CN1032443C

CN1032443C - Centrifugal pump

Info

Publication number: CN1032443C
Application number: CN93105676A
Authority: CN
Inventors: 弗兰克·G·克利福德; 威廉·T·M·塔休
Original assignee: Falmer Investments Ltd
Current assignee: Falmer Investments Ltd
Priority date: 1992-05-07
Filing date: 1993-05-07
Publication date: 1996-07-31
Anticipated expiration: 2013-05-07
Also published as: CN1079537A; GB2266749B; HK37396A; GB2266749A; GB9209824D0

Abstract

A centrifugal pump comprises a pump casing 15 and a pump backplate 9 which together define a pump chamber in which an open impeller 14 is mounted for rotation. Means 25, 26, 27, 28 are provided to effect axial adjustment between the pump casing 15 and the pump backplate 9, whereby the axial clearance between the pump casing 15 and the impeller 14 can be accurately set, and sealing means 12, 13, 24 are provided to effect a seal between the pump backplate 9 and the pump casing 15 at all relative positions of adjustment thereof.

Description

Centrifugal pump

The present invention relates to a kind of centrifugal pump.Wherein impeller stationary plane rotation flat or coupling on contiguous pump case or impeller housing, the clearance of being set up in the routine techniques of processing pump parts is by keeping its approaching machining tolerance to make clearance within desired lit range.

The present invention has narrated a kind of device of simplifying pump processing and improving precision, for this reason, does not need later on to adjust near tolerance with thousand fens instrument at the processing pump and also can keep clearance.At pump between the whole spreadable life, will the parts dismounting, or when the device running, adjust the pressure of " cut-off valve " safely, and under high temperature and high pressure, carry out simultaneously its normal tasks and at any time in can keep and readjust this clearance.

The dish that impeller and so on can be arranged in centrifugal pump, be generally used for rotating by motoring around its center, impeller has and extends to its peripheral passage from its center, makes usually the liquid that is fed to the impeller center vertically by the pump drinking-water pipe be subjected to the outside acceleration of impeller rotation.Liquid is collected in the peripheral chamber of impeller and by outer pipe and discharges.

In the manufacturing of small-sized centrifugal pump, there is quality Control all the time in the production of impeller.Can prove, when the total cross section of flow channel in the impeller does not substantially exceed the sectional area of water pump suction pipe, can obtain best performance.The idea of casting " being close to " impeller, also promptly cast the idea by the impeller that self limits all conduit walls that extend to impeller periphery from the center, the result forms the area of throat and shape is lack of consistency and metal quality and the unbalance problem of liquid flow area.These difficult points have been directed to be done liquid chunnel more much bigger than hydraulic pressure correction access desired, so that provide enough solid core to impact can sustain molten metal flow when molten metal injects the die casting impeller.

So proposed open impeller, promptly the passage of impeller is made the groove that forms on impeller disk, and by between the static internal surface of the surface of this wheel rotor and pump case, keeping very little clearance to come closed channel effectively.These internal surfaces according to designing requirement can be the plane or slightly taper.

Leak into downwards between two internal surfaces for the highly pressurised liquid that prevents the impeller periphery place the impeller suction link of impeller plate center, the clearance between two internal surfaces must accurately keep very little size.

Contain the wearing and tearing that corrosion that sand, salt or other particulate matter produce or corrosion function may cause internal surface in the liquid of being introduced by pump, this will change the clearance between the pump case of impeller.

In order in manufacture process and in the required tight clearance of length of life maintenance of machine, to have adopted diverse ways.

In first method, parts are machined into high tolerance, therefore, can reach correct clearance during assembling.This method is very expensive, because it requires all very accurately processing of all parts, and lacks the means of adjusting clearance in the open air, must accurately be installed and is carried out machined components again by the maintenance man, with compensate for wear.

Another kind of approach is to improve the effect that clearance is adjusted, and way is to insert the shim of large washer form between the back plate of pump case and pump.This kind packing ring requires to have 8 to 12 access holes that stove bolt is used, and stove bolt is generally used for pump case is fastened on the back plate of pump.Need the maintainer with the pump case emplace, measure and satisfy the shim thickness of required clearance requirement, thereby select suitable shim, and finish installation.This needs the spare unit of skill and patient and necessary replacement parts.

