Method for reverse arrangement of double flat keys of motor shaft and upper half coupling of nuclear main pump

Abstract

The application discloses a method for reversely arranging double flat keys for a motor shaft and an upper half coupling of a nuclear main pump, relates to the technical field of main pump maintenance, and adopts a special tool to reversely push the upper half coupling, a first flat key is prepared through a suitable calculation method, then the size of a second flat key is prepared through the cooperation of a tool key, the upper half coupling is reversely pushed through the special tool, and a suitable flat key is prepared through the gap between the suitable key and the key groove, so that the method avoids the disassembly process of the motor when the flat key and the upper half coupling need to be replaced in the maintenance process of the nuclear power station and in the special situation of a manufacturing factory, avoids the disassembly of parts such as the motor, a motor support and a thrust bearing, greatly saves the maintenance time, avoids the waste of the operation time of the nuclear power station, saves manpower and material resources, avoids many potential adverse factors such as bumps and bruises generated in the disassembly process, greatly improves the production capacity and economic benefits of an enterprise during in-plant assembly, and increases a technical capacity of nuclear main pump localization.

Description

Technical Field

[0001] This invention relates to the field of main pump maintenance technology, and in particular to a method for reverse-configuring double flat keys for the motor shaft and upper coupling of a nuclear main pump. Background Technology

[0002] During the assembly, testing, and maintenance of the main shaft seal pump of a nuclear power plant, it is necessary to replace the coupling or the two flat keys of the coupling, and the keys need to be refitted during the replacement process.

[0003] The keying process between the motor shaft and the upper coupling requires first removing the upper motor support and thrust bearing before the motor can be removed from the upper motor support. After the motor is removed, the motor rotor is taken out and turned over. The position that mates with the upper coupling is placed on top, and the motor rotor is placed in the designated keying position to ensure that the motor rotor is stable and vertically positioned. Then, the keying is performed. After the keying is completed, the motor is assembled and then installed on the upper motor support. The thrust bearing is installed, the center of the motor and the upper motor support is adjusted, the main pump is hoisted back, and the center of the main pump is readjusted. The entire disassembly and installation process is very complex. The total weight of the motor is about 65 tons, and the motor rotor is about 20 tons. The disassembly process not only poses a risk of impact but also consumes a lot of time, affecting the operation of the nuclear power plant and causing huge economic losses.

[0004] Therefore, there is an urgent need for a method for configuring double flat keys that does not require disassembling the upper motor support and thrust bearing, nor does it require disassembling the motor, and can simplify the operation process. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for reverse-configuring double parallel keys between the motor shaft and the upper coupling of a nuclear main pump. This method eliminates the need to disassemble the upper motor support and thrust bearing, disassemble the motor, or flip the motor, thus greatly simplifying the operation process.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for reverse-configured double parallel keys for the motor shaft and upper coupling of a nuclear main pump. The motor shaft has a first shaft keyway and a second shaft keyway, and the upper coupling has a first coupling keyway and a second coupling keyway. The first shaft keyway corresponds to the first coupling keyway, and the second shaft keyway corresponds to the second coupling keyway. The method for configuring the motor shaft and upper coupling of the nuclear main pump with a double flat key in reverse configuration includes the following steps: Step 1: Measure the dimensions of the keyway of the first shaft and the keyway of the first coupling, respectively; Step 2: Configure the first flat key. The gap between the two sides of the first flat key and the keyway of the first shaft is A. The gap A is less than a first preset value. The gaps between the two sides of the first flat key and the keyway of the first coupling are B1 and B2, respectively. The sum of gaps B1 and gaps B2 is less than a second preset value. Step 3: Install the prepared first flat key and perform a trial installation of the upper coupling; Step 4: Remove the upper coupling and install the tool key onto the keyway of the second shaft. Measure the gaps E1 and E2 between the two sides of the tool key and the keyway of the second coupling. The gaps between the two sides of the tool key and the keyway of the second shaft are both D, and the gap D is less than the fourth preset value. The second flat key is configured according to the measured dimensions of gaps E1 and E2. The gaps between the second flat key and the two sides of the keyway of the second coupling are F1 and F2, and the sum of gaps F1 and F2 is less than the fifth preset value. Step 5: Remove the upper coupling and the tool key; Step six: Install the prepared second flat key and test install the upper coupling. If it cannot be installed in the designated position, grind the side of the second flat key with smaller gap and test install again until it can be installed in the designated position.

[0007] Optionally, the first preset value is 0.01 mm.

[0008] Optionally, the gap B1 and the gap B2 are equal, and the second preset value is 0.063 mm.

