PTO vs mounted engine chippers?

[treequip]

Excellent. Thanks! Know anything about vee-belt transmissions and why they're suitable for tow-behind chippers?

 

Just thought I'd chance asking!

 

If I may,

 

Vee belt transmissions are widely used in engineering, they are relatively cheap, low maintenance and compact. They are light and also offer the ability to introduce gearing into the drive.

[Stephen Blair]

offer the ability to introduce gearing into the drive.

 

a bit more info please:thumbup1:

[s o c]

v-belts cope better to fluctuations in load than chain or gear or chain drives. also dont need lubrication or slip/overload clutches. weigh less and relatively inexpensive

[treequip]

a bit more info please:thumbup1:

 

Engine output speeds tend to be in the 2700 to 3000 rpm range, your chipper wants to be doing about 1000rpm so the output shaft gets a pulley about 2/3rds the size of the flywheel input shaft pulley which gives you an appropriate speed.

 

Gearing on the cheap and light doing the same thing with a gearbox would be cumbersome and heaaaavy

[Stephen Blair]

I suppose they are a cheap weak link aswell, i would rather a belt slipped and squeaked than a drive shaft break or pto go boom!!!

[treequip]

They will slip (and ruin the belts) if they aren’t tensioned properly.

 

If properly installed between an engine and a flywheel there should be enough transmission to stall the engine

[skyhuck]

They will slip (and ruin the belts) if they aren’t tensioned properly.

 

If properly installed between an engine and a flywheel there should be enough transmission to stall the engine

 

Mine has 5 V belts that are tensioned with a sprung loaded tensioner, if I put through a piece of 9" Oak without stopping and starting the rollers, the belts just disintegrate and the engine rev's don't even drop.

[Root Beard]

Blimey! Thanks Peeps! Very useful info.

[treequip]

Mine has 5 V belts that are tensioned with a sprung loaded tensioner, if I put through a piece of 9" Oak without stopping and starting the rollers, the belts just disintegrate and the engine rev's don't even drop.

 

I have a 9" chipper being driven a 245hp unmog

 

As a rule of thumb 10hp per inch is adequate

 

Modern machines with stress control can get away with a lot less.

 

So 245hp less, lets say 45(for the sake of round numbers) in mechanical loss through the gearbox leaves you with about 200hp at the output shaft. Your chipper could get away with half of that.

 

Power is nothing without control.

[Root Beard]

As a result of all your help, I've hit my deadline. Thank you!