EP1672659A2 - Disconnecting switch with lineraly moving contact - Google Patents

Abstract

A linear-travel disconnector (1) has two post insulators (3,4) and a contact blade (5) electrically joining the insulators (3,4). The contact blade (5) carries a contact arrangement (53) on one end and its contacts point towards the second post insulator (4) where the contact arrangement (53) contact, in the switched-on state, a fixed-point contact (42) of the second post insulator (4) and is removed from this with the switch-off movement.

Description

The invention relates to a push-disconnect switch with two post insulators and a switched on the support insulators electrically connecting switch blade, which has a contact arrangement for contacting a fixed contact of the first post insulator at its front in the closing movement, and in the region of his turn-in direction rear end on the second post insulator is movably guided in a guide device.

Such thrust disconnectors are often used in the operated in the medium voltage range power grids of railway systems, in which case they are then usually carried out unipolar. In multi-pole design, however, such slide-type disconnectors are increasingly also used in supply networks of the electricity companies.

Such a slide disconnector serves to open or close a circuit, in which case it is only actuated when there are no excessive currents and / or there is no significant voltage change between the terminals of each disconnect switch pole. Typical rated currents of such slide switch are, for example, 630 A or 2500 A, each with a rated voltage of 12-38.5 kV. Such currents can be performed continuously. However, under exceptional conditions, such as a short circuit, such push-pull disconnectors can withstand significantly higher currents of, for example, 20 kA up to 31.5 kA for current designs over a certain period of time.

Conventional constructions such shear switches have a base frame, are arranged on the two support insulators spaced from each other. The connection between the contact portions in the head region of the support insulators is via a switch blade, usually a pair of knives, produced. The switch blade is mounted longitudinally displaceable in a support insulator, so that it is movable to a fixed contact on the other support insulator to or from this.

DE 20 64 037 describes a known construction of a push-break switch with a partially insulated sheathed switching pin, which is slidably mounted in a stationary, isolierstoffgekapselten sliding contact and after passing through an isolating distance in a stationary, surrounded by a Isolierstoffhülle mating contact is retracted. The mating contact piece as well as the sliding contact piece is obviously provided with contact fingers, which bear resiliently on the contact pin and thus at the same time also provide the electrical contact in addition to a guiding function.

Another construction of a push-release switch for switching and distribution systems in medium voltage or high voltage power range is disclosed in DE 32 24 743 C2. Serving as a shear contact switching pin is fully supported here by means of rollers, rollers or the like in a support insulator, which hereby at the same time the electrical contact is made. The contacting takes place here via a number of balls or rollers corresponding plurality of point-shaped contact points between them and the switching pin.

Further thrust-breakers, which have proven very successful in practice and are widely used today, the applicant sells under the switch type designation L31 / 59871 and L31 / 59872. In these push-disconnect switches, a switch blade in the form of a separating knife pair is actuated by a crank drive for closing or opening the switch. The front end of the separating knife pair at the switch-on movement has a contact arrangement which contacts a fixed contact on the first support insulator in the closed state of the push-disconnector. In the area of the rear end of the separating knife pair in the switching-on direction, the second supporting insulator is present, in which the separating knife pair is longitudinally displaceable and, due to the pivoting movement of the crank drive, is also pivotally mounted in a certain frame. For this purpose, a guide device is arranged in the second support insulator, which contains two mutually facing sliding guide elements, which are present at the top or bottom of the separating knife pair. The sliding guide elements are rounded at the contact points, so that they produce a linear contact with the separating knife pairs and so assume the leadership function in cooperation with the crank drive. In this case, however, the sliding guide elements also serve to produce the electrical contact, wherein due to the linear contact higher rated currents than in the above-discussed prior art can be performed with punctiform contact points.

However, these known from practice push-disconnect switches are also limited in terms of leading to short-circuit currents. However, an enlargement of the contact surfaces on the second post insulator is only possible to a limited extent since this would suffer the sliding guide properties. In particular, such a structural change would be associated with an increase in the friction effect. Furthermore, a departure from a linear contact with such types of switches constructive hardly possible because the lever mechanism, the switch blade leads not in a pure linear motion but in a combined linear and tilting movement. In non-linear with the switch blade cooperating guide elements, it would therefore come to a tilting of the arrangement.

Nevertheless, due to changing conditions of use increasingly a push-disconnector is required, which shows a relation to known designs increased short-circuit strength.

