Servo Valve Spool Geometry for Integrated Meter-In and Meter-Out Control
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Solution Overview
Problem
Existing servo valves require an additional speed controller to perform meter-out or meter-in control, which complicates the system and increases costs.
Innovation Solution
A servo valve with a unique structure featuring a sleeve and spool design, where the spool has lands and grooves of varying sizes to create different flow path areas, allowing for meter-out or meter-in control without the need for an external speed controller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an additional speed controller is provided to perform meter-out control or meter-in control, then the control functionality is improved, but the device complexity increases
Solution Approach 1:
The patent combines the meter-out control and meter-in control functionalities directly into the servo valve structure by designing the spool with asymmetric flow path areas. The first flow path area (supply side) and second flow path area (discharge side) are made different in size, allowing the valve to perform both meter-in and meter-out control functions without requiring separate speed controllers. This merging of functions resolves the technical contradiction by eliminating additional control components while maintaining full control capability.
2Adaptability or versatility
If an additional speed controller is provided to perform meter-out control or meter-in control, then the control functionality is improved, but the system cost increases
Solution Approach 1:
The invention merges the meter-out and meter-in control functionalities into the servo valve itself through the asymmetric spool design with different first and second flow path areas. This eliminates the need for separate speed controllers, thereby reducing system cost and simplifying manufacturing while maintaining complete control functionality for both meter-in and meter-out operations.
3Adaptability or versatility
If the first flow path area is made different from the second flow path area, then the meter-out control or meter-in control is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies asymmetry by designing the spool with a first flow path area that is intentionally made different from the second flow path area. This asymmetric design enables the valve to perform meter-in control when the first flow path area is smaller, and meter-out control when the second flow path area is smaller. While this does require precise manufacturing to achieve the desired flow path area differences, the asymmetric geometry is clearly defined in the drawings, allowing for controlled manufacturing processes that can achieve the required precision.
Data Source
AI summary
A first flow path area at a position where one of multiple openings of a sleeve and one of multiple grooves of a spool overlap with each other is different in size from a second flow path area at a position where another one of the openings of the sleeve and another one of the grooves of the spool overlap with each other. The one opening and the one groove form a flow path for connecting one of one pressure chamber and the other pressure chamber to a fluid supply source, due to displacement of the spool. The other opening and the other groove form a flow path for connecting another one of the other pressure chamber and the one pressure chamber to a fluid discharge port, due to the displacement of the spool.