CN210290259U

CN210290259U - Impeller, fan and motor

Info

Publication number: CN210290259U
Application number: CN201921289479.XU
Authority: CN
Inventors: 胡义明; 闫甜甜
Original assignee: Midea Welling Motor Technology Shanghai Co Ltd
Current assignee: Midea Welling Motor Technology Shanghai Co Ltd
Priority date: 2019-08-09
Filing date: 2019-08-09
Publication date: 2020-04-10
Anticipated expiration: 2029-08-09

Abstract

The utility model provides an impeller, fan and motor, the impeller includes: the cover plate is provided with an outer peripheral surface formed by rotating around the central axis of the cover plate, and the diameter of the outer peripheral surface is gradually increased from one end to the other end along the axial direction of the outer peripheral surface; and a plurality of blades arranged on the outer circumferential surface at intervals in the circumferential direction, the blades including leading edges adjacent to the central axis and trailing edges distant from the central axis, the leading edges being located on a downstream side of the trailing edges in a rotation direction of the impeller; the blade root part is arranged at the end where the blade is intersected with the peripheral surface, and the blade top part is arranged at the end of the blade, which is deviated from the peripheral surface; wherein, the projection of blade on the plane of perpendicular central axis satisfies: the wrap angle theta 1 of the root of the blade is within a first preset range, and the wrap angle theta 2 of the top of the blade is within a second preset range. This application carries out optimal design through the cornerite to root of the leaf and the cornerite at blade top, can make the operating speed of impeller obtain promoting to realize high-efficient work in broad rotational speed within range, with the different demands that satisfy the consumer, reduce the sensitivity of complete machine efficiency to the design input.

Description

Impeller, fan and motor

Technical Field

The utility model relates to an impeller field particularly, relates to an impeller and have its fan, motor.

Background

The maximum rotating speed of a small high-speed fan in the prior art is 100000-120000 rpm and no more than 125000rpm due to the limitation of an impeller and a bearing; the highest overall efficiency can reach 52.5% under the working condition of 400W-120000 rpm, and the efficiency does not exceed 50% under the working condition of 500W-125000 rpm. When the consumer demand changes, such as the demand for larger suction force (power increase) or low power and light weight, the power section and the rotating speed section which can be efficiently covered by the prior art are very narrow, and the sensitivity of the whole machine efficiency to the design input is high.

SUMMERY OF THE UTILITY MODEL

In order to solve at least one of the above technical problems, an object of the present invention is to provide an impeller.

Another object of the present invention is to provide a fan comprising the above impeller.

It is still another object of the present invention to provide a motor including the above impeller.

In order to achieve the above object, the present invention provides an impeller, including: the cover plate is provided with an outer peripheral surface formed by rotating around the central axis of the cover plate, and the diameter of the outer peripheral surface is gradually increased from one end to the other end along the axial direction of the outer peripheral surface; and a plurality of blades arranged on the outer peripheral surface at intervals in a circumferential direction, the blades including a leading edge adjacent to the central axis and a trailing edge distant from the central axis, the leading edge being located on a downstream side of the trailing edge in a rotational direction of the impeller; the blade root part is arranged at the end where the blade intersects with the peripheral surface, and the blade top part is arranged at the end of the blade departing from the peripheral surface; wherein a projection of the blade on a plane perpendicular to the central axis satisfies: the wrap angle theta 1 of the blade root is within a first preset range, and the wrap angle theta 2 of the blade top is within a second preset range.

The utility model discloses technical scheme of the first aspect provides an impeller carries out optimal design through the cornerite to the cornerite of blade root portion and leaf top, can make the operating speed of impeller obtain promoting to realize high-efficient work in broad rotational speed within range, with the different demands that satisfy the consumer, reduce the sensitivity of complete machine efficiency to design input.

Specifically, the leading edge of the blade is located at the small end of the impeller, i.e., the air inlet end, the trailing edge of the blade is located at the large end of the impeller, i.e., the air outlet end, and the leading edge is forward in the rotation direction (denoted as R) with respect to the trailing edge, i.e., the leading edge is located at the downstream side of the trailing edge with respect to the rotation direction of the impeller. The wrap angle theta 1 of the blade root is a fan-shaped angle drawn by a projection streamline of the blade root on a plane vertical to the axial direction, namely an included angle between the root of the front edge, the root of the rear edge and the axis; the wrap angle theta 2 of the blade top is a fan-shaped angle drawn by a projection streamline of the blade top on a plane vertical to the axial direction, namely included angles between the top of the front edge, the top of the rear edge and the axis. The larger the wrap angle of the blade is, the smaller the flow shedding and the swirl in the flow channel are, the closer the flow is to the molded line of the blade, and the higher the lower rotating speed of the impeller is in the same diameter; however, the excessive wrap angle of the blade causes large friction loss, the high-efficiency point moves to the direction of small flow, and the demolding is difficult, so that the reasonable control of the wrap angle of the blade is very important. According to the scheme, through optimization design, the wrap angle of the root part of the blade and the wrap angle of the top part of the blade are respectively controlled within a first preset range and a second preset range according to specific conditions, the working rotating speed of the impeller can be increased, high-efficiency work within a wide rotating speed range is realized, different requirements of consumers are met, the sensitivity of the whole efficiency to design input is reduced, and meanwhile, the friction loss and the demolding difficulty of airflow are also considered.

It should be noted that the root of the leading edge refers to a point at which the axial distance between the blade root and the thin end of the outer circumferential surface is minimum, the root of the trailing edge refers to a point at which the axial distance between the blade root and the thin end of the outer circumferential surface is maximum, the tip of the leading edge refers to a point at which the axial distance between the blade tip and the thin end of the outer circumferential surface is minimum, and the tip of the trailing edge refers to a point at which the axial distance between the blade tip and the thin end of the outer circumferential. The thin end of the outer peripheral surface refers to the end with the relatively smaller diameter of the outer peripheral surface and is also an air inlet end, and the thick end of the outer peripheral surface refers to the end with the relatively larger diameter of the outer peripheral surface and is also an air outlet end.

Additionally, the utility model provides an impeller among the above-mentioned technical scheme can also have following additional technical characterstic:

in the technical scheme, theta 2 is more than or equal to theta 1.

The wrap angle theta 2 of the blade top is larger than or equal to the wrap angle theta 1 of the blade root, so that the length of the streamline of the blade top is slightly larger than or equal to that of the streamline of the blade root, and the fluid has a more uniform flowing state at the outlet.

In the above technical solution, the first preset range is 120 ° ± 3 °; and/or, the second preset range is 123 ° ± 3 °.

The larger the wrap angle of the blade is, the smaller the flow shedding and the swirl in the flow channel are, the closer the flow is to the molded line of the blade, and the higher the rotating speed under the same diameter of the impeller is; however, an excessively large blade wrap angle increases the friction loss, and the high-efficiency point moves in the small flow direction, which makes the mold release difficult. The wrap angle range given by the scheme can enable the impeller to efficiently work within the rotating speed range of 100000-150000 rpm, compared with the prior art, the maximum rotating speed of the impeller is improved, the rotating speed range of the impeller is also enlarged, the friction loss and the demolding difficulty of airflow are considered, the excessive friction loss of the airflow is prevented, and demolding is facilitated.

In any of the above technical solutions, a projection of the blade on a plane perpendicular to the central axis satisfies: the tip of the leading edge is located on a downstream side of the root of the leading edge in a rotation direction of the impeller.

In the above technical solution, an included angle γ 1 between the top of the leading edge and a line connecting the root of the leading edge and the central axis satisfies: gamma 1 is more than or equal to 0 degree and less than or equal to 5 degrees.

In the scheme, the projection of the front edge on the plane vertical to the axial direction is approximately arranged along the radial direction, so that the fluid loss of the inlet end is reduced, the top of the front edge is forward relative to the rotating direction, the forward angle is not more than 5 degrees, the forward angle is relatively small, the fit fluid drainage is facilitated, and the impeller is ensured to be manufacturable.

