RU2521609C2 - Vacuum switch - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: vacuum switch comprises a steel base with vertical ribs and horizontal racks on which at least two identical phase modules divided by vertical ribs are installed in the upper and middle part of the casing. In the lower part of the casing there are blocking and synchronising shafts common for all modules and at least one deflecting electromagnet. The blocking shaft is connected to the shaft of the deflecting electromagnet and is fitted by a lever to which one spring end is attached. The second end of the spring is fixed on the base. Each of the phase modules comprises the following units installed in the upper casing part: a vacuum chamber with a stationary contact and a movable contact, current leads, supporting and traction insulators set vertically along the central axis of the module, a rod, an opening spring and a loading spring mounted coaxial to the rod, and a separate-phase linear electromagnetic drive mounted in the middle part of the casing. A drive armature is placed in the inner cavity of a stator and is fixed on the rod. The stator is fitted by an axial vertical slot. A fixing pin fixed on the rod is set in the slot and is able of moving. Each rod is coupled to the traction insulator by its upper end. The lower end of the rod is equipped by a rolling bearing and rests against an eccentric installed on the common blocking shaft. Rods of all phase modules are fitted by linear gear rims made so that to be able of engagement with the gears installed on the common synchronising shaft.

EFFECT: provision for reliable fixation of the switch status "ON" and reduced time for opening of contacts of its vacuum chambers.

5 dwg

Description

The invention relates to electrical engineering, namely to the design of vacuum circuit breakers.

The invention is known "Vacuum circuit breaker modular series" TEL ", protected by RF patent No. 2020631 (application No. 503479/07 with priority dated 04/02/1992), IPC Н01Н 33/66, publ. September 30, 1994

The patent materials describe the design of a modular type vacuum circuit breaker with an electromagnetic drive. The modular type switch contains vacuum chambers that disconnect the compression and compression springs, a shaft, and block contacts, each vacuum chamber having a separate drive with a winding and a magnetic latch, which is located coaxially with the vacuum chamber, all drives are connected by a common shaft with a position indicator fixed to it and a permanent magnet, near which are magnetically controlled block contacts.

The described apparatus is a high-speed protective switch, although it does not have a free trip mechanism. Performance is achieved due to the intense suppression of the switching current in the drive windings, which ends 15 ms after the opening of the block contacts. The power consumed by the drive is 6-10 times less than that of devices of a similar class. The absence of loaded friction units provides the circuit breaker a high resource for wear of drive components. Such a switch is used in installations with frequent switching, for example in arc steel furnaces.

The disadvantage of this design is the unreliable fixation of the circuit breaker with the closed contacts of the vacuum chamber.

It is also known that the closest in technical essence to the claimed device is the invention "Vacuum Circuit Breaker", protected by RF patent No. 22989874 (application 2003108296/09 with priority dated March 26, 2003), IPC Н01Н 33/66, publ. 04/10/2005 (prototype).

The specified vacuum circuit breaker consists of phase modules mounted on a metal base, inside of which there are drives with magnetic systems forming magnetic latches, consisting of a stator, armature and coil, as well as a trip spring, synchronizing and locking shafts, contact block. A cam is located at the end of the locking shaft for mechanically opening and blocking the drive in the off position. The use of a locking shaft allows the circuit breaker to lock without mechanical stress on the synchronizing shaft.

Phase modules consist of support insulators with vacuum chambers inside, filled with silicone rubber, contact terminals, a preload spring and traction insulators. The magnetic drive system, consisting of two cup-shaped parts made of hard magnetic material with a coil located inside (one cup-anchor is attached to the base of the switch and the other is a stator to the traction insulator), allows for a simple and reliable magnetic latch drive.

In the gap between the terminal of the movable contact and the sleeve of the movable contact with the possibility of rolling between their surfaces installed elastic conductive spirals. Spiral conductive elements rolling during the operation of the switch between the movable surface of the sleeve and the fixed surface of the terminal create a constant multipoint contact and are a movable current collector of the switch. The circuit breaker is equipped with a manual shutdown generator, which is a closed magnetic system including a permanent magnet and a coil electrically connected to the coils of the circuit breaker drives. The manual shutdown button is rigidly connected to the armature of the magnetic system of the specified generator. In addition, the switch is equipped with a remote indicator, which is connected with the mechanism of the synchronizing shaft of the switch through flexible communication.