The invention is therefore the object of developing a generic slide switch so that higher compared with conventional push-breakers higher short-circuit currents can be performed.

This object is achieved by a push-disconnect switch with the features of claim 1. This is characterized in particular by the fact that the switch blade carries at its rear end in the switch-on a contact arrangement, the contact elements have in the direction of the second support insulator, the contact arrangement contacted in the on state of the rear side in the switch-on direction fixed contact of the second post insulator and is removed at the turn-off of this.

The invention thus provides for the first time a functional separation of the guide function on the second post insulator from the production of the electrical contact. Thus, although the desired and advantageous effect of simplifying the design and particularly compact embodiment is abandoned in the prior art; By contrast, the complete departure from these conventional approaches according to the invention, however, now for the first time achieves a considerably greater constructive freedom with regard to the design of the contact elements. This can be used advantageously to provide larger contact surfaces and thus to provide a higher current carrying capacity of the arrangement as a whole.

In practical experiments, it has been shown that with the arrangement according to the invention can also easily carry rated holding short-time currents of 40 kA, without causing a destruction of the arrangement. This considerably increases the possible field of application of such slide-type disconnectors, which meets customer requirements.

At the same time, a greater constructive freedom in terms of the design of the guide means on the second post insulator is achieved in an advantageous manner, so that can be achieved in this regard, an optimization in particular with regard to a reduction of the frictional resistance and an increase in the life.

Another advantage here is that can also be realized with the inventive push-break switch higher switching speeds, which extend the application possibilities in practice.

Advantageous developments of the slide switch according to the invention are the subject of the dependent claims.

Thus, it is possible according to claims 2 and 3, that the contact arrangement at the front in the switch-on direction of the switch blade and / or the contact arrangement in the switch-on direction rear end of the switch blade contact fingers, which in the course of the switch-on with at least one contact plate of the fixed contact of the first Support insulator and / or engage with at least one contact plate of the fixed contact of the second post insulator. Such contact finger contact plate assignments have proven successful in practice in other circuit breakers many times with great success, especially when it came to reliably transmit even high currents. In the context of the invention can thus be used on proven design means to provide a push-break switch particularly high reliability, robustness and at the same time with a relatively simple structural design.

Further, it is also possible according to claims 4 and 5, that the fixed contact of the first post insulator and / or the fixed contact of the second post insulator comprises contact fingers, which in the course of the closing movement into engagement with at least one contact plate of the contact arrangement at the front in the switch-on direction and / or get to the rear of the switch blade in the switch-on direction. In this embodiment, the contact fingers are fixedly arranged on a support insulator or on both support insulators, so that they are not moved or only at one point with the switch blade. The moving mass can be reduced thereby, which has an advantageous effect on the switching speed as well as the energy consumption.

It is also possible that such contact fingers are present only at one end of the switch blade or a support insulator and at the other contact a conventional Kontaktierweise example, with a linear contact means of rollers, sliders, etc. is applied. Furthermore, contact fingers can also be present once at the stationary contact and at the other contact point on the switchgear.

Another advantage is when the guide device of the switch blade is designed as a roller guide. Then, a particularly low-friction guidance of the switch blade can be achieved, whereby an even higher switching speed while reducing wear and increased service life can be achieved.

Here, the roller guide may have two spaced-apart bearing rollers, which receive the switch blade between them. Then, a reliable guidance of the switch blade is achieved by simple means, wherein further linear guide points are provided so that not only linear movements of the switch blade but also e.g. can be absorbed by a crank drive tilting movements reliably and without increased wear.

Alternatively, it is also possible that the guide means of the switch blade is designed as a sliding guide, whereby the design effort for a provision of the guide means can be kept low and, for example, can be used substantially on known guide elements.

Fig. 1

eine Seitenansicht des erfindungsgemäßen Schubtrennschalters in geöffneter Stellung;

Fig. 2

eine Seitenansicht des erfindungsgemäßen Schubtrennschalters in geschlossener Stellung; und

Fig. 3

eine Draufsicht auf den erfindungsgemäßen Schubtrennschalter in der geschlossenen Stellung.

The invention will be explained in more detail in exemplary embodiments with reference to the figures of the drawing. It shows:

Fig. 1

a side view of the slide switch according to the invention in the open position;

Fig. 2

a side view of the slide switch according to the invention in the closed position; and

Fig. 3

a plan view of the diverter switch according to the invention in the closed position.

