The cylindrical pin is fixed in the hole by interference, and is used to fix parts, transmit power, or as a positioning member.
Cylinder pins are basically positioning pins, which are used to fix the relative position between parts. It is an important auxiliary part for combined processing and assembly.
Parallel pins are mostly made of high-quality carbon structural steel at present.
Generally, C35 and C45 are mostly used as materials, but heat treatment is required. Bearing steel is selected under high strength requirements.
Parallel pins are mostly used for positioning and connection, and they are fixed in the pin holes by interference fit. Cylindrical pins are usually not loaded or subjected to very small loads for positioning, and the number is not less than two, distributed in the symmetrical direction of the overall structure of the connected parts, the farther apart the better, the pins are in each connected part The length is about 1 to 2 times the minor diameter.
The types of cylindrical pins basically include ordinary cylindrical pins, internal thread cylindrical pins, threaded cylindrical pins, hole pins, and elastic cylindrical pins.
The cylindrical pin is fixed in the hole by a small amount of interference, which requires high requirements on the size, shape and surface roughness of the pin hole, and the pin hole must be reamed before assembly. Generally, the two holes of the connected parts should be drilled and reamed at the same time, and the roughness of the hole wall should not be greater than ra0.6μm. When assembling, apply lubricating oil to the pin, and drive the pin into the hole with a copper rod.
Parallel pins can also be used as shafts, and a straight shaft can also be used as cylindrical pins, or even centering pins. So what is the difference between a shaft and a pin? The shaft can be used to transmit torque, withstand bending moments and torques, and the cylindrical pin is used for positioning, and to withstand extrusion and shear forces.
In a sense (such as small equipment), cylindrical pins can also be used as shafts.
