JPS6044812B2 - Load tap selector for on-load tap-changing transformers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a load selector for an on-load tap-switching transformer.

A load selector of this type is known (West German Patent Application Publication No. 226005). With this load selector, there are difficulties in adapting the switching speed to different step widths, especially if sudden actuation of the contact lever is to be carried out. In known load selectors, the switching speed is adapted via differently configured Geneva gear notches into which the two pins of the drive crank enter simultaneously or directly one after the other for large switching steps. However, this method is complicated and makes high demands on the Geneva gearing due to the desired sudden actuation of the contact lever. A precise cooperation between the drive pin and the Geneva gear notch is required, which can only be achieved at great expense. In particular, this method faces difficulties when, for example, two contact levers are actuated one after the other at short intervals, so that the contact lever comes into contact with both adjacent stationary contacts for a short time during the switching process. . The object of the invention is to develop the known load selector in such a way that the various switching steps of the contact lever can be carried out directly by means of a power accumulator.

- According to the invention, this problem is achieved in the load selector mentioned at the outset by the measures specified in the characterizing part of patent claim 1. By means of the load selector according to the invention, the energy accumulator is energized differently depending on the various step widths of the contact lever.
However, it is then possible for the switching step of the contact lever to be carried out directly by the energy accumulator.

In a further embodiment of the invention, two contact levers are provided by the use of two energy accumulators, both of which are energized by the same Geneva gear, but which are released one after the other! First, one contact lever advances the load selector to the adjacent fixed contact,
Immediately after contact of this contact lever with a new fixed contact, it is possible to activate the other contact lever to follow. Both movement courses of the two contact levers are then carried out abruptly in a similar manner, which is very advantageous for overcoming switching forces. Embodiments of the present invention will be described in detail based on the drawings.

As is clear from FIGS. 1 and 2, in the new load selector, a plurality of fixed contacts 1, 2, 3, 4, 5 are arranged in a circle on the substrate 6.

Two contact levers 7, 8 are supported on an axis 91 in the center of the circle, which can be moved in steps from stationary contact 1 to an adjacent stationary contact 2 or 3, etc. This means that the two insulating shafts 9, 1 coaxially inserted into each other
0, the inner insulating shaft 9 is connected to the intermediate part 9
2 through one contact levano 7 and the outer insulating shaft 1
0 moves the other contact lever 8. In this case, the contact lever 8 is held by a pivotable support 11, which is fixed to the lower end of the insulating shaft 10 by an intermediate member 12 and carries a switching resistor 131. One contact lever 7 has a shaft 9
1 , while the contact lever 8 is firstly connected via a screw 81 to a resistor 131 , which in turn is connected to the shaft 91 via a screw 82 , a flexible conductor 83 and a sliding contact 84 . The two insulating shafts 9, 10, which are electrically connected to the housing base plate 14, are mounted on bearing flanges 13 of the housing base plate 14 and are each provided with a toothed disc 15, 16. Each of the toothed disks 15 and 16 has a double energy accumulator 1.
The driven discs 17, 18 of 9, 20 are engaged and the energy accumulator can be energized by the Geneva gear 21 (see also FIG. 3).
In this case, the double energy accumulators 19, 20 are essentially the aforementioned Geneva gear 21 with a projection 22 and one spring 23 in each case gripping the projection 22 with legs 25, 26 (see also FIG. 4). . Each pawl mechanism consists of a two-armed pawl lever 30, 31 or 32, 33 supported on a plate 17, 18 and is arranged concentrically with respect to the driven disc 17 or 18, and the pawl lever 30, 31 or each one toothed ring 34 or 3 which comes to be abutted by 32, 33;
5 (see Figures 4 and 5). Geneva gear 2
1 is supported on the housing base plate 14 by an axle 56 in a manner not shown in detail. The shaft 56 is then simultaneously used as a bearing for the two driven discs 17, 18, and the torsion springs 23, 24 are fitted onto the bearing bushes 57, 58. Further details of the embodiments will be explained in detail based on the method of operation described below.

The function of the new load selector is as follows. The load selector is shown in the reference position with both contact levers 7, 8 resting on fixed contact 1, with both contact levers 7, 8 resting on fixed contact 1.
connects the fixed contact 1 to the shaft 91.

