Vacuum tube combination opening and closing device of vacuum on-load tap changer

Abstract

The present application relates to the field of high-voltage switch, specifically relates to a kind of vacuum on-load tap-changer vacuum tube combination opening and closing device, including insulating support disc, the lower side of the insulating support disc is equipped with vacuum tube A and vacuum tube B located in the side of vacuum tube A, rotatable cam disc is arranged on the lower side of the insulating support disc, the movable contact of the vacuum tube A is connected with connecting rod A, the movable contact of the vacuum tube B has connecting rod B, cam structure A for driving connecting rod A to realize lifting action and cam structure B for driving connecting rod B to realize lifting action are arranged on the cam disc.The vacuum tube combination opening and closing device compact structure, high reliability, improve transmission efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-voltage switches, in particular to a vacuum tube combined switching device of a vacuum on-load tap changer. BACKGROUND

[0002] The importance of maintaining the stability of the power supply voltage is self-evident, and the main means to achieve voltage stability is to use on-load tap changer to regulate the voltage of the transformer; most large transformers are oil-immersed, and on-load tap changers are also often oil-immersed, which is the most commonly used voltage regulating means in the current power system. The development of on-load tap changer has evolved from the initial "mechanical copper-tungsten contact structure" to "vacuum tube switching type" and "solid-state switching type".

[0003] The "mechanical copper-tungsten contact structure" on-load tap changer causes carbonization of oil due to the electric arc generated between the copper-tungsten contacts during voltage regulation. As the number of operations increases, the amount of carbon in the oil increases, which severely affects the insulation strength. Therefore, this type of tap changer often needs to be equipped with an online oil filter to reduce the free carbon in the oil to ensure the insulation strength and extend the oil change cycle, but the oil and arc contacts still need to be replaced periodically, resulting in high maintenance and repair costs and many inconveniences for use.

[0004] The "solid-state switching type" on-load tap changer does not cause degradation of the insulating oil because the voltage regulation switching process is completed within the power electronic device and no electric arc is generated. However, the power electronic device is fragile and has weak overload capacity, and is easily damaged or misoperated by the fault overvoltage and overcurrent that occasionally occur in the power system. At the same time, high-voltage and high-capacity power electronic devices are costly, which has led to the difficulty of popularizing and applying "solid-state switching type" on-load tap changers at the present stage.

[0005] The "vacuum tube switching type" is also a mechanical switch, but the electric arc generated during voltage regulation is confined in the vacuum tube, so it does not cause carbonization of the oil and affect the insulation strength. At the same time, the strong breaking capacity of the vacuum tube enables it to have a very long electrical life, so the "vacuum tube switching type" has become the mainstream of the development of on-load tap changers.

[0006] In order to reduce the frequency of transformer power outages caused by routine maintenance of on-load tap changers, more and more large transformers use vacuum switching type on-load tap changers to replace traditional mechanical switching type on-load tap changers, which has become a trend in product development. Because the vacuum tube (vacuum arc-extinguishing chamber) has a strong arc-extinguishing capability, its breaking life is more than 10 times that of traditional switches. At the same time, since the vacuum tube is a sealed structure, the electric arc does not come into contact with the oil medium around the vacuum tube during arc extinction, and the electric arc does not cause carbonization and pollution of the oil, so the oil does not need to be regularly purified and maintained, thereby extending the service life of the oil. Therefore, the vacuum switching type on-load tap changer greatly extends the maintenance cycle, reduces the number and time of transformer power outages.

[0007] But the conventional vacuum load tap changer adopts a planar lever mechanism to realize the transmission between different vacuum tubes and multiple cams distributed at different radii, so that different vacuum tubes correspond to different cams, and the closing and opening actions of each vacuum tube are performed according to a specific logical relationship. Since the two ends of the planar lever mechanism move in opposite directions, the middle support point of the lever bears the sum of the forces acting on the two ends of the lever, which increases the friction loss of the support point and reduces the mechanical transmission efficiency. Meanwhile, the opposite movement directions of the two ends of the planar lever also make it difficult to design the lever into a short handle structure (otherwise, the displacement of the dynamic contact rod of the vacuum tube and the roller of the cam mechanism, which should be vertically up and down, will be very serious in the horizontal direction), thereby causing a large space occupation and an uncompact structure.

