80b are still closed to prevent the closing of the power line.

[0051] In addition, the rotating shaft 62 from the gearbox 64 can drive the rotatable insulating member to rotate so as to actuate the movable contact / movable arm of the vertical-break disconnector 90 to pivot about the pivot axis. Thus, the vertical-break disconnector 90 can be actuated to be in a closed position and an open position.

[0052] According to the prior art, the vertical-break disconnector includes a compression spring assembly that provides the torque required to operate the vertical-break disconnector. Similarly, the earthing switch includes a deadweight assembly that provides the torque required to operate the earthing switch. However, the compression spring assembly and the deadweight assembly are large in volume because they include multiple components. In addition, the compression spring assembly and the deadweight assembly can be arranged around the pivot shafts of the vertical-break disconnector and the earthing switch respectively using high skills. Therefore, the time involved in arranging the compression spring assembly and the deadweight assembly may be long. In addition, the compression spring assembly and the deadweight assembly may only be applicable to vertical-break disconnectors and earthing switches operating at higher voltage ratings.

[0053] According to the present disclosure, a simple and easily assembled torsion spring assembly is provided for the switchgear 90 and 80. In addition, the torsion spring assembly provided herein can be suitable for switchgear operating at lower or higher voltage ratings. The switchgear 90 and 80 herein can refer to the vertical-break disconnector 90 and / or the earthing switch 80.

[0054] The torsion spring assembly includes at least one torsion spring configured to be arranged around a pivot axis for pivoting at least one movable arm 60 and 50 between a closed position and an open position, where in the closed position the current path is closed and in the open position the current path is open. At least one torsion spring is configured to be connected to the pivot axis at a first end and to a base structure supporting the pivot axis at a second end.

[0055] Various examples of the switchgear 90 and 80 and the torsion spring assembly provided for the switchgear 90 and 80 are illustrated in the later part of the specification in conjunction with the accompanying drawings. The switchgear 90 and 80 and thus the circuit 100 may include several components other than Figure 2 the components shown. For the sake of brevity, the description of other components is omitted herein.

[0056] Figure 3 A switchgear including a torsion spring assembly 25 is disclosed, where the switchgear is a vertical-break disconnecting switch 90. The vertical-break disconnecting switch 90 may form part of a circuit 100 as Figure 2 shown. The vertical-break disconnecting switch 90 may consist of a single pole or three poles, each pole being operated by a single operating mechanism and a mechanical link between the poles or by one mechanism for each pole simultaneously. Each pole of the vertical-break disconnecting switch 90 includes a movable arm 60 and a base structure 22.

[0057] The movable arm 60 may include movable contacts 13a, 13b, 402a, and 402b. In some examples, the movable contacts 13a, 13b, 402a, and 402b may be made of an aluminum alloy tube having copper finger-like members (also referred to as copper contacts) at its ends. The number and size of the copper finger-like members may vary according to the rated current. In some examples, the copper finger-like members may be silver-plated, and the thickness of the silver depends on the rated current. Additionally, the copper finger-like members may be self-cleaning and are suitably designed to withstand considerable short-circuit stress. In some examples, the fixed contacts may include an aluminum alloy welded support including two high-voltage terminals of the main circuit and at least one copper flat bar, which is suitably shaped for proper engagement with the movable contacts 13a, 13b, 402a, and 402b.

[0058] The base structure 22 supports the pivot axis 18. The two ends of the pivot axis 18 may be supported by the base structure 22 at the two sides 14a and 14b. The pivot axis 18 may rotate or revolve about an axis to pivot the movable arm 60 between a closed position and an open position, where in the closed position the current path is closed and in the open position the current path is open. This axis may be the axis of the drive member to which the pivot axis 18 is connected. In some examples, the drive member may be a drive insulator.

[0059] The base structure 22 may also support at least one post insulator and a rotating insulating rod / driving insulator (shown as insulators 58a and 58b in Figure 2 ), which allows the movement of the operating mechanism to be transmitted to the main circuit. The rotation of the insulating rod may be transmitted to the movable arm 60 through a crank and connecting rod mechanism 410, which causes the movable arm 60 to rotate in a vertical plane.

[0060] The vertical-break disconnect switch 90 includes a torsion spring assembly 25. The torsion spring assembly 25 may provide the torque required to operate the vertical-break disconnect switch 90.

