cylinder jun

8/6/2019 Cylinder Jun

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Cylinders are linear actuators whichconvert fluid power into mechanicalpower. They are also known as JACKS or

RAMS. Once actuated, compressed air enters

into the tube at one end of the pistonand, hence, imparts force on the piston.

Consequently, the piston becomesdisplaced (moved) by the compressedair expanding in an attempt toreach atmospheric pressure.


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The fluid pushes against the face of the pistonand produces a force.

F = pA

p is the pressure in N/m and A is the area thepressure acts on in m.

Let A be the full area of the piston and a be the

cross sectional area of the rod. If the pressure isacting on the rod side, then the area on which the

pressure acts is is (A - a).

F = pA on the full area of piston.

F = p(A-a) on the rod side.


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The speed of the piston and rod

depends upon the flow rate of fluid. The

volume per second entering the cylindermust be the change in volume per

second inside. It follows then that:

Q m3/s = Area x distance moved per second

Q m3/s = A x velocity (full side)

Q m3/s = (A-a) x velocity (rod side)


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Mechanical power is defined as Force x

velocity. This makes it easy to calculate

the power of a cylinder. The fluid powersupplied is more than the mechanical

power output because of friction

between the sliding parts.


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Single acting cylinder It has power stroke in one direction only

A small air vent is require at the end of the cylinder to

prevent air locking A compression spring returns the piston to its original

position when the compressed is exhausted

Used for clamping, ejecting, lifting & feeding


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Double acting cylinder

It has power stroke in both directions

No air vent is needed as pressure is require inboth extracting and retracting motion.


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Through rod air cylinders

Piston rod extends through both sides of the

cylinder, allowing for equal forces andspeeds on either side.


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Telescopic cylinder

These cylinders

produce long strokesfrom an initial shortlength. Each sectionslides inside a larger

section.


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Cylinder cushioning

Th are double acting cylinder come with the

feature cushioning Pston will slow down toward the end of the

stroke in either direction of movement


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Tandem cylinder Consist of 2 or more cylinders mounted inline

with pistons connected by common piston rod

Increased output force Small diameter

Shorter stroke


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cylinder jun

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