One of the disadvantages of the prototype as well as the analogue is the unreliable fixation of the circuit breaker with the closed contacts of the vacuum chamber. When a current pulse is applied to the drive coils, each of them closes the stator and the armature, which is accompanied by compression of the trip and preload springs, while the contacts of the vacuum chambers close. When the drive coils are de-energized, the armature maintains its position relative to the stator due to the forces of magnetic attraction due to the presence of residual magnetic flux. The return of the armature to the initial state, in which the contacts of the vacuum chambers open, occurs under the action of a tripping spring after applying a reverse current to the drive coil to demagnetize the stator and the armature. However, the use of a magnetic latch cannot provide reliable fixation of the on state of the circuit breaker, since when exposed to external factors, such as vibration, temperature and radiation, the residual magnetic flux of the steel decreases, which can lead to spontaneous opening of the contacts. In addition, due to the fact that to disconnect the magnetic latch there is a need to demagnetize the stator and the armature by the reverse current of the coil, it is impossible to use material with high coercive force, such as rare-earth magnets, to manufacture the stator and armature.

Another disadvantage of the prototype is the large opening time of the contacts when the circuit breaker is turned off, which is also a consequence of the use of a magnetic latch. In the magnetic latch, the anchor is held in a state that is pulled up to the stator even after the coil is turned off due to the forces of magnetic attraction created by the residual magnetic flux. To overcome the forces created by the residual magnetic flux, the breaking spring must be stiff enough, so in the prototype it takes more time to open the contacts when the circuit breaker is turned off.

The objective of the invention is to develop the design of a vacuum circuit breaker that provides reliable fixation of the on state of the circuit breaker and a shorter opening time of the contacts of its vacuum chambers.

The problem is solved due to the fact that the vacuum circuit breaker contains a steel base with vertical ribs and horizontal shelves, on which at least two identical phase modules are installed in the upper and middle parts of the housing, separated by vertical ribs, and common for of all modules, locking and synchronizing shafts and at least one rotary electromagnet, and the locking shaft is connected to the shaft of the rotary electromagnet and is equipped with a lever to which One end of the spring is attached, the second end of which is attached to the base.

At the same time, each of the phase modules contains a vacuum chamber located in the upper part of the housing with contacts, conductors, support and traction insulators, and a phase-phase drive with a magnetic system consisting of a stator, armature, winding and magnetic circuit located in the middle of the housing, as well as vertically along the central axis of the module disconnecting and compressing springs and a rod mounted with the possibility of vertical movement.

Two contacts are placed in the inner cavity of each vacuum chamber: the upper fixed contact is connected to the upper fixed horizontal current lead separated from the upper horizontal shelf of the housing by a support insulator, and the lower movable contact is connected via a flexible electrical lead to the lower fixed horizontal current lead separated from the horizontal shelf of the housing, on which has a traction insulator connected to the movable contact of the vacuum chamber.

The disconnecting and pressing springs located under each vacuum chamber and mounted coaxially with the rod abut the upper part in the horizontal shelf on which the traction insulator is located, and in the lower part of the traction insulator, respectively, and the lower part - in the thrust disk mounted on the rod, and the rod is equipped with a pin installed with the possibility of movement in the vertical groove of the stator of the phase-by-phase drive of the corresponding phase module.

Each phase-by-phase drive is located on a horizontal shelf of the housing, and the elements of its magnetic system are mounted on a non-magnetic disk, and the armature located in the internal cavity of the stator is mounted on the rod of the corresponding phase module.

In this case, each rod with its upper end is connected to the traction insulator of its phase module, and the lower end, equipped with a rolling bearing, relies on an eccentric mounted on a common locking shaft.

Moreover, the rods of all phase modules are equipped with linear gear rims made with the possibility of their interaction with gears mounted on a common synchronizing shaft.

