External Rotor and Direct Drive: The Evolution of Electric Propulsion
UMBRAGROUP’s contribution through innovative architectures, thermal management, and system integration
What does it really take today to make electric aviation take off? Increasing power alone is not enough, what’s required is a complete rethinking of propulsion systems, making them more compact, efficient, and reliable.
In this context, the growing adoption of eVTOL (electric Vertical Take-Off and Landing) aircraft represents one of the most compelling developments of recent years. These platforms are designed around fully electric architectures and are setting new standards in terms of power density, integration, and safety.
To address these challenges, UMBRAGROUP has developed an advanced study on a permanent magnet synchronous motor with an external rotor, specifically designed for high-performance aerospace applications. This solution introduces a new approach to propulsion system design: the external rotor configuration increases torque density and optimizes inertia distribution, while enabling direct propeller integration and simpler, more efficient direct-drive architectures.
The project also stands out for its focus on operational continuity. Thanks to a multiphase architecture, the motor can maintain operation even in the event of a fault, improving system resilience and meeting the highest safety requirements in the aerospace sector. One of the most critical aspects of the project is thermal management, now a key enabler for the electrification of flight. UMBRAGROUP has developed a solution based on forced air cooling and passive physical principles, capable of efficiently dissipating heat while reducing weight, complexity, and the need for active components.
The motor is also part of a fully integrated electromechanical unit, which simplifies onboard architecture, optimizes space, and enhances overall system performance.
This study reinforces UMBRAGROUP’s goal of being the problem-solving partner in the development of advanced solutions for the next generation of electric aircraft, contributing to lighter, more efficient, and more sustainable flight platforms.
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