Pivotable Tensioner Housing for Engine Belt Drive

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Solution Overview

Problem

Existing tensioning devices for traction mechanism drives, particularly in internal combustion engine systems, are complex and require additional fastening to the machine and starter generator, leading to increased component complexity and vibration issues due to rotational irregularities.

Innovation Solution

A pivotable tensioner housing mounted on the drive shaft with a roller bearing, allowing the tensioning device to participate in the tensioning motion and reducing the need for separate fastening, while minimizing friction and damping, thus enabling a compact and simplified design that dynamically decouples the generator from rotational irregularities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tensioner housing is fastened to the machine and starter generator, then the tensioning device is securely mounted, but the component complexity increases

Engineering Contradiction:

Improvesecure mountingVSAvoidcomponent complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The tensioner housing is merged with the drive wheel assembly, forming an integrated unit that is screwed as one onto the drive shaft. This eliminates the need for separate fastening to the machine and starter generator, reducing component complexity while maintaining secure mounting through the unified attachment to the rotating drive shaft.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of manufacture

If a slide bearing is used for mounting the tensioner housing, then the mounting is simple, but friction and damping are high

Engineering Contradiction:

Improvemounting simplicityVSAvoidfriction and damping

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The slide bearing is replaced with a roller bearing, which substitutes sliding friction with rolling friction. This reduction in friction coefficient significantly decreases energy loss and damping during the oscillating pivot motions of the tensioner housing, while the roller bearing remains straightforward to mount.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If the tensioning device is rigidly fastened, then the mounting is stable, but vibrations from rotational irregularities are transmitted to the generator

Engineering Contradiction:

Improvemounting stabilityVSAvoidvibrations transmitted to generator

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The mounting is changed from a rigid fixed connection to a dynamic pivotable connection on the rotating drive shaft. The roller bearing enables oscillating pivot motions that allow the tensioning device to dynamically adapt to rotational irregularities, maintaining mounting stability while decoupling vibrations from the generator through the compliant rotational joint.

Inventive Principle:

Principle #15Dynamics

4Reliability

If multiple separate fastenings are used, then the mounting is secure, but the installation process becomes complex

Engineering Contradiction:

Improvemounting securityVSAvoidinstallation simplicity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The tensioner housing and drive wheel are merged into a single integrated assembly that is screwed as one unit onto the drive shaft. This consolidation reduces multiple separate fastening operations to a single installation process, maintaining secure mounting through the unified attachment while dramatically simplifying installation.

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

The solution reduces component complexity, simplifies installation, and effectively minimizes vibrations caused by rotational irregularities, achieving a durable and low-friction mounting that maintains torque equilibrium and reduces wear and acoustics in the belt drive.

Implementation Method 1

The friction of the roller bearing, which is considerably less than that of a slide bearing, not only ensures a durable and low-friction mounting of the tensioning device on the rotating drive shaft

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

is also accompanied by a correspondingly low damping of the tensioning device during the oscillating pivot motions of the tensioner housing

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS9182015B2Tensioning device for a traction mechanism drive of an internal combustion engine

Publication Date: 2015.11.10 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A tensioning device (11) for a traction mechanism drive (1) which is arranged on an internal combustion engine and includes a drive wheel (3) arranged on a drive shaft (30) of an engine (4), one or more additional driving wheels (5, 6), and a continuously revolving traction element (2), which wraps around the drive wheel and additional driving wheels. The tensioning device has two tensioning arms (13, 14) having tensioning wheels (9, 10) mounted thereon, which apply a tensioning force to the traction element in front of and behind the drive wheel in the direction of revolution, and is provided with a spring (16) generating the tensioning force, and a tensioner housing (12), which movably mounts at least one of the tensioning arms to which the force of the spring means is applied. The tensioner housing is mounted on the engine pivotably about the axis (29) of the drive shaft.