MacPherson Strut Bump Stop with Deformable Annular Bead
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Solution Overview
Problem
Existing suspension thrust bearings for struts with telescopic shock absorbers and coil springs face issues such as shock transmission to the vehicle body, difficulty in accommodating radial deformation of the bump stop, and vulnerability to pollutants due to non-deformable components, particularly when the impact stop is fixed to the upper or lower washer.
Innovation Solution
A compact suspension thrust bearing design featuring a deformable impact stop with an annular bead housed in an annular volume, directly fixed to the vehicle superstructure, allowing radial deformation and secure positioning, with a deformable sleeve for protection and an elastomeric filter block for enhanced vibration absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the impact stop is fixed to the lower washer or a fixed element, then the bearing can be compact, but the significant forces applied to the shock abutment are transmitted to the body of the vehicle via the bearing, which is not favorable
Solution Approach 1:
The impact stop is segmented into a deformable portion (housed in the annular volume) and a rigid fixing element portion. This segmentation allows the deformable part to absorb impact energy locally while the rigid part transmits forces directly to the vehicle body, preventing force transmission through the bearing.
Solution Approach 2:
The deformable impact stop acts as an intermediary between the shock absorber and the bearing. It absorbs impact energy through deformation rather than transmitting it directly to the bearing, thereby protecting the bearing from significant forces while maintaining compact dimensions.
2Device complexity
If the impact stop is fixed to the upper washer or a rigid cover, then the bearing structure is simplified, but it is difficult to provide space for the radial deformation of the bump stop, and a significant part is housed in a non-deformable cup
Solution Approach 1:
The impact stop is designed to deform radially (in the radial dimension) rather than axially. The annular volume provides space for radial deformation, allowing the bump stop to adapt to inclined stops and provide effective shock absorption without complicating the bearing structure.
Solution Approach 2:
The impact stop has different local properties: a deformable portion housed in the annular volume for shock absorption, and a rigid fixing element portion for secure attachment. This local differentiation allows radial deformation capability while maintaining structural simplicity.
3Reliability
If the bearing is directly fixed to the body of the vehicle independently of the bearing structure, then the shock stop can be positioned securely, but the bearing becomes vulnerable due to unprotected passage for pollutant introduction
Solution Approach 1:
The fixing element is merged with the bearing structure, forming an integrated assembly. The deformable impact stop is housed within the bearing structure itself, creating a unified design that secures the shock stop positioning while protecting the bearing from pollutants through the enclosed annular volume.
4Device complexity
If the impact stop is not held axially, then the structure is simplified, but the shock absorption effectiveness is reduced
Solution Approach 1:
The impact stop is designed with dynamic deformation capability within the annular volume. While not axially constrained, it can deform radially to absorb impact energy, providing effective shock absorption without requiring complex axial constraint structures. The deformability allows energy dissipation through controlled deformation.
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 reduces the axial bulk of the bearing, securely transmits forces without passing through the bearing, and provides effective shock absorption and protection against pollutants, while maintaining a compact geometry and efficient force transmission.
Implementation Method 1
an impact stop made of deformable material to dissipate the impact energy transmitted by the shock absorber, the impact stop comprises an annular bead housed in an annular volume
Implementation Method 2
made of deformable material to dissipate the impact energy
Implementation Method 3
an elastomeric filter block for enhanced vibration absorption
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The stop has a bearing (12) comprising an upper washer (14) and a lower washer (16) defining a rolling path on which rolling bodies (18) are rolled, where the lower washer integrates a support interface against an upper end of a helical spring (22). A rigid fixing element (26) fixes a MacPherson strut to a superstructure of a vehicle. An impact stop (30) comprises an annular strip (36) placed in an annular volume (38) delimited axially by a lower bearing (40) integrated to the upper washer and an upper bearing integrated to a rigid element. An independent claim is also included for a MacPherson strut comprising a telescopic shock absorber.