Spool Valve Dual Angle Cut Notch Metering Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spool valve systems experience imbalanced forces and differential leak paths due to asymmetric dual notched configurations, leading to friction and hysteresis, which can result in binding and inadequate control of fluid flow.
Innovation Solution
A spool valve configuration with at least two angle cut notches, where the first angle cut is shallow and the second angle cut is deeper, providing a gradual change in area over a long spool stroke for precise metering and uniform leakage paths, reducing friction and hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional asymmetric dual notched configurations are used, then multiple flow rates can be controlled, but imbalanced forces and differential leak paths occur leading to friction and hysteresis
Solution Approach 1:
The patent applies asymmetry in reverse by creating a symmetric notch configuration where the first and second notches are positioned symmetrically on opposite sides of the spool. This symmetry balances the forces acting on the spool during operation, eliminating the imbalanced forces and differential leak paths that cause hysteresis and binding in conventional asymmetric designs, while still providing multiple flow rate control through the different notch positions and sizes
2Device complexity
If singular stepped notches are used, then the structure is simple, but only one flow rate can be controlled
Solution Approach 1:
The patent segments the flow control function by creating multiple separate notches (first and second notches) in the spool, each capable of controlling flow independently. This segmentation allows the valve to provide multiple flow rates by selectively positioning different notches in the flow path, thereby increasing adaptability while maintaining relatively simple individual notch structures
3Ease of operation
If dual steps notches are used, then better flow control is achieved, but asymmetric configuration causes imbalanced forces and friction
Solution Approach 1:
The patent applies asymmetry in reverse by creating a symmetric notch configuration where the first and second notches are positioned symmetrically on opposite sides of the spool. This symmetry balances the forces acting on the spool during operation, eliminating the imbalanced forces and differential leak paths that cause hysteresis and binding in conventional asymmetric designs, while still providing multiple flow rate control through the different notch positions and sizes
Data Source
AI summary
A spool component for use in a spool valve has a cylindrical body including a first diameter portion and a second diameter portion, the first diameter portion having a diameter that is larger than a diameter of the second diameter portion. A metering notch is cut into the first diameter portion and extends toward the second diameter portion. The metering notch includes a first angle cut and a second angle cut that are sloped at different depth angles toward the first diameter portion. A spool valve assembly includes a housing defining a bore, and the spool component, which is moveable within the bore along a stroke distance comprising a metering band for metering a flow of fluid across the spool component. The metering notch provides precise metering of the flow of fluid across the spool component based on the different depth angles of the cuts in the metering notch.