阅读说明：本技术 一种高效低噪的多层集流器及离心风机 (High-efficient low-noise multilayer collector and centrifugal fan ) 是由 李帅领 陈宗华 于 2021-01-11 设计创作，主要内容包括：本发明公开了一种高效低噪的多层集流器及离心风机,本发明通过在集流器本体上设置集流筒、叶栅和导流锥,使叶栅能够起到前导叶和支撑集流筒和导流锥的作用,同时集流筒起到对进入集流器的气体进行分层使气体变的更加顺畅进入叶轮,导流锥起到对气体进行引流的作用。同时将本发明有多层集流筒与导流锥结合的集流器用于轴向插入叶轮后,通过叶栅、集流筒和导流锥的相互配合使气体进入叶轮更加顺畅,进而控制集流器进口截面每一个小单元气体的流入情况,降低叶轮进口涡流损失和叶片进口冲击损失,从而达到提效和降噪的目的。(The invention discloses a high-efficiency low-noise multilayer collector and a centrifugal fan. Meanwhile, after the current collector with the multi-layer current collecting barrel and the flow guide cone combined is axially inserted into the impeller, the mutual matching of the blade grids, the current collecting barrel and the flow guide cone enables gas to enter the impeller more smoothly, the inflow condition of each small unit of gas at the inlet section of the current collector is further controlled, the vortex loss at the inlet of the impeller and the impact loss at the inlet of the blade are reduced, and therefore the purposes of efficiency improvement and noise reduction are achieved.)

1. A high efficiency, low noise multilayer current collector comprising: -a header body (1), said header body (1) comprising an inlet section (11) and an outlet section (12), the gas flowing in from said inlet section (11) and out from said outlet section (12); the current collecting cylinder (3) is arranged in an outlet section (12) of the current collector body (1), and the current collecting cylinder (3) is connected with the outlet section (12); the blade cascade (2) is arranged in the inner ring of the outlet section (12), and the blade cascade (2) is used for connecting the collecting cylinder (3) and the inner ring of the outlet section (12); the collecting cylinder (3) and the collector body (1) are concentrically arranged, and the collecting cylinder (3) extends along the direction from the inlet section (11) to the outlet section (12).

2. A high-efficiency low-noise multilayer collector as claimed in claim 1, wherein a plurality of collecting barrels (3) are arranged along the radial direction of the collector body (1), the side walls of the collecting barrels (3) are formed in an extending mode along the direction from an inlet section (11) to an outlet section (12), and the side walls of the collecting barrels (3) are in circular arc cross sections along the transverse cross section perpendicular to the axial direction of the collector.

3. An efficient low noise multilayer collector as claimed in claim 1, wherein the axial section of said collector cylinder (3) from said inlet section (11) to said outlet section (12) is formed by a number of unit axial lines, said axial lines being one or more of single circular arc, double circular arc, multiple circular arc or spline curve.

4. A high-efficiency low-noise multilayer collector as claimed in claim 3, wherein, from the inlet section (11) to the outlet section (12), the inner diameter of the collector cylinder (3) gradually decreases and then gradually increases, and the axial section of the collector cylinder (3) is composed of a plurality of single circular arcs.

5. A high efficiency and low noise multilayer collector according to claim 3, characterized in that at least two layers of collecting cylinders (3) are arranged in the inlet section (11) in the radial direction of the collector body (1).

6. An efficient low-noise multilayer current collector as claimed in claim 1, wherein said cascades (2) are uniformly spaced between said collector barrel (3) and said collector body (1), said cascades (2) are at least two in number, one end of said cascades (2) is arranged inside the side wall of the outlet section (12) of said collector body (1), and the side wall of said collector barrel (3) is arranged at the other end of said cascades (2) or on the body of said cascades (2) between the two ends of said cascades (2).

7. A high efficiency and low noise multilayer collector according to claim 1, characterized in that said cascade (2) extends in the axial direction in the same direction as the axial direction of the collector body (1) in the direction of the flow of the gas; or the blade cascade (2) forms an included angle with the axial direction of the current collector body (1) in the axial extending direction.

