Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Miscellaneous and Off Topic Forums > Off Topic Discussions


Reply
 
LinkBack Thread Tools Rating: Thread Rating: 1 votes, 1.00 average.
Author
Thread Post New Thread    Reply
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
Belt / pulley engineers

Is there a rule of sorts for power losses on a pulley?
I checked google for a hour.......sort of got lost...they did 90 deg turns......
Just pulley to pulley........
Is there A rule of thumb of sorts per belt?
thanx!

__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between
Old 01-07-2014, 12:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Get off my lawn!
 
GH85Carrera's Avatar
 
Join Date: Nov 2007
Location: Oklahoma
Posts: 85,086
Garage
Use suspenders not a belt and your pants don't lose any power. For ultimate power use both a belt and suspenders!
__________________
Glen
49 Year member of the Porsche Club of America
1985 911 Carrera; 2017 Macan
1986 El Camino with Fuel Injected 350 Crate Engine
My Motto: I will never be too old to have a happy childhood!
Old 01-07-2014, 12:27 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
wow........................This used to a place of great thought.
__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between
Old 01-07-2014, 12:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Did you get the memo?
 
onewhippedpuppy's Avatar
 
Join Date: Mar 2003
Location: Wichita, KS
Posts: 32,541
You would have a coefficient of friction between the belt/pulley, which would be a function of materials, interface, and belt tension. That would be one way to calculate the losses, though guys that do it for a living probably have a more clever way.
__________________
‘07 Mazda RX8-8
Past: 911T, 911SC, Carrera, 951s, 955, 996s, 987s, 986s, 997s, BMW 5x, C36, C63, XJR, S8, Maserati Coupe, GT500, etc
Old 01-07-2014, 12:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
beepbeep's Avatar
 
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
Rule of thumb:
1. V-belt will loose more than flat-belt.
2. The more "bends" you do the more power you loose.
__________________
Thank you for your time,
Old 01-07-2014, 12:45 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Ayo Irpin, Ukraine!
 
70SATMan's Avatar
 
Join Date: Mar 2004
Location: Santa Cruz, CA
Posts: 12,552
For every 2 pulleys you lose 288.
__________________
Harmlessly passing gas in the grassland away;
Only dimly aware of a certain smell in the air
Old 01-07-2014, 01:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
závodník 'X'
 
intakexhaust's Avatar
 
Join Date: Sep 2010
Posts: 8,185
Garage
OP - wide open that leads to a 1000 questions with a 10000 different answers. For example, cogged belt (as in an engine timing belt) vs. V type smooth vs. V w/notched....

For start > Belt Tension Theory: Factors

Timing belts > http://apps.gatesmectrol.com/applications/doc/Belt_Theory.pdf
__________________
“When these fine people came to me with an offer to make four movies for them, I immediately said ‘yes’ for one reason and one reason only… Netflix rhymes with ‘wet chicks,'” Sandler said in a prepared statement. “Let the streaming begin!” - Adam Sandler

Last edited by intakexhaust; 01-07-2014 at 01:12 PM..
Old 01-07-2014, 01:09 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
V belts
this particular application runs about 7 pulleys
engine, jack shaft,
then sprocket 15 pound chain to a HUGE sprocket (to gear it all dwn)
I can do this with one drive shaft, and a ring gear (ring and pinion type )
I am thinking this would be so much simpler get rid of a bunch of stuff
__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between

Last edited by afterburn 549; 01-07-2014 at 02:10 PM..
Old 01-07-2014, 02:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Navin Johnson
 
TimT's Avatar
 
Join Date: Mar 2002
Location: Wantagh, NY
Posts: 8,808
Took a few seconds to find this

TUTORIAL – PULLEY DRIVE SYSTEMS


It is not a simple exercise, It is a dynamic system with many variable..Your going to need some good math skills, DiffEq's etc..


This is also some light reading on the subject
__________________
Don't feed the trolls. Don't quote the trolls
http://www.southshoreperformanceny.com
'69 911 GT-5
'75 914 GT-3
and others

Last edited by TimT; 01-07-2014 at 02:15 PM..
Old 01-07-2014, 02:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
WOW
and thanx
Some one was a genius to come up with this belt system.....
I think one more tweek is to get rid of it all togther
__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between
Old 01-07-2014, 02:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Ayo Irpin, Ukraine!
 
70SATMan's Avatar
 
Join Date: Mar 2004
Location: Santa Cruz, CA
Posts: 12,552
Quote:
Originally Posted by afterburn 549 View Post
V belts
this particular application runs about 7 pulleys
engine, jack shaft,
then sprocket 15 pound chain to a HUGE sprocket (to gear it all dwn)
I can do this with one drive shaft, and a ring gear (ring and pinion type )
I am thinking this would be so much simpler get rid of a bunch of stuff
What's the transmission loss of your drive shaft idea? How much weight will your application add for a drive shaft and ring gear sized to take the stress compared to the weight of the pulleys and belts? Adding weight results in power loss as well.

Are there multiple speeds involved with driving individual components off the pulleys?

How are you going to keep that drive shaft lubed? How many hours are you going to get on that drive shaft before the lash wear is out of spec? What will be needed to R/R that drive shaft as opposed to R/R belts?