[0061] The torsion spring assembly 25 includes at least one torsion spring 12a and 12b, which are configured to be arranged around a pivot shaft 18 for pivoting at least one movable arm 60 between a closed position and an open position. In the closed position, the current path is closed, and in the open position, the current path is open. For simplicity, Figure 3 a torsion spring assembly including two torsion springs 12a and 12b is depicted in, with one torsion spring arranged at each end of the pivot shaft 18. This arrangement of the torsion springs 12a / 12b eliminates multiple components from the torsion spring assembly. Thus, the torsion spring assembly 25 is simple. In addition, the torsion springs 12a / 12b of the torsion spring assembly 25 can be easily assembled around the pivot shaft 18 without any high skills.

[0062] As Figure 3 shown, the torsion springs 12a / 12b are configured to be connected to the pivot shaft 18 at a first end and to the base structure 22 that supports the pivot shaft 18 at a second end.

[0063] The torsion springs 12a / 12b are configured to be arranged around the same pivot shaft 18, and the movable arm 60 / current path conductor rotates on the pivot shaft 18. Thus, the torsion springs 12a / 12b can directly support and balance the self-weight of the current path conductor and reduce the energy requirement from the operating driver for operating the vertical-break disconnect switch 90.

[0064] Various embodiments describing the arrangement of at least one torsion spring 12a / 12b around the pivot shaft 18 of the vertical-break disconnect switch 90 are illustrated in the later part of the specification in conjunction with the accompanying drawings.

[0065] Figure 4A A vertical-break disconnect switch 90 according to an example of the present disclosure is disclosed. The vertical-break disconnect switch 90 may be configured as the Figure 3 vertical-break disconnect switch shown. The vertical-break disconnect switch 90 includes a torsion spring 12a arranged at one end of the pivot shaft 18.

[0066] As Figure 4A shown, the vertical-break disconnect switch 90 includes a base structure 22 that supports a pivot shaft 18 and a torsion spring assembly 25. In Figure 4A it, a depiction is shown where the pivot shaft 18 is supported by the base structure 22 at the side portion 14a in the vertical-break disconnect switch 90.

[0067] The torsion spring 12a is configured to be connected to the pivot shaft 18 at a first end and to a fixed surface of the base structure 22 that supports the pivot shaft 18 at a second end. In one example, as Figure 4A shown, the fixed surface of the base structure 22 may be a stop plate 502. The stop plate 502 may be configured to be arranged on the base structure 22 for holding the second end of the torsion spring 12a in a fixed position. Thus, the second end of the torsion spring 12a may be configured to be held on the base structure 22 at the fixed position using the stop plate 502. It should be noted that the fixed surface of the base structure 22 may also include, for example, an ES mounting bracket, a frame surface, etc.

[0068] The first end of the torsion spring 12a may include an annular portion 504a. The annular portion 504a may be configured to be connected to the pivot shaft 18 by means of a fastener that extends through the annular portion 504a. In one example, as Figure 4A shown, the fastener may be a bolt 506.

[0069] The second end of the torsion spring 12a may include a spring leg 504b. The spring leg 504b may be configured to be connected to the fixed surface / stop plate 502 of the base structure 22.

[0070] Figure 4B A vertical-break disconnect switch 90 according to an example of the present disclosure is disclosed. The vertical-break disconnect switch 90 may be configured to be Figure 3 or Figure 4A the vertical-break disconnect switch in. The vertical-break disconnect switch 90 includes a torsion spring 12b arranged at one end of the pivot shaft 18.

[0071] As Figure 4B shown, the vertical-break disconnect switch 90 includes a base structure 22 that supports a pivot shaft 18 and a torsion spring assembly 25. The pivot shaft 18 is supported by the base structure 22 at the side portion 14b. The torsion spring assembly 25 includes a torsion spring 12b. The torsion spring 12b is arranged around the pivot shaft 18. The second end of the torsion spring 12b may include a spring leg 504b, and the spring leg 504b is configured to be connected to the fixed surface / stop plate 502 of the base structure 22. Thus, the second end of the torsion spring 12b may be configured to be held on the base structure 22 at the fixed position using the stop plate 502.

[0072] It should be noted that in this example, the second end of the torsion spring 12b points upward when the second end is held in a fixed position using the stop plate 502. The second end of the torsion spring 12a can point downward when the second end is held in a fixed position using the stop plate, as Figure 4A shown.

[0073] Figure 4C A torsion spring 12b arranged around the pivot shaft 18 of the vertical-break disconnect switch 90 is disclosed. The vertical-break disconnect switch 90 can be configured as in Figure 3 , Figure 4A or Figure 4B shown. In this example, the second end of the torsion spring 12b includes an annular portion 504c as shown in Figure 4C shown. The annular portion 504c can be configured to be connected to the base structure 22 by means of a fastener (such as a bolt) extending through the annular portion 504c.

