Aerodynamic component, vacuum cleaner and compressor comprising an axial diffuser

Abstract

The application provides a pneumatic component, a dust collector and a compressor comprising an axial diffuser, the pneumatic component comprising: a wheel cover, an impeller and an axial diffuser, the impeller is located in the wheel cover, an air flow channel is formed between the impeller and the wheel cover, the axial diffuser is connected to an axial end of the impeller, the air flow from the air flow channel can enter the axial diffuser to be pressurized, the air flow outlet end width of the impeller is smaller than the air flow inlet end width of the axial diffuser, and there is a gap between the air flow outlet end of the impeller and the air flow inlet section of the axial diffuser, forming a bladeless diffuser section. The application can ensure that the effective diffuser capacity is not reduced, the structure of the diffuser is axially extended, the radial structure size of the motor is effectively reduced, and the noise is reduced.

Description

Technical Field

[0001] This invention relates to the field of diffuser technology, and more specifically to a pneumatic component, a vacuum cleaner, and a compressor that includes an axial diffuser. Background Technology

[0002] Small compressors are increasingly used in the home appliance industry, and their structure tends to be miniaturized. Home appliance compressors are usually characterized by low pressure ratio and small size. The typical compressor structure is a centrifugal impeller + radial diffuser. The radial diffuser is characterized by a significant diffusion effect, but its large outer diameter is a limiting factor for its application in products such as vacuum cleaners. In addition, the impeller outlet end is close to the leading edge of the diffuser blades, which affects the acoustic performance of the compressor.

[0003] Because existing diffusers have large radial dimensions, resulting in poor acoustic performance, this invention designs a pneumatic component, a vacuum cleaner, and a compressor that includes an axial diffuser. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of large radial dimensions in the diffuser of the prior art, which leads to poor acoustic performance, and thus provide a pneumatic component, vacuum cleaner and compressor including an axial diffuser.

[0005] To address the above problems, the present invention provides a pneumatic component including an axial diffuser, comprising:

[0006] The device comprises a wheel cover, an impeller, and an axial diffuser. The impeller is located within the wheel cover, forming an airflow channel between the impeller and the wheel cover. The axial diffuser is connected to one axial end of the impeller, allowing airflow from the airflow channel to enter the axial diffuser for pressurization. The width of the airflow outlet end of the impeller is smaller than the width of the airflow inlet end of the axial diffuser, and there is a certain gap between the airflow outlet end of the impeller and the airflow inlet section of the axial diffuser, forming a bladeless diffuser section.

[0007] In some embodiments, the axial diffuser includes an outer wall, a hub, and blades, wherein the blades are located between the outer wall and the hub, and the blades extend along the axial direction of the axial diffuser.

[0008] In some embodiments, there are multiple blades, which are circumferentially spaced between the outer wall and the hub; adjacent blades, the outer wall and the hub together form a flow passage; the wheel cover is connected to the outer wall of the axial diffuser, and the airflow passage is located upstream of the flow passage, so that the airflow from the airflow passage reaches the flow passage.

[0009] In some embodiments, the flow outlet end of the impeller and the flow inlet end of the blade form the vaneless diffuser section, which is formed in part of the flow passage and part of the flow passage; the inner wall of the shroud forms part of the outer wall of the vaneless diffuser section, and the inner wall of the outer wall forms part of the outer wall of the vaneless diffuser section.

[0010] In some embodiments, the meridian plane of the blade is parallel to the axis, the inlet cross section of the vaneless diffuser section is parallel to the outlet end cross section of the impeller, the outlet end of the vaneless diffuser section is connected to the flow passage, and the cross sections are uniformly transitioned, the flow area of the vaneless diffuser section uniformly increases from its inlet to outlet; the flow area of the flow passage gradually increases along the fluid flow direction.

[0011] In some embodiments, the outer wall, the hub and the blade are an integral structure.

[0012] In some embodiments, the shroud is further provided with a first step at the joint with the outer wall, and the axial end of the outer wall opposite to the shroud forms a second step, the first step and the second step are clamped to form a first sealing structure.

