EP2604860A1 - Wet rotor pump with pre-chamber - Google Patents

Abstract

The pump (1) has a rotor shaft (5) i.e. hollow shaft, carrying an impeller (7) at an axial end. The impeller is arranged in a pump chamber (15). A gap pipe (2) includes a radially outwardly extending flange (8) at an impeller side end. A bearing support (9) with a sliding bearing (10) for bearing the shaft is arranged between the flange and the shaft. An annular prechamber (11) lies between the impeller and the flange, limited into the impeller by a dimensionally-stable separator (12), and communicatingly connected with a rotor chamber (4) by inner and outer channels (13, 14).

Description

The invention relates to a wet-running pump with a stator and a rotor separated by a split tube from this, comprising a rotor shaft and a rotor core and is rotatably mounted in a rotor space formed by the gap tube, wherein the rotor shaft at one axial end disposed in a pump chamber impeller contributes to the promotion of a liquid and the split tube at its impeller end has a substantially radially outwardly extending flange, wherein between the split tube and the rotor shaft, a bearing support with a bearing for supporting the rotor shaft is arranged and held by the split tube.

In wet-runner pumps, the rotor rotates in a liquid which generally corresponds to the fluid to be pumped, so that there is a fluid exchange between the liquid in the rotor chamber and the pumped medium and at the same time a heat exchange and thus cooling of the rotor is achieved. On the other hand, the fluid in the rotor chamber lubricates the bearings, which are designed as plain bearings. As a rule, water is pumped and used in the rotor space.

For heavily contaminated with particles fluids, these particles, such as magnetic iron or rust particles, lubricants or additives, store in the rotor space and lead to wear and even to a blocking of the rotor and storage. For this reason, the rotor chamber could basically liquid-tight separated from the pump chamber and the pumped medium become. However, this would mean that no fluid exchange between the rotor chamber and the pump chamber can take place and thus a small cooling of the rotor space takes place. It is therefore advantageous if a liquid circulation takes place through the rotor space.

In general, the rotor space is the hottest place in a wet-running pump, because a large part of the waste heat generated in the stator is discharged via the can into the rotor space. If plastic components are used in the rotor space, for example, a bearing or bearing plate made of plastic, the resulting heat in the motor due to the plastic-specific insulation properties is insufficient dissipated to the flowing medium in the pump housing. From a temperature of about 60 ° C is also added that more lime precipitation occurs, as long as the rotor space is filled conventionally with water. Depending on the hardness of the water, more or less lime precipitates. It would therefore be desirable for this reason, to keep the liquid exchange between the rotor space and the medium as low as possible.

It is therefore the object of the present invention to provide a wet-running pump in which sufficient and efficient heat removal of the heat in the rotor space to the conveyed medium is achieved while minimizing the liquid exchange, while at the same time avoiding or at least minimizing the risk of the incorporation of solid particles and lime precipitation is minimized.

This object is achieved by the wet-running pump with the features of claim 1. Advantageous developments are specified in the subclaims and are explained in more detail below.

According to the invention, a wet-running pump with a stator and a rotor separated by a split tube from this rotor, which comprises a rotor shaft and a rotor package and is rotatably mounted in a rotor space formed by the gap, proposed, wherein the rotor shaft at one axial end arranged in a pump chamber Impeller to promote a liquid carries and the split tube at its impeller end a substantially radially to having outwardly extending flange, between the gap tube and the rotor shaft, a bearing support is arranged with a bearing for supporting the rotor shaft and held by the split tube, and between the impeller and the flange a pre-chamber, the impeller out through a separator and the stator through the flange is limited, wherein the antechamber is communicatively connected via channels with the rotor space.

The core idea of the present invention is to provide a comparatively large prechamber between the rotor space and the pump chamber, i. behind the impeller and in front of the flange, so that the strong turbulence of the flow in the pump chamber can not get into the antechamber. In the prechamber is rather a largely calm flow relative to the pump chamber. This is achieved by the separator which spatially separates the prechamber from the pump chamber so that the rotor space is separated from the swirl caused by the impeller. The separator also has a comparatively large surface and can serve as a heat exchanger. Furthermore, this prechamber / settling chamber is separated from the rotor space by the bearing carrier and the bearing received therein, whereby a sufficient fluid exchange takes place between the prechamber and the rotor space via channels and thus the necessary heat exchange is ensured.

The channels may be located in the bearing carrier and / or between the bearing carrier and the can and / or between the bearing and the bearing carrier. The heat is then transferred to the pumped fluid in the pump chamber via the separating element, whose inner wall surface is overflowed by the circulating liquid. The partition thus acts here as a heat exchanger.

