Bearing structure for movable energizing shaft, vacuum interrupter, method for manufacturing a vacuum interrupter

Abstract

To provide a technique capable of contributing to productivity improvement, etc., by preventing a bearing from being desorbed from a flange penetration ole even without using an adhesive agent, a bolt, etc.SOLUTION: A bearing 4 is applied which is configured by including a flange-shaped part 5, which is an annular shape of a larger diameter than an opening diameter in a flange penetration hole 3 at the other side in a shaft center direction, and a cylindrical wall part 6 extending from an inner peripheral edge of the flange-shaped part 5 in the shaft center direction. In the cylindrical wall part 6, a claw portion 61 is formed on an outer peripheral surface 6b and an outer diameter in a location, where the claw portion 61 is formed, is larger than an opening diameter in the flange penetration hole 3 at one side in the shaft center direction. In the cylindrical wall part 6, a plurality of slit holes in a shape extending in the shaft center direction while penetrating in a radial direction and in a shape opened at one side in the shaft center direction is formed while being spaced at a predetermined interval in a circumferential direction and each cylindrical wall part piece, which is a portion between the slit holes, is elastically freely deformable in the radial direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a bearing structure for a movable energizing shaft, a vacuum interrupter, and a method for manufacturing a vacuum interrupter, and particularly relates to a technology applicable to, for example, various electric power facilities.

Background Art

[0002] As an example of a vacuum interrupter applied to, for example, various electric power facilities, there is a vacuum container configured by sealing one side (fixed side) and the other side (movable side) in the axial direction of an insulating cylindrical main body (hereinafter, simply referred to as the axial direction as appropriate) with a fixed flange and a movable flange respectively. Both a fixed electrode and a movable electrode are disposed inside this vacuum container so as to face each other in the axial direction.

[0003] On the inner side of the vacuum container of the fixed flange, a fixed energizing shaft is provided so as to extend in the axial direction from the inner side of the vacuum container, and the fixed electrode is supported at the end of the fixed energizing shaft.

[0004] The movable flange is provided with a flange through-hole penetrating the movable flange in the axial direction, and a bearing that guides the movable energizing shaft in the axial direction (for example, guides the movable energizing shaft in a non-rotatable state) is provided in the flange through-hole. The movable energizing shaft is supported on the inner side of the vacuum container of the movable flange via a bellows that can expand and contract in the axial direction.

[0005] According to the vacuum interrupter having the above configuration, the movable energizing shaft (and the movable electrode) can be moved while being guided in the axial direction while maintaining the vacuum state inside the vacuum container (specifically, on the outer peripheral side of the bellows inside the vacuum container), and the movable electrode can be brought into contact with and separated from the fixed electrode (the contact is opened and closed) in accordance with the movement of the movable energizing shaft.

[0006] When the movable energizing shaft is moved in the axial direction, frictional force may be generated between the movable energizing shaft and the bearing, which may cause the bearing to detach (fall out) from the flange through-hole due to this frictional force. In such cases, as shown in Patent Document 1, for example, one method is to bond the bearing to the movable flange using an adhesive to prevent the bearing from detaching from the flange through-hole.

[0007] Furthermore, if the movable energizing shaft rotates, the rotational force may be applied to the bellows or other components, potentially causing damage. In such cases, the bearing can be configured to guide the movable energizing shaft in the axial direction while it is in a non-rotatable state (for example, in Patent Document 2, a contact surface (reference numeral 12) corresponding to the width of two flats is formed in the insertion guide (reference numeral 11)).

[0008] In addition, a configuration is known in which the diameter of the opening side of the cylindrical wall portion (guide hole) of the bearing through which the movable energizing shaft is inserted is increased to allow a certain degree of radial oscillation of the movable energizing shaft (for example, the configuration shown in Patent Document 3). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 9-17298 [Patent Document 2] Special Publication No. 2016-535400 [Patent Document 3] Japanese Patent Publication No. 2016-110920 [Overview of the project] [Problems that the invention aims to solve]

[0010] To bond a bearing to a movable flange using an adhesive, for example, the adhesive is interposed between the bearing and the movable flange, and then dried and solidified. However, since it takes a certain amount of time for the adhesive to solidify, this may lead to a decrease in productivity.

[0011] Furthermore, since many adhesives are flammable, this can lower the heat resistance temperature of the vacuum interrupter. In this case, the use of the vacuum interrupter may be restricted (for example, to prevent the area where the adhesive is applied from becoming too hot).

[0012] It is also conceivable to fasten and fix the bearing to the movable flange using bolts or the like instead of adhesive, but this may lead to increased assembly time, structural complexity, larger size, and higher costs.

