CN118273973A

CN118273973A - Centrifugal fan impeller, centrifugal fan assembly and ventilation treatment equipment

Info

Publication number: CN118273973A
Application number: CN202211712525.9A
Authority: CN
Inventors: 毕唯东; 庄志
Original assignee: Xi'an Yenisei Electronic Technology Co ltd
Current assignee: Xi'an Yenisei Electronic Technology Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2024-07-02
Also published as: WO2024140176A1

Abstract

The invention relates to the field of impeller machinery, and discloses a centrifugal fan impeller, a centrifugal fan assembly and ventilation treatment equipment, wherein the centrifugal fan impeller comprises a central shaft (1) and a plurality of 3D curved blades (2) which are circumferentially distributed along the peripheral surface of the central shaft (1), each 3D curved blade respectively comprises an inner edge connected to the central shaft, an outer edge opposite to the inner edge and an upper edge and a lower edge which extend between the inner edge and the outer edge, and the inner edge and/or the outer edge extend along curves and/or multiple sections. The centrifugal fan impeller omits an impeller chassis in the prior art, so that the moment of inertia in the rotation process can be greatly reduced; depending on the axial length of the central shaft, the 3D curved blades may be provided with a relatively large size, whereby the centrifugal fan impeller can be ensured to have a good functioning capability, and thus be suitable for use as a backward curved impeller in ventilation therapy devices such as ventilators, operating at high rotational speeds.

Description

Centrifugal fan impeller, centrifugal fan assembly and ventilation treatment equipment

Technical Field

The invention relates to impeller machinery, in particular to a centrifugal fan impeller. On the basis, the invention also relates to a centrifugal fan assembly comprising the centrifugal fan impeller and ventilation treatment equipment provided with the centrifugal fan assembly.

Background

As an important power plant and medium delivery plant, an impeller machine transfers energy to a fluid medium flowing continuously through the impeller machine by converting other forms of energy (e.g., electrical energy) into mechanical energy that turns the impeller. A fan is a typical impeller machine, and is mainly classified into a centrifugal fan, an axial flow fan, and the like.

In order to avoid overload and overheat of the motor driving the centrifugal fan during the operation of the centrifugal fan, the rotational inertia and weight of the fan need to be strictly controlled, wherein the rotational inertia is closely related to the material density and structural form of the rotating part (impeller), and therefore, the centrifugal fan impeller needs to be reasonably designed. In particular, in ventilation therapy apparatuses such as ventilators, there is generally provided a miniature centrifugal fan having characteristics of small volume, high rotation speed, high pressure, high noise requirement, etc., and the blades of such centrifugal fans are generally provided in a twisted shape, together with a small overall volume, resulting in difficulty in processing.

Typically, to ensure high work efficiency, centrifugal fan impellers for ventilators are rotatably disposed within a volute and include an impeller chassis and a plurality of blades disposed on the impeller chassis. In view of the structural strength requirements of higher rotational speeds, impeller chassis are typically provided with a thickness that results in centrifugal fan impellers having a large moment of inertia that can easily overload or overheat the fan that drives them.

Disclosure of Invention

The invention aims to solve the problem of large rotational inertia of a centrifugal fan impeller in the prior art, and provides the centrifugal fan impeller which can greatly reduce the rotational inertia and has good functional capability.

In order to achieve the above object, an aspect of the present invention provides a centrifugal fan impeller comprising:

a central shaft having a first end and a second end opposite each other;

A plurality of 3D curved blades circumferentially distributed along an outer circumferential surface of the central shaft, and the 3D curved blades include an inner edge connected to the central shaft, an outer edge opposite the inner edge, and upper and lower edges extending between the inner and outer edges, wherein the inner and/or outer edges extend along curves and/or multi-segment lines.

Preferably, the upper edge of the 3D curved blade is flush with the first end of the central shaft, the lower edge is flush with the second end, and the first end is connected with a guide cone.

Preferably, the upper edge and the lower edge of the 3D curved blade extend along a straight line, respectively, and are different from each other.

Preferably, the thickness of the 3D curved blade decreases in a direction from the inner edge to the outer edge.

Preferably, the maximum thickness of the 3D curved blade is 1.0mm-1.4mm, and the minimum thickness is 0.6mm-10 mm.

Preferably, the outer edge of the 3D curved blade is formed with a radially inwardly contracting concave structure.