Another advantage of the pre-chamber is that in the rotor chamber or possibly resulting particles, for example, by lime precipitation or due to wear collect in the antechamber. If the pump is switched off, they fall to the bottom and accumulate in the lower part of the pre-chamber, so that they can not get into the rotor space or enter the bearing gap of the plain bearings and cause wear or damage there.

The flange can be integrally formed on the split tube or be attached or plugged on or in this as a separate component.

Preferably, the pre-chamber is at least during operation of the wet-running pump to the pump chamber structurally completed. However, this does not necessarily have to be the case for the idle state. As will be clarified below, this means that the pre-chamber in the pressureless state of the wet-running pump, i. in the off mode, either also closed to the pump chamber or is open to the pump chamber. The latter embodiment will be explained below. With regard to that variant in which the antechamber is completed both in operation of the pump and in the idle state, the pre-chamber in the wet-running pump can be formed by a dimensionally stable component comprising the separating element. This completely prevents the penetration of particles from the fluid into the rotor space.

In an advantageous development of one of the stated embodiment variant, the separating element can form a filter. The pre-chamber is then still spatially separated from the pump chamber during operation of the wet-running pump, but the separating element is then liquid-flowable. In this way, an exchange of liquid between the antechamber and the pump chamber can take place, so that the heat dissipation is further improved, but at the same time the pump chamber is kept free of larger particles from the pumped medium.

The separating element may itself be designed as a filter and / or contain one or more filter elements. They can lie symmetrically along a concentric circle of the separating element. As a result, the separating element is independent of a specific mounting position. It is advantageous to arrange the filter element or filters for better venting of the pre-chamber and / or the rotor chamber radially far outside.

The filter elements can sponge-like filter body or mesh-like fabric of metal or plastic or by corresponding to the particles to be filtered small be formed sized openings. In the case of filter bodies, these are used in the separator, in the case of a net-like fabric made of metal or plastic, this is held on the separator, and in the case of openings, these are introduced into the separator, so that the separator itself forms the filter. The openings may be distributed over the entire or part of the surface of the separating element in the manner of a perforation. Alternatively, the separating element may have a net-like structure and thereby form the filter itself.

Preferably, the pre-chamber is bounded radially outwardly by a tubular outer wall which is connected at one axial end to the flange and which carries at its other axial end of the separating element, abuts this or passes into this. Accordingly, the separating element can either be formed integrally with the outer wall, so that the outer wall merges into the separating element at the other axial end, or it can be a component that is separate from the outer wall, so that the separating element lies or rests only on the outer wall.

In both said cases, the partition may be solid, i. be dimensionally stable and relentless. Alternatively, however, it may also have some flexibility and compliance in both cases. These properties are mainly dependent on the material used and the thickness of the separating element.

For example, the separating element may consist of a material which, although having a certain dimensional stability, is yielding. This means that the separating element is movable under pressure, in particular expandable. For this purpose, in particular an elastomeric plastic of a certain thickness or a thin metal sheet is suitable. In this embodiment, the separating element may be integrally formed with the outer wall or on her or lie.

Alternatively, the separating element can not be completely formed dimensionally stable, at least in its radial outer region, preferably completely. Such a partition member is obtained, for example, by having the aforementioned net-like structure or formed of a membrane. In this case The separator also has a compliance, but must be additionally supported. Due to lack of dimensional stability, it can be attached to the other axial end of the outer wall, in particular be clamped there, so that this end of the outer wall carries the separating element.

In contrast, it can be provided in a dimensionally stable, yielding separating element that it comes to rest only at the other axial end of the outer wall without being fastened or clamped there, since this is not necessary due to the dimensional stability. It is then on this or on, in particular during operation of the pump, as will be explained below.

In order to obtain a largely closed pre-chamber also towards the stator, the outer wall can bear sealingly against the flange. This can be done for example directly or indirectly by a sealing lip, a sealing washer or a sealing ring, which is integrally formed on the outer wall or as a separate part between the outer wall and the flange.

Preferably, the pre-chamber is limited to the rotor shaft at least partially by an inner ring, which is connected to the bearing carrier and carries the separator or passes into this. In particular, the inner ring may be connected at one axial end to the bearing carrier and carry at the other axial end of the separating element or pass into this.

Furthermore, the pre-chamber may be sealed towards the rotor shaft. This can also be done directly or indirectly by a sealing lip, a sealing washer or a sealing ring, but preferably by means of a dynamic seal or a mechanical seal.

Preferably, the separating element is formed by a heat-conducting material, in particular of metal. For example, the separating element made of sheet metal, steel or brass. Also, a thermally conductive plastic can be used. The heat-conducting property of the separating element ensures that effective heat can be released via the separating element to the conveying medium in the pump chamber.

