Magnetic Levitation Vacuum Pump Signal Resolution Control
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Solution Overview
Problem
Magnetic levitation vacuum pumps face challenges with vibration and noise due to rotor imbalance and whirling displacement, particularly in applications like electron microscopes and semiconductor manufacturing, where high-resolution and quiet operation are critical. Existing solutions, such as switching between high-resolution and low-resolution displacement signals, suffer from chattering and limited vibration reduction performance.
Innovation Solution
A magnetic bearing vacuum pump system that includes a first displacement signal generation section for amplifying rotor displacement signals to generate high-resolution signals, a second section for generating low-resolution signals, and a selection mechanism to choose between these based on unsteady-state response signals, with a resolution multiplying factor that can be adjusted according to the steady-state whirling radius, to optimize control and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If switching between high-resolution and low-resolution displacement signals is implemented, then measurement precision is improved, but device complexity increases and chattering occurs
Solution Approach 1:
The patent implements dynamic switching between high-resolution and low-resolution signal processing modes based on the magnitude of rotor displacement. When displacement exceeds a threshold, the system switches to low-resolution mode to prevent overflow; otherwise, it uses high-resolution mode for precise control. This dynamic adaptation resolves the contradiction by adjusting processing complexity according to actual operational needs.
Solution Approach 2:
The patent changes the resolution parameter of the displacement signal processing system based on operational conditions. By adjusting the signal processing path (high-resolution vs. low-resolution) according to displacement magnitude, the system optimizes measurement precision while avoiding the complexities and instability associated with continuous high-resolution processing under all conditions.
2Stability of the object's composition
If threshold hysteresis is provided to prevent chattering, then stability is improved, but resolution improvement is limited in the high-resolution region
Solution Approach 1:
The patent segments the displacement signal processing into distinct regions: a high-resolution region for small displacements and a low-resolution region for large displacements. By dividing the operating range and assigning different processing modes to different segments, the system achieves both high resolution when needed and stability when switching, avoiding the chattering problem while maintaining precision in the appropriate operating range.
3Measurement precision
If high-resolution signal processing is used continuously, then measurement precision is improved, but vibration and noise increase due to chattering
Solution Approach 1:
The patent dynamically adjusts the signal processing resolution based on displacement magnitude. By switching to low-resolution processing when displacement exceeds the high-resolution region threshold, the system eliminates the chattering that would otherwise occur during mode transitions, thereby reducing vibration and noise while maintaining high measurement precision during stable operation in the high-resolution region.
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 effectively reduces vibration and noise by improving resolution and control adaptability, preventing chattering and enhancing the pump's performance in maintaining stable operation even with increased whirling displacements.
Implementation Method 1
a magnetic bearing configured to magnetically levitate a rotor
Data Source
AI summary
A magnetic bearing vacuum pump comprises: a first displacement signal generation section configured to amplify, by a resolution multiplying factor K of K>1, a displacement modulated wave signal modulated according to a displacement of the rotor from a predetermined position to generate a high-resolution displacement signal in a first displacement region including the predetermined position; a second displacement signal generation section configured to generate a low-resolution displacement signal in a larger second displacement region including the first displacement region; a selection section configured to select either one of the high-resolution displacement signal or the low-resolution displacement signal based on an unsteady-state response signal obtained by excluding a steady-state whirling displacement component from the high-resolution displacement signal or the low-resolution displacement signal; and a bearing control section configured to control the magnetic bearing based on the displacement signal selected by the selection section.