Kinematic Coupling for Electron Beam Gun Alignment

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Solution Overview

Problem

Current high power RF electron beam guns face issues with reproducibility and efficiency due to material variations and mechanical alignment precision, particularly in gyrotrons, where velocity spread and frequency deviation are significant, limiting the consistency and performance of devices.

Innovation Solution

The implementation of a kinematic coupling with convex ceramic elements and a high temperature active metal brazing alloy for direct metal-to-ceramic bonding, creating a deterministic interface that withstands high temperature and vacuum conditions, enabling precise and repeatable alignment of electron beam device components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional assembly techniques with pinned joints and manual alignment are used, then ease of manufacture is improved, but manufacturing precision deteriorates due to clearances and tolerances limiting alignment precision

Engineering Contradiction:
Improveease of assemblyVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces conventional pinned joints with magnetic coupling mechanisms. Magnets embedded in alignment features provide automatic alignment and holding forces, eliminating the need for mechanical pins and manual adjustment. This substitution achieves sub-micron alignment precision while maintaining ease of assembly through automatic magnet-based coupling.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the alignment mechanism from mechanical contact with clearances to magnetic field interaction. By using magnetic coupling, the system achieves contactless alignment with precision beyond conventional mechanical tolerances, transforming the alignment parameter from micrometer-level mechanical fit to sub-micron magnetic field control.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If clearance is provided between parts for assembly, then ease of manufacture is improved, but manufacturing precision deteriorates due to inherent limitation in achievable precision

Engineering Contradiction:
Improveease of assemblyVSAvoidposition precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical clearance-based assembly with magnetic coupling. Magnets provide holding force without physical contact, eliminating the need for assembly clearances. This allows parts to be positioned with sub-micron precision while maintaining ease of assembly through automatic magnetic attraction and alignment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If conventional alignment pins with oblong and triangular features are used, then ease of manufacture is improved, but manufacturing precision deteriorates due to moderate complexity and variation in fabrication

Engineering Contradiction:
Improveease of alignmentVSAvoidalignment repeatability
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces complex mechanical alignment pins with magnetic coupling mechanisms. Embedded magnets automatically align components through magnetic attraction, eliminating the need for manually configured alignment pins. This achieves superior alignment repeatability while maintaining ease of manufacture through standardized magnetic component integration.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If machining tolerances of ±.0005 in. are applied to alignment bores, then ease of manufacture is improved, but manufacturing precision deteriorates due to failure to achieve sub-micron precision

Engineering Contradiction:
Improveease of machiningVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces precision-machined alignment bores with magnetic coupling mechanisms. Instead of requiring sub-micron machined holes, magnets embedded in alignment features provide automatic positioning. This maintains ease of machining with standard tolerances while achieving sub-micron alignment precision through magnetic field control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution achieves high precision and repeatability in electron beam alignment, reducing velocity spread and improving device efficiency, while being compatible with ultrahigh vacuum and high temperature environments, thus enhancing the reproducibility and performance of high power RF vacuum devices.

Implementation Method 1

convex ceramic elements composed of silicon nitride or silicon carbide directly bonded to the first component using a high temperature active metal brazing alloy

Methodology Applied
Scientific EffectBrazing: Brazing

Data Source

PatentEP3394875B1Electron beam gun with kinematic coupling for high power RF vacuum devices
Publication Date: 2020.03.25 DYMENSO LLC
  • EP3394875B1 patent drawingFigure 1A~1C
  • EP3394875B1 patent drawingFigure 2A~2B
  • EP3394875B1 patent drawingFigure 3A~3B

AI summary

An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling [8a] to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling [8a] has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves [9] in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode [6, 7] to a gun stem [10], which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.