Grinding method and clamp for inner circle of movable blade retaining ring

Abstract

The invention relates to the technical field of moving blade retaining ring machining, and provides a moving blade retaining ring inner circle grinding method and a clamp. The grinding method comprises the following steps that all arc sections forming a moving blade retaining ring are fixed respectively, and all the arc sections form a circular ring structure simulating the working state of the moving blade retaining ring; and then the inner sides of all the arc sections are polished through inner circle polishing equipment. According to the inner circle grinding device, an existing single arc section independent grinding mode is converted into an inner circle grinding mode, grinding consistency of all arc sections is conveniently guaranteed, the roundness of the inner circle of the whole moving blade protection ring is guaranteed, all the arc sections are ground at the same time, and the machining period is conveniently shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of moving blade retaining ring processing, and more specifically, to a method and fixture for grinding the inner circle of a moving blade retaining ring. Background Art

[0002] In an aeroengine, a moving blade retaining ring is a key component installed around the periphery of a turbine moving blade. It mainly forms a closed flow passage by wrapping the tip region of the turbine moving blade, restricts the high-temperature and high-pressure airflow to flow along the designed path to reduce leakage, and at the same time provides structural support for the turbine moving blade, resists the centrifugal force and airflow excitation force during high-speed rotation, and ensures the stability and safety of the blade operation.

[0003] In order to reduce the processing difficulty, adapt to thermal expansion deformation, and reduce the influence of thermal stress on components, the moving blade retaining ring is usually designed as a segmented type, that is, a circular ring structure composed of several arc segments. In some existing moving blade retaining rings, the structure of a single arc segment is as Figure 1 and Figure 2 shown. The arc segment 1 includes an arc segment body and upper and lower rows of protruding hook-shaped hanging ears 101 arranged on the outer side. Among them, there are three hanging ears 101 in the upper row, and two hanging ears 101 at both the left and right ends in the lower row. The two ends of the hanging ear 101 are rounded with the arc segment body to form a fillet 102.

[0004] To meet the normal working requirements, the inner sides of each arc segment usually need to be ground to ensure the accuracy requirements. Currently, the grinding of the moving blade retaining ring is usually carried out by grinding the inner sides of each arc segment separately. This method has a long processing cycle and is difficult to ensure the grinding consistency of each arc segment, and thus it is difficult to ensure the overall inner circle roundness after assembling each arc segment into a moving blade retaining ring. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and fixture for grinding the inner circle of a moving blade retaining ring to solve the above-mentioned defects of the existing grinding method.

[0006] The present invention is realized through the following technical solutions: A method for grinding the inner circle of a moving blade retaining ring, the method is as follows: Fix each arc segment constituting the moving blade retaining ring respectively, and make all arc segments form a circular ring structure simulating the working state of the moving blade retaining ring; then grind the inner sides of all arc segments through an inner circle grinding device.

[0007] The present invention also provides a fixture for grinding the inner circle of a moving blade retaining ring, which is applied to the above-mentioned grinding method, and includes an annular chassis, an annular positioning seat, and fixing mechanisms corresponding to each arc segment one by one. The annular positioning seat is fixedly arranged on the top of the annular chassis and is used to support each arc segment and fit with the outer sides of the lower row end hanging ears one by one; The fixing mechanism includes a fixing base, an auxiliary positioning block, a tensioning block, a pressing block and a circumferential fixing component. The fixing base and the auxiliary positioning block are fixedly arranged, and the auxiliary positioning block is in contact with the outer side of the middle hanger ear in the upper row; the tensioning block is connected to the fixing base and is used to tension the middle hanger ear in the lower row outward; the pressing block is connected to the fixing base and is used to press the middle hanger ear in the upper row downward; the circumferential fixing component includes a positioning pin and a side pressing member arranged on the annular positioning seat. The positioning pin cooperates with the rounded corner of one of the hanger ears in the lower row, and the side pressing member is used to press the other hanger ear in the lower row and jointly limit the circumferential position of the arc segment with the positioning pin.

[0008] Optionally, the side pressing member is strip-shaped and is rotatably connected to the annular positioning seat through a pin. One end of the side pressing member is provided with a pressing portion for contacting the hanger ear, and a pressing screw is connected to the fixing base by a thread and is used to push the other end of the side pressing member so that the pressing portion presses the hanger ear.