[0008] Therefore, as the most important component in the structure of the vacuum load tap changer, whether the design of the vacuum tube closing and opening device is reasonable and reliable largely determines the performance and reliability of the vacuum load tap changer. SUMMARY

[0009] The purpose of the present application is to provide a vacuum load tap changer vacuum tube closing and opening device, which is compact in structure, high in reliability and improves transmission efficiency.

[0010] The technical scheme of the present application is as follows: a vacuum load tap changer vacuum tube closing and opening device, comprising an insulating support disc, a vacuum tube A and a vacuum tube B located beside the vacuum tube A are installed on the lower side of the insulating support disc, a rotatable cam disc is arranged on the lower side of the insulating support disc, a connecting rod A is connected to the dynamic contact head of the vacuum tube A, a connecting rod B is connected to the dynamic contact head of the vacuum tube B, a cam structure A for driving the connecting rod A to realize lifting action and a cam structure B for driving the connecting rod B to realize lifting action are arranged on the cam disc.

[0011] Further, a plurality of vacuum tube A are installed on the lower side of the insulating support disc at intervals, and a vacuum tube B is arranged between adjacent two vacuum tube A.

[0012] Further, a guide disc is arranged below the insulating support disc, the lower ends of the connecting rod A and the connecting rod B pass through the guide disc respectively, adjusting nuts are arranged on the connecting rod A and the connecting rod B, and closing springs are arranged between the adjusting nuts and the guide disc.

[0013] Further, hinged seats A and B are fixed on the lower side of the guide disc at intervals, and a crank arm is hinged to each of the hinged seats A and B, and the other end of the crank arm is hinged to the lower end of the corresponding connecting rod A or connecting rod B.

[0014] Further, the cam structure A includes a roller A installed at the lower end of the connecting rod A, and the bottom side of the cam disc is provided with a groove A recessed upward, and the side of the groove A is provided with a slope A for the roller A to slide to the bottom of the cam disc to realize the lowering of the connecting rod A.

[0015] Further, the cam structure B includes a roller B installed at the lower end of the connecting rod B, and the bottom side of the cam disc is provided with a pair of grooves B recessed upward, and the adjacent sides of the pair of grooves B are provided with slopes B connected with the bottom of the cam disc and used for the roller B to slide into the groove B to realize the lifting of the connecting rod B.

[0016] Further, the number of the grooves A is equal to the number of the vacuum tubes A, the number of the grooves B is twice the number of the grooves A, and the grooves A and the grooves B are distributed at different circumferential radii.

[0017] Further, the bottom of the insulating support disc is provided with installation recesses for the upper ends of the vacuum tubes A and B to extend into, and the upper ends of the vacuum tubes A and B and the top of the installation recess are both provided with a closing buffer wave-shaped elastic pad, and the insulating support disc is provided with a conductive stud connected with the vacuum tubes A and B, and the upper part of the conductive stud is sleeved with a separation buffer wave-shaped elastic pad located on the upper side of the insulating support disc and connected with a fastening nut.

[0018] Further, the upper end of the vacuum tube A and the closing buffer wave-shaped elastic pad are both provided with a lock washer, the lock washer is provided with a pin limiting the circumferential rotation degree of freedom of the vacuum arc-extinguishing chamber, the fastening nut is sleeved with a nut lock washer, and the insulating support disc is provided with a positioning screw limiting the circumferential rotation degree of freedom of the lock washer and the nut lock washer.

