Spin a heavy weight and its inertia helps it continue spinning between power pulses. Just like a flywheel in an engine, the center portion’s mass is designed to add smooth power flow through inertia. A rubber isolation harmonic balancer has three components a heavy cast or machined center portion designed to create mass, a rubber isolation ring and an outer pulley. Most car makers choose the rubber isolation ring style because it’s much cheaper than the fluid isolation style and it does the job. The harmonic balancer can be constructed in two ways: with a rubber isolation ring or with a fluid isolation system. So the role of the harmonic balancer is to isolate the pulses and prevent the belt and driven components from vibrating. The end result would be a vibration or harmonic noise similar to plucking a guitar string. If you were to mount a solid pulley on the front of the crankshaft, each power pulse and crankshaft twist would transfer to the drive belt, causing them to vibrate from the constant stretch/release of the power pulses. Why you need a damper or harmonic balancer Between each power pulse, the crankshaft twist tends to spring back, so there’s really a forward and backwards twist.
WHAT DOES HARMONIC BALANCER DO SERIES
So what you see at the front of the engine is a series of pulsed rotations due to each power stroke and crankshaft twist. In fact, the power stroke on a cylinder can cause the crankshaft to twist by as much as 2°. The crankshaft is designed to bend slightly to accommodate the counteracting forces to prevent breakage. So there’s tremendous counteracting forces being applied to the crankshaft. At the same time the crankshaft is in the process of pushing another piston up on a compression or exhaust stroke. Each time a piston fires, the piston connecting rod applies rotational force to the crankshaft.
Most people think the engine rotates smoothly. Why would a pulley need to dampen anything, and what’s the deal with using the word “harmonic” in reference to a pulley? To understand what a harmonic balancer does, you find have to understand how an internal combustion engine works. It’s also referred to a crankshaft damper, vibration damper and a crank pulley damper. Repair Topics > Engine > What is a Harmonic balancer? What is a Harmonic balancer? How does a Harmonic work and how do they fail?Ī harmonic balancer is similar to an ordinary pulley but with several important additions.