Damper Piston Fluid Ramping for Cavitation and Noise Control

Solution Overview

Problem

Shock assemblies in suspension systems experience cavitation and noise issues during rapid compression, leading to malfunction and discomfort due to inadequate fluid flow management and heat exchange, especially under high loads.

Innovation Solution

Incorporating a base valve and an external reservoir with a floating piston, along with a fluid ramp on the damper piston to redirect fluid flow and improve heat exchange, preventing cavitation and reducing noise by ensuring timely fluid backfill and redirecting fluid flow to minimize shear forces against the cylinder walls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fluid flow through the damper piston is increased to improve heat exchange, then temperature stability improves, but cavitation occurs during rapid compression

Engineering Contradiction:

Improvetemperature stabilityVSAvoidcavitation prevention

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The damper piston is segmented into multiple sections with separate fluid flow paths: a first fluid flow path for rapid compression that prevents cavitation, and a second fluid flow path for rebound that improves heat exchange. This segmentation allows each path to be optimized for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fluid flow paths are designed to be dynamically active only during specific stroke directions. The first fluid flow path is activated during rapid compression to prevent cavitation, while the second fluid flow path is activated during rebound to enhance heat exchange, making the system adapt to real-time operational conditions.

Inventive Principle:

Principle #15Dynamics

2Reliability

If fluid flow is restricted to prevent cavitation, then reliability improves, but heat exchange becomes inadequate leading to temperature fluctuations

Engineering Contradiction:

Improvecavitation preventionVSAvoidtemperature stability

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The damper piston is segmented into multiple sections with separate fluid flow paths: a first fluid flow path for rapid compression that prevents cavitation, and a second fluid flow path for rebound that improves heat exchange. This segmentation allows each path to be optimized for its specific function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fluid flow paths are designed to be dynamically active only during specific stroke directions. The first fluid flow path is activated during rapid compression to prevent cavitation, while the second fluid flow path is activated during rebound to enhance heat exchange, making the system adapt to real-time operational conditions.

Inventive Principle:

Principle #15Dynamics

3Object-generated harmful factors

If fluid flow redirects are added to minimize shear forces and reduce noise, then noise mitigation improves, but device complexity increases

Engineering Contradiction:

Improvenoise reductionVSAvoidpiston structure complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The noise mitigation feature is merged into the existing damper piston structure by incorporating a fluid flow redirect at the fluid outlet. This redirect is integrated into the piston body itself, combining noise reduction functionality with the structural components already present in the damper system.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The fluid flow redirect converts the potentially harmful high-velocity fluid jet that causes noise and shear forces into a beneficial controlled flow pattern. By redirecting the fluid flow away from the cylinder wall, the harmful impingement is transformed into a controlled discharge that reduces noise while maintaining damping performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively prevents cavitation, maintains damping performance, and significantly reduces noise and temperature fluctuations, enhancing the shock assembly's responsiveness and comfort by improving fluid dynamics and heat exchange.

Implementation Method 1

improve heat exchange by ensuring timely fluid backfill and redirecting fluid flow to minimize shear forces against the cylinder walls

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

redirecting fluid flow to minimize shear forces against the cylinder walls

Methodology Applied

Scientific EffectShear forces: Shear Stress

Implementation Method 3

preventing cavitation by ensuring timely fluid backfill

Methodology Applied

Scientific EffectCavitation: Cavitation

Data Source

PatentUS20240410440A1Piston fluid flow dynamics, temperature stability, and noise mitigation

Publication Date: 2024.12.12 FOX FACTORY INC

AI summary

Disclosed herein is a fluid redirection system comprising a damper piston with a plurality of compression ports and a plurality of rebound ports. The damper piston also has a fluid ramp on a first side where the fluid ramp is of a shape that creates an angled exit for fluid exiting the damper piston.