In the prototype, fixing the drive armature in a position pulled to the stator is ensured by forces created by the residual magnetic flux, which can decrease due to external factors (vibration, temperature and radiation), as a result of which spontaneous opening of the contacts can occur. In the claimed technical solution, the drive armature is fixed to the rod and the anchor with the rod is secured by creating a mechanical bearing stop attached to the end of the rod in an eccentric mounted on the locking shaft. And since the mechanical stop does not depend on external factors, its use in the design of the switch provides a more reliable fixation of the contacts.

In the prototype, the stiffness of the tripping spring should be limited so that the strength of the tripping spring does not exceed the fixing force created by the "magnetic latch", otherwise the contacts will open. In the proposed vacuum circuit breaker, the stiffness of the breaking spring can be greatly increased compared with the prototype, since the force of the breaking spring is compensated by the mechanical stop of the rod bearing in the eccentric mounted on the locking shaft. Therefore, in the inventive device, the opening time of the contacts of the switch by increasing the stiffness of the breaking spring is significantly reduced in comparison with the prototype.

The invention is illustrated by the following drawings:

figure 1 presents a vacuum circuit breaker in a three-phase design;

figure 2 shows a view of the spring retainer in section aa of figure 1;

figure 3 shows the kinematic diagram of one phase module of the vacuum circuit breaker (section B-B of figure 1) in the "off" state with the contacts of the vacuum chamber open;

figure 4 shows the kinematic diagram of one phase module of the vacuum circuit breaker (section BB of figure 1) in the "on" state with the contacts of the vacuum chamber closed;

figure 5 shows a diagram of a rotary magnet.

The vacuum circuit breaker (Fig. 1) contains a housing with a steel base 1, vertical ribs 2 and horizontal shelves 3, on which phase modules 4, separated by vertical ribs 2, are installed on the upper and middle parts of the housing, the number of which corresponds to the number of electric lines switched by the circuit breaker .

The device phase modules 4 of the vacuum circuit breaker is the same. Each of the phase modules 4 (Fig. 3, 4) contains a vacuum chamber 5 located in the upper part of the housing with contacts 6.7, conductors 8, 9, 10, support 11, 12 and traction 13 insulators; located in the middle part of the housing, a phase-by-phase drive 14 with elements of the magnetic system 15-18, as well as a disconnecting spring 19, a pressing spring 20 and a rod 21 located vertically along the central axis of the module, the rod being mounted with the possibility of vertical movement.

In the lower part of the housing (Fig.1, 2) are common to all phase modules 4, the locking shaft 22, the synchronizing shaft 23 and at least one rotary electromagnet 24.

In the inner cavity (Figs. 3, 4) of each vacuum chamber 5 there are two contacts: the upper fixed 6 and the lower movable contact 7. The upper fixed contact 6 of the vacuum chamber 5 is connected to the upper stationary horizontal current lead 8, separated from the upper horizontal shelf 3 by a support insulator 11, and the lower movable contact 7 of the vacuum chamber 5 is connected through a flexible current lead 9 to the lower stationary horizontal current lead 10 separated by a support insulator 12 from the horizontal shelf 3 on which the traction insulator 13 is mounted, United with the movable contact 7 of the vacuum chamber 5.

Under each vacuum chamber 5 (Figs. 3, 4), two springs are installed on the rod 21, coaxially with it, disconnecting 19 and pressing 20, which abut with their upper part in the horizontal shelf 3, on which the traction insulator 13 is located, and in the lower part of the traction insulator 13, respectively, and the lower part - in the thrust disk 25, mounted on the rod 21.

Each phase-by-phase drive 14 of the phase modules 4 (FIGS. 3, 4) is located on a horizontal shelf 3 and contains a stator 15, an armature 16, a winding 17 and a magnetic circuit 18 that are mounted on a non-magnetic disk 26. An armature 16 made of magnetic steel is placed in the inner cavity of the stator 15, also made of magnetic steel, is fixed on the rod 21. The stator 15 is made with an axial vertical groove in which the fixing pin 27 mounted on the rod 21 is placed with the possibility of movement in this groove.

