Helix, a UK manufacturer of the world's most power-dense electric motors and inverters, is continuing its expansion into sectors beyond motorsport and automotive with the completion of a Direct Drive Scaleable Aerospace Electric Propulsion Demonstrator technology project. Known internally as XBS, the project ran in partnership with the Midlands Aerospace Alliance (MAA), and the Aerospace Unlocking Potential (Aerospace UP) project between the MAA and the University of Nottingham.

Having identified an aerospace requirement for a direct-drive motor and supported by MAA funding and Aerospace UP, Helix developed the XBS project within its X-Division. The company offers its advanced Scalable Core Technology (SCT) in three Product Levels: Stock, Configured and Custom; X-Division takes Helix's unique capability a step further, developing innovative solutions that push performance beyond established boundaries.

Under the guidance of Chief Engineer Derek Jordanou-Bailey, the XBS project took an existing SCT motor configuration and adapted it to suit a 38mm through-shaft. The through-shaft architecture enables considerable versatility and optimisation for multiple aerospace applications. Mounted to a piston engine, for example, the motor could augment engine power in a parallel hybrid arrangement. Alternatively, a propeller could be driven from one end of the motor via a gearbox, while the other provided an auxiliary drive to generators, pumps and other ancillaries.

Integrated mechanical cooling pump and advanced sealing technology further enhanced the XBS demonstrator. The integrated mechanical cooling pump removed any requirement for a separate motor, cables, brackets and other items associated with an external cooling pump, while X-Division employed advanced sealing technology to retain Helix's patented rotor cooling in the design.

Chief Engineer Derek Jordanou-Bailey says, “With our seal technology the demonstrator ran up to 15,000rpm, developing high power from a relatively small package diameter. We could easily adapt it to drive a gearbox, gearing down to propeller speed. We ran it at 310kW continuous, 380kW peak andndash; geared to drive a shaft at 2,500rpm that means huge torque suitable for driving a large-diameter propeller and a significant mass saving over a larger direct drive motor of the same power.”

At the conclusion of a robust test programme, the Direct Drive Scaleable Aerospace Electric Propulsion Demonstrator had proven its reliability and performance. Compared to a piston aeroengine or turbine delivering power in a similar range, the XBS was an order of magnitude lighter, considerably smaller and virtually maintenance free.