Fan volute and fan

The fan volute comprises a top plate, a bottom plate, a stand column of a sleeve-shaped structure, a transmission shaft, a detachable device arranged on the transmission shaft, blades installed on the detachable device and a baffle arranged between the top plate and the bottom plate, a notch is formed in the stand column along the circumferential face of the stand column, and the blades penetrate through the notch. And the transmission shaft is connected with a non-full-circle rotary motor. The fan comprises an outer shell covering a fan volute, a rod body arranged below the outer shell and connected with the outer shell, and a heat dissipation device arranged between the outer shell and the fan volute. By the adoption of the structure, the transmission shaft penetrates through the stand column, the stand column is provided with the notch allowing the blade installed on the transmission shaft to penetrate through, the rotation motor is used for driving the transmission shaft to do reciprocating non-whole-circ