the crankshaft bearing is one of the most important engine parts, its function is to bear the piston connecting rod group to the gas pressure into the crankshaft torque and external output, in addition, the crankshaft bearing is also used to drive the engine gas distribution mechanism and other auxiliary devices, such as: generators, fans, water pumps, power steering pumps, balance shaft mechanism, etc. .
The crankshaft is generally composed of front end, main journal, crank, balance weight, connecting rod journal and rear end. By a connecting rod journal and it left and right main journals to form a crankshaft. The number of crankshaft crank depends on the number of cylinders and arrangement.
2 – crankshaft timing toothed pulley.
5-Crankshaft main bearing (top).
7-Tachometer sensor signal generator.
9-Crankshaft main bearing (lower).
Crankshaft bearing cover crankshaft work, to withstand periodic changes in gas pressure, reciprocating inertia forces and centrifugal forces, as well as their high-speed operation under the torque and bending moment, prone to bending and torsional deformation, therefore, the crankshaft bearing should have sufficient strength and stiffness, good wear resistance and good balance. Crankshaft bearings are generally calcined from medium carbon alloy steel, and the surface of the journal is quenched or nitrided by high frequency.
inline four-stroke engine crankshaft crank arrangement inline four-cylinder four-stroke engine work interval angle is 720 ° / 4 = 180 °, four crank arrangement in the same plane, the engine work order (or ignition order) for 1-3-4-2 or 1-2-4-3 two The work cycle inline four-cylinder four-stroke engine crank arrangement sketch inline six-cylinder four-stroke engine crank arrangement sketch V arrangement eight-cylinder engine crank arrangement sketch thrust device commonly used are single-sided system with anti-wear alloy layer of the semi-circular thrust pad, with a flap crankshaft main bearing and circular thrust ring has three forms.
crankshaft arrangement principles crankshaft shape and the relative position of the crankshaft depends mainly on the number of cylinders, the cylinder arrangement and the working order of the cylinders. In the arrangement of the engine work order should try to follow the following rules: so that the continuous work of the two cylinders as far apart as possible to reduce the load on the main bearings, to avoid the process of air intake connected to the two valves open at the same time, the phenomenon of “gas grabbing”, affecting the efficiency of engine inflation.