A clamping system to eliminate blade vibration on blisks

Turbine blades are typically mounted on compressor disks and milled from a single piece of material rather than constructed blade by blade. These are known as blade-integrated disks, or blisks, and their main function is to compress air in the turbine. These turbine blades are long and thin, which can cause problems when manufacturing them all at once, according to Roman Kalocsay, a former engineer at the Fraunhofer Institute for Production Technology. (The clamping system prototype was created by the Fraunhofer Innovation Cluster Adaptive Production for Resource Efficiency in Energy Generation and Mobility.)

For starters, the blades vibrate like a tuning fork during production, forcing manufacturers to process the outer edge of a blade to its finished state before moving on to other areas. Additionally, the tension on the turbine blades causes the geometry to be slightly warped. Kalocsay promises a remedy for eliminating blade vibration with a new clamping system that absorbs 12.5 percent of the vibration in titanium blisks compared to just 0.027 percent without it. “Using the clamping system, manufacturers can rough mill the blades first, and then perform the precise finishing work because the blades no longer vibrate,” he said.

Blisks are long and thin, which can cause vibration and warped geometry problems.