[0013] Therefore, it is desirable to prevent the bearing from detaching from the flange through-hole without using adhesives, bolts, or the like.

[0014] This invention has been made in view of the above technical problems, and aims to provide a technology that can prevent a bearing from detaching from a flange through-hole without using adhesives, bolts, etc., and that can contribute to improving productivity. [Means for solving the problem]

[0015] The bearing structure for the movable energizing shaft, the vacuum interrupter, and the method for manufacturing the vacuum interrupter according to this invention can contribute to solving the aforementioned problems.

[0016] First, one embodiment of the bearing structure for the movable current-carrying shaft is a bearing structure for the movable current-carrying shaft that supports the movable electrode so that it can move freely in the axial direction, among the fixed electrode and movable electrode that are provided facing each other in the axial direction of the cylindrical body within a vacuum vessel having an insulating cylindrical body.

[0017] The cylindrical body is sealed on one side in the axial direction, which is the fixed side, by a fixed side flange, and sealed on the other side in the axial direction, which is the movable side, by a movable side flange. The movable side flange is provided with a flange through-hole that penetrates the movable side flange in the axial direction. The movable side energizing shaft is inserted through the flange through-hole and extends in the axial direction. One side of the movable side energizing shaft is supported on the inside of the vacuum container of the movable side flange via a bellows that is expandable and contractible in the axial direction. The flange through-hole is provided with a bearing that guides the movable side energizing shaft in the axial direction in a non-rotatable state, in a non-rotatable state relative to the flange through-hole.

[0018] The bearing has an annular flange-like portion having a diameter larger than the opening diameter of the other side opening in the flange through-hole and extending along the opening edge surface of the other side opening, and a cylindrical wall portion extending from the inner peripheral edge of the flange-like portion to the one side, which is inserted into the flange through-hole from the other side toward the one side and guides the movable energizing shaft inserted on the inner peripheral surface side of the cylindrical portion in the axial direction.

[0019] The cylindrical wall portion has claws formed on its outer circumferential surface that protrude radially outward from the cylindrical wall portion, and multiple slit holes are formed at predetermined intervals in the circumferential direction of the cylindrical wall portion, with some having a shape that penetrates the cylindrical wall portion radially and extends in the axial direction, and others having a shape that opens to one side, and each cylindrical wall portion piece that is the part of the cylindrical wall portion between each of the slit holes in the circumferential direction is elastically deformable in the radial direction, and the outer diameter of the portion of the cylindrical wall portion where the claws are formed is larger than the opening diameter of the opening on one side of the flange through hole.

[0020] Furthermore, when the distance between the flange-like portion and the claw portion is L, and the axial dimension in the flange through-hole is T, the following equation (1) is satisfied. L≧T ……(1).

[0021] Further, assuming that the dimensional tolerance of the hole diameter of the flange through-hole is Δφ, the dimension of the claw portion in the protruding direction is t1, the clearance dimension between the cylindrical wall portion and the movable energizing shaft is C, the dimensional tolerance related to T is ΔT, and the dimension of the clearance provided between the opening edge surface of the opening on the one side and the claw portion is α, the following formulas (2) and (3) may be satisfied. Δφ<t1<C ……(2) L=T+ΔT+α ……(3).

[0022] Further, the claw portion may have a shape protruding outward in the radial direction as it approaches the other side from the one side, and a surface of the claw portion on the other side is formed flat along the opening edge surface of the opening on the one side of the flange through-hole.

[0023] Further, at least one recess may be formed on the opening edge surface of the opening on the other side, and a protrusion that can be fitted into the recess may be formed at a position facing the recess on the flange-shaped portion.

[0024] Further, the plurality of recesses may be formed on the opening edge surface of the opening on the other side at predetermined intervals in the circumferential direction, and may be formed to be rotationally symmetric on the opening edge surface when the axial direction is taken as the axis of symmetry.

[0025] Further, the protrusion may be formed on a root portion side of the cylindrical wall portion piece in the flange-shaped portion.

[0026] Further, assuming that the dimensional tolerance related to T is ΔT, the dimension of the clearance provided between the opening edge surface of the opening on the one side and the claw portion is α, and the dimension of the protrusion in the protruding direction is t2, the following formula (4) may be satisfied. t2>ΔT+α ……(4).

[0027] One embodiment of a vacuum interrupter is characterized by having a bearing structure for the movable energizing shaft as described above.

