EP3267042A1 - Pump unit - Google Patents

Abstract

The invention relates to a pump unit having a pump housing (2), an impeller rotatably mounted in the pump housing (2), an electric drive motor connected to the impeller (14) which is selectively drivable in two rotational directions (A, B), and a valve arrangement (28) arranged in the pump housing (2), which is designed such that, depending on the direction of rotation (A, B) of the impeller (14), it has a flow path downstream of the impeller between two outlets (24, 24) formed in the pump housing. 26), the valve assembly having a first movable valve member (34) on a first of the two outlets (24) and a second movable valve member (36) on a second of the two outlets (26), the valve members (34, 36) each in a closed position in a rest position, in which the first valve element (34) at least partially closes the first outlet (24) and the second e valve element (36) at least partially closes the second outlet (26), and the first valve element (34) is movable into an open position by a flow caused by the impeller (14) in its first direction of rotation (A) and the second valve element ( 36) is movable into an open position by a flow caused by the impeller (14) in its second rotational direction (B).

Description

The invention relates to a pump unit with the features specified in the preamble of claim 1.

In heating systems, especially compact heating systems, there is the problem of switching the heating water circuit between two flow paths, namely once through a heating circuit in the building and once through a heat exchanger for heating domestic water. For this purpose, it is known to use pump units with integrated valve elements, which switch depending on the direction of rotation of the impeller of the pump unit between two possible flow paths. As a rule, a movable valve element is provided for this purpose, which is entrained by the flow around the impeller and, depending on the flow direction, is pressed against one of two possible outlets in order to close it, so that the flow leaves the pump unit through the respective other outlet. That is, the valve member alternately closes the outputs such that one output is always closed and at the same time the other output is opened. In such embodiments are problematic water hammer in the system, which lead to unwanted noise.

In view of this problem, it is an object of the invention to improve a pump unit with a switchable by the direction of rotation of the drive motor valve element to the effect that as quiet as possible switching of the valve element is possible.

This object is achieved by a pump unit having the features specified in claim 1. Preferred embodiments will become apparent from the subclaims, the following description and the accompanying figures.

The pump unit according to the invention has a pump housing, in which an impeller is rotatably arranged. The impeller rotates in the interior of the pump housing. The impeller is connected in a known manner with a suction port or suction. The pump unit also has an electric drive motor whose rotor is connected in such a rotationally fixed manner with the impeller that the electric drive motor can drive the impeller rotationally. Preferably, the drive motor or its stator housing is connected to the pump housing in a known manner.

The drive motor is designed so that it can be selectively driven selectively in two directions of rotation. For this purpose, a suitable control device can be provided, which controls the drive motor so that it rotates in a desired direction of rotation. For this purpose, the control device preferably controls the energization of the stator coils of the drive motor. The control device may in particular include a frequency converter, via which, in addition to the direction of rotation, preferably also the rotational speed of the drive motor can be regulated. Depending on the direction of rotation of the drive motor, the impeller also rotates selectively in two desired opposite directions of rotation.

In the pump housing, a valve arrangement is further arranged, which can switch an outlet-side flow path, that is, the flow path downstream of the impeller between two outputs formed in the pump housing. When using the pump unit in a heating system, for example, one of the outputs with a heating circuit through the building and the other outlet may be provided with a secondary heat exchanger for heating the service water. The valve assembly is preferably designed such that it can be moved by the flow caused by the impeller between two switching positions, wherein, depending on the direction of rotation of the impeller, the flow in the peripheral region of the impeller is also directed in different directions. Due to the different flow directions, a valve element of the valve arrangement can be selectively moved between several switching positions.

