Device and method for measuring assembly clearance of steam turbine

Abstract

A steam turbine assembly clearance measuring device and measuring method belong to the technical field of steam turbine measurement, the steam turbine assembly clearance measuring device comprises a clearance distance measuring unit, a mobile support and a mobile distance measuring unit, the mobile support is connected to one end of the clearance distance measuring unit, and the mobile distance measuring unit is elastically connected to the other end of the clearance distance measuring unit; in the process that the movable support moves in the spanwise direction of the blades, the gap distance measuring unit and the movable distance measuring unit are jointly matched to dynamically measure the assembling gap between the two adjacent blades, and meanwhile the movable distance measuring unit synchronously measures the moving distance of the movable support in the spanwise direction of the blades. According to the invention, the assembly distance between the two blades at different positions measured by the gap distance measurement unit and the mobile distance measurement unit is used as a standard value, whether the gap width of the other blades meets the standard can be rapidly detected through the standard value, and the measurement result is relatively accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of steam turbine measurement, and in particular relates to a steam turbine assembly clearance measuring device and a measuring method. Background Art

[0002] A steam turbine is a rotary power machine that converts the energy of steam into mechanical work. After the steam from the boiler enters the steam turbine, it passes through a series of annular nozzles and impellers in turn, converting the thermal energy of the steam into mechanical energy for the rotation of the turbine rotor. In order to ensure the use effect, the installation clearance of the steam turbine impeller needs to be measured during the assembly process of the steam turbine. However, when measuring the assembly clearance between adjacent blades, in order to ensure measurement efficiency, the existing technology usually only measures a few positions, while the rest of the positions are not measured, resulting in poor measurement accuracy.

[0003] The existing technology mainly includes the traditional spiral gauge measurement method. The above method uses a spiral gauge (also known as a caliper) to manually measure the size of the gap between blades along the circumference of the blade gap. However, this measurement method is limited by the measurement range and cannot meet the measurement requirements of larger gaps. It is not applicable to complex-shaped or non-planar blades. It can only measure the local part of the blade gap and cannot obtain the full picture of the entire blade gap. Some subtle changes or problems may be ignored, resulting in low measurement efficiency.

[0004] In the prior art, a Chinese patent with the authorization announcement number CN102829699B discloses a device and method for measuring the clearance between a turbine blade and the inner wall of a cylinder, which includes a connecting sleeve, a connecting thread is provided on the outer peripheral surface of the connecting sleeve, a measuring rod that can move back and forth is provided in the connecting sleeve, the front end of the measuring rod extends from the front end of the connecting sleeve, the rear end of the measuring rod is connected to a dial indicator, the dial indicator is fixedly connected to the connecting sleeve, and the measuring rod is also connected to an elastic mechanism that can reset the measuring rod. This patent can determine the size of the dynamic clearance between the turbine blade and the inner wall of the cylinder, but for the blades arranged in a circular array around the turbine wheel body, the existing detection scheme is not applicable because it is necessary to detect the assembly clearance of multiple groups of blades and perform a lateral comparison. Summary of the invention

[0005] The present invention aims to solve the above-mentioned problems existing in the prior art in measuring the installation clearance of steam turbine blades, and provides a steam turbine assembly clearance measuring device and a measuring method, which can quickly and accurately detect the assembly clearance of blades, and the measurement result is relatively accurate.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows: A steam turbine assembly gap measuring device comprises a gap distance measuring unit, a mobile bracket and a mobile distance measuring unit, wherein the mobile bracket is connected to one end of the gap distance measuring unit, and the mobile distance measuring unit is elastically connected to the other end of the gap distance measuring unit; when the mobile bracket moves along the blade span direction, the gap distance measuring unit and the mobile distance measuring unit cooperate to dynamically measure the assembly gap between two adjacent blades, and at the same time, the mobile distance measuring unit synchronously measures the distance moved by the mobile bracket along the blade span direction.

[0007] The gap distance measuring unit comprises a guide rail body with one end fixedly connected to a movable bracket, a straight groove is provided on the guide rail body, a sliding support rod is slidably connected inside the straight groove along its length direction; the sliding support rod is connected to the movable distance measuring unit at one end away from the movable bracket.

