CN108695103B

CN108695103B - Grounding switch

Info

Publication number: CN108695103B
Application number: CN201710221744.XA
Authority: CN
Inventors: 王腊洪; 王玉军; 吕文彬
Original assignee: Eaton Electrical Equipment Co Ltd
Current assignee: Eaton Electrical Equipment Co Ltd
Priority date: 2017-04-06
Filing date: 2017-04-06
Publication date: 2022-07-12
Anticipated expiration: 2037-04-06
Also published as: CN108695103A

Abstract

The invention provides a grounding switch, comprising: a frame; a fixed contact fixed on the frame; a rotating shaft disposed on the frame; the moving contact corresponds to the fixed contact, and one end of the moving contact is fixed on the rotating shaft; when the grounding switch is in an opening state, the spring mechanism is used for applying an acting force on the rotating shaft to keep the rotating shaft at an opening position, and in a closing process of the grounding switch, the spring mechanism releases elastic potential energy thereof to drive the movable contact to move towards the fixed contact. The grounding switch has high closing speed.

Description

Grounding switch

Technical Field

The invention relates to the field of high-voltage switch cabinets, in particular to a grounding switch.

Background

The earthing switch is a special-purpose mechanical switch with a certain ability to close short-circuit current. The grounding device is used for grounding the switch cabinet when the high-voltage switch cabinet and the circuit thereof are overhauled, and personal safety is protected. In addition, since there may be a short circuit fault in the circuit, the grounding switch needs to quickly ground the switchgear to eliminate the fault arc within the switchgear.

As the voltage class of high-voltage switch cabinets continuously rises, the closing speed of the grounding switch is required to be faster and faster.

Because the closing speed of the existing grounding switch is slow, the existing grounding switch cannot bear higher short-circuit fault current, has poor performance reliability, and has the advantages of easy burning loss of a moving contact and short service life.

Disclosure of Invention

To solve the above technical problems in the prior art, an embodiment of the present invention provides an earthing switch, including:

a frame;

a fixed contact fixed on the frame;

a rotating shaft disposed on the frame;

the moving contact corresponds to the fixed contact, and one end of the moving contact is fixed on the rotating shaft;

the grounding switch further comprises a spring mechanism, one end of the spring mechanism is fixed to the frame through a first rotating shaft, the other end of the spring mechanism is fixed to the rotating shaft through a second rotating shaft, when the grounding switch is in an opening state, the spring mechanism is used for exerting acting force on the rotating shaft to enable the rotating shaft to be kept at an opening position, and in the closing process of the grounding switch, the spring mechanism releases elastic potential energy of the spring mechanism to drive the moving contact to move towards the fixed contact.

Preferably, when the grounding switch is in a brake-off state, a first plane where the first rotating shaft and the second rotating shaft are located and a second plane where the first rotating shaft and the second rotating shaft are located have a predetermined included angle.

Preferably, the frame comprises:

the static contact is fixed on the base frame;

the rotating shaft penetrates through the first side plate and the second side plate;

the spring mechanism and the movable contact are positioned in a rectangular parallelepiped accommodating space defined by the first side plate, the second side plate and the base frame.

Preferably, the frame further includes a support member located between the first side plate and the second side plate, one end of the support member is welded to the base frame, and the one end of the spring mechanism is fixed to the other end of the support member by the first rotating shaft.

Preferably, the support member comprises two support plates arranged in parallel.

Preferably, the spring mechanism includes a compression spring, and a positioning block and a driving block located at both ends of the compression spring, the positioning block is fixed to the other end of the support member by the first rotating shaft, the spring mechanism is configured to rotate around the first rotating shaft, and the earthing switch further includes a supporting block fixed on the rotating shaft, the supporting block being connected to the driving block by the second rotating shaft.

Preferably, the spring mechanism comprises a guide rod penetrating through the positioning block and the pressure spring, and one end of the guide rod is connected to the driving block.

Preferably, the grounding switch includes:

the first moving contact, the second moving contact and the third moving contact are arranged in parallel;

the first busbar is positioned between the first moving contact and the second moving contact, and two ends of the first busbar are respectively connected with the first moving contact and the second moving contact;

and the two ends of the second busbar are respectively connected with the second moving contact and the third moving contact.

Preferably, the first and second busbars are U-shaped metal plates.

Preferably, the earthing switch further comprises an output shaft, the output shaft comprising:

a receiving cylinder defining a receiving space for receiving an end of the rotating shaft, a sidewall of the receiving cylinder having two through holes oppositely disposed; and

an operating shaft connected with the accommodating cylinder.

