Fluid Controller With Selector Valve For Steering Displacement
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Solution Overview
Problem
Current two-speed hydraulic steering units for off-highway vehicles lack efficiency in providing different fluid displacement rates for a given steering actuator rotation speed, limiting their performance in various applications.
Innovation Solution
A fluid controller with a valving assembly and gerotor gear sets that allow for two metered modes of fluid displacement, enabling different fluid flow rates by selectively engaging first and second fluid meters through a selector assembly, which includes a selector valve and valve plates, to accommodate varying steering wheel rotation rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a two-speed hydraulic steering unit uses a single displacement assembly, then the structure is simple, but the fluid displacement rate cannot be adjusted for different steering speeds
Solution Approach 1:
The displacement assembly is segmented into a first displacement assembly and a second displacement assembly that can operate independently or together. This allows the system to provide different fluid displacement rates (first rate when only first assembly operates, second rate when both assemblies operate) while maintaining a manageable modular structure rather than requiring a completely redesign of the displacement mechanism.
Solution Approach 2:
The first displacement assembly is designed to serve dual functions: it can operate alone to provide normal steering fluid displacement, and it can work in conjunction with the second displacement assembly to provide high-speed steering fluid displacement. This multi-functionality allows a single component to adapt to different operational requirements without requiring entirely separate systems for each mode.
2Productivity
If a two-speed hydraulic steering unit engages both displacement assemblies simultaneously, then high fluid displacement rate is achieved, but the device complexity increases
Solution Approach 1:
A valving assembly acts as an intermediary mechanism that controls the engagement and disengagement of the second displacement assembly. This valving assembly, which includes selective fluid communication pathways and control valves, manages the complexity of coordinating two displacement assemblies by providing a centralized control point that can route fluid to either or both assemblies based on steering speed requirements, rather than requiring direct mechanical coupling of all components.
3Adaptability or versatility
If the hydraulic steering unit uses fixed displacement assembly, then the structure is simple, but it cannot provide different fluid displacement rates for varying steering wheel rotation speeds
Solution Approach 1:
The system transitions from fixed displacement to dynamic displacement by incorporating a selector assembly that can switch between different displacement configurations. The selector assembly, which includes movable selector plates and fluid communication pathways, allows the system to dynamically adjust which displacement assembly(ies) are active based on the steering wheel rotation speed, providing adaptability while maintaining relatively simple individual assembly designs.
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
The fluid controller enhances steering efficiency by allowing for higher fluid displacement rates in the second mode, reducing the number of steering wheel turns required for lock-to-lock movement, thereby improving vehicle maneuverability and operational efficiency.
Implementation Method 1
A fluid controller with a valving assembly and gerotor gear sets that allow for two metered modes of fluid displacement
Data Source
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AI summary
A fluid controller (18) includes a first fluid meter (36) defining a first plurality of volume chambers (68) and a second fluid meter (38) defining a second plurality of volume chambers. A selector assembly (44), disposed between the first fluid meter and the second fluid meter, includes a selector plate (106) defining a bore (112) and a selector valve (108) disposed in the bore. The selector valve is adapted for rotational movement between a first position and a second position and includes a first face (152) and an oppositely disposed second face (154). The selector valve defines a plurality of thru-passages that extend axially through the first and second faces and that is adapted to provide fluid communication between the first and second volume chambers (68) in the first position. The selector valve defines a groove (164b) disposed on the second face. The groove recirculates fluid from the second plurality of volume chambers when the selector valve is in the second position.