[0008] A return spring that resists the sliding support rod is arranged in the straight groove; a distance measuring piece is fixedly connected to one end of the sliding support rod close to the mobile bracket, and an infrared rangefinder is arranged in the straight groove at one end close to the mobile bracket corresponding to the distance measuring piece.

[0009] One end of the sliding support rod away from the movable bracket extends out of the straight groove and is fixedly connected to a C-shaped frame, and a rotating wheel is rotatably connected to the C-shaped frame.

[0010] The mobile distance measuring unit comprises a rotating distance meter fixedly connected to the C-shaped frame, the rotating distance meter is provided with a rotating end, the rotating end of the rotating distance meter is fixedly connected to a second gear, and the rotating wheel is fixedly connected to a first gear meshing with the second gear.

[0011] The movable bracket comprises a first elastic clamping plate and a second elastic clamping plate which are arranged in parallel, and a spacing adjustment member which is arranged between the first elastic clamping plate and is used to adjust the gap between the first elastic clamping plate and the second elastic clamping plate; one side end surface of the first elastic clamping plate is fixedly connected to the guide rail body.

[0012] On one end surface where the first elastic clamp is connected to the guide rail body, rotating brackets are respectively arranged at both ends with the guide rail body as the axis of symmetry, and both rotating brackets are rotatably connected with diagonal braces; a straight rail is fixedly connected to one side of the guide rail body, and a connecting seat is slidably connected to the straight rail, and the ends of the two diagonal braces away from the rotating bracket are rotatably connected to the connecting seat.

[0013] The spacing adjustment member includes a connecting rail with one end fixedly connected to the first elastic clamp, and a sliding seat fixedly connected to the second elastic clamp is slidably connected inside the connecting rail; a screw is threadedly connected to the end of the connecting rail away from the guide rail body, and the end of the screw close to the guide rail body extends to the interior of the connecting rail and is rotatably connected to a pressure plate.

[0014] The starting end of the mobile bracket is provided with an electromagnetic starting member, and the electromagnetic starting member cooperates with the magnetic member to adsorb a limit plate covering the starting end surface of the mobile bracket; the electromagnetic starting member is electrically connected to the distance measuring element in the gap distance measuring unit and the mobile distance measuring unit.

[0015] The present invention also proposes a method for measuring the assembly clearance of a steam turbine, comprising the following steps: Step 1, install the mobile bracket: put the edge of the blade into the sliding groove body formed by the first elastic clamping plate and the second elastic clamping plate in the mobile bracket, and change the width of the sliding groove body through the spacing adjustment member to make it fit with the wall surface on both sides of the blade; Step 2: Push the mobile bracket to separate the electromagnetic starter from the magnetic part, so that the electromagnetic starter sends a start detection signal to the distance measuring elements in the gap distance measuring unit and the mobile distance measuring unit; Step 3, when the mobile bracket slides along the blade track, the gap distance measuring unit and the mobile distance measuring unit are both located between two adjacent blades, and the rotating wheel of the gap distance measuring unit at one end away from the mobile bracket is always kept against the side wall of the opposite blade under the action of the elastic member, and the distance measuring element in the gap distance measuring unit dynamically detects the assembly gap between the two blades; at the same time, when the rotating wheel rotates in close contact with the surface of the blade side wall, the distance measuring element in the mobile distance measuring unit is driven to rotate through the gear transmission to calculate the moving distance of the mobile bracket; Step 4: Take the spacing value at different positions between the two blades measured in the above steps as the standard value, then install the mobile bracket on another blade, measure the spacing between the other two blades at different positions in the same way, and compare it with the standard value during the measurement process. If it does not exceed the allowable error value, it is qualified; if it exceeds the allowable error value, it is unqualified.

