RU2756294C1 - Mechanism for manual disconnection of the drive of a high-voltage vacuum circuit breaker - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, to high-voltage apparatus building, namely to structures of drives of high-voltage vacuum circuit breakers configured to be manually disconnected, and pertains to a structure of high-voltage circuit breakers with vacuum arc-interruption chambers. The manual drive mechanism comprises three phase-by-phase drives with a mobile element in the form of a cylindrical armature, the manual disconnection and locking shaft comprises eccentrics intended, upon pressing the manual disconnection button followed by turning the manual disconnection and locking shaft, to impact the disconnection levers connected with the release bolts intended for detaching the armature from the magnetic circuit and disconnecting the drive of the circuit breaker.

EFFECT: increase in the safety and security of performing the manual operation, as well as provided possibility of increasing the retaining force on the drives and creating a more powerful apparatus intended for significantly higher currents, exhibiting higher safety.

1 cl, 3 dwg

Description

The invention relates to electrical engineering, to high-voltage apparatus, namely to the design of drives for high-voltage vacuum switches with the possibility of manual shutdown, and concerns the design of high-voltage switches with vacuum interrupting chambers.

Known designs of high-voltage vacuum circuit breakers, consisting of three poles, three phase-by-phase electromagnetic drives with a magnetic latch, kinematically connected to the moving contacts of the arc-extinguishing chambers and the housing, inside which the synchronization shaft is horizontally placed.

For example, a high-voltage vacuum circuit breaker of the TEL series is known, the design of which is described in patent RU 2249874, H01H 33/66 (2000.01), containing a base, vacuum chambers with contacts, phase-by-phase drives with magnetic systems forming magnetic latches containing a stator, an armature and a winding, common synchronizing shaft and blocking shaft, simultaneously performing the function of manual shutdown.

The blocking shaft is equipped with a cam for mechanical opening and blocking of the drive in the disengaged position in the form of a flat plate.

The blocking shaft is located perpendicular to the synchronization shaft and during manual disconnection, the action from the manual shutdown button is transmitted directly to the flat mechanical opening cam, which evenly distributes this force through the synchronization shaft to all three circuit breaker drives simultaneously and in equal proportions. The technical result consists in the fact that the entire force of external influence from the manual (emergency) shutdown button, limited in accordance with GOST 12.2.007.3, is not more than 25 kgf. through the cam of the locking shaft, it is initially applied to only one, the central drive and from it through the synchronization shaft it is evenly distributed and applied to all three drives. As a result, it is no more than one third for each drive.

It becomes necessary to artificially limit the holding force of each drive to no more than 8-16 kgf. This design has disadvantages: limiting the possibility of increasing the holding force and limiting the possibilities of use in areas of increased seismicity and vibration (construction sites, quarries, metro, etc.), in addition, the design of the drive requires periodic magnetization, and if the operating power is lost impossible, as a result of which the drive, artificially limited in part holding forces, begin to lose holding force and when exposed to vibration or shock loads, the switch spontaneously trips.

Also known is the design of a vacuum circuit breaker produced by the Limited Liability Company "Scientific and Production Firm" Radius "", patent (RU) 2545163, which contains the following set of essential features: at least one module with an electromagnetic drive with a magnetic latch in the lock zone, having an armature , vacuum chamber, traction isolator, synchronizing shaft, manual emergency shutdown. The manual emergency shutdown is made by a lever-acting mechanism on the armature with blocking from accidental switching on, and the armature is made with the possibility of tilting and weakening the magnetic coupling of the lock zone. The lever-acting mechanism contains a shaft, the ends of which are provided with mutually perpendicular protrusions, one of which is made with the possibility of disconnection, and the other - blocking from accidental activation. This design is a close analogue of the patent TEL RU 2249874, Н01Н 33/66 (2000.01), with the only difference that the shaft of the lever-acting mechanism is not perpendicular to the switch body, but parallel to the body and is located between two drives. The disadvantage of this design is that the mechanism has a tripping effect on only one armature (out of three available in the switch) and through 2 synchronization shafts the tripping action is evenly distributed between the two remaining drives.