[0019] Further, the upper end of the vacuum tube A and the closing buffer wave-shaped elastic pad are both provided with a lock washer, the lock washer is provided with a pin limiting the circumferential rotation degree of freedom of the vacuum arc-extinguishing chamber, the fastening nut is sleeved with a nut lock washer, and the insulating support disc is provided with a positioning screw limiting the circumferential rotation degree of freedom of the lock washer and the nut lock washer.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1. The vacuum tube closing and separating device has compact structure, high reliability, improves transmission efficiency, and is easy to install.

[0022] 2. The swing end of the toggle arm of the vacuum tube closing and opening device is provided with a connecting rod pivot, the pull rod of the vacuum tube is coupled with the connecting rod pivot, a roller is installed on the connecting rod pivot at a corresponding cam position, the roller cooperates with the cam disc to realize the closing and opening movement of the dynamic connecting rod of the vacuum tube according to the movement track of the cam, the opening distance of the vacuum tube is equal to the height of the roller being lifted by the slope of the cam disc, the direct transmission of the cam and the dynamic contact head of the vacuum tube is realized, the mechanical transmission efficiency is improved, the transmission space occupied is reduced, the friction force generated due to the guidance when the connecting rod of the vacuum tube moves up and down is greatly reduced, and the mechanical transmission efficiency of the cam mechanism is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present application;

[0024] Figure 2 It is a bottom perspective view of the present application;

[0025] Figure 3 It is a bottom view of the present application;

[0026] Figure 4 It is a connecting structure diagram of the vacuum tube and the insulating support disc of the present application;

[0027] Figure 5 It is a schematic diagram of A of the present application; Figure 4

[0028] It is a B-B sectional view diagram of the present application; Figure 6 Figure 4 It is a structural schematic diagram of the closing of the vacuum tube A and the opening of the vacuum tube B of the present application;

[0029] Figure 7 It is a structural schematic diagram of the closing of the vacuum tube A and the opening of the vacuum tube B of the present application;

[0030] Figure 8 It is a structural schematic diagram of the closing of the vacuum tube A and the opening of the vacuum tube B of the present application;

[0031] Figure 9 It is a structural schematic diagram of the closing of the vacuum tube A and the opening of the vacuum tube B of the present application;

[0032] Figure 10 It is a structural schematic diagram of the closing of the vacuum tube A and the opening of the vacuum tube B of the present application;

[0033] ​In the figure: 10. support disc; 11. mounting recess; 20. vacuum tube A; 21. connecting rod A; 22. adjusting nut; 23. closing spring; 24. lock nut; 25. roller A; 26. movable contact; 30. vacuum tube B; 31. connecting rod B; 32. roller B; 40. cam disc; 41. groove A; 42. slope A; 43. groove B; 44. slope B; 50. guide disc; 51. hinge seat A; 52. hinge seat B; 53. crank; 54. crank pivot; 55. connecting rod pivot; 60. opening buffer wave-shaped elastic pad; 61. closing buffer wave-shaped elastic pad; 62. conductive stud; 63. fastening nut; 64. lock washer; 64a. notch; 65. pin; 66. lock catch; 66a. connecting part; 66b. polygonal inner hole; 67. positioning screw; 68. insert nut; 69. washer. DETAILED DESCRIPTION

[0034] In order to make the above features and advantages of the present application more apparent, specific embodiments are described below with reference to the accompanying drawings, and the following detailed description is given to make the above features and advantages of the present application more apparent.

[0035] REFERENCE Figures 1 to 10

[0036] A vacuum load-tap-changer vacuum tube opening and closing device comprises an insulating support disc 10, a vacuum tube A 20 and a vacuum tube B 30 are mounted on the lower side of the insulating support disc, a rotatable cam disc 40 is arranged on the lower side of the insulating support disc, a connecting rod A 21 is connected to the movable contact 26 (arc chamber movable contact) of the vacuum tube A, a connecting rod B 31 is connected to the movable contact (arc chamber movable contact) of the vacuum tube B, cam structures A and B are arranged on the cam disc to drive the connecting rod A to realize lifting action and to drive the connecting rod B to realize lifting action, so as to respectively drive the connecting rod A and the connecting rod B to realize the opening and closing action of the vacuum tube A and the vacuum tube B.

