Control unit for an earthing switch drive of an air-insulated switchgear

Abstract

An operating unit (1) for an earthing switch drive (17) of an air-insulated switchgear, the operating unit (1) comprising at least a shaft (3.1, 3.2) rotatably mounted in a bearing (2), which has at a first end a socket (4) for a hand-operated crank and at a second end an eccentric (5) for transmitting a rotary movement of the shaft (3.1, 3.2) to the earthing switch drive (17), wherein the shaft (3.1, 3.2) also has at least one pin (6) extending radially away from the shaft (3.1, 3.2), and the operating unit (1) has a first stop (8) and a second stop (9) for the at least one pin (6), wherein the first stop (8) and the second stop (9) are arranged relative to the shaft (3.1, 3.2) such that the shaft (3.1, 3.2)2) between a first shaft position in which the at least one pin (6) abuts the first stop (8) and a second shaft position in which the at least one pin (6) abuts the second stop (9), and wherein the at least one of the first and second stops (8, 9) is designed as a slot which is arranged relative to the shaft (3.1, 3.2) such that the at least one pin (6) is freely movable in the slot in an intermediate shaft position between the first shaft position and the second shaft position and abuts at one end of the slot in the first or second shaft position, characterized in that the slot is arranged in a flat section of a sheet (7).

Description

Technical area

[0001] The invention relates to an operating unit for an earthing switch drive of an air-insulated switchgear and an air-insulated switchgear with such an operating unit. Technical background

[0002] Air- and gas-insulated switchgear is used for the distribution and switching of voltages. Voltages typically used here are in the so-called medium-voltage range, which ranges from 1 kV to 52 kV. Air-insulated switchgear refers to systems in which the essential components are surrounded by ordinary air, thus eliminating the need for gas sealing. Only the actual switching operation itself is carried out in vacuum tubes to suppress the formation of arcs during a switching operation as much as possible.

[0003] If a section of a medium-voltage network is taken out of service, for example for maintenance work, the vacuum tubes are usually first switched to an open switch position. To prevent electricity from jumping across the relatively short isolating distance between the vacuum tubes, a disconnector electrically connected in series with the vacuum tubes is then opened, providing a relatively large isolating distance. As a third and final step, the disconnected line section is earthed by closing an earthing switch. This prevents the buildup of dangerous voltage due to space charges created during operation, allowing safe work to be carried out on the disconnected line section. The line section can be a busbar of the air-insulated switchgear or an underground cable connected to the air-insulated switchgear.

[0004] When the severed line section is put back into operation, the three steps mentioned above are performed in reverse order. This means that first, the earthing switch is opened, then the disconnector is closed, and finally, the vacuum tubes are moved to a closed switch position.

[0005] Earthing switches are typically designed for both manual and motorized operation. In manual operation, the earthing switch can be manually switched between the closed and open positions; in motorized operation, this can be done by an auxiliary motor, particularly automatically and / or remotely. Both operating modes are usually provided, with a protective circuit preventing motorized operation if a control unit of the earthing switch drive is made accessible for manual operation.

[0006] Since work on a line section may only be carried out when the earthing switch is closed, it is desirable to indicate the switching state of the earthing switch to the maintenance personnel.

[0007] German patent application DE 41 11 942 A1 discloses an operating unit for an earthing switch drive of an air-insulated switchgear assembly with a status indicator. The device is designed to close or open actuating openings, indicate clear switch positions, and lock cable connection compartments depending on the switching action. European patent application EP 2 787 519 A1 discloses a drive mechanism with a shaft whose rotational freedom is determined by a pin extending radially from a shaft and notches in a ring arranged around the shaft.

[0008] The object of the invention is to provide an operating unit for an earthing switch drive that allows manual operation of the earthing switch and is space-saving and inexpensive to manufacture. Furthermore, the object of the invention is to provide an improved air-insulated switchgear that offers a high level of operational safety. Summary of the invention

[0009] These objects are achieved by an operating unit for an earthing switch drive according to claim 1 and by an air-insulated switchgear according to claim 8. Preferred embodiments of the invention are the subject of the subclaims.