8. An efficient low-noise multilayer current collector as claimed in any one of claims 1 to 7, characterized in that the current collector further comprises a flow guiding cone (4), the flow guiding cone (4) is arranged in the inner ring of the current collecting barrel (3) adjacent to the center of the current collector body (1), and the flow guiding cone (4) is connected with the blade cascade (2).

9. A high efficiency and low noise multilayer collector as claimed in claim 8, wherein, in the gas flow direction, the side surface (41) near the apex of said deflector cone (4) is connected to one end of said cascade (2), and the bottom surface (42) of said deflector cone (4) is arranged to protrude from the lower end surface gas outlet of said outlet section (12).

10. A centrifugal fan, comprising a current collector, an impeller and a motor, wherein the motor is installed in a motor installation hole in a rear disc of the impeller, the current collector is installed in an upper disc inner ring of the impeller, the current collector is the current collector of any one of claims 1-9, a current collecting barrel (3) in the current collector extends from a current collecting body (1) to a front disc of the impeller, and part of side walls of the current collecting barrel (3) extending to the impeller is arranged at an included angle with the horizontal direction of an inlet of the front disc of the impeller.

Technical Field

The invention relates to the field of fans, in particular to a high-efficiency low-noise multilayer current collector and a centrifugal fan.

Background

In the ventilation industry, the existing collector mostly adopts a single-layer form to guide gas to flow into the impeller, but the inflow condition of each small unit of gas at the inlet section of the collector cannot be specifically controlled, and in the centrifugal fan, the problems are particularly obvious, so that the collector with the multilayer collector cylinder is necessary to be designed for being axially inserted into the impeller and combined with the guide cone, so as to restrain the inflow state of the gas at the inlet of the impeller, control the flow state of each small unit of gas, improve the efficiency of the impeller and reduce the noise of the fan.

The patent publication No. CN101846087A relates to a centrifugal fan and a sealed motor provided with the centrifugal fan. The centrifugal fan also comprises a current collector for converting gas thrown out from an impeller outlet along the radial direction of the impeller into gas along the axial direction of the impeller, wherein the current collector comprises a first disk body and a second disk body, the bottom surfaces of the first disk body and the second disk body are parallel to each other, coaxial circular openings are formed in the bottom surfaces of the first disk body and the second disk body, the impeller is arranged between the two openings and can rotate under the driving of a driving mechanism, an annular inlet communicated with the impeller outlet along the radial direction of the impeller is formed between the bottom surfaces of the first disk body and the second disk body, an annular outlet along the axial direction of the impeller is formed between the side walls of the first disk body and the second disk body, a plurality of arc-shaped guide plates are arranged between the outer sides of the bottom surface and the side walls of the first disk body and the inner sides of the bottom surface and the side walls of the second disk body. This patent does not address the problem of controlling the flow of small cells of gas in the central region of the header.

The patent publication CN105402170A relates to an air intake silencer for a local ventilator. The silencer is in a straight cylinder shape, the end with the larger diameter of the current collector is mutually matched and fixedly connected with the silencer, and the current collector comprises a current collecting cylinder, a first support, a first conical cylinder and a plastic suction diversion cap; the silencer comprises a first outer barrel, a first inner barrel, a second outer barrel and a first conical reflecting plate, wherein the first outer barrel and the first inner barrel are coaxially arranged, and the first outer barrel and the second outer barrel are fixedly connected with each other through a first arc-shaped reflecting plate. This patent does not address the problem of controlling the flow of small cells of gas in the region between the first conical barrel and the manifold barrel.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a high-efficiency low-noise multilayer collector, wherein a collector body is provided with a collector cylinder, a blade grid and a guide cone, so that the blade grid can play a role in front guide blades and supporting the collector cylinder and the guide cone, meanwhile, the collector cylinder is used for layering gas entering the collector to enable the gas to more smoothly enter an impeller, and the guide cone is used for guiding the gas. The mutual matching of the blade grids, the flow collecting cylinder and the flow guide cone enables gas to enter the impeller more smoothly, so that the inflow condition of each small unit of the inlet cross section of the flow collector is controlled, the vortex loss of the inlet of the impeller and the impact loss of the inlet of the blade are reduced, and the purposes of efficiency improvement and noise reduction are achieved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a high efficiency, low noise multilayer current collector comprising: a header body including an inlet section into which gas flows and an outlet section from which gas flows; the current collecting barrel is arranged in the outlet section of the current collector body and is connected with the outlet section; the blade cascade is arranged in the inner ring of the outlet section and is used for connecting the collecting cylinder and the inner ring of the outlet section; the collecting cylinder and the collector body are arranged concentrically, and the collecting cylinder extends along the direction from the inlet section to the outlet section.

