Impeller and blower

Abstract

The invention provides an impeller and a blower, and relates to the technical field of household appliances. The impeller comprises a hub and a plurality of blades arranged on one side of the hub. The shape of each blade is of a three-dimensional twisted structure. Each blade comprises a suction curved surface, a pressure curved surface, an upper curved surface, a lower curved surface and a trailing edge curved surface. The pressure curved surface and the suction curved surface intersect at the front edge of the blade to form a front edge line. And the pressure curved surface and the suction curved surface intersect with the trailing edge curved surface at the trailing edge of the blade. A plurality of noise reduction tooth grooves are formed in the curved surface of the tail edge of each blade in an inwards-concave mode. The noise reduction tooth grooves are formed in the curved surface of the tail edge, so that the problem that noise is large when the impeller operates can be solved, and the fluid dynamic performance of the impeller can also be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to an impeller and a hair dryer. Background Art

[0002] As the core moving part of the fan, the impeller does work on the gas, allowing the gas to gain energy and thus achieve the purpose of compressing the gas. The quality of the impeller design plays a decisive role in the performance of the fan.

[0003] The trailing edge of the impeller blade is the rearmost edge of the leeward or leeward side of the blade and is the last part where the fluid leaves the blade. The design of the trailing edge has an important influence on the performance and noise of the impeller.

[0004] In the prior art, the trailing edge of the blade is not properly arranged. When the airflow passes through the trailing edge, vortices are easily formed and boundary layer separation is caused, resulting in high noise. Summary of the invention

[0005] The purpose of the present invention includes providing an impeller and a hair dryer, which can improve the problem of high noise during operation of the impeller and improve the fluid dynamics performance of the impeller.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present application provides an impeller, comprising a hub and a plurality of blades arranged on one side of the hub;

[0008] The shape of the blade is a three-dimensional twisted structure;

[0009] The blade comprises a suction curved surface, a pressure curved surface, an upper curved surface, a lower curved surface and a trailing edge curved surface;

[0010] The pressure curved surface and the suction curved surface intersect with the upper curved surface at the top end of the blade; the pressure curved surface and the suction curved surface intersect with the lower curved surface at the bottom end of the blade; the pressure curved surface and the suction curved surface intersect at the leading edge of the blade to form a leading edge line; the pressure curved surface and the suction curved surface intersect with the trailing edge curved surface at the trailing edge of the blade;

[0011] The trailing edge curved surface of the blade is inwardly concavely provided with a plurality of noise reduction tooth grooves.

[0012] In an optional embodiment, the noise reduction tooth groove is triangular.

[0013] In an optional embodiment, a plurality of the noise reduction tooth grooves are arranged in sequence, and a triangular convex tooth is formed between two adjacent noise reduction tooth grooves.

[0014] In an optional embodiment, the angle between the two side walls of the noise reduction tooth groove close to the lower curved surface is smaller than the angle between the two side walls of the noise reduction tooth groove close to the upper curved surface;

[0015] and / or,

[0016] The depth of the noise reduction tooth groove ranges from 0.5 mm to 1 mm;

[0017] and / or,

[0018] The tooth tips of all the triangular convex teeth are on a concave spline curve.

[0019] In an optional embodiment, the inlet angle at any point on the leading edge line ranges from -45° to -7°, and the outlet angle ranges from 15° to 30°.

[0020] In an optional embodiment, in the height direction of the blade, the leading edge line has a first control point, a second control point, a third control point, a fourth control point, a fifth control point and a sixth control point which are arranged at equal intervals from low to high;

[0021] At the first control point, the inlet angle ranges from -45° to -40°, and the outlet angle ranges from 15° to 20°; at the second control point, the inlet angle ranges from -35° to -30°, and the outlet angle ranges from 18° to 23°; at the third control point, the inlet angle ranges from -34° to -32°, and the outlet angle ranges from 19° to 22°; at the fourth control point, the inlet angle ranges from -23° to -28°, and the outlet angle ranges from 21° to 24°; at the fifth control point, the inlet angle ranges from -17° to -13°, and the outlet angle ranges from 23° to 28°; at the sixth control point, the inlet angle ranges from -10° to -7°, and the outlet angle ranges from 25° to 30°.

[0022] In an optional implementation, the first control point is the intersection of the leading edge line and the lower curved surface, and the sixth control point is the intersection of the leading edge line and the upper curved surface;

[0023] The second control point, the third control point, the fourth control point and the fifth control point are arranged on the leading edge line at equal intervals from bottom to top.

[0024] In a second aspect, the present application provides a hair dryer, comprising a motor, a housing, and an impeller as described in any one of the above items;

[0025] The shell is provided with a cavity and an air inlet and an air outlet communicated with the cavity;

[0026] The motor is installed in the cavity and fixed to the housing, and the wheel hub is fixedly connected to the output shaft of the motor;

[0027] The operation of the motor can drive the impeller to rotate so as to draw external air into the cavity through the air inlet and send it out through the air outlet.

