Rotor assembly and motor including same

A motor comprising:

• a housing having a plurality of through holes formed on an outer circumferential surface thereof;
• a stator part supported by the housing;
• and
• a rotor assembly disposed to be rotatable around the stator part,
• wherein the rotor assembly includes:
• a rotor part;
• and
• a first cover including a first fixed plate covering one side of the rotor part, and a plurality of first vane parts protruding from the first fixed plate,
• wherein a first angle between an imaginary line extending from an outer end of each of the first vane parts and a tangential line of a first imaginary circle is greater than a second angle between an imaginary line extending from an inner end of each of the first vane parts and a tangential line of a second imaginary circle,
• wherein centers of the first imaginary circle and the second imaginary circle correspond to a center of the first fixed plate,
• wherein the tangential line of the first imaginary circle is a tangential line at a point at which the first imaginary circle and the outer end meet,
• wherein the tangential line of the second imaginary circle is a tangential line at a point at which the second imaginary circle and the inner end meet,
• wherein the first vane parts are configured to have the first angles greater than 50° and smaller than 60° and the second angles greater than 25° and smaller than 35° such that noise generated by the rotor part is inhibited, and
• wherein the first fixed plate includes:
• a ring-shaped edge part having the first vane parts formed thereon,
• a center part sunken from the edge part, and
• a plurality of through holes for heat dissipation formed in both the ring-shaped edge part and the center part.