Valve Shaft Axial Locking via Rotating Collar

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Solution Overview

Problem

Existing axial locking solutions for valve shafts in valve housings are either material-inefficient, costly, and prone to leakage, often requiring additional components and complex manufacturing processes, which can compromise the operation and reliability of the valve, especially when coupled to sensitive control devices.

Innovation Solution

A collar part with axial projections and a central hole is used to securely lock the valve shaft by fitting into a pivot recess, allowing rotation for secure locking, reducing material consumption and manufacturing complexity while preventing axial displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a shouldered shaft is used for axial locking, then the valve shaft can be prevented from pushing out axially, but material consumption increases and manufacturing costs rise

Engineering Contradiction:
Improveaxial locking reliabilityVSAvoidmaterial consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The locking function is segmented from the shaft body and implemented through a separate collar component that can be mounted on the shaft. This allows the shaft itself to remain simple and economical while the collar provides the necessary locking feature through its geometry and interaction with the valve housing bore.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a shouldered shaft is used for axial locking, then axial displacement is prevented, but device complexity and manufacturing complexity increase

Engineering Contradiction:
Improveaxial locking reliabilityVSAvoidvalve structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The collar serves multiple functions: it provides axial locking through its position on the shaft, enables rotational locking through interaction with the housing bore, and maintains shaft alignment. This multi-functionality is achieved without requiring complex internal structures within the collar itself.

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

3Reliability

If cover sleeve or bottom plug arrangements are used for axial locking, then the valve shaft is secured axially, but manufacturing costs and leakage risk increase

Engineering Contradiction:
Improveaxial locking reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The locking function is extracted from complex housing modifications (cover sleeves, bottom plugs) and concentrated in a simple collar component. The housing bore remains simple and unchanged, eliminating the need for additional sealing arrangements while the collar provides all necessary locking functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If a short shouldered shaft with shaft coupling is used, then axial locking is achieved without additional housing openings, but shaft structure looseness increases affecting valve operation

Engineering Contradiction:
Improveaxial locking reliabilityVSAvoidvalve operation stability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The axial locking and rotational locking functions are merged into a single integrated solution using the collar and housing bore interaction. This eliminates the need for separate shaft couplings and extension parts, providing a compact and rigid shaft structure that maintains valve operational stability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2153094B1Simple axial locking of a valve shaft
Publication Date: 2018.10.10 METSO FLOW CONTROL OY
  • EP2153094B1 patent drawingFigure 1
  • EP2153094B1 patent drawingFigure 2
  • EP2153094B1 patent drawingFigure 3

AI summary

The invention concerns axial locking of a valve shaft (5) to be non-turnably attached to a closing element (3) of a valve, an end (5a) of the shaft (5) to be attached to the closing element (3) being machined on two opposite sides in order to fit into a pivot recess (6) formed in the outer perimeter of the closing element (3). The invention is characterized by a collar part (7) to be fitted to said end (5a) of the shaft and to be turned into a locking position, one of the end surfaces of the main part of said collar part having at least one axial projection (7b) that fits into the pivot recess (6) of the closing element (3) of the valve when the collar part (7) is in the locking position and the end of the shaft (5a) is positioned into the pivot recess (6) of the closing element (3).