[0016] The technical effects achieved by the present invention are: 1. The present invention measures the assembly spacing between two blades at different positions as a standard value through a gap distance measuring unit and a mobile distance measuring unit, and can quickly detect whether the gap width of the remaining blades meets the standard through this standard value, and the measurement result is relatively accurate; 2. The present invention adjusts the gap between the first elastic clamping plate and the second elastic clamping plate through the gap adjusting member, and can quickly measure the assembly gap between blades of different specifications and different complexities; 3. In the present invention, the sliding support rod in the gap distance measuring unit can make the rotating wheel installed at the front end move in a state of abutting against the side of the blade under the action of the return spring, so as to facilitate the measurement of the blade gap; 4. In the present invention, the rotating wheel transmits the moving distance signal to the rotary distance meter in the moving distance measuring unit by means of gear meshing, so that the moving distance matches the measured assembly spacing; 5. In the present invention, the electromagnetic starter cooperates with the magnetic part to send a start signal to the rotary distance meter and the infrared distance meter, thereby completing self-starting. When used in conjunction with the limit plate, the rotary distance meter and the infrared distance meter can be started at the same position of multiple blades, thereby quickly detecting whether the gap width of the remaining blades meets the standard; 6. In the present invention, in order to make the guide body maintain a specific angle during the movement of the curved blade edge, diagonal braces are symmetrically arranged on both sides of the guide body. The angle of the guide body can be controlled by the two diagonal braces, so that the guide body maintains a specific angle at the fixed position of the blade, thereby improving the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the impeller of the present invention; Figure 2 It is a schematic diagram of the structure of the present invention; Figure 3 It is a schematic structural diagram of a gap distance measuring unit of the present invention; Figure 4 The present invention Figure 3 A partial enlarged view of the middle A; Figure 5 is a structural side view of the mobile bracket of the present invention; Figure 6 It is a structural schematic diagram of the mobile bracket of the present invention.

[0018] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Mobile bracket; 2. Gap distance measuring unit; 3. Mobile distance measuring unit; 4. Wheel body; 5. Blade; 6. Guide rail body; 7. Straight groove; 8. Sliding support rod; 9. Return spring; 10. Distance measuring plate; 11. Infrared distance meter; 12. C-shaped frame; 13. Rotating wheel; 14. Rotating distance meter; 15. First meshing gear; 16. Second meshing gear; 17. First elastic clamping plate; 18. Second elastic clamping plate; 19. Connecting rail; 20. Sliding seat; 21. Pressing plate; 22. Screw; 23. Diagonal support; 24. Straight rail; 25. Connecting seat; 26. Rotating bracket; 27. Limiting plate; 28. Magnetic part; 29. ​​Electromagnetic starting part. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the present invention, it should be noted that the terms "upper", "vertical", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1: like Figure 1 The impeller of a steam turbine shown includes a wheel body 4, which is mounted on the rotor of the steam turbine. A plurality of blades 5 in a ring array are fixedly connected to the circumferential side of the wheel body 4. In order to measure the assembly gap between the plurality of blades 5, the present technical solution discloses a steam turbine assembly gap measuring device.

[0025] like Figure 1-2As shown, a steam turbine assembly gap measuring device includes a mobile bracket 1, which can move along the trajectory of any blade 5. A gap distance measuring unit 2 is installed on the mobile bracket 1. When the gap distance measuring unit 2 is located between two blades 5, it is used to measure the spacing between two adjacent blades 5. A mobile distance measuring unit 3 is elastically installed at one end of the gap distance measuring unit 2 away from the mobile bracket. The mobile distance measuring unit 3 is used to measure the moving distance of the mobile bracket 1 on the blade 5.