Preferably, the recess structure extends from the upper edge, and a distance between a deepest portion of the recess structure and the upper edge is greater than a distance between the recess structure and the lower edge.

Preferably, the central shaft is a solid of revolution structure, and the diameter of the central shaft increases progressively in a direction from the first end to the second end.

A second aspect of the present invention provides a centrifugal fan assembly comprising a noise reduction box and the above centrifugal fan impeller rotatably mounted within the noise reduction box, the centrifugal fan impeller being capable of being driven to rotate within the noise reduction box and such that the angle between the extension of the 3D curved blades at the outer edge and the tangent of rotation of the outer edge is an obtuse angle.

A third aspect of the present invention provides a ventilation therapy device comprising the centrifugal fan assembly described above.

Through the technical scheme, the centrifugal fan impeller omits an impeller chassis in the prior art, and the 3D curved surface blades are directly connected to the outer peripheral surface of the central shaft, so that the moment of inertia in the rotation process can be greatly reduced, and the risk of overload or overheating of a motor for driving the centrifugal fan impeller is reduced. Depending on the axial length of the central shaft, the 3D curved blades may be provided with relatively large dimensions at the upper and lower edges, so that a good functioning of the centrifugal fan wheel can be ensured, and thus be suitable for use as a backward curved impeller in ventilation therapy devices such as ventilators, operating at high rotational speeds.

Drawings

FIG. 1 is a perspective view of a centrifugal fan impeller according to a preferred embodiment of the present invention;

FIG. 2 is a top view of the centrifugal fan wheel of FIG. 1;

fig. 3 is a bottom view of the centrifugal fan impeller of fig. 1.

Description of the reference numerals

1-A central axis; 11-a first end; 12-a second end; 2-3D curved blades; 21-inner edge; 22-outer edge; 22 a-a recessed structure; 23-upper edge; 24-lower edge; 3-diversion cone.

Detailed Description

The following describes specific embodiments of the present invention in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

Referring to fig. 1 to 3, a centrifugal fan impeller according to a preferred embodiment of the present invention includes a central shaft 1 and a plurality of 3D curved blades 2 uniformly connected to an outer circumferential surface of the central shaft 1 in a circumferential direction, the 3D curved blades 2 respectively extending radially outward from the outer circumferential surface of the central shaft 1. In order to meet the high rotational speed requirements for applications in small devices such as ventilators, the centrifugal fan blades are provided as backward curved impellers, whereby good aerodynamic properties can be maintained even at high speed operation.

Specifically, the center shaft 1 has a first end 11 and a second end 12 opposite to each other at both axial ends thereof. Each 3D curved blade 2 includes an inner edge 21, an outer edge 22, an upper edge 23, and a lower edge 24, respectively, wherein the inner edge 21 is connected to the outer circumferential surface of the center shaft 1; the outer edge 22 is opposite to the inner edge 21 and is located at an end remote from the central axis 1; the upper edge 23 and the lower edge 24 extend between the inner edge 21 and the outer edge 22, respectively.

In the centrifugal fan impeller provided by the invention, the lower edges 24 of the 3D curved blades 2 are suspended, so that an impeller chassis in the prior art is omitted, and a plurality of 3D curved blades 2 are directly connected to the outer peripheral surface of the central shaft 1 and are uniformly distributed along the outer peripheral surface in the circumferential direction, so that larger moment of inertia can not be caused by the impeller chassis with a certain thickness in the process of being driven to rotate. Accordingly, the centrifugal fan impeller of the present invention can greatly reduce the moment of inertia during rotation, thereby reducing the risk of overload or overheating of the motor used to drive it.

As illustrated, in the centrifugal fan impeller of the present invention, at least one of the inner edge 21 and the outer edge 22 of the 3D curved blade 2 is provided to extend along a curved line and/or a multi-sectional line, whereby the 3D curved blade 2 has an axial 3D structure, and depending on the axial length of the center shaft 1, the 3D curved blade 2 may be provided to have a relatively wide dimension between the upper edge 23 and the lower edge 24, for example, the width dimension may be provided to be not smaller than the radial dimension from the inner edge 21 to the outer edge 23, thereby enabling not only the 3D curved blade 2 to be firmly connected, but also being advantageous in ensuring good functional capability. In this case, the 3D curved blade 2 may be configured such that its characteristic curve is consistent with that of the backward curved fan, i.e., the centrifugal fan impeller is suitable for being used as a backward curved impeller, such that an angle between an extension line of the centrifugal fan impeller at the outer edge 22 and a rotation tangent line of the outer edge 22 is an obtuse angle (i.e., an outlet mounting angle is less than 90 °), thereby maintaining good aerodynamic characteristics even if driven to rotate at a high speed, and being particularly suitable for application scenarios requiring a high rotational speed, such as a ventilator.

