Serial-type diagonal fan assembly

A serial-type diagonal fan assembly, comprising:

• a first fan, comprising a first rear fan frame, a first front fan frame covering the first rear fan frame, and a first fan wheel arranged in the first front fan frame, the first fan wheel disposed in the first rear fan frame and located in the first front fan frame, the first fan wheel comprising a first hub and a plurality of first blades, the first blades annularly arranged on a periphery of the first hub, a cross-sectional area of the first hub being increased along a first direction from a top of the first hub toward a bottom the first hub so as to form a first cone surface on the first hub, wherein a gap between the first cone surface and an internal surface of the first front fan frame is substantially uniform along the first direction, and the first blades are disposed on the first cone surface;
• and
• at least one second fan, comprising a second rear fan frame, a second front fan frame covering the second rear fan frame, and a second fan wheel arranged in the second front fan frame, the second fan wheel disposed in the second rear fan frame and located in the second front fan frame, the second fan wheel comprising a second hub and a plurality of second blades, the second blades annularly arranged on a periphery of the second hub, a cross-sectional area of the second hub being increased along a second direction from a top of the second hub toward a bottom of the second hub so as to form a second cone surface on the second hub, wherein a gap between the second cone surface and an internal surface of the second front fan frame is substantially uniform along the second direction, and the second blades are disposed on the second cone surface,
• wherein one end of the second front fan frame comprises a second air inlet, another end of the second front fan frame comprises a second outlet, the second air inlet is connected with the first rear fan frame and the second outlet is connected with the second rear fan frame, a positioning groove is arranged on an inner wall of the second air inlet, a spoiler is arranged in the second front fan frame and an outer edge of the spoiler is mortised in the positioning groove,
• wherein the first fan further comprises a first base connected with the first rear fan frame, the first base is surrounded by the first rear fan frame, and the first fan wheel is connected with the first base, and
• wherein the first base is stacked on the spoiler,
• wherein a diverged conical surface is formed by an inner edge of a first air inlet of the first front fan frame, and the top of the first hub is disposed within the diverged conical surface of the first air inlet, such that each first blade exceeds the top of the first hub and extends into a space enclosed by the diverged conical surface, and each second blade exceeds the top of the second hub.