Abstract:
The hybrid circuit breaker has at least two series-connected arcing chambers, which are operated by a commmon drive via a transmission ( 29 ) connected upstream from it. It is intended to be possible to assemble this transmission ( 29 ) easily in the interior of the hybrid circuit breaker. This is achieved in that the transmission ( 29 ) is formed from at least two transmission parts which can be plugged together, with a first transmission part being firmly connected to the at least one first arcing chamber and a second transmission part being firmly connected to the at least one second arcing chamber. The transmission ( 29 ) also has means which allow the movements of the at least two arcing chambers to be technically suitably matched to one another and to be optimized with respect to the time sequence and switching speed thereof.

Description:
This application claims priority under 35 U.S.C. §§ 119 and/or 365 to Ser. No. 01811082.5 filed in Europe on Nov. 9, 2002; the entire content of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention is based on a hybrid circuit breaker having a transmission, as claimed in the precharacterizing clause of claim  1 . 
     BACKGROUND OF THE INVENTION 
     The document EP 0 847 586 B 1 discloses a hybrid circuit breaker which can be used in an electrical high-voltage network. This hybrid circuit breaker has two series-connected arcing chambers, a first of which is filled with sulfahexafluoride gas as a quenching and insulating medium, and a second of which is in the form of a vacuum interrupter chamber. The second arcing chamber is surrounded by sulfahexafluoride gas on the outside. The main contacts of the two arcing chambers are operated simultaneously by a common drive via a simple lever transmission. Both arcing chambers have a power current path, in each of which the erosion-resistant main contacts are located and, in parallel with this, a rated current path, with this rated current path having only a single interruption point. During disconnection, the rated current path is always interrupted first of all, after which the current to be disconnected commutates onto the power current path. The power current path then continues to carry the current until it is definitively disconnected. 
     Simple lever transmissions such as these are comparatively difficult to match to the movement profiles required in hybrid circuit breakers. Furthermore, the bearing points are subject to mechanically very severe stresses, which results in the bearing points having a complex and expensive design, as a result of which the hybrid circuit breaker price is increased. If this configuration of the bearing points is dispensed with, then the time penalty for the maintenance work which is then required more frequently restricts the availability of the hybrid circuit breaker in a disadvantageous manner. Furthermore, the complexity for installing the lever transmission in the interior of the hybrid circuit breaker is comparatively great, owing to the restricted accessibility in this area. 
     SUMMARY OF THE INVENTION 
     The invention, as it is characterized in the independent claims, achieves the object of providing a hybrid circuit breaker having a transmission, which can be joined together easily in the interior of the hybrid circuit breaker. 
     The hybrid circuit breaker has at least two series-connected arcing chambers, which are operated by a common drive. These arcing chambers are preceded by a common transmission. This transmission has at least two transmission parts, which are designed such that they can be plugged together, with the first transmission part being firmly connected to the at least one first arcing chamber, and the second transmission part being firmly connected to the at least one second arcing chamber. The transmission has means which allow the movements of the at least two arcing chambers to be technically sensibly matched to one another and to be optimized with respect to the time sequence and switching speed thereof. It has been found to be particularly advantageous for the transmission to be designed such that it is self-locking both in the connected position and in the disconnected position since this means that there is no need for any additional locking apparatus or catches. Furthermore, the drive does not need to apply any particular holding forces in the two limit positions, so that a simple and particularly low-cost drive can be used here. The transmission can be installed comparatively easily, so that the time required for installation work for maintenance purposes is advantageously reduced. This simplified installation requires a comparatively short amount of time, so that the operational availability of the hybrid circuit breaker is advantageously increased. 
     The longitudinal axes of the two arcing chambers in one preferred embodiment of the hybrid circuit breaker lie in one plane and are inclined at an angle α to one another, with the angle α being less than 90°, and preferably being in the range between 68° and 800°. This arrangement of the arcing chambers makes it possible to produce a hybrid circuit breaker which has a comparatively short extent in the axial direction, so the space required for this hybrid circuit breaker is particularly small. 
     The further refinements of the invention are the subject matter of the dependent claims. 
     The invention, its development and the advantages which can be achieved by it are explained in more detail in the following text with reference to the drawing, which illustrates only one possible embodiment approach. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the figures: 
