Machining method of axial flow pump impeller

Abstract

The invention discloses a machining method of an axial flow pump impeller. Clamping and alignment are easy, and deformation caused in the machining process is reduced. The machining method of the axial flow pump impeller comprises the steps that a blade is machined, and a blade semi-finished product is obtained; hub machining is conducted, and a hub semi-finished product is obtained; and the blade semi-finished product and the hub semi-finished product are combined for impeller machining, and an impeller finished product is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of axial flow pumps, and particularly to a processing method for an impeller of an axial flow pump. Background Art

[0002] The impeller is the core component of the axial flow pump, and its manufacturing quality directly affects the intake efficiency of the axial flow pump. The impeller is divided into two parts: a hub and blades. The blades and the hub are in clearance fit. After the blades and the hub are assembled, they are integrally welded into a compressed air impeller.

[0003] The impeller hub is a casting blank. The casting of the part has large deformation and is prone to eccentricity, which affects the machining quality of the hub and further affects the position after the blades are assembled. The blade blank is of a casting structure, and the overall profile is precision cast and no further machining is carried out later, only the mating position between the blade and the hub is machined. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a processing method for an impeller of an axial flow pump, which is easy to clamp and align, and reduces the deformation caused during the processing.

[0005] The purpose of the present invention is achieved as follows:

[0006] A processing method for an impeller of an axial flow pump includes: performing blade processing to obtain a blade semi-finished product; performing hub processing to obtain a hub semi-finished product; and performing impeller processing on the combined blade semi-finished product and hub semi-finished product to obtain an impeller finished product.

[0007] Further, the blade processing includes the following steps:

[0008] 110. Heat treatment;

[0009] 120. Clamp the outer circle of the assembly end of the blade with a three-jaw chuck, and rough-turn the outer circle and end face of the other end of the blade.

[0010] 130. Clamp the turned outer circle of the blade blank with a three-jaw chuck, rough-turn the end face of the assembly end of the blade, leave a process chuck on the end face of the process chuck, drill a center hole on the end face of the process chuck, drill the center hole, and rough-turn the outer circle and step face of the assembly end of the blade.

[0011] 140. Clamp the outer circle of the process chuck at the assembly end of the blade with a three-jaw chuck, and finish-turn the outer circle of the other end of the blade.

[0012] 150. Clamp the finished-turned outer circle, drill the center hole, and finish-turn the outer circle, assembly thread and end face of the assembly end of the blade.

[0013] 160. Cut off the process chuck by wire cutting;

[0014] 170. Deburr.

[0015] Further, in step 120, an outer circle is machined on the inner side of the assembly end of the blade, and this outer circle is used for alignment in step 130.

[0016] Further, the hub machining includes the following steps:

[0017] 210. Mark the machining line of the hub end face;

[0018] 220. Clamp the outer circle of the small end of the hub with a three-jaw chuck, and rough machine the large end face and inner hole of the hub;

[0019] 230. Support the inner hole of the large end of the hub with a three-jaw chuck, and rough machine the small end face, outer circle and inner hole of the hub;

[0020] 240. Install the milling tooling, and finish-mill the large end plane of the hub;

[0021] 250. Position through the large end plane of the hub, and mill the blade assembly positioning holes and planes on the hub;

[0022] 260. Deburr.

[0023] Further, the milling tooling includes a tooling body 1, a washer 2, and a bolt 4. The tooling body 1 is in a convex shape. The upper end face of the large end of the tooling body 1 is used for abutting and positioning with the small end face of the hub. The outer circle of the small end of the tooling body 1 is used for clearance fit positioning with the inner hole of the small end of the hub. The washer 2 is used for positioning by fitting the bottom surface of the inner hole of the large end of the hub. The bolt 4 passes through the washer 2 and is threadedly engaged and fixed with the small end face of the tooling body 1. The bolt 4 tightens and fixes the hub on the milling tooling.

[0024] Further, the impeller machining includes the following steps:

[0025] 310. Assemble the blade and the hub and weld them into one body;

[0026] 320. Heat treatment to remove welding stress;

[0027] 330. Weld seam flaw detection;

[0028] 340. Support the inner hole of the large end of the hub with a three-jaw chuck, and semi-finish machine the outer circle and end face of the small end of the hub;

[0029] 350. Clamp the outer circle of the small end of the hub with a three-jaw chuck, and finish machine the outer circle, inner hole and end face of the large end of the hub;

[0030] 360. Install the lathe tooling, align the outer circle of the small end of the hub, finish machine the outer circle of the impeller, and finish machine the end face, inner hole and outer circle of the small end of the hub;

[0031] 370. Deburr.

