Abstract This contribution investigates the influence of outgassing processes on vibration behavior a hydrodynamic bearing supported turbocharger rotor. The examined rotor is radially by floating rings with outer squeeze-film damping and axially thrust bearings. Due to highly nonlinear properties, can be excited via lubricating film, which results in subsynchronous vibrations known as oil-whirl...

Abstract Purpose Thrust bearings play a critical role in high-speed rotating machinery, such as turbines, pumps, compressors, and turbogenerators, by transferring axial loads between the collar bearing pads. The lubricating fluid prevents contact, friction, wear solid parts acts cooling medium. purpose of this study is to evaluate first- second-order coefficients an inclined pad hydrodynamic th...

The influence of physical damping on the numerical stability of time integration analysis is an open question since decades ago. In this paper, it is shown that, under specific very general conditions, physical damping can be disregarded when studying the numerical stability. It is also shown that, provided the specific conditions are met, analysis of structural systems involved in extremely hi...

Abstract Transient startup operating parameter has a serious influence on the stability of water-lubricated bearings. In this study, CFD method was used to predict rotordynamic coefficients water lubricated bearings under transient loads. The stiffness and damping versus time for are given. different loads also results show that will increase rapidly in very short time. With impact time, both t...

The author carried out dynamic load test research on a prestressed concrete rigid frame bridge. Under load, the ratios of measured and theoretical frequencies first four vertical vibrations bridge were 1.081, 1.153 respectively. corresponding damping are 0.011, 0.010 maximum coefficient sports car is 1.049, strain increment 0.059. impact between 0.012 0.049, which basically equivalent to design...

Ultrahigh molecular weight polyethylene (UHMWPE) is a unique polymer with outstanding physical and mechanical properties that makes it particularly attractive to fabricate the bearing surface for artificial joints. The growing demand for UHMWPE as a bearing material for joint replacement has lead to active research in the development and understanding of its properties in addition to nanocompos...

Oil-free micro turbomachinery implementing gas foil bearings (GFBs) has improved mechanical efficiency and reliability. Adequate thermal management for operation in high temperature environments is an issue of importance in applications such as in gas turbines and turbochargers. GFBs often need a cooling gas flow, axially fed through one end of the bearings, to transport the heat conducted from...

Gearboxes sustain a variety of faults such as broken-shafts, eroded, broken, or missing teeth, and even broken-cases. Casing mounted accelerometers can detect fault patterns but the signals are complicated and difficult to interpret. This study considers the tooth loading of ideal gears and gears with defects. A large industrial gearbox used in a 12m electric mining shovel is modeled. The nonli...

In order to improve the service life of needle roller bearing used in a precision cycloid reducer, and reveal skew collision phenomenon bearing, based on force analysis transmission mechanism reducer considering friction between wheel, roller, cage, crank shaft, dynamic contact rolling bodies is simulated by Hertz elastic contact, where cage pocket hole equivalent spring damping, nonlinear mode...