In any of the above technical solutions, a projection of the blade on a plane perpendicular to the central axis satisfies: the included angle gamma 2 between the top of the rear edge and the connecting line of the root of the rear edge and the central axis satisfies the following conditions: gamma 2 is more than or equal to minus 2 degrees and less than or equal to 2 degrees.

In the above solution, the projection of the trailing edge on the plane perpendicular to the axial direction is arranged substantially in the axial direction, i.e.: the included angle between the imaginary straight line of the rear edge and the central axis is not more than 2 degrees, so that the uniformity of the airflow at the outlet end is ensured.

In any of the above solutions, the projection of the blade on the plane perpendicular to the central axis of the cover plate satisfies that the inlet placement angle β 1 of the blade root is in the range of 23.5 ° ± 3 °, the outlet placement angle β 2 of the blade root is in the range of 33.5 ± 3 °, and/or the inlet placement angle β 3 of the blade top is in the range of 0 ° to 3 °, and the outlet placement angle β 4 of the blade top is in the range of 28.5 ± 3 °.

Specifically, the root edge line is the intersection line of the side surface and the outer peripheral surface of the blade, i.e., the intersection curve between the surfaces, and the inlet placement angle β 1 of the blade root is the angle between two tangent lines at the most leading edge point of the blade root edge line (i.e., the root of the leading edge), one of which is the tangent line at the most leading edge point relative to the blade root edge line (i.e., the tangent line in the direction of the flow line) and the other of which is the tangent line of a circle having a radius equal to the distance between the most leading edge point and the central axis (i.e., the tangent line in the circumferential direction).

Specifically, the exit placement angle β of the root is the angle between two tangent lines at the last edge point of the root edge line (i.e., the root of the trailing edge), one tangent line at the last edge point relative to the root edge line (i.e., the tangent line in the direction of the flow line), and the other tangent line of a circle having a radius of the distance between the last edge point and the central axis (i.e., the tangent line in the direction of the circumference).

Specifically, the blade tip inlet placement angle β is the angle between two tangent lines at the most forward edge point of the blade tip edge line (i.e., the top of the leading edge), one tangent line to the blade tip edge line at the most forward edge point (i.e., the tangent line in the direction of the flow line), and the other tangent line to a circle having a radius defined by the distance between the most forward edge point and the central axis (i.e., the tangent line in the direction of the circumference).

Specifically, blade tip exit placement angle β is the angle between two tangent lines at the last edge point of the blade tip edge line (i.e., the top of the trailing edge), one tangent line at the last edge point relative to the blade tip edge line (i.e., the tangent line in the flow line direction), and the other tangent line of a circle having a radius of the distance between the last edge point and the central axis (i.e., the tangent line in the circumferential direction).

The selection of the inlet placing angle can influence the flow state when fluid enters the impeller flow channel, the proper inlet placing angle can reduce the displacement effect of the inlet at the root of the small blade, the flow area is increased, meanwhile, the serious flow separation of the inlet end of the suction surface is avoided, and the flow loss is reduced.

The selection of the outlet placement angle can influence the vacuum degree of the fan; reducing the outer diameter of the impeller while reducing the outlet placement angle is an effective measure for improving the efficiency of the centrifugal fan. Because the impeller operating speed of this scheme can reach 150000rpm, too big impeller diameter can cause structural strength not enough and unbalanced mass to the influence of rotor assembly. However, the outlet placement angle is too small, which may affect the manufacturability of the product.

By selecting the inlet and outlet placement angle, the inlet and outlet fluid state of the impeller can be kept uniform within the rotating speed range of 100000-150000 rpm, the fluid loss is reduced, the vacuum degree and the efficiency of the fan are improved, the outer diameter of the impeller is reduced, and the strength and the manufacturability are ensured.

In any of the above technical solutions, an axial distance between a top of the leading edge and the thin end of the outer circumferential surface is smaller than an axial distance between a root of the leading edge and the thin end of the outer circumferential surface, and an included angle α between an imaginary straight line where the leading edge is located and the central axis is within a range of 76 ° ± 2 °.

In this embodiment, the axial distance between the apex of the leading edge and the thin end of the outer peripheral surface (i.e., the end of the outer peripheral surface having a smaller diameter) is smaller than the axial distance between the root of the leading edge and the thin end of the outer peripheral surface, and the apex of the leading edge is higher than the root of the leading edge in the axial direction when the thin end of the outer peripheral surface is the upper end and the thick end (i.e., the end of the outer peripheral surface having a larger diameter) is the lower end. Therefore, the leading edge extends from the root of the leading edge to the radial outside and upward (i.e. the side close to the thin end of the outer peripheral surface), so that the fluid flows in an oblique direction when flowing in through the leading edge surface of each blade, the air volume and the air pressure at the inlet end of each blade are effectively controlled, and the loss of the fluid at the inlet end is reduced. Meanwhile, the length of the streamline at the top of the blade is slightly larger than that of the streamline at the root of the blade, so that the fluid has a more uniform flowing state at the outlet.

In any of the above aspects, the outer peripheral surface is formed as a smooth concave surface, the thin end inflow angle δ 1 of the outer peripheral surface is in the range of 4 ° ± 2 °, and the thick end outflow angle δ 2 of the outer peripheral surface is in the range of 57.5 ° ± 2 °.

The inflow angle delta 1 of the thin end of the outer peripheral surface is an included angle between the streamline tangent of the thin end of the outer peripheral surface and the central axis; and the thick end outflow angle delta 2 of the peripheral surface is an included angle between the thick end streamline tangent line of the peripheral surface and the central axis. Specifically, the projections of the outer peripheral surface on a plane parallel to the central axis of the outer peripheral surface are two symmetrically distributed curves, wherein an included angle between a tangent line of an upper end point (corresponding to the thin end of the outer peripheral surface) of one curve relative to the curve and the central axis is an inflow angle δ 1 of the thin end of the outer peripheral surface, and an included angle between a tangent line of a lower end point (corresponding to the thick end of the outer peripheral surface) of one curve relative to the curve and the central axis is a thick end outflow angle δ 2 of the outer peripheral surface. The thin end inflow angle of the outer peripheral surface influences the inflow direction of the airflow, the thick end outflow angle of the outer peripheral surface influences the outflow direction of the airflow, the thin end inflow angle and the thick end outflow angle of the outer peripheral surface are limited in the range, fluid loss at the inlet end and the outlet end of the impeller can be effectively reduced, and the working efficiency of the impeller is improved.

In any of the above technical solutions, an axial distance between the thin end of the outer peripheral surface and the thick end of the outer peripheral surface is greater than an axial distance between the top of the leading edge and the thick end of the outer peripheral surface.

The axial distance between the thin end of the outer peripheral surface and the thick end of the outer peripheral surface is greater than the axial distance between the top of the front edge and the thick end of the outer peripheral surface, and the thin end of the outer peripheral surface (i.e., the end of the outer peripheral surface having a smaller diameter) is the upper end, and the thick end (i.e., the end of the outer peripheral surface having a larger diameter) is the lower end, which means that the upper end of the outer peripheral surface is higher than the top of the front edge. Therefore, after entering the flow channel, the fluid firstly passes through the upper end part of the peripheral surface to obtain a more uniform flow field and then enters the independent flow channel space formed by the front edges of the two adjacent blades, and the influence of the cover plate on the movement of the fluid between the blades is avoided.

In any of the above embodiments, the thick end of the outer peripheral surface is formed in a cylindrical shape extending along the axis thereof in a direction away from the thin end thereof.

The thick end of the outer peripheral surface is formed in a cylindrical shape extending in a direction away from the thin end thereof along the axis thereof, and the thin end of the outer peripheral surface (i.e., the end of the outer peripheral surface having a smaller diameter) is an upper end, and the thick end (i.e., the end of the outer peripheral surface having a larger diameter) is a lower end, and the thick end corresponds to the lower end of the outer peripheral surface and is formed in a cylindrical shape extending downward. Thus, the outer peripheral surface has a variable diameter section from the upper end to the lower end and an equal diameter section extending further downward from the lower end. The outer peripheral surface with the same diameter can be effectively in small clearance fit with the inner peripheral surface features on the guide vane, so that the leakage of fluid entering the inner cavity of the impeller from the flow channel is reduced, and the efficiency is improved; meanwhile, the equal-diameter section is positioned below the fluid working surface and can be used as an impeller balance ring for balancing and removing the weight, the impeller end balance ring does not need to be separately arranged, the number of parts is reduced, the assembly process is simplified, and the cost is reduced.

