High strength steam turbine rotor blade and method of processing

Abstract

The application discloses a high-strength steam turbine rotor blade and a processing method, and relates to the technical field of steam turbine rotor blades. The high-strength steam turbine rotor blade comprises a impeller, circular grooves are arranged on the two sides of the impeller, fixing structures are arranged on the two sides of the impeller, blades are arranged in the two circular grooves, the blades are provided in a plurality of groups, blade roots are welded on the sides of the blades, connecting portions are fixedly installed on the sides of the blade roots, limit grooves are arranged on the inner side walls of the circular grooves, and the limit grooves are provided in a plurality of groups. The connecting portions with special shapes and structures are arranged on the blade roots, so that the blade roots have better structural stability when being connected with the impeller or the rotating drum, the shape and the setting angle of the blades are changed, the blades are arranged in a circumferential direction, the axes of the blades and the rotor main shaft are perpendicular, the torque of the centrifugal force on the blades can be eliminated when the blades work, and the structural strength of the blades is improved.

Description

Technical Field

[0001] This invention relates to the field of steam turbine rotor blade technology, specifically to a high-strength steam turbine rotor blade and its processing method. Background Technology

[0002] A steam turbine, also known as a steam engine, is a rotary steam power unit. High-temperature, high-pressure steam passes through a fixed nozzle, becomes an accelerated airflow, and is then injected onto blades, causing a rotor equipped with rows of blades to rotate and perform work. Steam turbines are the main equipment in modern thermal power plants and are also used in the metallurgical industry, chemical industry, and ship propulsion systems. The rotor of a steam turbine has multiple stages of impellers, each stage equipped with several blades.

[0003] In the prior art, for radial turbine rotors, the blades are subjected to huge centrifugal forces during high-speed rotation. If the structural strength of the blades is insufficient, they will vibrate due to the centrifugal force. If the vibration force is too large, the blades will break, affecting the normal operation of the rotor. The blades also have blade roots for connecting the impeller or the drum, and the structure of the blade roots also determines the stability of the connection between the blades and the impeller. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength steam turbine rotor blade and its processing method, in order to solve the problem mentioned in the background art that, for radial steam turbine rotors, the blades will be subjected to huge centrifugal forces during high-speed rotation. If the structural strength of the blade itself is insufficient, it will be affected by the centrifugal force and vibrate. If the vibration force is too large, the blade will break, affecting the normal operation of the rotor. The blade also has a blade root for connecting the impeller or the drum, and the structure of the blade root also determines the stability of the connection between the blade and the impeller.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-strength steam turbine rotor blade, comprising an impeller, wherein circular grooves are provided on both sides of the impeller, and a fixing structure is provided on both sides of the impeller, and a plurality of blades are provided inside each circular groove;

[0006] Each blade has a blade root welded to one side, and a connecting part is fixedly installed on one side of each blade root. The inner sidewall of the circular groove has a limiting groove corresponding to each connecting part. In the corresponding connecting parts and limiting grooves: limiting posts are provided on both the left and right sides of the connecting part near the front and rear edges; limiting holes are provided on both inner sidewalls of the limiting groove; a fixing plate is fixedly installed inside the connecting part at the middle position; four support springs are fixedly installed on both sides of the fixing plate; and a push plate is provided inside the connecting part at both sidewalls.

[0007] Preferably, the fixing structure includes a circular ring plate and hexagon socket head cap bolts. Threaded grooves are provided on both sides of the impeller and near the circular groove. Long plates are welded to the outer side walls of the circular ring plate, and the number of long plates is twice that of the blade root. A limit plate is welded to one side of each long plate.

[0008] Preferably, in each connecting part, between the two push plates: the inner side of each push plate is fixedly connected to one end of the two support springs.

[0009] Preferably, the connecting parts are respectively connected to the inside of the corresponding limiting groove, and the limiting posts are respectively disposed inside the corresponding limiting holes.

[0010] Preferably, a through hole is formed on one side of the annular plate, and a placement groove is formed on the other side of the annular plate.

