Piston Assembly With Variable Damping for Vibration Wear Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing piston assemblies in lift mechanisms for large pivoting bodies, such as truck hoods, experience increased wear due to vibrational forces, which are not effectively mitigated by current damping systems.

Innovation Solution

A piston assembly design featuring a piston housing with a piston rod, first and second plates, and a piston head, along with first and second energy storage members, including springs, that provides adjustable damping by engaging the plates at different positions to minimize wear during vibrations and optimize damping forces during opening and closing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the piston assembly provides continuous damping force during operation, then the damping effect is improved, but wear on the hood and lift mechanism increases

Engineering Contradiction:
Improvedamping effectVSAvoidwear
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The piston assembly dynamically adjusts its damping characteristics by allowing the piston rod to move between extended and retracted positions. The system transitions from providing continuous damping force to providing intermittent damping force, reducing wear during vibration while maintaining damping effectiveness during operation. This is achieved through the mechanical design that allows the piston rod to disengage and reengage with the energy storage members based on operational conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The piston assembly implements periodic damping action rather than continuous damping. The piston rod alternates between engaging the energy storage members (providing damping) and disengaging (reducing damping during vibration). This periodic engagement pattern reduces cumulative wear on the hood and lift mechanism while maintaining adequate damping support during actual opening and closing operations.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the piston rod is kept in extended position, then the damping force is maintained, but the ability to respond to vibration is reduced

Engineering Contradiction:
Improvedamping forceVSAvoidvibration response
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The piston rod is designed to be dynamic rather than fixed in position. It can extend to provide damping force during opening and closing operations, then retract to reduce damping during vibration periods. This dynamic positioning allows the system to adapt to different operational states, maintaining damping force when needed while responding to vibration conditions by reducing engagement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of piston rod position between extended and retracted states. This parameter change allows the piston assembly to adjust its damping characteristics based on operational requirements. When the piston rod is extended, full damping force is provided; when retracted, damping force is reduced to minimize vibration transmission and wear.

Inventive Principle:
Principle #35Parameter changes

3Force

If the piston assembly provides high damping force, then the support during opening and closing is improved, but the wear during vibration increases

Engineering Contradiction:
Improvedamping forceVSAvoidwear
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The piston assembly dynamically modulates the damping force it provides. During opening and closing operations, the piston rod engages the energy storage members to provide high damping force for support. During vibration periods, the piston rod disengages to reduce or eliminate damping force, thereby minimizing wear on the hood and lift mechanism while maintaining adequate support during operational phases.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The piston assembly provides high damping force periodically during opening and closing operations, then reduces or eliminates damping force during vibration periods. This periodic modulation of damping force levels allows the system to achieve adequate support when needed while minimizing wear during vibration, resolving the contradiction between force provision and wear prevention.

Inventive Principle:
Principle #19Periodic action

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 design reduces wear on the lift mechanism by minimizing damping forces during vibrations and providing controlled damping forces during the opening and closing of the pivoting body, thus extending the lifespan of the components.

Implementation Method 1

a first energy storage member disposed within the housing proximate the first housing end, and includes a second energy storage member disposed proximate the second housing end. At least one of the first and second energy storage members includes a spring.

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP3071774B1Systems and methods for piston assemblies
Publication Date: 2021.03.17 STABILUS INC
  • EP3071774B1 patent drawingFigure 1
  • EP3071774B1 patent drawingFigure 2
  • EP3071774B1 patent drawingFigure 3~5

AI summary

Piston assembly includes a piston housing defining an interior and having a first housing end and a second housing end, a piston rod having a first rod end extending into the interior and moveable therein between an extended position toward the first housing end and a retracted position toward the second housing end, a first plate joined to the piston rod proximate the first rod end, a second plate joined to the piston rod and spaced apart a distance along the piston rod from the first plate, and a piston head slidably joined to the piston rod between the first plate and the second plate. A lift assembly including a piston assembly and configured to provide a damping force to a pivotable body during pivoting of the pivotable body relative a stationary body between a closed position and an open position is provided.