Xiexiang Machinery

∮ 20 × ∮ 8 × 49 (sandblasting)

The piston pin is a cylindrical pin mounted on the piston skirt. Its middle part passes through the small end hole of the connecting rod to connect the piston and the connecting rod. Its function is to transmit the gas force of the piston to the connecting rod, or to make the small end of the connecting rod drive the piston to move together. In order to reduce weight, the piston pin is generally made of high-quality alloy steel and made hollow.

∮ 20 ×∮ 8 × 49

The piston pin bears a large periodic impact load under high temperature conditions, and because the swing angle of the piston pin in the pin hole is not large, it is difficult to form a lubricating oil film, so the lubrication condition is poor. For this reason, the piston pin must have sufficient rigidity, strength and wear resistance. The quality is as small as possible, and the pin and pin hole should have appropriate fit clearance and good surface quality. In general, the rigidity of the piston pin is particularly important. If the piston pin is bent and deformed, the piston pin seat may be damaged.

* 23.1 × 39 (Type 70)

The crank pin is composed of a pin and a countersunk screw. It is characterized in that the pin is two deed bodies 1 and 2, the inner surfaces of the two deed bodies 1 and 2 are inclined surfaces, and the outer surface of the deed body 2 is a plane, which is flat with the bicycle center shaft. The outer surface of the deed body 1 is a circular arc surface, which is connected with the circular arc surface of the bicycle crank pin hole, the two ends of the deed body 1, 2 are screwed with a countersunk screw 3, so that the inclined surfaces of the two deed bodies 1, 2 are matched together under the action of the two countersunk screws 3 and slide axially until the crank is locked.

* 25.1 × 39(100 type)

In small and medium-displacement motorcycle engines, the left and right cranks and crankpins are generally pressed to form a split crank connecting rod combination, and the big end of the connecting rod adopts needle bearings with cages. Using combined crank, for the manufacture of blank. There is no need for large forging equipment, and it is convenient for various heat treatment and machining, which can effectively shorten the production cycle.