[0028] One embodiment of a method for manufacturing a vacuum interrupter is characterized by comprising: a vacuum brazing step in which, with the movable energizing shaft inserted through a flange through-hole and extending in the axial direction, one side of the movable energizing shaft is brazed to the inside of the vacuum container of the movable flange via the bellows; and a bearing engagement step in which, after the vacuum brazing step, the bearing is fitted into the flange through-hole from the other side of the movable energizing shaft. [Effects of the Invention]

[0029] As described above, according to the present invention, it is possible to prevent the bearing from detaching from the flange through hole without using adhesives or bolts, thereby contributing to improved productivity and other benefits. [Brief explanation of the drawing]

[0030] [Figure 1] A schematic diagram illustrating the general configuration of the vacuum interrupter 1A according to Example 1 (longitudinal cross-sectional view in the axial direction). [Figure 2] A schematic diagram (enlarged view) illustrating the main part of Figure 1 (the location of bearing 4). [Figure 3] A schematic diagram illustrating the general configuration of bearing 4 ((A) is a view from the radially outer side, and (B) is an enlarged view of the area enclosed by the symbol X in (A)). [Figure 4] A schematic diagram illustrating the general configuration of bearing 4 ((A) is a view from one side in the axial direction, (B) is a view from the other side in the axial direction, and (C) is a radial cross-sectional view of the movable energizing shaft 13b). [Figure 5] A schematic diagram illustrating the general configuration of the movable flange 1b ((A) is a longitudinal section view in the axial direction ((B) is a section view along line BB), and (B) is a view from the other side in the axial direction). [Modes for carrying out the invention]

[0031] The bearing structure for the movable energized shaft, the vacuum interrupter, and the method for manufacturing the vacuum interrupter according to the embodiments of the present invention are completely different from configurations in which the bearing is simply bonded to the movable flange using an adhesive (hereinafter referred to as the conventional configuration).

[0032] In other words, this embodiment is a configuration that applies a bearing that can be inserted through a flange through-hole with elastic deformation (so-called snap-fit ​​structure that can be engaged).

[0033] Specifically, the bearing is made up of an annular flange-like portion having a larger diameter than the opening diameter of the opening on the other side (movable side) in the axial direction of the flange through hole, and a cylindrical wall portion extending in the axial direction from the inner peripheral edge of the flange-like portion.

[0034] The cylindrical wall portion of this bearing has a claw portion formed on its outer circumferential surface that protrudes radially outward from the cylindrical wall portion, and the outer diameter of the portion where the claw portion is formed is larger than the opening diameter of the opening on one side (fixed side) in the axial direction of the flange through hole.

[0035] Furthermore, in the cylindrical wall portion, multiple slit holes are formed at predetermined intervals in the circumferential direction (hereinafter simply referred to as the circumferential direction) of the cylindrical wall portion, with some having a shape that penetrates the cylindrical wall portion radially (hereinafter simply referred to as the radial direction as appropriate) and extends in the axial direction, and others having a shape that opens on one side in the axial direction. As a result, each cylindrical wall portion piece, which is the part of the cylindrical wall portion between each of the slit holes, becomes elastically deformable in the radial direction.

[0036] Furthermore, when L is the distance between the flange-like portion and the claw portion, and T is the axial dimension in the flange through-hole, the following equation (1) is satisfied.

[0037] L≧T ……(1) When the cylindrical wall portion of such a bearing is inserted through the flange through-hole from one side in the axial direction to the other, the cylindrical wall portion elastically deforms radially inward while the claw portion of the cylindrical wall portion is positioned inside the flange through-hole. Then, after the claw portion of the cylindrical wall portion disengages from the flange through-hole to the other side in the axial direction, the cylindrical wall portion elastically returns to its original position. As a result, the bearing engages with the flange through-hole in a position where the movable flange (the hole wall of the flange through-hole) is sandwiched axially by both the flange-like portion and the claw portion.

[0038] In this manner, with the bearing engaged with the flange through-hole, detachment from the flange through-hole is suppressed (the engaged state is maintained) without the need for adhesives or bolts. Furthermore, since adhesives are not required, it is possible to avoid limitations on the use of vacuum interrupters, as is the case with conventional configurations.

[0039] To create a vacuum inside a vacuum container, the various components that form the vacuum (e.g., cylindrical body, fixed flange, movable flange, bellows, movable current-carrying shaft, etc.) are assembled using a vacuum brazing process.

[0040] However, in the vacuum brazing process, the brazing material placed at the assembly location is heated and melted. Therefore, if a flammable adhesive is present, as in the conventional configuration, the vacuum brazing process may be hindered (or made impossible). For this reason, when using an adhesive, the movable current-carrying shaft is first inserted through the flange through-hole and extended in the axial direction. After performing the vacuum brazing process as described above, the bearing is fitted from the other side of the movable current-carrying shaft in the axial direction and bonded to the movable flange.

