Wing Nut Rib and Thread Geometry for Fatigue Resistance
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Solution Overview
Problem
Wing nuts used in high-stress pumping operations, such as hydraulic fracking and concrete pouring, have a limited service life due to deformation from repeated loading and are prone to cracks and fatigue failures under cyclic pressure loading.
Innovation Solution
A wing nut design featuring a cylindrical body with varying wall thickness, three radially extending wings with curved outer faces and offset lug centerlines, a rib around the sidewall, and a thread shape with flat internal crests and rounded roots, along with a thread release undercut and guide bore, to enhance strength and resilience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional uniform wall thickness design is used, then manufacturing is simpler, but the nut is prone to cracks and fatigue failures under cyclic pressure loading
Solution Approach 1:
The patent applies local quality by varying the wall thickness of the nut body along its axial length. The wall thickness is increased in the region subjected to cyclic pressure loading (where the threaded portion is located) and can be reduced in other regions. This localized thickening provides enhanced fatigue strength and crack resistance precisely where the highest stresses occur during pumping operations, while maintaining manufacturing feasibility through a controlled gradient design.
2Strength
If repeated impact loading is applied during installation, then the nut can be tightened securely, but the wings become deformed and service life is limited
Solution Approach 1:
The patent applies beforehand cushioning by incorporating a rib extending peripherally around the nut body at a location that provides structural reinforcement before the wings are subjected to repeated impact loading during installation. This rib feature, combined with the optimized wall thickness distribution, creates a stress-absorbing structure that cushions the impact forces, allowing secure tightening while preventing wing deformation and extending service life.
3Strength
If the threaded portion extends the full length of the nut, then connection is more secure, but stress concentration occurs at the threaded roots leading to fatigue failures
Solution Approach 1:
The patent applies parameter changes by modifying the thread root geometry and the axial distribution of wall thickness. The threaded portion is designed with optimized root radius and the wall thickness is increased in the threaded region to reduce stress concentration at the thread roots. This parameter optimization maintains secure connection strength while significantly improving resistance to fatigue failures under cyclic pressure loading.
Data Source
AI summary
A wing nut includes a body having a sidewall that surrounds a central opening. The central opening is threaded along a threaded portion having a threaded length extending from the back end towards the front end of the body. At least two wings are integrated with the sidewall and extend away from the sidewall in a radial direction relative to the centerline. A rib extend peripherally around the sidewall in a radially outward direction such that a wall thickness of the sidewall increases to a maximum value moving along the centerline away from the rear end, and decreases along the centerline moving towards the front end from the maximum value.