Educational Set-Up for Vibration Measurements in Vehicle Gearboxes

Abstract

In this paper we present a set-up specifically prepared for an educational application. The aim of the set-up is to build an educational tool for students of automotive engineering. The open test stand we used is equipped with two dynamometers and can accommodate various automotive gearboxes. The most common type of gearbox intended for transversal powertrain placement in small and midsize vehicles was chosen as the test gearbox. At our disposal we had two identical and completely new gearboxes provided by a car manufacturer. The differential of the gearbox was blocked. The total power is taken-off from one side only. In one gearbox two artificial faults were introduced: • An orthogonal placed groove on the inner race with the initial width of 1 mm. The damaged bearing is a roller bearing located on the gearbox input shaft – on the clutch side. • Pitting defect ground on the teeth sides of the IV th speed. The mounting base of the test stand allows easy changing of the gearboxes. During the student training, the new undamaged gearbox is first measured. After completion of signal measurement and analysing by means of FFT, Order and Envelope analysis, the gearbox is changed for the damaged one. After measurements under the same conditions, the same type of analysis of the measured signal is performed. The students have to identify the type of damage(s) present in the damaged gearbox.