In any of the above technical solutions, the leading edge is formed as a smooth curved surface, and the smooth curved surface is smoothly connected with the pressure surface and the suction surface of the blade; and/or the rear edge is formed into a cylindrical surface, and the projection of the rear edge on a plane vertical to the central axis is coincident with the projection of the thick end of the cover plate on the plane vertical to the central axis.

The leading edge is configured as a smooth curve so that the pressure side and suction side of the blade are smoothly connected so that the blade extends toward the suction side and is thinned, thereby increasing the length of the blade path and reducing the relative velocity spread.

The trailing edge forms the face of cylinder, and the projection of trailing edge on the plane of perpendicular central axis coincides with the projection of the butt of apron on the plane of perpendicular central axis, is equivalent to the trailing edge and forms the face of cylinder to form same cylinder with the face of cylinder of outer peripheral face lower extreme, the structure is comparatively regular like this, and makes the trailing edge along axial setting, has guaranteed the homogeneity of exit end air current, has reduced the loss of air current.

In any of the above solutions, the length of the trailing edge is smaller than the length of the leading edge.

In the above technical solution, a ratio of the length of the trailing edge to the length of the leading edge is in a range of 40% to 46%.

The lengths of the front edge and the rear edge are reasonably set, so that the ratio of the inlet area and the outlet area of the flow channel between the adjacent blades can be effectively controlled, and the diffusion loss of the flow is further reduced; the width of the outlet of the flow channel can be reasonably controlled, so that the proper absolute speed of the outlet of the impeller can be obtained, the flow channel loss is reduced, the high-efficiency area range under the working condition of small flow is widened, and meanwhile, the pneumatic noise can be reduced.

The optimal design of the length of the rear edge and the length of the front edge is beneficial to obtaining the proper absolute speed of the impeller outlet, reducing the flow passage loss, widening the high-efficiency area range under the working condition of low flow and simultaneously being beneficial to reducing the aerodynamic noise.

In any of the above solutions, the thickness of the blade gradually increases from the leading edge to the trailing edge.

In the above technical solution, a ratio of the thickness of the leading edge to the thickness of the trailing edge is not less than 80%.

Through the thickness of reasonable setting blade, both can guarantee the structural strength of blade, can reduce the weight of blade as far as possible again, be favorable to realizing the lightweight of wind wheel. In addition, the thicknesses of the front edge and the rear edge are reasonably set, so that the ratio of the inlet area and the outlet area of the flow channel between the adjacent blades can be effectively controlled, and the diffusion loss of the flow is further reduced; the width of the outlet of the flow channel can be reasonably controlled, so that the proper absolute speed of the outlet of the impeller can be obtained, the flow channel loss is reduced, the high-efficiency area range under the working condition of small flow is widened, and meanwhile, the pneumatic noise can be reduced.

The thickness of the rear edge and the thickness of the front edge are optimally designed, so that the structural strength of the blade can be ensured, the weight of the blade can be reduced as much as possible, and the lightweight of the wind wheel is facilitated; meanwhile, the method is not only favorable for reducing the diffusion loss of flow, but also favorable for obtaining proper absolute speed of the impeller outlet, reducing the flow passage loss, widening the range of a high-efficiency area under a low-flow working condition and simultaneously being favorable for reducing the aerodynamic noise.

In any of the above technical solutions, the leading edge is a curved surface that is recessed toward the suction surface of the blade.

In the scheme, the front edge is a curved surface which is concave towards the suction surface of the blade, an imaginary connecting line from the root part to the top part of the front edge is a curve and is concave towards the suction surface, the design of the front edge is more in line with the flow rule, and the impact loss during the flow can be reduced.

In any of the above technical solutions, the number of the blades is 7.

The number of the blades is 7, so that the impeller is guaranteed to have high-efficiency working efficiency, and the weight and the production cost of the impeller are considered. Of course, the number of the blades is not limited to 7, but may be 5, 6, 8, 10, 12, etc., and may be adjusted as necessary.

The utility model discloses technical scheme of second aspect provides a fan, include as in any one of the technical scheme of first aspect the impeller.

The utility model discloses the fan that technical scheme of second aspect provided, because of including any in the first aspect technical scheme impeller, therefore have all beneficial effects that any above-mentioned technical scheme had, no longer describe herein.

A third aspect of the present invention provides an electric machine comprising an impeller according to any one of the first aspect of the present invention.

The utility model discloses the motor that technical scheme of third aspect provided, because of including any in the first aspect technical scheme impeller, therefore have all beneficial effects that any above-mentioned technical scheme had, no longer describe herein.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic perspective view of an impeller according to some embodiments of the present invention;

fig. 2 is a schematic top view of an impeller according to some embodiments of the present invention;

fig. 3 is a schematic top view of an impeller according to some embodiments of the present invention;

fig. 4 is a schematic cross-sectional view of an impeller according to some embodiments of the present invention.

Wherein, the correspondence between the reference numbers and the part names in fig. 1 to 4 is:

1: an impeller;

10: a cover plate; 11: an outer peripheral surface; 11a upper end of the outer peripheral surface; 11b lower end of the outer peripheral surface;

20: a blade; 21: a leading edge; 22: a trailing edge; 23: the root of the leaf; 24: the top of the leaf; 25: a pressure surface; 26: a suction surface;

20 a: a root of the leading edge; 20 b: a top of the leading edge; 20 c: a top of the trailing edge; 20 d: a root of the trailing edge;

γ 1: the included angle between the top 20b of the front edge and the root 20a of the front edge and the axis;

γ 2: the included angle between the top 20c of the rear edge and the root 20d of the rear edge and the axis;

β 1 root inlet setting angle;

β 2 root exit setting angle;

β 3 setting angle of inlet at top of blade;

β 4 setting angle of outlet at top of blade;

θ 1: a blade root wrap angle;

θ 2: wrap angle of the top of the blade;

α the included angle between the imaginary straight line of the front edge and the axis;

δ 1: a peripheral surface thin end inflow angle;

δ 2: a thick end outflow angle on the peripheral surface;

r: the direction of rotation.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

Wind wheels, fans and motors according to some embodiments of the present invention are described below with reference to fig. 1 to 4.

Example one

As shown in fig. 1, the present invention provides an impeller 1, including: a cover plate 10 and a plurality of blades 20.

Specifically, the cover plate 10 has an outer peripheral surface 11 formed to be turned around its central axis, and the diameter of the outer peripheral surface 11 becomes gradually larger from one end to the other end in its axial direction; a plurality of blades 20 are arranged on the outer circumferential surface 11 at intervals in the circumferential direction, the blades 20 include leading edges 21 adjacent to the central axis and trailing edges 22 distant from the central axis, the leading edges 21 are located on the downstream side of the trailing edges 22 in the rotation direction of the impeller 1; the blade 20 has a blade root 23 at the end where it intersects the outer circumferential surface 11 and a blade tip 24 at the end of the blade 20 facing away from the outer circumferential surface 11.

Wherein, as shown in fig. 2, the projection of the blade 20 on the plane perpendicular to the central axis satisfies: the wrap angle θ 1 of the blade root 23 is within a first predetermined range, and the wrap angle θ 2 of the blade tip 24 is within a second predetermined range.

The utility model discloses the impeller 1 that the embodiment of the first aspect provided carries out optimal design through the cornerite to blade root 23 and blade top 24, can make impeller 1's operating speed obtain promoting to realize high-efficient work in broad rotational speed within range, with the different demands that satisfy the consumer, reduce the sensitivity of complete machine efficiency to design input.

