Increasing the service life prediction accuracy of linear guideways considering real operating conditions

Abstract

The paper describes two novel calculation methods that can predict the service life of linear guideways more accurately than the conventional method. The first method is based on a linear damage accumulation in each rolling contact, which can take into account changing load cycles for a statistically based long-term remaining service life estimation. Since this statistically based estimation still has some inaccuracies, a second method is proposed that uses a dynamic simulation model of the linear guideway to perform a model-based condition monitoring. With this method, a more accurate damage-based prediction of the remaining useful service life can be made in the short term. The dynamic model takes into account both the elasticity of the Hertzian rolling contact and the elasticities of the carriage and rail depending on the dynamic rolling element circulation. The model also includes a simplified pitting model which allows the actual pitting size to be calculated by comparing the simulated vibration behaviour with the measured vibration behaviour. The calculated pitting propagation velocity is used to estimate the remaining useful service life.