DE3838195A1 - Power tap changer - Google Patents

Abstract

A power tap changer has a first Maltese-cross mechanism for opening the moving contacts from stationary contacts before the movement of the moving contacts in conjunction with control elements (into connection with control elements), and a second Maltese-cross mechanism for moving the moving contacts to adjacent, stationary contacts. The first and second Maltese-cross mechanisms are each provided with Maltese-cross drives and Maltese discs which are driven intermittently by the corresponding Maltese-cross drive (Geneva drive).

Description

The invention relates to a power tap switching device device and in particular contactor elements of a tap len selector for power tapping points which are suitable for gas-insulated transformers.

With a contactor for a tap or step selector of a conventional power tap change The oil protection device serves as an insulating oil Lubricating oil, which causes the formation of metal dust due to Frictional wear of the contactors of the type prevented such as this in Japanese Patent Application Laid-Open No. 42 293/1976. With a contact for egg A tap error of the gas-protected type is not, however Contain medium that fulfills a lubrication function, so that it therefore, the surface of the contacts with a To coat lubricants, such as grease. At gasge Protected transformers, however, it is necessary to turn off the gas seal, so that the degassing process is required every time is when grease is placed on the contactor, taking it Process is cumbersome and laborious maintenance leads.

Japanese patent application 49 126/1977 relates to one Power tap changer of the roller type, wel accomplished a role contact to the disadvantage of the above to avoid described, gas-protected type and in out sufficient generation of metal dust due to Avoids sliding wear of the conventional sliding contacts.

But even with the type of roller contacts, it is just as difficult rig, the wear due to the "roll" process increases significantly suppress and in devices and units such as power Changeover switches, which are required for frequent changes, it is extremely difficult due to the creation of metal dust  switch off from wear.

The object of the invention is to overcome the disadvantages described above to avoid and a power tap changer or power Tap switch with a contact device to create wel avoiding the formation of metal dust during the Exchange process allows.

Another object of the invention is to provide a power tap switch with a Maltese cross mechanism for the contact Setting up the level changer to avoid metal dust Provide education due to wear.

These and other objects can be achieved according to the invention enough that a power tap switch is provided which has a plurality of stationary contacts, the operatively connected to the tap turns of a transformer are, as well as movable contacts for contacting the Sta tionary contacts, the changeover switch being characterized by that the movable contacts by a first Maltese cross Mechanism to be opened if these are to be moved the first Maltese cross mechanism with disc elements is equipped, in which a gear engages, the movable Contacts from the stationary contacts through a control curve on direction for opening and closing the contacts are separated, which are directly connected to the gear elements that are on this way separate movable contacts to neighboring ones Stationary contacts through a second Maltese cross mechanism be moved and then the first Maltese cross mechanism is driven that the movable contacts with the stationary contacts can be brought into contact.

In a preferred embodiment of the invention, the Control elements formed with a groove in which intervene in a large number of cam sequences, which are operatively associated with the movable contacts are connected to these upwards and move down.  

Furthermore, the first and second Maltese cross mechanism with a Maltese cross drive (genever drives) and Maltese cross-discs provided by the Maltese cross drive be intermittent, preferably with an angular offset of Can be turned 180 °.

According to the constructive features of the inven described above the movable contacts are closed by their Condition first separated from the stationary contacts Direction to the next, neighboring stationary contacts in order to be closed there again, the process for the movable contacts through two Maltese cross mechanisms in the way is organized that the movable contacts initially from the stationary contacts through the activity of the first Maltese Cross mechanism are separated and the abge in this way raised movable contacts then to the next, adjacent ten stationary contacts through action of the second Maltese cross mechanism to be moved. The first Maltese cross mecha then works again to close the moving contacts shut down. During these activities, no grinding another rolling contact in relation to the contact surfaces of the mov liche and stationary contacts instead, which also means no measurement tall dust due to wear between the two contacts ten is generated and therefore the reliability in the insulation is increased. Also, because of the avoidance of metal Dust due to wear will noticeably affect the life of the contacts be improved. After all, the whole structure of the Power tap switch by using the tax extremely compact curve with only one groove.

In the following, a preferred embodiment of the Invention in detail with reference to the drawings wrote.

