BG112464A - Selector with preselector for on-load tap changer - Google Patents

Abstract

The selector comprises an upper metal flange (1) with a housing (6), a lower metal flange (2) and fastened between them fixed number of segments (3), cutted from an insulation cylinder and arranged in a cage-like manner. On the segments there are mounted in tiers odd (4) and even (5) stationary contact elements. In the centre of the selector there is an insulating tube (7) with even (9) and, odd (8) current-carrying rings arranged in tiers thereon. To them are connected conductors (13) passing upwards in the insulating tube. The selector actuating system is located in the body (6). It is composed of a drive shaft (31) with a double transmission (25). On an adjacent axis (32) are mounted via bearings an even unit (26) and an odd unit (27) each of which is composed from one Geneva drive wheel (28) and one toothed gear (29). These toothed gear are engaged with one large even toothed gear (16) and one large odd toothed gear (19). They are mounted via rolling-contact bearings (15) coaxially at the top section of the insulation tube (7). To the elongated cylindrical portion (17) of the toothed gear (16) is attached an even drive segment (18) cutted from an insulation cylinder. An analogous odd drive sector (21) is connected to the metal sector (20) of the toothed gear (19). The two drive sectors have profile-cut lugs to which are fastened the contact carriers (35) of the contact pins (36). The selector is of known construction and is mounted sideways to the selector. It has a simplified and compact actuating system of Geneva drive sector (50) with a toothed rim, engaged with toothed rim of a actuating arm (48).

Description

FIELD OF THE INVENTION

The invention relates to a selector with a preselector, which is used in a step voltage regulator. Step regulators are built into the power transformers and regulate their high voltage under load, ie. without interrupting the power supply to consumers. The pre-selector is three-phase and is used for star center windings.

BACKGROUND OF THE INVENTION

Known voters who have a central insulating tube with current rings arranged on a floor and connected wires passing inside the central tube up to the oil vessel of the step regulator are compared. The pre-selector is mounted on the side of the voter.

1/13

A three-phase selector with a preselector (1) is known, comprising an insulating central tube on which six conductive rings are arranged in layers, one even and one odd for each phase. A wire is connected to each ring, and the six wires are located inside the pipe. They pass vertically upwards to the bottom of the oil tank, in which a power switch is built-in. Between the upper housing and the lower flange are attached columns of insulating rails, on which fixed contact elements are mounted. In the upper body there are two Maltese wheels located one below the other concentrically on the central tube. The Maltese wheels rotate alternately from a double gear with two pairs of drive rollers located 180 ° to each other. The Maltese wheels rotate in two successive steps at a certain angle, depending on whether 10 positions or 12 positions or more are required. Therefore, the Maltese wheels and the double translation are different for the specific number of situations. Attached to each Maltese wheel is a drive column composed of insulating rails carrying movable contact bridges that connect the guide rings to the fixed contact elements. The preselector is mounted on the side of the dialer. It contains two insulating columns of rails carrying fixed contact elements and driving rails with movable contact bridges. The insulation columns are reinforced with profile plastic arches.

The disadvantage of this pre-selected is that the Maltese wheels are large in size and complex to manufacture. If the dimensions are not correct, the Maltese gear can lock. For a different number of situations, the Maltese gears are different, which makes production difficult. Another disadvantage is that the entire load-bearing structure requires strong and straight insulating rails in order to ensure

2/13 stability. Another disadvantage is that the fixed even and odd contact elements are not arranged in sequence, which increases the requirements for insulation distances. Another disadvantage is that the design of the pre-selector is complicated.

Another known selector with a preselector (2) also comprising a central tube is contact rings and wires passing vertically inside it and a cage of insulating rails fastened between the upper housing and the lower flange. Fixed contact elements are mounted on the rails, which are arranged here in sequence. The housing has a Maltese gear of two Maltese wheels is large in size and complex configuration in order to achieve rotation at two different angles. The movable contact bridges are mounted on profile insulating girders, sliding on the contact rings, which have a special profile. They are driven by vertical columns. The pre-selector is located on the side of the selector and has a complex structure with large contact nodes.

The disadvantage of this selector is that it has large dimensions and complex construction. Maltese gears are large and complex and require very precise workmanship. For different numbers of situations are different, which complicates the production. Another disadvantage is that the pre-selector also has a complicated construction and relatively large dimensions.

