Processing method of non-axisymmetric wheel disc surface and fillet and impeller

Abstract

The present application provides a method for machining a non-axisymmetric disk surface and fillet, and an impeller, comprising: performing a cutting operation from the impeller inlet side to the outlet side according to the streamline from L1 to L2 to obtain a long fillet on the main blade pressure surface; performing a cutting operation from the impeller inlet side to the outlet side according to the streamline from L3 to L4 to obtain a long fillet on the main blade suction surface; performing a cutting operation from the impeller inlet side to the outlet side according to the streamline from L5 to L6 to obtain a short fillet on the splitter blade pressure surface; performing a cutting operation from the impeller inlet side to the outlet side according to the streamline from L7 to L8 to obtain a short fillet on the splitter blade suction surface; obtaining a first reference disk surface tool tip machining trajectory, and adding the non-axisymmetric disk surface as an additional curved surface to obtain a non-axisymmetric disk surface. This method realizes the machining and manufacturing of impellers with non-axisymmetric disk surfaces, paving the way for the application of impellers with non-axisymmetric disk surfaces.

Description

Technical Field

[0001] The present application belongs to the technical field of centrifugal pump impeller processing and manufacturing, and specifically relates to a processing method and impeller for non-axisymmetric wheel disc surface and fillet. Background Art

[0002] Centrifugal compressors, as a type of rotary machine that uses fluid as a working medium to achieve functional conversion, are widely used in fields such as petrochemicals, metallurgy, civil air conditioning, and aerospace. Improvements in their performance can often bring considerable economic benefits. As the core component of a centrifugal compressor, the spatial geometry of the centrifugal impeller will affect the flow conditions of the working medium inside it, which often determines the upper limit of the machine's performance. There is currently a semi-open centrifugal impeller with a freely concave and convex wheel surface and splitter blades, collectively referred to as a non-axisymmetric wheel surface impeller. This type of impeller is concave near the air inlet, which is beneficial for improving maximum efficiency and increasing blockage flow. The convexity near the splitter flow channel on the pressure side of the air outlet is beneficial for improving maximum efficiency, but it will reduce the impeller's pressure ratio. This type of impeller has broad application prospects in improving the efficiency of turbine compressor units.

[0003] The non-axisymmetric impeller disc structure differs from conventional designs. The disc surface between its two main blades is composed of three free-form surfaces, evenly distributed around the circumference according to the number of main blades. The disc surface between blades alters the direction and velocity of gas flow on both the suction and pressure sides of the blades, requiring a smoother disc surface. Because both the blades and disc are free-form surfaces during machining, rounding the corners at their intersection is challenging. Consequently, existing three-dimensional impeller machining methods are no longer sufficient for machining non-axisymmetric impeller discs. Summary of the Invention

[0004] Therefore, the technical problem to be solved by this application is to provide a method and impeller for processing non-axisymmetric disc surfaces and fillets, which can meet the processing requirements of disc surfaces and fillets in impellers with non-axisymmetric disc surfaces, and pave the way for the application of impellers with non-axisymmetric disc surfaces.

[0005] In order to solve the above problems, the first aspect of the present application provides a method for processing a non-axisymmetric wheel disc surface and fillet, comprising:

[0006] Finishing the main blade pressure surface long fillet, suction surface long fillet and splitter blade pressure surface short fillet and suction surface short fillet

[0007] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L1; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L2; and the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain the tool center trajectory for machining the long fillet of the main blade pressure surface;

[0008] Among them, during the tool-feeding process, the pressure surface of the main blade is selected as the machining surface, and the non-axisymmetric wheel surface and the suction surface of the splitter blade are selected as the stopping surfaces;

[0009] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; and the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain the tool center trajectory for machining the long fillet of the main blade suction surface;

[0010] Among them, during the tool-feeding process, the suction surface of the main blade is selected as the processing surface, and the non-axisymmetric wheel surface and the pressure surface of the splitter blade are selected as the stopping surface.

[0011] The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L6; and the tool is moved from the impeller inlet side to the outlet side according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface.