As shown in the figures, a push-disconnector 1 has a base frame 2 on which a first support insulator 3 and a second support insulator 4 are mounted. Furthermore, the diverter switch 1 contains a switch blade 5, which can be moved by means of a drive 6 between an open position (FIG. 1) and a closed position (FIGS. 2 and 3). Here, the switching blade 5 is movably mounted by means of a guide device 7 in the second support insulator 4.

The first support insulator 3 and the second support insulator 4 are formed substantially identical. They each have an insulator body 31 or 41 as well as a fixed contact 32 or 42 on the head area remote from the base frame 2. The fixed contacts 32 and 42 respectively contain on the upper side connecting plates 33 and 43, by means of which lateral contact plates 34 and 44 are connected. The two contact plates 34 and 44 of each fixed contact 32 and 42 respectively point to the section chamfers 35 or 45, which are to be pointed out in more detail below, on the switch blade 5 (see FIG facilitate.

The switching blade 5 has a separating knife pair 51, as can be seen in particular from FIG. In this case, a first contact arrangement 52 is arranged at the front end of the switch blade 5 which is in the direction of switch-on movement, that is to say the end pointing to the first support insulator 3. A second contact arrangement 53 is arranged at the rear end in the direction of switch-on movement, that is to say in the region of the second support insulator 4 on the switch blade 5. The first contact arrangement 52 and the second contact arrangement 53 are formed substantially identically and each have a holder 54, which on both sides of the separating knife pair 51st Retraction contacts 55 stops. These each have to the fixed contacts 32 and 42 of the support insulators 3 and 4. At each Einfahrkontakt 55 while two successive assigning rows of contact fingers 56 are arranged such that they, as can be seen from Fig. 3, in the closed state of the slide switch 1 each receive a contact plate 34 and 44 between them. To produce a reliable contact, the contact fingers 56 are in each case resiliently biased in the direction of the contact plate 34 and 44, so that it is clamped between the two rows of contact fingers 56.

As a base material for the current-carrying components such as the terminal plates 33 and 43, the contact plates 34 and 44, the separating blade pair 51 and the contact assemblies 52 and 53, electrolytic copper is used, which is galvanically silvered.

As can be seen in particular from FIGS. 1 and 2, the drive 6 has a drive shaft 61, which in a manner not shown here can be coupled with a drive motor or, in particular for emergency, with a manually operated hand crank. The drive shaft 61 acts in the present embodiment on a four-bar linkage, which has a rocker 62, a coupling 63 and a crank member 64. The crank member 64 is rotatably connected to a switching shaft 65 which is mounted in the base frame 2. One end of an actuator 66 is also also rotatably connected to the switching shaft 65, so that a rotation of the drive shaft 61 can be transferred directly to the actuator 66. The other end of the actuator 66 is pivotally coupled to the switch blade 5 to move it upon actuation of the drive shaft 61 between a closed and an open position of the slide switch 1 back and forth.

To guide this movement of the switch blade 5, the guide device 7 is arranged in the head region of the second support insulator 4 within the contact arrangement 53, which has two bearing rollers 71 and 72. As can be seen from the figures, the two bearing rollers 71 and 72 are mounted in the two contact plates 44 and extend transversely to the longitudinal direction or direction of movement of the switch blade 5. The bearing rollers 71 and 72 are arranged at such a distance from each other that they take each cutting blade of the separating knife pair 51 between them. Each bearing roller 71 or 72 has for this purpose a collar 73, which can be seen in particular in Fig. 3. By means of this, the two separating blades of the separating blade pair 51 on the one hand kept at a distance to each other and on the other hand in the lateral direction in plan view of FIG. 3 out, in order to avoid tilting.

Hereinafter, the operation of the push-break switch 1 will be explained.

To close the push-release switch 1, the drive shaft 61 is driven to move the switch blade 5 by means of the actuator 66 from the open position shown in FIG. 1 in the closed position shown in FIGS. 2 and 3. In the course of this movement, the switching blade 5 is guided by the guide means 7 and the actuator 66 stabilized. In this case, the first contact arrangement 52 engages with the fixed contact 32 on the first support insulator 3, while the second contact arrangement 53 simultaneously comes into engagement with the fixed contact 42 on the second support insulator 4. The resiliently biased contact fingers 56 slide over the chamfers 35 and 45 of the contact plates 34 and 44 away and provide a clamping connection between the Einfahrkontakten 55 and the contact plates 34 and 44 ago. Thus, the main flow path of the slide-break switch 1 is closed.