[0009] Optionally, the pressing portion has a convex arc structure.

[0010] Optionally, two tensioning portions are provided at one end of the tensioning block, and the two tensioning portions are in one-to-one contact with the two middle hanger ears in the lower row. The tensioning block is slidably connected to the fixing base, and a tensioning screw is rotatably connected to the other end of the tensioning block. The tensioning screw is connected to the fixing base by a thread.

[0011] Optionally, a through chute is provided on the fixing base, the tensioning block is slidably matched with the through chute, a support seat is fixedly connected to the outer end of the through chute, and the tensioning screw is connected to the support seat by a thread.

[0012] Optionally, the tensioning portion has a convex arc structure.

[0013] Optionally, a limiting groove is provided at the top of the fixing base, the pressing block is arranged in the limiting groove, one end of the pressing block is provided with a supporting top portion in contact with the bottom of the limiting groove, the supporting top portion has a convex arc structure, and the other end of the pressing block is provided with a pressing surface; a waist-shaped through hole extending along the length direction of the pressing block is provided in the middle of the pressing block, and the pressing block is connected to the bottom of the limiting groove through a locking screw passing through the waist-shaped through hole.

[0014] Optionally, a pressing screw is connected to the top of the end of the pressing block provided with the pressing surface by a thread, and the pressing screw is inclined and is used to press the middle hanger ear in the upper row obliquely outward.

[0015] Optionally, a support positioning structure identical in number to the arc segments is provided on the annular positioning seat. The support positioning structure includes two support positioning blocks. The support positioning blocks are provided with support steps. The bottom of the support steps is used to support the arc segment, and the side of the support steps is used to be in contact with the outer side of the hanger ear.

[0016] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, each arc segment constituting the moving blade retaining ring is fixed separately, and all the arc segments form a circular ring structure simulating the working state of the moving blade retaining ring. Then, the inner sides of all the arc segments are polished by an inner circle polishing device, that is, the existing method of independently polishing a single arc segment is converted into polishing the inner circle, which is convenient for ensuring the polishing consistency of each arc segment, thereby ensuring the inner circle roundness of the whole moving blade retaining ring. Moreover, all the arc segments are polished simultaneously, which is convenient for shortening the processing cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the arc segment structure of a moving blade retaining ring in the prior art Figure 1 ; Figure 2 is a schematic diagram of the arc segment structure of a moving blade retaining ring in the prior art Figure 2 ; Figure 3 is a usage state diagram of an inner circle polishing fixture for a moving blade retaining ring provided by the present invention; Figure 4 is a schematic diagram of the structures of an annular chassis and an annular positioning seat; Figure 5 is a schematic diagram of the usage state of a single fixing mechanism; Figure 6 is a front view of the usage state of a single fixing mechanism; Figure 7 is Figure 6 the A-A cross-sectional view in Figure 8 is Figure 6 the B-B cross-sectional view in Figure 9 is a top view of the usage state of a single fixing mechanism; Figure 10 is Figure 9 the C-C cross-sectional view in Figure 11 is a schematic diagram of the structure of a tensioning block; Figure 12 is a schematic diagram of the structure of a pressing block; Figure 13 is a schematic diagram of the structure of a side tightening member; Reference numerals: 1 - arc segment, 101 - hanging ear, 102 - fillet, 2 - annular chassis, 3 - annular positioning seat, 301 - support positioning block, 4 - fixed seat, 5 - auxiliary positioning block, 6 - tensioning block, 601 - tensioning part, 7 - pressing block, 701 - supporting top part, 702 - kidney-shaped through hole, 8 - positioning pin, 9 - side tightening member, 901 - tightening part, 10 - tightening screw, 11 - tensioning screw rod, 12 - pressing screw, 13 - support seat. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] A method for grinding the inner circle of a moving blade retaining ring is as follows: Fix each arc segment 1 that makes up the moving blade retaining ring respectively, and make all the arc segments 1 form a circular ring structure simulating the working state of the moving blade retaining ring; then grind the inner sides of all the arc segments 1 through an inner circle grinding device. That is, the present invention converts the existing method of independently grinding a single arc segment 1 into grinding the inner circle, which is convenient for ensuring the grinding consistency of each arc segment 1, thereby ensuring the roundness of the overall inner circle of the moving blade retaining ring. Moreover, all the arc segments 1 are ground simultaneously, which is convenient for shortening the processing cycle.