According to the invention, the valve arrangement has two valve elements, wherein a first movable valve element is arranged on a first of the two outlets and a second movable valve element is arranged on a second of the two outlets. Thus, the first valve element serves to close the first outlet, while the second valve element serves to close the second outlet. The valve elements are arranged so that they are in a rest position, that is, when the impeller is stationary, in its closed position. That is, in the rest position, the first valve element at least partially closes off the first outlet, and the second valve element at least partially closes off the second outlet. For the purposes of this invention, a partial closure of the outlets means that the outlet in the closed position is reduced in cross-section with respect to the open position, preferably reduced by more than half, more preferably by more than two-thirds. As explained below, preferably in the closed position, a certain flow passage remains.

Further, the valve elements are arranged and configured such that the first valve element is movable to an open position by a flow caused by the impeller in its first rotational direction, while the second valve element is moved by one of the Impeller in the second direction of rotation caused flow is movable to an open position. When the first valve element is moved to its open position by the flow, the second valve element remains in its closed position at the same time. Conversely, the first valve element remains in its closed position when the second valve member is moved to its open position by the flow which occurs upon rotation of the impeller in the second rotational direction.

The embodiment of the invention has the advantage over the known direction of rotation dependent switching devices that the outputs are substantially closed in the rest position. This causes that upon start-up of the pump assembly, a flow is initially generated substantially only in the interior of the pump housing to move depending on the direction of rotation of the valve elements in its open position. Due to the fact that substantially no flow takes place through the outputs, water hammer during switching when commissioning the pump unit are minimized or avoided. This means that during startup of the pump unit, a flow is initially generated in the interior of the pump unit, the hydraulic energy of which is used to move one of the valve elements.

When commissioning the pump unit always opens a valve element, that is, one of the valve elements is moved depending on the direction of rotation in its open position. When the pump unit is turned off, that is, the impeller comes to a standstill, the valve element moves back to its closed position. To switch the valve device, the drive motor is then driven in the reverse direction of rotation, so that the impeller generates a flow in the opposite direction in the interior of the pump housing, which opens the other valve element and so the flow through the other outlet from the pump housing leads to the outside.

The inventive design allows by the targeted control of the drive motor, that is, in particular, not only by the choice of the direction of rotation, but also the acceleration curve, a very gentle and quiet switching between the two flow paths, which are defined by the two outputs.

Preferably, the first and the second valve element are independently movable. It allows the first valve member to remain in its closed position while the second valve member is moving to its open position and vice versa.

Furthermore, the first and the second valve element are each preferably designed as a flap pivotable about a pivot axis between the open position and the closed position. In this case, the flap preferably comes with a surface sealingly against a valve seat surrounding an associated outlet to the plant. Preferably, the valve elements are arranged so that their pivot axis is located at a longitudinal end, said longitudinal end is preferably the one longitudinal end which is furthest from the impeller. The pivot axis or pivot axes of the flaps further preferably extend parallel to the axis of rotation of the impeller, wherein the flaps extend substantially radially to the impeller.

More preferably, the valve elements have a sealing area or a sealing surface, which can come into sealing contact with a corresponding valve seat, which surrounds the associated outlet. In addition, the valve elements preferably have one An attack surface or an attack area on which the flow generated by the impeller acts to move the valve element. When the valve member is formed as a flap as described above, the engagement portion is preferably formed by an axial end portion of the flap spaced from the pivot axis. The engagement region preferably extends into an annular space of the pump housing surrounding the impeller, so that the flow generated by the impeller in this annular space can act directly on the engagement area.

According to a further preferred embodiment, the first and the second valve element are pivotable about the same pivot axis. This may, as described above, be a pivot axis, which preferably extends parallel to the axis of rotation of the impeller. Preferably, the valve elements in the manner described above are flap-shaped, wherein the flaps are articulated at one end to the pivot axis and the opposite free end of the flaps each forms an attack surface or an attack area for the flow. The sealing region or the sealing surface is preferably located between the engagement region and the pivot axis. The pivot axis is preferably arranged at the end of the flap, which is the furthest from the impeller.