[0032] Further, the wheel tooling includes a base 1. The edge part of the upper end surface of the base 1 is used for fixedly connecting with the large end of the wheel hub through bolts 2. A mandrel 4 is fixedly installed at the center part of the upper end surface of the base 1 through a bolt 3. The mandrel 4 is in a convex shape. The outer circle of the large end of the mandrel 4 is in clearance fit with the inner hole of the large end of the wheel hub for positioning. A guide shaft 7 is fixedly connected by threading at the center part of the upper end of the mandrel 4. A top plate 6 is positioned on the guide shaft 7 with a clearance fit. A plurality of compression springs 5 are evenly arranged between the top plate 6 and the upper end surface of the mandrel 4. The compression springs 5 press the top plate 6 upward, so that the top plate 6 presses the bottom surface of the inner hole of the large end of the wheel hub, realizing the positioning of the wheel hub.

[0033] Further, positioning grooves for the compression springs 5 are correspondingly arranged on the top plate 6 and the mandrel 4.

[0034] Due to the adoption of the above technical solutions, the present invention solves the problems that the hub blank of the axial flow pump casting impeller has large deformation, is difficult to align, and the parts of the manufacturing method are prone to deformation and the machining results are difficult to detect. The present invention has the following beneficial effects:

[0035] 1. Aiming at the problems of large deformation of the impeller casting, non-concentric blades, and difficult alignment of eccentricity, a process chuck is reserved at one end of the blade. First, the non-process chuck end is machined. By enlarging the diameter of the process chuck part, it is ensured that both ends can be machined. After machining, the process chuck is cut off by wire cutting, minimizing the deformation caused during the machining process and ensuring the position after assembly.

[0036] 2. Aiming at the problems of large deformation of the hub casting and difficult clamping during milling, a special hub milling tool is designed. By positioning through the inner hole and pressing the inner end face, the clamping problem is solved. During milling, first align the runout of the tooling, and then align the part to ensure the milling quality.

[0037] 3. When the impeller is finish-machined after combination, the inner hole and the inner end face need to ensure the perpendicularity requirement and there are high dimensional tolerance requirements from the inner hole end face to the inner end face. However, due to the limitation of the hub structure, the inner hole and the inner end face cannot be machined together, and the form and position tolerance are difficult to guarantee. And the depth dimension from the inner hole end face to the inner end face cannot be detected by conventional methods. To solve this problem, when machining the reference surface, the inner end face and the large end face are machined together to ensure their parallelism. Then when machining the inner hole, a special small-end turning tooling is designed. In the tooling, the form of a spring plus a top plate is used to increase the positioning reference surface, ensuring that the inner end face fits with the top plate and the large end face fits with the tooling base, so as to ensure the perpendicularity requirement between the inner hole and the inner end face after the impeller is machined. When measuring, directly use a depth micrometer to measure the depth dimension from the inner hole end face to the tooling top plate end face to obtain the depth dimension from the inner hole end face to the inner end face. Description of the Drawings

[0038] Figure 1 It is the front view of the blade;

[0039] Figure 2 It is the left view of the blade;

[0040] Figures 3 to 6 It is the process drawing for blade machining;

[0041] Figure 7 It is the front view of the hub;

[0042] Figure 8 It is the sectional view of the hub;

[0043] Figures 9 - 11 It is the process drawing for hub machining;

[0044] Figure 12 It is the general assembly drawing of the milling tool;

[0045] Figure 13 It is the front view of the impeller;

[0046] Figure 14 It is the E-E sectional view of the impeller;

[0047] Figures 15 - 17 It is the process drawing for impeller machining;

[0048] Figure 18 It is the general assembly drawing of the turning tool. Specific implementation method

[0049] A processing method for the impeller of an axial flow pump. For blade machining, a semi-finished blade is obtained; for hub machining, a semi-finished hub is obtained; after combining the semi-finished blade and the semi-finished hub, impeller machining is carried out to obtain a finished impeller.

