The scroll compressor

The scroll compressor is an interesting system for compressing gases. The principle of operation allows different applications. The scroll compressor itself works almost wear-free, which in turn means that the maintenance intensity is rather low and therefore cost-efficient.

Compressors and pumps - differences between the two turbomachines

The difference between a compressor and a pump such as the centrifugal pump or the suction pump is quickly explained: turbomachines that promote fluids, so liquids, are referred to as pumps. Turbomachines that pump gases, on the other hand, are called compressors. From this it can already be concluded that the scroll compressor is used for compressing and transporting gases.

The scroll compressor

If you are familiar with the Internet, you know that you can "scroll" websites, ie move them up or down. Accordingly, the scroll compressor also performs a similar job. Inside are two sheets that are spirally "rolled up". In the outer view, the two spirals are then pushed together.

Operating principle of the scroll compressor

While one spiral is fixed, the second spiral or spiral sheet moves on an eccentric disk, so that both spirals touch from the inside to the outside. In principle, this is like rolling one on the other spiral until the point of contact has reached the very inside.

Air chambers that get smaller and smaller

Depending on how many spiral turns the spiral now has, the two spirals always touch each other inwards on the same side, turning inwards. This in turn means that several chambers are formed in such a way that they become smaller and smaller inside. Thus, the inwardly transported gases are more and more, but above all evenly increasing, compressed.

Unrolling instead of friction

Following this principle of operation, the gas is sucked in from the outside and compressed inwards. The connection point for the compressed gas or the outlet is therefore inside. The interesting thing about the rotary movement is that the two spirals do not grind and rub against each other.

Extremely low in wear and maintenance

As already mentioned, it is rather a rolling motion, which is generated, which continues inward. Since there is no friction, there is no frictional wear. But the heating of the spirals is significantly lower without friction. This mode of operation means that the scroll compressor is extremely efficient, yet wear-resistant and therefore low-maintenance.

Applications for scroll compressors

Thus, the scroll compressor can be used for many gases. But conventional air can of course be compacted with the scroll compressor. Here are some of the best known and widely used scroll compressor applications:

  • Compressor for refrigeration and air conditioning
  • Heat pump (warm gas is compressed)
  • Compression of intake air in internal combustion engines
  • vacuum pumps

G-loader and Hartmann spiral loader - typical scroll compressors

In internal combustion engines, it is above all the Volkswagen Group, which has repeatedly used scroll compressors in the past. In VW, these are referred to as G-loader. The G-Lader is also the origin of another compressor to compress the charge air - the Hartmann spiral loader.

Tips & Tricks

In contrast to conventional gas compressors, which are used in the vehicle (compressor, turbocharger), the scroll compressor is interesting here because of the extremely low wear. In addition, gases can be further compressed by several scroll compressors running one behind the other on the same shaft. The gas is then compressed further and further from one compressor to the next.

Video Board: Scroll compressor / spiral compressor / scroll pump - How it works! (Animation)