Preferably, the inlet section and the outlet section are in circular arc transition, the outlet section is tubular, the inlet section comprises an inner ring and an outer ring, the outlet section and the inner ring of the inlet section are in circular arc transition, and gas flows from the inlet section to the outlet section, so that the upper end face of the inlet section is a gas inlet, the lower end face of the outlet section is a gas outlet, the inner side wall of the collector body is streamline, and the thickness of the outlet section is kept unchanged or gradually reduced along the direction from the gas inlet to the outlet.

Preferably, the inner diameter of the outlet section gradually increases from the gas inlet to the outlet.

Preferably, the inner diameter of the outlet section gradually decreases and then gradually increases from the gas inlet to the gas outlet.

Preferably, the axial cross-section of the outlet section in the gas inlet to outlet direction is in the form of a single circular arc.

Preferably, the axial cross-sectional form of the outlet section in the gas inlet-to-outlet direction comprises a horizontal section plus a circular arc section.

Preferably, the outlet section is a multi-segment circular arc, and the axial cross-sectional form along the direction from the gas inlet to the outlet comprises a plurality of segments of circular arcs.

Preferably, a plurality of collecting barrels are arranged along the radial direction of the collector body, the side walls of the collecting barrels extend along the direction from the inlet section to the outlet section, and the cross section of the side walls of the collecting barrels along the direction perpendicular to the axial direction of the collector is an arc cross section.

Preferably, the cross section of the collecting barrel along the transverse direction perpendicular to the axial direction of the current collector is circular, and the collecting barrel is of a cylindrical structure.

Preferably, the current collecting cylinder is provided with a layer along the radial direction of the current collector.

Preferably, from the inlet section to the outlet section, the axial cross section of the manifold hub is formed by a plurality of unit axial lines, and the axial lines are one or more of single circular arcs, double circular arcs, multiple circular arcs or spline curves. The manifold headers so arranged may conform to various forms of flow field distribution.

Preferably, the thickness of the current collector is uniform or varies in airfoil shape.

Preferably, the inner diameter of the collecting cylinder gradually decreases and then gradually increases from the inlet section to the outlet section, and the axial section of the collecting cylinder consists of a plurality of single arcs.

Preferably, the inner diameter of the upper end inlet of the collecting cylinder is smaller than that of the lower end outlet, the upper end inlet of the collecting cylinder is adjacent to the inlet section of the collector body, and the lower end outlet of the collecting cylinder is adjacent to the outlet end of the collector body.

Preferably, the inner diameter of the collecting cylinder is gradually increased from the inlet section to the outlet section, namely the arc section radian radius of the side wall of the collecting cylinder close to the gas outlet side is larger and smaller, and the arc section radian radius of the side wall far away from the gas outlet side and close to the gas inlet side is smaller and larger.

Preferably, the inner diameter of the collecting cylinder is kept constant from the inlet section to the outlet section and then gradually increases.

Preferably, the shapes of the unit axial lines of the axial cross section of the current collecting cylinder and the outlet section of the current collecting body are the same and are both single circular arcs or multiple circular arcs.

Preferably, the smallest inner diameter of the outlet section of the collector body is on the same cross section as the smallest inner diameter of the collector barrel.

Preferably, the height of the collector barrel is greater than the height of the collector body.

Preferably, the upper end inlet of the collecting cylinder and the upper end surface of the inlet section of the collector body are on the same cross section, that is, the upper end inlet of the collecting cylinder is flush with the upper end surface of the inlet section of the collector body; the lower end outlet of the collecting barrel is arranged to protrude out of the lower end face of the outlet section of the collector body, namely, the lower end of the collecting barrel extends out of the lower end face of the outlet section of the collector body.

