Circuit breaker

Abstract

To provide a breaker capable of avoiding deterioration of breaking performance.SOLUTION: A circuit breaker (100) includes a three phase connecting shaft (3) that moves movable electrode units (23) of vacuum interrupters (2) for three phases, a mechanism unit (4) that connects the movable electrode units and the three phase connecting shaft and converts rotation of the three phase connecting shaft about an axis into opening and closing operations of the movable electrode units, and at least three or more bearing units (31 to 33) that rotatably support the three phase connecting shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A vacuum interrupter is known, which has a pair of contacts inside a vacuum vessel that can make contact and separate from each other. The vacuum interrupter is installed in, for example, a circuit breaker in a power interruption facility to interrupt an electric circuit.

[0003] In recent years, a technology has become known that switches between contact and separation between a pair of contacts in such a vacuum interrupter by providing a mechanism that mechanically operates one of the contacts (movable electrode portion).For example, Patent Document 1 discloses a circuit breaker that is provided with a mechanism that transmits the extension and compression of a breaking spring and a closing spring in a spring operating mechanism to the movable electrode portion, thereby moving the movable electrode portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6781514 specification Summary of the Invention [Problem to be solved by the invention]

[0005] The movable electrode of a vacuum interrupter is moved in the direction of movement by the mechanism. The reaction force of this movement of the movable electrode can cause vibrations in the parts of the mechanism. The vibrations of the parts of the mechanism are transmitted to the movable electrode, which can ultimately affect the interruption performance between the electrodes when the vacuum interrupter is opened or closed.

[0006] One aspect of the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a circuit breaker that can avoid a decrease in interrupting performance. [Means for solving the problem]

[0007] In order to solve the above problems, the circuit breaker according to aspect 1 of the present invention comprises a tank, three-phase vacuum valves housed in the tank, a three-phase connecting shaft that moves the movable electrode portions of the three-phase vacuum valves, a mechanism that connects the movable electrode portions to the three-phase connecting shaft and converts rotation of the three-phase connecting shaft around its axis into opening and closing operations of the movable electrode portions, and at least three bearing portions that support the three-phase connecting shaft so that it can rotate freely.

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

[0009] A circuit breaker according to aspect 3 of the present invention may be configured as in aspect 1 or 2 above, and further include a movable electrode portion side conductor portion that forms an electrical path on the movable electrode portion side within the tank, the movable electrode portion side conductor portion having a connecting portion that connects to the mechanism portion, and that, 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 opposite to the one side, thereby being electrically connected to the outside of the tank; a first support portion that supports the movable electrode portion side conductor portion relative to the tank on the one side of the connecting portion; and a second support portion that supports the movable electrode portion side conductor portion relative to the tank on the other side of the connecting portion.

[0010] A circuit breaker according to a fourth aspect of the present invention is the same as that of the third aspect, wherein the at least three bearing portions include a first bearing portion and a second bearing portion that respectively support one end and the other end of the three-phase connecting shaft within the tank, and a third bearing portion that supports the three-phase connecting shaft between the first bearing portion and the second bearing portion, and the first support portion includes a support plate fixed to the tank and an insulating support base that connects the support plate and the movable electrode portion side conductor portion, and the three-phase connecting shaft is located on the one side within 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, it is possible to avoid a decrease in the interrupting performance of a circuit breaker. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an internal configuration of a circuit breaker according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the circuit breaker shown in FIG. 1 taken along the line AA'. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Embodiment 1] (Schematic configuration of circuit breaker 100) FIG. 1 is a schematic diagram showing the internal configuration of a circuit breaker 100 according to a first embodiment. FIG. 2 is a cross-sectional view of the circuit breaker 100 shown in FIG. 1 taken along the line AA'. As shown in FIGS. 1 and 2, the circuit breaker 100 includes a tank 1, vacuum valves 2A to 2C for three phases, a three-phase connecting shaft 3, and a mechanism unit 4. The circuit breaker 100 is used, for example, to interrupt an electric circuit in a power interruption facility. In FIG. 1, the circuit breaker 100 in a conductive state is indicated by a solid line, and the circuit breaker 100 in an insulated state is indicated by a dashed line.