Are both adjacent fixed contacts 2 and 3 in one drawing? As can be seen, it is arranged at a greater distance from the fixed contact 1 than from the other two adjacent fixed contacts 4, 5, depending on the voltage occurring here. This means that during the subsequent switching process both contact levers 7, 8 move from fixed contact piece 1 to fixed contact piece 2 or 3J, from fixed contact piece 2 to fixed contact piece 4 or from fixed contact piece 3 to fixed contact piece 2 or 3J. This means that a larger switching step than the switching process to the fixed contact piece 5 has to be carried out. To initiate the switching process, the crank 36 is rotated by the shaft 37, for example, by 3603 in the direction of the arrow (switching from contact 1 to contact 3). At this time, the upper pin 38 of the crank 36 engages with the geneva notch 39. This general notch 39 corresponds to the large distance between the fixed contact 1 and (FIG. 2), for example, so that the general notch 41 has a center line 42 (
3) from the centerline 40. Corresponding to the geneva notches 39, 41, the geneva gear 21 is rotated differently, with the I-crank 3 being rotated in a different manner for the geneva notch 41 of the subsequent cutoff.
The pin 43 at the bottom of No. 6 is used.

During rotation of the Geneva gear 21, the projections 22 each carry one leg 25 of the torsion springs 23, 24, and the torsion springs are biased. This is because the driven discs 17, 18 in this case have their claws 30, 3 in contact with the teeth 45 with their claw surfaces 44.
2 so that the projections 27 of the two driven discs 17, 18 are held in place by the other leg 26 of the associated torsion spring 23 or 24.
This is because it holds it immovably. Both torsion springs 23, 24
After the Geneva gear 21 is rotated by a certain angle while the Geneva gear 21 is energized, the protrusion 46 that connects the Geneva gear 21 is connected to the pawl lever 3.
0 towards the end 47 of the upper accumulator 19 , in which case the claw surface 44 of the upper energy accumulator 19 slides off the teeth 45 and releases the driven disc 17 so that it is forced by the leg 26 of the torsion spring 23 . to complete the rotational movement of the Geneva gear (the only thing that this process has in common is that, if it is to be switched in the opposite direction, the projection 48 is moved towards the end 49 of the other pawl lever 31). is self-evident). The driven disc 17 released by the protrusion 46 and the pawl lever 30 is moved into the toothed disc 15 via a pin 50 which engages in a corresponding recess in the toothed disc 15.
The contact lever 7 is pivoted via the associated insulated shaft 9 while maintaining
reach. In this case, an electrical connection is created between the fixed contact 1 and the fixed contact 3, i.e. the electrical connection is made from the fixed contact 1 to the contact lever 8, the resistor 131, the flexible conductor 83, the shaft 91 and the contact lever as described above. The fixed contact 3 is configured to come into contact with the fixed contact 3 via the contact 7. However, this electrical connection is established only for a short time. This is because as soon as the driven disk 17 of the first energy accumulator 19 has completed a part of its movement, this movement is caused by the driven disk 1 corresponding to the projection 46 of the Geneva gear 21.
7 causes the second energy accumulator 20 to be released in the same way as was done with the energy accumulator 19. The thus released driven disc 18 then of course drives the toothed disc 16 in the same manner as the driven disc 17. In this way, the outer insulating shaft 10 and the contact lever 8 are pivoted, so that the contact lever 8 also reaches from the contact point 1 to the contact point 3.
In this process, the claw levers 30 and 32 of both accumulators 19 and 20 are
is the next tooth 46 of both toothed rings 34, 35 with its short claw surface 51.
be detained. At this time, this tooth 46 as well as other teeth 461 are in a state of cooperating with a claw surface 51 in a plane other than the aforementioned tooth 45, and since the tooth 45 must cooperate with the long claw surface 44, the claw surface It is located in the same plane as 44. This means that for a standard equal switching step, the switching step is outside the range of contacts 1, 2 and 3 or teeth 45, 45.
For switching steps other than 1, 53, the long pawl surfaces 44, 4 of the one-jaw levers 30, 32 or 31, 33 are used.
41 moves freely in the toothed rings 34, 35, meaning that it is not constrained. Detention via the long pawl surface 44 is only possible between the pawl surface 44 and the tooth 45 if switched clockwise starting from FIG. 4, or between the pawl surface 441 and the tooth 451 in the opposite switching direction. It will be done. The long nail surface 44 is 44
Engagement according to 1 will only otherwise take place if the pawl mechanism is, for example, at the level of the tooth 451 corresponding to the locking contact 2 and is to be switched in the clockwise direction. In this case the long claw surface 44 is restrained by the teeth 53. The same applies if the contact 3 is to be switched counterclockwise outside the position of the tooth 45 from the other side. In this case the long claw surface 441 is also restrained by the teeth 53. Since both claw surfaces 44 and 441 are in different planes, this tooth 53 is attached to the toothed ring 34 or 3.
It extends over both planes forming a total height of 5. On the other hand, in the case of switching, for example in the clockwise direction, starting from the position of the tooth 461; another standard switching step is carried out in which a pawl lever 30 with a short pawl surface 51 is required, so that the plane of this pawl surface 51 In this case, tooth 451 is also designed as a standard tooth corresponding to tooth 461. The same thing naturally applies to the teeth 45 that are formed as standard teeth even on short claw surfaces. It will of course be understood that both accumulators with toothed rings 34, 35, torsion springs 23, 24, pawl mechanisms are similarly constructed and function in a similar manner.