[0028] In an optional embodiment, the hair dryer further comprises a support base, a heating wire and a plurality of heat insulation sheets;

[0029] The support seat is arranged in the cavity, a plurality of the heat insulation sheets are arranged on the support seat at intervals along the circumference of the support seat, and a flow channel is formed between the outer side of the support seat and the inner wall of the shell;

[0030] The length direction of the heat insulation sheet is parallel to the axial direction of the support seat;

[0031] The heating wire is wound around the outer periphery of the thermal insulation sheet;

[0032] The length of the heat insulation sheet is negatively correlated with the depth of the noise reduction tooth groove.

[0033] In an optional embodiment, the length of the heat insulation sheet is inversely proportional to the depth of the noise reduction tooth groove;

[0034] and / or,

[0035] The length of the thermal insulation sheet ranges from 33 mm to 40 mm.

[0036] The beneficial effects of the impeller and the hair dryer provided by the embodiments of the present invention include:

[0037] The present application arranges a plurality of inwardly concave noise reduction grooves on the trailing edge curved surface of the blade. When the impeller is running, the noise reduction grooves can reduce the generation of vortices at the trailing edge of the blade, change the frequency of the vortices, and reduce the separation of the boundary layer, thereby making the flow field relatively smooth, thereby reducing the noise during the operation of the impeller and improving the fluid dynamics performance of the impeller. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A schematic diagram of the structure of a hair dryer provided by an embodiment of the present invention;

[0040] Figure 2 A partial cross-sectional schematic diagram of a hair dryer provided by an embodiment of the present invention;

[0041] Figure 3 A schematic diagram of the exploded structure of a hair dryer provided in an embodiment of the present invention;

[0042] Figure 4 A schematic diagram of the motor installation structure of a hair dryer provided in an embodiment of the present invention;

[0043] Figure 5 A schematic structural diagram of a middle shell of a hair dryer provided in an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of the structure of an impeller provided in an embodiment of the present invention;

[0045] Figure 7 A schematic structural diagram of another viewing angle of an impeller provided by an embodiment of the present invention;

[0046] Figure 8 A schematic diagram of a projection of one side of the suction curved surface of an impeller blade provided in an embodiment of the present invention;

[0047] Fig. 9 A schematic diagram of an axial side of a pressure curved surface of a blade of an impeller provided in an embodiment of the present invention;

[0048] Fig.10 A schematic diagram of the axial side of the blades of the impeller provided in an embodiment of the present invention;

[0049] Fig.11 This is a schematic diagram of fluid simulation before the value ranges of the inlet angle and outlet angle at each point on the leading edge line are optimized;

[0050] Fig.12 Schematic diagram of fluid simulation after optimizing the value range of inlet angle and outlet angle at each point on the leading edge line;

[0051] Fig.13 A comparison diagram of test characteristic curves of an impeller with a conventional structure and an impeller provided in this application;

[0052] Fig.14 It is a comparison chart of the test characteristic curves when the inlet angle and outlet angle are within the value range and those that are not within the value range.

[0053] Icons: 100 - impeller; 110 - hub; 111 - conical surface; 130 - blades; 131 - suction surface; 132 - pressure surface; 133 - upper surface; 134 - lower surface; 135 - trailing edge surface; 136 - leading edge line; 137 - noise reduction tooth groove; 138 - triangular convex teeth; 139 - first control point; 141 - second control point; 142 - third control point; 143 - Four control points; 144 - fifth control point; 145 - sixth control point; 300 - hair dryer; 310 - motor; 330 - shell; 331 - cavity; 333 - air inlet; 335 - air outlet; 337 - front shell; 339 - middle shell; 341 - rear shell; 343 - outer shell; 345 - motor seat; 347 - guide vane; 348 - flow channel; 350 - support seat; 370 - thermal insulation sheet. DETAILED DESCRIPTION

[0054] The trailing edge of the impeller blade is the rearmost edge of the leeward or leeward surface of the blade, and is the last part where the fluid leaves the blade. The design of the trailing edge has an important impact on the performance and noise of the impeller. In the prior art, the trailing edge of the blade is not set properly, and when the airflow passes through the trailing edge, it is easy to form vortices and cause boundary layer separation, resulting in high noise.

[0055] In view of the above problems, the present invention provides an impeller and a hair dryer which can improve the problem of high noise during operation of the impeller and can also improve the fluid dynamics performance of the impeller.

[0056] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0059] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0060] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0061] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0062] The overall structure, working principle and technical effects of the impeller and hair dryer provided by the present invention are described in detail below through embodiments and in conjunction with the accompanying drawings.

[0063] Please refer to Figures 1 to 5 The present embodiment provides a hair dryer 300, which includes a motor 310, a housing 330 and an impeller 100. The housing 330 is provided with a cavity 331 and an air inlet 333 and an air outlet 335 connected to the cavity 331. The motor 310 is installed in the cavity 331 and fixed to the housing 330. The impeller 100 is fixedly connected to the output shaft of the motor 310. The operation of the motor 310 can drive the impeller 100 to rotate so as to suck the external air from the air inlet 333 into the cavity 331 and send it out from the air outlet 335.

