Comparative analysis of grease types on bearing performance: time-frequency and statistical investigations

Authors

• Nazik Jebur Mechanical Engineering Department, College of Engineering, Mustansiriyah University, Baghdad, Iraq https://orcid.org/0000-0002-1516-8223
• Wafa Abd Soud

DOI: https://doi.org/10.30678/fjt.157405

Keywords:

Lubrication, Vibration, Stability, Bearing Life, Performance

Abstract

This study focuses on evaluating the behavior of three commercially available lithium-based lubricating greases—77 EP (from 77 Lubricants), LGMP3 (AXCL Lubes), and LHTG3 (XADO)—when applied to journal bearings operating at low (600 RPM) and high (2400 RPM) speeds. The purpose is to understand how different grease types influence the vibration performance of bearings under dynamic conditions. The analysis includes both time-domain statistical indicators and vibration characteristics in the frequency domain. Measurements such as RMS, standard deviation, skewness, kurtosis, and variance were gathered using a real-time LabVIEW setup. These metrics helped in identifying differences in system response under each lubrication condition. The outcomes revealed that higher rotational speeds significantly amplified both vibration levels and system irregularities. This behavior demonstrates the critical impact of selecting the proper lubricant, particularly in fast-moving machinery. Among the samples tested, LHTG3 achieved the most consistent results, showing lower fluctuations in vibration readings, which implies effective damping properties. LGMP3, on the other hand, showed greater variability in its data, suggesting reduced vibration stability. Although 77 EP did not score highest in time-domain statistics, it performed strongly in frequency-based analysis, reducing the effect of sudden shocks and high-frequency responses Long-term performance could benefit from LHTG3; 77 EP would be preferable for machines with varying or fast dynamic loads. These results underline the need of choosing lubricant for stability and condition of journal bearings.