[0050] Blade machining includes the following steps:

[0051] 110. Heat treatment;

[0052] 120. Clamp the outer circle of the assembly end of the blade with a three-jaw chuck, and rough-turn the outer circle and end face of the other end of the blade; see Figure 3 .

[0053] 130. Clamp the turned outer circle of the blade blank with a three-jaw chuck, rough-turn the end face of the assembly end of the blade, leave a process chuck on the end face of the assembly end of the blade, drill a center hole on the end face of the process chuck, drill the center hole, and rough-turn the outer circle and step face of the assembly end of the blade; see Figure 4 .

[0054] 140. Clamp the outer circle of the process chuck at the assembly end of the blade with a three-jaw chuck, and finish-turn the outer circle of the other end of the blade;

[0055] 150. Clamp the finished-turned outer circle with a three-jaw chuck, drill the center hole, and finish-turn the outer circle, assembly thread and end face of the assembly end of the blade; see Figure 5 .

[0056] 160. Wire cutting to remove process chuck; see Figure 6 .

[0057] 170. Deburring.

[0058] In step 120 , an outer circle is machined inside the assembly end of the blade, and the outer circle is used for alignment in step 130 .

[0059] Wheel hub machining includes the following steps:

[0060] 210. Marking wheel hub end surface processing line; see Figure 9 .

[0061] 220, three-claw clamp wheel hub small end outer circle, rough wheel hub large end face, inner hole; see Figure 10 .

[0062] 230, three-claw support wheel hub big end inner hole, rough wheel hub small end face, outer circle, inner hole; see Figure 11 .

[0063] 240, milling tool, fine milling of the big end surface of the wheel hub; see Figure 12 (Threaded holes for connection are processed at the same time).

[0064] 250. Position through the large end plane of the hub, and mill the blade assembly positioning holes and planes on the hub; (A lathe can be used here.)

[0065] 260. Deburring.

[0066] The milling tooling includes a tooling body 1, a washer 2, and a bolt 4. The tooling body 1 is in a convex shape. The upper end surface of the large end of the tooling body 1 is used for abutting against the small end surface of the wheel hub for positioning. The outer circle of the small end of the tooling body 1 is used for positioning with the clearance of the inner hole of the small end of the wheel hub. The washer 2 is used for positioning in contact with the bottom surface of the inner hole of the large end of the wheel hub. The bolt 4 passes through the washer 2 and is fixed with the thread of the small end surface of the tooling body 1. The bolt 4 tightens the wheel hub and fixes it on the milling tooling.

[0067] Impeller machining includes the following steps:

[0068] 310. Assemble the blades and the hub and weld them together;

[0069] 320. Heat treatment to remove welding stress;

[0070] 330. Weld flaw detection;

[0071] 340, three-claw support wheel hub big end inner hole, semi-finished wheel hub small end outer circle and end face; see Figure 15 .

[0072] 350, three-claw clamping wheel hub small end outer circle, fine wheel hub large end outer circle, inner hole and end face; see Figure 16 .

[0073] 360. The loading tooling for getting on the vehicle aligns the outer circle of the small end of the hub, precisely turns the outer circle of the impeller, and precisely turns the end face, inner hole, and outer circle of the small end of the hub; see Figure 17 .

[0074] 370. Deburr.

[0075] The turning tooling includes a base 1. The edge part of the upper end face of the base 1 is used for fixedly connecting with the large end of the hub through bolts 2. A mandrel 4 is fixedly installed at the center part of the upper end face of the base 1 through a bolt 3. The mandrel 4 is in a convex shape. The outer circle of the large end of the mandrel 4 is in clearance fit with the inner hole of the large end of the hub for positioning. A guide shaft 7 is fixedly connected by thread at the center part of the upper end of the mandrel 4. A top plate 6 is positioned on the guide shaft 7 with clearance fit. A plurality of compression springs 5 are evenly arranged between the top plate 6 and the upper end face of the mandrel 4. The compression springs 5 press the top plate 6 upward, so that the top plate 6 presses the bottom surface of the inner hole of the large end of the hub, realizing the positioning of the hub.

[0076] The top plate 6 and the mandrel 4 are respectively provided with positioning grooves for the compression springs 5.

