Inducer and blade shaping method

Abstract

The invention relates to an inducer and a blade shaping method. The inducer comprises a wheel shaft and blades, the blades are arranged on the wheel shaft, and the blades are in a spiral shape rotating along the spiral reference trajectory. Two side surfaces of the blade are respectively a working surface and a non-working surface, the non-working surface is provided with a diversion area and a flowing area, and the diversion area is provided with an initial area line and an end point area line; a plurality of flow track line segments are arranged between the initial area line and the end point area line, the flow track line segments extend along the spiral reference track line, the initial point of each flow track line segment is located on the initial area line, and the end point of each flow track line segment is located on the end point area line. In the height direction of the blades, the height direction of the blades is perpendicular to the spiral reference trajectory, and the lengths of the flow trajectory line segments are gradually increased. According to the inducer, the anti-cavitation capacity is high, the flow resistance on the inlet side of the inducer is lower, and the inducer has high performance.

Description

Technical Field

[0001] The present application relates to the technical field of fluid machinery, and in particular to an inducer and a blade modification method of the inducer. Background Art

[0002] An inducer is an impeller used in a centrifugal pump. The inducer is installed at the front end of the centrifugal impeller to increase the pressure at the inlet of the centrifugal impeller of the centrifugal pump, thereby improving the anti-cavitation ability of the centrifugal pump. The blades of the inducer are spiral-shaped and evenly arranged along the circumference of the inducer. When the inducer rotates, the inducer is used to transport the liquid from one side to the other side along the axial direction of the inducer, that is, along the axial direction of the inducer, one side of the inducer has an inlet and the other side is an outlet. It can be understood that when the inducer rotates, the liquid flows from the inlet to the outlet side along the axial direction of the inducer.

[0003] In the related art, the anti-cavitation capability of the inducer is low, which causes cavitation of the inducer during operation and also weakens the boost performance of the inducer. Summary of the invention

[0004] Based on this, it is necessary to provide an inducer to address the problem of low anti-cavitation ability.

[0005] An inducer wheel comprises:

[0006] axle;

[0007] The blade is arranged on the wheel shaft, and the blade is a spiral shape rotating along the spiral reference trajectory line; the two side surfaces of the blade are respectively a working surface and a non-working surface, the non-working surface is provided with a guide area and a flow area, and the guide area has an initial area line and an end area line;

[0008] There are several flow trajectory segments between the initial area line and the terminal area line, and the flow trajectory segments extend along the spiral reference trajectory line. The starting point of each flow trajectory segment is located on the initial area line, and the end point of each flow trajectory segment is located on the terminal area line. Along the height direction of the blade, the height direction of the blade is perpendicular to the spiral reference trajectory line, and the lengths of several flow trajectory segments tend to gradually increase.

[0009] In one embodiment, the leading edge of the blade has an initial edge, and the initial area line is a line formed by the initial edge.

[0010] In one embodiment, the flow guide area includes a flow guide curved surface and a transition curved surface, the transition curved surface is connected between the flow guide curved surface and the flow area, the slope of the flow guide curved surface is K1, and satisfies the relationship: 0.2≤K1≤0.5.

[0011] The above-mentioned inducer, because the flow trajectory line segments of the blades extend along the spiral reference trajectory line, and along the height direction of the blades, the lengths of several flow trajectory line segments tend to gradually increase, so in the process of liquid flowing from the guide area to the flow area relative to the blades, the liquid in the initial area line at the same time can reach the terminal area line at the same time, which can also be understood as that the liquid flowing along the guide area at the same time can flow into the flow area at the same time, ensuring the flow consistency of the liquid, avoiding the cavitation phenomenon, improving the anti-cavitation ability of the inducer, and at the same time increasing the effective thrust area of ​​the inducer, and reducing the resistance of the inducer. Therefore, the inducer manufactured according to the present application has high anti-cavitation ability, and the flow resistance of the inducer on the inlet side is smaller, the internal flow field turbulence is lower, and the inducer has higher comprehensive performance.

