What is a roots blower?

Question

I tired Wikipedia, but I am still confused; what exactly is a roots blower?

Answer 1

Well, I know a little about locomotives and I am an NHRA fan.  And, Rango is correct.    But, there are differences.

For the 8000 hp nitro burning 1/4 milers, a super-charger is used.  Often called a blower.  But, these are driven by a pulley system with idlers, running off of the crankshaft..

On EMD prime movers, the Roots blower system is gear driven internally, with no belts, pulleys or other parts of the mechanism outside.  Older EMD prime movers utilized the Roots system.

When EMD began applying turbo-chargers to their engines, they opted for a hybrid.  It is gear driven, like a roots blower, up through the run#5 throttle position.  Then, above that, a clutch disengages the gear works, and it begins to operate as a true turbo-charger, exhaust driven.  EMD prime movers are two stroke engines and the gear drive was more efficient until the engine was run at higher speeds.

Both are used with a rack injection fuel system on the EMD prime movers.

A very good question.  Thanks for asking.

Answer 2

Roots was the last name of the inventors.Wikipedia should have stated that.its basic purpose is to pump air.Most often these days into  car/truck engines.The internal combustion engine itself is basically just an air pump.Unfortunately it is fairly inefficient.By installing a blower,which forces air into the cylinders,you can increase the amount of air pumped through the engine,greatly increasing its output(Horsepower and torque)

Answer 3

http://www.theblowershop.com/ Inefficient?  Why are the guys in the NHRA still use them, I guess they need to be educated.

Answer 4

Dr.Phil...production engines are fairly inefficient, they usually hit about 75-80% volumetric efficiency, modified and high performance engines about 80-90% and your, race engines will reach 100% and those 'NHRA' engines will acheive over 100% volumetric efficiency. How??? Forced induction.

A roots blower, like charger_.. said, is called a 'Roots' after the creator. it is a belt driven air pump that uses opposing 'gears' with very tight clearances between them to force air into the engine, thus creating more hp/torque, and increasing the volumetric efficiency of the engine.