Abstract: A centrifugal blower for an air conditioner may include a centrifugal fan rotatably coupled to a motor, and a bell mouth guiding air into the centrifugal fan. The centrifugal fan may include a hub fixed to the motor, a main plate provided at an outer circumferential surface of the hub, a shroud surrounding the rotary shaft, the shroud positioned opposite the main plate to define a main gas flow path, and wings arranged along a circumferential direction of the suction opening between the main plate and the shroud. A rear axial end of the bell mouth may be inserted into the shroud through the suction opening so as to form a predetermined radial gap with the suction opening. A rear portion of the bell mouth may include alternately formed protrusions and recesses inserted into the shroud.

Abstract: Disclosed herein is a centrifugal fan. The centrifugal fan includes a back plate having a central portion for coupling with a rotation center shaft, a plurality of blades extending from the back plate, and a shroud which is connected to end portions of the blades and has an introduction end portion and a discharge end portion through which fluid passes, and the discharge end portion is rounded with a predetermined curvature in a direction away from the back plate.

Abstract: A centrifugal blower for an air conditioner may include a centrifugal fan rotatably coupled to a motor, and a bell mouth guiding air into the centrifugal fan. The centrifugal fan may include a hub fixed to a rotary shaft of the motor, a main plate provided at an outer circumferential surface of the hub, a shroud having a suction opening surrounding the rotary shaft, the shroud positioned opposite the main plate to define a main gas flow path, and a plurality of wings arranged along the circumferential direction of the suction opening between the main plate and the shroud. A rear axial end portion of the bell mouth may be inserted into the shroud through the suction opening so as to form a predetermined radial gap with the suction opening. The rear portion of the bell mouth may include a plurality of alternately formed protruding portions and recessed portions, with the protruding portions and the recessed portions inserted into the shroud.