CN114526262B - Volute component and air compressor - Google Patents

Abstract

The invention discloses a volute assembly and an air compressor, wherein the volute assembly comprises a shell, an impeller and a plurality of flow guide pieces, the shell comprises a cavity, a first flow channel and a second flow channel, the first flow channel is communicated with the cavity and surrounds the outer peripheral side of the cavity, the second flow channel is suitable for introducing gas and discharging the gas into the cavity under reduced pressure, the impeller is rotatably arranged in the cavity, a part of the impeller is matched with an inlet of the first flow channel, the outer peripheral surface of the impeller is arranged at intervals with the inner peripheral surface of the first flow channel, the plurality of flow guide pieces are arranged at one side of the inlet of the first flow channel adjacent to the second flow channel, the flow guide pieces and the part of the impeller are arranged at intervals along the axial direction of the impeller, the plurality of flow guide pieces are arranged at intervals along the circumferential direction of the impeller to form an airflow channel, and the extending direction of the flow guide pieces and the radial direction of the impeller intersect to form an included angle. The volute component has the advantages of simple structure, high working efficiency, small energy loss and the like.

Description

Volute component and air compressor

Technical Field

The invention relates to the technical field of fuel cell engines, in particular to a volute component and an air compressor.

Background

An air compressor is one of the core components of a hydrogen fuel cell and continuously supplies high-pressure air to a fuel cell stack. In a fuel cell system, the power consumption of an air compressor is about 20% of the output power of the fuel cell, and the reduction of the power consumption of the air compressor has important significance for improving the efficiency and the output power of the fuel cell system.

In the related art, the air compressor has the disadvantages of large energy loss, high noise and low working efficiency.

Disclosure of Invention

The present invention has been made based on the findings and knowledge of the inventors regarding the following facts and problems:

In the related art, for example, patent numbers: CN202021771557.2, the pressure of high-pressure air in the pile is reduced after reaction and then enters the turbine, so that the pressure difference exists between the compressor impeller and the turbine impeller in the technical scheme, and the pressure difference between the compressor end and the turbine end in the integral impeller structure leaks driving air flow from the gap to the turbine impeller through the compressor impeller. This leakage flow has a versatile negative impact on the performance of the air compressor: 1. as gas leaks from the high pressure stage impeller outlet into the turbine (the second impeller portion in the present application), the air compressor outlet flow is reduced, i.e., the amount of air entering the fuel cell stack is reduced. Therefore, to achieve the same stack intake air amount, it is necessary to increase the compressor inlet flow rate, resulting in an increase in power consumption of the motor. 2. The leakage flow entering the turbine from the gap has a high axial velocity, and causes extremely strong disturbance to the internal flow field of the turbine at the inlet of the turbine wheel, so that the flow loss in the wheel is increased. The turbine efficiency is reduced, the energy of the recovered waste gas is reduced, and the power consumption of the motor is indirectly increased. Under the influence of the leakage flow, the performance of the air compressor is reduced, the power consumption of the motor is increased, and the output power of the fuel cell system is reduced. 3. The amount of leakage between the integral impellers is closely related to the pressure differential across the compressor and turbine. When the stack is operated in a high power state, the air compressor pressure ratio is high, and the pressure difference with the turbine end is increased, resulting in an increase in leakage. This will cause a further decrease in the efficiency of the air compressor at the time of high power operation of the stack, which will significantly affect the output power of the fuel cell system.

The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, embodiments of the present invention provide a lightweight, small-sized, pneumatically efficient volute assembly.

The embodiment of the invention provides an air compressor with high pneumatic efficiency, low noise and high working efficiency.

The volute assembly of the embodiment of the invention comprises: the shell comprises a cavity, a first flow passage and a second flow passage, wherein the first flow passage is communicated with the cavity and surrounds the outer peripheral side of the cavity, the second flow passage is communicated with the cavity and surrounds the outer peripheral side of the cavity, the first flow passage is suitable for introducing gas, pressurizing the gas into high-pressure gas and then discharging the gas, and the second flow passage is suitable for introducing gas and discharging the gas into the cavity in a decompression way; the impeller is rotatably arranged in the cavity, a part of the impeller is matched with the inlet of the first flow channel, and a part of the outer peripheral surface of the impeller is arranged at intervals with the inner peripheral surface of the first flow channel; the plurality of flow guiding pieces are arranged at one side of the inlet of the first flow channel adjacent to the second flow channel, the plurality of flow guiding pieces are arranged at intervals along the circumferential direction of the impeller to form an airflow channel, and the extending direction of the flow guiding pieces and the radial intersection of the impeller form an included angle.

