CN1214107A

CN1214107A - Diffuser and conveyer device for single-impeller centrifugal self-priming pump

Info

Publication number: CN1214107A
Application number: CN97193111.9A
Authority: CN
Inventors: C·瑟拉芬
Original assignee: Calpeda SpA
Current assignee: Calpeda SpA
Priority date: 1996-11-27
Filing date: 1997-11-26
Publication date: 1999-04-14
Anticipated expiration: 2017-11-26
Also published as: WO1998023864A1; AU5655398A; IT1287367B1; CN1082630C; DE69705296D1; ITVI960192A1; BR9707307A; ATE202407T1; ES2160375T3; EP0879360B1; EP0879360A1

Abstract

The invention relates to a diffuser and conveyor device (2, 102, 202, 302) for a single-impeller centrifugal self-priming pump, with conveyor channels (15, 115, 215, 315) radially located outside the diffuser (13, 113, 213, 313) and inside the pump casing (3, 103, 203, 303) with a width comprised between the casing cover (7, 107, 207, 307) and a frontal wall (16, 116, 216, 316) next to the circular wall (17, 117, 217, 317) of the diffuser but not frontally overlapped to the latter. The diffuser and conveyor device (2, 102, 202, 302) deflects the flow from the tangential peripheral direction towards a centripetal direction reducing the rotation and the speed of said flow, it can be constructed in a single piece and it provides for frontal ports (25, 125, 225, 325) for the inspection of the internal parts of the pump.

Description

The diffusion and the feedway that are used for single-impeller centrifugal self-priming pump

Diffusion that to the present invention relates to a kind of single-impeller centrifugal self-priming pump that is particularly useful for having sparger also be common described shallow well jet pump and feedway its also be applicable to swimming pool and Whirlwind tank class not with the self-priming pump of sparger.

It is that this point is known on the surface by the common suction lift of atmospheric pressure decision that self-priming pump must be contained in apart from the water surface, and this pump has an immersion tube that is full of air when starting and is suitable for promoting liquid, is charged into liquid then, as long as and reach in the pump case.After starting is separating process in the contained fluid in air from pump from pumping phases, is a process that air contained in the suction pipe is discharged from outlet side, and the liquid that these air are risen below pushes in the pump.In the outlet side diffusion, water remains in the pump case at air.When the liquid from suction pipe enters pump and should finish in the stage when outlet is discharged.But said process still can continue under the general work situation, contains considerable air of promising number or gas if having air pocket or gas to enter pump or the institute's pump water from the suction source frequently.

Be well known that in a hydraulic circuitry, as in a self-priming pump, can air or gas be separated from water or liquid by two kinds of diverse ways, these two kinds of methods utilized simultaneously air and water different specific weight and state of rest or in liquid in rotation motion the different qualities of the light air in the heavier water:

-utilize the gravity in the static chamber, by reducing eddy current and flow velocity, make air in this static chamber, be air bubble-shaped and separate, float on the liquid.

-utilize the centrifugal force of rotating liquid, as with a centrifugal or cyclone separation device, with air accumulation in part near the center.

Some shallow well jet pumps include a diffusion and feedway, this is known, this device has two kinds of functions, a kind of function is to change the pressure energy as much as possible into from the kinetic energy of the fluid of rotor output, another kind of function is that conveyance fluid makes it by outlet or the some outlets that is positioned at around sparger or the rotor suction pipe with an annular shape, thereby this fluid can be rotated and flow velocity enters the center portion of pressure chamber with as far as possible little remnants, even so that suck lift when maximum, under the state of rest in the pressure chamber that obtains, in pumping phases, still can utilize gravity air to be easy to and water separation.

Described well known device, European patent EP 0361328 described device as the applicant, and, there are some defectives as European patent EP 0401670, U.S. Pat 5100289, European patent EP 0406787 and 5040946 tracing devices of U.S. Pat.

One of them defective is at least to need two assemblings together parts to form this device required structure by the passage between two walls towards pump shaft line conveyance fluid at the pressure chamber central position.

An if shallow well jet pump, another defective is when sparger and will constitutes a time-out with the suction chamber that top inlet is fixed, the circumferential annular extension of Diffuser and feedway can not in sightly can not catch in assembly process and contact, thereby make the alignment of parts and insertion become very difficult, so that these plug-in units can not be in coaxial position.

