Apparatus for removing magnetic foreign matter, brushless motor, and propulsion machine

A brushless motor comprising:

• a base member supporting a stator;
• a shaft supported by the base member;
• a rotor supported by the shaft and including a rotor housing covering the stator;
• and
• an apparatus for removing magnetic foreign matter arranged on an air flow path including a first ventilation hole in the rotor housing and a second ventilation hole in the base member, wherein
• the apparatus for removing magnetic foreign matter includes
• a magnetic force generator, and
• a magnetic material configured to
• be magnetized by the magnetic force generator and
• be brought into contact with fluid in a flow path that allows the fluid to flow therethrough,
• the magnetic material includes a first magnetic material and a second magnetic material,
• the first magnetic material is configured to
• be magnetized by a N pole of a magnet, which is the magnetic force generator and
• allow the fluid to pass therethrough,
• the second magnetic material is configured to
• be magnetized by an S pole of the magnet and
• allow the fluid to pass therethrough,
• the first magnetic material and the second magnetic material are arranged face to face and spaced from each other in a flow direction in which the fluid is to flow,
• the base member includes, as an outer peripheral portion, an outer peripheral wall portion,
• the second ventilation hole is formed in the outer peripheral wall portion,
• the apparatus for removing magnetic foreign matter covers the second ventilation hole along the outer peripheral wall portion,
• the second ventilation hole includes a plurality of second ventilation holes formed in a circumferential direction of the outer peripheral wall portion,
• the magnet includes a plurality of magnets arranged in the circumferential direction of the outer peripheral wall portion, and
• the magnets are arranged, such that each of the plurality of magnets overlaps a portion of the outer peripheral wall portion between the second ventilation holes, which are adjacent to each other, as viewed in a thickness direction of the outer peripheral wall portion.