Magnetic Flywheel Bearing Layout for Axial Stability
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Solution Overview
Problem
Magnetic bearings using permanent magnets face instability due to curved magnetic flux lines causing repulsion points to misalign, leading to axial direction friction and reduced rotational energy maintenance.
Innovation Solution
A flywheel device with inner and outer cylindrical members made of permanent magnets, offset in the axial direction, providing repulsive forces to support the rotation shaft non-contactually, integrating a flywheel and magnetic bearing functions to stabilize both radial and axial directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If magnets are made to face each other so that repulsion between the magnets increases, then the support force in radial direction is improved, but the repulsion point becomes unstable and misalignment occurs in axial direction
Solution Approach 1:
The patent resolves the instability issue by shifting the magnetic interaction from a single-plane configuration to a two-plane configuration. The first and second disk-shaped magnets are arranged on different axial planes, with their magnetic poles facing each other across the axial gap. This dimensional transition allows the repulsive force to act primarily in the radial direction while the axial offset prevents magnetic flux line curvature from causing instability, as the magnetic fields interact in a more controlled three-dimensional geometry.
Solution Approach 2:
The patent employs disk-shaped magnets with curved surfaces instead of flat planar magnets. The curved surfaces of the first and second disk-shaped magnets are positioned to face each other, creating a more uniform magnetic flux distribution. This curvature modification reduces the instability caused by magnetic flux line bending in planar configurations, allowing strong repulsive forces to be generated while maintaining axial stability through the inherent geometric symmetry of the curved surfaces.
2Loss of energy
If non-contact type bearings are used to reduce energy loss, then friction is reduced, but axial direction friction may be generated due to misalignment
Solution Approach 1:
The patent eliminates axial friction by transitioning from a single-plane magnetic bearing configuration to a dual-plane configuration. The first and second disk-shaped magnets are positioned on different axial planes, creating a magnetic field interaction that provides stable support in both radial and axial directions. This dimensional change ensures that the repulsive magnetic force acts primarily in the radial direction while the axial separation prevents flux line curvature from causing misalignment and subsequent axial friction, maintaining the non-contact support benefit.
3Use of energy by moving object
If magnetic bearings using permanent magnets are used, then electric power consumption is reduced, but repulsion point instability occurs due to curved magnetic flux lines
Solution Approach 1:
The patent maintains the energy efficiency of permanent magnet bearings while resolving stability issues by arranging the first and second disk-shaped magnets on different axial planes. This three-dimensional configuration allows the magnetic fields to interact in a manner that produces stable repulsive forces without the misalignment problems of single-plane arrangements. The axial separation between the magnet planes creates a more stable magnetic equilibrium point, eliminating the need for electric power consumption while maintaining repulsion point stability.
Solution Approach 2:
The patent uses curved surfaces on the disk-shaped magnets to improve magnetic flux distribution and stabilize the repulsion point. The curved surfaces of the first and second disk-shaped magnets face each other across the axial gap, creating a more uniform magnetic field interaction. This curvature modification reduces the instability caused by magnetic flux line bending in flat configurations, allowing permanent magnets to provide stable support without requiring external power input.
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 flywheel device maintains stable rotation with reduced friction, ensuring prolonged rotational energy retention by balancing magnetic forces without complex control, integrating size reduction and extended energy maintenance.
Implementation Method 1
the inner cylindrical members are formed by continuous inner magnets in a circumference direction, having magnetic poles on outer peripheral surfaces thereof; the outer cylindrical members having outer magnets that face the inner magnets with the same polarity facing each other; the rotation shaft is rotatably supported with respect to the support body in a non-contact manner due to repulsive force between the inner magnets and the outer magnets
Data Source
AI summary
A flywheel device including a support body, a rotation shaft, a pair of disk members spaced apart from each other, a pair of inner cylindrical members that are connected to outer circumferences of the disk members, respectively, and a pair of outer cylindrical members that are arranged to the support body. The inner cylindrical members are formed by continuous inner magnets in a circumference direction, having magnetic poles on outer peripheral surfaces thereof. The outer cylindrical members has outer magnets that face the inner magnets with the same polarity facing each other. The rotation shaft is rotatably supported with respect to the support body in a non-contact manner due to repulsive force between the inner magnets and the outer magnets, and centers of widths of the inner magnets in an axis direction are offset from centers of widths of the outer magnets in the axis direction.