EP1369884A1 - Disconnector for the galvanic isolation of conductor rails with contact cleaning - Google Patents

Abstract

Each contact carrier (1.1, 1.2) includes two contact fingers (2.1, 2.2). Each is carried in bearings. Each can be moved against the action of a contact pressure spring (3.1, 3.2), perpendicular to the plane of the bus bars (S), in the Z- direction. A push lever (4.1, 4.2) causes the movement, and is pivoted on the contact carrier at one end, and at the other on the contact finger. A constant acute angle is included by contact finger and push lever, during movement towards the bus bar ends (S) in the X-direction. The mechanism ensures axial motion of the contact finger in the X-direction, on relative motion between contact finger and contact finger in the Z-direction.

Description

The invention relates to a circuit breaker for the electrical isolation of Busbars used in switchgear and one Cleaning the contact surfaces between the contact fingers and the to connecting busbars takes place with every switch-on.

Disconnectors are mainly used in switchgear for the safe disconnection and / or connection of electrical system parts, when defining or changing certain system configurations. The disconnector also serves to ensure the required work safety by creating a visible disconnection point of the system parts to be processed.
The operating intervals of the isolating switches are usually so long that between the switch-on processes it must always be assumed that there is environmental contamination of the contacts due to deposits or corrosion, which causes increased contact resistance.

So always to establish a connection between two busbar ends A good galvanic contact is made possible in DE 198 50 199 A1 a disconnector version for contacting two busbar ends described over a number of contact fingers pressed on both sides. There can be a vertical offset as well as an angular offset of the two Busbar ends through the individual contact fingers of the disconnector are bridged and when used as a run-in contact are none Guide structures required. Because the current from the first Busbar end to the second busbar end via the parallel led contact finger flows, is advantageously due to the current attraction forces the contact pressure of the contact fingers on the Track ends increased. By dividing the switch contact into there are many individually stored contact fingers Contact transitions that each carry only part of the total current have to.

The disadvantage of this design is that the only means of Torsion spring in its position fixed contact fingers in the event of a fault, z. B. at Break of the spring from which the contact carrier can fall and the Disconnector is no longer operational.

The task is to specify a disconnector at which individual Contact fingers for establishing the galvanic connection between the Busbars are used that are secured against falling out and cleaning each time the disconnector is closed or opened Contact points takes place.

This task is performed by a generic disconnector with the Features of claim 1 solved by the disconnector for Connection or disconnection of busbars via two contact carriers has, which are moved in opposite directions via a common drive with at least two individual contact fingers in each contact carrier are arranged. Since the two contact carriers are constructed analogously and in two different levels are arranged to the busbar ends, is in the further description only the structure and mode of operation of one Contact carrier shown. Each contact finger is in the contact carrier in this way stored that he on the one hand against the pressure of a contact pressure spring perpendicular to the plane of the busbars, is movable in the z direction and on the other hand, by means of a push lever in the direction of the two Busbar ends, the x direction, is movable. The thrust lever is with one end rotatable with the contact carrier and with the other End rotatably connected to the contact finger, being between Contact fingers and thrust levers are always included at an acute angle. As a result, each time the contact finger moves relative to the Contact carrier in the z direction an axial displacement of the contact finger in the x direction causes. This axial movement of the contact fingers, which under the Contact spring pressure against the busbar ends takes place, causes the corresponding contact surfaces to be cleaned each time the disconnector is closed or opened.

Because each contact finger on the one hand by means of a push lever and on the other hand is connected to the contact carrier via the contact pressure spring it does not accidentally fall out of the contact carrier.

The two contact carriers are on two angled connecting rods on two outside arranged pivot points of an eccentrically trained Driving plate fastened in a rotatable manner. This will make the two Contact carrier counter-rotating with every rotation of the drive plate emotional. Either in the direction of the two busbar ends (ON position) or away from the two busbar ends (OFF position).