Show it:

Fig. 1 is an elevation section of an embodiment of the invention;

Fig. 2 is a perspective view of a circuit breaker according to the embodiment of FIG. 1 in an exploded form (exploded view).

Fig. 3 is a diagram of the sequence of operations of the embodiment of Fig. 1 or 2;

Fig. 4 to 12 representations on an enlarged scale of the Malteserrad mechanism of the embodiment shown in Fig. 1 or 2 illustrated to explain the operation of the main switch;

FIG. 13 is a view showing a movable contact along the section plane XIII-XIII according to FIG. 14;

FIG. 14 shows a cross section XIV-XIV according to FIG. 13, which also shows the structure of the movable contact;

FIGS. 15 and 16 are diagrams for explaining the joint effect as the movable contact and the Nutensteuerkurve which is provided with a groove in connection with the stationary contact provided.

An embodiment according to the invention is first described with reference to FIGS. 1 to 16. Is shown in Figs. 1 and 2, a transmission mechanism is provided with the reference numeral 1 describes the effect (not shown) with an electrical Antriebsmechanis mechanism is connected for rotation to He or lowering ben a tap in response to the Variegated tion a reference voltage suitable . A drive shaft 2 made of insulating material is connected to the transmission mechanism 1 via a clutch shaft and designed to transmit its rotation. The reference numeral 3 denotes an indicator for displaying a switching operation to be described later on the basis of the driving force, which is transmitted from the drive shaft 2 to an external unit. The indicator 3 is formed with a viewing hole or shop window in an area near the transmission mechanism 1 in order to be able to observe its operating conditions from the outside. The first Maltese disk mechanism is formed by disks and elements 4 , 6 and 7 and the second Maltese disk mechanism by disks and elements 5 , 8 and 9 .

The first Maltese disc mechanism is initially in the after described below.  

The component 4 is a Maltese cross drive (genever drive), which is operatively connected to the drive shaft 2 in order to rotate clockwise or counterclockwise depending on the activity of the external, electrical drive mechanism in its lifting or lowering direction. A plurality of pins 4 a , 4 b , 4 c and 4 d for driving the Maltese discs (A) 6 and (C) 7 are arranged on the surface of the Maltese cross drive (A) 4 , so that the pins 4th c and 4 d lie on its rear surface at locations at angles of 180 ° with respect to the arrangement of the pins 4 a and 4 b on its front. The pins 4 a and 4 b drive the Maltese cross (A) 6 and the pins 4 c and 4 d drive the Maltese cross (C) 7 . If the Maltese cross drive (A) 4 is rotated continuously in one direction or in the opposite direction, the Maltese disks (A) 6 and (C) 7 can alternately by the pins te 4 a , 4 b and 4 c in this structure , 4 d are rotated, which are arranged symmetrically at angles of 180 °.

A Maltese cross drive (B) 5 is also connected to the drive shaft 2 to drive A 4 to be rotated simultaneously with the Maltese cross drive. As described above in connection with the Maltese cross drive (A) 4 , a plurality of pins 5 a , 5 b , 5 c and 5 d for driving the Maltese cross disks (B) 8 and (D) 9 on the front and rear surface of the Maltese cross drive (B) 5 arranged in a symmetrical arrangement at angles of 180 °, so that the pins 5 a , 5 b and 5 c , 5 d alternately the Maltese discs (C) 8 and (D) 9 can drive.

