EP1930930B1 - Transmission for a high-voltage circuit breaker - Google Patents

Description

Technical area

The present invention relates to the field of dual power electrical circuit breakers. The invention further relates to a method for opening the contacts of an electrical circuit breaker.

State of the art

Circuit breakers usually have two contact pieces, each with a consumable contact (tulip and pin), which can be separated if necessary. To disconnect either only one contact piece or both contact pieces can be moved. In the second case, usually a drive drives the tulip, and a gear or auxiliary transmission transmits the movement of the tulip on the pin are linear transmissions with a transmission ratio of typically 1: 1, such. In EP 0 822 565 from which the invention proceeds, or in US 5,478,980 disclosed. The transmission ratio of the transmission is defined as the ratio of a speed of movement of the gear transmitted or generated (output motion, typically movement of the pin) to a speed of movement of a gear driving movement (drive motion, typically movement of the tulip).

It can also be realized constant gear ratios that are greater than 1: 1 In this case increases the relative speed between the two switching pieces at a given drive speed, so that the switch contacts can be separated quickly However, with increasing constant gear ratio of the stroke of the output side contact piece and thus the required length of the quenching chamber.

Transmissions with a non-constant gear ratio are also known. Such transmissions are for example in EP 0 992 050 . EP 1 211 706 and DE 100 03 359 disclosed.

In the EP 0 809 269 An auxiliary transmission with a stationary rotatably mounted, two-sided lever arm is shown. The lever arm has on one side a slot for engagement with an axially displaceable, driving pull rod and on the other side a firmly articulated lever for transmitting power to the mating contact

In the EP 0 696 040 an auxiliary gear is shown with a stationary rotatably mounted gear The gear is driven by a rack. On the tooth loading surface, a lever for transmitting power to the mating contact is articulated at a fixed position.

However, transmissions with a non-constant transmission ratio typically require a lot of space. Also, the time course of the transmission ratio of these transmissions is often satisfactory.

Presentation of the invention

Object of the present invention is to provide an improved dual drive for a circuit breaker. The object is achieved by the electric circuit breaker according to independent claim 1 and by the method for making contact opening of an electric circuit breaker according to independent claim 13. Further advantages, features and details of the invention as well as preferred embodiments and particular aspects of the invention will become apparent from the dependent claims, the description and the figures.

According to one aspect of the invention, there is shown an electrical circuit breaker comprising: a first contact having a first contact, in particular a consumable contact cuff; a second contact piece with a second contact, in particular a consumable contact pin; a drive for moving the first contact piece longitudinally, ie parallel or anti-parallel to, a switching movement axis or switch axis, in particular relative to a housing of the circuit breaker; and a transmission for transmitting the movement of the first contact piece to a movement of the second contact piece. The transmission comprises: a first lever, a pivot member pivotable about a pivot axis, and a transmission mechanism for transmitting pivotal movement of the pivot member to movement of the second contact. The first lever is hinged to the first contact piece with a hinge and articulated to the pivot member by a thrust joint. The sliding joint defines a fixed angular relationship between the first lever and the pivot member such that rotational movement of the first lever pivots the pivot member whereas a thrust movement of the first pivot Levers does not pivot the pivot member. The hinges are preferably pure hinges, ie they do not allow relative thrust between the hinged parts. The thrust joint preferably defines a thrust axis which intersects the pivot axis.

According to a further aspect of the invention, a method for contact opening of an electrical circuit breaker is proposed. The power switch comprises a first contact piece with a first burnup contact, a second contact piece with a second burnup contact, a drive for moving the first contact piece along a switch axis and a transmission for moving the second contact piece, wherein the transmission has a first lever, which with a The method comprises the following steps: the first lever is moved by the movement of the first contact piece, the movement of the first lever preferably a rotational movement approximately about the pivot axis and thus superimposed a thrust movement is; the pivot member is pivoted by the movement, and preferably by the rotational movement, of the first lever about the pivot axis; and the pivoting movement of the pivoting member is transmitted by a transmission mechanism to a movement of the second contact piece, preferably to a longitudinal movement along the switching movement axis or switch axis. The first lever is articulated with a hinge to the first contact piece and hinged with a sliding joint to the pivot member. Preferably, the circuit breaker further features, which are described in claims 2 to 12.