According to the volute component provided by the embodiment of the invention, the plurality of guide pieces are arranged, so that leakage flow and pile waste gas enter the second impeller part along the radial direction of the impeller, severe mixing loss of the leakage flow and the waste gas at the inlet of the second impeller part caused by different directions is avoided, and further, energy loss of the second impeller part recovered from the leakage flow and the pile waste gas is avoided, and therefore, the overall performance of the air compressor is improved.

In some embodiments, the two adjacent flow guiding elements comprise a first flow guiding element and a second flow guiding element, and at least part of the first flow guiding element and the second flow guiding element are arranged opposite to each other at intervals in the inner-outer direction.

In some embodiments, the cross-sectional area of the baffle increases gradually from the inside to the outside.

In some embodiments, the angle between the direction of extension of the flow guide and the radial direction of the impeller is 70 ° -80 °.

In some embodiments, the chamber includes a first chamber and a second chamber in communication, the first flow passage is in communication with the first chamber and surrounds the outer peripheral side of the first chamber, the second flow passage is in communication with the second chamber and surrounds the outer peripheral side of the second chamber, a portion of the impeller is rotatably disposed within the first chamber, and another portion of the impeller is rotatably disposed within the second chamber.

In some embodiments, a mounting groove is formed in one side, adjacent to the second flow channel, of the inlet of the first flow channel, the mounting groove is communicated with the second cavity, a part of the impeller is arranged in the mounting groove and is arranged at intervals along the inner circumferential surface of the mounting groove in the inner-outer direction, and the flow guide piece is arranged on one side, adjacent to the second flow channel, of the mounting groove.

In some embodiments, the first flow channel includes a first sub-section and a second sub-section that are in communication with each other, the first sub-section encircling an outer peripheral side of the chamber, the second sub-section extending in a radial direction of the impeller, the first sub-section being in communication with the chamber through the second sub-section, the mounting groove being provided on a side of the second sub-section remote from the second flow channel.

In some embodiments, the impeller includes a first impeller portion rotatably disposed within the first chamber and a second impeller portion rotatably disposed within the second chamber, the second impeller portion having a number of blades less than the number of flow directors.

In some embodiments, the number of flow guides and the number of blades of the second impeller portion are non-integers.

The air compressor of the embodiment of the invention comprises: a housing; the rotating shaft is rotatably arranged in the shell; the volute component is any one of the volute components in the above embodiments, and the rotating shaft is connected with an impeller of the volute component, so that the rotating shaft drives the impeller to rotate.

Drawings

Fig. 1 is a schematic structural diagram of an air compressor according to an embodiment of the present invention.

Fig. 2 is a schematic structural view of a volute assembly according to an embodiment of the invention.

Fig. 3 is a perspective view of a volute assembly of an embodiment of the invention.

Fig. 4 is a schematic view of the installation of a baffle of a volute assembly of an embodiment of the invention.

Reference numerals:

a volute assembly 100;

An air compressor 10;

A housing 1; a chamber 11; an inlet 111; an outlet 112; a first cavity 113; a second chamber 114;

A first flow channel 12; a first air inlet 121; a first air outlet 122; a first portion 123; a second portion 124; a mounting groove 125; a first subsection 126; a second sub-segment 127;

A second flow channel 13; a second air inlet 131; a second air outlet 132;

An impeller 2; a first impeller portion 21; a second impeller portion 22;

A flow guide 3; a first deflector 31; a second flow guide 32;

A housing 4; a rotating shaft 5; and a motor 6.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The following describes a volute assembly according to an embodiment of the present invention with reference to the drawings.

As shown in fig. 1-4, the volute assembly of the present embodiment includes a housing 1, an impeller 2, and a plurality of flow directors 3.

The housing 1 comprises a chamber 11, a first flow passage 12 and a second flow passage 13, wherein the first flow passage 12 is communicated with the chamber 11 and surrounds the outer peripheral side of the chamber 11, the second flow passage 13 is communicated with the chamber 11 and surrounds the outer peripheral side of the chamber 11, the first flow passage 12 is suitable for introducing gas and pressurizing the gas into high-pressure gas and then discharging the gas, and the second flow passage 13 is suitable for introducing gas and depressurizing the gas and discharging the gas into the chamber 11.

