Combined type efficient low-noise three-dimensional impeller with retroverted blades

Abstract

According to the combined type efficient low-noise three-dimensional impeller with the backward-inclined blades, the impeller of a combined type structure combining the double-layer blades and the single-layer blades is adopted, the first blades are the backward-inclined bent and twisted blades, the second blades are the forward-inclined bent and twisted blades, and the third blades are the radial blades, so that the flow state of fluid in a flow channel can be dredged more effectively, and noise is lowered; bending parts protruding towards the inner side of the flow channel are arranged at the positions, close to the outlet side, of the first outlet blade and the second outlet blade of the third blade, the flow passing area of the flow channel at the bending parts is the smallest, the flow passing area of the flow channel at the outlet of the radial outer side of the third blade is the largest, pressurization is more effective through the arrangement of the structure, and the operation efficiency of the draught fan is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid machinery, in particular to a three-dimensional impeller, and more particularly to a composite high-efficiency and low-noise three-dimensional impeller with backward-inclined blades. Background Art

[0002] The fan impeller is the "heart" of the fan equipment. Its design (such as blade shape and angle) and material directly affect the fan's efficiency, energy consumption, and reliability. Its core function is to achieve energy conversion through mechanical movement and drive gas flow to meet the needs of different scenarios. Existing fan impellers on the market generally have problems such as high noise and low efficiency. As people's requirements for fans increase, the demand for efficiency improvement of fan impellers is becoming increasingly strong. Therefore, it can be seen that optimizing the design of fan impellers is very necessary.

[0003] Prior art CN104500445A discloses a novel axial flow fan comprising: a main cylinder 1, an impeller assembly 2 disposed within the main cylinder 1, a guide vane assembly 3 disposed within the main cylinder 1, and a motor 4 disposed within the main cylinder 1. The motor 4 is secured to the main cylinder 1 via a bracket. The impeller assembly 2 includes multiple impellers 5, each having a polytetrafluoroethylene coating on its outer surface, making the impeller 5 relatively smooth and resistant to dust. The outer wall of the main cylinder 1 is provided with a sound-absorbing panel for sound absorption and noise reduction. The fan has a simple and rational structure, and the blades have a relatively smooth surface, making them resistant to dust adhesion.

[0004] However, the above structure has design limitations, and in the actual application of the fan, there are still problems of high noise and low efficiency. Therefore, to address these problems, the applicant proposes a composite high-efficiency and low-noise three-dimensional impeller with backward-inclined blades. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a composite high-efficiency and low-noise three-dimensional impeller with backward-inclined blades.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A composite high-efficiency and low-noise three-dimensional impeller with backward-inclined blades, the impeller adopts a double-suction structure, which includes an upper wheel cover, a middle wheel cover, a wheel disc, a first blade, a second blade, a third blade, and a wheel hub. The first blade is installed between the upper wheel cover and the middle wheel cover, the second blade is installed between the middle wheel cover and the wheel disc, and the third blade is installed between the upper wheel cover and the wheel disc. The wheel disc is sleeved and fixed on the wheel hub; it is characterized in that: the first blade is a backward-inclined bent and twisted blade, the second blade is a forward-inclined bent and twisted blade, and the third blade is a radial blade; at the same radial position, the flow cross section of the first blade is axially The length W1 is greater than the axial length W2 of the flow cross-section of the second blade; the flow cross-section of the first blade and the flow cross-section of the second blade are arranged side by side to form an inlet flow channel, and the third blade is located in the outlet flow channel; the leading edge of the first blade is farther away from the central axis than the leading edge of the second blade, and the trailing edge of the second blade is farther away from the central axis than the trailing edge of the first blade; an outlet premixing tank is provided at the overlapping position of the trailing edge of the first blade and the middle wheel cover, and the outlet premixing tank includes a first premixing tank located on the first blade and a second premixing tank located on the second blade, and the first premixing tank is arranged in communication with the second premixing tank.

[0008] Furthermore, the backward inclination angle of the first blade is A, and the forward inclination angle of the second blade is B, wherein A<B.