[0037] In the embodiment, in order to realize lifting and guiding, a guide disc 50 is arranged on the upper side of the cam disc, and the guide disc is fixedly connected to the framework of the vacuum load-tap-changer. The lower ends of the connecting rod A and the connecting rod B respectively pass through the guide disc, adjusting nuts 22 are arranged on the connecting rod A and the connecting rod B, and closing springs 23 are arranged between the adjusting nuts and the guide disc, so as to drive the connecting rod A and the connecting rod B to realize closing by the closing springs.

[0038] In the embodiment, in order to prevent the adjusting nuts from loosening, lock nuts 24 are screwed on the connecting rod A and the connecting rod B.

[0039] In this embodiment, in order to better control the lifting and guiding of the connecting rods A and B, the lower side of the guiding disc is fixed with hinged seats A51 and B52, and the hinged seats A and B are respectively hinged with a crank 53, one end of the crank is hinged with the hinged seat A or B through a crank rotating shaft 54, and the other end of the crank is hinged with the lower end of the corresponding connecting rod A or B through a connecting rod rotating shaft 55. The ratio of the length of the crank hinged on the connecting rod A to the opening distance of the vacuum tube A is >10, and the ratio of the length of the crank hinged on the connecting rod B to the opening distance of the vacuum tube B is >10.

[0040] In this embodiment, in order to drive the lifting action of the connecting rod A, the cam structure A includes a roller A25 installed on one side of the lower end of the connecting rod A, and the roller A25 is installed on the corresponding connecting rod rotating shaft. The bottom side of the cam disc is provided with a groove A41 recessed upward, and one side of the groove A is provided with a slope A42 for the roller A to slide to the bottom of the cam disc to realize the lowering of the connecting rod A, see Figure 3 . Thus, when the cam disc rotates, the roller A rolls to the bottom of the cam disc through the slope A to realize the lowering of the connecting rod A and complete the opening of the vacuum tube A, or the roller A enters the groove A on the bottom of the cam disc through the slope A, and the closing spring is pushed to realize the lifting of the connecting rod A and complete the closing of the vacuum tube A.

[0041] In another embodiment, the groove A of the cam disc can be directly hollowed through the cam disc, so that the peripheral part of the cam disc forms a protrusion, the slope A is arranged on the protrusion, and the groove A is formed between the two protrusions, thereby reducing the processing difficulty, see Figure 2 .

[0042] In this embodiment, in order to drive the lifting action of the connecting rod B, the cam structure B includes a roller B32 installed on the lower end of the connecting rod B, and the roller B32 is installed on the corresponding connecting rod rotating shaft. The bottom side of the cam disc is provided with a pair of recessed grooves B43 spaced apart upward, and the adjacent side of the pair of grooves B is provided with a slope B44 connected with the bottom of the cam disc, see Figure 2 or Figure 3 When the cam disc rotates, the roller B slides into the groove B through the slope B under the pushing of the closing spring to complete the lifting of the connecting rod B and realize the closing of the vacuum tube B, or the roller B rolls from the groove B to the bottom of the cam disc through the slope B to complete the opening of the vacuum tube B.

[0043] In another embodiment, the groove B of the cam disc can be directly hollowed through the cam disc, thereby reducing the processing difficulty.

[0044] In the embodiment, the lower side of the insulating support disc is provided with a plurality of vacuum tubes A, and a vacuum tube B is arranged between two adjacent vacuum tubes A. The number of the grooves A is equal to the number of the vacuum tubes A, the number of the grooves B is twice the number of the grooves A, and the number of the grooves B is twice the number of the vacuum tubes B, that is, the number of the grooves B is equal to the number of the vacuum tubes B. The grooves A and the grooves B are arranged on the bottom surface of the cam disc in the circumferential direction and are arranged in a staggered manner.

