Bayonet Locking Vibration Damper Resists Tear-Out Forces

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vibration dampers for motor vehicle clutch systems are prone to damage when high tear-out forces exceed 1200 Newtons, as the existing play between the cylinder pin and damping housing leads to the axial end stop being torn out.

Innovation Solution

A bayonet-like closure is designed between the first plate of the piston rod and the damping housing, distributing pull-out forces and preventing damage, with a radial projection and recess configuration for secure locking, and optionally a hexagonal pin for anti-twist protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a cylinder pin with floating bearing and predetermined play is used to allow rotation of the piston rod, then the piston rod can rotate freely in the damping housing, but the axial end stop is vulnerable to tear-out forces exceeding 1200 Newtons

Engineering Contradiction:
Improverotation freedom of piston rodVSAvoidresistance to tear-out forces
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The locking mechanism transitions from a simple axial insertion to a multi-dimensional bayonet locking system. The projection on the first plate engages with a recess in the damping housing at an angle, creating a locked position that resists tear-out forces in multiple directions, not just axially.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The locking mechanism combines multiple functional elements: the projection-recess geometric interlocking for primary locking, the bayonet angular engagement for force distribution, and optionally a tensioning element or hexagonal pin for additional anti-twist protection. This composite approach creates a robust locking system.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If a simple axial locking with end stop is used, then the assembly is simple and costs are low, but the end stop is torn out under high forces

Engineering Contradiction:
Improveassembly simplicityVSAvoiddamage resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The locking function is segmented into distinct components: the projection on the piston rod's first plate and the corresponding recess in the damping housing. This segmentation allows each component to be optimized for its specific function while maintaining overall simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bayonet-like closure is designed to lock automatically when the piston rod is inserted into the damping housing. The projection naturally engages with the recess at the correct angle, providing self-locking functionality without requiring additional fastening operations or complex assembly steps.

Inventive Principle:
Principle #25Self-service

3Strength

If the projection and recess are designed radially on the piston rod and damping housing, then a reliable locking is achieved stable against tear-out forces, but the assembly precision requirements increase

Engineering Contradiction:
Improvelocking stabilityVSAvoidassembly precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The projection and recess are pre-positioned on the piston rod and damping housing respectively, at the correct radial locations and orientations. This preliminary positioning ensures that when the piston rod is inserted, the bayonet locking engages automatically at the correct angle, reducing the need for high-precision alignment during assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bayonet locking mechanism changes the engagement angle parameter from the conventional 0-degree axial alignment to an angled configuration. This angular parameter change allows the locking forces to be distributed more effectively, increasing stability while maintaining manufacturability through standard machining operations.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2852774B1Vibration damper, in particular a piston-rod damper for a motor vehicle
Publication Date: 2016.07.27 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP2852774B1 patent drawingFigure 1
  • EP2852774B1 patent drawingFigure 2I~2VII
  • EP2852774B1 patent drawingFigure 3

AI summary

A vibration damper, in particular a piston-rod damper for a motor vehicle, comprising a damping housing (2) which receives a piston rod (3), the piston rod comprising a pin (4) which is mounted with play in the damping housing (2), wherein a first plate (6) of the piston rod (3) is locked to the damping housing (2), and a damping element (5) is mounted between the piston rod (3) and the damping housing (2), wherein the locking between the first plate (6) of the piston rod (3) and the damping housing (2) is realized in the form of a bayonet-like lock (9, 10).