[0009] Furthermore, the first premixing groove is a fan-shaped groove, the second premixing groove is a semicircular groove, and the radius of the fan-shaped groove is equal to that of the semicircular groove.

[0010] Furthermore, the third blade is a plate-shaped blade group structure, which includes a first outlet blade and a second outlet blade arranged at intervals, the inlet ends of the first outlet blade and the second outlet blade are close to each other, and the outlet ends are far away from each other, and the first outlet blade and the second outlet blade are provided with a bending portion protruding toward the inside of the flow channel near the outlet side, the flow area of the flow channel is the smallest at the bending portion, and the flow area of the flow channel at the radially outer outlet of the third blade is the largest.

[0011] Furthermore, the flow area from the flow channel at the radial inner inlet of the third blade to the flow channel at the bending portion tends to first increase and then decrease, and the flow area from the flow channel at the bending portion to the flow channel at the radial outer outlet of the third blade tends to gradually expand.

[0012] Further, the outlet end of the upper wheel cover is farther from the central axis than the outlet end of the wheel disc, and the radially outer outlet end of the third blade is aligned with the outlet end of the wheel disc.

[0013] Furthermore, the main body of the hub is a hollow cylindrical structure, and an umbrella-shaped guide surface is provided at the end of the hub. The inlet end of the umbrella-shaped guide surface is axially at the same position as the inlet end of the middle wheel cover, and the outlet end of the umbrella-shaped guide surface points axially to the side of the second blade flow channel close to the wheel disc.

[0014] Furthermore, the mid-arc line of the umbrella-shaped guide surface is a part of a hyperbola.

[0015] Furthermore, the top of the umbrella-shaped guide surface is a spherical structure.

[0016] Furthermore, A=(0.2~0.6)B.

[0017] Furthermore, W1=(1.1-1.5)W2.

[0018] Furthermore, the thickness δ1 of the first blade is greater than the thickness δ2 of the second blade, and 1.2 mm ≤ δ2 ≤ 3 mm.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. Most of the impellers in the prior art use single-layer blades, which have low conveying efficiency. The present invention uses a composite structure impeller combining double-layer blades and single-layer blades, which can more effectively clear the flow state of the fluid in the flow channel; specifically, since the upper layer of turbulence at the impeller inlet is relatively larger, the present invention uses backward-inclined bent and twisted blades on the upper layer, while the lower layer of turbulence at the impeller inlet is relatively stable, the present invention uses forward-inclined bent and twisted blades on the lower layer. In order to better boost conveying, the present invention provides a third blade of a plate-shaped blade group structure at the outlet, and a bending portion protruding toward the inside of the flow channel is provided on the first outlet blade and the second outlet blade near the outlet side. The flow area of the flow channel is the smallest at the bending portion, and the flow area of the flow channel at the outlet radially outside the third blade is the largest. The above-mentioned structure is more effective in boosting pressure. At the same time, the design of the above-mentioned third blade also effectively reduces noise and improves the efficiency of the fan operation.

[0021] 2. Due to the structural differences between the first blade and the second blade, the two blades will interfere with each other at the overlapping position at the outlet. Based on this, in the present invention, an outlet premixing tank is provided at the overlapping position of the trailing edge of the first blade and the middle wheel cover. The outlet premixing tank includes a first premixing tank located on the first blade and a second premixing tank located on the second blade. The first premixing tank is connected to the second premixing tank. The above structure enables premixing before interference, effectively reducing the vibration and noise of the fan.

[0022] 3. The flow area from the flow channel at the radial inner inlet of the third blade to the flow channel at the bending portion tends to first increase and then decrease, and the flow area from the flow channel at the bending portion to the flow channel at the radial outer outlet of the third blade tends to gradually expand; the above structure can improve airflow, reduce flow losses, and improve air outlet efficiency.

[0023] 4. The main part of the hub is a hollow cylindrical structure, and an umbrella-shaped guide surface is provided at the end of the hub. The inlet end of the umbrella-shaped guide surface is in the same position as the inlet end of the middle wheel cover in the axial direction, and the outlet end of the umbrella-shaped guide surface is axially directed to the side of the second blade flow channel close to the wheel disc. The design of the guide structure effectively changes the inlet flow state of the lower blades and has a suppressive effect on the generation of noise and vibration.