[0012] The present application further proposes a blade shaping method based on the inducer in some of the above embodiments, and the blade shaping method comprises the following steps:

[0013] Determining the flow guide area in some of the above embodiments in the non-working surface;

[0014] The steps of determining the diversion area include:

[0015] Constructing an axial orthographic projection surface of the inducer, wherein the axial orthographic projection surface has an initial region projection line;

[0016] Constructing a plurality of concentric circles in the axial orthographic projection plane, the center of each concentric circle coincides with the axis of the inducer, the intersection of the concentric circle and the initial area projection line is the starting reference point, the initial area projection line is the projection of the initial area line in the axial orthographic projection plane, and the starting reference point is the projection of the starting point in the axial orthographic projection plane;

[0017] Constructing a connecting radial line in the axial orthographic projection plane, the connecting radial line connects the center of the concentric circle corresponding to the starting reference point;

[0018] Select the rotation angle θ;

[0019] In the circumferential direction of the axial orthographic projection surface, the connecting radial line is rotated at a rotation angle θ in a direction away from the initial area projection line to construct a corresponding deflected radial line, and the intersection of the deflected radial line and the corresponding concentric circle is the termination reference point, and the termination reference point is the projection of the termination point on the axial orthographic projection surface; multiple termination reference points are connected in sequence to form an end point area projection line, wherein two adjacent termination reference points are connected by a smooth curve segment, and the end point area projection line is the projection of the end point area line on the axial orthographic projection surface; a flow trajectory projection line segment is connected between the starting reference point and the termination reference point in the same concentric circle, the curvature of the flow trajectory projection line segment is equal to the curvature of the concentric circle, and the flow trajectory projection line segment is the projection of the flow trajectory line segment on the axial orthographic projection surface;

[0020] The projection line of the initial area and the projection line of the terminal area together constitute the projection surface of the diversion area, and the projection surface of the diversion area is the projection of the diversion area on the axial orthographic projection surface;

[0021] Grind the diversion area;

[0022] Inspect the diversion area.

[0023] In one embodiment, in the step of selecting the rotation angle θ, the length L1 of the flow trajectory projection line segment and the diameter D of the corresponding concentric circle are determined to satisfy the relationship: θ=L1 / D.

[0024] In one embodiment, the step of determining the diversion area further includes marking the diversion area, and the step of marking the diversion area includes,

[0025] Printing a projection surface of the guide area in the first cover, and attaching the first cover to the non-working surface;

[0026] Remove the portion of the first cover member that illustrates the projection surface of the flow guide area;

[0027] Alternatively, a marking tool may be used to mark along the edge of the projection surface of the diversion area.

[0028] In one embodiment, the step of determining the diversion area further includes marking the diversion area, and the step of marking the diversion area includes,

[0029] Projecting an image of a projection surface with a diversion area drawn onto a non-working surface;

[0030] The diversion area is indicated by the projection surface of the diversion area projected onto the non-working surface;

[0031] Alternatively, a marking tool may be used to mark along the edge of the projection surface of the diversion area.

[0032] In one embodiment, in the step of inspecting the flow diversion area,

[0033] Mark the flow trajectory segments;

[0034] Select at least two measuring points in the flow trajectory segment;

[0035] Measure the thickness value H2 of each measuring point, and measure the distance L2 between the measuring point and the starting point in the same flow trajectory segment;

[0036] Compare the slope values ​​K2 of multiple measuring points and satisfy the relationship: K2 = L2 / H2.

[0037] In one embodiment, in the step of marking the flow trajectory segment,

[0038] A strip-shaped through hole indicating a projection line segment of the flow trajectory is provided in the second cover, and the second cover is attached to the non-working surface;

[0039] The strip-shaped through-hole portion is used to illustrate the flow trajectory segment.

[0040] In one embodiment, in the step of marking the flow trajectory segment,

[0041] Projecting an image with flow trajectory projection line segments drawn onto a non-working surface;

[0042] The flow trajectory line segments are illustrated by the flow trajectory projection line segments projected onto the non-working surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 is a three-dimensional view of an inducer wheel from one perspective according to an embodiment of the present application.

