Belt drive nuclear primary pump shaft radial force free mechanical seal test bed

Abstract

The application relates to the technical field of nuclear power generation, and discloses a belt transmission nuclear main pump shaft radial force-free mechanical seal test bed, wherein the upper end of a pump shaft coupling is connected with the lower end of a pump end belt pulley; the lower end of the pump shaft coupling is connected with the pump shaft key of the mechanical seal test bed; the pump end belt pulley and the pump end belt pulley bearing sleeve are arranged on the lower outer side of the lower bearing box cover of the mechanical seal test bed; the lower part of the lower bearing box cover is sleeved on the outer side of the pump shaft; the pump end belt pulley is driven to rotate through a driving device, the pump end belt pulley bearing and the pump shaft coupling are further driven to rotate, and finally the pump shaft is driven to rotate; at this time, the radial pulling force generated on the pump shaft by the driving device is completely applied to the lower bearing box cover, so that the influence of the radial force on the pump shaft is eliminated. The mechanical seal test bed can effectively reduce the pump shaft radial force, reduce the wear of the mechanical seal in the test process, and make the test process closer to the actual operation state of the nuclear main pump.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power generation technology, specifically relating to a test bench for a belt-driven nuclear main pump shaft without radial force mechanical seal. Background Technology

[0002] The primary loop main pump in a nuclear power plant is a core piece of equipment ensuring the safe operation of the nuclear island. Online main pumps are top-driven, and the main pump and drive motor are typically connected either directly or via a coupling. To accommodate repeated disassembly and reassembly of the mechanical seal and to reduce the platform height, nuclear main pump mechanical seal test benches generally use a bottom-mounted motor driven by a belt drive to rotate the pump shaft. The structure involves mounting pulleys on both the pump shaft end and the motor output shaft end, with the drive motor rotating the pump shaft via the belt. To improve transmission efficiency, a considerable tension is generally required between the belt and pulleys to ensure that the friction between them can drive the load to rotate. However, this structure causes the tension to be transmitted to the pump shaft, creating a radial force that causes bending deformation. This alters the original operating conditions of the test setup and affects the test results of the main pump mechanical seal.

[0003] Therefore, there is an urgent need to design a test bench for a belt-driven nuclear main pump shaft without radial force mechanical seal to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a test bench for a belt-driven nuclear main pump shaft without radial force mechanical seal, which can effectively eliminate the adverse effects of radial force on the pump shaft.

[0005] The technical solution of the present invention is as follows:

[0006] A test bench for a belt-driven nuclear main pump shaft without radial force mechanical seal, comprising a mechanical seal test bench, a radial force bearing and pump shaft power transmission mechanism, and a drive device;

[0007] The mechanical seal test bench includes a sealing body, an upper end cover, a lower end cover, a pump shaft, a mechanical seal, an upper bearing housing, a lower bearing housing, an upper bearing housing cover, a lower bearing housing cover, an upper bearing, a lower bearing, an upper shaft sleeve, a lower shaft sleeve, an upper bearing end cover, a lower bearing end cover, and a pump end bracket.

[0008] The sealing body is provided with an upper end cover and a lower end cover. It is installed on the pump end bracket through the lower end cover. A mechanical seal is installed in the sealing body. The mechanical seal includes a stationary ring and a rotating ring. The stationary ring is connected to the sealing body, and the rotating ring is installed on the pump shaft that passes through the sealing body. The sealing surfaces of the stationary ring and the rotating ring are in contact.

[0009] The pump shaft is installed in the sealing body, and the upper and lower ends of the pump shaft pass through the upper end cover and the lower end cover respectively; the lower end of the pump shaft is equipped with a lower shaft sleeve, which is connected to the inner ring of the lower bearing; the upper end of the pump shaft is equipped with an upper shaft sleeve, which is connected to the inner ring of the upper bearing.

[0010] An upper bearing housing is installed above the upper end cover, and a lower bearing housing is installed below the lower end cover; the upper bearing housing is connected to the outer ring of the upper bearing, and the lower bearing housing is connected to the outer ring of the lower bearing.