[0012] Among them, during the tool-feeding process, the pressure surface of the splitter blade is selected as the machining surface, and the non-axisymmetric wheel surface and the adjacent main blade suction surface are selected as the stopping surface;

[0013] The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L7; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L8; the tool is moved from the impeller inlet side to the outlet side according to the streamline from L7 to L8 to obtain the tool center trajectory for machining the short fillet of the splitter blade suction surface;

[0014] Among them, during the tool-feeding process, the suction surface of the splitter blade is selected as the machining surface, and the non-axisymmetric wheel surface and the adjacent main blade pressure surface are selected as the stopping surface;

[0015] Finishing of non-axisymmetric wheel disc surfaces

[0016] The tool tip machining trajectory of the first reference disc surface is obtained. Based on the first reference disc surface tool tip machining trajectory, the non-axisymmetric disc surface is added as an additional surface. The tool is moved from the air inlet side to the air outlet side of the impeller to obtain the tool tip machining trajectory of the non-axisymmetric disc surface.

[0017] Optionally, the first reference disc surface is selected by taking the extension line of the root line of the neutral plane of the main blade as the disc line, and rotating the disc line to generate an initial disc surface; the initial disc surface is offset along the normal phase toward the side of the impeller without blades, and the offset distance is the normal phase distance H from the concave part of the non-axisymmetric disc surface to the initial disc surface, to obtain the first reference disc surface.

[0018] Optionally, the first offset surface of the non-axisymmetric disk surface is selected by offsetting the non-axisymmetric disk surface along the normal phase toward the impeller blade side with an offset distance of M to obtain the first offset surface of the non-axisymmetric disk surface;

[0019] The offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface to the initial wheel surface, and the normal distance H from the concave part of the non-axisymmetric wheel surface to the initial wheel surface.

[0020] The second offset surface of the non-axisymmetric disk surface is selected by offsetting the non-axisymmetric disk surface along the normal phase toward the impeller blade side with an offset distance of R1 to obtain the second offset surface of the non-axisymmetric disk surface;

[0021] Among them, the offset distance R1 is the finishing tool radius R.

[0022] Optionally, the main blade pressure surface offset surface is selected by offsetting the main blade pressure surface along the normal phase toward the splitter blade with an offset distance of R2 to obtain the main blade pressure surface offset surface;

[0023] The main blade suction surface offset surface is selected by offsetting the main blade suction surface along the normal phase toward the splitter blade with an offset distance of R3 to obtain the main blade suction surface offset surface;

[0024] Among them, the offset distance R2 and the offset distance R3 are both the finishing tool radius R.

[0025] Optionally, the offset surface of the splitter blade pressure surface is selected by offsetting the splitter blade pressure surface along the normal phase toward the main blade with an offset distance of R4 to obtain the offset surface of the splitter blade pressure surface;

[0026] The offset surface of the pressure surface of the splitter blade is selected by shifting the suction surface of the splitter blade along the normal phase toward the main blade with an offset distance of R5 to obtain the offset surface of the pressure and suction surface of the splitter blade;

[0027] Among them, the offset distance R4 and the offset distance R5 are both the finishing tool radius R.

[0028] Optionally, before finishing the long fillet of the pressure surface and the long fillet of the suction surface of the main blade and the short fillet of the pressure surface and the short fillet of the suction surface of the splitter blade, the following steps may be further included:

[0029] Obtain a three-dimensional model of the impeller;

[0030] Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool;

[0031] Constructing the machining model of the impeller

[0032] Select the main blades, splitter blades and the first reference wheel disc surface component impeller processing model in the impeller three-dimensional model;

[0033] Rough machining of main blades and splitter blades;

[0034] Finishing of main blades and splitter blades.

[0035] Optionally, the steps of selecting a non-axisymmetric disc surface finishing tool and a fillet finishing tool include:

[0036] The non-axisymmetric disc surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

[0037] Optional, non-axisymmetric disc surface finishing tools and fillet finishing tools are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size. Steps include:

[0038] Perform curvature analysis on the non-axisymmetric disk surface in the impeller 3D model to obtain the minimum radius of the concave area. If the minimum radius of the concave area is smaller than the blade fillet marked on the impeller design drawing, select the finishing tool based on the minimum radius of the concave area.

[0039] When the minimum radius value of the concave area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

[0040] Optionally, the step of finishing the main blades and splitter blades includes:

[0041] The initial disk surface is shifted along the normal phase toward the impeller blade side, and the shift distance is the normal phase distance h from the convex part of the non-axisymmetric disk surface to the initial disk surface, to obtain a second reference disk surface;

[0042] The machining depth of the finishing main blades and splitter blades is from the wheel cover surface to the second reference wheel disc surface.

[0043] A second aspect of the present application provides an impeller, which is manufactured using any of the above-mentioned methods for processing the non-axisymmetric wheel disc surface and fillet.