[0064] Specifically, the housing 330 includes a front housing 337, a middle housing 339 and a rear housing 341. The front housing 337 and the rear housing 341 are installed at both ends of the middle housing 339. Generally, the air inlet 333 is arranged at the rear housing 341, which has the function of collecting air. The motor 310 is installed in the middle housing 339, and the air outlet 335 is arranged on the end surface of the front housing 337. The operation of the motor 310 drives the impeller 100 to rotate, and the impeller 100 can suck the external air into the middle housing 339 through the air inlet 333, and then send it out through the air outlet 335 after being compressed and accelerated.

[0065] Please refer to Figures 1 to 5 In detail, the middle shell 339 includes a shell 343, a motor seat 345 and a plurality of guide vanes 347. The shell 343 is in a hollow cylindrical shape. The motor seat 345 is arranged in the shell 343, and a plurality of guide vanes 347 are arranged at equal intervals along the circumferential direction on the outer periphery of the motor seat 345, and the guide vanes 347 are all connected to the inner wall of the shell 343.

[0066] The cross section of the guide vane 347 is a spline curve. The guide vane 347 is bent in the direction from the rear shell 341 to the front shell 337 and in the direction of rotation of the impeller 100. That is, the end of the guide vane 347 close to the impeller 100 is bent clockwise.

[0067] Please refer to Figures 1 to 5 Specifically, the inlet angle at the leading edge of the guide vane 347 is in the range of 28° to 32°, and the inlet angle at the trailing edge is 0°. That is, the tail of the guide vane 347 is perpendicular to the axial direction of the impeller 100 .

[0068] After the airflow is accelerated by the impeller 100, there is not only an axial velocity but also a large circumferential velocity. The airflow of the middle shell 339 of the traditional structure will have obvious impact losses when entering, which has a significant negative impact on the performance of the hair dryer 300. In this embodiment, by setting the guide vane 347 in the gap between the motor base 345 and the outer shell 343, the guide vane 347 can effectively reduce the flow loss generated when the gas passes through the motor base 345 and the outer shell 343, and inhibit the development of the flow separation vortex formed on the inner side of the channel of the motor base 345 and the outer shell 343, thereby improving the working efficiency of the hair dryer 300. Secondly, the guide vane 347 can also be used as a mechanical connection component between the motor base 345 and the outer shell 343, thereby improving the structural stability.

[0069] Please refer to Figures 1 to 5 , Secondly, in this embodiment, the hair dryer 300 further includes a support base 350, a heating wire (not shown) and a plurality of heat insulating sheets 370. The support base 350 is mounted at the rear end of the motor base 345 and abuts against the rear shell 341. A plurality of heat insulating sheets 370 are installed on the support base 350 at intervals along the circumference of the support base 350 for heat insulation. The heating wire is wound around the outer circumference of the heat insulating sheet 370. The heating wire can heat the airflow passing through.

[0070] In this embodiment, the impeller 100 includes a hub 110 and a plurality of blades 130 disposed on one side of the hub 110. The shape of the blade 130 is a three-dimensional twisted structure. The blade 130 includes a suction curved surface 131, a pressure curved surface 132, an upper curved surface 133, a lower curved surface 134 and a trailing edge curved surface 135. The pressure curved surface 132 and the suction curved surface 131 intersect with the upper curved surface 133 at the top of the blade 130. The pressure curved surface 132 and the suction curved surface 131 intersect with the lower curved surface 134 at the bottom of the blade 130. The pressure curved surface 132 and the suction curved surface 131 intersect at the leading edge of the blade 130 to form a leading edge line 136. The pressure curved surface 132 and the suction curved surface 131 intersect with the trailing edge curved surface 135 at the trailing edge of the blade 130. The trailing edge curved surface 135 is concavely provided with a plurality of noise reduction tooth grooves 137.

[0071] In this embodiment, a plurality of inwardly recessed noise reduction grooves are provided on the trailing edge curved surface 135 of the blade 130. When the impeller 100 is in operation, the noise reduction grooves can reduce the generation of vortices at the trailing edge of the blade 130, change the frequency of the vortices, and reduce the separation of the boundary layer, thereby making the flow field relatively smooth, thereby reducing the noise during the operation of the impeller 100 and improving the fluid dynamics performance of the impeller 100.