If the drive shaft 2 is rotated in one direction by 180 °, the Geneva discs (A) 5 and (C) 8 through the pins 4 a and 4 b of the Maltese cross drive (A) 4 or through the pins 5 a and 5 b of the Maltese cross drive (B) 5 driven in a predetermined time sequence. The subsequent rotation of the drive shaft 2 by 180 ° drives the Maltese disks (C) 7 and (D) 9 by means of the pins 4 c and 4 d of the Maltese cross drive (A) 4 or the pins 5 c and 5 d of the Maltese cross At drives (B) 5 in the predetermined time sequence. The disks (A) 6 and (C) 7 have inner, circular recesses, the inner circumference of which is formed with an inner ring gear in which rotatable toothed wheels 10 and 12 engage. With the toothed wheels 10 and 12 , rotary shafts 11 and 13 made of insulating material are directly coupled, which serve to transmit the rotations via the isolation shafts 16 to the movable contact elements 17 of the main tap changer on the even-numbered side and the odd-numbered side. The insulation shafts 16 are, as shown in Fig. 1, inserted between the corresponding movable contact elements 17 on the even and odd the sides of the corresponding phases, thereby affording the state of insulation between the corresponding phases. In the central areas of the Geneva discs (B) 8 and (D) 9 cylindrical elements are used, so that the inner cylindrical element of the Geneva disc (B) 8 has an outer diameter which is smaller than that of the outer cylindrical element of the Geneva disc ( D) 9 , wherein an inner and an outer drive insulation cylinder 14 and 15 are connected to these inner and outer cylindrical elements in order to be able to rotate together with the Geneva disks (B ) 8 and (D) 9 . On the drive isolation cylinders 14 and 15 , three pairs of movable contact elements 17 for the main stage switch are attached to the even and odd sides at predetermined intervals to thereby form a 3-phase structure.

The paragraph of the movable contact elements 17 will now be described with reference to FIGS. 13 to 15, which shows the construction of a single movable contact element which is attached to the outer drive insulation cylinder 15 of the main switch. The inner drive insulation cylinder 14 and a movable contact 23 of a sub-switch have substantially the same inner structure as the Isolationszy cylinder 15 and the movable contact elements 17 , except for a slight difference in their BEFE stigungsaufbau.

The reference numeral 17 a denotes a plurality of movable contact pairs, each pair comprising an upper and a lower contact, which are arranged such that they clasp a stationary contact 24 and a collector ring 17 d .

A plurality of slide springs 17 c are provided for corresponding to the movable contacts 17 a to a Kontaktan pressure to the movable contacts 17 a exercise which is required for the current flow. A carrier elements 17 f serves to hold the movable contacts 17 a and is guided by linear bearings 17 k for a movement up and down, which che are attached to both side surfaces of the inside of a housing 17 e . A rotary shaft 17 is in the upper and lower loading area rotatably supported by bearings 17 j and cam followers 17 g are attached to the rotary shaft 17 h in symmetrical bearings at angles of 180 °, which are guided in a groove of a control curve 17 b when rotating, as can be seen from Fig. 15.

The groove has a maximum offset with each rotation by 90 ° to move the movable contacts 17 a in the upper and lower direction, as shown in Fig. 15. The housing 17 e is attached to the drive insulation cylinder 15 in the manner shown in Fig. 13, so that the movable contact 17 a can be brought from one stationary contact to another stationary contact in the rotation of the drive insulation cylinder. The stationary contacts 24 of the required number for the three-phase structure are attached to a plurality of Isolationsää len 25 , which are arranged in a circle at certain distances from each other and are supported in the upper and lower region by holding elements 30 and 31 .

Next, the sub switch will be described below. The Maltese cross disk (D ) 9 has a front and three drive pins 9 a , 9 b and 9 b , which are arranged in a rich area of the front, the pins 9 a in the middle and the pins 9 b are on both sides . The arrangement of the pins 9 a and 9 b is such that they meet with the locations of the three recesses which are formed in a Maltese cross disk (E) 18 as soon as they are to engage with one another. The Maltese disc be (E) 18 has an outer peripheral edge with a loading area, which is designed as an external gear, which in turn engages a gear 20 to transmit the rotation of the Maltese disc (E) 18 . The gear 20 is rotatably connected to a part of a fork element 19 which is located below the gear 20 . The Geneva plate (E) 18 and the Ga belelement 19 are mounted together on a shaft 32 for a corresponding rotation and the fork element 19 is provided with a recess 19 a , the shape of the shape of the central recess 18 a of the Geneva plate (E) 18 corresponds so that the fork member 19 can be rotated together with the Geneva disk 18 via the drive pin 9 a . The gear 20 is mounted on a rotary shaft 27 , which is operatively connected to the movable contact 23 of the sub-switch to move the movable contact 23 of the sub-switch in the upper and lower direction via a control curve 23 b and through with a stationary contact 28 and a collector 23 e in contact or to separate from this. At 22 , three pairs of drive plates are designated, to which the movable contacts 23 are attached at predetermined intervals between them and one of whose ends is attached to the fork element so that the movable contacts 23 to the other adjacent, stationary contacts 28 can be moved due to the rotation of the fork member 19 . A plurality of stationary contacts 28 is attached to the insulation column 29 , as can be seen from FIG. 2.