[0044] Beneficial effects

[0045] The embodiment of the present application provides a method for processing a non-axisymmetric wheel disc surface and a fillet, wherein the offset surface of the pressure surface of the main blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines L1 and L2; the offset surface of the suction surface of the main blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines L3 and L4; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines L5 and L6; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines ...7 and L8; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines L8 and L9; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface respectively to obtain intersection lines L9 and L10. The offset surface of the suction surface intersects with the first offset surface of the non-axisymmetric disc surface and the second offset surface of the non-axisymmetric disc surface respectively, obtaining intersection lines L7 and L8; according to the streamlines L1 and L2, L3 and L4, L5 and L6, and L7 and L8 respectively, the tool is moved from the air inlet side to the air outlet side of the impeller to machine the long fillet of the pressure surface and suction surface of the main blade to divert the short fillet of the pressure surface and suction surface of the blade; on the basis of the tool tip machining trajectory of the first reference disc surface, the non-axisymmetric disc surface is added as an additional curved surface, and the tool is moved from the air inlet side to the air outlet side of the impeller to machine the non-axisymmetric disc surface. The present application solves the processing problems of the disc surface and fillet of the non-axisymmetric disc surface impeller, realizes the machining and manufacturing of the non-axisymmetric disc surface impeller, and paves the way for the application of the non-axisymmetric disc surface impeller. Compared with other impeller machining methods that cannot complete the machining and manufacturing of non-axisymmetric disc surface impellers, the present application has achieved it from scratch. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the wheel disc surface and fillet processing method according to an embodiment of the present application;

[0047] Figure 2 Schematic diagram of a non-axisymmetric semi-open centrifugal impeller with splitter blades according to an embodiment of the present application;

[0048] Figure 3 This is an end view of a non-axisymmetric semi-open centrifugal impeller with splitter blades according to an embodiment of the present application;

[0049] Figure 4 This is a schematic diagram of the blade processing area according to an embodiment of the present application;

[0050] Figure 5 Schematic diagram of the long fillet processing area on the pressure surface of the main blade in an embodiment of the present application;

[0051] Figure 6 Schematic diagram of the long rounded corner processing area of ​​the main blade suction surface in an embodiment of the present application;

[0052] Figure 7 Schematic diagram of the short fillet processing area on the pressure surface of the splitter blade in an embodiment of the present application;

[0053] Figure 8Schematic diagram of the short fillet processing area of ​​the splitter blade suction surface in an embodiment of the present application;

[0054] Figure 9 This is a schematic diagram of the tool tip machining trajectory of the first reference wheel disc surface in an embodiment of the present application;

[0055] Figure 10 Schematic diagram of the tool tip machining trajectory of the non-axisymmetric wheel disc surface according to an embodiment of the present application.

[0056] The reference numerals indicate:

[0057] 1. Main blade, 2. Splitter blade, 3. First reference disc surface, 4. Main blade pressure surface, 5. Non-axisymmetric disc surface, 6. Splitter blade suction surface, 7. Splitter blade pressure surface, 8. Main blade suction surface, 9. Initial disc surface, 10. First offset surface of non-axisymmetric disc surface, 11. Second reference disc surface, 12. Blade machinable area, 13. Blade non-machinable area. DETAILED DESCRIPTION

[0058] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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 should not be understood as limiting the present invention.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0060] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0061] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0062] See also Figures 1 to 4 As shown, according to an embodiment of the present application, a method for processing a non-axisymmetric wheel disc surface and fillet is provided, which is used to process and manufacture an impeller with a non-axisymmetric wheel disc.

[0063] Among them, the impeller includes an impeller cover body, on which a plurality of main blades 1 and splitter blades 2 are arranged circumferentially, and the main blades 1 and the splitter blades 2 are arranged alternately; the main blades 1 and the splitter blades 2 are curved surface structures, the outer convex surface of the main blade 1 is the main blade pressure surface 4, and the inner concave surface is the main blade suction surface 8, the outer convex surface of the splitter blade 2 is the splitter blade pressure surface 7, and the inner concave surface is the splitter blade suction surface 8, and the surface of the impeller cover body on which the main blades 1 and the splitter blades 2 are arranged is a non-axisymmetric wheel disc surface 5.

