CN218347622U

CN218347622U - Impeller for air compressor, air compressor and fuel cell system

Info

Publication number: CN218347622U
Application number: CN202222909064.6U
Authority: CN
Inventors: 贾岩巍
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2022-11-02
Filing date: 2022-11-02
Publication date: 2023-01-20
Anticipated expiration: 2032-11-02

Abstract

The utility model relates to an impeller for air compressor, impeller (12) include: a hub (121); and a plurality of blades (122) projecting from the hub (121), wherein the blades (122) have blade leading edges (1222) that face axially towards an air inlet (14) of the air compressor (1) in the assembled state, and wherein at least the blade leading edges (1222) of a first group of blades (122) of the plurality of blades (122) that are axially adjacent to the air inlet (14) are each arranged obliquely forward and extend obliquely outward towards the direction of the air inlet (14). The utility model discloses still relate to a corresponding air compressor and a corresponding fuel cell system. According to certain exemplary embodiments of the present invention, an air compressor can be made to have better workability.

Description

Impeller for air compressor, air compressor and fuel cell system

Technical Field

The utility model relates to an impeller, a corresponding air compressor and a corresponding fuel cell system for air compressor.

Background

Air compressors are widely used in various fields for pressurizing low-pressure air or other types of gas to output high-pressure gas.

For example, with the development of new energy technology, such as new energy vehicles, the development and application of fuel cells are accelerated. An air compressor is used in the fuel cell to generate and supply compressed air to the cathode side of the fuel cell, which provides air to meet the flow, pressure, temperature and humidity requirements of the stack when the stack is operating under different operating conditions in the fuel cell.

Air compressors come in a variety of forms, among which centrifugal air compressors, which are the more common type of air compressor, typically have a volute and an impeller, the impeller being located within the volute and fixed to a drive shaft so as to be rotatable therewith, the rotating impeller pressurizing gas entering through an inlet port and discharging it from an outlet port.

In a centrifugal air compressor, an impeller drives gas to be pressurized to rotate at a high speed, so that the gas generates centrifugal force, and because the gas flows in the impeller in a diffusion mode, the flow speed and pressure of the gas passing through the impeller are improved, and compressed air is continuously produced. Therefore, the configuration of the impeller has a significant influence on the operating characteristics of the air compressor, and in particular, it has been found in practice that there is a problem in that the local pressure increase is slow in the supercharging region of the impeller.

For this reason, improvement is required.

SUMMERY OF THE UTILITY MODEL

In order to overcome one of the above-mentioned drawbacks and/or other possible drawbacks not mentioned herein, it is an object of the present invention to provide an improved impeller for an air compressor, a corresponding air compressor and a corresponding fuel cell system.

According to a first aspect of the present invention, there is provided an impeller for an air compressor, the impeller comprising: a hub; and a plurality of blades projecting from the hub, wherein the blades have blade leading edges that face axially toward an intake port of the air compressor in an assembled state, and blade leading edges of a first group of blades at least axially adjacent to the intake port of the plurality of blades are each arranged obliquely forward to extend obliquely outward toward the direction of the intake port.

According to an optional embodiment of the present invention, the first set of blades are circumferentially evenly arranged.

According to an optional embodiment of the invention, the blade leading edges of the first set of blades are configured to coincide with each other while overlapping each other in the circumferential direction.

According to an alternative embodiment of the invention, the leading edges of the first set of blades are straight edges.

According to an alternative embodiment of the invention, the blade leading edges of the first set of blades extend at a predetermined angle deviating from the radial direction, wherein the predetermined angle is in the range of 0-8 °.

According to an optional embodiment of the present invention, the plurality of vanes further comprises a second set of vanes arranged axially further from the air inlet relative to the first set of vanes.

According to an optional embodiment of the present invention, the first set of blades and the second set of blades are circumferentially arranged alternately and uniformly with each other.

According to a second aspect of the present invention, there is provided an air compressor comprising an impeller for an air compressor according to any of the above exemplary embodiments.

According to a third aspect of the present invention, there is provided a fuel cell system including the air compressor according to any one of the above-described exemplary embodiments.