[0044] FIG. 2 is a front view of an inducer according to an embodiment of the present application.

[0045] FIG. 3 is a top view of an inducer according to an embodiment of the present application.

[0046] FIG. 4 is a cross-sectional view taken along line AA in FIG. 3 .

[0047] FIG5 is a flow chart of a blade profiling method according to an embodiment of the present application.

[0048] FIG. 6 is a schematic diagram of an axial orthographic projection surface of an inducer according to an embodiment of the present application.

[0049] Reference numerals

[0050] 100. Inducer;

[0051] 1. Axle;

[0052] 2. Blade; 21. Working surface; 22. Non-working surface; 22a. Flow guide area; 22b. Flow area;

[0053] 23, outer edge; 23a, leading edge; 23b, trailing edge;

[0054] 10. Spiral reference trajectory;

[0055] 11a, initial area line; 11b, end area line;

[0056] 12. Flow trajectory segment; 12a. Starting point; 12b. Ending point;

[0057] 13a, initial area projection line; 13b, end area projection line;

[0058] 14. Flow trajectory projection line segment; 14a. Starting reference point; 14b. Ending reference point;

[0059] 15a, connecting radial lines; 15b, deflecting radial lines;

[0060] 16. Measurement point. DETAILED DESCRIPTION

[0061] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0062] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does 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 application.

[0063] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0065] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0067] Referring to FIGS. 1 to 4 , according to some embodiments of the present application, the inducer 100 includes an axle 1 and blades 2, and the number of blades 2 is configured to be at least two. Exemplarily, referring to FIGS. 2 to 4 , in one embodiment of the present application, the number of inducers 100 is configured to be three. The blades 2 are arranged on the axle 1, and as shown in FIG. 1 , the blades 2 are connected to the outer peripheral surface of the axle 1. It should be noted that, in some embodiments, the blades 2 and the axle 1 are integrally formed to ensure the connection strength between the blades 2 and the axle 1. A spiral reference trajectory 10 is arranged on the circumference of the axle 1, and the spiral reference trajectory 10 is extended in the axial direction and circumferential direction of the axle 1 so that the spiral reference trajectory 10 is in a spiral state on the outer peripheral surface of the axle 1, and the blades 2 are spirals rotating along the spiral reference trajectory 10.

[0068] Along the axial direction of the inducer 100 (i.e., the axial direction of the wheel shaft 1), the two side surfaces of the blade 2 are respectively a working surface 21 and a non-working surface 22. As shown in FIG. 3 to FIG. 5, the non-working surface 22 is provided with a guide area 22a and a flow area 22b, and the guide area 22a has an initial area line 11a and an end area line 11b. There are a plurality of flow trajectory segments 12 between the initial area line 11a and the end area line 11b, and the flow trajectory segments 12 extend along the spiral reference trajectory line 10. It can also be understood that in the radial direction of the inducer 100, the flow trajectory segments 12 are parallel to the spiral reference trajectory line 10, and the starting point 12a of each flow trajectory segment 12 is located on the initial area line 11a, and the end point 12b of each flow trajectory segment 12 is located on the end area line 11b. In the height direction of the blade 2, the height direction of the blade 2 is perpendicular to the spiral reference trajectory line 10, and the lengths of the plurality of flow trajectory segments 12 tend to increase gradually.

[0069] For example, referring to FIG. 1 , in one embodiment of the present application, three flow trajectory segments 12 are provided in each blade 2 for illustration, but the present application is not limited thereto, and the number of flow trajectory segments 12 provided in each blade 2 can be configured to be five, ten, or even countless. It should also be noted that the flow trajectory segments 12 mentioned above can be virtual segments, which can be understood as the flow trajectory segments 12 are not presented on the surface of the blade 2.