Preferably, the earthing switch further comprises a driving pin located in the two through holes, and a plane in which the driving pin rotates in the two through holes is perpendicular to the central axis of the accommodating cylinder.

Preferably, the movable contact includes:

two grounding knives which are oppositely arranged; and

and the grounding knife mounting bracket is positioned between the two grounding knives and provided with one end and the other end which are oppositely arranged, one end of the grounding knife mounting bracket is fixedly connected with the two grounding knives, and the other end of the grounding knife mounting bracket defines a through hole for the rotating shaft to pass through.

The grounding switch has the advantages of high closing speed, capability of bearing higher short-circuit fault current, reliable performance and long mechanical life, and the moving contact can be reliably contacted with the static contact.

Drawings

Embodiments of the invention are further described below with reference to the accompanying drawings, in which:

fig. 1 is a perspective view of a grounding switch in an open state according to a preferred embodiment of the present invention.

Fig. 2 is an exploded view of the earthing switch shown in fig. 1.

Fig. 3 is a further exploded view of the movable contact shown in fig. 2.

Fig. 4 is an enlarged schematic view of the output shaft shown in fig. 2.

Fig. 5 is a schematic plan view of the earthing switch shown in fig. 1 viewed in the direction indicated by the arrow a.

Fig. 6 is a schematic perspective view of the spring mechanism in the earthing switch shown in fig. 1 at a dead-center position.

Fig. 7 is a schematic plan view of the earthing switch shown in fig. 6 viewed in the direction indicated by the arrow B.

Fig. 8 is a perspective view of the earthing switch shown in fig. 1 in a closed state.

Fig. 9 is a schematic plan view of the earthing switch shown in fig. 8, viewed in the direction indicated by the arrow C.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail by embodiments with reference to the accompanying drawings.

Fig. 1 is a perspective view of a grounding switch in an open state according to a preferred embodiment of the present invention. As shown in fig. 1, the grounding switch includes a frame 1, a rotating shaft 2 installed on the frame 1,

stationary contacts

31, 32 and 33 sequentially arranged along an axis of the rotating shaft 2,

movable contacts

41, 42 and 43 respectively corresponding to the

stationary contacts

31, 32 and 33 and arranged in parallel, a spring mechanism 51 located between the

movable contacts

41 and 42, and a spring mechanism 52 located between the

movable contacts

42 and 43. Wherein the spring means 51, 52 are substantially in the same plane as the

movable contacts

41, 42, 43 in the open position.

In summary, one end of the

movable contacts

41, 42, 43 and one end of the spring mechanisms 51, 52 (which will be described in detail in conjunction with fig. 2) are fixed on the rotating shaft 2, the

spring mechanisms

51, 52 are used for applying a force to the rotating shaft 2 to rotate the rotating shaft 2, and the rotating shaft 2 drives the

movable contacts

41, 42, 43 to rotate together during rotation, thereby realizing the closing and opening of the grounding switch.

Fig. 2 is an exploded view of the earthing switch shown in fig. 1. As shown in fig. 2, the frame 1 includes a base frame 13 having a substantially rectangular parallelepiped shape,

side plates

11 and 12 located at opposite ends of the base frame 13, the

side plates

11, 12 and the base frame 13 defining a receiving space 16 having a rectangular parallelepiped shape. The spring means 51, 52 and the

movable contacts

41, 42, 43 are located in the cuboid-shaped receiving space 16. The

side plates

11, 12 have through

holes

111, 121, respectively, through which the rotary shaft 1 passes and rotates therein. The frame 1 further comprises

support members

14, 15 located between the

side plates

11, 12. The supporting

members

14 and 15 are the same, and only the supporting member 14 will be described as an example. The support 14 includes

support plates

141, 142 arranged in parallel, and the oppositely arranged

support plates

141, 142 define a receiving space for receiving the spring mechanism 51. One end of the

support plates

141, 142 is welded to the base frame 13, and the other end thereof has a rotation shaft 143.

The

static contacts

31, 32 and 33 are respectively fixedly connected to one side of the base frame 13 through the

insulating columns

61, 62 and 63, and form an integrated structure with the static contacts, so that the structural stability is improved.

The earthing switch further comprises a U-shaped busbar 71 connected between the

movable contacts

41, 42, and a U-shaped busbar 72 connected between the

movable contacts

42, 43. The

U-shaped busbars

71, 72 electrically connect the

movable contacts

41, 42, 43 so that the currents in the

movable contacts

41, 42, 43 have the same phase.

