POWER TO THE PUMP.(mechanics, analysis)

The best hydraulic drive system is one that dovetails with a boat's equipment and runs quietly with minimal maintenance.

Think of all the ways hydraulics are used on a fishing boat: running winches, steering, deck cranes and haulers, to name a few. If any one of these systems goes out, the trip may be over. So obviously, fishing boats need trouble-free hydraulic systems. And since each system is like a chain, the means of driving the hydraulic pump can easily become the weakest link, if it isn't set up properly.

The source of power for most marine hydraulic pumps is the boat's main engine, an auxiliary generator engine or an electric motor. Hydraulic pumps can be driven by a shaft, with or without a clutch between the power source and the hydraulic pump, or the pump shaft can plug into a standardized Society of Automotive Engineers (SAE) pad on one of the boat's engines.

Once the name "Frigidaire" was synonymous with refrigerator. However, your fridge may be some brand other than Frigidaire and it may be powered by propane, oil or electricity. The term "power-take-off" (PTO) is a similar catch-all phrase, which describes, the place from which rotary power is taken. Under the PTO heading there are hundreds of combinations of equipment used to power hydraulic pumps.

Clutched PTOs

Twin-Disc, Funk and Rockwell all make engine-driven mechanical clutches, which take power from the front or rear of marine engines. Clutched PTOs can easily handle all the power an engine is rated for, from its front crankshaft snout or at the rear, when connected to the engine flywheel. Rear drive, from the flywheel, works well for applications where large pumps must be driven by a dedicated hydraulic engine.

There are multiple-pump drive units too, where more than one pump plugs into the drive. These multiple-pump drives are a gearbox, and, like a transmission, do generate heat. Most manufacturers like to see oil temperature in multiple drives kept under 215 degrees Fahrenheit. If the oil temperature rises above that, it's time to install a larger cooling fan in the engine room. Everything in an engine room will work better and last longer if the air temperature is kept under 70 degrees Fahrenheit.