One or more embodiments of the present invention may relate to a medium voltage circuit breaker switching pole, and to a medium voltage switching system.
Medium voltage (MV) switching poles or circuit breakers use for example levers or shafts to connect several switching poles (usually 3) mechanically to one drive. The poles themselves require a translational movement (like SF6 poles or vacuum poles). With levers and shafts, it is difficult to connect several switching poles unless they are arranged in one line.
There is a need to provide for an improved medium voltage circuit breaker switching pole.
One or more embodiments of the present invention may provide a medium voltage circuit breaker switching pole that comprises: a fixed contact of a vacuum interrupter; a movable contact of the vacuum interrupter; and a threaded drive element. The movable contact may be configured to move along a longitudinal axis of the vacuum interrupter and a centre axis of the threaded drive element may be parallel to the longitudinal axis of the vacuum interrupter. When in an open configuration the fixed contact and the movable contact may be separated from one another; and when in a closed configuration the fixed contact and the movable contact may be in contact with one another. Rotation of the threaded drive element about the centre axis of the threaded drive element in a first direction may be configured to transition the switching pole from the open configuration to the closed configuration, and rotation of the threaded drive element about the centre axis in a second direction counter to the first direction may be configured to transition the switching pole from the closed configuration to the open configuration.
Therefore, it may be advantageous to have an improved medium voltage circuit breaker switching pole.
An object of one or more embodiments of the present invention may be solved with the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims.
One or more embodiments of the present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
In a first aspect, there is provided a medium voltage circuit breaker switching pole, comprising:
The movable contact is configured to move along a longitudinal axis of the vacuum interrupter. A centre axis of the threaded drive element is parallel to the longitudinal axis of the vacuum interrupter. When in an open configuration the fixed contact and movable contact are separated from one another. When in a closed configuration the fixed contact and movable contact are in contact with one another. Rotation of the threaded drive element about its centre axis in a first direction is configured to transition the switching pole from the open configuration to the closed configuration. Rotation of the threaded drive element about its centre axis in a second direction counter to the first direction is configured to transition the switching pole from the closed configuration to the open configuration.
In this way, the rotational movement of a motor associated with the circuit breaker can be utilized itself in a direct manner, rather than transitioning to linear movement through levers or shafts. This leads to a simpler, more robust, switching pole and where a number of poles can be arranged more flexibly in relation to each other, whilst being driven from a common motor.
In an example, the centre axis of the threaded drive element is aligned along the longitudinal axis of the vacuum interrupter.
In an example, rotation of the threaded drive element about its centre axis in the first direction through a rotational angle of less than or equal to 360 degrees is configured to transition the switching pole from the open configuration to the closed configuration. Rotation of the threaded drive element about its centre axis in the second direction through a rotational angle of less than or equal to 360 degrees is configured to transition the switching pole from the closed configuration to the open configuration.
In this manner, a relatively small rotational movement leads to the required translational movement of the movable contact, that occurs within the required transition timescale.
In an example, an end of the threaded drive element distil to the movable contact comprises a ball bearing configured to rotate in a ball bearing socket.
In an example, the ball bearing and/or the ball bearing socket comprise a low friction surface material.
In an example, the switching pole comprises a threaded pushrod connected to the movable contact. The thread of the pushrod is configured to engage with the thread of the threaded drive element. Rotation of the threaded drive element is configured to move the threaded pushrod along the centre axis of the threaded drive element.
In an example, the threaded pushrod is movable connected to the movable contact. A contact pressure spring is configured to move the moveable contact relative to the threaded pushrod.
In an example, the threaded pushrod comprises an insulating material.
In an example, the threaded pushrod is configured not to rotate as the threaded drive element rotates.
In an example, an outer surface of the threaded pushrod comprises a groove extending in an axial direction of the threaded pushrod. The groove is configured to engage with a fixed pin such that axial movement of the threaded pushrod leads to the fixed pin moving within the groove.
In an example, the threaded drive element comprises a coupling. The coupling is configured to engage with a gear wheel or belt associated with a drive motor. Rotational movement of the coupling is configured to lead to an associated and equivalent rotational movement of the threaded drive element.
In a second aspect, there is provided a medium voltage switching system, comprising:
The first, second and third circuit breaker switching poles are configured to be driven by a single motor such that simultaneous rotation of each threaded drive of each switching pole is configured to transition each switching pole from the open configuration to the closed configuration.
In an example, rotation of the threaded drive element of each switching pole in the same direction is configured to transition each switching pole from the open configuration to the closed configuration.
In an example, rotation of the threaded drive element of the first and second switching poles in the same direction is configured to transition each switching pole from the open configuration to the closed configuration. Rotation of the threaded drive element of the third switching pole in the opposite direction is configured to transition the switching pole from the open configuration to the closed configuration.
In an example, at least one of the switching poles comprises a threaded drive element comprising an additional section to extend the length of the threaded drive element in the direction of its centre axis.
The above aspects and examples will become apparent from and be elucidated with reference to the embodiments described hereinafter.
In an example, the thread of the threaded drive element is a high helix thread.
In an example, the centre axis of the threaded drive element is aligned along the longitudinal axis of the vacuum interrupter.