More preferably, the valve elements are configured and arranged so that, when one of the valve elements is in its open position, they are in contact with each other. That is, preferably, the valve element which moves into the open position pivots until it comes into abutment against the other valve element which lingers in its closed position. This embodiment has the advantage that the released flow path is maximized to the open outlet and that open valve element additionally presses the valve element located in its closed position into its closed position and / or can take on an additional sealing function, as will be described below.

According to a preferred embodiment of the invention, the valve elements each have an opening which allows a flow passage into the associated outlet even in a closed position of this valve element. That is, the opening extends from that side of the valve element, which faces the interior of the pump housing, that is, the impeller, into the outlet. These openings in the valve elements are preferably dimensioned so that the outputs in the closed positions of the valve elements substantially, that is, as described above, are largely closed, but a small flow passage remains. The opening essentially ensures that a pressure equalization between both sides of the valve element is given. This pressure compensation ensures that when starting the impeller, the valve element is not pressed by the pressure generated in the pump housing against the valve seat. As a result, the holding force to be overcome by the flow is reduced, so that the valve element can be moved more easily from the closed to the open position. This assists a silent soft switching of the valve means by movement of one of the valve elements.

Preferably, the opening in the first valve element and the opening in the second valve element are arranged offset from one another such that the opening in the first valve element by the second valve element and the opening in the second valve element are closed by the first valve element, when the two valve elements together are in plant. That is, the valve element located in its open position closes thereby, that it comes to rest on the other valve element, which is in its closed position, at the same time the opening in that valve element, which is in its closed position. Only by opening one of the valve elements, the other valve element and thus the associated output is completely closed. In this state, then the pressure generated by the pump unit acts on the two valve elements, so that these valve elements against each other and the valve element, which is in its closed position, is pressed against the associated valve seat. In this state, the associated output from the valve element, which is in its closed position, is then completely closed. That is, due to the so arranged openings is achieved that in the rest position and when starting the pump unit, when both valve elements are in its closed position, the valve elements are essentially not pressurized. However, when one of the valve elements is in its open position, the other valve element, which is in its closed position, is acted upon by the pressure generated by the impeller and held in the closed position.

Further preferably, the first and the second valve element are subjected to force by at least one return element so that they are each held in its closed position at standstill of the impeller, wherein preferably the first and the second valve element by a common return element, in particular by an arranged between the valve elements Spring, are subjected to force. The or the return elements thus ensure that after switching off the pump unit, when the impeller comes to a standstill, the valve elements are moved back to their rest position, that is, their closed position. If a common spring element is present, the spring element can be particularly Preferably be designed as a torsion spring, which rotates about a common rotational or pivot axis of the two valve elements and with their free legs in each case with one of the valve elements into engagement or conditioning. This allows a particularly simple structure and easy installation, since the torsion spring can be pushed together with the two valve elements on a common pivot or rotation axis.

The valve elements may be elastic or rigid. If the valve elements are elastic, they can be formed in the simplest case as tabs or flaps made of a rubber or elastomeric material. If the valve elements are designed to be elastic, the elastic restoring forces that are generated when the valve element is deformed can form the described restoring element. Such valve elements can be moved by deformation from the closed to the open position. If the valve elements are rigid, they preferably rotate about fixed pivot or rotation axes, in particular about a common pivot or rotation axis. The rigid valve elements are substantially rigid, but may additionally have elastic regions or sections, which may particularly preferably be connected in a materially bonded manner to the rigid sections. The rigid valve elements may e.g. be additionally provided with elastic sealing surfaces or elastic sections.

Preferably, an elastic seal is arranged in each case on the valve elements and / or these opposite valve seats. This provides a reliable seal of the outlet when the valve member is in its closed position. In addition, an elastic seal between the two valve elements may be provided when they have openings in the manner described above. Such an additional sealing element provides a seal in the Area of the opening of that valve element, which is in its closed position, when the second valve element comes to rest on this. Thus, the opening in the valve element on the side of the valve element, which faces the second valve element, be surrounded by an elastic seal. Alternatively or additionally, a sealing surface may be formed there on the valve elements in a region which covers the opening of the other valve element when the two valve elements come into contact with each other.