The invention also relates to a circuit breaker for carrying out the disclosed method. The invention is further directed to methods according to which the respective circuit breaker described work.

Brief description of the figures

• Fig. 1 ein erstes Ausführungsbeispiel eines erfindungsgemässen Hilfsgetriebes;
• Fig. 2 ein zweites Ausführungsbeispiel eines erfindungsgemässen Hilfsgetriebes;
• Fig. 3 ein Diagramm, das den Hub des zweiten Schaltstücks als Funktion des Hubs des ersten Schaltstücks darstellt.

Embodiments of the invention are illustrated in the figures and will be described in more detail below. It shows for a circuit breaker:

• Fig. 1 a first embodiment of an inventive auxiliary transmission;
• Fig. 2 A second embodiment of an inventive auxiliary transmission;
• Fig. 3 a diagram illustrating the stroke of the second contact piece as a function of the stroke of the first contact piece.

Ways to carry out the invention

Fig. 1 shows a first embodiment of a circuit breaker according to the invention. The circuit breaker comprises a first contactor 10 having a first consumable contact (not shown), which is typically configured as a tulip, and a second contactor 20 having a second consumable contact (not shown), which is typically configured as a pin. The Abbrandkontakte and other elements of the circuit breaker, not shown, such as extinguishing devices for an arc by a protective gas, are designed in the usual way. Of the first and the second contact piece 10, 20 sliding elements or tie rods or push rods 14, 24 are shown, which are connected in a suitable manner with the Abbrandkontakten or generally to be switched contacts of the switch. The contact pieces 10, 20 are typically longitudinal, ie parallel or antiparallel, movable to a switch axis or switching movement axis 3 by being mounted on rails or in plain bearings.

The power switch further comprises an auxiliary gearbox or gearbox 2. The gearbox 2 has a first lever 30, a pivoting element 50, and a second lever 40. The first lever 30 is articulated with a rotary joint 31 to the first contact piece 10, and articulated with a sliding joint 35 or rotary sliding joint 35 to the pivot member 50. The pivoting element 50 is pivotably mounted about a pivot axis 56 with a pivot joint 55. The hinge 55 is advantageous to a stationary part of the circuit breaker, z. B. on its housing attached. Then the pivot axis 56 is stationary, for example, relative to the housing of the circuit breaker. Furthermore, the pivot axis 56 should be aligned perpendicular to the switch axis 3 in the rule.

Advantageously, the pivot axis 56 is laterally offset from the switch axis 3 at a distance d. In particular, the pivot axis 56 in a laterally offset position between the switch axis 3 and the first contact piece 10, ie. As in Fig. 1 shown offset upwards, arranged.

The articulation 35 defines a fixed angular relationship between the lever 30, i. between an axis defined by the lever 30 and its longitudinal extension, and the pivoting element 50. The pivoting element 50 is thus entrained by a rotational movement of the lever 30 at a constant relative angle and thus pivotable. A pushing movement of the lever 30 along a thrust axis of the sliding joint 35, however, does not pivot the pivoting element 50.

Advantageously, the first lever 30 on a cylindrical or pestle-shaped end which is slidably mounted in the sliding joint 35. As in Fig. 1 or 2 can also be the entire first lever 30 is cylindrical and in particular have a round cross-section. Especially on the length of the first lever 30, which slides in a switching operation in the sliding joint 35, the first lever 30 could also be another, z. B. have rectangular cross-section. The sliding joint 35 then has a bore and in particular sliding surface or cylindrical guide of appropriate shape, so that a good positive contact for transmitting the rotational movement of the first lever 30 is effected on the pivot member 50. In any case, a thrust axis for the first lever 30, ie a sliding direction of the first lever 30 in the sliding joint 35, defined by the sliding joint 35. The sliding joint 35 is advantageously arranged so that the thrust axis is perpendicular to the pivot axis 56, and / or that the thrust axis intersects the pivot axis 56; however, this is not mandatory. Typically, the thrust axis is perpendicular to the pivot axis 56.

The second lever 40 is pivotally connected to the swivel element 50 by means of a swivel joint 45 eccentrically to the swivel axis 56 and is rotatably connected to the second contact piece 20 by means of a further swivel joint 42. The second lever 40 thereby forms a transmission mechanism 40 for transmitting a pivotal movement of the pivot member 50 about the pivot axis 56 to a longitudinal movement of the second contact piece 20th

Fig. 1 shows the circuit breaker in a closed state in which the Abbrandkontakte the two contact pieces 10, 20 are in electrical contact with each other. To disconnect the electrical contact, the first contact piece 10 can be moved by a drive (not shown) along the switch axis 3 to the left. The transmission 2 can transmit this movement of the first contact piece 10 to an opposite movement with non-linear transfer characteristic for the second contact piece 20 to the right. For this purpose, the lever 30 is first pushed by the movement of the first contact piece 10 to the left into the sliding joint 35, so that the distance between the pivot 31 and the sliding joint 35 is shortened. Simultaneously, the lever 30 is rotated counterclockwise. Since the thrust joint 35 defines a fixed angular relationship between the lever 30 and the pivot member 50, the pivot member 50 is also pivoted about the pivot axis 56 in the counterclockwise direction. The pivoting movement of the pivoting element 50 is then transmitted by the lever 40 to a longitudinal movement of the second contact piece 20 along the switch axis 3 to the right. The movement of the second contact piece 20 is thus opposite to the movement of the first contact piece 10, ie directed to the right, so that the relative speed between the contact pieces 10 and 20 is increased by the additional movement, which is transmitted by the transmission 2 to the second contact piece 20.

The lever 30 performs both a sliding and a rotating movement relative to the pivot axis 56. At the beginning of the movement, ie in the in Fig. 1 illustrated state of the transmission 2, the lever 30 is pushed into the sliding joint 35, and rotated only by a relatively small amount. When the first contact is moved further to the left, the rotational movement of the lever 30 gradually increases in proportion to the longitudinal movement of the first contact 10, whereas the sliding movement of the lever 30 decreases until the pivot 31 is vertically above the pivot 55. At this time, only a rotating movement and no sliding movement of the lever 30 takes place. If the first contact piece 10 is moved even further to the left, the lever 30 is pulled out of the sliding joint 35 again, and the rotating movement of the lever 30 gradually decreases again. Since only the rotating movement and not the pushing or pulling movement of the lever 30 is transmitted to the pivot member 50, thus a variable transmission ratio of the transmission 2 is made possible. In particular, it is possible that the transmission ratio of the current position of the first contact piece 10, ie, depends on its deflection along the switch axis 3.

Fig. 3 shows a hub-stroke diagram, wherein stroke equal to the distance covered movement distance of the contact pieces 10, 20 and the associated contacts referred. The diagram shows the lift curve 60, ie the stroke of the second contact piece 20 in mm (contact 2, vertical axis) as a function of the stroke of the first contact piece 10 in mm (contact 1, horizontal axis). The transmission ratio of the transmission 2 is given by the derivation of the lift curve 60.

The stroke curve 60 shows that the transmission ratio is variable or not constant during a switching operation of the power switch, ie varies depending on the position of the contact pieces 10, 20 or the rotational position of the pivoting element 50. In a first phase 61, the stroke of the second contact piece 20 hardly changes, ie the transmission ratio of the transmission 2 is approximately zero or small. This phase 61 corresponds to the in Fig. 1 illustrated state in which the lever 30 is pushed mainly into the sliding joint 35 and rotated only by a relatively small amount. In a subsequent second phase 62, the transmission ratio of the transmission 2, ie the slope of the lifting cam 60, large and in particular passes through a maximum when the pivot 31 is positioned vertically above the sliding joint 55. This phase 62 corresponds to the state in which almost exclusively a rotating movement and hardly a sliding movement of the lever 30 takes place. In a subsequent third phase 63, the transmission ratio of the transmission 2 decreases again.

