Double-Acting Valve Unit for Hydraulic Charge Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic systems require two separate valve devices to maintain minimum charge pressure and allow free flow of oil from a clean oil reservoir to a piston pump, resulting in a complex and bulky setup.
Innovation Solution
A compact double acting valve unit with a hollow housing, a movable valve member, and a spring mechanism that maintains minimum charge pressure and allows free flow of oil by shifting in response to fluid pressure, utilizing a single moving part to manage fluid flow between the charge pump and the clean oil reservoir.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two separate valve devices are used to maintain minimum charge pressure and allow free flow of oil, then the required functions are achieved, but the device complexity and size increase
Solution Approach 1:
The patent combines two separate valve functions (check valve for pressure maintenance and bypass valve for free flow) into a single double-acting valve unit with a shared housing, valve body, and actuating mechanism. This merging reduces the number of discrete components while maintaining both pressure maintenance and free flow capabilities through the unified valve's ability to respond to pressure differentials across its sealing elements.
Solution Approach 2:
The single valve unit performs multiple functions: it acts as a check valve to maintain minimum charge pressure, functions as a bypass valve to allow free oil flow when needed, and responds dynamically to pressure conditions. The universal design eliminates the need for separate specialized valves by integrating these functions into one multi-functional component.
2Reliability
If two separate valve devices are used, then the required valve functions are achieved, but the overall system size and compactness are reduced
Solution Approach 1:
By merging two separate valve devices into one integrated unit with a common housing and shared internal passages, the overall volume is reduced. The unified structure eliminates redundant external connections and mounting requirements, creating a more compact assembly that occupies less space in the hydraulic system.
Solution Approach 2:
The valve design features nested components where the valve member is received within the valve body, which is contained within the housing. The piston and sealing elements are nested within the valve member, creating a compact nested arrangement that maximizes functional density while minimizing external dimensions.
3Device complexity
If a single valve unit is used, then the device complexity is reduced, but the ability to maintain charge pressure and allow free flow may be compromised
Solution Approach 1:
The valve employs dynamic response to pressure differentials, where the valve member moves between sealed and open positions based on real-time pressure conditions. The spring-loaded piston and sealing elements dynamically adjust the valve's state, maintaining charge pressure when needed and allowing free flow when pressure differentials exceed the spring force, ensuring reliable performance despite the simplified single-unit design.
Solution Approach 2:
The spring-loaded piston acts as an intermediary mechanism that translates pressure differentials into valve member movement. This intermediary converts hydraulic pressure signals into mechanical displacement of the sealing elements, enabling the single valve to reliably sense and respond to pressure conditions for both charge pressure maintenance and free flow functions.
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 valve unit effectively maintains minimum charge pressure and allows high flow rates, ensuring efficient oil flow to the piston pump, even during high demand conditions, while maintaining a compact, in-line design that fits within existing tubing.
Implementation Method 1
A spring is mounted in the sleeve, engages an end of one of the valve stems and is biased to urge the valve member towards the other end plate
Implementation Method 2
The valve disk, in response to fluid pressure, is movable out of said central position to displaced positions on opposite sides of the land member
Data Source
AI summary
A hydraulic system includes a charge pump which supplies fluid to variable displacement main pump, a fluid reservoir and valve unit. The valve unit includes a hollow housing having a first end communicated with the reservoir and a second end communicated with the charge pump and the main pump. A housing valve land member is located between the first and second ends. A valve member is movably mounted in the housing. The valve member has a valve disk attached to first and second valve stems which project from opposite sides of the valve disk. The valve disk has a central position wherein the valve disk is received by the ring. The valve stems are slidably supported by stem support members at opposite ends of the housing. A hollow sleeve projects from an end of the valve unit. A spring is mounted in the sleeve and is engagable with an end of one of the valve stems and is biased to urge the valve member away from the sleeve.