Do not have anterior opening just can not check inner member and make not with suction pipe from pump case pull down or not with pump case when suction pipe is pulled down because can not to hook thereby dismantle Diffuser internally when extracting out very difficult, especially more difficult when some lime precipitation things or analog exist.

In addition, described diffusion and feedway, be provided for liquid cycles through sparger all the time in a successive loops along same direction jet pump, be not suitable for the self-priming pump of not being with sparger, as those pumps that is suitable for using in swimming pool, water must be fed back into rotor with the form of a continuous backflow to take away the new air that need be output from suck fluid from pressure chamber from pumping phases in these pumps.

Outlet is arranged at the Path too long that the pressure chamber central position will cause a quick reflux fluid process, and the less liquid of contained air in the disengagement chamber bottom below the central outlets can not be utilized.

The embodiment of the self-priming pump of describing in European patent EP 0460597 that is provided with by identical inventor and the U.S. Pat 5226790 also is known, and this pump has a Diffuser, and this Diffuser has a peripheral longitudinal flow.The embodiment that this is last, although it has avoided above-mentioned defective on the basis that reaches the identical function purpose, it has also manifested the defective that a kind of corresponding reduction function of noise is provided when Zhou Liuti flows outside in the pump case of being made by a kind of sheet metal; In addition, even need two parts form Diffuser and feedway, even when cap is made by steel rolling, still need to provide in addition an edge that inserts the band blade between pump case and the cap, this also is a defective.

The said apparatus that belongs to the known embodiment of self-priming pump all tries hard to reduce the interior fluid whirling motion of pressure chamber of pump, so that make air only depend on gravity to separate from water, reduces the negative effect of centrifugal force.

The device that belongs to the shallow well jet pump is known, these pumps from pumping phases for centrifugal force is separated even utilized to air from water.That wherein, need point out emphatically is known embodiment in B. P. GB1201721, U.S. Pat 2941474, the European patent EP 0323384.There is same defective in the known embodiment of same these shallow well jet pumps: because anterior overlapping wall and grooving do not allow to form independent parts, they need a plurality of parts to form the device that air is separated from water, if not can only obtain single parts by the casting process that utilizes fuse; Also have when sparger be fixed on inlet when going up they just can not in sightly again can not to pass through assembly apparatus approaching by hand, and their overslaughs to the inspection of pump inner member.

Also have, even if utilized these devices of the shallow well jet pump of centrifugal force also to be unsuitable for not being with the self-priming pump of sparger.

The present invention attempts to overcome above-mentioned all defect.

An object of the present invention is to provide a kind of diffusion and feedway, thereby it utilizes gravity in case of necessity even utilize centrifugal force to make to be easy to carry out, make from the separation of pumping phases hollow gas from water and suck the stage endurance of lift when maximum and reduce to overcome above-mentioned defective as far as possible.

Another object of the present invention is to reach elimination or greatly reduce diffuser exit place periphery tangential cpmponent, and the direction that making flows is partial to radial centripetal is so that these fluids rotate with very little remnants and speed enters pressure chamber.

Another object of the present invention is to reduce the noise that the pump case fluid movement is impacted its wall and slip produces on its wall, by suitably changing the direction that flows and weakening its eddy current and flow velocity in diffusion feedway outlet port.

Another object of the present invention is the function that reaches diffusion and feedway with independent parts, this separate part inserts between other necessary parts of pump, this separate part is by molded formation, even if the joint of no grooving, no detachable component does not need several parts are connected after non-disconnectable with in producing yet, even has got rid of the necessity of utilizing the fuse founding.

Another object of the present invention is to obtain a kind of diffusion and feedway, and it can provide under the prerequisite of the size that does not increase pump to the inner member of visual examination pump of great use and make assembling and dismounting be easy to the open front of carrying out.

What do not include the last purpose of the present invention is to obtain a kind ofly to have suitable construction and to be used for one not with the self-priming pump of sparger, i.e. the pump of using in the swimming pool.

