Telescopic Passive Damper Layout for Shorter Suspension Packaging

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Solution Overview

Problem

Conventional damper assemblies are length-intensive, posing installation and packaging challenges, especially in electric vehicles, where space is limited and unique suspension component placement is required.

Innovation Solution

A telescopic damper assembly design featuring an inner and outer damper configuration with sequential rod movement, utilizing a main piston and second piston to divide chambers and provide fluid communication, allowing for a shorter body length while maintaining similar stroke and damping performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a conventional twin-tube damper assembly is used, then damping performance is maintained, but the compressed length is excessive causing installation and packaging challenges

Engineering Contradiction:
Improvecompressed lengthVSAvoiddamping performance
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent implements a telescopic configuration where the inner damper (first tube with main piston) is nested within the outer damper (second tube with second piston). This nested structure allows both dampers to share the same axial space, reducing the overall compressed length by approximately 20% compared to conventional twin-tube dampers while maintaining the necessary damping functions through sequential operation of the inner and outer dampers

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If the damper assembly length is reduced for better packaging, then installation space is improved, but the structural complexity increases

Engineering Contradiction:
Improvebody lengthVSAvoidtelescopic configuration complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The damper assembly is segmented into distinct functional modules: the inner damper with its main piston and first chamber, the outer damper with its second piston and oil chambers, and the fluid communication passages connecting them. This segmentation allows each module to be optimized independently while working together to achieve the overall damping function, making the complex structure more manageable and maintainable

Inventive Principle:
Principle #1Segmentation

3Length of moving object

If sequential piston movement is implemented, then compressed length is reduced, but the fluid communication system becomes more complex

Engineering Contradiction:
Improvecompressed lengthVSAvoidfluid communication complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The working fluid serves multiple functions within the telescopic damper system: it provides damping force through pressure differential across pistons, enables fluid communication between chambers for sequential piston movement, and acts as a medium for energy transfer between the inner and outer dampers. The displacement fluid passage and second passage are designed to facilitate these multiple functions through a unified fluid communication system

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 telescopic damper assembly achieves a 20% reduction in compressed length compared to conventional twin-tube dampers, offering a more compact design that suits electric vehicles, providing additional space for batteries or trunk area without compromising damping performance.

Implementation Method 1

The main piston divides an interior of the first tube into a first chamber and a second chamber

Methodology Applied
Scientific EffectFluid pressure: Pressure Gradient

Implementation Method 2

The second piston defining a second passage providing fluid communication between the upper oil chamber and the lower oil chamber

Methodology Applied
Scientific EffectFluid communication: Hydraulic Press

Implementation Method 3

The damper assembly also includes a displacement fluid passage providing fluid communication between the first chamber and the upper oil chamber

Methodology Applied
Scientific EffectHydraulic fluid flow: Hydraulic Press

Implementation Method 4

Sequential telescopic passive damper

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP4421346A1Sequential telescopic passive damper
Publication Date: 2024.08.28 BEIJING WEST IND CO LTD
  • EP4421346A1 patent drawingFigure 1
  • EP4421346A1 patent drawingFigure 2A~2C
  • EP4421346A1 patent drawingFigure 3

AI summary

A damper assembly (20) comprises a inner damper (22) and an outer damper (24) in a telescopic configuration. The inner damper includes a first tube (40), a rod (30) disposed at least partially within the first tube and coaxially therewith, and a main piston (50) connected to the rod and slidably disposed within the first tube. The main piston divides an interior of the first tube into a first chamber (52) and a second chamber (54). The outer damper includes a second tube (80) disposed coaxially around the inner damper and a second piston (84) connected to an axial end of the first tube and dividing an interior of the second tube into an upper oil chamber (86) and a lower oil chamber (88), the second piston defining a second passage providing fluid communication between the upper oil chamber and the lower oil chamber. A displacement fluid passage (110) provides fluid communication between the first chamber and the upper oil chamber.