[0009] Optionally, a first sub-step is included between step two and step three: if the upper coupling needs to be replaced, the old upper coupling to be replaced is removed, and the new upper coupling is tested separately. If the upper coupling cannot be installed in the designated position, the outer diameter of the motor shaft and the inner diameter of the upper coupling need to be measured respectively. Based on the measurement results, the inner diameter of the upper coupling is machined according to the clearance requirements. The clearance between the inner diameter of the upper coupling and the outer diameter of the motor shaft is C, and the range of clearance C is a third preset interval. If the upper coupling is not replaced, proceed to step three.

[0010] Optionally, the range of the third preset interval is 0.02mm≤C≤0.03mm.

[0011] Optionally, the fourth preset value is 0.01 mm.

[0012] Optionally, the gap F1 and the gap F2 are equal, and the fifth preset value is 0.093mm.

[0013] Optionally, before step one, the motor shaft is adjusted to the center position of the nuclear main pump.

[0014] Optionally, tools are used to install and remove the upper coupling.

[0015] Optionally, the first flat key, the tool key, and the second flat key are respectively connected to the motor shaft by screws.

[0016] The present invention achieves the following technical effects compared to the prior art: When using the method for reverse-fitting double parallel keys for the motor shaft and upper coupling of the nuclear main pump provided by this invention, the dimensions of the first shaft keyway and the first coupling keyway are measured respectively, and the first parallel key is fitted. Then, a tool key is installed, and the clearance between the tool key and the second coupling keyway and the second shaft keyway is measured. Based on the measurement results, the second parallel key is fitted, and after the fitted second parallel key is installed, the upper coupling is installed. This eliminates the need to remove the upper motor support and thrust bearing, as well as the overall disassembly of the motor, avoiding high-risk operations such as turning the motor rotor over and hoisting it. It reduces the risk of equipment collisions, ensures the assembly accuracy and equipment integrity of key components of the nuclear main pump, significantly shortens the keying and replacement operation time, effectively reduces interference with the nuclear power plant's operation plan, and significantly reduces economic losses caused by downtime. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the method for reverse-configuring double parallel keys between the motor shaft and the upper coupling of the nuclear main pump of the present invention. Figure 2 This is a cross-sectional schematic diagram showing the connection between the motor shaft and the upper coupling of the nuclear main pump of the present invention. Figure 3 This is a schematic cross-sectional view of the assembly structure of the motor shaft and the upper coupling of the nuclear main pump of the present invention, which are equipped with double flat keys in opposite directions. Figure 4 This is a schematic diagram of the gap position structure of the double flat key in the reverse configuration of the motor shaft and the upper coupling of the nuclear main pump of the present invention; Figure 5 This is a schematic diagram of the upper half coupling in the reverse configuration of the motor shaft and the upper half coupling of the nuclear main pump of the present invention. Figure 6 This is a schematic diagram of the motor rotor shaft in the reverse-configured double parallel key of the main pump of the nuclear pump of the present invention; Figure 7 This is a schematic diagram of the tool key in the double parallel key configuration between the motor shaft and the upper coupling of the nuclear main pump of the present invention. Figure 8 This is a schematic diagram of the structure of the double parallel key in the reverse configuration of the motor shaft and the upper coupling of the nuclear main pump of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 1. Motor shaft; 2. First shaft keyway; 3. Upper coupling; 4. First coupling keyway; 5. First parallel key; 6. Tool; 7. Handwheel; 8. Tool key; 9. Second shaft keyway; 10. Second coupling keyway; 11. Second parallel key; 12. Motor; 13. Upper motor support; 14. Thrust plate; 15. Thrust bearing; 16. Motor rotor. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: like Figures 1 to 8 As shown, this embodiment provides a method for reverse-configured double parallel keys for the motor shaft and upper coupling of a nuclear main pump. The motor shaft 1 is provided with a first shaft keyway 2 and a second shaft keyway 9, and the upper coupling 3 is provided with a first coupling keyway 4 and a second coupling keyway 10. The first shaft keyway 2 and the first coupling keyway 4 correspond to each other, and the second shaft keyway 9 and the second coupling keyway 10 correspond to each other. The method for configuring a double flat key between the motor shaft and the upper coupling of the nuclear main pump in reverse configuration includes the following steps: Step 1: Adjust the motor shaft 1 to the center position of the main pump. If the motor shaft 1 is not in the center position, it will affect the verticality when using tool 6 when replacing the upper coupling 3, which will cause the upper coupling 3 to be not horizontal, and thus cause damage to the upper coupling 3 and the motor shaft 1. Then, measure the dimensions of the first shaft keyway 2 and the first coupling keyway 4 respectively. Step two, prepare the first flat key 5. The gap between the two sides of the first flat key 5 and the first shaft keyway 2 is A. The gap A is less than a first preset value, which is 0.01mm. That is, A≤0.01mm; The gaps between the two sides of the first flat key 5 and the keyway 4 of the first coupling are B1 and B2, respectively. Gap B1 and gap B2 are equal, and the sum of gaps B1 and gap B2 is less than a second preset value, which is 0.063mm. That is, B1=B2, B1+B2≤0.063mm; If the upper half coupling 3 needs to be replaced, use tool 6 to install it in reverse. By rotating the handwheel 7 in tool 6, push the upper half coupling 3 upwards. Rotating the handwheel 7 in the reverse direction can remove the upper half coupling 3 downwards. Use tool 6 to test install the upper half coupling 3 separately. If the upper half coupling 3 cannot be installed in the specified position, the outer diameter of the motor shaft 1 and the inner diameter of the upper half coupling 3 need to be measured separately. According to the measurement results, the inner diameter of the upper half coupling 3 is machined according to the clearance requirements. The clearance between the inner diameter of the upper half coupling 3 and the outer diameter of the motor shaft 1 is C. The range of clearance C is the third preset interval. That is, 0.02mm≤C≤0.03mm.

