Sealing assembly and vertical thrust sliding bearing

Abstract

The present disclosure belongs to the field of nuclear power technology, and particularly relates to a sealing component and a vertical thrust sliding bearing. The sealing component of the present disclosure is provided with a plurality of circumferential grooves extending radially outward from top to bottom on the inner sidewall of the sealing seat, which gradually absorb and relieve the pressure of a large amount of oil mist generated during the high-speed rotation of the main machine, providing sufficient time for the condensation of the oil mist. In addition, a plurality of axial through holes are provided on the sidewall at the lower end of each groove, which can guide the oil droplets condensed from the oil mist in the groove to flow back to the bearing oil tank under the action of gravity. Thus, the leakage of oil mist from the gap between the sealing ring and the sealing seat is effectively avoided, and the problem of oil leakage of the bearing is effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power, and particularly relates to a sealing assembly and a vertical thrust sliding bearing. Background Art

[0002] In related technologies, the vertical thrust bearings of condensate pumps in nuclear power plants generally have relatively serious problems of oil leakage from the bearing oil seals, with frequent historical defects and often requiring refueling due to low oil levels, threatening the normal and stable operation of the equipment.

[0003] The thrust sliding bearing at the upper part of the condensate pump is used to bear the axial force and radial force of the pump. The bearing adopts a self-lubricating method, and the lubricating oil is cooled by a copper wire wound spring tube oil-water cooler installed inside the bearing chamber. The top of the bearing adopts a sealing structure combining a sealing seat and a floating ring. There is a unilateral floating amount of 2 mm, that is, a unilateral gap of 2 mm, between the outer side of the floating sealing ring of the top sealing assembly of the bearing and the sealing seat. For a thrust sliding bearing with a compact axial dimension, when the main machine rotates at a high speed, a large amount of oil mist will leak from the gap between the sealing ring and the sealing seat. In addition, the material of the sealing seat is Q235A, and the material of the floating sealing ring is polyimide, with poor thermal stability. During operation, the floating sealing ring becomes smaller in size and deformed in structure due to reasons such as friction and wear, resulting in an increase in the sealing gap and sealing failure. Summary of the Invention

[0004] To overcome the problems existing in related technologies, a sealing assembly and a vertical thrust sliding bearing are provided.

[0005] According to one aspect of the embodiments of the present disclosure, a sealing assembly is provided, and the sealing assembly includes: a sealing seat and a sealing ring;

[0006] The sealing seat is of an annular structure, the sealing seat is sleeved outside the thrust head of the vertical thrust sliding bearing, and there is a gap between the inner side wall of the inner circle of the sealing seat and the outer side wall of the thrust head;

[0007] A plurality of circumferential grooves extending radially outward are formed on the inner side wall of the inner circle of the sealing seat from top to bottom. Except for the lowermost groove, a plurality of axial through holes are formed on the side wall at the lower end of each groove, and the plurality of axial through holes communicate the groove with the adjacent groove;

[0008] The sealing ring is arranged in the lowermost groove on the inner side wall of the sealing seat.

[0009] In a possible implementation manner, the groove volumes of the plurality of grooves on the inner side wall of the sealing seat decrease in sequence from top to bottom.

[0010] In a possible implementation, the groove depths of the multiple grooves on the inner sidewall of the sealing seat inner ring gradually decrease in the order from top to bottom, and the groove widths of the multiple grooves on the inner sidewall of the sealing seat inner ring gradually decrease in the order from top to bottom.

[0011] In a possible implementation, the end of the sidewall of the multiple grooves on the inner sidewall of the sealing seat inner ring close to the thrust head is a tip.

[0012] In a possible implementation, the clearance width between the inner sidewall of the sealing ring and the outer sidewall of the thrust head is between 0.05 - 0.35 millimeters.

[0013] In a possible implementation, the clearance width between the inner sidewall of the sealing seat and the outer sidewall of the thrust head is between 0.05 - 0.25 millimeters.

[0014] In a possible implementation, the material of the sealing seat is aluminum alloy.

[0015] According to another aspect of the embodiments of the present disclosure, a vertical thrust sliding bearing is provided, and the vertical thrust sliding bearing includes the sealing assembly as described above.

[0016] The beneficial effects of the present disclosure are as follows: The sealing assembly of the present disclosure absorbs and relieves a large amount of oil mist generated during the high-speed rotation of the main engine step by step by arranging multiple circumferential grooves extending radially outward from top to bottom on the inner sidewall of the sealing seat, providing sufficient time for the condensation of the oil mist. In addition, multiple axial through holes opened on the sidewalls at the lower ends of the grooves can guide the oil droplets condensed from the oil mist in the grooves to flow back to the bearing oil tank under the action of gravity. Thus, it effectively avoids the leakage of oil mist from the clearance between the sealing ring and the sealing seat, and effectively solves the problem of oil leakage of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an axial sectional view of a sealing assembly shown according to an exemplary embodiment.

[0018] In the figure:

[0019] 1. Sealing seat; 2. Sealing ring; 3. Thrust head. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 is an axial sectional view of a sealing assembly shown according to an exemplary embodiment. As Figure 1 shown, the sealing assembly may include: a sealing seat 1 and a sealing ring 2;

[0022] As an example of this embodiment, the sealing seat 1 is of an annular structure. The sealing seat 1 is sleeved outside the thrust head 3 of the vertical thrust sliding bearing, and there is a gap between the inner ring side wall of the sealing seat 1 and the outer side wall of the thrust head 3. For example, the gap width between the inner ring side wall of the sealing ring and the outer side wall of the thrust head is between 0.05 - 0.35 millimeters. The gap width between the inner ring side wall of the sealing seat and the outer side wall of the thrust head is between 0.05 - 0.25 millimeters.