[0072] It should also be noted that the suction surface 131 of the blade 130 refers to the side of the blade 130 with lower pressure. Usually, this side is located on the concave surface of the blade 130, that is, the upstream side in the direction of fluid flow. Opposite to the suction surface 131 is the pressure surface 132, which is the side of the blade 130 with higher pressure, usually located on the convex surface of the blade 130, that is, the downstream side in the direction of fluid flow. There is a transition zone between the pressure surface 132 and the suction surface 131, which are called the leading edge and trailing edge of the blade 130. The leading edge is the part that the fluid contacts first, and the trailing edge is the part that the fluid leaves last. The upper surface 133 corresponds to the tip of the blade 130. The lower surface 134 corresponds to the root of the blade 130. The leading edge line 136 refers to the intersection of the pressure surface 132 and the suction surface 131 at the front end of the blade 130, which is the part that the fluid contacts first. The leading edge line 136 is usually a curve connecting the leading edge points of the blade 130. The trailing edge curved surface 135 refers to the curved surface at the trailing edge of the blade 130 .

[0073] Furthermore, the noise reduction tooth groove 137 is triangular. The sharp edges of the triangular noise reduction tooth groove 137 can more effectively break up large vortices and reduce noise. Disturbances can also be introduced in multiple directions to further smooth the flow field. Secondly, symmetry can ensure uniform distribution of airflow at the trailing edge and reduce irregular vortex generation.

[0074] In some embodiments of the present application, the noise reduction tooth groove 137 can be an equilateral triangle. The equilateral triangle has a high degree of symmetry, each angle is 60 degrees, and each side is of equal length. The symmetry ensures the uniform distribution of the airflow at the trailing edge, reduces the generation of irregular vortices, and improves the stability of the flow field. Uniform disturbances can more effectively break up large vortices and reduce noise. The sharp edges of the equilateral triangle can improve the flow characteristics of the boundary layer and reduce the separation of the airflow at the trailing edge. Reducing separation can reduce the irregular movement of the airflow and reduce separation noise. The geometric shape of the equilateral triangle can smooth the flow field and reduce the irregular movement of the airflow.

[0075] Of course, in other embodiments of the present application, in order to take into account other aspects of the performance of the impeller 100, such as wind pressure, wind volume and other performance, other acute angle triangles or obtuse angle triangles may be used. The angle of each noise reduction tooth groove 137 may also be different.

[0076] In this embodiment, a plurality of noise reduction tooth grooves 137 are arranged in sequence, and a triangular convex tooth 138 is formed between two adjacent noise reduction tooth grooves 137. Such an arrangement forms a sawtooth shape on the trailing edge curved surface 135 of the blade 130.

[0077] The plurality of noise reduction tooth grooves 137 are arranged in a row, so that by introducing a small irregular structure at the trailing edge, the large vortex in the airflow can be broken up and decomposed into smaller vortices. The energy of the small vortex is lower and the noise generated is also smaller.

[0078] In this embodiment, the included angle between the two side walls of the noise reduction tooth groove 137 close to the lower curved surface 134 is smaller than the included angle between the two side walls of the noise reduction tooth groove 137 close to the upper curved surface 133 .

[0079] The angle of the noise reduction tooth groove 137 in the upper area is large, while the angle of the noise reduction tooth groove 137 in the lower area is small, so that the noise reduction tooth groove 137 with a larger angle in the upper area can better guide the airflow to flow upward, while the noise reduction tooth groove 137 with a smaller angle in the lower area can better guide the airflow to flow downward. Overall, the distribution of the airflow at the trailing edge can be optimized, the generation of irregular vortices can be reduced, and the uniformity and stability of the flow field can be improved.

[0080] In this embodiment, the angle of the noise reduction tooth groove 137 in the lower area is an acute angle, which increases upwards until the uppermost one is an obtuse angle, wherein the value range of the included angle is 66° to 106°.

[0081] It should be noted that the two side surfaces forming the angle of the noise reduction tooth groove 137 are spline surfaces, which can guide the flow more smoothly and further reduce the generation of noise.

[0082] In this embodiment, the depth of the noise reduction tooth groove 137 ranges from 0.5 mm to 1 mm.

[0083] The depth of the noise reduction tooth groove 137 is set to 0.5 mm to 1 mm, which can significantly improve the aerodynamic performance of the blade 130 and reduce noise.

[0084] In this embodiment, the tooth tips of all triangular convex teeth 138 are on a concave spline curve (such as Figure 8 In other words, before the trailing edge curved surface 135 is provided with the noise reduction tooth groove 137, the blade shape of the blade 130 is that the middle area of ​​the trailing edge curved surface 135 is a spline curved surface that is concave inward. This arrangement can significantly improve the aerodynamic performance of the blade 130 and reduce noise. The concave design achieves the purpose of optimizing performance by changing the flow characteristics of the airflow, reducing vortex generation and boundary layer separation.

[0085] Please refer to 1 to 10. In this embodiment, the specific heat insulation sheet 370 is a mica sheet. A plurality of heat insulation sheets 370 are arranged on the support seat 350 at intervals along the circumference of the support seat 350. A flow channel 348 is formed between the outer side of the support seat 350 and the inner wall of the housing 330. When the impeller 100 rotates, the airflow flowing in from the air inlet 333 can flow forward through the flow channel 348. The length direction of the heat insulation sheet 370 is parallel to the axial direction of the support seat 350. The length of the heat insulation sheet 370 is negatively correlated with the depth of the noise reduction tooth groove 137.

