Analysis of middle bearing failure in rotor jet engine using tip-timing and tip-clearance techniques

• Published in: Mechanical systems and signal processing Vol. 76-77; pp. 213 - 227
• Main Authors: Rzadkowski, R., Rokicki, E., Piechowski, L., Szczepanik, R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-08-2016
• Subjects: Aerospace engines; Aircraft; Aircraft engine; Bearing; Blades; Failure; Gas turbine engines; Mechanical systems; Rotors; Tip-clearance; Tip-timing; foi; BTT; fi; VAR; Ai; φij; EO; fr; n; Tip-timing; Bearing; ϕI; xik; Aircraft engine; Tip-clearance; FE; ts
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2016.01.014

The reported problem is the failure of the middle bearing in an aircraft rotor engine. Tip-timing and tip-clearance and variance analyses are carried out on a compressor rotor blade in the seventh stage above the middle bearing. The experimental analyses concern both an aircraft engine with a middle bearing in good working order and an engine with a damaged middle bearing. A numerical analysis of seventh stage blade free vibration is conducted to explain the experimental results. This appears to be an effective method of predicting middle bearing failure. The results show that variance first increases in the initial stages of bearing failure, but then starts to decrease and stabilize, and then again decrease shortly before complete bearing failure.
•In this paper we proposed new methods to diagnose the middle bearing failure of aircraft engine using the tip-timing and tip-clearance methods.•The reported problem is the failure of the middle bearing in an aircraft rotor engine. Tip-timing and tip-clearance and variance analyses are carried out on a compressor rotor blade in the seventh stage above the middle bearing. The experimental analyses concern both an aircraft engine with a middle bearing in good working order and an engine with a damaged middle bearing and was carried out in the Air Force Institute in Warsaw.•The original contribution of this paper is a methodology of assessing bearing health using tip-timing, tip-clearance and variance techniques.