Rolling Bearing Strain Sensor Mount for Replaceable Piezo Sensing
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Solution Overview
Problem
Classically, strain sensors in rolling bearings are permanently bonded and cannot be replaced during service, limiting their effectiveness in condition monitoring and reliability prediction.
Innovation Solution
A piezoelectric strain sensor unit with a sensor holder featuring flexible arms and a central pin, which allows for three-point bending measurement, reducing parasitic stress and temperature influence, and enabling repeatable deformation measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a strain sensor is permanently bonded to the surface of the rolling bearing, then the sensor can measure deformation, but the sensor cannot be replaced in service
Solution Approach 1:
The sensor system is divided into two separate parts: a permanently mounted sensor holder attached to the rolling bearing, and a replaceable piezoelectric strain sensor that interfaces with the holder. This segmentation allows the sensor to be replaced during service while the mounting structure remains fixed, resolving the contradiction between measurement reliability and sensor replaceability.
2Measurement precision
If the piezoelectric strain sensor is supported by flexible arms, then parasitic stress and temperature influence are reduced, but the device complexity increases
Solution Approach 1:
The sensor holder employs flexible arms made of elastic material that support the piezoelectric strain sensor. These flexible arms act as compliant mounts that reduce parasitic stress and temperature influence on the sensor, improving measurement precision despite the increased structural complexity.
3Measurement precision
If the central pin axially abuts onto the piezoelectric strain sensor, then three-point bending measurement is enabled, but stress concentration increases
Solution Approach 1:
The central pin is designed with a localized contact area that axially abuts onto the piezoelectric strain sensor at its center. This concentrated contact enables three-point bending measurement for accurate dynamic deformation detection, while the pin's geometry is optimized to minimize stress concentration and protect the sensor from damage.
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
The solution provides accurate and repeatable measurement of dynamic deformation in rolling bearings, enhancing condition monitoring and reliability prediction without the need for sensor replacement.
Implementation Method 1
piezoelectric strain sensor
Implementation Method 2
The flexible arms act as leaf springs
Data Source
AI summary
A piezoelectric strain sensor unit for a rolling bearing includes a piezoelectric strain sensor, and a sensor holder provided with a main body having a front face intended to be into contact with a component of the rolling bearing and a rear face, and with at least two flexible arms mounted on the main body and supporting opposite ends of the piezoelectric strain sensor, the piezoelectric strain sensor being axially located on the side of the rear face of the main body while remaining spaced apart from the rear face. The sensor holder is provided with a central pin which protrudes axially with regard to the front face of the main body and which is axially moveable with regard the main body, the central pin axially abutting onto the piezoelectric strain sensor.