The contact carrier is advantageously produced from a hollow profile with a rectangular cross section, which has laterally arranged window-shaped openings through which the contact fingers protrude sideways to such an extent that they can bridge the two busbar ends. Due to the spring forces of the contact pressure springs acting on the contact fingers, the contact fingers are pressed with the required contact force against the contact surfaces of the conductor rail ends in the closed state of the disconnector or pressed against the edges of the openings of the contact carrier in the open state. In the immediate vicinity of the two edges of the contact carrier facing away from the busbar ends, two bearing axes are arranged, each of which forms the pivot point of the push lever connected to the contact carrier and at the same time represent the bearing for each contact pressure spring, which are preferably designed as torsion springs. The other side of each thrust lever is not directly connected to a contact finger via a thrust piece. A pin is arranged on each thrust piece, which on the one hand represents the stop for the contact pressure spring and on the other hand forms the rotatable bearing of the contact finger for the thrust lever. The thrust piece is inserted in a form-fitting manner in a dovetail-shaped recess which is provided in the area of the contact finger which is opposite the contact area. As a result, the contact finger is connected directly to the contact carrier, but can be moved in two directions.
The contact pressure spring is mounted on the bearing axis in such a way that its one end rests on the inner surface of a wall of the contact carrier and the other end rests on the pin of the thrust piece under a corresponding pretension, so that the required contact force acts on the contact fingers when switched on ,

So that the contact carriers do not shift in the opposite direction due to the axial forces in the direction of the contact fingers during the switching operations, the contact fingers are inserted in the opposite direction in the contact carrier. As a result, the adjacent contact fingers move in the opposite direction and the axial forces cancel each other out.
The dovetail-shaped recess in the surface of the contact finger is arranged offset in the longitudinal direction from the center. This offset and the opposite installation position of the contact fingers ensures that there can be no unintentional lateral displacement of the thrust pieces into the dovetail-shaped recess of the adjacent contact finger. As a result of the offset of the dovetail-shaped recesses and the opposite installation position of the adjacent contact fingers in the contact carrier, the contact fingers protrude equally far from the contact carrier in the open position of the isolating switch; due to the axial displacement during the switching movement, the adjacent contact fingers protrude when the isolating switch is switched on both sides of the contact carrier at different distances.

Fig. 1

Schnittdarstellung im geöffneten Zustand

Fig. 2

Schnittdarstellung im geschlossenen Zustand

Fig. 3

Schnittdarstellung in der Draufsicht (Ausschnitt)

The disconnector is explained in more detail below using an exemplary embodiment. The associated drawings show:

Fig. 1

Sectional view in the open state

Fig. 2

Sectional view in the closed state

Fig. 3

Sectional view in plan view (detail)

1 shows a sectional view through the isolating switch in the open state. The two contact carriers 1.1 , 1.2 are constructed analogously and are arranged in mirror image such that they point with the inserted contact fingers 2.1 , 2.2 in the direction of the busbar ends S to be connected.
The two contact carriers 1.1, 1.2 are guided in their direction of movement (z direction) via a rail, not shown. The switching movement is realized by means of an eccentric drive plate 9 and two angled and mirror-symmetrically arranged connecting rods 10.1 , 10.2, which are rotatably mounted on the one hand on each driver 9.1 , 9.2 and on the other hand are connected to a contact carrier 1.1 , 1.2 via a fork head, also not shown. By rotating the drive plate 9 , the two connecting rods 10.1 , 10.2 are shifted in their position such that an axis-parallel displacement of the two contact carriers 1.1 , 1.2 in their direction of movement in the z direction is either moved towards or away from the busbar ends S, whereby the disconnector is closed or opened. Due to the bending of the two connecting rods 10.1, 10.2 and the vertical position of the eccentric drive plate 9 , a certain locking is achieved in the two rest positions, ON position and OFF position, of the disconnector.