[0013] In some embodiments, a casing is further included, the casing has a hollow cavity, the axial diffuser is arranged in the hollow cavity, the peripheral wall of the outer wall is connected to the inner wall of the casing, and the casing is further provided with a third step, the axial end of the outer wall away from the shroud is clamped with the third step to form a second sealing structure.

[0014] In some embodiments, the blade is a non-uniform thickness blade, the maximum thickness of the blade is located at a position of 45% to 55% of the axial direction distance from the leading edge of the blade along the chord line, and the maximum thickness of the pressure surface of the blade from the internal center line of the blade is greater than the maximum thickness of the suction surface of the blade from the internal center line of the blade.

[0015] In some embodiments, the chord length of the blade is in the range of 18 to 21 mm; and / or, the blade solidity of the blade is between 2.3 and 2.7.

[0016] In some embodiments, the included angle between the chord line of the blade and the axis of the axial diffuser is in the range of 45 to 50°.

[0017] In some embodiments, the axial length of the blade along the axial length of the axial diffuser is in the range of 14 to 15 mm, and the height of the blade is in the range of 3 to 4 mm.

[0018] In some embodiments, the inlet section of the impeller is perpendicular to the axis of the axial diffuser, a tangent of the leading edge of the blade forms an angle with the inlet section of the blade, and the side of the leading edge close to the shroud is inclined towards the incoming direction of the airflow.

[0019] The application also provides a dust collector comprising the pneumatic component of any of the preceding.

[0020] The application also provides a compressor comprising the pneumatic component of any of the preceding.

[0021] The pneumatic component, the dust collector and the compressor comprising the axial diffuser provided by the application have the following beneficial effects:

[0022] The application forms an impeller and an axial diffuser through the cooperation of the impeller and the axial diffuser and the shroud, the impeller is located upstream of the axial diffuser, the width of the airflow outlet end of the impeller is smaller than the width of the airflow inlet end of the axial diffuser, and there is a gap between the airflow outlet end of the impeller and the airflow inlet section of the axial diffuser, which can effectively form a bladeless diffuser section between the impeller and the axial diffuser, thereby effectively forming a combination of a bladeless diffuser and an axial blade diffuser, which can extend the structure of the diffuser in the axial direction while ensuring the effective diffusing capacity, effectively reducing the radial structure size of the motor and reducing noise; compared with the radial diffuser, the axial diffuser extends in the axial direction, the blade extends in the axial direction, and the angle of the airflow direction is changed, which can reduce the length of the airflow channel in the casing and thereby reduce the energy loss. The bladeless diffuser section between the moving blade and the stationary blade can flexibly adjust the distance between the moving blade and the stationary blade while ensuring that the radial size of the entire structure does not increase, and increasing the length can effectively reduce the noise. The number of diffuser blades and the blade profile of the application can be adjusted independently, the flow field distribution at different axial positions can be changed, and the impact loss at the inlet end of the diffuser and the separation loss at the outlet end of the diffuser can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is an internal sectional view of the pneumatic component comprising the axial diffuser of the application;

[0024] Figure 2 It is an internal sectional view of the axial diffuser of the application;

[0025] Figure 3 It is a meridian plane structure diagram of the impeller + diffuser in the axial diffuser of the application;

[0026] Figure 4 It is a blade profile structure diagram of the application;

[0027] Figure 5 It is a blade angle structure diagram of the application.

[0028] The reference signs are as follows:

[0029] 100 axial diffuser; 1 outer wall; 2 hub; 3 blade; 4 flow passage; 5 vaneless diffuser; 6 first step; 7 second step; 8 shroud; 9 impeller; 10 flow passage; 11 third step; 13 casing; 14 fourth step; 16 leading edge; 17 trailing edge; 18 pressure surface; 19 suction surface; 20 centerline; h1 first thickness; h2 second thickness; 21 chord line; L chord length; t pitch. DETAILED DESCRIPTION

[0030] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0031] In connection with Figures 1-5 The embodiments of the present application provide an aerodynamic component comprising an axial diffuser, which comprises:

[0032] A shroud 8, an impeller 9 located in the shroud 8, a flow passage 10 formed between the impeller 9 and the shroud 8, and an axial diffuser 100 connected to an axial end of the impeller 9, capable of allowing the airflow from the flow passage 10 to enter the axial diffuser 100 for pressure increase, the airflow outlet end width of the impeller 9 being smaller than the airflow inlet end width of the axial diffuser 100, and a certain gap being provided between the airflow outlet end of the impeller 9 and the airflow inlet section of the axial diffuser 100, forming a vaneless diffuser.

