Anyone Know?

View previous topic View next topic Go down

Anyone Know?

Post  TomBreeds Agricultural on Thu 03 Aug 2017, 11:52 am

Does anyone know the throw on the crank, i'm currently at college and conversation has been sparked to do the maths on torque output of the Burrell
avatar
TomBreeds Agricultural

Number of posts : 36
Age : 21
Location : Bedfordshire
Registration date : 2014-12-03

View user profile

Back to top Go down

Re: Anyone Know?

Post  JayBee on Thu 03 Aug 2017, 12:12 pm

Can't help for the agricultural but the Showman is 99mm full movement making the crank 44.5 on radius if that helps. That's 1 3/4" in old money.

Ooooops bad maths 49.5 throw.


Last edited by JayBee on Thu 03 Aug 2017, 12:31 pm; edited 1 time in total

JayBee

Number of posts : 84
Location : Cumbria UK
Registration date : 2015-11-23

View user profile

Back to top Go down

Re: Anyone Know?

Post  Lynn@STW on Thu 03 Aug 2017, 12:21 pm

Hi

48mm between centres on the crank. So should be 96mm total travel.
Cylinder bore between ports is 104mm

Lynn@STW

Number of posts : 87
Location : Daventry
Registration date : 2017-07-19

View user profile http://www.steamtractionworld.co.uk

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Thu 03 Aug 2017, 9:58 pm

TomBreeds Agricultural wrote:Does anyone know the throw on the crank, i'm currently at college and conversation has been sparked to do the maths on torque output of the Burrell

Oh this will be interesting I get quite a lot of questions on output power on the Agri.

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  LazySmurfer on Thu 03 Aug 2017, 11:10 pm

I'm sure I read on here somewhere its only 1hp
avatar
LazySmurfer

Number of posts : 64
Age : 50
Location : Potton Bedfordshire
Registration date : 2016-10-21

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Mon 07 Aug 2017, 9:23 pm

Do we need to get one on a Dyno Laughing Laughing Laughing

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  TomBreeds Agricultural on Tue 08 Aug 2017, 9:52 am

LiveSteam wrote:Do we need to get one on a Dyno Laughing Laughing Laughing

this sounds like a better idea than what we done at college, not sure f were correct but we worked out 4hp approx. at the axle
avatar
TomBreeds Agricultural

Number of posts : 36
Age : 21
Location : Bedfordshire
Registration date : 2014-12-03

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Tue 08 Aug 2017, 9:11 pm

TomBreeds Agricultural wrote:
LiveSteam wrote:Do we need to get one on a Dyno Laughing Laughing Laughing

this sounds like a better idea than what we done at college, not sure f were correct but we worked out 4hp approx. at the axle

That would seem quite a bit more than I would expect, would mean it would have the ability to generate nigh on 3kw Exclamation I could be barking up the completely wrong tree here but if you take say a regular petrol generator to get something like 3kw of output power you need to feed it with around 6-7hp of petrol power, I have a 5kw genny and that needs 10hp lump to to get that output.

Its an interesting topic

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Steve Traill on Fri 11 Aug 2017, 9:16 pm

I think we're talking about different horses here! The horse power of a steam engine is based on the cylinder size not it's power output which is a measurement of the power generated by a diesel or petrol engine.
avatar
Steve Traill

Number of posts : 684
Age : 60
Location : Illogan Redruth Cornwall
Registration date : 2008-06-29

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Sat 12 Aug 2017, 12:26 pm

Steve Traill wrote:I think we're talking about different horses here!  The horse power of a steam engine is based on the cylinder size not it's power output which is a measurement of the power generated by a diesel or petrol engine.


But surely the two are linked, its all power at the end of the day 1hp = about 750W thus if you want to produce 750W you need 1hp, of course in the real world you have losses and thus you need more that 1hp to produce 750w, unless there is a completely different set of horses ?? Although Wiki seems to say they are similar https://en.wikipedia.org/wiki/Horsepower


LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Steve Traill on Sun 13 Aug 2017, 11:28 pm

I don't think the two are linked in any way as we are talking about different periods in time and before steam power there was only muscle power. With steam they needed a way of expressing the power of the engine and the cylinder size was proportional to it's power. With combustion engines they needed a more accurate way of measuring power at different revs. Steam has maximum power from the start (that's how it can pull a train) a combustion engine needs to rev up first to get any power.
avatar
Steve Traill

Number of posts : 684
Age : 60
Location : Illogan Redruth Cornwall
Registration date : 2008-06-29

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Mon 14 Aug 2017, 9:21 pm

Ah but arnt we now talking about torque, electric motors offer max torque from zero RPM.

While I'm in no way proclaiming I know what I'm talking about here just an interest in finding out, digging about it seems that it all revolves around the PLAN/33000 calculation which as you say is down to cylinder size etc

P=Mean Effective Pressure in Cylinder, which we can assume is steam pressure
L=Length of Stroke in FEET which for a double acting I assume would need to be x 2
A=Area of Piston in Inches, thats simple enough.
N=Revolutions per minute, again simple enough

1HP = the amount of power necessary to raise 33,000 lbs. one foot in one minute.

