Transmission for an electrical circuit breaker
An electrical circuit breaker includes a first contact piece with a first consumable contact; a second contact piece with a second consumable contact; a drive for moving the first contact piece along a switching movement axis; and a transmission for transmitting the movement of the first contact piece to a movement of the second contact piece. The transmission has a first lever, a pivoting element which can pivot about a pivoting shaft, and a transmission mechanism for transmitting a pivoting movement of the pivoting element to a movement of the second contact piece.
1. An electrical circuit breaker, comprising:
a first contact piece having a first contact;
a second contact piece having a second contact;
a drive for moving the first contact piece along a switch axis; and
a transmission for transmitting movement of the first contact piece to a movement of the second contact piece, wherein the transmission includes a pivoting element for pivoting about a pivoting shaft, and a transmission mechanism for transmitting pivoting movement of the pivoting element to a movement of the second contact piece, and wherein
the transmission includes a first lever for articulation by a rotating joint on the first contact piece, and by a slider joint on the pivoting element, the slider joint defining a fixed angle between the first lever and the pivoting element.
2. The electrical circuit breaker as claimed in claim 1 , wherein a transmission ratio of the transmission during a switching process varies as a function of a position of the first and second contact pieces.
3. The electrical circuit breaker as claimed in claim 2 , wherein the transmission ratio of the transmission during a switching process is approximately zero in a first phase, passes through a maximum in a subsequent second phase, and decreases again in a subsequent third phase.
4. The electrical circuit breaker as claimed in claims 3 , wherein movement of the first contact piece results in disconnection of first and second consumable contacts, and the transmission ratio of the transmission on contact disconnection of the first and second consumable contacts is greater than at a start of the first contact piece movement.
5. The electrical circuit breaker as claimed in claim 4 , wherein at least one of
a time of contact disconnection of the first and second consumable contacts occurs in the second phase; and
a maximum transmission ratio is achieved only when the first and second consumable contacts have been disconnected, the maximum transmission ratio being greater than 1:1.
6. The electrical circuit breaker as claimed in claim 4 , wherein at least one of:
the transmission ratio in the second phase or between contact disconnection of the consumable contacts or the transmission ratio in the second phase and or between contact disconnection of the consumable contacts, and the enabling of a dielectric nozzle for quenching the arc is to be above a value of 1:1; and
a transmission ratio of greater than the value is limited to a time period between contact disconnection of the consumable contacts and a moment at which the nozzle is enabled.
7. The electrical circuit breaker as claimed in claim 1 , wherein at least one of
the pivoting shaft of the pivoting element is mounted in a fixed position;
the pivoting shaft is aligned at right angles to the switch axis; and
the pivoting shaft is arranged laterally offset at a distance from the switch axis, in a laterally offset position between the switch axis and the first contact piece.
8. The electrical circuit breaker as claimed in claim 1 , wherein at least one of
the first lever has a cylindrical end which is mounted such that it slides in the slider joint; and
a thrust axis of the thrust joint is at right angles to the pivoting shaft and/or intersects the pivoting shaft.
9. The electrical circuit breaker as claimed in claim 1 , wherein the transmission mechanism is configured to transmit the pivoting movement of the pivoting element about the pivoting shaft to a longitudinal movement of the second contact piece along the switch axis.
10. The electrical circuit breaker as claimed in claim 1 , wherein the transmission mechanism comprises:
a second lever which is articulated to rotate by a rotating joint, on the pivoting element, and to rotate by a further rotating joint, on the second contact piece.
11. The electrical circuit breaker as claimed in claim 1 , wherein the transmission mechanism comprises:
a gearwheel and a toothed rod which can move with the second contact piece and engages with the gearwheel.
12. The electrical circuit breaker as claimed in claim 11 , wherein the gearwheel comprises:
a rotation axis which is located on the pivoting shaft to pivot together with the pivoting element about the pivoting shaft.
13. The electrical circuit breaker as claimed in claim 2 , wherein movement of the first contact piece results in disconnection of first and second consumable contacts, and the transmission ratio of the transmission on contact disconnection of the first and second consumable contacts is greater than 5:1.
14. The electrical circuit breaker as claimed in claim 4 , wherein at least one of
a time of contact disconnection of the first and second consumable contacts occurs in the second phase; and
a maximum transmission ratio is achieved when the first and second consumable contacts have been disconnected, the maximum transmission ratio being greater than 1.5:1.
15. The electrical circuit breaker as claimed in claim 4 , wherein at least one of
a time of contact disconnection of the first and second consumable contacts occurs in the second phase; and
a maximum transmission ratio is achieved when the first and second consumable contacts have been disconnected, the maximum transmission ratio being greater than 2:1.
16. The electrical circuit breaker as claimed in claim 4 , wherein at least one of:
the transmission ratio in the second phase or between contact disconnection of the consumable contacts or the transmission ratio in the second phase and or between contact disconnection of the consumable contacts, and the enabling of a dielectric nozzle for quenching the arc is to be above a value of 1.5:1; and
a transmission ratio of greater than the value is limited to a time period between contact disconnection of the consumable contacts and a moment at which the nozzle is enabled.
17. The electrical circuit breaker as claimed in claim 4 , wherein at least one of:
the transmission ratio in the second phase or between contact disconnection of the consumable contacts or the transmission ratio in the second phase and or between contact disconnection of the consumable contacts, and the enabling of a dielectric nozzle for quenching the arc is to be above a value of 2:1; and
a transmission ratio of greater than the value is limited to a time period between contact disconnection of the consumable contacts and a moment at which the nozzle is enabled.
18. The electrical circuit breaker as claimed in claim 6 , wherein at least one of
the pivoting shaft of the pivoting element is mounted in a fixed position;
the pivoting shaft is aligned at right angles to the switch axis; and
the pivoting shaft is arranged laterally offset at a distance from the switch axis, in a laterally offset position between the switch axis and the first contact piece.
19. A method for opening the contacts of an electrical circuit breaker, which has a first contact piece with a first consumable contact, a second contact piece with a second consumable contact, a drive for moving the first contact piece along a switch axis and a transmission for moving the second contact piece, with the transmission comprising a first lever which is articulated by a rotating joint on the first contact piece, and a pivoting element which can pivot about a pivoting shaft, with the first lever being articulated by a slider joint on the pivoting element, the method comprising:
moving the first lever by movement of the first contact piece;
pivoting the pivoting element by movement of the first lever about the pivoting shaft; and
transmitting pivoting movement of the pivoting element by a transmission mechanism to a movement of the second contact piece.
20. The method as claimed in claim 19 , wherein the movement of the first lever is a rotary movement about the pivoting shaft, with a linear movement superimposed thereon.
21. The method as claimed in claim 19 , comprising:
defining a fixed angle between the first lever and the pivoting angle with the slider joint, such that a rotary movement of the first lever pivots the pivoting element while, in contrast, a translational movement of the first lever does not pivot the pivoting element.
22. The method as claimed in claim 19 , comprising at least one of:
mounting the pivoting shaft of the pivoting element in a fixed position;
aligning the pivoting shaft at right angles to the switch axis; and
arranging the pivoting shaft laterally offset at a distance from the switch axis, in a laterally offset position between the switch axis and the first contact piece.