[0026] When in use, the device is installed between two blades 5, and the mobile bracket 1 is moved along the edge track of one of the blades 5. The mobile distance measuring unit 3 measures the dimension L of the movement of the mobile bracket 1, and the gap distance measuring unit 2 dynamically measures the distance X between the two blades 5 during the movement of the mobile bracket 1. The multiple dimensions L measured during the movement and the corresponding multiple distances X are automatically recorded as a dimension table, as shown in Table 1: Table 1 Moving distance and spacing size table Moving distance L1 L2 L3 … Ln Spacing value X1 X2 X3 … Xn like Figure 2-3 As shown, the gap distance measuring unit 2 can have multiple distance measuring methods, such as infrared distance measuring and ultrasonic distance measuring. In this embodiment, the gap distance measuring unit 2 includes a guide rail body 6 fixedly connected to the mobile bracket 1 at one end. The guide rail body 6 is in a rectangular shape. A straight groove 7 is provided on the guide rail body 6. A sliding support rod 8 is slidably mounted inside the straight groove 7. The sliding support rod 8 can slide along the length direction of the straight groove 7. The end of the sliding support rod 8 away from the mobile bracket 1 can extend out of the straight groove 7 and abut against another blade 5. A return spring 9 is also provided in the straight groove 7. The two ends of the return spring 9 respectively abut against the sliding support rod 8 and the inner wall of the straight groove 7 close to the mobile bracket 1. The elastic force of the return spring 9 can make the sliding support rod 8 automatically extend out of the straight groove 7 and abut against the blade 5.

[0027] In order to measure the distance between the two blades 5 more accurately, a distance measuring piece 10 is fixedly connected to one end of the sliding support rod 8 close to the mobile bracket 1, and an infrared rangefinder 11 is fixedly connected to one end of the straight groove 7 close to the mobile bracket 1. The laser generated by the infrared rangefinder 11 is directly opposite to the distance measuring piece 10 to obtain the distance between the distance measuring piece 10 and the infrared rangefinder 11. By measuring the position change of the infrared rangefinder 11, the dynamically changing distance between two adjacent blades 5 can be determined.

[0028] Further, such as Figure 3-4 As shown, in order to reduce the wear of the sliding support rod 8 on the blade 5, one end of the sliding support rod 8 extending out of the straight slot 7 is fixedly connected to a C-shaped frame 12, and a rotating wheel 13 is rotatably connected to the C-shaped frame 12. When the movable bracket 1 drives the sliding support rod 8 to move, the rotating wheel 13 also rolls and moves closely against the surface of the blade 5, thereby reducing wear.

[0029] In this embodiment, the mobile distance measuring unit 3 includes a rotating distance meter 14 fixedly connected to the C-shaped frame 12, the rotating distance meter 14 is provided with a rotating end, the rotating end of the rotating distance meter 14 is fixedly connected to the second meshing gear 16, and the rotating wheel 13 is fixedly connected to the first meshing gear 15 meshing with the second meshing gear 16. When the rotating wheel 13 rotates, the first meshing gear 15 drives the second meshing gear 16 to rotate, and one rotation of the second meshing gear 16 indicates that the mobile bracket 1 moves a specific distance B. At this time, the distance moved by the gap distance measuring unit 2 can be obtained by measuring the number of rotations of the second meshing gear 16.

[0030] Further, in this embodiment, the structure of the mobile bracket 1 can refer to Figure 1 , Figure 5 and Figure 6 .like Figure 5 As shown, the mobile bracket 1 includes a first elastic clamping plate 17 and a second elastic clamping plate 18 arranged in parallel, the first elastic clamping plate 17 is perpendicular to the guide rail body 6, and the middle position of the first elastic clamping plate 17 is fixedly connected to the guide rail body 6. The gap between the first elastic clamping plate 17 and the second elastic clamping plate 18 constitutes a sliding groove body that cooperates with the edge of the blade. After the blade 5 extends into the sliding groove body, the first elastic clamping plate 17 and the second elastic clamping plate 18 move along the two side end surfaces of the blade 5 respectively.

[0031] Furthermore, since the blade 5 has an arc shape, as shown in FIG. Figure 5-6 As shown, in order to make the guide rail body 6 maintain a specific angle during the movement, two rotating brackets 26 are symmetrically arranged at both ends of the end surface of the first elastic clamping plate 17 close to the guide rail body 6 with the guide rail body 6 as the symmetry axis, and the two rotating brackets 26 are both rotatably connected with diagonal braces 23, and one side of the guide rail body 6 is fixedly connected with a straight rail 24, and the inside of the straight rail 24 is slidably connected with a connecting seat 25, and the ends of the two diagonal braces 23 away from the rotating bracket 26 are both rotatably connected with the connecting seat 25. Since the shapes of the first elastic clamping plate 17 and the second elastic clamping plate 18 can change under the shape of the blade 5, when the shape of the first elastic clamping plate 17 is deformed, the angle of the guide rail body 6 can be controlled by the two diagonal braces 23, so that the guide rail body 6 maintains a specific angle at the fixed position of the blade 5.

