They’re the true workhorses of American industry, though we rarely give them a thought. Hyrdraulic cylinders use simple mechanics to accomplish incredible feats, and yet most of us couldn’t explain their function satisfactorily. How do they work? How does something so small and simple perform so efficiently? Let’s find out!
Parts of the Hydraulic System
- Piston- the part within the cylinder against which the fluid pushes
- Bore- diameter of the piston
- Gland- head of the cylinder through which the piston rod travels
- Rod (shaft)- travels through the gland and attaches the piston to the end fitting
- Butt- base of the cylinder
- Grease fittings- occasionally used to promote piston movement
With Our Powers Combined…
Separately, the parts of hydraulic cylinders aren’t anything special. It’s when they combine that they become exceptional. A hydraulic hose, much like a coolant hose, filled with hydraulic fluid has two hydraulic cylinders attached to it. When the piston in one cylinder pushes down on the fluid, the force is transferred to the other piston which raises, providing power to the machine of which it’s a part.
The principle is simple: The amount of pressure applied to an object increases in force as the area of the object increases. The larger the pistons inside hydraulic cylinders, the more pushing they can do.
What Can Hydraulic Cylinders Really Do?
The effective pressures of hydraulic cylinders can range from .99 PSI to 6.51 PSI. The math works like this: If you put one pound of pressure on a one inch object, you get a pound of pressure per square inch (PSI). But, if you put the same one pound of pressure on a two pound object, you get two pounds of pressure per square inch. Hydraulic cylinders with larger pistons exert more force per square inch than those with smaller pistons.
Though hydraulic pumps represent one of the most basic mechanical concepts, they are understood by so few. Count yourself among the few, though, and go share your new found hydraulic knowledge with the masses.