Elastomer Shaft-Hub Connection for Backlash Compensation

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Solution Overview

Problem

Existing shaft-hub connections in motor vehicle drive trains face challenges in achieving a low-noise, structurally simple, and space-saving design due to tolerance-related backlashes and rattling noises during torque transmission.

Innovation Solution

A connecting element with a first and second toothing element connected via an elastomer body, which exerts a restoring torque to align and secure the toothed elements, eliminating backlash and damping torsional vibrations, thereby avoiding rattling noises and allowing for a thin, space-efficient design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If metal spiral springs are used to brace the disks against each other, then tolerance-related backlash can be eliminated, but the structural complexity and space requirements increase

Engineering Contradiction:
Improvebacklash eliminationVSAvoidstructural complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the material parameter from rigid metal spiral springs to elastomeric material, which provides both the necessary restoring torque to eliminate backlash and the flexibility to reduce structural complexity. The elastomeric body deforms elastically under torque, automatically compensating for tolerance variations without requiring complex mechanical spring structures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical spring system with an elastomeric body that uses elastic deformation to achieve the same function. Instead of metal spiral springs requiring complex winding structures and attachment mechanisms, the elastomeric body provides restoring torque through its inherent elastic properties, significantly simplifying the overall structure.

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

2Manufacturing precision

If metal spiral springs are used to eliminate backlash, then precision is improved, but the space requirement increases

Engineering Contradiction:
Improvebacklash eliminationVSAvoidspace requirement
Core Design Contradiction:
Manufacturing precisionVSVolume of moving object

Solution Approach 1:

The patent changes the material parameter from rigid metal to elastomeric material, which provides both the necessary restoring torque to eliminate backlash and the flexibility to reduce structural complexity. The elastomeric body deforms elastically under torque, automatically compensating for tolerance variations without requiring complex mechanical spring structures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical spring system with an elastomeric body that uses elastic deformation to achieve the same function. Instead of metal spiral springs requiring complex winding structures and attachment mechanisms, the elastomeric body provides restoring torque through its inherent elastic properties, significantly simplifying the overall structure.

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

3Volume of moving object

If a thin elastomer body is used, then space is saved, but the restoring torque capability may be reduced

Engineering Contradiction:
Improvespace savingVSAvoidrestoring torque
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The patent employs elastomeric material with specific viscoelastic properties that provide high restoring torque relative to their size. The elastomeric body's material composition and damping characteristics enable it to generate sufficient restoring torque even with reduced thickness, overcoming the traditional trade-off between size and force capability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameter from rigid metal to elastomeric material, which provides both the necessary restoring torque to eliminate backlash and the flexibility to reduce structural complexity. The elastomeric body deforms elastically under torque, automatically compensating for tolerance variations without requiring complex mechanical spring structures.

Inventive Principle:
Principle #35Parameter changes

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 provides a backlash-free, low-noise shaft-hub connection that compensates for tolerance-related issues and dampens vibrations, ensuring a structurally simple and space-saving design for motor vehicle drive trains.

Implementation Method 1

an elastomer body (16) connected to the first toothing element (12) and the second toothing element (18), which exerts a restoring torque in the circumferential direction on the first toothing element (12) and/or on the second toothing element (18) when the first toothing (14) is aligned with the second toothing (20)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

In addition, the elastomer body can act as a damper, with the help of which torsional vibrations can be damped

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3004675B1Connection element for a shaft-hub connection, in particular for torque transmission in a power train of a motor vehicle, and use of such a connection element
Publication Date: 2017.10.04 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3004675B1 patent drawingFigure 1
  • EP3004675B1 patent drawingFigure 2~3

AI summary

The invention relates to a connection element for a shaft-hub connection, in particular for torque transmission in a power train of a motor vehicle, comprising a first toothed element that has a first set of teeth for forming a spline system having a counter toothed element, a second toothed element that has a second set of teeth for forming a spline system having the same counter toothed element, and an elastomer body that is connected to the first toothed element and to the second toothed element, the elastomer body exerting a restoring moment in the circumferential direction on the first toothed element and/or on the second toothed element when the first set of teeth is aligned with the second set of teeth. The offset connection of the toothed elements by means of the elastomer body means that a tolerance-induced tooth play in the circumferential direction can be compensated automatically, allowing a shaft-hub connection for a power train of a motor vehicle that is of low noise and simple design and saves installation space.