In an example, rotation of the threaded drive element about its centre axis in the first direction through a rotational angle of less than or equal to 360 degrees is configured to transition the switching pole from the open configuration to the closed configuration. Rotation of the threaded drive element about its centre axis in the second direction through a rotational angle of less than or equal to 360 degrees is configured to transition the switching pole from the closed configuration to the open configuration.
In an example, an end of the threaded drive element distil to the movable contact comprises a ball bearing configured to rotate in a ball bearing socket 7.
In an example, the ball bearing and/or the ball bearing socket comprise a low friction surface material.
In an example, the function of the ball bearing and/or the ball bearing socket 7 is fulfilled by an industrially available inclined ball bearing. This can comprise a low friction surface material.
In an example, the switching pole comprises a threaded pushrod 4 connected to the movable contact. The thread of the pushrod is configured to engage with the thread of the threaded drive element. Rotation of the threaded drive element is configured to move the threaded pushrod along the centre axis of the threaded drive element.
In an example, the threaded pushrod has a female thread and the threaded drive element has a male thread.
In an example, the threaded pushrod has a male thread and the threaded drive element has a female thread.
In an example, the threaded pushrod is movable connected to the movable contact. A contact pressure spring 3 is configured to move the moveable contact relative to the threaded pushrod.
In an example, the threaded pushrod comprises an insulating material.
In an example, the threaded pushrod is configured not to rotate as the threaded drive element rotates.
In an example, an outer surface of the threaded pushrod comprises a groove extending in an axial direction of the threaded pushrod. The groove is configured to engage with a fixed pin such that axial movement of the threaded pushrod leads to the fixed pin moving within the groove.
In an example, the threaded drive element comprises a coupling 6. The coupling is configured to engage with a gear wheel or belt 30 associated with a drive motor 20. Rotational movement of the coupling is configured to lead to an associated and equivalent rotational movement of the threaded drive element.
Thus, in this manner a thread is used to convert a rotational movement from a drive to a fast translational movement of the pole, where for example that thread can be a high helix thread giving a large translational movement for a relatively small rotational movement.
In an example, rotation of the threaded drive element of each switching pole in the same direction is configured to transition each switching pole from the open configuration to the closed configuration.
Thus, the threaded drive elements all have right hand threads or left hand threads.
In an example, rotation of the threaded drive element of the first and second switching poles in the same direction is configured to transition each switching pole from the open configuration to the closed configuration. Rotation of the threaded drive element of the third switching pole in the opposite direction is configured to transition the switching pole from the open configuration to the closed configuration.
Thus, the threaded drive elements of two of the switching pols is right handed and the other pole has a threaded drive element that is left handed, or vice versa.
In an example, at least one of the switching poles comprises a threaded drive element comprising an additional section 8 to extend the length of the threaded drive element in the direction of its centre axis.
Thus, the manner in which the poles are driven enables several poles to be connected to one or more drives using toothed belts, chains, gear-wheels or alike, enabling arbitrary arrangement of the switching poles.
Continuing with the figures, the medium voltage circuit breaker switching pole and medium voltage switching system are described in further detail, with respect to specific embodiments.
In
When the drive element 5 is rotated by a certain angle, the pushrod 4 moves upwards due to the thread. With industrially available high helix threads, it is possible to achieve the full stroke of the pushrod 4 with about one rotation of the drive element 5. The upward movement of the pushrod 4 drives the movable contact against the fixed contact of the vacuum interrupter. A relatively small further upward movement of the pushrod 4 further compresses the contact pressure spring 3, to ensure the required contact pressure.
The pushrod 4 is configured not to rotate during the upward or downward motion. This can be done in a number of different ways, with one way being to have a vertical groove in the pushrod 4 that runs over a pin that is fixedly connected to the environment.
As shown a ball bearing, consisting of the lower end of the drive element 5, that is generally formed like a ball, and the fixed part of the ball bearing 7, that is generally formed like a pit, is used to support the pushrod vertically against the force of the contact pressure spring 3. The ball bearing also supports the switching pole 10 against lateral forces generated by the coupling 6 to a chain, belt or gear-wheel. The ball bearing joint can be formed in a known manner to minimise frictional forces.
The function of the ball bearing and/or the ball bearing socket 7 can as well be fulfilled by an industrially available inclined ball bearing.
Here, a drive system can have a double sided toothed belt 30 as an example. Alternatively, a chain or a single-sided toothed belt with pulleys can be used. The drive or motor 20 is located in the center as an example; other locations are also possible.
What is further shown in
Further, it is possible to connect more than one drive to the switching poles, when more drive power is required for a certain application. One drive can be used for a low-duty CB, while for a high-duty CB two drives can be used.
While one or more embodiments of the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
Number | Date | Country | Kind |
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19181805.3 | Jun 2019 | EP | regional |
This application is a continuation of International Patent Application No. PCT/EP2020/066054, filed on Jun. 10, 2020, which claims priority to European Patent Application No. EP 19181805.3, filed on Jun. 21, 2019. The entire disclosure of both applications is hereby incorporated by reference herein.
Number | Date | Country | |
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Parent | PCT/EP2020/066054 | Jun 2020 | US |
Child | 17556190 | US |