Closer to the proposed design is the design according to the patent BY 6870 U2010.12.30, which has high holding forces of the drives and contains an auxiliary shaft and a manual shutdown mechanism, implemented in the form of a special removable handle. Switching off the circuit breaker in manual mode is carried out by external force action of the removable handle (41) through the hole in the housing (1) on the auxiliary shaft (37), as a result of which the action is transmitted through the system of levers (33) to the synchronizing shaft (31), which makes the transition of the drives from steady state "on" to steady state "off" and opening of the upper (6) and lower contacts (7) of the switch (main circuits).

The main disadvantage of the known technical solution is the absence of a manual shutdown button on the switch body and the impossibility of quickly and efficiently performing an emergency manual shutdown, since for this it is necessary to insert the manual shutdown handle into a special hole in the front cover of the switch and fix it on the stop inside the switch, after which it is possible to perform shutdown. The amount of force applied is determined by the length of the outer shut-off handle and the ratio of the lever arms. This design achieves high holding forces for the actuators in the engaged state, but an external lever is required to overcome these holding forces in the event of manual disconnection. Thus, the use of a removable manual shutdown handle results in an increased response time to an emergency and can have catastrophic consequences in the event of an emergency.

A common disadvantage of the known technical solutions is low safety due to the artificially limited (reduced) retention force of the drives and the possibility of spontaneous shutdown in the first two cases, and the complexity and inoperability of performing manual shutdown in the third. All known designs are limited in their application, which is determined by the maximum holding force that they can develop, as well as by the amount of force applied to the manual shutdown mechanisms, which guarantees the safety of personnel and equipment. Another common drawback of all of the above designs is that the tripping effect from the shutdown button through the synchronization shaft is evenly and synchronously distributed to three drives, respectively, each drive accounts for only one third of the applied shutdown force, and the value of the shutdown force applied to the button is normalized in accordance with GOST 12.2 .007.3 and should not exceed 25 kgf. Thus, in all cases, each actuator is actually affected by only one third of the applied action to the manual trip button. This is a limiting factor for the holding force for the drives and, accordingly, for the capabilities of the switches themselves.

The disadvantages of known analogs should also include the fact that without significant alteration of the design of the high-voltage vacuum circuit breaker, it is impossible to significantly (2 or more times) increase the force of holding the circuit breaker drives in the "on" position, since this will entail an increase in the force developed by the manual shutdown mechanism ., which is necessary to create on the basis of this prototype a whole line of vacuum switches designed for high currents of 1250A 1600A, in which it is necessary to use drives with high holding forces.

The problem solved by the claimed technical solution is that in order to increase safety and guaranteed shutdown in manual mode of drives with large holding forces, a significant increase in the efforts developed by the manual shutdown levers is required, which entails a change in the size, weight and proportions of these levers and mechanisms in overall, as well as an increase in strength characteristics and weight. An increase in the mass of moving parts in such a fast-acting mechanism as an electromagnetic drive, operating with high accelerations and shock loads, leads to a decrease in the speeds of the mechanisms and a decrease in the resource of the entire switch as a whole.

In practice, the designs of the prototypes discussed above become difficult to implement with a further increase in the holding forces developed by the drive and, in connection with this, an increase in the length of the shutdown levers by 1.5-2 times, since the internal layout of the switches does not allow this to be done in the same dimensions.

The technical result of the proposed invention is to increase the safety and reliability of the manual shutdown operation in the absence of operational power due to a significant (from 3 to 10 times) decrease in the effort required to open the circuit breaker in manual mode, the implementation of the mechanism for blocking the circuit breaker drive in the "Off" position, and also the possibility of increasing the holding force of the drives and creating in the same dimensions without increasing the weight of the components and the switch itself, a more powerful device designed for significantly higher currents, with increased safety.

The technical result is achieved due to the disconnecting action on the armature of the linkage drive with a variable force and with a large transmission ratio, enhancing the disconnecting effect applied to the emergency (manual shutdown) button. When the shaft is turned to the extreme stable position, the mechanism is locked in the “Disconnected” position, thereby realizing the “Disabled and locked” function.

