EP3299627A1 - Feed pump - Google Patents

Abstract

The invention relates to a delivery pump for fluid media, in particular circulation pump for swimming pools or swimming pools, with a pump housing (35), one in the pump housing (35) arranged impeller (19) which is rotatably mounted on a pump shaft (22), a drive unit ( 27,28), which is connectable to a drive motor (32), wherein the drive unit (24,25,27,28) and the pump shaft (22) via inner and outer magnets (25,28) through a split pot (29 ) are in mutually active magnetic connection, and the drive unit (24, 25, 27, 28) has an inner rotor (27) on which the inner magnets (28) are arranged and which is non-rotatably connected to a motor shaft (21) of the drive motor (32 ), and an outer rotor (24) rotatably connected to the pump shaft, wherein the outer rotor (24) carries the outer magnets (25) and the inner rotor (27) engages, and wherein the inner rotor (27) additional weights (33), the as a starting book act.

Description

The present invention relates to a feed pump for fluid media, in particular a circulation pump for swimming pools or swimming pools or a feed pump for fluid chemicals in the system engineering, with a pump housing, arranged in the pump housing impeller which is rotatably mounted on a pump shaft, and a drive unit, which is connectable to a drive motor, wherein the drive unit and the pump shaft are in magnetic operative connection with each other via inner and outer magnets, which are separated from each other by a containment shell. Because of this magnetic drive concept such pumps are also referred to as magnetic coupling pumps.

Magnetic clutch pumps are among the most versatile types of pumps. They are robust and capable of delivering fluids of varying densities, from gases to liquids, at temperatures up to 400 ° C. The pump part of a magnetic coupling pump usually corresponds to a conventional centrifugal pump and has a non-rotatably mounted on a pump shaft radial impeller. While in a conventional pump, the pump shaft is mechanically coupled to the drive motor, has a typical magnetic coupling pump driven by an electric or internal combustion engine cup-shaped drive member with an outer rotor, on the inner surfaces of which outer magnets are arranged radially. In the heretofore known magnetic drive pumps, an inner rotor connected to the pump shaft, on the outer surface of which inner magnets are arranged, is surrounded at its engine facing end by the outer rotor of the drive member so that the outer and inner magnets are opposed to the reverse polarity. The inner rotor is hermetically separated from the outer rotor by means of a split pot, the inner magnets of the inner rotor being in magnetic operative connection with the outer magnets of the outer rotor over the split pot. Due to the hermetic separation of the inner rotor from the outer rotor through this split pot, which thus replaces the corresponding shaft seals of conventional motor-driven pumps, a leak-free delivery of the fluids is possible. The storage of the pump shaft is usually done by several Sliding bearings that radially and axially support the inner rotor and the pump shaft and are typically lapped for lubrication and cooling of the fluid.

Due to the necessary use of permanent magnets magnetic coupling pumps are more expensive than corresponding pumps in which the pump shaft is mechanically connected to the drive motor. Therefore, magnetic coupling pumps have not yet been used in areas where there is a particularly high cost pressure, for example in the field of circulation pumps for swimming pools and swimming pools, where the clientele often consists of public and private end users. Meanwhile, however, permanent magnets are available at such low cost that magnetic coupling pumps can also be used in such areas. At the same time, the legal requirements for the energy efficiency of electric motors, which are preferably used for magnetic drive pumps as driving motor, are increasing more and more, so that from January 2017 for motor powers from 0.75 kW compliance with a minimum efficiency IE3 in the EU is legally required (energy efficiency classification according to IEC 60034-30). The engine manufacturers can only meet these requirements by installing high-quality components, so that, for example, more copper has to be used for the windings of electric motors. The engines are not only more efficient, but then have a larger torque when starting the engine. In a magnetic drive pump in this case there is the risk of slippage, d. H. The magnetic contact of the magnets of the rotor of the pump breaks off, so that the impeller can not be rotated despite the rotating motor.

From the European patent application EP-A-0 237 868 , the German utility model DE 20 2006 005 189 and the German patent DE 102 61 079 For example, pumps with magnetic coupling drive are known in which the motor side, the permanent magnets on an inner rotor and the pump side are arranged on an outer rotor.

The present invention is therefore based on the technical problem of providing a feed pump for fluid media, in particular a circulating pump for Swimming pools and swimming pools, which allows the use of a magnetic drive coupling and is particularly inexpensive to produce when using energy efficient drive motors.

This technical problem is solved by a feed pump with the features of the present claim 1. Advantageous developments of the feed pump according to the invention are the subject of the dependent claims.

According to a first aspect of the invention, the invention therefore solves the technical problem by reversing the assignment of the inner and outer rotors, which are separated by a containment shell, compared with conventional magnetic coupling pumps. In conventional magnetic coupling pumps, namely, the rotor connected to the motor shaft is designed as an outer rotor specifically with respect to a high tightening torque while the inner rotor is connected to the pump shaft, in the pump of the present invention, the outer rotor is connected to the pump shaft and the inner rotor is connected to the drive motor. The present invention thus relates to a pump for fluid media of the type described above, which is characterized in that the drive unit, an inner rotor on which the inner magnets are arranged and which is rotatably connected to a motor shaft of the drive motor, and a rotationally fixed to the pump shaft connected outer rotor, wherein the outer rotor carries the outer magnet and engages around the inner rotor.

Already due to the fact that the motor now drives an inner rotor instead of an outer rotor, the tightening torque acting on the outer rotor connected to the pump shaft is reduced, which reduces the danger of slippage when starting the engine.

It is also provided that the inner rotor has additional weights, which serve to increase the moment of inertia of the inner rotor and thus act as a starting brake. Therefore, the additional weights slow down the start of the engine in the first few seconds after switching on, so that the risk of tearing of the magnetic coupling is reduced and the outer rotor synchronously with the Inner rotor can start. Surprisingly, it was found that despite the additional weights with the engine running no increased energy consumption is observed.

From the German patent application DE 29 12 938 Although a arranged on the motor-side drive shaft flywheel is known to prevent tearing of the magnetic coupling when starting the pump. However, in the pump described there in a conventional manner, the outer magnet on the drive side and the inner magnet are arranged on the pump side. In addition, the pump described there is a liquid ring pump in which the impeller when starting the pump, starting from a stationary operating fluid, the liquid ring must generate. In the DE 29 12 938 Therefore proposed solution can not be transferred to the pump according to the invention.

The additional weights can be adjusted in the function for increasing the moment of inertia of the respective engine power and the efficiency of the engine, so that for example the same feed pump can be used with motors in a power range of 0.75 to 2.2 kW.

The additional weights can be integrated into the inner rotor, for example, be sprayed as metal rings with an inner rotor made of die-cast metal or plastic. According to a preferred embodiment of the invention, the additional weights are designed as a flywheel, which is preferably replaceably mounted on the inner rotor. For example, the flywheel can be easily replaced by discs of different thicknesses or different materials, thus modifying the effect of the starting brake and adapting it to engine performance. Such a flywheel also ensures, with its circularly symmetrical mass distribution, an equalization of the rotation of the inner rotor, so that a tearing off of the magnetic coupling during load fluctuations can be avoided.

When the outer rotor is made of the same material as the pump shaft, for example, the pump shaft and the outer rotor can be manufactured as an injection molded part. When using different materials, the outer rotor and the Pump shaft are connected in many ways with each other. For example, the outer rotor can be sprayed against rotation on the pump shaft, so that the pump shaft and outer rotor in turn form a one-piece component.

The outer rotor has at its motor end a pot-like general shape, wherein the dimensions are selected so that the outer rotor engages around the inner rotor and the split pot disposed between the inner rotor and outer rotor.

Unlike the in DE 20 2006 005 189 U1 or EP 0 237 868 A described pumps in which the impeller is fixedly connected to the outer rotor, according to the invention is preferred that the impeller of the pump replaceable plugged onto the pump shaft rotatably and, for example, by means of a screw and / or tolerance rings is fixed, which simplifies the maintenance of the pump. In addition, the use of different impellers in the pump is made possible by simply replacing the wheels.

The feed pump also preferably includes a fluid circuit via which for cooling and lubricating the bearings of the outer rotor, the can and the seal housing. This fluid circuit is configured more complex than in a conventional magnetic coupling pump, in which fluid only needs to be guided close to the axis of the pump shaft to the plain bearings. In the pump according to the invention is proposed to lead a portion of the fluid from a pressure chamber of the feed pump to the outer rotor and the pump shaft and then axially back along the pump shaft to the impeller and from there radially on the back of the impeller back into the pressure chamber of the feed pump. For this purpose, the feed pump preferably has a seal housing, in which the outer rotor is arranged and which together with the containment shell defines a part of the fluid housing provided for cooling and lubrication.

The pump shaft is preferably rotatably supported by at least one sliding bearing, particularly preferably two plain bearings, wherein the sliding bearing of the in the Fluid circulation guided fluid to be cooled and lubricated. As plain bearings preferably ceramic plain bearings are used.

According to a preferred embodiment, the feed pump has an axial suction opening, through which the medium to be conveyed is sucked by the impeller and, for example, is conveyed radially into the pressure space on the outer circumference of the impeller.

The feed pump according to the invention can be used for different purposes, for example as a feed pump for fluid chemicals in systems engineering or as a circulation pump for swimming pools or swimming pools. In particular, in the case of the use of the feed pump according to the invention as a circulation pump, a fiber catcher is preferably arranged in front of the suction opening of the feed pump. The fiber catcher can be connected to the suction opening via a hose or a line, but preferably the fiber catcher is integrated in the pump housing immediately before the suction opening of the pump.

The drive unit of the feed pump according to the invention may have a drive shaft which is centrally mounted in the inner rotor or sprayed with this, and which can be connected via a mechanical coupling with a motor shaft of a drive motor.

In a particularly compact embodiment of the feed pump according to the invention, the inner rotor has a central bore, in which the motor shaft of a drive motor can engage in rotation, so that the drive motor can be flanged directly to the drive unit of the pump.

Figur 1

eine als Umwälzpumpe für Swimmingpools ausgebildete erfindungsgemäße Förderpumpe im Teilquerschnitt;

Figur 2

eine vergrößerte Detailansicht der Schnittdarstellung der Figur 1;

Figur 3

eine isolierte Darstellung des Außenrotors der Figuren 1 und 2 im Querschnitt;

Figur 4

den Außenrotor der Figur 3 in perspektivischem Teilquerschnitt;

Figur 5

eine isolierte Darstellung des Innenrotors der Figuren 1 und 2 im Querschnitt;

Figur 6

den Innenrotor der Figur 5 in perspektivischer Darstellung;

Figur 7

eine isolierte Darstellung des Spalttopfes der Förderpumpe der Figuren 1 und 2 im Querschnitt;

Figur 8

eine Draufsicht auf den Spalttopf der Figur 7;

Figur 9

eine isolierte Darstellung des Dichtungsgehäuses der Förderpumpe der Figuren 1 und 2 im Querschnitt; und

Figur 10

eine Draufsicht auf das Dichtungsgehäuse der Figur 9.