[0070] Exemplarily, referring to Figures 1 and 2, the blade 2 has an inner edge and an outer edge 23, wherein the inner edge of the blade 2 is connected to the outer peripheral surface of the wheel shaft 1, and the inner edge of the blade 2 extends along the spiral reference trajectory line 10, and along the extension direction of the blade 2, the outer edge 23 of the blade 2 includes a leading edge 23a and a trailing edge 23b, wherein the leading edge 23a of the blade 2 is the portion on the inlet side, and the trailing edge 23b of the blade 2 is the portion close to the outlet side, and the leading edge 23a and the trailing edge 23b are connected to form the outer edge 23 of the blade 2.

[0071] As shown in FIG. 1 to FIG. 3 , during the operation of inducer 100, inducer 100 rotates axially around its axis. Specifically, as shown in FIG. 3 , inducer 100 rotates clockwise during the operation, and leading edge 23a of blade 2 moves relative to liquid to cut the liquid, so that blade 2 guides the liquid, so that the liquid flows from the inlet side of inducer 100 to the outlet side of inducer 100 along the axial direction of inducer 100. In one embodiment, initial area line 11a is selected to coincide with leading edge 23a of blade 2, and during the flow of liquid from the inlet side to the outlet side along non-working surface 22, the liquid passes through guide area 22a and flow area 22b in sequence, so that the liquid flows from the inlet side of inducer 100 to the outlet side of inducer 100 along the axial direction of inducer 100.

[0072] As shown in FIG. 1 to FIG. 3 , during the operation of the inducer 100, when the rotation speed of the inducer 100 is constant, the number of revolutions per second of the inducer 100 as a whole is fixed. However, in the radial direction of the inducer 100 (i.e., in the direction from the inner edge of the blade 2 to the outer edge 23 of the blade 2), as the distance between the inner edge of the blade 2 and the outer edge 23 of the blade 2 gradually increases, the tangential speed of the point on the outer edge 23 of the blade 2 will also increase accordingly. This is because the tangential speed (i.e., the linear speed) is the product of the rotation speed and the radius, so as the radius increases, the tangential speed of the point on the outer edge 23 of the blade 2 will also increase accordingly. Therefore, in the process of the inducer 100 rotating and cutting the liquid, in the radial direction of the inducer 100, the closer to the outside, the greater the relative speed between the liquid and the blade 2.

[0073] Based on the above reasons, in inducer 100 according to the present application, since flow trajectory line segments 12 of blade 2 extend along spiral reference trajectory line 10, and along the width direction of blade 2 (i.e., in the direction from the inner edge of blade 2 to the outer edge 23 of blade 2), the lengths of several flow trajectory line segments 12 tend to gradually increase, so in the process of liquid flowing from guide area 22a to flow area 22b relative to blade 2, the liquid micro-element in initial area line 11a at the same time can approach and reach terminal area line 11b at the same time. It can also be understood that the liquid flowing along guide area 22a at the same time can flow into flow area 22b at the same time, ensuring that the ratio of the flow field velocity entering flow area 22b to the diameter at the location is consistent, no shear occurs in the blade height direction, and eddy and turbulent disturbances are avoided, thereby reducing cavitation, improving the anti-cavitation ability of inducer 100, and reducing the resistance of inducer 100, thereby improving the performance of inducer 100.

[0074] It should be explained that cavitation is a special physical phenomenon that occurs in liquid media, involving the generation, development and collapse of bubbles. The generation of cavitation is a dynamic process, usually accompanied by drastic changes in pressure. In the first stage of cavitation, the cavitation area is local, the cavitation is formed in the low-pressure area, and it collapses after entering the high-pressure area. In the second stage, the cavitation may form a large cavitation cavity on the upper surface of an object such as a hydrofoil or propeller, and the cavitation collapses behind the object. In the third stage, the cavitation cavity may cover the entire surface of the object, resulting in the deterioration of the fluid dynamic performance of the object. Cavitation has a significant impact on many engineering fields. In ship engineering, cavitation can cause corrosion on the propeller surface, increase resistance and reduce efficiency. In hydrofoil ship design, cavitation can deteriorate the fluid dynamic performance of the hydrofoil and even cause hull vibration and noise problems. In addition, the shock waves and microjets generated when the cavitation collapse will cause erosion damage to the metal surface. This phenomenon is called cavitation corrosion or cavitation erosion. Cavitation corrosion mainly occurs when high-speed fluid flows through metal surfaces with complex shapes, such as turbine blades, pump impellers, etc. When a blunt object cuts a liquid at high speed, it is easy to cause a sudden drop in local pressure at the shearing position, causing liquid vaporization; at the same time, it will also cause vortices and turbulence, causing the spread of cavitation, and thus affecting a large range of flow fields.

