Double acting cylinder:
• The force exerted by the compressed air moves the piston in two directions in a double acting cylinder. They are used when the piston is required to produce thrust not only on the advance movement but on the return.
• The thrust available on the retracting stroke is reduced due to the smaller effective piston area, but is only a consideration if the cylinder is to ‘pull’ the same load in both directions.
Double acting cylinder: 1.Tube 2.Piston 3.Piston rod 4.Double 0-ring packing on piston5.0-ring for piston rod 6.End cover 7.Bush 8. Cushion assembly
• A double acting cylinder consists the following elements:
(i) Cylinder tube
(ii) Piston unit
(iii) Piston rod
(iv)Double cup packing on piston and rod packing of O rings
(v) End covers
(vi)Bronze rod guide
(vii) Port connectors
The cylinder tube is normally made of seamless tube which may be hard coated and upper finished on the inner working surface to minimize wear and friction. The end caps may be aluminum alloys or malleable iron castings held in place by tie rods.
— Various types of seals ensure that the cylinder is airtight.
— Double acting cylinders are preferred when reciprocating action with moderate forces in either direction is required. The force produced by a
Cylinder is equal to the cross sectional area of the cylinder multiplied by
Pressure difference between the two sides of piston.
— In this cylinder, the stroke length is unlimited, although buckling and
Bending must be considered before we select a particular size of piston
Diameter, rod length and stroke length.