[0045] Since the switching process of the tap changer needs two or more vacuum tubes to be cooperated to complete, the closing and opening actions of the vacuum tubes must be performed according to a specific logical relationship, and two or more different cams are usually arranged to realize the specific logical relationship. Since all the vacuum tubes are usually arranged on the same circumference, the different cams are necessarily distributed on different circumferential radii. Therefore, the grooves A and the grooves B are distributed on different circumferential radii.

[0046] In the embodiment, in order to prevent the closing bounce, the bottom surface of the insulating support disc is provided with mounting recesses 11 for the upper ends (static ends) of the vacuum tubes A and the vacuum tubes B to extend into, and a closing buffer wave-shaped elastic pad 61 is arranged between the upper end of each of the vacuum tubes A and the vacuum tubes B and the top surface of the mounting recess. A conductive stud 62 connected with the vacuum tubes A and the vacuum tubes B is arranged on the insulating support disc, and a closing buffer wave-shaped elastic pad 60 is arranged on the upper side of the insulating support disc and connected with the upper part of the conductive stud, and a fastening nut 63 is connected with the conductive stud.

[0047] In the embodiment, in order to prevent the connection between the conductive stud and the vacuum tube from being loose, a loosening prevention washer 64 is arranged between the upper end of each of the vacuum tubes A and the vacuum tubes B and the closing buffer wave-shaped elastic pad, a pin 65 for limiting the circumferential rotation degree of freedom of the vacuum interrupter is arranged on the loosening prevention washer, a nut loosening prevention lock 66 is sleeved on the fastening nut, and a positioning screw 67 for limiting the circumferential rotation degree of freedom of the loosening prevention washer and the nut loosening prevention lock is arranged on the insulating support disc.

[0048] In the embodiment, in order to better realize the limitation of the circumferential rotation degree of freedom of the vacuum interrupter, the upper end of each of the vacuum tubes A and the vacuum tubes B is provided with a positioning hole, and the lower part of the pin extends into the corresponding positioning hole.

[0049] In the embodiment, the side part of the nut loosening prevention lock has an outwardly protruding connecting part 66a, a plurality of notches 64a are arranged on the circumferential part of the loosening prevention washer, an insert nut 68 is fixed on the insulating support disc, the positioning screw passes through the connecting part and is screwed with the insert nut, and the lower end of the positioning screw passes through the insert nut and is inserted into one of the notches, so as to realize the limitation of the circumferential rotation degree of freedom of the loosening prevention washer and the nut loosening prevention lock.

[0050] In this embodiment, a washer 69 is also provided between the opening buffer waveform spring pad and the upper end face of the insulating support plate.

[0051] In this embodiment, in order to better secure the fastening nut, the nut anti-loosening lock has a polygonal inner hole 66b, and the fastening nut is embedded in the polygonal inner hole.

[0052] The working principle of closing bounce elimination: The stationary end of the vacuum interrupter is floatingly fixed to the insulating support plate by closing and opening buffer wave spring pads. When the vacuum tube closes upwards, the moving contact of the vacuum tube contacts the stationary contact, generating an upward impact force on the stationary contact. The vacuum tube compresses the closing buffer wave spring pads upwards, and part of the collision energy between the moving and stationary contacts is absorbed by the closing buffer wave spring pads, reducing the impact energy and decreasing closing bounce. In addition, the floating and fixed structure of the closing and opening buffer wave spring pads can also effectively absorb the mechanical vibration transmitted through the insulating support plate caused by the operation of adjacent vacuum tubes or the gun mechanism. This prevents the conduction state of the vacuum tube already in the closed state from being disturbed and disrupted, avoiding bounce.

[0053] Anti-loosening principle: Because the lower end of the positioning screw is inserted into the notch of the anti-loosening washer, the anti-loosening washer is restricted from circumferential rotation by the two-point positioning of the positioning screw and the conductive stud; the anti-loosening washer of the arc-extinguishing chamber restricts the circumferential rotation of the vacuum tube by the pin; the anti-loosening lock of the nut is restricted from circumferential rotation by the two-point positioning of the positioning screw and the fastening nut, and the outer hexagonal side of the fastening nut is embedded in the polygonal inner hole of the anti-loosening lock of the nut, thus effectively achieving the fastening and anti-loosening of the vacuum tube.

