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Key Differences Between Combustion Engine Bearings and Electric Motor Bearings Used In Automobiles 

Posted: Nov 10, 2020 11:54:02 AM

Bearings differ between internal combustion engines and electric motors used in automobiles.  Internal combustion engines require main crankshaft bearings, connecting rod bearings, camshaft bearings, and more. Electric motors, on the other hand, are more simple and only require a shaft to spin as the oscillating electric/magnetic field drives the rotational motion of the shaft. To learn more about these automotive bearings, read on.

Bearings in Internal Combustion Engines

For the last 100 years automotive bearings in an internal combustion engine consisted primarily of the main (crank shaft) bearings, connecting rod bearings, piston head bearings, and camshaft bearings. It truly was brilliance in tribology to allow all these parts to move in perfect harmony. It all started in 1864 when Nicolas Otto developed and patented the first IC engine. Auto enthusiasts still love the sound that is generated from this engineering marvel. Most bearings were and still are made from high strength alloy steel to allow for the rigors of today’s high revving motors and long service requirement.

Main crankshaft bearings

Used to support the crankshaft and allow smooth rotation. These bearings allow the oscillating forces to be transmitted to the connecting rods.

Connecting rod bearing

These bearings allow smooth conversion of power from the main crank to the connect rods.

Piston head bearings

The articulating motion of the head of the piston is critical to proper sealing inside the cylinder.  The bearings in the head of the piston allow for the constant oscillating of the crack mechanism.

Camshaft bearings and cam followers

Finally you have bearings on the cam shaft that simply allow the shaft to rotate. Oftentimes there are cam followers and/or a lifter mechanism that allows the valve to be opened and closed.

Bearings in Electric Motors

Electric motors simplify the bearing requirements markedly as there are much less moving parts.  The reality is that the only bearing required is to allow a shaft to spin as the oscillating electric/magnetic field drives the rotational motion of the shaft.  Each wheel oftentimes will have its own electric motor powering it as opposed to a single IC power-plant. Even with multiple motors, there are undoubtedly fewer moving parts. Because of the simplicity and kinetic directness to the wheels, they are inherently more efficient. Much to the chagrin of many automotive enthusiasts, they are almost completely silent because of the lack of the complicated mechanical assembly.

In the coming years, as more states and countries begin to adopt and/or mandate electric vehicles, automotive bearing technology will evolve. Ceramic bearings are already becoming more commonplace as they are harder, stronger, and should inherently last longer than metallic bearings. Perhaps the greatest benefit of the ceramic bearing is that they are not electrical conducts so they don’t have any impact on the electrical/magnetic field. It’s not much of a stretch to imagine a time when all vehicles are driven by an energy source other than an internal combustion engine.  Engineers may one day marvel at the inefficiencies of the internal combustion engine and  view it  as a relic similar to a fax machine!


Whether or not you need automotive bearings for internal combustion engines, electric motors, or something else altogether, Hartford Technologies has the expertise and deep industry knowledge to assist. To learn more about our pins, our precision specialty balls, our customized bearing assemblies for automotive manufacturing, we invite you to contact us today.