[0041] On the other hand, the bearing according to this embodiment only needs to be in a configuration that allows it to be inserted through the flange through-hole with elastic deformation, and can be easily constructed using various materials. For example, if the bearing according to this embodiment is made of a resin material, and the heat resistance temperature of the resin material is higher than the vacuum brazing temperature, the bearing may be engaged with the flange through-hole in advance in a step prior to the vacuum brazing process as described above.

[0042] Furthermore, each component after the vacuum brazing process described above may undergo thermal expansion depending on its material and shape. For example, if the movable flange undergoes thermal expansion, dimensional tolerances may occur in the axial dimension (T) and hole diameter of the flange through-hole.

[0043] The bearing of this embodiment may be designed in advance to take into account the dimensional tolerances resulting from the vacuum brazing process described above (for example, as in Embodiment 1 described later, it may be designed to satisfy equations (2) and (3)). This makes it possible to engage the bearing with the flange through-hole as desired in a subsequent process after the vacuum brazing process, even if dimensional tolerances are introduced into the flange through-hole due to the vacuum brazing process.

[0044] This embodiment only requires that the bearing structure be such that it can be inserted through a flange through-hole with elastic deformation, as described above. It is possible to appropriately apply common technical knowledge from various fields (vacuum interrupter field, bearing field, mechanical joining field, vacuum brazing field, etc.) and modify the design as needed by referring to prior art documents, etc.

[0045] In the following Examples 1 and 2, detailed explanations have been omitted as appropriate, for example, by using the same reference numerals for similar components. Also, in Figure 2, which will be described later, the dimensions t1, clearance C, dimensional tolerance ΔT, and play dimension α are depicted in an exaggerated manner for convenience.

[0046] Example 1 <Examples of main configurations for vacuum interrupters using bearing structures> Based on Figures 1 to 5, a schematic configuration example of a vacuum interrupter 1A to which the bearing structure according to Example 1 is applied will be described. This vacuum interrupter 1A includes a vacuum container 1 formed by sealing one side of an insulating cylindrical body 10 in the axial direction with a fixed flange 1a and sealing the other side in the axial direction with a movable flange 1b.

[0047] In the case of the cylindrical body 10 shown in Figure 1, the configuration mainly comprises a cylindrical intermediate shield (arc shield) 20 surrounding the outer circumference of the fixed electrode 14a and movable electrode 14b described later, a fixed-side insulating portion 21a connected to one side of the intermediate shield 20 in the axial direction, and a movable-side insulating portion 21b connected to the other side of the intermediate shield 20 in the axial direction.

[0048] Furthermore, the intermediate shield 20 is provided with a fixed-side extension portion 20a in the central part, which extends from the central part to one side in the axial direction and overlaps with the inner circumference of the fixed-side insulating portion 21a, and a movable-side extension portion 20b extending from the central part to the other side in the axial direction and overlapping with the inner circumference of the movable-side insulating portion 21b.

[0049] The fixed flange 1a has a disc-shaped portion 11a and an outer peripheral edge portion 12a that extends from the outer circumference of the disc-shaped portion 11a to the other side in the axial direction and is supported by the end face 2aa of the fixed insulating portion 21a, and as a whole it has a bottomed cylindrical structure.

[0050] A columnar fixed current-carrying shaft 13a is provided in the center of the disc-shaped portion 11a, extending from the center to the other side in the axial direction (in Figure 1, it extends through from one side in the axial direction to the other side in the axial direction). A fixed electrode 14a is supported at the other end of this fixed current-carrying shaft 13a in the axial direction.

[0051] The movable flange 1b has a disc-shaped portion 11b and an outer peripheral edge portion 12b that extends from the outer circumference of the disc-shaped portion 11b toward one side in the axial direction and is supported by the end face 2bb of the movable insulating portion 21b, and as a whole it has a bottomed cylindrical shape.

[0052] A flange through-hole 3 is provided in the center of the disc-shaped portion 11b, with the shape penetrating the central portion in the axial direction. A columnar movable current-carrying shaft 13b is inserted through the flange through-hole 3 and extends in the axial direction.

[0053] A movable electrode 14b is supported at one end of the movable current-carrying shaft 13b in the axial direction. Furthermore, one end of the movable current-carrying shaft 13b in the axial direction (the side with the movable electrode 14b) is supported inside the vacuum vessel 1 of the movable flange 1b via a cylindrical bellows 15 that is extendable and retractable in the axial direction and is arranged coaxially with the movable current-carrying shaft 13b. In the case of the movable current-carrying shaft 13b shown in Figure 1, a cylindrical bellows shield 16 is provided so as to cover and surround the outer circumference of the bellows 15.

