Circuit breaker

Abstract

To provide a circuit breaker capable of avoiding a decrease in interruption performance. [Solution] The circuit breaker (100) comprises a three-phase connecting shaft (3) that moves the movable electrode portion (23) of a three-phase vacuum valve (2), a mechanism (4) that connects the movable electrode portion to the three-phase connecting shaft and converts the rotation of the three-phase connecting shaft around its axis into opening and closing operation of the movable electrode portion, and at least three bearing portions (31-33) that support the three-phase connecting shaft so that it can rotate freely.

Description

Technical Field

[0001] The present invention relates to a circuit breaker.

Background Art

[0002] There is known a vacuum valve (vacuum interrupter) in which a pair of contacts that can contact and separate from each other are provided inside a vacuum container. The vacuum valve is installed in, for example, a circuit breaker provided in a power cutoff facility to cut off an electric circuit.

[0003] In recent years, there is known a technique for realizing switching between contact and separation of a pair of contacts in such a vacuum valve by providing a mechanism unit that mechanically operates one of the contacts (movable electrode unit). For example, Patent Document 1 discloses a circuit breaker provided with a mechanism unit that transmits the extension and compression of a cutoff spring and an insertion spring in a spring operator to the movable electrode unit to move the movable electrode unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The movable electrode unit of the vacuum valve moves along the operating direction by the mechanism unit. The reaction force of such movement of the movable electrode unit may vibrate the components of the mechanism unit. The vibration of the components of the mechanism unit is transmitted to the movable electrode unit, and as a result, it may affect the cutoff performance between the electrodes during the opening and closing operation of the vacuum valve.

[0006] One aspect of the present invention has been made in view of the above problems, and an object thereof is to provide a circuit breaker capable of avoiding a decrease in cutoff performance.

Means for Solving the Problems

[0007] To solve the above problems, a circuit breaker according to embodiment 1 of the present invention comprises a tank, three-phase vacuum valves housed in the tank, a three-phase connecting shaft for moving the movable electrode portions of the three-phase vacuum valves, a mechanism that connects the movable electrode portions and the three-phase connecting shaft and converts the rotation of the three-phase connecting shaft around its axis into opening and closing operations of the movable electrode portions, and at least three or more bearing portions that rotatably support the three-phase connecting shaft.

[0008] In the circuit breaker according to embodiment 2 of the present invention, in embodiment 1, the at least three bearing portions may include a first bearing portion and a second bearing portion that pivotally support one end and the other end of the three-phase connecting shaft in the tank, respectively, and a third bearing portion that pivotally supports the three-phase connecting shaft between the first bearing portion and the second bearing portion.

[0009] A circuit breaker according to embodiment 3 of the present invention may further include, in embodiment 1 or 2 above, a movable electrode side conductor portion that forms an electrical circuit on the movable electrode side within the tank, having a connecting portion that connects to the mechanism, and which, when viewed from the operating direction of the movable electrode portion, extends from the connecting portion to one side and also extends to the other side in the opposite direction to the one side to conduct electricity with the outside of the tank; a first support portion that supports the movable electrode side conductor portion with respect to the tank on the one side of the connecting portion; and a second support portion that supports the movable electrode side conductor portion with respect to the tank on the other side of the connecting portion.

[0010] A circuit breaker according to aspect 4 of the present invention, in aspect 3 above, the at least three bearing portions include a first bearing portion and a second bearing portion that pivotally support one end and the other end of the three-phase connecting shaft in the tank, respectively, and a third bearing portion that pivotally supports the three-phase connecting shaft between the first bearing portion and the second bearing portion, the first support portion comprises a support plate fixed to the tank and an insulating support base connecting the support plate and the movable electrode side conductor portion, the three-phase connecting shaft is located on one side in the tank, and the support plate may further support the third bearing portion. [Effects of the Invention]

[0011] According to one aspect of the present invention, a decrease in the circuit breaker's breaking performance can be avoided. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing the internal configuration of a circuit breaker according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view of the circuit breaker shown in Figure 1, taken along the line AA'. [Modes for carrying out the invention]

[0013] [Embodiment 1] (Outline configuration of circuit breaker 100) Figure 1 is a schematic diagram showing the internal configuration of a circuit breaker 100 according to Embodiment 1. Figure 2 is a cross-sectional view of the circuit breaker 100 shown in Figure 1, taken along the line AA'. As shown in Figures 1 and 2, the circuit breaker 100 comprises a tank 1, three-phase vacuum valves 2A to 2C, a three-phase connecting shaft 3, and a mechanism 4. The circuit breaker 100 is used, for example, to interrupt an electrical circuit in a power interruption system. In Figure 1, a circuit breaker 100 in a conductive state is shown with a solid line, and a circuit breaker 100 in an insulated state is shown with a dashed line.