In the further description, only the structure of a contact carrier is explained in more detail.
The contact carrier 1.1 is made of a hollow profile with a rectangular cross section and serves to accommodate the contact fingers 2.1, 2.2 and their actuating elements. The contact carrier 1.1 has in its two longitudinal sides in the area which faces the busbar ends, a window-shaped opening 11 through which the contact fingers 2.1 , 2.2 protrude on both sides so far that the distance between the busbar ends S is bridged and a sufficient contact area between the contact fingers 2.1 , 2.2 and the busbar ends S is available. In the surfaces of the contact fingers 2.1, 2.2 opposite the contact surfaces, a dovetail-shaped recess 6 is made perpendicular to the longitudinal direction, into which a thrust piece 5 is inserted in a form-fitting manner. This thrust piece has a pin 7 , which on the one hand represents a rotatable bearing for the contact finger-side attachment of the thrust lever 4.1 , 4.2 and at the same time is the contact finger-side support of the contact pressure spring 3.1 , 3.2 . In the vicinity of the two angles of the contact carrier 1.1 , which face away from the busbar ends S , two bearing axes 8.1 and 8.2 are arranged in the longitudinal direction of the contact carrier 1.1 . In each case one bearing axis 8.1 or 8.2 represents on the one hand the rotatable contact carrier-side bearing of the push lever 4.1 or 4.2 and is at the same time the bearing of the contact pressure spring 3.1 or 3.2 designed as a torsion spring . One end of the contact pressure spring 3.1 , 3.2 rests on the inner surface of the side of the contact carrier 1.1 facing away from the busbar ends S. About the pivot point, which is formed by the bearing axis 8.1 or 8.2 , the other end of the contact pressure spring 3.1 , 3.2 is under a corresponding preload on the pin 7 of the thrust piece 5.1 or 5.2 . Thus, in the opened state of the disconnector, sufficient pressure is exerted on the contact fingers 2.1, 2.2 that they are pressed against the edge of the window-shaped opening 11 , thereby ensuring a defined position of the contact fingers 2.1, 2.2 in the contact carrier 1.1 . When the isolating switch is closed, the contact pressure spring 3.1, 3.2 exerts such contact pressure on the contact fingers 2.1, 2.2 that a sufficiently low contact resistance can be ensured. Because each contact finger 2.1, 2.2 is connected via a thrust piece 5, a push lever 4.1, 4.2 to the bearing axis 8.1 or 8.2 of the contact carrier 1.1 , the contact fingers 2.1 , 2.2 are movable in the vertical and horizontal directions relative to the contact carrier 1.1 but also firmly connected to it, so that an unintentional displacement of a contact finger 2.1 , 2.2 or even falling out of the contact carrier 1.1 is prevented. This ensures a high level of mechanical reliability of the disconnector.

The dovetail-shaped recess 6, which is in each case provided in the surface of the contact finger 2.1 , 2.2 opposite the contact surface to the busbar ends S , is arranged offset in the longitudinal direction (x direction) of the contact finger 2.1 , 2.2 from the center.

Adjacent contact fingers 2.1 and 2.2 and their actuating elements are alternately inserted in the contact carrier 1.1 on the opposite side. This means that the first contact finger 2.1 with the thrust piece 5.1 is inserted into the contact carrier 1.1 such that the associated thrust lever 4.1 and the associated contact pressure spring 3.1 are mounted on the contact carrier side on the one bearing axis 8.1 and the associated thrust lever 4.2 and the associated contact pressure spring 3.2 of the adjacent one Contact fingers 2.2 are mounted on the other bearing axis 8.2 .
As a result of this alternately reversed installation position of the contact fingers 2.1 , 2.2 in the contact carrier 1.1 and the previously described offset of the dovetail-shaped recesses 6 , the dovetail-shaped recesses 6 of adjacent contact fingers 2.1 and 2.2 are never directly next to one another. The dovetail-shaped recesses 6 of the adjacent contact fingers 2.1 and 2.2 are in the OFF position in the longitudinal direction of the contact fingers 2.1 , 2.2 in different positions. Due to the axial displacement during the closing movement, the distance between the dovetail-shaped recesses 6 of the adjacent contact fingers 2.1 and 2.2 increases further. As a result, it cannot happen that a thrust piece 5.1 unintentionally slips laterally in such a way that it can engage in the dovetail-shaped recess 6 of the adjacent contact finger 2.2 or the thrust piece 5.2 in the dovetail-shaped recess 6 of the adjacent contact finger 2.1 .

The horizontal distance between the two bearing axes 8.1 and 8.2 and the vertical distance between the two bearing axes 8.1 and 8.2 and the respective contact finger 2.1 , 2.2 is selected such that there is always an acute angle between the respective contact finger 2.1 , 2.2 and the associated push lever 4.1 , 4.2 exists.

The size of the offset of the dovetail-shaped recess 6 in the contact fingers 2.1 , 2.2 from the center and the reverse installation position of the contact fingers 2.1 , 2.2 are selected so that in the open position (OFF position) of the disconnector all contact fingers 2.1 , 2.2 on each side of the contact carrier 1.1 protrude equally far.