[0086] The length of the heat shield 370 determines the size of the airflow loss along the way and the degree of development of the vortex structure in the flow channel 348. However, a heat shield 370 that is too short has limited guiding effect on the airflow, causing the airflow to still have a large circumferential velocity. A heat shield 370 that is too long will cause the size of the vortex structure in the flow channel 348 to develop significantly in the flow direction. According to the vortex size caused by the concave structure at the trailing edge of the blade 130, the appropriate length of the heat shield 370 is matched to ensure the operating efficiency of the hair dryer 300.

[0087] Specifically, the length of the heat insulation sheet 370 is inversely proportional to the depth of the noise reduction tooth groove 137. The length of the heat insulation sheet 370 ranges from 33 mm to 40 mm. Such a setting and value can better improve the fluid dynamics performance and noise reduction performance of the hair dryer 300.

[0088] Please refer to Figures 6 to 10 In this embodiment, the value range of the inlet angle at any point on the leading edge line 136 is -45° to -7°, and the value range of the outlet angle is 15° to 30°.

[0089] In this embodiment, the value range of the inlet angle at any point on the leading edge line 136 of the blade 130 of the impeller 100 is set to -45° to -7°, and the value range of the outlet angle is set to 15° to 30°. Through flow field analysis, it can be obtained that the improved impeller 100 not only suppresses the vortex structure on the surface of the blade 130, but also weakens the axial movement of the airflow at the top of the blade 130, thereby enhancing the axial working ability of the impeller 100 on the airflow.

[0090] It should be noted that the inlet angle and outlet angle of each point on the leading edge line 136 are important parameters for describing the geometric features of the blade 130 and the fluid flow characteristics. These angles directly affect the aerodynamic performance and efficiency of the blade 130. The inlet angle refers to the angle of the fluid entering the leading edge of the blade 130 relative to the tangent direction of the leading edge line 136 of the blade 130. The inlet angle can be measured by the angle between the fluid velocity vector and the tangent direction of the leading edge line 136. The inlet angle directly affects the flow conditions when the fluid enters the blade 130. The optimization of the inlet angle helps to smooth the airflow and reduce turbulence and resistance. The outlet angle refers to the angle of the fluid leaving the trailing edge of the blade 130 relative to the tangent direction of the trailing edge line of the blade 130. The outlet angle can be measured by the angle between the fluid velocity vector and the tangent direction of the trailing edge line.

[0091] Please refer to Fig.11 and Fig.12 , Fig.11 It is a schematic diagram of fluid simulation before the value ranges of the inlet angle and the outlet angle at each point on the leading edge line 136 of the blade 130 are optimized. Fig.12 FIG. 1 is a schematic diagram of fluid simulation after optimizing the value range of the inlet angle and outlet angle at each point on the leading edge line 136 of the blade 130. Figure 1 and Figure 2 By comparing the fluid simulation diagram of FIG. 1 , it can be clearly seen that the surface of the optimized blade 130 has fewer vortices and the axial movement of the airflow at the top of the blade 130 is weakened, thereby enhancing the axial working ability of the impeller 100 on the airflow.

[0092] Please refer to Figures 6 to 10 Specifically, in the height direction of the blade 130, the leading edge line 136 has a first control point 139, a second control point 141, a third control point 142, a fourth control point 143, a fifth control point 144 and a sixth control point 145 which are arranged in sequence from low to high. At the first control point 139, the value range of the inlet angle is -45° to -40°, and the value range of the outlet angle is 15° to 20°. At the second control point 141, the value range of the inlet angle is -35° to -30°, and the value range of the outlet angle is 18° to 23°. At the third control point 142, the value range of the inlet angle is -34° to -32°, and the value range of the outlet angle is 19° to 22°. At the fourth control point 143, the value range of the inlet angle is -23° to -28°, and the value range of the outlet angle is 21° to 24°. At the fifth control point 144, the inlet angle ranges from -17° to -13°, and the outlet angle ranges from 23° to 28°. At the sixth control point 145, the inlet angle ranges from -10° to -7°, and the outlet angle ranges from 25° to 30°.

[0093] This embodiment optimizes the value ranges of the inlet angle and the outlet angle at different control points, thereby improving the vortex problem and enhancing the axial working ability of the impeller 100 on the airflow.

[0094] In this embodiment, the first control point 139 , the second control point 141 , the third control point 142 , the fourth control point 143 , the fifth control point 144 and the sixth control point 145 are arranged at equal intervals.

[0095] In this embodiment, these control points are arranged at equal intervals, so as to improve the vortex problem and enhance the axial working ability of the impeller 100 on the airflow, thereby increasing the air volume and air pressure.

