Is this the correct motor for my application?

Cord · Feb 3, 2017

I want to build a boom pole for mounting on my skidsteer. So I can use it as a light duty mobile crane I want to mount a hoist on the boom pole and then have a drop line for picking stuff. I already have a worm drive winch and per the documents I know what the hydraulic motor specs would be: 900 rpm max and 300 inlb torque. I'll use a coupler to direct drive the winch so I'd like to have a Imperial keyed shaft. To simplify mounting I'd rather have a SAE 2 bolt mount because mounting flanges are readily available. My machine has a large amount of hydraulic flow (30 gpm) but I'm planning to run the machine at idle. System pressure is 3,000 psi, but the relief starts opening at 2,750. I've been searching Surplus Center for a while now I can't find the right pump. Is this one close enough? 2.5 cu in WHITE DRIVE PRODUCTS 276

A111BAAAA HYDRAULIC MOTOR

bigdeano · Feb 3, 2017

Sure looks like it would work.

Cord · Feb 3, 2017

bigdeano said:
Sure looks like it would work.

Yea, I've pretty well conviced myself of that. The only thing that's making me hesitant is the torque output of the motor is 3-600 inlb over the winch input rating. I'm afraid this will allow the winch to be overloaded before the relief opens. I'm thinking the torque rating should be equal or slightly less than the winch rating so I can't break the winch.

CJONE · Feb 3, 2017

You will be pushing it, if this is the case for the torque rating. If you get a adjustable cross over relief and adjust the pressure down to the specified torque you need it would solve that problem. CJ
After looking at the motor you need to adjust it down to 2000psi anyway and that is 630inlbs. if your winch is rated lower you need to adjust accordingly.

Cord · Feb 3, 2017

What's the duty cycle for it to be considered "intermittent"?

jenkinsph · Feb 12, 2017

From what I see on the motor specs you need to get the pressure down to about 1000-1200 psi with a relief valve. This RV needs to be just ahead of the motor lines on the pulling side of the circuit. This would limit the pressure when tugging on the winch but would not affect the playing out of the cable. You may need flow restrictors to limit the flow too. Some thought as to what works best in a bidirectional flow needs to be considered since you are hooking this up to the skidsteer aux valve quick couplers. I don't think you can use an adjustable flow control valve in a bidirectional loop which is what the winch and motor would be.

Rustyiron · Feb 12, 2017

Cord, the above posters have given me hyd. advice before and I trust & defer to them, but you didn't describe your "carrier" and unless you're mounting it on a BIG unit, wouldn't the chances of harming the winch be well after the "weak link" of damaging the pole or upsetting the whole carrier itself? Just thinking out loud and assuming you'll be the operator yourself combined with keeping things simple & cheap, my mantra.:thumbsup:
edit; are you using your Gehl SS?