A primary pump seal pre-installation structure

Abstract

The utility model relates to the field of nuclear power plant main pump dynamic pressure shaft seal, especially is a main pump sealing preinstallation structure. Including: the first -level seal, second -level seal, third -level seal are connected in sequence along the axial direction, every level seal includes the sealing cavity, the shaft sleeve connected on the pump shaft, the stationary ring assembly between the shaft sleeve and the sealing cavity, the sealing spring seat on the sealing cavity, the spring on the sealing spring seat, the spring is connected stationary ring assembly in the axial direction, and the stationary ring assembly is driven by the spring and moves in the axial direction, is equipped with first peg, second peg on second -level seal, first peg is worn into stationary ring assembly, and second pin is located stationary ring assembly half, half extends into sealing spring seat, the utility model discloses through spring, boss, butterfly spring and carries out spacing and adjustment, and the structure is simple and reliable.

Description

Technical Field

[0001] This utility model relates to the field of dynamic pressure shaft seals for main pumps in nuclear power plants, and in particular to a pre-installed structure for main pump seals. Background Technology

[0002] The main pump is a key piece of equipment in a nuclear power plant. The mechanical seal is one of the key components of the main pump, used to limit the leakage of reactor coolant. It is also the most easily damaged component on the main pump. Even a slight operational deviation can cause abnormal leakage, or even lead to an emergency reactor shutdown, threatening the safe operation of the power plant and causing huge economic losses.

[0003] The main pump seal pre-installation structure is the key structure for the quality of the seal dynamic pressure effect. It is difficult to control the process assembly due to its high design and machining precision requirements. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a pre-installed structure for a main pump seal.

[0005] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows: A pre-installed seal structure for a main pump includes: a primary seal, a secondary seal, and a tertiary seal connected sequentially along the axial direction. The primary seal includes a primary sealing cavity 1.1, a primary shaft sleeve 3.1 connected to the pump shaft, a stationary ring assembly 7 located between the primary shaft sleeve 3.1 and the primary sealing cavity 1.1, a primary sealing spring seat 2.1 located on the primary sealing cavity 1.1, and a spring 4 on the primary sealing spring seat 2.1. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The primary seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the primary sealing spring seat 2.1. The secondary seal includes: a secondary sealing cavity 1.2, a secondary shaft sleeve 3.2 connected to the pump shaft, a stationary ring assembly 7 located between the secondary shaft sleeve 3.2 and the secondary sealing cavity 1.2, a secondary sealing spring seat 2.2 located on the secondary sealing cavity 1.2, and a spring 4 on the secondary sealing spring seat 2.2. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The secondary seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the secondary sealing spring seat 2.2. The three-stage seal includes: a three-stage sealing cavity 1.3, a three-stage bushing 3.3 connected to the pump shaft, a stationary ring assembly 7 located between the three-stage bushing 3.3 and the three-stage sealing cavity 1.3, a three-stage sealing spring seat 2.3 located on the three-stage sealing cavity 1.3, and a spring 4 on the three-stage sealing spring seat 2.3. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The three-stage seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the three-stage sealing spring seat 2.3. The right side of the three-stage sealing spring seat 2.3 is provided with a limiting screw 5. After passing through the three-stage sealing cavity 1.3, the limiting screw 5 axially limits the right side of the three-stage sealing spring seat 2.3. A limiting step 6 is provided on the inner surface of the three-stage sealing cavity 1.3 to limit the left side of the three-stage sealing spring seat 2.3. Multiple limiting screws 5 are evenly distributed along the circumference on the three-stage sealing cavity 1.3.

[0006] As a preferred embodiment, the stationary ring assembly 7 includes a stationary ring seat 71 and a stationary ring 72. A stationary retaining ring 73 is provided on the outer surface of the stationary ring assembly 7. The stationary retaining ring 73 is engaged with the outer diameter of the stationary ring seat 71 and the stationary ring 72, and the stationary ring seat 71 and the stationary ring 72 are connected into a whole by the stationary retaining ring 73.

[0007] As a preferred embodiment, a cavity boss 13 is provided on the inner surface of each sealing cavity, and a retaining ring boss 12 is provided on the stationary retaining ring 73. The axial distance between the cavity boss 13 and the retaining ring boss 12 of the stationary retaining ring 73 in the cavity is adjustable. The spring 4 is used to push the retaining ring boss 12 so that it fits and limits the cavity boss 13 in the axial direction.

[0008] As a preferred embodiment, a first disc spring 10 is provided on the left side of the first-stage bushing 3.1 to compress and adjust the cumulative axial error of the first-stage bushing 3.1, the second-stage bushing 3.2, and the third-stage bushing 3.3.

[0009] As a preferred embodiment, a second butterfly spring 11 is provided on the left side of the primary sealing cavity 1.1 to compress and adjust the cumulative axial error of the primary sealing cavity 1.1, the secondary sealing cavity 1.2, and the tertiary sealing cavity 1.3.

[0010] As a preferred embodiment, half of the second pin 9 is located in the stationary ring seat 71 of the stationary ring assembly 7, and the other half extends into the spring seat.

