CN102606512A

CN102606512A - Structure for reducing abrasion of seal ring for coolant drain tank pump

Info

Publication number: CN102606512A
Application number: CN201210083329XA
Authority: CN
Inventors: 陆金琪; 陈超
Original assignee: Shanghai Apollo Machinery Co Ltd
Current assignee: Shanghai Apollo Machinery Co Ltd
Priority date: 2012-03-27
Filing date: 2012-03-27
Publication date: 2012-07-25

Abstract

The invention discloses a structure for reducing abrasion of a seal ring for a coolant drain tank pump, which comprises an impeller, the seal ring and a guide bearing, wherein the impeller is arranged at the lower portion of a pump shaft and located in a pressurized-water chamber of a pump body, the seal ring is arranged between the outlet end of a rear cover plate of the impeller and the middle of a cavity of the pump body, and the guide bearing is arranged on the pump shaft and located at the upper portion of the cavity of the pump body. The guide bearing comprises a metal outer cover and a sliding bush, the sliding bush is embedded in a cavity of the metal outer cover in interference fit mode, the sliding bush is made of engineering rubber, the upper end of the metal outer cover is provided with a cover plate, a plurality of installation holes are evenly distributed on the cover plate, and the guide bearing is fixed on the pump body through a plurality of screws. The structure for reducing the abrasion of the seal ring can control transient swing amplitude in the radial direction in the transient of starting and stopping, further can reduce the gap between the impeller and the seal ring, and enables the seal ring to have longer service life.

Description

A kind of structure that is used for the minimizing seal wears of freezing mixture drain tank pump

Technical field

The present invention relates to a kind of reactor with freezing mixture drain tank pump, be specifically related to a kind of structure that reduces seal wears that is used for freezing mixture drain tank pump.

Background technique

The function of reactor coolant drain tank pump (abbreviation main pump) is to make freezing mixture form forced circulation, thereby is sent to steam generator to the heat energy that produces in the reactor, to produce steam, the driving steam turbine acting.Basic demand to it is:

1) can under the unmanned maintenance condition, work safely and reliably for a long time; Be convenient to maintenance, auxiliary system is simple;

2) Runner assembly should be able to provide enough rotary inertias, so that under the station blackout situation, utilizes the running down of main pump that enough flows are provided, and makes reactor core obtain suitable cooling;

3) to lack with the leakage rate of radioactive freezing mixture.

Impeller ring in the reactor coolant drain tank pump belongs to easily damaged parts; Because pump radial force, particularly pump have very big radial force starting and shut down moment, pump shaft and impeller can produce rigid deformation; Make the mutually friction and wearing and tearing of seal ring and impeller, thereby influence the working life of pump.Present freezing mixture drain tank pump adopts guide bearing to come bearing radial force in the bottom of pump shaft; This guide bearing is made by the tetrafluoro rubber material; So wearing and tearing are very fast; If things go on like this not only do not have the effect of bearing radial force, the wearing and tearing between impeller and the seal ring are also strengthened, and then the leakage rate of pumping chamber has also been strengthened.

Summary of the invention

The objective of the invention is in order to overcome the deficiency of existing technology; A kind of structure that is used for the minimizing seal wears of freezing mixture drain tank pump is provided; It can control the amplitude that radially wobble of rotor part in the moment that starts and shut down; And then can dwindle the gap between impeller and the seal ring, make seal ring obtain the longer life-span.

The technological scheme that realizes above-mentioned purpose is: a kind of structure that is used for the minimizing seal wears of freezing mixture drain tank pump; Seal ring between the outlet end of the back shroud that comprise the bottom and the impeller in the pumping chamber of the pump housing that are installed in pump shaft, is located at impeller and the inner chamber of the pump housing middle part and be installed on the pump shaft and be positioned at the guide bearing on the inner chamber top of the pump housing; Wherein, Said guide bearing comprises metal-coating and slide bushing; Be inlaid in the inner chamber of metal-coating to said slide bushing interference fit, the material of this slide bushing is an engineering rubber, and the upper end of said metal-coating has cover plate; Be provided with some mounting holes on this cover plate in uniform way, said guide bearing through some screw on the said pump housing.

The structure of the above-mentioned minimizing seal wears that is used for freezing mixture drain tank pump wherein, also is provided with the axle sleeve that is solidly set on the pump shaft between said pump shaft and the said guide bearing, is Spielpassung between the internal diameter of the slide bushing of said guide bearing and the external diameter of said axle sleeve.