[0096] Please refer to Figures 6 to 10 In detail, the blade 130 further includes an upper curved surface 133 and a lower curved surface 134. The upper ends of the pressure curved surface 132 and the suction curved surface 131 intersect with the upper curved surface 133, and the lower ends of the pressure curved surface 132 and the suction curved surface 131 intersect with the lower curved surface 134. The first control point 139 is the intersection of the leading edge line 136 and the lower curved surface 134, and the sixth control point 145 is the intersection of the leading edge line 136 and the upper curved surface 133. The second control point 141, the third control point 142, the fourth control point 143 and the fifth control point 144 are arranged at equal intervals on the leading edge line 136 from bottom to top.

[0097] It can be understood that the first control point 139 and the sixth control point 145 are two end points of the front edge line 136. The second control point 141, the third control point 142, the fourth control point 143 and the fifth control point 144 divide the front edge line 136 into five equal length segments.

[0098] It should be noted that the leading edge line 136 is curved in three-dimensional space. The leading edge line 136 can be obtained by sequentially connecting the first control point 139, the second control point 141, the third control point 142, the fourth control point 143, and the fifth control point 144. The upper curved surface 133 corresponds to the tip of the blade 130, and the lower curved surface 134 corresponds to the root of the blade 130.

[0099] Please refer to Figures 6 to 10 In a side view, it can be seen that the leading edge line 136 extends from low to high in the height direction of the blade 130 in a reverse curvature toward the trailing edge. It can be seen that the lower area is slightly concave, while the upper area is convex. The bottom of the leading edge line 136 is directly connected to the hub 110.

[0100] In some other embodiments of the present application, the first control point 139, the second control point 141, the third control point 142, the fourth control point 143, the fifth control point 144 and the sixth control point 145 are respectively the intersection points of the cross sections at 0%, 20%, 40%, 60%, 80%, and % in the height direction of the blade 130 and the leading edge line 136.

[0101] Optionally, the inlet angle at the first control point 139 is -43°, and the outlet angle is 17°. The inlet angle at the second control point 141 is -34°, and the outlet angle is 18°. The inlet angle at the third control point 142 is -33.1°, and the outlet angle is 19.2°. The inlet angle at the fourth control point 143 is -25.5°, and the outlet angle is 21.7°. The inlet angle at the fifth control point 144 is -16°, and the outlet angle is 23.5°. The inlet angle at the sixth control point 145 is -9.1°, and the outlet angle is 26°.

[0102] This embodiment optimizes these controlled angles that are evenly spaced in the height direction of the blade 130, thereby further improving the vortex problem, thereby increasing the axial working ability of the impeller 100 on the airflow, and further increasing the air volume and pressure.

[0103] Optionally, the inlet angle at the first control point 139 is -42°, and the outlet angle is 18°. The inlet angle at the second control point 141 is -33.5°, and the outlet angle is 19.5°. The inlet angle at the third control point 142 is -33°, and the outlet angle is 20.7°. The inlet angle at the fourth control point 143 is -27°, and the outlet angle is 22.4°. The inlet angle at the fifth control point 144 is -15.5°, and the outlet angle is 24.5°. The inlet angle at the sixth control point 145 is -8°, and the outlet angle is 27.5°.

[0104] This embodiment optimizes these controlled angles that are evenly spaced in the height direction of the blade 130, thereby further improving the vortex problem, thereby increasing the axial working ability of the impeller 100 on the airflow, and further increasing the air volume and pressure.

[0105] Optionally, the inlet angle at the first control point 139 is -40°, and the outlet angle is 19.7°. The inlet angle at the second control point 141 is -31.3°, and the outlet angle is 21.5°. The inlet angle at the third control point 142 is -32.5°, and the outlet angle is 22°. The inlet angle at the fourth control point 143 is -23°, and the outlet angle is 23.8°. The inlet angle at the fifth control point 144 is -13°, and the outlet angle is 26°. The inlet angle at the sixth control point 145 is -7°, and the outlet angle is 29°.

[0106] This embodiment optimizes these controlled angles that are evenly spaced in the height direction of the blade 130, thereby further improving the vortex problem, thereby increasing the axial working ability of the impeller 100 on the airflow, and further increasing the air volume and pressure.

[0107] In this embodiment, at the first control point 139, the centerline length of the blade 130 is 24.15 mm. At the second control point 141, the centerline length of the blade 130 is 22.25 mm. At the third control point 142, the centerline length of the blade 130 is 20.41 mm. At the fourth control point 143, the centerline length of the blade 130 is 19.58 mm. At the fifth control point 144, the centerline length of the blade 130 is 19.32 mm. At the sixth control point 145, the centerline length of the blade 130 is 19.1 mm.

[0108] In this embodiment, the centerline length of the blade 130 at the corresponding control point is set to the above-mentioned corresponding value, which can further improve the vortex problem, thereby improving the axial working ability of the impeller 100 on the airflow, and further increasing the air volume and air pressure.

[0109] Please refer to Figures 6 to 10 In this embodiment, a conical surface 111 is provided on one side of the hub 110 , and the blades 130 include nine blades 130 . The nine blades 130 are evenly spaced and arranged on the conical surface 111 , and the lower curved surface 134 is coplanar with the conical surface 111 .