[0054] In the flange through-hole 3, a bearing 4 capable of guiding the movable energizing shaft 13b in the axial direction in a non-rotatable state is provided inserted through the flange through-hole 3 (inserted so as to be coaxially positioned on the outer circumference side of the movable energizing shaft 13b in the flange through-hole 3).

[0055] This bearing 4 has a structure that can be inserted through the flange through-hole 3 with elastic deformation (for example, it has a flange-like portion 5 and a cylindrical wall portion 6 as described later, and is a structure that can be inserted through with a so-called snap-fit ​​structure), and is installed in a state where it cannot rotate in relation to the flange through-hole 3.

[0056] With the vacuum interrupter 1A configured as described above, the movable energizing shaft 13b (and movable electrode 14b) can be moved while being guided in the axial direction, while maintaining the vacuum state inside the vacuum container 1 (specifically, the outer circumference of the bellows 15 inside the vacuum container 1). In accordance with the movement of the movable energizing shaft 13b, the movable electrode 14b can be brought into contact with and separated from the fixed electrode 14a (the contact point 14 can be brought into contact with and separated from it).

[0057] The materials, shapes, and other characteristics of each component of the vacuum interrupter 1A, as well as the processing methods and assembly methods for each component, can be appropriately applied in various forms depending on the intended use of the vacuum interrupter 1A.

[0058] For example, insulating materials (e.g., alumina ceramics) may be applied to the fixed-side insulating part 21a and the movable-side insulating part 21b of the vacuum interrupter 1A, resin materials (e.g., heat-resistant resin materials) may be applied to the bearing 4, and metal materials (e.g., stainless steel (SUS304), oxygen-free copper, titanium) may be applied to the others. However, it is preferable to select these materials appropriately, taking into account that expansion (thermal expansion) and residual stress may occur when assembling each component.

[0059] <Example of bearing 4 configuration> The bearing 4 has a structure that can be inserted through the flange through-hole 3 with elastic deformation, and can move while guiding the movable energizing shaft 13b in the axial direction in a non-rotatable state, and various configurations can be applied.

[0060] One example is the bearing 4 shown in Figures 1 to 4, which has a flange-like portion 5 and a cylindrical wall portion 6, and can be installed by being inserted through the flange through-hole 3 with elastic deformation (a so-called snap-fit ​​structure that can be inserted through).

[0061] The flange-like portion 5 is an annular shape with a larger diameter than the opening 3b on the other axial side of the flange through hole 3, and extends along the opening edge surface 31b of the opening 3b.

[0062] The cylindrical wall portion 6 is cylindrical, extending from the inner peripheral edge 51 of the flange-shaped portion 5 to one side in the axial direction, and is shaped to allow insertion into the flange through hole 3 from the other side in the axial direction toward the one side in the axial direction. Furthermore, the inner peripheral surface 6a side of the cylindrical wall portion 6 is shaped to allow insertion of the movable energizing shaft 13b into that inner peripheral surface side, and is shaped to guide the inserted movable energizing shaft 13b in the axial direction.

[0063] A claw portion 61 is formed on the outer circumferential surface 6b of the cylindrical wall portion 6, protruding radially outward from the cylindrical wall portion 6. The outer diameter of the portion of the cylindrical wall portion 6 where the claw portion 61 is formed is larger than the opening diameter of the opening 3a on one side in the axial direction of the flange through hole 3.

[0064] Furthermore, when the distance between the flange-like portion 5 and the claw portion 61 is L, and the axial dimension of the flange through-hole 3 (a dimension equivalent to the wall thickness of the disc-shaped portion 11b in the figure) is T, the following equation (1) is satisfied.

[0065] L≧T ……(1) The cylindrical wall portion 6 is provided with a slit hole 62 that penetrates the cylindrical wall portion 6 in the radial direction. This slit hole 62 has a shape that extends in the axial direction and in the axial direction one The cylindrical wall portion 6 has an opening on one side and is formed in multiple locations (four in Figures 3 and 4) at predetermined intervals in the circumferential direction of the cylindrical wall portion 6. As a result, in the four cylindrical wall portion pieces 60 located between each slit hole 62 in the circumferential direction of the cylindrical wall portion 6, one side of each cylindrical wall portion piece 60 in the axial direction is configured to be elastically deformable in the radial direction.

[0066] When the cylindrical wall portion 6 of such a bearing 4 is inserted into the flange through hole 3 from the other side in the axial direction toward one side in the axial direction, while the claw portion 61 of the cylindrical wall portion 6 is located inside the flange through hole 3, one side of each cylindrical wall portion piece 60 in the axial direction elastically deforms radially inward. Then, after the claw portion 61 of the cylindrical wall portion 6 disengages from inside the flange through hole 3 toward one side in the axial direction, the cylindrical wall portion piece 60 elastically returns to its original position.