[0011] The beneficial effects of this utility model are as follows: This invention utilizes springs, bosses, and butterfly springs for limiting and adjusting. Spring 4 drives the stationary ring assembly 7 to move axially. Limiting screw 5 passes through the three-stage sealing cavity 1.3 to axially limit the right side of the three-stage sealing spring seat 2.3. A limiting step 6 is provided on the inner surface of the three-stage sealing cavity 1.3 to limit the left side of the three-stage sealing spring seat 2.3. The axial distance between the cavity boss 13 and the retaining ring boss 12 of the stationary retaining ring 73 within the cavity is adjustable. Spring 4 is used to push the retaining ring boss 12 to make it axially fit and limit the cavity boss 13. The first butterfly spring 10 is used to compress and adjust the cumulative axial error of the first-stage bushing 3.1, the second-stage bushing 3.2, and the third-stage bushing 3.3. The second butterfly spring 11 is used to compress and adjust the cumulative axial error of the first-stage sealing cavity 1.1, the second-stage sealing cavity 1.2, and the third-stage sealing cavity 1.3. Attached Figure Description

[0012] Figure 1 This is the front view of this utility model.

[0013] Among them, 1.1-first-stage sealing cavity, 1.2-second-stage sealing cavity, 1.3-tertiary sealing cavity, 2.1-first-stage sealing spring seat, 2.2-second-stage sealing spring seat, 2.3-tertiary sealing spring seat, 3.1-first-stage bushing, 3.2-second-stage bushing, 3.3-tertiary bushing, 4-spring, 5-limiting screw, 6-limiting step, 7-stationary ring assembly, 71-stationary ring seat, 72-stationary ring, 73-stationary retaining ring, 8-first pin, 9-second pin, 10-first butterfly spring, 11-second butterfly spring, 12-retaining ring boss, 13-cavity boss. Detailed Implementation

[0014] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0015] like Figure 1 As shown, this embodiment provides a main pump seal pre-installation structure, including: a primary seal, a secondary seal, and a tertiary seal connected sequentially along the axial direction; The primary seal includes a primary sealing cavity 1.1, a primary shaft sleeve 3.1 connected to the pump shaft, a stationary ring assembly 7 located between the primary shaft sleeve 3.1 and the primary sealing cavity 1.1, a primary sealing spring seat 2.1 located on the primary sealing cavity 1.1, and a spring 4 on the primary sealing spring seat 2.1. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The primary seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the primary sealing spring seat 2.1. The secondary seal includes: a secondary sealing cavity 1.2, a secondary shaft sleeve 3.2 connected to the pump shaft, a stationary ring assembly 7 located between the secondary shaft sleeve 3.2 and the secondary sealing cavity 1.2, a secondary sealing spring seat 2.2 located on the secondary sealing cavity 1.2, and a spring 4 on the secondary sealing spring seat 2.2. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The secondary seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the secondary sealing spring seat 2.2. The three-stage seal includes: a three-stage sealing cavity 1.3, a three-stage bushing 3.3 connected to the pump shaft, a stationary ring assembly 7 located between the three-stage bushing 3.3 and the three-stage sealing cavity 1.3, a three-stage sealing spring seat 2.3 located on the three-stage sealing cavity 1.3, and a spring 4 on the three-stage sealing spring seat 2.3. The spring 4 is axially connected to the stationary ring assembly 7 and drives the stationary ring assembly 7 to move axially. The three-stage seal is provided with a first pin 8 and a second pin 9. The first pin 8 passes through the stationary ring assembly 7, and the second pin 9 is half located on the stationary ring assembly 7 and half extended into the three-stage sealing spring seat 2.3. The right side of the three-stage sealing spring seat 2.3 is provided with a limiting screw 5. After passing through the three-stage sealing cavity 1.3, the limiting screw 5 axially limits the right side of the three-stage sealing spring seat 2.3. A limiting step 6 is provided on the inner surface of the three-stage sealing cavity 1.3 to limit the left side of the three-stage sealing spring seat 2.3. Multiple limiting screws 5 are evenly distributed along the circumference on the three-stage sealing cavity 1.3.

[0016] Preferably, the stationary ring assembly 7 includes a stationary ring seat 71 and a stationary ring 72. A stationary retaining ring 73 is provided on the outer surface of the stationary ring assembly 7. The stationary retaining ring 73 is engaged with the outer diameter of the stationary ring seat 71 and the stationary ring 72, and the stationary ring seat 71 and the stationary ring 72 are connected into a whole by the stationary retaining ring 73.

[0017] Preferably, each sealing cavity has a cavity boss 13 on its inner surface and a retaining ring boss 12 on its stationary retaining ring 73. The axial distance between the cavity boss 13 and the retaining ring boss 12 of the stationary retaining ring 73 in the cavity is adjustable. The spring 4 is used to push the retaining ring boss 12 so that it fits and limits the cavity boss 13 in the axial direction.

