Rotary Valve Buffer Port Structure for Low-Resistance Flow Switching

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Solution Overview

Problem

Existing rotary valves face challenges in reducing flow path resistance, especially when flow paths are connected at angles close to a tangent line, leading to increased resistance and reduced fluid flow efficiency.

Innovation Solution

The configuration includes a valve chamber with at least three ports and external flow paths, where a valve rotor is rotatable to switch fluid flow between ports, with a first buffer portion covering the first port and having a larger circumferential width than the valve flow path, allowing fluid to flow orthogonally and reducing resistance, even when external flow paths are disposed at angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If external flow paths are connected to the valve housing at an angle close to a tangent line to accommodate device structure and space constraints, then adaptability of the device is improved, but flow path resistance at the boundary between ports and valve rotor is increased

Engineering Contradiction:
Improveadaptability of device structureVSAvoidflow path resistance
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

A buffer portion is introduced as an intermediary space between the external flow path and the port. This buffer portion receives fluid from the external flow path and directs it to the port, mediating the connection between the tangentially connected external flow path and the radially oriented port. The buffer portion effectively decouples the external flow path's tangential connection from the port's radial flow direction, allowing the external flow path to be connected at an angle close to a tangent line while maintaining low flow path resistance at the port boundary.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the opening area of ports facing the stem shell is made smaller to enable flow switching, then switching capability is improved, but flow path resistance is increased leading to reduction of fluid flow

Engineering Contradiction:
Improveswitching capabilityVSAvoidfluid flow
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The buffer portion extends in the axial direction of the valve housing, utilizing the third dimension (axial direction) to provide additional flow path area. By expanding the buffer portion axially, the overall flow path cross-sectional area is increased without enlarging the port opening area in the radial direction. This allows the port opening area to remain small for effective switching while the axial extension of the buffer portion compensates for the reduced area, preventing increase in flow path resistance and maintaining fluid flow productivity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4151891A1Rotary valve
Publication Date: 2023.03.22 AISIN CORP
  • EP4151891A1 patent drawingFigure 1
  • EP4151891A1 patent drawingFigure 2~3
  • EP4151891A1 patent drawingFigure 4~5

AI summary

A rotary valve (V) includes: a valve chamber (2) in which at least three ports (P) including at least a first port (P1), a second port (P2), and a third port (P3) are disposed in a circumferential direction; at least three external flow paths (L) communicating with the three ports, respectively; and a valve rotor (R) accommodated in the valve chamber so as to be rotatable and configured to switch a flow of a fluid between the ports by a rotation operation. The first port extends in the circumferential direction of a wall portion (3) of the valve chamber. A first buffer portion (Sa) is formed between the first port and the external flow path corresponding to the first port. The first buffer portion covers the entire first port and serves as a space having a circumferential width larger than a circumferential width of a valve flow path (14).