[0033] The application can effectively form a vaneless diffuser section between the impeller and the axial diffuser, effectively form a combination of vaneless+axial vane diffuser, effectively reduce the radial structure size of the motor, reduce noise, and effectively reduce the length of the flow channel in the casing, thereby reducing energy loss.

[0034] In some embodiments, the axial diffuser 100 comprises an outer wall 1, a hub 2 and vanes 3, wherein the vanes 3 are located between the outer wall 1 and the hub 2, and the vanes 3 extend along the axial direction of the axial diffuser 100. This is the preferred structure of the axial diffuser of the application. The axially extending vanes can drive the airflow to move in the axial direction to expand, thereby forming an axial diffuser. The axial diffuser structure can effectively reduce the radial structure size of the motor while ensuring effective diffuser capacity, thereby reducing noise.

[0035] The application provides a high-speed compressor aerodynamic component, which comprises an impeller, a wheel cover, a diffuser, a sealing ring and a casing, the impeller, the wheel cover and the diffuser are coaxially assembled, the outlet end of the impeller is aligned with the inlet end of the diffuser, the width of the outlet end of the impeller is slightly smaller than the width of the inlet end of the diffuser, and the outlet end of the impeller and the inlet end of the diffuser have a certain gap.

[0036] The technical problems can be solved as follows:

[0037] 1. The distance between the moving vanes and the static vanes can be flexibly adjusted, and the radial size of the entire structure can be ensured not to be increased.

[0038] 2. The structure of the diffuser is axially extended, and the radial structure size of the motor is reduced.

[0039] 3. The vanes are axially extended, the angle of the airflow direction is changed, and the length of the flow channel in the casing is reduced.

[0040] Advantages:

[0041] 1. The space between the moving blades and the stationary blades is equivalent to a bladeless diffuser; increasing its length can effectively reduce noise.

[0042] 2. Compared with radial diffusers, axial extension of diffusers can reduce the length of the airflow channel and reduce energy loss.

[0043] This invention provides a pneumatic structure for a small compressor, characterized by an impeller, impeller cover, diffuser, sealing ring, and housing. It is used in vacuum cleaner motors or as a pneumatic component of a small compressor. Its advantages include reducing the radial dimension of the motor, improving overall efficiency, and reducing overall noise. Its working principle involves the impeller rotating at high speed to perform work on the air, increasing the kinetic and pressure energy of the gas. The airflow then enters a bladeless diffuser section. The purpose of adding a bladeless diffuser section is to reduce the impact between the airflow and the diffuser blades, which could cause significant pressure pulsations. The bladeless diffuser reduces the airflow velocity, thus mitigating the pressure pulsations caused by the impact. The airflow then enters a vaned diffuser section (i.e., an axial diffuser). The vaned diffuser can change the airflow angle, which is more conducive to the flow state of the airflow at the diffuser outlet.

[0044] Because the circumferential gap between the impeller and the shroud was not kept uniform, the coaxiality of the shroud and the impeller is required to be high. At the same time, it is necessary to ensure that the airflow at the impeller outlet end enters the diffuser internal channel uniformly and stably. The coaxiality of the impeller and the diffuser is subject to certain constraints. To prevent assembly positioning errors, the width of the diffuser inlet section is slightly larger than the width of the impeller outlet, and there is a certain gap between the impeller outlet section and the diffuser inlet section section.

[0045] In some embodiments, there are multiple blades 3, which are distributed circumferentially between the outer wall 1 and the hub 2; the two adjacent blades 3, the outer wall 1 and the hub 2 together form a flow channel 4;

[0046] The wheel cover 8 is connected to the outer wall 1 of the axial diffuser 100, and the airflow channel 10 is located upstream of the flow channel 4, so that the airflow from the airflow channel 10 reaches the flow channel 4.

