Friction Clutch Lever Spring Bolt Pre-Assembly

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Solution Overview

Problem

The assembly of friction clutches with two-part lever spring bolts is complex due to their design, making it difficult to insert the lever spring bolt between the housing and the lever spring, leading to potential disassembly issues during installation.

Innovation Solution

A friction clutch design where the sleeve is fixed to the shaft or head using a non-positive or material connection, allowing for simpler assembly by connecting the separate components before installation, and providing options for temporary or permanent fixation, including threaded engagement, magnetization, and material-based connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lever spring bolt is designed in two parts (shaft and bushing) to improve service life and actuation, then reliability is improved, but device complexity increases making assembly difficult

Engineering Contradiction:
Improveservice lifeVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bushing is pre-assembled onto the shaft before installation into the clutch housing, creating a pre-assembled unit that simplifies the final installation process while maintaining the reliability benefits of the two-part design

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bushing is inserted onto the shaft in a nested configuration, with the bushing surrounding the shaft along its axial extent, creating a compact pre-assembled unit that reduces assembly complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the lever spring bolt is designed in two parts to improve service life, then reliability is improved, but ease of operation deteriorates during insertion

Engineering Contradiction:
Improveservice lifeVSAvoidinsertion ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The bushing and shaft are pre-assembled before insertion into the clutch, transforming a complex two-step insertion process into a single operation that maintains reliability while improving ease of operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bushing and shaft are combined into a single pre-assembled unit, merging two separate components into one that functions as an integrated assembly during insertion, thereby simplifying the operation

Inventive Principle:
Principle #5Merging (Combining)

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

This design simplifies the assembly process, reduces the risk of component disassembly during installation, and enhances the structural integrity and service life of the friction clutch by allowing pre-assembly and reducing mechanical stress on the components.

Implementation Method 1

The socket/sleeve is fixed to the shank or the head with a non-positive or material connection

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 2

The socket/sleeve is fixed to the shank or the head with a non-positive or material connection

Methodology Applied
Scientific EffectMaterial connection: Chemical Bonding

Implementation Method 3

The fixation between the shaft or head and bushing/sleeve can be designed to be permanent for the entire service life of the lever spring bolt or the friction clutch, or only for a temporary fixation

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP3134657B1Mounting-optimized friction clutch having lever spring pin subsections that are force-locked or bonded with one another
Publication Date: 2019.11.27 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3134657B1 patent drawingFigure 1~2c
  • EP3134657B1 patent drawingFigure 3~4
  • EP3134657B1 patent drawingFigure 5a~6b

AI summary

The invention relates to a friction clutch for a powertrain of a motor vehicle, having a cover (5) on which a lever spring (6) is mounted by means of a lever spring pin (12), said lever spring pin having a shank (12) with a head (14), the outer diameter of which is larger than that of the shank. The shank is at least partially surrounded by a bushing (15), said bushing being force-locked with or bonded to the shank or the head.