Camshaft Module Actuator Support Thermal Expansion Isolation

Solution Overview

Problem

Camshaft modules in internal combustion engines face operational reliability issues due to thermal expansion differences between aluminum or plastic module bodies and steel camshafts, leading to dimensional deviations and increased wear, especially in wide temperature ranges.

Innovation Solution

A support element with a coefficient of thermal expansion matching the camshaft is introduced, decoupling actuators from the module body and ensuring they remain aligned with sliding cam pieces by being mechanically fixed on this support element, which runs parallel to the camshaft, thereby isolating them from thermal expansions of the module body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the module body is produced from aluminum or plastic for lightweight construction, then weight is reduced, but dimensional deviations arise due to differing coefficients of thermal expansion between the module body and steel camshaft

Engineering Contradiction:

Improveweight of module bodyVSAvoiddimensional precision of actuator position

Core Design Contradiction:

Weight of moving objectVSManufacturing precision

Solution Approach 1:

The actuator support is segmented from the module body as a separate component. This allows the support to be made from a material with a coefficient of thermal expansion matching the camshaft, while the module body remains lightweight aluminum or plastic. The segmentation isolates the precision-critical actuator positioning function from the lightweight structural function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The actuator support acts as an intermediary component between the module body and the camshaft/actuators. It mediates the thermal expansion differences by providing a stable reference structure that expands at the same rate as the camshaft, thereby maintaining precise dimensional relationships despite temperature variations.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Weight of moving object

If the module body is produced from aluminum or plastic, then weight is reduced, but operational reliability decreases due to thermal expansion differences

Engineering Contradiction:

Improveweight of module bodyVSAvoidoperational reliability of actuator engagement

Core Design Contradiction:

Weight of moving objectVSReliability

Solution Approach 1:

The actuator support is segmented from the module body as a separate component. This allows the support to be made from a material with a coefficient of thermal expansion matching the camshaft, while the module body remains lightweight aluminum or plastic. The segmentation isolates the precision-critical actuator positioning function from the lightweight structural function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The actuator support acts as an intermediary component between the module body and the camshaft/actuators. It mediates the thermal expansion differences by providing a stable reference structure that expands at the same rate as the camshaft, thereby maintaining precise dimensional relationships despite temperature variations.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If actuators are fixed directly to the module body, then device complexity is reduced, but wear increases due to thermal misalignment between actuators and sliding cam pieces

Engineering Contradiction:

Improvestructural complexity of actuator mountingVSAvoidwear of camshaft module

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The actuator support is segmented from the module body as a separate component. This allows the support to be made from a material with a coefficient of thermal expansion matching the camshaft, while the module body remains lightweight aluminum or plastic. The segmentation isolates the precision-critical actuator positioning function from the lightweight structural function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The actuator support acts as an intermediary component between the module body and the camshaft/actuators. It mediates the thermal expansion differences by providing a stable reference structure that expands at the same rate as the camshaft, thereby maintaining precise dimensional relationships despite temperature variations.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution ensures secure engagement of actuator pins in slotted guides and maintains axial position coordination between actuators and sliding cam pieces across severe temperature fluctuations, reducing wear and ensuring reliable operation even in long camshaft modules.

Implementation Method 1

coefficients of thermal expansion which differ from one another arise for the material of the module body and for the camshaft

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10247051B2Camshaft module

Publication Date: 2019.04.02 THYSSENKRUPP PRESTA TECCENTER AG

AI summary

A camshaft module may include a module body in which at least one camshaft for controlling valves for a charge cycle of an internal combustion engine is accommodated. The camshaft may comprise a support shaft and sliding cam pieces that are accommodated on the support shaft so as to be displaceable in an axial direction of the support shaft. A support element may also be provided on which actuators for the axial displacement of the sliding cam pieces are accommodated. The support element may extend in the axial direction and therefore parallel to the support shaft. In some cases, a coefficient of thermal expansion of the support element substantially corresponds to a coefficient of thermal expansion of the support shaft.