Questions about hydraulic motors for a front mounted shredder build

[J_J]

The valve that operates a hyd motor shodld be either an open center valve or a motor spool.


OPEN CENTER VALVES
Open center valves are the same as the tandem center, except that in the neutral position all lines are connected back to the reservoir. The primary use of this system is to prevent "shock" loading when the valve is placed in neutral. This takes pressure off the motor. This system is used in situations where the operating device needs to be moved by hand.


4 way motor spool

This spool option is used to control
a reversing motor or a double acting
cylinder. In neutral the work ports are
connected to tank and oil goes through
the open center passage to the outlet.
This allows a motor to free-wheel or a
cylinder to float in the neutral position.

 

[bigdeano]

The Char Lynn catalog shows 3000 psi cont, 4500 int for this motor. I have one hooked to a Vickers hydrostatic pump on my garden tractor. Works great.

 

[J_J]

You are right, I found the data I was looking for.

Tractor will flow about 16 gpm at 2770 psi, the skid will flow 21 gpm at 3000 psi.

The AUX valve and the Tractor FEL valve will have their relief valve set , so the double relief valve is an extra protection.

The rpm on the cutter driven by the skid steer will run at a 21 GPM flow rate, and the tractor will run the cutter at a 16 GPM flow rate.

Blade tip speed will change a little.

 

[tmc_31]

J_J,

The tractor spec says open center hydraulics. The remotes on the front of the loader are operated through an electric diverter valve from the bucket curl circuit. So, is the joystick FEL control an open center valve? I am a little concerned about the flow rate through those valves. Is there a convenient way to check this? If necessary I have a set of remotes at the back of the tractor with full flow that I could pipe up to the front to run the brush cutter.

Not sure yet about the aux control valve on the skid, but sounds like you are confirming that the cushion valve plumbed at the motor will add some protection from hydraulic shock when the control valve is suddenly shut off or if one of the blades meets the "immovable object". Are we on the same page?

Tim

 

[J_J]

Yes, to same page.

I am not sure about how your hyd circuits are plumbed.

This is how most of them are plumbed. Pump to FEL, to remotes, to 3pt, to tank.

All valves in an open center hyd circuit are in series.

You mentioned an electric diverter valve, or is that a third function valve? If it is a 3 ed valve, it would normally be after the FEL valve.

There is another diverter /selector valve that connects in the curl circuits and switched fluid between the curl and say, the grapple.

If your valves are rated for 16 GPM's, they will work, but to control a hyd motor, you need to be able to detent the valve for continuous flow or use a valve similar to this.

Surplus Center - 1/2 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS150-16

http://www.princehyd.com/Portals/0/products/valves/catalog/valvesRd100.pdf

The valve you need should have a 3000 psi adjustable relief.

The above valve is what I use to control the speed of my PTO hyd motor. With this valve I can get different speeds , and it also has relief.

Instant on and off, and reverse to the hyd motor can be done with a 3ed function valve using a switch, but it is full on or off.

Your AUX valve on the skid steer is probably a motor spool or an open center valve where all ports are connected to together internally in the neutral position.

Some valves will provide reverse flow for things like Augers, or any function that needs reverse flow.