EP4343806A1

EP4343806A1 - Operation apparatus

Info

Publication number: EP4343806A1
Application number: EP21940709.5A
Authority: EP
Inventors: Kozo Tamura; Masato Kobayashi; Shinichi Shibayama
Original assignee: Hitachi Industrial Equipment Systems Co Ltd
Current assignee: Hitachi Industrial Equipment Systems Co Ltd
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2024-03-27
Also published as: JP7422947B2; JPWO2022244092A1; CN116261766A; WO2022244092A1

Abstract

The present invention provides an operation apparatus which needs no additional shock mitigating functional component to attain the labor reduction, and allows reduction in the number of components to prevent increase in the apparatus size. The operation apparatus is provided with a moveable iron core which drives a drive shaft for operating a moveable-side electrode opposingly disposed to a fixed-side electrode to bring the moveable-side electrode and the fixed-side electrode into an electrical contact state, and a coil disposed around the moveable iron core. The drive shaft and the moveable iron core are integrally operated in association with a switching operation into an open/close state between the moveable-side electrode and the fixed-side electrode. The operation apparatus has the drive shaft slidably supported by a first bearing at a side of the moveable-side electrode, the moveable iron core slidably supported by a second bearing at a side opposite the moveable-side electrode, and a stopper plate for stopping an axial movement of an end of the moveable iron core at a side opposite the moveable-side electrode. When the moveable-side electrode and the fixed-side electrode are in a connected (closed) state, a space is defined by the moveable iron core, the second bearing, and the stopper plate.

Description

Technical Field

The present invention relates to an operation apparatus, more specifically, to the operation apparatus suitable for operating a moveable side of opposingly arranged electrodes of a breaker via an insulation operation rod as a drive shaft.

Background Art

Patent literature 1 discloses a vacuum circuit breaker as an example of the breaker which allows the operation apparatus to operate the electrode at the moveable side.
The vacuum circuit breaker as disclosed in the patent literature 1 includes the vacuum valve, the operation apparatus, and the fixing member for reducing deflection of a casing of the operation apparatus by suppressing the impact resulting from opening/closing operations of the vacuum circuit breaker, or stress caused by vibration without increasing weight and size of the vacuum circuit breaker so that reliability in the opening/closing operations is, improved. Specifically, the vacuum valve stores at least the fixed-side electrode and the moveable-side electrode, and has its periphery covered with a molding part. The operation apparatus drives the moveable-side electrode via the insulation operation rod as the drive shaft. The fixing member fixes the vacuum valve and the operation apparatus which are linearly arranged across the molding part of the vacuum valve and the operation apparatus.

Citation List

Patent Literature

PTL 1: Japanese Patent Application Laid-Open No. 2018-147643

Summary of Invention

Technical Problem

The above-described operation apparatus includes the moveable iron core to be operated integrally with the insulation operation rod, the stator iron core (which may be omitted) disposed opposingly to the moveable iron core in the axial direction, the coil disposed around the moveable iron core and the stator iron core, and wound around the bobbin which forms the magnetic field for driving the moveable iron core, the cylindrical first yoke which is provided on an outer circumferential side of the coil, and second and third yokes which are disposed at both sides of the coil in the axial direction. The insulation operation rod which is integrally operated with the moveable iron core is supported by the bearing held by the second and the third yokes.
However, in the above-structured operation apparatus, when the moveable-side electrode and the fixed-side electrode are in a disconnected state, an end of the insulation operation rod at the side opposite the moveable-side electrode protrudes from the third yoke in the axial direction. Accordingly, the operation apparatus has to be designed in consideration with such protrusion of the insulation operation rod, resulting in the problem of increase in the apparatus size.
Generally, the operation apparatus is provided with the damper (shock mitigating functional component) which serves to mitigate the shock resulting from collision of the axially protruding end of the insulation operation rod from the third yoke against the wall of the container when the moveable-side electrode and the fixed-side electrode are in the disconnected state.
Preparation of the damper as described above, may increase the number of components as well as take much labor, which causes the problem of increase in the apparatus size.
In view of the above-described problem, it is a first object of the present invention to provide the operation apparatus which requires no increase in the apparatus size.
It is a second object of the present invention to provide the operation apparatus which eliminates the need of the shock mitigating functional component (damper) to attain the labor reduction, and ensures reduction in the number of components to prevent increase in the apparatus size.

