By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Pulley Size calculation

All Topics | Latest Posts

Search for:  in Thread Title in  
Jose Aviles06/03/2018 15:27:52
2 forum posts

Thanks in advance for any help I needed to come up with a pulley drive system for a piece of equipment I am putting to together. I have an out put shaft spinning at 3000 RPM I need to reduce it down to 750 RPM what sizes pulleys would I need, I've tried some of the calculator's on line but I get different results any help is appreciated,

Brian Wood06/03/2018 16:28:38
2742 forum posts
39 photos

Hello Jose,

The actual pulley sizes you need will be those closest to giving you a ratio reduction of 1:4. The smallest diameter goes on the motor and the largest diameter goes on the piece of equipment.

Welcome to the forum

Regards Brian

Ian P06/03/2018 16:32:35
avatar
2747 forum posts
123 photos

The pulley diameters (or one of them anyway) might limit the maximum or minimum size of the pulleys you can use (or obtain) but the ratio of the two pulley diameters will stay the same.

3000 down to 750 rpm requires a reduction ration of 4:1 which is quite reasonable in one stage of belt drive. If the motor pulley was 2" it would need to drive an 8" on the output device.

Ian P

Ian P06/03/2018 16:33:19
avatar
2747 forum posts
123 photos

Brian was a lot more concise than my effort

Ian P

not done it yet06/03/2018 16:33:32
7517 forum posts
20 photos

1:4 ratio of effective diameter. Problem with fancy on-line calculators is that they use the particular effective pulley diameter - and that may be different for different belt cross sections.

Is your input speed actually 3000rpm under operating conditions? Do younneed exactly 750rpm output? Somehow I doubt one, or both are true.

Jose Aviles06/03/2018 16:43:38
2 forum posts

Thanks to all of you for your response , to be more exact it a 4cyl, diesel engine driving a high pressure water pump. the diesel max RPM is 3000 and the max pump operating RPM is 750 . also any recommendations where I might be able to get these pulley on line I may have to have them custom cut to the shaft sizes ill need. thank again to all

not done it yet06/03/2018 16:47:06
7517 forum posts
20 photos

With no idea of power requirements, can’t say.

Solutions using taper-lock systems will cover most sensible shaft sizes.

Almost certainly the engine will have some form of speed regulation.  More likely to need to pick an engine speed that matches the power of the pumping head.

Edited By not done it yet on 06/03/2018 16:49:50

J Hancock06/03/2018 16:55:54
869 forum posts

If this is a reciprocating plunger type pump you may need to do a bit of research into the type of belt and/or

pulley size (not ratio ) required.

The torque requirement may be a bit high/low through the revolutions.

inapickle06/03/2018 17:36:39
12 forum posts
Im not sure if this will be of any help, but it did help me
https://www.blocklayer.com/pulley-belteng.aspx
Brian Sweeting06/03/2018 17:42:36
453 forum posts
1 photos

Get in touch with a drive line supplier who will help with both the sizing and supply of the parts.

Someone like Brammer might be a starting point....

**LINK**

Howard Lewis06/03/2018 20:13:46
7227 forum posts
21 photos

Presumably the pump needs to be driven at 750 rpm, maximum for full capacity pumping?

Is the 3000 rpm of the engine the Rated Speed for full power, or the Flight Speed (Max No Load Speed)?

If 3000 rpm is Flight Speed then you may require a ratio of probably 2,700:750, or 2800:750 to obtain 750 rpm on the pump with the engine fully loaded.

The section of belt, and how many, will depend on what power the pump requires to be driven at 750 rpm fully loaded.

Howard

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate