CN101113741B

CN101113741B - Automatic balance device for shielding force at direction of pump spindle

Info

Publication number: CN101113741B
Application number: CN200610029360XA
Authority: CN
Inventors: 韩元平; 彭昌荣
Original assignee: SHANGHAI XINHU ELECTRIC MACHINE FACTORY CO Ltd
Current assignee: Hefei Xinhu Canned Motor Pump Co Ltd
Priority date: 2006-07-26
Filing date: 2006-07-26
Publication date: 2011-03-16
Anticipated expiration: 2026-07-26
Also published as: CN101113741A

Abstract

The invention discloses an auto-balancing device used for shielding pump axial force, comprising a pump body, an inducing wheel, an impeller, a seal gasket, a graphite bearing, a shaft sleeve, a thrust disk, a stator, a rotor, a stator shield, a rotor shied, a thrust disk, a shaft sleeve, a graphite bearing, a seal gasket, a back bearing seat, a connected box, a front bearing seat , an impellor back choma, a front bearing seat lug boss, an impeller balancing hole, impeller taper and a pump body input pipe cone. A first set of the balanced front bearing seat lug boss covers a balancing hole of the impeller; the taper pipe of the impellor back choma of a second set of the balanced impeller is matched with the pump body input pipe cone. The structure of the invention is characterized by two balancing structures which can balance the shaft thrust power between front and back change to the greatest extent, ensuring no failure operation in a long time and effectively ensuring the normal operation of the equipment.

Description

A kind of automatic balancing arrangement of shielding force at direction of pump spindle

One, technical field

The automatic balancing arrangement of a kind of shielding force at direction of pump spindle of the present invention relates to electric pump design and manufacturing technology field.Be applied to the autobalance of use in refrigeration system shielded electric-pump and pump axial force of the same type.

Two, background technique

Canned motorpump is widely used in liquid such as conveying acid in the industry such as oil, chemical industry, refrigeration, food, national defence, atomic power, alkali, inflammable, explosive, severe toxicity with its absolute no leaks.In pump-unit, annual maintenance expenses is all very big, and canned motorpump is no exception.An important indicator weighing the canned motorpump functional reliability is that the mean free error time, the longer the better.The time of the average failure-free operation of decision shielded electric-pump is the working life of friction pair.The stressed of strict control thrust bearing friction pair is the key that improves the pump reliability.The factor that influences the working life of friction pair comprises the material of friction pair, friction pair cooperation and axial force etc.Be key point with axial force to friction pair influence especially wherein, and this point is often ignored by our many artificers and manufacturer.

At present domestic and international most of companies all adopt back shroud of impeller to add the back seal ring to mismatch equalizing orifice and come balancing axial thrust, and this conclusion can only be adapted to the operating mode that a fixing operating point definitely can not adapt to variation, and its balanced capacity is also limited.After the balance limit that reaches it we how to strengthen equalizing orifice all can not be more further adjustment state, some enterprises are arranged also at impeller back design automatic balancing structure, but this mode also has it self defective, it can only adapt to axial force operating mode backward, and our pump axial force overwhelming majority is forward in our actual production.When axial force forward the time, this unidirectional automatic balancing structure is then inoperative.

