Damped Support Disc for Idler Gear Shaft Assembly

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Solution Overview

Problem

Idler gears in transmissions experience undesirable vibrations and noise when support disks are unloaded, and the assembly/disassembly of support washers is complex and costly due to tight tolerances.

Innovation Solution

A shaft arrangement with a coupling element and a support disk featuring an elastic damping element, such as rubber, that can be easily installed and removed, allowing the idler gear to move axially between coupled and decoupled positions, reducing vibrations and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If support discs are installed with axial and radial play, then assembly is simple, but vibration and noise occur when unloaded

Engineering Contradiction:
Improveassembly simplicityVSAvoidvibration and noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a damping element as an intermediary component between the support disc and the shaft. This damping element absorbs vibrations and prevents noise while maintaining the ease of assembly with axial and radial play, resolving the contradiction between assembly simplicity and vibration control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If support discs are pressed onto the shaft, then vibration and noise are reduced, but assembly and disassembly become complex and expensive

Engineering Contradiction:
Improvevibration and noiseVSAvoidassembly and disassembly complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The damping element serves as a mediator that allows the support disc to be mounted with play rather than pressed tightly onto the shaft. This eliminates the need for complex pressing operations and expensive tight tolerances while still reducing vibration and noise through the damping properties of the element.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If tight tolerances are used for support discs, then vibration is reduced, but manufacturing cost increases

Engineering Contradiction:
ImprovevibrationVSAvoidmanufacturing cost
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The damping element acts as a cost-effective intermediary that reduces vibration without requiring tight manufacturing tolerances on the support disc and shaft. This allows for more relaxed tolerances and simpler, less expensive manufacturing processes while achieving the desired vibration reduction.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If axial forces are absorbed by rigid support discs, then structural stability is maintained, but vibration occurs when unloaded

Engineering Contradiction:
Improvestructural stabilityVSAvoidvibration when unloaded
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical parameters of the support disc system by introducing a damping element with viscoelastic properties. This element maintains structural stability under load while providing vibration damping when unloaded, resolving the contradiction between stability and vibration control through parameter modification.

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 elastic support disk effectively absorbs axial forces, preventing vibrations and noise, simplifying assembly and reducing costs by eliminating the need for pressing the support disk onto the shaft.

Implementation Method 1

The support disk has an elastic damping element. The damping element can consist of or comprise an elastic material. The elastic material can be rubber and/or an elastomer.

Methodology Applied
Scientific EffectElastic damping: Elasticity

Implementation Method 2

This prevents or at least reduces vibration of the support disc and the associated unwanted noise.

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP4428386A1Shaft arrangement, drive arrangement and vehicle
Publication Date: 2024.09.11 ROBERT BOSCH GMBH
  • EP4428386A1 patent drawingFigure 1
  • EP4428386A1 patent drawingFigure 2
  • EP4428386A1 patent drawingFigure 3

AI summary

The invention relates to a shaft arrangement (10) comprising a shaft (14), a loose gear (16), a coupling element (18), a clutch element (20), and a support disc (24) for axially supporting the loose gear (16), wherein the support disc (24) is arranged axially adjacent to the loose gear (16) on the shaft (14), and wherein the support disc (24) has an elastic damping element (25). The invention also relates to a drive arrangement (12) with such a shaft arrangement (10) and a vehicle with such a drive arrangement (12).