These purposes realize that by a kind of diffusion and feedway that belongs to single-impeller centrifugal self-priming pump the pump that is limited by independent claims comprises:

One pump case;

The one fixedly suction pipe that links to each other with a rotor and center on by pressure chamber;

One cap;

Described diffusion feedway is fixed between cap and the pump case and links to each other with suction pipe by a annular wall between rotor and pressure chamber, this diffusion feedway provides a Diffuser, this Diffuser is positioned at the peripheral of rotor and comprises one or more diffusion passages, this Diffuser extends beyond described annular wall at centrifugal direction radially, it is characterized in that each described diffusion passage is positioned at outside the described Diffuser and the transfer passage of described inside pump casing on continuing to extend to radially, this width of channel is formed in described cap and is close between the antetheca of described annular wall, thereby retained outlet that communicates with described pressure chamber radial centripetal direction between Liang Bi, described antetheca radially extends but does not overlap with the front annular wall, described transfer passage be a circular arc angle shape extend be suitable for fluid up to one that trend towards the radial centripetal direction and make this fluid flow through the end wall of described outlet from peripheral tangent direction deflection to one.

In conjunction with the accompanying drawings and following description, by the embodiment of the invention that does not provide by way of example for the purpose that interprets both the specification and the claims book as the restriction purpose, can more be expressly understood above-mentioned purpose of the present invention and other purpose, these embodiments are illustrated by the accompanying drawing of back, and these accompanying drawings comprise:

Fig. 1 is the sectional arrangement drawing that is used for apparatus of the present invention of a jet pump;

Fig. 2 is the front elevation of apparatus of the present invention shown in Figure 1;

Fig. 3 is a sectional drawing of taking from the transfer passage of apparatus of the present invention of B section among Fig. 1;

Fig. 4 is an improvement project of taking from the transfer passage of apparatus of the present invention of C-C line section among Fig. 2;

Fig. 5 is another embodiment's of apparatus of the present invention the sectional arrangement drawing of transfer passage;

Fig. 6 is the front elevation of apparatus of the present invention shown in Figure 5;

Fig. 7 is a sectional drawing of taking from the transfer passage of apparatus of the present invention of B section among Fig. 5;

Fig. 8 is an improvement project of taking from the transfer passage of apparatus of the present invention of C-C line section among Fig. 6;

Fig. 9 is another embodiment's of apparatus of the present invention the sectional arrangement drawing of transfer passage;

Figure 10 is a sectional drawing of taking from the transfer passage of apparatus of the present invention of B section among Fig. 9;

Figure 11 is the sectional arrangement drawing that is used for another embodiment of the apparatus of the present invention on the swimming pool self-priming pump;

To shown in Figure 10, Diffuser and feedway are done as a wholely to be marked with 2,102,202, belong to one by whole 1 the single-impeller centrifugal self-priming pump that is designated as Fig. 1, and this pump has an involved sparger, and this pump also comprises:

One pump case 3,103,203, this pump case have an inlet 4 and outlet 5, form pressure chamber 6,106 in this pump case;

One is locked at the injector device 10 on the inlet 4, and this injector device 10 that is surrounded by pressure chamber 6,106 also includes suction chamber 11;

One cap 7,107,207; One is fixed on the live axle 9,109,209 and the rotor 8,108,208 between cap 7,107,207 and diffusion feedway 2,102,202;

A fixed suction pipe 12,112,212 can be set between sparger 10 and rotor 8,108,208.

The described cap 7 that is fixed on, 107,207 with pump case 3,103, between 203 and by placing rotor 8,108,208 with pressure chamber 6, annular wall 17 between 106,117,217 are connected suction pipe 12,112, diffusion feedway 2 on 212,102,202 form a Diffuser 13,113,213, this Diffuser is from described annular wall 17,117,217 further extend and place rotor 8 along centrifugal radial, 108,208 outside, this Diffuser by with cap 7,107,207 engage and form, and this Diffuser is by one or more diffusion passages 14,114 form.

In another embodiment, as shown in figure 11, belonged to one and be marked with 301 the single-impeller centrifugal self-priming pump that is applicable to swimming pool by integral body by whole 302 Diffuser and the feedway of being marked with.

This pump also comprises: a pump case 303 that has an inlet 304 and outlet 305 and comprise pressure chamber 306; One by fixed suction pipe 312 that pressure chamber 306 centered on and linked to each other with rotor 308; A cap 307; One be fixed on the live axle 309 and place cap 307 and diffusion feedway 302 between rotor 308; Describedly be fixed between cap 307 and the pump case 303 and have a Diffuser 313 by the diffusion feedway 302 that links to each other with suction pipe 312 in rotor 308 and a annular wall 317 between the pressure chamber 306, this Diffuser further extends and places the periphery of rotor 308 along centrifugal radial from described annular wall 317.

The foregoing description belongs to known technology.The new common characteristic of above-mentioned each embodiment and its application comprises: each diffusion passage 14,114 continue to extend into and place Diffuser 13,113,213,20 of 313 start-up portions, 120,220,320 radially outside side and pump case 3,103,203, side and its width are cap 7 within 303,107,207,307 with described annular wall 17,117,217, near 317 a antetheca 16,116,216, the transfer passage 15 of the distance between 316,115,215,315, in this annular wall 17,117,217,317 the outside, Diffuser 13,113,213,313 footpaths are upwards at two walls 16,116,216,316 and 17,117,217, extend between 317 and become one along centripetal direction and pressure chamber 6,106,306 outlets that communicate 18,118,218,318, this transfer passage 15,115,215,315 antetheca 16,116,216,316 radially extend but its front portion not with annular wall 17,117,217,317 is overlapping, described transfer passage 15,115,215,315 as the circular-arc extension of an angle up to final and a perisporium 23,119,219,223,323 and radially 24,124 tangent curved walls 22,122,222, this curved wall 22,122, trend towards the radial centripetal direction and make it thereby 222 are suitable for that liquid stream is deflected into one from peripheral tangent direction from exporting 18,118,218,318 flow out.

According to most preferred embodiment of the present invention, the end wall of transfer passage 15,115,215,315 22,122,222 angled intervals be provided with in case its with reserve a freedom that is between Diffuser 13,113,213,313 outsides and pump case 3,103,203,303 inboards between the start-up portion of next diffuser passage or diffuser passage is when it has only one before export 25,125,225,325.

Transfer passage 15,315 can be included in that cap 7,307 and belongs to diffuser arrangement 2,302 and by between initial wall 21 and end wall 22 and the antetheca 16,316 that side 20,320 outside annular wall 17,317 and the Diffuser 13,313 links to each other, between initial wall 21 and end wall 22, form transfer passage 15,315 at a certain angle, this passage 15,315 fully can be by constituting single parts, no grooving, non-joint realizes, only requires that antetheca 16,116 has an inner diameter 27,327 that is equal to or greater than the initial outer profile 20,320 of Diffuser 13,313.Thereby obtain having the present embodiment of the no grooving non-joint one-piece element of a uniqueness, make before the transfer passage wall 16,316 anterior not overlapping with described annular wall 17,317.

Transfer passage 115 can also be comprised between the antetheca 116 that cap 107 and belongs to pump case 103, as long as the minimum diameter 127 of antetheca 116 is equal to or greater than the initial outer profile 120 of Diffuser 113, still can make diffusion feedway 102 be single parts, make open front 125 keep existence.

Adopt one differ from than requirements of the object of the invention mode of execution the time, if clearly do not take the benefit that the diffusion feedway constitutes single parts into account, then antetheca 216, also has perisporium 223 if desired, can be discerptible parts, can also be different with other parts of diffusion feedway, make by another material.Under latter event, consider the grooving when the overlapping setting of the wall that belongs to separate parts can not produce the combination of different parts, so antetheca 216 can also be made into the annular wall 217 of Diffuser 213 partly and overlapping anteriorly.If antetheca 216 forms independent parts, if be considered to useful or necessary, can also correspondingly obtain a free open front 225, but export the initial outer profile 220 that 227 internal diameter will be equal to or greater than Diffuser 213.

Transfer passage 15,315 can by a periphery arcwall 23,323 that belongs to diffusion feedway 2,302 from the sealing of outer radial ground or by the cylindrical wall 119,219,319 of pump case 103,203,303 and/or cap 207 from external lateral portion or sealing fully, or by three parts 202,302; 103,203,303; 207 with the peripheral wall 223 of the combined diffusion feedway 202 that forms of other mode from external lateral portion or close fully.