Specifically, the leading edge 21 of the blade 20 is located at the small end of the impeller 1, i.e., the air inlet end, the trailing edge 22 of the blade 20 is located at the large end of the impeller 1, i.e., the air outlet end, and the leading edge 21 is forward in the rotation direction (denoted by R) with respect to the trailing edge 22, i.e., the leading edge 21 is located at the downstream side of the trailing edge 22 with respect to the rotation direction of the impeller 1. The wrap angle theta 1 of the blade root 23 is a fan-shaped angle drawn by a projection streamline of the blade root 23 on a plane vertical to the axial direction, namely an included angle between the root 20a of the front edge and the root 20d of the rear edge and the axis; the wrap angle θ 2 of the blade tip 24 is a fan angle drawn by a projection streamline of the blade tip 24 on a plane perpendicular to the axial direction, that is, an angle between the tip 20b of the leading edge and the tip 20c of the trailing edge and the axial center. The larger the wrap angle of the blade 20 is, the smaller the flow shedding and the swirl in the flow channel are, the more the flow is close to the molded line of the blade 20, and the higher the rotating speed of the impeller 1 under the same diameter is; however, an excessively large wrap angle of the blade 20 increases the friction loss, and the high-efficiency point moves in the small flow direction, and it is difficult to remove the mold, so that it is important to control the wrap angle of the blade 20 appropriately. According to the scheme, through optimization design, the wrap angle of the blade root part 23 and the wrap angle of the blade top part 24 are respectively controlled within a first preset range and a second preset range according to specific conditions, the working rotating speed of the impeller 1 can be increased, high-efficiency work within a wide rotating speed range is realized, different requirements of consumers are met, the sensitivity of the whole efficiency to design input is reduced, and meanwhile, the friction loss and the demolding difficulty of airflow are also considered.

It should be noted that the root 20a of the leading edge refers to a point at which the axial distance between the blade root 23 and the thin end of the outer circumferential surface 11 (i.e., the upper end 11a of the outer circumferential surface) is minimum, the root 20d of the trailing edge refers to a point at which the axial distance between the blade root 23 and the thin end of the outer circumferential surface 11 is maximum, the tip 20b of the leading edge refers to a point at which the axial distance between the blade tip 24 and the thin end of the outer circumferential surface 11 is minimum, and the tip 20c of the trailing edge refers to a point at which the axial distance between the blade tip 24 and the. The thin end of the outer peripheral surface 11 refers to the end of the outer peripheral surface 11 with a relatively small diameter, which is also an air inlet end, and the thick end of the outer peripheral surface 11 refers to the end of the outer peripheral surface 11 with a relatively large diameter, which is also an air outlet end. In other words, when the direction toward the downstream side is referred to as the front and the direction toward the upstream side is referred to as the rear with reference to the rotation direction R of the impeller 1, the root 20a of the leading edge refers to the front end point of the blade root 23, the root 20d of the trailing edge refers to the rear end point of the blade root 23, the tip 20b of the leading edge refers to the front end point of the blade tip 24, and the tip 20c of the trailing edge refers to the rear end point of the blade tip 24. Alternatively, when the direction toward the end with the smaller diameter of the outer peripheral surface 11 is upward and the direction toward the end with the larger diameter of the outer peripheral surface 11 is downward with reference to the central axis of the outer peripheral surface 11, the root 20a of the leading edge refers to the axially highest point of the blade root 23, the root 20d of the trailing edge refers to the axially lowest point of the blade root 23, the tip 20b of the leading edge refers to the axially highest point of the blade tip 24, and the tip 20c of the trailing edge refers to the axially lowest point of the blade tip 24.

Further, θ 2 ≧ θ 1.

The wrap angle theta 2 of the blade top 24 is greater than or equal to the wrap angle theta 1 of the blade root 23, so that the length of the streamline of the blade top 24 is slightly greater than or equal to that of the streamline of the blade root 23, and the fluid has a more uniform flowing state at an outlet.

Of course, the wrap angle θ 2 of the tip portion 24 may be smaller than the wrap angle θ 1 of the root portion 23.

Optionally, the first preset range is 120 ° ± 3 °.

Optionally, the second preset range is 123 ° ± 3 °.

Because the larger the wrap angle of the blade 20 is, the smaller the flow shedding and the swirl in the flow channel are, the flow is closer to the molded line of the blade 20, and the lower rotating speed of the diameter of the impeller 1 is also higher; however, an excessively large wrap angle of the blade 20 increases the frictional loss, and the high-efficiency point moves in the small flow direction, which makes the mold release difficult. The wrap angle range given by the scheme can enable the impeller 1 to work efficiently within the rotating speed range of 100000-150000 rpm, compared with the prior art, the maximum rotating speed of the impeller 1 is improved, the rotating speed range of the impeller 1 is also expanded, the friction loss and the demolding difficulty of airflow are considered, the excessive friction loss of the airflow is prevented, and demolding is facilitated.

Of course, the first preset range and the second preset range are not limited to the above ranges, and may be adjusted as needed.

Example two

The difference from the first embodiment is that: on the basis of the first embodiment, further, the projection of the blade 20 on the plane perpendicular to the central axis satisfies: the tip 20b of the leading edge is located on the downstream side of the root 20a of the leading edge in the rotation direction of the impeller 1, as shown in fig. 3.

Optionally, the included angle γ 1 between the top 20b of the leading edge and the root 20a of the leading edge and the line of the central axis satisfies: gamma 1 is more than or equal to 0 degree and less than or equal to 5 degrees.

In the solution described above, the projection of the leading edge 21 onto a plane perpendicular to the axial direction is arranged substantially radially, which reduces the fluid loss at the inlet end, the top 20b of the leading edge being forward with respect to the direction of rotation and the forward angle not exceeding 5 °, being relatively small, facilitating a conforming fluid conduction while ensuring manufacturability of the impeller 1.

EXAMPLE III

The difference from any of the above embodiments is that: on the basis of any of the above embodiments, further, as shown in fig. 3, the projection of the blade 20 on the plane perpendicular to the central axis satisfies: the included angle gamma 2 between the top 20c of the rear edge and the connecting line of the root 20d of the rear edge and the central axis satisfies that: gamma 2 is more than or equal to minus 2 degrees and less than or equal to 2 degrees.

In the above solution, the projection of the trailing edge 22 on a plane perpendicular to the axial direction is arranged substantially in the axial direction, i.e.: the included angle between the imaginary straight line of the rear edge 22 and the central axis is not more than 2 degrees, and the uniformity of the airflow at the outlet end is ensured.

Example four

The difference from any of the above embodiments is that, on the basis of any of the above embodiments, further, as shown in fig. 2, the projection of the blade 20 on the plane perpendicular to the central axis of the shroud 10 satisfies that the inlet placement angle β 1 of the root portion 23 is in the range of 23.5 ° ± 3 °, the outlet placement angle β 2 of the root portion 23 is in the range of 33.5 ± 3 °, the inlet placement angle β 3 of the tip portion 24 is in the range of 0 ° to 3 °, and the outlet placement angle β 4 of the tip portion 24 is in the range of 28.5 ± 3 °.

Specifically, the root edge line is the intersection line of the side face of the blade 20 and the outer peripheral face 11, i.e., the intersection curve between the faces, and the inlet placement angle β 1 of the blade root 23 is the angle between two tangent lines at the most leading edge point of the blade root edge line, wherein one tangent line is the tangent line to the blade root edge line at the most leading edge point (i.e., the tangent line in the direction of the flow line) and the other tangent line is the tangent line of a circle having a radius equal to the distance between the most leading edge point and the central axis (i.e., the tangent line in the circumferential direction).

Specifically, the outlet placement angle β 2 of the root 23 is the angle between two tangent lines at the last edge point of the root edge line, one tangent line being the tangent line at the last edge point relative to the root edge line (i.e., the tangent line in the direction of the line), the other tangent line being the tangent line of a circle having a radius of the distance between the last edge point and the central axis (i.e., the tangent line in the direction of the circumference).

