Three-pole Circuit Breaker Tripping Shaft Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing four-pole circuit breakers require structural modifications and increased restoring forces when converting to a three-pole configuration with an additional quick-action short-circuit release, due to additional frictional forces and balance of forces issues, especially when soiled.
Innovation Solution
The tripping shaft is composed of two aligned partial shafts, where the additional quick-action short-circuit release acts on the second partial shaft, which pivots the first partial shaft via coupling means to trigger the switching mechanism, without requiring increased restoring forces or structural modifications to the original switching mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an extended tripping shaft is used to accommodate an additional quick-action short-circuit release, then the circuit breaker can be converted from four-pole to three-pole configuration, but additional frictional forces increase and require modified switching mechanism structure and higher restoring forces
Solution Approach 1:
The tripping shaft is divided into two separate partial shafts: a first partial shaft that remains in the original switching mechanism and a second partial shaft that is actuated by the additional quick-action short-circuit release. This segmentation allows the additional release to be added without modifying the original switching mechanism structure, as the second partial shaft independently transmits its motion to the first partial shaft through coupling means.
2Adaptability or versatility
If an extended tripping shaft is used to accommodate an additional quick-action short-circuit release, then the circuit breaker can be converted from four-pole to three-pole configuration, but the restoring forces required increase due to additional friction in bearing points
Solution Approach 1:
By segmenting the tripping shaft into two separate partial shafts, each with its own bearing points, the frictional forces are localized rather than accumulated along an extended shaft. The second partial shaft has its own compact bearing arrangement that minimizes friction, and only transmits motion to the first partial shaft when needed, rather than continuously increasing the friction load on a single extended shaft.
3Adaptability or versatility
If the original tripping shaft is replaced with a new extended tripping shaft, then the additional short-circuit release can be integrated, but the original switching mechanism balance is disrupted and structural modifications are required
Solution Approach 1:
The first partial shaft corresponds to the original tripping shaft and maintains its original dimensions, mounting positions, and coupling interfaces. This allows the original switching mechanism to remain unchanged and retain its optimized force balance. The second partial shaft is added as a separate component that couples to the first partial shaft, enabling the additional short-circuit release to be integrated without disrupting the original mechanism's balance or requiring structural modifications.
4Adaptability or versatility
If a single extended tripping shaft is used, then the additional quick-action short-circuit release can act on it, but the frictional forces from additional bearing points require different force balance interpretation
Solution Approach 1:
The force balance of the original switching mechanism is preserved because the first partial shaft maintains its original characteristics and operating conditions. The second partial shaft introduces minimal additional friction through its own compact bearing arrangement and only interacts with the first partial shaft through the coupling means when actuation is required. This segmentation allows the original force balance calculations and interpretations to remain valid without requiring different interpretations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for a three-pole circuit breaker to be produced from a modified four-pole circuit breaker without structural changes or increased restoring forces, ensuring efficient operation and reduced frictional forces, maintaining the original switching mechanism's balance.
Implementation Method 1
In the event of a short-circuit, the electromagnetic induction of the high short-circuit current flowing through the corresponding main busbar causes the flat armature to be attracted by the main busbar against the force of the return spring.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The three pole power switch (1) has a switch lock (14), where each pole (5-7) has its own rapid short circuit trip (19-22) to act on a trip shaft. The lock has four adjacent poles, where the two inner poles (6',6") are switched in parallel as a common inner pole. The inner poles and an outer pole (5), on a short circuit, act against the pressure of an elastic return unit (24) at a part shaft (23) of the trip shaft. The trip, on a short circuit at the other outer pole (7), acts against an elastic return unit on a second plastics part shaft (28) to lock the part shafts together.