As already mentioned, the separating element may be at least partially formed by a flexible membrane. A membrane has the advantage that it can absorb pressure pulses that arise, for example, when switching on and off the pump. Furthermore, it can provide a pressure equalization between the rotor chamber and the pump chamber. The membrane may be made of a resilient plastic material or a metal, for example a steel membrane. This has a higher heat transfer coefficient than plastic, so that a better heat transfer is achieved.

In the embodiment as a membrane, the separating element can be held on the inside of the inner ring, for example glued to a collar of the inner ring, welded or clamped firmly. Also, the membrane can be firmly fixed to the outer wall.

However, it is advantageous if it rests loosely on the outside of the end face of the wheel facing axial end of the outer wall. To increase the support surface, the outer wall may have a radially inwardly directed projection on which the membrane can come to rest. Since the pressure in the pump chamber is greater than the pressure in the rotor chamber, the membrane is pressed against the end face of the outer wall. An additional, full-scale fixation of the membrane is therefore not required. However, securing the membrane to the outer wall at discretely discrete locations may be helpful, particularly for assembly, to maintain the membrane in position. The membrane is thus liquid-tight but not gas-tight at the end of the outer wall during operation of the pump. This ensures that gas can escape from the top of the rotor chamber when it is filled with liquid during commissioning of the pump. When the pump is shut down, the fluid in the rotor chamber can also escape through the gap between the diaphragm and the end face of the outer wall at the bottom.

Preferably, the separating element is brought close to the impeller, wherein the distance between the impeller and the separating element should be selected depending on the impeller diameter, in particular between 0.015 and 0.04 may be impeller diameter. Since behind the impeller strong turbulence exist that lead to hydraulic losses, causes a comparatively small gap between the impeller and separator an improvement in efficiency by reducing this turbulence.

In the wet-running pump according to the invention, the bearing carrier may be formed integrally with the gap tube. In this case, the bearing carrier together with the can, preferably made of plastic. Furthermore, additionally or alternatively, the bearing carrier may be formed integrally with the bearing and thus form a bearing carrier assembly. Also in this case, the assembly of bearing and bearing carrier may preferably be made of plastic.

Finally, in a further embodiment variant or further development, in addition to or as an alternative to the aforementioned variants, the separating element or at least the inner ring may be formed integrally with the bearing carrier. Additionally or alternatively, the separating element may be formed integrally with the inner ring, in particular made of plastic. This is particularly suitable if the partition is to form a dimensionally stable wall, for example for receiving the aforementioned filter elements.

In addition or as an alternative to the aforementioned features, the split tube may have, at its axial end facing away from the impeller, a bottom closing the rotor space, so that the split tube forms a so-called split pot.

In combination or as an alternative to the features of one of the previously described embodiments, the outer wall can preferably be connected to the coaxial inner ring for stabilizing the separating element via radial transverse webs. This is particularly advantageous if the separating element is designed as a membrane, in particular as a non-dimensionally stable membrane. This can then rest on the transverse webs, in particular loosely or only be supported fixed at discrete locations, and be supported by the transverse webs.

According to another advantageous aspect of the invention, in addition to or as an alternative to the features described above, the separating element in the pressureless state of the wet-running pump may be gap-formingly spaced from the outer wall in at least a portion of its radially outer peripheral edge and pressed against the outer wall during operation of the wet-running pump. If the separating element is located on the outer wall, the pre-chamber is closed. Is it in the off state of the pump spaced from the outer wall, there is a gap between this and the separator so that depending on the location of this gap on the one hand gas and / or other particles can escape from the antechamber, and also liquid during filling of the pump can occur there.

Preferably, that portion of the radially outer peripheral edge of the separating element at a standstill of the pump are spaced from the outer wall, which is based on their installation position at the bottom of the pump. The particles swirling around in the pre-chamber then sink to the bottom in the switched-off state of the pump and can sink further into the pump chamber through the gap between separating element and outer wall, from where they are conveyed out of the pump the next time the pump starts up.

In order to allow the particles to sink into the pump chamber, the inside of the outer wall can drop off at an angle to the impeller, at least in this area. The particles then slide down this slope and fall into the pump chamber.

To achieve the aforementioned mobility, the separating element may be a flexible annular disc, in particular of dimensionally stable, elastomeric plastic or a thin, movable plate. The sheet or the dimensionally stable plastic has the advantage over an elastic membrane that it / he is dimensionally stable with the same thickness and does not need to be fixed to the outer wall. Furthermore, it / he can absorb higher forces and better deliver the heat from the antechamber to the liquid in the pump chamber. On transverse webs between outer wall and inner ring can then be dispensed with, so that the Liquid in the prechamber the separating element can easily flow over for heat dissipation.

