What is the purpose of a rocker arm?

The rocker arm is the part responsible for transmitting the movement of the camshaft towards the intake and exhaust valves of the engine, a process that occurs through the direct contact of these parts with the tappets and according to the movement of the shaft.

Do overhead cams have rocker arms?

Some overhead cam engines employ short rocker arms in which the cam lobe pushes down (rather than up) on the rocker arm to open the valve. The opposite end opens the valve. These types of rocker arms are particularly common on dual overhead cam motors, and are often used instead of direct tappets.

What does the camshaft push on?

In an overhead valve engine, the camshaft presses on a pushrod which transfers the motion to the top of the engine, where a rocker opens the intake/exhaust valve. For OHC and DOHC engines, the camshaft operates the valve directly or via a short rocker arm.

What is the difference between camshaft and rocker arm?

The camshaft in an engine is responsible for the timing, lift, and the duration the valves stay open and closed. The profile of the camshaft lobe determines the valve action. That motion is first transmitted to the valve lifter and onto the pushrod and finally, the rocker arm, which contacts the stem of the valve.

Who invented rocker arms?

Jonathan “Rundle” Bacon
Jonathan “Rundle” Bacon created Rocker arms in the 19th century, rocker arms have been made with and without “rundle” roller tips that depress upon the valve, as well as many lightweight and high strength alloys and bearing configurations for the fulcrum, striving to increase the RPM limits higher and higher for high …

How does an overhead cam work?

The camshaft uses rotating lobes, called cams, that push against the valves to open them. The main benefit of dual overhead cams is that they allow an engine to have four valves per cylinder. Each camshaft operates two of the valves, one camshaft handles the intake valves, and one handles the exhaust valves.

How does a push rod work?

Pushrods are long, slender metal rods that are used in overhead valve engines to transfer motion from the camshaft (located in the engine block) to the valves (located in the cylinder head). The camshaft lobe moves the lifter upwards, which moves the pushrod.

Why is rocker arm made of I section?

The rocker arm is used to actuate the inlet and exhaust valves motion as directed by the cam and follower. It may be made of cast iron, cast steel, or malleable iron. In order to reduce inertia of the rocker arm, an I-section is used for the high speed engines and it may be rectangular section for low speed engines.

Is the rocker arm connected to the crankshaft?

the valves, push rods which connect the rocker arms and the cams on the camshaft and a drive connecting the camshaft to the crankshaft. In this way any motion of the cam is transferred to the valve by push rods and rocker arms.

What do you mean by rocker?

Definition of rocker 1a : either of two curving pieces of wood or metal on which an object (such as a cradle) rocks. b : any of various objects (such as a rocking chair or an infant’s toy having a seat placed between side pieces) that rock on rockers.