Papers by Author: Yi Min Shao

Abstract: The surge of a sintered exhauster is regarded as a safety hazard during production. The occasional machine shutdown may be caused by the exhauster surge. Severe surge my cause the damages of the exhauster, injuries to personnel, and potentially casualties. In this paper, a curve that describes the character of a sintered exhauster is presented based on the site testing and analysis. The aim of this work is to avoid exhauster surge and to guarantee safe production. The working conditions for technicians and efficiency of operations for the exhauster will be insured through the use of the characteristic curve presented in the paper.

Abstract: Involute helical gears, with advantages of large carrying capacity, smooth transmission and long life, etc., are widely used in automotive, mining, helicopters and other high-speed and heavy-load transmission system. Poor working conditions lead to fatigue crack and other faults of gear key parts such as tooth root and tooth face. To identify the root causes of gear faults, strain monitoring methods are often used to monitor the stress changes of gear key parts so as to work out individualized improvement plants. Good test results can be obtained using real-time wireless data collection technology when the gear is in low-speed and light loading condition, and we can get important data such as speed, torque and dynamic strain on tooth root, etc. However, involute helical gears tend to work in high-speed and heavy harsh conditions, especially when the gear speed reaches a large value (eg. 10000r/min above), gear strain measurement device will suffer big centrifugal force and the impact of shear force which may results partial bonded adhesive failure (cracks, erosion, etc.) and even whole peeling of strain gages, thus inaccurate and even error results will be obtained. Transient finite element analysis method is used in this paper to study the relationship between rotation velocity and test accuracy of strain gauge as well as the process of the bonded adhesive failure, which may provide effective guidance for the fault diagnoses of gear meshing.

Abstract: As the complicate structure and unstable working condition, the vibration signal of engines always be non-stationary and drown in strong noise, especially for the case of slight quality defection. Such case directly results in difficulties for inspection and diagnosis of engine incipient defection. A new inspecting method based on empirical mode decomposition (EMD) and envelope spectrum is proposed in this paper. In the new method, the intrinsic mode functions (IMF) of de-noised angular vibration signals are firstly obtained; then the envelope spectrums of IMFs are obtained through envelope analysis, lastly the discrepancy of the envelope spectrums between normal and abnormal case is extracted to be the feature indicator for the engine quality inspection. This method is validated experimentally. The results show that the proposed method has an excellent performance in the quality inspecting in the presence of abnormal clearance between crankshaft and connecting rod of the engine.

Abstract: In this paper we develope and analyse a 3D model of horse’s musculo-skeletal system as a bionic inspiration which can lead to the design of a cross-country motorcycle frame. Based on the great running and load carrying ability of the horse we were inspired to observe its biomechanical functions, extract useful principles, and simplify the extracted information for modeling. We represent the horse’s musculo-skeletal system by seven cylindrical beams connected together by hinge joints, and then analyze it using ANSYS software. The analysis results shows that the vibration and stress in the model can be minimize by changing the joints between the beams from rigid to hinge joints under different spring bars’ stiffness. This model can provide useful information to improve the functional characteristics of motorcycle frames.

Abstract: The present study investigates the dynamic response of single-cylinder reciprocating engines. In particular, simplified models of the crank-connecting rod mechanism are examined, which take into the flexibility of the crankshaft. Crankshaft, connecting rod and piston are major parts of the crank-connecting rod mechanism, and their size, mass, centroid location parameters are required precisely in manufacturing process. However, manufacturing error cannot be avoided completely in practical manufacturing process, and it would lead to different vibration performance of engine. Therefore, understanding the effect of manufacturing error on the vibration performance of engine is the aim of this paper. In order to obtain dynamic characteristics of engine, both rigid and flexible body dynamics simulation were done by using software ADAMS.

Abstract: The induction motor is the most common driver in industry and has been previously proposed as a means of inferring the condition of an entire equipment train, predominantly through the measurement and processing of power supply parameters. This has obvious advantages in terms of being non-intrusive or remote, less costly to apply and improved safety. This paper describes the use of the induction motor current to identify and quantify a number of common faults seeded on a two-stage reciprocating compressor. An analysis of the compressor working cycle leads to current signal the components that are sensitive to the common faults seeded to compressor system, and second- and third-order signal processing tools are used to analyse the current signals. It is shown that the developed diagnostic features: the bispectral peak value from the amplitude modulation bispectrum and the kurtosis from the current gives rise to reliable fault classification results. The low feature values can differentiate the belt looseness from other fault cases and valve leakage and inter-cooler leakage can be separated easily using two linear classifiers. This work provides a novel approach to the analysis stator current data for the diagnosis of motor drive faults.