Brake Unit Press-Fit Sleeve Connection Against Screw Loosening

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Solution Overview

Problem

Existing brake units with screw connections between friction rings and holding parts face complexity in production and potential loosening due to mechanical and thermal stresses, requiring costly additional measures for stability.

Innovation Solution

A brake unit design featuring an axially projecting connecting piece on the friction ring with an external profile and a corresponding internal profiling on the holding part's sleeve section, forming a non-positive and positive, rotation-proof connection through a press fit and caulking, enhancing the connection's strength as the brake load increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screw connections are used to connect the friction ring and retaining part, then the brake unit can be assembled, but the connection becomes complex to manufacture and may loosen due to mechanical and thermal stresses

Engineering Contradiction:
Improveconnection stabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the connection method from threaded screw joints to a press-fit connection with interference dimensions. The connecting stub on the friction ring is designed with specific dimensional parameters that create an interference fit with the retaining part, eliminating threads and simplifying manufacturing while maintaining connection stability under thermal and mechanical loads.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical screw thread system with a direct press-fit connection system. Instead of using threaded fasteners that require threading operations and may loosen, the design uses a stub protruding from the friction ring that fits directly into the retaining part with interference dimensions, creating a more reliable and simpler connection.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If additional retaining devices are added to prevent loosening, then connection stability improves, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveconnection stabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The press-fit connection with interference dimensions creates a self-locking mechanism that prevents loosening without requiring additional retaining devices. The dimensional interference between the connecting stub and the retaining part socket creates friction and mechanical interlocking that maintains connection stability under braking loads, eliminating the need for extra fasteners or locking mechanisms.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a wave-like circumferential wall is formed on the retaining element, then the friction ring can be slid onto the retaining element, but the manufacturing becomes complex and additional axial retaining devices are required

Engineering Contradiction:
Improveassembly capabilityVSAvoidstructural complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex wave-like circumferential wall feature from the retaining element design. Instead of using undulating surfaces to guide assembly, the design uses a simple cylindrical socket that receives the connecting stub, reducing structural complexity while maintaining assembly capability through the press-fit connection mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

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 production, provides a strong and reliable connection that strengthens with increased braking load, ensuring operational safety and stability without additional costly measures.

Implementation Method 1

This joining can be effected, in particular, by an interference fit, so that, in addition to a positive-locking, rotationally fixed connection via, in particular, axially oriented profile elements of the external and internal profiles, a force-locking axial positional locking between the two parts is also simultaneously provided.

Methodology Applied
Scientific EffectInterference fit:

Implementation Method 2

with increasing brake load, the friction ring heats up faster and more intensely than the retaining part. Due to the material expansion with increasing temperature, this results in an increasingly strong connection between the inner connecting studs of the friction ring and the outer sleeve section of the retaining part as the braking load increases.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4145011B1Brake unit and method for the production of same
Publication Date: 2023.11.01 FISCHER & KAUFMANN GMBH & CO KG
  • EP4145011B1 patent drawingFigure 1~3
  • EP4145011B1 patent drawingFigure 4~5

AI summary

The invention relates to a brake unit comprising a disc-shaped friction ring and a retaining part, which are connected to each other. According to the invention, the friction ring has an axially projecting, annular connecting sleeve with an external profile, the retaining part has an axially extending sleeve section with an internal profile corresponding to the external profile, and the sleeve section of the retaining part is axially joined to the connecting sleeve of the friction ring to form the brake unit, with the external and internal profiles interlocking to form a force-fit and form-fit, rotationally fixed connection.