Crankshaft

Alloy cast irons. Alloy additions are made to cast irons to improve the properties for particular purposes. Alloy cast irons can be used in engineering applications where plain cast iron is unsuitable and may even replace steel for some components such as crankshafts. 

Technora. In 1985, Teijin Ltd. introduced Technora fiber, previously known as HM-50, into the high performance fiber market. Technora is based on the 1 1 copolyterephthalamide of 3,4 -diaminodiphenyl ether and/ -phenylenediamine (8). Technora is a whoUy aromatic copolyamide of PPT, modified with a crankshaft-shaped comonomer, which results in the formation of isotropic solutions that then become anisotropic during the shear alignment during spinning. The polymer is synthesized by the low temperature polymerization of/ -phenylenediamine, 3,4 -diaminophenyl ether, and terephthaloyl chloride in an amide solvent containing a small amount of an alkaU salt. Calcium chloride or lithium chloride is used as the alkaU salt. The solvents used are hexamethylphosphoramide (HMPA), A/-methyl-2-pyrrohdinone (NMP), and dimethyl acetamide (DMAc). The stmcture of Technora is as follows ... 

Power Take-Off From Engine or Transmission. This type of system is limited to tmcks and there are several take-off means available. Most are some form of electric power generation equipment, belt-driven from the engine crankshaft, which produces either a regulated a-c voltage or rectified direct current for the compressor and fan motors in the body. 

Enichem and DuPont ate two suppHers of acryHc elastomers. It is estimated there ate - 9000 t/yr of these elastomers used in the United States. The principal uses of acryHc elastomers ate in automotive appHcations requiring both oil and heat resistance. These include transmission, valve stem, crankshaft, pinion, and odpan gaskets and seals. In addition hose, tubing, toUs, and belts ate made from acryHc polymers. 

Babbitt ahoys ate suitable for hundreds of types of iastahations involving the movement of machinery, eg, the main, crankshaft, connecting tod big end, camshaft, and journal bearings associated with marine propulsion, tailtoad and automotive transportation, compressors, motors, generators, blowers, fans, rolling-mill equipment, etc. 

Pipe-hne and marine installations are frequently arranged so that the engine drives all its auxiharies from the crankshaft by means of chains and V belts. But process-plant practice is to have all the auxiliaries independently driven, using standby pumps to minimize engine downtime. 

Now for the snag of a soft bearing material - will it not fail to support the normal operating forces imposed on it by the crankshaft All bearing materials have a certain p - v envelope within which they function safely (Fig. 26.3). The maximum pressure, p, that the bearing can accept is determined by the hardness of the surface the maximum velocity, v, is determined by heating, and thus by the thermal conductivity... 

Copper-lead 70% Cu - 30% Pb Crankshaft and camshaft bearings of i.c. engines turbocharger bearings... 

Aluminium-tin 60% Al - 40% Sn Heavily loaded crankshaft bearings for diesel engines. Can be used with overlay of softer material... 

Increasing vibration with speed. Unbalanced reciprocating Crankshaft or piston type machinery... 

CRANKSHAFT OIL SEAL LEAKS 1. Faulty seal installation. 2. Clogged drain hole. 

A more rare form of driver is the steam cylinder. Most arrangements combine the steam driver and compressor on the same frame with the steam cylinder opposite the compressor cylinder. Each cylinder s connecting rod is connected to a common throw on the crankshaft. A flywheel is used to provide inertia. For air service, the units are built as single- and two-stage units, with other combinations available for process service. 

The lowly piston, one of the more simple items, has one of the most important functions of the entire compressor. The piston must translate the energy from the crankshaft to the gas in the cylinder. The piston is... 

Larger compressors, normally above 150 to 200 horsepower, have forged steel crankshafts. Cast crankshafts are used in medium-size machines. Crankshafts should have removable balance weights to compensate for rotary unbalance as well as reciprocating unbalance. The crankshaft should be dynamically balanced when above 800 rpm. 

Figure 3-15. A five throw crankshaft with drilled oil passages. Courtesy of Dresser-Rand)...

The pressurized lubrication system is a more elaborate lubrication method (.see Figure 3-19). The system has a main oil pump, either crankshaft or separately driven, a pump suction strainer, a cooler when needed, a... 

Balance piston, 208, 209 Balance piston, axi.al, 252 Balancing crankshaft, 74 dcfinilion of terms, 369... 

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