[0047] Multiple blades spaced circumferentially together define a flow channel between the two, with the flow area of ​​the flow channel gradually increasing to effectively reduce the flow velocity and increase the pressure, thus achieving a diffusion effect. Meanwhile, the gas in the airflow channel is accelerated by the impeller and enters the flow channel to achieve a deceleration and pressurization effect, thereby increasing the gas pressure.

[0048] In some embodiments, the flow outlet end of the impeller 9 and the flow inlet end of the blade 3 form the vaneless diffuser 5, which is formed in part of the flow passage 10 and part of the flow passage 4; the inner wall of the shroud 8 forms part of the outer wall of the vaneless diffuser 5, and the inner wall of the outer wall 1 forms part of the outer wall of the vaneless diffuser 5. This is the preferred location of the vaneless diffuser of the present application, i.e. formed between the downstream end of the impeller and the upstream end of the blade, the flow area of this part of space can be gradually increased, thereby effectively increasing the pressure of the gas.

[0049] In some embodiments, the meridian plane of the blade 3 is parallel to the axis, the inlet cross section of the vaneless diffuser 5 is parallel to the outlet end cross section of the impeller 9, the outlet end of the vaneless diffuser 5 is connected to the flow passage, and the cross section is uniformly transitioned, the flow area of the vaneless diffuser from its inlet to outlet is uniformly increased; the flow area of the flow passage 4 gradually increases along the fluid flow direction. Through this means, the pressure can be gradually increased along the fluid flow. The inner wall surface of the shroud and the diffuser wall surface combine to form a vaneless diffuser, and the channel cross-sectional area of the vaneless diffuser gradually increases from the inlet to the leading edge position of the vane diffuser blade, which mainly functions to increase the pressure and reduce the speed.

[0050] The diffuser structure of the present application is composed of two parts, vaneless and vane (blade 3), the meridian plane of the vane part is parallel to the axis, the inlet cross section of the vaneless part is parallel to the outlet cross section of the impeller, and the outlet end is connected to the vane part.

[0051] Preferably, the flow area at the leading edge 16 of the blade 3 is a3, and the flow area at the trailing edge 17 of the blade 3 is a4.

[0052] Flow area between two blades Where Q is the flow rate, Z is the number of blades, b is the blade height, c is the flow velocity, and a3 and a4 are the effective flow areas at the inlet and outlet of the two blades, respectively, and the flow area gradually increases from a3 to a4. By increasing the flow area in the single flow channel, the effect of diffuser is achieved, and if the flow area is too large, vortex will be generated, and if the flow area is too small, the diffuser effect cannot be maximized.

[0053] In some embodiments, the outer wall 1, the hub 2 and the blade 3 are of an integral structure.

[0054] The outer wall 1, the hub 2 and the blade 3 are integrally formed by plastic casting.

[0055] In some embodiments, the wheel cover 8 is further provided with a first step 6 at the joint with the outer wall 1, and the axial end of the outer wall 1 opposite to the wheel cover 8 forms a second step 7, the first step 6 is clamped with the second step 7 to form a first sealing structure.

[0056] The wheel cover is located above the impeller and forms a fluid cavity with the impeller, and the centrifugal force generated by the high-speed rotation of the impeller is large, so the deformation of the impeller has a large influence on the tip clearance, in order to control the friction between the impeller and the wheel cover, the inlet clearance gradually decreases to the outlet clearance. The fluid cavity (i.e. the airflow passage 10) is formed between the wheel cover and the impeller, so the upper end surface of the wheel cover needs to be aligned with the inlet of the impeller or contain the height of the inlet of the impeller, and the lower end surface of the wheel cover is provided with a step and an outer ring of the diffuser to form a first sealing structure.

[0057] In some embodiments, a casing 13 is further included, the casing 13 has a hollow cavity, the axial diffuser 100 is arranged in the hollow cavity, the outer peripheral wall of the outer wall 1 is connected with the inner wall of the casing 13, and a third step 11 is further arranged on the casing 13, and the axial end of the outer wall 1 away from the wheel cover 8 is clamped with the third step 11 to form a second sealing structure.

