The camshaft is a component in a piston engine. Its role is to control the opening and closing actions of the valve. Although the speed of the camshaft in a four-stroke engine is half that of the crankshaft , it is usually still high in speed and needs to withstand a large amount of torque. Camshafts have high requirements on strength and support, and their materials are generally high-quality alloy steel or alloy steel. Because the valve motion is related to the power and running characteristics of an engine, the camshaft design occupies a very important position in the engine design process.
Cam bearings are subject to periodic shock loads. The contact stress between the cam and the tappet is very large, and the relative sliding speed is also high, so the working surface of the cam is relatively worn. In view of this situation, in addition to the high dimensional accuracy, small surface roughness, and sufficient rigidity that the camshaft journal and cam working surface should have, it should also have high wear resistance and good lubrication.
Camshafts are usually forged from high-quality carbon steel or alloy steel, and can also be cast from alloy cast iron or ductile iron. The journal and cam working surfaces are polished after heat treatment.
The camshaft is one of the key parts of the engine. The hardness of the peach tip of the camshaft and the depth of the white layer are the key technical indicators that determine the camshaft's service life and engine efficiency. On the premise of ensuring that the cam has a sufficiently high hardness and a relatively deep white mouth layer, it should also be considered that the journal does not have higher carbides, so that it has better cutting performance.