The invention is explained in more detail below with reference to a preferred embodiment illustrated with reference to the attached drawings. In the drawings show:

FIG. 1

a trained as a circulation pump for swimming pools invention feed pump in partial cross section;

FIG. 2

an enlarged detail view of the sectional view of FIG. 1 ;

FIG. 3

an isolated view of the outer rotor of Figures 1 and 2 in cross-section;

FIG. 4

the outer rotor of FIG. 3 in perspective partial cross-section;

FIG. 5

an isolated view of the inner rotor of Figures 1 and 2 in cross-section;

FIG. 6

the inner rotor of the FIG. 5 in perspective view;

FIG. 7

an isolated view of the split pot of the feed pump of Figures 1 and 2 in cross-section;

FIG. 8

a plan view of the containment shell of FIG. 7 ;

FIG. 9

an isolated view of the seal housing of the feed pump of Figures 1 and 2 in cross-section; and

FIG. 10

a plan view of the seal housing the FIG. 9 ,

In the Figures 1 and 2 an embodiment designated overall by the reference numeral 10 of the feed pump according to the invention is shown. FIG. 2 shows an enlarged detail view of the FIG. 1 , The illustrated feed pump 10 can be used for example as a circulation pump for swimming pools or swimming pools. The feed pump 10 has a suction nozzle 11 which opens into an inlet opening 12 of an upstream fiber catcher 13. The fiber catcher 13 comprises a filter basket 14 which can be removed via an opening 15 provided on the upper side of the fiber catcher 13. The opening 15 of the fiber catcher 13 is closed by a screw 16. An outlet opening 17 of the fiber trap opens into an axial suction opening 18 of the feed pump. Adjoining the suction opening 18 is a radial impeller 19, which axially sucks the fluid to be delivered and transports it radially into a pressure chamber 20 of the delivery pump. From the pressure chamber 20, the fluid to be delivered is discharged via a pressure port 21.

The impeller 19 is stuck on a free end of a pump shaft 22 and there is rotationally fixed by means of tolerance ring and a screw 23. On the pump shaft 22, an outer rotor 24 is sprayed. The pump shaft 22 and the outer rotor 24 are isolated in the FIGS. 3 and 4 shown in more detail. The impeller 19 opposite end of the outer rotor 24 is cup-shaped and has outer magnets 25 which are arranged on the inner circumference of the outer rotor 24. The outer magnets 25 are permanent magnets, for example, on the outer rotor can be plugged in Nuttaschen or can be encapsulated by this. In the example shown, the outer magnets are fixed by means of a steel ring 26 in a recess of the outer rotor 24. The recess is welded in the example shown by a frontal cover 50 gas-tight. In the pot formed by the outer rotor 24 is an inner rotor 27, on the outer circumference, the outer magnet 25 of the outer rotor 24 opposite, inner magnets 28 are arranged. The inner rotor is insulated and detailed in the FIGS. 5 and 6 shown. Between the outer rotor 24 with its outer magnet 25 and the inner rotor 27 with its inner magnet 28, a split pot 29 is arranged, which consists of a non-magnetizable material. The containment shell 29 is insulated and detailed in FIGS FIGS. 7 and 8 shown.

The inner rotor 27 has a drive shaft bore 30 into which a motor shaft 31 of a drive motor 32 flanged to the feed pump 10 can engage in a rotationally fixed manner. The drive motor 32 may be, for example, an electric motor.

To reduce a possible slip when switching on the drive motor 32, the inner rotor 27 on a flywheel 33 which is rotatably connected to the motor side end side of the inner rotor 27 and serves as additional weight to slightly delay the tarnishing of the inner rotor immediately after switching on the drive motor, so that the magnetic coupling between inner magnet 28 and outer magnet 25 does not break off in this phase. To adapt to different engine performance, the flywheel 33 is replaceably formed and fixed by means of two screws 34 on the motor-side end face of the inner rotor 27.

The feed pump 10 has a pump housing 35, which surrounds the impeller 19 and the pressure chamber 20. Adjoining the pump housing 35 is an intermediate housing 36, which surrounds the drive unit of the feed pump 10 which consists of the inner rotor and outer rotor. In the interior of the intermediate housing 36, a seal housing 37 is arranged, which together with the containment shell 29 forms a fluid channel 38 for a fluid for cooling and lubrication of the outer rotor and the bearings of the pump shaft. The seal housing 37 is insulated in the FIGS. 9 and 10 shown in more detail.