[0024] 5. The middle arc line of the umbrella-shaped guide surface is part of the hyperbola, and the top of the umbrella-shaped guide surface is a spherical structure. This is a further optimization of the guide structure. The design of the middle arc line is more in line with the fluid flow state in the impeller. The spherical structure also more effectively reduces noise, reduces the degree of airflow turbulence, and reduces pressure loss, thereby ensuring the stability and uniformity of the fan flow and improving the fan efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the impeller structure of the present invention;

[0026] Figure 2 for Figure 1 A partial enlarged view of the outlet premixing tank;

[0027] Figure 3 is a schematic diagram of the third blade structure of the present invention;

[0028] Figure 4 for Figure 3 Enlarged view of the structure of the third blade flow channel.

[0029] In the figure: upper wheel cover 1, middle wheel cover 2, wheel disc 3, first blade 4, second blade 5, third blade 6, hub 7, outlet premixing tank 8, first premixing tank 81, second premixing tank 82, first outlet blade 61, second outlet blade 62, bending portion 63, hollow cylindrical structure 71, umbrella-shaped guide surface 72, axial length W1 of the flow cross section of the first blade 4, axial length W2 of the flow cross section of the second blade 5, backward inclination angle A of the first blade 4, forward inclination angle B of the second blade 5, thickness δ1 of the first blade 4, thickness δ2 of the second blade 5. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] The present invention will be described in further detail below with reference to the accompanying drawings.

[0032] like Figure 1-4 As shown, a composite high-efficiency and low-noise three-dimensional impeller with backward-inclined blades adopts a double-suction structure, which includes an upper wheel cover 1, a middle wheel cover 2, a wheel disc 3, a first blade 4, a second blade 5, a third blade 6, and a hub 7. The first blade 4 is installed between the upper wheel cover 1 and the middle wheel cover 2, the second blade 5 is installed between the middle wheel cover 2 and the wheel disc 3, and the third blade 6 is installed between the upper wheel cover 1 and the wheel disc 3. The wheel disc 3 is sleeved and fixed on the hub 7; it is characterized in that: the first blade 4 is a backward-inclined bent and twisted blade, the second blade 5 is a forward-inclined bent and twisted blade, and the third blade 6 is a radial blade; at the same radial position, the flow cross-section of the first blade 4 is The axial length W1 is greater than the axial length W2 of the flow section of the second blade 5; the flow section of the first blade 4 and the flow section of the second blade 5 are arranged side by side to form an inlet flow channel, and the third blade 6 is located in the outlet flow channel; the leading edge of the first blade 4 is farther away from the central axis than the leading edge of the second blade 5, and the trailing edge of the second blade 5 is farther away from the central axis than the trailing edge of the first blade 4; an outlet premixing tank 8 is provided at the overlapping position of the trailing edge of the first blade 4 and the middle wheel cover 2, and the outlet premixing tank 8 includes a first premixing tank 81 located on the first blade 4 and a second premixing tank 82 located on the second blade 5, and the first premixing tank 81 is connected to the second premixing tank 82.

[0033] Furthermore, the backward inclination angle of the first blade 4 is A, and the forward inclination angle of the second blade 5 is B, wherein A<B.

[0034] Furthermore, the first premixing groove 81 is a fan-shaped groove, and the second premixing groove 82 is a semicircular groove, and the radius of the fan-shaped groove is equal to that of the semicircular groove.

[0035] Furthermore, the third blade 6 is a plate-shaped blade group structure, which includes a first outlet blade 61 and a second outlet blade 62 arranged at intervals. The inlet ends of the first outlet blade 61 and the second outlet blade 62 are close to each other, and the outlet ends are far away from each other. The first outlet blade 61 and the second outlet blade 62 are provided with a bending portion 63 protruding toward the inside of the flow channel near the outlet side. The flow area of the flow channel is the smallest at the bending portion 63, and the flow area of the flow channel at the radially outer outlet of the third blade 6 is the largest.

