Fault detection method and device for aircraft engine intermediate bearing

Abstract

The invention provides a fault detection method and device for an aircraft engine intermediate bearing. A low-voltage rotor and a high-voltage rotor in the detection device are mounted among three supporting frames; reflective paper patches are attached to a rotor shaft of the low-voltage rotor close to one end of a motor and a rotor shaft of the high-voltage rotor respectively. Two photoelectric sensors are utilized to collect rotational speed pulse signals, and an eddy current displacement sensor is utilized to collect vibration signals of the intermediate bearing; the problems that bearing fault characteristic frequency is poor in drift on a frequency spectrum and leptokurtosis can be well solved by determining fault characteristic frequency doubling, collecting the rotational speed pulse signals and original time domain vibration signals, obtaining zero phase position of an intermediate bearing slip domain, calculating a rotational speed-time function, converting original time-domain signals into intersection-angle-domain vibration signals and detecting the bearing fault through an envelope spectrum.

Description

technical field [0001] The invention relates to the field of fault diagnosis of aero-engines, in particular to a method for detecting faults of intermediary bearings of aero-engines under variable speed conditions. Background technique [0002] Modern aero-engines generally have a dual-rotor structure. In order to reduce the weight and simplify the structure, the intermediate bearing is usually used as the rear support of the high-pressure rotor, that is, the rear fulcrum of the high-pressure rotor is supported on the low-pressure shaft through the intermediate bearing. The outer ring of the intermediate bearing is installed on the high-pressure rotor, and the inner ring is installed on the low-pressure rotor; or the outer ring is installed on the low-pressure rotor, and the inner ring is installed on the high-pressure rotor, so it is called an intermediate bearing. The outer ring and the inner ring of the intermediate bearing rotate at the same time, and there are two mode...

AI Technical Summary

Problems solved by technology

However, this method is only applicable to conventional bearings with fixed outer ring and rotating inner ring, not applicable to intermediate bearings

In addition, the analysis data used in this method is a short-term sample, which has a large randomness in the diagnosis of bearing faults, and is not as accurate as the analysis data obtained from a long-term large sample.

[0005] The invention with patent publication number 103018043A discloses a fault diagnosis method for variable speed bearings, which introduces an analysis method for converting vibration signals from the time domain to the rotation angle domain, but this invention is not suitable for fault diagnosis of intermediate bearings

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