CZ20004212A3 - Load selector switch - Google Patents

Abstract

The invention relates to a selector switch for tapped transformers to enable continuous tap switching with respect to a tapped winding, whereby fixed stepped contacts are arranged inside a cylinder made of insulating material on a horizontal plane for each phase. A rotating actuating shaft is located inside the insulating cylinder. The actuating shaft has a moveable hinged contact carrier for each phase that is to be switched and vacuum switching cells are respectively and vertically arranged on said contact carrier.

Description

The voter selector

Technical field

The present invention relates to a load selector for stepped voltage transformers.

BACKGROUND OF THE INVENTION

Such load selectors are already known from DE 38 33 126

The load selector in transformers is used to switch the control windings of these transformers and thus to compensate for voltage variations that are otherwise normally used with the load on the product and selectors

The load selector can be separated by a selector at low cost.

Reason and switches When switching different contacts, an electric branch turns to a specific load waiver in an arc. In order to prevent this, DE 38 33 is mentioned above

126 C2 is a voltage selector in which, in each switching phase, two simultaneously rotatably movable mechanical switch contacts are arranged on a common contact carrier, and a vacuum cell is also formed on each of the two movable mechanical switch contacts located also on the contact carrier. The fixed load cell stepped contacts, which are switched by rotary mechanical switching contacts, are located from i z o1 and n t u. The vacuum contact carriers are horizontal and are controlled or actuated by means of an additional concentric ring of the thumb positioned axially between the fixed step ring and the additional slip ring.

on the wall of the cylinder on the concentric circle the cells are placed on the contacts

These known load selectors have a number of disadvantages. Firstly, they are undesirable due to the horizontal arrangement of the vacuum cells, n and the common contact carrier. the large diameter of the cylinder is made of three and three selectors. V a n d e c t i n i n s depending on · 0 ·

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- 2 at switching power, specified minimum dimensions, in particular also a considerable longitudinal dimension. In addition, the actuating tappets protrude from the vacuum cell in the longitudinal direction. It is therefore clear that the entire contact carrier must have a radial dimension determined by the dimensions of the vacuum cells, which determines the diameter of the load selector. In addition to this dimensional problem, the horizontal installation of the vacuum cell consists in the fact that, when the bellows selector is filled with the upper bends of the bellows, the vacuum filling of the oil is not completely displaced. that an uneven load of the respective bellows of the vacuum cell is created, which creates a risk of bursting. Such a residual air residue in the area of the vacuum cell bellows can only be reliably eliminated by a vacuum load selector when lying down, but such vacuum filling is in place, for example after a revision has been impracticable or only possible at high cost. Furthermore, the load selector should generally have a large that means a considerable construction height.

The fixed stage contacts of the individually switched phases are located one above the other, the means for actuating the rotatable control shafts within the load selector carrying the contact carrier of each phase in the load selector head to accommodate this control shaft also require space so that the load selector has a considerable length dimension. As a result, said control shaft is also quite long inside.

take into account the axial length dimension as well as the means of the load selector bottom

Such control shafts are usually made of GRP or other insulating material, but other metal control shafts have also been proposed. In the known load selectors, the contact carriers are fastened to the control shaft by means of fastening screws.

DE 44 14 941 C1 describes a further fixed attachment of the contact carrier to the control shaft by means of a clamping flange.

Tolerances, different thermal expansion of the oil tank and the control column, deflections, and the like can cause problems with known load selectors when components, especially vacuum cells located on individual carriers, interact with the circularly located control means, especially since vacuum cell control tappets usually have only relatively small linear control paths.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to overcome these disadvantages and to provide a load selector having a space-saving vacuum cell arrangement and safe and reliable operation in all working conditions.

This object is achieved by a load selector with features according to the first claim.

Particularly advantageous further embodiments of the invention are set out in the dependent claims.

In the load selector according to the invention, the vacuum cells of the carrier contacts are upright. The contact carriers have contacts and are precisely guided in rollers by means of rollers

The fingers located in this drain ring are controlled placed on the vacuum tube pickup ring. Knife pickups that are supported by the ring. Others on the contact carrier divert the blade current through the drain collector contacts on the contact carrier to allow current to be supplied. According to a further feature of the invention, the contact carriers are mounted movably on the control shaft. A particular advantage of the load selector according to the invention is that, in addition to the small dimensions, all the forces for operating the vacuum cells as well as the contact forces are axially retained by means of a drain ring and fixed.