     FIG. 1 shows a section through a first embodiment of the transmission, which is illustrated in a highly simplified and schematic form, and with the hybrid circuit breaker in the connected state. 
     FIG. 2 shows the first schematically illustrated embodiment of the transmission in the disconnected state. 
     FIG. 3 shows a section through a second embodiment of the transmission, which is illustrated in a highly simplified and schematic form, and with the hybrid circuit breaker in the connected state. 
     FIG. 4 shows the second schematically illustrated embodiment of the transmission in the disconnected state. 
     Elements having the same effect are provided with the same reference symbols in all the figures. Only those elements which are required for direct understanding of the invention are illustrated and described. In order to make the figures clearer, the majority of the viewing edges are not shown in each case. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows, schematically, a section through a first embodiment of a transmission  29 , which is illustrated in a highly simplified form, with the hybrid circuit breaker in the connected state. This hybrid circuit breaker has two series-connected arcing chambers, which are not illustrated but in this case, by way of example, are mounted at an angle to one another. The first arcing chamber, for example an arcing chamber which is filled with insulating gas, is arranged such that it extends along a first longitudinal axis  1  and concentrically with respect to it, and the other arcing chamber, for example a vacuum interrupted chamber, is arranged such that it extends along a second longitudinal axis  2 , and concentrically with respect to it. In this case, the two longitudinal axes intersect at an angle α, with this angle α preferably being in the range between 68° and 80°. The two longitudinal axes generally lie in one plane, but it is normally possible for these longitudinal axes to be provided in two planes arranged parallel to one another, or in two planes which intersect at an angle which is sensible for design purposes. 
     The hybrid circuit breaker is driven by a drive, which is not illustrated but is generally at ground potential, via a drive linkage  3 , part of which is composed of electrically insulating material. The drive linkage  3  is connected by means of a bolt  4  to a tubular contact rod  5  which can move in the direction of the first longitudinal axis  1 . The contact rod  5  operates the contact or contacts itself, depending on the nature of the arcing chamber that is filled with insulating gas. As already stated, this arcing chamber is not shown here. The contact rod  5  is arranged concentrically with respect to the first longitudinal axis  1 , and is guided such that it slides axially in guide parts, which are not shown, in a stationary enclosure  6 . The contact rod  5  has a slot  7 , which runs parallel to the plane of the drawing. A roller  8  is mounted in this slot  7  such that it can rotate on a bolt  9  which is connected to the contact rod  5 , with the rotation axis  10  running at right angles to the first longitudinal axis  1 , and generally intersecting it. 
     The roller  8  projects upward out of the slot  7  and in this case forces a planar surface  11  of a slotted guide disk  12 , which is mounted such that it can rotate, upward. In the illustrated connected position, this surface  11  runs parallel to the first longitudinal axis  1 . The slotted guide disk  12  is fitted to a bolt  13 . The bolt  13  is held in a guide enclosure  14 , which is rigidly connected to the enclosure  6 . The guide enclosure  14  has an axial slot  15 , in which the slotted guide disk  12  can move in the radial direction with respect to the first longitudinal axis  1 . The rotation axis  16  of the slotted guide disk  12  runs parallel to the rotation axis  10  of the roller  8 . The bearing points for the roller  8  and for the slotted guide disk  12 , which are in the form of sliding bearings, are provided with insulating parts, which are not illustrated but prevent stray currents from being able to flow through these bearing points, and being able to damage them, during operation. The guide enclosure  14  merges on the drive side into a schematically illustrated insulating enclosure  17 . On the drive side, the enclosure  6  merges into a schematically illustrated insulating enclosure  18 . These insulating enclosures  17  and  18  are fitted with the active parts of the hybrid circuit breaker. The enclosures which surround the active parts of the hybrid circuit breaker and at the same time seal the gas areas of the hybrid circuit breaker from the outside are not shown here. 
     A further bolt  19  is mounted in the slotted guide disk  12  such that it can rotate, and one end of a double lever  20  is hinged on it, while the other end of this double lever  20  is connected to a bolt  21  such that it can rotate. The bolt  21  is held in a contact rod  22 , which operates the moving contact of a vacuum interrupter chamber, which is not illustrated. In this case, the contact rod  22  extends concentrically with respect to the second longitudinal axis  2 . The enclosure  6  is firmly connected to a flange  23 , to which the vacuum interrupter chamber (which is not illustrated) is fitted and which guides the contact rod  22 . A stop part  24  is inserted firmly in the flange  23  and concentrically surrounds the contact rod  22 . The contact rod  22  has a collar  25 , on which a cup spring pack  26  is supported. The cup spring pack  26  is  6  guided centrally through a cylindrical step  27  on the contact rod  22 . The cup spring pack  26  is supported against a first shoulder  24  a on the stop part  24 , on the side opposite the collar  25 . The cup spring pack  26  is in this case prestressed in the connected position, and ensures that the contacts of the connected vacuum interrupted chamber are always pressed against one another with the necessary contact force. 
