Internal combustion engines are energy transformation mechanisms utilized by the vast majority of motor vehicles, basically comprising two principal parts: one or more heads and the engine block. The combustion chambers are located in the base of the head(s) (in Diesel engines in general the combustion chambers are in the piston heads) and the cylinders and the cranked shaft assembly or crankshaft assembly are located in the engine block.
The crankshaft is a fundamental part in the operation of combustion engines, being responsible for transforming the energy generated by the combustion of the air/fuel mixture into torque. Also known as a cranked shaft, the crankshaft is associated with the connecting rods coupled to the pistons, and transmits the moment generated to the other components connected to the extremities of the shaft thereof.
At one extremity of the shaft of the crankshaft there is located the flywheel of the engine, associated with the gearbox. At the other extremity of the shaft there is a pulley responsible for causing the rotation of diverse devices, principally lubrication devices, such as for example hydraulic steering pump, air conditioning pump, water pump, etc.
The pulley utilized on the crankshaft is manufactured by a sintering process and mounted upon the extremity of the shaft by means of a bolt, applying a force required to maintain the assembly secured during the entire working period of the engine. When the bolt is in a system with vibration a deformation may be occasioned on the face of contact of the pulley with the bolt, there occurring compaction of the pulley. This deformation, consequent upon the compaction of the material of the pulley, results in play between the pulley and the bolt, the utilization being necessary of a washer positioned between the pulley and the bolt, normally composed of a conventional steel material comprising a density greater than that of the density of the pulley, eliminating the possibility of compaction of the material.
However, the use of washers to accommodate the play between the pulley and the bolt is extremely undesirable by virtue of the fact that it increases the quantity of components to be utilized in the assembly of the crankshaft, reducing the productivity of the process, and reducing the quality index of the process, by virtue of the fact that the possibility exists of the assemblies being constructed without the washer.
Consequent upon all the aforestated, until the present moment there a pulley had not been developed manufactured by a sintering process and provided with a density such as to confer upon the pulley excellent resistance to the effect of compaction of the material composing it, in this manner preventing the deformation of the pulley and the emergence of play of between the pulley and the securing component.