[0019] Reference Figures 2 - 5 , the present invention also provides an inner circle grinding fixture for a moving blade retaining ring, which is applied to the above grinding method, that is, it is used to fix each arc segment 1 respectively and make all the arc segments 1 form a circular ring structure simulating the working state of the moving blade retaining ring.

[0020] The grinding fixture includes an annular chassis 2, an annular positioning seat 3, and a fixing mechanism corresponding to each arc segment 1 one by one. The annular positioning seat 3 is fixedly arranged on the top of the annular chassis 2. Specifically, the annular positioning seat 3 is connected and fixed to the annular chassis 2 by screws. In actual application, the relative positions of the two are ensured by a cylindrical pin. The annular positioning seat 3 is used to support each arc segment 1 and is in one-to-one correspondence and fit with the outer side of the lower row end ear 101. That is, after the annular positioning seat 3 preliminarily positions each arc segment 1, the fixing mechanism accurately positions and fixes each arc segment 1.

[0021] In this embodiment, the annular positioning seat 3 is provided with a support positioning structure having the same number as the arc segments 1, and each arc segment 1 is placed at the corresponding support positioning structure. Specifically, referring to Figure 3 and Figure 5 , the support positioning structure includes two support positioning blocks 301. The support positioning blocks 301 are provided with support steps. The bottom of the support steps is used to support the arc segment 1, and the side of the support steps is used to fit with the outer side of the ear 101. It is easy to understand that the side of the support steps is designed to be similar to the outer side of the ear 101.

[0022] Reference Figure 5 , the fixing mechanism includes a fixing seat 4, an auxiliary positioning block 5, a tensioning block 6, a pressing block 7, and a circumferential fixing component. The fixing seat 4 and the auxiliary positioning block 5 are fixedly arranged. Specifically, the fixing seat 4 is connected and fixed to the annular chassis 2 by screws, and the auxiliary positioning block 5 is connected and fixed to the annular positioning seat 3 by screws. In actual application, the relative position between the auxiliary positioning block 5 and the annular positioning seat 3 is ensured by a cylindrical pin.

[0023] Reference Figure 9 and Figure 10 , the auxiliary positioning block 5 fits with the outer side of the upper row middle ear 101. Similarly, the surface of the auxiliary positioning block 5 in contact with the ear 101 is designed to be similar. The auxiliary positioning block 5 and the support positioning structure work together to achieve the preliminary positioning of each arc segment 1.

[0024] Reference Figure 6 、 Figure 7 and Figure 13 Figure 13 , the circumferential fixing member includes a positioning pin 8 and a side pressing member 9 provided on the annular positioning seat 3. The positioning pin 8 cooperates with the rounded corner 102 of one of the lower row of lugs 101, and the side pressing member 9 is used to press the other lug 101 in the lower row tightly, and jointly with the positioning pin 8 to limit the circumferential position of the arc segment 1. Preferably, the positioning pin 8 and the side pressing member 9 are respectively arranged at two symmetrically arranged lugs 101 in the lower row. As an option, the side pressing member 9 is in a strip shape and is rotatably connected to the annular positioning seat 3 through a pin. One end of the side pressing member 9 is provided with a pressing portion 901 for contacting the lug 101. A pressing screw 10 is threadedly connected to the fixing seat 4. By screwing the pressing screw 10, the other end of the side pressing member 9 (i.e., the end far from the pressing portion 901) can be pushed, that is, the side pressing member 9 is rotated around the pin, so that the pressing portion 901 presses the lug 101 tightly. Further, the pressing portion 901 is in a convex arc structure, so that the contact surface with the lug 101 is a line contact, ensuring that the lug 101 can be pressed tightly by rotating the side pressing member 9. It should be understood that in other embodiments, the side pressing member 9 may of course also be other structures. For example, the side pressing member 9 is also a cylindrical pin like the positioning pin 8. After the arc segment 1 is initially positioned, the positioning pin 8 and the cylindrical pin are installed to jointly realize the circumferential positioning of the arc segment 1.

