DYNAMIC STRUCTURAL ANALYSIS OF ENGINE CRANKSHAFT AT DIFFERENT ANGLE OF CRANK TURNS FOR THREE DIFFERENT MATERIALS

For many years, engines have been one of the main power machinery of different kinds of applications, and the main part of power machinery is a crankshaft that converts the piston’s reciprocating displacement with four-link mechanisms into rotary motion. . The major limitation of the engine crankshaft is fatigue failure due to repeated load caused by bending and torsional load. In this paper, the comparative dynamics structural analysis was carried out for three different materials such as forged steel, cast iron, and chromium-molybdenum steel with different angles of turns of cranks from 0° to 720° and to predict the stresses, deformation, and fatigue life of crankshaft without compromising its weight, strength and reliability. The 3D CAD model was simulated with FEA software. The simulated results show that by applying bending load and torsional load for three materials, the maximum stresses produced in the fillet area of the main bearing journal and in the fillet area of the crankpin journal at a crank angle of 360° respectively. The deformation results revealed that maximum deformation occurs at the mid-surface of the crankpin. From fatigue life prediction it was observed that forged steel and chromium-molybdenum steel shows better fatigue life as compared to cast iron. Moreover, in the comparative study, it was concluded that chromium-molybdenum steel shows fewer stresses and better fatigue life. Therefore it is suggested that chromium-molybdenum steel would be the better option for manufacturing crankshaft.

The study of influencing factors on working capability of “Agco sisu power” engine utilized for crop production in Mongolia

Due to our country’s weather conditions and improper exploitation of these macheries, there has been occurring series of technical failure, and the down state of the power machinery equipped with smart system CRD engine. Moreover, technical idle and the product cost industrial has been increased. As a result of above mentioned problem, we need to use efficiently the technical resource of agricultural power machines with CRD engine. The aim of our research work was to determine the factors influencing on engine working power, to increase the technical resource and to use it efficiently. Within the frame work of our research study, we are introducing the determination of the influencing factors of working capability of engine in field case, and the result of the laboratory testing the and plan model. “Agco sisu power” Хөдөлгүүрийн ажлын чадварт нөлөөлөх хүчин зүйлийн судалгаа Хураангуй: Монгол орны нөхцөлд ХАА-н зүтгэх хүчний машины CRD хөдөлгүүрийн техникийн нөөцийг бүрэн ашиглах, шинэ техник технологийг нутагшуулан тогтвортой үйлдвэрлэлийг хангах явдал зүй ёсоор тулгарч байна. Иймд уг хөдөлгүүрийн ажлын чадварт нөлөөлөх хүчин зүйлсийг тогтоох, нөөцийг нэмэгдүүлэх, бүрэн ашиглах зорилгоор уг судалгааг гүйцэтгэсэн болно. Энэхүү судалгааны ажлын хүрээнд бид талбайн нөхцөлд хөдөлгүүрийн ажлын чадварт нөлөөлөх хүчин зүйлсийг тогтоож лабораторийн туршилт төлөвлөлтийн загварыг гаргасан үр дүнг танилцуулж байна. Түлхүүр үг: CRD хөдөлгүүр, ажлын чадвар, саатал, хүчин зүйл, туршилт

H∞ active control of frequency-varying disturbances in a main engine on the floating raft vibration isolation system

Reducing the vibration of marine power machinery can improve warships' capabilities of concealment and reconnaissance. Being one of the most effective means to reduce mechanical vibrations, the active vibration control technology can overcome the poor effect in low frequency of traditional passive vibration isolation. As the vibrations arising from operation of marine power machinery are actually the frequency-varying disturbances, the H∞ control method is adopted to suppress frequency-varying disturbances. The H∞ control method can solve the stability problems caused by the uncertainty of the model and reshape the frequency response function of the closed loop system. Two-input two-output continuous transfer function models were identified by using the system identification method and are validated in frequency domain of which all values of best fit exceeds 89%. The method of selecting the weighting functions on the mixed sensitivity problem is studied. Besides, the H∞ controller is designed for a multiple input multiple output (MIMO) system to suppress the single-frequency-varying disturbance. The numerical simulation results show that the magnitudes of the error signals are reduced by more than 50%, and the amplitudes of the dominant frequencies are attenuated by more than 10 dB. Finally, the single excitation source dual-channel control experiments are conducted on the floating raft isolation system. The experiment results reveal that the root mean square values of the error signals under control have fallen by more 74% than that without control, and the amplitudes of the error signals in the dominant frequencies are attenuated above 13 dB. The experiment results and the numerical simulation results are basically in line, indicating a good vibration isolation effect.