[0014] Tank 1 is a sealed tank that houses three-phase vacuum valves 2A to 2C. Tank 1 is filled with insulating gas (e.g., dry air). The pressure of the insulating gas inside tank 1 is higher than atmospheric pressure, which improves the insulation properties inside tank 1.

[0015] Furthermore, a first electric circuit 5, which is an electric circuit upstream of the vacuum valves 2A to 2C in the power interruption equipment, and a second electric circuit 6, which is an electric 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 electric circuit 5 is introduced into the interior of the tank 1 via a first insulating spacer 91 provided on the top surface of the tank 1. The second electric circuit 6 is introduced into the interior of the tank 1 via a second insulating spacer 92 provided on the side surface of the tank 1. In the following description, the side on which the second insulating spacer 92 is located relative to the vacuum valve 2 is referred to as the right side, and the opposite side is referred to as the left side.

[0016] The vacuum valves 2A to 2C for three phases are arranged side by side inside one tank 1. That is, the circuit breaker 100 is equipped with the vacuum valves 2A to 2C for three phases all together. The vacuum valves 2A to 2C are arranged side by side in the front-to-rear direction, for example, in the center of the left-to-right direction inside the tank 1. Hereinafter, when there is no need to particularly distinguish between the vacuum valves 2A to 2C for three phases, they will be simply referred to as vacuum valves 2.

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

[0018] The fixed electrode portion 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 portion 22 has a fixed shaft portion 22a and a fixed contactor 22b. The fixed shaft portion 22a is electrically connected to the first electric circuit 5 and extends in the vertical direction inside the vacuum vessel 21. The fixed contactor 22b is a contact point located at the lower end of the fixed shaft portion 22a.

[0019] The movable electrode portion 23 is held so as to be movable in the vertical direction relative to the vacuum vessel 21. The movable electrode portion 23 has a movable shaft portion 23a, a movable contactor 23b, and a movable electrode portion-side connecting portion 23c. The movable shaft portion 23a is electrically connected to the second electric circuit 6, and extends in the vertical direction, penetrating the bottom of the vacuum vessel 21 while keeping the vacuum vessel 21 airtight. The movable contactor 23b is a contact point located at the upper end of the movable shaft portion 23a. The movable electrode portion-side connecting portion 23c is located at the lower end of the movable shaft portion 23a, and is a member that connects to the mechanism portion 4.

[0020] The movable electrode portion 23 moves up and down by a driving force transmitted from the three-phase connecting shaft 3 via the mechanism portion 4. When the movable electrode portion 23 moves to the upper limit position, the fixed contact 22b and the movable contact 23b come into contact and become electrically conductive. When the movable electrode portion 23 moves to the lower limit position, the fixed contact 22b and the movable contact 23b are separated and become electrically insulated.

[0021] The three-phase connecting shaft 3 moves the movable electrode portions 23 of the vacuum valves 2A to 2C for three phases. Specifically, the three-phase connecting shaft 3 rotates about its axis to simultaneously move the vacuum valves 2A to 2C for three phases in the up and down direction. This allows pairs of contacts in the vacuum valves 2A to 2C to be switched between contact and separation. The three-phase connecting shaft 3 extends in the front-to-rear direction at the lower left part inside the tank 1. At one end of the front-to-rear direction (hereinafter referred to as the rear), the three-phase connecting shaft 3 penetrates the side of the tank 1 and extends to the outside while keeping the tank 1 airtight. The three-phase connecting shaft 3 is connected to a circuit breaker operating source 10 outside the tank 1 and is rotationally driven by the circuit breaker operating source 10.

[0022] The three-phase connecting shaft 3 is rotatably supported by at least three bearings. In this embodiment, the at least three bearings include a first bearing 31, a second bearing 32, and a third bearing 33. The first bearing 31 and the second bearing 32 support the front end (one end) and the rear end (the other end) of the three-phase connecting shaft 3, respectively, within the tank 1. The third bearing 33 supports the three-phase connecting shaft 3 between the first bearing 31 and the second bearing 32. By supporting the three-phase connecting shaft 3 with the three bearings 31 to 33, deflection of the three-phase connecting shaft 3 during rotational driving and, consequently, vibration of the three-phase connecting shaft 3 can be suppressed. Therefore, vibration of the movable electrode 23, which is structurally connected to the three-phase connecting shaft 3, can also be suppressed, and a deterioration in the interrupting performance of the circuit breaker 100 due to vibration of the three-phase connecting shaft 3 can be avoided. The three-phase connecting shaft 3 may be supported by four or more bearings. The first bearing 31 and the second bearing 32 may support the three-phase connecting shaft 3 near its front end and rear end within the tank 1, respectively, so as to stably hold the three-phase connecting shaft 3.