[0075] Referring to Fig. 3, in some embodiments of the present application, the leading edge 23a of the blade 2 has an initial edge, and the initial area line 11a is a line formed by the initial edge. Since the leading edge 23a is the portion of the blade 2 that starts to contact the liquid, by setting the initial edge at the leading edge 23a of the blade 2 and reducing the thickness of the blade at the leading edge 23a, the cavitation phenomenon can be more effectively reduced.

[0076] Referring to FIG. 3 and FIG. 4 , in some embodiments of the present application, the flow guide area 22a includes a flow guide surface and a transition surface, the transition surface is connected between the flow guide surface and the flow area 22b, and the slope of the flow guide surface is K1, which satisfies the relationship: 0.2≤K1≤0.5. When the inducer 100 is rotating, the liquid moves along the flow guide surface to the transition surface during the movement of the blade 2 relative to the blade 2, and then flows toward the flow area 22b. Since the flow guide surface has an angle, the thickness of the flow guide surface in the blade 2 tends to gradually increase. In this way, while ensuring the thickness of the blade 2, when the blade 2 starts to cut the liquid, the resistance of the blade 2 can be reduced, the bluntness of the inlet side edge can be reduced, the turbulent transition position can be moved closer to the inlet side position, the transition zone length is reduced, the stability of the flow field in the flow area is improved, and the performance of the inducer 100 is improved. It should be noted that, in combination with FIG3 and FIG4, K1=L / H, where L is the arc length of the guide surface in AA in FIG3, and H is the thickness of the area. Therefore, in the radial direction of inducer 100, the inclination angles of the guide surfaces at different positions are also different.

[0077] It should be noted that the transition surface is a smooth transition area between the guide surface and the flow area 22b to avoid the terminal area line 11b from forming an edge. If the terminal area line 11b is an edge, the liquid will undergo flow separation (i.e., separation from the wall) during the process of flowing through the terminal area line 11b, generating a separation vortex. The vortex close to the wall will shear the outer streamline, causing local turbulence and reducing the efficiency of the inducer 100. Therefore, according to some embodiments of the inducer 100 of the present application, a smoothly transitioned transition surface is provided between the guide surface and the flow area 22b, thereby suppressing the intensity of flow separation or increasing the critical speed of flow separation, so as to avoid the occurrence of local turbulence, thereby ensuring the efficiency of the inducer 100.

[0078] Referring to FIG. 5 , the blade shaping method of the inducer according to some of the above embodiments includes the following steps:

[0079] S1. Determine the flow guide area in some of the above embodiments in the non-working surface.

[0080] S2. Grind the diversion area.

[0081] S3. Inspect the diversion area.

[0082] Wherein, step S1 includes:

[0083] S11. Construct an axial orthographic projection surface of the inducer, wherein the axial orthographic projection surface has an initial area projection line.

[0084] S12. Construct multiple concentric circles in the axial orthographic projection plane, the center of each concentric circle coincides with the axis of the induction wheel, the intersection of the concentric circle and the initial area projection line is the starting reference point, the initial area projection line is the projection of the initial area line in the axial orthographic projection plane, and the starting reference point is the projection of the starting point in the axial orthographic projection plane.

[0085] S13. Construct a connecting radial line in the axial orthographic projection plane, wherein the connecting radial line connects the center of the concentric circle corresponding to the starting reference point.

[0086] S14, select a rotation angle θ.

