Composite Crossarm Structure for Stable Grading Ring Mounting
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Solution Overview
Problem
Current composite crossarms in power transmission towers are unstable and prone to failure when insulators break, necessitating a more stable structure that allows for mounting grading rings and ensures structural integrity.
Innovation Solution
A composite crossarm design featuring two post insulators and two suspension insulators, forming a stable triangular structure with specific angles between them, along with a flange cylinder and link fittings to enhance stability and bonding, and incorporating sealing and drying mechanisms to prevent corrosion and improve torsion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single post insulator or single suspension insulator structure is used, then the device complexity is reduced, but the reliability of the composite crossarm deteriorates because the whole crossarm may fail when one insulator breaks
Solution Approach 1:
The composite crossarm is divided into multiple independent insulator units (two post insulators and two suspension insulators) that are separately connected to the tower body. This segmentation ensures that if one insulator fails, the other insulators remain functional and can still support the crossarm, preventing total collapse and enabling safer maintenance operations.
2Ease of manufacture
If the angle between insulators is not optimized, then the ease of manufacture is improved, but the strength of the composite crossarm deteriorates due to poor stress distribution
Solution Approach 1:
The patent specifies optimal angle ranges for insulator arrangement (angle between post insulators: 20°-50°, angle between post insulator and suspension insulator: 15°-45°). These parameter optimizations ensure favorable conditions for mounting grading rings while maintaining good stress distribution and mechanical strength, balancing manufacturing ease with structural performance.
3Manufacturing precision
If the insulating body is solid, then the manufacturing precision is improved, but the reliability deteriorates due to lack of corrosion protection and maintenance access
Solution Approach 1:
The insulating body is designed as a hollow structure rather than solid, creating different functional zones: the hollow interior provides corrosion protection and allows for drying agent placement, while the exterior maintains manufacturing precision and insulation performance. This local quality differentiation optimizes both durability and fabrication accuracy.
4Device complexity
If no sealing mechanism is provided, then the device complexity is reduced, but the reliability deteriorates due to moisture and corrosion ingress
Solution Approach 1:
A sealing structure is provided at the open end of the hollow insulating body to prevent moisture and corrosive substances from entering the hollow interior before corrosion can occur. This preliminary protective action ensures long-term reliability by blocking degradation pathways at the design stage.
Solution Approach 2:
A drying agent is placed inside the hollow insulating body to actively absorb any moisture that penetrates the sealing structure or condenses internally. This self-service mechanism continuously protects the insulator interior without requiring external maintenance, enhancing reliability through autonomous corrosion prevention.
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 design enhances the stability and structural integrity of the composite crossarm, allowing for efficient mounting of grading rings and reducing maintenance needs while maintaining mechanical strength and corrosion resistance.
Implementation Method 1
an insulating gas is sealed in the hollow insulating tube, and an absolute pressure value of the insulating gas ranges from 0.1 MPa to 0.15 MPa
Implementation Method 2
The binding grooves and the flow groove are filled with an adhesive to fixedly connect the flange cylinder and the insulating body
Implementation Method 3
The arrangement that the shed bodies are radially symmetric with respect to the insulating body is conducive to self-cleaning of the shed and enables the post insulator to have characteristics of pollution resistance, rain resistance and ice resistance
Data Source
AI summary
The present disclosure discloses a composite crossarm and a power transmission tower. The composite crossarm includes two post insulators and two suspension insulators. Of the two post insulators and the two suspension insulators, one ends are configured to be connected to a tower body of a power transmission tower, and the other ends are connected together to form an end portion of the composite crossarm to hang a power transmission line. The two suspension insulators are located on same sides of the two post insulators and respectively arranged adjacent to the two post insulators. At the same time, an angle between the two post insulators ranges from 20° to 50°, and an angle between the post insulator and the suspension insulator adjacent thereto ranges from 15° to 45°. The composite crossarm according to the present disclosure is highly stable and convenient to for mounting grading ring.