Hydraulic Compression Stop Assembly for Smooth Damper End-Stroke Damping
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Solution Overview
Problem
Existing hydraulic dampers face challenges in durability and cost-efficiency, particularly at high piston rod velocities, where high pressures can lead to component damage, and require complex modifications to achieve monotonic damping force characteristics.
Innovation Solution
A hydraulic compression stop assembly with a radially displaceable tenon and insert, featuring monotonically diminishing and increasing diameters, respectively, and equiangularly spaced grooves, provides axial guidance and tunable damping force without requiring substantial modifications to existing damper designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a hydraulic compression stop assembly is used to provide additional damping force at high velocities, then the damping performance is improved, but the risk of component damage due to high pressure increases
Solution Approach 1:
The compression stop assembly is segmented into multiple functional components: a base valve assembly, an insert with flow passages, and an additional piston assembly with a tenon. This segmentation allows each component to handle specific aspects of the high-pressure, high-velocity damping function, distributing stress and improving overall reliability while maintaining high damping force capability
Solution Approach 2:
The insert is positioned beforehand in the compression chamber to create a controlled flow restriction. The flow passages within the insert are designed to gradually build pressure and provide cushioning effect before the additional piston assembly engages, preventing sudden pressure spikes that could damage components
2Ease of operation
If the tenon is made radially displaceable with monotonically diminishing diameter, then smooth activation and axial guidance are achieved, but manufacturing precision requirements increase
Solution Approach 1:
The tenon features a monotonically diminishing diameter along its length, creating a tapered or curved geometry that guides it radially into the insert during compression. This curved profile ensures smooth activation by progressively engaging the insert's flow passages, while the monotonic nature of the diameter change simplifies manufacturing compared to complex multi-step profiles
Solution Approach 2:
The radially displaceable tenon design allows the component to self-align and self-guide into the insert through its own geometry. The monotonically diminishing diameter creates a natural ramp effect that guides the tenon radially inward as it compresses, eliminating the need for separate alignment mechanisms or precision-guided features in the insert
3Adaptability or versatility
If equiangularly spaced grooves are added to the additional piston assembly, then tuning versatility is improved, but device complexity increases
Solution Approach 1:
Equiangularly spaced grooves are added locally to the additional piston assembly, specifically on the tenon or piston surface. These grooves create localized flow channels that allow precise tuning of the damping characteristic by controlling fluid flow paths. The grooves are strategically positioned to affect only the compression phase damping without complicating the overall assembly structure
Solution Approach 2:
The grooves enable tuning of the damping force by changing the effective flow area and flow path length parameters. By varying the groove depth, width, or angular spacing, the damping characteristic can be adjusted without changing the fundamental geometry or adding complex adjustable mechanisms, maintaining simplicity while achieving versatility
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 enhances durability and cost-efficiency by eliminating peak forces at high speeds, ensuring smooth activation and tunable damping force, while maintaining simplicity and versatility.
Implementation Method 1
a hydraulic compression stop assembly (HCS) located in the compression chamber and comprising an insert fixed on the base valve assembly, configured to allow the flow of fluid between the insert and the main tube through the base valve assembly
Implementation Method 2
said tenon is terminated with a first entry surface having diameter monotonically diminishing towards the compression end of said tenon, while the insert is provided with a second entry surface having diameter monotonically increasing towards the rebound end of the insert
Implementation Method 3
said additional piston assembly is provided with a number of, preferably equiangularly spaced, axially extending grooves, each having a cross-sectional surface that diminishes along its length towards the main piston assembly
Data Source
Figure 1
Figure 2
Figure 3a~4
AI summary
a hydraulic damper (1) comprising a main tube (3); a main piston assembly (4); a base valve assembly (7); and a hydraulic compression stop assembly (8) comprising an insert (81) fixed on the base valve assembly (7), and an additional piston assembly (83) apt to be introduced inside the first inner chamber (84) of the insert (81) at the end of the damper compression stroke to generate additional damping force. Said additional piston assembly (83) comprises a piston rod extender (832) fixed to the piston assembly (4) or the piston rod (5) at the side of the compression chamber (12), and a tenon (831) fixed to said piston rod extender (832) and radially displaceable with regard thereto, wherein said tenon (831) is terminated with a first entry surface (8316) having diameter monotonically diminishing towards the compression end of said tenon (831), while the insert (81) is provided with a second entry surface (813) having diameter monotonically increasing towards the rebound end of the insert (81).