[0087] S15. In the circumferential direction of the axial orthographic projection plane, the connecting radial lines are rotated at a rotation angle θ in a direction away from the projection line of the initial area to construct corresponding deflected radial lines. The intersection of the deflected radial lines and the corresponding concentric circles is the termination reference point. The termination reference point is the projection of the termination point on the axial orthographic projection plane.

[0088] S16. Connecting a plurality of terminal reference points in sequence to form a terminal area projection line, wherein two adjacent terminal reference points are connected by a smooth curve segment, and the terminal area projection line is a projection of the terminal area line on the axial orthographic projection plane.

[0089] S17, connecting the starting reference point and the ending reference point in the same concentric circle to form a flow trajectory projection line segment, the curvature of the flow trajectory projection line segment is equal to the curvature of the concentric circle, and the flow trajectory projection line segment is the projection of the flow trajectory line segment on the axial projection plane.

[0090] S18, the initial area projection line and the terminal area projection line together form a diversion area projection surface, where the diversion area projection surface is a projection of the diversion area on the axial orthographic projection surface.

[0091] According to the blade shaping method in some embodiments of the present application, the inducer 100 in some of the above-mentioned embodiments can be manufactured. The inducer 100 according to the present application can avoid the cavitation phenomenon, improve the anti-cavitation ability of the inducer 100, and at the same time increase the effective thrust area of ​​the inducer 100, and reduce the resistance of the inducer 100, thereby improving the performance of the inducer 100.

[0092] Exemplarily, referring to FIG. 6 , FIG. 6 is an axial orthographic projection surface of the inducer 100 according to an embodiment of the present application, and the axial orthographic projection surface has an initial area projection line 13a. And a plurality of concentric circles are constructed in the axial orthographic projection surface. Referring to FIG. 6 , in an embodiment of the present application, three concentric circles are constructed in the axial orthographic projection surface as an example, and the center of each concentric circle coincides with the axis of the inducer 100, and the intersection of the concentric circle and the initial area projection line 13a is the starting reference point 14a, that is, three starting reference points 14a are provided in each initial area projection line 13a. It should be noted that the initial area projection line 13a is the projection of the initial area line 11a in the axial orthographic projection surface, and the starting reference point 14a is the projection of the starting point 12a in the axial orthographic projection surface.

[0093] Then, a connecting radial line 15a is constructed in the axial orthographic projection surface, and the connecting radial line 15a is connected to the center of the concentric circle corresponding to the starting reference point 14a. Then, a rotation angle θ is selected, and in the circumferential direction of the axial orthographic projection surface, the connecting radial line 15a is rotated in a direction away from the initial area projection line 13a at the rotation angle θ to construct a corresponding deflected radial line 15b. The intersection of the deflected radial line 15b and the corresponding concentric circle is the termination reference point 14b. It should be noted that the termination reference point 14b is the projection of the termination point 12b on the axial orthographic projection surface.

[0094] In addition, a flow trajectory projection line segment 14 is connected between the starting reference point 14a and the ending reference point 14b in the same concentric circle. It should be noted that the curvature of the flow trajectory projection line segment 14 is equal to the curvature of the concentric circle, and the flow trajectory projection line segment 14 is the projection of the flow trajectory line segment 12 on the axial orthographic projection surface. The initial area projection line 13a and the end area projection line 13b together constitute the diversion area projection surface, which is the projection of the diversion area 22a on the axial orthographic projection surface.

[0095] It should be noted that, in the above-mentioned embodiment, three concentric circles are constructed in the axial orthographic projection plane for explanation, but the present application is not limited to this. The number of concentric circles constructed in the axial orthographic projection plane is at least two, and the number of concentric circles can be configured to be ten, twenty, fifty, or even countless.

[0096] In some embodiments of the present application, in combination with FIG. 6 , in the step of selecting the rotation angle θ, the length L1 of the flow trajectory projection line segment 14 and the diameter D of the corresponding concentric circle are determined to satisfy the relationship: θ=L1 / D.

