CN211387999U

CN211387999U - Nuclear main pump main shaft mechanical seal wave-shaped end face static ring

Info

Publication number: CN211387999U
Application number: CN201922278842.4U
Authority: CN
Inventors: 冯晓东; 李梦启; 杨立峰; 赵鹏; 梅子逸; 田秀兰; 王磊
Original assignee: Harbin Electric Power Equipment Co Ltd
Current assignee: Harbin Electric Power Equipment Co Ltd
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-09-01
Anticipated expiration: 2029-12-18

Abstract

The utility model relates to a quiet ring of nuclear main pump main shaft mechanical seal wave form terminal surface, quiet ring working face comprises nine wave form grooves 1 and a dam district 2. Each wave-shaped shallow groove is in a semicircular shape, the cosine angle of the wave-shaped shallow groove is 40 degrees, the outer circle of each wave-shaped shallow groove is sequentially connected with the adjacent wave-shaped grooves end to end, the top of the wave-shaped shallow groove is connected with a dam area, and the dam area is a plane. When in manufacturing, the grinding of the working surface and the base surface of the static ring is firstly completed. The first step grinds the base and working surfaces to the flatness and parallelism design values. And secondly, grinding the first group of three wave-shaped grooves of the working surface to reach a wave amplitude design value, and synchronously polishing the first group of three wave-shaped grooves to reach the wave amplitude design value. And thirdly, rotating the static ring by 40 degrees, repeating the first group of procedures to finish the manufacture of a second group of three wave-shaped grooves. And the fourth step stationary ring rotates by 40 degrees again to repeat the first group of procedures to finish the manufacture of the third group of three wave-shaped grooves. And fifthly, polishing the dam region of the working face to reach the planeness design value, wherein the width of the dam region is required to be reached by the polished dam region of the working face, and manufacturing the static ring is finished.

Description

Nuclear main pump main shaft mechanical seal wave-shaped end face static ring

The technical field is as follows:

the utility model relates to a quiet ring of nuclear main pump main shaft mechanical seal wave form terminal surface.

Background art:

the mechanical seal of the main shaft of the nuclear main pump is known as the heart of the nuclear main pump, and mainly prevents the coolant medium of the reactor from leaking to the outside to cause environmental pollution, so the reliability and the safety of the mechanical seal are very important to the safe and stable operation of the nuclear power station. The mechanical seal of the nuclear main pump mainly adopts dynamic pressure type mechanical seal, and the reliability is relatively higher. The dynamic pressure type mechanical seal can be further divided into a wave-shaped shallow groove, a strip-shaped shallow groove, a spiral groove, a dense cylindrical groove and the like according to the structural shape of the surface of the static ring. At present, the mechanical seal is most widely applied to the wave-shaped end face mechanical seal of the nuclear power station, has small leakage amount and higher safety and stability, and is deeply favored by the nuclear power station. The manufacturing accuracy requirements of mechanical seals directly affect the manufacturing time and service life of the seal. The common processing methods mainly comprise grinding, photoetching, electrolytic machining, electric spark machining, ultrasonic machining, laser machining, composite machining and the like. The ultra-precise grinding processing equipment based on the three-axis linkage cup-shaped line contact grinding principle is developed aiming at the manufacture of the wave-shaped shallow slot of the stationary ring by overseas mexico university and domestic university of great chain of sciences, the manufacture of the wave-shaped shallow slot is realized mainly by adjusting the running track of a grinding wheel, the surface roughness can reach 0.54 mu m, and the manufacturing method has higher cost and poorer surface quality of the wave-shaped end face. The static ring wave-shaped shallow groove sealing end face is machined by adopting electric spark in Qinghua university, but the method has long machining time and serious carbon deposition, and the surface roughness can not meet the requirement that Ra is less than or equal to 0.4 mu m. The electrical discharge machining experiment is carried out on the mechanical sealing groove of the tungsten carbide and silicon carbide materials by Taiwan national high-male application science and technology university, and a spiral groove of the gas mechanical sealing ring with the groove depth not more than 3 mu m and Ra less than 0.35 is machined in less than two hours. The Nanjing aerospace university provides a cathode mask electrolytic processing method, thousands to tens of thousands of tiny micro-pits with diameters ranging from tens of microns to hundreds of microns and depths ranging from several microns to tens of microns can be processed on a metal matrix at the same time, the processing only needs a few seconds to a few minutes, and a mask can be reused, so that the electrolytic processing efficiency is greatly improved.