[0058] The diffuser blades are uniformly distributed between the two cylinders in the circumferential direction, the inner ring flow passage surface of the diffuser is formed by an arc surface and a cylindrical surface, one end of the arc surface extends to the position of the outlet end of the impeller, and the other end extends to the position of the casing, and the non-flow passage surface of the inner ring is provided with a sealing step (fourth step 14) to separate the fluid cavity of the impeller and the diffuser from the inner cavity of the motor in cooperation with a sealing ring.

[0059] In some embodiments, the blade 3 is a non-equal-thickness blade, the maximum thickness of the blade 3 is located at a position of 45% to 55% of the axial direction distance from the leading edge of the blade 3 along the chord line, and the maximum thickness of the pressure surface 18 of the blade 3 from the internal center line 20 of the blade is greater than the maximum thickness of the suction surface 19 from the internal center line 20 of the blade.

[0060] The number of diffuser blades is selected to effectively avoid airflow blockage at the inlet end of the diffuser, and to reduce the separation loss of the airflow at the outlet end of the diffuser, and the number of diffuser blades is preferably 17, the thickness of the blade is a non-equal-thickness blade, the maximum thickness of the blade is located at a position of 45% to 55% of the chord line, and the thickness of the pressure surface relative to the center line is greater than the thickness of the suction surface relative to the center line. The reason is that the airflow is prone to separation at the position of large curvature of the suction surface, so the pressure surface is raised at this position, the flow area is reduced, the generation of separation vortex is reduced, and the loss is reduced.

[0061] In some embodiments, the chord length of the blade 3 is in the range of 18-21 mm; and / or, the solidity of the blade 3 is in the range of 2.3-2.7. In order to achieve the optimal aerodynamic performance, the chord length of the blade of the diffuser is in the range of 18-21 mm, and the solidity of the blade is in the range of 2.3-2.7.

[0062] In some embodiments, the angle between the chord line of the blade 3 and the axis of the axial diffuser 100 is in the range of 45-50°. Preferably, the angle is 45°.

[0063] In some embodiments, the axial length of the blade 3 along the axial length of the axial diffuser 100 is in the range of 14-15 mm, and preferably 15 mm. The height of the blade is in the range of 3-4 mm.

[0064] In some embodiments, the inlet section of the impeller 9 is perpendicular to the axis of the axial diffuser 100, the tangent line of the leading edge 16 of the blade 3 forms an angle with the inlet section of the blade 3, and the side of the leading edge 16 close to the shroud 8 is inclined towards the incoming flow direction. The impeller structure of the present application adopts a mixed flow structure, the inlet section of the impeller is perpendicular to the axis, the leading edge line of the blade forms an angle with the inlet section, and the leading edge close to the shroud is inclined forward, thereby improving the suction performance and the vacuum degree.

[0065] The present application also provides a dust collector comprising the above-mentioned aerodynamic component with an axial diffuser. The aerodynamic structure of the present application is preferably applied to high-speed dust collectors, and can also be applied to other air compression products.

[0066] The present application also provides a compressor comprising the above-mentioned aerodynamic component with an axial diffuser.

[0067] It is easy for those skilled in the art to understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0068] The above description is only the preferred embodiments of the present application, and should not be used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application. The above description is only the preferred embodiments of the present application, and should not be used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A pneumatic component including an axial diffuser, characterized in that: include: The impeller (9) is located in the wheel cover (8), and an airflow channel (10) is formed between the impeller (9) and the wheel cover (8). The axial diffuser (100) is connected to one axial end of the impeller (9), which allows the airflow from the airflow channel (10) to enter the axial diffuser (100) for pressurization. The width of the airflow outlet end of the impeller (9) is smaller than the width of the airflow inlet end of the axial diffuser (100), and there is a certain gap between the airflow outlet end of the impeller (9) and the airflow inlet section of the axial diffuser (100), forming a bladeless diffuser section (5). The axial diffuser (100) includes an outer wall (1), a hub (2) and blades (3), wherein the blades (3) are located between the outer wall (1) and the hub (2), and the blades (3) extend along the axial direction of the axial diffuser (100); The blade (3) is a non-uniform thickness blade. The maximum thickness of the blade (3) is located at a position 45% to 55% away from the leading edge of the blade (3) along the axial direction on its chord line. The maximum thickness of the pressure surface (18) of the blade (3) from the inner center line (20) is greater than the maximum thickness of the suction surface (19) from the inner center line (20).