- 4 • The contacts on the stable oil tank. This prevents radial loading of the switching column, in particular its deflection, and prevents the resulting changeover of the vacuum cell control times and the reduction of the contact forces. By means of a rotatable or axially displaceably mounted contact carrier, which is guided axially by means of a drain ring, the switching is also ensured even at large displacements due to the tolerance and the different thermal expansion of the oil tank and the switching column.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail below with reference to the drawings.

The drawings show: giant . 1 a first embodiment in side section, voters load according to invention giant . 2 part of the contact carrier of this load selector from above in section, in perspective giant . 3 a second embodiment in side section, voters load according to invention giant . 4 schematic view load according to the invention, switches 1 based on the voter giant . 5 a modified switch; and giant . 6 typical switching sequence invention. load selector according to

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the invention 0 0 0 0 0 0 0 0 0 »000♦» 000 · 0 00

The load selector shown in FIG. 1 shows an embodiment of the invention with a contact carrier 3 rotatably mounted on the control shaft 2 and with vacuum cells 27, 28 positioned thereon.

The load selector consists of a cylinder 1 of insulating material, in which the control shaft 2, preferably of insulating material, is located concentrically. The control shaft 2 is rotatable, for this purpose conventional Maltese actuators, which are not shown. At least the bearing of the control shaft 2 at the bottom of the insulating material cylinder 1 is also shown.

The control shaft 2 carries fixed stage contacts 16 in each plane, which are described in greater detail below, and a contact carrier 3 which is rotatably mounted on the control shaft 2 in a bearing rack 1. The bearing stand 1 is fastened to the control shaft 2 using screws 4.1, 4.2.

The contact carrier 1 consists of the bearing part 1, the support shell Q and the contact shell 7. The individual components of the contact support 3 are connected to each other by means of connecting screws 8, 9, 8. The contact sheath 7 in the illustrated embodiment consists of the upper part 10 of the contact sheath 11 and the lower part 11 of the contact sheath 7. The two parts 10, 11 are again connected to each other by further screws 12. However, the contact skin 7 may also be formed in one piece. The bearing part 5 has a bearing location 13 in which a pin 14 is received, by means of which the bearing stand 4 is connected and thus a rotational movement is ensured. The pin 14 is positionally secured by a transverse pin 15.

As a result, the entire contact carrier 3 is rotatable as a complete part about the pin 14 and thus relative to the control shaft 2 standing. On the wall of the insulating material cylinder 1, for each switching phase in a separate plane, fixed step contacts 16 are provided. electrically connected to φφφφ • * Φ · Φ * · · «9 φ

I φ • • φ φ φ φ φ φ Φ Φ I I I I I · I I I I I I I I I I I I I I I · I · I I I I I I · I · I I · · The fixed step contacts 16 are switched by the corresponding contacts 17, 18. These contacts 17, 18 are placed side by side on the contact carrier 3 in a horizontal direction so that when the control shaft 2 and thereby the contact carrier 3 are rotated, one of the contacts 17, 18 reaches the adjacent new fixed step contact 16 and the other one The first contact 17 acts as a make contact and the second contact 18 acts as an auxiliary contact.

FIG. 2 shows the arrangement of the two contacts 17, 18, located side-by-side on the contact carrier 3, and shows the interaction with the fixed one shown in FIG. 2 as a switching contact, i.e. consists of a step contact 16. In the arrangement, the first contact 17 is formed, for reasons of maximum conductivity, of a double, two electrically connected parts 17a, 17b. Each of the contacts 17, 18 consists of a part 17.1, 18.1 and a lower contact part of the upper contact 17.2, 18.2. Thus, in the special embodiment shown in FIG. 2, the first contact 17 comprises a total of four parts, two upper contact parts 17.1a and 17.1b as well as two lower contact parts 17.2a and 17.2b. This dual embodiment of the first contact 17 acting as a switch contact is suitable for various embodiments but is not essential to the invention. Both the upper contact portions 17.1, 18.1 and the lower contact portions 17.2, 18.2 of each of the two contacts

17, 18 are pivoted about each other on the contact sheath 7 of a separate center 19, 20. 2 1. 2, rotate, compressed by springs 23, 24, 25, 26 in the direction of the fixed step contact 16, in the closed state between them.

In other words, the upper contact portion 17.1, 18.1 as well as the corresponding lower contact portion 172, 18.2 presses on the fixed fixed contact 16 via a defined contact force from both sides.

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4> «· ··, 20, 21. In Fig. 1 and 2, only the front or top contact portions 17.1 are seen. 18.1, 17.2 and 18.2. Wednesday 19, 20, 21. 22 of rotation and springs 23, 24, 25, 26.

