Ironless Disc Rotor Machine Torque Density
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Solution Overview
Problem
Existing electrical machines are inefficient in providing high torque density and rapid operation in compact, lightweight designs suitable for limited spaces, especially in applications requiring rotary movement and multi-phase power electronic actuation.
Innovation Solution
The development of disc rotor machines with iron-free rotors and stators, utilizing rare-earth magnets and multilayer field coils, which allow for high copper fill factor, reduced inductive losses, and efficient power handling without the need for gears, enabling high torque density and rapid acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional electrical machine with iron circuits is used, then the machine structure is stable, but the machine occupies more space and has higher weight, reducing torque density
Solution Approach 1:
The patent removes the iron circuit from the machine design, extracting the harmful element that caused weight and space issues. The ironless rotor and stator eliminate the need for heavy iron components while maintaining magnetic field functionality through direct magnet-to-coil interaction, thereby reducing weight and increasing torque density.
Solution Approach 2:
The patent employs composite material structures by combining non-magnetic materials (such as plastic or ceramic disks) with magnetic components (permanent magnets or field coils). This composite approach allows the machine to function without traditional iron circuits while achieving the desired mechanical and magnetic properties.
2Volume of moving object
If the machine is designed for compact installation in limited space, then the installation footprint is reduced, but the cooling requirements become more complex
Solution Approach 1:
The patent eliminates the need for complex external cooling systems by removing the iron circuit that generated excessive heat. The ironless design with direct magnetic coupling reduces ohmic losses and heat generation, allowing the compact machine to operate without elaborate cooling infrastructure.
Solution Approach 2:
The machine design allows the housing and structural components to serve dual purposes as both structural elements and heat dissipation surfaces. The compact machine cools itself through its operational design and natural convection, eliminating the need for separate cooling systems.
3Speed
If traditional electrical machines are used, then the machine can operate continuously, but the start-up time and acceleration are delayed
Solution Approach 1:
By removing the iron circuit and its associated magnetic inertia and saturation effects, the machine achieves much faster response times. The direct magnetic field interaction between coils and permanent magnets enables instantaneous torque generation, dramatically reducing start-up time and acceleration delays.
Solution Approach 2:
The patent changes the fundamental magnetic circuit parameters by eliminating iron saturation effects. This allows the machine to respond instantaneously to control signals with linear magnetic field generation, enabling rapid acceleration and quick start-up times that were not achievable with traditional iron-based designs.
4Loss of energy
If iron circuits are used in the machine, then the magnetic field is concentrated, but ohmic losses increase due to space competition between iron and field coils
Solution Approach 1:
The patent removes the iron circuit that was causing space competition between the iron core and field coils. This elimination allows the field coils to be positioned optimally close to the permanent magnets, maximizing magnetic field efficiency while minimizing ohmic losses through reduced current requirements.
Solution Approach 2:
The patent transitions from a two-dimensional plane of competition (iron core occupying space that could be used for coils) to a three-dimensional optimization where the magnetic field interacts directly across the air gap without iron interference. This dimensional change allows optimal coil placement and maximizes the effective use of copper conductors.
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
These machines achieve high torque density, rapid start-up times, and efficient operation in small spaces with reduced noise and cooling requirements, supporting multiple overload operations and precise control of speed and position.
Implementation Method 1
The field coils, when current is flowing through them, and/or the permanent magnets at least temporarily produce magnetic fields in the same or opposite directions, which cause a rotary or longitudinal relative movement of the rotor 14 to the stator 16
Implementation Method 2
The field coils, when current is flowing through them, and/or the permanent magnets at least temporarily produce magnetic fields in the same or opposite directions
Data Source
Figure 1~3
Figure 2d
Figure 2a~2c
AI summary
An electric disc rotor machine is equipped with at least one rotor and at least one at least partially corresponding stator, wherein the at least one rotor and the at least one stator each have an end face facing each other, wherein the at least one rotor and the at least one stator each have an ironless carrier disk which carries field coils or permanent magnets, an air gap is formed between the carrier disk of each rotor and the carrier disk of each stator, the field coils and/or the permanent magnets are aligned and arranged on the carrier disk of each rotor or the carrier disk of each stator in such a way that the field coils in the current-carrying state and/or the permanent magnets generate at least temporarily synchronous or opposing magnetic fields which cause a rotational or longitudinal relative movement of the rotor to the stator.