01-09-2012, 03:23 PM
PNEUMATICS
PNEUMATICS.docx (Size: 88.64 KB / Downloads: 40)
PNEUMATICS
neumatics is a branch of technology, which deals with the study and application of use of pressurized gas to affect mechanical motion. Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or other compressed inert gases. This is because a centrally-located and electrically-powered compressor that powers cylinders and other pneumatic devices through solenoid valves is often able to provide motive power in a cheaper, safer, more flexible, and more reliable way than a large number of electric motors and actuators. Pneumatics also has applications in dentistry, construction, mining, and other areas.
GASES USED IN PNEUMATIC SYSTEMS:
Pneumatic systems in fixed installations such as factories use compressed air because a sustainable supply can be made by compressing atmospheric air. The air usually has moisture removed and a small quantity of oil added at the compressor, to avoid corrosion of mechanical components and to lubricate them. Factory-plumbed, pneumatic-power users need not worry about poisonous leakages as the gas is commonly just air. Smaller or stand-alone systems can use other compressed gases which are an asphyxiation hazard, such as nitrogen - often referred to as OFN (oxygen-free nitrogen),when supplied in cylinders. Any compressed gas other than air is an asphyxiation hazard - including nitrogen, which makes up 77% of air. Compressed oxygen (approx. 23% of air) would not asphyxiate, but it would be an extreme fire hazard, so is never used in pneumatically powered devices. Portable pneumatic tools and small vehicles such as Robot Wars machines and other hobbyist applications are often powered by compressed carbon dioxide because containers designed to hold it such as soda stream canisters and fire extinguishers are readily available, and the phase change between liquid and gas makes it possible to obtain a larger volume of compressed gas from a lighter container than compressed air would allow. Carbon dioxide is an as phyxiant and can also be a freezing hazard when vented inappropriately.
COMPARISION TO HYDRAULICS:
Both pneumatics and hydraulics are applications of fluid power. Pneumatics uses an easily compressible gas such as air or a suitable pure gas, while hydraulics uses relatively incompressible liquid media such as oil. Most industrial pneumatic applications use pressures of about
80 to 100 psi (550 to 690 KPa)
. Hydraulics applications commonly use from
1,000 to5,000 psi (6.9 to 34 MPa)
, but specialized applications may exceed 10,000 psi (69 MPa).
ADVANTAGES OF PNEUMATIC SYSTEM:
Simplicity of Design And Control
Machines are easily designed using standard cylinders & other components. Control isas easy as it is simple ON - OFF type control
Reliability
Pneumatic systems tend to have long operating lives and require very little maintenance.
Because gas is compressible, the equipment is less likely to be damaged by shock. Thegas in pneumatics absorbs excessive force, whereas the fluid of hydraulics directly transfers force.
Storage
Compressed Gas can be stored, allowing the use of machines when electrical power islost.
Safety
Very low chance of fire (compared to hydraulic oil).
Machines can be designed to be overload saf
USES OF PNEUMATIC CYLINDERS:
Pneumatic cylinders turn air pressure into linear motion. They are like automobile pistons except the piston (and connecting rod) is pushed by an influx of pressurized gas instead of a gasoline explosion. The piston must be returned to the starting position after each stroke. If a spring is used to return the piston, it is a single acting cylinder. If air pressure is used to return the piston, it is a double acting cylinder.
INDUSTRIAL USES:
Double acting pneumatic cylinders are more expensive than single acting pneumatic cylinders, but double acting cylinders are superior to single acting cylinders by any other important measure. Double acting cylinders are faster, stronger and use less energy to do the same job. In industrial applications, single acting cylinders are used if possible, but when speed or force is important, double acting cylinders are employed. Applications include opening and closing valves and doors, taking things off conveyor belts and putting things on conveyor belts .They are also used for lifting merchandise and moving merchandise around as well as for presses and punches.
ROBOTIC USES:
Pneumatic cylinders including double acting cylinders have been an important component of robots since the introduction of Mc Kibben artificial muscles. Robotic arms move in a much more natural way if the arms are fitted with muscles resembling those of the human arm. Mc Kibben artificial muscles consist of rubber tubes enclosed in a metal mesh. When the rubber tubes are inflated, the metal mesh expands in diameter and decrease in length—pulling the arm. Arms (both artificial and natural) really have two sets of muscles--one on the front(biceps) to decrease the joint angle and another on the back of the arm (triceps) that increases the joint angle. Because these muscles must work together, the pressures must be coordinated very quickly, so double acting cylinders are essential for supplying air to the Mc Kibbens.
OTHER USES:
Double acting cylinders are used in automobile, motorcycle, Automated Transfer Vehicle (ATV) and airplane landing gear suspensions because the bumps come so fast that a single acting cylinder would be impractical. Double acting cylinders are used in drilling, log splitters and earth moving equipment because the forces required make single acting cylinders impractical. Double acting cylinders are found in back hoes, elevators, trash compactors, garbage trucks, fork lifts, jacks and those machines in junk yards that compress old cars. They are also used in medical applications that power ventilators--those machines that help people breath.