[0011] Preferably, one side of the internal hexagonal bolt passes through the corresponding through hole and is disposed inside the threaded groove.

[0012] Preferably, in each leaf root: the two side walls of the leaf root are in contact with the limiting plate, and the two limiting plates form a group.

[0013] Preferably, one side of each of the blade roots is in contact with the inner wall of the circular groove, and each hexagonal socket bolt is threadedly connected to the corresponding threaded groove.

[0014] Preferably, a mounting hole is provided through one side of the impeller, and a circular hole is provided through one side of the impeller, and there are several circular holes. A circular ring is fixedly installed on the outer wall of the impeller at both sides.

[0015] A method for processing high-strength steam turbine rotor blades includes the following steps:

[0016] S1. Load the blade to be processed into the first set of tooling, clamp it, and send it into the machine tool;

[0017] S2. The machine tool calls the probe to inspect the reference surface of the part and corrects the zero point of the part machining. If the setting requirements are met, the machine tool continues to run; otherwise, the machine tool stops running.

[0018] S3. When the setting requirements are met, the following processing is performed: milling the edges of the inlet and outlet sides, milling the transition R between the blade plate and the blade body, milling the perimeter and all surfaces of the damping platform on the blade basin side, milling the perimeter and all surfaces of the damping platform on the blade back side, and milling the reference surface of the part and the blade root of special shape.

[0019] S4. Replace the blade with the second set of tooling and clamp it, then feed it into the machine tool and perform the following processing: mill the process bosses at both ends, mill the tenon end face and edge R angle, mill the tenon side, mill the tenon profile and its R angle, mill the blade tip and blade root of special shape.

[0020] S5. After processing the blades and blade roots, fix the impeller on the machine tool. Install a suitable rotating head on the machine tool to make circular grooves on both sides of the impeller. Then change the structure on the machine tool to process the limiting groove. Then change the rotating head on the machine tool according to the diameter of the limiting post so that it can process the limiting holes on both sides of the limiting groove.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. In this invention, by providing blades and blade roots, and by providing connecting parts with special shapes and structures on the blade roots, the blade roots have better structural stability when connected to the impeller or drum. By changing the shape and setting angle of the blades and setting the blades circumferentially, the blades are perpendicular to the axis of the rotor main shaft, so that the centrifugal force torque on the blades can be eliminated when the blades are working, thereby improving the structural strength of the blades.

[0023] 2. In this invention, by providing a connecting part, the connecting part is first inserted into the limiting groove. Under the elastic force of the four support springs, the four support springs will push the push plate on one side to move inside the connecting part, and the push plate will drive the limiting post on one side to move, so that the limiting post is inserted into the limiting hole, thereby fixing the connecting part inside the limiting groove, thereby fixing the leaf root and ensuring a stable connection.

[0024] 3. In this invention, by setting a fixing structure, by contacting one side of several limiting plates with the outer surface of the blade root, and aligning the through holes on one side of the annular plate with the threaded groove, several hexagonal socket head cap screws are inserted into the through holes one by one, and the hexagonal socket head cap screws are rotated one by one, so that the hexagonal socket head cap screws rotate inside the threaded groove. With the threaded engagement between the hexagonal socket head cap screws and the threaded groove, the hexagonal socket head cap screws can fix the annular plate to one side of the impeller, and make the several limiting plates in close contact with the outer surface of the blade root, thereby further fixing the blade root and improving the stability of the blade. Attached Figure Description

[0025] Figure 1 This is a perspective view of a high-strength steam turbine rotor blade according to the present invention;

[0026] Figure 2 This is a partial exploded view of a high-strength steam turbine rotor blade according to the present invention;

[0027] Figure 3 This is a perspective view of the rotor body of a high-strength steam turbine rotor blade according to the present invention;

[0028] Figure 4 This is a partial perspective view of a fixing structure for a high-strength steam turbine rotor blade according to the present invention;

[0029] Figure 5 This is a cross-sectional view of a high-strength steam turbine rotor blade according to the present invention;

[0030] Figure 6 This is a perspective view of the blade root and connecting part of a high-strength steam turbine rotor blade according to the present invention;

[0031] Figure 7 This is a cross-sectional view of the connection part of a high-strength steam turbine rotor blade according to the present invention;

[0032] Figure 8 This invention relates to a high-strength steam turbine rotor blade. Figure 5 A magnified structural diagram of A in the diagram.