As shown in fig. 1-2, the chamber 11 penetrates the casing 1 in the left-right direction, a first flow passage 12 and a second flow passage 13 are provided around the outer peripheral side of the chamber 11, the chamber 11 has an inlet 111 and an outlet 112 communicating with the chamber 11 in the left-right direction, the first flow passage 12 has a first air inlet 121 and a first air outlet 122, the second flow passage 13 has a second air inlet 131 and a second air outlet 132, the first air inlet 121 communicates with the chamber 11, the first air outlet 122 is connectable with external devices (such as an intercooler, a humidifier and a fuel cell stack), the second air inlet 131 communicates with the outlet of the exhaust gas of the fuel cell stack, the second air outlet 132 communicates with the chamber 11, and the first flow passage 12 cooperates with the impeller 2 of the external compressor to pressurize the gas into high pressure gas, so that the high pressure gas enters the chamber 11 through the inlet 111, the first air inlet 121 and the first air outlet 122 flows into the external devices and works. The gas with certain pressure discharged from the outlet of the waste gas of the fuel cell stack flows into the second flow channel 13 through the second air inlet 131, then enters the chamber 11 to expand and drive the impeller 2 to do work and discharge from the outlet 112, the waste gas expands and absorbs heat in the second flow channel 13, the wall surface temperature of the second flow channel 13 is reduced, and meanwhile, part of heat in the adjacent first flow channel 12 is taken away, so that the temperature in the first flow channel 12 is reduced, and the working efficiency of pressurizing the gas in the first flow channel 12 is improved.

The impeller 2 is rotatably provided in the chamber 11, a part of the impeller 2 is fitted at the inlet of the first flow passage 12, and the outer peripheral surface of the impeller 2 is spaced apart from the inner peripheral surface of the first flow passage 12. Specifically, as shown in fig. 1-2, the impeller 2 includes a first impeller portion 21 and a second impeller portion 22, the first impeller portion 21 is disposed at the left side of the second impeller portion 22, the first impeller portion 21 and the second impeller portion 22 are rotatably disposed in the chamber 11, the first impeller portion 21 is matched with the first flow channel 12, the first impeller portion 21 rotates to enable gas to flow out through the first flow channel 12 after being pressurized, the second impeller portion 22 is matched with the second flow channel 13, gas from an outlet of the exhaust gas of the fuel cell stack flows into the chamber 11 through the second flow channel 13, thereby driving the second impeller portion 22 to rotate, releasing energy drives the second impeller portion 22 to rotate to do work, and then driving the first impeller portion 21 to rotate, thereby realizing the purpose of recovering energy from the exhaust gas and being used for a compressor, reducing the power consumption of the motor 6, and improving the output power of the fuel cell system. In addition, a part of the impeller 2 is arranged at the inlet of the first flow channel 12 in a penetrating manner and spaced from the first air inlet 121 of the first flow channel 12, so that the first air inlet 121 of the first flow channel 12 is divided into a first part 123 and a second part 124, the first part 123 is positioned at the left side of the second part 124, the air flow flows into the first flow channel 12 through the first part 123, most of the air in the first part 123 flows out through the first air outlet 122, and due to the pressure difference between the outlet of the first impeller part 21 and the inlet of the second impeller part, part of the compressed air will flow from the first part 123 into the second impeller part 22 through the second part 124, i.e. leakage flow.

The plurality of flow guiding pieces 3 are arranged at one side of the inlet of the first flow channel 12 adjacent to the second flow channel 13, the plurality of flow guiding pieces 3 are arranged at intervals along the circumferential direction of the impeller 2 to form an airflow channel, and the extending direction of the flow guiding pieces 3 and the radial intersection of the impeller 2 form an included angle. Specifically, as shown in fig. 2-4, the plurality of flow guiding elements 3 are disposed on the right side surface of the second portion 124, and the plurality of flow guiding elements 3 are disposed at intervals along the circumferential direction of the impeller 2, so that an extending direction of the flow guiding elements 3 intersects with the radial direction of the impeller 2 to form an included angle, an airflow channel formed between two adjacent impellers 2 intersects with the radial direction of the impeller 2 to form an included angle, and a leakage flow flows into the chamber 11 at a certain angle to drive the second impeller portion 22 to rotate, thereby avoiding energy loss of the airflow caused by severe mixing of the leakage flow caused by different directions and the exhaust gas flowing out of the second flow channel 13 at the second air outlet 132 of the second flow channel 13, and further avoiding energy loss recovered from the leakage flow and the pile exhaust gas by the second impeller portion 22, and improving the overall performance of the air compressor 10.