[0054] Working principle of the vacuum tube closing and opening device of the direct-acting vacuum on-load tap changer:

[0055] like Figure 7 As shown: Roller A25 is located on the bottom surface of cam disk 40, connecting rod A21 is in its lowest position, the closing spring on connecting rod A21 is in a compressed and energy-storing state, and vacuum tube A20 is in the open position. Roller B32 is located in groove B43 and is not constrained by cam disk 40. Under the action of the closing spring, connecting rod B31 is in its highest position, the closing spring on connecting rod B31 is in a pre-compressed state, and vacuum tube B30 is in the closed state. At this time, current flows through the vacuum tube B30 side.

[0056] When the cam disc rotates counterclockwise to the point... Figure 8 At the position shown:

[0057] ① Roller A25 quickly leaves the bottom surface of cam disk 40. At this time, the energy stored in the closing spring on connecting rod A21 is rapidly released, causing connecting rod A21 to move upward. Roller A25 slides along slope A into groove A41, vacuum tube A20 closes, and the closing spring on connecting rod A21 is in a pre-compressed state. During the upward movement of connecting rod A21, constrained by crank arm 53, the movement trajectory of connecting rod shaft 55 on connecting rod A21 is an upward arc, causing the lower end of connecting rod A21 to swing horizontally. However, since the ratio of the length of crank arm 53 hinged on connecting rod A21 to the opening distance of vacuum tube A20 is >10, the horizontal displacement of connecting rod shaft 55 on connecting rod A21 is relatively very small, and the movement trajectory of connecting rod A21 is approximately vertically upward.

[0058] ② When roller A25 quickly leaves the bottom surface of cam disk 40, roller B32 rapidly climbs from groove B43 along slope B to the bottom surface of cam disk 40, driving connecting rod B31 to move downwards, and vacuum tube B30 is opened; at this time, the closing spring on connecting rod B31 is compressed and stores energy. When roller B32 climbs from groove B43 along slope B to the bottom surface of cam disk 40, constrained by the crank arm on connecting rod B31, the movement trajectory of the connecting rod shaft on connecting rod B31 is a downward arc, causing the lower end of connecting rod B31 to swing horizontally. However, the ratio of the length of the crank arm on connecting rod B31 to the opening distance of vacuum tube B is >10, so the horizontal displacement of the connecting rod shaft on connecting rod B31 is relatively very small, and the movement trajectory of connecting rod B31 is approximately vertically downward.

[0059] ③ At this time, if Figure 8 As shown, vacuum tube A20 is in the closed state, vacuum tube B30 is in the open state, and current flows through the side of vacuum tube A20.

[0060] When the cam disc rotates counterclockwise to the point... Figure 9 At the position shown:

[0061] ① Roller A25 remains in groove A41, connecting rod A21 does not move, and vacuum tube A20 remains in the closed state.

[0062] ② Roller B32 quickly leaves the bottom surface of the cam disc and enters another groove B43. At this time, the energy stored in the closing spring on connecting rod B31 is rapidly released, driving connecting rod B31 to move upward. Roller B32 slides along slope B into another groove B43, vacuum tube B30 closes, and the closing spring on connecting rod B31 is in a pre-compressed state. During the upward movement of connecting rod B31, constrained by the crank arm on connecting rod B31, the movement trajectory of the connecting rod shaft on connecting rod B is an upward arc, causing the lower end of connecting rod B31 to swing horizontally. However, since the ratio of the length of the crank arm on connecting rod B31 to the opening distance of vacuum tube B30 is >10, the horizontal displacement of the lower end of connecting rod B31 caused by the swing is relatively small, and the movement trajectory of connecting rod B is approximately vertically upward.