Solution to Problem

The first object of the present invention is to provide the operation apparatus having a moveable iron core which drives a drive shaft for operating a moveable-side electrode opposingly disposed to a fixed-side electrode to bring: the moveable-side electrode and the fixed-side electrode into an electrical contact state, and a coil disposed around the moveable iron core. The drive shaft and the moveable iron core are integrally operated in association with a switching operation into an open/close state between the moveable-side electrode and the fixed-side electrode. The operation apparatus has the drive shaft supported by a first bearing at a side of the moveable-side electrode, and has the moveable iron core supported by a second bearing at a side opposite the moveable-side electrode. When the moveable-side electrode and the fixed-side electrode are in a disconnected (open) state, an end of the drive shaft at the side opposite the moveable-side electrode does not protrude from an axial end of the operation apparatus.
The second object of the present invention, is to provide the operation apparatus having a moveable iron core which drives a drive shaft for operating a moveable-side electrode opposingly disposed to a fixed-side electrode to bring the moveable-side electrode and the fixed-side electrode into an electrical contact state, and a coil disposed around the moveable iron core. The drive shaft and the moveable iron core are integrally operated in association with a switching operation into an open/close state between the moveable-side electrode and the fixed-side electrode. The operation apparatus has the drive shaft supported by a first bearing at a side of the moveable-side electrode, the moveable iron core supported by a second bearing at a side opposite the moveable-side electrode, and a stopper plate for stopping an axial movement of an end of the moveable iron core at a side opposite the moveable-side electrode. When the moveable-side electrode and the fixed-side electrode are in a connected (closed) state, a space is defined by the moveable iron core, the second bearing, and the stopper plate.

Advantageous Effects of Invention

The present invention does not require the shock mitigating functional component (damper) for labor reduction without increasing the apparatus size. It is further possible to reduce the number of components, preventing increase in the apparatus size.

Brief Description of Drawings

Figure 1 is a sectional view of a part of a vacuum circuit breaker which adopts an operator apparatus according to the present invention.
Figure 2 is a sectional view of a generally employed operation apparatus.
Figure 3 is a sectional view of an operation apparatus as an example 1 according to the present invention.
Figure 4 represents that a comparison of an axial length is made between the generally employed operation apparatus and the operation apparatus of the example.
Figure 5(a) is a sectional view of an operation apparatus as an example 2 according to the present invention in the state where a fixing bolt is invisible.
Figure 5(b) is a sectional view of the operation apparatus as the example 2 according to the present invention in the state where the fixing bolt is visible.
Figure 6 represents, an operation state of the operation apparatus as the example 2 according to the present invention.
Figure 7 is a sectional view of an exemplary shock mitigating functional component (damper) adopted by the operation apparatus as the example 2 according to the present invention.
Figure 8 is a sectional view of an exemplary unit for controlling an air clearance amount in the space as the shock mitigating functional component adopted by the operation apparatus as the example 2 according to the present invention.
Figure 9 is a sectional view of an operation apparatus as an example 3 according to the present invention.
Figure 10 is a sectional view of an exemplary process for fixing a transmission filter of the operation apparatus as the example 3 according to the present invention.
Figure 11 is a sectional view of another example of an operation apparatus according to the present invention.
Figure 12 is a sectional view of a modified example of the operation apparatus as illustrated in Figure 11.

