An impeller is part of a centrifugal pump. The main purpose of this component is to transfer energy from the motor to the fluid, accelerating the fluid outwards from the rotation centre.
Impellers are used in applications as varied as washing machines and turbocharges in automotive engines. The latter are normally made of aluminium whereas aerospace turbocharges are made of titanium.
Regardless of whether the impellers are open or closed, they all have one thing in common – extremely complicated shapes.
The impeller challenge
The freeform shapes of the blades and the narrow spaces between them make access with tools really complicated and make it even harder to program these parts.
Leading CAM manufacturers, such as Siemens NX or Hypermill, have specific modules for programming these components but even so, the geometry and material are a challenge.
This is particularly true of titanium impellers, where the approach and retract are so important for the life of the tools.
Titanium impellers
In the case of this sample part, we used a D500 5-axis vertical machining centre D500 equipped with a 20,000-rpm spindle with an HSK-A63 tool interface.
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