Hydraulic Motor off Rear Remotes

[dieselscout80]

If I want to run a hydraulic motor off my rear remote valve/coupler, do I need more than just the two lines? In other words, do I also need a tank return, so when turn the rear remote valve/coupler off it doesn't just slam to a stop?

If I do how is it plumbed?

 

[scootr]

I have a hydraulic motor BH on my SS. It uses two lines basically an in and out. What you need to figure out is FLOW. Google your tractor specs and match your flow to the motor demands... a little headroom, more supply than demand, is wise.

 

[USMC43]

Depends on the motor and it’s function.

A lot of larger motors have a case drain. Most high flow equipped skid steers have a third connection for the case drain and if you don’t use it it will quickly blow the seals out.

Small motors usually don’t have a case drain

If the motor has a high mass rotational load such as a mower it’s wise to put a dual crossover valve plumbed in between the motor and tractor to keep sudden closing of the valve from destroying motor shafts and hoses.

Dual Crossover Hydraulic Relief Cushion Valve, 3/8" NPT Ports, 12 GPM

 

[scootr]

Depends on the motor and it’s function.

A lot of larger motors have a case drain. Most high flow equipped skid steers have a third connection for the case drain and if you don’t use it it will quickly blow the seals out.

Small motors usually don’t have a case drain

If the motor has a high mass rotational load such as a mower it’s wise to put a dual crossover valve plumbed in between the motor and tractor to keep sudden closing of the valve from destroying motor shafts and hoses.

Dual Crossover Hydraulic Relief Cushion Valve, 3/8" NPT Ports, 12 GPM

That's what my BH has on it

 

[bdhsfz6]

I use two hoses (No tank line) from a rear remote to power a small hyd. motor. It turns the spinner plate on the spreader shown in my avatar pic. That way, it spins independently of the PTO shaft. I had to use a flow restrictor though, to get the right motor speed.

I also use a two hose setup for a hyd. motor that turns the chute rotator on a snow blower.

In most cases, no tank line is necessary for these small hydraulic motors.

 

[CliffordK]

A lot of larger motors have a case drain. Most high flow equipped skid steers have a third connection for the case drain and if you don’t use it it will quickly blow the seals out.

Thanks. I was wondering a bit about that.
A hydraulic bucket has two hoses. Let's call them raise and drop.

So one has:
Raising bucket:
Raise hose goes to inflow.
Drop hose goes to outflow.

Holding bucket:
Both hoses goes to a closed valve.

Dropping bucket:
Raise hose goes to outflow.
Drop hose goes to inflow.

And the problem occurs with a motor, slamming it from run to stop. Especially if everything on the outflow side gets pressure when it wasn't supposed to.

Of course there are also single acting hydraulics that still would need an outflow if one was driving a motor.

 

[dieselscout80]

The use case is I am wanting to build a hydraulic driven string trimer to time the weeds and grass growing under my fencing, so it will be powering something like a 22" to 36" push lawn mower.

My TC45DA has 10 GPM of hydraulic flow.

 

[ptsg]

Either run a dedicated tank line from the motor, or simple run the two lines from the remotes as you would for a cylinder, but Tee both lines together with a check valve in the middle before the motor.

If the motor has a case drain line, you'll have to connect that to the tank regardless.

 

[USMC43]

The use case is I am wanting to build a hydraulic driven string trimer to time the weeds and grass growing under my fencing, so it will be powering something like a 22" to 36" push lawn mower.

My TC45DA has 10 GPM of hydraulic flow.

That small of motor is unlikely to have a separate case drain. I would always recommend a cross over relief valve like I linked above.

What is your desired rpm and diameter of rotor/string?

 

[ptsg]

OP, something like this?

Over here is very common to mount these on the brush cutters. These strimmers are either spring loaded or hydraulically actuated with a finger that retracts the head once a tree or post pushes the finger.