Electric propulsion device

An electric propulsion device comprising:

• a propeller;
• and
• a motor adapted to rotate the propeller,
• wherein the propeller comprises a rotary boss secured to a rotating shaft of the motor, and a blade protruding radially outward from the rotary boss,
• wherein the blade includes a base end portion with an airfoil continuously changing such that a trailing edge comes to be in parallel to the rotating shaft of the motor from a radially outer side to the rotary boss, in a vicinity of the rotary boss,
• wherein, in an axial direction of the rotating shaft, the motor is disposed below the trailing edge of the base end portion such that an upper end portion of the motor faces the trailing edge of the base end portion,
• wherein the base end portion of the blade has a curved surface having an opposing surface facing a housing of the motor and being concavely curved, and the blade forms a discharge angle which is a right angle with respect to a virtual plane orthogonal to the rotating shaft of the motor, and
• wherein the motor is provided with a plurality of opening holes in a facing surface of the housing of the motor to which the base end portion of the blade faces, and
• the plurality of opening holes are inclined with respect to an axial direction of the rotating shaft and is extended in a direction orthogonal to the curved surface.