Valve Shaft Friction Angle Design for Axial Fixing
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Solution Overview
Problem
Existing valve designs face challenges in cost-effectively axially fixing the shaft within the valve housing, particularly when high torque is applied, leading to potential damage to the wedge, shaft, or collar, and require multiple friction surfaces to ensure sufficient friction to prevent damage, which increases manufacturing costs and complexity.
Innovation Solution
The valve incorporates a set of shaft and collar friction surfaces arranged at angles between 110° and 175°, allowing for reduced surface area requirements while generating sufficient friction to prevent damage, with optional features like identical surface angles, multiple sets of friction surfaces, and different materials to enhance durability and ease of assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the collar and shaft are designed with multiple friction surfaces to ensure sufficient friction force, then the reliability of preventing component damage is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent changes the geometric parameter of the friction surfaces by using obtuse angles (greater than 90 degrees) instead of conventional acute angles. This parameter change allows a single friction surface configuration to generate sufficient friction force through increased normal force, eliminating the need for multiple friction surfaces while maintaining reliability
Solution Approach 2:
Instead of using multiple small-angle friction surfaces as in conventional design, the patent inverts the approach by using a single (or reduced number of) obtuse-angle friction surfaces. This inversion of the conventional design paradigm achieves the same or better friction effect with fewer surfaces, reducing complexity
2Device complexity
If the friction surface angle is increased to reduce the number of surfaces needed, then the device complexity is reduced, but the risk of wedging and difficulty of separation increases
Solution Approach 1:
The patent optimizes the obtuse angle parameter within a specific range (greater than 90 degrees but less than 180 degrees) to balance two competing requirements: generating sufficient friction force to prevent damage while maintaining ease of separation. This precise parameter control resolves the contradiction between reduced complexity and operational ease
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
This design reduces manufacturing costs and prevents damage to valve components by generating a strong friction force without increasing the risk of wedging, maintaining efficiency and functionality while ensuring parts can be easily separated, even at extreme positions.
Implementation Method 1
a great friction force between the shaft means and the collar means will be generated as soon as the axial force is increased
Data Source
AI summary
A valve for control of a fluid flow including a valve housing, fluid control means arranged inside the valve housing, shaft means having a first shaft friction surface and a second shaft friction surface arranged in a mutual shaft friction surface angle, where the fluid control means is arranged to be displaced along a rotational axis of the shaft means in accordance with a rotation of the shaft means, and collar means having a first collar friction surface and a second collar friction surface arranged in a mutual collar friction surface angle, where the collar friction surfaces are arranged to mesh with the shaft friction surfaces, and where the shaft friction surface angle and the collar friction surface angle are between 120° and 170° and the collar means are fixed inside the valve housing.