Hydraulic cylinder

[cnw...@gmail.com]

Hydraulic cylinders get their power from pressurized hydraulic fluid,
which is typically oil. The hydraulic cylinder consists of a cylinder
barrel, in which a piston connected to a piston rod moves back and
forth. The barrel is closed on each end by the cylinder bottom (also
called the cap end) and by the cylinder head where the piston rod
comes out of the cylinder. The piston has sliding rings and seals. The
piston divides the inside of the cylinder in two chambers, the bottom
chamber (cap end) and the piston rod side chamber (rod end). The
hydraulic pressure acts on the piston to do linear work and motion.
Flanges, trunnions, and/or clevisses are mounted to the cylinder body.
The piston rod also has mounting attachments to connect the cylinder
to the object or machine component that it is pushing.
A hydraulic cylinder is the actuator or "motor" side of this system.
The "generator" side of the hydraulic system is the hydraulic pump
which brings in a fixed or regulated flow of oil to the bottom side of
the hydraulic cylinder, to move the piston rod upwards. The piston
pushes the oil in the other chamber back to the reservoir. If we
assume that the oil pressure in the piston rod chamber is
approximately zero, the force on the piston rod equals the pressure in
the cylinder times the piston area (F=PA) .
The piston moves instead downwards if oil is pumped into the piston
rod side chamber and the oil from the piston area flows back to the
reservoir without pressure. The pressure in the piston rod area
chamber is (Pull Force) / (piston area - piston rod area)