And the Lanzhou university of Ridgeman adopts laser to carry out dynamic pressure groove processing on the dry gas sealing end face to obtain a spiral groove with higher processing precision. Research on singapore fabrication techniques has indicated that damage to the surface layer due to the inherent removal mechanism of ultrasound cannot be eliminated, but the use of relatively small abrasives may result in improved micropore processing. The disadvantages of the above-mentioned manufacturing processes are mainly concentrated on low efficiency, poor environmental protection, poor precision, thermal deformation effects, brittle surface, long processing time, high investment or poor economy, etc.

The invention content is as follows:

the utility model aims at disclosing a quiet ring of nuclear main pump main shaft mechanical seal wave form terminal surface that equipment drops into low, the productivity is high, economic nature is high, simple and easy high-efficient, personnel drop into less, manufacturing cycle is short, product reliability is high. The technical scheme of the utility model is that: a static ring for mechanically sealing a corrugated end face of a main shaft of a nuclear main pump is characterized in that the working end face of the static ring consists of nine identical corrugated shallow grooves (1) which are uniformly distributed in three groups and a dam area (2), each corrugated shallow groove (1) is in a semicircular shape, the cosine angle of each corrugated shallow groove (1) is 40 degrees, the excircle of each corrugated shallow groove is sequentially connected with the adjacent corrugated grooves end to end, the top of each corrugated shallow groove (1) is connected with the dam area (2), and the dam area (2) is a plane.

The technical advantages of the utility model are that:

1. the mechanical sealing static ring with nine cosine wave-shaped shallow grooves on the sealing end surface is manufactured, each wave-shaped shallow groove is in a semicircular shape, and when the mechanical sealing static ring runs normally, the pressure distribution area of the wave-shaped groove end surface between low pressure and high pressure is completely different from the linear pressure distribution of static pressure sealing, and the high-pressure distribution characteristic can obviously enhance the stability, safety, reliability and leakage control of the mechanical sealing.

2. Different from the traditional working procedures of grinding, photoetching, electrolysis, electric spark, ultrasonic wave and laser processing, the method adopts a grinding and polishing process, boron carbide grinding powder with the granularity of about 1-7 mu m is selected for grinding, the surface roughness is very low and can reach 0.05 mu m, and the final surface roughness reaches 0.005 mu m by matching with diamond paste for polishing, so that the method is very beneficial to reducing the abrasion loss between sealing friction pairs and prolonging the service life of mechanical sealing.

3. The method is characterized in that a pre-deformation tool is used for distributing according to an angle of 120 degrees, a static ring is pressed out to form three deformation high points, the three deformation high points are placed on a curved surface grinding disc for grinding, the three deformation points are ground to be consistent with the taper of the curved surface grinding disc, then the three deformation high points are synchronously placed on the curved surface polishing disc for polishing to reach the same taper, and then the three deformation high points are disassembled to release deformation stress and rebound to be in an undeformed state, so that the manufacturing of a group of three waveform shallow grooves is realized, the whole grinding and polishing process only needs 10 minutes, compared with other process methods, the manufacturing time is greatly reduced, the preset waveform state is realized, and the surface.

4. The pre-deformation tool for manufacturing is simple in structure, low in raw material cost, processing time and cost investment, and high in economic applicability compared with pure grinding equipment. The grinding and polishing manufacturing process focuses on manual controllability and has strong flexibility.

The utility model discloses a manufacturing approach of quiet ring of wave form terminal surface mainly uses the extrusion deformation frock as the main, grinds the manufacturing that realizes quiet ring working face wave form shallow slot through the extrusion deformation, has not only greatly reduced manufacturing cost, grinds the surface moreover and can reach very high surface accuracy, has improved sealed life under the prerequisite that satisfies the operation requirement.

Drawings

FIG. 1 is a schematic structural diagram of a wave-shaped end face static ring of a mechanical seal of a main shaft of a nuclear main pump.

Fig. 2 is a flow chart of a manufacturing process of the wavy end face stationary ring.

Detailed Description

As shown in figure 1, the working end face of the stationary ring is composed of nine identical wave-shaped shallow grooves 1 and a dam area 2 which are uniformly distributed in three groups, wherein each wave-shaped shallow groove 1 is in a semicircular shape, the cosine angle of each wave-shaped shallow groove 1 is 40 degrees, the outer circle of each wave-shaped shallow groove is sequentially connected with the adjacent wave-shaped groove in an end-to-end mode, the top of each wave-shaped shallow groove 1 is connected with the dam area 2, and the dam area 2 is a plane.

