Eccentric pin matching method between inner cylinder upper half and stator part sleeve

Abstract

The invention relates to an eccentric pin illumination matching method, in particular to an eccentric pin illumination matching method between an inner cylinder upper half and a stator part sleeve. The invention aims to solve the problems of inconvenience and low assembly efficiency during assembly of a part sleeve upper half part and an inner cylinder upper half part of a thermal power steam turbine at present. The process pin is manufactured before formal assembly, the eccentric distance of the eccentric pin is determined through the process pin, then the eccentric pin assembly efficiency is greatly improved, the calculation precision of the eccentricity is improved through a back arc gap measurement method, the trial assembly frequency is greatly reduced, assembly can be completed only through trial assembly for 1-2 times, and the assembly efficiency is greatly improved. The damage rate of the eccentric pin hole and the key groove is reduced to 5%, the first-pass yield of assembly reaches 95% or above, and the assembly period of a unit is remarkably shortened. The invention belongs to the technical field of turbine cylinder assembly.

Description

Technical Field

[0001] The invention relates to an eccentric pin matching method, in particular to an eccentric pin matching method between an inner cylinder upper half and a stator sleeve, and belongs to the technical field of steam turbine cylinder assembly. Background Art

[0002] When assembling the stator sleeve and the upper half of the inner cylinder of a thermal power steam turbine, it is necessary to open a keyway on the outer surface of the upper half of the sleeve and an eccentric pin hole on the inner surface of the upper half of the inner cylinder in advance, and the keyway and the eccentric pin hole are arranged eccentrically with the turbine rotation axis (such as Figure 1 As shown in the figure), the two are fixed together by an eccentric pin. Currently, there are the following technical difficulties in the assembly process: 1. The size matching between the eccentric pin hole and the keyway relies on manual experience measurement, which can easily lead to deviation in the eccentric pin processing due to measurement errors, thereby causing the mating surface to become stuck, roughened, or even damaged.

[0003] 2. The calculation error of the eccentricity of the eccentric pin is large, resulting in insufficient eccentric pin supplementation accuracy, which makes the tooth misalignment value of the upper and lower halves of the guide and stator sleeve larger after assembly.

[0004] 3. Low adjustment efficiency: When installing the upper sleeve, repeated trial installation is required due to measurement errors, which consumes a lot of time.

[0005] Therefore, providing a reasonable eccentric pin matching method to address the above technical difficulties has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for aligning an eccentric pin between the upper half of an inner cylinder and a stator sleeve.

[0007] The technical solution of the present invention is: a method for aligning an eccentric pin between an inner cylinder upper half and a stator sleeve, wherein the stator sleeve comprises an upper sleeve half and a lower sleeve half connected by bolts. Further, the method is carried out in the following steps: Step 1: Preparation process Accurately measure the inner diameter Φ1 of the eccentric pin hole on the upper inner surface of the inner cylinder, and accurately measure the keyway width B on the upper outer surface of the sleeve, and process the process pin based on Φ1 and B; The process pin includes a first cylindrical pin body and a first positioning key arranged coaxially; The outer diameter of the first cylindrical pin body is Φ2, and the nominal size of Φ2 is the same as that of Φ1; The cross section of the first positioning key is a racetrack shape, the distance between one side of the first positioning key and the outer diameter of the first cylindrical pin is E, the distance between the other side of the first positioning key and the outer diameter of the first cylindrical pin is F, and E=F=[(Φ1+B) / 2]-0.02mm; Step 2: Assemble the process pin into the eccentric pin hole Step 3: Assemble the upper half of the sleeve First, assemble the upper half of the housing into the upper half of the inner cylinder, ensuring that the first positioning key is inserted into the keyway and that the parallelism between the center plane of the upper half of the housing and the center plane of the inner cylinder is ≤0.1mm; Then, measure the first left back arc gap a and the first right back arc gap b between the upper half of the sleeve and the upper half of the inner cylinder, record the data and mark the measurement positions; Step 4: Eccentric pin processing and assembly First, measure the second left back arc gap c and the second right back arc gap d between the lower half of the housing and the lower half of the inner cylinder. Before this, the lower half of the inner cylinder and the lower half of the housing have been assembled. Then, an eccentric pin is processed according to steps a, b, c and d, wherein the eccentric pin includes an eccentrically arranged second cylindrical pin body and a second positioning key; The outer diameter of the second cylindrical pin body is the same as the nominal size of Φ1, and the key width of the second positioning key is the same as the slot width B; The eccentricity between the second positioning key and the second cylindrical pin is e=[(cd)-(ab)] / 2; Finally, remove the upper half of the sleeve and the process pin from the upper half of the inner cylinder, and insert the second cylindrical pin into the eccentric pin hole. The verticality between the eccentric pin and the center plane of the upper half of the inner cylinder should be ≤0.02mm. Step 5: Test assembly, verification and correction of eccentric pin First, install the upper half of the housing on the lower half of the housing; Then, lift the upper half of the inner cylinder with its center facing downwards, and slowly lower the upper half of the inner cylinder until the center surface of the upper half of the inner cylinder touches the center surface of the lower half of the inner cylinder. During the lowering process, ensure that the second positioning key is inserted into the keyway. Finally, separate the upper and lower halves of the inner cylinder and inspect whether the contact surface between the second positioning key and the keyway is roughened. If there is no burring, the eccentric pin size is correct; If burring occurs, it means that there is an error in the eccentricity. The eccentricity is corrected according to the depth of the burring scratch, and a new eccentric pin is processed based on the corrected eccentricity.