According to a particular embodiment of the invention, the pump housing has a receiving opening located between the two outputs, which is open to the interior of the pump housing and in which the two valve elements are inserted from the outside of the pump housing, wherein the two valve elements preferably in one in the Receiving opening inserted valve insert are stored. The receiving opening is sealed to the outside by a lid, this cover is preferably part of the valve core. As a result, the assembly is simplified because the valve elements can be inserted from the outside into the pump housing. Furthermore, the valve elements for maintenance purposes are easily accessible without having to disassemble the other parts of the pump unit. The receiving opening is preferably shaped so that it has no undercuts when viewed from the outside. Thus, the pump housing with the receiving opening can be easily manufactured as a casting, in particular as an injection molded part made of plastic, wherein a core, which defines the receiving opening, can be pulled out of the pump housing. Thus, a lost core can be dispensed with at this point.

The described two outputs of the pump housing are preferably located in the receiving opening or branches of the Receiving opening. That is, the flow, starting from the interior of the pump housing, in which the impeller rotates, first enters the receiving opening and then from there into one of the two outlets, depending on which valve element is in its open position.

According to a further preferred embodiment of the invention, the two outputs each have a the interior of the pump housing facing or in the flow path of the interior valve seat on which the associated valve element comes with a sealing surface in its closed position to the plant to the respective output at least partially closed. The valve seats of the two exits are preferably opposite one another, wherein the valve seats particularly preferably extend substantially parallel to one another. When the valve seats are located in the receiving opening, the valve seats preferably extend substantially parallel to the longitudinal direction of the receiving opening on two opposite side walls of the receiving opening. A substantially parallel arrangement of the valve seats means that slight draft angles, which are required to remove a core from the receiving opening after casting, are still considered in this sense as a parallel arrangement. The opposite arrangement of the valve seats allows that valve element which moves into its open position to move towards the second valve element, which is in a closed position, and can come into abutment with this valve element as described above , This is especially true when the valve elements perform a pivoting movement from the closed to the open position. If the valve elements are arranged pivotably in such a way, the pivot axes preferably extend parallel to the surfaces spanned by the valve seats. In a common pivot axis, this is preferably Located in a plane which is located between the surfaces formed by the valve seats.

The valve elements further preferably each have a sealing surface provided for engagement with a valve seat, which extends at an angle to a radius with respect to the pivot axis of the respective valve element. Such valve elements preferably have a substantially triangular shape in a plane normal to the pivot axis, wherein one side of the sealing element, which forms the sealing surface and a second side of the valve element, which is provided for bearing against the second valve element, preferably in an acute Extend angle to each other. The pivot or rotation axis is preferably on or in the surface which is provided for engagement with the second valve element. The angled arrangement of the sealing surface makes it possible, despite the intended pivoting movement in a common pivot axis, the valve seats may be located in mutually parallel planes.

Particularly preferably, the pump unit is designed as Umwälzpumpenaggregat and more preferably as Heizungsumwälzpumpenaggregat. In particular, it may be a Heizungsumwälzpumpenaggregat, which is used in a gas boiler. In this respect, a gas boiler with a pump unit, as described above and below, the subject of the invention and this patent application. In this case, the pump unit may be part of a hydraulic block, which forms an integrated unit for a compact heating system and in particular for a gas boiler.

The drive motor is preferably a wet-running drive motor, that is, a drive motor in which rotor and stator a split tube or a split pot are separated from each other. Particularly preferably, the drive motor has a permanent magnet rotor. More preferably, the drive motor may have a frequency converter for speed control.