[0063] ③ At this time, as shown in Figure 9 , the vacuum tube A20 is in the closed state, and the vacuum tube B30 is in the closed state. The current can pass through the vacuum tube A or the vacuum tube B.

[0064] When the cam plate rotates clockwise to the position as shown in Figure 10 :

[0065] ① The roller A25 continuously stays in the groove A41, the connecting rod A21 has no movement, and the vacuum tube A20 continuously stays in the closed state.

[0066] ② The roller B32 quickly climbs along the slope of the other groove B43 of the cam plate 40 to the bottom surface of the cam plate 40, drives the connecting rod B31 to move downward, and the vacuum tube B30 is opened. At this time, the closing spring on the connecting rod B31 is compressed and stored. When the roller B32 climbs along the groove B43 to the bottom surface of the cam plate 40, the connecting rod B31 is constrained by the crank on the connecting rod B31, and the movement trajectory of the connecting rod shaft on the connecting rod B31 is downward arc movement, causing the lower end of the connecting rod B31 to swing horizontally. However, since the length ratio of the crank on the connecting rod B31 to the opening distance of the vacuum tube B30 is >10, the horizontal displacement of the lower end of the connecting rod B31 is relatively very small, and the movement trajectory of the connecting rod B31 is approximately vertical downward movement.

[0067] ③ At this time, as shown in Figure 10 , the vacuum tube A20 is in the closed state, and the vacuum tube B30 is in the open state. At this time, the current passes through the side of the vacuum tube A20.

[0068] When the cam plate rotates clockwise to the position as shown in Figure 7 :

[0069] ① The roller A25 quickly climbs along the slope A to the bottom surface of the cam plate 40, drives the connecting rod A21 to move downward, and the vacuum tube A20 is opened. At this time, the closing spring on the connecting rod A21 is compressed and stored.

[0070] When the roller A25 climbs along the slope A to the bottom surface of the cam plate 40, the connecting rod A21 is constrained by the crank 53, and the movement trajectory of the connecting rod shaft 55 on the connecting rod A21 is downward arc movement, causing the lower end of the connecting rod A21 to swing horizontally. However, since the length ratio of the crank 53 on the connecting rod A21 to the opening distance of the vacuum tube A20 is >10, the horizontal displacement of the lower end of the connecting rod A21 is relatively very small, and the movement trajectory of the connecting rod A21 is approximately vertical downward movement.

[0071] ② As roller A25 climbs up the slope A towards the bottom of cam disk 40, roller B32 quickly leaves the bottom of cam disk 40. At this time, the energy stored in the closing spring on connecting rod B31 is released rapidly, causing connecting rod B31 to move upward. Roller B32 slides along the slope B into the groove B43 on one side, vacuum tube B30 closes, and the closing spring on connecting rod B31 is in a pre-compressed state.

[0072] During the upward movement of connecting rod B31, constrained by the crank arm on connecting rod B31, the movement trajectory of the connecting rod shaft on connecting rod B31 is an upward arc, causing the lower end of connecting rod B31 to swing horizontally. However, since the ratio of the length of the crank arm on connecting rod B31 to the opening distance of vacuum tube B30 is >10, the horizontal displacement of the lower end of connecting rod B31 caused by the swing is relatively small, and the movement trajectory of connecting rod B31 is approximately vertically upward.

[0073] ③ At this time, if Figure 7 As shown, vacuum tube A20 is in the open state and vacuum tube B30 is in the closed state. At this time, the current flows through the side of vacuum tube B30.

[0074] The above process enables vacuum tubes A20 and B30 to be closed and opened according to the design program. With the help of the isolating switching knife switch and the transition resistor, the tap position switching of the vacuum on-load tap changer can be realized.

[0075] The above description is only a preferred embodiment of the present invention. For those skilled in the art, designing different forms of vacuum tube closing and opening devices for vacuum on-load tap changers based on the teachings of the present invention does not require creative labor. All equivalent changes, modifications, substitutions and variations made in accordance with the scope of the patent application of the present invention without departing from the principles and spirit of the present invention shall be covered by the present invention.