It will be appreciated that in order to ensure smooth rotation, each 3D curved blade 2 in the centrifugal fan wheel of the present invention should be configured to have the same structure, i.e. the extension of each corresponding edge thereof, the blade shape should be consistent. The upper edge 23 of each 3D curved blade 2 may be disposed flush with the first end 11 of the central shaft 1, and the lower edge 24 may be flush with the second end 12 of the central shaft 1, thereby fully utilizing the axial space of the central shaft 1 and ensuring higher working capacity.

In the centrifugal fan impeller, a guide cone 3 may be further connected to the first end 11 of the central shaft 1, and the guide cone 3 may be sized to fit the dimensions of the central shaft 1 and the 3D curved blade 2, etc. For example, in a preferred embodiment, the overall radius of the centrifugal fan wheel is set to 30.2mm, wherein the radial dimension of the 3D curved blades 2 is 22mm, the flow cone 3 may be set to have a radius of 8 mm.

As described above, the centrifugal fan impeller of the present invention is provided as the 3D curved blade 2 having the axial 3D structure. In order to reduce the difficulty of forming, the upper edge 23 and the lower edge 24 of the 3D curved blade 2 may be respectively arranged to extend along a straight line, and the straight lines where the two are located are different from each other. With this arrangement, it is also convenient to precisely determine the mounting position thereof on the central shaft 1 by means of the upper edge 23 and the lower edge 24.

During the use, the gas medium enters the space between the adjacent 3D curved blades 2 from the radial outer side of the centrifugal fan impeller and is discharged along the radial direction, so that the circumferential space occupied by the 3D curved blades 2 can be reduced as much as possible. Furthermore, since the impeller chassis is omitted, it is necessary to secure the stability of the connection thereof to the center shaft 1 by appropriately increasing the strength of the 3D curved surface blade 2. For this reason, in a centrifugal fan impeller of a preferred embodiment, the thickness of the 3D curved blades 2 decreases in a direction from the inner edge 21 to the outer edge 22. For example, the thickness of the 3D curved blade 2 may be set to 1.2mm near its inner edge 21, and 0.8mm near its outer edge 22. In other embodiments, the material and thickness of the 3D curved blade 2 should meet the medium conveying requirement, and according to the actual situation of air flow conveying in the breathing machine, the 3D curved blade 2 may have the maximum thickness (1.0 mm-1.4 mm) and the minimum thickness (0.6 mm-10 mm) with other dimensions, and the material is PP plastic. In other embodiments, the 3D curved blade 2 may be made of other materials such as metal, which may increase the weight, which is not beneficial to the light design requirement of the device.

In the illustrated preferred embodiment, 10 3D curved surface blades 2 arranged in the circumferential direction are uniformly distributed on the outer circumferential surface of the central shaft 1, whereby the corresponding central angle between adjacent 3D curved surface blades 2 is 36 °. In other embodiments, other numbers of main blades 2, such as 8, 12, etc., may be evenly arranged.

In the centrifugal fan impeller of the present invention, the wide 3D curved blades 2 may cause aerodynamic separation on the blades. For this reason, in a preferred embodiment, the outer edge 22 of the 3D curved blade 2 may be formed with a radially inwardly converging concave structure 22a, which may prevent premature aerodynamic separation at a location near the trailing edge (outer edge 22) of the blade during operation, thereby preventing severe aerodynamic noise. For ventilation therapy devices such as ventilators, reducing fan noise has an important role in improving the user experience.

Further, the concave structures 22a may extend from the upper edge 23 of the 3D curved blade 2 with a greater spacing from the deepest portion to the upper edge 23 than from the lower edge 24. Thus, since the portion of the 3D curved blade 2 near the lower edge 24 has a relatively large size, the overall center of gravity position thereof can be lowered, which is advantageous in ensuring good rotational stability.

