Centrifugal fan with adjustable air volume

Abstract

A spindle (10) of a motor penetrates through a right wall (7) of the shell to be connected with an impeller, a shaft sleeve (15) is fixedly connected to a left wall (3) of the shell, a sleeve (13) is inserted into the shaft sleeve, the right end of the sleeve extends into a cavity (19) of the impeller, a screw (16) is fixed to a flange at the left end of the shaft sleeve, an annular plate (17) is fixedly connected to the outer circle of the left portion of the sleeve, and the screw penetrates through the annular plate. Adjusting nuts (18) are screwed on the screws, located on the two sides of the annular plate and tightly attached to the annular plate. The device has the advantages that the sleeve is moved by rotating the adjusting nut, the depth of the sleeve in the impeller is increased, and the air volume is reduced; the depth is reduced and the air volume is increased; airflow is not blocked when passing through the sleeve, turbulent flow and vibration cannot be generated, additional loss can be reduced, and in addition, the adjusting device is simple in structure and can reduce production cost.

Description

Technical Field

[0001] This utility model relates to a centrifugal fan with adjustable air volume. Background Technology

[0002] The air volume of a centrifugal fan is usually adjusted by installing a valve at the fan outlet. By changing the opening of the valve, the air volume is changed. However, the drawback is that when the airflow passes through the valve, the valve obstructs the airflow, which will generate turbulence and vibration, resulting in additional losses. Utility Model Content

[0003] To address the aforementioned problems, this utility model proposes a centrifugal fan with adjustable air volume. It has a simple structure, does not generate turbulence or vibration when adjusting the air volume, and can reduce additional losses.

[0004] The technical solution of this utility model is a centrifugal fan with adjustable air volume, which includes a housing and a motor. The motor and the housing are connected to a base 12. The main shaft 10 of the motor passes through the right wall 7 of the housing and is connected to the impeller. The feature is that a bushing 15 is fixedly connected to the left wall 3 of the housing. A sleeve 13 is inserted into the bushing. The right end of the sleeve extends into the cavity 19 of the impeller. The depth of the sleeve in the impeller is adjusted by an adjustment device.

[0005] The structure of the adjusting device includes a screw 16 fixed on the left flange of the bushing, an annular plate 17 fixedly connected to the left outer circle of the sleeve, the screw passing through the annular plate, and an adjusting nut 18 screwed on the screw. The adjusting nut is located on both sides of the annular plate and is in close contact with the annular plate.

[0006] The beneficial effects of this utility model are that rotating the adjusting nut causes the sleeve to move, increasing the depth of the sleeve in the impeller and decreasing the air volume; decreasing the depth increases the air volume; the airflow passes through the sleeve without obstruction, without generating turbulence and vibration, which can reduce additional losses. In addition, the simple structure of the adjusting device can reduce production costs. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of this utility model.

[0008] Figure 2 This is a schematic diagram when the sleeve depth is large.

[0009] Figure 3 This is a schematic diagram for when the sleeve depth is small.

[0010] Attached Figure

[0011] 1-Small sleeve, 2-Large sleeve, 3-Left wall, 4-Front cover, 5-Impeller, 6-Guide vane, 7-Right wall, 8-Rear cover, 9-Motor, 10-Main shaft, 11-Outer shell, 12-Base, 13-Sleeve, 14-Sealing ring, 15-Shaft sleeve, 16-Screw, 17-Ring plate, 18-Adjusting nut, 19-Cavity. Detailed Implementation

[0012] A centrifugal fan with adjustable air volume includes a housing 11 and a motor 9. The motor and housing are connected to a base 12. The main shaft 10 of the motor passes through the right wall 7 of the housing and is connected to an impeller 5. A bushing 15 is fixedly connected to the left wall 3 of the housing. A sleeve 13 is inserted into the bushing. The right end of the sleeve extends into the cavity 19 of the impeller. The depth of the sleeve in the impeller is adjusted by an adjustment device.

[0013] The structure of the adjusting device includes a screw 16 fixed on the left flange of the bushing 15, an annular plate 17 fixedly connected to the left outer circle of the sleeve, the screw passing through the annular plate, and an adjusting nut 18 screwed on the screw. The adjusting nut is located on both sides of the annular plate and is in close contact with the annular plate.

[0014] When adjusting the airflow, turning the adjusting nut changes the left and right position of the sleeve in the impeller cavity. When the sleeve enters the cavity more deeply (e.g., Figure 2 As shown), the impeller's air passage surface is small, resulting in reduced airflow; when the sleeve enters the cavity shallowly (e.g. Figure 3 As shown in the figure, the impeller has a larger air passage surface, resulting in a larger air volume.

[0015] The air pressure at the edge of the impeller is greater than the external pressure. To prevent air leakage along the gap between the sleeve and the shaft sleeve, a sealing ring 14 is provided between the sleeve and the shaft sleeve.

[0016] To improve the stability of the impeller during rotation, a large sleeve 2 extends to the left on the front cover 4 of the impeller, and a small sleeve 1 is connected to the left wall of the casing. The small sleeve is inserted into the large sleeve to prevent the impeller from shaking.

[0017] The wind pressure at the edge of the impeller is greater than the external pressure. To prevent air leakage along the gap between the main shaft and the impeller back cover, guide vanes 6 are provided radially on the impeller back cover. When the impeller rotates, the guide vanes rotate accordingly, and the pressure generated by the guide vanes is opposite to the leakage direction.

Claims

1. A centrifugal fan with adjustable air volume, comprising a housing, a motor, the motor and the housing being connected to a base (12), a main shaft (10) of the motor being connected with an impeller through a right wall (7) of the housing, characterized in that, A bushing (15) is fixedly connected to the left wall (3) of the outer casing. A sleeve (13) is inserted into the bushing. The right end of the sleeve extends into the cavity (19) of the impeller. The depth of the sleeve in the impeller is adjusted by an adjustment device. The structure of the adjusting device includes a screw (16) fixed on the left flange of the bushing, a ring plate (17) fixedly connected to the left outer circle of the sleeve, the screw passing through the ring plate, and an adjusting nut (18) screwed on the screw. The adjusting nut is located on both sides of the ring plate and is in close contact with the ring plate.

2. The variable volume centrifugal fan of claim 1 wherein, A sealing ring (14) is provided between the sleeve and the bushing.

3. The variable volume centrifugal fan of claim 1 wherein, A large sleeve (2) extends to the left on the front cover (4) of the impeller, and a small sleeve (1) is connected to the left wall of the housing. The small sleeve is inserted into the large sleeve.

4. The centrifugal fan with adjustable air volume according to claim 1, characterized in that, Guide vanes (6) are provided radially on the rear cover (8) of the impeller.

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