What's harmonic balancer in an engine?

A harmonic balancer sounds like a crucial part on a spaceship in some pulpy1950ssci-fi story, or something you need so you can play music with hobos when you're ridin' the rails. However, it's actually an important part on your engine that helps your crankshaft last as long as possible.

As the cylinders in your engine fire, they move up and down, generating torque that's transferred into the crankshaft. As you may already know, the crankshaft is what converts the engine's power into rotational movement, eventually turning the wheels of the car.

But consider for a second the forces that are acting on the crankshaft -- they're tremendous. Each time a cylinder fires, a force acts upon the crankshaft, causing it to twist. But this force also causes vibrations in the crankshaft, and at certain frequencies, the shaft can resonate, which makes the vibrations even worse.

These vibrations from the engine can become too much for the crankshaft to bear, causing it to fail. And when that happens, your car won't run and you'll be facing some expensive repairs.

This is where the harmonic balancer comes in. The circular device, made of rubber and metal, is bolted at the front end of the crankshaft to help absorb vibrations. It's usually connected to the crank pulley, which drives accessories like the air conditioner. The rubber inside the pulley is what actually absorbs the vibrations and keeps them at a safe level. In essence, the device is designed to help prevent crankshaft failure. It's also sometimes called a "dampener."

However, the rubber material can deteriorate over time. So if your harmonic balancer is going bad, you could get rough engine vibrations, a cracked crankshaft, or even a serpentine belt that gets thrown off its track. Replacing one is excellent preventative maintenance, and that's exactly what we'll talk about next.

A harmonic balancer is a device that is connected to an engine’s crankshaft in order to reduce any vibration’s negative impact on the crankshaft and to dissipate the energy that shaft rotation creates. Since the device is the engine compartment’s first element that is connected to the shaft, it absorbs the majority of the energy generated during engine use. By absorbing this energy, only the harmonic balancer (instead of more vital engine components) fails, thereby preventing catastrophic engine failure

1. A harmonic balancer reduces destructive crankshaft torsional vibration, which is the end-to-end twisting/rebound motion, that is naturally generated during each power stroke.  A harmonic balancer contributes to greater valve train and timing efficiency, plus reduces wear of critical engine components such as main bearings, oil pump and the crankshaft itself. A harmonic balancer often incorporates the main drive pulley and by appearance is often overlooked as having no essential function to the life of the engine. If the drive pulley is incorporated with the harmonic balancer, removing or changing it to a lightweight design, or using a low quality product MAY BE THE SINGLE BIGGEST COSTLY MISTAKE YOU CAN DO TO YOUR ENGINE.

    

A harmonic balancer (also called crank pulley damper, crankshaft damper, torsional damper, or vibration damper) is a device connected to the crankshaft of an engine to reduce torsional vibration and serves as a pulley for drive belts

I agree with Mr. Jetley's answer ... and have nothing to add at this time

Basically # 161.........................................