[0011] An upper bearing end cover is installed inside the upper bearing housing, and an upper bearing housing pressure cover is installed above the upper bearing housing; a lower bearing end cover is installed inside the lower bearing housing, and a lower bearing housing pressure cover is installed below the lower bearing housing. The radial force bearing and pump shaft power transmission mechanism includes a pump end pulley, a pump end pulley bearing, and a pump shaft coupling;

[0012] Among them, the upper end of the pump shaft coupling is connected to the lower end of the pump end pulley; the lower end of the pump shaft coupling is connected to the pump shaft key of the mechanical seal test bench; the pump end pulley and the pump end pulley bearing are fitted on the lower outer side of the lower bearing housing cover of the mechanical seal test bench.

[0013] The lower part of the lower bearing housing cover is fitted onto the outside of the pump shaft;

[0014] A gap is left between the lower bearing housing cover and the pump shaft;

[0015] The pump end pulley is driven to rotate by the drive device, which in turn drives the pump end pulley bearing and the pump shaft coupling to rotate, ultimately causing the pump shaft to rotate. At this time, the radial tension generated on the pump shaft by the drive device is completely applied to the lower bearing housing cover, thereby eliminating the influence of radial force on the pump shaft.

[0016] The pump shaft coupling is a tire-type coupling, which includes an upper end of the pump shaft coupling, a rubber connector, and a lower end of the pump shaft coupling connected in sequence by bolts.

[0017] The lower bushing is interference-fitted with the inner ring of the lower bearing, and the upper bushing is interference-fitted with the inner ring of the upper bearing.

[0018] The upper bearing housing is interference-fitted with the outer ring of the upper bearing, and the lower bearing housing is interference-fitted with the outer ring of the lower bearing.

[0019] The drive device includes a motor, a motor end coupling, a motor end pulley, a support shaft, a motor bracket, and a belt;

[0020] The motor is mounted on a motor bracket, and the motor output shaft is connected to a motor end coupling. The other end of the motor end coupling is connected to a support shaft. A motor end pulley is mounted on the support shaft, and the motor end pulley is connected to the pump end pulley via a belt.

[0021] The significant advantages of this invention are:

[0022] (1) The mechanical seal test bench of the present invention can effectively reduce the radial force of the pump shaft, reduce the wear of the mechanical seal during the test, and make the test process closer to the actual operating state of the nuclear main pump.

[0023] (2) The pulley of the present invention is mounted on the lower bearing housing cover by bearing. The lower bearing housing cover and the pump shaft do not contact each other, and there is a gap between them, so that the radial tension transmitted by the belt acts on the lower bearing housing cover and is transmitted to the bearing housing by the lower bearing housing cover.

[0024] (3) The present invention transmits torque through a tire-type pump shaft coupling installed between the pulley and the pump shaft, ensuring that the pump shaft works in an ideal state without radial force.

[0025] (4) The rubber connection part of the tire-type pump shaft coupling of the present invention has excellent buffer and shock absorption performance, excellent compensation performance for axial and radial offsets, can eliminate the additional load between shafts during the automatic control of the motor, improve flexibility, and is easy to disassemble and assemble, making the simulation test process more in line with the actual working conditions. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the mechanical seal test bench of the present invention;

[0027] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0028] In the diagram: 1. Upper bearing housing cover; 2. Upper bearing; 3. Upper bearing housing; 4. Upper end cover; 5. Pump shaft; 6. Mechanical seal; 7. Sealing body; 8. Lower end cover; 9. Lower bearing housing; 10. Lower bearing end cover; 11. Lower bearing; 12. Lower shaft sleeve; 13. Lower bearing housing cover; 14. Belt; 15. Pump end pulley; 16. Upper shaft sleeve; 17. Upper bearing end cover; 18. Stationary ring; 19. Dynamic ring; 20. Pump end bracket; 21. Motor; 22. Motor end coupling; 23. Motor end pulley; 24. Support shaft; 25. Motor bracket; 26. Lower end of pump shaft coupling; 27. Upper end of pump shaft coupling; 28. Pump end pulley bearing. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 The test bench for a belt-driven nuclear main pump shaft without radial force mechanical seal is shown, including a mechanical seal test bench, a radial force bearing and pump shaft power transmission mechanism, and a drive device.

