Conical Clamping Ring Fastener for Tolerance Compensation

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Solution Overview

Problem

Existing fastening devices for precise component connections, such as in motor vehicle drive train assembly, face challenges with tolerance compensation, leading to complex assemblies and potential misalignment or excessive tension due to large tolerances at attachment points.

Innovation Solution

A device comprising a screw with an axially displaceable clamping element and a radially expandable clamping ring with conical surfaces, allowing for snap-in connection and axial-to-radial force transmission, enabling flexible tolerance compensation with a simplified two-part design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional fastening devices are used for precise component connections, then manufacturing precision can be maintained, but device complexity increases due to the need for multiple parts and washers for tolerance compensation

Engineering Contradiction:
Improvecomponent alignment precisionVSAvoidnumber of fastening parts
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The fastening device is segmented into two functional parts: a clamping element with an outer conical surface and a clamping ring with an inner conical surface. This segmentation allows each part to perform a specific function (axial clamping and radial expansion) while working together to achieve precise alignment and compensate for tolerances without requiring multiple separate components like washers and additional fasteners.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamping element is inserted into the clamping ring, creating a nested structure where the smaller component fits within the larger one. This nesting approach consolidates multiple functions into a compact integrated assembly, reducing the overall number of parts needed while maintaining the ability to compensate for both axial and radial tolerances through the interaction of the conical surfaces.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If tolerance compensation mechanisms are added to avoid excessive tension, then connection reliability improves, but ease of operation deteriorates due to complex assembly procedures

Engineering Contradiction:
Improveconnection stabilityVSAvoidassembly simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The clamping ring is designed to be radially expandable, allowing it to dynamically adapt to tolerance variations during assembly. When the clamping element is inserted, the clamping ring expands radially to accommodate the specific tolerance conditions, ensuring reliable connection without requiring complex pre-adjustment procedures or multiple operational steps.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device changes the geometric parameters of the clamping ring by expanding it radially during assembly. This parameter change allows the fastening device to compensate for tolerance variations in the workpiece, ensuring reliable connection while maintaining simple assembly operations. The conical surfaces transform axial insertion force into radial expansion, automatically adapting to tolerance conditions.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If conical surfaces are used for tolerance compensation, then adaptability improves, but manufacturing precision requirements worsen due to the complexity of conical surface fabrication

Engineering Contradiction:
Improvetolerance compensation capabilityVSAvoidconical surface accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The device uses conical surfaces (curved geometric forms) on both the clamping element and clamping ring. These curved surfaces provide inherent adaptability to tolerance variations while being manufacturable using standard machining processes. The conical geometry transforms axial forces into radial expansion forces, achieving tolerance compensation through geometric design rather than requiring high-precision adjustable mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 device effectively compensates for both axial and radial tolerances, ensuring a mechanically stable attachment with reduced complexity and preventing misalignment, particularly suitable for connecting motor housings to transmission housings with direct gear meshing.

Implementation Method 1

the outer conical surface of the clamping element rests against the inner conical surface of the clamping ring

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

an axial force can be transmitted at least partially in the radial direction via the inner and outer conical surfaces that rest against one another

Methodology Applied
Scientific EffectNormal force: Force

Implementation Method 3

expands as a result and thus creates a frictional connection that is effective in the radial direction at the fastening point

Methodology Applied
Scientific EffectFrictional connection: Friction

Data Source

PatentEP3321519B1Device for connecting two components
Publication Date: 2021.03.03 VALEO EAUTOMOTIVE GERMANY GMBH
  • EP3321519B1 patent drawingFigure 1

AI summary

A device (1) for connecting two components (30, 40) comprises a clamping element (2) which is guided in an axially displaceable manner on a shank (21) of a screw (20) and has an outer conical surface (6) and a radially expandable, inner conical surface ( 5) having clamping ring (4). The clamping element (2) is inserted into the clamping ring (4) in such a way that the outer conical surface (6) of the clamping element (2) rests against the inner conical surface (5) of the clamping ring (4). According to the invention, the clamping ring (4) has an annular bearing surface (7), which rests on a component (40) to be connected when the screw (20) is screwed in, so that an axial force is at least partially transmitted via the inner and outer conical surfaces (5, 6) can be mediated in the radial direction.