Tap Changer Static Contact Unit With Torsion Spring Biasing
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Solution Overview
Problem
Existing tap changers face challenges in providing a stable and reliable mechanism for electrically engaging movable and stationary contacts, often requiring complex setups that occupy more space and increase electrodynamic forces.
Innovation Solution
A static contact unit with cylindrical coil torsion springs and guiding elements ensures a compact design that biases contact elements for secure and reliable electrical engagement, using spring arms and axles to maintain contact force and reduce space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex setups are used to engage movable and stationary contacts, then reliability of electrical engagement is improved, but device complexity and space occupation increase
Solution Approach 1:
The contact mechanism is divided into separate functional components: a movable contact unit with movable contacts, stationary contact units with contact elements, and spring elements. Each component is independently designed and assembled, allowing for simplified manufacturing and maintenance while ensuring reliable electrical engagement through coordinated interaction of segments.
Solution Approach 2:
Instead of using complex mechanical linkages to ensure contact pressure, the patent inverts the approach by using spring elements that inherently provide continuous contact force. The spring elements are positioned to directly bias the contact elements toward the movable contacts, eliminating the need for complex positioning and actuation mechanisms.
2Ease of manufacture
If more space is allocated for contact mechanism, then ease of assembly and manufacturing is improved, but volume of the tap changer increases
Solution Approach 1:
The spring elements are nested within the stationary contact units, with the spring arms positioned inside recesses of the contact body. The axles supporting the spring elements are integrated into the contact body structure, creating a compact nested arrangement that maximizes space utilization while maintaining ease of assembly through modular design.
Solution Approach 2:
The contact elements and spring elements are arranged in a three-dimensional configuration that optimizes space utilization. The spring elements are positioned at different heights and angles relative to the movable contacts, allowing for compact packaging of the contact mechanism without compromising assembly ease or electrical engagement reliability.
3Stability of the object's composition
If contact elements are pre-loaded with spring force, then stability of electrical contact is improved, but force requirements and electrodynamic forces increase
Solution Approach 1:
The spring elements provide localized pre-loading force at the contact points between stationary contact elements and movable contacts. This localized force application ensures stable electrical contact exactly where needed without requiring excessive force throughout the entire mechanism, thereby minimizing electrodynamic forces while maintaining contact stability.
4Volume of moving object
If compact design is implemented, then volume and production costs are reduced, but manufacturing precision requirements increase
Solution Approach 1:
The spring elements are pre-loaded and positioned in advance during assembly, with the spring arms initially positioned in recesses of the contact body. This preliminary positioning ensures that the correct amount of pre-loading force is applied before final assembly, reducing the need for precise post-assembly adjustments and maintaining compact dimensions while managing manufacturing precision requirements.
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
The solution enables a compact, reliable, and efficient electrical contact system with reduced electrodynamic forces, minimizing space and production costs while ensuring stable electrical switching.
Implementation Method 1
the spring element is formed as a cylindrical coil torsion spring and comprises two spring arms at opposite ends which are coupled to a respective associated contact element
Data Source
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AI summary
A static contact unit (20) for a tap changer comprises a contact body (4), a pair of contact elements (5) and a spring element (6). The contact body (4) is configured to be arranged statically with respect to a movable contact (3) that is arranged at a moving shaft (1) of the tap changer. The two contact elements (5) are coupled to the contact body (4) configured to establish an electrical contact to the movable contact (3) of the moving shaft (1). The spring element (6) is coupled to both contact elements (5) inbetween with respect to a longitudinal axis (L1) of the moving shaft (1) configured to bias the contact elements (5) so that, with respect to a state in which the tap changer is assembled, the contact elements (5) are biased simultaneously in direction towards each other in sections at least.