Abstract: A direct current induced draft fan includes: a volute, a wind wheel, a motor, and a locking assembly. The motor includes a motor body and a motor controller. The motor is disposed on the top of the volute, and the wind wheel is disposed in the volute. The motor is configured to drive the wind wheel to rotate. The motor controller is disposed on one side of the motor body and is fixed on the motor body through the locking assembly. The side wall of the motor controller extends from the motor body towards the volute.

Abstract: A volute assembly includes a volute body, a cover plate, and a seal. The volute body includes a top plate, a side plate protruding axially from an edge of the top plate, a cavity formed by the top plate and the side plate, and an exhaust duct disposed on the side plate and communicating with the cavity. The side plate includes a first bottom edge and a plurality of clamping blocks disposed at intervals on the first bottom edge. The cover plate includes a bottom plate and an annular sleeve surrounding the bottom plate. The annular sleeve includes a second bottom edge and a flange protruding from the second bottom edge. The flange includes a plurality of buckles disposed at intervals. The seal is disposed around the annular sleeve and is supported by the flange. The side plate is matched with the annular sleeve in shape.