[0033] In the picture:

[0034] 1. Impeller; 10. Circular groove; 11. Mounting hole; 12. Blade; 13. Circular hole; 14. Blade root; 141. Connecting part; 142. Limiting groove; 143. Limiting post; 144. Limiting hole; 145. Fixing plate; 146. Support spring; 147. Push plate; 15. Circular ring sleeve; 2. Fixing structure; 21. Circular ring plate; 22. Threaded groove; 23. Socket head bolt; 24. Long plate; 25. Limiting plate; 26. Through hole; 27. Placement groove. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] Reference Figure 1-8As shown: A high-strength steam turbine rotor blade includes an impeller 1. Circular grooves 10 are formed on both sides of the impeller 1, and fixing structures 2 are provided on both sides of the impeller 1. Several blades 12 are arranged inside each circular groove 10. A blade root 14 is welded to one side of each blade 12, and a connecting part 141 is fixedly installed on one side of each blade root 14. Limiting grooves 142, corresponding one-to-one with the connecting parts 141, are formed on the inner sidewalls of the circular grooves 10. Limiting posts 143 are provided on the left and right sides of the connecting parts 141 near their front and rear edges. Limiting holes 144 are formed on the inner sidewalls of the limiting grooves 142. A connecting part 143 is fixedly installed inside the connecting part 141 at its center position. There is a fixed plate 145, and four support springs 146 are fixedly installed on both sides of the fixed plate 145. Push plates 147 are provided inside the connecting part 141 and at both side walls. In each connecting part 141, between two push plates 147, the inner side of each push plate 147 is fixedly connected to one end of two support springs 146. Several connecting parts 141 are respectively connected to the inside of the corresponding limiting groove 142. Several limiting posts 143 are respectively set inside the corresponding limiting holes 144. An installation hole 11 is opened through one side of the impeller 1. A circular hole 13 is opened through one side of the impeller 1 and there are several circular holes 13. Circular rings 15 are fixedly installed on the outer side wall of the impeller 1 at both side edges.

[0038] The overall effect of this embodiment is that, by providing blades 12 and blade roots 14, and by providing a connecting part 141 with a special shape and structure on the blade root 14, the blade root 14 has better structural stability when connected to the impeller 1 or the drum. Changing the shape and setting angle of the blades 12 and making the blades 12 circumferentially positioned so that the blades 12 are perpendicular to the axis of the rotor main shaft, allows the centrifugal force torque on the blades 12 to be eliminated during operation, improving the structural strength of the blades 12. Secondly, by providing the connecting part 141, the blades 12 are first... The connecting part 141 is inserted into the limiting groove 142. Under the elastic force of the four support springs 146, the four support springs 146 will push the push plate 147 on one side to move inside the connecting part 141. The push plate 147 will drive the limiting post 143 on one side to move, so that the limiting post 143 is inserted into the limiting hole 144. This will fix the connecting part 141 inside the limiting groove 142, thereby fixing the blade root 14 and ensuring a stable connection. It can also be connected and fixed to the external rotor through the mounting hole 11.

[0039] Example 2

[0040] like Figure 2 , Figure 3 and Figure 4As shown, the fixing structure 2 includes a circular ring plate 21 and hexagon socket head cap bolts 23. Threaded grooves 22 are provided on both sides of the impeller 1 near the circular groove 10. Long plates 24 are welded to the outer side wall of the circular ring plate 21, and the number of long plates 24 is twice that of the blade roots 14. A limiting plate 25 is welded to one side of each long plate 24. A through hole 26 is provided on one side of the circular ring plate 21, and a placement groove 27 is provided on the other side of the circular ring plate 21. One side of each hexagon socket head cap bolt 23 passes through the corresponding through hole 26 and is placed inside the threaded groove 22. In each blade root 14: the two side walls of the blade root 14 are in contact with the limiting plate 25, and two limiting plates 25 form a group. One side of each blade root 14 is in contact with the inner side wall of the circular groove 10, and each hexagon socket head cap bolt 23 is threadedly connected to the corresponding threaded groove 22.

