Rail Vehicle Axle Bearing Temperature Estimation via Thermal Conduction
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Solution Overview
Problem
Existing methods for monitoring the temperature of wheel set bearings in rail vehicles are structurally difficult and costly due to the need for direct mounting of temperature sensors in high-temperature zones, especially in multiple load zones within a bearing unit, which complicates mechanical connection and cabling.
Innovation Solution
A calculation model is used to estimate the temperature of wheel set bearings based on input variables such as speed and ambient temperature, with a correction element for calibration, allowing for precise temperature estimation without direct sensor mounting, using a component thermally connected to the bearing for measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are mounted directly on the wheel set bearing in high-temperature zones, then temperature measurement precision is improved, but device complexity and ease of manufacture deteriorate due to mechanical connection and cabling requirements
Solution Approach 1:
The patent introduces a sealing element as an intermediary component that thermally connects the bearing to the external environment. Temperature sensors are mounted on this sealing element rather than directly on the bearing, allowing indirect temperature measurement while simplifying installation and cabling requirements
Solution Approach 2:
The patent replaces direct mechanical mounting of temperature sensors on the bearing with a thermal conduction-based measurement system. By measuring temperature at the sealing element which is thermally coupled to the bearing, the complex mechanical connection and cabling requirements are eliminated
2Measurement precision
If temperature sensors are mounted directly on the wheel set bearing, then temperature measurement precision is improved, but ease of manufacture worsens due to structural difficulty in implementation
Solution Approach 1:
The sealing element serves as a mediator that provides both sealing functionality and thermal conduction path. Temperature sensors are mounted on this intermediary component which is already part of the bearing assembly, eliminating the need for separate mounting structures and simplifying manufacturing
Solution Approach 2:
The sealing element performs multiple functions: it provides mechanical sealing for the bearing and simultaneously serves as a mounting substrate for temperature sensors. This multi-functionality eliminates the need for separate sensor mounting structures, improving ease of manufacture
3Reliability
If multiple temperature sensors are mounted for double bearings, then measurement coverage is improved, but device complexity and cost increase due to additional mechanical connection and cabling
Solution Approach 1:
The sealing element is designed to accommodate multiple temperature sensors for monitoring both bearings in a double bearing arrangement. This universal mounting structure allows comprehensive monitoring coverage while maintaining simple installation and cabling requirements
Solution Approach 2:
The patent combines the sealing function with the sensor mounting function in a single integrated sealing element. This merging of functions allows multiple sensors to be mounted on one component rather than requiring separate mounting structures for each sensor, reducing overall device complexity
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 method provides precise temperature estimation with reduced signal-processing expenditure, avoiding incorrect fault detection and enabling monitoring of wheel set bearings and adjacent brake states, while simplifying sensor installation and cabling by using a thermally connected component for measurement.
Implementation Method 1
The calculation model is based on modeling of thermal capacities of components of the wheel set or of the wheel set bearing, the conduction of heat in components of the wheel set or of the wheel set bearing
Implementation Method 2
the heat transfer resistances between components of the wheel set or of the wheel set bearing and the forced convection brought about by the speed of the rail vehicle
Implementation Method 3
The temperature of a component of the wheel set, which is different from the wheel set bearing but is directly or indirectly connected to the wheel set bearing in a thermally conductive manner, is measured during operation as a measured temperature
Data Source
AI summary
A method for estimating the temperature (TB, est) of a wheel bearing of a wheelset of a rail vehicle by means of a calculation model (Tbearingestimator). The calculation model (Tbearing,estimator) estimates the temperature of the axle bearing, according to the speed (vtrain) and the ambient temperature (Tamb) of the rail vehicle as input variables of the calculation model (Tbearing estimator), and the temperature of a component of the wheelset, different from the axle bearing but directly or indirectly connected to the axle bearing in a heat-conducting manner, is measured as the measuring temperature (Tmeas) during operation. The temperature of the component different from the axle bearing is estimated by means of the calculation model (Tbearingestimator) as the estimated temperature (Tmeas,est). In order to improve the accuracy of the calculation model (Tbearingestimator) in terms of the estimation of the temperature (TB,est) of the axle bearing, the calculation model (Tbearingestimator) has a corrective element (Kb) that is used to continuously, temporarily or cyclically calibrate or adjust it on the basis of a comparison of the measuring temperature (Tmeas) with the estimated temperature (Tmeas,est).