     A first arrow  28  indicates the direction, in this case to the right, in which the drive (which is not illustrated) for the drive linkage  3  and, via it, the contact rod  5  which produces the connection movement of the arcing chamber that is filled with insulating gas, has moved. The transmission  29  converts this axial movement with the contact rod  5  to a movement of the contact rod  22  in a direction which is indicated by a second arrow  30 , in this case pointing obliquely upward in the direction of the second longitudinal axis  2 . The following parts interact in the transmission  29 ; the contact rod  5  interacts with the roller  8  on its bearings, the slotted guide disk  12 , the bolts  13  and  19 , the double lever  20 , the bolt  21  and the contact rod  22 , and the transmission  29  is operated by the drive linkage  3 . The transmission  29  links the movements of the two arcing chambers to one another, and technically matches the movement sequences sensibly to one another. The transmission  29  is designed such that it acts in a self-locking manner in the connected position, that is to say the hybrid circuit breaker is held in this position even in the event of vibration, without any additional locking and without any need for the drive to apply force. 
     FIG. 2 shows a schematically illustrated section through the first embodiment of the transmission  29 , which is illustrated in highly simplified form, with the hybrid circuit breaker in the disconnected state. An arrow  31  indicates the direction of the disconnection movement, in this case to the left, in which the drive (which is not illustrated) has moved the drive linkage  3  and, via this, the contact rod  5 , which causes the disconnection movement of the arcing chamber that is filled with insulating gas. The transmission  29  converts this axial movement of the contact rod  5  to a movement of the contact rod  22  in a direction which is indicated by a second arrow  32 , and which in this case is obliquely downward in the direction of the second longitudinal axis  2 . The disconnection movement is complete when the collar  25  of the contact rod  22  strikes the shoulder  24   b  of the stop part  24 , and there is then virtually no stress on the cup spring pack  26 . 
     At the start of the disconnection movement, the roller  8  moves along the planar surface  11  of the slotted guide disk  12 , with the prestressed cup spring pack  26  pressing the slotted guide disk  12  against the roller  8 . A curved surface  33  with a radius of curvature R is tangentially adjacent to the planar surface  11 . The radius of curvature R is slightly larger than the radius of the roller  8 , so that the roller  8  cannot become jammed when it reaches this area. As soon as the roller  8  reaches the curved surface  33 , it presses with the force of the drive against this curved surface  33 , and the slotted guide disk  12  starts to rotate in the clockwise direction about the rotation axis  16 , with this rotary movement being supported by the energy stored in the cup spring pack  26 . The rotary movement of the slotted guide disk  12  is matched to the predetermined linear travel of the vacuum interrupter chamber. Immediately before the vacuum interrupter chamber reaches the disconnected position, the curved surface  33  of the slotted guide disk  12  merges into a planar surface  34  which runs tangentially with respect to the roller  8 . On reaching the disconnected position, the roller  8  holds the vacuum interrupter chamber in its open position by means of the slotted guide disk  12  and by means of the further elements which are connected to it. The transmission  29  is thus designed such that it is also self-locking in the disconnected position, that is to say the hybrid circuit breaker is held in this position even in the event of vibration, without any additional locking and without any need for the drive to apply force. 
     The movement sequence of the vacuum interrupter chamber is optimally matched to the arcing chamber, which is filled with insulating gas, by virtue of the external shape of the slotted guide disk  12 . Furthermore, this slotted guide disk  12  controls the time sequence of the movement of the vacuum interrupter chamber with respect to the movement of the arcing chamber that is filled with insulating gas so that, by way of example, modifications to the timing of the movement sequence can be achieved very easily by moving the roller  8  in the direction of the first longitudinal axis  1 . 
     FIG. 3 shows a section through a second embodiment of a transmission  29 , which is illustrated in highly simplified form and schematically, with the hybrid circuit breaker in the connected state. The arcing chamber, which is filled with insulating gas, extends along a first longitudinal axis  1  and is arranged concentrically with respect to it, while the other arcing chamber, for example a vacuum interrupter chamber, extends along a second longitudinal axis  2  and is arranged concentrically with respect to it. In this case, the two longitudinal axes intersect at an angle α. The two longitudinal axes generally lie in one plane, but it is also possible for these longitudinal axes to be provided in two planes which are arranged parallel to one another or in two planes which intersect at an angle which is sensible from the design point of view. The arcing chamber, which is filled with insulating gas, is operated by a contact rod  5 . Of the other active parts of this arcing chamber, only a metallic guide tube  35  is shown here, which has an axially extending slot  36  pointing upward, and which is rigidly connected to the arcing chamber. A collar  37  on the contact rod  5  is guided such that it slides in this guide tube  35 . 
