Shaft Stays Put, Motor Spins

I think any motor, if the shaft is held stationary, will spin...

I know that the old aero piston engines where the cylinders spun around the stationary crankshaft were called rotary or radial engines?

John.

Good after-morning John, are you sure the old rotary engines spun around the crank? Or is there some obscure Tommy Sopwith creation I'm not familiar with?

Hi Plbmak, I'm fairly sure the very old radial engines spun round, i might well be wrong of course.

But I remember reading how they were much more efficient, not just in heat cooling but for the fuel and lubrication, as well as for working in any attitude (upside down etc...).. ?

Maybe I've had too much sunshine!!! Time for my afternoon 'power nap' methinks!

John.

Plbmak, this is from the rafmuseum web site....

Radial
The engine cylinders are arranged in a circular (or radial) fashion, in one or two rows, around the central spinning crankshaft.

Rotary
These look very similar to radial engines, but with a rotary engine the entire crankcase and cylinders rotate around the central crankshaft, which remains stationary.

In-line
As implied by the name, these engines have the cylinders set in banks or rows along the crankcase, giving them a narrow cross-section.

Are, the radial engine is what I thought, the rotary engine, I'd forgot! I have seen a motorcycle with a radial engine as power plant, I'll try to find the web site.

There you go, two of 'em!

Coooo....... I guess it makes sense to use all 360 degrees... but I wouldn't like to ride one of them..

Besides the heat just look at the size of them!!! Good job they aren't rotary engines then !!!

John. (I bet they give a smooth ride though!)

I want one. No, both of 'em.

Apparently the one on the right has a custom built gearbox, the shop who got the job were convinced it was for a huge diesel engine because of the torque requirements.

Now here's a bike with an integral hub motor and forward gravity modulators. Shown with optional flocked dice and minigun for the occasional rude auto driver or blathering cellphone bimbo on her way to Neiman Marcus. (RPG version also available for some truly hard-core road rage adventure.) You drive it while lying on your tummy. Black vertical rods brace your shoulders while your feet push against stirrups just fore of the rear axle:

I would like to see one of these rotary engines on a cycle... like the kind of engine that they put on WWI airplanes... Just wouldn't want to get your shoe strings stuck in it... or anything else for that matter. This would make for the most intimidating bike possible I think...

http://www.keveney.com/gnome.html

He is right the cylinders rotated, to cool them when they were running when the plane is stationary, as the engines were air cooled. I think you maybe able to see this in the film the Aviator (don't hold me to it).

I have an old engineering book printed in 1934 stating that a engine was made (or designed) with shaft stationary and rotating cylinders. (the propeller was attached to the outer part)

I will post a copy tomorrow.

Such an engine is however hard to visualize.

I have given a little thought to the subject, and decided that the advantage of not having a flywheel is outweighed (sic) by the rotating mass of the engine. Incredible to watch though! (from a safe distance)

Doesn't spinning the motor housing instead of the shaft over complicate things a bit? Especially a hydraulic drive (how are you planning to RELIABLY connect the supply lines, etc? Unless we're talking about a garden hose reel I'd be afraid of long-term performance).

I'll assume you have a plan for that, and a good reason to go through all the trouble (like you said, "saving space"). I can't remember a time when I've seen anyone do this, so unfortunately, no help here. I would love to hear how it turns out though!

Good Luck!

Can we assume you've googled for this information already? Assuming you have, as you've had some difficulty locating a source you might be better off using a conventional hydraulic motor to power your rollers. Even if you were to find a vendor for these, you'd be wise to have a second source should your vendor go belly-up. Either way you're gonna pay through the nose as 1) the motor is unconventional and probably has a limited audience, and 2) the motor's bearings would have to deal with the roller's load as well as it's own, making them much more expensive for heavy-duty rollers. Looks pretty expensive from where I'm sitting, IMHO.