[0041] The overall effect of this embodiment is that, by setting up a fixing structure 2, by contacting one side of several limiting plates 25 with the outer surface of the blade root 14, and aligning the through hole 26 on one side of the annular plate 21 with the threaded groove 22, and then inserting several hexagonal socket head cap screws 23 one by one into the through hole 26, and rotating the hexagonal socket head cap screws 23 one by one, so that the hexagonal socket head cap screws 23 rotate inside the threaded groove 22. Under the threaded engagement between the hexagonal socket head cap screws 23 and the threaded groove 22, the hexagonal socket head cap screws 23 can fix the annular plate 21 to one side of the impeller 1, and make several limiting plates 25 in close contact with the outer surface of the blade root 14, thereby further fixing the blade root 14 and improving the stability of the blade 12.

[0042] A method for processing high-strength steam turbine rotor blades includes the following steps:

[0043] Step 1: Load the blade 12 to be processed into the first set of tooling, clamp it, and send it into the machine tool.

[0044] Step 2: The machine tool calls the probe to inspect the reference surface of the part and corrects the zero point of the part machining. If the setting requirements are met, the machine tool continues to run; otherwise, the machine tool stops running.

[0045] Step 3: When the setting requirements are met, perform the following processing: mill the edges of the inlet and outlet sides, mill the transition R between the blade and the blade body, mill the perimeter and all surfaces of the damping platform on the blade basin side, mill the perimeter and all surfaces of the damping platform on the blade back side, and mill the reference surface of the part and the blade root 14 with special shape.

[0046] Step 4: Replace blade 12 with the second set of tooling and clamp it, then send it into the machine tool for the following processing: mill the process bosses at both ends, mill the tenon end face and edge R angle, mill the tenon side, mill the tenon profile and its R angle, mill the blade tip and the special-shaped blade root 14.

[0047] Step 5: After machining the blade 12 and blade root 14, fix the impeller 1 on the machine tool. Install a suitable rotating head on the machine tool to make circular grooves 10 on both sides of the impeller 1. Then change the structure on the machine tool to machine the limiting groove 142. Then, according to the diameter of the limiting post 143, change the rotating head on the machine tool to make limiting holes 144 on both sides of the limiting groove 142.

[0048] The working principle of this invention is as follows: First, during use, several connecting parts 141 are inserted into several limiting grooves 142. Under the elastic force of four support springs 146 in each group, the four support springs 146 push the push plate 147 on one side to move inside the connecting part 141. The push plate 147 drives the limiting post 143 on one side to move, so that the limiting post 143 is inserted into the limiting hole 144. This fixes the connecting part 141 inside the limiting groove 142, thereby fixing the blade root 14 and ensuring a stable connection. Through the mounting hole 11, it can be connected and fixed to the external rotor. Then, by contacting one side of several limiting plates 25 with the outer surface of the blade root 14, and making the through hole 26 on one side of the annular plate 21... Aligning with the threaded groove 22, insert several hexagon socket head cap screws 23 one by one into the through holes 26, and rotate the hexagon socket head cap screws 23 one by one, so that the hexagon socket head cap screws 23 rotate inside the threaded groove 22. With the threaded engagement between the hexagon socket head cap screws 23 and the threaded groove 22, the hexagon socket head cap screws 23 can fix the annular plate 21 to one side of the impeller 1, and make several limiting plates 25 in close contact with the outer surface of the blade root 14, thereby further fixing the blade root 14 and improving the stability of the blade 12. Finally, by repeating the above two steps on the other side of the impeller 1, the other side of the impeller 1 is assembled.