The

spring mechanisms

51 and 52 are identical, and the following description will be given only by taking the spring mechanism 51 as an example. The spring mechanism 51 comprises a compression spring 511, a positioning block 512 and a driving block 513 which are respectively arranged at two ends of the compression spring 511, and a guide rod 514 which penetrates through the compression spring 511 and the positioning block 512, wherein one end of the guide rod 514 is fixed on the driving block 513. The positioning block 512 is connected to one end of the

support plate

141, 142 via the rotating shaft 143, so that one end of the spring mechanism 51 can rotate around the rotating shaft 143 as an axis, thereby realizing energy release and energy storage of the pressure spring 511. The driving block 513 is connected to the supporting block 515 through a rotating shaft 516. The support block 515 has a through hole 5151 through which the rotation shaft 2 passes, and is fixedly connected to the rotation shaft 2. The compression spring 511 in a compressed state applies a certain force to the rotary shaft 2 through the driving block 513 and the supporting block 515.

The rotating shaft 2 passes through the through hole 4131 of the movable contact 41 (described below with reference to fig. 3), the through hole 5151 of the spring mechanism 51, the through hole 4231 of the movable contact 42, the through hole 5251 of the spring mechanism 52, and the through hole 4331 of the movable contact 43 in this order. The rotating shaft 2 is provided with through holes 21, 22, 23, 24 and 25 corresponding to the positions of the movable contacts 41, the spring mechanism 51, the movable contacts 42, the spring mechanism 52 and the movable contacts 43. The pins perpendicular to the axis L2 of the rotating shaft 2 are inserted into the through holes 21, 22, 23, 24, and 25, respectively, thereby fixedly connecting the rotating shaft 2 with the movable contact 41, the spring mechanism 51, the movable contact 42, the spring mechanism 52, and the movable contact 43.

The earthing switch of the present invention further comprises an output shaft 8 adapted to be fitted over one end portion of the rotating shaft 2, and the drive pin 261 is inserted into the through-hole 812 of the output shaft 8 and the through-hole 26 of the rotating shaft 2, thereby allowing the output shaft 8 and the rotating shaft 2 to be connected together with a predetermined degree of rotational freedom therebetween. Meanwhile, by rotating the operation shaft 82, the rotation shafts 2 can be rotationally moved in the same direction.

Fig. 3 is a further exploded view of the movable contact and U-shaped buss bar shown in fig. 2. As shown in fig. 3, the

movable contacts

41, 42, 43 are the same, and only the movable contact 41 will be described as an example. The movable contact 41 includes grounding

blades

411, 412 disposed opposite to each other, and a grounding blade mounting bracket 413 disposed between the grounding

blades

411, 412. The grounding

knives

411 and 412 increase the conducting area of the short-circuit current, and avoid burning of the moving contact 41. The grounding switch mounting bracket 413 is integrally formed by a metal material, and has high mechanical strength and rigidity. The grounding blade mounting bracket 413 has one end connected to the

grounding blades

411 and 412 and the other end extending between the grounding

blades

411 and 412, and has a through hole 4131 through which the rotary shaft 2 passes.

The

U-shaped busbars

71, 72 are made of a copper plate having a substantially rectangular shape, and have a large rigidity and mechanical strength. The U-shaped bus bar 71 has bent portions 711 and 712 disposed opposite to each other, and the bent portion 711 is parallel to the grounding blade 412 and is fixedly connected to the movable contact 41 by a bolt (not shown in fig. 3). The bent portion 712 is parallel to the grounding blade 421 of the movable contact 42 and is fixedly connected to the movable contact 42 by a bolt (not shown in fig. 3). The mounting of the U-shaped bus bar 72 is the same as the mounting of the U-shaped bus bar 71 and will not be described further. The U-shaped bus bars 71, 72 increase the bus area and increase the supporting strength between the

movable contacts

41, 42, 43, compared to the cylindrical conductive members of the prior art.

Fig. 4 is an enlarged schematic view of the output shaft shown in fig. 2. As shown in fig. 4, the output shaft 8 includes a receiving cylinder 81 and an operating shaft 82 connected. The accommodation cylinder 81 defines an accommodation space 811 for accommodating an end of the rotary shaft 2, and a side wall of the accommodation cylinder 81 has two through holes 812 oppositely disposed. When the drive pin 261 is inserted into the through hole 812, the drive pin 261 is rotationally movable in a plane perpendicular to the central axis L of the accommodation cylinder 81.