[0067] As a result, the bearing 4 engages with the flange through-hole 3 in a position where it sandwiches the movable flange 1b (the hole wall of the flange through-hole 3) in the axial direction with both the flange-shaped portion 5 and the claw portion 61, and this engaged state is easier to maintain.

[0068] In the case of the claw portion 61 shown in the figure, it has a shape that protrudes radially outward as it approaches the other side in the axial direction from one side in the axial direction. Furthermore, the surface of the claw portion 61 on the other side in the axial direction is formed flat along the opening edge surface 31a of the opening 3a in the flange through hole 3. With a claw portion 61 of this shape, it becomes easier to insert the bearing 4 into the flange through hole 3, and the engaged state of the bearing 4 after insertion and engagement is more easily maintained.

[0069] <An example of how to assemble bearing 4> Each component that creates a vacuum inside the vacuum container 1 (in Figure 1, the cylindrical body 10, the fixed flange 1a, the movable flange 1b, the bellows 15, the movable current-carrying shaft 13b, etc.; hereinafter, these will be simply referred to as vacuum state components as appropriate) is assembled by a vacuum brazing process. However, in the case of the bearing 4, if the heat resistance temperature of the bearing 4 is higher than the vacuum brazing temperature, it may be engaged in a step prior to the vacuum brazing process or in a step after the vacuum brazing process.

[0070] On the other hand, if the heat resistance temperature of bearing 4 is lower than the vacuum brazing temperature, the vacuum brazing process and the bearing engagement process can be performed in order as shown below. First, in the vacuum brazing process, brazing material is appropriately placed in advance at the assembly locations of the vacuum state components, and the vacuum state components are assembled as shown in Figure 1. Then, the assembled vacuum state components are heat-treated in a vacuum furnace and vacuum brazed.

[0071] This vacuum brazing process causes the movable energizing shaft 13b to be inserted through the flange through-hole 3 and extend in the axial direction, with one axial side of the movable energizing shaft 13b being supported (brazed) to the inside of the vacuum container 1 of the movable flange 1b via the bellows 15.

[0072] Next, in the bearing engagement process, the cylindrical wall portion 6 of the bearing 4 is first positioned opposite the other side in the axial direction of the movable energizing shaft 13b, and then fitted into the other side in the axial direction of the movable energizing shaft 13b. Then, the fitted bearing 4 is moved to one side in the axial direction and inserted into the flange through hole 3 (inserted into the outer circumference side of the movable energizing shaft 13b), thereby achieving the engagement state shown in Figures 1 and 2.

[0073] Furthermore, if dimensional tolerances or other issues arise in the flange through-hole 3 after the vacuum brazing process described above, it may hinder the subsequent bearing engagement process. In such cases, it is advisable to design the bearing 4 appropriately in advance, taking dimensional tolerances and other issues into consideration, as shown below.

[0074] First, the bearing 4 is designed to satisfy the following equations (2) and (3), with the dimensional tolerance of the diameter of the flange through-hole 3 being Δφ, the dimension of the claw portion 61 in the protruding direction being t1, the clearance dimension between the cylindrical wall portion 6 and the movable energizing shaft 13b being C, the dimensional tolerance of the axial dimension T in the flange through-hole 3 being ΔT, and the dimension of the play (for example, an extremely narrow gap) provided between the opening edge surface 31a of the opening 3a in the flange through-hole 3 and the claw portion 61 being α.

[0075] Δφ <t1<C ……(2) L = T + ΔT + α ……(3) With the bearing 4 designed in this way, even if dimensional tolerances occur in the flange through-hole 3 after the vacuum brazing process, the bearing engagement process can be carried out appropriately, and the bearing can be engaged with the flange through-hole 3 as desired.

[0076] <Example of a configuration that makes the movable energizing shaft 13b non-rotatable> The configuration that prevents the movable energizing shaft 13b from rotating relative to the cylindrical wall portion 6 of the bearing 4 is not particularly limited, and various embodiments can be applied.

[0077] One example is a configuration in which an outer peripheral flat surface 13d is formed on the outer peripheral surface 13c of the movable energizing shaft 13b, with a shape that follows the tangent plane of the outer peripheral surface 13c, and an inner peripheral flat surface 6c is formed on the inner peripheral surface 6a of the cylindrical wall portion 6 at a position opposite to the outer peripheral flat surface 13d, with a shape that follows the outer peripheral flat surface 13d.