Description of Embodiments

An operation apparatus according to the present invention will be described as exemplified cases illustrated in the drawings. The same codes are given to the same components.
Referring to Figure 1, a vacuum circuit breaker which adopts the operation apparatus according to the present invention will be described prior to explanations of examples of the operation apparatus according to the present invention.
As Figure 1 illustrates, a vacuum circuit breaker 100A is provided with a vacuum valve 1 (having its circumference covered with a molding part 1A), which is integrally molded (mold) using such solid insulator as an epoxy resin, a fixed-side cable bushing 2 having a periphery of a fixed-side cable bushing conductor 15 molded, a moveable-side cable bushing 3 having an outer periphery of a moveable-side cable bushing conductor 16 molded, and an operation apparatus 4 for operating a moveable-side electrode 13 to be described later.
The vacuum valve 1 integrally molded using the solid insulator such as the epoxy resin is usually called a mold vacuum valve. Although not shown specifically, the surface part of the mold is grounded, and kept electrically insulated with the solid insulator such as the epoxy resin.
The vacuum valve 1 as described above, includes a fixed-side end plate 6 bonded to one end of a cylindrical insulator 5, a fixed-side conductor 7 which penetrates through the fixed-side end plate 6 air-tightly, a moveable-side end plate 8 bonded to the other end of the cylindrical insulator 5, a bellows portion 9 having one end bonded to the moveable-side end plate 8 to allow the moveable section to be driven, and a moveable-side conductor 10 which penetrates through the bellows portion 9 air-tightly for driving in the axial direction while maintaining vacuum. The internal pressure is kept to the vacuum degree of approximately 10^-2 Pa or lower.
Inside of the vacuum valve 1, a floating potential metal 11 supported by the cylindrical insulator 5, a fixed-side electrode 12 connected to an end of a fixed-side conductor 7, and the moveable-side electrode 13 connected to an end of the moveable-side conductor 10 are arranged.
The moveable-side conductor 10 is connected to an insulation operation rod 14. The insulation operation rod 14 is connected to the operation apparatus 4 linked with a wipe mechanism for applying the contact load to an electrode pair. The space around the insulation operation rod 14 is filled with insulation gas 18 such as air and sulfur hexafluoride.
The moveable-side electrode 13 is driven via the insulation operation rod 14 associated with driving of the operation apparatus 4. This makes the contact/separation state between the fixed-side electrode 12 and the moveable-side electrode 13 switchable, in other words, makes the open/close state of the vacuum valve 1 switchable. Figure 1 illustrates the vacuum valve 1 in the open state between the fixed-side electrode 12 and the moveable-side electrode 13.
The fixed-side cable bushing 2 electrically connects the fixed-side cable bushing conductor 15 to the fixed-side conductor 7 of the vacuum valve 1. In the case of the moveable-side cable bushing 3, the moveable-side cable bushing conductor 16 disposed at the moveable side of the vacuum valve 1 is integrally molded with the vacuum valve 1 using the solid insulator such as the epoxy resin. The moveable-side conductor 10 of the vacuum valve 1 and the moveable-side cable bushing conductor 16 are electrically connected via a sliding current carriable contact 17. The fixed-side cable bushing 2 and the moveable-side cable bushing 3 are connected to a not shown power supply side cable, and a not shown load-side cable to make the operation ready.
In the case of the vacuum circuit breaker 100A as illustrated in Figure 1, the vacuum valve 1 and the operation apparatus 4 are substantially linearly arranged. A fixing member 19 across the molding part 1A around the vacuum valve 1 and the operation apparatus 4 serves to integrally fix the vacuum valve 1 and the operation apparatus 4.
The vacuum valve 1 and the operation apparatus 4 are fixed using the fixing member 19. Specifically, using bolts 21a, 21b as fastening members, the section of the fixing member 19 at the side of the vacuum valve 1 is fixed via a plurality of mold projection parts (integrally molded with the molding part 1A) 20a, 20b each embedding an insert nut outwardly protruded to the side surface of the molding part 1A of the vacuum valve 1. Meanwhile, the section of the fixing member 19 at the side of the operation apparatus 4 is directly fixed to the casing of the operation apparatus 4 using bolts 21c, 21d as fastening members.
The generally employed operation apparatus 4A used for the above-described vacuum circuit breaker 100A will be described with reference to Figure 2.
As Figure 2 illustrates, the generally employed operation apparatus 4A includes a moveable iron core 22 to be operated integrally with a drive shaft 14a connected to the insulation operation rod 14, a stator iron core 25 (if the stator iron core 25 is not adopted, a first bearing 27a to be described later has to be kept from contact with the moveable iron core 22), which faces the moveable iron core 22 in the axial direction, a coil 23 which is disposed around the moveable iron core 22 and the stator iron core 25, and wound around a bobbin 24 which forms a magnetic field for driving the moveable iron core 22, a cylindrical first yoke 26a provided on an outer circumferential side of the coil 23, a disc-like second yoke 26b provided around the coil 23 at the side of the moveable-side electrode 13, and a disc-like stopper (non-magnetic body such as aluminum and SUS) which is provided around the coil 23 at the side opposite the moveable-side electrode 13 for stopping the axial movement of the moveable iron core 22. The drive shaft 14a integrally operated with the moveable iron core 22 has the side of the moveable-side electrode 13 slidably supported by the first bearing (slide bearing, for example) 27a which is force-fitted and held with the disc-like second yoke 26b and the stator iron core 25, and has the side opposite the moveable-side electrode 13 slidably supported by a second bearing (slide bearing, for example) 27b which is force-fitted and held with the disc-like stopper 26c.
In the case of the generally employed operation apparatus 4A, when the moveable-side electrode 13 and the fixed-side electrode 12 are in a disconnected (open) state, an end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 protrudes axially from the stopper 26c. Accordingly, the generally employed operation apparatus 4A has to be designed taking the protrusion of the drive shaft 14a into consideration. This may cause the problem of increase in the apparatus size.
The operation apparatus according to the present invention has been made to solve the problem as described above, which will be described in detail hereinafter.