[0010] The operating unit for an earthing switch drive of an air-insulated switchgear according to the invention has at least one shaft rotatably mounted in a bearing, which shaft has a socket for a manually operable crank at a first end and an eccentric for transmitting a rotary movement of the shaft to the earthing switch drive at a second end. The shaft also has at least one pin extending radially away from the shaft. In addition, the operating unit has a first stop and a second stop for the at least one pin. The first stop and the second stop are arranged relative to the shaft such that the shaft is rotatable between a first shaft position in which the at least one pin strikes the first stop, and a second shaft position in which the at least one pin strikes the second stop.

[0011] The at least one pin and the two stops allow for easy definition of the respective end positions of the shaft (the first and second shaft positions), so that the shaft or the manually operable crank connected to the shaft can only be rotated between the end positions. Each end position corresponds to a switch position of the earthing switch. Because the end positions are defined by the at least one pin arranged on the shaft of the control unit, a particularly compact installation space for the control unit can be achieved.

[0012] At least one of the first and second stops is designed as a slot that is arranged relative to the shaft such that the at least one pin is freely movable in the slot in an intermediate shaft position between the first shaft position and the second shaft position and abuts against one end of the slot in the first or second shaft position. Both stops can be designed as respective slots, but it is also possible to design the stops as opposite ends of a single slot. When using exactly one pin, the slots or the opposite ends of the single slot can be arranged on opposite sides of the shaft.

[0013] According to the invention, the slot or slots are arranged in a flat section of a sheet metal. When the shaft is rotated, the at least one pin enters the slot and, upon further rotation, protrudes so far into the slot that it finally stops at its end. Such a sheet metal can be manufactured cost-effectively, for example by stamping, and requires very little space. For example, the sheet metal can be part of a housing of the control unit or a side wall of a compartment of the air-insulated switchgear.

[0014] Preferably, the at least one pin comprises a first pin and a second pin, which extend radially away from the shaft and are arranged offset from one another along a longitudinal direction of the shaft. The use of two pins allows greater freedom in the arrangement of the two stops and thus in the definition of the two end positions of the shaft. The stops can be arranged in particular such that in the first shaft position, the second pin is free, i.e., does not strike any stop, and in the second shaft position, the first pin is free.

[0015] Embodiments with two pins offset in this way are particularly advantageous in combination with the use of slots for the pin stops, because this allows the slots to be offset from one another, allowing greater freedom in defining the shaft positions at which one of the pins engages the respective associated slot. Furthermore, it is possible to arrange the stops on the same side of the shaft, which can further save space. For example, as explained above, a flat section of sheet metal with respective slots for the two stops can be used.

[0016] The angle of rotation between the first shaft position and the second shaft position can be at least approximately 180 degrees. The eccentric mounted on the shaft can thus achieve the maximum possible stroke to switch the earthing switch between its closed and open states.

[0017] The operating unit preferably has a carrier for at least one status indicator, wherein the carrier is arranged relative to the shaft such that the carrier is held in a first indicator position by the at least one pin in the first shaft position and that the carrier is held in a second indicator position by the at least one pin in the second shaft position. This means that in such embodiments of the invention, the pin or pins of the shaft serve not only to define the end positions of the shaft but also to move a mechanical status indicator. Such a status indicator is advantageous over other forms of display such as light or sound because it functions reliably even if an auxiliary voltage supply for operating such a non-mechanical status indicator fails.Embodiments of the operating unit according to the invention with such a carrier for the status indicator also have the advantage that the functionality of the status display can be realized with a small construction volume.

[0018] The carrier is preferably spring-mounted. The carrier can be spring-mounted in such a way that it is arranged in an intermediate indicator position located between the first indicator position and the second indicator position without the action of force from the at least one pin. For example, the carrier can be held by two spring elements such as coil springs, which have spring forces with opposing force components. The intermediate indicator position is particularly advantageous when two pins are used because the intermediate indicator position can be selected such that, depending on the direction of rotation of the shaft, one of the two pins can engage the carrier in order to move the carrier from the intermediate indicator position.

