Heavy-lift drone motors are used for UAVs (unmanned aerial vehicles) that need to carry heavier payloads such as LiDAR scanners or bulky sensors, or to transport significant amounts of cargo. They provide the high levels of thrust required for these greater take-off weights.
Motors used for large drones tend to be electric brushless DC motors, as these are more efficient than brushed motors. Brushless motors use non-contact methods to transfer current from the commutator to the rotor, meaning that less energy is lost through friction.
Other methods for enhancing the efficiency of high-thrust motors include the use of:
Brushless heavy-lift motors for drones often utilize an “outrunner” design, meaning that the rotor rotates outside of the stator as opposed to within it. This means that the diameter over which the forces are applied is greater, due to being further from the centre of rotation, and hence the torque generated is greater.
Some heavy-lift drones also take advantage of a unique counter-rotating motor setup. This design uses a mechanism with a slip ring that harnesses the energy from both the active and reactive force of the spinning motor. The energy from the reactive counter-force, usually absorbed by the non-moving stator and the body of the UAV, can be used to drive a counter-rotating propeller from the same motor, resulting in greater efficiency compared to standard motors.