harmonic vibrations/ how can anyone explain

[gtech12v]

this in on the steam action website :to extend the life of an air-cooled engine. Balance the engine to remove the harmonic vibrations
can the experts elaborated please

 

[Lee Stockwell]

Smooth out the pulses.

 

[Lee Stockwell]

When you push someone in a swing you try to do it just at the right time to smoothly accelerate them. Do it at the wrong instant and you will both know it

 

[Lee Stockwell]

2 cylinder engine have one powerpulse per revolution, alternating sides. If you have a direct coupled load with a similar irregular rotating load vibrations can multiply.

 

[gtech12v]

Thank's Lee
can the blower and the small engine be synchronize to achieve less vibration on a TM

 

[Lee Stockwell]

Yes. Belt driven blowers are less susceptible to harmonic vibration.

Direct coupled can be rotated a few degrees to minimize the effect.

 

[gtech12v]

Yes. Belt driven blowers are less susceptible to harmonic vibration.

Direct coupled can be rotated a few degrees to minimize the effect.

can you explain how to
please

 

[Lee Stockwell]

If you have a noticeable vibration at speed or under load, uncouple and rotate the blower, perhaps 90 degrees, and re couple.

See if that helps.

 

[dgardner]

Only if the blower is direct coupled or driven with a timing belt - won't help if the blower is v-belt driven - you alluded to this earlier Lee....

 

[dgardner]

And the statement on the website is a little misleading - "balancing the engine" typically refers to static balancing the reciprocating parts (piston, rings, conrod, etc against the crank counterweight) and rotating parts such as flywheel.

Harmonic vibrations are usually related to torsional flex and not related to static balance.

A good deal of the Harmonic vibration acts on the crankshaft and is not felt outside the engine.

A very complex subject - and I'm by no means an expert btw....

 

[bob vawter]

great answers Lee