Magnetic Gear Arrangement With Variable Ratio

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Solution Overview

Problem

Traditional gearboxes are noisy, require lubricating oils that can be hazardous and ineffective in extreme environments, and have mechanical contact issues, while existing magnetic gearboxes rely on permanent magnets and have limited gear ratio variability.

Innovation Solution

A magnetic gear arrangement using a magnetically passive gear member formed of magnetically hard material, where magnetic poles are generated through a modulated magnetic field from a magnetically active member, allowing for variable gear ratios and high-speed operation without permanent magnets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional gearboxes with gear wheels are used, then mechanical coupling and gear ratio are achieved, but noise is generated and lubricating oils are required which pose environmental hazards and fail in extreme environments

Engineering Contradiction:

Improveoperation in extreme environmentsVSAvoidnoise and environmental hazards from lubricating oils

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the traditional mechanical contact-based gear system with a magnetic field-based transmission system. Magnetically active and passive members interact through magnetic fields without mechanical contact, eliminating the need for lubricating oils and significantly reducing noise. The magnetically passive member is formed of magnetically hard material that responds to the modulated magnetic field from the active member, achieving gear ratio transmission without physical gear teeth or lubrication.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If existing magnetic gearboxes with permanent magnets are used, then mechanical contact is avoided, but gear ratio variability is limited

Engineering Contradiction:

Improvegear ratio variabilityVSAvoidstructure with permanent magnets

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a modifiable magnetic field configuration where the number of magnetic poles on the magnetically passive member can be dynamically adjusted. By changing the number of poles in the modulated magnetic field from the magnetically active member, different gear ratios can be achieved. The magnetically passive member, made of magnetically hard material, can have its effective pole count varied by the external magnetic field modulation, enabling variable gear ratios without permanent magnet constraints.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the magnetic field parameters (number of poles, field strength distribution) to achieve different gear ratios. The magnetically passive member's interaction with the modulated magnetic field allows the effective number of poles to be varied by changing the magnetic field configuration from the magnetically active member, providing gear ratio variability through parameter modification rather than structural reconfiguration.

Inventive Principle:

Principle #35Parameter changes

3Speed

If magnetically passive gear member is formed of magnetically hard material, then high-speed operation is enabled, but manufacturing complexity increases

Engineering Contradiction:

Improverotational speed capabilityVSAvoidmanufacturing of magnetically hard material components

Core Design Contradiction:

SpeedVSEase of manufacture

Solution Approach 1:

The patent uses the magnetic field from the magnetically active member to induce the required magnetic pole configuration in the magnetically passive member. Rather than requiring complex permanent magnet arrangements in the passive member, the magnetic field from the active member effectively 'copies' or induces the necessary magnetic pattern, simplifying the manufacturing of the passive member while enabling high-speed operation through the use of magnetically hard material.

Inventive Principle:

Principle #26Copying

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 provides a quieter, more environmentally friendly gearbox with increased gear ratio variability and high-speed capability, suitable for specialized applications like gyroscopes, and can be adapted into hysteresis motors and generators for efficient power generation.

Implementation Method 1

the first magnetic field couples to the second magnetic field to produce a gear ratio between the magnetically active and the magnetically passive gear members

Methodology Applied

Scientific EffectMagnetic flux coupling: Magnetic Field

Implementation Method 2

the magnetically passive gear member is formed of sufficiently magnetically hard material

Methodology Applied

Scientific EffectMagnetic hysteresis: Magnetic Hysteresis

Data Source

PatentUS9356502B2Magnetic gear arrangement having a variable gear ratio

Publication Date: 2016.05.31 ROLLS ROYCE PLC

AI summary

A magnetic gear arrangement is provided having a magnetically active gear member that generates a first magnetic field, which is modulated by interpoles. The modulated magnetic field generates magnetic poles on a magnetically passive gear member, and these poles form a second magnetic field. The material of the passive gear member is sufficiently magnetically hard that the first and second magnetic fields interact to couple the motion of the active and passive gear members according to a given gear ratio.