JPH0835500A - Double-current type axial flow fan - Google Patents

Abstract

PURPOSE:To raise a static pressure and also lower noise by constituting an axial flow fan for sending gas in an axial direction in a cylindrical casing with a conical double-current type multi-blades impeller whose diameter is large on an intake side and small on a discharge side. CONSTITUTION:A conical double current type multi-blades impeller 5 is constituted by slantly stretching and fixing lots of long and narrow blade plates 4 in a circumferential direction at an equal interval across a main disc 2 fixed on a power shaft 1 and a doughnut shape side plate 3 with an outer diameter larger than that of the main disc 2 and provided on the opposite side facing thereto and this impeller 5 is installed in the center of a casing 8 having a closed end 6 provided with an intake port 9 and a released end 7 serving as a discharge port. When such double-current type multi-blades impeller 5 is rotated by a motor 10, pressure is high on its large outer diameter side and low on its small diameter side, because the impeller 5 is in a conical shape and an air current can be sent efficiently in an axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan which blows gas from a suction port to a discharge port in an axial direction in a cylindrical casing.

[0002]

2. Description of the Related Art Conventionally, fans used for such purposes include a blow-type fan and a propeller-type axial flow fan, but the former requires a spiral chamber having a complicated shape and the air flow direction changes. Therefore, the duct connection becomes complicated, and the latter has the drawback of low static pressure and high noise.

[0003]

SUMMARY OF THE INVENTION The present invention seeks to eliminate these drawbacks and provide a fan with simple duct connection and low noise.

[0004]

Now, the structure will be described with reference to the drawings. A main disk 2 fixed to a power shaft 1 and a donut shape having a larger outer diameter than the main disk 2 provided on the opposite side to the main disk 2 are provided. A cylinder with a swirl-type multi-blade impeller 5 in which a large number of elongated blades 4 are obliquely inserted at equal intervals and fixed to each other on the circumference between the side plates 3 to form a conical shape, with one end 6 closed and the other end 7 open. It was installed at the center of the casing 8 of the shape, the suction port 9 was provided at the center of the closed side, and the axial end fan having the open end 7 as the discharge port was constructed.

[0005]

[Operation] Next, the operation of the present invention will be described. When the conical swirl-type multi-blade impeller 5 is rotated, gas enters the center of the impeller 5 through the suction port 9 and the vanes around the circumference of the impeller 5 are rotated. The pressure is increased by the centrifugal force of 4 and flows in the radial direction of the impeller and flows out from the outer periphery thereof. However, since the impeller 5 has a conical shape, the pressure is high on the side where the outer diameter is large and the pressure is small on the side. Since it becomes low, the air flow smoothly flows from the high pressure side to the low pressure side and can be efficiently blown in the axial direction from the suction port 9 to the discharge port 7.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The blades of an impeller can be straight or rearward bent, in addition to the forward bent shown in the drawing.

[0007]

The fan of the present invention is a cone-shaped swirl-type multi-blade wheel whose impeller has a large diameter on the suction side and a small diameter on the discharge side. The large diameter side with a high peripheral speed has a higher static pressure than the small diameter side. It is possible to obtain a smooth axial air flow from the suction side to the discharge side, high static pressure, low noise, and an axial fan.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of the present invention.

FIG. 2 is a cross-sectional view of the main part of the present invention.

[Explanation of symbols]

 1 is a power shaft 2 is a main disk 3 is a side plate 4 is a vane plate 5 is a conical multi-blade impeller 6 is a closed end of a cylindrical casing 7 is its open end 8 is a cylindrical casing 9 is a suction port 10 The motor 11 is its supporting leg

Claims (1)

[Claims] A large number of elongated blade plates 4 are obliquely inserted and fixed at equal intervals on the circumference between a main disk 2 fixed to the power shaft 1 and a donut-shaped side plate 3 having an outer diameter larger than that provided on the opposite side. The multi-blade impeller 5 formed in a conical shape is installed at the center of a cylindrical casing 8 having one end 6 closed and the other end 7 open, and a suction port 9 concentric with the impeller 5 is provided on the closed side. A blower type axial fan that uses as a discharge port.