[0078] With this configuration, even if a rotational force is applied to the movable energizing shaft 13b, for example, the outer peripheral flat surface 13d and the inner peripheral flat surface 6c come into contact with each other, thereby suppressing the rotation of the movable energizing shaft 13b (maintaining a non-rotatable state).

[0079] Such outer peripheral flat surfaces 13d and inner peripheral flat surfaces 6c may be provided not only as one each, but also in multiples spaced at predetermined intervals in the circumferential direction. In Figure 4, two outer peripheral flat surfaces 13d are formed parallel to each other on the outer peripheral surface 13c of the movable energizing shaft 13b, thereby creating a so-called two-sided width shape.

[0080] Furthermore, instead of simply providing multiple outer circumferential flat surfaces 13d and inner circumferential flat surfaces 6c, they may be appropriately provided so as to be rotationally symmetrical (180-degree rotational symmetry in Figure 4) with respect to the axial direction as the axis of symmetry. In this case, the insertion position of the movable energizing shaft 13b when it is inserted into the bearing 4 will have rotational symmetry, which may make the insertion work (positioning, etc.) easier.

[0081] <Example configuration for making bearing 4 unable to rotate> The configuration for making the bearing 4 immobile relative to the flange through-hole 3 is not particularly limited, and various embodiments can be applied. For example, an embodiment similar to the one described above for making the movable energizing shaft 13b immobile (a configuration forming an outer peripheral flat surface 13d and an inner peripheral flat surface 6c) can be applied, but an embodiment as shown in Embodiment 2 described later can also be applied.

[0082] According to the embodiment 1 described above, it becomes easier to insert the bearing 4 into the flange through-hole 3 and engage it without using adhesives or bolts, and to maintain this engaged state, thereby contributing to improved productivity and other benefits.

[0083] Example 2 Next, an embodiment 2 in which the bearing 4 is made non-rotatable relative to the flange through-hole 3 will be described. In this embodiment 2, for example as shown in Figure 5, a recess 32 is formed on the opening edge surface 31b of the opening 3b of the movable flange 1b. Also, for example as shown in Figures 3 and 4, a protrusion 52 is formed on the flange-like portion 5 of the bearing 4 at a position opposite to the recess 32, with a shape that can be fitted into the recess 32.

[0084] With this configuration in which the recess 32 and the protrusion 52 are formed, it becomes possible to engage the bearing 4 with the flange through-hole 3 such that the protrusion 52 is fitted into the recess 32. As long as the state in which the protrusion 52 is fitted into the recess 32 (hereinafter referred to as the fitted state as appropriate) is maintained, even if a rotational force is applied to the bearing 4, the rotation of the bearing 4 will be suppressed (a non-rotational state will be maintained).

[0085] The protrusion 52 may be formed at any position opposite the recess 32 as described above, but preferably it is formed on the root side of the cylindrical wall piece 60 in the flange-like portion 5. This increases the thickness of the cylindrical wall piece 60 according to the shape and position of the protrusion 52, thereby improving its mechanical strength.

[0086] The recessed portion 32 and the protruding portion 52 may be provided not only as one of each, but also in multiples (four of each in Figures 3 to 5) spaced at predetermined intervals in the circumferential direction.

[0087] Furthermore, instead of simply providing multiple recesses 32 and protrusions 52, they may be appropriately arranged to be rotationally symmetrical (90-degree rotational symmetry in Figure 4) with respect to the axial direction. In this case, the engagement position of the bearing 4 when engaging with the flange through-hole 3 will have rotational symmetry, which may make the engagement process (positioning, etc.) easier.

[0088] Furthermore, if dimensional tolerances occur in the flange through-hole 3 after the vacuum brazing process described above, it may become impossible to maintain the fitted state of the protrusion 52 in relation to the recess 32. In such cases, it is advisable to design the bearing 4 appropriately so as to satisfy equation (4) below. Note that t2 in equation (4) below represents the dimension of the protrusion 52 in the direction of projection.

[0089] t² > ΔT + α ……(4) With the bearing 4 designed in this way, even if dimensional tolerances occur in the flange through-hole 3 after the vacuum brazing process, the bearing engagement process can be carried out appropriately, and it becomes easier to maintain the state in which the protrusion 52 is fitted into the recess 32.

[0090] According to the above-described Example 2, in addition to achieving the same effects as Example 1, the following can be said. That is, since the flange through-hole 3 itself does not need to be designed considering a non-rotatable state, it is possible to contribute to cost reduction, for example, by making it a shape that is relatively easy to manufacture (for example, a circular shape).