A detailed illustration of the movable contacts 23 of the sub-switch is omitted here, since the structure is essentially the same as that of the movable contact elements 17 of the main switch, except that a housing 23 d is attached to the drive plate 22 .

The operation of the power tap changer according to the invention with the structure described above will now be explained with reference to FIGS . 3 to 12. Since the operation of the main switch and that of the secondary switch are in principle essentially the same, the detailed analysis is given only with respect to the main switch.

Fig. 3 is a diagram showing the operation during the period of changing a stage, means or elements are described in the drive system on the left side of the diagram and the operating states of these elements in the direction of the horizontal axis of the diagram are Darge .

The Maltese disks (A) 6 and (B) 8 are rotated by the pins 4 a , 4 b and 5 a , which on the front sides (upper surfaces according to FIGS. 1 and 2) of the Maltese cross drives (A) 4 and (B) 5 are arranged when the tapping points are changed on the odd-numbered side. On the other hand, the Maltese disks (C) 7 and (D) 9 are rotated by the pins 4 c , 4 d and 5 b , which are arranged on the rear surfaces of the Maltese cross drives (A) 4 and (B) 5 when the tap digits to be changed on the even numbered side. In Fig. 3, the even-numbered operation is shown by broken lines.

As described above, in actual operation, provided that the tapping points on the odd-numbered side initially start the operation, the Geneva plates (A) 6 and (B) 8 are first rotated to end the changing operation of the first ON step. The Geneva discs (C) 7 and (D) 9 are held stationary during the first ON-step process, since the pins 4 c , 4 d and 5 b are idle. In the next step, the mal tester discs (C) 7 and (D) 9 are rotated and the Maltese discs ( A) 6 and (B) 8 are held stationary. The Geneva wheels (A) 6 , (B) 8 and (C) 7 , (D) 9 are thus rotated alternately. The Geneva disk (E) 18 for the auxiliary switch is rotated by the Geneva disk (D) 9 only in the predetermined position, to thereby carry out the changing operation.

The positional relationship between the Maltese cross drives (A) 4 and (B) 5 and the Maltese disks (A) 6 and (B) 8 during the operating period, ie in the regular positions, is shown in Fig. 4, which represents the state caused by At the tap marking n is marked according to FIG. 3, the changeover process from this state being as follows.

The Maltese cross drives (A) 4 and (B) 5 are rotated in the direction of the arrow by the external, electrical drive mechanism (not shown), by the drive mechanism 1 and the insulation drive shaft 2 simultaneously. Due to the rotation of the Maltese cross drives, one of the drive pins 4 b engages in the corresponding recess in the Maltese disk (A) 6 in order to rotate the same by a predetermined angle. Due to the water rotation of the Geneva wheel (A) 6 , the internal ring gear, the gear 10 and the cam 17 b of the movable contact elements 17 are rotated and the movable contact 17 a is from the stationary contact 24 and the collector ring 17 d due to the offset of the control groove separated by the rotation of the control cam 17 b . This state is shown in Fig. 3 by the marking (I) and shown in Fig. 5 concretely.

In the next step, the pin 4 a of the Maltese cross drive (A) 4 and the pin 5 b of the Maltese cross drive (B) 5 synchronously with each other in the recesses of the Maltese discs (A) 6 and (B) 8 and the Geneva discs (A) 6 and (B) 8 are rotated in a synchronous manner in order to move the movable contact elements 17 to the next, adjacent stationary contact and stop there in a regular position, which is indicated by the state (II) in FIG. 3 is shown and shown in Fig. 6. In the next step, the other of the drive pins 4 b engages in the recess of the Geneva disk (A) 6 , in order to thereby rotate it again. The control curve 17 b of the movable contact elements 17 then rotates simultaneously in order to make contact with the movable contact 17 a and the stationary contact 24 and the collector 17 d again , whereby the movable contact elements return to their starting position, which is determined by the state (III ) is shown in Fig. 3. The Maltese cross drives (A) 4 and (B) 5 continue to rotate (ie an idle rotation) by 180 ° according to FIG. 7 and stop in a regular position of the tap number (n 1 ) with completion of the tap changing process in one step.