When the differential pressure between the outlet 112 of the first impeller portion 21 and the inlet of the second impeller portion 22 increases (i.e., when the air compressor 10 is operating in a low flow to high pressure ratio condition, i.e., near surge condition), the leakage flow rate through the airflow passage into the second impeller portion 22 will increase. When the fuel cell system operates, the flow entering the fuel cell stack is required to be kept the same, and at the moment, the flow of the inlet 111 of the air compressor is increased due to the existence of leakage flow, so that the pneumatic stability of the air compressor is improved, and the stable operation range of the system is widened. The leakage flow entering the second impeller portion 22 through the air flow channel is increased, so that the energy recovered by the second impeller portion 22 is increased, and the overall performance of the air compressor 10 under the working condition of low flow rate and high pressure ratio is improved.

According to the volute assembly 100 provided by the embodiment of the invention, the plurality of guide pieces 3 are arranged, leakage air flow enters the second impeller part 22 from the radial direction of the impeller 2, so that the interference and impact of the leakage air flow on the air flow at the air outlet of the second flow passage 13 are avoided, the influence of the leakage air flow on the pneumatic efficiency of the second impeller part 22 is obviously reduced, the energy recovery of the second impeller part 22 is further ensured, and the efficiency of the air compressor and the fuel cell system is improved.

According to the inventors the findings are achieved: the leakage flow rate in the first flow channel 12 is closely related to the working condition of the air compressor 10, and is a passive control method for the system operation condition of the air compressor 10. During the life cycle of the fuel cell system, there is a partial operating condition requiring the air compressor 10 to operate in a near surge region of small flow, high pressure ratio, where the pressure differential across the first impeller portion 21 and the second impeller portion 22 increases, and therefore the leakage flow rate will increase. In order to maintain the same flow rate of the electric pile, the inlet flow rate of the air compressor is increased, so that the air compressor is operated at a high-efficiency position with slightly larger flow rate, and the pneumatic stability of the air compressor 10 can be improved. In addition, the leakage flow performs more work in the second impeller part 22, so that the recovery work of the second impeller part 22 is increased, the power consumption of the motor 6 of the air compressor 10 is reduced, and the overall performance of the air compressor 10 system under non-design working conditions is improved.

In some embodiments, the cross-sectional area of the baffle 3 increases gradually from inside to outside. Specifically, as shown in fig. 4, the outer contour of the flow guiding member 3 is in an airfoil shape so that the airflow channel gradually decreases from inside to outside, under the action of the pressure difference between the air compressor and the impeller 2, the airflow accelerates in the airflow channel, the pressure energy of the airflow is converted into kinetic energy, the airflow is higher in energy after being accelerated and expanded through the airflow channel, the airflow with higher energy enters the second impeller portion 22 from an ideal direction, the airflow further expands in the impeller 2 to do work, the energy recovered by the second airflow portion is further increased, the power consumption of the air compressor motor 6 is reduced, and the efficiency of the air compressor 10 is improved.

In some embodiments, two adjacent flow guiding members 3 include a first flow guiding member 31 and a second flow guiding member 32, and at least part of the first flow guiding member 31 is disposed opposite to the second flow guiding member 32 in the inner-outer direction. Specifically, as shown in fig. 4, the first flow guiding member 31 and the second flow guiding member 32 have overlapping areas in the inner and outer directions, and an air flow channel with a small effective flow area is formed, so that the leakage flow increases by accelerating the air flow passing through the air flow channel, the pressure energy decreases, the air flow enters the second impeller portion 22 in the radial direction in a high-speed state, the high-speed air flow acts in the turbine, and the energy is recovered by the turbine, thereby improving the performance of the air compressor 10.

In some embodiments, the angle between the direction of extension of the flow guide 3 and the radial direction of the impeller 2 is 70 ° -80 °. Specifically, the included angle between the extending direction of the flow guiding element 3 and the radial direction of the impeller 2 is 70 °, 72 °, 74 °, 76 °, 78 ° and 80 °, so that the included angle between the extending direction of the flow guiding element 3 and the radial direction of the impeller 2 is close to the flowing direction of the leakage flow, thereby reducing the flowing loss of the leakage flow, and simultaneously having the function of guiding the leakage flow, and realizing the effective work of the leakage flow entering the second impeller portion 22.