In this case, each rod 21 of the phase module 4 (Figs. 3, 4) is connected with its upper end to a traction insulator 13, in the cavity of which the head 28 of the rod 21 is located, and the lower end, equipped with a rolling bearing 29, relies on an eccentric 30 mounted on a common locking shaft 22.

The common locking shaft 22, connected by means of couplings to the shaft of the rotary electromagnet 24, is equipped with a lever 31 to which one end of the spring 32 is attached, the second end of which is attached to the base 1 (Fig.1, 2).

The rods 21 of all phase modules 2 (Figs. 1, 3, 4) are provided with linear gear rims 33 made with the possibility of their interaction, i.e. with the formation of engagement, with gears 34 mounted on a common synchronizing shaft 23.

Figure 5 shows the axial section of the rotary electromagnet 24.

In the housing 35 of the rotary electromagnet 24, the stator magnetic circuit 36 is fixed with a winding 37 located on two teeth of the stator magnetic circuit 36. The rotor 38 is passive, also made with two teeth and mounted on the shaft 39.

The vacuum switch operates as follows.

As indicated above, the number of identical phase modules 4 of the vacuum circuit breaker (FIG. 1) corresponds to the number of electrical lines that the circuit breaker switches. Phase modules 4 of the vacuum circuit breaker are arranged and work in the same way, and therefore, below, when describing the operation of all phase modules of the circuit breaker, the operation of one phase module 4 is described.

In the initial position, the switch is in the off state (Figure 3). In this case, the winding 17 of the electromagnetic phase-shifting drive 14 and the winding of the rotary electromagnet 37 are de-energized. The breaking spring 19, operating in tension, is supported by the upper part in a horizontal shelf 3, on which the traction insulator 13 is located, and the lower part presses on the thrust disk 25 mounted on the rod 21. Under the action of the spring 19, the thrust disk 25 together with the rod 21 and the armature 16 of the phase drive 14 is in the lower position. In this case, the head 28 of the rod 21 biases the traction insulator 13 to the lower position, in which the contacts 6 and 7 of the vacuum chamber 5 are open. The eccentric 30 with the locking shaft 22 is deployed so that the contact point between the eccentric 30 and the rolling bearing 29 fixed to the end of the rod 21 is at a minimum distance from the center of the locking shaft 22. The spring 32 of the lever 31 with the position of the locking shaft 22 shown in FIG. 3 stretched and tends to rotate the locking shaft 22 with the eccentric 30 clockwise, but then the spring 32, when the eccentric 30 is rotated, should move the rod 21 upwards and compress the disconnecting spring 19. The force of the spring 32 is too small compared to the force sensing spring 19, therefore, the state of the switch shown in FIG. 3 is stable.

When you turn on the vacuum circuit breaker (Figure 4) on the winding 17 of the electromagnetic phase-by-phase drive 14 serves a supply voltage. The electromagnets of the phase-by-phase actuator 14 bias the armature 16 with the rod 21 to the upper position, while the gap between the armature 16 and the stator 15 is reduced. A linear gear ring 33 made on the rod 21 of each phase module 4 is engaged with the corresponding gear 34, which is mounted on a common synchronizing shaft 23. Due to the mechanical connection of each rod 21 of the phase module 4 with a common synchronizing shaft 23, all the rods 21 of the vacuum circuit breaker move synchronously and phase modules 4 of the vacuum circuit breaker operate in a similar manner. When shifted to the upper position of the armature 16 with the rod 21 and the thrust disk 25, the disconnecting spring 19 is compressed. The head 28 of the rod 21 when displaced upwards releases the traction insulator 13, which also moves upward under the action of the compression spring 20, which creates a force in the direction of tension. Together with the traction insulator 13, the movable contact 7 of the vacuum chamber 5 is shifted upward, as a result of which its contacts 6 and 7 are closed. Since the closure of the contacts 6 and 7 occurs under the action of the pressing spring 20, a hard blow of the contacts 6 and 7 against each other is excluded, which could lead to damage. When the rod 21 moves, the protruding pin 27, mounted on the rod 21, also moves in the axial vertical groove of the stator 15 of the phase drive 14 and this groove does not allow the rod 21 to rotate around its axis. As soon as the rod 21 under the action of the electromagnetic force of the linear electromagnet of the phase-shifted actuator 14 is shifted up, the common locking shaft 12 and the cam 30 under the action of the spring force 32 of the lever 31 rotates clockwise. Now the contact point of the rolling bearing 29 and the eccentric 30 is located on its circular part having the largest radius. After disconnecting the winding 17 of the linear electromagnet of the phase-by-phase actuator 14, the disconnecting spring 19 tends to shift the rod 21 down to its original position, in which the contacts 6 and 7 of the vacuum chamber 5 are open, but the bearing 29 mounted on the end of the rod 21 rests on the circular part of the eccentric 30 and the rod 21 cannot move down. The spring 32 of the lever 31 fixes the position of the locking shaft 22 and the rod 21.