[0019] The operating unit can be equipped with a panel having a window. The window is arranged relative to the carrier such that, in the first indicator position, the at least one status indicator is visible through the window, and in the second indicator position, the at least one status indicator is not visible through the window. If the carrier has two status indicators, a respective status indicator of the two status indicators can be visible through the window in a respective assigned indicator position of the two indicator positions. For example, the carrier can be displaced laterally behind the window between the two indicator positions.

[0020] In a combination of the embodiments with a carrier spring-mounted in the intermediate indicator position or with a window, the window is preferably arranged relative to the carrier in such a way that the status indicator or the status indicators are not or not completely perceptible through the window in the intermediate indicator position.

[0021] In all embodiments with a carrier for a status indicator, the carrier is preferably made from a sheet metal having one or more flat sections. Operating units according to the invention are particularly preferred in which both the stops and the carrier are made from such sheets, wherein the respective flat section is arranged parallel to one another with the stops designed as slots or of the carrier. For example, the carrier can have one or more slots into which the at least one pin can engage in order to move the carrier between the indicator positions. If the carrier and stops are arranged parallel, the slots of the carrier can fully or partially overlap with the stops designed as slots.

[0022] A second aspect of the invention introduces an air-insulated switchgear assembly comprising an earthing switch, an earthing switch drive for driving the earthing switch, and an operating unit for the earthing switch drive. According to the invention, the operating unit is designed according to the first aspect of the invention. Short description of the characters

[0023] The invention is explained in more detail below with reference to exemplary embodiments. They show: Fig. 1 a first side view of an embodiment of an operating unit according to the invention in an open switch position of the earthing switch; Fig. 2 a second side view of the embodiment of Fig. 1 in a closed switch position of the earthing switch; Fig. 3 a detailed view of the embodiment of the Fig. 1 and Fig. 2 in a position between the open and closed switch positions of the earthing switch; and Fig. 4 one opposite the Fig. 1 to 3 rear side view of the embodiment. Detailed character description

[0024] Fig. 1 shows a first side view of an embodiment of an operating unit 1 according to the invention in an open switch position of the earthing switch. The operating unit 1 has a shaft, which in the present case is advantageous but not necessarily within the scope of the invention, composed of two parts: a first shaft section 3.1 and a second shaft section 3.2. The first shaft section 3.1 is provided with an eccentric 5, which serves to transmit the rotary movement of the shaft to an earthing switch drive 17. The second shaft section 3.2 has a plug socket 4 at its free end (see Fig. 2 and Fig. 3), which can accommodate a hand-operated crank for rotating the shaft. The two-part design of the shaft is advantageous because the socket 4 can be manufactured more easily and cost-effectively as a separate part, which is then connected to the other shaft section.

[0025] The socket 4 is in Fig. 1, since a plug-in eyelet 13 provided for inserting the crank is closed by a vertically displaceable closure 14. In the exemplary embodiment shown, the closure 14 is pulled, merely by way of example, by a return spring 20 into a position closing the plug-in eyelet 13 and can be moved by maintenance personnel against the spring force of the return spring 20 by means of a sliding handle or the like in order to open the plug-in eyelet 13.

[0026] The lock 14 serves to protect maintenance personnel. If the lock 14 is moved to insert a crank into the insertion eye 13, the lock 14 triggers a detector (not shown) that prevents motor operation of the earthing switch. Otherwise, motor operation could occur with the crank inserted, causing the crank to move with great force, which could result in injury to the maintenance personnel.

[0027] According to the invention, the shaft 3.1, 3.2 has at least one pin 6. In the embodiment shown in the figures, the shaft 3.1, 3.2 has two such pins, which extend radially away from the shaft, of which in Fig. 1, however, only one pin is visible, since the other is located on the side of the shaft 3.1, 3.2 facing away from the viewer.

[0028] A plate 7 is permanently mounted in the control unit 1 and has stops 8 and 9 for the pins 6, which are designed as slots. Each of the pins 6 is assigned a respective stop 8 or 9. As the shaft 3.1, 3.2 rotates, a pin 6 enters the associated slot until, upon further rotation, it strikes one end of the slot, thus preventing the shaft 3.1, 3.2 from moving any further in this direction of rotation. Upon rotation in the opposite direction of rotation, the pin pivots out of its slot, and the other pin enters its associated slot until, in turn, it strikes the end of the slot. In this way, the rotation of the shaft 3.1, 3.2 is restricted according to the invention in a simple and space-saving design using inexpensive components between two shaft positions that correspond to the respective switch states of the earthing switch.