Furthermore, they are fastened to each contact carrier 3 by means of upper and lower clips 29, 30, 31. 32 so that the bellows 31, 34 and the actuating tappets 35, 36 of the vacuum cells 27, 28 face upwards. Of the components just described, only those that are in the front view direction are shown in FIG. For operating the control tappets 35, .36. The vacuum cells 27, 28 serve two levers 37. 38, which have at their free end a pulley pin 41, 42 with a control pulley 39, 44). At its other free end it acts on the actuating tappet 35 already described. 36. Both levers 3 7. 38 are rotatably mounted about the sixth and seventh pivot centers 43, 44, respectively. It is also possible to create a common pivot point. The control rollers 3.9, 40 of both levers 37, 38 correspond to a control ring 45 having an upper control contour 46 and a lower control contour 47. The control ring 45 is positioned radially on the inner wall of the insulating material cylinder 1. It can be seen from FIG. 1 that the first control pulley 39 corresponds to the lower control contour 47, that is to say, circulates thereon and the second control pulley 40 circulates on the upper control contour 46. The two control contours 4.6, 47 thus serve to control the vacuum cells 27, 28 by pivoting the respective levers 37, 38 around the sixth and seventh centers 42, respectively, when the respective control pulley 39, 40 is pulled on the finger. 44 and thus controls the respective actuator tappet 35, 36 of the vacuum cell 27, 28.

Further, on the inside of the insulating material cylinder 1 there is a drain ring 48 having an outside connecting element 49 extending outwards. In particular, the control ring 45 and the drain ring 48 can be connected in a simple manner to a single component of conductive material, as shown in FIG. 1. The drain ring 48 again corresponds to the mechanical drainage.

8, which is disposed on the contact carrier 3 and consists, similarly to the contacts 17, 18 described above, of the upper and lower portions 50.1, 50.2 of the drain contact 50. Both portions 50.1, 5.2 of the drain contact 50 are analogous they are mounted separately around the seventh and eighth pivot centers 53, 54 and are pressed against each other by means of further springs 51, 52 so that they surround the outlet ring 48 with a defined contact pressure.

Furthermore, the contact carrier 11 also has two rollers 55, 56 which roll on both sides of the drain ring 48, thereby guiding the entire contact carrier 3. The described arrangement makes it possible to compensate for all tolerances and in particular to compensate for the deflection of the long control shaft 2. The contact carrier 3 rotatably mounted on the control shaft 2 is in each case guided in a defined manner by means of a drain ring 48 so that precise control of the control pulley is achieved. 39, 40 and thus control of the vacuum cells 27, 28.

FIG. 3 shows another embodiment of a load selector according to the invention. In contrast to the example explained above, the other support 10 is not rotatably supported, but is mounted longitudinally displaceably.

Inside another cylinder 101 of insulating material there is again a concentrically positioned further control shaft 102 which carries a longitudinally displaceable further contact carrier 103. The longitudinal displacement is realized by means of a guide 104. Also in this case, two vacuum cells, of which only the front vacuum cell 105 is shown, are positioned upright. Again, in each plane there are fixed further step contacts 106, of circularly placed insulating material, which are of contact and auxiliary contact, are again switched in the wall of the other cylinder 101 by means of the switching ones of which 107. 1 and Similar to FIG. 3, only a further lower contact portion 107,22 is shown in a manner similar to the upper contact portion. the previous case is again inside φ

φ · • φ

A further drain ring 108 is located to the other insulating material cylinder 101 to which the drain contact is assigned, which again consists of another upper drain contact portion 109.1 and another lower drain contact portion 109.2. The guidance of the complete further contact carrier 103 in this case is by means of a pulley 110 which orbits the surface of another drain ring 108. The control of the vacuum cells 105 again takes place by means of levers 115, 116 which have control rollers 113, 114 at their free ends. on the lower control surface 111 or on the upper control surface 112 and thereby control the other control tappets 117 of the vacuum cells 105.

FIG. 4 schematically illustrates a circuit that is implemented by a load selector according to the invention. Electrical connections between contacts 17, 18 and vacuum cells 2 7. 28 and between them and the drain contact 50 and the drain ring 48 are not shown in FIG.

FIG. 5 shows a circuit in which, as shown in FIG. 2, the first contact 17 consists of two side-by-side connected parts 17a, 17b. Also in this representation corresponding to FIG. 2, the connections are shown. It can be seen that the functional principle means that both the connection according to Fig. 4 and Fig. 5 can achieve the same switching behavior only

An example of such a switchable course is shown in FIG. 6.

