Crank mechanism: let's figure it out

Crank mechanism: let's figure it out
Crank mechanism: let's figure it out
Anonim

Modern engine consists of many systems, including lubrication system, fuel system and ignition system. All of them change over time, undergo changes, become more perfect. But there are other details that have remained unchanged throughout its existence. For example, a crank mechanism. The fact is that since its invention, it has remained in its original form.

crank mechanism
crank mechanism

Its application is quite wide and it is not limited to internal combustion engines. It is used in such units where translational movement is required, since only it is able to provide not only the same period of such movements, but also a constant stroke, which is limited by the length of the crankshaft knee.

The crank mechanism was first used on a steam plant, after which, after the invention of the internal combustion engine, it migrated to the latest development. There are two types of such installations: one transmits the force from the crankshaft to the part that performs translational movement, the second receives this force from the piston, whichlocated on the other end of the connecting rod.

Consider the purpose of each part separately. The main part is the crankshaft. It can transmit force to the connecting rod or, conversely, receive it. It is made from high-strength steels, most often from cast iron. It also houses the flywheel, which serves to store the energy received. Many motorists install a lightweight flywheel on their engine, which makes the crank mechanism more mobile. It just picks up speed faster.

engine crank mechanism
engine crank mechanism

Now let's talk about the connecting rod. It is also made from hard steel, because the pressure on it can be enormous. In addition, its shaft is in the form of an I-channel, since its deformation is fraught with serious consequences that will damage the cylinder.

The crank mechanism has more torque than rotary engines because it uses the principle of leverage, that is, its force is proportional to the length of the knee. Hence the conclusion: the larger the knee, the higher the torque. The next part is the piston. The piston can drive the crankshaft, as in an internal combustion engine, or receive force from it, as in compressors. It is usually made of aluminum as it requires a soft metal so as not to damage the cylinder walls if touched. Along the perimeter of the circle there are grooves into which piston rings are inserted, they serve to seal and increase pressure.

vaz engine assembly
vaz engine assembly

In this case, the gasesdoing a great job.

The crank mechanism of an engine is calculated to average torque and RPM values, since a shift towards one indicator results in a loss in the other. The method of increasing the first is described above, but in this case the piston will have to travel a greater distance, which affects the "ceiling" of revolutions.

The assembly of the VAZ engine does not differ from that described above. It should be remembered that all parts of the crank must be thoroughly lubricated, as it rotates very quickly. From the very beginning of production, an oil film is created between the mating parts under pressure, which significantly reduces wear.

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