[0025] Reference Figure 6 、 Figure 8 and Figure 11 Figure 11 , the tensioning block 6 is connected to the fixing seat 4 and is used to tension the middle lug 101 in the lower row outward, that is, through the joint action of the tensioning block 6, the above-mentioned supporting and positioning mechanism and the above-mentioned auxiliary positioning block 5, the radial positions of the respective arc segments 1 are fixed. In this embodiment, two tensioning portions 601 are provided at one end of the tensioning block 6, and the two tensioning portions 601 are in one-to-one contact with the two middle lugs 101 in the lower row. The tensioning block 6 is slidably connected to the fixing seat 4, and a tensioning screw 11 is rotatably connected to the other end of the tensioning block 6. The tensioning screw 11 is threadedly connected to the fixing seat 4. In practical applications, the tensioning block 6 is integrally in a U-shaped structure, the tensioning portions 601 are arranged at the open end of the U-shaped structure, and the tensioning screw 11 is rotatably connected to the closed end of the U-shaped mechanism. By screwing the tensioning screw 11, the tensioning block 6 can be driven to move along the chute, so as to realize tensioning the lug 101 outward. Preferably, the tensioning portion 601 is in a convex arc structure, so that its contact with the lug 101 is a line contact, avoiding affecting the tensioning effect due to machining errors.

[0026] In order to facilitate the rotation of the tensioning screw 11, a handle is provided at the outer end of the tensioning screw 11. The manner of rotatably connecting the tensioning screw 11 to the tensioning block 6 is not limited. For example, in this embodiment, a T-shaped groove is provided on the tensioning block 6, and the end of the tensioning screw 11 is designed as a T-shaped head that mates with the T-shaped groove. In other embodiments, the manner of rotatably connecting the tensioning screw 11 to the tensioning block 6 may of course be other ways, such as connecting the tensioning screw 11 and the tensioning block 6 through a bearing. The manner of slidably connecting the tensioning block 6 to the fixed seat 4 is also not limited. For example, in this embodiment, a through chute is provided on the fixed seat 4, and the tensioning block 6 is slidably engaged with the through chute. A support seat 13 is fixedly connected (preferably by screw connection) to the outer end of the through chute, and the tensioning screw 11 is threadedly connected to the support seat 13.

[0027] Reference Figure 5 、 Figure 10 and Figure 12 , the pressing block 7 is connected to the fixed seat 4 and is used to press the upper row of middle hanging ears 101 downward to fix the axial positions of the respective arc segments 1. Specifically, the connection manner between the pressing block 7 and the fixed seat 4 is as follows: a limiting groove is provided at the top of the fixed seat 4, the pressing block 7 is disposed in the limiting groove, a supporting top 701 that contacts the bottom of the limiting groove is provided at one end of the pressing block 7, the supporting top 701 has an arc-shaped convex structure, and a pressing surface is provided at the other end of the pressing block 7; a kidney-shaped through hole 702 extending along the length direction of the pressing block 7 is provided in the middle of the pressing block 7, and the pressing block 7 is connected to the bottom of the limiting groove through a locking screw passing through the kidney-shaped through hole 702. It should be noted that since the supporting top 701 has an arc-shaped convex structure, the contact between the supporting top 701 and the bottom of the limiting groove is a line contact, which allows the end of the pressing block 7 provided with the pressing surface to rotate around the supporting top 701. After the locking screw is tightened, it is convenient to ensure that the pressing surface presses the upper row of middle hanging ears 101 downward.

[0028] Furthermore, a pressing screw 12 is threadedly connected to the top of the end of the pressing block 7 provided with the pressing surface. The pressing screw 12 is inclined and is used to press the upper row of middle hanging ears 101 in the obliquely outward direction. It is easy to understand that the pressing screw 12 presses on the inner side of the hook portion of the hanging ear 101 and applies downward and outward forces thereto to assist in pressing and tensioning the respective arc segments 1. It should be noted that since the hole for installing the locking screw on the pressing block 7 is a kidney-shaped through hole 702 extending along its length direction, this setting facilitates the adjustment of the position of the pressing block 7 in the radial direction of the arc segment 1 and avoids the pressing screw 12 being unable to press due to machining errors.