Typically, the point in time at which the physical contact between the first and second burnup contacts is disconnected and to which an arc occurs is after the first phase 61 and thus in the second phase 62. At this time, the gearbox 2 has a much larger size Gear ratio as at the beginning of the movement, ie when fully closed circuit breaker. For example, compared to the beginning of the movement, the transmission ratio of the transmission 2 in separating the contact may be greater by a factor greater than 2: 1 or even greater than 5: 1. As a result, a high relative speed between the contact pieces 10 and 20 is made possible at this time. However, in order to avoid excessive wear of the contact pieces, it is preferred that a maximum transmission ratio is reached only when the contacts are disconnected. It is generally advantageous that the maximum transmission ratio is greater than 1: 1, preferably greater than 1.5: 1, and more preferably greater than 2: 1.

Typically, the period between the physical separation or contact separation of the consumable contacts and the release of an insulating nozzle to extinguish the arc is selected to include the second phase 62, or at least part of the high gear ratio lift curve. It is therefore advantageous that the transmission ratio of the transmission 2 in the second phase 62 and / or between the contact separation of the Abbrandkontakte and the release of the insulating nozzle for extinguishing the arc constantly above the value 1: 1, preferably above the value 1.5: 1, and more preferably above the value 2: 1 is selected. As a result, a high relative speed between the contact pieces 10 and 20 can be achieved in this entire period.

Characterized in that the transmission ratio of the transmission 2 is limited in other than the above periods, yet the entire stroke of the contact pieces 10 and 20 can be kept low. Therefore, the quick pen movement, in particular, a gear ratio greater than 2: 1 or 1.5: 1 or 1: 1, can be limited to the period between contact separation and nozzle enable moment, and the power switch can be made compact at the same time. Due to the initially low transmission ratio can also be the period in which the first contact piece 10 must be accelerated by the drive, be separated from the period in which the second contact piece 20 is accelerated via the transmission 2 by the drive. Thus, the drive load can be distributed over a longer period, and load peaks for the drive can be reduced. As a result, the drive can be made weaker or a higher acceleration of the contacts or burned contact can be achieved.

Fig. 2 shows a second inventive circuit breaker. In it are opposite Fig. 1 the same or similar parts with the same reference numerals. Unlike the transmission of Fig. 1 has the transmission 2 of Fig. 2 no second lever 40. Instead, the transmission mechanism for transmitting a pivotal movement of the pivot member 50 is formed on a movement of the second contact piece 20 by a gear 47 and a rack 48. The gear 47 is fixed to the pivot member 50 so that it is pivotally mounted or rotatable together with the pivot member 50 about the pivot axis 56. It has an axis of rotation which lies on the pivot axis 56. The rack 48 is mitbewegbar with the second contact piece 20 and attached thereto. The gear 47 is engaged with the rack 48 and drives it when needed.

Fig. 2 illustrates that the transmission of the inventive circuit breaker with any known transmission mechanism 40; 47, 48 may be provided for transmitting a pivoting movement of the pivoting element 50 to a movement of the second contact piece 20.