[0023] A plurality of circumferential grooves extending radially outward are formed in the inner ring side wall of the sealing seat 1 from top to bottom. Except for the lowermost groove, a plurality of axial through - holes are formed in the side wall at the lower end of each groove, and the plurality of axial through - holes communicate the groove with the adjacent groove; the sealing ring 2 is arranged in the lowermost groove of the inner ring side wall of the sealing seat 1.

[0024] For example, when the main engine rotates at a high speed, a large amount of oil mist will be generated. After the oil mist is generated, it will rise along the gap between the inner ring of the sealing ring and the thrust head. When the rising oil mist reaches each groove, the air pressure generated by the oil mist will be released in the groove. In this way, the air pressure of the oil mist is gradually released in each groove from bottom to top. The oil mist in each groove will slowly condense into oil droplets, and under the action of gravity, it will flow into the next groove along the plurality of through - holes at the lower end of each groove and flow out from the penultimate groove, and then flow back to the bearing oil tank along the gap between the inner ring of the sealing ring and the thrust head. In addition, when the oil mist rises to the uppermost groove, the pressure of the remaining oil mist still in the gap between the inner ring of the sealing ring and the thrust head is basically completely released, and this part of the remaining oil mist has sufficient time to condense into oil droplets and flow back to the bearing oil tank under the action of gravity, thus effectively controlling the oil leakage problem of the oil seal of the vertical thrust bearing.

[0025] In a possible implementation manner, the groove volumes of the plurality of grooves on the inner ring side wall of the sealing seat decrease in sequence from top to bottom. For example, the groove depths of the plurality of grooves on the inner ring side wall of the sealing seat decrease in sequence from top to bottom, and the groove widths of the plurality of grooves on the inner ring side wall of the sealing seat decrease in sequence from top to bottom. In this way, under the action of gravity, the rising speed of the oil mist becomes slower and slower, and it will encounter grooves with larger volumes. In this way, when the oil mist reaches the uppermost groove, it can further effectively ensure that the pressure of the oil mist is more fully dissipated.

[0026] In a possible implementation manner, the end of the side wall of the plurality of grooves on the inner ring side wall of the sealing seat close to the thrust head is a tip. In this way, when the thrust head rotates at a high speed, during the process of the oil mist passing between the grooves, a certain - width oil film is established between the sharp edges of each groove and the thrust head, which reduces the friction force and wear. The existence of the hydraulic film also hinders the leakage of the sealing medium and improves the sealing effect.

[0027] In a possible implementation, the material of the sealing seat is aluminum alloy. In this way, the sealing seat has good thermal stability, is not easily deformed, has a better sealing effect, and a longer service life.

[0028] In a possible implementation, a vertical thrust sliding bearing is provided, and the vertical thrust sliding bearing includes the sealing component as described above.

[0029] In an application example, replacing the sealing component of the present disclosure includes the following steps:

[0030] Step 1: Remove the baffle, the original ring seal, and the sealing seat;

[0031] Step 2: Install the floating seal ring matching the sealing component of the present disclosure on the thrust head;

[0032] Step 3: Disassemble the fastening screws on the split surface of the sealing seat of the sealing component of the present disclosure, and install the floating seal into its lowermost groove (which can also be called the installation ring groove).

[0033] Step 4: Reinstall and tighten the fastening screws on the split surface, and install them into the large end cover spigot.

[0034] The above has described the embodiments of the present disclosure. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the technical improvement of the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments.

Claims

1. A sealing assembly, characterized in that, the sealing assembly comprises: a sealing seat and a sealing ring; the sealing seat is of an annular structure, the sealing seat is sleeved outside the thrust head of a vertical thrust sliding bearing, and there is a gap between the inner side wall of the inner ring of the sealing seat and the outer side wall of the thrust head; a plurality of circumferential grooves extending radially outward are formed in the inner side wall of the inner ring of the sealing seat from top to bottom. Except for the lowermost groove, a plurality of axial through holes are formed in the side wall at the lower end of each groove, and the plurality of axial through holes communicate the groove with the adjacent groove; the sealing ring is arranged in the lowermost groove of the inner side wall of the inner ring of the sealing seat; the groove depths of the plurality of grooves on the inner side wall of the inner ring of the sealing seat decrease in sequence from top to bottom, and the groove widths of the plurality of grooves on the inner side wall of the inner ring of the sealing seat decrease in sequence from top to bottom; the groove volumes of the plurality of grooves on the inner side wall of the inner ring of the sealing seat decrease in sequence from top to bottom.

2. The sealing assembly according to claim 1, characterized in that, the end portions of the side walls of the plurality of grooves on the inner side wall of the inner ring of the sealing seat close to the thrust head are pointed tips.

3. The sealing assembly according to claim 1, characterized in that, the gap width between the inner side wall of the sealing ring and the outer side wall of the thrust head is between 0.05 - 0.35 mm.

4. The sealing assembly according to claim 1, characterized in that, the gap width between the inner side wall of the sealing seat and the outer side wall of the thrust head is between 0.05 - 0.25 mm.

5. The sealing assembly according to claim 1, characterized in that, the material of the sealing seat is aluminum alloy.

6. A vertical thrust sliding bearing, characterized in that, the vertical thrust sliding bearing comprises the sealing assembly according to any one of claims 1 to 5.

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