Variable-frequency centrifugal fan

Abstract

The utility model relates to a variable-frequency centrifugal fan which comprises a volute, a rotating impeller is arranged in the volute, a plurality of blades are fixedly connected to the impeller, the blades are perpendicular to the impeller in a circumferential array mode, scraping discs are connected to the blades in a sliding mode, an outer wheel ring is arranged at the other ends of the blades, and an air inlet and an air outlet are further formed in the volute. According to the variable-frequency centrifugal fan, dust attached to the blades is scraped off through the scraping disc in sliding connection with the blades of the fan, and the situation that due to long-term accumulation of the dust, the operation load of the fan is increased, and the use efficiency of the fan is affected is avoided.

Description

Technical Field

[0001] The utility model relates to ventilation machinery technology, in particular to a variable frequency centrifugal fan. Background Art

[0002] A centrifugal fan is a machine that relies on input mechanical energy to increase gas pressure and discharge gas. It is a driven fluid machine. Centrifugal fans are widely used in ventilation, dust removal and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; ventilation and air intake of boilers and industrial furnaces; cooling and ventilation in air conditioning equipment and household appliances; drying and selection of grains; wind tunnel wind source and inflation and propulsion of hovercraft, etc.

[0003] Centrifugal fans in cement production are widely used in dusty environments, whether they are used for induced air or supplied air. When the centrifugal fans are running, the high temperature generated by the long-term friction between the blades and the air can easily cause dust to adhere to the blades, causing the fan load to increase, affecting the fan's service life and reducing the fan's operating efficiency. Utility Model Content

[0004] The utility model aims to provide a variable frequency centrifugal fan, which is used to solve the problem that when the variable frequency centrifugal fan is running, dust adheres to the blades, causing the fan load to increase and affecting the service life and operating efficiency of the fan.

[0005] In order to solve the above problems, the utility model provides a variable frequency centrifugal fan, including a volute, a rotating impeller is arranged in the volute, a plurality of blades are fixedly connected to the impeller, the blades are in a circular array perpendicular to the impeller, a scraper is slidably connected to the blade, an outer rim is arranged at the other end of the blade, and an air inlet and an air outlet are also arranged on the volute.

[0006] The variable frequency centrifugal fan provided by the utility model also has the following technical features:

[0007] Furthermore, the scraper disc is provided with a plurality of through holes matched with the blades, so that the scraper disc can be sleeved on the blades.

[0008] Furthermore, an outwardly inclined guide rod is fixedly connected between the outer rim and the impeller, an oblong hole is provided on the scraper for the guide rod to pass through, an eccentric slider is slidably connected to the guide rod, the eccentric slider abuts against the scraper, and a blind hole adapted to the eccentric slider is provided on the impeller.

[0009] Furthermore, the center of gravity of the eccentric slider is far away from the center of the impeller.

[0010] Furthermore, a central shaft is fixedly connected to the impeller, a motor is fixedly connected to the volute, and a driving shaft of the motor is fixedly connected to the central shaft.

[0011] Furthermore, a wing disc is provided on the central axis, and a spring is fixedly connected between the relative position of the wing disc and the scraper disc.

[0012] Furthermore, the number of guide rods is 4, the number of springs is 4, and they are evenly arranged in a circular array.

[0013] The utility model has the following beneficial effects: the variable frequency centrifugal fan described in the present application utilizes a scraper disk slidably connected to the fan blades to scrape off the dust attached to the blades, thereby preventing long-term accumulation of dust from increasing the fan operating load and affecting the fan's efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an axonometric schematic diagram of a variable frequency centrifugal fan according to an embodiment of the utility model;

[0015] Figure 2 This is an axonometric view of the internal components of the variable frequency centrifugal fan of the embodiment of the utility model;

[0016] Figure 3 The variable frequency centrifugal fan of the utility model embodiment Figure 2 Schematic diagram of node A in the middle;

[0017] Figure 4 It is a top cross-sectional schematic diagram of a variable frequency centrifugal fan according to an embodiment of the utility model;

[0018] Figure 5 It is a front cross-sectional schematic diagram of a variable frequency centrifugal fan according to an embodiment of the utility model.

[0019] (1-volute, 2-impeller, 3-blade, 4-scraper, 5-outer rim, 6-air inlet, 7-air outlet, 8-guide rod, 9-oblong hole, 10-eccentric slider, 11-blind hole, 12-center shaft, 13-motor, 14-wing disc, 15-spring) DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0021] like Figures 1 to 5 In the embodiment of the variable frequency centrifugal fan of the utility model shown, the variable frequency centrifugal fan includes a volute 1, a rotating impeller 2 is arranged in the volute 1, a plurality of blades 3 are fixedly connected to the impeller 2, the blades 3 are in a circular array perpendicular to the impeller 2, a scraper 4 is slidably connected to the blades 3, an outer rim 5 is arranged at the other end of the blades 3, and an air inlet 6 and an air outlet 7 are also arranged on the volute 1.

[0022] Specifically, the scraper disc 4 on the blade 3 slides back and forth between the outer rim 5 and the impeller 2, and the dust attached to the blade 3 is scraped off during the sliding, and the wind force when the fan is running takes away the scraped dust.

[0023] In one embodiment of the present application, preferably, the scraper disc 4 is provided with a plurality of through holes matched with the blades 3 , so that the scraper disc 4 is sleeved on the blades 3 to scrape away the dust around each blade 3 .