[0097] In some embodiments of the present application, in combination with FIG. 3 , the step of determining the guide area 22a also includes marking the guide area 22a, and the step of marking the guide area 22a includes printing the guide area projection surface in the first cover, and attaching the first cover to the non-working surface 22, and then removing the portion of the first cover that indicates the guide area projection surface, or using a marking tool to mark along the edge of the guide area projection surface, thereby marking the guide area 22a portion in the non-working surface 22, so that the operator can grind the non-working surface 22 to form the guide area 22a. Exemplarily, the first cover can be a transparent film.

[0098] In some other embodiments of the present application, in combination with FIG. 3 , the step of marking the guide area 22a includes projecting an image with a guide area projection surface drawn onto the non-working surface 22. The guide area 22a is indicated by the guide area projection surface projected onto the non-working surface 22, or a marking tool is used to mark along the edge of the guide area projection surface. Thereby, a portion of the guide area 22a is marked on the non-working surface 22, so that the operator can grind the non-working surface 22 to form the guide area 22a. Exemplarily, the image of the guide area projection surface can be projected onto the non-working surface 22 by laser projection, and the marking tool can be a pen, a carving knife, or other tools that can be used to mark on the non-working surface 22.

[0099] In some embodiments of the present application, as shown in FIG3 , the step of inspecting the flow guide area 22a includes first marking the flow trajectory segment 12, then selecting at least two measuring points 16 in the flow trajectory segment 12, and measuring the thickness value H2 of each measuring point 16, and measuring the distance L2 between the measuring point 16 and the starting point 12a in the same flow trajectory segment 12, and comparing the slope values ​​K2 of multiple measuring points 16, where the relationship is satisfied: K2 = L2 / H2. If the slope values ​​K2 of each measuring point 16 are the same value, it means that the flow guide area 22a is a smooth surface, and preferably, after inspection, K2 = K1.

[0100] In some embodiments of the present application, in conjunction with FIG. 3 , in the step of marking the flow trajectory line segment 12, a strip-shaped through hole indicating the flow trajectory projection line segment 14 is provided in the second cover, and the second cover is attached to the non-working surface 22 so that the strip-shaped through hole portion is used to indicate the flow trajectory line segment 12, thereby marking the flow trajectory line segment 12 in the non-working surface 22, so that the operator can select the measurement point 16 in the flow trajectory line segment 12 in the guide area 22a. Exemplarily, the second cover can be a transparent film.

[0101] In some other embodiments of the present application, as shown in FIG3 , in the step of marking the flow trajectory segment 12, an image with the flow trajectory projection segment 14 drawn is projected onto the non-working surface 22, and the flow trajectory projection segment 14 projected onto the non-working surface 22 indicates the flow trajectory segment 12, thereby marking the flow trajectory segment 12 in the non-working surface 22, so that the operator can select the measurement point 16 in the flow trajectory segment 12 in the diversion area 22a. Exemplarily, the image of the diversion area projection surface can be projected onto the diversion area 22a by laser projection, and the marking tool can be a pen or other tool that can mark in the diversion area 22a.

[0102] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0103] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. An inducer, characterized in that: include: axle; A blade, wherein the blade is arranged on the wheel shaft, and the blade is a spiral shape rotating along a spiral reference trajectory line; two side surfaces of the blade are respectively a working surface and a non-working surface, and the non-working surface is provided with a guide area and a flow area, and the guide area has an initial area line and an end area line; There are several flow trajectory segments between the initial area line and the terminal area line, and the flow trajectory segments extend along the spiral reference trajectory line. The starting point of each flow trajectory segment is located on the initial area line, and the ending point of each flow trajectory segment is located on the terminal area line, wherein along the height direction of the blade, the height direction of the blade is perpendicular to the spiral reference trajectory line, and the lengths of several flow trajectory segments tend to gradually increase.

2. The inducer according to claim 1, characterized in that: The leading edge of the blade has an initial edge, and the initial area line is a line formed by the initial edge.

3. The inducer according to claim 1 or 2, characterized in that: The flow guide area includes a flow guide curved surface and a transition curved surface. The transition curved surface is connected between the flow guide curved surface and the flow area. The slope of the flow guide curved surface is K1, which satisfies the relationship: 0.2≤K1≤0.

