Bearing Load Estimation from Rotor Speed and Angular Acceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Determining the loading of bearings in electrical machines is challenging, especially for those with varying rotational speeds, leading to frequent and often unnecessary maintenance, and excessive lubrication can cause thermal overload and failure.
Innovation Solution
A method involving determining rotational speed and angular acceleration of the rotor, assigning matrix elements to corresponding ranges, and calculating bearing loading as a weighted sum of these elements, allowing for timely maintenance planning and avoiding over-lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequent maintenance and relubrication are performed, then bearing reliability is improved, but productivity deteriorates due to excessive maintenance work
Solution Approach 1:
The patent replaces mechanical monitoring methods with electrical measurement systems. Current sensors and evaluation circuits continuously monitor the electrical characteristics of the bearing to detect loading conditions and relubrication needs, eliminating the need for frequent manual inspections and maintenance interventions.
Solution Approach 2:
The patent implements a feedback system where the evaluation circuit continuously monitors bearing current characteristics and provides information about loading conditions and relubrication needs. This feedback enables condition-based maintenance scheduling, allowing maintenance to be performed only when actually needed rather than on fixed schedules.
2Reliability
If excessive lubricant is supplied, then bearing reliability is improved, but temperature increases causing harmful thermal effects
Solution Approach 1:
The patent replaces mechanical lubrication monitoring with electrical measurement methods. By analyzing the current flowing through the bearing, the system determines relubrication needs without physical inspection or lubricant quantity measurement, enabling precise control that prevents both under-lubrication and over-lubrication.
Solution Approach 2:
The patent changes the monitoring parameter from mechanical/physical to electrical. Instead of measuring lubricant quantity or temperature, the system measures electrical current characteristics that correlate with bearing loading and lubrication status, providing an indirect but accurate method to control lubrication levels.
3Loss of time
If bearing loading is not accurately determined, then maintenance planning becomes difficult, but frequent maintenance is performed unnecessarily
Solution Approach 1:
The patent replaces manual assessment methods with automated electrical measurement systems. Current sensors and evaluation circuits continuously monitor bearing conditions and automatically determine loading levels and relubrication timing, providing objective data for maintenance planning without requiring expert judgment or frequent manual inspections.
Solution Approach 2:
The patent enables the bearing monitoring system to automatically assess its own condition through electrical measurements. The evaluation circuit processes current signals to determine loading levels and relubrication needs without external intervention, providing self-diagnostic capability that improves maintenance planning efficiency.
Data Source
AI summary
In a method for determining loading of a bearing supporting a rotor of an electrical machine, the rotational speed and angular acceleration of the rotor is determined, matrix elements of a matrix are assigned to respective ranges of the angular acceleration and to respective ranges of the rotational speed, when the electrical machine is operated in a respective range of the angular acceleration and the rotational speed corresponding to the respective matrix element for a predefined time unit, an elementary variable, for example a value of 1, is added to the respective matrix element, and the loading of the bearing is determined as a weighted sum of the matrix elements. Thus, the matrix forms a representation of the operating time of the bearing and of the service life over time in relation to the rotational speeds and angular accelerations. The loading can be shown on a display.