[0023] 2, a front fitting portion 11 that receives 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 protrusion that protrudes outward from the rest of the front surface of the tank 1. The three-phase connecting shaft 3 is inserted into this front fitting portion 11 and is journaled relative to the front fitting portion 11 by a first bearing portion 31.

[0024] Furthermore, a rear fitting portion 12 that receives 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 protrusion that protrudes outward from the rest of the rear surface of the tank 1, and is a through-hole that penetrates the tank 1. The three-phase connecting shaft 3 is inserted into this rear fitting portion 12 and is journaled relative to the rear fitting portion 12 by a second bearing portion 32.

[0025] The mechanism 4 is a member that connects the movable electrode portion 23 to the three-phase connecting shaft 3 and converts rotation of the three-phase connecting shaft 3 around its axis into opening and closing movement (up and down movement) of the movable electrode portion 23. The mechanism 4 is made up of three parts that are connected to the movable electrode portions 23 of the vacuum interrupters 2A to 2C, respectively. Each of the three parts of the mechanism 4 includes 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 end 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 about its axis.

[0027] The link member 42 is a member that links the tip of the lever member 41 and the force point portion 43a of the rotation 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 force point portion 43a, a fulcrum portion 43b, and an action point portion 43c. The force point portion 43a is a portion connected to the link member 42. The fulcrum portion 43b is a portion connected to the second electric circuit 6 fixed to the tank 1. The action point portion 43c is a portion connected to the movable electrode unit side connecting portion 23c. The rotating member 43 rotates around the fulcrum portion 43b as the link member 42 moves in the front-to-rear direction. At this time, the action point portion 43c moves in the vertical direction. Therefore, the movable electrode unit 23 connected to the action point portion 43c also moves in the vertical direction. With this configuration, the mechanism portion 4 converts the rotation of the three-phase connecting shaft 3 about its axis into opening and closing operations of the movable electrode unit 23.

[0029] The configuration of the mechanism 4 according to this embodiment is an example of a configuration for converting rotation around the axis of the three-phase connecting shaft 3 into opening and closing operations of the movable electrode portion 23, and is not limited to this.

[0030] (Regarding the second circuit 6) The circuit breaker 100 further includes a conductive tube 61 and an extension 62 as a second electric circuit 6 (movable electrode portion side conductor portion) introduced into the tank 1. Three conductive tubes 61 and three extensions 62 are provided lined up in the front-to-rear direction to match the three-phase vacuum valves 2A to 2C.

[0031] The conductive cylinder 61 is a conductive cylindrical member provided below the vacuum vessel 21 and accommodating the portion where the movable electrode unit 23 and the mechanism unit 4 are connected. The conductive cylinder 61 is electrically connected to the movable shaft unit 23a. The conductive cylinder 61 also has a connecting portion (not shown) that connects to the fulcrum unit 43b of the mechanism unit 4. When viewed from the top-bottom direction (the direction of movement of the movable electrode unit 23), the conductive cylinder 61 extends from the connecting portion to one side (i.e., left) and also extends to the other side opposite to the one side (i.e., right). The extension portion 62 is a conductor that extends to the right from the conductive cylinder 61 and is electrically connected to the outside of the tank 1.

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

[0033] The support plate 71 is a flat plate member attached to the left surface 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 between the support plate 71 and the fixed electrode unit 22. Three upper insulating support bases 72 are provided on the support plate 71, aligned in the front-to-rear direction, to accommodate the three-phase vacuum valves 2A to 2C (see Figure 2). The vacuum vessel 21 and the fixed electrode unit 22 are fixed to the tank 1 by the support plate 71 and the upper insulating support base 72.

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

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

[0036] The support plate 71 also 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 the three-phase connecting shaft 3 from bending, to be supported by the support plate 71, which 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 for supporting the third bearing portion 33, and the structure of the circuit breaker 100 can be simplified.