[0074] Thus, in some examples, the second end of the torsion spring 12b can include an annular portion 504c connected to the base structure 22 by means of a fastener as shown in Figure 4C shown, and in some examples, the second end of the torsion spring can include a spring leg 504b configured to be connected to the fixed surface / stop plate 502 of the base structure 22 as shown in Figure 4A shown.

[0075] Figure 5A and Figure 5B An exemplary illustration of arranging two torsion springs 12a and 12b is disclosed, with one torsion spring arranged at each end of the pivot shaft 18 of the vertical-break disconnect switch 90.

[0076] As Figure 5A and Figure 5B shown, the vertical-break disconnect switch 90 includes a movable arm 60, a base structure 22 supporting the pivot shaft 18, and a torsion spring assembly 25. The movable arm 60 is connected to the pivot shaft 18. The pivot shaft 18 pivots the movable arm 60 between a closed position where the current path is closed and an open position where the current path is open.

[0077] The torsion spring assembly includes two torsion springs 12a and 12b. The two torsion springs 12a and 12b can be assembled at the respective ends of the pivot shaft 18, and the movable arm 60 / current path conductor rotates on the pivot shaft 18. Thus, the torsion springs 12a and 12b can support the self-weight of the movable arm 60 / current path conductor and reduce the energy required for the operating driver to operate the vertical-break disconnect switch 90.

[0078] To assemble the torsion springs 12a and 12b, the torsion springs 12a and 12b are respectively disposed at the ends 18a and 18b of the pivot shaft 18, as Figure 5A shown. When disposing, as Figure 5B shown, at the end 18a, the first end of the torsion spring 12a is connected to the pivot shaft 18, and the second end of the torsion spring 12a is connected to the base structure 22 that supports the pivot shaft 18. Similarly, as Figure 5B shown, at the end 18b, the first end of the torsion spring 12b is connected to the pivot shaft 18, and the second end of the torsion spring 12b is connected to the base structure 22 that supports the pivot shaft 18. The second ends of the torsion springs 12a / 12b can be held in fixed positions on the base structure 22.

[0079] Connecting the first ends of the torsion springs 12a / 12b to the pivot shafts 18a / 18b can involve connecting the annular portions 504a of the torsion springs 12a / 12b to the pivot shaft 18. The annular portion 504a can be connected to the pivot shaft 18 by means of a fastener (such as a bolt 506) that extends through the annular portion 504a, as Figure 5B shown. Connecting the second ends of the torsion springs 12a / 12b to the base structure 22 can involve connecting the spring legs 504b of the torsion springs to the base structure 22.

[0080] Figure 6A and 6B An exemplary illustration of disposing the torsion spring 12a at the end of the pivot shaft 18 of the vertical-break disconnect switch 90 is disclosed. The vertical-break disconnect switch 90 includes a pivot shaft 18 supported by a base structure 22. The pivot shaft 18 pivots the movable arm 60 between a closed position and an open position. In the closed position of the movable arm 60, the current path is closed, and in the open position of the movable arm 60, the current path is open.

[0081] Figure 6A and Figure 6B show that the pivot shaft 18 is supported by the side portion 14a of the base structure 22 at one end.

[0082] As Figure 6A and Figure 6B shown, the vertical-break disconnect switch 90 includes a torsion spring 12a that is connected to the pivot shaft 18 at a first end and to the base structure 22 at a second end.

[0083] Figure 7A and Figure 7B Another exemplary illustration of disposing the torsion spring 12b at the end of the pivot shaft 18 of the vertical-break disconnect switch 90 is disclosed.

[0084] Figure 7A and7B A torsion spring assembly including a torsion spring 12b is shown. The torsion spring 12b is arranged around a pivot shaft 18 for balancing the self-weight of the movable arm 60 and providing the torque required to operate the vertical-break disconnector 90.

[0085] In some examples, the spring leg 504b of the second end of the torsion spring 12b can be connected to a fixed surface on the base structure 22, such as Figure 7A and Figure 7B shown. In some examples, the fixed surface can be the ES mounting bracket 510, such as Figure 7A and Figure 7B shown.

[0086] Figure 8 An example switchgear including a torsion spring assembly is disclosed, where the switchgear is an earthing switch 80. The earthing switch 80 can be operated together with the vertical-break disconnector. The earthing switch 80 can be used to connect an isolated electrical device to the ground so that the capacitive current or inductive current remaining on the isolated electrical device can be eliminated, and the isolated electrical device can be operated or repaired more safely.