-e

Here is another link for drum motors:

http://www.rulmecacorp.com/

HTRN

Claymoore,

You don't really want this. Any space saving you might (?) get is not worthy of the complications associated with the feeding of the hydraulic pressure to your motor. The way to do this if you insist, is through what is known as slip-rings. There are electrical slip rings, air slip rings (used on auto inflating truck tires for example) and custom made hydraulic slip rings. I am not aware of high pressure slip ring. I yet have to see an air and/or liquid slip ring that doesn't leak after some time, although the air slip-rings are pretty good. (up to 250-300 psi).

Back in the early years of aviation two companies that I am aware of, LEROHN, and SIEMENS and surely few others, made ROTARY engines, where the crankshaft was attached to the fuselage and the propeller was part of the engine case (block). They had a very good reason to try and do this. Due to poor efficiency and terrible weight to power ratio, The weight of the engine was used as a flywheel to achieve greater inertia. After speed (RPM) was slowly built, the throttle was retarded and the prop kept it's speed over a wider range of loads. The idea was physically correct, but the mechanical complications and poor reliability made it impractical and obsolete.

If you will explain exactly what your problem is, I am sure that we might help you at least with an idea.

Wangito.

Are slip rings really required? Seems to me the motor is turned "inside out" with the hydraulic connections going to the stationary part in a similar manner as the wiring to a ceiling-fan motor.

-e

Not so simple.

In the fan configuration, the EMF is the "rotating" magnetic field. No physical (mechanical) connection required. Not so in an hydraulic motor.

Wangito.

I can understand that in the hydraulic case rotating seals are required between the stationary and moving parts, but I still don't understand why hydraulic "slip rings" are required in a hydraulic motor. In this case the core is stationary, whilst the outer casing is what's moving. Hence my confusion as to why "slip rings" would be required to connect to a stationary assembly - the motor core in this case. If you have a diagram of some sort that demonstrates why hydraulic slip rings are required in this configuration, it would help a great deal at this point.

In a ceiling-fan motor, what would be the stator in a conventional induction motor takes the place of the rotor and vice versa. The roles are reversed. The power is fed to the stator, of course, but in this case it is physically the motor core that is stationary, contains the field windings, and functions as the stator - not an annular ring around it as would be the configuration in an ordinary motor. The motor is, in effect, turned "inside out." Power is fed, without the need for slip rings, to the core whilst the case is free to rotate. All of the ceiling fans in my house are built this way.

-e

E...check out the link I provided above, and it will explain how the drum motor operates. No slip-rings required.

PS: They have been making these since the 1950's.

All the motors I could find on the 'net were built in a manner requiring slip rings, but this is not an intrinsic requirement as I'm discussing here. Most of these were "motorized pulleys" built in this way, I suspect, because the design doesn't require a custom motor. If you have picture of a specific hydraulic motor in mind, would you post the pic or, better yet, a link?

Thanks!

-e

Hi europium. The way these insideout hydraulic motors work is quite simple. The shaft is hollow, and the hydraulic fluid is pumped through the shaft, the shaft has a number of transport ports in it and as the motor revolves the oil is forced into the cylinders and then exausted out through the opposing port. A number of steam engines were produced to work in this fashion in the early 1900s, as I said, simple really. Spencer.

Check the link to the original posting above.

I followed those links, but they lead to sites showing rollers built using conventional motor construction. In all the cutaway views you can see a conventional rotor surrounded by a stator containing the field windings. Furthermore, the housing for the slip rings is seen at one shaft end. The hydraulic-roller pics on these sites don't show a cutaway view at all, but only the complete roller assembly and its hydraulic fittings. Nothing is seen of the roller interior and how it is constructed.

-e

The text on one of their associated links says that the fluid is fed and returned thru galleries inside the shaft.

Ok. Thanks.

E- re slip-rings, No, you really don't need them.

As I am not a hydraulic motor expert, I took a closer look at some motors cross sections, and really it is possible to make it without slip-rings. However, I couldn't find such a readily available of the shelf motor. And again, not knowing exactly what the application is, as claymoore didn't answer my question regarding this, I still think that being a sizable motor, (must be, if it is a crasher drum,) that the associated complications are not worthy of the possible advantages from both price and maintenance points of view. If needs to be installed inside the drum, I see no problem, further more there's room for gearbox if needed etc. I can not be more specific as I don't have enough information.