2. The pneumatic component including an axial diffuser according to claim 1, characterized in that: There are multiple blades (3), and the multiple blades (3) are distributed circumferentially between the outer wall (1) and the hub (2); the two adjacent blades (3), the outer wall (1) and the hub (2) together form a flow channel (4). The wheel cover (8) is connected to the outer wall (1) of the axial diffuser (100), and the airflow channel (10) is located upstream of the flow channel (4) so ​​that the airflow from the airflow channel (10) reaches the flow channel (4).

3. The pneumatic component including an axial diffuser according to claim 2, characterized in that: The bladeless diffuser section (5) is formed between the airflow outlet end of the impeller (9) and the airflow inlet end of the blade (3). The bladeless diffuser section is formed in a portion of the airflow channel (10) and a portion of the flow channel (4). The inner wall of the wheel cover (8) is formed as a portion of the outer wall of the bladeless diffuser section (5), and the inner wall of the outer wall (1) is formed as a portion of the outer wall of the bladeless diffuser section (5).

4. The pneumatic component including an axial diffuser according to claim 2, characterized in that: The meridional plane shape of the blade (3) is parallel to the axis, the inlet section of the bladeless diffuser section (5) is parallel to the outlet section of the impeller (9), the outlet end of the bladeless diffuser section (5) is connected to the flow channel, and the section is uniformly transitioned. The flow area of ​​the bladeless diffuser section increases uniformly from its inlet to its outlet. The flow area of ​​the flow channel (4) gradually increases along the direction of fluid flow.

5. The pneumatic component including an axial diffuser according to claim 1, characterized in that: The outer wall (1), the hub (2) and the blade (3) are an integral structure.

6. The pneumatic component including an axial diffuser according to claim 1, characterized in that: A first step (6) is provided at the junction of the wheel cover (8) and the outer wall (1). A second step (7) is formed at one axial end of the outer wall (1) opposite to the wheel cover (8). The first step (6) and the second step (7) are engaged to form a first sealing structure.

7. The pneumatic component according to claim 1, characterized in that: It also includes a housing (13), which has a hollow cavity. The axial diffuser (100) is disposed in the hollow cavity. The outer peripheral wall of the outer wall (1) is connected to the inner wall of the housing (13). The housing (13) is also provided with a third step (11). The axial end of the outer wall (1) away from the wheel cover (8) is engaged with the third step (11) to form a second sealing structure.

8. The pneumatic component including an axial diffuser according to claim 1, characterized in that: The chord length of the blade (3) is in the range of 18~21mm; and / or the blade consistency of the blade (3) is between 2.3 and 2.

7.

9. The pneumatic component including an axial diffuser according to claim 1, characterized in that: The angle between the chord of the blade (3) and the axis of the axial diffuser (100) is 45~50°.

10. The pneumatic component including an axial diffuser according to any one of claims 1-9, characterized in that: The axial length of the blade (3) along the axial diffuser (100) ranges from 14 to 15 mm, and the height of the blade ranges from 3 to 4 mm.

11. The pneumatic component including an axial diffuser according to any one of claims 1-9, characterized in that: The inlet section of the impeller (9) is perpendicular to the axis of the axial diffuser (100), the tangent of the leading edge (16) of the blade (3) forms a certain angle with the inlet section of the blade (3), and the side of the leading edge (16) near the wheel cover (8) is inclined toward the direction of the incoming airflow.

12. A vacuum cleaner, characterized in that: Includes the pneumatic component containing an axial diffuser as described in any one of claims 1-11.

13. A compressor, characterized in that: Includes the pneumatic component containing an axial diffuser as described in any one of claims 1-11.

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