MXPA00009165A - Surge diverter - Google Patents

Abstract

The inventive surge diverter has an axially symmetrical active part (2) which is located between two connection armatures (1, 2). This active part (2) contains cylindrical varistor elements (12) which are stacked on top of each other, and an axially symmetrical connecting element (13) which is situated in the diverter active part (2) between two consecutive varistor elements (12) and consists of an electrically conductive material. At least four bearing points (16, 16') are formed in the connecting element (13), said bearing points being evenly distributed around the axis in a circumferential direction. Two first bearing points (16) each support one of two first loops (15) which exert a contact force on the connecting element (13) and varistor elements (12) placed on the connecting element (13). Two second bearing points (16') each support one of two second loops (15) which exert a contact force on the connecting element (13) and varistor elements (12) located under the connecting element (13). A surge diverter of this kind can be of a considerable construction height and still have excellent mechanical and electrical properties.

Description

PROTECTOR AGAINST OVERVOLTAGES TECHNICAL FIELD The starting point of the invention is an overvoltage protector according to the introductory part of the first patent claim.

STATE OF THE ART The present invention refers to a state of the art as given by EP 0 614 198 Bl. An overvoltage protector described in this state of the art, contains two accessories for connection and a column of varistor elements, stacked one on top of the other, between the connection accessories. The electrical contact between the connection accessories and the varistor elements is produced by two or more turns of insulating material, and the ends of these are mounted respectively in one of the two connection accessories, and thus also act with a force of contact on the varistor elements located between them. REF .: 122916 For construction or structurally large heights, such as those required for nominal voltages of more than 70 kV, a surge protector built in this way is generally not used, given its subsequent additional relatively expensive measurements that are what to do in its manufacture. An overvoltage protector is known from EP 0 335 479 Bl, which has a housing that protects against weather inclemency, two connection accessories outside the housing, and an active portion of axially symmetrical construction, located inside the housing , arranged between the connection accessories. The active portion is constructed of several cylindrical modules, which are stacked one on top of the other in the form of "one column, each module has several varistor elements whose ends abut along the cylindrical axis. it is achieved by winding the wire which is predominantly axially directed, and which acts with a pressing force in two metal end portions joining the module at the ends.The end portions of the adjacent modules are electrically connected by means of a threaded bolt The production of such an overvoltage protector is relatively expensive, since the modules are produced by winding yarn in a first step, and a successor second step the modules are subsequently joined by threading the adjacent end portions, with the formation of a connecting portion that has good electrical conductivity.

BRIEF DESCRIPTION OF THE INVENTION The invention as set forth in the patent claims is intended to provide an overvoltage protector of the type initially established, which can also be produced with a large structural or construction height in a simple and cost-effective manner . The overvoltage protector of the present invention is distinguished from comparable overvoltage protectors according to the state of the art, in that it can be manufactured practically with an optional construction height in a simple and economical way. In addition, only one connection element, which is arranged between two successive varistor elements, is embedded in the active portion of the overvoltage protector only, and is of a material that conducts electricity with mounting sites with an appropriate construction and arrangement. The turns applied or sustained in the assembly sites are passed through the opposite directions and are fixed to the mounting sites of the connection accessories or an additional connection element or two additional connection elements, with the production of force contact. Therefore, for its assembly, substantially only one of the prefabricated templates is necessary which has already been provided for being effective in the state of the art in the manufacture of overvoltage protectors, and which mainly ensures the axial guidance, and in which connection accessories, the varistor elements, and in addition, according to the diameter of the varistor elements and the height of the construction or structural, one or more of the connection elements are stacked, and these are subsequently connected together in the active, mechanically stable portion of the overvoltage protector, through the installation of the turns and the application of pressure. During stacking, the mechanical stability of the active portion can be achieved by the successive consolidation of the following partial stacks, the pressing force that is achieved by the securing devices integrated in the accessories and / or connecting elements, or in addition by the spring elements which are embedded in the pile or stack formed in the template and which, in the installation of the turns, provide the desired contact force and with this also the mechanical stability required. An additional securing device, or additional spring elements, can be spared if the turns are respectively formed by an elastically deformable strip, possibly of glass fibers.

Four turns mounted on the connecting element are generally sufficient for a good mechanical stability of the active portion; for example, two of them arranged with respect to the diameter of each other, and directed in the opposite direction of the other two turns. With the use of six mounting sites an increased stability is obtained, with a compensation arrangement of approximately 60 ° in the circumferential direction and of which, respectively, three serve to guide the turns in a predetermined first direction and three in the opposite direction. The stability is improved only a little by eight or more assembly sites, and this requires, however, an additional expense of technical production. The turns that are directed in an opposite manner in a connection piece can also be arranged without any inclination or compensation in the circumferential direction and only with inclination or compensation in the axial direction. If necessary, the connecting piece can be formed by two parts that can be connected together so that they can be released or mutually separated, and which respectively carry turns that only align in one direction. An example of the preferred embodiment of the invention, and the advantages that can be obtained with this, are described in greater detail hereinafter, with reference to a drawing.