It is particularly advantageous if, in the non-pressurized state of the wet-running pump, the separating element lies gap-formingly spaced apart from the outer wall not only in a partial region of its radially outer circumferential edge but also pressed against the outer wall during operation of the wet-running pump. As a result, below the particles and gas above escape from the antechamber, without it depends on an orientation of the mounting position of the separating element with respect to the installation position of the wet-running pump.

In addition or as an alternative to the aforementioned features, the inner side of the outer wall can drop toward the impeller, at least in the lower region of the pre-chamber. In this sense, dropping means that the distance between the inside of the outer wall and the axis of rotation of the impeller and the pump shaft increases in the direction of the impeller. In the lower part of the pre-chamber means in this sense that the slope with respect to the installation position of the wet-running pump, i. in the direction of gravitational force is below. In a preferred development, this gradient can continue in full, so that the antechamber is rotationally symmetrical. In other words, the pre-chamber opens with respect to its shape towards the pump chamber or the inside of the outer wall runs conically towards the stator. This has the advantage that it does not depend on the installation position of the pump even with the outer wall, so that the particles collecting at the bottom of the prechamber can slide forward into the pump chamber.

For the realization of a prechamber, whose radially delimiting outer wall with its inner side drops towards the impeller, for example, a single-walled outer wall of constant thickness can be used, which is conical overall to the stator. This means that also the outside of the outer wall to the stator runs conically. Alternatively, the outer wall may be triangular in axial section, wherein its thickness decreases towards the impeller under increasing inner radius of the antechamber. Further alternatively, the outer wall in each of the embodiments may also be formed zwewandig, wherein an inner first wall bounded the antechamber and in shape of said single-walled exterior wall design the constant thickness corresponds, whereas an outer second wall is axially parallel to the rotor shaft. The inner first wall and the outer second wall then go over at their end facing the impeller at an acute angle into one another.

In a further development of one of the variants, in addition or as an alternative to the other features described for improving the heat release to the liquid in the pump chamber, the separating element may have structural elements for increasing the surface. Such structural elements may be, for example, ribs, grooves, nubs, beads or depressions.

Preferably, the structural elements are present at least at the back of the separating element directed to the antechamber, since they would cause hydraulic losses on the front side directed towards the pumping chamber. At the rear, the structural elements improve the heat absorption. As far as such structural elements on the front for better heat dissipation or are formed, they should not rise too far in the direction of impeller, so that the hydraulic losses are not too strong. The structural elements can in principle be arbitrarily shaped, for example, extend radially, secantially, in concentric circles or helically.

According to a further development of the wet-running pump according to the invention, in addition or as an alternative to the other features described, the bearing carrier may have a collar extending toward the outer wall at its axial end facing the impeller. This is designed such that it separates the antechamber into a front, directed to the pump chamber chamber chamber, and a rear chamber facing away from the pump chamber chamber. Through this collar, which also acts as a partition, the flow in the pre-chamber can be targeted.

Preferably, the two chamber spaces can be connected to each other via at least one opening, so that the liquid can flow from one chamber space to the other chamber space. The at least one opening may be in the Collar be present or be formed by a distance between the collar and outer wall.

The at least one opening may be annular. That is, the collar ends at a distance in front of the inside of the outer wall. Alternatively, several openings may be present. Again, the plurality of openings may be present in the collar or be formed by a distance between the collar and outer wall.

If a plurality of openings are present, the collar can integrally merge into the outer wall, wherein the opening are provided in the collar.

In each of the aforementioned variants, the opening or the openings can be located radially far outward, so that the separating element is overflowed as far as possible.

In an advantageous development of one of the abovementioned embodiments, the pre-chamber, in particular the front chamber space, may have a space region open to the rotor shaft. In this area, the rotor shaft can carry a further impeller, which causes an at least partially radially directed flow in the pre-chamber. The further impeller may be an impeller or a disk, whose axial end face or end faces has grooves and / or ribs / and thereby also causes a liquid delivery. For example, these grooves or ribs may be helical. The impeller should be made very small, so that only a minimal flow is generated. Thus, the length of the wings in the case of an impeller in the radial direction need only be between 1/4 and 1/3 of the radius of the rotor shaft.

Preferably, the rotor shaft is designed as a hollow shaft with a flüssigkeitsdurchströmbaren, preferably central bore, which is open at the end facing away from the impeller of the shaft and there opens into the rotor chamber.