[0031] The mechanical seal test bench includes a sealing body 7, an upper end cover 4, a lower end cover 8, a pump shaft 5, a mechanical seal 6, an upper bearing housing 3, a lower bearing housing 9, an upper bearing housing cover 1, a lower bearing housing cover 13, an upper bearing 2, a lower bearing 11, an upper shaft sleeve 16, a lower shaft sleeve 12, an upper bearing end cover 17, a lower bearing end cover 10, and a pump end bracket 20.

[0032] The radial force bearing and pump shaft power transmission mechanism includes a pump end pulley 15, a pump end pulley bearing 28, and a pump shaft coupling.

[0033] The drive device includes a motor 21, a motor end coupling 22, a motor end pulley 23, a support shaft 24, a motor bracket 25, and a belt 14.

[0034] The motor 21 is mounted on the motor bracket 25. The output shaft of the motor 21 is connected to the motor end coupling 22, and the other end of the motor end coupling 22 is connected to the support shaft 24. The motor end pulley 23 is mounted on the support shaft 24, and the motor end pulley 23 is connected to the pump end pulley 15 through the belt 14.

[0035] The sealing body 7 is provided with an upper end cover 4 and a lower end cover 8. The lower end cover 8 is installed on the pump end bracket 20. A mechanical seal 6 is installed inside the sealing body 7. The mechanical seal 6 includes a stationary ring 18 and a rotating ring 19. The stationary ring 18 is connected to the sealing body 7, and the rotating ring 19 is installed on the pump shaft 5 that passes through the sealing body 7. The sealing surfaces of the stationary ring 18 and the rotating ring 19 are in contact.

[0036] The pump shaft 5 is installed in the sealing body 7, and the upper and lower ends of the pump shaft 5 pass through the upper end cover 4 and the lower end cover 8 respectively; the lower end of the pump shaft 5 is equipped with a lower shaft sleeve 12, which is interference-fitted with the inner ring of the lower bearing 11; the upper end of the pump shaft 5 is equipped with an upper shaft sleeve 16, which is interference-fitted with the inner ring of the upper bearing 2.

[0037] An upper bearing housing 3 is installed above the upper end cover 4, and a lower bearing housing 9 is installed below the lower end cover 8. The upper bearing housing 3 is interference-fitted with the outer ring of the upper bearing 2, and the lower bearing housing 9 is interference-fitted with the outer ring of the lower bearing 11. An upper bearing end cover 17 is installed inside the upper bearing housing 3, and an upper bearing housing pressure cover 1 is installed above the upper bearing housing 3. A lower bearing end cover 10 is installed inside the lower bearing housing 9, and a lower bearing housing pressure cover 13 is installed below the lower bearing housing 9. A pump end pulley bearing 28 and a pump end pulley 15 are fitted onto the lower outer side of the lower bearing housing pressure cover 13.

[0038] The pump shaft coupling is a tire-type coupling, which includes an upper end 27 of the pump shaft coupling, a rubber connector, and a lower end 26 of the pump shaft coupling connected in sequence by bolts; the upper end 27 of the pump shaft coupling is connected to the lower end of the pump end pulley 15 above by bolts; the lower end 26 of the pump shaft coupling is connected to the pump shaft 5 by a key.

[0039] The lower part of the lower bearing housing cover 13 is fitted onto the outside of the pump shaft 5, with a gap between it and the pump shaft 5.