Sometimes engineering is not driven entirely by complexity or the number of components used.
__________________
Harmlessly passing gas in the grassland away;
Only dimly aware of a certain smell in the air
Old 01-07-2014, 02:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
Right now the system is toast between 1oo and 200 hours
A simple ring gear arrangement will weigh no more, should out last all other components involved.
I do appreciate everyone's help.
If in a car loses are 10 to 15% through a simple drive train. these belts is a parasitical nightmare .
Plus all the adjusting all the time
__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between
Old 01-07-2014, 02:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Unregistered
 
sammyg2's Avatar
 
Join Date: Aug 2000
Location: a wretched hive of scum and villainy
Posts: 55,652
I have all that info in some books in my office, it'd prolly take an hour to find all the info to answer your questions given that there are a go-zillion variables.

Are you talking about a standard V belt? Which size, A,B,C,D, DD? Yeppers just like bras.

Pitch diameter of each shieve, RPM of smallest, etc.
Number of belts, seperated or banded?
Or are you referring to a serpantine belt?
Which belt manufacturer?

I'm not aware of any general rule of thumb that applies to all V belts. Life ain't that simple in my world. Too damn many variables.

BUT, I will say that a properly designed and installed belt system can reach 95% efficiency and should always be over 90% efficient or someone screwed up.
Old 01-07-2014, 02:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Navin Johnson
 
TimT's Avatar
 
Join Date: Mar 2002
Location: Wantagh, NY
Posts: 8,808
Quote:
BUT, I will say that a properly designed and installed belt system can reach 95% efficiency and should always be over 90% efficient

Yes

Quote:
Most references cite efficiencies between 90 and 98
percent for various belts with 95 percent being a typical
value [1-11]. Experimental data, however, for the current
spectrum of belt types, constructions, and application con-
ditions is not generally available.
Energy Loss and Belt Efficiency

Quote:
Too damn many variables.
Yes
__________________
Don't feed the trolls. Don't quote the trolls
http://www.southshoreperformanceny.com
'69 911 GT-5
'75 914 GT-3
and others
Old 01-07-2014, 02:41 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Unregistered
 
sammyg2's Avatar
 
Join Date: Aug 2000
Location: a wretched hive of scum and villainy
Posts: 55,652
Quote:
Originally Posted by afterburn 549 View Post
V belts
this particular application runs about 7 pulleys
engine, jack shaft,
then sprocket 15 pound chain to a HUGE sprocket (to gear it all dwn)
I can do this with one drive shaft, and a ring gear (ring and pinion type )
I am thinking this would be so much simpler get rid of a bunch of stuff
Just saw this. Reminds me of some old nightmare papermills I worked in as a kid.
Needs some serious engineerin'.
Old 01-07-2014, 02:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Air Medal or two
 
afterburn 549's Avatar
 
Join Date: Jul 2003
Location: cross roads
Posts: 14,081
Thanx
i could live with a couple belts.......but OMG!
From engine to 1st jackshaft its a set of 4
thats right, engine shaft with 4 pulleys to jackshaft again 4 pulleys
they are about 6 inches across on the jack. maybe 4" on the engine...i understand they were stepping torq up and RPM dwn........
I am thinking cause they are "V" belts...there is a loss right there...
__________________
D troop 3/5 Air Cav,( Bastard CAV) and 162 Assult Helicopter Co- (Vultures) South of Saigon, U Minh Forest, Delta, and all parts in between
Old 01-07-2014, 02:51 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Un-Registered User
 
Join Date: Apr 2007
Location: Upstate New York
Posts: 902
A ring gear would be a solid coupling whereas the belts/pulleys have more compliance.
__________________
Don
1988 Targa
Old 01-07-2014, 05:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
You do not have permissi
 
john70t's Avatar
 
Join Date: Aug 2001
Location: midwest
Posts: 39,923
Best guess:
Large lightweight balanced pulleys(aluminum/mag) using the same overall ratio, thin flat ribbed belt, add tensioners where needed to make the path round but flexible under heavy load.
Old 01-07-2014, 05:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Max Sluiter
 
Flieger's Avatar
 
Join Date: Mar 2006
Location: So Cal
Posts: 19,644
Garage
Quote:
Originally Posted by Red88Carrera View Post
A ring gear would be a solid coupling whereas the belts/pulleys have more compliance.
A long shaft to the back of a helicopter would/could have plenty of compliance. I actually would worry about too much compliance without extra bearings, especially when pulling g's or in turbulence.



But I guess he must be talking about shafts directly from the engine/transmission rather than with some layshafts.
__________________
1971 911S, 2.7RS spec MFI engine, suspension mods, lightened
Suspension by Rebel Racing, Serviced by TLG Auto, Brakes by PMB Performance
Old 01-07-2014, 05:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Un-Registered User
 
Join Date: Apr 2007
Location: Upstate New York
Posts: 902
Quote:
Originally Posted by Flieger View Post
A long shaft to the back of a helicopter would/could have plenty of compliance. I actually would worry about too much compliance without extra bearings, especially when pulling g's or in turbulence.



But I guess he must be talking about shafts directly from the engine/transmission rather than with some layshafts.
A shaft with compliance is not a shaft, it is a torsion bar.

__________________
Don
1988 Targa
Old 01-07-2014, 05:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply


 


All times are GMT -8. The time now is 07:15 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.