According to certain exemplary embodiments of the present invention, the air compressor may be made to have better performance, particularly overcoming the problem of slow local pressurization.

Drawings

The principles, features and advantages of the present invention may be better understood by describing the invention in more detail below with reference to the accompanying drawings. The drawings comprise:

fig. 1 shows a schematic partially cut-away view of an impeller region of an air compressor according to an exemplary embodiment of the present invention. For the sake of simplicity, fig. 1 shows only the structure closely related to the improved portion of the present invention.

Fig. 2 shows a side view of an impeller for an air compressor according to an exemplary embodiment of the present invention.

Fig. 3 shows a top view of the impeller shown in fig. 2.

List of reference numerals

1 air compressor

11 drive shaft

12 impeller

13 spiral case

14 air inlet

121 hub

122 blade

1211 profile

1221 wheel rim

1222 blade leading edge

1223 blade set leading edge

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and a plurality of exemplary embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Fig. 3 shows a top view of the impeller shown in fig. 2.

As shown in fig. 1, the air compressor 1 comprises a drive shaft 11, an impeller 12 fixedly mounted on the drive shaft 11 so as to be rotatable with the drive shaft 11, a volute 13 covering the impeller 12, and a gas inlet 14 (shown very schematically) opening axially into the impeller 12 for supplying gas to be compressed to the impeller 12. As can be seen from fig. 1, only the upper half is shown, but this is sufficient to illustrate the basic idea of the invention.

As can be seen from fig. 1, 2 and 3, the impeller 12 has a hub 121 and a plurality of blades 122 protruding from the hub 121, which plurality of blades 122 can pressurize the gas to be compressed when the impeller 12 rotates. In fig. 1, a profile 1211 of the side of the hub 121 facing the blades 122 is schematically shown.

Referring to fig. 2 in conjunction with fig. 1, when viewed laterally, the circumferential outer edges of all the blades 122 facing the volute 13 collectively constitute a rim (i.e., the overall peripheral profile of the blades 122), in fig. 1, a rim 1221 is schematically illustrated in dashed lines.

As shown in FIG. 2, the edge of each vane 122 on the side axially facing the air inlet 14 may be referred to as a vane leading edge 1222. As shown in fig. 2, in some embodiments, the axial extension of the vane 122 is different, especially in the position extending axially toward the inlet 14, in order to be able to pressurize the gas to be compressed in stages in cooperation with the volute 13. As exemplarily shown in fig. 2, the plurality of vanes 122 may include a first set of vanes 122 that extend axially furthest toward the air inlet 14, i.e., axially immediately adjacent to the air inlet 14, and a second set of vanes 122 that extend axially shorter toward the air inlet 14 and axially relatively farther away from the air inlet 14. The first set of vanes 122 has a longer axial length and the second set of vanes 122 has a shorter axial length. The first set of blades and the second set of blades are circumferentially alternated and uniformly arranged with respect to each other. Of course, in practice, there may be more sets of blades arranged.

As shown in fig. 1 in conjunction with fig. 2, the vane leading edges 1222 of the first set of vanes in fig. 2, which are the vanes 122 that extend axially furthest toward the air inlet 14, can form a common vane set leading edge 1223.

As shown in fig. 1 in conjunction with fig. 2, according to an exemplary embodiment of the present invention, the vane leading edges 1222 of a set of vanes 122 disposed axially adjacent to the air intake 14 are each disposed in a forward-leaning arrangement. This means that the vane leading edges 1222 do not extend perpendicularly radially outward with respect to the axis of rotation of the drive shaft 11, but rather extend obliquely outward with respect to the axis of rotation in the direction of the air inlet 14 such that the radially outer portions of the vane leading edges 1222 are axially closer to the air inlet 14 than the radially inner portions of the vane leading edges 1222.

It will be appreciated by those skilled in the art that the angled arrangement provides for an increased length of the blades 122 at the rim 1221, thereby increasing the ability of the impeller 12 to work at the rim 1221, which in turn improves the uniformity of pressure build-up in the blade area.

