Advice / Dictionary: Crankshaft
02:43 PM | 22.09.2016 | Klosters
Dictionary: Crankshaft 22 September 2016 | Klosters

Dictionary: Crankshaft

The hip bone's connected to the ...


Dictionary: Crankshaft

The hip bone's connected to the ...

Let's not beat around the bush: some things about cars can be a bit boring, especially when it comes to engines.

Welcome to our Klosters guide to all the terms you hear thrown about in the dealership or workshop.


At the same time, engines are fascinating because of what they manage to do. Who would have thought that carrying out a rapid and ongoing series of controlled explosions within a modestly-sized metal box would make a 1.5-tonne vehicle roll smoothly along the road?

And it is the component that allows that process to happen that is the subject of this Dictionary story. That particular piece? The crankshaft.

When it comes to important components, the crankshaft pretty much tops the list because it converts the up-and-down (linear) action of the pistons -- the engine's reciprocation – into the rotational movement that drives the shafts which turn the wheels.

The crankshaft is made up of several offset sections (also known as ‘throws') to which the connecting rods are attached. Those rods also connect to the pistons so each explosion in the engine's combustion chambers turns the crankshaft.

Each connecting rod has a bearing which allows it to move freely around the crankshaft and is attached to the shaft by a crankpin journal.

The crankshaft lives at the bottom of the engine, below the cylinders, in a sealed, oil-filled box known as the crankcase. The crankcase often houses the drives for such items as the water and oil pumps and has an external pulley at its forward end to drive a mechanical radiator fan and water pump through a V-belt.

As well as managing all of that, the crankshaft is also linked to the camshaft(s) by a timing belt or timing chain which runs through and around the engine's timing gear.

The timing gear manages or ‘times' the operation of the inlet and exhaust valves relative to the crankshaft angle and fires the spark plugs when the pistons reach their optimum position in the cylinders.

The timing belt or chain is also used to drive other engine components and accessories.


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