Preferably, the lower outlet of the collecting barrel and the lower end surface of the outlet section of the collector body are on the same cross section, that is, the lower outlet of the collecting barrel is flush with the lower end surface of the outlet section of the collector body; the inlet of the upper end of the flow collecting cylinder is arranged to protrude out of the upper end surface of the inlet section of the flow collecting body, namely, the upper end of the flow collecting cylinder extends out of the upper end surface of the inlet section of the flow collecting body. The included angle between the inlet at the upper end of the collecting cylinder and the upper end surface of the inlet section of the collector body is 5-30 degrees.

Preferably, at least two layers of collecting cylinders are arranged in the inlet section in the radial direction of the collector body.

Preferably, the spacing distance between adjacent collecting cylinders is the same.

Preferably, the current collecting barrels are arranged in two layers along the radial direction of the current collector, and the two layers of current collecting barrels are identical in shape and different in size.

Preferably, the blade cascades are uniformly distributed between the current collecting barrel and the current collecting body at intervals, the number of the blade cascades is at least two, one end of each blade cascade is arranged on the inner side of the side wall of the outlet section of the current collecting body, and the side wall of each current collecting barrel is arranged at the other end of each blade cascade or on the blade cascade body between the two ends of each blade cascade.

Preferably, when the number of the current collecting barrels is at least two, the central current collecting barrel close to the center of the current collector body is fixedly connected with one end of the blade cascade, the other end of the blade cascade is connected with the inner side of the side wall of the current collector body, the other middle current collecting barrels arranged between the central current collecting barrel and the current collector body are arranged on the blade cascade body between the two ends of the blade cascade, the middle current collecting barrels are clamped and fixed on the blade cascade body, and the blade cascade mainly plays a role in connecting and fixing the current collecting barrels.

Preferably, an extension line of one end of the blade cascade, which is adjacent to the collecting barrel, passes through a central axis of the collector body, so that the concentricity of the blade cascade, the collecting barrel and the collector body can be guaranteed, and noise increase caused by eccentric play can be prevented.

Preferably, in the flow direction of the gas, the cascade extends in the axial direction in the same direction as the axial direction of the collector body; or the extending direction of the blade cascade in the axial direction forms an included angle with the axial direction of the current collector body.

More preferably, the blade cascade extends in an axial direction at an angle to the axial direction of the collector body, so that the blade cascade and the inlet gas direction in the inlet section of the collector body form a certain angle to guide the gas.

Preferably, the thickness of the body of the header may vary in equal or unequal thickness along the axial direction; the thickness of the blade cascade is uniform in thickness or airfoil-shaped change along the radial direction or the axial direction.

Preferably, the cascade is arranged radially parallel to the inlet section upper end face of the collector body.

Preferably, the cascade is arranged inclined downwards in the radial direction from the collector body to the collector barrel, i.e. in the direction of flow of the gas, one end of the cascade adjacent to the collector body being axially higher than the other end of the cascade adjacent to the collector barrel.

Preferably, the current collector further comprises a guide cone, the guide cone is arranged in an inner ring of the current collecting barrel adjacent to the center of the current collector body, and the guide cone is connected with the blade cascade. The collecting cylinder is axially inserted into the impeller and is matched with the guide cone structure so as to better guide gas to enter the impeller, and the design aim is to optimize the flow field at the inlet of the impeller, improve the efficiency of the fan and reduce the noise of the fan.

Preferably, in the flowing direction of the gas, the side surface near the vertex of the guide cone is connected with one end of the blade cascade, and the bottom surface of the guide cone is arranged to protrude from the gas outlet at the lower end surface of the outlet section.

Preferably, the diameter of the outlet circular surface at the bottom surface of the guide cone is smaller than or equal to the outer diameter of the motor, and the arrangement is to ensure that the gas enters the impeller and has no obvious impact with the motor.

The invention also provides a centrifugal fan, which comprises a current collector, an impeller and a motor, wherein the motor is arranged in a motor mounting hole in a rear disc of the impeller, the current collector is arranged in an upper disc inner ring of the impeller, the current collector is the current collector in the embodiment, a current collecting cylinder in the current collector extends from a current collector body to a front disc of the impeller, and part of side wall of the current collecting cylinder extending to the impeller forms an included angle with the horizontal direction of an inlet of the front disc of the impeller.