[0032] Embodiment 2: On the basis of Example 1, further, a turbine assembly gap measuring device in this embodiment is provided with a spacing adjustment member between the first elastic clamp plate 17 and the second elastic clamp plate 18, so as to adjust the spacing between the first elastic clamp plate 17 and the second elastic clamp plate 18 to adapt to blades 5 of different thicknesses.

[0033] Preferably, the spacing adjustment members are located on the sides of the first elastic clamping plate 17 and the second elastic clamping plate 18 , and preferably three groups are provided in the middle and two end positions of the elastic clamping plate.

[0034] like Figure 5-6 As shown, in this embodiment, the spacing adjustment member includes a connecting rail 19 with one end fixedly connected to the side of the first elastic clamp 17, and the connecting rail 19 is internally slidably connected to a slide seat 20 fixedly connected to the second elastic clamp 18. When the slide seat 20 slides inside the connecting rail 19, the spacing between the first elastic clamp 17 and the second elastic clamp 18 can be adjusted.

[0035] Furthermore, in order to limit the width of the sliding groove between the first elastic clamping plate 17 and the second elastic clamping plate 18, a screw rod 22 is threadedly connected to one end of the connecting rail 19 away from the guide rail body 6, and an end of the screw rod 22 close to the guide rail body 6 extends to the inside of the connecting rail 19 and is rotatably connected to a pressing plate 21, which is slidably connected to the inside of the connecting rail 19. When the screw rod 22 rotates, the position of the pressing plate 21 can be adjusted, so that the pressing plate 21 limits the sliding seat 20, thereby limiting the maximum width of the sliding groove between the first elastic clamping plate 17 and the second elastic clamping plate 18.

[0036] Embodiment 3: On the basis of Example 1, further, in this embodiment, a turbine assembly gap measuring device is provided, in order to improve the starting accuracy, an electromagnetic starting component 29 is provided at the starting end of the movable bracket 1, and the electromagnetic starting component 29 cooperates with the magnetic component 28 to adsorb the limit plate 27 covering the starting end surface of the movable bracket 1; the electromagnetic starting component 29 is electrically connected to the gap ranging unit 2 and the ranging elements in the mobile ranging unit 3.

[0037] The magnetic member 28 is used to provide magnetic adsorption force so that the limit plate 27 is vertically attached to the starting end surface of the mobile bracket 1. When the mobile bracket 1 is installed at the starting end of the blade 5, the limit plate 27 and the starting end of the blade 5 (i.e., the free end of the blade) are abutted against each other, pushing the mobile bracket 1. Since the limit plate 27 is restricted by the blade 5, it will drive the magnetic part 28 and the electromagnetic starting part 29 to separate. Since the rotating rangefinder 14 and the infrared rangefinder 11 are both electrically connected to the electromagnetic starting part 29, when the magnetic part 28 and the electromagnetic starting part 29 are separated, the electromagnetic starting part 29 will send a starting signal to the rotating rangefinder 14 and the infrared rangefinder 11, thereby completing self-starting and allowing the rotating rangefinder 14 and the infrared rangefinder 11 to start at the same position of multiple blades 5.

