Hydraulic pump

[DavidF]

Been lurking for a bit. Thought it was time to say hello.
Have been searching for small hydraulic systems on the net for my project and found myself here. Nice site you have and the r/c construction area was just what i needed.

[tc1cat]

Welcome to the forum. Glad that the members could be of help to you on your project.

[Cooper]

Welcome and where you from? Wealth of knowledge on this forum and people eager to help!!

[DavidF]

Im in Delaware usa. Not easy finding a small by hydraulic pump around here, looking to build one.
Ill get profile filled out shortly....

[Cooper]

In my opinion, premacon.com has the best ones out there, (Jung pump), on the less expensive side, rc4wd offers two also. If you need the site address just ask, on phone right now and not easy typing:)

[DavidF]

The jung pump is nice, ive looked into them. But looking more at building my own. Finished my 2nd rendition of the pump and 3d printed it. Now working on 3rd and final model.
Also did some test machining of some spur gear stock. Looks very promising. Making it myself is more fun anyway. Ill post pic after work. 2 hours to go.

[DavidF]

http://i1102.photobucket.com/albums/g446/davidflowers1/20170524_201120.jpg

Lets see if this works....

[DavidF]

Doing some numbers checking, the pinion wire im using to make the gears is from mcmaster carr https://www.mcmaster.com/#standard-gears/=17s4i0k Its 24p 12t with an od of .580" which I can force into a 9/16" collet to machine. I turn down the shaft dia to .250 and then take a light skim cut over the tooth profile to ensure its concentric.
I modeled the cavity of the tooth to calculate out the flow per rpm, my guess of what tooth thickness I needed was way way off at approx 1700ml/min @ 3k rpms, thats what I get for guessing... Going to thin down the gear a bit so i get 1000ml/min.

Problem is the motor. Im thinking that a 320Kv motor will do the trick but need to figure out how much pressure it will be able to generate (more research needed) assuming the pup is 80% efficient.
http://i1102.photobucket.com/albums/g446/davidflowers1/Screenshot_1.jpg

[DavidF]

So I went ahead with the .250" thickness of the gears and ordered a 190Kv motor to drive it. That should put me about right on the flow. spent some time on the mill tonight and got the body done. Just need to tap some holes and make the cover next.
http://i1102.photobucket.com/albums/g446/davidflowers1/20170526_195057.jpg

[Cooper]

Looks good!! I've been wanting to tackle making one of them but I don't think I could get the tolerances need for adequate pressure. Keep in mind when your using aluminum, it will turn your oil dark or black quick. Not to panic but if you encounter discoloration that's what it's from. What kind of seal are you using for motor shaft side?

[DavidF]

Im going to try to use some fluorosilicone o rings first. I think I can get them to work by cutting a passage from the back of the shafts and running it to the suction side of the pump. If they dont work out i will be using a graphite impregnated teflon lip seal but they are 25.00 ea and Im a cheapo.....

[DavidF]

cover made. still waiting on motor and esc, might be awhile....
http://i1102.photobucket.com/albums/g446/davidflowers1/20170527_152222.jpg
http://i1102.photobucket.com/albums/g446/davidflowers1/20170527_152617.jpg

[sparkycuda]

Very nice work! Will be interesting to see how it tests out.

Ken

[DavidF]

Very nice work! Will be interesting to see how it tests out.

Ken

Im keeping my fingers crossed ;)