The invention relates to the technical field of an axial flow fan, in particular to a
volute-free
centrifugal fan. The
volute-free
centrifugal fan is characterized by being provided with a motor, an
impeller, a mounting disc, a motor bracket, a motor mounting frame and an air cylinder, wherein one end of the motor is fixedly connected with the motor mounting frame through a fastening bolt; an output shaft at the other end of the motor penetrates through the center of the
impeller through a bolt to be fixedly connected with the
impeller, so that an air outlet of the impeller corresponds to a motor rotor, and the effect of automatic cooling is achieved; the air cylinder sleeves the motor and is horn-shaped; the small-
diameter end of the air cylinder is connected with an air inlet of the impeller in a sleeving way and the large-
diameter end of the air cylinder is fixedly connected with the mounting disc; the motor mounting frame is fixedly connected with the mounting disc through the motor bracket, so that the effect of supporting the motor is achieved. Due to the adoption of the structure, the
volute-free
centrifugal fan has the advantages of reasonable structure, compact appearance, convenience in
assembly and disassembly, capability of automatically cooling and the like.