A turbine rotor low speed tip grinding fixture

Abstract

The present application relates to a kind of turbine rotor low-speed tip grinding clamps, comprising: pressing plate, two pressing plates are connected by long screw, and the opposite side of pressing plate is equipped with the stop face for clamping turbine disc;Two pressing plates are equipped with convex edge on opposite side, and a plurality of air inlet side taper face jacking blocks are fixed on the convex edge of one pressing plate, and corresponding air outlet side taper face jacking blocks are fixed on the convex edge of another pressing plate.The beneficial effects of the present application are: by the same number of independent taper face jacking blocks as blade, it can slide in the direction perpendicular to pressing plate, each is individually with the edge plate of blade, ensure that different batches of different tolerance blades can be radially jacked, so that different inner diameter processing size blade edge plate can be uniformly radially jacked, and the independent adjustment of air inlet side taper face jacking block and air outlet side taper face jacking block can be carried out for the inconsistent size of air inlet side and air outlet side edge plate of blade.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine rotor blade tip machining, and particularly relates to a low-speed blade tip grinding fixture for turbine rotors. Background Technology

[0002] Gas turbine rotors are typically composed of turbine disks, turbine blades, and corresponding locking devices. Due to machining errors, it is difficult to ensure the consistency of blade tip size after the turbine blades are installed on the turbine disk. Therefore, blade tip grinding is required after the rotor assembly is completed.

[0003] Blade tip grinding is generally divided into two types: high-speed grinding and low-speed grinding. High-speed blade tip grinding can better simulate the effect of centrifugal force during the operation of the grinding rotor, ensuring that the blade is consistent with the working process during grinding. However, high-speed grinding equipment is expensive, which is not economical for research and development and small-batch trial production. Low-speed blade tip grinding can be carried out using ordinary cylindrical grinding machines, but it cannot simulate the centrifugal force during the working process. Special tooling is required to limit the radial clearance between the turbine blade and the turbine disk to ensure the stability of the grinding process.

[0004] Taking a new type of gas turbine blade as an example, after the blade is assembled with the turbine disk, the gap between the tenon and the mortise is small. At the same time, due to structural limitations, it is not possible to insert a wedge block into the gap between the tenon and the mortise for radial clamping. Therefore, a special low-speed blade tip grinding fixture is needed to limit the radial displacement of the turbine blade. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a grinding fixture for low-speed blade tips of turbine rotors.

[0006] This turbine rotor low-speed blade tip grinding fixture includes: a pressure plate, two pressure plates connected to each other by long screws, and a stop surface for clamping the turbine disk on the opposite side of the pressure plate; a convex edge on the opposite side of the two pressure plates, several intake side conical surface clamping blocks are circumferentially fixed on the convex edge of one pressure plate, and an exhaust side conical surface clamping block is correspondingly fixed on the convex edge of the other pressure plate.

[0007] The intake-side conical clamping block and the exhaust-side conical clamping block have a conical surface on the side away from the long screw. Both the intake-side conical clamping block and the exhaust-side conical clamping block are fixed to the convex edge by hexagonal head screws. When the hexagonal head screws are rotated, the intake-side conical clamping block and the exhaust-side conical clamping block move perpendicularly to the pressure plate.

[0008] When the turbine disk is clamped and fixed between two pressure plates, the intake side conical clamping block and the exhaust side conical clamping block support the blade edge plates on the intake side and exhaust side of the turbine blade, respectively.

[0009] Preferably, the intake-side conical clamping block and the exhaust-side conical clamping block are provided with grooves that match the convex edge. The convex edge of the pressure plate is inserted into the groove, and the length of the convex edge inserted into the groove changes when the hexagonal head screw is rotated.

[0010] Preferably, both the intake-side conical clamping block and the exhaust-side conical clamping block are provided with thin nuts. The intake-side conical clamping block and the exhaust-side conical clamping block are provided with slots for installing thin nuts on the side facing the axis of the pressure plate. A hexagonal head screw passes through the pressure plate and is screwed into the thin nut, and the end of the hexagonal head screw is fixed to the thin nut.

[0011] Preferably, the number of intake-side conical clamping blocks and exhaust-side conical clamping blocks are matched with the number of turbine blades.