According to a further preferred embodiment of the invention, the impeller and the interior of the pump housing can be dimensioned such that in the peripheral region of the impeller in the interior of the pump housing remains an annular space. This annular clearance preferably has a size at which the radius of the inner circumference of the pump housing is at least 1.4 times and preferably at least 2 times as large as the radius of the impeller, at least in a circumferential section in the peripheral region of the impeller. Particularly preferably, the radius of the inner circumference of the pump housing over the entire circumference is dimensioned accordingly. More preferably, the radius of the inner circumference of the pump housing in at least one peripheral portion at least 2 or 3 times as large as the radius of the impeller. Through this annular space, which surrounds the impeller, the formation of a circumferentially rotating flow is favored, which depends on the direction of rotation of the impeller and thus can move the valve elements in the desired switching position. The valve elements are preferably arranged or dimensioned so that in each position, a clearance between the valve element and the outer periphery of the impeller remains, so that the circulating flow is not prevented by the valve element.

Fig. 1

eine perspektivische Gesamtansicht eines erfindungsgemäßen Pumpenaggregates,

Fig. 2

eine Explosionsansicht des Pumpenaggregates gemäß Fig. 1,

Fig. 3

eine perspektivische Draufsicht auf das Pumpengehäuse mit herausgenommenem Ventileinsatz,

Fig. 4

die Anordnung der Ventilelemente in perspektivischer Ansicht,

Fig. 5

eine perspektivische Ansicht des offenen Pumpengehäuses, wobei sich die Ventilelemente in ihrer Ruhestellung befinden,

Fig. 6A

eine Ansicht gemäß Fig. 5, in welcher sich das erste der Ventilelemente in seiner geöffneten Stellung befindet,

Fig. 6B

eine Ansicht gemäß Fig. 5, in welcher sich das zweite Ventilelement in seiner geöffneten Stellung befindet,

Fig. 7

eine Schnittansicht des Pumpengehäuses, in welcher sich die Ventilelemente in ihrer Ruhestellung befinden,

Fig. 8A

eine Schnittansicht gemäß Fig. 7, wobei sich das erste der Ventilelemente in einer geöffneten Stellung befindet,

Fig. 8B

eine Schnittansicht gemäß Fig. 7, wobei sich das zweite der Ventilelemente in einer geöffneten Stellung befindet,

Fig. 9

schematisch eine Anordnung der Ventilelemente im Pumpengehäuse gemäß einer zweiten Ausführungsform der Erfindung, wobei sich die Ventilelemente in ihrer geschlossenen Stellung befinden,

Fig. 10

eine Ansicht gemäß Fig. 9, in welcher sich eines der Ventilelemente in einer geöffneten Stellung befindet, und

Fig. 11

das Schaltbild einer Heizungsanlage mit einem erfindungsgemäßen Pumpenaggregat.

The invention will now be described by way of example with reference to the accompanying drawings. In these shows:

Fig. 1

an overall perspective view of a pump unit according to the invention,

Fig. 2

an exploded view of the pump unit according to Fig. 1 .

Fig. 3

a perspective top view of the pump housing with the valve insert removed,

Fig. 4

the arrangement of the valve elements in perspective view,

Fig. 5

a perspective view of the open pump housing, wherein the valve elements are in their rest position,

Fig. 6A

a view according to Fig. 5 in which the first of the valve elements is in its open position,

Fig. 6B

a view according to Fig. 5 in which the second valve element is in its open position,

Fig. 7

a sectional view of the pump housing, in which the valve elements are in their rest position,

Fig. 8A

a sectional view according to Fig. 7 with the first of the valve elements in an open position,

Fig. 8B

a sectional view according to Fig. 7 with the second of the valve elements in an open position,

Fig. 9

FIG. 2 schematically shows an arrangement of the valve elements in the pump housing according to a second embodiment of the invention, FIG. with the valve elements in their closed position,

Fig. 10

a view according to Fig. 9 in which one of the valve elements is in an open position, and

Fig. 11

the diagram of a heating system with a pump unit according to the invention.

