Magnetron Vane Height Optimization for Load Stability
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Solution Overview
Problem
Magnetrons used in microwave ovens face challenges in achieving high efficiency and load stability while maintaining cost-effectiveness, as reducing the anode cylinder size to narrow the magnetic field gap compromises oscillation stability.
Innovation Solution
The magnetron design includes specific gap configurations between the end hats, vanes, and pole pieces, with conditional expressions to optimize magnetic flux density and electric field distribution, ensuring improved load stability and efficiency without increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the anode cylinder size is reduced to narrow the magnetic field gap, then magnetic field intensity is enhanced and efficiency is improved, but oscillation stability (load stability) deteriorates
Solution Approach 1:
The patent applies different gap configurations to different regions of the magnetron structure. Specifically, the gap between the input side end hat and input side end of vane (IPevg) is set to be larger than the gap between output side end hat and output side end of vane (OPevg), satisfying IPevg > OPevg. Similarly, the pole piece-vane gaps are configured asymmetrically with IPpvg > OPpvg. This local differentiation allows optimization of magnetic field intensity in the electron interaction region while maintaining oscillation stability through asymmetric field distribution.
Solution Approach 2:
The patent optimizes specific dimensional parameters of the magnetron structure to resolve the contradiction. The gap between end hats (EHg) and vane height (Vh) are configured to satisfy the ratio condition 1.12 ≤ EHg/Vh ≤ 1.26. The asymmetric configuration of end hat-vane gaps and pole piece-vane gaps creates optimized magnetic flux density distribution that enhances efficiency while maintaining load stability, allowing smaller anode cylinder dimensions without sacrificing stability.
2Loss of energy
If the gap between end hats is reduced to improve magnetic field intensity, then efficiency is improved, but manufacturing complexity and cost control become more difficult
Solution Approach 1:
The patent defines specific parameter ranges for the gap configurations that balance performance and manufacturability. The ratio condition 1.12 ≤ EHg/Vh ≤ 1.26 provides a clear design guideline that achieves high efficiency while maintaining reasonable dimensions for manufacturing. The asymmetric gap configurations (IPevg > OPevg and IPpvg > OPpvg) are designed within practical manufacturing tolerances, avoiding overly complex or tight tolerance requirements that would increase cost.
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 optimized gap configurations enhance load stability and maintain high efficiency, allowing for the use of less expensive magnets while improving magnetic field intensity, thus achieving improved performance at reduced costs.
Implementation Method 1
magnets respectively disposed on the outside of the input side pole piece and the output side pole piece in the central axis direction
Implementation Method 2
In an electron interaction space surrounded by free ends of the plurality of vanes, a spiral cathode is disposed along the central axis of the anode cylinder
Data Source
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AI summary
To provide a magnetron improved in high efficiency and load stability while suppressing costs. By shortening the height of vane (Vh) so that the ratio of the height of vane (Vh) to a gap between end hats (EHg) (EHg/Vh) satisfies a condition 1.12≦ EHg/Vh≦1.26, an input side pole piece-vane gap (IPpvg) becomes larger than an output side pole piece-vane gap (OPpvg), and an input side end hat-vane gap (IPevg) becomes larger than an output side end hat-vane gap (OPevg), load stability at high efficiency can be improved while shortening the height of vane (Vh). Therefore, it is possible to provide a magnetron improved in high efficiency and load stability while suppressing costs.