[0110] In this embodiment, the side of the hub 110 where the blades 130 are arranged is set as a conical surface 111, which can reduce turbulence and resistance of airflow. Setting the blades 130 to nine can provide greater wind pressure.

[0111] It can be understood that the lower curved surface 134 is coplanar with the conical surface 111 , and it can be understood that the blade 130 is intercepted by the conical surface 111 of the hub 110 to form the lower curved surface 134 of the blade 130 .

[0112] Furthermore, the upper curved surface 133 is bent downwardly and extends from a section connected with the leading edge of the blade 130 to an end connected with the trailing edge of the blade 130. Bending and extending the upper curved surface 133 of the blade 130 downwardly can improve fluid flow efficiency, reduce flow separation, optimize pressure distribution, increase lift and thrust of the blade 130, reduce vibration and noise, and improve structural strength.

[0113] From a perspective of the impeller 100, it can be seen that the upper curved surface 133 is a spiral three-dimensional curved surface, and its curvature gradually decreases toward the trailing edge. That is, the upper curved surface 133 is more curled in the area close to the leading edge, while the area close to the trailing edge is smoother. Secondly, the upper curved surface 133 is slightly inclined toward one side of the pressure curved surface 132 in the area close to the leading edge, and the inclination angle in this direction gradually decreases toward the trailing edge.

[0114] Furthermore, the blade 130 is a backward-bent three-dimensional twisted shape. In this embodiment, the blade 130 is set to a backward-bent three-dimensional twisted shape to improve efficiency, increase flow, improve flow stability, and reduce noise.

[0115] In this embodiment, the trailing edge of the blade 130 is concave to form a curved surface, which can reduce noise.

[0116] Please refer to Fig.13 , Fig.13 1 is a comparison diagram of the experimental characteristic curves of the impeller 100 of the conventional structure and the improved impeller 100 of the embodiment of the present invention. Figure 5 The horizontal axis in the figure is the rotation speed of the impeller 100, the vertical axis on the right is the air volume of the hair dryer 300, and the vertical axis on the left is the wind pressure of the noise.

[0117] Depend on Fig.13 It can be clearly seen that the air volume and air pressure of the hair dryer 300 provided in this embodiment are significantly greater than those of the hair dryer 300 using the traditional impeller 100 at the same speed. While the air pressure and air volume of the hair dryer 300 provided in this embodiment are significantly improved compared to those of the hair dryer 300 using the traditional impeller 100, the noise of the hair dryer 300 provided in this embodiment is not much increased compared to the noise of the traditional hair dryer 300. In particular, as the speed increases, the difference between the two in terms of noise gradually narrows or even becomes the same, which shows that the impeller 100 provided in this embodiment has a noise reduction effect.

[0118] It should be noted that the wind pressure and air volume of the hair dryer 300 are important indicators for measuring its performance, while noise is one of the key factors affecting user experience. Increasing wind pressure and air volume is often accompanied by an increase in noise, because increasing wind pressure and air volume usually requires a higher rotation speed and a stronger airflow. The hair dryer 300 provided in this embodiment and the traditional hair dryer 300 have the same noise when the impeller 100 rotates at a speed of 20,000 revolutions, the air volume is better than about 5, and the wind pressure is better than about 4. It can be clearly seen that the hair dryer 300 provided in this embodiment has a stronger overall performance.

[0119] Please refer to Fig.14 , Fig.14The inlet angle and outlet angle of each control point of the blade 130 of the impeller 100 of the hair dryer 300 are not within the parameter range of the present application and the experimental characteristic curve comparison diagram of the hair dryer 300 provided in this embodiment. Figure 6 The horizontal axis in the figure is the rotation speed of the impeller 100, the vertical axis on the right is the air volume of the hair dryer 300, and the vertical axis on the left is the wind pressure of the noise. Figure 6 It can be seen that at any rotation speed, the air volume and air pressure of the hair dryer 300 provided in this embodiment are better than the air volume and air pressure of the hair dryer 300 whose structure is not within the parameter range, and the hair dryer 300 provided in this embodiment also has less noise at the same rotation speed.

[0120] It should be noted that the structure not within the parameter range means that the inlet angle at any point on the leading edge line 136 of the blade 130 of the impeller 100 is not within the range of -45° to -7°, and the outlet angle is not within the range of 15° to 30°. When other structures of the blade 130 are basically the same.

[0121] It is understandable that the impeller 100 provided in this embodiment can also be used in other household appliances or equipment in other fields to deliver air. The present application does not limit the impeller 100 to be used only in the hair dryer 300.

[0122] In summary, the impeller 100 and the hair dryer 300 provided in this embodiment are provided with a plurality of inwardly recessed noise reduction grooves 137 on the trailing edge curved surface 135 of the blade 130. When the impeller 100 is running, the noise reduction grooves 137 can reduce the generation of vortices at the trailing edge of the blade, change the frequency of the vortices, and reduce the separation of the boundary layer, thereby making the flow field relatively smooth, thereby reducing the noise during the operation of the impeller 100 and improving the fluid dynamics performance of the impeller 100.