A selector (3) is also known, in which the fixed contact elements are mounted on sectors cut out of an insulating glass roving cylinder. Even and odd contact rings are arranged on the central insulation pipe, and six wires are placed in it, passing upwards to the bottom of the oil vessel. Maltese gears and pre-selector are not shown, but it is assumed that they are similar to those of (1). The insulation sectors are attached to the upper body and lower flange.

3/13

The contact bridges are driven by vertical columns of insulating rails.

The disadvantage of this choice is that the fixed contact elements are not arranged in series, which impairs the insulation coordination. Other disadvantages are analogous to those of (1).

SUMMARY OF THE INVENTION

The object of the invention is to provide a selectable pre-selector for a step voltage regulator which has a compact, simple and stable construction. It shall have a central tube with six conductive rings arranged in layers, connected by six conductors passing axially inside the tube. Maltese gears should be simplified and unified for 10, 12 and 14 positions. The supports of the movable contact bridges should be stable with a small number of simple elements, providing work with sequentially arranged fixed contact elements. The pre-selector should be located on the side of the dialer and have a simple and stable construction.

The problem is solved with a pre-selector for a step voltage regulator, containing an upper metal flange and a lower metal flange with cage-shaped segments of insulating material attached between them, on which even and odd fixed contact elements are mounted. In the center of the chosen one there is an insulating pipe with even and odd current-carrying rings arranged on it in layers, which are connected by wires passing vertically upwards inside the pipe. Above the upper shield is mounted a housing with a drive system located in it with Maltese mechanisms, which are connected to vertical drive columns carrying movable current-carrying contact pins. Laterally on the dialer is located pre-selector is movable and immovable contact elements.

4/13

According to the invention, the drive system consists of a double gear attached to a drive shaft. On one side of the double translation there are two pins and rollers, which are located at a certain angle to each other. On the other side of the double translation, opposite 180 °, there are also two roller pins. An even block consisting of a Maltese wheel and a gear and a similar odd block consisting of a Maltese wheel and a gear are mounted on a vertical axis parallel to the drive shaft. The gear of the even block is engaged with a larger even gear bearing coaxially at the upper end of the central tube. At the elongated cylindrical end of this gear is bearing an odd gear with the same number of teeth that is engaged with the gear of the odd block.

To the elongated cylindrical part of the even large gear wheel is attached an even driving insulating segment and profile-cut ears, on which are mounted brackets with even contact pins with contact springs. To an elongated segment of the odd large gear is attached an odd drive insulating segment with profile-cut lugs, on which there are supports with odd contact pins.

The Maltese wheels of the two blocks have six channels with an angle between them of 60 °. The angle between the two pins with rollers of the double translation is similar. It complies with the requirement that when rotating the double gear 180 °, the Maltese wheel rotates smoothly and continuously in two steps of a total of 120 °.

In the 10, 12 and 14 positions selected, the double gear and the Maltese wheels do not change, and the achievement of the respective angles of rotation in a shift of 72 °, 60 ° and 51 ° 26 'is achieved by changing the gear ratio between the gears. The center distance is the same.

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The large even and odd gears are coaxially mounted on the central tube by rolling bearings.

In a different number of positions, respectively a different number of fixed contact elements per phase, there may be a different number of insulating segments, but it is recommended that for 12 positions the segments be four pieces with three contact elements each. For 14 positions, it is recommended that the segments be four, of which two segments with three contact elements each and two segments with four contact elements each. For 10 positions a good option is five segments with two contact elements. The arrangement of the insulation segments must be such that there is always oil insulation between the first and the last contact element in number.

The drive of the pre-selector is characterized by the fact that on the axis of the two blocks with gears and Maltese wheels is mounted a Maltese sector with a gear ring. The sector is connected on one side by a pin with a roller, which is mounted on a disk connected to the large odd gear. On the other hand, the Maltese sector is connected by its ring gear to a ring gear mounted on the drive shaft of the double gear. The arm is connected to vertical insulating rails carrying movable contact pins of the pre-selector.

An advantage of the selector with a pre-selector for a step voltage regulator according to the invention is that it has a simple, small-sized and light construction. Another advantage is that the Maltese wheels are the same in different positions. In general, they are more difficult to make than gears, for which there are specialized high-performance machines.