[0077] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for processing an axial flow pump impeller, characterized in that: The method comprises: processing blades to obtain semi-finished blades; processing hubs to obtain semi-finished hubs; and processing impellers after combining the semi-finished blades and the semi-finished hubs to obtain finished impellers.

2. The method for processing an axial flow pump impeller according to claim 1, characterized in that: Blade processing includes the following steps:

110. Heat treatment; 120. Clamp the outer circle of the blade assembly end with three claws, and rough turn the outer circle and end surface of the other end of the blade; 130. The outer circle of the three-jaw clamp blade blank has been turned, the end face of the blade assembly end is roughly turned, a process chuck is left on the end face of the blade assembly end, and a center hole is drilled on the end face of the process chuck, the center hole is drilled, and the outer circle and step surface of the blade assembly end are roughly turned; 140. Clamp the outer circle of the process chuck at the assembly end of the blade with three jaws, and finish the outer circle of the other end of the blade; 150. The three-jaw clamp has been precision-turned on the outer circle, top center hole, and precision-turned on the outer circle, assembly thread and end face of the blade assembly end; 160. Wire cutting to remove process chuck; 170. Deburring.

3. The method for processing an axial flow pump impeller according to claim 2, characterized in that: In step 120 , an outer circle is machined inside the assembly end of the blade, and the outer circle is used for alignment in step 130 .

4. The method for processing an axial flow pump impeller according to claim 1, characterized in that: Wheel hub machining includes the following steps:

210. Wheel hub end surface processing line; 220. Three-claw clamping wheel hub small end outer circle, rough wheel hub large end face, inner hole; 230. The inner hole of the big end of the three-claw support hub, the small end face, outer circle and inner hole of the rough hub; 240. Milling tooling, precision milling of the big end plane of the wheel hub; 250. Position through the large end plane of the hub and mill the blade assembly positioning holes and plane on the hub; 260. Deburring.

5. The method for machining an axial flow pump impeller according to claim 4, characterized in that: The milling tooling includes a tooling body 1, a washer 2, and a bolt 4. The tooling body 1 is in a convex shape. The upper end surface of the large end of the tooling body 1 is used for abutting against the small end surface of the wheel hub for positioning. The outer circle of the small end of the tooling body 1 is used for positioning with the clearance of the inner hole of the small end of the wheel hub. The washer 2 is used for positioning in contact with the bottom surface of the inner hole of the large end of the wheel hub. The bolt 4 passes through the washer 2 and is fixed with the thread of the small end surface of the tooling body 1. The bolt 4 tightens the wheel hub and fixes it on the milling tooling.

6. The method for machining an axial flow pump impeller according to claim 1, characterized in that: Impeller machining includes the following steps:

310. Assemble the blades and the hub and weld them together; 320. Heat treatment to remove welding stress; 330. Weld flaw detection; 340, three-claw support wheel hub big end inner hole, semi-finished wheel hub small end outer circle and end face; 350. Clamp the outer circle of the small end of the wheel hub with three jaws, and polish the outer circle, inner hole and end face of the large end of the wheel hub; 360. Install the tooling, align the outer circle of the small end of the hub, finish the outer circle of the impeller, and finish the end face, inner hole and outer circle of the small end of the hub; 370. Deburring.

7. The method for machining an axial flow pump impeller according to claim 6, characterized in that: The lathe tooling includes a base 1, the edge portion of the upper end surface of the base 1 is used to be fixedly connected to the big end of the wheel hub by bolts 2, the center portion of the upper end surface of the base 1 is fixed with a core shaft 4 by bolts 3, the core shaft 4 is convex, the big end outer circle of the core shaft 4 is positioned by clearance fit with the big end inner hole of the wheel hub, a guide shaft 7 is threadedly fixed to the center portion of the upper end of the core shaft 4, a top plate 6 is positioned by clearance fit on the guide shaft 7, a number of compression springs 5 ​​are evenly arranged between the top plate 6 and the upper end surface of the core shaft 4, the compression springs 5 ​​press the top plate 6 upward, so that the top plate 6 presses the bottom surface of the inner hole of the big end of the wheel hub to achieve positioning of the wheel hub.

8. The method for machining an axial flow pump impeller according to claim 7, characterized in that: Positioning grooves for the compression spring 5 are correspondingly provided on the top plate 6 and the core shaft 4 .

Images