6 Spool Valve to Control Motor - "D" spool?

[BxB301]

Hello,
Newbie here - I have the below control valve, and I want to connect it to a hydraulic motor.
Listing states:

Common Uses:
Operate hydraulic cylinders (Double-Acting or Single-Acting)
Operate hydraulic motors ("D" Spool Required)

Well, what the heck is a "D" spool?
Ive googled it, all I find is other valves for sale that say the same thing.

Ideas?

 

[ptsg]

Best thing to do, is to go straight to the manufacturers website, which is Badestnost and check the description/brochure. These valves are rebranded to a bunch of different names ( Summit, Chieft, etc) but the actual manufacturer is Badestnost in Bulgaria.

http://www.hydraulic-vlv.com/files/mf/products/12_file.pdf - On page 3, Table 5, you'll see the list of the available spools. The D type is the one used on motors as it connects both A and B ports to Tank when the spool is centered, usually used on high speed and/or high inertia applications. Depending on your application, you may or may not want this feature.

 

[BxB301]

Best thing to do, is to go straight to the manufacturers website, which is Badestnost and check the description/brochure. These valves are rebranded to a bunch of different names ( Summit, Chieft, etc) but the actual manufacturer is Badestnost in Bulgaria.

http://www.hydraulic-vlv.com/files/mf/products/12_file.pdf - On page 3, Table 5, you'll see the list of the available spools. The D type is the one used on motors as it connects both A and B ports to Tank when the spool is centered, usually used on high speed and/or high inertia applications. Depending on your application, you may or may not want this feature.

Well, I see I know more and more about hydraulics every day.

With a D spool, does that mean the motor can free wheel when the valve is centered/not in use? I dont want this.

 

[ptsg]

Well, I see I know more and more about hydraulics every day.

With a D spool, does that mean the motor can free wheel when the valve is centered/not in use? I dont want this.

That's correct. With the D type spool, the motor will free spool with the valve centered.

This would be good for, let's say an hydraulic mower, so it would let the motor coast down without blowing the seals. But wouldn't work very good for a let's say an hydraulic winch, as there would be no way to hold the load on the winch.

 

[LouNY]

In the absence of a "D" spool a valve with a float mode can also be used for motor control,
when the valve is moved from the center off to the acting position just before float it can run a motor,
and when moved to float will allow the load to coast down or free wheel and be locked when the valve is
returned to center.

 

[BxB301]

this is for the rotation of the mini excavator I'm making.
Small motor spins (or will) the machine.
I'll need it to 'lock' when not in use.
its a 400rpm motor, with a 1:32ish gear reduction - It shouldn't be too shocking when the motor stops.
Should I not worry about it - thus leaving it as is? Or look for something with a 'float' mode?

 

[oldnslo]

For swing feature you might need to consider some type of brake feature to control slow down and stop of rotation. This depends a lot on inertial load and how quickly you want to stop. You should not need float feature for swing on excavator.

 

[LouNY]

You could add a cross over relief valve if needed after using it.