Dataset of Vibration, Temperature and Speed Measurements for Multiple Types of Localized Defects on Spherical Roller Bearings across Multiple Operating Conditions

Description:

This dataset has been created by the ISED group of Politecnico di Torino to address the lack of data available for developing fault detection models and/or predictive maintenance systems for medium/large-sized spherical roller bearings, commonly used in industrial settings.

The data were collected using SKF 22240 CCK/W33 spherical roller bearings through an extensive experimental campaign on the medium/large-scale bearing test rig (capable of testing bearings with an outer diameter up to 420 mm), developed by the ISED research group at Politecnico di Torino (ISED Research Group). The technical details of the test rig can be found in this Paper.

The dataset contains data for individual localized defects applied to one of the four bearings tested simultaneously on the rig, which is capable of independently applying both axial and radial loads.

Dataset Structure:

The dataset is organized into four folders:

• Undamaged
• InnerRaceDamage
• OuterRaceDamage
• RollerDamage

The Undamaged folder contains data for all bearings in healthy condition. The other folders contain data from tests where one of the bearings presents a localized defect. The defects, introduced by chip removal, have a diameter of 2 mm and a depth of 0.5 mm, affecting either the inner race (IR), outer race (OR), or roller elements (B). More detailed information about the defect geometry and location can be found in the following publications:

• Intelligent Fault Diagnosis of Industrial Bearings Using Transfer Learning and CNNs Pre-Trained for Audio Classification
• Explainable AI for Machine Fault Diagnosis: Understanding Features’ Contribution in Machine Learning Models for Industrial Condition Monitoring
• Zero-Shot Generative AI for Rotating Machinery Fault Diagnosis: Synthesizing Highly Realistic Training Data via Cycle-Consistent Adversarial Networks

Each folder contains .mat files named according to the following format:

(Nominal_Rotation_Speed)rpm_(Radial_Force)kN_(Axial_Force)kN.mat

Where:

• Nominal_Rotation_Speed is the machine's nominal rotational speed
• Radial_Force is the radial force applied to the bearing
• Axial_Force is the axial force applied to the bearing

The dataset includes measurements from 10 different nominal rotation speeds and four load conditions, one of which includes an axial load. In some cases, "ramp" files are included, containing data where the rotational speed was linearly varied during the test.

Each .mat file contains multiple structures, depending on the type of test. Each structure is labeled as Signal_ followed by a number (0, 1, 2, 3, 4), where each represents a specific signal extracted during the test. There is no fixed correspondence between the signal number and the type of measurement. For example, Signal_2 does not always represent the accelerometer signal. Users are encouraged to inspect the y_values.quantity field to identify the signal's unit and nature. For instance, if y_values.quantity.label shows "g", the signal corresponds to an accelerometric measurement.

All signals have been exported using the MKS system, so y_values.values contains data in units of m/s² for acceleration signals. To convert the values to the unit indicated in y_values.quantity.label, users can apply the multiplication factor and offset provided in y_values.quantity.unit_transformation. In the case of accelerometric data, the multiplication factor is 0.1020, converting y_values.values from m/s² to g.

A more detailed description of the data structure can be found in the Test.Lab documentation.

In addition to acceleration data, the files include temperature signals, tacho sensor signals measuring shaft speed, and tacho impulse signals. In some cases, there is also a signal measured in "N", representing the frictional force generated by the bearings (as detailed in this Paper). This friction force signal is not always present, as the load cell could go into overload during certain tests.

Sensor Data Organization:

Acceleration and temperature data are presented in tables with four columns, each corresponding to one of the four bearings. In the damaged condition tests, the damaged bearing is always the one corresponding to sensor 4 (i.e., y_values.values(:, 4)).