In this embodiment, one end of the cascade is connected to the current collector body, the other end of the cascade is connected to the side of the guide cone, and the guide cylinder is disposed on the cascade bodies at the two ends of the cascade.

Preferably, the outlet at the lower end of the collecting cylinder extends to the position above the blades of the impeller, so that the collision between the blades can be prevented.

Preferably, the included angle between the part of the side wall of the collecting cylinder extending into the impeller and the horizontal direction of the front disk inlet of the impeller is 5-35 degrees.

Preferably, the material of the current collector body, the current collecting cylinder, the blade grids and the flow guide cone is plastic or metal.

The invention has the beneficial effects that:

the high-efficiency low-noise multilayer current collector has the advantages that the current collector body is provided with the current collecting cylinder, the blade grid and the flow guiding cone, so that the blade grid can play a role in front guide vanes and supporting the current collecting cylinder and the flow guiding cone, meanwhile, the current collecting cylinder plays a role in layering gas entering the current collector so that the gas can smoothly enter the impeller, and the flow guiding cone plays a role in guiding the gas. Meanwhile, after the current collector with the multi-layer current collecting barrel and the flow guide cone combined is axially inserted into the impeller, the mutual matching of the blade grids, the current collecting barrel and the flow guide cone enables gas to enter the impeller more smoothly, the inflow condition of each small unit of gas at the inlet section of the current collector is further controlled, the vortex loss at the inlet of the impeller and the impact loss at the inlet of the blade are reduced, and therefore the purposes of efficiency improvement and noise reduction are achieved.

Drawings

Fig. 1 is a schematic structural view of example 1 of a high efficiency, low noise multilayer current collector of the present invention;

fig. 2 is a schematic structural view of example 2 of a high efficiency, low noise multilayer current collector of the present invention;

fig. 3 is a front view of example 2 of a high efficiency, low noise multilayer current collector of the present invention;

fig. 4 is a schematic diagram of the structure of example 9 of a high efficiency, low noise multilayer current collector of the present invention.

Reference numerals:

the flow collector comprises a collector body 1, an inlet section 11, an outlet section 12, a cascade 2, a collector barrel 3, an upper inlet 31, a lower outlet 32, a central collector barrel 33, a middle collector barrel 34, a flow guide cone 4, a side face 41 and a bottom face 42.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.

As shown in fig. 1, a high efficiency, low noise multilayer current collector includes: the collector body 1 comprises an inlet section 11 and an outlet section 12 along the flowing direction of gas, wherein the gas flows in from the inlet section 11 and flows out from the outlet section 12; the collecting cylinder 3 is arranged in the outlet section 12 of the collector body 1, and is connected with the outlet section 12; the blade cascade 2 is arranged in the inner ring of the outlet section 12, and the blade cascade 2 is used for connecting the collecting cylinder 3 and the inner ring of the outlet section 12; the collector cylinders 3 and the collector body 1 are arranged concentrically, and the collector cylinders 3 extend in the direction from the inlet section 11 to the outlet section 12. The shapes of unit axial lines of the axial section of the collecting cylinder 3 and the outlet section 12 of the collector body 1 are the same and are respectively one or more of single circular arcs or multiple circular arcs.

The inlet section 11 and the outlet section 12 are in circular arc transition, the outlet section 12 is tubular, the inlet section 11 comprises an inner ring and an outer ring, the outlet section 12 and the inner ring of the inlet section 11 are in circular arc transition, and gas flows from the inlet section 11 to the outlet section 12, so that the upper end face of the inlet section 11 is a gas inlet, the lower end face of the outlet section 12 is a gas outlet, the inner side wall of the collector body 1 is streamline, and the thickness of the outlet section 12 is kept unchanged or gradually reduced along the direction from the gas inlet to the outlet. The axial cross-section of the outlet section 12 in the gas inlet-to-outlet direction is in the form of a single circular arc. The inner diameter of the outlet section 12 gradually decreases and then gradually increases from the gas inlet to the gas outlet.

