Magnetic Bearing Rotary Assembly for Stable Rotor Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic bearings in rotary assemblies face instability due to varying repulsive forces and sensitivity to resonance, leading to misalignment and inaccurate measurements, especially in applications requiring precise oscillations.
Innovation Solution
A rotary assembly with a magnetic bearing using spherical magnets and axial retaining means, where the magnetic elements are configured to attract each other, maximizing the return force and stability, and allowing for easy adjustment and replacement of parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repulsive toroidal magnets are used in the magnetic bearing, then the rotor can be retained in the axis during rotation without mechanical friction, but the retaining precision is reduced and the rotor becomes unstable when moving away from the centered position
Solution Approach 1:
The patent inverts the magnetic interaction principle from repulsion to attraction. Instead of using repulsive toroidal magnets that push the rotor away from the stator, the invention uses attractive magnets that pull the rotor toward a centered position. This inversion transforms the unstable repulsive force into a stable attractive force that automatically centers the rotor, solving both the retention stability and positioning precision problems simultaneously.
2Loss of energy
If the rotor is retained by axial retaining means with toroidal magnets, then mechanical friction is eliminated, but the assembly becomes sensitive to resonance at medium to high rotation speeds
Solution Approach 1:
The patent changes the magnetic interaction parameter from repulsive to attractive, which fundamentally alters the dynamic characteristics of the system. The attractive magnetic force creates a restoring force that counteracts resonant oscillations at medium to high rotation speeds, thereby reducing resonance sensitivity while maintaining the frictionless operation achieved by the magnetic bearing.
3Reliability
If toroidal magnets are used in the magnetic bearing, then the rotor can be retained without mechanical contact, but the parts cannot be easily changed or replaced
Solution Approach 1:
The patent segments the magnetic bearing into modular components, with the rotor and stator magnets as separate replaceable parts. This segmentation allows the magnets to be independently accessed and replaced without disassembling the entire bearing assembly, maintaining the frictionless magnetic operation while significantly improving ease of repair and part replacement.
4Loss of energy
If repulsive magnetic force is used to retain the rotor, then the rotor can rotate without mechanical friction, but the return force decreases when the rotor is centered, creating an unstable position
Solution Approach 1:
The patent inverts the magnetic force direction from repulsive to attractive. The attractive magnetic force creates a stable equilibrium where the maximum return force occurs when the rotor is centered, rather than when it is displaced. This inversion transforms the unstable repulsive system into a stable attractive system that automatically returns the rotor to the centered position, eliminating the instability problem while preserving frictionless operation.
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 stable and precise retention of the rotor in the axis of rotation, minimizing misalignment and resonance issues, enabling accurate measurements and simplified maintenance.
Implementation Method 1
the elements made of magnetic material are configured to attract each other, so as to generate a return force which opposes the axial misalignment of said rotor
Data Source
AI summary
The present invention relates to a rotary assembly (1), in particular for a rheological measurement apparatus, comprising:a stator (3),a rotor (2) that can rotate with respect to the stator (3), the rotor (2) being axially retained by an axial retaining means (4) preventing the movement of the rotor (2) along the axis of rotation (A) thereof, the axial retaining means (4) comprising a flexible rod suitable for being attached to a frame (5) and which allows a radial movement of the rotor (2),a magnetic bearing comprising a rotor element (6) made of magnetic material mounted on the rotor (2) and a stator element (7) made of magnetic material mounted on the stator (3), at least one of the rotor and stator elements made of magnetic material being a spherical magnet,wherein the rotary assembly (1) has a stable position in which the rotor (2) is aligned with the axis of rotation (A) thereof, and the elements made of magnetic material are facing each other along the axis of rotation (A) of the rotor and are separated from each other by a given distance (M), and wherein the elements made of magnetic material are configured to attract each other, so as to generate a return force which opposes the axial misalignment of said rotor (2).The invention also relates to a rheological measurement apparatus comprising at least one such rotary assembly (1).