Rotary Shaft Radial Deformation Estimation Across Speed States
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Solution Overview
Problem
Existing methods are inadequate for accurately measuring radial deformation of a rotary shaft under loaded conditions, particularly due to local irregularities and fluctuations in angular speed, which can lead to significant measurement errors and poor synchronization.
Innovation Solution
A method using displacement sensors to measure radial deformation by recording radial displacement at different angular speeds, applying harmonic analysis and differential techniques to compensate for local irregularities, and using a processor to estimate radial deformation with high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contactless sensors are used to measure radial displacement at high angular speed, then measurement capability under loaded conditions is improved, but measurement precision deteriorates due to local irregularities and angular speed fluctuations
Solution Approach 1:
The patent applies preliminary action by performing measurements at low angular speed first to establish a reference state before measuring at high angular speed. The low-speed measurement captures the basic shaft geometry and position, which is then used to compensate for irregularities in the high-speed measurement data. This sequential approach allows the system to account for local irregularities and speed fluctuations by comparing against the pre-established reference.
Solution Approach 2:
The patent implements feedback through an iterative compensation process where the measured radial displacement at high speed is continuously refined using the reference data from low speed. The system calculates the difference between high-speed and low-speed measurements, identifies deviations caused by local irregularities and speed variations, and applies corrections to improve the final deformation estimate. This feedback loop enhances measurement precision while maintaining the ability to measure under loaded conditions.
2Reliability
If measurements are taken at high angular speed to capture loaded condition deformation, then relevance to operational state is improved, but synchronization accuracy deteriorates due to angular speed fluctuations
Solution Approach 1:
The patent uses preliminary low-speed measurements to establish a reference trajectory and timing relationship before high-speed operation. This reference framework allows the system to predict expected positions and compare them with actual high-speed measurements, thereby maintaining synchronization accuracy despite speed fluctuations during operational loading.
Solution Approach 2:
The patent applies parameter changes by varying the angular speed between two distinct states (low and high) to capture different deformation regimes. By measuring at low speed first to establish baseline parameters and then at high speed to capture operational deformation, the system can separate the effects of speed variation from actual deformation, maintaining synchronization accuracy while measuring relevant operational states.
3Measurement precision
If reference runs at low angular speed are performed to establish baseline measurements, then measurement stability is improved, but measurement time increases due to multiple measurement phases
Solution Approach 1:
The patent employs periodic action by structuring the measurement process into distinct phases: a low-speed reference phase followed by high-speed measurement phases. The low-speed phase is performed once to establish stable baseline data, after which multiple high-speed measurements can be rapidly acquired. This periodic structure minimizes the time penalty by limiting the slow measurements to only what is necessary for reference establishment.
Solution Approach 2:
The patent applies preliminary action by performing the time-consuming low-speed reference measurement only once before the actual high-speed measurements. The stable baseline data obtained from this preliminary phase is then reused for multiple high-speed measurement cycles, avoiding the need to repeatedly perform slow reference measurements and significantly reducing the total measurement time while maintaining baseline stability.
4Measurement precision
If multiple measurement phases (low speed reference and high speed deformation) are implemented, then measurement comprehensiveness is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by using a single contactless sensor system to perform multiple functions: measuring shaft position at low speed to establish reference, measuring radial displacement at high speed to capture deformation, and providing angular position data for synchronization. This multi-functional approach eliminates the need for separate measurement systems for each phase, reducing overall device complexity while maintaining comprehensive measurement capability.
Solution Approach 2:
The patent merges the reference measurement and deformation measurement functions into a unified measurement framework using the same contactless sensor and processing system. By combining the low-speed reference phase and high-speed deformation phase into a single integrated system rather than separate systems, the patent reduces device complexity while achieving comprehensive and accurate deformation estimation through the coordinated execution of multiple measurement phases.
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
Enables reliable detection of early non-ideal operation conditions in electric motors by accurately estimating radial deformation, even under dynamic loads, with a correlation coefficient of 0.99 between radial load and shaft displacement.
Implementation Method 1
a contactless displacement sensor (234) is fixed to the bearing housing (222) and is directed at the rotary shaft (290)
Implementation Method 2
a contactless zero-marker sensor, the distance measurements can be performed as a function of the angle
Data Source
Figure 1
Figure 2
Figure 3a~4
AI summary
A method of estimating a radial deformation of a rotary shaft (290) in a loaded condition, comprising: recording a first radial displacement of the shaft's surface while rotating the shaft at a first angular speed corresponding to a relaxed condition of the shaft; on the basis of the first radial displacement, providing a first shape description representing the shaft's cross section in the relaxed condition; recording a second radial displacement of the shaft's surface while rotating the shaft at a second angular speed corresponding to said loaded condition of the shaft; on the basis of the second radial displacement, providing a second shape description representing the shaft's cross section in the loaded condition; and determining the radial deformation as a difference of the first and second shape descriptions.