Pull-in Head Clamping Segments for HV Cable Force Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pull-in heads for high voltage cables face challenges in efficiently transferring pulling and torsional forces due to the sliding motion between layers of multi-wire conductors, and the resin filling process is time-consuming and hazardous.
Innovation Solution
A pull-in head with clamping segments having central channels that match the tapering configuration of the multi-wire conductor, allowing individual clamping of each layer and improved grip through uneven surfaces, along with a support structure and connection flange for secure attachment and water-tight sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resin is injected into the pull-in head to improve grip of the conductor, then the pulling force can be better transferred to the entire conductor, but the filling process is time-consuming and requires careful control of parameters to obtain reliable filling and hardening with the intended strength
Solution Approach 1:
The patent removes the resin filling process entirely from the system. Instead of injecting resin into the pull-in head to achieve grip, the invention uses a mechanical clamping mechanism with a clamping cone that directly grips the conductor through friction and mechanical interlocking, eliminating the time-consuming resin filling and hardening process while maintaining reliable force transfer.
Solution Approach 2:
The patent replaces the chemical bonding mechanism (resin hardening) with a mechanical clamping mechanism. The clamping cone applies radial pressure to the conductor, creating friction-based grip and mechanical interlocking, which substitutes the chemical bonding process with a purely mechanical system that is faster and more controllable.
2Reliability
If resin is used to transfer force from the cable to the pull-in head, then better grip is obtained, but it is difficult to afterwards assess how successful the filling process has been and whether the casting meets the requirements
Solution Approach 1:
The patent eliminates the resin filling process, removing the associated quality assessment problems. The mechanical clamping mechanism allows for direct visual inspection and measurement of clamping parameters (such as clamping force and cone position), making quality control straightforward without the need to assess resin filling completeness or hardening quality.
Solution Approach 2:
The clamping mechanism is designed to be self-indicating of its proper function. The mechanical arrangement allows operators to verify correct installation and clamping through simple visual checks and measurements, without requiring complex testing procedures to assess whether the grip has been properly established.
3Reliability
If resin filling process is used to secure the conductor in the pull-in head, then the pulling force can be transferred to the entire conductor, but the process requires special measures to protect against the toxic gases released during the process
Solution Approach 1:
The patent completely removes the resin filling process from the system, eliminating the source of toxic gases. The mechanical clamping mechanism achieves force transfer through physical contact and friction without any chemical reactions, thereby eliminating the harmful emissions associated with resin curing while maintaining effective force transfer to the conductor.
Solution Approach 2:
The patent replaces the chemical bonding process (resin curing) with a mechanical clamping system. This substitution eliminates the need for chemical reactions that produce toxic gases, while still achieving the goal of transferring pulling force from the pull-in head to the entire conductor cross-section through mechanical means.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present disclosure relates to a pull-in head (1) for a high voltage cable (19) provided with a multi-wire conductor (15), wherein the pull-in head (1) comprises: a conductor clamp assembly (9) comprising a plurality of clamping segments (9a), wherein each clamping segment (9a) has an axial first central channel (9d) configured to receive the multi-wire conductor (15), wherein at least some of the clamping segments (9a) have mutually differing central channel width and central channel depth dimensions, the clamping segments (9a) being configured to be arranged one after the other in an order with a decreasing central channel width and central channel depth dimension, whereby the first central channels (9d) together form a multi-wire conductor channel which is tapering in an axial direction, and wherein each clamping segment (9a) is configured to provide individual clamping of the multi-wire conductor (15).