Need help picking hyd. motor

[afish]

I need some help, I'm in the process of building a FEL mounted 55 gallon drum cement mixer. It will be run from a third function remote on my Kubota L39 which believe is 11 gpm. Problem I have is I know vary little about hydraulics . I have been looking on surplus center and found this: Surplus Center - 4.6 cu in WHITE 200080A1110CAAAA HYD MOTOR

Will this work for spinning the drum ? The thing that worries me is it says pressure range is 1750-2000 psi. I'm pretty sure the l39 is more like 2500-2900 psi.

I would also like to have the option of dialing in the RPM of the mixer, will either of these work I would rather use the second one just for budget reasons. Another dumb question will I need two one on each line or if i only use one will it just limit my rpm rotation in one direction and operate at full speed in the other direction ? I plan on using sprockets and chain drive to get the rpm's around 30 but thought a little extra adjustment wouldnt be a bad idea

Thanks for your help.
Surplus Center - 1/2 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS150-16
Surplus Center - 1/2 NPT 15 GPM PRINCE WFC-800 IN-LINE FLOW CONTROL

 

[J_J]

The flow control valve you have listed will control the speed by regulating the GPM's the motor uses. The GPM's will also dictate the hyd motor rpm. There is an adjustable relief on the valve that you can set for the motor.

Although the hyd motor has the potential to build up the pressure if ran hard or stalled, it probably will run very well at some lower pressure.

Pressure is dictated by the load the motor has to work against. You will have to reduce the speed by belt/pulley, or sprocket and chain. The motor is also reversible.

Several people on TBN has already converted a cement mixer to hyd.

Your pump capacity is about 17 GPM's, and engine rpm can control the GPM's.

The manual valve you posted will shut off flow in one direction.

Have you considered a motor spool valve with 3 position detent?

 

[J_J]

Some on TBN built this.

http://www.tractorbynet.com/forums/hydraulics/154151-power-take-off-cement-mixer.html#post1772452

http://www.tractorbynet.com/forums/showthread.php?t=152388&highlight=mixer

 

[dfkrug]

I have been looking on surplus center and found this: Surplus Center - 4.6 cu in WHITE 200080A1110CAAAA HYD MOTOR

Will this work for spinning the drum ? The thing that worries me is it says pressure range is 1750-2000 psi. I'm pretty sure the l39 is more like 2500-2900 psi.

I like to match the hyd motor to the tractor, rather than use an
additional relief valve to protect a motor that can not handle your
tractor's pressure. Furthermore, if you use a spool valve to control
the motor, and you lower it's built-in RV, you will limit your other
implements (including FEL) to that low pressure.

I do not think a barrel mixer will see high loads, so it is not a problem
in your application, but I try to get White 255 or 300 series motors,
versus that 200 series you linked. I just got a 300 series on eBay
for about $85 (new).

These motors are reversible, which is very valuable in a mixer.

I would also go with direct drive of the barrel axle, rather that use
any belts or chains. The only reason that I used a chain and sprocket
for my mixer (see the link JJ posted) is that I converted a mixer that
already had the drive sprocket setup. A low speed motor that will
turn your barrel at the speed you want with your hyd flow will put
out hundreds of ft-lbs of torque.

 

[afish]

J J thanks for the quick and easy to understand answer you are the man.

I did some double checking on the Kubota website and it says pump capacity is 23.4 gpm 11 gpm for loader and backhoe, 6.2 backhoe swing, 6.2 for power steering. So as long as I understand this correctly 11 gpm would be the max flow at the 3rd. function remote.

Good point on engine rpm controlling gpm. Sometimes I try to make things more complicated than they need to be. Yes I was planning on using sprockets and chain to reduce drum rpm's


Which brings me to my next question if I do have 11 gpm max. with a motor rpm of 500 what do you think the motor rpm would be at idle?

No I didnt consider a spool valve, This is my first foray into hydraulics My loader has two buttons on it to control the third function and just plan on using that.

 

[afish]

Thanks for the reply dfkrug

I think I have decided to not worry about any additional valves and KISS it.

What is the main difference between the 200,250,and 300 series motors?

I didnt see any motors with rpm's lower than around 400 and figured I would shoot for 30 rpm's on the mixer. So was planning on using the sprockets to reduce the final drum rpm.

I agree the mixer dosnt seem like it would create much of a load on the motor. So as long as the load on the motor dosnt increase to much the psi's will stay bellow the 2000 int. rating on the motor correct ?

 

[dfkrug]

What is the main difference between the 200,250,and 300 series motors?

I didnt see any motors with rpm's lower than around 400 and figured I would shoot for 30 rpm's on the mixer. So was planning on using the sprockets to reduce the final drum rpm.

I agree the mixer dosnt seem like it would create much of a load on the motor. So as long as the load on the motor dosnt increase to much the psi's will stay bellow the 2000 int. rating on the motor correct ?

The 200 series is least expensive, and that's what I used for my mixer,
only because the low pressure rating (2000psi) was not going to be
exceeded for this application. The 255 (WR) series handles 2500psi
continuous pressure under most operating conditions; the 300 series,
3000psi. SurplusCntr even has a 500 series motor or two (5000psi).

You will need a motor that is about 25cubic in/rev for the speed you want
at low idle (about 3 GPM), if it is direct drive. If these larger motors cost
much more than smaller ones, that is another reason to use chain or
belt drive to reduce speed.

 

[J_J]

afish,

As you increase the cu in of the motor, the rpm will decrease. You could find a large motor that will turn at a slow rpm, with lots of torque, and drive the mixer directly. However the cost will increase also.

Don't know your pump GPM's at idle, but here is some data.

11 GPM, 6 cu in, = 508 rpm
1 GPM, 6 cu in, = 39 rpm



A 4.6 cu in motor using 2 GPM's, will turn at 100 rpm. 1 GPM will turn the motor at 50 rpm.