Fig. 5 is a schematic plan view of the earthing switch shown in fig. 1, viewed from the spring mechanism 52 in the direction indicated by the arrow a, wherein the movable contact 43 is shielded by the spring mechanism 52. As shown in fig. 5, when the movable contact 43 is in the open position, the compressed spring 521 in the spring mechanism 52 is in a compressed energy storage state. Since the axis L2 of the rotating shaft 2 is not on the first plane (shown by a broken line L1 in fig. 5) on which the

rotating shafts

153 and 526 are located, the compressed spring 521 applies the opening holding force to the rotating shaft 2 via the drive block 523 and the support block 525. The

spring mechanisms

51, 52 of the present invention are arranged substantially on the same plane as the

movable contacts

41, 42, 43 in the opening position, and therefore, the angle α between a first plane on which the rotation axes 153, 526 of the spring mechanism 52 lie and a second plane (indicated by a dashed line L12 in fig. 5) on which the rotation axis 153 and the rotation axis 2 lie is only 5 °. As can be seen from fig. 5, rotating the rotating shaft 2 clockwise by a very small angle causes the spring mechanism 52 to rotate counterclockwise about the rotating shaft 153 by a correspondingly small angle, so that the

rotating shafts

153, 526 are completely in the same plane as the axis L2 of the rotating shaft 2.

The closing process of the grounding switch of the above embodiment is described below with reference to fig. 6 to 9.

The output shaft 8 is rotated by a small angle in the direction indicated by the arrow R shown in fig. 1, and the output shaft 8 drives the rotary shaft 2 to rotate in the same direction. The rotating shaft 2 drives the

movable contacts

41, 42, 43 to move rotationally together with the support blocks 515, 525 of the

spring mechanisms

51, 52 in the direction indicated by the arrow R, and the guide bars 514, 524 of the

spring mechanisms

51, 52 rotate counterclockwise (viewed in the direction B) by a small angle around the rotating

shafts

143, 153, respectively. When the

rotating shaft

153, 526 and the axis L2 of the rotating shaft 2 are rotated to be located on the same plane, the

spring mechanisms

51, 52 are located at the dead point position, that is, the direction of the acting force applied by the

spring mechanisms

51, 52 to the rotating shaft 2 is just passing through the rotating shaft 2, and the

movable contacts

41, 42, 43 of the earthing switch are located at the unsteady critical position, wherein fig. 6 shows the schematic perspective view of the earthing switch with the

spring mechanisms

51, 52 located at the dead point position.

Fig. 7 is a schematic plan view of the earthing switch shown in fig. 6, viewed from the spring mechanism 52 in the direction indicated by the arrow B. As shown in fig. 7, the included angle θ between the first plane where the

rotating shafts

153 and 526 of the spring mechanism 52 are located and the axial direction of the movable contact 43 is 15 °, that is, the over-center angle θ of the

movable contacts

41, 42 and 43 is 15 °.

Further rotation of the output shaft 8 in the direction indicated by the arrow R causes the rotation axes 153, 526 to be out of plane with the axis L2 of the rotation shaft 2, so that the

movable contacts

41, 42, 43 pass their critical position. After which the output shaft 8 is released, i.e. the force that rotates the output shaft 8 is no longer applied. At this time, the acting force of the

spring mechanisms

51 and 52 on the rotating shaft 2 can make the rotating shaft 2 continuously rotate around the axis thereof in the direction indicated by the arrow R, and the rotating shaft 2 continuously drives the

movable contacts

41, 42 and 43 to rotate in the direction indicated by the arrow R until the switch is closed. During the closing process, the

spring mechanism

51, 52 releases its stored elastic potential energy and converts it into kinetic energy of rotation of the rotating shaft 2 and the

movable contacts

41, 42, 43, so that the

movable contacts

41, 42, 43 move towards the

stationary contacts

31, 32, 33.

Fig. 8 is a perspective view of the earthing switch shown in fig. 1 in a closed state, and fig. 9 is a plan view of the earthing switch shown in fig. 8, as viewed from the spring mechanism 52 in a direction indicated by an arrow C. As shown in fig. 8 and 9, the

spring mechanisms

51 and 52 are in the energy release state, and the

movable contacts

41, 42 and 43 are respectively in contact with the fixed

contacts

31, 32 and 33. It is clear that the turning

shafts

153, 526 are in different planes from the axis L2 of the turning shaft 2.