[0012] Preferably, the pressure plate has holes, and long screws pass through the holes of the two pressure plates in sequence and are fixed by fastening nuts.

[0013] Preferably, a flat washer is provided between the screw head of the long screw and the hole of the pressure plate, and an elastic washer and a flat washer are provided between the hole of the fastening nut and the other pressure plate.

[0014] Preferably, grooves are provided on the edges of opposite sides of the pressure plate, and protrusions corresponding to the grooves are provided on the intake-side conical clamping block and the exhaust-side conical clamping block, with the protrusions of the intake-side conical clamping block and the exhaust-side conical clamping block inserted into the grooves.

[0015] The method of using this turbine rotor low-speed blade tip grinding fixture includes the following steps:

[0016] Step 1: Install two pressure plates in sequence. The stop surfaces of the pressure plates should mate with the machining reference surfaces of the turbine disk's inlet and outlet sides, respectively. Adjust the angular position of the pressure plates so that both the inlet-side conical clamping block and the outlet-side conical clamping block are covered by the turbine blade's edge plate.

[0017] Step 2: Long screws are inserted through the two pressure plates and secured with fastening nuts;

[0018] Step 3: Use a torque wrench to rotate the hexagonal head screws on the two pressure plates to the given torque value, so that the conical surfaces of the intake side conical clamping block and the exhaust side conical clamping block support the turbine blade edge plate.

[0019] Step 4: Clamp the fixture onto the cylindrical grinding machine. After clamping and centering, perform step-by-step grinding on the tip of the turbine blade. After grinding to the given value, remove the fixture.

[0020] As a preferred option, in step four, when disassembling the fixture, first unscrew the fastening nut to separate the two pressure plates from the turbine rotor, and then rotate the hexagonal head screw to move the intake side conical clamping block and the exhaust side conical clamping block to the convex edge of the pressure plate, that is, the relative distance between the intake side conical clamping block and the exhaust side conical clamping block reaches the maximum, thus completing the restoration of the fixture.

[0021] The beneficial effects of this invention are:

[0022] 1) This invention can achieve centering and axial tensioning of the turbine rotor system. Centering is achieved by matching the stop surface on the pressure plate with the machining datum of the turbine disk. The entire system is tensioned by long screws between the pressure plates. The shaft end on one side of the pressure plate can be directly ground on an external cylindrical grinding machine for blade tip grinding.

[0023] 2) This invention uses independent conical clamping blocks, the same number as the blades, which can slide in a direction perpendicular to the pressure plate. Each block acts independently on the blade's edge plate, ensuring that blades from different batches with different tolerances can be radially clamped. Therefore, it can uniformly clamp the blade edge plates with different inner diameter machining dimensions. It can also independently adjust the conical clamping blocks on the inlet and outlet sides of the blade when the edge plate dimensions are inconsistent. The conical clamping blocks in this invention have a certain gap between them, reducing the difficulty of aligning with the blade's angular direction during clamping.

[0024] 3) This invention achieves a clearance fit between the pressure plate and the conical top block through the cooperation of the convex edge and the groove, allowing relative sliding and ensuring the centering of the conical top block; after the hexagonal head screw and the thin nut are fixed together, the relative rotational movement of the hexagonal head screw and the threaded hole on the pressure plate drives the thin nut to move perpendicular to the screw, and the thin nut drives the movement of the conical top block through the inner groove of the conical top block. The force on the outer conical surface of the conical top block is perpendicular to the surface of the conical surface, and its radial component is transmitted to the pressure plate through the cooperation of the convex edge and the groove, ensuring the overall stability of the fixture. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a low-speed blade tip grinding fixture;

[0026] Figure 2 This is a partial schematic diagram of the working mechanism of the blade tip grinding fixture;

[0027] Figure 3 This is a schematic diagram of the use of a low-speed blade tip grinding fixture.