The design of the proposed technical solution consists of the following main parts: Phase-by-phase drives containing a magnetic circuit and an armature, equipped with releases in the form of vertical rods fixed on an anchor, a synchronizing shaft of the switch, a manual shutdown mechanism, characterized in that it has independent shut-off levers for each drive in the form of a half-ring and not rigidly connected to the manual shutdown and blocking shaft intended for transmission and distribution between the switch mechanisms of the forces and influences aimed at opening the breaker in manual mode and performing the function of blocking the breaker in the "off" position.

The claimed technical solution is illustrated by images: Fig. 1 shows the design of the mechanism for manual disconnection of the drive of the high-voltage vacuum circuit breaker;

in fig. 2 shows a diagram of the operation of the mechanism for manual shutdown of the drive of the high-voltage vacuum circuit breaker in the manual shutdown mode from the emergency shutdown button;

in fig. 3 shows the position of the manual release mechanism in the "Disconnected and locked" mode.

To achieve this technical result, a design of a mechanism for manually disabling the drive of a high-voltage vacuum circuit breaker is proposed, which contains (Fig. 1, 2): a cylindrical magnetic circuit (1), an armature (2) installed in it, with release bolts symmetrically installed on the armature surface (3 ) and (4), at the same time, to the heads of the release bolts (3) and (4), the shutdown levers in the form of a half-ring (5), the manual shutdown and blocking shaft (6), not rigidly connected with the mechanisms and shutdown levers, are freely installed, equipped with eccentrics (7) placed in phases above each actuator. The manual shutdown button (8) is connected to the manual shutdown and blocking shaft (6) by means of the shutdown button bracket (9).

The inventive design works as follows (Fig. 1, 2): when you press the manual shutdown button (8), the force is transmitted through the shutdown button bracket (9) to the manual shutdown and blocking shaft (6), on which the eccentrics (7) are fixed, which, turning, transmit the movement to the shutdown levers (5), on which the release bolts (3) (4) are fixed. The release levers (5), in turn, give movement to the release bolts (3) (4) attached to the armature (2). Release bolts (3) (4), moving by means of shutdown levers (5), detach the armature (2) from the magnetic circuit (1). The drive is disconnected.

The presence of eccentrics (7) allows you to smoothly change during the lifting of the armature (2) the coefficient of force transfer from the manual shutdown button (8) to the shutdown armature (2) through the shutdown lever (5), since at the beginning of the movement of the release bolts (3), (4) the shoulder with which the eccentric (7) acts on the shut-off lever (5) is minimal and, therefore, the ratio of the arms is maximum. As the armature breaks off and an air gap appears, the holding magnetic field drops exponentially and together with it the force required for further separation of the anchor decreases, which also falls exponentially, the eccentric turns and changes the size of the shoulder and the force that is needed at this moment applied to the shutdown lever and release bolts for reliable shutdown and separation of the armature from the magnetic circuit. The drive is disconnected. Depending on the angle of rotation of the eccentric, it is possible to implement two positions and states of the switch: "Off" and "Off and locked". The "Disabled and locked" function is realized with further rotation of the eccentric from the "Disabled" position to its lower position (Fig. 3).

As an additional opportunity, by slightly changing the shape of the eccentrics, the effect of a different effect on the drives can be realized, while the manual shutdown and blocking shaft redistributes the force applied to the manual shutdown button to all the drives in turn. The force is transmitted at each moment of time in the maximum size only to one set of release bolts of one drive of the high-voltage vacuum circuit breaker, which ensures a decrease in the force applied to the manual shutdown mechanisms and an increase in the reliability of the manual shutdown mechanism, while only due to the sequential operation of eccentrics of various shapes , the shutdown force is reduced by half. It becomes possible to increase the efforts of holding the drives while maintaining the ease of disconnection and, accordingly, increasing the consumer properties, reliability and, as a consequence, the safety of equipment and personnel.

Claims (1)

The mechanism for manual shutdown of the drive of a high-voltage vacuum circuit breaker, containing three phase-by-phase drives with a movable element in the form of a cylindrical armature, characterized in that the manual shutdown and blocking shaft contains eccentrics, which, when the manual shutdown button is pressed and the subsequent rotation of the manual shutdown and blocking shaft, are intended to act on trip levers associated with release bolts, which, in turn, are designed to detach the armature from the magnetic circuit and turn off the circuit breaker drive.

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