According to an exemplary embodiment of the present invention, each blade leading edge 1222 of a set of blades 122 arranged axially adjacent to the air inlet 14 is configured as a straight edge. This is an advantageous arrangement, but in principle other suitable curved shapes etc. are theoretically possible.

As shown in fig. 1, in the case of a straight edge, the degree of forward lean of the blade leading edge 1222 can be characterized by an angle α that deviates from the radial direction. The larger the angle α, the larger the degree of inclination with respect to the radial direction. According to an exemplary embodiment of the present invention, 0 ° < α < 8 °.

According to an exemplary embodiment of the present invention, the respective blade leading edges 1222 of a set of blades 122 arranged axially adjacent to the air inlet 14 are configured to coincide with each other while overlapping each other circumferentially. In other words, the leading edges 1222 are rotationally symmetric with respect to each other. This means that they overlap each other in fig. 1, for example at the leading edge 1223 of the blade set. This uniform arrangement is clearly advantageous for the smoothness of the operation of the air compressor 1, since they face directly towards the air inlet 14 so that the action of the pressure of the respective blades 122 on the gas to be compressed is circumferentially uniform during rotation, thereby facilitating stable rotation of the impeller.

As shown in fig. 2 and 3, the set of vanes 122 arranged axially adjacent to the air inlet 14 includes a plurality of vanes 122 evenly arranged in the circumferential direction. In this case, it is also possible in principle to select only a subset of the blades 122 of the set of blades 122 which are uniformly distributed circumferentially so that their leading blade edges 1222 are uniformly forwardly inclined, and the remaining blades or another subset of the remaining blades which are uniformly distributed circumferentially may be configured in a conventional manner or may be configured so that they are uniformly forwardly inclined, but the angle of inclination may be different from the other sets of blades.

As described above, the forward-leaning arrangement is primarily with respect to a set of vanes 122 arranged axially adjacent to the air intake 14. For those groups of blades 122 that are axially further away from the air inlet 14, the blade leading edge 1222 may be disposed in a forward-inclined manner or in a conventional manner, which is not limited by the present invention, but may be adjusted according to the actual situation.

Obviously, the present invention also relates to an air compressor comprising such an impeller 12. Such air compressors are also referred to as centrifugal air compressors.

The utility model discloses still relate to a fuel cell system including this kind of air compressor.

Other advantages and alternative embodiments of the present invention will be apparent to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative structures, and illustrative examples shown and described. Rather, various modifications and substitutions may be made by those skilled in the art without departing from the basic spirit and scope of the invention.

Claims

1. An impeller for an air compressor, characterized in that said impeller (12) comprises:

a hub (121); and

a plurality of blades (122) protruding from the hub (121),

wherein the blades (122) have blade leading edges (1222) which in the assembled state face axially towards the air inlet (14) of the air compressor (1), the blade leading edges (1222) of a first group of blades (122) of the plurality of blades (122), which are at least axially adjacent to the air inlet (14), each being arranged obliquely forwards and extending obliquely outwards in the direction of the air inlet (14).

2. Impeller for an air compressor, according to claim 1,

the first set of blades (122) are uniformly circumferentially arranged.

3. Impeller for an air compressor, according to claim 1,

the blade leading edges (1222) of the first set of blades (122) are configured to coincide with each other while overlapping each other in a circumferential direction.

4. Impeller for an air compressor according to any one of claims 1 to 3,

the leading edges (1222) of the first set of blades (122) are all straight edges.

5. Impeller for an air compressor according to claim 4,

the vane leading edges (1222) of the first set of vanes (122) extend offset from a radial direction by a predetermined angle, wherein the predetermined angle is in the range of 0 ° -8 °.

6. Impeller for an air compressor, according to any one of claims 1 to 3, 5,

the plurality of vanes (122) further includes a second set of vanes (122) disposed axially farther from the air inlet (14) relative to the first set of vanes (122).

7. Impeller for an air compressor, according to claim 6,

the first set of blades (122) and the second set of blades (122) are uniformly arranged circumferentially alternating with each other.

8. An air compressor (1), characterized in that the air compressor (1) comprises an impeller for an air compressor according to any one of claims 1-7.

9. A fuel cell system characterized by comprising the air compressor according to claim 8.