When the switching movement from the OFF position to close the disconnector is initiated by the rotary movement of the driving plate 9 , the two contact carriers 1.1, 1.2 are moved in their direction of movement via the connecting rods 10.1 , 10.2, which are attached to the driving elements 9.1 , 9.2 (e.g. Direction) towards each other. As long as the contact fingers 2.1 , 2.2 are not yet touching the busbar ends S , the contact fingers 2.1 , 2.2 lie unchanged on the edges of the window-shaped opening 11 of the respective contact carrier 1.1, 1.2 . As soon as the contact fingers 2.1 , 2.2, due to the movement of the contact carriers 1.1 , 1.2, touch the busbar ends S , the contact fingers 2.1 , 2.2 cannot move any further in the z direction. Since the movement of the contact carriers 1.1 , 1.2 continues in the z direction, the contact fingers 2.1 , 2.2 are moved relative to the contact carrier 1.1 against the force of the contact pressure springs 3.1 , 3.2 . Since each contact finger 2.1 , 2.2 is connected via a thrust piece 5.1 , 5.2 and the associated pin 7 to one end of the thrust lever 4.1 , 4.2 and the thrust lever 4.1 , 4.2 is fastened with its other end to the bearing axis 8.1 or 8.2 , one means relative movement of the contact fingers 2.1 , 2.2 in the z direction to the contact carrier 1.1 , that the push lever 4.1, 4.2 is rotated in the direction of the surface of the contact carrier 1.1 that faces away from the busbar ends S. However, this rotary movement of the push lever 4.1 , 4.2 means that the horizontal distance (x direction) between the push piece 5.1 , 5.2 and the respective bearing axis 8.1 or 8.2 is increased, ie the contact finger 2.1 , 2.2 changes its position in the horizontal direction (x -Direction). Since this horizontal movement of the contact fingers 2.1 , 2.2 takes place on the surface of the busbar ends S in the direction of the busbar ends S against the pressure of the contact pressure spring 3.1 , 3.2 , there is a sliding relative movement between the contact fingers 2.1 , 2.2 and the busbar ends S, which results in a superficial cleaning of the contact points is effected. This relative movement of the contact fingers 2.1 , 2.2, in the x direction and in the y direction with respect to the contact carrier 1.1 and in the x direction with respect to the busbar ends S , is continued until the two contact carriers 1.1 , 1.2 reach their rest position in the ON position to have.

This position is shown in FIG. 2. The two contact carriers 1.1 , 1.2 have reached their minimum distance from one another, the drive plate 9 has been rotated by 180 °, the two drivers 9.1 and 9.2 have exchanged their positions and the connecting rods 10.1 , 10.2 have reached their other end position. The contact carrier 1.1 , 1.2 of the disconnector are locked in this position against an unintentional change in position.

As a result of the opposing displacement of the contact fingers 2.1 , 2.2 in the x-direction, they now protrude differently from the contact carrier 1.1 , 1.2 on each side and the adjacent contact fingers 2.1 , 2.2 project on each side of the contact carrier 1.1 , 1.2 different out. This opposite displacement of the adjacent contact fingers 2.1 , 2.2 ensures that the axial forces that occur due to the sliding relative movement between the contact fingers 2.1 , 2.2 and the busbar ends S cancel each other out, so that no resulting transverse force in the x-direction is eliminated the contact carrier 1.1, 1.2 can result.

In this illustration it can be clearly seen that the angle between the contact fingers 2.1 , 2.2 and the respective thrust levers 4.1 , 4.2 has decreased significantly, ie the horizontal distance in the x direction between the bearing axis 8.1 , 8.2 and the pin 7 of the thrust piece 5.1 , 5.2 has increased compared to FIG. 1 in the OFF position.

Should a contact pressure spring 3.1 , 3.2 actually break in this embodiment of the isolating switch, the contact finger 2.1 , 2.2 nevertheless remains firmly connected to the contact carrier 1.1 , 1.2 and would always rest on the lower edge of the window-shaped opening 11 due to gravity. Depending on the contact carrier 1.1 , 1.2 in which the relevant contact finger 2 is located, it rests on the edge of the window-shaped opening 11 which faces or faces away from the busbar ends S.