     On the drive side, a cylindrical slotted guide part  38  is attached to this collar  37  and likewise has an axially extending slot  39  pointing upward in the region of the slot  36 . The slotted guide part  38  is provided with a coincident guide slot  40  both on the front face and on the rear face. A cylindrical bolt  41  is guided in the two guide slots  40  and is fitted in the center, between the two guide slots  40 , with the contact rod  22 , which operates the vacuum interrupter chamber. The contact rod  22  is flattened in the region of the slots  36  and  39 , so that these slots  36  and  39  can be designed to be comparatively narrow, so that they only insignificantly weaken the carrying capacity of the guide tube  35  and of the slotted guide part  38 . The axis of the bolt  41  is at right angles to the plane of the drawing, and the bolt  41  can move, during switching, along a dashed line of action  42 , which is at the same time the center line of the guide slots  40 . The dashed line of action  42  initially runs parallel to the first longitudinal axis  1 , and a section  42   a  of the dashed line of action  42  is then inclined at an angle β to the first longitudinal axis I before once again then merging into a section  42   b  which runs parallel to the first longitudinal axis  1 . The larger the angle β, the higher is the disconnection speed, as well as the connection speed, of the vacuum interrupter chamber. If the transition of the dashed line of action  42  is shifted axially from the parallel section to the inclined section  42   a , then the switching times of the two arcing chambers can be matched to one another. 
     On the drive side, the two guide slots  40  are open, so that when the transmission  29  is being installed, the bolt  41  can be inserted from this side into the two guide slots  40  in the slotted guide part  38 . It is also possible to widen the guide slots  40  roughly in the form of a funnel on the drive side, in order to make it easier to insert the bolt  41 . Once the bolt  41  has been inserted, the drive linkage  3  is inserted from the drive side, and the bolt  4  and its holder  43  are mounted such that they can rotate on each end facing the slotted guide part  38 . The holder  43  is centered by the slotted guide part  38  and is pressed against it in a force-fitting manner by means of a union nut  44  that is screwed to the slotted guide part  38 , and is thus held in position. The union nut  44  is firmly tightened and secured from the drive side. This makes it very much easier to install the transmission  29 . No complex installation or adjustment work is required in the interior of the transmission  29 , thus allowing advantageously fast installation. 
     This second embodiment of the transmission  29  is likewise self-locking not only in the connected position but also in the disconnected position. No complex additional locks or additional holding forces to be applied by the drive are required, thus advantageously reducing the price of the hybrid circuit breaker. 
     FIG. 4 shows a schematically illustrated section through the second embodiment of the transmission  29 , which is illustrated in highly simplified form, with the hybrid circuit breaker in the disconnected state. The arrow  31  indicates the direction of the disconnection movement, in this case to the left, in which the drive, which is not illustrated, has moved the drive linkage  3  and, via it, the contact rod  5 , which produces the disconnection movement of the arcing chamber which is filled with insulating gas. The transmission  29  converts this axial movement of the contact rod  5  to a movement of the contact rod  22  in a direction which is indicated by a second arrow  32 , which in this case is obliquely downward in the direction of the second longitudinal axis  2 . At the start of the disconnection movement, the bolt  41  slides to the right along the dashed lines of action  42 . Since the dashed lines of action  42  initially run parallel to the first longitudinal axis  1 , the pressure of the prestressed cup spring pack  26  cannot initially produce any movement of the contact rod  22  in the direction of the arrow  32 . As soon as the bolt  41  reaches the inclined section  42   a , the movement of the vacuum interrupter chamber in the disconnection direction starts. The disconnection movement of the vacuum interrupter chamber is complete when the collar  25  on the contact rod  22  strikes against the shoulder  24   b  on the stop part  24 , and there is then virtually no stress on the cup spring pack  26 . The bolt  41  has then reached the section  42   b  of the dashed line of action  42 . The vacuum interrupter chamber is then held in the disconnected position by the contact rod  22 . 
     Since the transmission  29  can be installed easily, this advantageously reduces the time required for installation work during maintenance tasks, the installation process is highly simplified and the operational availability of the hybrid circuit breaker is advantageously increased. The two illustrated embodiments of the transmission  29  are self-locking not only in the connected position but also in the disconnected position. There is therefore no need for any complex additional locks or additional holding forces to be applied by the drive, which advantageously reduces the price of hybrid circuit breaker. 
     LIST OF DESIGNATIONS 
     
