Patent Application
20080088396
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
The object, the construction for achieving the object, and an operational effect of the present invention will be clearly understood through the following description on the embodiment of the present invention made with reference to
For the sake of convenience in understanding the present invention in comparison with the related art, elements of a switching mechanism according to the present invention which perform the same or similar functions are given the same reference numerals, and a description will be made rather than being omitted although it is repeated.
Like the switching mechanism of the air circuit breaker according to the related art as described above with reference to
As shown in
The main shaft lever 10-1 is generally used when the air circuit breaker opens and closes 3 phases alternating current conducting lines, so three main shaft levers 10-1 are provided to correspond to each phase and drive the movable contactor 11 of a corresponding phase.
In order to simultaneously drive the three main shaft levers 10-1, the respective main shaft levers 10-1 are coaxially connected with a single common main shaft 10.
Accordingly, the main shaft 10 penetrates both side plates 1 supporting the switching mechanism so as to extend to be connected with the main shaft lever 10-1 of a different phase.
Among the main shaft levers 10-1, the central main shaft lever 10-1 connected with the switching mechanism has one end connected with the main shaft 10 and the other end connected with a first link 6.
Like gears which have a different rotational shaft with the main shaft lever 10-1 and are in mesh with each other, one end of the first link 6 is connected with the main shaft lever 10-1, and the main shaft lever 10-1 and the first link 6 are rotated in the mutually opposite directions. The first link 6 provides a driving force to the central main shaft lever 10-1, among the three main shaft levers 10-1, to make the central main shaft lever 10-1 to drive the movable contactor 11 to an opening or closing position.
A second link 4 is connected with the other end of the first link 6, and the first and second links 6 and 4 are rotated in the same direction.
One end of a third link 3 is rotatably provided at the other end of the second link 4 and connected by a driving connection pin (P) to transfer the driving force to the second link 4.
A closing spring unit includes a closing spring 13 for providing a driving force to drive the movable contactor 11 to the closing position and a closing spring seat which is not reference numeral designated. The closing spring 13 charges elastic energy or discharges it to provide a driving force to drive the movable contactor 11 to the closing position.
In order to prevent the closing spring 13 from being released and support the rotation of the closing spring seat, a closing spring support bracket 15 is provided to support the other end of the opposite side of the end portion that provides the driving force.
The switching mechanism of the air circuit breaker according to the present invention comprises a charging cam 2 for providing a driving force for charging elastic force of the closing spring unit, and the charging cam 2 is rotatable together with the rotational shaft 2a. The charging cam 2 includes a cam roller 2b indicated as a dotted line on one side thereof as shown in
The third link 3 is coaxially connected with the rotational shaft 2a of the charging cam 2 and rotatable together.
A pair of driving levers 16 include a driving lever pin 16b that contacts with the second link 4. The pair of driving levers 16 are separately connected by the driving lever pin 16b, and the second and third links 4 and 3 are interposed between the pair of levers 16. The driving levers 16 can be connected with the closing spring unit to provide a driving force for charging elastic energy to the closing spring unit, or can be rotatable upon receiving charged elastic energy from the closing spring unit.
The switching mechanism of the air circuit breaker according to the present invention includes a spring support pin 18 protrusively fixed at the side plate 1.
As shown in
Preferably, the third link elastic bias spring 17 is formed as a torsion spring which includes the end portion 17a supported by the spring support pin 18, the operation portion 17b for providing elastic force for rotation in one direction onto the third link 3, and a central portion 17c wound on the rotational shaft 2a of the charging cam 2.
The one direction in which the third link elastic bias spring 17 acts on one surface (the lower surface) of the third link 3 is a direction in which the third link 3 drives the movable contactor 11 to the closing position. Namely, the one direction is the counterclockwise direction on the drawing, and accordingly, the interlocked second link 4 and the first link 6 are also rotated counterclockwise while the main shaft lever 10-1 and the main shaft 10 are rotated clockwise. The movable contactor 11 is rotated counterclockwise to the closing position at which it contacts with the stationary contactor 12.
More preferably, the third link elastic bias spring 17 can be formed as a double torsion spring including both end portions supported by the spring support pin 18, the operation portion 17b for providing elastic force for rotation in one direction onto the third link 3, and a pair of central portions 17c wound on the rotational shaft 2a of the charging cam 2.
The closing latch 5 extends long in a vertical direction in order to have one surface positioned on a moving locus of the cam roller 2b provided on one surface of the charging cam 2, and latches rotation of the charging cam 2. An upper end portion of the closing latch 5 is positioned on a rotating path of an on-shaft 8, so it can be latched or released by the on-shaft 8.
The on-shaft 8 is connected with an on-button (not shown) so as to be rotated manually or automatically rotated by being connected with an electrical driving control device or an actuator.
A recess portion 3a is formed at an upper portion of the third link 3, an opening latch roller 7a is provided at a position at which it can enter the recess portion 3a of the third link or released therefrom. An opening latch 7 that can be rotatable centering around a rotational shaft 7b is provided at an upper portion of the third link 3. One end of the opening latch 7 is connected with an opening latch spring 7c by a pin to thus receive an elastic bias force for rotation counterclockwise in
An off-shaft 9 is provided to contact with the other end of the opening latch 7 in a lengthwise direction, and the rotation of the opening latch 7 is latched or released by the off-shaft 9.