Example 1

Figure 3 illustrates an operation apparatus as an example 1 according to the present invention.
An operation apparatus 4B as illustrated in Figure 3 is similarly configured to the generally employed operation apparatus 4A as illustrated in Figure 2. In this example, the drive shaft 14a operated integrally with the moveable iron core 22 has its section at the side of the moveable-side electrode 13 slidably supported by the first bearing (slide bearing, for example) 27a which is force-fitted and held with the disc-like second yoke 26b and the stator iron core 25 (if the stator iron core 25 is not adopted, the first bearing 27a has to be kept from contact with the moveable iron core 22). At the side opposite the moveable-side electrode 13, the moveable iron core 22 operated integrally with the drive shaft 14a is slidably supported by the second bearing (slide bearing, for example) 27c which is force-fitted and held with the resin bobbin 24. When the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 does not protrude from the axial end of the operation apparatus 4B, that is, the stopper 26c.
In the example as illustrated in Figure 3, the second bearing 27c is force-fitted and held with the bobbin 24. A flanged bearing can be used for the second bearing 27c to be held between the bobbin 24 and the stopper (non-magnetic body such as aluminum and SUS) 26c. Alternatively, it is possible to cause the bobbin 24 to function as the second bearing 27c so that the moveable iron core 22 is supported.
In this example, when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the position of the end 14b of the drive shaft 14a at the side opposite the moveable-electrode 13, and the position of the axial end of the second bearing 27c are substantially aligned to each other.
As described above, similar to the generally employed operation apparatus 4A as illustrated in Figure 2, the operation apparatus 4B of the example includes the moveable iron core 22 which is operated integrally with the drive shaft 14a, the coil 23 which is disposed around the moveable iron core 22, and wound around the resin bobbin 24 which forms the magnetic field for operating the moveable iron core 22, the cylindrical first yoke 26a provided on the outer circumferential side of the coil 23, the disc-like second yoke 26b provided around the coil 23 at the side of the moveable-side electrode13, and the disc-like stopper 26c which is formed of the non-magnetic body such as aluminum and SUS, and provided around the coil 23 at the side opposite the moveable-side electrode 13 for stopping the axial movement of the moveable iron core 22. The first bearing 27a is force-fitted and held with the second yoke 26b and the stator iron core 25 (the first bearing 27a does not have to be force-fitted and held with the stator iron core 25 so long as it is force-fitted with the second yoke 26b), and the second bearing 27c is force-fitted and held with the bobbin 24.
In the case of the operation apparatus 4B of the example, when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 does not protrude axially from the stopper 26c.
Then, the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13, the axial end of the second bearing 27c, and the axial end of the coil 23 are all positioned at an inner side of the stopper 26c in the axial direction.
In this example, a notch 22a is formed in the moveable iron core 22 at an inner diameter side, at which the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 is positioned so that a nut 28 is fitted with the end 14b of the drive shaft 14a at the side opposite the moveable-sideelectrode 13 in the notch 22a.
As the nut 28 is fitted with the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13, the bottom of the nut 28 can be held with a part of the surface of the notch 22a. This makes it possible to prevent fall-off of the drive shaft 14a.
Figure 4 represents a comparison of the axial length between the generally employed apparatus 4A and the operation apparatus 4B of the example.
Figure 4(a) illustrates the generally employed operation apparatus 4A, and Figure 4(b) illustrates the operation apparatus 4B of the example.
Referring to the generally employed operation apparatus 4A as illustrated in Figure 4(a), when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 protrudes axially from the stopper 26c.
Meanwhile, referring to the operation apparatus 4B of the example as illustrated in Figure 4(b), when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 does not protrude axially from the stopper 26c.
Therefore, compared with the generally employed operation apparatus 4A, the operation apparatus 4B of the example has its size reduced by the amount (indicated by a code L) corresponding to the axially un-protruded portion of the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 from the stopper 26c. This makes it possible to prevent increase in the apparatus size (operation apparatus 4B and the vacuum circuit breaker 100A provided therewith).

