Efficient inspection of screw compressor parts

How to maximise throughput for complex rotor assemblies


As one of the most widely used air compressor models on the market, screw compressors are in high demand. With tight tolerances, these parts require an inspection solution that delivers both high accuracy and the fastest possible scanning speeds for maximised throughput.

Functioning as a positive displacement pump, screw compressors are designed to run 24/7, using two meshing rotors to push a steady stream of continuous air through a compressor to create pressure with great efficiency and at low noise level.

Screw compressors are an essential source of power in aerospace, automotive, power generation, and other sectors. In manufacturing, compressed air is often used for cutting and welding equipment, ejecting pieces from production moulds, sandblasting and finishing metal, machine tooling, air-operated tools, and many other operations. With such a wide variety of daily operations relying on this technology, ensuring the quality of their construct for reliable long-term use is a priority for screw compressor manufacturers.

Screw compressor effectiveness relies on highly-precise clearances, between the rotors themselves and between the rotors and the compressor housing. The interlobe clearances must be as small as possible to maximise compression and efficiency while ensuring there is no hard contact between the rotors. An inaccurately measured discharge port could result in a lack of compression or over-compression, in which case extra power is consumed due to gas squeezing through the rotor mesh.

Maximise scanning efficiency

The GLOBAL S coordinate measuring machine (CMM) platform allows customers to select a specific productivity driver and target their inspection objectives. The range of tools and technologies that come with the Throughput capability package make it the ideal configuration for screw compressor manufacturers seeking throughput.

Fast scanning with high accuracy is maximised with the system’s Compass technology, which uses elastic joints between the drive system and the frame and firmware algorithms to significantly reduce the effects of vibrations during high speed scanning. Fly2 Mode also drives efficiency by automatically calculating and generating the most efficient paths between measurement points, decreasing program execution times.

The array of sensors available optimises GLOBAL S to measure the various components of a screw compressor. The HP-S-X1 scanning probe with the HH-AS8-T2.5 indexing probe offers great versatility for the screw compressor’s different surfaces as the probe axes are not fixed, meaning it moves in a direction perpendicular to the surface of the measurement object. As well as offering versatility and accuracy, the machine enhances efficiency with continuous scanning.

Save time with the right software

The Throughput capability package comes equipped with PC-DMIS metrology software, perfect for the accuracy and throughput required for screw compressor inspection. The software’s QuickScan feature can reduce measurement routine creation by up to 90%, while the INSPECT application can enhance throughput by allowing users to run complex inspections without having to launch PC-DMIS. To free up valuable resource in mass production environments, PC-DMIS offers machine status alerts that enable operators to focus on other tasks rather than watching the CMM. Messaging lights are also available for GLOBAL S, offering a visual status check.

Ultimately, the combination of advanced solutions in the GLOBAL S Throughput capability package can significantly reduce measuring cycle times, boosting productivity and enabling opportunities for further inspection advancements such as increased palletisation and automation.