OVERVIEW OF PNEUMATIC CAN CRUSHER:
A can crusher is basically used to smash empty aluminum cans so as to decrease the volume of waste disposal. You can save considerable amount of storage space by purchasing a can crusher. Although, there are different styles and sizes available in can crushers, the most preferred one is the pneumatic can crusher. This tool is capable of crushing a can into the smallest possible unit. These devices are commonly seen in bars, restaurant sand catering halls. Even heavy drinkers keep this device in their home in order to
PNEUMATICS.docx (Size: 88.64 KB / Downloads: 40)
PNEUMATICS
neumatics is a branch of technology, which deals with the study and application of use of pressurized gas to affect mechanical motion. Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or other compressed inert gases. This is because a centrally-located and electrically-powered compressor that powers cylinders and other pneumatic devices through solenoid valves is often able to provide motive power in a cheaper, safer, more flexible, and more reliable way than a large number of electric motors and actuators. Pneumatics also has applications in dentistry, construction, mining, and other areas.
GASES USED IN PNEUMATIC SYSTEMS:
Pneumatic systems in fixed installations such as factories use compressed air because a sustainable supply can be made by compressing atmospheric air. The air usually has moisture removed and a small quantity of oil added at the compressor, to avoid corrosion of mechanical components and to lubricate them. Factory-plumbed, pneumatic-power users need not worry about poisonous leakages as the gas is commonly just air. Smaller or stand-alone systems can use other compressed gases which are an asphyxiation hazard, such as nitrogen - often referred to as OFN (oxygen-free nitrogen),when supplied in cylinders. Any compressed gas other than air is an asphyxiation hazard - including nitrogen, which makes up 77% of air. Compressed oxygen (approx. 23% of air) would not asphyxiate, but it would be an extreme fire hazard, so is never used in pneumatically powered devices. Portable pneumatic tools and small vehicles such as Robot Wars machines and other hobbyist applications are often powered by compressed carbon dioxide because containers designed to hold it such as soda stream canisters and fire extinguishers are readily available, and the phase change between liquid and gas makes it possible to obtain a larger volume of compressed gas from a lighter container than compressed air would allow. Carbon dioxide is an as phyxiant and can also be a freezing hazard when vented inappropriately.
COMPARISION TO HYDRAULICS:
Both pneumatics and hydraulics are applications of fluid power. Pneumatics uses an easily compressible gas such as air or a suitable pure gas, while hydraulics uses relatively incompressible liquid media such as oil. Most industrial pneumatic applications use pressures of about
80 to 100 psi (550 to 690 KPa)
. Hydraulics applications commonly use from
1,000 to5,000 psi (6.9 to 34 MPa)
, but specialized applications may exceed 10,000 psi (69 MPa).
ADVANTAGES OF PNEUMATIC SYSTEM:
Simplicity of Design And Control
Machines are easily designed using standard cylinders & other components. Control isas easy as it is simple ON - OFF type control
Reliability
Pneumatic systems tend to have long operating lives and require very little maintenance.
Because gas is compressible, the equipment is less likely to be damaged by shock. Thegas in pneumatics absorbs excessive force, whereas the fluid of hydraulics directly transfers force.
Storage
Compressed Gas can be stored, allowing the use of machines when electrical power islost.
Safety
Very low chance of fire (compared to hydraulic oil).
Machines can be designed to be overload saf
USES OF PNEUMATIC CYLINDERS:
Pneumatic cylinders turn air pressure into linear motion. They are like automobile pistons except the piston (and connecting rod) is pushed by an influx of pressurized gas instead of a gasoline explosion. The piston must be returned to the starting position after each stroke. If a spring is used to return the piston, it is a single acting cylinder. If air pressure is used to return the piston, it is a double acting cylinder.
INDUSTRIAL USES:
Double acting pneumatic cylinders are more expensive than single acting pneumatic cylinders, but double acting cylinders are superior to single acting cylinders by any other important measure. Double acting cylinders are faster, stronger and use less energy to do the same job. In industrial applications, single acting cylinders are used if possible, but when speed or force is important, double acting cylinders are employed. Applications include opening and closing valves and doors, taking things off conveyor belts and putting things on conveyor belts .They are also used for lifting merchandise and moving merchandise around as well as for presses and punches.
ROBOTIC USES:
Pneumatic cylinders including double acting cylinders have been an important component of robots since the introduction of Mc Kibben artificial muscles. Robotic arms move in a much more natural way if the arms are fitted with muscles resembling those of the human arm. Mc Kibben artificial muscles consist of rubber tubes enclosed in a metal mesh. When the rubber tubes are inflated, the metal mesh expands in diameter and decrease in length—pulling the arm. Arms (both artificial and natural) really have two sets of muscles--one on the front(biceps) to decrease the joint angle and another on the back of the arm (triceps) that increases the joint angle. Because these muscles must work together, the pressures must be coordinated very quickly, so double acting cylinders are essential for supplying air to the Mc Kibbens.
OTHER USES:
Double acting cylinders are used in automobile, motorcycle, Automated Transfer Vehicle (ATV) and airplane landing gear suspensions because the bumps come so fast that a single acting cylinder would be impractical. Double acting cylinders are used in drilling, log splitters and earth moving equipment because the forces required make single acting cylinders impractical. Double acting cylinders are found in back hoes, elevators, trash compactors, garbage trucks, fork lifts, jacks and those machines in junk yards that compress old cars. They are also used in medical applications that power ventilators--those machines that help people breath.
OVERVIEW OF PNEUMATIC CAN CRUSHER:
A can crusher is basically used to smash empty aluminum cans so as to decrease the volume of waste disposal. You can save considerable amount of storage space by purchasing a can crusher. Although, there are different styles and sizes available in can crushers, the most preferred one is the pneumatic can crusher. This tool is capable of crushing a can into the smallest possible unit. These devices are commonly seen in bars, restaurant sand catering halls. Even heavy drinkers keep this device in their home in order to