[0029] The preferred embodiment of the invention shown in the figures also has a support 10, which can be made of sheet metal. The support 10 is provided with at least one status indicator 16. In the embodiment shown, a status indicator 16 is provided for the closed and the open switch state of the earthing switch, wherein in Fig. 1 the status indicator 16 for the open switch status can be seen through a window 15 of a panel 19, which also includes the insertion eye 13.

[0030] In the illustrated embodiment, the carrier 10 for the at least one status indicator 16 is arranged between the shaft 3.1, 3.2 and the metal plate 7 with the stops 8, 9 and, for this reason, has passages 11 and 12 through which the pins 6 can engage the stops, designed as slots, of the metal plate 7. If the shaft 3.1, 3.2 is rotated to move the earthing switch from one switch state to the other, the respective pin 6 passes through the respective passage in the manner already described. However, the pin 6 also moves the carrier 10 as soon as it reaches its end and the pin 6 thus comes into contact with the carrier 10. The carrier 10 is thereby displaced in a vertical direction corresponding to the respective direction of rotation of the shaft 3.1, 3.2, whereby the at least one status indicator 16 arranged on the carrier 10 is correspondingly displaced relative to the window 15. Depending on the shaft position of the shaft 3.1, 3.2, the at least one status indicator 16, or a respective one of the two status indicators present in the exemplary embodiment, is positioned relative to the window 15 in such a way that it is visible from the outside. The resulting display of the earthing switch status functions reliably even in the event of malfunctions such as the failure of auxiliary power supplies, etc., thus protecting maintenance personnel who are required to work on the switchgear.

[0031] Fig. 2 shows a second side view of the embodiment of Fig. 1 in a closed switch position of the earthing switch. In comparison with the Fig. 1 shows that the closure 14 is displaced vertically downwards against the spring force of the return spring 20, so that the insertion eye 13 is opened and the socket 4 is visible. It can also be seen that the rear pin 6, seen from the perspective of the maintenance personnel, is now visible, meaning that the front pin is now on the opposite side of the shaft 3.1, 3.2. According to the changed shaft position, the eccentric 5 is also displaced relative to the Fig. 1 is rotated and the earthing switch drive 17 is opposite the Fig. 1 is shifted vertically. The carrier 10 is shifted downward due to the action of pin 6, which is now located behind the shaft. Accordingly, the other status indicator 16, corresponding to the changed switching status of the earthing switch, becomes visible through the window 15 of the cover 19.

[0032] Fig. 3 shows a detailed view of the embodiment of the Fig. 1 and Fig. 2 in a position between the open and the closed switch position of the earthing switch. Due to the position of the shaft 3.1, 3.2, Fig. 3 both pins 6 can be seen simultaneously. The intermediate position of the shaft 3.1, 3.2 also has a corresponding effect on the positions of the eccentric 5 and the earthing switch drive 17. Comparing the figures, it can be seen that the carrier 10 is also in an intermediate position because now none of the pins 6 engages in the penetrations 11, 12 of the carrier 10. Accordingly, the two status indicators 16 arranged on the carrier 10 are not or not fully visible in the window 15. Since a bistable flip-flop, for example with two opposing springs, is usually provided in the earthing switch or its drive, the earthing switch does not remain in such an intermediate position, but will flip into one of its two switch states. Accordingly, even in a stable state, only one status indicator 16 will ever be visible in the window 15.