Three, summary of the invention

The objective of the invention is in order to overcome above-mentioned defective, the automatic balancing arrangement of a kind of shielding force at direction of pump spindle of bidirectional balanced structure is adopted in design.Its technology is achieved in that the structure that comprises choma behind the pump housing, inducer, impeller, first sealing gasket, graphite bearing, first axle sleeve, first thrust disc, stator, rotor, stator can, Rotor can, second thrust disc, second axle sleeve, second graphite bearing, second sealing gasket, rear bearing block, terminal box, front-end bearing pedestal, the impeller, and it is characterized in that: described first thrust disc, first axle sleeve and second thrust disc, second axle sleeve are separately fixed at the front end and back end of rotor; Gap between the equalizing orifice of front-end bearing pedestal boss covering back shroud of impeller is in 0.5～2.8mm scope, and the gap that impeller tapering pipe and pump housing import tapering pipe match is in 0.2～0.5mm, when the operating conditions variation of pump makes axle thrust forward; Axle thrust drives whole rotor and moves forward, and at this moment the distance between the equalizing orifice of back shroud of impeller and the front-end bearing pedestal boss widens, and can reach 2.8mm apart from maximum, makes the leakage rate increasing by the equalizing orifice of back shroud of impeller, make impeller after cavity pressure further reduce; The matching gap of impeller tapering pipe and pump housing import tapering tubular portion is dwindled when impeller moves forward, minimum clearance can reach 0.2mm, leakage rate by the impeller preoral loop is reduced, thereby the suffered pressure of front shroud of impeller is increased, and back shroud of impeller pressure reduces to increase both actings in conjunction with front shroud pressure makes impeller reach new balance very soon; Otherwise, when the operating conditions variation of pump makes axle thrust backward, axle thrust drives whole rotor and moves backwards, at this moment the distance between the equalizing orifice of back shroud of impeller and the front-end bearing pedestal boss is dwindled, minimum range can arrive 0.5mm, the leakage rate of the equalizing orifice by back shroud of impeller is reduced, make impeller after cavity pressure increase; Impeller tapering tubular portion increases with the matching gap of pump housing import tapering tubular portion when impeller moves backward, and the gap maximum can reach 0.5mm, and the leakage rate by the impeller preoral loop is increased, from but make the suffered pressure reduction of front shroud of impeller; Increase of back shroud of impeller pressure and front shroud pressure reduce both actings in conjunction makes impeller reach new balance very soon.

The positive effect of implementing this technology is that the characteristics of this structure are that it has two equilibrium structures, becomes unidirectional autobalance and is two-way autobalance.It is the axial force that changes of former and later two directions of balance to greatest extent, has prolonged bearing working life, has guaranteed long failure-free operation.Thereby guaranteed the normal operation of equipment effectively.

Four, description of drawings

Fig. 1 looks the sectional structure schematic representation for master of the present invention;

Wherein: the 1------pump housing, 2------inducer, 3------impeller, the 4-----sealing gasket, 5------graphite bearing, 6-------axle sleeve, the 7-------thrust disc, 8-------stator, 9-------rotor, the 10-------stator can, the 11-------Rotor can, 12-------thrust disc, 13-------axle sleeve, the 14------graphite bearing, the 15------sealing gasket, 16------rear bearing block, 17--------terminal box, the 18------front-end bearing pedestal, choma behind the 19-------impeller, 20-------front-end bearing pedestal boss, 21-------impeller balance hole, 22-------impeller tapering pipe, 23------pump housing import tapering pipe.

Five, embodiment

Below in conjunction with accompanying drawing the present invention is further described:

See accompanying drawing 1, stator can 10 is welded on stator 8 inner chambers.Rotor can 11 is welded on the cylindrical of rotor 9, graphite bearing 14 is pressed into rear bearing block 16, graphite bearing 5 is pressed into front-end bearing pedestal 18, sealing gasket 15 is enclosed within on the rear bearing block 16, rear bearing block 16 is fixed by bolts on the stator rear flange, with thrust disc 7,12 and axle sleeve 6,13 are separately fixed at the front end and back end of rotor 9, with rotor 9 in the front loaded stator cavity of stator 8, front-end bearing pedestal 18 is fixed by bolts on the stator forward flange, press impeller 3, the priority of inducer 2 is fixed on the front end of rotor 9, sealing gasket 4 is enclosed within on the front-end bearing pedestal 18, at last the pump housing 1 is fixed by bolts on the stator forward flange, front-end bearing pedestal boss 20 covers impeller balance hole 21, and impeller tapering pipe 22 and pump housing import tapering pipe 23 have the cooperation in gap.

See accompanying drawing 1, connect power supply, stator 8 produces rotating magnetic field, drives rotor 9 rotations, 3 rotations of rotor 9 impeller, and electric pump enters normal operating condition.

When the operating conditions variation of pump makes axle thrust forward; Axle thrust drives whole rotor 9 and moves forward, and at this moment the distance between the equalizing orifice 21 of impeller 3 back shrouds and front-end bearing pedestal 18 boss widens, and can reach 2.8mm apart from maximum, and the leakage rate by equalizing orifice 21 is strengthened, and impeller 3 back cavity pressures are further reduced; Impeller tapering pipe 22 dwindles with the matching gap of pump housing import tapering pipe 23 parts when impeller 3 moves forward, minimum clearance can reach 0.2mm, leakage rate by the impeller preoral loop is reduced, thereby the suffered pressure of front shroud of impeller is increased, and back shroud of impeller pressure reduces to increase both actings in conjunction with front shroud pressure makes impeller 3 reach new balance very soon.