[0008] Compared with the prior art, the present invention has the following effects: 1. After applying the present invention, the efficiency of eccentric pin assembly is greatly improved, the calculation accuracy of the eccentricity is improved by measuring the back arc gap, the number of trial assembly times is greatly reduced, and the assembly can be completed after only 1-2 trial assembly times. The damage rate of the eccentric pin hole and the keyway is reduced to 5%, and the qualified rate of assembly in one time is more than 95%, which significantly shortens the assembly cycle of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of a keyway and an eccentric pin hole in the prior art; Figure 2 It is a front view of the process pin 5 of the present invention; Figure 3 It is a top view of the process pin 5 of the present invention; Figure 4 This is a schematic diagram of the assembly of the upper sleeve half 3 and the upper inner cylinder half 1 of the present invention; Figure 5 It is a front view of the eccentric pin 6 of the present invention; Figure 6 It is a schematic diagram of the trial assembly and verification of the eccentric pin (6) of the present invention.

[0010] In the figure: 1. Upper half of inner cylinder; 2. Lower half of inner cylinder; 3. Upper half of lower sleeve; 4. Lower half of lower sleeve; 5. Process pin; 5-1. First cylindrical pin body; 5-2. First positioning key; 6. Eccentric pin; 6-1. Second cylindrical pin body; 6-2. Second positioning key. DETAILED DESCRIPTION