[0036] Furthermore, the flow area from the flow channel at the radial inner inlet of the third blade 6 to the flow channel at the bend 63 tends to first increase and then decrease, and the flow area from the flow channel at the bend 63 to the flow channel at the radial outer outlet of the third blade 6 tends to gradually expand.

[0037] Furthermore, the outlet end of the upper wheel cover 1 is farther away from the central axis than the outlet end of the wheel disc 3 , and the radially outer outlet end of the third blade 6 is aligned with the outlet end of the wheel disc 3 .

[0038] Furthermore, the main part of the hub 7 is a hollow cylindrical structure 71, and an umbrella-shaped guide surface 72 is provided at the end of the hub 7. The inlet end of the umbrella-shaped guide surface 72 is axially at the same position as the inlet end of the middle wheel cover 2, and the outlet end of the umbrella-shaped guide surface 72 is axially directed to the side of the flow channel of the second blade 5 close to the wheel disc 3.

[0039] Furthermore, the middle arc line of the umbrella-shaped guide surface 72 is a part of a hyperbola.

[0040] Furthermore, the top of the umbrella-shaped guide surface 72 is a spherical structure.

[0041] Furthermore, A=(0.2~0.6)B.

[0042] Furthermore, W1=(1.1-1.5)W2.

[0043] Furthermore, the thickness δ1 of the first blade 4 is greater than the thickness δ2 of the second blade 5 , and 1.2 mm ≤ δ2 ≤ 3 mm.

[0044] In the prior art, most impellers use single-layer blades, which have low conveying efficiency. The present invention uses a composite structure impeller that combines double-layer blades with single-layer blades, which can more effectively clear the flow state of the fluid in the flow channel; specifically, since the upper layer of turbulence at the impeller inlet is relatively larger, the present invention uses backward-inclined bent and twisted blades in the upper layer, and the lower layer of turbulence at the impeller inlet is relatively stable, the present invention uses forward-inclined bent and twisted blades in the lower layer. In order to better boost conveying, the present invention provides a third blade of a plate-shaped blade group structure at the outlet, and a bending portion protruding toward the inside of the flow channel is provided at the first outlet blade and the second outlet blade near the outlet side. The flow area of the flow channel is the smallest at the bending portion, and the flow area of the flow channel at the radially outer outlet of the third blade is the largest. The above-mentioned structure is more effective in boosting pressure. At the same time, the design of the above-mentioned third blade also effectively reduces noise and improves the efficiency of the fan operation.

[0045] Due to the structural differences between the first blade and the second blade, the two blades will interfere with each other at the overlapping position at the outlet. Based on this, in the present invention, an outlet premixing tank is provided at the overlapping position of the trailing edge of the first blade and the middle wheel cover. The outlet premixing tank includes a first premixing tank located on the first blade and a second premixing tank located on the second blade. The first premixing tank is connected to the second premixing tank. The above structure enables premixing before interference, effectively reducing the vibration and noise of the fan.

[0046] The flow area from the flow channel at the radial inner inlet of the third blade to the flow channel at the bending portion tends to first increase and then decrease, and the flow area from the flow channel at the bending portion to the flow channel at the radial outer outlet of the third blade tends to gradually expand; the above structure can improve airflow, reduce flow losses, and improve air outlet efficiency.

[0047] The main part of the hub is a hollow cylindrical structure, and an umbrella-shaped guide surface is provided at the end of the hub. The inlet end of the umbrella-shaped guide surface is in the same position as the inlet end of the middle wheel cover in the axial direction, and the outlet end of the umbrella-shaped guide surface points to the side of the second blade flow channel close to the wheel disc in the axial direction. The design of the guide structure effectively changes the inlet flow state of the lower blades, and has a suppressive effect on the generation of noise and vibration.

[0048] The middle arc line of the umbrella-shaped guide surface is part of the hyperbola, and the top of the umbrella-shaped guide surface is a spherical structure. This is a further optimization of the guide structure. The design of the middle arc line is more in line with the fluid flow state in the impeller, and the spherical structure also more effectively reduces noise, reduces the degree of airflow turbulence, and reduces pressure loss, thereby ensuring the stability and uniformity of the fan flow and improving the fan efficiency.