To turn off the vacuum circuit breaker and open the contacts 6 and 7 of the vacuum chamber 5, it is necessary to supply power to the winding 37 of the rotary electromagnet 24 (figure 5). The rotor 38 with the shaft 39 of the rotary electromagnet 24 under the influence of electromagnetic moment rotates and rotates counterclockwise the locking shaft 22 with the eccentric 30. The contact point of the rolling bearing 29 and the eccentric 30 is shifted from the circular part of the eccentric to its part with a smaller radius, resulting in the rod 21 under the action of the force of the breaking spring 19 is shifted down to its original position (figure 3). The head 28 of the rod 11 biases down the traction insulator 13 with the movable contact 7 of the vacuum chamber 5, as a result of which the contacts 6 and 7 of the vacuum circuit breaker open. The rolling bearing 29, mounted on the rod 21, reduces the friction forces when the eccentric 30 is rotated and reduces the torque of the rotary electromagnets 24.

Thus, the proposed design of the vacuum circuit breaker can improve the reliability of fixing the armature in the on state of the switch and reduce the opening time of the contacts of the switch.

The inventive device of the vacuum circuit breaker can be made of materials conventional for this type of device using standard equipment using tools used to manufacture components and parts of industrial equipment.

Claims (1)

A vacuum circuit breaker containing a housing with a steel base, vertical ribs and horizontal shelves, on which at least two identical phase modules are installed in the upper and middle parts of the housing, separated by vertical ribs, and in the lower part of the housing there are blocking and synchronizing modules common to all modules shafts and at least one rotary electromagnet, and the locking shaft is connected to the shaft of the rotary electromagnet and is equipped with a lever to which one end of the spring is attached, W the end of which is attached to the base; wherein each of the phase modules contains a vacuum chamber located in the upper part of the housing with contacts, conductors, support and traction insulators and a phase-phase drive with a magnetic system consisting of a stator, armature, winding and magnetic circuit located in the middle of the housing, as well as vertically along the central axis of the module disconnecting and pressing the springs and the rod mounted with the possibility of vertical movement; the contacts located in the inner cavity of each vacuum chamber are connected to the horizontal current conductors, the upper fixed contact being connected to the upper stationary horizontal current lead separated from the upper horizontal shelf of the housing by the support insulator, and the lower mobile contact is connected through a flexible current lead to the lower stationary horizontal current lead separated by the supporting insulator from the horizontal shelf on which the traction insulator is mounted, connected to the movable contact of the vacuum chamber; the disconnecting and pressing springs located under each vacuum chamber and installed coaxially with the rod abut the upper part in the horizontal shelf on which the traction insulator is located, and in the lower part of the traction insulator, respectively, and the lower part - in the thrust disk mounted on the rod, and the rod is equipped with a pin mounted to move in the vertical stator groove of the phase-by-phase drive of the corresponding phase module; each phase-by-phase drive is located on a horizontal shelf of the housing, with elements of its magnetic system mounted on a non-magnetic disk, and an anchor located in the internal cavity of the stator, mounted on the rod of the corresponding phase module; in this case, each rod with its upper end is connected to the traction insulator of the corresponding phase module, and the lower end, equipped with a rolling bearing, is supported by an eccentric mounted on a common locking shaft; moreover, the rods of all phase modules are equipped with linear gear rims made with the possibility of their interaction with gears mounted on a common synchronizing shaft.

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