Based on the axial direction of the rotor shaft, this may have one or more transverse bores through which liquid can flow from the rotor shaft into the prechamber. The cross hole or cross holes connect / connect the central hole with the antechamber to achieve a liquid circulation. Already these transverse bores cause a flow, so that the aforementioned further impeller is basically not necessary. However, it can be used additionally.

If an impeller is used as an additional impeller, its wings can advantageously extend in the axial direction to the bore, so that they additionally drive the flow when rotating the rotor shaft. They generate in the / the transverse bores a negative pressure, through which the liquid is sucked in the rotor space in the rotor shaft. In addition, they promote the liquid in the antechamber radially outward, wherein the liquid flows over the back of the partition and thereby release its heat to this.

However, even if the other impeller were not present, a circulation of the liquid in the rotor chamber and in the antechamber would result due to the temperature gradient and the centrifugal forces acting in the region of the transverse bore (s).

At the outer peripheral region, the liquid can then flow from the front chamber space in the rear chamber space in the axial direction and from there through the channels between the bearing support and the can and / or the bearing support and the bearing in the rotor chamber, where the liquid heats up and at the end of the rotor shaft enters this. As a result, an effective cooling circuit is maintained, through which the heat in the rotor chamber is effectively guided to the separating element between the prechamber and pump chamber, which then emits the heat to the pumping chamber located in the pumped conveying medium.

Fig. 1:

Teilansicht einer Axialschnittdarstellung durch eine erfindungsgemäße Nassläuferpumpe mit großer Vorkammer und formstabilem Trennelement

Fig. 2:

Teilansicht einer Axialschnittdarstellung durch eine andere erfindungsgemäße Nassläuferpumpe mit großer Vorkammer und Membran als flexibles Trennelement

Fig. 3:

Axialschnittdarstellung durch eine weitere erfindungsgemäße Nassläuferpumpe mit getrennter Vorkammer und flügelradgetriebenem Wärmekreislauf

Fig. 4:

Vergrößerte Darstellung der Lagerträgerbaugruppe gemäß Figur 3

Further advantages and features of the invention will be explained in more detail with reference to embodiments and the accompanying figures. Show it:

Fig. 1:

Partial view of an axial section through a wet-runner pump according to the invention with a large pre-chamber and dimensionally stable separating element

Fig. 2:

Partial view of an axial section through another inventive wet-running pump with large pre-chamber and membrane as a flexible separating element

3:

Axial section through another inventive wet-running pump with separate pre-chamber and Flügelradgetriebenem heat cycle

4:

Enlarged view of the bearing carrier assembly according to FIG. 3

FIG. 1 shows a partial view of an axial sectional view of a wet-running pump according to the invention 1. Shown is only the hydraulic part of the pump 1 and the transition region to the electric motor of the pump 1, the only in the embodiment according to Fig. 3 is completely visible. The pump 1 comprises a stator 3 and a rotor 5, 6 which is separated therefrom by a split tube 2 and which in turn comprises a rotor shaft 5 and a rotor core 6 and is rotatably mounted in a rotor space 4 formed by the split tube 2, see Fig. 3 , The rotor core 6 comprises permanent magnets, which are not shown in detail.

The rotor shaft 5 protrudes at an axial end into a pump chamber 15 and carries there an impeller 7 for conveying a liquid. The split tube 2 has at its impeller-side end a substantially radially outwardly extending flange 8. Between the flange 8 and the rotor shaft 5, a bearing support 9 is arranged with a sliding bearing 10 for supporting the rotor shaft 5. The sliding bearing 10 is firmly inserted in the bearing bracket 9. The bearing support 9 is in turn firmly inserted in the can 2. Between the impeller 7 and the flange 8 is an annular pre-chamber 11 for flow calming, which is limited to the impeller 7 through a separating element 12, which is dimensionally stable in this embodiment. Towards the stator 3, the antechamber 11 is limited by the flange 8. The prechamber 11 is communicatively connected only via outer channels 14 between the bearing bracket 9 and the split tube 2 and inner channels 13 between the bearing 10 and the bearing bracket 9 with the rotor chamber 4.

On the side of the bearing support 9 directed towards the pump chamber 15 there is a receptacle 30a for inserting a dynamic seal 30, which takes over the seal to the rotating rotor shaft 5. As a dynamic seal 30 It is also possible to use a labyrinth seal or a gap seal which keeps the media throughput small. Furthermore, the pump chamber 15 facing side of the bearing support 9 includes a receptacle 35 in the form of an annular groove into which the separating element 12 is inserted non-positively. The contact surface between separating element 12 and bearing support 9 thereby forms a circumferential sealing surface.