FIG. 3 shows a sectional view of the contact carrier 1.1 in a top view. The isolating switch is in the ON position, the contact fingers 2.1 , 2.2 rest on the busbar ends S. In this illustration, the arrangement and the position of the adjacent contact fingers 2.1 , 2.2 can be clearly seen. The thrust lever 4.1 and the contact pressure spring 3.1 of the contact finger 2.1 are mounted on the bearing axis 8.1 . The push lever 4.2 and the contact pressure spring 3.2 of the contact finger 2.2 are mounted on the bearing axis 8.2 . The contact finger 2.1 was displaced axially in the direction of one busbar end to the left as a result of the horizontal movement in the contact carrier 1.1 during the closing movement of the disconnector, while the contact finger 2.2 was shifted to the right in the direction of the other busbar end. The contact fingers 2.1 and 2.2 are flush next to each other in the contact carrier 1.1 .

Claims (8)

Disconnector for electrical isolation of busbars in which two contact carriers are moved in opposite directions via a common drive and individual contact fingers are arranged in each contact carrier,
characterized in that
at least two contact fingers (2.1, 2.2) are arranged in each contact carrier (1.1, 1.2) and each contact finger (2.1, 2.2) is mounted in such a way that, on the one hand, it rests against the pressure of a contact pressure spring (3.1, 3.2) perpendicular to the plane of the busbars (p ), can be moved in the z-direction and, on the other hand, by means of a push lever (4.1, 4.2), which is rotatably connected at one end to the contact carrier (1.1, 1.2) and at the other end rotatably connected to the contact finger (2.1, 2.2), whereby an acute angle is always included between the contact finger (2.1, 2.2) and thrust lever (4.1, 4.2), in the direction of the two busbar ends (S), in the x direction, which means that each time the contact finger (2.1, 2.2) moves relative to the Contact carrier (1.1, 1.2) in the z direction an axial displacement of the contact finger (2.1, 2.2) in the x direction is effected. Disconnector for electrical isolation of busbars according to claim 1,
characterized in that
the contact carrier (1.1, 1.2) is formed from a hollow profile with a rectangular cross-section, which has window-shaped openings (11) arranged on the side, the contact fingers (2.1, 2.2) protruding laterally through them and on the basis of the spring force of the contact pressure spring (3.1, 3.2) either pressed onto the contact surfaces of the busbar ends (S) or onto the edges of the openings (11) of the contact carrier (1.1, 1.2) facing the busbar ends (S). Isolating switch for electrical isolation of busbars according to claims 1 and 2,
characterized in that
a thrust piece (5.1, 5.2) on which a pin (7) is arranged, which on the one hand represents a stop for the contact pressure spring (3.1, 3.2) and on the other hand the rotating bearing of the contact finger (2.1, 2.2) for the thrust lever (4.1, 4.2 ), is positively inserted into a dovetail-shaped recess (6), which is provided in the surface of the contact finger (2.1, 2.2) opposite the contact surface, so that the contact finger (2.1, 2.2), movable in two directions, directly with the contact carrier (1.1, 1.2) is connected. Isolating switch for electrical isolation of busbars according to claims 1 to 3,
characterized in that
the contact carrier (1.1, 1.2) in the vicinity of the two edges facing away from the busbar ends (S) each has an internal bearing axis (8.1, 8.2), which each has the pivot point of the push lever (4.1, 4.2) on the contact carrier side and at the same time the bearing for the contact pressure spring ( 3.1, 3.2), which is preferably designed as a torsion spring. Disconnector for electrical isolation of busbars according to claims 1 to 4,
characterized in that
one end of the contact pressure spring (3.1, 3.2) rests on an inner surface of the contact carrier (1.1, 1.2) while the other end rests on the pin (7) of the thrust piece (5.1, 5.2) under a corresponding preload. Disconnector for electrical isolation of busbars according to claims 1 to 4,
characterized in that
the dovetail-shaped recess (6) of the contact finger (2.1, 2.2) is arranged offset from the center in the longitudinal direction of the contact finger (2.1, 2.2). Isolating switch for electrical isolation of busbars according to claims 1 to 6,
characterized in that
the contact fingers (2.1, 2.2) including the corresponding thrust levers (4.1, 4.2) and the contact pressure springs (3.1, 3.2) are inserted alternately on the side in the contact carrier (1.1, 1.2), which are alternately supported either on the bearing axis 8.1 or the bearing axis 8.2 , whereby the adjacent contact fingers (2.1, 2.2) are axially displaced in opposite directions with each switching movement. Disconnector for electrical isolation of busbars according to claim 1,
characterized in that
the two contact carriers (1.1, 1.2) are moved in opposite directions by means of an eccentrically designed driving plate (9) and two angular connecting rods (10.1, 10.2) which are attached to this diagonally rotatably.

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