Analysis of lathe vibration severity level based on spindle rotation speed variations referring to the ISO 20816-3 standard

Abstract

Vibration is an important parameter in monitoring machine condition because each rotating component produces a certain vibration pattern. Vibration frequency can identify mechanical damage before it develops into more serious damage. This study aims to analyse the vibration severity of the Weiler Gedee lathe, which is categorised as group 2 with a nominal power of more than 15 kW to 300 kW, using the ISO 20816-3 standard to evaluate machine condition. The research uses an experimental method to measure vibration with a vibration meter; the values ​​obtained represent the maximum values ​​in the horizontal, vertical, and axial directions. The rotation speeds used are 60 rpm, 120 rpm, 330 rpm, 450 rpm, 660 rpm, and 900 rpm. The average vibration values ​​obtained are 0.55 mm/s, 0.98 mm/s, 1.87 mm/s, 2.11 mm/s, 3.63 mm/s, and 5.32 mm/s. Based on the ISO 20816-3 classification, the condition of the machine at 60-120 rpm is in zone A which means very good, 330–450 rpm is in zone B which is still suitable for operation, at 660 rpm it has entered zone C which indicates a warning condition for long-term operation, while at 900 rpm the highest vibration value is obtained which is in the dangerous zone D. It can be concluded that the vibration level of the machine is influenced by variations in spindle rotation and the higher the rotation, the greater the measured vibration level.