Pump drive and mounting recommendations

[ajbachhuber]

Hi folks. I'm at a roadblock and I'm hoping you can help.

I, like many homeowners, am looking to heat with wood and I want to build a log splitter that is better than what I can buy at Tractor Supply or wherever else.

I believe that I will end up using the Haldex two stage 16 GPM (nominal) pump that is available at Northern Tool. Oddly the model # that Northern provides doesn't match the # given at Haldex's website for the performance curves that they have available. Really, not much info is available. Northern is as useless as you might expect them to be.

My lawn tractor has a vertical shaft below it that is used to run the mower deck or the snow blower. I want to use that same shaft to run the pump. I intend to couple the pump to the shaft via a v-belt of some sort.

Now the questions: Can this pump handle the side load inherent with trying to transmit 15 or so horsepower to the pump in this method? Could you recommend an alternative? I'm told the unit has needle bearings. Also, is it acceptable to mount the pump in a shaft down orientation? If not specifically for this pump, is it generally OK to mount a gear pump shaft down?

This is a link to the performance curves and dimensional drawings available from Haldex.

http://www.haldex.com/Global/Hydraulics/Product Catalogs/hi_lo_pg_rev1203.pdf

This is the link to the pump at the Northern Tool website.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200321055_200321055

I contacted the manufacturer and because I'm not a distributor, I can't talk to any of the apps engineers. "We're hiring someone to help with end user applications but don't have anyone yet." Typically they try to push that stuff off onto distributors as I understand it.

Thanks in advance for any help you can provide. I realize that you have probably been getting many requests from "weekend warriors" trying to do something similar. FWIW I do have a little hydraulic design experience but the more I read around on this site the more I realize I have too much to learn.

 

[IceStationZebra]

As for the belt drive, the correct way to do it is use an overhung load adapter.

http://www.vonruden.com/overhung_load_adapters/overhung_load_adapters.html

ISZ

 

[MikeHalloran]

You'd better look in a v-belt catalog before you get all lathered up about this scheme. Transmitting 15HP takes some fairly serious belts. I.e., don't drop a pulley on your foot.

Have you got enough ground clearance to mount the pump below the shaft and drive it with a straight coupling?



Mike Halloran
Pembroke Pines, FL, USA

 

[hydromech]

It would be better to use a positive drive for this application rather than a belt. We only use belts to drive low pressure pumps such as coolant pumps.

Also the needle bearings would not work very well. For applications with side loads, you need to a have ball or roller bearing to support the shaft.

A gear drive would be better as I suspect that you would not have enough room the mount the pump under the shaft.

The orientation of the pump is not restricted.

Regards

Adrian
Senior Design Engineer
Concentric Pumps Limited-Haldex Hydraulics Group

 

[kcj]

good source of info on logsplitters is either
machinebuilders.net
or
arboristsite.com


I write quite a bit there trying to help people with hydraulics and keep the splitter questions off the professional fluid power boards.

my opinions: no on vbelts, they will be big as noted above. The side load is too much, pump bearings not rated for that.
I looked at timing belts, maybe, but still high side loads and they are too expensive. (Swisher?) I think makes a splitter with timing belt drive. I would not go there. Also, you need to match rotation of pump which is opposite a direct drive direction (if the pump is along and parallel to the engine, shaft down like engine shaft down.)

Mounting the pump to a bearing block, or Helland/zeromax overhung load adaptor, is about the only choice for vbelt drive.

kcj

 

[IceStationZebra]

OK, I did the calculations.

assumptions
max rpm: 3600 (normal for small single engines)
max pressure: 3000 psi
drive ratio: 1:1
Haldex model 1001507 is volumetrically equivalent to 1300487

HP draw
Haldex graph - low pressure: ~11hp, high pressure ~9hp
my conservative calculations - low pressure: 9.6hp, high pressure 6.3hp

Belt calculations according to the Gates literature using 11hp with correction factors.
"A" or "AX" cross section (>6" shieves cause excessive belt speed.)
4" shieves: 4 belts
4.5" or 5" shieves: 3 belts
5.5" shieves: 2 belts
"3VX" cross section (>6.5" shieves cause excessive belt speed.)
4" or 4.5" shieves: 3 belts
5" or 5.5" shieves: 2 belts

As far as can it be done? Sure, many skid steer pumps have been belt driven. With this kind of side load I would wonder about the engine bearing too.

ISZ