Influences of abrasive particles on tribological behaviours of rotary vane steering gear seals under oil

Abstract

The wear particles often cause the abnormal wear processes to the rotary vane seals, which lead to seals failure and dropping hydraulic oil pressure, and eventually result in losing of the function of rotary vane steering gear. Clarifying the friction and wear mechanisms between the vane seals and the cylinders and extracting their key wear characteristics are the keys to extend the service life and realize intelligent fault diagnosis of the rotary vane steering gears. Different kinds of hydraulic oils mixed up with different sizes of iron particles were chosen to investigate the abrasive particles on the wear behaviours between the polyurethane polymer and carbon steel specimens. The wear characteristics such as coefficients of friction (COF), wear morphologies, frictional-induced vibration signals were examined and analyzed synthetically. The results showed that the coefficients of friction, wear morphologies, surface roughnesses and vibration signals increased as a function of the iron particle sizes, which indicated that the wear state was gradually worsening. The three-body friction and wear mechanisms were disclosed clearly. There was a certain mapping relationship between the wear characteristics and wear states, and sensing the tribological information between the rubbing pairs, including coefficient of friction, abrasive particle size in hydraulic oil, wear morphology, vibration signal and other characteristics, was a potential and effective way for evaluating or predicting the wear states or failure modes of rotary vane steering gear seals. This study provides a theoretical basis for revealing the friction and wear mechanisms of ship rotary vane steering gear seals, and is useful for accomplishing their intelligent monitoring and fault diagnosis.