[0037] Furthermore, it is preferable that the support plate 71 has enough rigidity to sufficiently reduce vibrations caused by reaction forces due to the opening and closing operations of the movable electrode portion 23. With this configuration, it is possible to suppress vibrations of the movable electrode portion 23, which is structurally connected to the support plate 71, and to avoid a decrease in the interrupting performance of the circuit breaker 100 caused by vibrations of the three-phase connecting shaft 3.

[0038] The extension portion support base 74 may also have a support insulator that supports the extension portion 62 and a mounting base for mounting the support insulator to the bottom surface of the tank 1.

[0039] Furthermore, the extension portion support base 74 may be provided so that the center of the extension portion support base 74 in the left-right direction is located at a distance of about two-thirds of the left-right length of the extension portion 62 from the right end of the extension portion 62. With this configuration, vibration of the second electrical circuit 6 can be appropriately suppressed.

[0040] (Action and effect) In this embodiment, the three-phase connecting shaft 3 is supported by three bearing portions 31 to 33. This configuration can suppress deflection of the three-phase connecting shaft 3 when it is driven to rotate, and therefore vibration of the three-phase connecting shaft 3. 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 interrupting performance of the circuit breaker 100 due to vibration of the three-phase connecting shaft 3 can be avoided.

[0041] Furthermore, circuit breakers with only one fixed point for the conductor that forms the electrical path on the movable electrode side within the tank have the following problems. The movable electrode of the vacuum interrupter is moved in the operating direction by the mechanism. The reaction force of this movement of the movable electrode is applied to the conductor that forms the electrical path on the movable electrode side. When the conductor is fixed to only one fixed point, the conductor that receives the reaction force of the movement of the movable electrode may vibrate around the fixed point. Because 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 interruption performance between the electrodes when the vacuum interrupter is opening and closing.

[0042] On the other hand, in the circuit breaker 100 according to this embodiment, the second electric circuit 6 (the conductor portion forming the electric circuit on the movable electrode portion side) introduced into the tank 1 is supported on both the left and right sides relative to the tank 1. In other words, the second electric circuit 6 is fixed at two points. This makes it possible to suppress vibration of the second electric circuit 6 caused by the reaction force of the opening and closing operation of the movable electrode portion 23 being applied to the second electric circuit 6. This also makes it possible to suppress vibration of the movable electrode portion 23, which is structurally connected to the second electric circuit 6, and makes it possible to avoid a decrease in the interrupting performance of the circuit breaker 100 caused by vibration of the second electric circuit 6.

[0043] (Additional notes) The present invention is not limited to the above-described embodiments, 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 valves 2A~2C Three-phase vacuum valve 10. Breaker operating source 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 part 32 Second bearing part 33 Third bearing part 4 Mechanism 5 1st electric circuit 6 Second circuit (movable electrode side conductor) 7 Fixed part 71 Support plate (support plate of first support part) 72 Upper insulating support base 73 Lower insulating support base (insulating support base for first support part) 74 Extension part support stand (second support part) 91 First insulating spacer 92 Second insulating spacer 100 Circuit Breaker

Claims

1. Tank and a three-phase vacuum valve housed in the tank; a three-phase connecting shaft for moving the movable electrode portions of the vacuum interrupters for the three phases; a mechanism that connects the movable electrode unit and the three-phase connecting shaft and converts rotation of the three-phase connecting shaft around its axis into opening and closing operations of the movable electrode unit; and at least three bearing portions that rotatably support the three-phase connecting shaft.

2. 2. The circuit breaker according to claim 1, wherein the at least three bearing portions include a first bearing portion and a second bearing portion that respectively support one end and the other end of the three-phase connecting shaft within the tank, and a third bearing portion that supports the three-phase connecting shaft between the first bearing portion and the second bearing portion.

3. a movable electrode portion-side conductor portion that forms an electric path on the movable electrode portion side in the tank, a connecting portion that connects to the mechanism portion, a movable electrode unit-side conductor portion that extends from the connecting portion to one side and also extends to the other side opposite to the one side when viewed from the operating direction of the movable electrode unit, and is electrically connected to the outside of the tank; a first support portion that supports the movable electrode portion side conductor portion relative to the tank on the one side of the connecting portion; 3. The circuit breaker according to claim 1, further comprising: a second support portion that supports the movable electrode portion side conductor portion relative to the tank on the other side of the connecting portion.

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

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