LIST OF REFERENCE NUMBERS

2

transmission

3

Central axis, switch axis, switching motion axis

10

First contact, contact 1

14

First sliding element, first pull rod

20

Second contact, contact 2

24

Second sliding element, second pull rod

30

First lever, first rod

31

Swivel 30-10

35

Rotary push joint 30-50

40

Second lever, second rod

42

Swivel 40-20

45

Swivel 40-50

47

gear

48

rack

50

pivoting element

55

Fixed swivel joint

56

swivel axis

60

stroke curve

61

First phase

62

Second phase

63

Third phase

d

Distance, lateral offset

Claims (21)

1. Electrical circuit breaker, comprising a first contact piece (10) having a first contact, a second contact piece (20) having a second contact, a drive for moving the first contact piece (10) along a switch axis (3), and a transmission (2) for transmitting the movement of the first contact piece (10) to a movement of the second contact piece (20), in which case the transmission (2) comprises a pivoting element (50), which can pivot about a pivoting shaft (56), and a transmission mechanism (40; 47, 48) for transmitting the pivoting movement of the pivoting element (50) to a movement of the second contact piece (20), in which case the transmission (2) has a first lever (30) which is articulated by means of a rotating joint (31) on the first contact piece (10), characterized in that

   - the first lever (30) is articulated by means of a thrust joint (35) on the pivoting element (50), the thrust joint (35) defining a fixed angle ratio between the lever (30) and the pivoting element (50).
2. Electrical circuit breaker according to Claim 1, characterized in that a transmission ratio of the transmission (2) during a switching process varies as a function of a position of the contact pieces (10, 20).
3. Electrical circuit breaker according to Claim 2, characterized in that the transmission ratio of the transmission (2) during a switching process is approximately zero in a first phase (61), passes through a maximum in a subsequent second phase (62), and decreases again in a subsequent third phase (63).
4. Electrical circuit breaker according to one of Claims 2-3, characterized in that the movement of the first contact piece (10) results in the disconnection of a first and second consumable contact, and in that the transmission ratio of the transmission (2) on contact disconnection of the first and second consumable contacts is greater than at the start of the movement, and in particular is greater than 2:1, and is preferably greater than 5:1.
5. Electrical circuit breaker according to Claims 3 and 4, characterized in that

   - the time of contact disconnection of the first and second consumable contacts occurs in the second phase (62), and/or

   - a maximum transmission ratio is achieved only when the consumable contacts have been disconnected, and in particular in that the maximum transmission ratio is greater than 1:1, preferably greater than 1.5:1, and particularly preferably greater than 2:1.
6. Electrical circuit breaker according to Claims 3 and 4 or according to Claim 5, characterized in that

   - the transmission ratio in the second phase (62) and/or between contact disconnection of the consumable contacts and the enabling of a dielectric nozzle for quenching the arc is always chosen to be above the value 1:1, preferably above the value 1.5:1 and particularly preferably above the value 2:1, and/or

   - a transmission ratio of greater than 2:1 or 1.5:1 or 1:1 is limited to the time period between contact disconnection of the consumable contacts and the moment at which the nozzle is enabled.
7. Electrical circuit breaker according to one of the preceding claims, characterized in that

   - the pivoting shaft (56) of the pivoting element (50) is mounted in a fixed position, and/or

   - the pivoting shaft (56) is aligned at right angles to the switch axis (3), and/or

   - the pivoting shaft (56) is arranged laterally offset at a distance (d) from the switch axis (3), in particular in a laterally offset position between the switch axis (3) and the first contact piece (10).
8. Electrical circuit breaker according to one of the preceding claims, characterized in that

   - the first lever (30) has a cylindrical end which is mounted such that it slides in the thrust joint (35), and/or