As already explained, the only connection and disengagement is in the energy accumulator 19 via the projections 46, 48 of the Geneva gear, and in the energy accumulator 20; This is done through a protrusion formed in the. The use of a second energy accumulator only makes sense if, as in the exemplary embodiment, the two contact levers 7, 8 are to be activated one after the other. For example, as long as only one contact lever with two separate contact pieces with an intermediately connected resistor is actuated,
The invention works with only one energy accumulator. However, this embodiment is also advantageously provided with a two-arm pawl mechanism and correspondingly designed teeth of the toothed ring, so that a completely identical movement course can be obtained for both switching directions. It may be advantageous for the contact levers to be arranged one above the other as in the exemplary embodiment, as long as two separately movable contact levers are used. Both contact levers have pairs of roller contacts 54, 55 rolling on fixed contacts, the roller contact 54 of the lower contact lever 7 on the inner circle and the roller contact 55 of the upper contact lever 8 on the outer circle. run.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal cross-sectional view of the load selector of the present invention, FIG. 2 is a cross-sectional view of the contact system taken along line E-F in FIG. 1, and FIG. 3 is a diagram of the Geneva gear engaged with the driven crank. A plan view, FIG. 4 shows a cross-sectional view of the accumulator along line A--B in FIG. 1, and FIG. 5 shows a partial cross-sectional view of the claw system along line G--H in FIG. Symbols 7, 8 in the figure... Contact levers, 17, 18...
Driven disc, 19, 20... Energy accumulator, 21...
...Geneva gear, 23,24... Energy accumulator, 30
, 31, 32, 33...Claw lever, 44, 45 or 441,511...Claw surface, 45, 46 or 4
51,461...teeth.

Claims (1)

[Scope of Claims] 1. The contact lever includes fixed contacts arranged at different intervals on the circumference and a contact lever that can be pivoted in steps around the axis of the circle. Under implementation, it can be actuated by a drive having a Geneva gear which in turn comes into contact with a fixed contact and is provided with different notches for the engagement of a crank with a pin, the pin being A load tap selector for on-load tap-changing transformers with different distances from the axis of rotation of the crank, characterized by accumulators 19, 20 which can be activated differently by means of Geneva gears 21; The actuator is coaxially supported on the Geneva gear and drives the contact levers 7 and 8, and the pawl lever 30,
having driven discs 17, 18 with 31, 32, 33;
The pawl lever is provided with teeth 45, 451 of toothed rings 34, 35, which are arranged coaxially with respect to the driven disc when the energy accumulators 23, 24 are energized.
46, 461, and 53, and at that time, the teeth 45,
46, 53, 451 are arranged at different radial distances from each other in accordance with the different switching steps, and the pawl lever has two pawl surfaces 4 forming different pawl lengths.
4, 51 or 441, 511, the pawl surfaces are located in two planes and have differently formed teeth 45, 46 or 451, 461, which are also arranged in two planes. A load selector for an on-load tap-changing transformer, characterized in that it cooperates in such a way that different pawl path lengths are produced upon energization of the energizer or upon release of the pawl. 2. characterized by two symmetrically designed and scissor-shaped mounted pawl levers 30, 31, 32, 33, one pawl lever 30, 32 or 31, 33 acting for each switching direction; A load selector according to claim 1. 3 characterized by two switching arms 7, 8, which can be actuated by respective switching shafts 9, 10 arranged concentrically with respect to each other, each switching shaft being both driven by a Geneva gear 21; It can be actuated by a separate energizable energy accumulator 19, 20, and the second energy accumulator 20 can be disengaged and disengaged after being released by the first energy accumulator 19. A load selector according to claim 1 or 2.