Detailed Product Description

The engine connecting rod is an important part of the engine, and its structural characteristics are:

The small end of the upper end of the connecting rod is connected to the piston pin, and the big end of the lower end is connected to the crankshaft, which can convert the reciprocating movement of the piston into the rotational movement of the crankshaft. It is just like the movement of your thighs when riding a bicycle. Connecting rods are generally made of medium carbon steel or alloy steel through forging, machining and heat treatment. Because the connecting rod is subjected to the cyclical force of compression, tension and bending when it works, it is required to have as small mass as possible, but also sufficient rigidity and strength. If the rigidity is not enough, it will cause the big head hole to be out of round, and the bearing bush will be burned due to poor lubrication ; The bending of the shaft will cause air leakage and oil blow-by in the cylinder.

The big end of the connecting rod is generally made of two semi-circular blocks, one is the lower end of the big end of the connecting rod, and the other is called the connecting rod cover. The two are screwed together with connecting rod bolts. These two pieces are processed together (boring). The surface of the big hole is very smooth in order to closely match the bearing bush. The surface is also milled with grooves for positioning the bearing bush and small oil holes.

The working conditions of connecting rod bolts are the same as those of connecting rods. They are generally made of high-quality alloy steel or high-quality carbon steel, which are forged or cold-headed. When installing the big connecting rod, the connecting rod bolts must be tightened according to the torque specified by the factory, and measures must be taken to prevent loosening by themselves. The connecting rod bush is made of two halves like the big end of the connecting rod. The base of the bush is thin steel plate, and the inner surface is cast with a wear-reducing alloy layer such as babbitt alloy. The anti-friction alloy has the function of reducing friction, accelerating running-in and maintaining oil film.

The surface of the bearing bush and the connecting rod head and the connecting rod cover must have a very high smoothness. Before the bearing shell is installed, the half of the bearing shell is not semi-circular. When it is installed, the bearing shell can be close to the wall of the large-head hole due to the pressure (interference). In order to prevent the bearing bush from rotating or axial displacement during operation, the positioning bosses are punched on the bearing bush to be respectively embedded in the grooves of the big head and the connecting rod cover. There are oil grooves on the inner surface of the bearing bush to ensure good lubrication.