BRIEF DESCRIPTION OF THE DRAWING In the single drawing, a side view of an overvoltage protector is shown according to the present invention, the axially symmetrical housing thereof is shown in section.

MODES OF THE INVENTION The overvoltage protector in the single Figure has a housing 1 of an axially symmetrical shape, and an active portion 2 of the overvoltage protector, of axially symmetrical construction, and is arranged thereon along the axis of the housing ( not shown). The housing is constructed of an insulating tube 3 provided with meshes and made of a material that is resistant to inclement weather, for example a polymeric material such as silicone, or a porcelain, and two metal connection accessories 4 and 5 which are attached to the ends of the tube of insulating material. The connection accessories 4 and 5 respectively have a metal plate (not shown, for clarity purposes) that closes with sealed gas to the housing 1, and in addition to a respective cylindrical closing portion 6 or 7, which is arranged with axial symmetry inside the housing 1, which respectively seals the active portion 2 of the overvoltage protector, above and below. A perforation provided with an internal thread is provided in the part of the closure 6 or 7. A pressure screw 8 6 9, placed on the outside along the axis of the housing through the plate of the connection accessory, cooperates with the thread internal. The lower part or tip of the pressure screw 8 or 9 is mounted on a metal pressure plate 10 or 11, which can be displaced axially in a cavity of the closing portion 6 6 7, of the active portion 2 of the guard against. overvoltages.

The active portion of the overvoltage protector is constructed as a stack or stack and also contains, in addition to the two closing portions 6 and 7, varistor elements 12 of non-linear resistance material, which may have an oxide base. metallic, such as the ZnO in particular, and the metallic connecting elements 13 in cylindrical form. In addition, additional pressure plates 10 ', 11' are provided in the active portion 2 of the overvoltage protector, and also disc-shaped contact elements 14, which can be arranged between a pressure plate 10, 10 ', 11, 11' and an adjacent varistor element 12; between the adjacent varistor elements 12; and between a connecting element 13 and a varistor element 12 or a pressure plate. The turns of insulating material are denoted by the reference number 15; these are preferably formed by means of a wound, reinforced fiber strip, which is embedded in a polymeric matrix and, with the production of contact force, secures two connecting elements 13, or secures the closing portion 6 and the connection element 13 attached to the portion 6 of the active portion 2 of the overvoltage protector, or secure the closing portion 7 and the connecting element 13 attached to the portion 7 in the active portion '2 of the overvoltage protector. The turns 15 have their ends guided in grooves 16,16 'which are formed on the wrapping or covering surfaces of the closing portions 6,7 and of the connecting elements 13. The closing portions 6,7 or the elements 13 are projecting beyond the pressure plates 10, 10 ', 11, 11' and the varistor elements 12 in the radial direction. The turns 15 mounted on the grooves 16,16 'in this manner have, in a dielectrically favorable manner, a defined distance from the varistor elements 12. An analogous guidance of the turns can be achieved if the closing portions 6, 7 and the connecting elements 13 in fact have the same diameter as that of the varistor elements 12, but now have, instead of the grooves, radially directed projections in which the turns 15 are mounted.

Each of the two connecting elements 13 has six grooves 16, 16 'which are arranged mutually offset or inclined, respectively by approximately 60 °, in the circumferential direction. All these grooves have a semicircular section which is open in the axial direction, and in which one end of one of the turns 15 is mounted. Adjacent to the semicircular section are two sections that pass predominantly in the axial direction and in the which fastens a portion of a respective return section, which runs straight and joins the end of the mounted turn. This section runs parallel, and at a predetermined dielectrically favorable distance, for the varistor elements which are driven with the contact force by the mounted turn. The sections of the grooves 16 which run straight run in a manner contrary to the corresponding sections of the grooves 16 '. A respective one of the three turns is supported in the groove 16 'and joins together with the production of the contact force, the connecting element 13 and the closing portion 6 and also the varistor elements arranged between them. The magnitude of the contact force is placed or exerted during the assembly of the surge protector by screwing the pressure screw 8 and by axially moving the pressure plate in this way. One of the respective three turns is supported in the groove 16, and joins the two connecting elements 13 and the varistor elements arranged between them, with the production of the contact force. The contact force is obtained here by the elastically deformable turns, and if desired can be varied in magnitude by means of a securing device, with a pressure screw and a securing plate, which can be embedded in the connecting element 13. A second additional securing element may necessarily be embedded in the connecting element 13, and act on the section that is above the active portion 2 of the surge protector. Then the fastening or securing screw 8 and the pressure plate 10 can be dispensed or supplied.