[0022] If the upper coupling 3 is not replaced, proceed to step three.

[0023] Step 3: Install the prepared first flat key 5, rotate the handwheel 7 of the tool 6 to push the upper half coupling 3 upwards, and perform a trial installation of the upper half coupling 3; Step 4: Remove the upper coupling 3, install the tool key 8 onto the second shaft keyway 9, and measure the gaps E1 and E2 between the two sides of the tool key 8 and the second coupling keyway 10; the gaps between the two sides of the tool key 8 and the second shaft keyway 9 are both D, and the gap D is less than the fourth preset value; the fourth preset value is 0.01mm. That is, D≤0.01mm; The second flat key 11 is configured according to the measured dimensions of the gaps E1 and E2. The gaps between the second flat key 11 and the two sides of the keyway 10 of the second coupling are F1 and F2. The gaps F1 and F2 are equal, and the sum of the gaps F1 and F2 is less than the fifth preset value, which is 0.093mm. That is, F1=F2, F1+F1≤0.093mm; Step 5: Remove the upper coupling 3 and the tool key 8; Step 6: Install the prepared second flat key 11. Use tool 6 to push the upper half coupling 3 upwards and try to install the upper half coupling 3. If it cannot be installed in the designated position, grind the side of the second flat key 11 with smaller gap and try to install it again until it can be installed in the designated position.

[0024] When using the method for reverse-configuring double parallel keys for the motor shaft 1 and upper coupling 3 of the nuclear main pump provided by this invention, the dimensions of the first shaft keyway 2 and the first coupling keyway 4 are measured respectively, and the first parallel key 5 is configured. Then, the tool key 8 is installed, and the clearance between the tool key 8 and the second coupling keyway 10 and the second shaft keyway 9 is measured. Based on the measurement results, the second parallel key 11 is configured. After installing the configured second parallel key 11, the upper coupling 3 is installed. This eliminates the need for removing the upper motor support 13, thrust bearing 15, and thrust disc 14, as well as the overall disassembly of the motor 12, avoiding high-risk operations such as turning over and hoisting the motor rotor 16. It can reduce the risk of equipment collisions, ensure the assembly accuracy and equipment integrity of key components of the nuclear main pump, significantly shorten the keying and replacement operation time, effectively reduce interference with the nuclear power plant operation plan, and significantly reduce economic losses caused by downtime.

[0025] In this specific embodiment, tool 6 is used for the installation and disassembly of the upper coupling 3. Tool 6 is the disassembly and installation tool 6 for the main shaft seal of the 300MW nuclear power plant main pump as disclosed in patent CN103465215A. The structure and usage method of tool 6 will not be described in this embodiment.

[0026] The first flat key 5, the tool key 8, and the second flat key 11 are respectively connected to the motor shaft 1 by screws.

[0027] The actual mating clearance between the first flat key 5, the second flat key 11, and the keyway of the motor rotor 16 is less than 0.01mm. This precision is better than the 0.036mm clearance requirement in the design drawings. The smaller mating clearance effectively ensures the installation stability of the flat keys within the keyway of the motor rotor, preventing loosening or displacement of the flat keys. During the installation of the upper coupling 3, if the mating clearance between the flat key and the keyway is too large, it will directly cause radial wobble of the flat key within the keyway. This wobble will not only cause deviations in the installation positioning of the upper coupling 3, but will also further interfere with the measurement of the clearance between the second flat key 11 and the corresponding keyway, ultimately leading to inaccurate measurement results and affecting subsequent assembly accuracy control.

