Wear Debris In Oil Research Articles

A Highly Sensitive Wear Debris Sensor Based on Differential Detection

Wear debris in the oil contains a wealth of information about the friction pairs of the mechanical equipment. By analyzing the size and type of wear debris through oil detection technology, condition monitoring and fault diagnosis of mechanical systems can be realized. This paper presents an inductive sensor based on differential detection and its signal conditioning circuit, which can detect metal wear debris in the oil. The sensor adopts the structure of two induction coils embedded in one excitation coil. The differential signal is obtained by reverse connecting two induction coils with the same parameters, which can suppress the common mode interference and eliminate the influence of ambient noise so that the sensor has extremely low noise. Through the designed signal conditioning circuit, the detection signal is phase-sensitive detected, and the information of wear debris is extracted by amplification and filtering. In this paper, the sensing principle of the sensor is derived, the spacing between the two induction coils is optimized using finite element simulation, and the optimal excitation frequency, detection limit, and detection error of the sensor are investigated through experiments. The experiment results show that the sensor can detect 20 μm iron particles and 130 μm copper particles in a 2 mm flow channel, and the detection error of the sensor is less than 22%. The sensor has the advantages of simple structure and high sensitivity and can be applied to detect metal wear debris in hydraulic oil.

High-sensitivity distinguishing and detection method for wear debris in oil of marine machinery

Oil debris distinguishing and detection is to characterize the wear position, rate and degree of mechanical system by detecting the properties, count and size of debris in the oil, which contributes to the health status monitoring and fault diagnosis of marine machinery. To improve the sensitivity of inductive detection method, especially for the detection of non-ferromagnetic particles, a double-wire solenoid coil and an inductance-resistance detection method are presented in the paper. The frequency characteristics of inductance and resistance detection are discussed, which shows that the first method is sensitive to ferromagnetic metal particles, and the second method is sensitive to non-ferromagnetic metal particles. We demonstrated that the double-wire solenoid coil sensor can detect iron particles with diameter of 20 μm onwards and copper particles with diameter of 60 μm onwards with inductance-resistance detection method.

An efficient method for adaptive segmentation of oil wear debris image

An efficient method for adaptive segmentation of oil wear debris image

An Inductive Debris Sensor Based on a High-Gradient Magnetic Field

The health condition of mechanical systems can be characterized by wear debris in lube oil. Therefore, wear debris detection is necessary for the fault prediction and diagnosis of mechanical systems. This paper presents an inductive debris sensor based on a high-gradient magnetic field. An induction coil is placed in a high-gradient magnetic field, and an induced voltage is generated when wear debris in the oil pipe flows through a magnetic field. A mathematical model of the sensor is established, and the output signal of the sensor is similar to that of a three-coil inductive debris sensor. The experimental results show that the sensor is capable of detecting 25- $\mu \text{m}$ ferromagnetic particles. The sensor driven by a constant current has a simple structure and is feasible for on-line wear monitoring.

Impact of dual biofuel approach on engine oil dilution in CI engines

Biodiesel can be considered to be the most capable alternate fuel for partial or complete replacement of the fossil fuel. Previous studies on biodiesel-oil blends have demonstrated that the use of double biofuels in engine can be a promising aspect for the complete elimination of diesel from compression-ignition (CI) engines. But its use increases the lubricating oil dilution to some extent due to the chemistry of biodiesel. The present experimental investigation describes the effect of biodiesel-oil blend, oxidized biodiesel-oil blend and diesel dilution in the engine oil by means of high frequency reciprocating rig (HFRR) and pin on disc (POD) friction monitor. Moreover, fresh lubricating oil, lubricating oil which was turned out from AB70EU30 operated engine with modified parameters after 100h and lubricating oil which was turned out from diesel operated engine after 100h were also considered for experimentation for clear comparison in results. The effects of engine oil dilution were studied on cylinder liner and piston ring as well as on cam and tappet on valve train. The present study revealed that the 10% dilution of biodiesel-oil blend in lubricating oil shows promising result in terms of coefficient of friction and diameter of wear scar as compared to other tested feedstocks. The effect of oxidation of the biodiesel-oil blend on the performance of engine oil is also assessed in the present study. Analytical ferrography of the used oil was also done to study the wear debris in oil.

Problems of Formation of Diagnostic Features in the Diagnosis of Aircraft Engines

The article is devoted to the evaluation of current technical condition of aircraft engines. Deals with the choice of the detection method of diagnostic features required for degradation assessment, emergency protection and detection of incipient defects on the example of cyclic machines and mechanisms. For the formation of diagnostic features in the diagnosis of aircraft engines use different physical effects (vibration, shock, heat radiation, electrodynamic and thermal processes, wear debris in oil, etc.). Classification of defects and requirements for the development of diagnostics systems is formed based on them. The article describes the requirements for diagnostic signs. The article provides a promising phase method that allows obtaining stable diagnostic characters in exploitation. The result of applying the method is shown. Diagnostic signs are formed. In mathematical modeling it was used the traditional theory of the description of rotary mechanisms. The data obtained are compared with experimental data.

An Improved Online De-Noising Method for Ultrasonic Echo Signal of Wear Debris in Oil

The ultrasonic echo signal of wear debris is influenced by many matters. It causes so much more noise. Therefore, it puts forward an improved online de-noising method for ultrasonic echo signal of wear debris in oil. In the dual-tree complex wavelet transform (DTCWT) field, a method, which combines the new non-linear threshold function with adaptive threshold, utilizes particle swarm optimization (PSO) for optimizing the parameter of non-linear threshold function to get the optimal solution. The result of de-noising method can be evaluated. Experimental results show that the proposed method has obvious effect on signal de-noising.

Effects of Eddy Current within Particles on the 3D Solenoid Microfluidic Detection Chip

Metal wear debris is an important component of contamination in lubrication oil, and is also an essential information carrier in hydraulic oil. Based on inductive Coulter counting principle, a microfluidic device to detect metal wear debris in oil is presented in this paper. The proposed device can make the distance between the particles in oil and the embedded induction coil very small, and hence greatly improve the sensitivity of the detection. The results indicate that eddy current within particles increase ability to detect copper particles, and decrease the sensitivity to iron particle.