[0091] Although the present invention has been described in detail only with respect to the specific examples described above, it will be obvious to those skilled in the art that a wide variety of modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims. [Explanation of Symbols]

[0092] 1A...Vacuum interrupter, 1...Vacuum vessel, 1a...Fixed flange, 1b...Movable flange, 13b...Movable energizing shaft, 14a...Fixed electrode, 14b...Movable electrode, 15...Bellows 3…Flange through hole, 32…Recess 4…Bearings 5...Flange-shaped portion, 52...Convex portion 6...Cylindrical wall portion, 60...Cylindrical wall portion piece, 61...Claw portion, 62...Slit hole

Claims

1. A bearing structure for a movable current-carrying shaft that supports a movable electrode so as to be movable in the axial direction, among fixed electrodes and movable electrodes provided facing each other in the axial direction of the cylindrical body within a vacuum vessel having an insulating cylindrical body, The vacuum vessel comprises the aforementioned insulating cylindrical body, the fixed electrode and the movable electrode, The cylindrical body is sealed on one side in the axial direction, which is the fixed side, by a fixed side flange, and sealed on the other side in the axial direction, which is the movable side, by a movable side flange. The movable flange is provided with a flange through-hole that penetrates the movable flange in the axial direction. The movable energizing shaft is inserted through the flange through-hole and extends in the axial direction, and one side of the movable energizing shaft is supported on the inside of the vacuum vessel of the movable flange via a bellows that is expandable and contractible in the axial direction. The flange through-hole is provided with a bearing that guides the movable energizing shaft in the axial direction in a non-rotatable state, and is provided in a non-rotatable state relative to the flange through-hole. The aforementioned bearing is A flange-like portion having an annular shape that is larger in diameter than the opening diameter of the other side opening in the flange through hole and extends along the opening edge surface of the other side opening, A cylindrical wall portion extending from the inner peripheral edge of the flange-like portion to one side, inserted through the flange through hole from the other side toward the one side, and guiding the movable energizing shaft inserted on the inner peripheral surface side of the cylindrical portion in the axial direction, It has, The cylindrical wall portion is, The inner circumferential surface of the cylindrical wall extends in the axial direction along the outer circumferential surface of the movable energizing shaft, A claw-shaped portion is formed on the outer circumferential surface of the cylindrical wall portion, protruding radially outward from the cylindrical wall portion. Multiple slit holes are formed at predetermined intervals in the circumferential direction of the cylindrical wall, with the slit holes extending from the flange-like portion side to one side and the slit holes opening to the one side, penetrating the cylindrical wall in the radial direction. Each cylindrical wall portion, which is the portion between each of the slit holes in the circumferential direction, is elastically deformable in the radial direction. The outer diameter of the portion of the cylindrical wall in which the claw portion is formed is larger than the opening diameter of the opening on one side of the flange through hole. The claw portion is provided at a position away from one end of each cylindrical wall portion piece, and at a position where the distance between the flange portion and the claw portion is L. A bearing structure for a movable energizing shaft, characterized in that, when the axial dimension of the flange through-hole is T, the following equation (1) is satisfied. L ≥ T ……(1)

2. The aforementioned claw portion is The shape protrudes radially outward as it approaches the other side from one side, The other surface of the claw portion is formed flat along the opening edge surface of the opening on one side of the flange through hole. The bearing structure for the movable energizing shaft according to feature 1.

3. At least one recess is formed on the opening edge surface of the other opening. The bearing structure for the movable energizing shaft according to claim 1, characterized in that the flange-like portion has a protrusion formed at a position opposite to the recess that can be fitted into the recess.

4. The bearing structure for a movable energizing shaft according to claim 3, characterized in that the recesses are formed in multiple locations at predetermined intervals in the circumferential direction with respect to the opening edge surface of the other opening, and are formed to be rotationally symmetrical with respect to the opening edge surface when the axial direction is the axis of symmetry.

5. The bearing structure for the movable energizing shaft according to claim 3, characterized in that the protrusion is formed on the root side of the cylindrical wall piece in the flange-like portion.

6. A vacuum interrupter characterized by having a bearing structure for a movable energizing shaft as described in any one of claims 1 to 5.

7. A method for manufacturing a vacuum interrupter according to claim 6, A vacuum brazing step is performed in which, with the movable current-carrying shaft inserted through the flange through-hole and extending in the axial direction, one side of the movable current-carrying shaft is brazed to the inside of the vacuum container of the movable flange via the bellows, After the vacuum brazing step, the bearing engagement step is performed in which the bearing is fitted into the flange through hole from the other side of the movable energizing shaft, A method for manufacturing a vacuum interrupter, characterized by having [a certain feature].

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