Hydraulic turbine motor 5HP 5,000 RPM

[strokersix]

I'm considering alternatives for a gear motor driving a fan to improve durability. Production volume is perhaps 6,000 units anually. Power source is an agricultural tractor. I'm not intimately involved with this issue so I don't have all the details; nor do I know much about hydraulics (yet) so please bear with me on this question:

It seems to me that a turbine would run very well at high speeds, have fewer parts and less critical machining tolerances. I googled a bit and found some discussions about hydroelectric powerplant turbines but nothing about small motors such as 5 horsepower and 5000 RPM using incompressible fluid power, say 1500psi. Is there some physical reason this can't be done? Does such a device exist commercially? What would such a turbine look like and how large would it be? Any links to information?

Thanks.

 

[bklauba]

Check out both Martin Eng. and Cougar Industries. They both offer hydraulic powered rotary eccentric vibrators that go up to 9KRPM, and operate at 1500 psi max. Their models that go 4500 RPM have about 1 - 2 HP, by the looks of the unbalance and speed. (They probably buy the motors.)

A vibrator's load profile is very similar to a fan, pretty much the square of speed, (until you get into the speeds you don't want to run the fan.)

BK

 

[GregLocock]

Toyota use a hydraulic drive on the cooling fan for the Camry. Probably nowhere near your pressure, speed and power, but it may give you some ideas.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Philrock]

I'm not aware of any hydraulic devices that run anywhere near this speed. A properly designed and applied gearbox should work well in this situation.

http://www.baymachinedesign.com

 

[unclesyd]

You might want to give these people a call. I know they have the speed not know the power ranges.

http://www.parker.com/ead/cm1.asp?cmid=262

 

[strokersix]

Thanks to all for the suggestions. I'll investigate some more.

My first reaction is to use a belt drive to reduce motor speed. And, of course a gearbox would work well too. The reason I asked my turbine question is because I thought it might offer a lower cost solution since belt and gear drives both will add cost.

Thanks. Any other ideas? I recall (25 years ago!) some sort of machine tool "speeder" that used spherical elements but I can't find reference to it.

 

[strokersix]

Greg,

Any links where I might find out more about what's inside this motor?

http://img127.ac.yahoo.co.jp/users/2/8/6/8/cychinen-img600x450-1086835321p6080003.jpg

 

[GregLocock]

I'd go to a scrap yard!

It won't be a serviceable item, so I doubt the workshop manual will cover the internals.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[bklauba]

I am pretty sure that the hydraulic motor in the pic is a Kubota. Besides the Orient, I believe they have a plant in Georgetown, VA.

BK

 

[strokersix]

I'm off to the junkyard sometime in the next couple days! Walking through junkyards is like a kid in a candy store. I'll post a photo of what I find.

Thanks.

 

[unclesyd]

I don't think the fan in the photo will provide 5 Hp @5000 RPM bu any sense of the imagination.

 

[GregLocock]

That's right, it'll be about 400W, 1800 rpm

It's just a different approach that may offer some insight.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[ccw]

Hi strokersix,
Hydraulic motors offer a rugged, self-lubricated, self-cooled, high power density package for agriculture applications. The motors are usually of the vane, gear, or piston type, not turbines as in gas turbines. Upscale industrial equipment use the hydraulic fans quite often. Many tractors have hydraulic PTO's built in. The 5000 rpm may be a bit high for a fan, but I think you are on the right track.

Punch in "hydraulic fan drive" on your google.

 

[unclesyd]

Fan Drives: High speed (up to 7500 RPM) capabilities means increased cooling capacity. Rugged bearing design allows the fan to be mounted directly on the motor shaft.

Click on view catalogue for M2/M4/VCR2 HIGH SPEED MOTORSat the site below

http://www.parker.com/frameless/Def...7&FamID=751&RelPSID=&TechID=&BulkID=&TypeID=0

 

[unclesyd]

Forgot to add that unless things have changed drastically you are talking OEM quantities and there is a substantial price break on components along with extra technical help from your supplier.

 

[strokersix]

I relieved a '92 Lexus of it's cooling fan yesterday. Externally the motor looks very similar to the photo in the link I provided above. Internally it is a gerotor design similar to the high speed Parker motors in the link unclsyd provided except it's been drastically cost-reduced (or optimized if you prefer) with thrust washers and plain bearings instead of needle bearings.

Anyone know what's inside the Valeo HDFS motor? The external geometry looks different from a gerotor design.

http://www.valeo.com/images/activity/img_moteurs/hdfs.jpg

 

[EdDanzer]

Gear type motors can run that fast if the return line goes directly to the filter and is large enough to limit back pressure to 10 psi. Barnes makes some that you can by from Grainger.
If the Valeo is not gerotor it could internal gear.

 

[strokersix]

Ed,

What limits the return pressure to 10 psi on a gear motor? Is it seal leakage or something else?