Magnetic Trigger Wheel for Camshaft Phaser Position Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The accuracy of metal trigger wheels in camshaft phasers depends on strict tolerances during fabrication, which can be challenging to maintain consistently.

Innovation Solution

Incorporating a magnetic material with alternating segments of first and second magnetic charges into the trigger wheel, allowing for precise rotational position identification and control through sensor detection and control signal transmission to adjust the phaser elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a metal trigger wheel is used with strict tolerances during fabrication, then measurement precision is improved, but manufacturing precision becomes more difficult to maintain consistently

Engineering Contradiction:

Improverotational position identification accuracyVSAvoidfabrication tolerance consistency

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent replaces the traditional mechanical metal trigger wheel with a magnetic trigger wheel that uses magnetic fields instead of mechanical structures for position detection. The magnetic wheel includes magnetic segments with alternating polarities that interact with a sensor to detect rotational position, eliminating the need for strict mechanical tolerances in the trigger wheel fabrication while maintaining high measurement precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental parameter of the trigger wheel from mechanical metal structure to magnetic material configuration. By using magnetic segments with specific polarity arrangements rather than mechanical teeth or notches, the system achieves accurate position detection through magnetic field variations detected by the sensor, bypassing the need for tight mechanical fabrication tolerances

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

This solution enhances the accuracy and reliability of camshaft phaser operation by enabling precise rotational position detection and control, improving the phaser's performance and consistency.

Implementation Method 1

a trigger wheel non-rotatably connected to the output element, arranged to identify a rotational position of the output element around the axis of rotation, and including a magnetic material with at least one segment having a first magnetic charge, and with at least one segment having a second magnetic charge, opposite the first magnetic charge

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentUS11891925B2Camshaft phaser with trigger wheel including magnetic material

Publication Date: 2024.02.06 SCHAEFFLER TECHNOLOGIES AG & CO KG

AI summary

A camshaft phaser, including: an input element arranged to receive a first rotational torque and rotatable about an axis of rotation; an output element rotatable about the axis of rotation, rotatable with respect to the input element, arranged to non-rotatably connect to a camshaft, and arranged to transmit the first rotational torque to the camshaft; and a trigger wheel non-rotatably connected to the output element, arranged to identify a rotational position of the output element around the axis of rotation, and including a magnetic material with at least one segment having a first magnetic charge, and with at least one segment having a second magnetic charge, opposite the first magnetic charge.