Rotary Disc Valve With Interference-Fit Sealing and Low Torque

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Solution Overview

Problem

Rotary valves in fluid delivery systems face challenges with high operating torque due to elastomer friction, increased complexity and costs from spring elements, and limited flexibility in port placement and orientation, especially when using ceramic materials for sealing components.

Innovation Solution

A rotary disc valve design that eliminates the need for a spring by utilizing an interference fit between the lid and diverter for sealing, featuring a disc-shaped diverter with a seal assembly comprising a thin, low-friction plastic seal plate and an elastic element, allowing for fluid-tight sealing without axial force application, and enabling flexible port placement and orientation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If elastomer materials are used for sealing components in rotary valves, then fluid-tight sealing is achieved, but operating torque increases due to higher friction factors

Engineering Contradiction:
Improvefluid-tight sealingVSAvoidoperating torque
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent employs composite material strategy by combining elastomer sealing elements with low-friction plastic materials (such as PTFE or UHMWPE) for the diverter and seal plate surfaces. This composite approach allows the elastomer to provide fluid-tight sealing while the low-friction plastic materials reduce contact friction, thereby resolving the contradiction between achieving reliable sealing and minimizing operating torque.

Inventive Principle:
Principle #40Composite materials

2Reliability

If spring elements are used to provide loading of sealing surfaces, then fluid sealing is maintained, but device complexity and manufacturing costs increase

Engineering Contradiction:
Improvesealing functionVSAvoidvalve structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the spring element from the valve assembly by utilizing the natural elasticity of elastomeric sealing elements and compliant seal plates to provide the necessary sealing force. This removal of the spring component simplifies the valve structure, reduces part count, and eliminates the need for spring installation and maintenance while maintaining reliable sealing through the elastic properties of the remaining sealing components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The elastomeric sealing elements and compliant seal plates provide self-adjusting sealing force through their elastic deformation, automatically compensating for wear and manufacturing tolerances without requiring external spring loading. This self-service mechanism maintains sealing reliability while eliminating complex spring-based loading systems.

Inventive Principle:
Principle #25Self-service

3Reliability

If ceramic materials are used for sealing components in disc-shaped diverters, then sealing performance is improved, but manufacturing costs increase

Engineering Contradiction:
Improvesealing performanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses composite material construction where ceramic or other hard, wear-resistant materials are applied only to the specific sealing contact surfaces of the diverter, while the bulk of the diverter body is made from more economical materials such as metal or plastic. This selective material application provides the necessary sealing performance and wear resistance at the contact points while keeping overall manufacturing costs lower than using ceramic for the entire component.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies high-performance sealing materials locally only where contact and sealing are required, rather than using expensive materials throughout the entire component. This local quality approach ensures optimal sealing performance at the sealing surfaces while using cost-effective materials for non-critical portions of the sealing components.

Inventive Principle:
Principle #3Local quality

4Force

If cylindrical diverters are used in rotary valves, then low-friction sealing is achieved, but flexibility in port placement and orientation is reduced

Engineering Contradiction:
Improveoperating torqueVSAvoidport configuration flexibility
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The patent employs a disc-shaped diverter that can be rotated to different angular positions, dynamically changing the flow paths and port connections. This dynamic rotational capability provides flexibility in port placement and orientation, allowing the same physical valve to achieve multiple flow configurations that would otherwise require fixed cylindrical geometries with limited port arrangements.

Inventive Principle:
Principle #15Dynamics

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 reduces complexity and costs, improves durability, and maintains fluid-tight sealing across the operating temperature range and lifetime of the valve, while minimizing operating torque and enhancing flexibility in port configuration.

Implementation Method 1

The valve body, the lid and the diverter are shaped and dimensioned so that an interference fit exists between the lid and the diverter that results in compression of the seal assembly between the diverter and the base

Methodology Applied
Scientific EffectInterference fit: Friction

Implementation Method 2

The elastic element provides elasticity, biases the seal plate toward the diverter seal surface, and allows the thin seal to conform to the flat seal surface of the diverter

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

The seal plate may be constructed from a plastic that has low friction and highly wear resistive properties

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4198356A1Rotary disc valve
Publication Date: 2023.06.21 ROBERT BOSCH GMBH
  • EP4198356A1 patent drawingFigure 1~2
  • EP4198356A1 patent drawingFigure 3
  • EP4198356A1 patent drawingFigure 4~6

AI summary

A rotary disc valve is used in a fluid delivery system to control flow of fluid between multiple ports. The valve may include a valve body having multiple ports that are connected to the system. In addition, the valve may include a diverter and seal assembly that are disposed in the valve body. The diverter is configured to rotate about a rotational axis and to control fluid flow through the valve body. The valve is free of an axial compression spring, and the valve body, the lid and the diverter are shaped and dimensioned so that an interference fit exists between the lid and the diverter that results in compression of the seal assembly between the diverter and the base.