Example 2

Figures 5(a) and 5(b) illustrate an operation apparatus as an example 2 according to the present invention.
An operation apparatus 4C of the example as illustrated in Figures 5(a) and 5(b) is similarly configured to the operation apparatus as the example 1 as illustrated in Figure 3. In this example, the drive shaft 14a operated integrally with the moveable iron core 22 has its section at the side of the moveable-side electrode 13 slidably supported by the first bearing (slide bearing, for example) 27a which is force-fitted and held with the disc-like second yoke 26b and the stator iron core 25 (if the stator iron core 25 is not adopted, the first bearing 27a has to be kept from contact with the moveable iron core 22). At the side opposite the moveable-side electrode 13, the moveable iron core 22 operated integrally with the drive shaft 14a is slidably supported by the second bearing (slide bearing, for example) 27c which is force-fitted and held with the resin bobbin 24. The operation apparatus is further provided with a stopper plate 30 for stopping the axial movement of an end of the moveable iron core 22 at the side opposite the moveable-side electrode 13. When the moveable-side electrode 13 and the fixed-side electrode 12 are in the connected (closed) state, a space 33 is defined by the moveable iron core 22, the second bearing 27c, and the stopper plate 30.
' Specifically, the operation apparatus 4C of the example includes the moveable iron core 22 which is operated integrally with the drive shaft 14a, the coil 23 which is disposed around the moveable iron core 22, and wound around the resin bobbin 24 which forms the magnetic field for operating the moveable iron core 22, the cylindrical first yoke 26a provided on the outer circumferential side of the coil 23, and disc-like second and third yokes 26b, 26d, which are provided at both sides of the coil 23 in the axial direction. The first bearing (slide bearing, for example) 27a is force-fitted and held with the second yoke 26b and the stator iron core 25 (if the stator iron core 25 is not adopted, the first bearing 27a has to be kept from contact with the moveable iron core 22). The second bearing (slide bearing, for example) 27c is force-fitted and held with the bobbin 24 while partially protruding from the third yoke 26d in the axial direction. The stopper plate 30 is fixed to an axially outer side of the third yoke 26d via a bearing holding member 29 which is formed of the non-magnetic body such as aluminum and SUS, and provided on the outer circumferential side of the second bearing 27c at eight positions on the whole circumference using third fixing bolts 32c. When the moveable-side electrode 13 and the fixed-side electrode 12 are in the connected (closed) state, the space 33 is defined by an axial end of the moveable iron core 22, an axially protruded section of the second bearing 27c, and the stopper plate 30.
In the case of the operation apparatus 4C of the example, the first yoke 26a and the second yoke 26b are fixed using the first fixing bolt 32a, and the first yoke 26a and the third yoke 26d are fixed using the second fixing bolt 32b at eight positions on the whole circumference.
In the example, the notch 22a is formed in the moveable iron core 22 at the inner diameter side, at which the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 is positioned so that the nut 28 is fitted with the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13 in the notch 22a.
As the nut 28 is fitted with the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13, the bottom of the nut 28 can be held by a part of the surface of the notch 22a to prevent fall-off of the drive shaft 14a.
Figure 6 illustrates operation states of the operation apparatus 4C of the example. Figure 6(a) illustrates the operation state when the moveable-side electrode 13 and the fixed-side electrode 12 are in the connected (closed) state. Figure 6(b) illustrates the operation state when the moveable-side electrode 13 and the fixed-side electrode 12 are in an intermediate (transitional) state. Figure 6(c) illustrates the operation state when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state.
Figure 6 indicates that the volume of the space 33 defined by the axial end of the moveable iron core 22, the axially protruded section of the second bearing 27c, and the stopper plate 30 changes as the state of connection between the moveable-side electrode 13 and the fixed-side electrode 12 makes the transition from the connected (closed) state as illustrated in Figure 6(a) to the disconnected state as illustrated in Figure 6(c) through the intermediate state as illustrated in Figure 6(b).
