TYPES OF VACUUM PUMPS

page 3, Rotary Vane Pumps

There are many types of vacuum pumps on the market to choose from. Here's some of the most common options to consider in CNC vacuum table applications.

Rotary Vane Pumps:

These pumps have a motor that drives an impeller most often installed inside the pump housing, although larger rotary vane vacuum pumps can have an independent motor and belt drive the impeller. All rotary pumps draws air in one side and out the other creating a vacuum in the process.

They come in a huge variety of sizes from 1HP up to 40 HP. and most units tend to be "oil-less" or "oil sealed", with carbon vanes that are self-lubricating, but be sure to read your maintenance manual before the first use.

They should be classified as to output in inches of Hg at a particular CFM, most maxing out at 27 to 29"Hg and CFM dictated by how much horsepower you're will to pay for. The more CFM it can handle at a set "Hg, the faster it will draw a vacuum and the more surface area it can handle.

Advantages of Rotary Vane Pumps:

Close tolerances between carbon impeller arms and the housing allows vane pumps to reach greater vacuum pressures than vacuum blowers. They have less air leakage or "slippage" >

This implies great vacuum clamping pressures for heavier material and heavier cuts.

Vane pumps are typically quieter, in the range of 75 to 85dB.

Disadvantages of Rotary Vane Pumps:

Tighter tolerances requires cleaner air so sawdust and other airborne particular content will cause wear on the vanes if the intake filters and shop dust collection are not doing their job.

In the same way, supply air that is excessively moist will also cause premature wear of the rotary vane pump's carbon blades.

If the motor is allow to overheat with blocked air filters or relief valves it will have the same effect and decrease the life of the pump.

Bottom line is that rotary vane pumps have to operate in a relatively clean environment with good ventilation and air that is relatively clean and dry.

Next Option: Vacuum Pump Blowers >>