Centrifugal air blower

A centrifugal air blower where a centrifugal fan and a motor for rotationally driving the centrifugal fan are housed inside a case body, and air is drawn in from a center in a radial direction of the case body and exhausted from an exhaust port provided on an outside in the radial direction of the case body,

• the case body including:
• a first case that is assembled to cover the centrifugal fan, is provided with an intake opening at a center in a radial direction, and has a first air passage, which is annular, formed at an outside in the radial direction;
• and
• a second case that has a second air passage, which is annular and is combined with the first air passage, formed further outside in the radial direction than an outer circumferential end of the centrifugal fan in an outer periphery of a base plate that rotatably supports the motor, and
• wherein the centrifugal fan:
• has a plurality of first blades formed at an uneven pitch in a circumferential direction so as to be erected on a main plate that extends continuously outward in a radial direction from a hub which is integrally assembled with a rotor yoke;
• and
• has a plurality of second blades, which are shorter in length than the first blades and are formed upright between the first blades so that a spacing from an adjacent first blade has an uneven pitch in the circumferential direction, and
• in a partial region in the circumferential direction, a length of inner end parts in the radial direction of a plurality of the second blades is formed shorter than a length of the second blades in another region so that a center of gravity position of the centrifugal fan matches the center of rotation.