[0049] The above-mentioned embodiments are illustrative of the present invention, not limiting thereof. It is understood that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades, wherein the impeller adopts a double-suction structure and comprises an upper wheel cover (1), a middle wheel cover (2), a wheel disc (3), a first blade (4), a second blade (5), a third blade (6), and a wheel hub (7); the first blade (4) is mounted between the upper wheel cover (1) and the middle wheel cover (2); the second blade (5) is mounted between the middle wheel cover (2) and the wheel disc (3); the third blade (6) is mounted between the upper wheel cover (1) and the wheel disc (3); and the wheel disc (3) is sleeved and fixed on the wheel hub (7); and the characteristics are: The first blade (4) is a backward-inclined twisted blade, the second blade (5) is a forward-inclined twisted blade, and the third blade (6) is a radial blade; at the same radial position, the axial length W1 of the flow cross section of the first blade (4) is greater than the axial length W2 of the flow cross section of the second blade (5); the flow cross section of the first blade (4) and the flow cross section of the second blade (5) are arranged side by side to form an inlet flow channel, and the third blade (6) is located in the outlet flow channel; The leading edge of the first blade (4) is further away from the central axis than the leading edge of the second blade (5), and the trailing edge of the second blade (5) is further away from the central axis than the trailing edge of the first blade (4); An outlet premixing groove (8) is provided at a position where the trailing edge of the first blade (4) overlaps with the middle wheel cover (2). The outlet premixing groove (8) comprises a first premixing groove (81) located on the first blade (4) and a second premixing groove (82) located on the second blade (5). The first premixing groove (81) and the second premixing groove (82) are arranged in communication.

2. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The backward tilt angle of the first blade (4) is A, and the forward tilt angle of the second blade (5) is B, wherein A<B.

3. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The first premixing groove (81) is a fan-shaped groove, and the second premixing groove (82) is a semicircular groove, and the radius of the fan-shaped groove is equal to that of the semicircular groove.

4. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The third blade (6) is a plate-shaped blade group structure, comprising a first outlet blade (61) and a second outlet blade (62) arranged at intervals, wherein the inlet ends of the first outlet blade (61) and the second outlet blade (62) are close to each other, and the outlet ends are far away from each other, and the first outlet blade (61) and the second outlet blade (62) are provided with a bent portion (63) protruding toward the inside of the flow channel near the outlet side, the flow area of the flow channel is the smallest at the bent portion (63), and the flow area of the flow channel at the radially outer outlet of the third blade (6) is the largest.

5. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades as claimed in claim 4, characterized in that: The flow area from the flow channel at the radial inner inlet of the third blade (6) to the flow channel at the bending portion (63) shows a trend of first increasing and then decreasing, and the flow area from the flow channel at the bending portion (63) to the flow channel at the radial outer outlet of the third blade (6) shows a trend of gradually expanding.

6. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The outlet end of the upper wheel cover (1) is further away from the central axis than the outlet end of the wheel disc (3), and the radially outer outlet end of the third blade (6) is aligned with the outlet end of the wheel disc (3).

7. The composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The main body of the hub (7) is a hollow cylindrical structure (71), and an umbrella-shaped guide surface (72) is provided at the end of the hub (7). The inlet end of the umbrella-shaped guide surface (72) is axially located at the same position as the inlet end of the middle wheel cover (2), and the outlet end of the umbrella-shaped guide surface (72) is axially directed to the side of the flow passage of the second blade (5) close to the wheel disc (3).

8. A composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades as claimed in claim 7, characterized in that: The mid-arc line of the umbrella-shaped guide surface (72) is a part of a hyperbola.

9. The composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 7, characterized in that: The top of the umbrella-shaped flow-guiding surface (72) is a spherical structure.

10. The composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 2, characterized in that: A=(0.2~0.6)B.

11. The composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: W1=(1.1~1.5)W2.

12. The composite high-efficiency, low-noise three-dimensional impeller with backward-inclined blades according to claim 1, characterized in that: The thickness δ1 of the first blade (4) is greater than the thickness δ2 of the second blade (5), and 1.2 mm ≤ δ2 ≤ 3 mm.

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