[0033] Fig. 4 shows a Fig. 1 to 3 rear side view of the embodiment. Two opposing spiral springs 18 are connected through a recess 21 in the sheet 7 to the in the viewing direction of Fig.4 on the opposite side and thus resiliently mount the carrier 10. Instead of coil springs 18, other mechanisms can of course be used which allow resilient mounting. The effect of the coil springs 18 holds the carrier 10 in an intermediate position when none of the pins 6 engages the carrier 10. The intermediate position is selected such that both pins 6 of the illustrated embodiment penetrate through the respective through-hole 11, 12 into their respective associated slot with the stops 8, 9, come into contact with the carrier 10 and can displace it vertically until further movement of the respective pin 6 and thus of the shaft 3.1, 3.2 is finally prevented by the respective stop 8, 9 and the carrier 10 assumes a position in which one of the status indicators 16 can be perceived through the window 15.

[0034] The control unit of the invention offers the advantage that it can be manufactured using cost-effective components and can provide the desired functionality in a small installation space.

[0035] The invention has been explained in more detail with reference to a preferred embodiment. Those skilled in the art may discover further embodiments of the invention by deviating from the illustrated embodiment. This embodiment should not be construed as limiting the scope of the invention, which is defined solely by the following claims. List of reference symbols 1 control unit 2 camps 3.1 Wave (first wave section) 3.2 Wave (second wave section) 4 socket 5 eccentric 6-pin 7 sheet metal 8 stop 9 stop 10 carriers 11 Reach through 12 penetration 13 Insert eye 14 Closure 15 windows 16 Status indicator 17 Earthing switch drive 18 spiral spring 19 aperture 20 return spring 21 recess

Claims

[1] An operating unit (1) for an earthing switch drive (17) of an air-insulated switchgear assembly, the operating unit (1) comprising at least one shaft (3.1, 3.2) which is rotatably mounted in a bearing (2) and which has a socket (4) for a manually operable crank at a first end and an eccentric (5) for transmitting a rotary movement of the shaft (3.1, 3.2) to the earthing switch drive (17) at a second end, wherein the shaft (3.1, 3.2) further comprises at least one pin (6) which extends radially away from the shaft (3.1, 3.2), and the operating unit (1) comprises a first stop (8) and a second stop (9) for the at least one pin (6), wherein the first stop (8) and the second stop (9) are arranged relative to the shaft (3.1, 3.2) in such a way that the shaft (3.1, 3.2) is rotatable between a first shaft position, in which the at least one pin (6) strikes the first stop (8), and a second shaft position, in which the at least one pin (6) strikes the second stop (9), and wherein at least one of the first and second stops (8, 9) is designed as a slot which is arranged relative to the shaft (3.1, 3.2) in such a way that the at least one pin (6) is freely movable in the slot in an intermediate shaft position lying between the first shaft position and the second shaft position and strikes one end of the slot in the first or second shaft position, . characterized by that the slot is arranged in a flat section of a sheet (7). [2] The operating unit (1) of the preceding claim, wherein the at least one pin (6) comprises a first pin and a second pin which extend radially away from the shaft (3.1, 3.2) and are arranged offset from one another along a longitudinal direction of the shaft (3.1, 3.2). [3] The operating unit (1) of any one of the preceding claims, wherein a rotation angle between the first shaft position and the second shaft position is at least approximately 180 degrees. [4] The operating unit (1) of any one of the preceding claims, comprising a carrier (10) for at least one status indicator (16), wherein the carrier (10) is arranged relative to the shaft (3.1, 3.2) such that the carrier (10) is held by the at least one pin (6) in the first shaft position in a first indicator position and that the carrier (10) is held by the at least one pin (6) in the second shaft position in a second indicator position. [5] The operating unit (1) of the preceding claim, in which the carrier (10) is spring-mounted. [6] The operating unit (1) of the preceding claim, wherein the carrier (10) is arranged in an intermediate indicator position located between the first indicator position and the second indicator position without the action of force by the at least one pin (6). [7] The operating unit (1) of any one of claims 4 to 6, comprising a panel (19) having a window (15) arranged relative to the support (10) such that in the first indicator position the at least one status indicator (16) is perceptible through the window (15) and that in the second indicator position the at least one status indicator (16) is not perceptible through the window (15). [8] An air-insulated switchgear assembly comprising an earthing switch, an earthing switch drive (17) for driving the earthing switch and an operating unit (1) for the earthing switch drive (17), characterized by that the operating unit (1) is designed according to one of the preceding claims.

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