Although Fig. 2 and 6 illustrates an embodiment who has three and four diffusion transfer passages respectively, but, the number of passage can be from one to forming free open front 25,125,225,325 maximum numbers that allowed the adjacency channel, as long as this opening is required and will considers that this Diffuser should have the lobe numbers that is different from rotor blade and a kind of number of blade should not be the multiple of another kind of blade, perhaps two kinds of blades should not comprise and have public divisor altogether, avoiding interfering the vibrations that caused, thereby reach the purpose that reduces noise.

Diffusion of the present invention and feedway need not increase the radial dimension of pump, because it has utilized the outside 20 of pump case 3,103,203,303 and Diffuser 13,113,213,313,120,220, free space between 320, as to want the diffusion passage be unique, also utilized diffusion passage 14,114 and Diffuser subsequently or the free space between the initial part.

The rotation flow velocity of ingress can be lowered in the pressure chamber 6,106,306, thereby reduced all tangential cpmponents outside the flowing of diffusion passage 14,114 back, by antetheca 16,116,216,316 and end wall 22,122,222 with it towards the deflection of radial centripetal direction.

Since transfer passage 15,115,215,315 by Diffuser 13,113,213, the existence of the outlet 18,118,218,318 that the axial position setting of 313 the antetheca that is right after annular wall 17,117,217,317 16,116,216,316 forms with position, the angle setting of end wall 22,122,222 relative initial walls 21,121,221, the flow velocity of ingress is minimized in the pressure chamber 6,106,306.

In the pressure chamber in (steady state) or the disengagement chamber (in pumping phases) thus the rate of flow of fluid of ingress and rotation reduce then can obtain state of rest and make air it to be moved upward and from water, separate by gravity.

If under optimum condition, adopt remaining fluid eddy current behind the foregoing description because some special selections or size relationship do not reduce, and its value is for still just excessive for the purpose of separating fast the liquid with air, and diffusion feedway of the present invention can also more easily be realized required separation in two stages subsequently.

Utilize the tangential component of centrifugal power on transfer passage 15,115 inner peripherys, just can just obtain the separation first time of air in the outlet of transfer passage 15,115.

Intermediate blade 26 by at least one radial skew, 126 at least two fan-shaped angles parts with transfer passage 15,115 outlet 18,118 separate and with this intermediate blade 26,126 axis towards pump be positioned one preferably be positioned at transfer passage 15 radially extend half below maximum diameter part 26 on or one and the outer profile 120 corresponding smallest diameter portion 126 of Diffuser 113 on, this intermediate blade 26,126 exterior section and downstream part since the cause of centrifugal force will mainly be covered by liquid, lighter air of while then by centrifugal power go forcibly to cover that more entad at intermediate blade 26, the path of 126 upstream.

In this manner, end wall 22,122 will be with the major part of a radial centripetal direction deflection liquid, and intermediate blade 26,126 will be with the most of air of a radial centripetal direction deflection.

Like this, in the fan-shaped part in angle subsequently, air carries out separating the first time with water, like this, exit portion 18b between intermediate blade 26,126 and the end wall 22,122, the liquid at 118b place contain the air of minimizing when discharging, air is tending towards towards the part discharge of outlet 18a, the 118a of intermediate blade 26,126 upstreams simultaneously.

Intermediate blade 26,126 is also for reducing the remaining tangential cpmponent of ingress fluid on the diametric(al) of the outlet 27,127 of antetheca 16,116 in pressure chamber 6,106 (in steady state) or static chamber or the disengagement chamber (from pumping phases), of great use.

Intermediate blade 26,126 makes the minimizing of residual eddy current can improve the state of rest of liquid in the disengagement chamber 6,106, and air in this chamber is tending towards floating on the liquid level because action of gravity moves upward, and separates at last.

A series of deflecting blades 226 are set in the curved portion of transfer passage 215, these blades begin configuration according to flow direction from the diameter that increases, and from initial wall 221 to end wall 222, the diameter of each blade so just can further weaken residual eddy current from the cumulative diameter to outer wall 223 of minimum diameter corresponding with profile 220 outside the Diffuser 213.