[0028] Explanation of reference numerals in the attached drawings: 1. Pressure plate; 2. Long screw; 3. Flat washer; 4. Hexagonal head screw; 5. Inlet side conical fastening block; 6. Thin nut; 7. Outlet side conical fastening block; 8. Elastic washer; 9. Fastening nut; 10. Turbine blade; 11. Turbine disk; 12. Locking plate. Detailed Implementation

[0029] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0030] Example 1

[0031] As one example, such as Figures 1 to 3 As shown, this turbine rotor low-speed blade tip grinding fixture includes: a pressure plate 1, two pressure plates 1 connected to each other by long screws 2, a hole in the center of the pressure plate 1, the long screws 2 passing through the holes of the two pressure plates 1 in sequence, and being fixed and locked by fastening nuts 9. A flat washer 3 is provided between the screw head of the long screw 2 and the hole of the pressure plate 1, and an elastic washer 8 and a flat washer 3 are provided between the fastening nut 9 and the hole of the other pressure plate 1.

[0032] Alternatively, multiple long screws 2 can be used to fix the two pressure plates 1, that is, more than one hole can be opened.

[0033] Both sides of the pressure plate 1 are provided with a stop surface for clamping the turbine disk 11, which is aligned and centered with the machining datum of the turbine disk 11; the turbine rotor is axially fixed by locking it with the fastening nut 9. The end of the two pressure plates 1 away from the stop surface is the shaft end, which is used to clamp the turbine rotor and then directly for clamping and positioning on the external cylindrical grinding machine for blade tip grinding.

[0034] Of the two pressure plates 1, one pressure plate 1 has several intake-side conical clamping blocks 5 fixed circumferentially around its edge, and the other pressure plate 1 has an exhaust-side conical clamping block 7 correspondingly fixed to its edge. There is a large gap between the intake-side conical clamping blocks 5 and the exhaust-side conical clamping blocks 7, and this gap is adjustable, reducing the difficulty of angular alignment with the turbine blade 10 during clamping and facilitating installation with the turbine blade 10. The intake-side conical clamping blocks 5 and the exhaust-side conical clamping blocks 7 are adaptively designed according to the blade edge of the turbine blade 10 they are mating with, ensuring that sufficient radial force can be applied to the turbine blade 10 during assembly.

[0035] The intake side conical clamping block 5 and the exhaust side conical clamping block 7 have a conical surface on the side away from the long screw 2. Each intake side conical clamping block 5 and exhaust side conical clamping block 7 is individually fixed to the edge of the corresponding pressure plate 1 by a hexagonal head screw 4.

[0036] When the hexagonal head screw 4 rotates, the intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 translate in a direction perpendicular to the pressure plate 1. The movement of the conical surfaces causes the distance between the intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 and their farthest points outside the pressure plate 1 to change. When the turbine disk 11 is clamped and fixed between the two pressure plates 1, by adjusting the hexagonal head screw 4, the intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 can respectively support the inlet and outlet edge plates of the turbine blade 10, thereby achieving radial fixation of the turbine rotor.

[0037] The number of inlet-side conical clamping blocks 5 and outlet-side conical clamping blocks 7, as well as the number of hexagonal head screw 4 through holes on the edge of the pressure plate 1, are equal to the number of turbine blades 10. Each conical clamping block acts independently on the rim plate of the turbine blade 10, ensuring that turbine blades 10 of different batches and tolerances can be radially clamped. This ensures that both sides of each turbine blade 10 are fixed by the inlet-side conical clamping blocks 5 and outlet-side conical clamping blocks 7. Furthermore, by controlling the tightening torque of the hexagonal head screws 4 to be consistent, the radial clamping force of the turbine blade 10 can be ensured to be consistent. In cases where the rim plate dimensions of the inlet and outlet sides of the turbine blade 10 are inconsistent, it is only necessary to design different inlet-side conical clamping blocks 5 and outlet-side conical clamping blocks 7 to meet the requirements of the blade tip grinding fixture. All other parts are interchangeable and universal.

[0038] Example 2

[0039] As another embodiment, this embodiment two, based on embodiment one, proposes a specific method for connecting the inlet-side conical surface clamping block 5 and the outlet-side conical surface clamping block 7 to the pressure plate 1 in this turbine rotor low-speed blade tip grinding fixture:

[0040] Both pressure plates 1 have protruding edges on opposite sides for mounting conical clamping blocks and transmitting radial force. Several intake-side conical clamping blocks 5 are circumferentially fixed on the protruding edge of one pressure plate 1, and an exhaust-side conical clamping block 7 is correspondingly fixed on the protruding edge of the other pressure plate 1. The intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 are provided with grooves that match the protruding edges, and the protruding edges of the pressure plates 1 are inserted into the grooves.