The separating element 12 is made of a dimensionally stable material with a high heat transfer coefficient, for example a thermally conductive plastic or metal, and separates the prechamber 11 from the pumping chamber 15. The separating element 12 has the shape of a perforated disc. As a result of the rotor package 6 rotating during operation, the liquid in the rotor chamber 4 is swirled and likewise set in a rotary motion. Heat is released from the stator 3 via the split tube 2 into the rotor chamber 4, which receives the liquid in the rotor chamber 4. Via the channels 13, 14, the liquid enters the antechamber 11. The separator 12 acts like a heat exchanger disc and transfers the heat to the fluid in the pump chamber 15 from.

In the execution according to FIG. 1 the pre-chamber 11 is carried out largely closed, both during operation of the wet-running pump 1 and in its off state. For this purpose, the pre-chamber 11 is bounded radially outwardly by a pipe-section-shaped outer wall 16. This outer wall 16 extends axially parallel to the rotor shaft 5 and is at an axial end to the flange 8 sealingly. For this purpose, the flange 8 has a to the pump chamber 15 extending annular projection 28, on the inside of the outer wall 16 comes to rest. This has in this investment area a survey 29 which extends along the circumference of the outer wall 16 and sealingly against the inside of the projection 28 presses. At its other axial end, the outer wall 16 merges into the separating element 12. That is, it is integrally formed with this. The axial length of the outer wall corresponds approximately to the width of the perforated disk-shaped separating element 12 in the radial direction, so that it is possible to speak of a large pre-chamber 11.

Furthermore, the antechamber 11 is also sealed to the rotor shaft 5.

In the embodiment according to FIG. 1 This is done by the pre-chamber 11 is limited to the rotor shaft 5 through an inner ring 17 which bears against the bearing support 9, in particular in the annular receptacle 35 rests. The inner ring 17 is also formed integrally with the separating element 12 and passes into this. The separating element 12, the inner ring 17 and the outer wall 16 form a hat-shaped bearing plate. As described above, the dynamic seal 30, which largely prevents liquid from passing along the rotor shaft 5 into open regions of the bearing carrier 9 and thus into the pre-chamber 11, is located on the axial end of the bearing carrier 9 facing the pump chamber 15.

The separating element 12 is brought close to the impeller 7. The distance between the impeller 7 and the separator 12 is less than 4% of the impeller diameter. This increases the hydraulic efficiency of the wet-running pump 1.

During operation of the wet-running pump 1, liquid flows from the pre-chamber 11 through a channel 14 between the can 4 and the bearing carrier 9 into the rotor space 4. Furthermore, liquid is conveyed through the bearing gap during a rotation of the shaft 5 and occurs at an axial end of the bearing 10 again, from where it flows into a channel 13 between the bearing 10 and bearing carrier 9. From this channel 13 enters a part of the liquid, which serves as lubrication, at the other axial end in the bearing gap again. Consequently, there is a circulation of the liquid in the rotor chamber 4 through the bearing gap.

FIG. 2 shows an alternative embodiment of the inventive wet-running pump 1. In this, instead of a dimensionally stable separating element 12, a flexible membrane 12a is used as a separating element. The membrane 12a is made of an elastic material.

The membrane 12 a is held on the inner ring 17, wherein it is firmly clamped to a collar of the inner ring 17. On the front side of the impeller 7 directed axial end of the outer wall 16, the membrane 32 is loose, at least when the impeller 7 rotates, whereby the membrane 32 is liquid-tight but not airtight pressed onto the outer wall 16. This has the advantage that when filling the Pump 1, with the medium to be pumped, this can flow into the rotor chamber 4 through a very small gap and the air at the highest point of the rotor chamber 4 and the prechamber 11 can escape. During operation of the pump 1, a pressure difference arises between the pump chamber 15 and the rotor chamber 4, which presses the separating element 12a firmly against the outer wall 16 and with the inner ring 17 into the receptacle 35 on the bearing carrier 9.

To stabilize the membrane 12a, the outer wall 16 is connected to the coaxial inner ring 17 via radial transverse webs 17a. On these transverse webs 17a, the membrane 12a is also on when it is pressed during operation of the pump 1 by the prevailing pressure in the pump chamber 15 to the rear.

