Hydraulic Presses

Hydraulic presses are most efficient and are based on advanced hydraulic mechanism for applying large lifting force/compressive force. With presses having one/more than one hydraulic pumps and hydraulic cylinders, these allow easily configured job parameters like :

• Travel distance
• Force and return position to perform variety of jobs

Various levels of sophistication as well as technical advancement are available in form of :

• Simple mechanical switches
• Digitally programmable control

Working:

• Hydraulic press works on Savannah's principle, stating “pressure throughout closed system is constant”
• In hydraulic press, there is piston at one end of system having small cross-sectional area
• This piston is driven by lever
• The other end of system has small-diameter tubing
• When fluid displaces, either of pistons is pushed inward
• Small piston displaces smaller amount of volume than large piston for given distance of movement
• Displaced fluid volume is proportional to ratio of pistons' head areas
• Large piston movement distance is equal to small piston movement distance divided by ratio of pistons' head areas

Illustration:

• If ratio of pistons head areas is 5 and force of 100 newtons is applied on small piston, it produces a force of 500 newtons on large piston.
• The smaller piston should be pushed at least 50 cm to get large piston to rise 10 cm.
• As force is increasing on larger piston, distance must be decreased.
• This way, it follows principles of conversation of energy
• Like for instance, work done by small piston is 50 Joules (100 newtons multiplied by 0.5 meter), which is equal to work done by large piston, 500 newtons multiplied by 0.1 meter