• OFF TOPIC fun forum - NO politics - NO religion - NO jerks. It's not complicated. Thanks!

Theory question - No, not homework!

Status
Not open for further replies.

J_Walker

New member
Messages
898
Reaction score
1
Location
Florida
For the sake of argument. Say you have an engine that runs a constant 5 HP at 2,000 RPM.

Lets say, the engine cannot be slowed down, and is stuck at a constant 2,000 RPM.

Is there a device that would allow for not the engine to slow down, but allow you to stop an go a moving let just say "kart" and control the speed? With keeping the engine at a constant speed. Remember, the engine is stuck at 2000 RPM. And braking the engine would shut it off and give you 0 RPM, so its either 0 RPM or 2000 RPM. And you want this kart to move but you don't wanna do a burn out dropping the clutch every time And also be stuck going "max speed" how would one go by with speed control? Really advanced transmission? I'm kinda stumped. I've got some time on my hands to theorize. Figured I'd get the ideas from others.

My idea behind this is, maybe to have more advanced transmissions that put less load on the engines [more so then now] the little more power you could squeeze out of one. Again, this is just me coming up with a theory and trying to wrap my head around how it could "possibly" be done. Also been staring at some alternative engines, Sterling engine is "Cool" but not "practi-cool." practical, in real world use. One I found very neat is the Co2 Engines.. Was thinking about them quiet a lot. more staring blankly.. but Just waiting for an idea to come up in my head! then thought of this question.

Co2 engine gave me a few ideas, now only if I knew how to chemically compress stuff..
 

B.M.800

TheBeal.
Messages
2,387
Reaction score
24
Location
Central PA
I think you would need a manual clutch a fancy transmission.
Depending on the speeds you want that may be difficult. If you wanted a "granny gear" and top speed of lets saw 30mph, there would need to be some crazy gear reduction going on...

Might end up being a big hunky unit.

I dunno...
 

J_Walker

New member
Messages
898
Reaction score
1
Location
Florida
I think you would need a manual clutch a fancy transmission.
Depending on the speeds you want that may be difficult. If you wanted a "granny gear" and top speed of lets saw 30mph, there would need to be some crazy gear reduction going on...

Might end up being a big hunky unit.

I dunno...

But what if lets say torque was a huge number... Would something really that heavy matter then??
 

B.M.800

TheBeal.
Messages
2,387
Reaction score
24
Location
Central PA
What like 400ft. lbs?:D
Imagine that on a go kart... *drool*

I rekon that would be the way to go, a manual clutch that you could slip to slow down or whatever, along with a good transmission...
 

machinist@large

Active member
Messages
2,865
Reaction score
32
Location
West Michigan, 49331
Transmissions

For the sake of argument. Say you have an engine that runs a constant 5 HP at 2,000 RPM.

Lets say, the engine cannot be slowed down, and is stuck at a constant 2,000 RPM.

Is there a device that would allow for not the engine to slow down, but allow you to stop an go a moving let just say "kart" and control the speed? With keeping the engine at a constant speed. Remember, the engine is stuck at 2000 RPM. And braking the engine would shut it off and give you 0 RPM, so its either 0 RPM or 2000 RPM. And you want this kart to move but you don't wanna do a burn out dropping the clutch every time And also be stuck going "max speed" how would one go by with speed control? Really advanced transmission? I'm kinda stumped. I've got some time on my hands to theorize. Figured I'd get the ideas from others.

My idea behind this is, maybe to have more advanced transmissions that put less load on the engines [more so then now] the little more power you could squeeze out of one. Again, this is just me coming up with a theory and trying to wrap my head around how it could "possibly" be done. Also been staring at some alternative engines, Sterling engine is "Cool" but not "practi-cool." practical, in real world use. One I found very neat is the Co2 Engines.. Was thinking about them quiet a lot. more staring blankly.. but Just waiting for an idea to come up in my head! then thought of this question.

Co2 engine gave me a few ideas, now only if I knew how to chemically compress stuff..

I think you would need a manual clutch a fancy transmission.
Depending on the speeds you want that may be difficult. If you wanted a "granny gear" and top speed of lets saw 30mph, there would need to be some crazy gear reduction going on...

Might end up being a big hunky unit.

I dunno...

