Mechanical

INTRODUCTION      A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a live axle.Often transmission refers simply to the gearbox that usesgears and gear trains to provide speed and torque conversions from a rotating power source to another device. In British English, the term transmission refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive), differential, and final drive shafts.

Carburetion  Introduction       Spark-ignition engines normally use volatile liquid fuels. Preparation of fuel-air mixture is done outside the engine cylinder and formation of a homogeneous mixture is normally not completed in the inlet manifold. Fuel droplets, which remain in suspension, continue to evaporate and mix with air even during suction and compression processes. The process of mixture preparation is extremely important for spark-ignition engines. The purpose of carburetion is to provide a combustible mixture of fuel and air in the required quantity and quality for efficient operation of the engine under all conditions.

How a Turbocharger Works            The turbocharger has been a great source of maximizing efficiency of an internal combustion engine since the late 1920’s. Alfred Buchi was the engineer that came up with the idea to utilize the wasted energy that is expelled through the exhaust system. It was in 1915 that he created his first prototype, which failed. This however did not stop the persistent inventor. He worked on it for another 10 years before he produced the first practical, functioning turbocharger that increase efficiency of an engine by 40%.

  Thermal processing of metals and alloys      Apart from mechanical processing, metals are very often subjected to thermal processing for various reasons, like: to refine grain structure/size, to minimize residual stresses, to impart phase changes, to develop special phases over external surfaces, etc. Metals and alloys develop requisite properties by thermal processing either through grain refinement of phase changes. Thermal processing is also known as heat treatment. Heat treatment originated as an ancient art in man’s attempts to improve the performance of materials in their practical applications. In present day metallurgical practice, heat treatment has become very important for obvious reasons.

Metal forming  In these techniques, a metallic piece is subjected to external pressures (in excess of yield strength of the material) to induce deformation, thus material acquires a desired shape.

Applications and Processing of Metals and Alloys       In the materials world we are living in, when making a new device/component, most often we come across a very familiar problem. This is nothing but select the right material. As learnt in earlier chapter, selection of material can play very important role preventing failures. Selection of material for a specific purpose depends on many factors. Some of the important ones are: strength, ease of forming, resistance to environmental degradation, etc. Another dimension an engineer should be aware of it is how to tailor the required properties of materials. 

Pump            A pump is a device used to move fluids, such as liquids, gases or scurries. A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps. Their names describe the method for moving a fluid. Positive displacement pumps  loop pump          A positive displacement pump causes a fluid to move by trapping a fixed amount of it then forcing (displacing) that trapped volume into the discharge pipe.