The containment shell 29 has on its outer periphery a plate-like collar 39 which is connected by screws 40 to the seal housing and thus serves as a motor-side cover for the seal housing. For reliable sealing, an O-ring 41 is arranged between the collar 39 acting as a cover for the seal housing of the can 29 and the seal housing 37. Depending on the pumped medium, the screws 40 can be protected by plugs 51 from the pumped medium. For example, for use in the chemical field, plugs and o-rings made of a chemical resistant material, such as a fluoroelastomer or an ethylene-propylene-diene rubber, may be used. In the Figures 1 and 2 For example, only the upper screw 40 is provided with a plug 51.

In particular, in the enlarged view of FIG. 2 is the central area of the feed pump 10 off FIG. 1 better recognizable. Additional arrows symbolized in FIG. 2 the fluid circuit for lubrication and cooling of the drive component. It can be seen that openings 43 are recessed between a pump-side cover 42 of the seal housing and the seal housing 37, via which conveying medium can pass from the pressure chamber 20 in a distributor space 44 formed by the seal housing. From the distributor space 44, the fluid passes through apertures 46 recessed in an inner wall 45 of the seal housing 37 into the fluid channel 38. There, the fluid flows around the cup-like region of the outer rotor 24 and the outer surface of the containment shell 29 between outer rotor 24 and containment shell 29 and passes over in the outer rotor provided openings 47 in the channel 38 back.

In the example shown, the pump shaft 22 is mounted at its ends in each case by a ceramic plain bearing 48a, 48b. In this case, in each case one component 48a is connected to the seal housing or the containment shell, while the other component 48b is connected to the pump shaft 22 or to the end of the outer rotor 24 sprayed onto the pump shaft. The pump-side cover 42 has a central opening through which projects the impeller-side end of the pump shaft. About the annular gap formed between the pump shaft and the inner edge of the opening, the fluid enters a formed on the back of the impeller in the cover 42 radial gap 49 through which the fluid can be directed in the direction of pressure chamber 20 again.

In the FIGS. 3 and 4 the outer rotor 24 of the feed pump 10 according to the invention is shown in more detail. It can be seen that the cup-shaped housing of the outer rotor 24, in which the outer magnets 25 are fixed by means of steel ring 26, is gas-tight welded at the motor-side front end by means of a cover 50. At the impeller-side end of the outer rotor, the outer rotor 24 is sprayed onto the pump shaft 22. Furthermore, the components 48b of the two ceramic plain bearings connected to the outer rotor 24 are shown.

In the FIGS. 5 and 6 the inner rotor 27 of the feed pump according to the invention with screwed flywheel 33 is shown. It can be seen in particular in the perspective view of FIG. 6 the inner magnets 28 glued distributed on the outer circumference of the inner rotor, which are likewise designed like the outer magnets 25 of the outer rotor as permanent magnets.

In the FIGS. 7 and 8 the containment shell 29 is shown in more detail in cross section and in plan view. The cross section corresponds to that in the FIG. 8 indicated section along the line VII-VII. It also recognizes the connected to the gap pot component 48a of the ceramic plain bearing, as well as acting as a motor-side cover of the seal housing collar 39 of the gap pot, which is formed as an integral component with the containment shell.

In the FIGS. 9 and 10 the seal housing 37 is shown in more detail in cross-section and in plan view. In FIG. 10 is the cut of the FIG. 9 indicated by the line IX-IX. In the example shown, the seal housing 37 is a complex injection-molded part, which has an inner wall 45 for forming a distribution chamber 44 for serving as a coolant and lubricant partial flow of the pumped medium. It also recognizes the connected to the seal housing component 48a of the ceramic plain bearing. The distribution chambers (44) are dimensioned large-scale for good cooling and lubrication of the ceramic bearings. In the illustrated embodiment, six chambers arranged in a star shape and separated by ribs enable a uniform, uniform flushing of the ceramic bearings over the openings 43, the chambers 44 and the openings 46 (cf. Fig. 2 ).