In some embodiments, the chamber 11 includes a first cavity 113 and a second cavity 114 in communication, the first flow passage 12 is in communication with the first cavity 113 and surrounds the outer peripheral side of the first cavity 113, the second flow passage 13 is in communication with the second cavity 114 and surrounds the outer peripheral side of the second cavity 114, a portion of the impeller 2 is rotatably disposed within the first cavity 113, and another portion of the impeller 2 is rotatably disposed within the second cavity 114. Specifically, as shown in fig. 1-2, the left part of the chamber 11 is a first chamber 113, the right part of the chamber 11 is a second chamber 114, the cross-sectional area of the first chamber 113 is smaller than that of the second chamber 114, the first impeller portion 21 is rotatably mounted in the first chamber 113, the first flow passage 12 surrounds the first chamber 113 and communicates with the first chamber 113, so that compressed gas generated by the rotation of the first impeller portion 21 flows out of the housing 1 through the first flow passage 12, the second impeller portion 22 is rotatably mounted in the second chamber 114, and the second flow passage 13 surrounds the second chamber 114 and communicates with the second chamber 114, so that exhaust gas discharged from the fuel cell stack flows into the second chamber 114 through the second flow passage 13 to drive the second impeller portion 22 to rotate.

In some embodiments, a mounting groove 125 is provided at a side of the inlet of the first flow passage 12 adjacent to the second flow passage 13, the mounting groove 125 communicates with the second chamber 114, a portion of the impeller 2 is provided in the mounting groove 125 and is disposed at a spacing in the inner and outer directions from the inner circumferential surface of the mounting groove 125, and the flow guide 3 is provided on a side surface of the mounting groove 125. Specifically, as shown in fig. 1-2, the right side surface of the inlet of the first flow passage 12 is provided with a mounting groove 125, the outer peripheral side of a part of the impeller 2 is spaced from the inner peripheral surface of the mounting groove 125, and the outer peripheral surface of a part of the impeller 2 is spaced from the inner peripheral surface of the mounting groove 125 in the inner-outer direction to form a gap, so that the leakage flow in the first flow passage 12 flows into the mounting groove 125 through the gap, the baffle 3 is provided on the right end surface of the mounting groove 125, and the left end surface of the baffle 3 is spaced from a part of the impeller 2 in the left-right direction, thereby preventing the mounting groove 125 and the baffle 3 from being worn.

In some embodiments, the first flow channel 12 comprises a first sub-section 126 and a second sub-section 127 in communication with each other, the first sub-section 126 surrounding the outer peripheral side of the chamber 11, the second sub-section 127 extending in the radial direction of the impeller 2, the first sub-section 126 in communication with the chamber 11 through the second sub-section 127, and the mounting groove 125 provided on the side of the second sub-section 127 remote from the second flow channel 13. Specifically, as shown in fig. 1-2, the first subsection 126 surrounds the outer peripheral side of the first cavity 113, the second subsection 127 extends along the inner and outer directions and is respectively communicated with the first cavity 113 and the first subsection 126, the inlet of the first flow channel 12 is located at one end of the second subsection 127 adjacent to the first cavity 113, the mounting groove 125 is arranged at the right side of the inlet of the second subsection 127 (i.e. the inlet of the first flow channel 12), a part of the impeller 2 is arranged in the mounting groove 125 in the second subsection 127 in a penetrating manner, the left side of the impeller 2 and the second subsection 127 form a first part 123, and the right side of the impeller 2 and the inner peripheral surface of the mounting groove 125 form a second part 124, so that the arrangement of the first flow channel 12 and the mounting groove 125 is more reasonable.

In some embodiments, the impeller 2 includes a first impeller portion 21 and a second impeller portion 22, the first impeller portion 21 being rotatably disposed within the first cavity 11311 and the second impeller portion 22 being rotatably disposed within the second cavity 11411, the number of blades of the second impeller portion 22 being less than the number of flow directors 3. Thereby, the number of the guide pieces 3 is increased, the flow area of the airflow channel is reduced, and the flow speed of the airflow is improved.

Since the impeller 2 is rotated during operation, the flow guide member 3 is always in a static state, and if the number of the blades of the second impeller portion 22 is the same as or multiple of the number of the flow guide member 3, resonance may occur, resulting in breakage of the blades of the second impeller portion 22. Thus, in some embodiments, the number of flow guides 3 and the number of blades of the second impeller portion 22 are non-integers. Thereby preventing breakage of the blades of the second impeller portion 22 and extending the service life of the second impeller portion 22.