The pump unit 1 shown in the figures is designed as a circulating pump unit with a wet-running electric drive motor. The pump unit 1 has a pump housing 2, which may be formed as a cast component of metal or plastic. The pump housing 2 has a suction port 4 and two discharge ports 6 and 8. Attached to the pump housing 2 is a motor or stator housing 10, in which the electric drive motor is arranged. At the axial end of the stator housing 10 facing away from the pump housing 2, an electronics housing 12 is arranged, in which a control or regulating device for controlling the electric drive motor is arranged.

As in the exploded view according to Fig. 2 can be seen, an impeller 14 is disposed inside the pump housing 2, which is rotatably connected to the rotor 16 of the electric drive motor. The rotor 16 is rotatably supported in a bearing 18 which is fixed to a bearing plate 20 in the pump housing 2. Inside the stator housing 10, the stator of the electric drive motor is arranged, on the inner circumference of a split pot 21 is located, which separates the rotor space, in which the rotor 16 is disposed from the stator, so that the rotor space can be filled with liquid. It is thus a wet-running drive motor.

Starting from the interior 15 of the pump housing 2, in which the impeller 14 rotates, a receiving opening 22 extends radially outwards. The receiving opening 22 forms part of an outlet-side flow path through which the flow accelerated by the impeller 14 emerges from the pump housing 2. Thus branch off the discharge nozzle 6 and 8 at a first output 24 and a second output 26, which are located in the interior of the receiving opening 22 from (see Fig. 7 ).

Inserted from the outside into the receiving opening 22 is a valve insert 28, which has a closure plate 30 which closes the receiving opening 22 to the outside. The closure plate 30 serves as a carrier and holds a pivot axis 32, to which a first valve element 34 and a second valve element 36 are pivotally mounted. On the pivot axis 32, a torsion spring 38 is also arranged, which forms a return element and in the mounted state, the first valve element 34 and the second valve member 36 presses apart. The two valve elements 34 and 36 are identical and arranged only rotated by 180 ° to each other.

Fig. 3 shows the valve core 28 in the assembled state prior to insertion into the receiving opening 22 of the pump housing 2. The first and second valve elements 34, 36 are rotated 180 ° to each other, facing away from each other on the pivot axis 32, so that their outer surfaces facing away from each other 40 sealing surfaces form, which come to close the outputs 24 and 26 on the outer circumference, which each forms a valve seat, sealingly to the plant. For this purpose, elastic sealing elements can be arranged on the outer circumference of the exits 24, 26 or on the sealing surfaces 40. The flap-shaped valve elements 34 and 36 are formed so that in each case an opening 42 is formed in the sealing surface 40, which is located extends transversely to the sealing surface 40 through the valve member 34, 36 therethrough. The opening 42 is seen in the direction of the pivot axis 32 eccentrically in the valve element 34, 36 is arranged. The opening 42 is arranged in one half in the sealing surface 40 in the direction of the pivot axis 32 seen. Since the two identically formed valve elements 34 and 36 are arranged rotated through 180 ° to each other, thus the opening 42 in the first valve element 34 is offset from the opening 42 in the second valve element 36th In Fig. 4 the opening 42 in the first valve element 34 is in the upper half, while the opening 42 in the second valve element 36 is located in the lower half. This causes that when the two valve elements 34 and 36 come into contact with each other, the openings 42 in the two valve elements 34 and 36 are not aligned. The valve elements 34 and 36 have, on their side facing away from the sealing surface 40, rather than the opening 42, an engagement element 44, which corresponds to its shape to the opening 42 on the same side. Thus, the engagement element 44 of the first valve element 34 engages in the opening 42 of the second valve element 36 when the two valve elements come to rest against each other by overcoming the spring force of the torsion spring 38. Thus, the opening 42 of the second valve element 36 is closed by the first valve element 34 and its engagement element 44. The engagement member 44 may be formed elastically in the form of a seal. Correspondingly, the engagement element 44 of the second valve element 36 engages in the opening 42 of the first valve element 34 to the closure thereof.