5.

4. A blade modification method for an inducer according to any one of claims 1 to 3, characterized in that: The following steps are involved: Determine a flow guide area according to any one of claims 1 to 3 in the non-working surface; The step of determining the diversion area includes: Constructing an axial orthographic projection surface of the induction wheel, wherein the axial orthographic projection surface has an initial area projection line; Constructing a plurality of concentric circles in the axial orthographic projection plane, the center of each of the concentric circles coincides with the axis of the induction wheel, the intersection of the concentric circles and the initial area projection line is the starting reference point, the initial area projection line is the projection of the initial area line in the axial orthographic projection plane, and the starting reference point is the projection of the starting point in the axial orthographic projection plane; Constructing a connecting radial line in the axial orthographic projection plane, wherein the connecting radial line connects the centers of the concentric circles corresponding to the starting reference point; Select the rotation angle θ; In the circumferential direction of the axial orthographic projection surface, the connecting radial line rotates at the rotation angle θ in a direction away from the initial area projection line to construct a corresponding deflected radial line, and the intersection of the deflected radial line and the corresponding concentric circle is a termination reference point, and the termination reference point is the projection of the termination point on the axial orthographic projection surface; a plurality of termination reference points are sequentially connected to form an end-point area projection line, wherein two adjacent termination reference points are connected by a smooth curve segment, and the end-point area projection line is the projection of the end-point area line on the axial orthographic projection surface; a flow trajectory projection line segment is connected between the starting reference point and the termination reference point in the same concentric circle, the curvature of the flow trajectory projection line segment is equal to the curvature of the concentric circle, and the flow trajectory projection line segment is the projection of the flow trajectory line segment on the axial orthographic projection surface; The initial area projection line and the terminal area projection line together constitute a diversion area projection surface, and the diversion area projection surface is a projection of the diversion area on the axial orthographic projection surface; grinding the flow guide area; The flow guide area is inspected.

5. The blade shaping method according to claim 4, characterized in that: In the step of selecting the rotation angle θ, the length L1 of the flow trajectory projection line segment and the corresponding diameter D of the concentric circle are determined to satisfy the relationship: θ=L1 / D.

6. The blade shaping method according to claim 4 or 5, characterized in that: The step of determining the diversion area also includes marking the diversion area, and the step of marking the diversion area includes: Printing the diversion area projection surface in the first cover member, and attaching the first cover member to the non-working surface; Removing a portion of the first cover member that illustrates a projection surface of the flow guide area; Alternatively, a marking tool is used to mark along the edge of the projection surface of the guide area.

7. The blade shaping method according to claim 4 or 5, characterized in that: The step of determining the diversion area also includes marking the diversion area, and the step of marking the diversion area includes: Projecting an image with the projection surface of the diversion area drawn onto the non-working surface; The flow guide area is illustrated by a projection surface of the flow guide area projected onto the non-working surface; Alternatively, a marking tool is used to mark along the edge of the projection surface of the guide area.

8. The blade shaping method according to claim 4 or 5, characterized in that: In the step of inspecting the diversion area, marking the flow trajectory segment; Selecting at least two measurement points in the flow trajectory segment; Measuring the thickness value H2 of each measuring point, and measuring the distance L2 between the measuring point and the starting point in the same flow trajectory segment; Comparing the slope values ​​K2 of the plurality of measuring points, the relationship is satisfied: K2 = L2 / H2.

9. The blade shaping method according to claim 8, characterized in that: In the step of marking the flow trajectory segment, A strip-shaped through hole indicating the projection line segment of the flow trajectory is provided in the second cover, and the second cover is attached to the non-working surface; The strip-shaped through-hole portion is used to illustrate the flow trajectory segment.

10. The blade shaping method according to claim 8, characterized in that: In the step of marking the flow trajectory segment, Projecting an image with the flow trajectory projection line segments drawn onto the non-working surface; The flow trajectory line segment is illustrated by the flow trajectory projection line segment projected onto the non-working surface.

Images