[0038] Embodiment 4: See also Figure 1-6 As shown, this embodiment discloses a method for measuring the assembly clearance of a steam turbine, which specifically includes the following steps: Step 1, installing the mobile bracket 1: placing the edge of the blade 5 into the sliding groove body formed by the first elastic clamping plate 17 and the second elastic clamping plate 18 in the mobile bracket 1, and changing the width of the sliding groove body by the spacing adjustment member to make it fit with the wall surfaces on both sides of the blade 5; In this step, the gap adjustment process of the mobile bracket 1 is as follows: after placing the end blade 5 of the blade 5 into the interior of the sliding slot, the screw 22 is rotated to adjust the position of the pressing plate 21, so that the pressing plate 21 limits the connecting rail 19, and the width of the sliding slot between the first elastic clamping plate 17 and the second elastic clamping plate 18 is adjusted; Step 2: Push the mobile bracket 1 to separate the electromagnetic starter 29 from the magnetic member 28, so that the electromagnetic starter 29 sends a start detection signal to the infrared rangefinder 11 in the gap distance measuring unit 2 and the rotary rangefinder 14 in the mobile distance measuring unit 3; Step 3, when the mobile bracket 1 slides along the track of the blade 5, the gap distance measuring unit 2 and the mobile distance measuring unit 3 are both located between two adjacent blades 5, and the rotating wheel 13 of the gap distance measuring unit 2 at one end away from the mobile bracket 1 always keeps against the side wall of the opposite blade 5 under the action of the elastic member. As the gap between the adjacent blades 5 changes, the rotating wheel 13 squeezes the sliding support rod 8 connected to the guide rail body 6, so that the sliding support rod 8 is forced to drive the distance measuring piece 10 to move, and the distance measuring piece 10 can be measured in real time by the infrared rangefinder 11, so as to obtain the distance between the two blades 5; at the same time, when the rotating wheel 13 rotates close to the side wall of the blade 5, the first meshing gear 15 on the rotating wheel 13 also rotates synchronously, and the rotation of the first meshing gear 15 drives the second meshing gear 16 in the mobile distance measuring unit 3 to rotate, so that the rotating rangefinder 14 measures the moving distance of the mobile bracket 1 according to the number of rotations; Step 4: Take the spacing value at different positions between the two blades 5 measured in the above step as the standard value, then install the mobile bracket 1 on another blade 5, measure the spacing at different positions between the other two blades 5 in the same way, and compare it with the standard value during the measurement process. If it does not exceed the allowable error value, it is qualified; if it exceeds the allowable error value, it is unqualified.

[0039] In summary, the technical solution measures the assembly spacing at different positions between two blades 5 as a standard value through the gap distance measuring unit 2 and the mobile distance measuring unit 3, and can use this standard value to quickly detect whether the gap width of the remaining blades 5 meets the standard, and the measurement result is more accurate.

[0040] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A steam turbine assembly clearance measuring device, characterized in that: The invention comprises a gap distance measuring unit (2), a mobile bracket (1) and a mobile distance measuring unit (3), wherein the mobile bracket (1) is connected to one end of the gap distance measuring unit (2), and the mobile distance measuring unit (3) is elastically connected to the other end of the gap distance measuring unit (2); when the mobile bracket (1) moves along the blade span direction, the gap distance measuring unit (2) and the mobile distance measuring unit (3) cooperate to dynamically measure the assembly gap between two adjacent blades, and at the same time, the mobile distance measuring unit (3) synchronously measures the distance moved by the mobile bracket (1) along the blade span direction.

2. A steam turbine assembly clearance measuring device according to claim 1, characterized in that: The gap distance measuring unit (2) comprises a guide rail body (6) having one end fixedly connected to the mobile bracket (1); a straight groove (7) is provided on the guide rail body (6); a sliding support rod (8) is slidably connected inside the straight groove (7) along its length direction; and the end of the sliding support rod (8) away from the mobile bracket (1) is connected to the mobile distance measuring unit (3).

3. A steam turbine assembly clearance measuring device according to claim 2, characterized in that: A return spring (9) is arranged in the straight groove (7) and is against the sliding support rod (8); a distance measuring piece (10) is fixedly connected to one end of the sliding support rod (8) close to the movable bracket (1); and an infrared distance measuring piece (11) is arranged in the straight groove (7) at one end close to the movable bracket (1) corresponding to the distance measuring piece (10).

4. A steam turbine assembly clearance measuring device according to claim 2, characterized in that: One end of the sliding support rod (8) away from the movable bracket (1) extends out of the straight groove (7) and is fixedly connected to a C-shaped frame (12), and a rotating wheel (13) is rotatably connected to the C-shaped frame (12).