[0041] Both the intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 are equipped with thin nuts 6. The intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 have slots for installing the thin nuts 6 on the side facing the axis of the pressure plate 1. A hexagonal head screw 4 passes through the pressure plate 1 and is screwed into the thin nut 6, with the end of the hexagonal head screw 4 fixed to the thin nut 6. When the hexagonal head screw 4 rotates, the intake-side conical clamping block 5 and the exhaust-side conical clamping block 7 translate in a direction perpendicular to the pressure plate 1, that is, the length of the protruding edge inserted into the groove changes when the hexagonal head screw 4 rotates.

[0042] Alternatively, grooves can be provided on the edges of opposite sides of the pressure plate 1, while protrusions corresponding to the grooves can be provided on the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7. The protrusions of the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7 are inserted into the grooves, thereby exchanging the concave-convex fit relationship between the pressure plate 1 and the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7.

[0043] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0044] Example 3

[0045] As another embodiment, this third embodiment proposes a method for using this turbine rotor low-speed blade tip grinding fixture based on embodiments one and two, including the following steps:

[0046] Step 1: Install the two pressure plates 1 in sequence. Apply thread-locking adhesive to the inner side of the thin nut 6. Place the thin nut 6 in the inner groove of the conical clamping block. Then install the air-side conical clamping block 5 and the air-outlet side conical clamping block 7 onto the corresponding pressure plates 1. Screw the hexagonal head screw 4 into the threaded hole on the pressure plate 1, pass it through the through hole on the conical clamping block, and screw it into the thin nut 6. Let it stand for a period of time to allow the thread-locking adhesive to cure, so that the thin nut 6 and the hexagonal head screw 4 are firmly connected, thus completing the assembly of the low-speed blade tip grinding fixture.

[0047] The turbine rotor consists of a turbine disk 11, turbine blades 10 and locking plates 12. In the turbine rotor assembly, there is a gap between the tenon of the turbine blade 10 and the tenon of the turbine disk 11. Therefore, the turbine blade 10 can swing on the turbine disk 11, so it needs to be aligned and fixed.

[0048] The stop surfaces of the two pressure plates 1 are respectively matched with the machining reference surfaces of the inlet and outlet sides of the turbine disk 11. The angular position of the pressure plates 1 is adjusted so that the inlet side conical clamping block 5 and the outlet side conical clamping block 7 are both covered by the edge plate of the turbine blade 10.

[0049] Step 2: The long screw 2 passes through the two pressure plates 1 and is fixed by the fastening nut 9 to achieve axial tension of the grinding rotor system.

[0050] Step 3: Rotate the hexagonal head screws 4 on the two pressure plates 1 to the given torque value using a torque wrench, so that the conical surfaces of the intake side conical clamping block 5 and the exhaust side conical clamping block 7 support the edge plate of the turbine blade 10, thereby achieving radial clamping of the intake and exhaust sides of the turbine blade 10 and preventing swaying.

[0051] Step 4: Clamp the fixture onto the cylindrical grinding machine, and after clamping and centering, perform step-by-step grinding on the tip of the turbine blade 10.

[0052] Example 4

[0053] As another embodiment, this fourth embodiment, based on the third embodiment, proposes a more specific method for using a turbine rotor low-speed blade tip grinding fixture:

[0054] In this embodiment, when the hexagonal head screw 4 is rotated clockwise, the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7 move toward each other, and the outer conical surface moves upward, thereby clamping the turbine blade 10 edge plate; when the hexagonal head screw 4 is rotated counterclockwise, the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7 move away from each other, thereby disengaging from the turbine blade 10 edge plate.

[0055] After grinding the turbine blade tip 10 to the given value in stages, the fixture is removed.

