Böcker av Ashutosh Mokate

The wear resistance of PTFE can be significantly improved by addition of suitable filler materials. Besides the type, the shape and size of the materials added also influence the tribological properties. In the past, research in this area has been confined to the PTFE filled with conventional filler materials like glass fibers, graphite, carbon fibers, etc. However, with the growing demand for utilizing PTFE in a variety of applications, significant effort is needed towards developing the novel composite materials by adding one or more non-conventional filler materials possessing the potential of increasing the wear resistance. It is established that PTFE exhibits significantly low coefficient of friction when sliding against steels. The low coefficient of friction results from the ability of its extended chain linear molecules, - (CF2-CF2) n-, to form low shear strength films upon its surface and mating counter-faces during sliding. PTFE is extensively used for a wide variety of structural applications as in aerospace, automotive, earth moving, medical, electrical, electronics, computer and chemical industries. On account of its good combination of properties, these are used for producing a number of mechanical components such as gears, cams, wheels, brakes, clutches, bearings, gaskets, seals as well as wires, cables, textile fibers, electronic components, medical implants, surgical instruments etc.

Gears are essential parts of many precision power transmitting machines such as automobiles. The major functions of a gearbox are to transform speed and torque in a given ratio and to change the axis of rotation. Planetary gears yield several advantages over conventional parallel shaft gear systems: They produce high speed reductions in compact spaces, a greater load sharing, a higher torque to weight ratio, diminished bearing loads, and reduced noise and vibration. They are used in automobiles, helicopters, aircraft engines, heavy machinery, and a variety of other applications. Despite their advantages, the noise induced by the vibration of planetary gear systems remains a key concern. Planetary gears have received considerably less research attention than single mesh gear pairs. There is a particular scarcity of analysis of two planetary gear systems and their dynamic response. Hence, this book focuses on the study of two PGTs with different phasing (angular positions) while every individual set remains unchanged.