Integrated Encoder Alternator for Crankshaft Position Detection

Solution Overview

Problem

Existing alternators for small, low-cost internal combustion engines are cost-prohibitive due to the need for externally mounted sensors and encoder wheels to determine crankshaft position, which are expensive.

Innovation Solution

An integrated engine encoder alternator that uses the alternator to provide the encoding function by incorporating a permanent magnet rotor with a periodic pattern of north-south pole borders and a stator with sensor coils to detect the angular position of the crankshaft through a missing pulse or reference signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If externally mounted sensors and encoder wheels are used to determine crankshaft position, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvecrankshaft position detectionVSAvoidencoder wheel and external sensor assembly

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the crankshaft position sensing function with the alternator assembly by integrating a sensor onto the alternator housing that detects the position of a reluctor tooth pattern on the crankshaft. This merging eliminates the need for separate external encoder wheels and sensors, reducing device complexity while maintaining measurement precision for crankshaft position detection.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The alternator assembly is given multiple functions: it serves both as the electrical power generation component and as the crankshaft position sensing system. The sensor integrated into the alternator housing performs dual roles in monitoring both electrical output and mechanical position, thereby reducing overall system complexity and eliminating the need for dedicated external encoding components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If externally mounted sensors and encoder wheels are used to determine crankshaft position, then measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvecrankshaft position detectionVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent combines the crankshaft position sensing function with the alternator assembly by integrating a sensor onto the alternator housing that detects the position of a reluctor tooth pattern on the crankshaft. This merging eliminates the need for separate external encoder wheels and sensors, reducing device complexity while maintaining measurement precision for crankshaft position detection.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The alternator assembly is given multiple functions: it serves both as the electrical power generation component and as the crankshaft position sensing system. The sensor integrated into the alternator housing performs dual roles in monitoring both electrical output and mechanical position, thereby reducing overall system complexity and eliminating the need for dedicated external encoding components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 eliminates the need for external sensors, providing a cost-effective means to determine the angular position of the crankshaft while maintaining the alternator's electrical power supply function, thereby reducing costs and enhancing engine control functionality.

Implementation Method 1

a permanent magnet rotor with a periodic pattern of north-south pole borders and a stator with sensor coils to detect the angular position of the crankshaft

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The sensor may be a Hall effect sensor, a VR (variable reluctance) sensor

Methodology Applied

Scientific EffectHall effect: Hall Effect

Implementation Method 3

a VR (variable reluctance) sensor

Methodology Applied

Scientific EffectVariable reluctance: Magnetic Reluctance

Data Source

PatentUS7362018B1Encoder alternator

Publication Date: 2008.04.22 WOODWARD INC

AI summary

An encoder alternator for an internal combustion engine has a rotor with a plurality of circumferential magnetic rotor poles in a periodic pattern except for at least one magnetic irregularity. A sensor coil is wound around a stator pole and outputs a crankshaft position sensor signal when the magnet irregularity of the rotor passes the stator pole.