The camshaft's function is to open and close the valves at the top of each cylinder within the engine. Each cylinder has at least two valves – one that draws in a combustible air and fuel mixture that, when ignited, forces the piston downwards in the cylinder.
In piston engines, the camshaft is used to operate the intake and exhaust valves. The camshaft consists of a cylindrical rod running the length of the cylinder bank with a number of cams (discs with protruding cam lobes) along its length, one for each valve.
The function of a camshaft is dependent on how a valve works and the function of the cam itself. A valve on a cylinder head consists of two basic parts, a stem and a head (see Figure 2). The head plugs the nozzle that allows fuel intake or exhaust flow and requires linear motion.
Cam is short for camshaft, the engine part that opens and closes the valves to let the air-fuel mixture in and out of combustion chambers. Every engine manufactured today has, if not one, then at least two or more installed. The camshaft's primary function is to close and open the valves.
As the pushrod rises on the cam it pivots the rocker arm, which pushes the valve down (open) against the pressure of its spring. As the cam lobe rotates further, the valve spring acts to close the valve.
As the heart muscle contracts and relaxes, the valves open and shut. This lets blood flow into the ventricles and atria at alternate times. Here is a step-by-step description of how the valves work normally in the left ventricle: When the left ventricle relaxes, the aortic valve closes and the mitral valve opens.
A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine.
The pushrods and rocker arms transfer the reciprocating motion generated by the camshaft lobes to the valves and injectors, opening and closing them as needed.
The camshaft and crankshaft, which run parallel down the center of the engine block, rotate at different speeds. The crankshaft turns at exactly twice the speed of the camshaft in four-cycle internal combustion engines. The four cycles are intake, compression, ignition/power, and exhaust stroke.
A cam and follower mechanism is a profiled shape mounted on a shaft that causes a lever or follower to move. Cams are used to convert rotary to linear (reciprocating) motion. As the cam rotates, the follower rises and falls in a process known as reciprocating motion.
Driven by the crankshaft, a camshaft transfers motion from the cams through various parts of the valve train to open and close engine valves. Cam lobes come in different shapes and sizes to control how much a valve opens, and for how long.
A camshaft acts as a timing device that controls the opening and closing of the intake and exhaust valves, as well as setting the valve overlap that occurs at the top dead centre on the exhaust stroke. The shaft is constructed with several journals that ride on bearings within the engine.
Camshaft endplay is adjusted with a thrust “button,” which rides on the front side of the camshaft. It rides against the timing chain cover, and serves as a stop for the camshaft. You can get a couple types of buttons: one is a steel roller and the other is a nylon button.
The basic function of a valve lifter is pretty simple. It sits on the camshaft and transfers the motions of the cam lobe up through the pushrods and rockers to open and close the valves. The size and shape of the cam lobe under the lifter (multiplied by the ratio of the rocker arms) determines valve lift and duration.
The camshaft, which opens and closes the valves, is driven from the crankshaft by a chain drive or gears on the front end of the engine.
Then gasoline can't get into the cylinders, and the exhaust gasses can't get out. Eventually, the valves won't open at all, and the car will stop running. It's not dangerous, but it will cause the car to go slower and slower over time, and may also in? crease the emissions.
The valves are actuated via the camshaft, which is in turn driven by the crankshaft and thus opens and closes the valves in synchronism with the motion of the piston. Combustion temperatures are emitted via the valves to the cylinder head and thus to the coolant circuit.
The actuator is the device connected to the valve through the valve stem that provides the force required to move the valve. As we said earlier, the actuator can be controlled electrically, pneumatically, or hydraulically. The most common and the most reliable is the “Pneumatic Actuator”.
The camshaft may have two sets of lobes where one set is designed for low and the other for high RPMs. As the camshaft rotates, the lobes push open the spring-loaded valves, which are then closed by the force of springs. An electronic control unit (ECU) selects which set of lobes to use based on the engine speed.
The motion of the engine valves is driven by the camshaft of the engine, which contains a series of lobes or cams that serve to create the linear motion of the valve from the rotation of the camshaft. The number of cam lobes on the camshaft is equal to the number of valves in the engine.
The camshaft is driven by the crankshaft by way of gearwheels, a toothed belt or a timing chain.
The camshaft controls the opening and closing of valves through the combustion process, and the crankshaft takes the energy from that process and connects it to the rest of the vehicle.
The function of camshaft:
The following three functions are: It promotes the opening of the inlet valve during the suction stroke. The second function is to open the exhaust valve during the exhaust stroke. Lastly, It keeps both the valves closed the rest of the time.
The camshaft's function is to open and close the valves at the top of each cylinder within the engine. Each cylinder has at least two valves – one that draws in a combustible air and fuel mixture that, when ignited, forces the piston downwards in the cylinder.