   - a thrust axis of the thrust joint (35) is at right angles to the pivoting shaft (56) and/or intersects the pivoting shaft (56).
9. Electrical circuit breaker according to one of the preceding claims, characterized in that the transmission mechanism (40; 47, 48) is used to transmit the pivoting movement of the pivoting element (50) about the pivoting shaft (56) to a longitudinal movement of the second contact piece (20) along the switch axis (3).
10. Electrical circuit breaker according to one of the preceding claims, characterized in that the transmission mechanism (40) comprises a second lever (40) which is articulated, such that it can rotate by means of a rotating joint (45), on the pivoting element (50), and such that it can rotate by means of a further rotating joint (42), on the second contact piece (20).
11. Electrical circuit breaker according to one of Claims 1-9, characterized in that the transmission mechanism (47, 48) comprises a gearwheel (47) and a toothed rod (48) which can move with the second contact piece (20) and engages with the gearwheel (47).
12. Electrical circuit breaker according to Claim 11, characterized in that the gearwheel (47) has a rotation axis which is located on the pivoting shaft (56), and the gearwheel (47) can pivot together with the pivoting element (50) about the pivoting shaft (56).
13. Method for opening the contacts of an electrical circuit breaker, which has a first contact piece (10) with a first consumable contact, a second contact piece (20) with a second consumable contact, a drive for moving the first contact piece (10) along a switch axis (3) and a transmission (2) for moving the second contact piece (20), with the transmission (2) comprising a first lever (30), which is articulated by means of a rotating joint (31) on the first contact piece (10), and a pivoting element (50) which can pivot about a pivoting shaft (56), with:

    - the first lever (30) being moved by the movement of the first contact piece (10),

    - the pivoting element (50) being pivoted by the movement of the first lever (30) about the pivoting shaft (56), and

    - the pivoting movement of the pivoting element (50) being transmitted by means of a transmission mechanism (40; 47, 48) to a movement of the second contact piece (20), characterized in that

    - the first lever (30) is articulated by means of a thrust joint (35) on the pivoting element (50), the thrust joint (35) defining a fixed angle ratio between the lever (30) and the pivoting element (50).
14. Method according to Claim 13, characterized in that a transmission ratio of the transmission (2) during a switching process varies as a function of a position of the contact pieces (10, 20) and the transmission ratio of the transmission (2) during a switching process is approximately zero in a first phase (61), passes through a maximum in a subsequent second phase (62), and decreases again in a subsequent third phase (63).
15. Method according to Claim 14, characterized in that the movement of the first contact piece (10) results in the disconnection of a first and second consumable contact, and in that the transmission ratio of the transmission (2) on contact disconnection of the first and second consumable contacts is greater than at the start of the movement, and is greater than 2:1, preferably greater than 5:1.
16. Method according to one of Claims 14-15, characterized in that

    - the time of contact disconnection of the first and second consumable contacts occurs in the second phase (62), and/or

    - a maximum transmission ratio is achieved only when the consumable contacts have been disconnected, and in particular in that the maximum transmission ratio is greater than 1:1, preferably greater than 1.5:1, and particularly preferably greater than 2:1.
17. Method according to Claims 14 and 15 or according to Claim 16, characterized in that

    - the transmission ratio in the second phase (62) and/or between contact disconnection of the consumable contacts and the enabling of a dielectric nozzle for quenching the arc is always chosen to be above the value 1:1, preferably above the value 1.5:1 and particularly preferably above the value 2:1, and/or

    - a transmission ratio of greater than 2:1 or 1.5:1 or 1:1 is limited to the time period between contact disconnection of the consumable contacts and the moment at which the nozzle is enabled.
18. Method according to one of Claims 13-17, characterized in that the pivoting shaft (56) is arranged laterally offset at a distance (d) from the switch axis (3), in particular in a laterally offset position between the switch axis (3) and the first contact piece (10).
19. Method according to one of Claims 13-18, characterized in that

    - the first lever (30) has a cylindrical end which is mounted such that it slides in the thrust joint (35), and/or

    - a thrust axis of the thrust joint (35) is at right angles to the pivoting shaft (56) and/or intersects the pivoting shaft (56).
20. Method according to one of Claims 13-19, characterized in that the transmission mechanism (47, 48) comprises a gearwheel (47) and a toothed rod (48) which can move with the second contact piece (20) and engages with the gearwheel (47).
21. Method according to Claim 20, characterized in that the gearwheel (47) has a rotation axis which is located on the pivoting shaft (56), and the gearwheel (47) can pivot together with the pivoting element (50) about the pivoting shaft (56).

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