[0029] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for grinding the inner circle of a moving blade retaining ring, characterized in that, Fix each arc segment that makes up the moving blade shroud ring respectively, and make all arc segments form an annular structure simulating the working state of the moving blade shroud ring; then polish the inner sides of all arc segments through an inner circle polishing device.

2. A clamping fixture for inner circle grinding of moving blade retaining rings, which is applied to the grinding method described in claim 1, and is characterized in that It includes an annular chassis, an annular positioning seat, and fixing mechanisms corresponding to each arc segment one by one. The annular positioning seat is fixedly arranged on the top of the annular chassis and is used to support each arc segment and fit with the outer sides of the lower row end lugs one by one; The fixing mechanism includes a fixing seat, an auxiliary positioning block, a tensioning block, a pressing block, and a circumferential fixing component. The fixing seat and the auxiliary positioning block are fixedly arranged, and the auxiliary positioning block fits with the outer side of the upper row middle lug; the tensioning block is connected to the fixing seat and is used to tension the lower row middle lug outward; the pressing block is connected to the fixing seat and is used to press the upper row middle lug downward; the circumferential fixing component includes a positioning pin and a side pressing member arranged on the annular positioning seat. The positioning pin cooperates with the rounded corner of one of the lower row lugs, and the side pressing member is used to press the other lower row lug and jointly limit the circumferential position of the arc segment with the positioning pin.

3. The inner circle grinding fixture for the moving blade retaining ring according to claim 2, characterized in that, The side pressing member is in a strip shape and is rotatably connected to the annular positioning seat through a pin. One end of the side pressing member is provided with a pressing portion for contacting the lug, and a pressing screw is threadedly connected to the fixing seat and is used to push the other end of the side pressing member so that the pressing portion presses the lug.

4. The inner circle grinding fixture for the moving blade retaining ring according to claim 3, characterized in that The pressing portion is in a convex arc structure.

5. The inner circle grinding fixture for the moving blade retaining ring according to claim 2, characterized in that, One end of the tensioning block is provided with two tensioning portions, and the two tensioning portions are in contact with the two middle lower row lugs one by one. The tensioning block is slidably connected to the fixing seat, and the other end of the tensioning block is rotatably connected to a tensioning screw, and the tensioning screw is threadedly connected to the fixing seat.

6. The inner circle grinding fixture for the moving blade retaining ring according to claim 5, characterized in that, A through chute is provided on the fixing seat, and the tensioning block is slidably matched with the through chute. The outer end of the through chute is fixedly connected to a support seat, and the tensioning screw is threadedly connected to the support seat.

7. The inner circle grinding fixture for the moving blade retaining ring according to claim 5, characterized in that, The tensioning portion is in a convex arc structure.

8. The inner circle grinding fixture for the moving blade retaining ring according to claim 2, characterized in that, A limiting groove is provided at the top of the fixing seat, and the pressing block is arranged in the limiting groove. One end of the pressing block is provided with a supporting top portion in contact with the bottom of the limiting groove, and the supporting top portion is in a circular arc convex structure. The other end of the pressing block is provided with a pressing surface; a waist-shaped through hole extending along the length direction of the pressing block is provided in the middle of the pressing block, and the pressing block is connected to the bottom of the limiting groove through a locking screw passing through the waist-shaped through hole.

9. The inner circle grinding fixture for the moving blade retaining ring according to claim 8, characterized in that, A pressing screw is threadedly connected to the top of the end of the pressing block provided with the pressing surface, and the pressing screw is inclined and is used to press the upper row middle lug obliquely outward.

10. The inner circle grinding fixture for the moving blade retaining ring according to claim 2, characterized in that, The annular positioning seat is provided with a support positioning structure having the same number as the number of arc segments. The support positioning structure includes two support positioning blocks. The support positioning blocks are provided with support steps. The bottom of the support steps is used to support the arc segments, and the side of the support steps is used to fit with the outer sides of the lugs.

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