The operation of the switching mechanism of the air circuit breaker according to the related art constructed as described can be divided into the elastic energy charging operation, the closing operation and the opening operation of the closing spring and will be described as follows.
First, the charging operation of the closing spring will be described with reference to
The rotational shaft 2a of the charging cam 2 is rotated by an operation handle (not shown) or a driving motor (not shown) counterclockwise on the drawing.
Then, the driving lever roller 16a of the driving lever 16 contacting with an outer circumferential surface of the charging cam 2 is pressed as a curvature radius of the outer circumferential surface of the charging cam 2 is reduced to press the spring seat of the closing spring unit that contacts with and pressed by the driving lever roller 16a to compress the closing spring 13.
At this time, as the charging cam 2 is rotated, the driving lever roller 16a rolls along the outer circumferential surface of the charging cam 2, and the charging cam 2 is rotated until the cam roller 2b provided at one surface of the charging cam 2 contacts with the closing latch 5.
As the charging cam 2 is rotated counterclockwise, the third link 3, the second link 4 and the driving lever 16 interlock to be rotated counterclockwise.
At this time, rotation of the main shaft 10 is latched by the opening latch 7, so that it is maintained to be separated from the movable contactor 11 and the stationary contactor 12 as shown in
As the third link 3 is rotated counterclockwise, the roller 7a of the opening latch 7 is received in the recess 3a of the third link 3 and the counterclockwise rotation of the third link 3 is latched.
When the cam roller 2b provided on one surface of the charging cam 2 contacts with the closing latch 5, it pushes the closing latch 5, making the closing latch 5 be rotated centering around its rotational shaft. The clockwise rotation of the closing latch 5 is restraining by the on-shaft 8, and the charging operation of the closing spring 13 is completed.
The closing operation of the switching mechanism of the air circuit breaker according to the related art will now be described with reference to
When the on-shaft 8 is connected with an ON-button (not shown) and rotated manually or when the on-shaft 8 is connected with the electrical driving control device or the actuator and automatically rotated, the closing latch 5 is released from the on-shaft 8 and rotated clockwise.
As the closing latch 5 is released, the cam roller 2b is also released from the closing latch 5.
Accordingly, the driving lever roller 16a which has restraining discharging of elastic energy of the closing spring 13 while contacting with the outer circumferential surface of the charging cam 2 gets out of the outer circumferential surface of the charging cam 2.
As the closing spring 13 is discharged, the driving lever 16 is pressed by the spring seat of the closing spring 13 and rotated counterclockwise, and accordingly, the driving lever pin 16b pushes the second link 4 to rotate it counterclockwise. Then, the third link 3 is rotated counterclockwise according to the counterclockwise rotation of the second link 4, and accordingly, the first link 6 is pushed up by the second link 4 and rotated counterclockwise.
The main shaft lever 10-1 and the first link 6 are connected with each other to interlock, so that as the first link 6 is rotated counterclockwise, the main shaft lever 10-1 is rotated clockwise and the main shaft 10 is also rotated clockwise. Accordingly, the movable contactor 11 connected with the main shaft lever 10-1 to interlock is rotated counterclockwise on the drawing and comes in contact with the stationary contactor 12 and thus the circuit is closed.
The circuit opening operation of the switching mechanism of the air circuit breaker according to the related art will now be described with reference to
When the off-shaft 9 is connected with the OFF-button (not shown) and rotated clockwise manually or when the off-shaft 9 is connected with the electrical driving control device and the actuator and rotated clockwise automatically, the opening latch 7 is released from the latched state by the off-shaft 9 and rotated counterclockwise due to elastic force of the opening latch spring 7c, and also released from the latched state by the recess 3a of the third link 3.
As the third link 3 is released from the latched state by the opening latch 7, the interlocked second and first links 4 and 6 are also released, and in a state that the opening spring 14 is stretched while closing operation, a support end portion of the main shaft lever 10-1 is returned to the spring support pin of the side plate 1 to discharge the charged elastic energy to thus rotate the main shaft lever 10-1 counterclockwise. Accordingly, the movable contactor 11 is rotated clockwise and separated from the stationary contactor 12. Thus, the circuit is opened.
As so far described, the switching mechanism of the air circuit breaker according to the present invention has the following advantages.
That is, compared with the related art in which the two springs are provided and one end of each spring is supplied by the driving lever and the other end of each spring is supported by both ends of the driving connection pins of the third and second links, to work, in the present invention, the third link elastic bias spring that elastically biasing the third link in one direction has one end for directly providing the elastic bias force onto one surface of the third link and the other end supported by the pin fixed on the side plate, not the driving lever.
That is, unlike the construction of the related art in which the support pin is protruded and the pin of the driving lever needs to extend to support the two springs, in the present invention, the space between the driving levers can be reduced to reduce the width of the switching mechanism, resulting in the reduction of the size of the air circuit breaker.
Such effect can be increased by forming the third link elastic bias spring as the torsion spring or the double torsion spring.
As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0101052 | Oct 2006 | KR | national |