[0014] Tank 1 is a sealed tank that houses three vacuum valves 2A to 2C. Tank 1 is filled with an insulating gas (e.g., dry air). The pressure of the insulating gas inside Tank 1 is greater than atmospheric pressure, thereby improving the insulation inside Tank 1.

[0015] Furthermore, the first circuit 5, which is the circuit upstream of the vacuum valves 2A to 2C in the power interruption equipment, and the second circuit 6, which is the circuit downstream of the vacuum valves 2A to 2C in the power interruption equipment, penetrate the tank 1 and are introduced into the interior of the tank 1. The first circuit 5 is introduced into the interior of the tank 1 via the first insulating spacer 91 provided on the top surface of the tank 1. The second circuit 6 is introduced into the interior of the tank 1 via the second insulating spacer 92 provided on the side of the tank 1. Hereinafter, the side where the second insulating spacer 92 is located relative to the vacuum valve 2 will be described as the right, and the opposite side will be described as the left.

[0016] The three-phase vacuum valves 2A to 2C are arranged side by side within a single tank 1. That is, the circuit breaker 100 houses all three-phase vacuum valves 2A to 2C together. The vacuum valves 2A to 2C are, for example, arranged side by side in the front-to-back direction in the center of the tank 1 in the left-to-right direction. Hereafter, unless there is a need to distinguish between the three-phase vacuum valves 2A to 2C, they will simply be referred to as vacuum valve 2.

[0017] The vacuum valve 2 comprises a vacuum vessel 21, a fixed electrode section 22, and a movable electrode section 23. The vacuum vessel 21 is maintained at a predetermined vacuum level and houses the fixed electrode section 22 and a portion of the movable electrode section 23.

[0018] The fixed electrode section 22 is fixed to the tank 1 via a support plate 71 and an upper insulating support base 72, which will be described later. The fixed electrode section 22 has a fixed shaft section 22a and a fixed contact 22b. The fixed shaft section 22a is electrically connected to the first circuit 5 and extends vertically inside the vacuum container 21. The fixed contact 22b is a contact located at the lower end of the fixed shaft section 22a.

[0019] The movable electrode part 23 is held so as to be movable in the vertical direction with respect to the vacuum vessel 21. The movable electrode part 23 has a movable shaft part 23a, a movable contact 23b, and a connecting part 23c on the movable electrode part side. The movable shaft part 23a is electrically connected to the second electric circuit 6 and extends vertically through the bottom of the vacuum vessel 21 while maintaining the airtightness of the vacuum vessel 21. The movable contact 23b is a contact located at the upper end of the movable shaft part 23a. The connecting part 23c on the movable electrode part side is a member located at the lower end of the movable shaft part 23a and is connected to the mechanism part 4.

[0020] The movable electrode part 23 moves in the vertical direction by the driving force transmitted from the three-phase connecting shaft 3 via the mechanism part 4. When the movable electrode part 23 moves to the upper limit position, the fixed contact 22b and the movable contact 23b come into contact with each other and an energized state is achieved. When the movable electrode part 23 moves to the lower limit position, the fixed contact 22b and the movable contact 23b are separated and an insulating state is achieved.

[0021] The three-phase connecting shaft 3 moves the movable electrode parts 23 of the three-phase vacuum valves 2A to 2C. Specifically, the three-phase connecting shaft 3 rotates around its axis to simultaneously move the three-phase vacuum valves 2A to 2C in the vertical direction. Thereby, it is possible to switch the contact and separation of the pair of contacts in the vacuum valves 2A to 2C. The three-phase connecting shaft 3 extends in the front-rear direction in the lower part and the left part inside the tank 1. The three-phase connecting shaft 3 extends to the outside through the side surface of the tank 1 while maintaining the airtightness of the tank 1 in one direction (hereinafter referred to as the rear direction) in the front-rear direction. The three-phase connecting shaft 3 is connected to the shutoff part operation source 10 outside the tank 1 and is rotationally driven by the shutoff part operation source 10.

