What Is A Camshaft? Its Parts and How It Works

Since the beginning of the internal combustion engine, the camshaft has been one of the most important components. In the 21st century, its working principle is still the same in automobile engines. Camshafts are simple component lengths of rod or shaft, with some individual cam lobes positioned along them.

The shaft rotates, allowing the shape of the cam to act upon a valve. It’s responsible for pushing against valves that open and close the compression and exhaust strokes. The speed of the rotation controls the rate of its actions.

In this reading, we’ll explore what a crankshaft is, how it works, its diagram, parts, and more.

Let’s get started!

What Is a Camshaft?

A camshaft is a shaft designed to convert rotational motion into reciprocating motion through a series of pointed cams. Early electric motor speed controllers and mechanically controlled ignition systems, as well as piston engines—which run the intake and exhaust valves—rely on camshafts.

The shaft consists of a cylindrical rod running the length of the cylinder bank. This camshaft works with a number of cams along its length. One lobe for each valve. These lobes force the valve to open by pressing on them.

Some intermediate mechanism is used for the valve closure. As the camshaft rotates, there are springs set in place to close the valve. This happens as the lobes reach their highest point on the push rod, which is when the valve is completely open. The spring pulls back the valve, causing the valve to close.

How a Camshaft Works

This camshaft working principle is different from modern vehicles. Modern internal combustion engines find camshafts useless in their work. Their calibration controls the amount of air-fuel mixture that enters the chamber. This air fuel enters at a precise level. After combustion, the exhaust gas exits the chamber, making way for the next mixture.

This design doesn’t just affect the engine’s efficiency and operation. The movement of the engine piston is supposed to be perfectly synchronized with the opening and closing of the valves. It has a drastic effect on the vehicle’s performance.

The camshafts are connected through a timing belt or chain to ensure their timing and turning. It directly moves the pistons inside the cylinder. The working design of the camshaft lobes also controls the speed at which the valves open and close. Thus, this is the working principle of the camshaft on modern engines.

Diagram Of a Camshaft

Camshaft

Camshaft Material

Camshafts are made from metal for rigidity. Cast iron is used because it offers such strength for mass production. Chilled iron camshafts have good wear resistance as the chilling process hardens the material. Some other elements are added to the iron before casting in order to obtain more suitable properties for its application.

When high-quality and low-volume production is necessary, manufacturers use billet steel. although it’s more time-consuming and expensive than other methods. Its construction method is either forging, casting, or machining (metal lathe or milling machine). Different steel bars can be used.

Major Parts Of The Camshaft

Below are the major parts of a camshaft:

Main Journals

The camshaft’s power comes from a constant rotation. The function of the journals is to keep the camshaft in place as it spins around the engine bay.

Lobes

as the piston spins, the lobes rotate together with the piston motion. The functions of the lobes are to open and close the valve for the intake and exhaust gases. The speed of the cam lobes depends on the engine’s speeds.

Ends

the front end of the cam is designed to carry a belt to connect with the crankshaft.  The rear end of the cam turns the distributor of the engine with special gear. The ignition timing is in tune with the rest of the engine with this part.

Bearings

This component is mounted in conjunction with the main journals. It helps prevent the camshaft from damaging the engine block when the engine becomes faulty. Bearings help to keep the rotation of the camshaft seamless.

Relationship Of Camshaft and Crankshaft

This two-drive system relationship, camshaft, and crankshaft rotation. Due to the fact that the valve controls the flow of the air/fuel mixture intake and exhaust gases,. For proper opening and closing timing during the piston stroke, the camshaft controls this valve.

This is the reason why the camshaft is connected to the crankshaft directly through a gear mechanism. It’s also connected indirectly via a belt or chain called a timing belt or timing chain. The direct mechanism process is unusual due to its cost.

Causes Of Camshaft Failure

There are several issues that can arise with the camshaft. If issues are not noticed, it can cause the engine to completely break down. Below are the major causes of camshaft failure:

  • Lobe wear.
  • Improper break-in.
  • Oil lifters with a new cam.
  • Mechanical interference occurs as the spring coil binds the retainer to the seals and the valve to the piston. interference, and a rocker arm slot to stud interference.
  • Broken cam.
  • Excessive end play.
  • Broken dowel pins or keys.
  • Incorrect valve spring pressure.
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