The blade tip 24 inlet placement angle β 3 is the angle between the tangent to the blade tip 24 at the leading edge tip 20b along the flow line and the circumferential direction, specifically, the blade tip 24 inlet placement angle β 3 is the angle between two tangents at the most leading edge point of the blade tip edge line, one tangent to the most leading edge point relative to the blade tip edge line (i.e., the tangent in the flow line direction) and the other tangent to a circle having a radius at the distance between the most leading edge point and the central axis (i.e., the tangent in the circumferential direction).

The blade tip 24 exit placement angle β 4 is the angle between the tangent to the blade tip 24 at the tip 20c of the trailing edge along the line and the circumferential direction, specifically, the blade tip 24 exit placement angle β 4 is the angle between two tangents at the last edge point of the blade tip edge line, one tangent to the last edge point relative to the blade tip edge line (i.e., the tangent in the line direction) and the other tangent to a circle having a radius of the distance between the last edge point and the central axis (i.e., the tangent in the circumferential direction).

The selection of the inlet placing angle can influence the flow state when the fluid enters the runner of the impeller 1, the proper inlet placing angle can reduce the displacement effect of the inlet of the root part 23 of the small blade, increase the flow area, and simultaneously avoid the serious flow separation of the inlet end of the suction surface 26 and reduce the flow loss.

The selection of the outlet placement angle can influence the vacuum degree of the fan; reducing the outer diameter of the impeller 1 while reducing the outlet placement angle is an effective measure for improving the efficiency of the centrifugal fan. Because the working speed of the impeller 1 can reach 150000rpm, the overlarge diameter of the impeller 1 can cause the structural strength insufficiency and the influence of unbalanced mass on the rotor assembly. However, the outlet placement angle is too small, which may affect the manufacturability of the product.

By selecting the inlet and outlet placement angles, the inlet and outlet fluid states of the impeller 1 can be kept uniform within the rotating speed range of 100000-150000 rpm, fluid loss is reduced, the vacuum degree and efficiency of the fan are improved, the outer diameter of the impeller 1 is reduced, and strength and manufacturability are guaranteed. Optionally, the impeller 1 has a maximum diameter of no more than 32 mm.

EXAMPLE five

The difference from any of the above embodiments is that, in addition to any of the above embodiments, as shown in fig. 4, the axial distance between the top portion 20b of the leading edge and the thin end of the outer peripheral surface 11 is smaller than the axial distance between the root portion 20a of the leading edge and the thin end of the outer peripheral surface 11, and the included angle α between the central axis and the imaginary straight line in which the leading edge 21 is located is within the range of 76 ° ± 2 °.

In this embodiment, the axial distance between the crest 20b of the leading edge and the thin end of the outer peripheral surface 11 (i.e., the end of the outer peripheral surface 11 having a smaller diameter) is smaller than the axial distance between the root 20a of the leading edge and the thin end of the outer peripheral surface 11, and the crest 20b of the leading edge is axially higher than the root 20a of the leading edge when the thin end of the outer peripheral surface 11 is the upper end and the thick end (i.e., the end of the outer peripheral surface 11 having a larger diameter) is the lower end. Therefore, when the leading edge 21 extends radially outward and upward (i.e., toward the thin end of the outer peripheral surface 11) from the root 20a of the leading edge, the fluid flows obliquely into the blade 20 through the leading edge 21 of each blade 20, so that the air volume and the air pressure at the inlet end of the blade 20 are effectively controlled, and the loss of the fluid at the inlet end is reduced. Meanwhile, the length of the streamline at the top of the blade 24 is ensured to be slightly larger than that of the streamline at the root of the blade 23, so that the fluid has a more uniform flowing state at the outlet.

EXAMPLE six

The difference from any of the above embodiments is that: in addition to any of the above embodiments, the outer peripheral surface 11 is formed as a smooth concave surface, the inflow angle δ 1 of the thin end of the outer peripheral surface 11 is in the range of 4 ° ± 2 °, and the outflow angle δ 2 of the thick end of the outer peripheral surface 11 is in the range of 57.5 ° ± 2 °, as shown in fig. 4.

The inflow angle delta 1 of the thin end of the outer peripheral surface 11 is an included angle between the streamline tangent of the thin end of the outer peripheral surface 11 and the central axis; the thick end outflow angle delta 2 of the outer peripheral surface 11 is an included angle between a thick end streamline tangent line of the outer peripheral surface 11 and the central axis. Specifically, the projections of the outer peripheral surface 11 on a plane parallel to the central axis thereof are two symmetrically distributed curves, wherein an included angle between a tangent line of an upper end point (corresponding to the thin end of the outer peripheral surface 11) of one curve relative to the curve and the central axis is an inflow angle δ 1 of the thin end of the outer peripheral surface 11, and an included angle between a tangent line of a lower end point (corresponding to the thick end of the outer peripheral surface 11) of one curve relative to the curve and the central axis is a thick end outflow angle δ 2 of the outer peripheral surface 11. The thin end inflow angle of the outer peripheral surface 11 affects the inflow direction of the air flow, the thick end outflow angle of the outer peripheral surface 11 affects the outflow direction of the air flow, and the thin end inflow angle and the thick end outflow angle of the outer peripheral surface 11 are limited in the above range, so that the fluid loss at the inlet end and the outlet end of the impeller 1 can be effectively reduced, and the working efficiency of the impeller 1 is improved.

EXAMPLE seven

The difference from any of the above embodiments is that: in addition to any of the above embodiments, further, the axial distance between the thin end of the outer peripheral surface 11 and the thick end of the outer peripheral surface 11 is greater than the axial distance between the crest 20b of the leading edge and the thick end of the outer peripheral surface 11, as shown in fig. 4.

The axial distance between the thin end of the outer peripheral surface 11 and the thick end of the outer peripheral surface 11 is greater than the axial distance between the apex 20b of the leading edge and the thick end of the outer peripheral surface 11, and when the thin end of the outer peripheral surface 11 (i.e., the end of the outer peripheral surface 11 having a smaller diameter) is the upper end and the thick end (i.e., the end of the outer peripheral surface 11 having a larger diameter) is the lower end, it corresponds to the upper end of the outer peripheral surface 11 being higher than the apex 20b of the leading edge, as shown in fig. Therefore, after entering the flow channel, the fluid firstly passes through the upper end part of the peripheral surface 11 to obtain a relatively uniform flow field, and then enters the independent flow channel space formed by the front edges 21 of the two adjacent blades 20, so that the influence of the cover plate 10 on the fluid movement between the blades 20 is avoided.

Example eight

The difference from any of the above embodiments is that: in addition to any of the above embodiments, the thick end of the outer peripheral surface 11 is formed in a cylindrical shape extending along the axis thereof in a direction away from the thin end thereof, as shown in fig. 1 and 4.

The thick end of the outer peripheral surface 11 is formed in a cylindrical shape extending along the axis thereof in a direction away from the thin end thereof, and the thin end of the outer peripheral surface 11 (i.e., the end of the outer peripheral surface 11 having a smaller diameter) is an upper end, and the thick end (i.e., the end of the outer peripheral surface 11 having a larger diameter) is a lower end, and is formed in a cylindrical shape extending downward corresponding to the lower end of the outer peripheral surface 11. Thus, the outer peripheral surface 11 has a variable diameter section from the upper end to the lower end and an equal diameter section extending further downward from the lower end. The outer peripheral surface 11 with the same diameter can be effectively in small clearance fit with the inner peripheral surface characteristics on the guide vane, so that the leakage of fluid entering the inner cavity of the impeller 1 from the flow channel is reduced, and the efficiency is improved; meanwhile, the equal-diameter section is located below the fluid working surface and can be used as a balance ring of the impeller 1 to balance and remove weight, the balance ring of the end of the impeller 1 does not need to be separately arranged, the number of parts is reduced, the assembly process is simplified, and the cost is reduced.

Example nine

The difference from any of the above embodiments is that: on the basis of any of the above embodiments, further, the leading edge 21 is formed as a smooth curved surface smoothly connecting the pressure surface 25 and the suction surface 26 of the blade 20, as shown in fig. 1.

