Drone with magnet fluid sealed bearing unit and drive motor having the bearing unit

A drone including a drive portion having a propeller, the drive portion being attached to a body, the drone being configured to fly by driving a motor to rotate the propeller, the drone comprising:

• a fixed section having a housing for housing therein the motor and/or a speed reducer;
• a rotary section having a propeller shaft, the propeller shaft being supported via a bearing so as to be rotatable with respect to the housing, the rotary section being configured to rotate integrally with the propeller;
• and
• a foreign matter entry prevention unit configured to prevent foreign matter from entering an inside of the housing, the foreign matter entry prevention unit being mounted at a passage for entry of foreign matter into the housing in an opposed portion where fixed-side components constituting the fixed section and rotary-side components constituting the rotary section are opposed to each other.