Rotary Valve Actuator Partial Stroke Damping for End-Stroke Cushioning

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Solution Overview

Problem

Existing rotary valve actuators with full stroke damping mechanisms reduce efficiency and output torque by slowing down pistons over the entire closing stroke, and often require external mounting, increasing the physical envelope of the actuator.

Innovation Solution

Implementing a partial stroke damping apparatus that slows down the actuator's pistons only over a portion of the stroke, specifically at the end of the closing stroke, using a damper and fluid circuits to control fluid flow, thereby reducing the need for external mounting and maintaining efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If full stroke damping mechanism is used to prevent noise and shock, then reliability is improved, but productivity deteriorates due to reduced closing speed

Engineering Contradiction:
Improveprevention of noise and shockVSAvoidclosing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The damping mechanism is segmented into two distinct phases: a first damping phase during the majority of the closing stroke that allows faster movement, and a second damping phase during the final portion that provides stronger cushioning. This segmentation resolves the contradiction by applying different damping levels at different stages of the closing stroke, maintaining both reliability and productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The damping characteristic is made dynamic rather than static. The damping force varies throughout the closing stroke, being lighter during the initial phase and heavier during the final phase. This dynamic adjustment allows the system to achieve both high-speed operation and effective shock prevention, resolving the contradiction between speed and reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If full stroke damping mechanism is used to prevent noise and shock, then reliability is improved, but use of energy deteriorates due to reduced efficiency

Engineering Contradiction:
Improveprevention of noise and shockVSAvoidactuator efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The damping action is segmented into phases, with the first phase allowing more efficient energy utilization during the majority of the stroke, and the second phase providing necessary cushioning only when needed. This reduces overall energy consumption while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of applying full damping throughout the entire stroke, the invention applies partial damping - sufficient to prevent noise and shock at critical moments (final phase) but not excessive enough to hinder overall efficiency. This resolves the contradiction between reliability and energy use.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If external damping mechanism is mounted to provide cushioning effect, then reliability is improved, but volume of stationary object deteriorates due to increased physical envelope

Engineering Contradiction:
Improvecushioning and deceleration effectVSAvoidphysical envelope
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The damping mechanism is merged with the actuator housing, integrating the damping function into the existing structure rather than adding separate external components. This eliminates the need for additional mounting space and reduces the overall physical envelope while maintaining the cushioning effect.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuator housing serves multiple functions: it contains the actuator components and simultaneously houses the damping mechanism. This multi-functionality eliminates the need for separate external damping components, reducing the physical envelope while maintaining reliability.

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

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 partial stroke damping mechanism enhances the actuator's efficiency and output torque by reducing speed only where necessary, while minimizing the physical footprint of the actuator.

Implementation Method 1

the damper restricts fluid flow between the inner chamber and the first port

Methodology Applied
Scientific EffectFluid flow restriction: Viscous Damping

Data Source

PatentEP2473768B1Rotary valve actuators having partial stroke damping apparatus
Publication Date: 2023.06.07 EMERSON PROCESS MANAGEMENT VALVE AUTOMATION INC
  • EP2473768B1 patent drawingFigure 1A
  • EP2473768B1 patent drawingFigure 1B~2
  • EP2473768B1 patent drawingFigure 3~4A

AI summary

Rotary valve actuators having partial stroke damping apparatus are described herein. An example rotary valve actuator described herein includes a housing containing a first piston and a second piston opposite the first piston, where the pistons move in opposite directions to rotate a shaft of the rotary valve actuator. A damper is operatively coupled to at least one of the first piston or the second piston to slow the movement of the piston for only a portion of a stroke of the rotary valve actuator.