The collector cylinders 3 are arranged in the radial direction of the collector body 1, the side walls of the collector cylinders 3 extend in the direction from the inlet section 11 to the outlet section 12, and the side walls of the collector cylinders 3 are circular arc sections along the transverse section which is vertical to the axial direction of the collector. The cross section of the collecting barrel 3 along the axial direction vertical to the current collector is circular, and the collecting barrel 3 is of a cylindrical structure.

The collecting cylinder 3 is provided with a layer along the radial direction of the collector. From the inlet section 11 to the outlet section 12, the axial cross section of the manifold cylinder 3 is formed by a plurality of unit axial lines, and the axial lines are one or more of single circular arcs, double circular arcs, multiple circular arcs or spline curves. Collector barrels 3 so arranged may conform to a variety of flow field distributions. The thickness of the current collector is equal or varies in an airfoil shape. The inner diameter of the collecting cylinder 3 gradually decreases and then gradually increases from the inlet section 11 to the outlet section 12, and the axial section of the collecting cylinder 3 consists of a plurality of single arcs.

The inner diameter of an upper end inlet 31 of the collecting cylinder 3 is smaller than that of a lower end outlet 32, the upper end inlet 31 of the collecting cylinder 3 is adjacent to the inlet section 11 of the collector body 1, and the lower end outlet 32 of the collecting cylinder 3 is adjacent to the outlet end of the collector body 1.

The minimum inner diameter of the outlet section 12 of the collector body 1 is on the same cross section as the minimum inner diameter of the collector cylinder 3.

The height of the collecting cylinder 3 is larger than that of the collector body 1.

The upper end inlet 31 of the collecting cylinder 3 and the upper end surface of the inlet section 11 of the collector body 1 are positioned on the same cross section, namely the upper end inlet 31 of the collecting cylinder 3 is flush with the upper end surface of the inlet section 11 of the collector body 1; the lower outlet 32 of the collecting cylinder 3 protrudes out of the lower end surface of the outlet section 12 of the collector body 1, i.e., the lower end of the collecting cylinder 3 protrudes out of the lower end surface of the outlet section 12 of the collector body 1. Preferably, the included angle between the upper end inlet 31 of the collecting cylinder 3 and the upper end surface of the inlet section 11 of the collector body 1 is 5-30 degrees.

The blade cascades 2 are uniformly distributed between the current collecting barrel 3 and the current collecting body 1 at intervals, the number of the blade cascades 2 is at least two, one end of each blade cascade 2 is arranged on the inner side of the side wall of the outlet section 12 of the current collecting body 1, and the side wall of the current collecting barrel 3 is arranged on the other end of each blade cascade 2 or the blade cascade 2 body between the two ends of each blade cascade 2.

The extension line of one end of the blade cascade 2, which is close to the collecting cylinder 3, passes through the central axis of the collector body 1, so that the concentricity of the blade cascade 2, the collecting cylinder 3 and the collector body 1 can be ensured, and the noise increase caused by the eccentric movement can be prevented. The extension direction of the blade cascade 2 in the axial direction is the same as the axial direction of the collector body 1 along the flow direction of the gas; the thickness of the current collector body 1 can be changed in an equal thickness or different thicknesses along the axial direction; the thickness of the blade row 2 is uniform or airfoil-shaped along the radial direction or the axial direction. The cascade 2 is arranged radially parallel to the upper end face of the inlet section 11 of the header body 1.

Example 2

As shown in fig. 3 and 4, this embodiment describes only the differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. The current collector further comprises a guide cone 4, the guide cone 4 is arranged in an inner ring of the current collecting barrel 3 adjacent to the center of the current collector body 1, and the guide cone 4 is connected with the blade cascade 2. The axial insertion of the collecting cylinder 3 into the impeller and the guide cone 4 is to better guide the gas to enter the impeller, so the design aims to optimize the flow field at the inlet of the impeller, improve the efficiency of the fan and reduce the noise of the fan. The material of the current collector body 1, the current collecting cylinder 3, the blade grids 2 and the flow guide cone 4 is plastic or metal.

Preferably, a side surface 41 adjacent to the vertex of the guide cone 4 is connected to one end of the blade row 2 in the flowing direction of the gas, and a bottom surface 42 of the guide cone 4 is protruded from the gas outlet of the lower end surface of the outlet section 12. The diameter of the outlet circular surface at the bottom surface 42 of the guide cone 4 is smaller than or equal to the outer diameter of the motor, and the arrangement is to ensure that gas enters the impeller and has no obvious impact with the motor.

