Complex Tooling for Jet Turbine Blades Created with ZW3D
"By taking advantage of ZW3D's integrated CAD/CAM, Amchem produces sophisticated and efficient engineering solutions in less time."
Look inside one of our economy’s essential high-tech products — a commercial jet engine — and you’ll see a bewildering array of pipes, bulges and electrical cables. But even more fascinating is the twisted, toothy fan of hundreds of turbine blades.
A careful look at these blades will reveal that not only do they vary in size and scale, but the shapes thicken, thin and turn in complex and unique ways for each blade. To produce these critical components, mechanical and aerospace engineers at some of the largest jet engine companies in the world rely on the highly-specialized manufacturing talents of Amchem of Birmingham, England—and ZW3D OverdriveTM CAD/CAM software.
Amchem uses ZW3D Overdrive to produce turbine blade manufacturing systems that precisely position and drill rows of cooling holes into the blades that drive a wide variety of commercial and military jet aircraft engines.
The stakes are very high within the aerospace industry. Amchem’s customers, through finite element analysis and experimentation, continually eke more and more thrust and efficiency out of their high-performance jet engines. This is achieved in part by engineering blades with more complex shapes and, in particular, with very complex cooling channels machined into them.
These cooling holes aren’t simple round holes drilled into the blades. Each blade in a jet engine has a unique shape and size and requires a uniquely engineered cooling regime appropriate to the complex, twisting surfaces of that blade. Amchem’s customers define these cooling requirements, and it is Amchem’s task then to engineer a solution, combining its machine, process, software and tooling design expertise. With ZW3D Overdrive, Amchem devises solutions that utilize Amchem’s non-conventional, multi-electrode electrical discharge machining (EDM).
The complexity is further compounded because Amchem needs to import CAD files in many different formats from its customers and then has to model—and directly manufacture—a difficult tooling solution. Fortunately, Amchem uses ZW3D integrated CAD/CAM software, which offers a very broad interoperability platform.
Simon Loynes, tooling manager at Amchem, notes that “film cooling” that stops the high-speed blades from melting is possible with smart design based on years of experience. “Our customer’s engine designers come up with cooling schemes based on holes in the blades of varying sizes and positions,” said Loynes. “They are creating blades with cooling holes of increasing complexity and accuracy, requiring more and more capability from Amchem’s machines and tooling. Thanks to the advancements in CAD at the front end of engine design, the precision required of Amchem has gotten significantly higher over the past several years.”
In response, tooling has gotten proportionately more complex. A precisely machined “nose guide” contains a multitude of tubes that carry the cutting electrodes and high-pressure water. Turbine blades typically require tiny holes ranging from .27 mm to .5 mm, and the number of holes drilled per machine stroke is limited only by space allocated at the machine EDM head.
The geometry of turbine blades is free form curves so the drill paths are also free form. In order to mirror the complex surface through the solid blade, Amchem uses ZW3D Overdrive CAD/CAM software because ZW3D integrates design through manufacturing and switches fluidly between free form surfacing, solids modeling and tool path generation. As the complexity of the cooling channels continues to increase, Amchem plans to move up to ZW3D’s five-axis machining in the near future.
Amchem typically begins a new engine project by importing an IGES design from a customer’s CAD file into ZW3D. Once in ZW3D, Amchem creates a complete 3D model that can be manipulated and rotated dynamically. Unlike many CAD/CAM systems, ZW3D selectively loads portions of the CAD model on the fly, enabling the quick display required by Amchem. After modeling the complex, twisting tool paths for the cooling channels, Amchem can then apply its unique machining capabilities to create turnkey manufacturing systems for jet engine builders.
While the entire process of transforming an initial turbine blade design into a final machining solution remains lengthy, the complexity has grown considerably. The bottom-line is that Amchem continues to produce much more sophisticated and efficient engineering solutions in less time by taking advantage of the complex modeling and tightly-integrated CAD/CAM capabilities of ZW3D Overdrive.
Note: VX CAD/CAM software and technology has been acquired by ZWCAD Software Co., Ltd. VX CAD/CAM has been rebranded as ZW3D. All the testimonials of ZW3D refer to its predecessor.