[0028] The tool key 8 adopts a stepped key structure, and the clearance between it and the keyway of the motor rotor 16 is less than 0.01mm. This ensures the stability of the tool key within the keyway and effectively reduces the error when measuring the clearance between the tool key 8 and the upper coupling 3. The flat key that mates with the keyway of the upper coupling 3 has dimensions on both sides that are 0.1mm smaller than the keyway of the motor rotor 16. This facilitates feeler gauge measurement and avoids assembly difficulties caused by machining errors in the symmetry of the keyway of the upper coupling 3. In addition, the tool key 8 is designed as an extended structure, extending to the outside of the keyway of the motor rotor 16. This facilitates the insertion of the feeler gauge from the side of the tool key for measurement and also serves as a guide for the installation of the upper coupling 3, replacing the flat key.

[0029] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for reverse-configuring double parallel keys for the motor shaft and upper coupling of a nuclear main pump, wherein the motor shaft (1) is provided with a first shaft keyway (2) and a second shaft keyway (10), and the upper coupling (3) is provided with a first coupling keyway (4) and a second coupling keyway (9), wherein the first shaft keyway (2) corresponds to the first coupling keyway (4), and the second shaft keyway (10) corresponds to the second coupling keyway (9), characterized in that, The method for configuring the motor shaft and upper coupling of the nuclear main pump with a double flat key in reverse configuration includes the following steps: Step 1: Measure the dimensions of the first shaft keyway (2) and the first coupling keyway (4) respectively; Step 2: Prepare the first flat key (5). The gap between the two sides of the first flat key (5) and the first shaft keyway (2) is A. The gap A is less than the first preset value. The gaps between the two sides of the first flat key (5) and the first coupling keyway (4) are B1 and B2 respectively. The sum of the gaps B1 and B2 is less than the second preset value. Step 3: Install the prepared first flat key (5) and perform a trial installation of the upper coupling (3); Step 4: Remove the upper coupling (3), install the tool key (8) onto the second shaft keyway (10), and measure the gaps E1 and E2 between the two sides of the tool key (8) and the second coupling keyway (9); the gaps between the two sides of the tool key (8) and the second shaft keyway (10) are both D, and the gap D is less than the fourth preset value; The second flat key (11) is configured according to the measured dimensions of the gaps E1 and E2. The gaps between the second flat key (11) and the two sides of the keyway (9) of the second coupling are F1 and F2, and the sum of the gaps F1 and F2 is less than the fifth preset value. Step 5: Remove the upper coupling (3) and the tool key (8). Step six: Install the prepared second flat key (11), and perform a trial installation of the upper coupling (3). If it cannot be installed in the designated position, grind the side of the second flat key (11) with a small gap, and try to install it again until it can be installed in the designated position.

2. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The first preset value is 0.01 mm.

3. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The gaps B1 and B2 are equal, and the second preset value is 0.063 mm.

4. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, Between step two and step three, there is also a first sub-step: if the upper half coupling (3) needs to be replaced, remove the upper half coupling (3) that needs to be replaced, and test install the new upper half coupling (3) separately. If the upper half coupling (3) cannot be installed in the specified position, the outer diameter of the motor shaft (1) and the inner diameter of the upper half coupling (3) need to be measured respectively. According to the measurement results, the inner diameter of the upper half coupling is machined according to the clearance requirements. The clearance between the inner diameter of the upper half coupling (3) and the outer diameter of the motor shaft (1) is C. The range of the clearance C is the third preset interval. If the upper half coupling (3) is not replaced, proceed to step three.

5. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 4, characterized in that, The range of the third preset interval is 0.02mm≤C≤0.03mm.

6. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The fourth preset value is 0.01 mm.

7. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The gaps F1 and F2 are equal, and the fifth preset value is ≤0.093mm.

8. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, Before step one, the motor shaft (1) is adjusted to the center position of the nuclear main pump.

9. The method for reverse-configuration of double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The upper coupling (3) is installed and disassembled using a tool (6).

10. The method for reverse-configuring double parallel keys between the motor shaft and the upper coupling of the nuclear main pump according to claim 1, characterized in that, The first flat key (5), the tool key (8) and the second flat key (11) are respectively connected to the motor shaft (1) by screws.

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