First of all we all know that a crankcase is the housing for the crankshaft in a reciprocating internal combustion engine. In most modern engines, the crankcase is integrated into the engine block.
The crank case is the opposite of the cylinder on which the piston is located. This crank case contains lubricating oil. With the pump, the oil is dispersed into various moving parts of the engine. In many cars, the upper part of the crank case is welded together with a cylinder block. Its bottom is made of cast iron or steel sheet. These two parts are connected by a nut-bolt. In most of our country, the engine crank case is made of separate aluminum alloy. Since the crank case usually does not have to withstand too much friction, it lasts for a long time and does not erode. If the crank case is welded with a cylinder block, it is necessary to always use a liner inside the cylinder. As a result, the original cylinder is not damaged and the cylinder with crank case is good.
Connecting Rod: Also we know that a connecting rod, also called a con rod, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. The connecting rod is required to transmit the compressive and tensile forces from the piston, and rotate at both ends.
The connecting rod attaches the crank pin to the wrist speed of the piston adjacent to the piston. This causes the piston to move in the direction of rotation speed of the crank shaft. The connecting rod has a bearing on the edge of the crank pin. It's called Bid End Bearing. It is added with two nut-bolts. Connecting rod, usually made of nickel and steel alloy or aluminum alloy steel. This rod has to withstand enough pressure. As a result, it does not bake easily, so it is necessary to make it with very strong metal; In many engines nowadays, connecting rods are made of aluminum alloy. Each cylinder and piston requires one rod. A bronze bush is fitted inside the small end toward the piston pin. The holes are drilled at the top and bottom of the connecting rod to provide lubricating oil.
Crank shaft: Also we know that a crankshaft is a rotating shaft which (in conjunction with the connecting rods) converts reciprocating motion of the pistons into rotational motion. Crankshafts are commonly used in internal combustion engines and consist of a series of cranks and crankpins to which the connecting rods are attached.
The function of the crank shaft and connecting rod is to change the movement of the piston inside the cylinder to Cyclic Motion. This is because it has to withstand the pressure and heat of the exploding gas. Depending on the number of cylinders in the cylinder block, the shape of the crank shaft varies and becomes larger. It looks like a curved iron rod. The higher the number of cylinders, the easier the pressure will be, the easier the rotation speed of the crank shaft will be. If the cylinders are large enough, the crank shaft works easily and the pressure is reduced and the shaft also lasts longer.