The leading edge 21 is configured to have a smooth curve so that the pressure side 25 and suction side 26 of the blade 20 are smoothly connected so that the blade 20 extends toward the suction inlet and is thinned to reduce the relative velocity spread while increasing the length of the blade path.

Example ten

The difference from any of the above embodiments is that: on the basis of any of the above embodiments, further, the rear edge 22 is formed in a cylindrical surface, as shown in fig. 1, and the projection of the rear edge 22 on the plane perpendicular to the central axis coincides with the projection of the butt end of the cover plate 10 on the plane perpendicular to the central axis.

The rear edge 22 is formed into a cylindrical surface, and the projection of the rear edge 22 on the plane perpendicular to the central axis coincides with the projection of the thick end of the cover plate 10 on the plane perpendicular to the central axis, which is equivalent to the fact that the rear edge 22 is formed into a cylindrical surface and is formed into the same cylindrical surface with the cylindrical surface at the lower end of the outer peripheral surface 11, so that the structure is more regular, the rear edge 22 is axially arranged, the uniformity of the air flow at the outlet end is ensured, and the air flow loss is reduced.

EXAMPLE eleven

The difference from any of the above embodiments is that: in addition to any of the above embodiments, further, the length of the trailing edge 22 is smaller than the length of the leading edge 21.

Optionally, the ratio of the length of the trailing edge 22 to the length of the leading edge 21 is in the range of 40% to 46%.

The lengths of the front edge 21 and the rear edge 22 are reasonably set, so that the ratio of the inlet area and the outlet area of the flow channel between the adjacent blades 20 can be effectively controlled, and the diffusion loss of the flow is reduced; the width of the outlet of the flow channel can be reasonably controlled, so that the proper absolute speed of the outlet of the impeller 1 can be obtained, the flow channel loss is reduced, the high-efficiency area range under the working condition of low flow is widened, and meanwhile, the pneumatic noise can be reduced.

The optimized design of the length of the rear edge 22 and the length of the front edge 21 is beneficial to obtaining proper absolute speed of the outlet of the impeller 1, reducing flow passage loss, widening the range of a high-efficiency area under a low-flow working condition and reducing aerodynamic noise.

Example twelve

The difference from any of the above embodiments is that: in addition to any of the above embodiments, further, the thickness of the blade 20 gradually increases from the leading edge 21 to the trailing edge 22.

Alternatively, the ratio of the thickness of the leading edge 21 to the thickness of the trailing edge 22 is not less than 80%.

Through the thickness of reasonable setting blade 20, both can guarantee the structural strength of blade 20, can reduce the weight of blade 20 as far as possible again, be favorable to realizing the lightweight of wind wheel. In addition, the thicknesses of the front edge 21 and the rear edge 22 are reasonably set, so that the ratio of the inlet area and the outlet area of a flow passage between adjacent blades 20 can be effectively controlled, and the diffusion loss of the flow is further reduced; the width of the outlet of the flow channel can be reasonably controlled, so that the proper absolute speed of the outlet of the impeller 1 can be obtained, the flow channel loss is reduced, the high-efficiency area range under the working condition of low flow is widened, and meanwhile, the pneumatic noise can be reduced.

The thickness of the rear edge 22 and the thickness of the front edge 21 are optimally designed, so that the structural strength of the blade 20 can be ensured, the weight of the blade 20 can be reduced as much as possible, and the lightweight of the wind wheel is facilitated; meanwhile, the method is not only beneficial to smaller flowing diffusion loss, but also beneficial to obtaining proper absolute speed of the outlet of the impeller 1, reducing flow passage loss, widening the range of a high-efficiency area under a low-flow working condition and simultaneously beneficial to reducing aerodynamic noise.

EXAMPLE thirteen

The difference from any of the above embodiments is that: in addition to any of the above embodiments, the leading edge 21 is a curved surface that is concave toward the suction surface 26 of the blade 20.

In this embodiment, the leading edge 21 is a curved surface that is concave toward the suction surface 26 of the blade 20, and an imaginary connecting line from the root to the top of the leading edge 21 is a curved line and is concave toward the suction surface 26, so that the design of the leading edge 21 is more in line with the flow law, and the impact loss at the time of reducing the flow rate can be reduced.

In any of the above embodiments, specifically, the number of the blades 20 is 7.

The number of the blades 20 is 7, so that the impeller 1 is ensured to have high-efficiency working efficiency, and the weight and the production cost of the impeller 1 are considered. Of course, the number of the blades 20 is not limited to 7, and may be 5, 6, 8, 10, 12, or the like, and may be adjusted as necessary.

An embodiment of the second aspect of the present invention provides a fan comprising an impeller 1 as defined in any one of the embodiments of the first aspect.

The embodiment of the second aspect of the present invention provides a fan, which comprises an impeller 1 of any one of the embodiments of the first aspect, and therefore has all the advantages of any one of the embodiments, and is not repeated herein.

An embodiment of the third aspect of the present invention provides an electric machine comprising an impeller 1 as defined in any one of the embodiments of the first aspect.

The embodiment of the third aspect of the present invention provides a motor, which includes the impeller 1 of any one of the embodiments of the first aspect, and therefore has all the advantages of any one of the embodiments, and is not repeated herein.

One specific example is described below.

The high-speed fan generally drives the impeller to rotate at a high speed through the motor so as to form a negative pressure environment in the sealed shell, so that dust and debris are sucked into the dust collecting device, thereby achieving the effect of cleaning or absorbing oil smoke. The impeller belongs to a key part of a high-speed fan, and the performance of the impeller directly determines the overall performance of a fan system.

The 3D impeller that prior art's high-speed fan adopted, the ubiquitous highest rotational speed is relative low, and high-efficient operating mode is regional narrow, and the shortcoming that the noise is big is efficient under the high-power high rotational speed operating mode, needs constantly optimal design impeller structure, further promotes working property.

To the above-mentioned defect or not enough of prior art, the utility model provides an impeller structure can make the fan efficient work in 100000 ~ 150000 rpm's rotational speed interval.

The concrete structure is as follows;

as shown in fig. 1, an impeller 1 includes a cover plate 10, the cover plate 10 having an outer peripheral surface 11 formed to rotate around an axis extending vertically, the outer peripheral surface 11 having a diameter gradually increasing from an upper side toward a lower side; the impeller further comprises a plurality of twisted blades 20 arranged at intervals on the outer circumferential surface 11. Said blade 20 comprises a leading edge 21 at the inlet end and a trailing edge 22 at the outlet end, said leading edge 21 being forward in the direction of rotation R with respect to the trailing edge 22; the blade 20 intersects the outer circumferential surface 11 to form a blade root portion 23, and the blade 20 extends in a direction away from the outer circumferential surface 11 and is formed as a blade tip portion 24 where the outer diameter is largest.

It should be noted that the references to up and down in this document generally refer to the description of the orientation shown in the drawings.

Specifically, the cover plate 10 of the impeller has an outer peripheral surface 11 which is substantially tapered from top to bottom, a plurality of twisted blades 20 are uniformly arranged on the outer peripheral surface 11, an intersection line of the blades 20 and the outer peripheral surface 11 is formed as a blade root portion 23, the blade root portion 23 is a bone line from a root portion 20a at a leading edge to a root portion 20d at a trailing edge, and an imaginary curved surface obtained by rotating the blade root portion 23 around an axis coincides with the outer peripheral surface 11. The root 20a of the leading edge is the highest axial point of the root portion 23 (near the upper end of the figure, i.e. the small end of the cover plate) and the root 20d of the trailing edge is the lowest axial point of the root portion 23 (near the lower end of the figure, i.e. the lower end of the cover plate) in the figure 4.

The blade 20 extends from the blade root portion 23 in a direction away from the outer peripheral surface 11, and is formed as a blade tip portion 24 where the outer diameter is largest, the blade tip portion 24 is a streamline (actually, a curved surface having a certain width) from the tip portion 20b of the leading edge to the tip portion 20c of the trailing edge, and an imaginary curved surface obtained by rotating the blade tip portion 24 around the axis is located outside the outer peripheral surface 11, and has a diameter gradually increasing from top to bottom. Wherein the leading edge tip 20b is the axially highest point of the blade tip 24 (as shown in FIG. 4 near the upper end of the illustration, i.e., the shroud tip) and the trailing edge tip 20c is the axially lowest point of the blade tip 24 (as shown in FIG. 4 near the lower end of the illustration, i.e., the shroud lower end).