The load selector is represented by different switching steps. Such a load selector with different switching steps is in principle already known from EP 0 160 125. In this case, the mean distance between the step contact fixed to the stem winding and the fixed step contact adjacent thereto is greater than the mean distance between the remaining fixed step contacts. This allows you to:

the use of a load selector also on transformers with higher rated voltages, a higher surge voltage can be achieved.

Irrespective of this, it is particularly advantageous that the step contacts 16 are not bent, as in the prior art, i.e. they are not parallel to the glazing of the insulating material roll 1, but are straight as shown in FIG. circulate the upper or lower contact portions 17.1, 18.1, 17.2, 18.2 on the same band of fixed step contacts 16, this embodiment is achieved by constantly contacting other points on the surface of the fixed step contact 16, minimizing abrasion thereof.

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Claims (8)

PATENT CLAIMS 1. A load selector for continuously switching between taps of a stepped voltage regulator of a transformer, the load selector having an insulating material cylinder (1) as a jacket, inside said insulating material cylinder (1) being arranged circularly in a horizontal plane for each fixed phase step contacts (16), which are electrically connected to the taps, in the middle of the insulating material cylinder (1) is a rotatable control shaft (2) having a rotatable contact carrier (3) for each horizontal plane of the fixed step contacts (16); each of the contact carriers (3) having at least two mechanical contacts (17, 18) for contacting the fixed step contacts (16) in a horizontal plane, wherein at least one of the contacts (17, 18) on each contact carrier (3) is electrically connected directly to the first vacuum cell (27, 28) and at least one further contact (17, 18) per ka each contact carrier (3) is electrically connected to the second vacuum cell (27, 28) by a switching resistor, the other side of the two vacuum cells (27, 28) on each contact carrier (3) is electrically connected to a load sink, that all contact carriers (3) are mounted movably on the control shaft (2) independently of one another and the two vacuum cells (27, 28) are mounted upright on the contact carrier (3), the actuating tappets (35, 36) being positioned axially direction. Load selector according to claim 1, characterized in that each contact carrier (3) is mounted on the control shaft (2) rotatably about the center of rotation. Load selector according to claim 1, characterized in that each contact carrier (103) is mounted axially displaceably on the control shaft (102). W ft ftft · F: jr · · ft · r · · - 12 • ftftft ft Load selector according to at least one of claims 1 or 2, characterized in that each of the contacts (17, 18) consists of at least one upper contact part (17.1, 18.1) and at least one lower contact part (17.2, 18.2) and each contact the part (17,1, 18.1, 17.2, 18.2) abuts the at least one spring (23, 24, 25, 26), and when the fixed step contact (16) of the contact part (17.1, 18.1, 17.2, 18.2) is closed they close this step contact (16) and are in electrical contact with it. Load selector according to one of Claims 1 to 4, characterized in that the fixed contacts (16) have inside the insulating material cylinder (1) in a horizontal direction a surface which is not adapted to the internal shape of the insulating material cylinder (1) and in particular is created direct. Load selector according to one of Claims 1, 2, 4 or 5, characterized in that on the inner wall of the insulating material cylinder (1), for each switching phase and thus for each horizontal plane of the fixed step contacts (16), a ring (45) having an upper control contour (46) and a lower control contour (47), with a lever (37, 38) mounted on each contact carrier (3) for each of the two vacuum cells (27, 28). pivotally about a pivot center (43, 44), each lever (37, 38) abutting one of its free ends on the actuator tappet (35, 36) of the vacuum cell (27, 28) and its other free end on one of the control contours (46) , 47) for operating the vacuum cell (27, 28) in dependence on the spatial shape of the control contour (46, 47). Load selector according to one of Claims 1, 2, 4 to 6, characterized in that each load drain consists of a concentric drain ring (48) located on the inner wall of the cylinder (1) of insulating material having an outside material. · Ta ta ta t t t ta * ta ta ta ta ta ta ta ta ta - 13 - tatata-leading connecting element (49) and in contact with the drain contact (50) located on the contact carrier (3), which is electrically connected to the vacuum cells (27, 28) on this carrier (3) contacts. Load selector according to one of Claims 1, 2, 4 to 7, characterized in that each of the contact carriers (3) has two rollers (55, 56) which are arranged for the forced guiding of the contact carrier (3) on both sides. the corresponding drain ring (48). Load selector according to one of Claims 1, 2, 4 to 8, characterized in that the control ring (45) and the drain ring (48) of each phase are connected in one piece. øl / ^ ooo -γζ / L