The tapping change operation with respect to the tapping points of the uneven-numbered side of the main tapping switch is described in the preceding, the description of the tapping-changing operation with respect to the tapping points of the even-numbered side of the main changeover switch is essentially the same as that of the odd-numbered side, so that their explanation can be omitted here. It is noted, however, that in the tapping change operation of the even-numbered side, the Geneva disk (E) 18 for the auxiliary switch and the fork element 19 are similar to the tapping change operation of the odd-numbered side described and the activities of a drive pin 9 a and two drive pins 9 b of the Geneva wheel (D) 9 work in the regular position. This state will now be described with reference to FIGS. 8 to 12.

Fig. 8 shows a state of the regular location, in which the movable contact 23 closed. When the Maltese disc (D) 9 rotates, as shown in FIG. 8, the drive pin 9 b engages with the recess of the Maltese disc (E) 18 and rotates it by a predetermined angle in the direction of the arrow. The rotation of the Geneva wheel (E) 18 is transmitted to the external ring gear, the gear 20 and the control cam 23 b , whereby the movable contact 23 a is separated from the stationary contact 28 and the collector ring 23 e according to FIG. 9. In this process, the central recess of the Maltese disc (E) 18 and the recess of the fork element 19 come into alignment with one another in a circumstance in which the painting disc (E) 18 and the fork element 19 are actuated by the drive pin 9 a synchronously. In connection with the rotation of the Geneva plate (D) 9 , the Geneva plates (E) 18 and the fork element 19 are rotated together and the movable contact element 23 is moved simultaneously, as shown in FIG. 10. The Maltese wheel (D) 9 continues to rotate and the movable Kontaktelmente 23 are to the adjacent Kon clock 28 moves, during which operation the movable contact 23 a the open state maintains, so that in this case no sliding movement or action in accordance with FIG. 11 is carried out.

The further rotation of the Geneva wheel (D) 9 is transferred to the Geneva wheel (E) 18 and then to the external ring gear, the gear 20 and the control cam 23 b in this order in order to thereby flow the contact and the entire tap- To complete the change process, as shown in Fig. 12.

As has been described above with reference to FIGS. 3 to 12, the movable contacts are separated from the stationary contacts and the collector rings or the collectors before the start of the movement sequence and then moved to the adjacent, stationary contacts. After reaching the neighboring stationary contacts, the moving contacts are closed. These operations are performed with each tap change operation.

Claims (5)

1. Power tap switch, with a variety of opera tively connected with tap windings of a transformer stationary contacts and with the stationary contacts touching, be movable contacts, characterized in that the movable contacts are opened by a first Maltese cross mechanism when these are moved are to be, wherein the first Maltese cross mechanism is formed with disks, in which che rotatable gear elements engage, and the movable contacts from the stationary contacts by a cam for opening and closing the elements directly connected to the gear elements can be lifted, that the on these Way lifted movable contacts are movable by a second time teserkreuz mechanism to the neighboring stationary contacts and that the movable contacts can then be brought into contact with these Sta tionärkontakte by the first Maltese cross mechanism. 2. Power tap switch according to claim 1, characterized ge indicates that the control cam has a groove in which attacks a large number of cam sequences, which operate with the movable contacts are connected in such a way that they and can be moved downwards. 3. Power tap switch according to claim 1, characterized ge indicates that the first Maltese cross mechanism with egg provided with a Maltese cross drive and Maltese cross discs which is intermittent through the Maltese cross drive are drivable. 4. Power tap switch according to claim 1, characterized ge indicates that the second Maltese cross mechanism one Maltese cross drive and Maltese cross discs, wel intermittent in one thanks to the Maltese cross drive Contextual connection with the Maltese cross drive of the first time teserkreuz mechanism are driven.   5. Power tap switch according to claim 4, characterized ge indicates that one of the Maltese cross discs of the second Maltese cross mechanism in a Maltese cross disk Intervening tap switch engages.