Wangito.

When you make your drum, make the end plates to fit the shaft from your hydraulic motor.Set the end plate in the drum far enough to include the whole motor inside the end of the drum.then fabricate mounts for mounting the motor as normal. Done all the time in road building equipment. You have all that space inside the drum going to waste anyhow.

Hi claymoore, I used to work on conveyors where the driving drum was an electric motor in reverse, ie. the shaft stood still while the drum which was the motor housing revolved. I have also worked on dump trucks at mine facilities where each wheel was driven by an independant hydraulic motor, the motor revolved thus driving the wheels while the shaft was clamped to the axle housing. So my advice to you is to get in touch with companies that produce hydraulic motors, they produce them in all sizes. Spencer.

Can't recall the brand name but similar hydraulic drives are used on many industrial forklifts, cranes, crawlers, etc. .... too early here .. . . need caffene!!

Building a better mousetrap?

Roller Crushers are 1930's technology. I've rebuilt hundreds of them.

The conventional design is to drive one roller and let the crushed product drive the other.

Also need to keep in mind the refacing of your wear surfaces. I've typically welded with hardfacing wire, as rollers wear quickly. One of the reasons Jaw, Cone, and Impact crushers were designed.

Best of luck redesigning the wheel...literally.

You are absolutely right.

I guess claymoore has it's own reasons for wanting to use drums. And when referring to maintenance complications, I was exactly referring to the re-dressing of the drum surface, actually welding directly onto the motor case. Not a good idea.

Wangito.

I think that I understand what you want to do, i.e., you wish to connect a hydraulic motor to a roller that is supported by a "dead shaft". This should require a simple interface sleeve to be built that would use the shaft for axial support and provide an interface between the hydraulic motor and the roller. Yes, this does add an extra piece of two to the design, and aligment issues may require the use of a compensating coupler-maybe not.

I have used many hydraulic motors and have never seen one such as you seek. I am very sure that one could be designed and manufactured, but it would be an expensive undertaking. The design of a simple sleeve that is supported by radial bearings and connected to the roller either in a rigid fashion (some allowance made for oscillation of the hydraulic motor) or in a coupled fashion where the interface coupling is free to oscillate and remove the adverse affects of alignment, tolerance stackup, etc. In the end, keep the design components as "off the shelf" as possible.

Good Luck,

Ing. Robert Forbus

you can try using hagglunds motor, very expensive but very compact and they have through shaft hole that you can mount it with your "shaft stays put, motor spins". I been using alot of their motor, It is rather reliable once you get every thing size up correctly. Just take note on the charge pressure and back pressure issue.

if you need more help can drop me a mail @ chihchau@gmail.com.

http://www.hagglunds.com/default.aspx?selBody=products&subBody=level2&category=Motors&treeID=a0_0

Hi Guest. Why does everyone including yourself think that they would be expensive to design and construct, when they can be bought of the shelf. You can get them from 3ins diameter to 3ftdia. There are a number of companies that produce them here in Europe. Spencer.

Outside of a water wheel, I don't think they exist. I expect keeping the seals from leaking is the problem.

Huh? Have you read anything of this thread?

I have read about an aircraft... vintage World War I... of French design...In which the engine turned rather than the crankshaft. For the life of me I cannot remember the make or model though.

Bill

Well, there you are. It was a French plane! (only ribbing the French here, guys. Keep your panties on) Those planes only worked like that when they were auguring-in. The prop remained stationary while the plane rotated about it.

See comments 3, 4 6..................oh, and 33! He He HE.

Artsmass, thou. I was so caught up in that sub-thread about hydraulic motors needing slip rings that I didn't much pay attention to the rest. Consider me duly chastised!

Since those posts are concerned with classifying such motors, what about a Wankel rotary engine? It's a rotary engine, but the case is stationary.