Claims

1. A vacuum tube combination opening and closing device for a vacuum on-load tap changer, comprising an insulating support disc, characterized in that, The lower side of the insulating support disc is provided with vacuum tubes A and vacuum tubes B beside the vacuum tubes A, a rotatable cam disc is arranged on the lower side of the insulating support disc, a connecting rod A is connected to the moving contact of the vacuum tube A, a connecting rod B is connected to the moving contact of the vacuum tube B, cam structures A and B are arranged on the cam disc, the cam structure A drives the connecting rod A to realize the lifting action, and the cam structure B drives the connecting rod B to realize the lifting action; a guide disc is arranged below the insulating support disc, the lower ends of the connecting rod A and the connecting rod B pass through the guide disc, adjusting nuts are arranged on the connecting rod A and the connecting rod B, closing springs are arranged between the adjusting nuts and the guide disc; hinge seats A and B are fixed on the lower side of the guide disc, a crank arm is hinged to each of the hinge seats A and B, and the other end of the crank arm is hinged to the lower end of the corresponding connecting rod A or connecting rod B; the cam structure A comprises a roller A arranged on the lower end of the connecting rod A, the bottom side of the cam disc is provided with a groove A with an upward recess, and one side of the groove A is provided with a slope A for the roller A to slide to the bottom surface of the cam disc to realize the lowering of the connecting rod A; the cam structure B comprises a roller B arranged on the lower end of the connecting rod B, the bottom side of the cam disc is provided with a pair of grooves B with upward recesses, and one side of each of the pair of grooves B is provided with a slope B connected to the bottom surface of the cam disc and used for the roller B to slide into the groove B to realize the lifting of the connecting rod B; the bottom surface of the insulating support disc is provided with mounting recesses for the upper ends of the vacuum tubes A and the vacuum tubes B to extend into, closing buffer wave-shaped elastic pads are arranged between the upper ends of the vacuum tubes A and the vacuum tubes B and the top surface of the mounting recesses, electrically conductive studs connected to the vacuum tubes A and the vacuum tubes B are arranged through the insulating support disc, and opening buffer wave-shaped elastic pads are arranged on the upper part of the electrically conductive studs on the upper side of the insulating support disc and connected to fastening nuts.

2. The vacuum tube combination opening and closing device of a vacuum on-load tap changer according to claim 1, characterized in that, A plurality of vacuum tubes A are arranged on the lower side of the insulating support disc at intervals, and a vacuum tube B is arranged between adjacent two vacuum tubes A.

3. The vacuum tube combination opening and closing device of a vacuum on-load tap changer according to claim 1, characterized in that, The number of the grooves A is equal to the number of the vacuum tubes A, the number of the grooves B is twice the number of the grooves A, and the grooves A and the grooves B are distributed on different circumferential radii.

4. The vacuum tube combination opening and closing device of vacuum on-load tap changer according to claim 1, characterized in that, A locking washer is arranged between the upper end of each of the vacuum tubes A and the vacuum tubes B and the closing buffer wave-shaped elastic pad, a pin is arranged on the locking washer and used for limiting the circumferential rotation degree of freedom of the vacuum interrupter, a nut locking lock is sleeved on the fastening nut, and a positioning screw is arranged on the insulating support disc and used for limiting the circumferential rotation degree of freedom of the locking washer and the nut locking lock.

5. The vacuum tube combination opening and closing device of a vacuum on-load tap changer according to claim 4, characterized in that, The upper end of each of the vacuum tubes A and the vacuum tubes B is provided with a positioning hole, the lower part of the pin extends into the corresponding positioning hole, the side part of the nut locking lock has an outward protruding connecting part, a plurality of notches are arranged at intervals on the peripheral part of the locking washer, the positioning screw passes through the connecting part and is screwed with the insulating support disc, and the lower end of the positioning screw is inserted into one of the notches.

Images