[0087] As Figure 8 shown, the earthing switch 80 includes a movable arm 50, a base structure 24, and a pivot shaft 20. In some examples, the movable arm 50 of the earthing switch 80 can include an aluminum conductor. The movable arm 50 can operate between a closed position and an open position. In the closed position, the earthing switch is closed, and in the open position, the earthing switch is open. The base structure 24 supports the pivot shaft 20, and the pivot shaft 20 is used to pivot the movable arm 50 between the closed position and the open position.

[0088] The torsion spring assembly includes a torsion spring 12c. The torsion spring 12c is arranged around the pivot shaft 20, and the movable arm 50 / earthing switch operating rod operates / rotates on the pivot shaft 20. Therefore, the torsion spring 12c can support the self-weight of the earthing switch operating rod and the movable arm, and reduce the energy requirement from the operating driver for operating the earthing switch 80.

[0089] Figure 9 An earthing switch 80 including a torsion spring 12c as Figure 8 shown is disclosed. As Figure 9 shown, the earthing switch 80 includes a movable arm 50, a base structure 24, and a torsion spring 12c. The base structure 24 supports the pivot shaft 20. The pivot shaft 20 pivots the movable arm 50 between the closed position and the open position.

[0090] The torsion spring 12c is arranged around the pivot shaft 20, and the earthing switch operating rod rotates on the pivot shaft 20. Therefore, the torsion spring 12c provides the torque required to operate the earthing switch by balancing the self-weight of the earthing switch operating rod and the movable arm 50.

[0091] As Figure 9 shown, the torsion spring 12c is connected to the pivot shaft 20 at the first end and to the base structure 24 that supports the pivot shaft 20 at the second end. The second end of the torsion spring 12c may be configured to be held in a fixed position on the base structure 24. The base structure 24 also includes a fixed surface (e.g., a stop plate, an ES mounting bracket, a frame surface, etc.). The fixed surface attached to the base structure 24 may be configured to hold the second end of the torsion spring 12c in a fixed position.

[0092] In addition, the first end and the second end of the torsion spring 12c may respectively include an annular portion 1204a and a spring leg 1204b. The annular portion 1204a associated with the first end of the torsion spring 12c may be configured to be connected to the pivot shaft 20 by means of a fastener extending through the annular portion 1204a. In some examples, the fastener may include a bolt. The spring leg 1204b associated with the second end of the torsion spring 12c may be configured to be connected to the base structure 24. In some examples, the spring leg 1204b may be configured to be connected to the base structure 24 by means of a fastener (e.g., a bolt) extending through the spring leg 1204b.

[0093] This disclosure describes some exemplary specifications and design details of torsion springs provided for switchgear operating at different voltage ratings. However, it will be apparent to those skilled in the art that any other similar specifications and design details (including the details described below) may be considered.

[0094] Figure 10 An exemplary torsion spring 12a / 12b of a torsion spring assembly according to this disclosure is disclosed. The torsion spring 12a / 12b may be provided for switchgear, wherein the switchgear is a vertical break disconnect switch operating at 72.5 kilovolts (kV) while supporting a current rating of 3000 amperes (A). Figure 10 The torsion spring 12a / 12b shown in shows a left-handed coil winding direction, but it should be understood that it may have a right-handed coil winding direction.

[0095] Torsion springs can be designed for different operating voltage ranges of disconnect switches and earthing switches. Therefore, different designs of torsion springs can be used for different operating voltage ranges of disconnect switches and earthing switches.

[0096] Various parameters can be considered for designing torsion springs. Some of the parameters may include the spring stiffness, maximum deflection, pitch, number of turns, and ends of the torsion spring.

[0097] The number of turns of the torsion spring may vary based on the application of the torsion spring to different operating voltage ranges of disconnect switches and earthing switches.

[0098] As an example, the inner coil diameter can be between 40 mm and 70 mm. The effective number of body turns can be any value between 7 and 13. The wire diameter can be between 8 mm and 12 mm.

[0099] The torsion spring can be configured for a vertical-break disconnect switch operating between 123 KV and 72.5 KV while supporting a 2000 A current rating. In some examples, the torsion spring can have a left-handed coil winding direction, and in some examples, the torsion spring can have a right-handed coil winding direction.

[0100] The torsion spring can be configured for an earthing switch operating between 145 KV and 170 KV. It should be noted that a torsion spring 12c with a similar design can be configured for an earthing switch with a voltage rating up to 800 KV.