Remind me sometime to buy you a pint of very warm beer...

-e

Crikey mate! you're up early! As for the beer, if it's not cold, forget it! And by the way, I don't drink anything stronger than gin before breakfast.

Up early? I haven't gone to bed. Astronomer's hours! You don't think we actually look at stars, do you? That's what the other computers are for.

I figured you'd just gotten up, considering your usual cheerful cheekiness at this hour. Me? I'm actually much less cranky than usual. However, would you like your warm beer on your corn flakes or in your lap? No sense in it going to waste.

Cheers, mate!

-e

Astronomy huh? Well, that explains everything!

Sciesis: Read posting #33 and than #13.

Not only French airplanes Bleriot in this case, but British as well Bristol for example. the French engine maker was LEROHN.

Wangito.

Hi Sciesis. I think that the French earo engines that you are talking about were built by the Gnome, Rhone company. They built many types of these engines from 5 cylinders to 9 cylinders. Another company called Anzani built the smallest rotory engine, it had 3 cylinders. Spencer.

Hydraulic motors get used in areas like mining where space is tight , but ive never seen one where the outside forms part of a crushing mill.

These people make them for winches . They may be as good as anybody to ask. www.offshore-technology.com/contractors/hydraulics/hagglunds/ - 18k -

Hydraulic motors are used because they are better at producing large amounts of torque at low speeds and they prevent any sparking from electrical contacts rotating parts commutator etc. The best form of motor for this application would be a rotary vane type, drive your liquid past a turbine witch is the outer part you want to turn.

Madness is only another form of genius?

Hi thanks very much for all your help only just had chance to look at the replies and many helpful ones their were to. I think i will go for the idea of putting a more standard motor inside the roller. This gives me me flexibility and choice of motor as the other motor i required seems to be as much available as rocking horse poo. Those bikes were a bit brill though.The item that we want to crush was plastic bottles by the way unless anybody had a better way of crushing them. The tops have to stay on as who takes them off. Why do we out them back on any way? Also it has to fit onto a vehicle so it cant be to big.

Have you considered shredding them at high speed, like these Asplundh trucks do with tree branches?

-e

Now heres the problem. The plastic bottles need to be whole as shredding them means all the different colored plastics would mix together making it a nightmare to separate them. The bottle's just need to be reduced in size but kept whole to aid sorting into their respected groups. Would love to shred them but alas it not an option. Bummer really.

Interesting concept.

How are you going to sort them out by colours? Manually? or did you develop some automatic way of doing this?

Motor inside the roller, KIS• and good engineering decision.

•KIS= Keep it simple.

Wangito.

The bottles would be sorted manually by colours at the customers end unless they have some other way. i don't know how though because its not like separating different metals. i suppose some colour recognition could be used somehow, but how you would then put them in the right groups i have no idea

That's what grad students are for! Need any?

PhD=Photocopying Degree

You mention bottle caps in an earlier post. Even if the bottles were all the same color, the caps may not be. Do you have to sort these out too?

Wish you'd added the extra detail earlier - My local Council tell my the bottle top and body are different category of plastic (LDP/HDP ). And the cap (whichever that is -High DP I guess) can't be recycled . Oddly the recyclable can be made into clothing (8 coke bottles = 1 'fleece' jacket). The sorting issue is a pain , people leave tops on to keep a crushed bottle flat /don't bother. Maybe I've got big feet (to match mouth) , but uncapped bottles stay flat when I stamp on them . Shredding sounds good to me - it saves somebody doing it later and keeps your volume lower . There must be some way of sorting ldp/hdp waste - flotation in a suitable dense media ?As Europium (I think it was e ) says somewhere , get a branch shredder and fit it on the truck.

The colour (ok 'color' US of A) problem is comparable to glass , except most plastic bottles are clear. It depends what it will be used for . With glass they use a lot of it for anti-slip road surfacing . If UK re-introduced bottle deposits , people would take them back to source and wino's would clear up those dropped as litter.

