TECHNICAL FIELD

The present disclosure generally relates to debris (particle) detection systems, including liquid debris (particle) detection systems that may include a fiber optic sensor and which may be used to detect non-metals.

BACKGROUND

This background description is set forth below for the purpose of providing context only. Therefore, any aspect of this background description, to the extent that it does not otherwise qualify as prior art, is neither expressly nor impliedly admitted as prior art against the instant disclosure.

Debris monitoring systems can, for example, be used to detect the presence of wear particles in lubricating oils that may be transferred from the oil-wetted surfaces of gears and bearing under mechanical distress. Automatic debris monitoring is often preferred from a maintenance perspective, as it may eliminate the need for certain routine inspections and may preempt the potential failure should an issue advance faster than an inspection interval. With a number of applications the aerospace industry is trending towards “on-condition” maintenance—meaning the Line Replaceable Unit (LRU) should not require routine maintenance or inspections, and preferably will fail “soft” (i.e., the LRU will signal when it needs calibration or service, while maintaining some level of degraded operability).

There are two general classes of debris monitors: (1) capturing and (2) flow-through. Capturing sensors may, for example, employ a high-strength magnet to attract particles and detects particles via inductive principles. The particles can then be inspected and further tested to determine if they are representative of gear or bearing steel, or if they are nuisance debris. A potential challenge with capturing type sensors is that the build-up of particles may affect the accuracy of size discrimination and eventually the sensor could become “saturated” and unresponsive to additional particle captures, and may therefore require routine maintenance.

Flow-through debris monitors generally work on the principle of induction and may respond to both ferrous and non-ferrous debris. Since flow-through debris monitors do not capture particles they generally do not require routine maintenance. However, particle inspections are not necessarily a feature or capability.

Moreover, with the introduction of hybrid bearings (e.g., steel races with ceramic rolling elements), there is currently a need for the detection of non-metals in the aerospace industry.

That is, hybrid bearings are now in use in many industries. Hybrid bearing have many important features or qualities that can improve engine efficiencies. Among other things, employing hybrid bearings may provide lower weight, higher DN speeds (bearing diameter times operating speed), higher temperature operation, less dependence on lubrication, and lower centrifugal forces (due to lighter weight), which may permit their operation at higher speeds.

However, the deployment of hybrid bearings may, among other things, require a viable technology that may need to be approved for various applications (such as flight), and that can detect non-metals.

Consequently, there is a desire for solutions/options that address one or more of the aforementioned challenges. The foregoing discussion is intended only to illustrate examples of the present field and should not be taken as a disavowal of scope.

SUMMARY

A debris (particle) detection system includes a chamber configured to permit debris (particles) to pass through the chamber; an optical fiber providing a light path; a collimator configured to channel light from the light path into the chamber; and a reflector configured to reflect light back to the collimator for signal detection. In embodiments, the reflector may include a mirror. Methods for detecting particles and information and/or parameters associated with particles within the chamber via reflected light are disclosed, including, inter alia, methods for detecting particle size by measuring reflected light within the chamber light signal amplitude blocked by individual particulates.

The foregoing and other aspects, features, details, utilities, and/or advantages of embodiments of the present disclosure will be apparent from reading the following description, and from reviewing the accompanying drawings.

