Composite Rod Joint With Nonlinear Wedge for High Tensile Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sucker rods lack sufficient tensile strength while occupying minimal cross-sectional area, particularly in applications like oil wells where rods must withstand high tension loads and fit within small diameters, and prior solutions using stranded wire or materials are suboptimal.
Innovation Solution
A joint design featuring a carbon or graphite composite rod with a smoothly varying nonlinear wedge inserted into a steel fitting, where the wedge's contour matches the fitting's internal diameter, ensuring maximum space utilization and high tensile strength without significant compression load bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If stranded wire is used to construct the rod, then the rod can be assembled from multiple strands, but the tensile strength is reduced because the strands do not occupy the entire cross-sectional area and are not perfectly aligned
Solution Approach 1:
The patent uses a solid composite rod made of carbon or graphite fibers embedded in a metal matrix (such as aluminum or magnesium). This composite structure provides both high tensile strength and light weight, resolving the contradiction between ease of manufacture and strength by eliminating the need for stranded wire assembly while achieving superior mechanical properties.
Solution Approach 2:
The patent changes the material parameters from traditional metal or stranded wire to carbon/graphite composite materials. This parameter change enables the rod to achieve both high tensile strength and minimal cross-sectional area, simultaneously improving strength while maintaining ease of manufacture through monolithic construction.
2Strength
If the rod cross-sectional area is increased to achieve higher tensile strength, then the rod can withstand higher tension loads, but the rod cannot fit within the tubing of relatively small diameter
Solution Approach 1:
The solid composite rod made of carbon or graphite fibers in a metal matrix provides exceptionally high tensile strength-to-area ratio. This allows the rod to achieve the required tensile strength while maintaining a minimal cross-sectional area that fits within the tubing constraints.
Solution Approach 2:
By changing to advanced composite materials with superior mechanical properties, the patent achieves higher tensile strength in a smaller cross-sectional area, simultaneously improving strength while reducing the area occupied.
3Strength
If a wedge is inserted into the rod to create a joint, then the joint achieves high tensile strength, but the rod must be slit to accommodate the wedge
Solution Approach 1:
The patent divides the rod into segments that can be joined using the wedge mechanism. The slit is made only at the joint location rather than along the entire rod length, minimizing rod modification complexity while achieving high joint tensile strength through the wedge insertion.
Solution Approach 2:
The wedge acts as an intermediary element that transfers and distributes tensile loads across the joint. By inserting the wedge into the slit and securing it with the fitting, the patent achieves high joint strength while limiting the rod modification to a localized slit at the joint only.
Data Source
AI summary
A joint includes a solid rod having a slit or opening into which a wedge is inserted. The rod and wedge are inserted into a fitting. The internal surface of the fitting has a contour which continuously and nonlinearly varies with distance along the fitting. The wedge has a dimension having a similar contour. The shape of the contour can be described by a polynomial of order two or higher.