Continuous Permanent Magnet Forming for Dense Elongate Shapes
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Solution Overview
Problem
Existing permanent magnets are limited in size and require chemical bonding agents, which reduce magnetic material density and are difficult to magnetize, leading to inefficiencies and discontinuities in magnetic fields, making it challenging to produce elongate shapes with precise magnetic field configurations.
Innovation Solution
A method and apparatus for producing elongate permanent magnets by filling a tube with magnetic powder, applying a pre-aligning magnetic field, compressing, and forming into desired shapes without binding agents, enabling continuous magnetization with minimal discontinuities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If chemical bonding agents are used to bind magnetic particles together, then the magnets can hold their shape and be machined, but the magnetic material density is reduced
Solution Approach 1:
The invention extracts and eliminates the chemical bonding agents from the magnet manufacturing process. By using a binderless approach where magnetic particles are directly compacted and sintered, the patent removes the harmful substance (bonding agent) that was reducing magnetic material density, while still achieving structural integrity through the sintering process
Solution Approach 2:
The invention changes the manufacturing parameters from chemical bonding to thermal sintering. By controlling temperature, pressure, and atmosphere during the sintering process, the patent achieves both structural integrity and high magnetic material density without requiring chemical bonding agents
2Length of moving object
If prior art magnets are made larger, then they can reduce the number of magnets needed in electrical machines, but the magnetizing coil size becomes infeasible
Solution Approach 1:
The invention applies preliminary magnetization during the sintering process itself, rather than requiring a separate post-manufacturing magnetization step with large coils. By incorporating the magnetizing action into the manufacturing process, the patent enables production of large magnets without requiring infeasibly large magnetizing coils
Solution Approach 2:
The invention replaces the mechanical/electromagnetic system of large magnetizing coils with a field-based approach during sintering. By applying a magnetic field during the sintering process, the patent achieves magnetization of large magnets without requiring the large coil systems that would be needed for post-manufacturing magnetization
3Ease of manufacture
If discrete magnets are assembled to create electrical machines, then the magnets can be manufactured with existing processes, but assembly becomes extremely problematic due to magnetic forces
Solution Approach 1:
The invention merges multiple discrete magnets into a single integrated structure by eliminating the need for assembly. The binderless sintering process allows magnetic particles from what would have been separate magnets to be consolidated into one continuous magnet, thereby eliminating assembly operations and the associated magnetic force challenges
Solution Approach 2:
The invention extracts and eliminates the assembly step from the manufacturing process. By producing magnets as a single continuous sintered piece rather than assembling discrete units, the patent removes the assembly operation that was problematic due to magnetic forces acting on individual magnets during assembly
4Ease of manufacture
If discrete magnets are used in magnet arrays, then they can be manufactured separately, but discontinuities in the magnetic field occur at boundaries
Solution Approach 1:
The invention merges discrete magnetic units into a continuous sintered structure, eliminating the boundaries between magnets that cause field discontinuities. By producing a single integrated magnet or continuously sintered magnet array, the patent removes the interfaces where magnetic field discontinuities would occur
Solution Approach 2:
The invention achieves homogeneity in the magnetic structure by eliminating boundaries between discrete magnets. The binderless sintering process creates a uniform, continuous magnetic material with consistent properties throughout, removing the heterogeneity introduced by discrete magnet boundaries and their associated field discontinuities
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 approach allows for the creation of high-density, elongate magnets with precise magnetic field configurations, reducing assembly challenges and enhancing electrical machine efficiency by minimizing field discontinuities.
Implementation Method 1
subjecting the magnetic powder material to a pre-aligning magnetic field
Implementation Method 2
compressing the magnetic powder material in the tube
Data Source
AI summary
A method for continuous manufacture of permanent magnets. A material sheet is formed into an open tube, having a lengthwise opening. Magnetic powder may be poured into the lengthwise opening on a continuous basis. The tube opening is then formed closed and sealed. The magnetic powder is magnetically pre-aligned by subjecting it to a first magnetic field. The tube containing the powder may be compressed into a desired shape, forming an elongated permanent magnet. After compression, the elongated magnet is magnetized by a second magnetic field in two-step process, wherein the elongated permanent magnet is subjected to a magnetic field from first magnetizing coil that is pulsed with a first electric current in a first direction, followed by a second magnetizing coil being pulsed with a second magnetizing electric current in a second direction. The elongated magnet may be formed into any arbitrary shape, such as a ring or coil.