Deflecting blade 26,126,226 can have different width in the middle of each, but all should be in the width range of transfer passage 15,115,215,315, they only extend in the opening of the outlet 118 between antetheca 116 and annular wall 117, or on all width between antetheca 16 and the cap 7, extend at transfer passage 15, the moving cumulative middle deflecting blade of direction width of several width differences or longshore current body also can be set, and make it turn to incoming flow the slick and sly bending of the initial edge of these blades, promptly identical with the shape of end wall 122 among Fig. 8.Number, layout, width and the shape of middle deflecting blade can suitably be selected, and the eddy current and the noise that can provide several optimum examples to reduce fluid simultaneously are so that air is easy to the separation from water.

The initial wall 21,121,221 of each transfer passage 15,115,215,315 and end wall 22,122,222, and the intermediate blade 26,126,226 that may be provided with can further radially extend towards the middle body of the annular wall 17,117,217,317 of Diffuser 13,113,213,313, do the effect of the rib enhancing that can play described annular wall 17,117 at least like this, shown in the dot and dash line in Fig. 2 and 6.

Beneficially, by utilizing the centrifugal force in the transfer passage earlier, then utilize the gravity in the static chamber, diffusion feedway of the present invention is being easy to and water separation air in pumping phases, thereby what obtain that the remnants that reduce rotate and flow velocity reduces flows, and diffusion feedway of the present invention makes that also this separation also is easier in two stages of back simultaneously.

Because said apparatus reduces the tangential cpmponent on the peripheral direction, thereby has reduced the pump case fluid movement, as fluid impact perisporium and the noise that flows and produced on this perisporium, this perisporium also is to hinder extraneous last one barrier of hearing noise.

Another advantage of the present invention is, can just can obtain diffusion of the present invention and feedway with less operating cost, because its can be made into independent parts insert other of pump must parts between, these parts can be by molded acquisition, do not exist grooving not have joint between several parts yet, do not need to carry out founding with fuse, owing to provide to device and dismounting open front of great use, the producer and user can benefit from it, and this opening also is very useful to the maintenance of pump.

Obtain not having the grooving non-joint only after the structure of a separate part, just can make transfer passage have once not and the anterior overlapping antetheca of the annular wall of Diffuser, can arrange and the space of limit transport passage between pump case inside and Diffuser outside in radially extension, thereby make this passage have enough width with liquid stream towards the deflection of heart radial direction, also just can eliminate or must the time reduce circumferential tangential cpmponent.

Transfer passage of the present invention need not increase the radial dimension of pump, because it has just utilized the available radial space of Diffuser outside, diffusion channel end place, if that is between the start-up portion of pump case and serial diffusion passage or the diffuser passage free space between the start-up portion of pump case and Diffuser one time only.

If jet pump, when injection apparatus must be inserted into the inlet that makes progress, the assembling work of in pump case, injection apparatus and diffusion feedway being carried out, since a promotion instrument (as a screw-driver, a drift or similar tool) can be inserted the inlet front be obliquely installed in the open front between a transfer passage and a diffusion passage with sparger is shifted onto on, thereby become and be easy to.

The feasible inner member of pump is checked of the existence of open front becomes possibility, allows to hold internally the diffusion feedway, has lime precipitation or analog to exist also easily with its extraction even if make.

Another advantage of the present invention is, apparatus of the present invention even can be applied to not be with on the self-priming pump of sparger, as be suitable for the pump of swimming pool, because being back to rotor for liquid fast, it provides short path in the self-priming process, even adopt contained liquid under the disengagement chamber.

If the present invention is applied to a jet pump, the foregoing description preferably is applied to one and has a pump case and by being fixed with on the pump of injection apparatus on the cap of steel rolling system and its inlet.However, said apparatus also can be applied in by other made and sparger and place by any way on the shallow well jet pump on the inner member of pump, as is applied to not be with on the single rotor self-priming pump of sparger.