The curved surface from the root 20a of the leading edge to the tip 20b of the leading edge is formed as a leading edge 21, and the curved surface from the root 20d of the trailing edge to the tip 20c of the trailing edge is formed as a trailing edge 22. The front edge 21 is located at the small end of the impeller, i.e. the air inlet end, the rear edge 22 is located at the large end of the impeller, i.e. the air outlet end, and the front edge 21 is arranged in front of the rear edge 22 along the rotation direction R.

Alternatively, as shown in fig. 2, the projection of the blade root 23 on the plane perpendicular to the axial direction satisfies: the wrap angle theta 1 is within the range of 120 degrees +/-3 degrees; the projection of the blade tip 24 on a plane perpendicular to the axial direction satisfies: the wrap angle θ 2 is in the range of 123 ° ± 3 °.

Alternatively, θ 2 ≧ θ 1.

Specifically, the wrap angle θ 1 is a fan angle drawn by a projection streamline of the blade root 23 on a plane perpendicular to the axial direction, that is, an included angle between the root 20a of the leading edge, the root 20d of the trailing edge, and the axis; the wrap angle θ 2 is a fan angle drawn by a projection streamline of the blade tip 24 on a plane perpendicular to the axial direction, i.e., an angle between the tip 20b of the leading edge, the tip 20c of the trailing edge, and the axis. The larger the wrap angle of the blade is, the smaller the flow shedding and the swirl in the flow channel are, the closer the flow is to the molded line of the blade, and the higher the lower rotating speed of the impeller is in the same diameter; however, an excessively large blade wrap angle increases the friction loss, and the high-efficiency point moves in the small flow direction, which makes the mold release difficult. The wrap angle range given in the scheme can enable the impeller to work efficiently within the rotating speed range of 100000-150000 rpm.

Further, as shown in fig. 3, the projection of the leading edge 21 on the plane perpendicular to the axial direction satisfies: the top part 20b of the front edge is arranged in front relative to the root part 20a of the front edge along the rotating direction R, and the included angle between the top part 20b of the front edge and the root part 20a of the front edge and the axis satisfies 0-gamma 1-5 degrees; the projection of the trailing edge 22 on a plane perpendicular to the axial direction satisfies: the included angle between the top 20c of the rear edge and the root 20d of the rear edge and the axis is more than or equal to-2 degrees and less than or equal to gamma 2 degrees and less than or equal to 2 degrees.

Specifically, the projection of the leading edge 21 in the vertical axis direction is arranged substantially in the radial direction, and the leading edge tip 20b may be slightly advanced in the rotational direction by an angle not exceeding 5 °; the projection of the trailing edge 22 in the direction perpendicular to the axis is arranged substantially axially, i.e. an imaginary straight line of the trailing edge 22 makes an angle of not more than ± 2 ° with the axis. The leading edge is arranged in a generally radial direction, reducing fluid loss at the inlet end; the rear edge is arranged along the axial direction approximately, so that the uniformity of airflow at the outlet end is ensured, and the fluid loss is reduced; the small lead angle at the top of the front edge is beneficial to fit fluid drainage, and the impeller is ensured to have manufacturability.

Further, as shown in fig. 2, the projection of the blade root 23 on the plane in the vertical axis direction satisfies that the inlet placement angle β 1 is in the range of 23.5 ° ± 3 °, the outlet placement angle β 2 is in the range of 33.5 ± 3 °, the projection of the blade tip 24 on the plane in the vertical axis direction satisfies that the inlet placement angle β 3 is in the range of 0 ° to 3 °, and the outlet placement angle β 4 is in the range of 28.5 ± 3 °.

Specifically, the root inlet placement angle β 1 is the angle between the tangent to the blade root 23 at the root 20a of the leading edge in the direction of the flow line and the circumferential direction, the root outlet placement angle β 2 is the angle between the tangent to the blade root 23 at the root 20d of the trailing edge in the direction of the flow line and the circumferential direction, the tip inlet placement angle β 3 is the angle between the tangent to the blade tip 24 at the tip 20b of the leading edge in the direction of the flow line and the circumferential direction, and the tip outlet placement angle β 4 is the angle between the tangent to the blade tip 24 at the tip 20c of the trailing edge in the direction of the flow line and the circumferential direction.

The selection of the outlet placement angle can influence the vacuum degree of the fan; reducing the outer diameter of the impeller while reducing the outlet placement angle is an effective measure for improving the efficiency of the centrifugal fan. Since the impeller of this embodiment can operate at up to 150000rpm, the excessive impeller diameter results in insufficient structural strength and the effect of unbalanced mass on the rotor assembly. However, the outlet placement angle is too small, which may affect the manufacturability of the product.

Optionally, the inlet and outlet placement angle is selected, so that the inlet and outlet fluid states of the impeller can be kept uniform within a rotation speed range of 100000-150000 rpm, fluid loss is reduced, the vacuum degree and efficiency of the fan are improved, the outer diameter of the impeller is reduced, and strength and manufacturability are guaranteed.

Optionally, the impeller maximum diameter does not exceed 32 mm.

Further, the tip 20b of the leading edge is axially higher than the root 20a of the leading edge, and the angle α between the imaginary line in which the leading edge 21 lies and the axis is in the range of 76 ° ± 2 °, as shown in fig. 4.

Specifically, the leading edge 21 extends from the leading edge root 20a to the outside and upward in the radial direction, and the fluid flowing in through the leading edge surface of each blade is in the oblique direction, so that the air volume and the wind pressure at the inlet end of the blade are effectively controlled, and the loss of the fluid at the inlet end is reduced. Meanwhile, the length of the streamline of the blade top 24 is ensured to be slightly larger than that of the streamline of the blade root 23, so that the fluid has a more uniform flowing state at the outlet.

Alternatively, as shown in fig. 4, the outer peripheral surface 11 is formed as a smooth concave surface, and the inflow angle δ 1 at the upper end of the outer peripheral surface 11 is in the range of 4 ° ± 2 °, and the outflow angle δ 2 at the lower end is in the range of 57.5 ° ± 2 °.

Optionally, the upper end 11a of the peripheral surface 11 is higher than the top 20b of the leading edge.

Specifically, after entering the flow channel, the fluid firstly passes through the upper end 11a of the outer peripheral surface to obtain a relatively uniform flow field, and then enters the independent flow channel space formed by the front edges 21 of two adjacent blades, so that the influence of the cover plate on the movement of the fluid between the blades is avoided.

Alternatively, the lower end 11b of the outer peripheral surface is formed to extend in a cylindrical shape toward the lower end, as shown in fig. 4.

Specifically, the outer peripheral surface 11 has a variable diameter section from an upper end (11a) to a lower end (11b), and an equal diameter section extending further downward from the lower end (11 b). The outer peripheral surface with the same diameter can be effectively in small clearance fit with the inner peripheral surface features on the guide vane, so that the leakage of fluid entering the inner cavity of the impeller from the flow channel is reduced, and the efficiency is improved; meanwhile, the equal-diameter section is positioned below the fluid working surface and can be used as an impeller balance ring for balancing and removing the weight, the impeller end balance ring does not need to be separately arranged, the number of parts is reduced, the assembly process is simplified, and the cost is reduced.

Alternatively, the leading edge 21 is formed as a smooth curved surface smoothly connecting the pressure surface 25 and the suction surface 26. The vanes extend towards the suction inlet and are thinned, so that the relative speed diffusion can be reduced while the length of the vane channel is increased.

Alternatively, the trailing edge 22 is formed in a cylindrical surface and is formed in the same cylindrical surface as the lower end 11b of the outer peripheral surface, as shown in fig. 1.

Optionally, the length of the trailing edge 22 is less than the length of the leading edge 21, and the ratio of the two is in the range of 40% to 46%.