In the ceramic bearings 48a, 48b longitudinal and end-side grooves are recessed, which ensure a good flow for lubrication. The in the Fig. 3 . 7, and 9 recognizable O-rings (52a, 52b, 52c) allow in the assembled state with the ceramic bearings 48a, 48b a certain axial angular flexibility and compensation or damping of vibrations. The ceramic plain bearing has only a small clearance to the plastic plain bearing seat. The pressed in between O-ring compensates any mechanical inaccuracies of the installed plastic parts environment, ie the ease of sliding bearing can thus be realized by plastic parts tend tend to slight distortion.

LIST OF REFERENCE NUMBERS

10

feed pump

11

suction

12

Entry opening of the fiber catcher

13

Strainer

14

filter basket

15

opening

16

screw

17

outlet opening

18

suction opening

19

Wheel

20

pressure chamber

21

pressure port

22

pump shaft

23

screw

24

outer rotor

25

external magnet

26

steel ring

27

inner rotor

28

interior magnet

29

containment shell

30

Drive shaft bore

31

motor shaft

32

drive motor

33

flywheel

34

screw

35

pump housing

36

intermediate housing

37

seal housing

38

fluid channel

39

Collar / lid

40

cover screws

41

O-ring

42

cover

43

openings

44

distribution space

45

Inner wall of the seal housing

46

Opening in inner wall

47

Opening in outer rotor

48a, b

ceramic bearings

49

radial gap

50

Cover of the outer rotor

51

Plug

52a, b, c

O-rings

Claims (11)

Feed pump for fluid media, in particular circulation pump for swimming pools or swimming pools, with a pump housing (35), an impeller (19) arranged in the pump housing (35) and non-rotatably mounted on a pump shaft (22), a drive unit (27, 28) which can be connected to a drive motor (32), wherein the drive unit (24, 25, 27, 28) and the pump shaft (22) are in magnetic operative connection with each other via inner and outer magnets (25, 28), which are separated from one another by a containment shell (29), and the drive unit (24 , 25, 27, 28) have an inner rotor (27) on which the inner magnets (28) are arranged and which can be connected in a rotationally fixed manner to a motor shaft (21) of the drive motor (32) and an outer rotor (24) connected non-rotatably to the pump shaft. wherein the outer rotor (24) carries the outer magnets (25) and surrounds the inner rotor (27), and wherein the inner rotor (27) has additional weights (33) which act as a starting brake. Feed pump according to claim 2, characterized in that the additional weights are designed as flywheel (33). Feed pump according to claim 3, characterized in that the flywheel (33) is replaceably mounted on the inner rotor (27). Feed pump according to one of claims 1 to 3, characterized in that the outer rotor (24) is sprayed onto the pump shaft (22). Feed pump according to claim 4, characterized in that the impeller (19) is exchangeably mounted on the pump shaft (22). Feed pump according to one of claims 1 to 5, characterized in that a fluid circuit is provided, via which for cooling and lubrication of the outer rotor (24) and the pump shaft (22) a part of the pumped medium from a pressure chamber (20) of the feed pump to the outer rotor (24) and the pump shaft (22) can be performed. Feed pump according to claim 6, characterized in that the outer rotor (24) in a seal housing (37) is arranged, which defines with the gap pot (19) a fluid passage (38) as part of the fluid circuit for cooling and lubrication. Feed pump according to claim 7, characterized in that the pump shaft (22) is rotatably supported by at least one slide bearing (48a, 48b), wherein the slide bearing is cooled and lubricated by the conveyed in the fluid circulation medium. Feed pump according to one of claims 1 to 8, characterized in that the feed pump (10) has an axial suction opening (18). Feed pump according to claim 9, characterized in that a fiber catcher (13) is arranged in front of the suction opening (18). Feed pump according to one of claims 1 to 10, characterized in that a drive motor (32) to the drive unit (24,25,27,28) is flanged.

Images