There is a student on this forum somewhere looking for an environmental project , try find him/her to get some ongoing research/collaboration perhaps.

Kris.

You indicted that you need to crush these plastic bottles to save shipping space.

They will be fairly difficult to crush with the lids on, unless you puncture them first.

Have you considered vacuum packing them?

This will crush the bottles due to atmospheric pressure, without the need for mechanical crushing.

Or a simple hydraulic compactor may do the job.

HTRN

Yes the tops would have to be separated we were think of putting a large mesh filter to separate them if the councils decide it would be wise to make people leave the tops off. We were also going to incorporate studs on the rollers to puncture the bottles thus making the bottle so much easier to flatten. You would be surprised how much a bottle with stands crushing with out this. Especially when there are a lot together thats why we couldn't you just a normal hydraulic crushing design. Also rollers are crushing at a steady stream as apposed to waiting for each stroke of a cylinder. the councils should let us shred them then mix them all together so we can make a nice dirty brown recycled plastic ,nice. Or if there is enough colours they might all mix together and we might end up with white.Pity there is any other use for them like making mini plant green houses or sticking them end on end to make hour glasses or making mini tornadoes when you fill them with water. Any body else have any ideas about making cool stuff out of bottles?

They make nice water rockets that'll scare the hell out of the neighbor's cat. Fill 'em up about three-quarters' full (the bottle, not the cat), then tightly plug the hole with a rubber stopper. You want to bore a small hole through the stopper with an ice pick (or drill it out using a small bit) so that you can insert an inflater needle through the hole. The kind you use to inflate a soccer ball. Put the bottle bottom-first into a short length of PVC pipe which is propped up to act like a bazooka. Using a hefty bicycle-tire pump, inflate the bottle until the stopper pops out. Since the bottle is tilted end-upward inside the pipe, the air pressure is above the water and stopper and, when the stopper blows, the water is forced out at high speed, turning the bottle into a missile. These things can really haul booty! Great for some summertime fun with the kids, although the neighbor's cat may beg to differ.

-e

Hi e ,

You can buy these , but they are used without water - I guess because air is more compressible and can store more energy . A mini rain storm sounds fun though . You could even have coloured rain using different density/coloured liquid . With some extra compartments even 'Rainbow in a Bottle' . Think of the sales potential !

ps - I want royalties if anyone does this.

You could add a whistle to the air only version and have a high pitch doodle-bug

Kris

Long ago a girlfriend used to make badges out of plastic crisp packets (honest !)- you put them under the grill for about 20 seconds and they shrink to a fraction of size , but retain the printing and go rigid.

Why do you want to save space? Do you have a very small factory? I would say use one normal hydraulic motor and connect the rollers with meshing gears so that they roll in opposite directions. Then the motor only will have to drive the one roller via a chain . The motor can be under the whole set-up. Easy for maintenance and no hydraulic fluid can contaminate the plastic.. Just a thought..

Why have you decided to go with hydraulic instead of electric gear-motor driven rollers? Hydraulics are less efficient (energy wise) overall, however they can tolerate stalling loads without damage, and can tolerate short cyling and constant reversal better, but for a continuous process,I would go with a electric motor with a properly sized gearbox.

Just my 2 cents worth.

HTRN

Hi, my name is Frank; I work for a bearing company and we assist companies (customers) with new designs and what bearings to use in applications. If you would like to provide as much info / data on your project as you can then I can give you some consultation / recommendation. One engineer here worked in applications for Link Belt for over 10 years. Write back at fmoosbrugger@nachiamerica.com.

The original motors were invented by Hagglunds and are still being made; http://www.hagglunds.com/

Also consider a motor/gear reducer combination. I have used these in hammer mills with over 1,000hp without problems. The newest are good for 18,000Nm. http://www.fairfieldmfg.com/

Now for the rest of you, check out this animation of a Gnome engine. It is great! Almost 100 years old.
www.keveney.com/gnome.html

Quick solution.

Bale the bottles.

I am in plastics recycling industry and this is how it is done in the industry.