[0049] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength steam turbine rotor blade, comprising an impeller (1), characterized in that: Both sides of the impeller (1) are provided with circular grooves (10), and both sides of the impeller (1) are provided with fixed structures (2). Each circular groove (10) is provided with several blades (12). Each blade (12) has a blade root (14) welded to one side, and a connecting part (141) is fixedly installed on one side of each blade root (14). The inner sidewall of the circular groove (10) is provided with a limiting groove (142) corresponding to the connecting part (141). In the corresponding connecting part (141) and limiting groove (142): a limiting post (143) is provided on the left and right sides of the connecting part (141) near the front and rear edges, and a limiting hole (144) is provided on the inner sidewall of the limiting groove (142). A fixing plate (145) is fixedly installed inside the connecting part (141) and at the middle position. Two support springs (146) are fixedly installed on both sides of the fixing plate (145), and there are four support springs (146). Push plates (147) are provided inside the connecting part (141) and at both side walls. In each connecting part (141), between the two push plates (147): the inner side of each push plate (147) is fixedly connected to one end of the two support springs (146). The fixing structure (2) includes a ring plate (21) and an internal hex bolt (23). Threaded grooves (22) are provided on both sides of the impeller (1) and near the circular groove (10). Long plates (24) are welded to the outer side walls of the ring plate (21), and the number of long plates (24) is twice that of the blade root (14). A limit plate (25) is welded to one side of each long plate (24).

2. The high-strength steam turbine rotor blade according to claim 1, characterized in that: Several of the connecting parts (141) are respectively connected to the inside of the corresponding limiting groove (142), and several of the limiting posts (143) are respectively disposed inside the corresponding limiting hole (144).

3. The high-strength steam turbine rotor blade according to claim 1, characterized in that: A through hole (26) is provided on one side of the annular plate (21), and a placement groove (27) is provided on the other side of the annular plate (21).

4. A high-strength steam turbine rotor blade according to claim 3, characterized in that: One side of the internal hex bolt (23) passes through the corresponding through hole (26) and is located inside the threaded groove (22).

5. A high-strength steam turbine rotor blade according to claim 1, characterized in that: In each leaf root (14): the two side walls of the leaf root (14) are in contact with the limiting plate (25) respectively, and the two limiting plates (25) form a group.

6. A high-strength steam turbine rotor blade according to claim 5, characterized in that: One side of each of the leaf roots (14) is in contact with the inner wall of the circular groove (10), and each hexagonal bolt (23) is threadedly connected to the corresponding threaded groove (22).

7. A high-strength steam turbine rotor blade according to claim 1, characterized in that: The impeller (1) has a through hole (11) on one side and a through hole (13) on one side, and there are several holes (13). A ring sleeve (15) is fixedly installed on the outer wall of the impeller (1) at both sides.

8. A method for processing high-strength steam turbine rotor blades, characterized in that, A high-strength steam turbine rotor blade used in any one of claims 1-7 comprises the following steps: S1. Load the blade (12) to be processed into the first set of tooling and clamp it, then send it into the machine tool; S2. The machine tool calls the probe to inspect the reference surface of the part and corrects the zero point of the part machining. If the setting requirements are met, the machine tool continues to run; otherwise, the machine tool stops running. S3. When the setting requirements are met, the following processing is performed: milling the edges of the inlet and outlet, milling the transition R between the blade plate and the blade body, milling the perimeter and all surfaces of the damping platform on the blade basin side, milling the perimeter and all surfaces of the damping platform on the blade back side, and milling the reference surface of the part and the blade root of special shape (14). S4. Replace the blade (12) with the second set of tooling and clamp it. Then send it into the machine tool and perform the following processing: mill the process bosses at both ends, mill the end face and edge R angle of the tenon, mill the side of the tenon, mill the tenon profile and its R angle, mill the blade tip and the blade root of special shape (14). S5. After processing the blade (12) and blade root (14), fix the impeller (1) on the machine tool. Install a suitable rotating head on the machine tool to make round grooves (10) on both sides of the impeller (1). Then change the structure on the machine tool to process the limiting groove (142). Then change the rotating head on the machine tool according to the diameter of the limiting column (143) so that limiting holes (144) are processed on both sides inside the limiting groove (142).

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