Wheel Speed Sensor Gear Amplification for Low-Speed Detection

Solution Overview

Problem

Existing wheel speed sensors in aircraft struggle to accurately detect rotational wheel speed at low speeds due to the weak sine wave produced, which is insufficient for reliable antiskid activity and speed calculations.

Innovation Solution

A wheel speed sensor system comprising a magnet, induction coil, and a gear system with a rotor having teeth, where the gear system amplifies the rotor's rotational speed by at least 2:1, creating a stronger magnetic field flux and sine wave at lower speeds, allowing accurate speed detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a wheel speed sensor uses a magnet and induction coil to detect rotational speed, then it can determine antiskid activity and vehicle speed, but at speeds below a threshold the sine wave produced is too weak to accurately read and calculate rotational wheel speed

Engineering Contradiction:

Improverotational wheel speed detection accuracyVSAvoidsignal strength at low speeds

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A gear system with a gear ratio of at least 2:1 is introduced as an intermediary mechanism between the wheel and the rotor. The gear system amplifies the rotational speed of the rotor relative to the wheel speed, causing the rotor to rotate faster than the wheel. This speed amplification strengthens the magnetic field variations and the resulting sine wave signal produced by the magnet and induction coil, enabling accurate detection at lower wheel speeds where the signal would otherwise be too weak.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the rotor rotates at the same speed as the wheel, then the structure is simple, but the sine wave produced is too weak at low speeds for accurate measurement

Engineering Contradiction:

Improvesignal strengthVSAvoidgear system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A gear system with a gear ratio of at least 2:1 is introduced as an intermediary mechanism between the wheel and the rotor. The gear system amplifies the rotational speed of the rotor relative to the wheel speed, causing the rotor to rotate faster than the wheel. This speed amplification strengthens the magnetic field variations and the resulting sine wave signal produced by the magnet and induction coil, enabling accurate detection at lower wheel speeds where the signal would otherwise be too weak.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If a gear system with a gear ratio of at least 2 to 1 is used to amplify rotor rotational speed, then the sine wave strength is increased for accurate low-speed detection, but the device complexity increases

Engineering Contradiction:

Improvelow speed detection accuracyVSAvoidgear system components

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

A gear system with a gear ratio of at least 2:1 is introduced as an intermediary mechanism between the wheel and the rotor. The gear system amplifies the rotational speed of the rotor relative to the wheel speed, causing the rotor to rotate faster than the wheel. This speed amplification strengthens the magnetic field variations and the resulting sine wave signal produced by the magnet and induction coil, enabling accurate detection at lower wheel speeds where the signal would otherwise be too weak.

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

The system effectively increases the strength of the sine wave produced, enabling accurate rotational speed calculation and antiskid activity determination at lower aircraft speeds, effectively reducing the speed threshold for reliable measurements.

Implementation Method 1

the rotation of the rotor may be configured to cause a magnetic field around the magnet to flux in response to the changing air gap

Methodology Applied

Scientific EffectMagnetic field flux: Magnetic Field

Implementation Method 2

an induction coil coupled to the magnet

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10598681B2Wheel speed sensor

Publication Date: 2020.03.24 GOODRICH CORP

AI summary

A wheel speed sensor may comprise a magnet; an induction coil coupled to the magnet; a rotor comprising a plurality of teeth, wherein the magnet is disposed proximate the plurality of teeth; a gear system coupled to the rotor comprising an initial gear, wherein the initial gear may be configured to be coupled to a wheel and configured to rotate at a speed equal to a wheel rotational speed of the wheel. The gear system may be configured to cause a rotor rotational speed of the rotor to be greater than the wheel rotational speed in response to the wheel rotating.