[0022] The three-phase connecting shaft 3 is rotatably supported by at least three or more bearing portions. In the present embodiment, the at least three or more bearing portions include a first bearing portion 31, a second bearing portion 32, and a third bearing portion 33. The first bearing portion 31 and the second bearing portion 32 respectively support the front end (one end) and the rear end (the other end) of the three-phase connecting shaft 3 in the tank 1. The third bearing portion 33 supports the three-phase connecting shaft 3 between the first bearing portion 31 and the second bearing portion 32. By supporting the three-phase connecting shaft 3 with the three bearing portions 31 to 33, the deflection during the rotational drive of the three-phase connecting shaft 3, and thus the vibration of the three-phase connecting shaft 3, can be suppressed. Therefore, the vibration of the movable electrode portion 23 structurally connected to the three-phase connecting shaft 3 can also be suppressed, and a decrease in the interruption performance of the circuit breaker 100 due to the vibration of the three-phase connecting shaft 3 can be avoided. Note that the three-phase connecting shaft 3 may be supported by four or more bearing portions. Further, the first bearing portion 31 and the second bearing portion 32 may respectively support the vicinity of the front end and the vicinity of the rear end of the three-phase connecting shaft 3 in the tank 1 so as to stably hold the three-phase connecting shaft 3.

[0023] Specifically, as shown in FIG. 2, a front fitting portion 11 for receiving the three-phase connecting shaft 3 is formed on the front surface of the tank 1. The front fitting portion 11 is formed by a protruding portion that protrudes outward from the other front surfaces of the tank 1. The three-phase connecting shaft 3 is inserted into such a front fitting portion 11 and is supported by the first bearing portion 31 with respect to the front fitting portion 11.

[0024] Also, a rear fitting portion 12 for receiving the three-phase connecting shaft 3 is formed on the rear surface of the tank 1. The rear fitting portion 12 is formed by a protruding portion that protrudes outward from the other rear surfaces of the tank 1 and is a through hole penetrating the tank 1. The three-phase connecting shaft 3 is inserted into such a rear fitting portion 12 and is supported by the second bearing portion 32 with respect to the rear fitting portion 12.

[0025] The mechanism 4 connects the movable electrode section 23 and the three-phase connecting shaft 3, and is a component that converts the rotation of the three-phase connecting shaft 3 around its axis into opening and closing operation (vertical movement) of the movable electrode section 23. The mechanism 4 consists of three parts, each connected to the movable electrode section 23 of the vacuum valves 2A to 2C. The three parts of the mechanism 4 each include a lever member 41, a link member 42, and a rotating member 43.

[0026] The base end of the lever member 41 is connected to the three-phase connecting shaft 3, and the tip of the lever member 41 is connected to the link member 42. The lever member 41 rotates around the three-phase connecting shaft 3 as the three-phase connecting shaft 3 rotates around its axis.

[0027] The link member 42 is a member that links the tip of the lever member 41 and the point of force application 43a of the rotating member 43. The link member 42 moves in the front-rear direction as the lever member 41 rotates.

[0028] The rotating member 43 has a point of force application 43a, a pivot point 43b, and a point of application 43c. The point of force application 43a is the part connected to the link member 42. The pivot point 43b is the part connected to the second circuit 6 fixed to the tank 1. The point of application 43c is the part connected to the movable electrode side connecting part 23c. The rotating member 43 rotates around the pivot point 43b as the link member 42 moves in the front-rear direction. At this time, the point of application 43c moves in the vertical direction. Therefore, the movable electrode 23 connected to the point of application 43c also moves in the vertical direction. With this configuration, the mechanism 4 converts the rotation around the axis of the three-phase connecting shaft 3 into an opening and closing operation of the movable electrode 23.

[0029] The configuration of the mechanism 4 according to this embodiment is just one example of a configuration that converts the rotation around the axis of the three-phase connecting shaft 3 into the opening and closing operation of the movable electrode 23, and is not limited thereto.

[0030] (Regarding the second circuit 6) The circuit breaker 100 further comprises a conductive cylinder 61 and an extension 62 as the second circuit 6 (movable electrode side conductor section) introduced into the tank 1. Three conductive cylinders 61 and three extension 62 are arranged in the front-to-back direction to match the three-phase vacuum valves 2A to 2C.

[0031] The conductive cylinder 61 is a conductive cylindrical member located below the vacuum vessel 21, housing the connection between the movable electrode portion 23 and the mechanism portion 4. The conductive cylinder 61 is electrically connected to the movable shaft portion 23a. The conductive cylinder 61 also has a connecting portion (not shown) that connects to the pivot portion 43b of the mechanism portion 4. When viewed from the vertical direction (the operating direction of the movable electrode portion 23), the conductive cylinder 61 extends from the connecting portion to one side (i.e., to the left) and also extends to the other side in the opposite direction (i.e., to the right). The extended portion 62 is a conductive portion that extends to the right from the conductive cylinder 61 and is electrically connected to the outside of the tank 1.