That's actually a problem that is being worked on by many of the world's automakers; an engine running at a constant speed can be tuned to give the best balance of power, efficiency & emissions- thats why most of the small engines that we use for karts have a governor, because they've been tuned for max power w/ efficiency at that RPM (when running a small engine for say, mowing the lawn, just push the throttle all the way forward and let the governor do it's job).

The two types of transmissions that currently come close to meeting that criteria is the hydrostatic and the computer controlled CVT (Constantly Variable Transmission). Hydrostat's are the simpler of the two and can be all H*** for stout; where they fall down is efficiency. The best systems are only around 60%~75% efficient; the average is closer to 50%. The CVT's are up around 80%; what's been holding them back has been reliability and cost (remember the Subaru Justy?). The OEM's are getting better, but so far CVT's are only showing up in small cars. From what little I've heard or read, the technology still has a ways to go before it gets spread across the board, weight being one of the big concerns (if anyone else has better info, chime in and let us all know!!).

:thumbsup::cheers2:
 

hardrock21

New member
Messages
34
Reaction score
0
Location
Ozark, MO
I second what daisan said about hydrostatic drive...lawn mowers do just that. BTW daisan, I see your location as nixa, MO... I live in Ozark now, but lived in Nixa most of my life... small world.
 

DaiSan76

New member
Messages
734
Reaction score
2
Location
Nixa, MO
I second what daisan said about hydrostatic drive...lawn mowers do just that. BTW daisan, I see your location as nixa, MO... I live in Ozark now, but lived in Nixa most of my life... small world.

What made you move so far away?? :lolgoku:

Seriously though, where do you ride your stuff? I wanted to go to Chadwick but they don't allow anything but dirt bikes and 4 wheelers.
 

J_Walker

New member
Messages
898
Reaction score
1
Location
Florida
I PM'd you so we aren't cluttering up his thread.

Paul

I thank you, but I don't mind. :) its in off topic for a reason, not as bad as some forums, Right now they'd be on talking about super man.. or just trolling. [motorcycle forums ARE THE WORST!]
 

Doc Sprocket

*********
Messages
15,677
Reaction score
146
Location
Ontario, Canada
A CVT. In its basic form, a manually controlled CVT. With the engine at a "set speed", consider a lever attached to the drive side of a CVT. Move the lever some, and the clutch portion begins to engage. Push the lever further, and it will begin to vary the ratios- speeding you up to your desired travel speed.

FWIW, manual CVT's are not new. Search the term, "variator" and you may see some interesting stuff. Uses include many things- like a drill press!
 

B.M.800

TheBeal.
Messages
2,387
Reaction score
24
Location
Central PA
^^Kinda sorta like this thing?
 

exenos

Project Nut
Messages
1,217
Reaction score
0
Location
Ontario, Canada
Ya, I was thinking a manual cvt also. I think they used to use something like it on low power lawn tractors (seems that everything is used on lawn tractors)
 

machinist@large

Active member
Messages
2,865
Reaction score
32
Location
West Michigan, 49331
A CVT. In its basic form, a manually controlled CVT. With the engine at a "set speed", consider a lever attached to the drive side of a CVT. Move the lever some, and the clutch portion begins to engage. Push the lever further, and it will begin to vary the ratios- speeding you up to your desired travel speed.

FWIW, manual CVT's are not new. Search the term, "variator" and you may see some interesting stuff. Uses include many things- like a drill press!

I personally haven't seen a variator that allows for the driven to come to a complete stop; a low speed yes, but not a complete halt. The biggest problem I can see with one that did would be that it would tear up drive belts on engagement; thats where most of the wear comes from on kart type torque converters. When the drive pulleys start to close and engage the belt, they do a low level burn out on it; have to much resistance at the driven end, and you'll just fry the belt in place. Add high RPM's to it (in this case our 2000 RPM scenario) and it would just make it worse.
 

machinist@large

Active member
Messages
2,865
Reaction score
32
Location
West Michigan, 49331
Okay, so- barring a "clutching" manual variator... Couple one with a clutch of your choosing...

That might work, but it would have to be on the driven side of the variator, and you would still have to remember to slow the unit down if you wouldn't want to burn the clutch. The thing to remember about most variators (like the one B.M.800 posted) is that they can also be used to multiply the speed coming out; do it wrong and you're basically doing a 6000 RPM hole shot.:oops:

This could all be done, it's just not as cut&dried as you could wish for.....:surrender:

:popcorn::cheers2:
 
Status
Not open for further replies.
Top