Another advantage is that the large gears are mounted coaxially on the central tube by rolling bearings due to the fact that their outer diameters are relatively small. This leads to

6/13 stable fastening of the drive sectors and their slight rotation. The sectors are shaped in such a way that the gripping of the movable contact thumb carriers does not require additional elements. Linear arrangement of the fixed contact elements is guaranteed, as there is an oil insulation distance between the first and the last number of contact elements. As an advantage, it can be taken into account that the drive system of the dialer is simple and stable.

EXPLANATION OF THE ATTACHED FIGURES

An exemplary embodiment of a pre-selector for a step voltage regulator according to the invention is shown in the attached figures, of which:

Figure 1 is a longitudinal section through the dialer and the pre-selector.

Figure 2 - Cross section over the Maltese and gears.

Figure 3 is a cross-sectional view above the selector drive mechanisms.

Figure 4 - cross section over the contact systems.

Figure 5 is a longitudinal section showing a front view of the movable contact bridge girders.

EXAMPLES OF EMBODIMENT OF THE INVENTION

Between the upper metal flange 1 and the lower metal flange 2 are fixed a number of segments 3 cut from an insulating cylinder and arranged as a round cage. On the segments 3 are mounted floor odd fixed contact elements 4 and even fixed contact elements 5. On the flange 1 is located a housing 6, which houses the actuators of the selected. In the center of the elected to

7/13 of the housing 6 above and the lower flange 2 below is attached an insulating pipe 7, around which odd conductive rings 8 and even current-carrying rings 9 are mounted on the floor. The central pipe 7 is connected to the housing 6 by a ring 10 and to the lower flange 2 by axis 11 is a flange 12. Inside the central tube 7 are six wires 13, three of which are connected to the odd conductive rings 8 and three - is the even conductive rings 9. The conductors 13 pass up into the central tube 7 and above the housing 6, have curved ends 14 by means of which they are connected in a known manner to an oil tank and a power switch not shown.

An even drive gear 16 is mounted on the ring 10 by a rolling bearing 15, connected by its cylindrical end 17 to an even drive insulating segment 18. An odd gear 19 is mounted on the end 17, the elongated segment 20 of which is connected to an odd drive segment. 21. At their lower end, the two segments 18 and 21 have arms 22 and 23 through which 24 are mounted on the shaft 11. The two gears 16 and 19 rotate alternately at a certain angle by a double gear 25 by two blocks 26 and 27 composed of one Maltese wheel 28 and one gear 29. The double gear 25 has four pins and rollers 30, two on one side and two on the other. It is mounted on a drive shaft 31, which is rotated in a known manner by a freewheel clutch not shown. The two blocks 26 and 27 are mounted on an axis 32. The conductors 13 are reinforced in their upper part by an insulating plate 33 with fixed channels. It is mounted on top of the housing 6.

The even insulating segment 18 has profile cut-out lugs 34, to which are mounted supports 35 with mounted contact pins 36 and contact springs 37. Similarly, the odd insulating segment 21 has lugs 38 on which such carriers 35 with contact pins are also mounted. 36 and contact springs 37.

8/13

In the considered example there are 12 pcs. fixed contact elements arranged sequentially clockwise. The odd contact elements 1,3,5,7,9,11 occupy the upper row of each phase, and the even 2, 4, 6, 8, 10, 12 (K) are arranged below them. There are selected ones in which the even contact elements are on top and the odd ones are below them, but this does not change the essence of the invention.

The pre-selector, designed as a reverser, is located on the side of the dialer. It has an upper sector 38 and a lower sector 39, between which is attached an insulating segment 40, on which are mounted two fixed contact elements 41 and 42 per phase. L-shaped conductive elements 43 are attached to the end contact elements 5. With them and alternatively the contact elements 41 and 42 contact the contact pins 44 with the contact springs 45. The pins 44 are attached to supports 46 mounted on insulating rails 47, which above are attached to a shoulder with a ring gear 48, and below - to a shoulder 49, bearing to the lower sector 39. The arm 48 is a bearing of a shaft 31, and its gear ring is engaged with a gear ring of the Maltese sector 50, mounted on a shaft 32. A disk 51 with a pin with a roller 52 is mounted to the segment 20 of the odd gear 19. The disk 51 rubs its rim on the respective arm of the Maltese sector 50 and blocks it in normal working position.

The action of the voter with a pre-voter is as follows. In the drawings, the even movable contact pins 36 connect the even contact rings 9 is a fixed even contact element 5 located in the twelfth position connected to the preselector. The voter is for twelve positions, ie. there are six odd contact elements 4 and six even contact elements 5 per phase. The odd movable contact thumbs are in the first position. When switching from the eleventh to the first position, the pre-selector is activated and the contact thumbs 44 are

9/13 passed from the contact element 42 to the contact element 41. The current flows through the contact circuit in the first position. When reversing the movement, due to the presence of a freewheel clutch, shaft 31 rotates at a small angle counterclockwise and the contact systems of the selector remain stationary, and only the power switch switches. The current is already flowing through the contact elements of the twelfth position. When the shaft 31 is further rotated 180 ° counterclockwise, the double gear 25 reverses the Maltese wheel 27 of the odd gear in two successive steps, as a result of which the gear 19 with disc 51 also rotates counterclockwise. at 30 °. The odd contact thumbs pass from the first position to the eleventh. A pin with a roller 52 turns the Maltese sector 50 and the contact pins 44 of the pre-selector pass from the contact element 41 to 42.

Claims (6)

PATENT CLAIMS 1. Selector with preselector for step voltage regulator, comprising an upper metal flange and a lower metal flange with cage-shaped segments of insulating material with fixed even and odd contact elements, and in the center of the selector there is an insulating tube with evenly arranged even and odd conductive rings connected by wires passing vertically upwards, inside the tube above the upper shield is mounted a housing with a drive system located in it with Maltese mechanisms connected to vertical drive columns bearing movable conductive contact pins, and a selector is located on the side of the selector. fixed contact elements, characterized in that the drive system consists of a double translation (25) with two pins with rollers (30) located at a certain angle on one side and two similar pins with rollers located at 180 ° on the other side, on a parallel vertical axis is mounted an even block (26) of a Maltese wheel (28) and a gear olelo (29) and mounted below it an odd block (27) of Maltese and gear, the even gear (29) is engaged with a large even gear (16) bearing coaxially at the upper end of the central tube (7), below it on its elongated cylindrical end (17) is a bearing of an odd gear (19) engaged with the gear (29) of the odd block (27), and to the elongated cylindrical end (17) of the even gear (16) is attached an even driving insulating segment. (18) with profile cut-out lugs (38) on which mounts (35) with even contact pins (36) with contact springs (37) are mounted, and to an elongated segment (20) of the odd gear 11/13 (19) is attached an odd drive segment (21) with profile-cut ears (34) on which there are brackets (35) with odd contact pins (36). Selected with a pre-selector for step voltage regulator according to claim 1, characterized in that the Maltese wheels (28) of the two blocks (26, 27) have six channels each with an angle between them of 60 ° and the angle between the two pins with rollers (30) of the double translation (25) are similar and comply with the requirement when rotating the double translation (25) by 180 °, the Maltese wheel (28) to rotate smoothly and continuously in two steps of a total of 120 ° . Selected with a preselector for step voltage regulator according to claims 1 and 2, characterized in that in positions selected with 10, 12 and 14 the double gear (25) and the Maltese wheels (28) do not change, but the achievement of the respective Rotation angles at a shift of 72 °, 60 ° and 51 ° 26 'are achieved by changing the gear ratio between the gears (26 - 16) and (26 - 19), respectively, the center distance not changing. Selected with a pre-selector for a step voltage regulator according to claims 1, 2 and 3, characterized in that the gears (16 and 19) are mounted by rolling bearings. A pre-selector for a step voltage regulator according to claims 1, 2, 3 and 4 is selected, characterized in that in a different number of positions, respectively a different number of fixed contact elements (4, 5) per phase, there may be a different number of insulating segments (3), but it is recommended for 12 positions the segments (3) to be four pieces with three contact elements (4, 5), for 12/13 14 positions - two segments is three contact elements and two segments is four contact elements and in 10 positions - five segments with two contact elements, but the arrangement of the segments should be such that always between the first and last by number contact element to there is also oil insulation. Selector with preselector for step voltage regulator according to claims 1, 2, 3, 4 and 5, characterized in that a Maltese sector with a ring gear (50) is mounted on an axis (32) below the block (27), which on one side is connected to a pin with a roller (52) mounted on a disk (51) attached to a gear wheel (19), and on the other side is connected to a toothed ring on a shoulder (48) mounted on the drive shaft (31) of the double translation (25), the arm (48) being connected to vertical insulating rails (47) bearing movable contact pins (44) of the preselector.