Switching Valve Structure to Prevent Fluid Port Cross-Contamination

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Solution Overview

Problem

Existing fluid switching valves often cause cross-contamination when switching between ports, leading to sample contamination and inaccurate analysis in applications like medical drug analysis and environmental monitoring.

Innovation Solution

A cross-contamination-free fluid switching valve design featuring a valve body with a rotatable valve-core seat and slidably mounted rotor valve-core, equipped with a sliding chute and guide groove, driven by eccentric shafts and deceleration mechanisms, allowing for precise control of fluid flow between ports without intersecting non-target ports.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional switching valve is used to switch between ports, then fluid flow control is achieved, but cross-contamination occurs when switching ports due to contact with non-target ports

Engineering Contradiction:
Improvefluid flow controlVSAvoidcross-contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The valve core is segmented into a stator portion (fixed) and a rotor portion (rotatable), with the groove divided into a communication groove in the stator and a switching groove in the rotor. This segmentation allows independent control of fluid communication and port switching, enabling the rotor to rotate and align the switching groove with the target port while the stator maintains sealed communication, thus preventing cross-contamination during port switching.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The eccentric shaft acts as an intermediary mechanism that converts rotational motion into the coordinated movement of the rotor valve-core relative to the valve-core seat. By using the eccentric shaft as a mediator, the system achieves precise control over the relative positioning of the rotor and stator portions, ensuring that the groove transitions smoothly between ports without simultaneous contact with multiple ports, thereby eliminating cross-contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the valve structure is simplified for ease of manufacture, then manufacturing cost decreases, but preventing cross-contamination during switching becomes more difficult

Engineering Contradiction:
Improvevalve structureVSAvoidcross-contamination
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The valve core is divided into a stator portion and a rotor portion that can be manufactured separately using conventional machining processes. The stator portion with the communication groove and the rotor portion with the switching groove are independently manufacturable, allowing for simplified production while maintaining the complex functional requirements for preventing cross-contamination during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of having a single rotating valve core that contacts multiple ports during switching, the invention inverts the approach by having a fixed stator portion and a rotatable rotor portion. The rotor rotates to select ports while the stator maintains sealed communication, reversing the traditional design and enabling both ease of manufacture and prevention of cross-contamination.

Inventive Principle:
Principle #13The other way round (Inversion)

3Object-affected harmful factors

If a rotatable valve-core seat with sliding rotor valve-core is used, then cross-contamination is prevented, but device complexity increases

Engineering Contradiction:
Improvecross-contamination preventionVSAvoidvalve structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The valve core is segmented into a stator portion (fixed) and a rotor portion (rotatable), with the groove divided into a communication groove in the stator and a switching groove in the rotor. This segmentation allows independent control of fluid communication and port switching, enabling the rotor to rotate and align the switching groove with the target port while the stator maintains sealed communication, thus preventing cross-contamination during port switching.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove structure serves multiple functions: it acts as both a communication groove in the fixed stator portion and a switching groove in the rotatable rotor portion. This multi-functional design consolidates what could be separate components into a unified structure, reducing overall device complexity while maintaining cross-contamination prevention capabilities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Manufacturing precision

If precise control of fluid flow is achieved through sliding mechanism, then flow rate control precision improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improveflow rate control precisionVSAvoidsliding mechanism
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Instead of having a single rotating valve core that requires high precision rotation to control flow, the invention inverts the approach by having a fixed stator portion and a rotatable rotor portion with a sliding mechanism. The sliding mechanism along the radial direction provides precise flow control through simple linear movement, reducing rotational precision requirements and easing manufacturing while maintaining flow control precision.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3872378B1Fluid non-crossover switching valve
Publication Date: 2023.11.08 NANJING RUNZE FLUID CONTROL EQUIP CO LTD
  • EP3872378B1 patent drawingFigure 1
  • EP3872378B1 patent drawingFigure 2
  • EP3872378B1 patent drawingFigure 3

AI summary

The present invention discloses a cross-contamination-free fluid switching valve, which comprises a valve body, a first drive assembly and a second drive assembly. The valve body comprises a valve head, a valve-core seat and a rotor valve-core. The valve-core seat is rotatable relative to the valve head. The rotor valve-core is mounted on the valve-core seat slidably. The rotor valve-core is fitted with the valve head. The valve head is provided with at least three switching ports. The rotor valve-core is provided with the groove that is in communication with the switching ports on a fitting surface of the rotor valve-core and the valve head. The first drive assembly is able to drive the valve-core seat to rotate, and the second drive assembly is able to drive the rotor valve-core to slide. The cross-contamination-free fluid switching valve of the present invention avoids cross-contamination with other non-target ports when switching to the target port.