Principle of Hydraulic Power Unit and its Structure

What's the connection between a water pistol and a hydraulic power plant? On the face of it, no connection at all. But think about the science behind them and you'll reach a surprising conclusion: water pistols and hydraulic power plant use the power of moving liquids in a very similar way. This technology is called hydraulics and it's used to power everything from marine hydraulic windlass and marine hydraulic winches to shark jaw and hydraulic Azimuth thruster. Let's take a closer look at how it works!

You can't squash a liquid!

Gases are easy to squash: everyone knows how easy it is to squeeze a balloon. Solids are just the opposite. If you've ever tried squeezing a block of metal or a lump of wood, with nothing but your fingers, you'll know it's pretty much impossible. But what about liquids? Where do they fit in? You probably know that liquids are an in-between state, a bit like solids in some ways and a bit like gases in others. Now, since liquids easily flow from place to place, you might think they'd behave like gases when you tired to squeeze them. In fact, liquids are virtually incompressible—much like solids. This is the reason a belly flop hurts if you mess up your dive into a swimming pool. When your body smacks into the pool, it's because the water can't squeeze downwards (like a mattress or a trampoline would) or move out of the way quickly enough. That's also why jumping off bridges into rivers can be very dangerous. Unless you dive correctly, jumping off a bridge into water is almost like jumping onto concrete. 

The fact that liquids don't compress easily is incredibly useful. If you've ever fired a water pistol (or a squeezy washing-up liquid bottle filled with water), you've used this idea already. You've probably noticed that it takes some effort to press the trigger of a water pistol (or to squeeze water from a washing-up bottle). When you press the trigger (or squeeze the bottle), you're having to work quite hard to force the water out through a narrow nozzle. You're actually putting pressure on the water—and that's why it squirts out at a much higher speed than you move the trigger. If water weren't incompressible, water pistols wouldn't work properly. You'd squeeze the trigger and the water inside would simply squash up into a smaller space—it wouldn't shoot out of the nozzle as you'd expect.

If water pistols (and squeezy bottles) can change force and speed, that means (in strict scientific terms) they work just like tools and machines. In fact, the science of water pistols powers some of the world's biggest machines—hydraulic power pack, cranes, tipper trucks, and diggers.

The basic principle of hydraulic explained why can the hydraulic power unit work, let’s learn more about its structure 

Virtually, all-hydraulic circuits are essentially the same regardless of the application. There are six basic components required for setting up a hydraulic pump system:

1. A reservoir to hold the liquid (usually hydraulic oil); 2. A pump to force the liquid through the system; 3. An electric motor or other power source to drive the pump; 4. Valves to control the liquid direction, pressure and flow rate; 5. An actuator to convert the energy of the liquid into mechanical force or torque, to do useful work. Actuators can either be cylinders which provide linear motion or motors which provide rotary motion; 6. Piping to convey the liquid from one location to another.

The extent of sophistication and complexity of hydraulic systems vary depending on the specific application.

Each unit is a complete packaged power system containing its own electric motor, pump, shaft coupling, reservoir and miscellaneous piping, pressure gauges, valves and other components required for operation.