Otherwise, when the operating conditions variation of pump made axle thrust backward, axle thrust drove whole rotor 9 and moves backwards, and at this moment the equalizing orifice 21 of back shroud of impeller and the distance between the front-end bearing pedestal boss 20 are dwindled, minimum range can arrive 0.5mm, and the leakage rate by equalizing orifice 21 is reduced.Cavity pressure increases after making impeller; The matching gap of impeller tapering pipe 22 parts and pump housing import tapering pipe 23 parts increases when impeller 3 moves backward, and the gap maximum can reach 0.5mm.Leakage rate by the impeller preoral loop is increased, from but the suffered pressure of front shroud of impeller is reduced.Increase of back shroud of impeller pressure and front shroud pressure reduce both actings in conjunction makes impeller 3 reach new balance very soon.

In sum, no matter be axial force forward or axial force backward two the cover axial thrust balancing device can make impeller return to intermediateness automatically, reach the equilibrium position.Make electric pump safe operation for a long time.

See accompanying drawing 3, adopt the canned motorpump of bi-directional axial power automatic balancing arrangement structure, in the working flow scope, rotor assembly is in state of suspension, and is in the intermediateness of axial displacement.Front and back bearings and front and back thrust disc are contactless, do not stress, and have prolonged the working life of bearing to greatest extent.

Claims

1. the automatic balancing arrangement of a shielding force at direction of pump spindle, comprise the pump housing (1), inducer (2), impeller (3), first sealing gasket (4), first graphite bearing (5), first axle sleeve (6), first thrust disc (7), stator (8), rotor (9), stator can (10), Rotor can (11), second thrust disc (12), second axle sleeve (13), second graphite bearing (14), second sealing gasket (15), rear bearing block (16), terminal box (17), front-end bearing pedestal (18), choma behind the impeller (19) is characterized in that in interior structure: described first thrust disc (7), first axle sleeve (6) and second thrust disc (12), second axle sleeve (13) is separately fixed at the front end and back end of rotor (9); Gap between the equalizing orifice (21) of front-end bearing pedestal boss (20) covering impeller (3) back shroud is in 0.5～2.8mm scope; The gap that impeller tapering pipe (22) and pump housing import tapering pipe (23) match is in 0.2～0.5mm scope; When the operating conditions variation of pump makes axle thrust forward; Axle thrust drives whole rotor (9) and moves forward, at this moment the distance between the equalizing orifice (21) of impeller (3) back shroud and front-end bearing pedestal (18) boss widens, can reach 2.8mm apart from maximum, make leakage rate increasing, impeller (3) back cavity pressure is further reduced by the equalizing orifice (21) of described impeller (3) back shroud; When the matching gap of impeller (3) impeller tapering pipe (22) and pump housing import tapering pipe (23) part when moving forward is dwindled, minimum clearance can reach 0.2mm, leakage rate by the impeller preoral loop is reduced, thereby the suffered pressure of front shroud of impeller is increased, and back shroud of impeller pressure reduces to increase both actings in conjunction with front shroud pressure makes impeller (3) reach new balance very soon; Otherwise, when the operating conditions variation of pump makes axle thrust backward, axle thrust drives whole rotor (9) and moves backwards, at this moment the equalizing orifice (21) of impeller (3) back shroud and the distance between the front-end bearing pedestal boss (20) are dwindled, minimum range can arrive 0.5mm, the leakage rate of the equalizing orifice (21) by described impeller (3) back shroud is reduced, make impeller after cavity pressure increase; Impeller tapering pipe (22) part increases with the matching gap of pump housing import tapering pipe (23) part when impeller (3) moves backward, the gap maximum can reach 0.5mm, leakage rate by the impeller preoral loop is increased, from but the suffered pressure of front shroud of impeller is reduced; Increase of back shroud of impeller pressure and front shroud pressure reduce both actings in conjunction makes impeller (3) reach new balance very soon.