The Analysis of the Characteristics of Infinitely Short Journal Bearings Modified by Equivalent Viscosity
The characteristics of unlimited short journal bearing has been analyzed by using the equivalent viscosity correction model under thin film lubrication conditions. The interaction between the lubricant and the surface within a very small gap has been seriously considered. The changes of regular pattern of lubricant properties are comprehensive analyzed and researched. Unlimited short journal bearing is regarded as the research object. After researching, the varying regularity of its characteristics has been received. At the same time, the relationship between parameters and bearing performance has been established. The basis are provided for theoretical research and practical engineering calculations.
Lubricant Shear Thinning Analysis of Engine Journal Bearings
The high shearing stresses encountered in the modern engine bearing lubricant film lead to significant drop in viscosity of multigrade oils and affect the values of film thickness, power loss and oil flow significantly in the engine bearings. The popular mobility method is incapable to incorporate shear thinning, and time-consuming numerical schemes are not readily acceptable in industry. The present study aims to provide an economic (time and effort saving) and reliable dynamic (considering load and speed variation with crank rotation) analysis to study the combined effect of temperature and lubricant shear thinning on the engine bearing performance. The variation in the lubricant viscosity with shear is considered as described by the Cecim-equation. An effective thermal analysis is used to evaluate the operating oil-temperature that determines the low and high shear viscosity, and shear stability parameter. A crankshaft bearing is analyzed and results are presented for various performance parameters such as minimum film thickness, maximum pressure and the friction loss. These results are compared with those obtained by steady state solutions and full scale numerical methods.
Trends in kiln drives
The heart of the cement plant is the rotary kiln, and continuous quality production of cement clinker depends on the continuous accurate performance of the rotary kiln drive.