[0064] Processing methods, including:

[0065] Step S1: Finishing the fillet of the main blade pressure surface

[0066] like Figure 5 As shown, the intersection line L1 is obtained by intersecting the first offset surface of the non-axisymmetric disk surface with the offset surface of the main blade pressure surface; the intersection line L2 is obtained by intersecting the second offset surface of the non-axisymmetric disk surface with the offset surface of the main blade pressure surface; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain the tool center trajectory for machining the long fillet of the main blade pressure surface;

[0067] During the tool-feeding process, the main blade pressure surface 4 is selected as the processing surface, and the non-axisymmetric wheel surface 5 and the splitter blade suction surface 6 are selected as the stop surfaces.

[0068] Step S2: Fine-machining the long fillet of the suction surface of the main blade

[0069] like Figure 6 As shown, the intersection line L3 is obtained by intersecting the first offset surface of the non-axisymmetric disk surface with the offset surface of the main blade suction surface; the intersection line L4 is obtained by intersecting the second offset surface of the non-axisymmetric disk surface with the offset surface of the main blade suction surface; and the tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain the tool center trajectory for machining the long fillet of the main blade suction surface;

[0070] During the tool-feeding process, the suction surface 8 of the main blade is selected as the processing surface, and the non-axisymmetric wheel surface 5 and the pressure surface 7 of the splitter blade are selected as the stopping surfaces.

[0071] Step S3: Finishing the short fillet of the pressure surface of the splitter blade

[0072] like Figure 7As shown, the intersection line L5 is obtained by intersecting the first offset surface of the non-axisymmetric disk surface with the offset surface of the splitter blade pressure surface; the intersection line L6 is obtained by intersecting the second offset surface of the non-axisymmetric disk surface with the offset surface of the splitter blade pressure surface; and the tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface;

[0073] During the tool-feeding process, the pressure surface 7 of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel surface 5 and the adjacent main blade suction surface 8 are selected as the stopping surfaces.

[0074] Step S4: Finishing the short fillet of the suction surface of the splitter blade

[0075] like Figure 8 As shown, the intersection line L7 is obtained by intersecting the first offset surface of the non-axisymmetric disk surface with the offset surface of the splitter blade suction surface; the intersection line L8 is obtained by intersecting the second offset surface of the non-axisymmetric disk surface with the offset surface of the splitter blade suction surface; and the tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L7 to L8 to obtain the tool center trajectory for machining the short fillet of the splitter blade suction surface;

[0076] During the tool-feeding process, the suction surface 6 of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel surface 5 and the adjacent main blade pressure surface 4 are selected as the stopping surfaces;

[0077] Step S5, finishing the non-axisymmetric wheel surface 5

[0078] like Figure 9 and Figure 10 As shown, the tool tip machining trajectory of the first reference disc surface 3 is obtained. On the basis of the tool tip machining trajectory of the first reference disc surface 3, the non-axisymmetric disc surface 5 is added as an additional surface, and the tool movement is performed from the air inlet side to the air outlet side of the impeller to obtain the tool tip machining trajectory of the non-axisymmetric disc surface.

[0079] The offset surface of the main blade pressure surface intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L1 and L2; the offset surface of the main blade suction surface intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L3 and L4; the offset surface of the splitter blade pressure surface intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L5 and L6; the offset surface of the splitter blade suction surface intersects with the non-axisymmetric disk surface, respectively, to obtain intersection lines L6. The first offset surface of the disc surface and the second offset surface of the non-axisymmetric disc surface intersect to obtain intersection lines L7 and L8; according to the streamlines L1 and L2, L3 and L4, L5 and L6, and L7 and L8, respectively, the tool is moved from the air inlet side to the air outlet side of the impeller to machine the long fillets of the pressure surface and suction surface of the main blade to divert the short fillets of the pressure surface and suction surface of the blade; on the basis of the tool tip machining trajectory of the first reference disc surface 3, the non-axisymmetric disc surface 5 is added as an additional curved surface, and the tool is moved from the air inlet side to the air outlet side of the impeller to machine the non-axisymmetric disc surface 5. The present application solves the processing problems of the disc surface and fillets of the non-axisymmetric disc surface impeller, realizes the machining and manufacturing of the non-axisymmetric disc surface impeller, and paves the way for the application of the non-axisymmetric disc surface impeller. Compared with other impeller machining methods that cannot complete the machining and manufacturing of non-axisymmetric disc surface impellers, the present application has achieved it from scratch.

[0080] The method of the present application also has the advantages of reducing processing difficulty, improving processing accuracy and processing efficiency.