Here, the drive 6 is designed so that the rocker 62 and the coupling 63 go beyond the dead center of the four-bar linkage and so produce an end position, which prevents inadvertent contact separation. This ensures that the drive mechanism even under exceptional conditions, such. B. a short circuit, no automatic counter-rotating movement and thus interrupts the main flow path. Especially in the event of a short circuit, enormous dynamic forces can occur due to the expanding current loop, which are, however, controlled by the over-center mechanism of the drive 6.

To open the slide switch 1, in turn, the drive shaft 61 is driven, in which case it is caused to rotate in the opposite direction. The actuator 66 then takes the switch blade 5 with so that the electrical connection between the two contact assemblies 52 and 53 and the fixed contacts 32 and 42 is repealed. Fig. 1 shows the push-break switch 1 in the end position with the switch open, in which a required separation distance and thus the dielectric strength of the slide-break switch 1 is ensured.

The function of the slide switch 1 is recognizable independent of the installation position.

In addition to the embodiment shown, the invention allows for further design approaches.

Thus, it is also possible that the contact assemblies 52 and 53 are equipped with other contacts, as the Einfahrkontakte shown in the figures. Examples of this are known to the skilled person to a large extent, such as resiliently biased rollers, balls or the like.

In particular, it is also possible that the Einfahrkontakte are not arranged on the switch blade 5 but on the support insulators 3 and 4 at one or both contact points of the slide switch, in which case corresponding contact plates, etc. are provided on the switch blade 5.

Accordingly, the fixed contacts on the support insulators 3 and 4 of a slide-break switch 1 need not be identical. The contact arrangements 52 and 53 on the switch blade 5 may have different shapes and provide different contacting possibilities.

The bearing rollers 71 and 72 of the guide means 7 may also have a different shape from the embodiment shown. For example it is possible to dispense with the collar 73 and / or provide additional frets laterally from the switch blade 5.

Furthermore, it is also possible that instead of the roller guide shown a sliding guide serves as a guide device for the switch blade 5.

Moreover, it is also possible that the drive 6 is configured in a different shape than a four-bar linkage. In addition, the drive for the movement of the switch blade 5 can be applied to the switch blade 5 elsewhere and by other means.

Claims (8)

Push-disconnect switch (1) with two support insulators (3, 4) and a switched in the support insulators (3, 4) electrically connecting switch blade (5), which at its front in the closing movement of a contact assembly (52) for contacting a fixed contact ( 32) of the first support insulator (3), and is movably guided in the region of its rear end in the switch-on direction on the second support insulator (4) in a guide device (7),
characterized,
in that the switch blade (5) carries, at its rear end in the switch-on direction, a contact arrangement (53) whose contact elements point in the direction of the second support insulator (4), wherein the contact arrangement (53) in the switched-on state establishes a fixed contact from the rear side in the switch-on direction (42) of the second post insulator (4) is contacted and removed during the turn-off movement thereof. A push-pull disconnector according to Claim 1, characterized in that the contact arrangement (53) has contact fingers (56) at the rear end of the indexing blade (5) in the switching-on direction with at least one contact plate (44) of the stationary contact (42) of the second Support insulator (4) engage. Push-disconnect switch according to Claim 1 or 2, characterized in that the contact arrangement (52) has contact fingers (56) at the front end of the switch blade (5) in the switching-on direction , which contact fingers engage with at least one contact plate (34) of the fixed contact (32). of the first post insulator (3). Push-disconnect switch according to Claim 1 or 3, characterized in that the fixed contact of the second post insulator has contact fingers which in the course of the closing movement come into engagement with at least one contact plate of the contact arrangement on the rear end of the indexing blade (5) in the switching-on direction. Push-disconnect switch according to Claim 1, 2 or 4, characterized in that the fixed contact of the first post insulator has contact fingers which come into engagement with at least one contact plate of the contact arrangement at the front end of the indexing knife (5) in the switch-on direction during the switch-on movement. Push-disconnect switch according to one of claims 1 to 5, characterized in that the guide device (7) of the switch blade (5) is designed as a roller guide. A push-pull disconnector according to claim 6, characterized in that the roller guide has two spaced-apart bearing rollers (71, 72) which receive the switch blade (5) between them. Push-disconnect switch according to one of claims 1 to 7, characterized in that the guide device of the switch blade is designed as a sliding guide.

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