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 1 
                 First longitudinal axis 
               
               
                   
                 2 
                 Second longitudinal axis 
               
               
                   
                 3 
                 Drive linkage 
               
               
                   
                 4 
                 Bolt 
               
               
                   
                 5 
                 Contact rod 
               
               
                   
                 6 
                 Enclosure 
               
               
                   
                 7 
                 Slot 
               
               
                   
                 8 
                 Roller 
               
               
                   
                 9 
                 Bolt 
               
               
                   
                 10 
                 Rotation axis 
               
               
                   
                 11 
                 Surface 
               
               
                   
                 12 
                 Slotted guide disk 
               
               
                   
                 13 
                 Bolt 
               
               
                   
                 14 
                 Guide enclosure 
               
               
                   
                 15 
                 Slot 
               
               
                   
                 16 
                 Rotation axis 
               
               
                   
                 17, 18 
                 Insulating enclosure 
               
               
                   
                 19 
                 Bolt 
               
               
                   
                 20 
                 Double lever 
               
               
                   
                 21 
                 Bolt 
               
               
                   
                 22 
                 Drive rod 
               
               
                   
                 23 
                 Flange 
               
               
                   
                 24 
                 Stop part 
               
               
                   
                 24a, 24b 
                 Shoulder 
               
               
                   
                 25 
                 Collar 
               
               
                   
                 26 
                 Cup spring pack 
               
               
                   
                 27 
                 Step 
               
               
                   
                 28 
                 Arrow 
               
               
                   
                 29 
                 Transmission 
               
               
                   
                 30, 31, 32 
                 Arrow 
               
               
                   
                 33 
                 Curved surface 
               
               
                   
                 34 
                 Planar surface 
               
               
                   
                 35 
                 Guide tube 
               
               
                   
                 36 
                 Slot 
               
               
                   
                 37 
                 Collar 
               
               
                   
                 38 
                 Slotted guide part 
               
               
                   
                 39 
                 Slot 
               
               
                   
                 40 
                 Guide slot 
               
               
                   
                 41 
                 Bolt 
               
               
                   
                 42 
                 Dashed line of action 
               
               
                   
                 42a, 42b 
                 Section 
               
               
                   
                 43 
                 Holder 
               
               
                   
                 44 
                 Union nut 
               
               
                   
                 a 
                 Angle 
               
               
                   
                 b 
                 Angle 
               
               
                   
                 R 
                 Radius of curvature