IceStationZebra
Gold Member
Another concern is motor shaft seals since 'tank' port will be at high pressure. Can be done but must be spec'd. Could also run out of power (pressure drop) for last motor. ISZ
Considerations for running 7 small hydraulic motor off tractor hydraulic system?
- Thread starter jakescia
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BHD
Veteran Member
I do not remember but there could have been an oil cooler on the machine.on the return line, and it could have had a spliter on the hydraulics, and had two blanks, thus two coolers, (I could not afford one and did not see how it could help me so I did not study the machine over that close,
The very first question that should be asked is, HOW MUCH HORSEPOWER, TORQUE AND SPEED DO THE MOWER HEADS REQUIRE?
Not how much hydraulic flow and pressure the tractor has
Not what Hp the tractor engine is
Not what motors you have selected (you need to know the requirement FIRST and then choose motors based on THAT)
If you know 2 of the 3 (Torque, speed, or power) you can calculate the rest. Otherwise you are just guessing if the motor you pick will work right
If you put flow dividers in , you will have to put several in series if you use cartridge type, or spend a lot of dough on a gear type if you want it all in one shot. If you take this route, remember that at best you only have 1/7th of your flow available to each motor
If you put the 7 motors in series remember you only get (basically) 1/7th of the available pressure at each motorto do work.
In series you have to always worry about the downstream pressure too. For example, if you have (for easy figuring) 7 motors in series with 2800 PSI into the first, each motor “uses” a pressure drop of 400 PSI (if everything is sized correctly). That means the outlet port “tank port” if motor number 1 still sees 2400 PSI at the outlet. Motor 2 sees 2400in and still 2000 at outlet, and so on. Quickest collateral damage here would be shaft seals
If you’re not sized right and each motor requires (per the above example) more than 400 PSI the motors will basically stall when they hit resistance (spinning freely they’ll go up to speed but when they hit whatever you’re mowing, they’ll stall).
Do you know the power requirements of your mowers ?
Not how much hydraulic flow and pressure the tractor has
Not what Hp the tractor engine is
Not what motors you have selected (you need to know the requirement FIRST and then choose motors based on THAT)
If you know 2 of the 3 (Torque, speed, or power) you can calculate the rest. Otherwise you are just guessing if the motor you pick will work right
If you put flow dividers in , you will have to put several in series if you use cartridge type, or spend a lot of dough on a gear type if you want it all in one shot. If you take this route, remember that at best you only have 1/7th of your flow available to each motor
If you put the 7 motors in series remember you only get (basically) 1/7th of the available pressure at each motorto do work.
In series you have to always worry about the downstream pressure too. For example, if you have (for easy figuring) 7 motors in series with 2800 PSI into the first, each motor “uses” a pressure drop of 400 PSI (if everything is sized correctly). That means the outlet port “tank port” if motor number 1 still sees 2400 PSI at the outlet. Motor 2 sees 2400in and still 2000 at outlet, and so on. Quickest collateral damage here would be shaft seals
If you’re not sized right and each motor requires (per the above example) more than 400 PSI the motors will basically stall when they hit resistance (spinning freely they’ll go up to speed but when they hit whatever you’re mowing, they’ll stall).
Do you know the power requirements of your mowers ?
4570Man
Super Star Member
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- Kubota M59, Kubota L3800, Grasshopper 428D, Topkick dump truck, 3500 dump truck, 10 ton trailer, more lighter trailers.
You don’t have very many hydraulic hp. A small fraction of the original machine. Have you looked into buying a dedicated machine to do the work? It seems like the more cost effective long run plan.