The camshaft structures
The main body of the camshaft is a same as the cylinder length cylindrical bar body. The above set of several CAM, used to drive the valve. One end of the camshaft is bearing strong point, the other end connected with the drive wheels.
The side of the CAM is the egg shape. The purpose of its design is to ensure that the cylinder full of intake and exhaust, specifically in the shortest possible time to complete the valve opening and closing action. Also considering the durability of the engine and comfort of operation, the valve can't because of the opening and closing action of the deceleration process to produce too much too much, otherwise it will cause the valve of the serious wear, noise or other serious consequences. Therefore, CAM and engine power and torque output and smooth operation has a direct relationship.
In-line engines in generally speaking, a CAM is corresponding to a valve, V type engine or horizontal contraposition type engine is every two valve share a CAM. And no valve with gas engine rotor engine and due to its special structure, does not need to CAM.
Classification of the camshaft
According to the CAM shaft of the number of how many, can be divided into single overhead camshaft (SOHC) and double overhead camshaft (DOHC) two kinds. Single overhead camshaft is only a camshaft, double overhead camshaft is two root, this is too straightforward explanation.
A single overhead camshaft in the cylinder head, with a convex shaft in direct drive inlet and exhaust valves, it has simple structure, suitable for high speed engine. Always by the side of the camshaft, namely the camshaft in the cylinder profile, directly by the timing gear drive. In order to put the CAM shaft rotational transform of the reciprocating movement of the valve, valve tappet must be used to transfer power. In this way, the reciprocating motion of parts is more, inertial mass is large, go against engine high speed movement. And have certain flexibility as a slender tappet, easy to cause vibration, accelerate the parts wear, even lose the valve control.
Overhead is double camshaft in the cylinder head is equipped with two CAM shaft, used to drive the inlet valve, a another used to drive the exhaust valve. Adopt double overhead camshaft on the camshaft and valve spring design requirements is not high, especially suitable for the valve v-shaped hemispherical combustion chamber configuration, also facilitate and four valve used valve-train