As shown in fig. 2, a method for manufacturing a stationary ring with a wave-shaped end face for mechanical seal of a main shaft of a nuclear main pump, 1) grinding a working surface and a base surface of the stationary ring, and turning to a grinding process after the working surface and the base surface are ground to be flat to meet the requirement of form and position tolerance; 2) grinding the base surface and the working surface of the stationary ring, adjusting the plane of a cast iron disc of a plane grinder in order to meet the requirement of the flatness of the grinding surface, grinding the cast iron disc by pressing a hexagon screw at the disc core of the grinder and combining a tool ring until the flatness is less than 0.5 mu m, and then grinding the base surface and the working surface of the stationary ring until the flatness is less than 0.5 mu m; 3) the second step is to grind a first group of three waveform shallow grooves on the working surface, on the premise that the adjustment of the conical surface of the cast iron disc of the curved surface grinding machine meets the taper design value of 0.0011-0.0015 rad, and the steps are as follows:

rad is radian, if the designed wave amplitude value of the first group of three wave-shaped shallow slots which are ground does not meet the requirement of 0.0011-0.0015 rad, the cast iron disc needs to be repeatedly ground, if the designed wave amplitude value of the first group of three wave-shaped shallow slots which are ground meets the requirement of 6-7 mu m of the error range of the wave amplitude, the first group of three wave-shaped shallow slots are polished, on the premise that the conical surface adjustment of the copper disc of the curved surface polishing machine meets the requirement of 0.0011-0.0015 rad of the designed taper value, if the error range of 0.0011-0.0015 rad of the designed taper value is not met, the copper disc needs to be repeatedly polished, and if the designed wave amplitude value of the first group of three wave-shaped shallow slots which are polished meets the requirement of 6-; 4) the third step is that the first group of same procedures are repeated to complete the manufacture of a second group of three waveform grooves, the static ring rotates 40 degrees relative to the installation position of the first group and is adjusted at the assembly position of the manufacturing tool, the taper of the cast iron disc of the curved surface grinding machine and the taper of the copper disc of the curved surface polishing machine are not changed, the second group of three waveform shallow grooves are firstly ground and reach the error range requirement of the wave amplitude design value of 6-7 mu m, then the second group of three waveform shallow grooves are polished and reach the error range requirement of the wave amplitude design value of 6-7 mu m, and then the manufacture of the second group of three waveform shallow grooves of the working surface is completed; 5) fourthly, the first group of same procedures are repeated to complete the manufacture of a third group of three wave-shaped grooves, the static ring rotates 40 degrees relative to the installation position of the second group to be adjusted at the assembly position of the manufacturing tool, the taper of the cast iron disc of the curved surface grinding machine and the taper of the copper disc of the curved surface polishing machine are not changed, the third group of three wave-shaped shallow grooves are firstly ground to reach the error range requirement of the wave amplitude design value of 6-7 mu m, then the second group of three wave-shaped shallow grooves are polished to reach the error range requirement of the wave amplitude design value of 6-7 mu m, and then the manufacture of the third group of three wave-shaped shallow grooves of the working; 6) The fifth step is polishing the dam area of the working face, and the premise is that the adjustment of the plane of the copper disc of the plane polishing machine meets the requirement that the planeness is less than 0.5 mu m, if the planeness is not less than 0.5 mu m, the copper disc needs to be repeatedly polished, and when the width value of the dam area of the polished working face meets 3-3.5 mu m, the manufacturing of the static ring is finished; 7) and finally, performing a post-assembly function test on the static ring as a part of the mechanical seal of the main shaft, checking whether the leakage is lower than 15L/h when the designed leakage pressure of the mechanical seal is 5.3MPa, if the leakage can be checked, and if the leakage is lower than 15L/h when the designed leakage pressure of the mechanical seal is not 5.3MPa, re-grinding and polishing are needed until the requirement is met.

Claims

1. A kind of nuclear main pump main axis mechanical seal wave form end face quiet ring, its characteristic is: the working end face of the static ring consists of nine identical wave-shaped shallow grooves (1) which are uniformly distributed in three groups and a dam area (2), each wave-shaped shallow groove (1) is in a semicircular shape, the cosine angle of each wave-shaped shallow groove (1) is 40 degrees, the outer circle of each wave-shaped shallow groove is sequentially connected with the adjacent wave-shaped grooves end to end, the top of each wave-shaped shallow groove (1) is connected with the dam area (2), and the dam area (2) is a plane.