Hydraulic Cylinder Stem Holding Valve With Throttled Decompression
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Solution Overview
Problem
Existing hydraulic check valve systems are prone to leakage due to contamination, vibrations, pressure and temperature fluctuations, and wear, leading to unreliable sealing and potential damage to elastomeric seals, especially when under load.
Innovation Solution
Incorporating a secondary check valve with throttles formed by the secondary control stem and hydraulic block, which have significantly smaller closing gaps than opening gaps, preventing fluid flow and minimizing decompression flows that could damage the seal, and using a resilient seal with a conical or toroidal design to maintain sealing integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a check valve is used to prevent fluid leakage, then sealing reliability is improved, but the valve is susceptible to failure due to contamination, vibrations, pressure and temperature fluctuations, and wear
Solution Approach 1:
The patent introduces a decompression flow path with throttles that activate before pressure builds up to damaging levels. The first throttle body and first throttle counter-body create a controlled decompression path that prevents sudden pressure spikes and fluid hammer effects, cushioning the seal against harmful pressure fluctuations before they can cause damage.
Solution Approach 2:
The patent introduces an intermediary decompression flow path between the sealed fluid path and the external environment. This intermediate path with controlled throttles acts as a mediator that gradually releases pressure and prevents direct exposure of the seal to extreme pressure fluctuations and contamination, thereby protecting the sealing system.
2Reliability
If the closing gap of the throttle is made smaller to prevent fluid flow, then sealing effectiveness is improved, but fluid flow restriction increases
Solution Approach 1:
The patent segments the throttle closing gap into multiple smaller gaps between the throttle body and throttle counter-body. This segmentation allows the throttle to maintain effective sealing through multiple narrow pathways rather than one large gap, preventing fluid flow while distributing the flow restriction across several smaller channels, thereby maintaining productivity.
Solution Approach 2:
The patent implements partial closing of the throttle gap, maintaining a small clearance rather than complete closure. This partial action allows minimal fluid flow through the decompression path while still providing effective sealing and pressure control, balancing sealing effectiveness with maintained fluid productivity.
3Reliability
If a resilient seal is used to maintain sealing integrity, then sealing reliability is improved, but the seal is susceptible to damage from decompression flows
Solution Approach 1:
The patent provides beforehand cushioning by creating a controlled decompression path with throttles that activates before harmful pressure builds up. The first throttle body and first throttle counter-body establish a gradual pressure release mechanism that cushions the resilient seal against sudden decompression flows, preventing seal damage while maintaining sealing integrity.
4Reliability
If throttles with small closing gaps are used to prevent fluid flow, then leakage prevention is improved, but pressure build-up may occur
Solution Approach 1:
The patent introduces an intermediary decompression path with throttles that acts as a pressure relief mediator. This intermediate system allows controlled pressure release while maintaining the small closing gaps needed for leakage prevention, balancing leakage protection with pressure management through the throttled decompression flow path.
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 solution enhances the functional reliability of the hydraulic cylinder by preventing leakage and seal damage, ensuring secure fluid containment and prolonged operational stability under varying conditions.
Implementation Method 1
The secondary valve body is provided with a resiliently compressible, preferably annular and especially circular, for example toroidal, seal, preferably of an elastomer, which in the secondary valve body closed setting of the secondary valve body tightly bears against a preferably circular contact surface of the secondary valve seat of the hydraulic block
Implementation Method 2
under loading by a spring force of a secondary spring
Implementation Method 3
the first throttle body in the secondary control stem closed setting is directly opposite the first throttle counter-body of the hydraulic block and is in a first throttle body closed setting in which a preferably annular, especially circular, first throttle closing gap which is very much smaller than the first throttle opening gap is formed between the first throttle body and the first throttle counter-body so that substantially no or only very little drive fluid per unit of time can pass the first throttle closing gap
Data Source
AI summary
A device for holding a hydraulic cylinder stem in position includes a hydraulic block having series-connected primary and secondary check valves. The latter includes a secondary control stem having a secondary valve body and a seal. A first throttle upstream and a second throttle downstream are closed in a secondary control stem closed position where the seal tightly blocks the secondary check valve, each throttle having a tiny throttle closing gap, preferably 0.1 mm or less. The control stem can move axially into an intermediate position where the throttles remain closed, that is, have a tiny closing gap, but valve body and seal are lifted from a secondary valve seat. The control stem can be moved further into an opening position where the throttles are open, each having an opening gap much larger than the closing gap, and the valve body and seal are lifted from the valve seat.