The operation apparatus 4C of the example is provided with a shock mitigating functional component (damper) which controls an air clearance amount in the space 33 defined by the axial end of the moveable iron core 22, the axially protruded section of the second bearing 27c, and the stopper plate 30, and mitigates shock to the stopper plate 30 when stopping the axial movement of the end 14b at the side opposite the moveable-side electrode 13 of the moveable iron core 22 when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state.
Specifically, the space 33 defined by the axial end of the moveable iron core 22, the axially protruded section of the second bearing 27c, and the stopper plate 30 has a small gap between the moveable iron core 22 and the second bearing 27c. Accordingly, air inside the space is unlikely to flow out (air passes through not in an instant but by degrees). When the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state, the moveable iron core 22 moves while reducing the space 33 (reducing the volume of the space 33). The counterforce caused by the small air escape route in the space 33 can be controlled by adding air clearance holes in the space 33 each serving as the shock mitigating functional component (damper).
The air clearance amount in the space 33 defined by the axial end of the moveable iron core 22, the axially protruded section of the second bearing 27c, and the stopper plate 30 is controlled to impart the air damper function (buffer function). This makes it possible to mitigate the shock resulting from collision of the moveable iron core 22 against the stopper plate 30 when the moveable-side electrode 13 and the fixed-side electrode 12 are in the disconnected (open) state. Mitigation of such shock eliminates or alleviates rebounding of the moveable iron core 22, which may suppress the movement of the moveable-side electrode 13 in the direction to the connected (closed) state.
The shock mitigating functional component (damper) will be described.
Figure 7 illustrates an example of the shock mitigating functional component (damper) to be adopted by the operation apparatus 4C of the example.
Referring to Figure 7, the shock mitigating functional component (damper) for mitigating the shock to the stopper plate 30 is constituted by a hole 30a formed in the center of the disc-like stopper plate 30, or a plurality of holes including the hole 30a formed in the center of the stopper plate 30, and holes 30b formed symmetrically with respect to the center axis of the stopper plate 30 (example as illustrated in Figure 7 shows the hole 30a formed in the center of the stopper plate 30, and the holes 30b formed symmetrically with respect to the center axis of the stopper plate 30). The air clearance amount in the space 33 from those holes 30a, 30b is controlled to mitigate the shock to the stopper plate 30 when stopping the axial movement of the end of the moveable iron core 22 at the side opposite the moveable-side electrode 13.
In one of the exemplified cases for controlling the air clearance amount in the space 33 from the holes 30a, 30b, the hole 30a formed in the center of the stopper plate 30 is threaded as illustrated in Figure 8, with which a through-holed bolt 34 is fitted. The air clearance amount in the space 33 is controlled by gradually releasing the fitted state between the through-holed bolt 34 and the hole 30a formed in the stopper plate 30.
If the hole 30a is formed in the center of the stopper plate 30, and the holes 30b are formed symmetrically with respect to the center axis of the stopper plate 30, each size of the through hole of the through-holed bolt 34 becomes different. This makes it possible to adjust the braking force of the shock mitigating functional component (damper).
The structure of the example may be provided with the shock mitigating functional component (damper) without making the axial length of the operation apparatus 4C largely different from the axial length of the generally employed operation apparatus 4A as illustrated in Figure 2. This eliminates the need for providing an additional shock mitigating functional component (damper) to attain the labor reduction. The number.of components may also be reduced to attain reduction in the apparatus size.
The braking force of the shock mitigating functional component (damper) may be adjusted by controlling the air clearance amount in the space 33 defined by the axial end of the moveable iron core 22, the axially protruded section of the second bearing 27c, and the stopper plate 30.