[0123] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An impeller, characterized in that: It comprises a hub (110) and a plurality of blades (130) arranged on one side of the hub (110); The shape of the blade (130) is a three-dimensional twisted structure; The blade (130) comprises a suction curved surface (131), a pressure curved surface (132), an upper curved surface (133), a lower curved surface (134) and a trailing edge curved surface (135); The pressure curved surface (132) and the suction curved surface (131) intersect with the upper curved surface (133) at the top end of the blade (130); the pressure curved surface (132) and the suction curved surface (131) intersect with the lower curved surface (134) at the bottom end of the blade (130); the pressure curved surface (132) and the suction curved surface (131) intersect at the leading edge of the blade (130) to form a leading edge line (136); the pressure curved surface (132) and the suction curved surface (131) intersect with the trailing edge curved surface (135) at the trailing edge of the blade (130); The trailing edge curved surface (135) of the blade (130) is inwardly concavely provided with a plurality of noise reduction tooth grooves (137).

2. The impeller according to claim 1, characterized in that: The noise reduction tooth groove (137) is triangular in shape.

3. The impeller according to claim 2, characterized in that: The plurality of noise reduction tooth grooves (137) are arranged in sequence and continuously, and a triangular convex tooth (138) is formed between two adjacent noise reduction tooth grooves (137).

4. The impeller according to claim 3, characterized in that: The included angle between the two side walls of the noise reduction tooth groove (137) close to the lower curved surface (134) is smaller than the included angle between the two side walls of the noise reduction tooth groove (137) close to the upper curved surface (133); and / or, The depth of the noise reduction tooth groove (137) ranges from 0.5 mm to 1 mm; and / or, The tooth tips of all the triangular convex teeth (138) are on a concave spline curve.

5. The impeller according to any one of claims 1 to 4, characterized in that: The value range of the inlet angle at any point on the leading edge line (136) is -45° to -7°, and the value range of the outlet angle is 15° to 30°.

6. The impeller according to claim 5, characterized in that In the height direction of the blade (130), the leading edge line (136) has a first control point (139), a second control point (141), a third control point (142), a fourth control point (143), a fifth control point (144) and a sixth control point (145) which are arranged at equal intervals from low to high. At the first control point (139), the inlet angle ranges from -45° to -40°, and the outlet angle ranges from 15° to 20°; at the second control point (141), the inlet angle ranges from -35° to -30°, and the outlet angle ranges from 18° to 23°; at the third control point (142), the inlet angle ranges from -34° to -32°, and the outlet angle ranges from 19° to 22°. ; At the fourth control point (143), the inlet angle ranges from -23° to -28°, and the outlet angle ranges from 21° to 24°; at the fifth control point (144), the inlet angle ranges from -17° to -13°, and the outlet angle ranges from 23° to 28°; at the sixth control point (145), the inlet angle ranges from -10° to -7°, and the outlet angle ranges from 25° to 30°.

7. The impeller according to claim 6, characterized in that The first control point (139) is the intersection point of the front edge line (136) and the lower curved surface (134), and the sixth control point (145) is the intersection point of the front edge line (136) and the upper curved surface (133); The second control point (141), the third control point (142), the fourth control point (143) and the fifth control point (144) are arranged on the leading edge line (136) at equal intervals from bottom to top.

8. A hair dryer, characterized in that: It comprises a motor (310), a housing (330) and an impeller according to any one of claims 1 to 7; The housing (330) is provided with a cavity (331) and an air inlet (333) and an air outlet (335) communicated with the cavity (331); The motor (310) is installed in the cavity (331) and fixed to the housing (330); the wheel hub (110) is fixedly connected to the output shaft of the motor (310); The operation of the motor (310) can drive the impeller to rotate so as to draw external air into the cavity (331) through the air inlet (333) and send it out through the air outlet (335).

9. The hair dryer according to claim 8, characterized in that: The hair dryer also includes a support base (350), a heating wire and a plurality of heat insulation sheets (370); The support seat (350) is arranged in the cavity (331), a plurality of the heat insulation sheets (370) are arranged on the support seat (350) at intervals along the circumference of the support seat (350), and a flow channel (348) is formed between the outer side of the support seat (350) and the inner wall of the shell (330); The length direction of the heat insulation sheet (370) is parallel to the axial direction of the support seat (350); The heating wire is wound around the outer periphery of the heat insulation sheet (370); The length of the heat insulation sheet (370) is negatively correlated with the depth of the noise reduction tooth groove (137).

10. The hair dryer according to claim 9, characterized in that: The length of the heat insulation sheet (370) is inversely proportional to the depth of the noise reduction tooth groove (137); and / or, The length of the heat insulation sheet (370) ranges from 33 mm to 40 mm.

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