In the closing process, firstly, the

spring mechanisms

51 and 52 start to release elastic potential energy when the angle of counterclockwise rotation around the rotating

shafts

143 and 153 from the opening position shown in fig. 5 is larger than the included angle α, and the process is short; secondly, the over-center angle θ of the

movable contacts

41, 42, 43 is small, and the energy released by the

spring mechanisms

51, 52 is large, so that the

movable contacts

41, 42, 43 have a fast closing speed. Therefore, the grounding switch has the advantages of high closing speed, capability of bearing higher short-circuit fault current, reliable performance and long mechanical life, and the moving contact can be reliably contacted with the static contact.

As can be seen from the above analysis, in order to increase the closing speed of the grounding switch, the included angle α between the first plane and the second plane may be made as small as possible. For example, such that the included angle α is less than 4 °; more preferably, less than 3.

In the closing process, when the rotation of the output shaft 8 is stopped, the

spring mechanisms

51 and 52 release the elastic energy and drive the rotating shaft 2 and the driving pin 261 to rotate in the direction indicated by the arrow R shown in fig. 6, and the driving pin 261 has a predetermined rotational degree of freedom, so that the driving pin can continue to rotate freely for a certain distance in the through hole 812 of the output shaft 8 without driving the output shaft 8 to rotate. Thus, the operating mechanism or operator for operating the output shaft 8 can be effectively protected, and the safety performance is improved.

During opening, the output shaft 8 is rotated in the direction opposite to the closing process to drive the rotating shaft 2 to rotate together, the moving

contacts

41, 42 and 43 are separated from the

static contacts

31, 32 and 33 by the rotating shaft 2 in the rotating process, and meanwhile, the driving block 513 is driven to compress the compression spring to store energy. The

movable contacts

41, 42, 43 and the

spring mechanisms

51, 52 are finally brought into the opening position shown in fig. 1.

In another embodiment of the invention, the earthing switch has more or less than two spring mechanisms, and correspondingly more or less than two supports on the base frame 13.

In a further embodiment of the invention, the support members welded to the base frame are formed by oppositely disposed support rods.

Although the present invention has been described by way of preferred embodiments, the present invention is not limited to the embodiments described herein, and various changes and modifications may be made without departing from the scope of the present invention.

Claims

1. An earthing switch comprising:

a frame;

a fixed contact fixed on the frame;

a rotating shaft disposed on the frame;

Characterized in that the earthing switch further comprises a spring mechanism having one end fixed to the frame through a first rotating shaft and the other end fixed to the rotating shaft through a second rotating shaft,

when the grounding switch is in an opening state, the spring mechanism can be arranged on the same plane with the moving contact after rotating relative to the moving contact by a corresponding small angle, and the spring mechanism is used for applying an acting force to the rotating shaft to keep the rotating shaft at an opening position;

and in the switching-on process of the grounding switch, the spring mechanism releases the elastic potential energy thereof to drive the moving contact to move towards the fixed contact.

2. The grounding switch of claim 1, wherein when the grounding switch is in the open state, a first plane in which the first rotating shaft and the second rotating shaft are located has a predetermined included angle with a second plane in which the first rotating shaft and the second rotating shaft are located.

3. The grounding switch of claim 1, wherein the frame comprises:

the static contact is fixed on the base frame;

4. The earthing switch according to claim 3, characterized in that the frame further comprises a support member between the first side plate and the second side plate, one end of the support member is welded to the base frame, and the one end of the spring mechanism is fixed to the other end of the support member by the first rotating shaft.

5. The grounding switch of claim 4, wherein the support member comprises two support plates arranged in parallel.

6. The earthing switch according to claim 5, characterized in that the spring mechanism comprises a compression spring and a positioning block and a driving block at both ends of the compression spring, the positioning block being fixed to the other end of the support member by the first rotating shaft, the spring mechanism being configured to rotate about the first rotating shaft, the earthing switch further comprising a supporting block fixed to the rotating shaft, the supporting block being connected to the driving block by the second rotating shaft.

7. The grounding switch of claim 6, wherein the spring mechanism comprises a guide rod passing through the positioning block and the compression spring, and one end of the guide rod is connected to the driving block.

8. The grounding switch according to any one of claims 1 to 7, characterized in that the grounding switch comprises:

9. The grounding switch of claim 8, wherein the first and second busbars are U-shaped metal sheets.

10. The grounding switch of any one of claims 1 to 7, further comprising an output shaft, the output shaft comprising:

an operating shaft connected with the accommodating cylinder.

11. The grounding switch of claim 10, further comprising drive pins in the two through holes, a plane of rotation of the drive pins in the two through holes being perpendicular to the central axis of the receiving cylinder.

12. The earthing switch according to any one of claims 1 to 7, characterized in that said movable contact comprises:

two grounding knives which are oppositely arranged; and