Diffusion of the present invention and feedway can be modified to raise the efficiency or manufacture easily.Therefore, for example size, width and the shape of passage 14,114,15,115,215,315 and opening 18,118,218,318,27,127,227,327 and intermediate blade 26,126,226 and end wall 22,122,222 can change, and the size between each parts also can be different with space proportion.Can select and material, shape, size and structures different shown in these, also can abandon some above-mentioned advantages, perhaps can point out alternate manner relevant with apparatus of the present invention or that interrelate with described content.Be appreciated that all be combined in shown in and above-mentioned improvement among the described embodiment and the protection that all is considered to be subjected to the back claim of possible modification.

Claims

1. the diffusion and the feedway (2,102,202,302) that belong to a kind of single-impeller centrifugal self-priming pump (1,301) comprising:

One pump case (3,103,203,303);

One fixing suction pipe (12,112,212,312), this suction pipe links to each other with a rotor (8,108,208,308) and is centered on by pressure chamber (6,106,306);

One cap (107,207,307);

Described diffusion feedway (2,102,202,302) be fixed on described cap (7,107,207,307) with described pump case (3,103,203,303) between and by being positioned at described rotor (8,108,208,308) and described pressure chamber (6,106,306) annular wall (17 between, 117,217,317) with described suction pipe (12,112,212,312) link to each other, this diffusion feedway provides one to place described rotor (8,108,208,308) Diffuser (13 that encloses outside, 113,213,313), this Diffuser comprises one or more diffusion passages (14,114), this Diffuser radially centrifugal direction extends beyond described annular wall (17,117,217,317), it is characterized in that: each diffusion passage (14,114) continuity forms transfer passage (15,115,215,315), this transfer passage is positioned at described Diffuser (13 on radially, 113,213,313) the outside and described pump case (3,103,203,303) inner and its width is formed in described cap (7,107,207,307) with the described annular wall (17 of a next-door neighbour, 117,217,317) antetheca (16,116,216,316) between, thereby at this two wall (16,116,216 and 17,117,217) retained one radially entad and described pressure chamber (6 between, 106,306) outlet (18 that communicates, 118,218,318), this antetheca (16,116,216,316) radially extend but not with annular wall (17 in front, 117,217,317) overlap described transfer passage (15,115,215,315) be that a circular arc angle shape extends and be suitable for fluid is tended to the radial centripetal direction and makes this fluid flow through described outlet (18 to one from peripheral tangent direction deflection up to one, 118,218,318) end wall (22,122,222).

2. diffusion as claimed in claim 1 and feedway, it is characterized in that: the end wall (22,122,222) of described transfer passage (15,115,215,315) places the several angle position with the outside (20 in described Diffuser (13,113,213,313), 120,220,320) a retained free open front (25,125,225,325) and between the inboard of described pump case (3,103,203,303).

3. diffusion as claimed in claim 1 and feedway, it is characterized in that: described transfer passage (15,315) is formed between a cap (7,307) and the antetheca (6,316), this antetheca belongs to diffusion feedway (2,302), and this antetheca (16,316) is made parts with diffusion feedway (2,302).

4. diffusion as claimed in claim 1 and feedway is characterized in that: described transfer passage (115) is formed between a described cap (107) and the antetheca (116), and this antetheca belongs to described pump case (103).

5. diffusion as claimed in claim 1 and feedway is characterized in that: the antetheca (216) of described transfer passage (215) is made the parts that can pull down from diffusion feedway (202).

6. diffusion as claimed in claim 1 and feedway is characterized in that: the peripheral wall (23,323) that described transfer passage (15,315) is belonged to diffusion feedway (2,302) from outer radial close.

7. diffusion as claimed in claim 1 and feedway is characterized in that: the wall spare (119,219,309) that described transfer passage (115,215,315) is belonged to pump case (103,203,303) and/or belongs to cap (107,207,307) closes or from the outside at least in part by dismountable or belong to peripheral wall (223) sealing at least in part from the outside of diffusion feedway (202).

8. diffusion as claimed in claim 1 and feedway, it is characterized in that: the outlet (18,118) of described transfer passage (15,115) is divided at least two fan-shaped parts, the part that the axis that this centre deflecting blade has pump on one day trends towards radially extending by deflecting blade (26,126) in the middle of at least one.

9. diffusion as claimed in claim 1 and feedway is characterized in that: be provided with a series of deflecting blades (226) in the described transfer passage (215), these deflecting blades originate in the diameter of increase, dispose according to flow direction.