[0081] In an embodiment of the present application, an intersection line L1 is obtained by intersecting the first offset surface of the non-axisymmetric disc surface with the offset surface of the main blade pressure surface; an intersection line L2 is obtained by intersecting the second offset surface of the non-axisymmetric disc surface with the offset surface of the main blade pressure surface; a tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain a tool center trajectory for machining the long fillet of the main blade pressure surface; during the tool path, the main blade pressure surface 4 is selected as the machining curved surface, and the non-axisymmetric disc surface 5 and the splitter blade suction surface 6 are selected as the stop curved surface, including the following steps:

[0082] Step S11, selecting the first offset surface of the non-axisymmetric disc surface, shifting the non-axisymmetric disc surface 5 along the normal phase toward the impeller blade side, with the offset distance being M, to obtain the first offset surface 10 of the non-axisymmetric disc surface;

[0083] The offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface 5 to the initial wheel surface 9, and the normal distance H from the concave part of the non-axisymmetric wheel surface 5 to the initial wheel surface 9.

[0084] Step S12, selecting the second offset surface of the non-axisymmetric disc surface, shifting the non-axisymmetric disc surface 5 along the normal phase toward the impeller blade side by a distance of R1, to obtain the second offset surface of the non-axisymmetric disc surface;

[0085] Among them, the offset distance R1 is the finishing tool radius R.

[0086] Step S13, selecting the offset surface of the main blade pressure surface, shifting the main blade pressure surface 4 along the normal phase toward the splitter blade 2 by a distance of R2, and obtaining the offset surface of the main blade pressure surface;

[0087] Among them, the offset distance R2 is the finishing tool radius R.

[0088] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; a tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain a tool center trajectory for machining the long fillet of the main blade suction surface; during the tool path machining, the main blade suction surface 8 is selected as the machining surface, and the non-axisymmetric disk surface 5 and the splitter blade pressure surface 7 are selected as the stop surfaces, including the following steps:

[0089] Step S21, selecting the offset surface of the main blade suction surface, offsetting the main blade suction surface 8 along the normal phase toward the splitter blade 2 by a distance of R3, and obtaining the offset surface of the main blade suction surface;

[0090] Among them, the offset distance R3 is the finishing tool radius R.

[0091] The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L6; a tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6 to obtain a tool center trajectory for machining the short fillet of the splitter blade pressure surface; during the tool path machining, the splitter blade pressure surface 7 is selected as the machining curved surface, and the non-axisymmetric disk surface 5 and the adjacent main blade suction surface 8 are selected as the stop curved surfaces, including the following steps:

[0092] Step S31, selecting the offset surface of the splitter blade pressure surface, offsetting the splitter blade pressure surface 7 along the normal phase toward the main blade 1, the offset distance is R4, and obtaining the splitter blade pressure surface offset surface; wherein the offset distance R4 is the finishing tool radius R.

[0093] The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L7; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L8; and a tool path is performed from the air inlet side to the air outlet side of the impeller according to the streamline from L7 to L8 to obtain a tool center trajectory for machining the short fillet of the splitter blade suction surface. During the tool path machining, the splitter blade suction surface 6 is selected as the machining curved surface, and the non-axisymmetric disk surface 5 and the adjacent main blade pressure surface 4 are selected as the stop curved surfaces, including the following steps:

[0094] Step S41, selecting the offset surface of the splitter blade pressure surface, offsetting the splitter blade suction surface 6 along the normal phase toward the main blade 1 by a distance of R5, and obtaining the splitter blade pressure-suction surface offset surface; wherein the offset distance R5 is the finishing tool radius R.

[0095] The steps of obtaining a tool tip machining trajectory of the first reference disc surface 3, adding the non-axisymmetric disc surface 5 as an additional curved surface based on the tool tip machining trajectory of the first reference disc surface 3, and performing tool movement from the impeller air inlet side to the air outlet side to obtain the tool tip machining trajectory of the non-axisymmetric disc surface include:

[0096] Step S51, selecting the initial wheel disc surface, using the extension line of the main blade neutral surface root line as the wheel disc line, and rotating the wheel disc line to generate the initial wheel disc surface 9;

[0097] Step S52, selecting the first reference disc surface 3, shifting the initial disc surface 9 along the normal phase toward the side of the impeller without blades, the shifting distance being the normal phase distance H from the concave part of the non-axisymmetric disc surface 5 to the initial disc surface 9, to obtain the first reference disc surface 3.