Similarly, the central shaft 1 may be provided as a solid of revolution, and the diameter of the central shaft 1 increases in the direction from the first end 11 to the second end 12, which also improves the rotational stability of the centrifugal fan impeller at high rotational speeds. By this arrangement, it is also possible to make the portion of the 3D curved blade 2 near the lower edge 24 have a relatively small radial extension, which is advantageous in ensuring that the strength of the 3D curved blade 2 can withstand high-speed rotation.

On the basis, the invention also provides a centrifugal fan assembly, which comprises the noise reduction box and the centrifugal fan impeller. In the centrifugal fan assembly, the centrifugal fan impeller may be of a volute-less design, and thus requires calibration of its mounting position when mounted into the noise reduction box, in which the centrifugal fan impeller can be driven to rotate. The side wall of the noise reduction box may be provided with an air inlet and an air outlet, and the centrifugal fan impeller may be mounted and driven such that the angle between the extension of the 3D curved blade 2 at its outer edge 22 and the tangent of rotation of the outer edge 22 is an obtuse angle, thereby forming a backward curved impeller. The top and the bottom of the centrifugal fan impeller can be respectively provided with a 3mm micro gap with the upper wall and the lower wall of the noise reduction box, so that scratch in the rotation process is prevented. The volute of the centrifugal fan is omitted, so that the integral weight of equipment such as a breathing machine can be reduced, reference is provided for the design of the integrated breathing machine, and meanwhile, the processing cost caused by the complex geometric design of the volute can be reduced.

In addition, the invention also provides ventilation treatment equipment such as a respirator comprising the centrifugal fan assembly.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of individual specific technical features in any suitable way. The various possible combinations of the invention are not described in detail in order to avoid unnecessary repetition. Such simple variations and combinations are likewise to be regarded as being within the scope of the present disclosure.

Claims

1. A centrifugal fan impeller, comprising:

a central shaft (1), the central shaft (1) having a first end (11) and a second end (12) opposite to each other;

A plurality of 3D curved blades (2), the plurality of 3D curved blades (2) being circumferentially evenly distributed along the outer circumferential surface of the central shaft (1), and the 3D curved blades (2) comprising an inner edge (21) connected to the central shaft (1), an outer edge (22) opposite the inner edge (21), and an upper edge (23) and a lower edge (24) extending between the inner edge (21) and the outer edge (22), wherein the inner edge (21) and/or the outer edge (22) extend along a curve and/or a multi-section line.

2. Centrifugal fan impeller according to claim 1, wherein the upper edge (23) of the 3D curved blade (2) is flush with the first end (11) of the central shaft (1), the lower edge (24) is flush with the second end (12), and the first end (11) is connected with a guide cone (3).

3. Centrifugal fan impeller according to claim 1, wherein the upper edge (23) and lower edge (24) of the 3D curved blade (2) extend along straight lines and are out of plane with each other, respectively.

4. Centrifugal fan impeller according to claim 1, wherein the thickness of the 3D curved blades (2) decreases in a direction from the inner edge (21) to the outer edge (22).

5. Centrifugal fan impeller according to claim 4, wherein the maximum thickness of the 3D curved blade (2) is 1.0-1.4 mm and the minimum thickness is 0.6-10 mm.

6. Centrifugal fan impeller according to claim 1, wherein the outer edge (22) of the 3D curved blade (2) is formed with a radially inwardly shrinking recess structure (22 a).

7. Centrifugal fan impeller according to claim 6, wherein the recess structure (22 a) extends from the upper edge (23) and the distance between the deepest part of the recess structure (22 a) and the upper edge (23) is larger than the distance between the recess structure and the lower edge (24).

8. Centrifugal fan impeller according to claim 1, wherein the central shaft (1) is of a solid of revolution construction and the diameter of the central shaft (1) increases in a direction from the first end (11) to the second end (12).

9. A centrifugal fan assembly comprising a noise reduction box and a centrifugal fan impeller according to any one of claims 1 to 8 rotatably mounted in the noise reduction box, the centrifugal fan impeller being drivable to rotate within the noise reduction box and such that the angle between the extension of the 3D curved blades (2) at the outer edge (22) and the tangent to rotation of the outer edge (22) is obtuse.

10. A ventilation therapy device, characterized in that it comprises a centrifugal fan assembly according to claim 9.