[0011] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0012] Specific implementation method 1: Combination Figures 2 to 6 This embodiment describes a method for aligning an eccentric pin between an inner cylinder upper half and a stator sleeve. In this method, the stator sleeve includes an upper sleeve half 3 and a lower sleeve half 4 connected by bolts. Further, the method is performed in the following steps: Step 1: Preparation process pin 5 Accurately measure the inner diameter Φ1 of the eccentric pin hole on the inner surface of the upper half 1 of the inner cylinder, and accurately measure the keyway width B on the outer surface of the upper half 3 of the housing, and process the process pin 5 based on Φ1 and B; The process pin 5 includes a first cylindrical pin body 5-1 and a first positioning key 5-2 arranged coaxially; The outer diameter of the first cylindrical pin body 5-1 is Φ2, and the nominal size of Φ2 is the same as that of Φ1; The cross section of the first positioning key 5-2 is a racetrack shape. The distance between one side of the first positioning key 5-2 and the outer diameter of the first cylindrical pin body 5-1 is E, and the distance between the other side of the first positioning key 5-2 and the outer diameter of the first cylindrical pin body 5-1 is F, and E=F=E=F=[(Φ1+B) / 2]-0.02mm; Step 2: Assemble the process pin 5 into the eccentric pin hole Step 3: Assemble the upper half of the sleeve First, assemble the upper half of the housing 3 into the upper half of the inner cylinder 1, ensuring that the first positioning key 5-2 is inserted into the keyway, and ensuring that the parallelism between the center plane of the upper half of the housing 3 and the center plane of the inner cylinder 1 is ≤0.1mm; Then, measure the first left back arc gap a and the first right back arc gap b between the upper half of the sleeve 3 and the upper half of the inner cylinder 1. The first left back arc gap a and the first right back arc gap b are respectively located on both sides of the axis of the upper half of the sleeve 3. Record the data and mark the measurement positions. Since the keyway and the eccentric pin hole are eccentrically arranged with respect to the rotary axis of the steam turbine, when the upper half of the sleeve 3 is assembled in the upper half of the inner cylinder 1 by the process pin 5, there is an eccentric distance L between the axis of the upper half of the sleeve 3 and the axis of the upper half of the inner cylinder 1. Step 4: Processing and assembly of eccentric pin 6 First, measure the second left back arc gap c and the second right back arc gap d between the lower half of the housing 4 and the lower half of the inner cylinder 2. Before this, the lower half of the inner cylinder 2 and the lower half of the housing 4 have been assembled. The second left back arc gap c and the second right back arc gap d are respectively located on both sides of the axis of the lower half of the housing 4; Then, an eccentric pin 6 is processed according to a, b, c and d. The eccentric pin 6 includes an eccentrically arranged second cylindrical pin body 6-1 and a second positioning key 6-2; The outer diameter of the second cylindrical pin body 6-1 is the same as the nominal size of Φ1, and the key width of the second positioning key 6-2 is the same as the slot width B; The eccentricity between the second positioning key 6-2 and the second cylindrical pin 6-1 is calculated as e = [(cd) - (ab)] / 2, with an eccentricity accuracy of ±0.01 mm. This formula eliminates the eccentricity L between the upper half of the housing 3 and the upper half of the inner cylinder 1, thereby reducing the misalignment between the upper half of the inner cylinder 1 and the lower half of the housing 4 after they are fastened together. Finally, remove the upper sleeve 3 and the process pin 5 from the upper inner cylinder 1, and insert the second cylindrical pin body 6-1 into the eccentric pin hole. The verticality of the eccentric pin 6 and the dividing plane of the upper inner cylinder 1 should be ≤0.02mm. Step 5: Test and verify the eccentric pin 6 First, install the upper sleeve 3 on the lower sleeve 4; Then, lift the inner cylinder upper half 1 with its center facing downward, and slowly lower the inner cylinder upper half 1 until the center surface of the inner cylinder upper half 1 abuts against the center surface of the inner cylinder lower half 2. During the lowering process of the inner cylinder upper half 1, ensure that the second positioning key 6-2 is inserted into the keyway; Finally, separate the inner cylinder upper half 1 from the inner cylinder lower half 2 and check whether the contact surface between the second positioning key 6-2 and the keyway is roughened. If there is no burring, it means that the size of the eccentric pin 6 is correct; If burring occurs, it means that there is an error in the eccentricity. The eccentricity is corrected according to the depth of the burring scratch, and a new eccentric pin 6 is processed based on the corrected eccentricity. For example, the scratch depth on the left side of the second positioning key 6-2 is 0.2mm. When the eccentric pin 6 is reprocessed, the left side of the second positioning key 6-2 is milled 0.2mm more, and the right side of the second positioning key 6-2 is milled 0.2mm less.

[0013] Specific implementation method 2: Combination Figures 2 to 6 To illustrate this embodiment, in step 2 of this embodiment, the process pin 5 is assembled in the eccentric pin hole according to the following steps: First, place the upper half of the inner cylinder 1 on the assembly platform with the center facing upwards; Then, apply lubricant on the first cylindrical pin body 5-1; Finally, the first cylindrical pin body 5 - 1 is inserted into the eccentric pin hole.

[0014] Other components and connection methods are the same as those in the first embodiment.

[0015] Specific implementation method three: Combination Figures 2 to 6 To illustrate this embodiment, in step 1 of this embodiment, the inner diameter Φ1 of the eccentric pin hole and the keyway width B are measured by an inside micrometer or a three-dimensional coordinate measuring machine.

[0016] Furthermore, Φ1-Φ2=(0.01~0.03)mm. Other components and connection methods are the same as those in the first and second embodiments.

[0017] Specific implementation method four: Combination Figures 2 to 6 To illustrate this embodiment, in step 4 of this embodiment, the verticality between the eccentric pin 6 and the center dividing surface of the upper half 1 of the inner cylinder is detected by a right-angle ruler.

[0018] Other components and connection methods are the same as those in the first to third embodiments.

