Bearing Raceway Flaking Analysis with Dynamic Load Prediction
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Solution Overview
Problem
Existing methods for predicting bearing raceway flaking propagation in large bearings like those used in wind turbine generators suffer from inaccuracies due to assumptions about initial flaking dimensions and neglecting shape changes during operation, leading to potential underestimation or overestimation of flaking propagation rates.
Innovation Solution
A method and device that analyze the shape and progression of flaking in rolling bearings by calculating rolling element loads and surface pressures using dynamic FEM analysis, considering the escape of rolling elements and concentrated surface pressures to accurately predict flaking propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the axial width of the initial flaking is assumed to be equal to the axial length of the rolling element, then the prediction process is simplified, but the prediction accuracy decreases
Solution Approach 1:
The invention changes the parameter representation from assuming axial width equals axial length to using actual measured flaking dimensions (axial width, radial depth, circumferential length) that evolve over time. This allows the model to capture the real shape changes of flaking during propagation while maintaining computational feasibility through systematic parameter tracking.
Solution Approach 2:
The invention transitions from a static assumption of flaking dimensions to a dynamic model where flaking shape parameters (axial width, radial depth, circumferential length) change over time. The model updates these parameters at each time step based on propagation rates, capturing the evolving geometry of flaking as it progresses through the bearing operation.
2Device complexity
If the shape of the flaking that changes during operation is not considered, then the prediction model is simpler, but an error occurs in prediction on propagation rate of the flaking
Solution Approach 1:
The invention implements a dynamic flaking shape model where axial width, radial depth, and circumferential length are updated at each time step. The propagation rate calculations incorporate these changing dimensions, particularly how the escape amount of rolling elements varies with flaking shape, leading to more reliable propagation rate predictions.
Solution Approach 2:
The invention performs preliminary measurements or estimations of initial flaking shape parameters (axial width, radial depth, circumferential length) before propagation begins. These initial parameters serve as the baseline for subsequent propagation calculations, allowing the model to track shape evolution from the onset of flaking.
3Device complexity
If the escape amount of the rolling element in axial direction is not considered, then the calculation is simpler, but the surface pressure derivation becomes inaccurate
Solution Approach 1:
The invention introduces the escape amount parameter that varies with flaking shape and incorporates it into the surface pressure calculation. As flaking progresses and its shape changes, the escape amount changes accordingly, and this dynamic parameter is used to derive accurate surface pressure values at each time step.
Solution Approach 2:
The invention uses the escape amount of rolling elements as an intermediary parameter that connects flaking shape to surface pressure. The escape amount serves as a mediator that translates the geometric changes of flaking into the mechanical loading conditions, enabling accurate surface pressure derivation without direct measurement.
Data Source
Figure 1
Figure 2A~2E
Figure 3~4B
AI summary
This flaking development analysis method involves: acquiring the presence or absence of flaking of a raceway ring and the shape of a flaked portion; calculating a rolling element load acting on a rolling element, in consideration of progression in the shape of the flaked portion, when the rolling element passes an exit portion of the flaked portion of the raceway ring, on the basis, at least, of the acquired shape of the flaked portion, the specifications of a rolling bearing, and the operating conditions of the rolling bearing; calculating a speed of development of flaking in consideration of progression in the shape of the flaked portion, on the basis of the rolling element load at the exit portion of the flaked portion; and calculating a relationship between elapsed time and the shape of the flaked portion on the basis of the speed of development of flaking.