[0024] In one embodiment of the present application, preferably, an outwardly inclined guide rod 8 is fixedly connected between the outer rim 5 and the impeller 2, an oblong hole 9 is provided on the scraper 4 for the guide rod 8 to pass through, an eccentric slider 10 is slidably connected to the guide rod 8, the eccentric slider 10 abuts against the scraper 4, and a blind hole 11 adapted to the eccentric slider 10 is provided on the impeller 2. When the variable frequency fan is running at a low speed, the centrifugal force of the eccentric slider 10 cannot overcome the friction force, and the eccentric slider 10 cannot push the scraper 4 toward the outer rim 5 when the fan is running at a low speed. When the centrifugal fan is running at a high speed, the eccentric slider 10 slides along the guide rod 8 toward the outer rim 5 under the action of centrifugal force, and the eccentric slider 10 pushes the scraper 4 so that the scraper 4 scrapes off the dust on the blade 3. When the scraper 4 is in the initial position, the eccentric slider 10 is in the blind hole 11 so that the working range of the scraper 4 can cover the entire length of the blade 3.

[0025] In one embodiment of the present application, preferably, the center of gravity of the eccentric sliding block 10 is far away from the center of the impeller 2, which is conducive to sliding on the guide rod 8 under the action of centrifugal force.

[0026] In one embodiment of the present application, preferably, a central shaft 12 is fixedly connected to the impeller 2, a motor 13 is fixedly connected to the volute 1, and a drive shaft of the motor 13 is fixedly connected to the central shaft 12 for driving the impeller 2 to rotate and drive the blades 3 to rotate.

[0027] In one embodiment of the present application, preferably, a wing disc 14 is provided on the central shaft 12, and a spring 15 is fixedly connected between the relative position of the wing disc 14 and the scraper disc 4, for pulling the scraper disc 4 pushed toward the outer rim 5 back to the initial position when the fan is running at a low speed.

[0028] In one embodiment of the present application, preferably, the number of guide rods 8 is 4, the number of springs 15 is 4, and they are evenly arranged in a circular array. When there are too many guide rods 8, the operating efficiency of the fan is affected and the air outlet is blocked. When there are too few guide rods 8, the force pushing the scraper 4 is unbalanced, which will cause it to tilt and unable to slide on the blade 3. When there are too few springs 15, they are not enough to resist the centrifugal action of the eccentric slider 10 and cannot pull the scraper 4 back. When there are too many springs 15, the centrifugal force of the eccentric slider 10 cannot push the scraper 4 toward the outer rim 5. The even arrangement can make the force around the scraper 4 balanced, which is conducive to sliding on the blade 3.

[0029] To sum up, the variable frequency centrifugal fan in the above-mentioned embodiment of the utility model, specifically, when the variable frequency fan is started at a low speed, the centrifugal force of the eccentric slider 10 cannot overcome the friction force and the pulling force of the spring 15, and the eccentric slider 10 cannot push the scraper 4 toward the outer rim 5. When the centrifugal fan is running at a high speed, the eccentric slider 10 slides toward the outer rim 5 along the guide rod 8 under the action of centrifugal force, and the eccentric slider 10 pushes the scraper 4 so that the scraper 4 scrapes off the dust on the blade 3. When the variable frequency fan is running at a low speed, the scraper 4 is pulled back to the initial position under the action of the spring 15. The device utilizes the different speeds of the variable frequency centrifugal fan to make the eccentric slider 10 obtain centrifugal forces of different sizes to push the scraper 4 to slide on the blade 3, scrape off the dust attached to the blade 3, and improve the operation efficiency of the fan.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A variable frequency centrifugal fan, characterized in that: It includes a volute, in which a rotating impeller is arranged, a plurality of blades are fixedly connected to the impeller, the blades are arranged in a circular array perpendicular to the impeller, a scraper is slidably connected to the blades, an outer rim is arranged at the other end of the blade, and an air inlet and an air outlet are also arranged on the volute.

2. The variable frequency centrifugal fan according to claim 1, characterized in that: The scraper disc is provided with a plurality of through holes matched with the blades so that the scraper disc can be sleeved on the blades.

3. The variable frequency centrifugal fan according to claim 1, characterized in that: An outwardly inclined guide rod is fixedly connected between the outer rim and the impeller, an oblong hole is provided on the scraper for the guide rod to pass through, an eccentric slider is slidably connected to the guide rod, the eccentric slider abuts against the scraper, and a blind hole adapted to the eccentric slider is provided on the impeller.

4. The variable frequency centrifugal fan according to claim 3, characterized in that: The center of gravity of the eccentric sliding block is far away from the center of the impeller.

5. The variable frequency centrifugal fan according to claim 3, characterized in that: The impeller is fixedly connected with a central shaft, the volute is fixedly connected with a motor, and the driving shaft of the motor is fixedly connected with the central shaft.

6. The variable frequency centrifugal fan according to claim 5, characterized in that: A wing disc is arranged on the central shaft, and a spring is fixedly connected between the relative positions of the wing disc and the scraper disc.

7. The variable frequency centrifugal fan according to claim 6, characterized in that: The number of the guide rods is 4, the number of the springs is 4, and they are evenly arranged in a circular array.

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