FIG. 3 shows a further embodiment of the inventive wet runner pump 1. In this variant, the bearing support 9 is double-walled. Between an outer wall and an inner wall, channels 34 are provided, wherein the outer wall rests against the inside of the split tube 2 and the sliding bearing 10 rests with its outer periphery on the inner wall. The pre-chamber 11 is communicatively connected by the channels 34 with the rotor chamber 4. Further, the bearing support 9 at its axial end facing the impeller 7, a collar 18 extending to the outer wall 16, which separates the pre-chamber 11 in a front, directed to the pump chamber 15 chamber chamber 19, and a rear, the pump chamber 15 facing away chamber chamber 20. The collar 18 is integrally formed with the outer wall 16 and merges into several joints in this. Bearing carrier 9, collar 18 and outer wall 16 thus form a common molding. Between the connection points openings 21, 22 are provided, through which the chamber chambers 19, 20 are interconnected. The openings 21, 22 are thus radially far outward, so that the separating element 12a can be almost completely overflowed with a circulating flow in the front chamber space 19.

The prechamber 11 has a space portion 23 at least partially open to the rotor shaft 5. In this space region 23, the rotor shaft 5 carries an impeller 24, 27 with wings 27, which has an at least partially radially directed flow generated. The impeller 24 is disposed between the shaft seal 30 and the bearing 10 on the shaft 5.

The rotor shaft 5 is formed as a hollow shaft with a central, liquid-flowable bore 25, which is open at the end facing away from the impeller 7 of the shaft 5 and there opens into the rotor chamber 4. The opposite end of the rotor shaft 5 is closed. The can 4 is closed at its end facing away from the pump chamber 15 by a bottom 31, so that it forms a split pot. At the bottom 31, another bearing 32 is held for the rotor shaft 5.

In the axial direction of the rotor shaft 5 at the level of the impeller 24, the rotor shaft 5 has one or more transverse bores 26 through which the liquid from the bore 25 of the rotor shaft 5 can flow into the pre-chamber 11. For this purpose, the wings 27 of the impeller 24 extend in the axial direction to the transverse bores 26, so that they produce a suction through which the liquid flows out of the hollow shaft 5. However, an at least partially radially directed flow would already be achieved by the transverse bores 26 alone, so that the impeller 24 is not absolutely necessary.

The impeller 24 conveys the liquid radially outward past the separator 12b, giving up its heat to it. Through the openings 21, 22 in the collar 18, the liquid then flows from the front chamber space 19 into the rear chamber space 20. The rear chamber space 20 is connected via radial inlet openings 33 with the channels 34 in the bearing carrier 9. The liquid flows through these inlet openings 33 and these channels 34 into the rotor chamber 4, wherein it absorbs heat. At the back of the rotor chamber 4, the liquid then flows into the open end of the rotor shaft 5 and flows to the transverse bores 26 in the shaft 5 at the level of the impeller 24 where it exits the shaft 5 again, flows through the separator 12 b and its Gives off heat to this. In this way, an effective, closed cooling circuit is formed.

An enlargement of the impeller-side bearing assembly is in FIG. 4 shown.

In the embodiment according to Figures 3 and 4 the partition member 12b is designed as a flexible sheet which is gap-forming spaced in the pressureless state of the wet-running pump 1 with its entire radially outer peripheral edge to the end face of the outer wall 16 and pressed during operation of the wet-running pump 1 by the pressure in the pump chamber 15 on the outer wall 16 is. If the hydraulic system in which the pump 1 is integrated, put into operation and filled with liquid, this liquid can penetrate through the gap between the separating element 12 and outer wall 16 in the rotor chamber 4 and fill it. At the same time, the air can escape through the gap at the top.

As a further advantage results that in the antechamber 11, in particular in the front chamber chamber 19 particles and sediment sink to the bottom and can settle down on the inside of the outer wall 16. In order for these particles to enter the pump chamber 15, in an embodiment of the pump 1 which is not shown, the inside of the outer wall 16 can drop toward the impeller 7. The particles then slide on the slope thus formed through the gap in the pump chamber 15 where they are conveyed out again as soon as the pump 1 goes back into operation.

Claims (23)