In a kind of trial of simplifying adjusting method, shim is cut into the space that is fit between the bolt, if but do not have shim below them and make the bolt overtorquing, doing like this can the damage pump case or the back plate of pump.The shim of the plain washer shape under each bolt is convenient to work unlike the U-shaped shim that is clipped in the bolt back.It is very difficult with the galvanized iron scissors shim blank being cut into this kind shape shim.

These difficult consequences are, adjust improperly that maintenance still can require pump to reprocess, even and after adjustment performance do not reach standard yet.

The purpose of this invention is to provide a kind of centrifugal pump, it can provide the adjustment of impeller clearance when pump work, and when might pump working under high pressure and high temperature condition, can reach desired safely and move axially.

According to a kind of centrifugal pump of the present invention, it comprises a pump case, the back plate of a pump, a pump chamber that limits by the back plate of pump case and pump, an open impeller that is installed in the pump chamber, thereby the motion to axial between the back plate of realization pump case and pump changes the mechanism of the clearance between impeller surface and the pump case respective surfaces, and the mechanism that between the back plate of realization pump case and pump on all the relative adjustment positions between the back plate of pump case and pump, seals, it is characterized in that: the mechanism of motion to axial between the back plate of described realization pump case and pump comprises elongated threaded piece and nut, another of described pump case and fixed block gone up and extended through to one of the fixed block that these elongated threaded pieces are fixed on the back plate of pump case and pump, and these nuts by be threadably engaged on the above-mentioned threaded piece and be pressed against described pump case that described threaded piece passes and the fixed block of the back plate of pump in another both sides, above-mentioned nut is with adjusting and locking nut, describedly move to axial and set up the axial position of pump case to produce, and thereby set up the position to axial on a surface of internal surface of pump case and impeller with respect to the back plate of pump.

Preferably, sealing mechanism has the columnar surface of matching that is generally of the back plate of pump and pump case, and one of them such cylinderical surface has a groove, holds an O shape ring in the groove, to realize the sealing with another surface.

But the passage that has feed flow stream in the impeller, liquid flows in the liquid-discharging tube of impeller periphery by the imbibition link of these passages from the impeller center, being shaped as by the surface of impeller is carried out machining and accurately formed groove of passage; To provide passage required sectional area.Preferably open passage is cast in the impeller, but because passage is open, thus the workman can contact channels to carry out the check of quality control, be easy to revise the defective of casting.

Utilize accompanying drawing to illustrate the present invention below as an example, in the accompanying drawing:

Fig. 1 is a kind of end elevation that is installed in the centrifugal pump of the present invention on the motor;

Fig. 2 is the section figure along II among Fig. 1-II line intercepting;

Fig. 3 is the perspective view of the another kind of available impeller that pump is used in the presentation graphs 1.

With reference to the accompanying drawings, motor 1 has a casing 2 and an output shaft 4 that mounting plate 3 is housed, and output shaft 4 stretches out and passes and perpendicular to the reference surface 5 of mounting plate 3.Centrifugal pump 6 has one to utilize plug 8 on the mounting plate 3 to be positioned at back plate 7 on its inner circumference, and 4 bolts 10 of back plate 9 usefulness of pump are anchored on the plate 7 of back.A groove 12 and an O shape ring 13 that is engaged in the groove are arranged in the cylindrical outer surface 11 of the back plate 9 of pump.Pump 6 also has an open impeller 14 and a pump case 15 on the axle 4 that is fastened on motor 1.

It is circular that pump case 15 profiles are generally, and it has the chamber that is shaped as circular radially extension that a fluid intake 1b who is positioned at axial centre, one limit by inner face 18 17, a peripheral chamber 19 and a fluid output 20.Be provided with bead with holes 21 on three positions around the pump case 15, the bead with holes 22 on bead 21 and the back plate 7 is aligned with each other.Pump case 15 also has a lobe 23, this protuberance inwardly limits the internal surface in peripheral chamber 19, the pump case termination is a cylinderical surface 24, the cylindrical outer surface 11 of the back plate 9 of this surface and pump is parallel to each other and be close to adjacent, inner face 24 cooperates with O shape ring 13, forms a Sealing between the back plate 9 of pump case 15 and pump.

Bolt 25 is tightened in the bead with holes 22 of back plate 7, tightens two nuts 26,27 on each bolt 25 between the bead 21 of back plate 7 and pump case 15, also tightens another nut 28 on the free end of each bolt 25.Utilize bolt 25 and nut 26,27,28, bead 21 and pump case 15 can move with respect to the back plate 7 of pump and with respect to the impeller 14 that is installed on the axle 4 vertically.