[0098] The embodiment of the present application provides a more specific processing method, which, before the step of fine-machining the long fillet of the main blade and the short fillet of the splitter blade, also includes:

[0099] Obtain a three-dimensional model of the impeller;

[0100] The pre-designed impeller 3D model is imported into the CAM-assisted processing software hyperCAD-S through the data interface.

[0101] Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool;

[0102] The non-axisymmetric disc surface finishing tools and fillet finishing tools are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

[0103] The curvature analysis of the non-axisymmetric disk surface in the impeller 3D model was performed to obtain the minimum radius of the concave area.

[0104] When the minimum radius of the concave area is smaller than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the minimum radius of the concave area;

[0105] When the minimum radius value of the concave area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

[0106] Among them, the wheel surface finishing tool and the fillet finishing tool are both ball-end cutters.

[0107] Among them, when finishing the long fillet of the main blade pressure surface, finishing the long fillet of the main blade suction surface, finishing the long fillet of the splitter blade pressure surface and finishing the long fillet of the splitter blade suction surface, the tool center spacing of each cut is one tenth of the finishing tool radius R.

[0108] Constructing the machining model of the impeller

[0109] Select the impeller processing model of the main blade 1, the splitter blade 2 and the first reference wheel disc surface 3 components in the impeller three-dimensional model;

[0110] The initial wheel disc surface 9 is shifted along the normal phase toward the impeller without blades. The shift distance is the normal phase distance H from the concave part of the non-axisymmetric wheel disc surface 5 to the initial wheel disc surface 9 to obtain the first reference wheel disc surface 3.

[0111] By building a processing model of the impeller and selecting a ball-end cutter, the tool center processing trajectory of the main blade 1 and the splitter blade 2, as well as the tool tip processing trajectory of the first reference disc surface, can be generated through the CAM-assisted processing software hyperCAD-S.

[0112] Rough machining of main blade 1 and splitter blade 2;

[0113] The main blades 1 and the splitter blades 2 may be rough-machined by fixed-axis high-speed milling. In other embodiments, they may also be rough-machined by cycloid machining and strip milling.

[0114] Finishing the main blade 1 and the splitter blade 2;

[0115] The initial wheel disc surface 9 is shifted along the normal phase toward the impeller blade side, and the shift distance is the normal phase distance h from the convex part of the non-axisymmetric wheel disc surface 5 to the initial wheel disc surface 9, to obtain a second reference wheel disc surface 11;

[0116] The CAM-assisted processing software hyperCAD-S can generate the tool center processing trajectory of the main blade 1 and the splitter blade 2. During processing, the tool is moved from the air inlet side to the air outlet side of the impeller, and the processing depth is from the wheel cover surface to the second reference wheel disc surface 11.

[0117] In a second aspect, the present application provides an impeller, which is manufactured using any of the above-mentioned methods for machining a non-axisymmetric wheel disc surface and fillet. The impeller manufactured using the method of the present application has the advantage of higher precision.

[0118] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0119] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A method for processing non-axisymmetric wheel disc surface and fillet, characterized in that: include: Finishing the fillet of the main blade pressure surface The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L1; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L2; and the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain the tool center trajectory for machining the long fillet of the main blade pressure surface; During the tool-feeding process, the main blade pressure surface (4) is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the splitter blade suction surface (6) are selected as the stop surfaces; Fine machining of the main blade suction surface fillet The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; and the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain the tool center trajectory for machining the long fillet of the main blade suction surface; During the tool-feeding process, the main blade suction surface (8) is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the splitter blade pressure surface (7) are selected as the stop surfaces. Finishing the short fillet of the pressure surface of the splitter blade The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade pressure surface to obtain an intersection line L6; and the tool is moved from the impeller inlet side to the outlet side according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface. During the cutting process, the pressure surface (7) of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the adjacent main blade suction surface (8) are selected as the stopping surfaces; Finishing the short fillet of the suction surface of the splitter blade The first offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L7; the second offset surface of the non-axisymmetric disk surface intersects the offset surface of the splitter blade suction surface to obtain an intersection line L8; the tool is moved from the impeller inlet side to the outlet side according to the streamline from L7 to L8 to obtain the tool center trajectory for machining the short fillet of the splitter blade suction surface; During the cutting process, the suction surface (6) of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the adjacent main blade pressure surface (4) are selected as the stopping surfaces; Finishing of non-axisymmetric wheel disc surface(5) A tool tip machining trajectory of a first reference wheel disc surface (3) is obtained. Based on the tool tip machining trajectory of the first reference wheel disc surface (3), a non-axisymmetric wheel disc surface (5) is added as an additional curved surface, and tool movement is performed from the air inlet side to the air outlet side of the impeller to obtain a tool tip machining trajectory of the non-axisymmetric wheel disc surface.

2. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The first reference disc surface is selected by taking the extension line of the main blade neutral surface root line as the disc line, rotating the disc line to generate an initial disc surface (9); the initial disc surface (9) is offset along the normal phase toward the side of the impeller without blades, and the offset distance is the normal phase distance H from the concave part of the non-axisymmetric disc surface (5) to the initial disc surface (9), thereby obtaining the first reference disc surface (3).

3. The method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The first offset surface of the non-axisymmetric wheel disc surface is selected by offsetting the non-axisymmetric wheel disc surface (5) along the normal phase toward the side of the impeller blades by an offset distance of M, thereby obtaining the first offset surface (10) of the non-axisymmetric wheel disc surface; Wherein, the offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface (5) to the initial wheel surface (9), and the normal distance H from the concave part of the non-axisymmetric wheel surface (5) to the initial wheel surface (9); The second offset surface of the non-axisymmetric wheel disc surface is selected by offsetting the non-axisymmetric wheel disc surface (5) along the normal phase toward the impeller blade side with an offset distance of R1 to obtain the second offset surface of the non-axisymmetric wheel disc surface; Among them, the offset distance R1 is the finishing tool radius R.

4. The method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The main blade pressure surface offset surface is selected by offsetting the main blade pressure surface (4) along the normal phase toward the splitter blade (2) by a distance of R2 to obtain the main blade pressure surface offset surface; The main blade suction surface offset surface is selected by offsetting the main blade suction surface (8) along the normal phase toward the splitter blade (2) by a distance of R3 to obtain the main blade suction surface offset surface; Among them, the offset distance R2 and the offset distance R3 are both the finishing tool radius R.

5. The method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The offset surface of the splitter blade pressure surface is selected by shifting the splitter blade pressure surface (7) along the normal phase toward the main blade (1) with a shift distance of R4 to obtain the offset surface of the splitter blade pressure surface; The offset surface of the pressure surface of the splitter blade is selected by shifting the suction surface (6) of the splitter blade in the normal direction toward the main blade (1) by a distance of R5, thereby obtaining the offset surface of the pressure and suction surface of the splitter blade; Among them, the offset distance R4 and the offset distance R5 are both the finishing tool radius R.

6. The method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: Before finishing the long fillet of the main blade pressure surface, the long fillet of the suction surface, and the short fillet of the splitter blade pressure surface, the following steps are also included: Obtain a three-dimensional model of the impeller; Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool; Constructing the machining model of the impeller Select the impeller processing model of the main blade (1), the splitter blade (2) and the first reference wheel disc surface (3) components in the impeller three-dimensional model; Rough machining of the main blade (1) and the splitter blade (2); The main blades (1) and the splitter blades (2) are finely machined.

7. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 6, characterized in that: The steps for selecting the non-axisymmetric disc surface finishing tool and the fillet finishing tool include: The non-axisymmetric disc surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

8. A method for machining a non-axisymmetric wheel disc surface and fillet according to claim 7, characterized in that: The non-axisymmetric disc surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size. The steps include: Perform curvature analysis on the non-axisymmetric disk surface in the impeller 3D model to obtain the minimum radius of the concave area. If the minimum radius of the concave area is smaller than the blade fillet marked on the impeller design drawing, select the finishing tool based on the minimum radius of the concave area. When the minimum radius value of the concave area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

9. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 6, characterized in that: The steps of fine-machining the main blade (1) and the splitter blade (2) include: The initial wheel disc surface (9) is offset along the normal phase toward the side of the impeller having blades, and the offset distance is the normal phase distance h from the convex part of the non-axisymmetric wheel disc surface (5) to the initial wheel disc surface (9), thereby obtaining a second reference wheel disc surface (11); The processing depth of the fine-machined main blades (1) and the splitter blades (2) is from the wheel cover surface to the second reference wheel disc surface (11).

10. An impeller, characterized in that: The impeller is manufactured by using the method for processing the non-axisymmetric wheel disc surface and fillet according to any one of claims 1 to 9.

Images