Abstract: A vacuum cleaner and a fan assembly that includes a shell, a rotation shaft, a first impeller, a diffuser and a second impeller. The shell includes an air inlet and an air outlet in communication with each other. The rotation shaft is arranged in the shell and extends from the air inlet to the air outlet. The first impeller is arranged on the rotation shaft and located at a side of the air inlet. The diffuser is arranged in the shell and located at a side of the air outlet. The second impeller is arranged on the rotation shaft and located between the first impeller and the diffuser. The fan assembly may reduce working noise of the fan assembly while ensuring an air supply capacity of the fan assembly, and may reduce a radial size of the fan assembly, and may improve gas flow efficiency.

Abstract: Disclosed are a fan apparatus and an air conditioner outdoor unit. The fan apparatus includes: a first wind wheel and a second wind wheel, axially arranged in an interval. A spacing S1 between the first wind wheel and the second wind wheel satisfies S1<(H1+H2)/2, where H1 is a length of the first wind wheel along the axial direction, and H2 is a length of the second wheel along the axial direction.

Abstract: The present disclosure provides an air conditioner outdoor unit that includes: a motor having first and second output shafts; a first-stage fan blade connected to the first output shaft; a second-stage fan blade connected to the second output shaft. The motor is configured to drive the first-stage and second-stage fan blades to rotate, and rotation directions of the first-stage and second-stage fan blades are opposite. The motor is located between the first-stage and second-stage fan blades, or on the same side of the first-stage and second-stage fan blades. The outdoor unit is provided with a motor, and first-stage and second-stage fan blades, so that the motor drives the first-stage fan blade to rotate through the first output shaft, and drives the second-stage fan blade to rotate in the opposite direction through the second output shaft. By recovering the rotational energy of the airflow, higher wind pressure is achieved.