The length of the front edge and the rear edge is reasonably set, so that the ratio of the inlet area and the outlet area of the flow channel between the adjacent blades can be effectively controlled, and the flowing diffusion loss is reduced. The reasonable setting of outlet width can gain suitable impeller export absolute speed, reduces the runner loss, widens the high efficiency district scope under the little discharge operating mode, can reduce aerodynamic noise simultaneously.

Optionally, the thickness of the blade 20 gradually increases from the leading edge 21 to the trailing edge 22, and the ratio of the thickness of the leading edge to the thickness of the trailing edge is not less than 80%.

Alternatively, the leading edge 21 is a curved surface that is concave like the suction surface 26.

Specifically, the imaginary connecting line of the leading edge 21 from the leading edge root 20a to the leading edge tip 20b is a curved line, and is recessed toward the suction surface 26. The design of the front edge is more consistent with the flow rule, and the impact loss in the process of reducing the flow can be reduced.

Optionally, the outer circumferential surface of the cover plate is distributed with 7 blades at equal intervals along the axial direction.

According to the utility model discloses a high-speed fan has above-mentioned impeller, can work at 100000 ~ 150000rpm rotational speed is high-efficient.

Specifically, the high-speed fan adopting the impeller can efficiently work in the rotating speed range of 100000 rpm-150000 rpm by adjusting input electrical parameters according to different design requirements on the premise of not changing the structure.

The test results shown in table 1 were obtained by testing a high-speed fan using the above-described impeller. As can be seen from Table 1, the fan can adjust the rotation speed through self-balancing according to the design requirements of different power sections, and can efficiently operate in the rotation speed range of 100000 rpm-150000 rpm. At 550W of high suction, it is possible to operate stably at 150000rpm and obtain a total efficiency of greater than 52.5% while covering down to 200W, with an efficiency of greater than 54.5%.

Table 1:

input power	W	539.5	496.9	445.1	398.9	346.4	300.6	248.5	204
										Rotational speed	rpm	150376	145985	139373	134680	126582	120120	112045	103627
Flow rate	dm^3/s	13.96	13.65	13.22	12.82	12.3	11.77	11.08	10.42
										Degree of vacuum	kPa	20.39	19.32	18	16.79	15.34	13.94	12.22	10.72
Suction power	W	284.08	263.58	238.02	215.29	188.43	163.98	135.43	111.69
										Efficiency of	％	52.66	53.04	53.47	53.96	54.39	54.55	54.49	54.76

To sum up, the utility model discloses owing to adopted above-mentioned technical scheme, have following positive effect: by adopting the impeller with the structure, through the optimized design of various parameters such as the wrap angle of the blades, the placement angle of the inlet and the outlet, the width of the inlet and the outlet and the like, the working rotating speed can reach 15 ten thousand revolutions, the fluid loss at the inlet end and the outlet end is effectively reduced, the design efficiency of the impeller reaches 85 percent, and meanwhile, the high-efficiency work within a wider rotating speed range (10 to 15 thousand revolutions) can be realized; the blade has simple shape, small inclination angle of the inlet and the outlet, easy demoulding of the product and good manufacturability; meanwhile, the optimized inlet and outlet width ratio effectively reduces the pneumatic noise on the premise of ensuring the pressure ratio.

In the present application, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or unit indicated must have a specific direction, be constructed and operated in a specific orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present specification, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means 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, the schematic representations of the terms used above do not necessarily refer 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.

The above description is only an example of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An impeller, comprising:

the cover plate is provided with an outer peripheral surface formed by rotating around the central axis of the cover plate, and the diameter of the outer peripheral surface is gradually increased from one end to the other end along the axial direction of the outer peripheral surface; and

a plurality of blades arranged on the outer peripheral surface at intervals in a circumferential direction, the blades including leading edges adjacent to the central axis and trailing edges remote from the central axis, the leading edges being located on a downstream side of the trailing edges in a rotational direction of the impeller; the blade root part is arranged at the end where the blade intersects with the peripheral surface, and the blade top part is arranged at the end of the blade departing from the peripheral surface;

wherein a projection of the blade on a plane perpendicular to the central axis satisfies: the wrap angle theta 1 of the blade root is within a first preset range, and the wrap angle theta 2 of the blade top is within a second preset range.

2. The impeller according to claim 1,

θ2≥θ1。

3. the impeller according to claim 1,

the first preset range is 120 degrees plus or minus 3 degrees; and/or

The second preset range is 123 ° ± 3 °.

4. The impeller according to any one of claims 1 to 3, characterized in that the projection of said blades on a plane perpendicular to said central axis satisfies:

the tip of the leading edge is located on a downstream side of the root of the leading edge in a rotation direction of the impeller.

5. The impeller according to claim 4,

the included angle gamma 1 between the top of the front edge and the connecting line of the root of the front edge and the central axis satisfies the following conditions: gamma 1 is more than or equal to 0 degree and less than or equal to 5 degrees.

6. The impeller according to any one of claims 1 to 3, characterized in that the projection of said blades on a plane perpendicular to said central axis satisfies:

the included angle gamma 2 between the top of the rear edge and the connecting line of the root of the rear edge and the central axis satisfies the following conditions: gamma 2 is more than or equal to minus 2 degrees and less than or equal to 2 degrees.

7. The impeller according to any one of claims 1 to 3, characterized in that the projection of said blades on a plane perpendicular to the central axis of said cover plate satisfies:

the inlet placement angle β 1 of the root of the lobe is in the range of 23.5 DEG + -3 DEG, the outlet placement angle β 2 of the root of the lobe is in the range of 33.5 + -3 DEG, and/or

The inlet placement angle β 3 at the top of the leaf is in the range of 0-3 deg., and the outlet placement angle β 4 at the top of the leaf is in the range of 28.5 + -3 deg..

8. The impeller according to any one of claims 1 to 3,

the axial distance between the top of the leading edge and the thin end of the outer peripheral surface is smaller than the axial distance between the root of the leading edge and the thin end of the outer peripheral surface, and the included angle α between the imaginary straight line where the leading edge is located and the central axis is within the range of 76 degrees +/-2 degrees.

9. The impeller according to any one of claims 1 to 3,

the outer peripheral surface is formed into a smooth concave surface, and a thin end inflow angle delta 1 of the outer peripheral surface is in the range of 4 DEG + -2 DEG, and a thick end outflow angle delta 2 of the outer peripheral surface is in the range of 57.5 DEG + -2 deg.

10. The impeller according to any one of claims 1 to 3,

the axial distance between the thin end of the peripheral surface and the thick end of the peripheral surface is greater than the axial distance between the top of the leading edge and the thick end of the peripheral surface.

11. The impeller according to any one of claims 1 to 3,

the thick end of the outer peripheral surface is formed into a cylindrical shape extending along the axis thereof in a direction away from the thin end thereof.

12. The impeller according to any one of claims 1 to 3,

the front edge is formed into a smooth curved surface which is smoothly connected with the pressure surface and the suction surface of the blade; and/or

The rear edge is formed into a cylindrical surface, and the projection of the rear edge on a plane perpendicular to the central axis coincides with the projection of the thick end of the cover plate on a plane perpendicular to the central axis.

13. The impeller according to any one of claims 1 to 3,

the length of the trailing edge is less than the length of the leading edge.

14. The impeller according to claim 13,

the ratio of the length of the trailing edge to the length of the leading edge is in the range of 40% to 46%.

15. The impeller according to any one of claims 1 to 3,

the thickness of the blade gradually increases from the leading edge to the trailing edge.

16. The impeller according to claim 15,

the ratio of the thickness of the leading edge to the thickness of the trailing edge is not less than 80%.

17. The impeller according to any one of claims 1 to 3,

the leading edge is a curved surface that is concave toward the suction surface of the blade.

18. The impeller according to any one of claims 1 to 3,

the number of the blades is 7.

19. A fan comprising an impeller according to any one of claims 1 to 18.

20. An electrical machine comprising an impeller according to any one of claims 1 to 18.