In the embodiment shown in Figure 2, impeller 14 comprises a rear disk 14a, and the blade 14b that is positioned at chamber 17 has been installed on it, and is tapered slightly by the axial external surface that blade 14b forms, blade 14b limits interlobate impeller passage, and this impeller passage is by internal surface 18 closures of pump case 15.

Fig. 3 represents that impeller 14 can be a square position with two opposing parallel faces, three curved grooves 29 between the periphery that extends in the axis hole 30 of admitting axle 4 and square position 14 are arranged, the cross section of curved groove 29 is generally rectangle, and its width and the degree of depth are along with the distance between interior center hole and the periphery increases gradually.

Use three bolts 25 and four bolts 10 to make to be mounted between pump and the waste pipe 20 vertical, level or be partitioned into 30 degree angles.

The degree of adjusting impeller 14 places clearance is as follows.At first unload motor bonnet 3, make it expose cooling fan, and can use finger rotatingshaft 4.Pump case 15 is assemblied on the O shape ring 13, adjusts nut 26,27 subsequently and turn round to the limit, it can not produced stop, promote pump case 15 more backward, be placed on the impeller 14 with aiming at up to its so that avoid bead 21.Nut 28 before the assembling rotates lightly with finger, makes nut contact bead 21.Whether all screw with 28 pairs of beads of finger all nuts of check 21, and axle 4 can not rotate with finger again.With the back side of back of the body nut 27 rotations up to bead 21.Preceding nut 28 is loosened the part circle, adjust clearance, till axle 4 can rotate, check every pair of nut 28,27 successively, only just do not contact impeller with conclusive evidence pump case 15 with back of the body nut 26.

Nut 28 should be return the sixth circle before each, and back of the body nut 27 faces toward it and tightens.The hexagon nut of use standard and corresponding spanner can accurately be finished this work.Whole device can connect suction and drainage connector again, after in the end proof bar 4 can rotate freely, load onto the motor bonnet again, so can recover to use.

If at will when the validity of position adjustment is suspected to some extent, can be checked and readjust clearance by this way so, and not need pump is influenced pipe network operation from using the scene to pull down.

Use suitable clamping tool for machine work,, can make it keep centering accurately carrying out machining by impeller casting being positioned in the passage itself, thus the concentricity of impeller and passage in guaranteeing to use.

Pump case can be designed to have the abundant degrees of freedom of the lateral movement that can use in same pump, can be designed to have the different impeller of width, and each impeller can be best suited for different purposes, makes a basic pump can be used for the different application of many kinds.

Claims

1. centrifugal pump, it comprises a pump case, the back plate of a pump, a pump chamber that limits by the back plate of pump case and pump, an open impeller that is installed in the pump chamber, thereby the motion to axial between the back plate of realization pump case and pump changes the mechanism of the clearance between impeller surface and the pump case respective surfaces, and the mechanism that between the back plate of realization pump case and pump on all the relative adjustment positions between the back plate of pump case and pump, seals, it is characterized in that: the mechanism of motion to axial between the back plate of described realization pump case and pump comprises elongated threaded piece and nut, another in described pump case and the fixed block gone up and extended through to one of the fixed block that these elongated threaded pieces are fixed on the back plate of pump case and pump, and these nuts by be threadably engaged on the above-mentioned threaded piece and be pressed against described pump case that described threaded piece passes and the fixed block of the back plate of pump in another both sides, above-mentioned nut is with adjusting and locking nut, describedly move to axial and set up the axial position of pump case to produce, and thereby set up the position to axial on a surface of internal surface of pump case and impeller with respect to the back plate of pump.

2. centrifugal pump as claimed in claim 1, it is characterized in that, the mechanism of described realization sealing comprises that the basic of back plate of pump case and pump is columnar respective surfaces, one of them such cylinderical surface has and holds an O type ring in a groove, the groove, to realize the sealing with another surface.

3. centrifugal pump as claimed in claim 1 or 2, it is characterized in that having passage in the impeller, liquid flows in the waste pipe in impeller periphery chamber by the suction link of these passages from the impeller center, the groove that is shaped as accurate manufacturing of passage can provide passage required sectional area.

4. a centrifugal pump as claimed in claim 3 is characterized in that, described groove is made by machining.

5. a centrifugal pump as claimed in claim 3 is characterized in that, described groove is cast as the open channel in the impeller.