Hydraulic Control Valve Diffuser Insert for Quiet Orthopaedic Actuation

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Solution Overview

Problem

Hydraulic actuators in orthopedic devices experience high noise levels and increased flow resistance due to turbulent flows within control valves, affecting the precision and control behavior of these devices.

Innovation Solution

A hydraulic actuator with a control valve featuring a diffuser insert within the valve body that deflects hydraulic fluid towards the outlet, preventing turbulence and reducing noise and flow resistance, while allowing for adjustable flow redirection through multiple passage openings and partition walls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If high pressure hydraulic fluid flows through control valve at high velocity, then actuation speed and responsiveness are improved, but noise levels increase and flow resistance increases

Engineering Contradiction:
Improveactuation speedVSAvoidnoise level
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The diffuser insert features a curved, tapered surface that gradually redirects the hydraulic fluid from radial flow to axial flow. This curved geometry prevents sudden flow direction changes, maintaining high flow velocities while eliminating turbulence-induced noise and reducing flow resistance.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The diffuser insert changes the flow parameters of the hydraulic fluid by gradually transforming the flow direction from radial to axial. This parameter change occurs through a tapered geometry that optimizes flow velocity distribution, preventing turbulence while maintaining actuation speed.

Inventive Principle:
Principle #35Parameter changes

2Speed

If high pressure hydraulic fluid flows through control valve at high velocity, then actuation speed and responsiveness are improved, but flow resistance increases

Engineering Contradiction:
Improveactuation speedVSAvoidflow resistance
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The curved, tapered surface of the diffuser insert creates a smooth flow transition that minimizes energy losses. By gradually redirecting the fluid rather than using sharp angles, the design maintains high flow velocities while reducing turbulence-induced flow resistance and energy dissipation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The diffuser insert optimizes flow parameters by transforming radial flow into axial flow through a tapered geometry. This parameter transformation maintains kinetic energy and flow velocity while minimizing pressure losses due to turbulence, thereby reducing flow resistance.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If hydraulic fluid flows directly opposite wall of valve body, then simple valve structure is maintained, but turbulent flow occurs causing noise and increased flow resistance

Engineering Contradiction:
Improvevalve structureVSAvoidturbulent flow
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The diffuser insert acts as an intermediary component between the radial inlet openings and the axial outlet. This mediator element redirects the hydraulic fluid through a tapered surface, preventing direct impact against the valve body wall and eliminating turbulence without complicating the overall valve structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The curved, tapered surface of the diffuser insert provides a smooth flow path that redirects hydraulic fluid away from direct wall impact. This curved geometry eliminates turbulence and noise while maintaining a relatively simple valve structure with minimal additional components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 significantly reduces noise and flow resistance, enhancing the comfort and control behavior of orthopedic devices by maintaining laminar flow and allowing for precise adjustment of hydraulic resistance.

Implementation Method 1

The diffuser insert prevents the radially incoming hydraulic fluid from impacting the opposite wall of the valve body or mixing with or impacting an incoming hydraulic flow from another inlet port. This would lead to turbulent flows within the cavity of the valve body and thus to high noise levels and increased flow resistance

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Implementation Method 2

The diffuser insert within the cavity of the valve body redirects the hydraulic fluid so that it is redirected toward the outlet instead of impacting a valve body wall at a right angle

Methodology Applied
Scientific EffectFlow redirection:

Data Source

PatentEP4487820A1Hydraulic actuator and control valve
Publication Date: 2025.01.08 OTTO BOCK HEALTHCARE PROD GMBH
  • EP4487820A1 patent drawingFigure 1~2
  • EP4487820A1 patent drawingFigure 3~4
  • EP4487820A1 patent drawingFigure 5

AI summary

Hydraulic actuator for orthopaedic devices with a control valve (10) in a flow channel (1) having an inlet (2) and an outlet (3) for a hydraulic fluid, - the control valve (10) has a valve sleeve (20) and a valve body (30), - the valve sleeve has a sleeve wall (22) which forms a receiving chamber (23) and in which at least one radially oriented inlet opening (24, 25, 26) is formed, - the valve body is displaceably arranged within the receiving chamber of the valve sleeve between a closed position and an open position and opens into the outlet, - the valve body has at least one valve body wall (32) which is opposite the at least one inlet opening and in which a through-opening (34, 35, 36) is formed which, in the open position, is opposite the corresponding inlet opening, wherein the valve body forms a cavity (31) in which a diffuser insert (40) is arranged,which deflects the hydraulic fluid towards the outlet.