Wet-runner pump (1) with a stator (3) and a rotor (5, 6) separated therefrom by a split tube (2), which comprises a rotor shaft (5) and a rotor core (6) and in one through the split tube (2). rotor space (4) is rotatably mounted, wherein the rotor shaft (5) at one axial end in a pump chamber (15) arranged impeller (7) for conveying a liquid carries and the can (2) at its impeller end one substantially has radially outwardly extending flange (8), between the gap tube (2) and the rotor shaft (5) a bearing support (9) with a bearing (10) for supporting the rotor shaft (5) and held by the split tube (2) characterized in that between the impeller (7) and the flange (8) an antechamber (11) is located towards the impeller (7) through a separating element (12, 12a, 12b) and towards the stator (3) through the flange (8) is limited, wherein the prechamber (11) via channels (13, 14, 34) with the Rotorra is communicatively connected to (4). Wet-runner pump (1) according to claim 1, characterized in that the pre-chamber (11) is closed at least during operation of the wet-running pump (1) to the pump chamber (15). Wet-runner pump (1) according to one of claims 1 or 2, characterized in that the channels (13, 14, 34) in the bearing support (9) and / or between the bearing support (9) and the can (2) and / or between the bearing (10) and the bearing carrier (9) lie. Wet-runner pump (1) according to claims 1, 2 or 3, characterized in that the separating element (12, 12a, 12b) forms a filter, in particular at least one filter element is arranged in it. A wet rotor pump (1) according to any one of the preceding claims, characterized in that the pre-chamber (11) is bounded radially outwardly by a tubular section-shaped outer wall (16) connected at one axial end to the flange (8) and at its other axial end of the separating element (12, 12 a, 12 b) carries, abuts this or passes into this. Wet-runner pump (1) according to one of the preceding claims, characterized in that the separating element (12, 12a, 12b) is formed by a heat-conducting material, in particular of metal, Wet-runner pump (1) according to one of the preceding claims, characterized in that the separating element (12, 12a, 12b) is at least partially formed by a flexible membrane (12a). Wet-runner pump (1) according to one of claims 5 to 7, characterized in that the separating element (12, 12a, 12b) rests loosely on the end face of the impeller (7) directed axial end of the outer wall (16). Wet-runner pump (1) according to one of the preceding claims, characterized in that the pre-chamber (11) is limited to the rotor shaft (5) at least partially by a coaxial inner ring (17) which is connected to the bearing carrier (9) and the separating element (12, 12a, 12b) bears or passes into this. Wet-runner pump (1) according to one of the preceding claims, characterized in that the bearing carrier (9) is formed integrally with the split tube (2). Wet-runner pump (1) according to one of the preceding claims, characterized in that the separating element (12, 12a, 12b) or at least the inner ring (17) is formed integrally with the bearing carrier (9). Wet runner pump (1) according to one of claims 9 to 11, characterized in that the outer wall (16) for stabilizing the separating element (12, 32) via radial transverse webs (17a) with the inner ring (17) is connected. Wet-runner pump (1) according to one of the preceding claims, characterized in that the pre-chamber (11) in the pressureless state of the wet-running pump (1) to the pump chamber (15) is open and closed during operation of the wet-running pump (1). Wet-runner pump (1) according to one of the preceding claims, characterized in that the separating element (12a, 12b) in the pressureless state of the wet-running pump (1) in at least a portion of its radially outer peripheral edge, preferably spaced along its entire radially outer peripheral edge, gap-forming to the outer wall (16), and is pressed during the operation of the wet-running pump (1) on the outer wall (16). Wet-running pump (1) according to claim 14, characterized in that the gap-forming distance of the peripheral edge of the separating element (12a, 12b) to the outer wall (16) in the pressureless state of the wet-runner pump (1) in the installation position of the wet-running pump (1) is below and the inside of Outside wall (16) sloping at least in this area, preferably full circumference, to the impeller (7) out. Wet-runner pump (1) according to one of the preceding claims, characterized in that the separating element (12, 12a, 12b) has structural elements for increasing the surface, in particular on its rear side directed towards the pre-chamber (11). Wet runner pump (1) according to one of the preceding claims, characterized in that the bearing support (9) at its the wheel (7) facing the axial end to the outer wall (16) extending collar (18), which the antechamber (11) in a front, to the pump chamber (15) directed chamber space (19), and a rear, the pump chamber (15) facing away chamber space (20) separates. Wet-runner pump (1) according to claim 17, characterized in that the two chamber spaces (19, 20) via at least one or more openings (21, 22) are interconnected. Wet-runner pump (1) according to claim 18, characterized in that the opening or openings (21, 22) in the prechamber (11) lies radially on the outside. Wet-runner pump (1) according to one of the preceding claims, characterized in that the prechamber (11) has a space (23) at least partially open to the rotor shaft (5), in which the rotor shaft (5) has a further impeller (24, 27) for Producing an at least partially radially directed flow carries. Wet-runner pump (1) according to one of the preceding claims, characterized in that the rotor shaft (5) is designed as a hollow shaft with a liquid-flowable bore (25) which at the pump chamber (15) facing away from the end of the shaft (5) is open and there in the rotor chamber (4) opens. Wet-runner pump (1) according to claims 20 or 21, characterized in that the rotor shaft (5) has one or more transverse bores (26) through which liquid from the rotor shaft (5) can flow into the prechamber (11). Wet-runner pump (1) according to claims 20 and 22, characterized in that the further impeller (24, 27) is an impeller whose wings (27) extend in the axial direction to the transverse bore (26) or transverse bores (26).

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