CN216407280U

CN216407280U - Diffuser with non-uniform blade distribution and air compressor

Info

Publication number: CN216407280U
Application number: CN202121935435.7U
Authority: CN
Inventors: 钟仁志; 袁军; 韩春江; 蒋玉玺; 姚莹海
Original assignee: Xinlei Compressor Co Ltd
Current assignee: Xinlei Compressor Co Ltd
Priority date: 2021-08-13
Filing date: 2021-08-18
Publication date: 2022-04-29
Anticipated expiration: 2031-08-18

Abstract

The utility model relates to the field of diffusers, in particular to a diffuser with unevenly distributed blades and an air compressor. The diffuser comprises a diffuser body and a plurality of blades; the diffuser body is provided with a diffuser inner hole which is sleeved on the outer wall of the motor shaft, and the air inlet ends of the blades are connected with the air outlet end of the impeller; the plurality of blades are respectively arranged at the periphery of the inner hole of the diffuser along the circumferential direction, the positions of the plurality of blades respectively correspond to the volute chambers at the corresponding positions on the volute, and the interval between the blades corresponding to each volute chamber is in inverse proportion to the size of the blades. The diffuser is in inverse proportion to the space between the blades and the size of the volute, so that the blades at the position of the large volute have larger space to meet the larger air inflow of the large volute, the blades at the position of the small volute have smaller space to avoid the gas flow blockage of the small volute, and the fluency of air flow and the performance and efficiency of the whole machine are improved.

Description

Diffuser with non-uniform blade distribution and air compressor

Technical Field

The utility model relates to the field of diffusers, in particular to a diffuser with unevenly distributed blades and an air compressor.

Background

In order to improve the efficiency of the compressor unit, the pressure of the output gas must be increased, and the diffuser converts the dynamic pressure of the fan into the static pressure, so that the speed is reduced and the static pressure is increased. So that its function is very important. Diffusers of centrifugal compressors are generally divided into two main categories, namely vaneless diffusers and vaned diffusers, wherein the vaneless diffusers are composed of annular passages formed by two flat walls; the vaned diffuser is formed by installing uniformly distributed vanes in the annular passage of the vaneless diffuser along the circumference, and the flow direction of the airflow is limited by the shape of the vanes, so that the overall structural size of the diffuser passage is shortened. The working principle of the vaned diffuser is that the speed energy is converted into the pressure energy by utilizing the difference of the cross-sectional areas of the through-flow.

The Chinese utility model patent application (publication No. CN206636838U, published: 20171114) discloses a novel diffuser and a fan comprising the same, which comprises a diffuser body which is a circular cylinder, a plurality of guide vanes arranged on the outer side wall of the diffuser body and a plurality of diffuser sheets arranged on the end surface of the diffuser body, wherein the plurality of diffuser sheets are distributed in a non-equiangular mode. The diffuser diffusion sheet of the utility model adopts non-equiangular distribution, can effectively reduce the aerodynamic noise of the fan, and has little influence on the performance of the fan.

The prior art has the following defects: the traditional vane diffuser consists of a row of uniformly distributed vanes, and the intervals between adjacent vanes are the same; the volute chambers in the volute are different in size, and the air inlet volume required by the large volute chamber is different from that required by the small volute chamber; when only one interval exists between adjacent blades, the big volute chamber and the small volute chamber can only intake air at one air intake speed; when the blade interval meets the air inlet speed of the large volute chamber, the air supply speed of the small volute chamber is higher, so that the air flow of the small volute chamber is easily blocked; therefore, when only one interval exists among the blades, the fluency of the airflow is reduced, and the performance and the efficiency of the whole machine are also reduced.

Disclosure of Invention

The purpose of the utility model is: aiming at the problems, the interval between the blades is inversely proportional to the size of the volute, so that the blades at the position of the large volute have larger interval to meet the larger air inflow of the large volute, and the blades at the position of the small volute have smaller interval to avoid the gas flow blockage of the small volute, thereby improving the fluency of air flow and the performance and efficiency of the whole machine.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a diffuser with non-uniform blade distribution comprises a diffuser body and a plurality of blades; the diffuser body is provided with a diffuser inner hole which is sleeved on the outer wall of the motor shaft, and the air inlet ends of the blades are connected with the air outlet end of the impeller; the plurality of blades are respectively arranged at the periphery of the inner hole of the diffuser along the circumferential direction, the positions of the plurality of blades respectively correspond to the volute chambers at the corresponding positions on the volute, and the interval between the blades corresponding to each volute chamber is in inverse proportion to the size of the blades.

In addition, the utility model also discloses an air compressor, which comprises a motor shell, a motor shaft, an air bearing device, a first volute, a first impeller, a second volute and a second impeller, wherein the motor shell is arranged on the motor shaft; the air bearing device is sleeved on the outer wall of the motor shaft, and the first impeller and the second impeller are respectively fixed at two ends of the motor shaft and are respectively positioned in the first volute and the second volute; diffusers are arranged at the air inlet ends of the first volute and the second volute and are respectively positioned at the backs of the first impeller and the second impeller;

as preferred, the motor shaft includes rotor shaft section, first shaft section and second shaft section, and rotor shaft section both ends are provided with the screw hole, and the screw hole to rotor shaft section both ends is screwed up respectively to the external screw thread that outer wall set up is passed through to first shaft section one end and second shaft section one end.

Preferably, the air bearing means comprises a radial air bearing and an axial air bearing; the first shaft section is sequentially sleeved with a first shaft sleeve, a thrust disc, a first bushing and a first impeller from inside to outside in the axial direction; a radial air bearing is fixed on the motor shell and sleeved on the outer wall of the first shaft sleeve, and two axial air bearings are fixed on the motor shell and respectively located on two axial sides of the thrust disc.

Preferably, the second shaft section is sleeved with a second shaft sleeve, a heat dissipation impeller, a second bushing and a second impeller from inside to outside in sequence in the axial direction; a radial air bearing is fixed on the motor shell and sleeved on the outer wall of the second shaft sleeve, and the heat dissipation impeller is used for stirring gas in the compressor so as to dissipate heat of the compressor.

Preferably, the first bushing outer end surface is bonded to the first impeller back end surface, and the second bushing outer end surface is bonded to the second impeller back end surface; the outer wall of the first bushing and the outer wall of the second bushing are sleeved with bushing seals, and the bushing seals are used for preventing working medium gas from entering the compressor.

Preferably, the first bushing outer surface, the second bushing outer surface, the first bushing outer surface and the second bushing outer surface are all composite materials for reducing wear, and the bushing seal material is PTFE.

Preferably, the first impeller and the second impeller are closed three-dimensional flow impellers made of composite materials; the first impeller and the second impeller are provided with fairings at air inlet ends, and the fairings are used for rectifying air and improving the compression efficiency of the compressor.

Preferably, the composite material of the first impeller and the second impeller is carbon fiber and polytetrafluoroethylene, and the first impeller and the second impeller are arranged in a back-to-back direction.

Preferably, an axial labyrinth seal is arranged between the air inlet end of the first impeller and the inner wall of the cavity of the first volute, and an axial labyrinth seal is arranged between the air inlet end of the second impeller and the inner wall of the cavity of the second volute.

The diffuser and the air compressor adopting the technical scheme have the advantages that the diffuser and the air compressor have non-uniform blade distribution:

the space between the blades is inversely proportional to the size of the volute chamber, namely the larger the volute chamber is, the more gas is needed, and the larger the space between the blades is, so as to meet the requirement of a large amount of gas in the large volute chamber; the smaller the volute chamber per se, the less gas is needed, and the smaller the interval between the blades is, so that the gas flow blockage of the small volute chamber caused by supplying a large amount of gas to the small volute chamber is avoided; thereby improving the fluency of the airflow and improving the performance and efficiency of the whole machine.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of an air suspension centrifugal compressor.

Fig. 3-5 are schematic structural views of the first impeller.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the drawings.

Example 1

A diffuser with non-uniform vane distribution as shown in fig. 1 includes a diffuser body 43 and a plurality of vanes 44; the diffuser body 43 is provided with a diffuser inner hole 45, the diffuser inner hole 45 is used for being sleeved on the outer wall of the motor shaft, and the air inlet ends of the blades 44 are connected with the air outlet end of the impeller; the vanes 44 are respectively arranged at the periphery of the inner hole 45 of the diffuser along the circumferential direction, the positions of the vanes 44 respectively correspond to the volute chambers at the corresponding positions on the volute, and the interval between the vanes 44 corresponding to each volute chamber is in inverse proportion to the size of the vane 44. In this way, the spacing between the vanes 44 is inversely proportional to the size of the volute itself, i.e. the larger the volute itself needs more gas, the larger the spacing between the vanes 44 is to meet the requirement of a large amount of gas in the large volute; the smaller the volute itself, the less gas required, and the smaller the spacing between the vanes 44 to avoid blockage of the gas flow in the small volute by supplying a large amount of gas to the smaller volute; thereby improving the fluency of the airflow and improving the performance and efficiency of the whole machine.

An air compressor as shown in fig. 2 includes a motor housing 1, a motor shaft 2, an air bearing device 3, a first volute 4, a first impeller 5, a second volute 6, and a second impeller 7; the air bearing device 3 is sleeved on the outer wall of the motor shaft 2, and the first impeller 5 and the second impeller 7 are respectively fixed at two ends of the motor shaft 2 and are respectively positioned in the first volute 4 and the second volute 6; the air inlet ends of the first volute 4 and the second volute 6 are provided with diffusers 42, and the diffusers 42 are respectively positioned at the backs of the first impeller 5 and the second impeller 7;

motor shaft 2 includes rotor shaft section 21, first shaft section 22 and second shaft section 23, and rotor shaft section 21 both ends are provided with the screw hole, and the screw hole to rotor shaft section 21 both ends is screwed up respectively to the external screw thread that outer wall set up is passed through to first shaft section 22 one end and second shaft section 23 one end. The air bearing device 3 includes a radial air bearing 31 and an axial air bearing 32; the first shaft section 22 is sleeved with a first shaft sleeve 221, a thrust disc 222, a first bush 223 and a first impeller 5 from inside to outside in sequence in the axial direction; a radial air bearing 31 is fixed on the motor housing 1 and sleeved on the outer wall of the first shaft sleeve 221, and two axial air bearings 32 are fixed on the motor housing 1 and located on two axial sides of the thrust disc 222 respectively. The second shaft section 23 is sleeved with a second shaft sleeve 231, a heat dissipation impeller 232, a second bushing 233 and a second impeller 7 from inside to outside in sequence in the axial direction; a radial air bearing 31 is fixed on the motor housing 1 and sleeved on the outer wall of the second shaft sleeve 231, and the heat dissipation impeller 232 is used for stirring the gas inside the compressor so as to dissipate the heat of the compressor. The radial air bearing 31 and the axial air bearing 32 are both air-floating bearings, and have the advantages of no mechanical contact, high temperature resistance, stable work, no pollution and long service life when in work.

The outer end surface of the first bush 223 is attached to the back end surface of the first impeller 5, and the outer end surface of the second bush 233 is attached to the back end surface of the second impeller 7; the outer wall of first bushing 223 and the outer wall of second bushing 233 are both sleeved with bushing seal 224, and bushing seal 224 is used for preventing working medium gas from entering the interior of the compressor.

The outer surface of the first bushing 223, the outer surface of the second bushing 233, the outer surface of the first bushing 221, and the outer surface of the second bushing 231 are all composite materials for reducing wear, and the bushing seal 224 material is PTFE.

The first impeller 5 and the second impeller 7 are closed three-dimensional flow impellers made of composite materials; the composite material can obviously improve the performance and the processing efficiency of the impeller; the first impeller 5 and the second impeller 7 are provided with a fairing 9 at the air inlet end, and the fairing 9 is used for rectifying air to improve the compression efficiency of the compressor.

The composite material of the first impeller 5 and the second impeller 7 is carbon fiber and polytetrafluoroethylene, and the first impeller 5 and the second impeller 7 are arranged in the back-to-back direction to offset the influence of the axial force generated by the first impeller 5 and the second impeller 7, so that the running stability of the whole machine is greatly improved.

As shown in fig. 3-5, an axial labyrinth seal 41 is disposed between the air inlet end of the first impeller 5 and the inner wall of the first volute 4, and an axial labyrinth seal 41 is disposed between the air inlet end of the second impeller 7 and the inner wall of the second volute 6. In the process that the compressed gas flows into the volute, a part of high-temperature and high-pressure gas flows back to the periphery of the closed impeller, so that the radial force of the closed impeller is not uniformly stressed and larger vibration is generated, and the service life of a bearing is damaged; the axial labyrinth seal 41 is arranged on the air inlet end sleeve of the impeller, so that the gas can generate throttling in the axial labyrinth seal 41, the temperature and the pressure are further reduced, and the harm is effectively avoided.