The technological scheme of the structure of the minimizing seal wears that is used for freezing mixture drain tank pump of the present invention; Between the pump housing on the top of impeller and pump shaft, guide bearing is set; This guide bearing adopts the composite structure of metal-coating and slide bushing, and slide bushing and axle sleeve Spielpassung can limit the amplitude that radially wobbles of pump shaft, promptly limits the rigid deformation of pump shaft and has limited the radial motion of impeller; And then can dwindle the gap between impeller and the seal ring; Reach the purpose that reduces seal wears, made seal ring obtain the longer life-span, can also reduce the leakage rate of pumping chamber simultaneously.

Description of drawings

Fig. 1 is the structural representation that is used for the minimizing seal wears of freezing mixture drain tank pump of the present invention.

Embodiment

In order to understand technological scheme of the present invention better, below through embodiment particularly and combine accompanying drawing at length to explain:

See also Fig. 1, a kind of structure that is used for the minimizing seal wears of freezing mixture drain tank pump of the present invention comprises pump shaft 1, the pump housing 2, impeller 3, seal ring 4 and guide bearing 5, wherein:

The inner chamber of the pump housing 2 comprise the bottom pumping chamber, middle part closed chamber and top bearing chamber and be up-small and down-big secondary stepped shaft cylindrical cavity; Pumping chamber is used to hold impeller 3; Closed chamber is used to install seal ring 4, the outer circumferential face gap of the outlet end of the inner peripheral surface of sealing ring 4 and impeller 3 back shrouds relatively; Bearing chamber is used to install guide bearing 5;

Pump shaft 1 overlaps an axle sleeve 6 admittedly at the position of the bearing chamber that is positioned at the pump housing 2, and this axle sleeve 6 is that hot jacket is being fixed on the pump shaft 1 on the pump shaft 1 and through the impeller 3 and the shaft shoulder;

Guide bearing 5 comprises metal-coating 51 and slide bushing 52; The material of this slide bushing 52 be engineering rubber and interference fit be inlaid in the inner chamber of metal-coating 51; The upper end of metal-coating 51 has cover plate, is provided with some mounting holes on this cover plate in uniform way, is installed on the axle sleeve 6 and through some screws 50 to these guide bearing 5 Spielpassung to be fixed on the pump housing 2.

Gap between the external diameter of internal diameter and axle sleeve 6 through control slide bushing 52; Can control the amplitude that radially wobble of rotor part in the moment that starts and shut down; And then can dwindle the gap between impeller 3 and the seal ring 4; Reduce the wearing and tearing of seal ring 4, make seal ring 4 obtain the longer life-span and reduce the leakage rate of pumping chamber.

Because the slide bushing 52 of guide bearing 5 is the WR300 engineering rubber that adopts U.S. Greene Tweed company, this project rubber is that a kind of long carbon fiber adds polyether-ether-ketone resin to strengthen pressing mold made.Polyether-ether-ketone resin has added intensity, stability and the thermal diffusivity of having strengthened material behind the long carbon fiber; And the thermoplastic engineering plastic that has surmounted other kind; The wear resistance of slide bushing 52 is strengthened; Pump is in operation can not take place seize to cause the phenomenon of pump shaft fracture, but bearing radial force well.Guide bearing also adopts the branch body structure, after slide bushing 52 wearing and tearing, can be convenient for changing.Axle sleeve 6 also can avoid pump shaft 1 directly relative with guide bearing in addition, plays the effect of protection pump shaft.

Those of ordinary skill in the art will be appreciated that; Above embodiment is used for explaining the present invention; And be not with opposing qualification of the present invention; As long as in connotation scope of the present invention, all will drop in claims scope of the present invention the above embodiment's variation, modification.

Claims

1. structure that is used for the minimizing seal wears of freezing mixture drain tank pump; Seal ring between the outlet end of the back shroud that comprise the bottom and the impeller in the pumping chamber of the pump housing that are installed in pump shaft, is located at impeller and the inner chamber of the pump housing middle part and be installed on the pump shaft and be positioned at the guide bearing on the inner chamber top of the pump housing; It is characterized in that; Said guide bearing comprises metal-coating and slide bushing; Be inlaid in the inner chamber of metal-coating to said slide bushing interference fit, the material of this slide bushing is an engineering rubber, and the upper end of said metal-coating has cover plate; Be provided with some mounting holes on this cover plate in uniform way, said guide bearing through some screw on the said pump housing.

2. the structure that is used for the minimizing seal wears of freezing mixture drain tank pump according to claim 1; It is characterized in that; Also being provided with the axle sleeve that is solidly set on the pump shaft between said pump shaft and the said guide bearing, is Spielpassung between the internal diameter of the slide bushing of said guide bearing and the external diameter of said axle sleeve.