[0032] (Regarding the fixing part 7) The circuit breaker 100 further includes a fixing part 7 for fixing each component inside the tank 1 to the tank 1. The fixing part 7 includes a support plate 71 (support plate of the first support part), an upper insulating support base 72, a lower insulating support base 73 (insulating support base of the first support part), and an extension part support base 74 (second support part).

[0033] The support plate 71 is a flat plate member attached to the left side of the tank 1 and extending in the vertical direction. The upper insulating support base 72 is an insulating member that connects the support plate 71 to the vacuum vessel 21 and to the support plate 71 to the fixed electrode section 22. Three upper insulating support bases 72 are provided on the support plate 71 in the front-to-back direction to match the three-phase vacuum valves 2A to 2C (see Figure 2). The support plate 71 and the upper insulating support bases 72 fix the vacuum vessel 21 and the fixed electrode section 22 to the tank 1.

[0034] The lower insulating support base 73 is an insulating member that connects the support plate 71 and the conductive cylinder 61. Three lower insulating support bases 73 are provided on the support plate 71 in the front-to-back direction for the three conductive cylinders 61 (see Figure 2). The conductive cylinder 61 is fixed to the tank 1 by the support plate 71 and the lower insulating support bases 73. The extension support base 74 is attached to the bottom surface of the tank 1 and is a member that supports the extension 62 from below.

[0035] The second circuit 6 introduced into the tank 1 is supported by a support plate 71 and a lower insulating support base 73 to the left of the connecting portion of the conductive cylinder 61, and by an extension support base 74 to the right of the connecting portion of the conductive cylinder 61. In other words, the second circuit 6 introduced into the tank 1 can be supported by the tank 1 from both the left and right sides. This suppresses vibrations of the second circuit 6 caused by the reaction force of the opening and closing operation of the movable electrode portion 23 applied to the second circuit 6. Therefore, vibrations of the movable electrode portion 23, which is structurally connected to the second circuit 6, can also be suppressed, and a decrease in the circuit breaking performance of the circuit breaker 100 caused by vibrations of the second circuit 6 can be avoided.

[0036] Furthermore, the support plate 71 further supports the third bearing portion 33. In other words, the third bearing portion 33 is fixed to the tank 1 via the support plate 71. This allows the third bearing portion 33, which prevents deflection of the three-phase connecting shaft 3, to be supported by the support plate 71 that supports the upper insulating support base 72 and the lower insulating support base 73. In other words, the support plate 71 supports the third bearing portion 33 in addition to the upper insulating support base 72 and the lower insulating support base 73. Therefore, there is no need to provide a new structure to support the third bearing portion 33, and the structure of the circuit breaker 100 can be simplified.

[0037] Furthermore, the support plate 71 should have sufficient rigidity to adequately reduce vibrations caused by the reaction force of the opening and closing operation of the movable electrode section 23. With this configuration, vibrations of the movable electrode section 23, which is structurally connected to the support plate 71, can also be suppressed, and a decrease in the circuit breaker 100's breaking performance caused by vibrations of the three-phase connecting shaft 3 can be avoided.

[0038] Furthermore, the extension support base 74 may include a support insulator for supporting the extension 62 and a mounting base for attaching the support insulator to the bottom surface of the tank 1.

[0039] Furthermore, the extension support base 74 may be provided such that its left-right center is located at a distance of approximately two-thirds of the left-right length of the extension 62 from the right end of the extension 62. With this configuration, vibrations of the second circuit 6 can be appropriately suppressed.

[0040] (Effects and Benefits) In this embodiment, the three-phase connecting shaft 3 is supported by three bearing portions 31 to 33. With this configuration, deflection of the three-phase connecting shaft 3 during rotational drive, and consequently vibration of the three-phase connecting shaft 3, can be suppressed. Therefore, vibration of the movable electrode portion 23, which is structurally connected to the three-phase connecting shaft 3, can also be suppressed, and a decrease in the circuit breaker 100's breaking performance caused by vibration of the three-phase connecting shaft 3 can be avoided.

[0041] Furthermore, a circuit breaker in which the conductor forming the circuit on the movable electrode side within the tank has only one fixed point presents the following problems. Specifically, the movable electrode of the vacuum valve moves along the direction of operation due to the mechanism. The reaction force of this movement of the movable electrode is applied to the conductor forming the circuit on the movable electrode side. If the conductor has only one fixed point, the reaction force of the movement of the movable electrode can cause vibration around the fixed point. Since the conductor is structurally connected to the movable electrode, the vibration of the conductor is transmitted to the movable electrode. Therefore, the vibration of the conductor may affect the circuit breaker performance between the electrodes during the opening and closing operation of the vacuum valve.