[0040] When in use, the motor 21 is started, which drives the pump end pulley 15 to rotate via the belt 14. This, in turn, drives the pump end pulley bearing 28 and the pump shaft coupling to rotate, ultimately causing the pump shaft 5 to rotate. At this time, the radial tension generated by the belt 14 driving the pump shaft 5 is entirely applied to the lower bearing housing cover 13, effectively eliminating the adverse effects of radial force on the pump shaft 5. The driving force transmitted by the belt 14 drives the pump shaft 5 to rotate through the tire-type pump shaft coupling. The tire-type pump shaft coupling has good vibration damping and shaft misalignment compensation performance to reduce the transmission of vibration to the pump shaft 5, thereby ensuring that the mechanical seal test bench simulation test is closer to the actual operating state and obtains reliable test results.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative 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. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A test bench for a belt-driven nuclear main pump shaft with no radial force mechanical seal, characterized in that: Includes a mechanical seal test bench, a radial force bearing and pump shaft power transmission mechanism, and a drive unit; The mechanical seal test bench includes a sealing body (7), an upper end cover (4), a lower end cover (8), a pump shaft (5), a mechanical seal (6), an upper bearing housing (3), a lower bearing housing (9), an upper bearing housing cover (1), a lower bearing housing cover (13), an upper bearing (2), a lower bearing (11), an upper bushing (16), a lower bushing (12), an upper bearing end cover (17), a lower bearing end cover (10), and a pump end bracket (20). The sealing body (7) is provided with an upper end cover (4) and a lower end cover (8). The lower end cover (8) is installed on the pump end bracket (20). A mechanical seal (6) is installed inside the sealing body (7). The mechanical seal (6) includes a stationary ring (18) and a rotating ring (19). The stationary ring (18) is connected to the sealing body (7), and the rotating ring (19) is installed on the pump shaft (5) that passes through the sealing body (7). The sealing surfaces of the stationary ring (18) and the rotating ring (19) are in contact. The pump shaft (5) is installed in the sealing body (7), and the upper and lower ends of the pump shaft (5) pass through the upper end cover (4) and the lower end cover (8) respectively; the lower end of the pump shaft (5) is equipped with a lower shaft sleeve (12), which is connected to the inner ring of the lower bearing (11); the upper end of the pump shaft (5) is equipped with an upper shaft sleeve (16), which is connected to the inner ring of the upper bearing (2); An upper bearing housing (3) is installed above the upper end cover (4), and a lower bearing housing (9) is installed below the lower end cover (8); the upper bearing housing (3) is connected to the outer ring of the upper bearing (2), and the lower bearing housing (9) is connected to the outer ring of the lower bearing (11). The upper bearing housing (3) is equipped with an upper bearing end cover (17), and the upper bearing housing (3) is equipped with an upper bearing housing pressure cover (1); the lower bearing housing (9) is equipped with a lower bearing end cover (10), and the lower bearing housing (9) is equipped with a lower bearing housing pressure cover (13). The radial force bearing and pump shaft power transmission mechanism includes a pump end pulley (15), a pump end pulley bearing (28), and a pump shaft coupling. Among them, the upper end (27) of the pump shaft coupling is connected to the lower end of the pump end pulley (15); the lower end (26) of the pump shaft coupling is keyed to the pump shaft (5) of the mechanical seal test bench; the pump end pulley (15) and the pump end pulley bearing (28) are fitted on the lower outer side of the lower bearing housing cover (13) of the mechanical seal test bench. The lower part of the lower bearing housing cover (13) is fitted onto the outside of the pump shaft (5); A gap is left between the lower bearing housing cover (13) and the pump shaft (5); The pump end pulley (15) is driven to rotate by the drive device, which in turn drives the pump end pulley bearing (28) and the pump shaft coupling to rotate, and finally makes the pump shaft (5) rotate. At this time, the radial tension generated by the drive device on the pump shaft (5) is completely applied to the lower bearing housing cover (13), thereby eliminating the influence of the radial force on the pump shaft (5). The pump shaft coupling is a tire-type coupling, which includes an upper end (27) of the pump shaft coupling, a rubber connector, and a lower end (26) of the pump shaft coupling connected in sequence by bolts.

2. The belt-driven nuclear main pump shaft radial force-free mechanical seal test bench as described in claim 1, characterized in that: The lower bushing (12) is interference-fitted with the inner ring of the lower bearing (11), and the upper bushing (16) is interference-fitted with the inner ring of the upper bearing (2).

3. The belt-driven nuclear main pump shaft radial force-free mechanical seal test bench as described in claim 1, characterized in that: The upper bearing housing (3) is interference-fitted with the outer ring of the upper bearing (2), and the lower bearing housing (9) is interference-fitted with the outer ring of the lower bearing (11).

4. The belt-driven nuclear main pump shaft radial force-free mechanical seal test bench as described in claim 1, characterized in that: The drive device includes a motor (21), a motor end coupling (22), a motor end pulley (23), a support shaft (24), a motor bracket (25), and a belt (14). The motor (21) is mounted on the motor bracket (25). The output shaft of the motor (21) is connected to the motor end coupling (22). The other end of the motor end coupling (22) is connected to the support shaft (24). The motor end pulley (23) is mounted on the support shaft (24). The motor end pulley (23) is connected to the pump end pulley (15) via a belt (14).

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