... To figure what size motor you need first find the gear ratio of the winch and the dia of the drum. After you have that info multiply the winch winch drum radius (1/2 the dia) with the line pull. Then divide that number by the gear ratio of the winch. That should give you the inch/lbs needed to turn the winch at max pull. Most hyd motors are rated in inch/lbs torque. That's pretty much going to tell you the motor you're going to need and you're going to have to size your pump for speed. ...
'Ty is alot closer to the money, although, as i found out there is
a lot more information required to do it 'right.'
i have a hydraulic PTO calculator spreadsheet that can be used, but we need lots of specific info, such as:
winch:
- drum OD
- cable size
- max layers
- max desired line speed
- max desired line pull
- drum reduction ratio
also need:
- pump displacement
- motor displacement
- motor effeciency
- PTO-Engine ratio
this info will give us:
- first thru final drum layer shaft torque
- hydraulic flow requirements at first layer
- hydraulic pressure requirements at final layer
- hydraulic motor HP
- mechanical HP
- actual pump speed
- engine speed required
- PTO torque
- max oil flow rate
- minimum hose and fitting diameter
if you don't have this info, then you can just start hooking things up and seeing what you end up with. likely, you won't get it right the first time. things that can go wrong:
- overspeed the pump
- overspeed the motor
- winch too slow
- winch not strong enough
- break the winch
- burn up the motor/pump seals
- shear the PTO off