The invention relates to an efficient axial
centrifugal fan. The efficient axial
centrifugal fan comprises an upper sealing ring, a lower sealing ring, an air inlet duct, an
impeller, a front-end oilfilling
pipe, a motor, a rear-end oil filling
pipe, an air cylinder, a connecting box and a ground lead. An
impeller of the fan is of a backward type centrifugal
impeller structure. A blade is of a straight plate blade profile structure. A front wheel disc, a rear wheel disc and a wheel core are connected through self-plugging rivets, the impeller flatness and end jump of the fan are better by theadoption of a riveting manner, and the impeller is more attractive in appearance; and a pneumatic structure is more optimized, the weight of the fan is reduced on the premise of guaranteeing the pneumatic performance and the structure performance of the fan, and the process is simple. The excellent pneumatic structure of the impeller and the pneumatic structure of the air cylinder are optimally matched so that the efficiency of the fan can be improved greatly. A guide vane of the fan is in a front end inclined form, the non-uniform
airflow velocity gradient can be well treated, the vibrationproblem is solved, and the
welding strength of the fan is improved; and lubricating
grease is regularly added to a motor bearing by the adoption of the oil pipes for both the front portion and the rear portion of the motor, the lubricating effect of the bearing is guaranteed, the reliability of the fan is improved, and the service life of the fan is prolonged.