Claims

1. A diffuser with non-uniform blade distribution is characterized by comprising a diffuser body (43) and a plurality of blades (44); the diffuser body (43) is provided with a diffuser inner hole (45), the diffuser inner hole (45) is sleeved on the outer wall of the motor shaft, and the air inlet ends of the blades (44) are connected with the air outlet end of the impeller; the vanes (44) are respectively arranged at the periphery of the inner hole (45) of the diffuser along the circumferential direction, the positions of the vanes (44) respectively correspond to the volute chambers at the corresponding positions on the volute, and the interval between the vanes (44) corresponding to each volute chamber is in inverse proportion to the size of the vane.

2. An air compressor, characterized in that it comprises a motor housing (1), a motor shaft (2), an air bearing arrangement (3), a first volute (4), a first impeller (5), a second volute (6) and a second impeller (7); the air bearing device (3) is sleeved on the outer wall of the motor shaft (2), and the first impeller (5) and the second impeller (7) are respectively fixed at two ends of the motor shaft (2) and are respectively positioned in the first volute (4) and the second volute (6); diffusers (42) are arranged at the air inlet ends of the first volute (4) and the second volute (6), and the diffusers (42) are respectively positioned at the backs of the first impeller (5) and the second impeller (7); the diffuser (42) of claim 1.

3. The air compressor as claimed in claim 2, wherein the motor shaft (2) comprises a rotor shaft section (21), a first shaft section (22) and a second shaft section (23), threaded holes are arranged at two ends of the rotor shaft section (21), and one end of the first shaft section (22) and one end of the second shaft section (23) are respectively screwed to the threaded holes at two ends of the rotor shaft section (21) through external threads arranged on the outer wall.

4. An air compressor according to claim 3, characterized in that the air bearing means (3) comprises a radial air bearing (31) and an axial air bearing (32); the first shaft section (22) is sleeved with a first shaft sleeve (221), a thrust disc (222), a first bush (223) and a first impeller (5) from inside to outside in sequence in the axial direction; a radial air bearing (31) is fixed on the motor shell (1) and sleeved on the outer wall of the first shaft sleeve (221), and two axial air bearings (32) are fixed on the motor shell (1) and respectively located on two axial sides of the thrust disc (222).

5. The air compressor as claimed in claim 3, wherein the second shaft section (23) is sleeved with a second shaft sleeve (231), a heat dissipation impeller (232), a second bushing (233) and a second impeller (7) in sequence from inside to outside in the axial direction; a radial air bearing (31) is fixed on the motor shell (1) and sleeved on the outer wall of the second shaft sleeve (231), and a heat dissipation impeller (232) is used for stirring gas in the compressor so as to dissipate heat of the compressor.

6. An air compressor according to claim 4 or 5, characterized in that the first bush (223) has an outer end surface abutting the back end surface of the first impeller (5), and the second bush (233) has an outer end surface abutting the back end surface of the second impeller (7); the outer wall of the first bushing (223) and the outer wall of the second bushing (233) are sleeved with bushing seals (224), and the bushing seals (224) are used for preventing working medium gas from entering the inside of the compressor.

7. The air compressor of claim 4 or 5, wherein the outer surface of the first bushing (223), the outer surface of the second bushing (233), the outer surface of the first bushing (221), and the outer surface of the second bushing (231) are all composite materials for reducing wear, and the material of the bushing seal (224) is PTFE.

8. An air compressor according to claim 2, characterized in that the first impeller (5) and the second impeller (7) are closed three-dimensional flow impellers made of composite material; the first impeller (5) and the second impeller (7) are provided with fairings (9) at the air inlet ends, and the fairings (9) are used for rectifying air and improving the compression efficiency of the compressor.

9. An air compressor according to claim 2, characterized in that the composite material of the first impeller (5) and the second impeller (7) is carbon fibre and polytetrafluoroethylene, and the first impeller (5) and the second impeller (7) are arranged in a back-to-back direction.

10. An air compressor according to claim 2, characterized in that an axial labyrinth seal (41) is arranged between the air inlet end of the first impeller (5) and the inner wall of the cavity of the first volute (4), and an axial labyrinth seal (41) is arranged between the air inlet end of the second impeller (7) and the inner wall of the cavity of the second volute (6).