[0019] The present invention has been disclosed as above in terms of preferred embodiments, but this is not intended to limit the present invention. Any simple modifications, equivalent changes, and modifications made to the above implementation cases by any person skilled in the art without departing from the content of the technical solution of the present invention based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for aligning an eccentric pin between an inner cylinder upper half and a stator housing, wherein the stator housing comprises an upper housing half (3) and a lower housing half (4) connected by bolts, characterized in that: The method proceeds as follows: Step 1: Preparation process pin (5) Accurately measure the inner diameter Φ1 of the eccentric pin hole on the inner surface of the upper half (1) of the inner cylinder, accurately measure the keyway width B on the outer surface of the upper half (3) of the sleeve, and process the process pin (5) based on Φ1 and B; The process pin (5) comprises a first cylindrical pin body (5-1) and a first positioning key (5-2) arranged coaxially; The outer diameter of the first cylindrical pin body (5-1) is Φ2, and the nominal size of Φ2 is the same as that of Φ1; The cross section of the first positioning key (5-2) is runway-shaped, the distance between one side surface of the first positioning key (5-2) and the outer diameter of the first cylindrical pin body (5-1) is E, the distance between the other side surface of the first positioning key (5-2) and the outer diameter of the first cylindrical pin body (5-1) is F, and E=F=E=F=[(Φ1+B) / 2]-0.02mm; Step 2: Assemble the process pin (5) into the eccentric pin hole Step 3: Assemble the upper part of the sleeve (3) First, assemble the upper half of the sleeve (3) into the upper half of the inner cylinder (1), ensure that the first positioning key (5-2) is inserted into the keyway, and ensure that the parallelism of the center plane of the upper half of the sleeve (3) and the center plane of the upper half of the inner cylinder (1) is ≤0.1mm; Then, measure the first left back arc gap a and the first right back arc gap b between the upper half of the sleeve (3) and the upper half of the inner cylinder (1), record the data and mark the measurement positions; Step 4: Processing and assembly of eccentric pin (6) First, the second left back arc gap c and the second right back arc gap d between the lower half of the housing (4) and the lower half of the inner cylinder (2) are measured. Prior to this, the lower half of the inner cylinder (2) and the lower half of the housing (4) have been assembled. Then, an eccentric pin (6) is processed according to a, b, c and d, wherein the eccentric pin (6) comprises an eccentrically arranged second cylindrical pin body (6-1) and a second positioning key (6-2); The outer diameter of the second cylindrical pin body (6-1) is the same as the nominal size of Φ1, and the key width of the second positioning key (6-2) is the same as the slot width B; The eccentricity between the second positioning key (6-2) and the second cylindrical pin body (6-1) is e=[(cd)-(ab)] / 2; Finally, the upper sleeve (3) and the process pin (5) are removed from the upper inner cylinder (1), and the second cylindrical pin body (6-1) is inserted into the eccentric pin hole, and the verticality of the eccentric pin (6) and the center plane of the upper inner cylinder (1) is ≤0.02mm; Step 5: Test assembly, verification and correction of eccentric pin (6) First, install the upper sleeve (3) on the lower sleeve (4); Then, the upper part (1) of the inner cylinder is lifted with its center facing downwards, and the upper part (1) of the inner cylinder is slowly lowered until the center surface of the upper part (1) of the inner cylinder abuts against the center surface of the lower part (2) of the inner cylinder. During the lowering process of the upper part (1) of the inner cylinder, ensure that the second positioning key (6-2) is inserted into the keyway; Finally, the upper half (1) of the inner cylinder is separated from the lower half (2) of the inner cylinder, and the contact surface between the second positioning key (6-2) and the keyway is checked to see if there is any roughness; If there is no burring, it means that the eccentric pin (6) is of correct size; If the scratch occurs, it means that there is an error in the eccentricity. The eccentricity is corrected according to the depth of the scratch, and a new eccentric pin (6) is processed based on the corrected eccentricity.

2. The eccentric pin matching method between the upper half of the inner cylinder and the stator sleeve according to claim 1 is characterized in that: In the second step, the process pin (5) is assembled in the eccentric pin hole according to the following steps: First, place the upper half of the inner cylinder (1) with the center facing upwards on the assembly platform; Then, lubricant is applied to the first cylindrical pin body (5-1); Finally, the first cylindrical pin body (5-1) is inserted into the eccentric pin hole.

3. The eccentric pin matching method between the upper half of the inner cylinder and the stator sleeve according to claim 2 is characterized in that: In the step 1, Φ1-Φ2=(0.01-0.03) mm.

4. The eccentric pin matching method between the upper half of the inner cylinder and the stator sleeve according to claim 3 is characterized in that: Use a right-angle ruler to check the verticality between the eccentric pin (6) and the center plane of the upper half of the inner cylinder (1).

5. The eccentric pin matching method between the upper half of the inner cylinder and the stator sleeve according to claim 4 is characterized in that: Use an inside micrometer or a three-dimensional coordinate measuring machine to measure the inner diameter Φ1 of the eccentric pin hole and the keyway width B.

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