[0018] Preferably, a first disc spring 10 is provided on the left side of the first-stage bushing 3.1 to compress and adjust the cumulative axial error of the first-stage bushing 3.1, the second-stage bushing 3.2, and the third-stage bushing 3.3.

[0019] Preferably, a second butterfly spring 11 is provided on the left side of the primary sealing cavity 1.1 to compress and adjust the cumulative axial error of the primary sealing cavity 1.1, the secondary sealing cavity 1.2, and the tertiary sealing cavity 1.3.

[0020] Preferably, half of the second pin 9 is located in the stationary ring seat 71 of the stationary ring assembly 7, and the other half extends into the spring seat.

[0021] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A pre-installed structure for a main pump seal, characterized in that: include: A primary seal, a secondary seal, and a tertiary seal are connected sequentially along the axial direction. The primary seal includes a primary sealing cavity (1.1), a primary shaft sleeve (3.1) connected to the pump shaft, a stationary ring assembly (7) located between the primary shaft sleeve (3.1) and the primary sealing cavity (1.1), a primary sealing spring seat (2.1) located on the primary sealing cavity (1.1), and a spring (4) on the primary sealing spring seat (2.1). The spring (4) is axially connected to the stationary ring assembly (7), and the spring (4) drives the stationary ring assembly (7) to move axially. The primary seal is provided with a first pin (8) and a second pin (9). The first pin (8) passes through the stationary ring assembly (7), and the second pin (9) is half located on the stationary ring assembly (7) and half extended into the primary sealing spring seat (2.1). The secondary seal includes: a secondary sealing cavity (1.2), a secondary shaft sleeve (3.2) connected to the pump shaft, a stationary ring assembly (7) located between the secondary shaft sleeve (3.2) and the secondary sealing cavity (1.2), a secondary sealing spring seat (2.2) located on the secondary sealing cavity (1.2), a spring (4) on the secondary sealing spring seat (2.2), the spring (4) being axially connected to the stationary ring assembly (7), and the spring (4) driving the stationary ring assembly (7) to move axially; the secondary seal is provided with a first pin (8) and a second pin (9), the first pin (8) passing through the stationary ring assembly (7), and the second pin (9) having half located on the stationary ring assembly (7) and half extending into the secondary sealing spring seat (2.2); The three-stage seal includes: a three-stage sealing cavity (1.3), a three-stage bushing (3.3) connected to the pump shaft, a stationary ring assembly (7) located between the three-stage bushing (3.3) and the three-stage sealing cavity (1.3), a three-stage sealing spring seat (2.3) located on the three-stage sealing cavity (1.3), a spring (4) on the three-stage sealing spring seat (2.3), the spring (4) being axially connected to the stationary ring assembly (7), and the spring (4) driving the stationary ring assembly (7) to move axially; the three-stage seal is provided with a first pin (8) and a second pin (9), the first pin (8) penetrating the stationary ring assembly (7), and the second pin (9) having half located on the stationary ring assembly (7) and half extending into the three-stage sealing spring seat (2.3); The third-stage sealing spring seat (2.3) is provided with a limiting screw (5) on the right side. The limiting screw (5) passes through the third-stage sealing cavity (1.3) and axially limits the right side of the third-stage sealing spring seat (2.3). A limiting step (6) is provided on the inner surface of the third-stage sealing cavity (1.3) to limit the left side of the third-stage sealing spring seat (2.3). Multiple limiting screws (5) are evenly distributed along the circumference on the third-stage sealing cavity (1.3).

2. The main pump seal pre-installation structure according to claim 1, characterized in that: The stationary ring assembly (7) includes a stationary ring seat (71) and a stationary ring (72). A stationary retaining ring (73) is provided on the outer surface of the stationary ring assembly (7). The stationary retaining ring (73) is engaged with the outer diameter of the stationary ring seat (71) and the stationary ring (72). The stationary ring seat (71) and the stationary ring (72) are connected as a whole by the stationary retaining ring (73).

3. The main pump seal pre-installation structure according to claim 2, characterized in that: Each sealing cavity has a cavity boss (13) on its inner surface and a retaining ring boss (12) on its stationary retaining ring (73). The axial distance between the cavity boss (13) and the retaining ring boss (12) of the stationary retaining ring (73) is adjustable. A spring (4) is used to push the retaining ring boss (12) so that it fits and limits the cavity boss (13) in the axial direction.

4. The main pump seal pre-installation structure according to claim 1, characterized in that: A first disc spring (10) is provided on the left side of the first-stage bushing (3.1) to compress and adjust the cumulative axial error of the first-stage bushing (3.1), the second-stage bushing (3.2), and the third-stage bushing (3.3).

5. The main pump seal pre-installation structure according to claim 1, characterized in that: A second butterfly spring (11) is provided on the left side of the primary sealing cavity (1.1) to compress and adjust the cumulative axial error of the primary sealing cavity (1.1), the secondary sealing cavity (1.2), and the tertiary sealing cavity (1.3).

6. The main pump seal pre-installation structure according to claim 2, characterized in that: The second pin (9) is half located in the stationary ring seat (71) of the stationary ring assembly (7) and half extends into the spring seat.

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