Example 3

Figure 9 illustrates an operation apparatus as an example 3 according to the present invention.
An operation apparatus 4D of the example as illustrated in Figure 9 uses an air-permeable filter 35 formed of a waterproof moisture permeable material which covers a hole 30c formed in the center of the stopper plate 30 as the shock mitigating functional component (damper) for mitigating the shock to the stopper plate 30. Other structures of the operator apparatus of the example are the same as those of the operation apparatus 4C as the example 2 as illustrated in Figure 5(a).
The air-permeable filter 35 is attached to the stopper plate 30 using the adhesive. Alternatively, as Figure 10 illustrates, the air-permeable filter 35 is clamped by a clamping member 36 having axial through holes 36a, and fixed to the stopper plate 30.
The air-permeable filter 35 adopted by the operation apparatus 4D of the example may be arbitrarily formed into, for example, a sheet-like film or of bolt type (to be applied using the bolt). The use of the filter makes the apparatus less subject to the lower interface environment (no entrance of water nor dust makes characteristics unlikely to be influenced by the ambient environment). The air permeable filter 35 of bolt type facilitates each attachment/detachment.
The structure of the example as described above provides similar effects to those derived from the example 2.
Other examples of the operation apparatus will be described referring to Figures 11 and 12.
In the example of the operation apparatus as illustrated in Figure 11, like the operation apparatus 4C of Figure 8, the threaded hole 30a is formed in the center of the stopper plate 30. When the moveable-side electrode 13 and the fixed-side electrode 12 are in the connected (closed) state, a fixing bolt 37 is fitted with the hole 30a to hold the end 14b of the drive shaft 14a at the side opposite the moveable-side electrode 13.
In the example as illustrated in Figure 11, the moveable iron core 22 can be pushed by the fixing bolt 37 through the hole 30a which is threaded in the similar way to the operation apparatus 4C as illustrated in Figure 8. In this case, it is preferable to position the threaded hole 30a on the center axis so that the moveable iron core 22 is pushed straightly.
The moveable iron core 22 can be pushed and fixed by the fixing bolt 37 to easily hold the connected (closed) state between the moveable-side electrode 13 and the fixed-side electrode 12. The connected (closed) state between the moveable-side electrode 13 and the fixed-side electrode 12 can be held without a power source such as utility power. This facilitates measurement of control dimensions of the contact pressure spring during inspection.
In the example as illustrated in Figure 12, instead of using the fixing bolt 37 as illustrated in Figure 11, an air piping joint 38 is fitted with the threaded hole 30a. When the moveable-side electrode 13 and the fixed-side electrode 12 are in the connected (closed) state, compressed air is introduced into the space 33 via the air piping joint 38 to hold the end 14b at the side opposite the moveable-side electrode 13 of the moveable iron core 22.
The use of the compressed air via the air piping joint 38 instead of the fixing bolt 37 allows the moveable-side electrode 13 and the fixed-side electrode 12 to be held. Switchable supply of the compressed air attains the switching operation of the vacuum circuit breaker 100A.
The present invention is not limited to the examples as described above, but includes various modifications. For example, the examples are described in detail for readily understanding of the present invention which is not necessarily limited to the one equipped with all structures as described above. It is possible to replace a part of the structure of one example with the structure of another example. The one example may be provided with an additional structure of another example. It is further possible to add, remove, and replace the other structure to, from and with a part of the structure of the respective examples. Reference Signs List

1... vacuum valve,
1A... molding part,
2... fixed-side cable bushing,
3...moveable-side cable bushing,
4, 4A, 4B, 4C, 4D... operation apparatus,
5... cylindrical insulator,
6... fixed-side end plate,
7... fixed-side conductor,
8... moveable-side end plate,
9... bellows portion
10... moveable-side conductor,
11... floating potential metal,
12... fixed-side electrode,
13... moveable-side electrode,
14... insulation operation rod,
14a... drive shaft,
14b... end of the drive shaft at a side opposite the moveable-side electrode,
15... fixed-side cable bushing conductor,
16... moveable-side cable bushing conductor,
17... contact,
18... insulation gas,
19... fixing member,
20a, 20b... mold projection part,
21a, 21b, 21c, 21d... bolt
22... moveable iron core,
22a... notch,
23... coil,
24... bobbin,
25... stator iron core,
26a... first yoke,
26b... second yoke,
26c... stopper,
26d... third yoke,
27a... first bearing,
27b, 27c... second bearing,
28... nut,
29... bearing holding member,
30... stopper plate,
30a, 30c... hole formed in the center of the stopper plate,
30b... holes formed symmetrically with respect to the center axis of the stopper plate,
32a... first bolt,
32b... second bolt,
32c... third bolt,
33... space,
34... through-holed bolt,
35... air-permeable filter,
36... clamping member,
36a... hole formed in the clamping member,
37... fixing bolt,
38... air piping joint,
100A... vacuum circuit breaker

Claims

An operation apparatus including a moveable iron core which drives a drive shaft for operating a moveable-side electrode opposingly disposed to a fixed-side electrode, the moveable-side electrode and the fixed-side electrode being brought into an electrical contact state, and a coil disposed around the moveable iron core, the drive shaft and the moveable iron core being integrally operated in association with a switching operation into an open/close state between the moveable-side electrode and the fixed-side electrode, characterized in that
the operation apparatus has the drive shaft supported by a first bearing at a side of the moveable-side electrode, and has the moveable iron core supported by a second bearing at a side opposite the moveable-side electrode; and

when the moveable-side electrode and the fixed-side electrode are in a disconnected (open) state, an end of the drive shaft at the side opposite the moveable-side electrode does not protrude from an axial end of the operation apparatus.
The operation apparatus according to claim 1, wherein
the operation apparatus includes the moveable iron core which is operated integrally with the drive shaft, a coil which is disposed around the moveable iron core, and wound around a bobbin which forms a magnetic field for operating the moveable iron core, a cylindrical first yoke provided on an outer circumferential side of the coil, a disc-like second yoke provided around the coil at a side of the moveable-side electrode, and a disc-like stopper which is provided around the coil at a side opposite the moveable-side electrode for stopping an axial movement of the moveable iron core;

