A few years ago, stores typically used a central power source to drive all tools through the belt, wheel and drive shaft system. Power is transmitted mechanically around the work space. Although belts and shafts may have disappeared, many stores still use mechanical systems to move power around the store. It is based on energy stored in the air under pressure, and the core of the system is the air compressor.


The biggest advantage of pneumatic air compressors is that each tool does not require its own bulky motor. Instead, a single motor on the compressor converts electrical energy into kinetic energy. This makes the lightweight, compact, easy-to-operate tool run quietly and with less wear on the part.

Air compressor type

Although there are compressors that use a rotating impeller to generate air pressure, volumetric compressors are more common, including models used by homeowners, woodworkers, mechanics, and contractors. Here, the air pressure is increased by reducing the size of the space in which the air is accommodated. Most compressors you will use use a reciprocating piston to do this.

Like a small internal combustion engine, a conventional piston compressor has a crankshaft, a connecting rod and a piston, a cylinder and a valve head. The crankshaft is driven by an electric motor or a gas engine. While some models consist only of pumps and motors, most compressors have a gas cylinder that maintains a certain amount of air within a preset pressure range. The compressed air in the gas tank drives the pneumatic tool, and the motor is turned on and off to automatically maintain the pressure in the gas tank.

At the top of the cylinder you will find a valve head with intake and exhaust valves. Both are simple thin metal discs - one mounted underneath and one mounted on top of the valve plate. When the piston moves down, a vacuum is created above it. This allows the outside air to push open the intake valve at atmospheric pressure and fill the area above the piston. As the piston moves up, the air above it compresses, keeping the intake valve closed and pushing the exhaust valve open. Air moves from the discharge port to the water tank. Each stroke, more air enters the tank and the pressure rises.

Typical compressors are available in 1- or 2-cylinder versions to accommodate the requirements of their powered tools. At the homeowner/contractor level, most 2-cylinder models operate in the same way as single-cylinder models, except that there are two strokes per revolution instead of one stroke. Some commercial 2-cylinder compressors are 2-stage compressors, and one piston pumps air into the second cylinder to further increase the pressure.

When the tank pressure reaches a preset limit (approximately 125 psi for many single-stage models), the compressor uses a pressure switch to stop the motor. However, in most cases, you don't need that much pressure. Therefore, the air line will include a regulator that you can set to match the pressure requirements of the tool you are using. The pressure gauge before the regulator monitors the tank pressure, and the pressure gauge after the regulator monitors the air pressure. In addition, the tank has a safety valve that will open if the pressure switch fails. The pressure switch can also include an unloading valve that reduces tank pressure when the compressor is turned off.

 

Many articulated piston compressors are oil lubricated. That is, they have an oil bath that splashes and lubricates the bearing and cylinder wall as the crank rotates. The piston has rings that help keep compressed air at the top of the piston and keep the lubricant away from the air. However, the ring is not completely effective, so some oil will enter the compressed air as an aerosol.

The oil in the air is not necessarily a problem. Many pneumatic tools require oiling and an in-line oiler is often added to increase the uniform supply of the tool. The downside is that these models require regular oil checks, regular oil changes, and must be operated on level ground. Most importantly, some tools and conditions require oil-free air. Spraying oil in the air stream can cause paint problems. And many new woodworking pneumatic tools (such as nails and sanders) are designed to be oil-free, so there is no chance of oil on the wood surface. Solutions to airborne oil problems include the use of oil separators or filters in air lines, but a better idea is to use oil-free compressors that use permanently lubricated bearings instead of oil baths. Use a one-piece piston/link model. Because there is no wrist pin, the piston will tilt left and right when the eccentric journal on the shaft moves up and down. The seal around the piston remains in contact with the cylinder wall and prevents air leakage.

Diaphragm compressors may be effective in situations where air demand is not high. In this design, the diaphragm between the piston and the compression chamber seals the air and prevents leakage.

 

Compressor power
One of the factors used to specify compressor power is motor power. However, this is not the best indicator. You really need to know the amount of air that the compressor can deliver at a certain pressure.

The rate at which the compressor can deliver a large amount of air is recorded in cubic feet per minute (cfm). Since air pressure plays an important role in the speed at which air enters the cylinder, cfm changes as the air pressure changes. It also varies with the temperature and humidity of the air. In order to establish a level playing field, manufacturers have an air level of 68 degrees Fahrenheit and a standard cubic foot per minute (scfm) of 36% relative humidity as cfm. For example, the Scfm rating is given at a specific pressure of 90 psi (3.0 scfm). If the pressure is reduced, scfm will increase, and vice versa.

You may also encounter a level called "displacement cfm". This number is the product of the cylinder displacement and the motor speed. It provides an indication of compressor pump efficiency compared to scfm.

The cfm and psi ratings are important because they represent the tools that a particular compressor can drive. When selecting a compressor, make sure it provides the amount of air and pressure required by the tool.

Linsheng  is a professional    Air Compressor Manufacturer    and   Air Compressor Supplier    in China, with its own laboratory and the most advanced testing equipment in the industry to ensure product quality. Https://www.linsheng.com