Scanning Probe System Enables Form Analysis of Impellers

GE Oil and Gas Florence, Italy, transformed the performance of a DEA Global coordinate measuring machine (CMM) with a REVO retrofit scanning probe system from Renishaw, producing higher data collection rates to allow form analysis – a function previously not practical due to the lengthy inspection times required. The retrofit, performed by Renishaw engineers, replaced the previous head, touch trigger probe, DEA controller and PC-DMIS® software with the Renishaw Renscan5™ system, including REVO 5-axis scanning head, UCC2 controller and MODUS™ software. The DEA Global is used to perform dimensional inspections on components varying in size and geometry up to 1000 mm diameter.

“Our inspection time on a standard impeller reduced by 4 times with the retrofit,” said Claudio Bartali, manufacturing technology project leader, GE Oil and Gas. “However, the exciting part will be using the massive amount of measurement data to compare the form of inspected surfaces with the 3D CAD models.”

REVO is a contact scanning probe with two integral measuring axes that can work in a true 5-axis measuring mode when using the three axes of the CMM, allowing a completely different method of checking the impeller dimensions. The top face, for example, is measured with a “gasket scan,” a rapid sweep of the top machined face in about 2 sec, gathering thousands of points. The previous method involved four touch trigger points and took close to 30 sec. A best-fit calculation of the scanned data allows the software to plot a plane through all the points, confirming the position of the face and its relation to other surfaces. This large amount of data will be used to calculate if the surface is deformed in any way, and exactly which parts of the face deviate from the ideal CAD model of the component.

The lightweight REVO head is fast when measuring, with the speed of the machine’s axes movement no longer the limiting factor – the machine is often acting just as a carrier for the REVO. In most circumstances this means inspection moves can be 50 or 100 times faster than before. Some moves, like scanning the outside diameter of the impeller, are limited by the machine speed, but in this case REVO still reduces overall inspection time.

The Renscan5 system has been integrated into GE Oil and Gas’ production systems, with the Renishaw MODUS software executing inspection moves generated by a Unigraphics CAD/CAM system. Each component is tracked throughout the process by its serial number, with a full record of every stage of production. The new system allows GE Oil and Gas to add extra quality data to the record and further improve machining operations.

Renishaw Inc.
renishaw.com

::Design World::