Presses, lifts, etc. I understand that they work on the basis of liquids being extremely difficult to compress, but how does a closed hydraulic system actually work? How are tens of thousands of PSIs actually generated?
I’ll try to explain this as simply as possible.
Hydraulics is a way of using liquids to create force and movement. Liquids are hard to compress, which means they don’t change their volume much when you squeeze them. This makes them good for transmitting pressure from one place to another.
A hydraulic system has a few basic parts: a pump, a valve, a piston (or cylinder), and pipes or hoses. The pump moves the liquid (usually oil or water) from a reservoir into the pipes. The valve controls how much liquid goes where in the system. The piston is a device that can move up and down when liquid pushes on it. The pipes or hoses connect everything together.
The key idea of hydraulics is that pressure is equal everywhere in the system. This means that if you apply a small force on one end of the system, you can get a large force on the other end. For example, imagine you have two pistons connected by a pipe filled with liquid. If you push down on the smaller piston with your hand, you create pressure in the liquid. This pressure pushes up on the larger piston with more force than your hand. This way, you can lift something heavy with something light.
The amount of force you can get depends on two things: how hard you push and how big the pistons are. The harder you push, the more pressure you create. The bigger the difference between the pistons’ sizes, the more force you can get out of them. You can calculate these using some simple formulas:
– Pressure = Force / Area
– Force = Pressure x Area
So if you want to generate tens of thousands of PSIs (pounds per square inch), you need either a very strong pump or a very small piston area (or both).
(PSIs are units of pressure that measure how much force is applied over an area.)
When there is a large surface area on one side pushing onto a liquid, the liquid pushes all that energy into the same direction the large surface is pushing it into. On the other side of that liquid, if there is another surface but that surface is smaller than the one originally pushing, the smaller surface will have more force per unit of area because the smaller surface area will have the SAME amount of force being exerted on it as the bigger area BUT the smaller area surface has less surface area to distribute the force so the smaller surface area (other part of the piston/hydrolic/ can have an incredible amount of force per square unit compared to the larger surface. In other words we take a bunch of energy that is easily applied to a large area and force that energy into a smaller area so that smaller area (using liquids in-between) has a larger ratio of power than the bigger one.