[0042] On the other hand, in the circuit breaker 100 according to this embodiment, the second circuit 6 (the conductor portion that forms the circuit on the movable electrode side) introduced into the tank 1 is supported by the tank 1 from both the left and right sides. In other words, the second circuit 6 has two fixed points. Therefore, vibration of the second circuit 6 caused by the reaction force of the opening and closing operation of the movable electrode portion 23 applied to the second circuit 6 can be suppressed. Consequently, vibration of the movable electrode portion 23, which is structurally connected to the second circuit 6, can also be suppressed, and a decrease in the circuit breaking performance of the circuit breaker 100 caused by vibration of the second circuit 6 can be avoided.

[0043] (Additional notes) The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0044] 1 tank 2 Vacuum valve Vacuum valves for 2A~2C three-phase systems 10. Source of the circuit breaker 11 Front fitting part 12 Rear fitting part 21 Vacuum container 22 Fixed electrode section 22a Fixed shaft part 22b Fixed contact 23 Movable electrode part 23a Movable shaft part 23b Movable contact 23c Movable electrode side connection part 3 Three-phase connected shaft 31 First bearing section 32 Second bearing section 33 Third bearing section 4 Mechanism 5 1st electric circuit 6. Second circuit (conductor section on the movable electrode side) 7 Fixed part 71 Support plate (support plate for the first support section) 72 Upper insulating support base 73 Lower insulating support base (insulating support base for the first support section) 74 Extension part support stand (second support part) 91 First insulating spacer 92 Second insulating spacer 100 Circuit breakers

Claims

1. Tank and, The tank contains three vacuum valves for each phase, A three-phase connecting shaft that moves the movable electrode portion of the three-phase vacuum valve, A mechanism that connects the movable electrode section and the three-phase connecting shaft, and converts the rotation of the three-phase connecting shaft around its axis into an opening and closing operation of the movable electrode section, The three-phase connecting shaft is rotatably supported by at least three bearing portions, The at least three bearing portions include a first bearing portion and a second bearing portion that support one end and the other end of the three-phase connecting shaft within the tank, respectively, and a third bearing portion that supports the three-phase connecting shaft between the first bearing portion and the second bearing portion. A conductor portion on the movable electrode side that forms the electrical circuit on the movable electrode side within the tank, It has a connecting part that connects to the aforementioned mechanism, When viewed from the direction of operation of the movable electrode, the movable electrode side conductor portion extends from the connecting portion to one side and also extends to the other side in the opposite direction to the one side, and is electrically connected to the outside of the tank, The system further includes a first support portion that supports the movable electrode side conductor portion relative to the tank on one side of the connecting portion, The first support portion comprises a support plate fixed to the tank and an insulating support base connecting the support plate and the conductor portion on the movable electrode portion side. The three-phase connecting shaft is located on one side within the tank. The support plate further supports the third bearing portion of the circuit breaker.

2. A tank and The tank contains three vacuum valves for each phase, A three-phase connecting shaft that moves the movable electrode portion of the three-phase vacuum valve, A mechanism that connects the movable electrode section and the three-phase connecting shaft, and converts the rotation of the three-phase connecting shaft around its axis into an opening and closing operation of the movable electrode section, At least three or more bearing parts that rotatably support the three-phase connecting shaft, A conductor portion on the movable electrode side that forms the electrical circuit on the movable electrode side within the tank, It has a connecting part that connects to the aforementioned mechanism, When viewed from the direction of operation of the movable electrode, the movable electrode side conductor portion extends from the connecting portion to one side and also extends to the other side in the opposite direction to the one side, and is electrically connected to the outside of the tank, A first support portion that supports the movable electrode side conductor portion relative to the tank on one side of the connecting portion, A circuit breaker comprising a second support portion that supports the movable electrode side conductor portion with respect to the tank on the other side of the aforementioned connecting portion.

3. The at least three bearing portions include a first bearing portion and a second bearing portion that support one end and the other end of the three-phase connecting shaft within the tank, respectively, and a third bearing portion that supports the three-phase connecting shaft between the first bearing portion and the second bearing portion. The first support portion comprises a support plate fixed to the tank and an insulating support base connecting the support plate and the conductor portion on the movable electrode portion side. The three-phase connecting shaft is located on one side within the tank. The circuit breaker according to claim 2, wherein the support plate further supports the third bearing portion.

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