Internal Rotor Generator Magnet Fixation via Lathe-Turned Ring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric generators for small-dimension, high-performance internal combustion engines face issues with high centrifugal forces affecting rare earth magnets, costly diecasting processes, and mechanical sealing problems due to limited diecast aluminium mass, which complicates the integration of external structures and increases magnetic reluctance.
Innovation Solution
The electric generator features a ferromagnetic ring produced by lathe turning with a ring of ferromagnetic material, a frusto-conical cavity, and rare earth magnets glued to the cylindrical surface, covered by a magnetic cap, allowing for secure positioning and easy integration of external structures without the need for diecasting, enabling customization and reduced production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If diecasting is used to fix magnets to the ferromagnetic ring, then the magnets are securely fixed to withstand high centrifugal forces, but the process requires costly moulds and high temperatures that can demagnetize rare earth magnets
Solution Approach 1:
The magnets are fixed to the ferromagnetic ring before magnetization, eliminating the need for post-magnetization assembly. This preliminary fixation allows the use of simpler, lower-cost attachment methods that do not require expensive diecasting moulds or high-temperature processes that would demagnetize the magnets.
Solution Approach 2:
A ferromagnetic ring serves as an intermediary component between the magnets and the rotor structure. This ring provides a secure mounting surface for the magnets while being compatible with lower-temperature fixation methods, thus avoiding demagnetization and reducing manufacturing costs.
2Strength
If diecasting is used to fix magnets, then secure fixation is achieved, but aluminium infiltration between magnets and ring increases magnetic reluctance
Solution Approach 1:
The harmful diecasting process is extracted and replaced with a different fixation method. By removing the diecasting step, aluminium infiltration is eliminated, thus preventing the increase in magnetic reluctance while still achieving secure magnet fixation through alternative means.
3Volume of moving object
If diecast aluminium mass is limited for dimensional reasons, then the generator fits size requirements, but fixing external structures becomes problematic with mechanical sealing issues
Solution Approach 1:
The ferromagnetic ring serves multiple functions: it provides magnetic circuit functionality, serves as a mounting surface for magnets, and acts as a base for attaching external structures like gear supports and cooling fans. This multi-functionality eliminates the need for additional diecasting operations and simplifies the integration of various components.
4Adaptability or versatility
If differentiated production of rotor is used to embed structures for each client requirement, then customization is achieved, but production complexity and mould requirements increase
Solution Approach 1:
The rotor is segmented into modular components: a standard ferromagnetic ring with magnets that can be universally produced, and separate external structures (gear supports, fan mounts) that can be customized and attached as needed. This segmentation allows the base rotor to be mass-produced while enabling customization through simple add-on components.
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 costly diecasting, reduces magnetic reluctance, and allows for personalized rotor production, enhancing engine stability and performance while simplifying the integration of external structures and spark control.
Implementation Method 1
a plurality of magnets applied to the periphery of this ring and arranged to generate a magnetic flux, the lines of force of which are closed via the stator ferromagnetic ring and core, and with the rotor rotation they generate within the stator windings the electrical energy
Implementation Method 2
a plurality of rare earth magnets glued to the cylindrical surface of the ring
Data Source
Figure 1~2
Figure 3~6
AI summary
An electric generator with internal rotor for small-dimension, high performance internal combustion engines, in which said rotor comprises a plurality of magnets (12) applied to a ring (2) of ferromagnetic material applicable to the end of the shaft of said engine, characterised in that said ring (2) is provided with means for stabilizing the angular position of said magnets (12), which have their outer surface positioned on a single cylindrical surface and are maintained adhering to said ring (2) by an annular band of non-ferromagnetic material.