5. A steam turbine assembly clearance measuring device according to claim 4, characterized in that: The mobile distance measuring unit (3) comprises a rotary distance meter (14) fixedly connected to a C-shaped frame (12), the rotary distance meter (14) being provided with a rotary end, the rotary end of the rotary distance meter (14) being fixedly connected to a second meshing gear (16), and the rotating wheel (13) being fixedly connected to a first meshing gear (15) meshingly connected to the second meshing gear (16).

6. A steam turbine assembly clearance measuring device according to claim 1, characterized in that: The movable bracket (1) comprises a first elastic clamping plate (17), a second elastic clamping plate (18) arranged in parallel, and a spacing adjustment member arranged between the first elastic clamping plate (17) and used to adjust the gap between the first elastic clamping plate (18); one end surface of the first elastic clamping plate (17) is fixedly connected to the guide rail body (6).

7. A steam turbine assembly clearance measuring device according to claim 6, characterized in that: On one end surface of the first elastic clamping plate (17) connected to the guide rail body (6), rotating brackets (26) are respectively provided at both ends with the guide rail body (6) as the symmetry axis, and the two rotating brackets (26) are both rotatably connected to the diagonal braces (23); a straight rail (24) is fixedly connected to one side of the guide rail body (6), and a connecting seat (25) is slidably connected to the straight rail (24), and the ends of the two diagonal braces (23) away from the rotating bracket (26) are both rotatably connected to the connecting seat (25).

8. The steam turbine assembly clearance measuring device according to claim 6, characterized in that: The spacing adjustment member comprises a connecting rail (19) having one end fixedly connected to the first elastic clamp (17); a sliding seat (20) fixedly connected to the second elastic clamp (18) is slidably connected inside the connecting rail (19); a screw rod (22) is threadedly connected to one end of the connecting rail (19) away from the guide rail body (6); and an end of the screw rod (22) close to the guide rail body (6) extends into the interior of the connecting rail (19) and is rotatably connected to a pressure plate (21).

9. A steam turbine assembly clearance measuring device according to claim 6, characterized in that: An electromagnetic starting member (29) is provided at the starting end of the movable bracket (1); the electromagnetic starting member (29) cooperates with the magnetic member (28) to adsorb a limit plate (27) covering the starting end surface of the movable bracket (1); the electromagnetic starting member (29) is electrically connected to the distance measuring elements in the gap distance measuring unit (2) and the movable distance measuring unit (3).

10. A method for measuring the assembly clearance of a steam turbine, characterized in that: The following steps are involved: Step 1, installing the mobile bracket (1): placing the edge of the blade (5) into a sliding groove body formed by a first elastic clamping plate (17) and a second elastic clamping plate (18) in the mobile bracket (1), and changing the width of the sliding groove body by a spacing adjustment member so that it fits with the wall surfaces on both sides of the blade (5); Step 2: Push the movable bracket (1) to separate the electromagnetic starting component (29) from the magnetic component (28), so that the electromagnetic starting component (29) sends a start detection signal to the distance measuring components in the gap distance measuring unit (2) and the movable distance measuring unit (3); Step 3: During the sliding of the movable bracket (1) along the track of the blade (5), the gap distance measuring unit (2) and the movable distance measuring unit (3) are both located between two adjacent blades (5); the rotating wheel (13) at one end of the gap distance measuring unit (2) away from the movable bracket (1) is always kept in contact with the side wall of the opposite blade (5) under the action of the elastic member, and the distance measuring element in the gap distance measuring unit (2) dynamically detects the assembly gap between the two blades (5); at the same time, during the rotation of the rotating wheel (13) in close contact with the side wall surface of the blade (5), the distance measuring element in the movable distance measuring unit (3) is driven to rotate through the gear transmission, thereby calculating the moving distance of the movable bracket (1); Step 4: The distance between the two blades (5) at different positions measured in the above step is taken as the standard value, and then the movable bracket (1) is installed on another blade (5), and the distance between the other two blades (5) at different positions is measured in the same way, and compared with the standard value during the measurement process. If it does not exceed the allowable error value, it is qualified; if it exceeds the allowable error value, it is unqualified.

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