Hydraulic bow Thruster, increasing power?

It’s on the engine side, the naiad stabilized pump is off the transmission.

Arthurc said:

It’s on the engine side, the naiad stabilized pump is off the transmission.

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Wow, and it has a clutch? Never seen that before. I've seen clutches off the gear, and off a large front mount PTO that coupled to the crank shaft. But never off one of the aux PTO pads.

Here is the control pack that’s mounted right near the actual Thruster.

That sandwich plate under the directional valve appears to have flow control valves with free return checks, which limit the flow rate to the motor but the checks allow bypass of the restriction from the motor, in each direction. Since the flow is being restricted without redirecting to the tank line, there must be a relief valve that's bypassed when less than full flow is directed to the motor, and that's probably that valve that's hiding under the flow limit plate, on the right under the hoses. But it looks like it's on the return side, not the pressure side, since there is a gauge on what I presume is the pressure side. Need more closeups from different angles to be sure.

But you may be able to open the flow up with those flow controls, assuming it's choked down to start with. And it would be helpful to know what the max intermittent design flow rate for the motor is, since you don't want to overspeed it.

Don't make any adjustments to the valve. the flow controls on there are just to dampen how fast the valve shifts to remove shock from the system. There is another tag on the valve down near the hoses. Can you take a photo of that tag so I can see what the flow capacity is for the valve.
Also, how is the pump being driven? Belts and pulleys? If we can determine how fast the pump is turning I can determine the flow.
John

Also, so far there is no photo of the relief valve. there has to be one between the pump and the Vickers valve that is shown. BTW prior to retiring last year I was the senior tech manager for Transaxle LLC. They are the Eaton Vickers distributor and warranty center for New England and the mid Atlantic so I'm very familiar with these products.
John

Thank you John! I’ll do some more discovery this weekend and take the photos. The pump is driven directly off the engine via an electronic clutch so operates at 600rpm.

twistedtree said:

Wow, and it has a clutch? Never seen that before. I've seen clutches off the gear, and off a large front mount PTO that coupled to the crank shaft. But never off one of the aux PTO pads.

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It’s off the front, likely directly mounted to the crank shaft, my stabilizers are off the standard pto pad.