[0101] In some examples, the torsion spring assembly disclosed herein can be used for any switchgear operating at a lower voltage rating or a higher voltage rating by changing at least some of the parameters associated with at least one torsion spring. Some of the parameters can include the wire diameter of the torsion spring, the wire cross-section, the number of turns of the torsion spring, and the diameter of the torsion spring.

[0102] The foregoing description of specific embodiments will fully disclose the general nature of the embodiments herein. Without departing from the general concept, others can easily modify and / or adapt these embodiments for various applications by applying current knowledge. Therefore, such modifications and adaptations should and are intended to be understood as being within the meaning and scope of the equivalents of the disclosed embodiments. It should be understood that the wording or terminology employed herein is for the purpose of description and not of limitation. Thus, although the embodiments herein are described in the form of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the scope of the present disclosure.

Claims

1. A torsion spring assembly (25) for a switching device (90, 80), the torsion spring assembly comprising: At least one torsion spring (12a, 12b, 12c), the at least one torsion spring being configured to be arranged around a pivot axis (18, 20) for pivoting at least one movable arm (60, 50) between a closed position and an open position, in the closed position, the current path is closed, and in the open position, the current path is open, Wherein the at least one torsion spring (12a, 12b, 12c) is configured to be connected to the pivot axis (18, 20) at a first end and to a base structure (22, 24) supporting the pivot axis (18, 20) at a second end.

2. The torsion spring assembly (25) according to claim 1, wherein, The second end of the at least one torsion spring (12a, 12b, 12c) is configured to be held in a fixed position on the base structure (22, 24).

3. The torsion spring assembly (25) according to claim 1 or 2, further comprising: A stop plate (502), the stop plate being configured to be attached to the base structure (22, 24) for holding the second end of the at least one torsion spring (12a, 12b, 12c) in the fixed position.

4. The torsion spring assembly (25) according to claim 1 or 2, wherein, The second end of the at least one torsion spring (12a, 12b, 12c) includes an annular portion (504a) and is configured to be connected to the base structure (22, 24) by means of a fastener, such as a bolt (506), extending through the annular portion (504a).

5. The torsion spring assembly (25) according to any one of the preceding claims, wherein, The first end of the at least one torsion spring (12a, 12b, 12c) includes an annular portion (504a, 1204a) and is configured to be connected to the pivot axis (18, 20) by means of a fastener, such as a bolt (506), extending through the annular portion (504a, 1204a).

6. The torsion spring assembly (25) according to any one of the preceding claims, comprising two torsion springs (12a, 12b), the two torsion springs being configured to have one torsion spring arranged at each end of the pivot axis (18).

7. A switching device (90, 80) for a circuit (100), the switching device (90, 80) comprising: At least one movable arm (60, 50), the at least one movable arm being connected to a pivot axis (18, 20) for pivoting the at least one movable arm between a closed position and an open position, in the closed position, the current path is closed, and in the open position, the current path is open; A base structure (22, 24), the base structure supporting the pivot axis (18, 20); And A torsion spring assembly (25), the torsion spring assembly including at least one torsion spring (12a, 12b, 12c), the at least one torsion spring being arranged around the pivot axis (18, 20) and connected to the pivot axis (18, 20) at a first end and to the base structure (22, 24) at a second end.

8. The switching device (90, 80) according to claim 7, wherein, The second end of the at least one torsion spring (12a, 12b, 12c) is arranged at a fixed position on the base structure (22, 24).

9. The switching device (90, 80) according to claim 7 or 8, wherein, The first end of the at least one torsion spring (12a, 12b, 12c) includes an annular portion (504a, 1204a) and is connected to the pivot shaft (18, 20) by means of a fastener, such as a bolt (506), extending through the annular portion (504a, 1204a).

10. The switching device (90, 80) according to any one of claims 7 to 9, wherein, The switching device (90, 80) is an earthing switch (80).

11. The switching device (90, 80) according to any one of claims 7 to 9, wherein, The switching device (90, 80) is a disconnector switch (90).

12. The switching device (90, 80) according to claim 7 or 8, further comprising: A stop plate (502) attached to the base structure (22, 24) for holding the second end of the at least one torsion spring (12a, 12b, 12c) in a fixed position.

13. The switching device (90, 80) according to claim 7 or 8, wherein, The second end of the at least one torsion spring (12a, 12b, 12c) includes an annular portion (504a, 1204a) and is configured to be connected to the base structure (22, 24) by means of a fastener, such as a bolt (506), extending through the annular portion (504a, 1204a).

14. The switching device (90) according to any one of claims 7 to 13, comprising two torsion springs (12a, 12b) arranged with one torsion spring at each end of the pivot shaft (18).

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