Thus its all of the above divided by the magic 33'000

This forumula works for steam and combustion engines as power is power at the end of the day, thus any form of HP can surely be expressed in Kw, Watts, or PS ?

So I agree its down to cylinder size but there are a number of other factors we need to take into consideration.

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Goliewogs on Mon 14 Aug 2017, 9:43 pm

Please correct me if I'm wrong (I probably am) - but I always thought 1HP = the ability to raise 1 ton (2240lbs) 1 foot in 1 minute. Where does the 33,000 lbs come from?
Greg

Goliewogs

Number of posts : 24
Age : 66
Location : FRANCE - Normandie
Registration date : 2016-03-28

View user profile

Back to top Go down

Re: Anyone Know?

Post  Mark the spark on Mon 14 Aug 2017, 10:20 pm

Steam also gives you max torque at zero revs that's why its difficult to pull away from a station with a loco

Mark the spark

Number of posts : 178
Location : Edinburgh
Registration date : 2015-04-26

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Tue 15 Aug 2017, 8:08 am

Goliewogs wrote:Please correct me if I'm wrong (I probably am) - but I always thought 1HP = the ability to raise 1 ton (2240lbs) 1 foot in 1 minute. Where does the 33,000 lbs come from?
Greg

As mentioned I am no mathmatics person so I am only going on what I am finding via the world of google, which isnt always correct I realise, however I do not ever take the first answer I find and like to find multiple places where the same things are mentioned and it does appear 1Hp = the ability to raise 33,000 lbs. one foot in one minute or 550 lbs one foot in one second, your 2240lbs appears to come from lifting items in water it seems, I could be wrong though.

There is also chatter about boiler capacity being a factor in steam HP but its very vague.

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Goliewogs on Tue 15 Aug 2017, 8:37 am

Hi, Yes I am wrong as usual!! The 2240 is a red herring and I don't know where it comes from - the 550 foot pounds/second is correct! I did a little revision last evening and there are many formulae nowadays, including 'boiler horsepower' - new one on me. There are also formulae for PS and BHP etc etc - I shall not try to remember them but they are easy enough to look up and apply when required I think! Good luck with your calculations!!

Goliewogs

Number of posts : 24
Age : 66
Location : FRANCE - Normandie
Registration date : 2016-03-28

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Tue 15 Aug 2017, 9:28 am

I wouldnt say wrong, just its used in a different calculation Smile

From what I can see the issue will be getting rpm, I've not got an rpm meter, might need to borrow one at somestage to get that or knock something up with some kind of sensor thingy on the flywheel. Everything else we can get.

Further musings, if this is how we get the engines power for say a single cylinder double acting agri, what happens when its a compound engine, I wonder if that changes anything or just increases efficiency ?

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Capricorn1 on Tue 15 Aug 2017, 11:21 am

http://www.paxmanhistory.org.uk/nhp-defn.htm

Have a chew on the above link.

Engines were classified by their NHP, IHP was derived from an engine indicator, BHP is taken from a dynamometer.

By definition Nominal is the lowest HP an engine may produce.... regardless apparently of rpm.

Steam engines do develop maximum torque at zero revolutions but that isn't the reason why some locomotives loose their feet pulling away, an experience driver with a heavy train would
go steady with the regulator and watch the steam chest pressure gauge.

As regards compound engines, the above link suggests treating the engine as a duplex - ie twin cylinder to calculate NHP.

Capricorn1

Number of posts : 64
Location : West Yorkshire.
Registration date : 2013-07-22

View user profile

Back to top Go down

Re: Anyone Know?

Post  LiveSteam on Wed 16 Aug 2017, 10:43 pm

Capricorn1 wrote:http://www.paxmanhistory.org.uk/nhp-defn.htm

Have a chew on the above link.

Engines were classified by their NHP, IHP was derived from an engine indicator, BHP is taken from a dynamometer.

By definition Nominal is the lowest HP an engine may produce.... regardless apparently of rpm.

Steam engines do develop maximum torque at zero revolutions but that isn't the reason why some locomotives loose their feet pulling away, an experience driver with a heavy train would
go steady with the regulator and watch the steam chest pressure gauge.

As regards compound engines, the above link suggests treating the engine as a duplex - ie twin cylinder to calculate NHP.

Thats an excellent link and one I found later today and was going to post and now have seen your post, the NHP thing is very interesting and while I've read and seen it before never actually understood it, love a bit of new learing Smile

So has our original poster sussed out the torque/HP/NHP of the little Agri yet, it looks like we need the piston diameter to finish things off. the websites says its Cylinder Size 2 3/4" x 3 1/4"

LiveSteam

Number of posts : 440
Location : Hampshire
Registration date : 2013-09-08

View user profile

Back to top Go down

Re: Anyone Know?

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum