Diaphragm Valve Stem Structure for Axis Shake Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diaphragm valves in semiconductor manufacturing face issues with axis shake of the stem due to insufficient holding force, leading to potential damage and adjustment problems, especially in miniaturized systems where slight axis shake causes significant eccentricity and stress on the diaphragm.
Innovation Solution
A diaphragm valve design where the stem is divided into a first stem member connected to a displacement transmitting member and a second stem member, with the second stem member guided by a high-rigidity sleeve, preventing moment transmission and reducing axis shake, and featuring a resin layer for low friction and self-lubrication, allowing point contact for minimized fluctuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an O-ring is used as a guide for the stem, then flexibility is provided, but the holding force is insufficient causing axis shake
Solution Approach 1:
The stem is divided into two separate stem members: a first stem member connected to the displacement transmitting member, and a second stem member that presses the diaphragm. This segmentation allows the first stem member to be guided by the O-ring (providing flexibility) while the second stem member is guided by a metal sleeve (providing high holding force and reducing axis shake).
Solution Approach 2:
A metal sleeve is introduced as an intermediary guide mechanism between the first and second stem members. The metal sleeve provides high holding force and guides the second stem member, preventing axis shake while allowing the first stem member to maintain flexibility through O-ring guidance.
2Reliability
If a metal sleeve is used as a guide to reduce axis shake, then holding force increases, but the sleeve is easily damaged by excessive reaction force
Solution Approach 1:
By dividing the stem into two members, the patent separates the guidance functions: the O-ring guides the first stem member (absorbing lateral movements and reducing reaction forces), while the metal sleeve guides only the second stem member (providing high holding force where needed). This segmentation protects the metal sleeve from excessive reaction forces.
3Productivity
If the diaphragm is miniaturized to reduce device size, then productivity increases, but axis shake causes larger eccentricity and stress
Solution Approach 1:
The segmented stem structure with dual guidance mechanisms (O-ring for first stem member, metal sleeve for second stem member) provides enhanced stability and reduced axis shake. This allows the diaphragm to be miniaturized while maintaining precise axis alignment, as the metal sleeve prevents eccentricity even in the smaller scale.
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 design effectively reduces axis shake and stress on the diaphragm, enhancing the valve's operational stability and longevity by utilizing a high guide-rigidity sleeve and low-friction resin layer, ensuring precise control and extended lifespan.
Implementation Method 1
a piezoelectric actuator 2 for driving it. When a voltage is applied, the piezoelectric actuator 2 is configured to extend
Implementation Method 2
it is considered that the axial displacement of the stem 8 is allowed by elastic deformation of the O-ring 14
Implementation Method 3
a diaphragm (17) that is disposed in the valve chamber and elastically deformable to open and close the flow path
Implementation Method 4
featuring a resin layer for low friction and self-lubrication
Data Source
AI summary
A diaphragm valve including: a valve body having a flow path formed therein and a valve chamber recessed from an upper surface of the valve body; a diaphragm that is disposed in the valve chamber and elastically deformable to open and close the flow path and adjust an opening degree of the flow path; a stem for pressing the diaphragm to elastically deform the diaphragm; an actuator for driving the stem; a support mechanism that is fixed to the valve body and supports the stem and the actuator; wherein the stem includes a first stem member connected to the actuator via a displacement transmitting member, and a second stem member held by the support mechanism so as to be movable in the axial direction via a sleeve, the second stem member has an upper end portion which abuts against a lower end portion of the first stem member.