Investigating Vibration Properties of a Planetary Gear Set with a Cracked Tooth in a Planet Gear

Abstract : Comparing with fixed shaft gearbox, vibration properties ofplanetary gearbox are much more complicated. In aplanetary gearbox, there are multiple vibration sources asseveral pairs of sun-planet gears and several pairs of ringplanetgears mesh simultaneously. In addition, the signaltransmission path changes due to the rotation of the carrier.To facilitate fault detection of a planetary gearbox and avoidcatastrophic consequences caused by gear failures, it isessential to understand the vibration properties of aplanetary gearbox. This paper aims to simulate vibrationsignals and investigate vibration properties of a planetarygear set when there is a cracked tooth in a planet gear.Displacement signals of the sun gear and the planet gear,and resultant acceleration signals of the whole planetarygear set will be simulated and investigated. Previous workmainly focuses on the vibration properties of a singlecomponent, like the sun gear, the planet gear or the carrier.This paper simulated the vibration signal of a wholeplanetary gear set when there is a cracked tooth in a planetgear. In addition, fault symptoms will be revealed, whichcan be utilized to detect the crack in the planet gear. Finally,the proposed approach is experimentally validated.