[0056] When disassembling the fixture, first unscrew the fastening nut 9 to separate the two pressure plates 1 from the turbine rotor. Then, rotate the hexagonal head screw 4 counterclockwise to make the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7 move and disengage from the turbine blade 10 edge plate. Finally, move them until the groove is completely engaged with the convex edge of the pressure plate 1, that is, the relative distance between the intake side conical surface clamping block 5 and the exhaust side conical surface clamping block 7 reaches the maximum, completing the restoration of the fixture. The turbine rotor has also completed the blade tip grinding.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A method of using a low-speed blade tip grinding fixture for turbine rotors, characterized in that, The turbine rotor low-speed blade tip grinding fixture includes: a pressure plate (1), two pressure plates (1) are connected to each other by long screws (2), and the opposing surfaces of the pressure plates (1) are provided with a stop surface for clamping the turbine disk (11); the opposing sides of the two pressure plates (1) are provided with convex edges, and several intake side conical surface clamping blocks (5) are circumferentially fixed on the convex edge of one pressure plate (1), and an exhaust side conical surface clamping block (7) is correspondingly fixed on the convex edge of the other pressure plate (1). The intake-side conical clamping block (5) and the exhaust-side conical clamping block (7) have conical surfaces on the side away from the long screw (2). The intake-side conical clamping block (5) and the exhaust-side conical clamping block (7) are both fixed to the convex edge by hexagonal head screws (4). When the hexagonal head screws (4) rotate, the intake-side conical clamping block (5) and the exhaust-side conical clamping block (7) translate perpendicularly to the pressure plate (1). The number of intake-side conical clamping blocks (5) and exhaust-side conical clamping blocks (7) are matched with the number of turbine blades (10). When the clamped turbine disk (11) is fixed between two pressure plates (1), the intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) respectively support the inlet and outlet side flanges of the turbine blade (10); The intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) are provided with grooves that match the convex edge. The convex edge of the pressure plate (1) is inserted into the groove. When the hexagonal head screw (4) is rotated, the length of the convex edge inserted into the groove changes. The pressure plate (1) has grooves on the opposite sides of its edge. The intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) have protrusions corresponding to the grooves. The protrusions of the intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) are inserted into the grooves. The method for using a low-speed blade tip grinding fixture for turbine rotors includes the following steps: Step 1: Install two pressure plates (1) in sequence. The stop surface of the pressure plate (1) is matched with the machining reference surface of the turbine disk (11) on the inlet side and the outlet side respectively. Adjust the angular position of the pressure plate (1) so that the inlet side conical clamping block (5) and the outlet side conical clamping block (7) are covered by the edge plate of the turbine blade (10). Step 2: The long screw (2) passes through the two pressure plates (1) and is fixed by the fastening nut (9); Step 3: Use a torque wrench to rotate the hexagonal head screws (4) on the two pressure plates (1) to the given torque value, so that the conical surfaces of the intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) support the edge plate of the turbine blade (10); the hexagonal head screws (4) on the two pressure plates (1) have the same torque value; Step 4: Clamp the fixture onto the cylindrical grinding machine. After clamping and centering, perform step-by-step grinding on the tip of the turbine blade (10). After grinding to the given value, remove the fixture.

2. The method of using the turbine rotor low-speed blade tip grinding fixture according to claim 1, characterized in that, Both the intake side conical clamping block (5) and the exhaust side conical clamping block (7) are equipped with thin nuts (6). The intake side conical clamping block (5) and the exhaust side conical clamping block (7) are provided with slots for installing thin nuts (6) on the side facing the axis of the pressure plate (1). The hexagonal head screw (4) passes through the pressure plate (1) and is screwed into the thin nut (6). The end of the hexagonal head screw (4) is fixed to the thin nut (6).

3. The method of using the turbine rotor low-speed blade tip grinding fixture according to claim 1, characterized in that, The pressure plate (1) has holes, and long screws (2) pass through the holes of the two pressure plates (1) in sequence and are fixed by fastening nuts (9).

4. The method of using the turbine rotor low-speed blade tip grinding fixture according to claim 3, characterized in that, A flat washer (3) is provided between the screw head of the long screw (2) and the hole of the pressure plate (1), and an elastic washer (8) and a flat washer (3) are provided between the hole of the fastening nut (9) and the hole of another pressure plate (1).

5. The method of using the turbine rotor low-speed blade tip grinding fixture according to claim 1, characterized in that, In step four, when disassembling the fixture, first unscrew the fastening nut (9) to separate the two pressure plates (1) from the turbine rotor, and then rotate the hexagonal head screw (4) to make the intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) move to the convex edge of the pressure plate (1), that is, the relative distance between the intake side conical surface clamping block (5) and the exhaust side conical surface clamping block (7) reaches the maximum, thus completing the restoration of the fixture.

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