The grooves 16 and 16 'follow one another alternately in the circumferential direction of the connecting elements 13. The force of pressure received by the turns is thus uniformly transmitted to the varistor elements 12. For the production of this overvoltage protector , the sealing portion 7, the pressure plate 11, the contact element 14, alternatively the additional ohmic contact elements and the varistor elements 12, the pressure plate 11 'are stacked one on top of the other on a template. , as well as the lower connecting element 13. The grooves 16 'of the closing portion 7 and the grooves 16 of the connecting element 13 are placed here, in such a way that they can be mutually aligned. Three prefabricated turns 15, which preferably respectively consist of a product previously impregnated in the form of a rolled strip, which hardens after the winding, are suspended in the mutually aligned grooves 16,16 'and by means of the rotation of the screws pressure 9, the force is exerted on the pressure plate 11 and thus, via the turns 15 which pass from one side to another, in addition to the varistor elements of the active portion of the overvoltage protector, which are arranged between the parts 7 and 13. The additional varistor elements 12 and the ohmic contact elements are now correspondingly stacked in the connecting element 13, and this partial stacking is concluded with the additional connecting element 13. This partial stacking of the active portion of the overvoltage protector can be secured with the turns which are respectively produced, during the production of the overvoltage protector, by winding a strip which is actuated by the pressing force and placed in the mutually aligned rows 16 and 16 '. In a corresponding manner, the active portion of the overvoltage protector can be extended by means of additional partial stacks, and finally it can be concluded by the closing portion 6. The active portion can now be placed in the housing 1, which can be closed after its filled with a stable insulation medium. Since the turns are applied at a distance from the varistor elements 12, here, the insulation means encloses the active portion with high reliability, free of voids and shrink holes. The overvoltage protector according to the present invention in this way has, notwithstanding the optional construction height, not only good mechanical properties but also good electrical properties. The housing does not necessarily have to contain insulating material; This can also be metallic. Additional potential control means are then provided between the wall of the housing and the active portion of the overvoltage protector, and the supply through these is provided at the ends of the housing.

REFERENCE LIST 1 housing 2 active portion of the protector 3 insulating tube 4,5 connection accessories 6,7 portions of the closure 8,9 pressure screws 10, 10 ', 11, 11' pressure plates 12 varistor elements 13 connection elements 14 elements of ohmic contact turns 16,16 'grooves, assembly sites It is noted that in relation to this date, the best method to implement the aforementioned invention, is that which is clear from the manufacture of the objects to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (8)

1 An overvoltage protector with two current-conducting connection accessories, separated along an axis, an axially symmetrical active portion arranged between the two connection accessories, and containing varistor cylindrical elements stacked on top of each other, with a housing that receives the active portion and with an assembly that has turns and that acts on the active portion with the contact force, characterized in that the active portion has at least one connecting element which is axially symmetric and conducts electricity, that the element connection is arranged between two successive varistor elements in the stack and has at least four mounting sites, which are formed in and / or the connection element and are distributed uniformly in the circumferential direction around the axis, which one of the first two turns are supported on the first two mounting sites and act with a first contact force on the element of connection, and a first of the two varistor elements, and that a respective one of the two second turns is supported in the second of the mounting sites and acts with a second contact force in the connecting element and a second of the two varistor elements.

2. An overvoltage protector according to claim 1, characterized in that the connection element has a device for securing that produces the first and / or second contact force.

3. An overvoltage protector according to one of claims 1 or 2, characterized in that each of the mounting sites is arranged between a respective one of the two mounting sites.

4. An overvoltage protector according to one of claims 1-3, characterized in that the contact portions project beyond the varistor elements in the radial direction, and the grooves forming the mounting sites are embedded in the projection section of the connection portion.

5. An overvoltage protector according to claim 4, characterized in that the grooves have a semicircular section which is open in the axial direction and on which an end of the first or second turn is mounted.

6. An overvoltage protector according to claim 5, characterized in that the sections join the semicircular section which are predominantly directed in the axial direction, and in which a portion of the return section running in a right line is respectively mounted, adjacent to the end of the turn, which runs parallel to and at a predetermined distance from the varistor elements in which the turn acts with the contact force.

7. An overvoltage protector according to claim 6, characterized in that the sections running in a right line, are aligned in an opposite manner in the circumferential direction of the successive grooves.

8. An overvoltage protector according to one of claims 1-7, characterized in that the connection portion has six grooves that mutually compensate each other by approximately 60 ° in the circumferential direction. SUMMARY OF THE INVENTION The overvoltage protector has an axially symmetrical active portion (2), arranged between two connection accessories (1,2). This active portion (2) contains the varistor elements (12) stacked one on top of the other and in addition an axially symmetrical connecting element (13), of an electrically conductive material arranged in the active portion (2) of the surge protector, between two successive varistor elements (12). In the connection element, at least four mounting sites (16, 16 ') are formed, which are distributed uniformly around the axis in the circumferential direction. Two first (16) of the assembly sites respectively support one of the first two rounds (15) which act with the contact force in the connecting element and in the varistor elements adjacent to the connecting element (13). The second (16 ') of the mounting sites (12) respectively supports one of the second turns (15) which acts with the contact force on the connecting element (13) and on the varistor elements (12) located under the connection element. Such an overvoltage protector has a large structural or construction height and is further distinguished by its good electrical and mechanical properties.