the moveable iron core is supported by force-fitting and holding the first bearing at least with the second yoke, and the second bearing with the bobbin, using a flanged bearing as the second bearing to be held between the bobbin and the stopper, or causing the bobbin to function as the second bearing; and

when the moveable-side electrode and the fixed-side electrode are in the disconnected (open) state, the end of the drive shaft at the side opposite the moveable-side electrode does not protrude axially from the stopper.
The operation apparatus according to claim 1 or 2, wherein when the moveable-side electrode and the fixed-side electrode are in the disconnected (open) state, a position of the end of the drive shaft at the side opposite the moveable-side electrode is substantially aligned with a position of an axial end of the second bearing.
The operation apparatus according to any one of claims 1 to 3, wherein a notch is formed in the moveable iron core at an inner diameter side, at which the end of the drive shaft at the side opposite the moveable-side electrode is positioned so that a nut is fitted with the end of the drive shaft at the side opposite the moveable-side electrode in the notch.
An operation apparatus including a moveable iron core which drives a drive shaft for operating a moveable-side electrode opposingly disposed to a fixed-side electrode, the moveable-side electrode and the fixed-side electrode being brought into an electrical contact state, and a coil disposed around the moveable iron core, the drive shaft and the moveable iron core being integrally operated in association with a switching operation into an open/close state between the moveable-side electrode and the fixed-side electrode, wherein
the operation apparatus has the drive shaft supported by a first bearing at a side of the moveable-side electrode, the moveable iron core supported by a second bearing at a side opposite the moveable-side electrode, and a stopper plate for stopping an axial movement of an end of the moveable iron core at a side opposite the moveable-side electrode; and

when the moveable-side electrode and the fixed-side electrode are in a connected (closed) state, a space is defined by the moveable iron core, the second bearing, and the stopper plate.
The operation apparatus according to claim 5, wherein
the operation apparatus includes the moveable iron core which is operated integrally with the drive shaft, a coil which is disposed around the moveable iron core, and wound around a bobbin which forms a magnetic field for operating the moveable iron core, a cylindrical first yoke provided on an outer circumferential side of the coil, and disc-like second and third yokes, which are provided at both sides of the coil in an axial direction;

the first bearing is force-fitted and held with at least the second yoke, and the second bearing is force-fitted and held with the bobbin while partially protruding from the third yoke in an axial direction;

the stopper plate is fixed to an axially outer side of the third yoke via a bearing holding member provided on an outer circumferential side of the second bearing; and

when the moveable-side electrode and the fixed-side electrode are in the connected (closed) state, the space is defined by an axial end of the moveable iron core, an axially protruded section of the second bearing, and the stopper plate.
The operation apparatus according to claim 5 or 6, wherein the operation apparatus is provided with a shock mitigating functional component which controls an air clearance amount in the space, and mitigates shock to the stopper plate when stopping the axial movement of the end of the moveable iron core at the side opposite the moveable-side electrode when the moveable-side electrode and the fixed-side electrode are in a disconnected (open) state.
The operation apparatus according to claim 7, wherein the shock mitigating functional component for mitigating the shock to the stopper plate includes at least one hole formed in the stopper plate, and controls the air clearance amount in the space from the hole to mitigate the shock to the stopper plate when stopping the axial movement of the end of the moveable iron core at the side opposite the moveable-side electrode.
The operation apparatus according to claim 8, wherein
the hole is formed at least in the center of the stopper plate, or a plurality of holes are formed, which include the hole formed in the center of the stopper plate, and the holes formed symmetrically with respect to a center axis of the stopper plate; and

if the holes each threaded to be fitted with a through-holed bolt include the hole formed in the center of the stopper plate, and the holes formed symmetrically with respect to the center axis of the stopper plate, through holes of the through-holed bolts are sized differently from one another.
The operation apparatus according to claim 7, wherein the shock mitigating functional component for mitigating the shock to the stopper plate includes a hole formed in the center of the stopper plate, and an air-permeable filter which covers the hole.
The operation apparatus according to claim 10, wherein the air-permeable filter is attached to the stopper plate using an adhesive, or clamped by a component having an axial through hole to be fixed to the stopper plate.
The operation apparatus according to any one of claims 5 to 11, wherein a notch is formed in the moveable iron core at an inner diameter side, at which the end of the drive shaft at the side opposite the moveable-side electrode is positioned so that a nut is fitted with the end of the drive shaft at the side opposite the moveable-side electrode in the notch.