Example 3

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, the inner diameter of the outlet section 12 gradually increases from the gas inlet to the outlet.

Example 4

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, the outlet section 12 is a multi-arc, and the axial cross-sectional form thereof along the gas inlet-outlet direction includes a plurality of arc sections.

Example 5

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, at least two layers of collecting cylinders 3 are arranged in the inlet section 11 in the radial direction of the collector body 1. Preferably, the spacing distance between adjacent collector cylinders 3 is the same. The two layers of the collecting barrels 3 are arranged along the radial direction of the collector, and the shapes of the two layers of the collecting barrels 3 are the same and the sizes of the two layers of the collecting barrels are different.

When the number of the collecting barrels 3 is at least two, the central collecting barrel 33 close to the center of the collector body 1 is fixedly connected with one end of the blade cascade 2, the other end of the blade cascade 2 is connected with the inner side of the side wall of the collector body 1, the other middle collecting barrels 34 arranged between the central collecting barrel 333 and the collector body 1 are arranged on the body of the blade cascade 2 between the two ends of the blade cascade 2, the middle collecting barrel 343 is fixed on the body of the blade cascade 2 in a clamping mode, and the blade cascade 2 mainly plays a role in connecting and fixing the collecting barrels 3.

Example 6

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, the inner diameter of the manifold cylinder 3 gradually increases from the inlet section 11 to the outlet section 12, that is, the arc radius of the circular arc section of the side wall of the manifold cylinder 3 near the gas outlet side is larger and smaller, and the arc radius of the circular arc section far from the gas outlet side and near the gas inlet side is smaller and larger.

Example 7

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, the inner diameter of the manifold cylinder 3 is constant from the inlet section 11 to the outlet section 12 and then gradually increases.

Example 8

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. As shown in fig. 4, in the present embodiment, the lower end outlet 32 of the collecting cylinder 3 is on the same cross section with the lower end surface of the outlet section 12 of the collector body 1, i.e. the lower end outlet 32 of the collecting cylinder 3 is flush with the lower end surface of the outlet section 12 of the collector body 1; the upper end inlet 31 of the collecting cylinder 3 protrudes out of the upper end surface of the inlet section 11 of the collector body 1, that is, the upper end of the collecting cylinder 3 protrudes out of the upper end surface of the inlet section 11 of the collector body 1.

Example 9

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In this embodiment, the blade cascade 2 extends in an axial direction at an angle with the axial direction of the current collector body 1, so that the blade cascade 2 and the inlet gas direction in the inlet section 11 of the current collector body 1 form a certain angle, thereby guiding the gas.

Example 10

This embodiment will be described only for differences from the above-described embodiment, and the remaining technical features are the same as those of the above-described embodiment. In the present embodiment, the blade row 2 is arranged in a radial direction from the collector body 1 to the collector barrel 3 with a downward inclination, i.e. in the flow direction of the gas, one end of the blade row 2 adjacent to the collector body 1 is higher in the axial direction than the other end of the blade row 2 adjacent to the collector barrel 3.

A centrifugal fan comprises a current collector, an impeller and a motor, wherein the motor is arranged in a motor mounting hole in a rear disc of the impeller, the current collector is arranged in an upper disc inner ring of the impeller, the current collector is the current collector in the embodiment, a current collecting cylinder 3 in the current collector extends from a current collector body 1 to a front disc of the impeller, and part of side wall of the current collecting cylinder 3 extending to the impeller forms an included angle with the horizontal direction of an inlet of the front disc of the impeller.

In this embodiment, one end of the cascade 2 is connected to the current collector body 1, the other end of the cascade 2 is connected to the side surface 41 of the guide cone 4, and the guide cylinders are disposed on the cascade 2 bodies at two ends of the cascade 2.

Preferably, the lower outlet 32 of the manifold block 3 extends above the blades of the impeller to prevent contact with the blades. The included angle between the part of the side wall of the collecting cylinder 3 extending into the impeller and the horizontal direction of the front disc inlet of the impeller is 5-35 degrees.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.