In some embodiments, the trailing edge of the impeller 2 of the second impeller portion 22 is disposed opposite the baffle in an inboard-outboard direction, and the leading edge of the impeller 2 of the second impeller portion 22 is disposed opposite the second flow passage 13 in an inboard-outboard direction. Accordingly, the leakage flow enters the second impeller portion 22 from the root position of the second impeller portion 22 in the radial direction in a high-speed state, so that the high-speed air flow does work in the second impeller portion 22, and the energy is recovered by the second impeller portion 22, thereby improving the performance of the air compressor 10.

The air compressor of the embodiment of the invention comprises a shell 4, a rotating shaft 5 and a volute assembly 100.

The rotary shaft 5 is rotatably provided in the housing 4.

The volute assembly 100 is any one of the volute assemblies 100 in the above embodiments, and the rotating shaft 5 is connected to the impeller 2 of the volute assembly 100, so that the rotating shaft 5 drives the impeller 2 to rotate. Specifically, as shown in fig. 1, a motor 6 is disposed in the housing 4, and the volute assembly 100 is disposed on the left side of the housing 4, where the motor 6 is connected to the impeller 2 of the volute assembly 100, so as to drive the motor 6 to drive the impeller 2 to rotate.

According to the air compressor 10 provided by the embodiment of the invention, the power consumption of the air compressor motor 6 is reduced, and the efficiency of the air compressor 10 is improved.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

For purposes of this disclosure, the terms "one embodiment," "some embodiments," "example," "a particular example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While the above embodiments have been shown and described, it should be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives, and variations of the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the invention.

Claims (7)

1. A volute assembly, comprising:

The shell comprises a cavity, a first flow passage and a second flow passage, wherein the first flow passage is communicated with the cavity and surrounds the outer peripheral side of the cavity, the second flow passage is communicated with the cavity and surrounds the outer peripheral side of the cavity, the first flow passage is suitable for introducing gas, pressurizing the gas into high-pressure gas and then discharging the gas, and the second flow passage is suitable for introducing gas and discharging the gas into the cavity in a decompression way;

The impeller is rotatably arranged in the cavity, a part of the impeller is matched with the inlet of the first flow channel, and a part of the outer peripheral surface of the impeller is arranged at intervals with the inner peripheral surface of the first flow channel;

the plurality of flow guiding pieces are arranged at one side of the inlet of the first flow channel adjacent to the second flow channel, the flow guiding pieces and one part of the impeller are arranged at intervals along the axial direction of the impeller, the plurality of flow guiding pieces are arranged at intervals along the circumferential direction of the impeller to form an airflow channel, and the extending direction of the flow guiding pieces and the radial direction of the impeller intersect to form an included angle;

the two adjacent flow guiding pieces comprise a first flow guiding piece and a second flow guiding piece, and at least part of the first flow guiding piece and the second flow guiding piece are oppositely arranged at intervals in the inner-outer direction;

the cross-sectional area of the flow guiding piece gradually increases from inside to outside.

2. The volute assembly of claim 1, wherein the angle between the direction of extension of the flow guide and the radial direction of the impeller is 70 ° -80 °.

3. The volute assembly of claim 1, wherein the chamber includes a first chamber and a second chamber in communication, the first flow passage in communication with and surrounding an outer peripheral side of the first chamber, the second flow passage in communication with and surrounding an outer peripheral side of the second chamber, a portion of the impeller rotatably disposed within the first chamber, and another portion of the impeller rotatably disposed within the second chamber.

4. A volute assembly according to claim 3, wherein the inlet of the first flow passage is provided with a mounting groove on a side thereof adjacent to the second flow passage, the mounting groove communicates with the second chamber, a portion of the impeller is provided in the mounting groove and is disposed at an interval in the inner-outer direction from the inner peripheral surface of the mounting groove, and the deflector is provided on a side thereof adjacent to the second flow passage.

5. The volute assembly of claim 4, wherein the first flow passage includes a first sub-section and a second sub-section in communication with each other, the first sub-section surrounding an outer peripheral side of the chamber, the second sub-section extending radially of the impeller, the first sub-section in communication with the chamber through the second sub-section, the mounting groove being provided on a side of the second sub-section remote from the second flow passage.

6. A volute assembly according to claim 3, wherein the impeller comprises a first impeller portion rotatably disposed within the first chamber and a second impeller portion rotatably disposed within the second chamber, the number of blades of the second impeller portion being less than the number of flow guides.

7. An air compressor, comprising:

A housing;

the rotating shaft is rotatably arranged in the shell;

a volute assembly according to any one of claims 1 to 6, wherein the shaft is connected to an impeller of the volute assembly such that the shaft drives the impeller to rotate.