As in Fig. 7 can be seen, are the first and the second output 24 and 26 in the receiving opening 22 opposite to each other, wherein the valve seats formed by the edge of the outputs 24 and 26 are located in mutually parallel planes. When the valve insert is inserted into the receiving opening 22, the first valve element 34 and the second valve element 36 by the torsion spring 38, which serves as a return element Pressed in its rest position, which represents a closed position in which the first valve element 34, the first output 24 and the second valve element 36, the second output 26 overlaps. Thus, the first output and the second output are substantially closed by the first valve element 34 and the second valve element 36, ie, closed except for the flow passage through the openings 42. As in the Fig. 5 . 6 . 7 and 8th can be seen, the valve elements 34 and 36 are formed in a direction transverse to the pivot axis 32 so long that their pivot axis 32 spaced ends 46 extend into the interior 15 and thus into an annular space surrounding the impeller 14. The adjoining the ends 46 surfaces in extension of the sealing surfaces 40 of the valve elements 34, 36 form engagement surfaces on which the rotating in the interior 15 flow upon rotation of the impeller 14 acts.

The arranged in the electronics housing 12 control device is designed so that it can drive the electric drive motor targeted in two different directions of rotation A and B. This can be done for example via a frequency converter, which energizes the coils in the stator targeted. The valve device in the valve core 28 is designed such that, depending on the direction of rotation A, B, it directs the flow into the first outlet 24 and thus to the first pressure port 6 or into the second outlet 26 and thus to the second pressure port 8. For example, the heating circuit of a heater for a building can be connected to the first pressure port 6, while a heat exchanger for heating service water connects to the second pressure port 8.

When the pump unit is started up, the direction of rotation is thus initially predetermined by the control device 12 in order to specify in which of the two outputs 24 or 26 is to be conveyed. If now the first output 24 with the subsequent Pressure port 6 is to be used, the pump unit is set in motion so that the impeller rotates in the first direction of rotation A. In the in Fig. 5 and 7 shown rest position, the outputs 24 and 26 are substantially closed except for the flow passages through the openings 42. The openings 42 effect a pressure equalization between both sides of the valve elements 34 and 36, so that the valve elements 34 and 36 are not pressed upon startup of the pump unit by the pressure forming in the interior 15 against the outputs 24 and 26. That is, the valve members 34 and 36 are held in position substantially only by the torsion spring 38. Upon rotation of the impeller in the direction A, a rotating flow in the peripheral region of the impeller is generated in the interior 15 of the pump housing 2. The flow also rotates in the direction of rotation A and thus acts on the engagement surface of the first valve element 34. The flow thus generates on the first valve element 34 a force which counteracts the spring force of the torsion spring 38 and thus the first valve element 34 from the closed position in FIG moves its open position, in which the valve member 34 abuts against the second valve element 36. In this case, the first valve element 34 closes the opening 42 in the second valve element 36. Thus, the second output 26, on which the second valve element 36 remains in abutment, is now completely closed. The first outlet 24 is fully open, so that the flow through this outlet 24 flows into the discharge nozzle 6. At the same time, the pressure prevailing in the interior 15 now acts on the sealing surface 40 of the first valve element 34, which via the abutment against the second valve element 36 presses this in additional sealing contact with the valve seat which surrounds the second outlet 26. This state, in which the first valve element 34 is opened and thus a flow path through the first output 24 is opened to the discharge port 6, is in the Fig. 6A and 8A shown.

When the drive motor is configured by the control device, the impeller 14 comes to a standstill and the flow and the pressure in the interior 15 disappear. Then, the first valve element 34 is brought by the torsion spring 38 back to its rest position, in which it substantially closes the first output 24. When the pump unit is operated in the opposite direction of rotation B, accordingly, the second valve element 36 will move to an open position, in which it comes to rest on the first valve element 34 and thus the opening 42 in the first valve element 34 and thus the first output 24 completely closes. At the same time, the second outlet 26 is opened and the flow can flow through this outlet into the second pressure port 8. This state, in which the second valve element 36 is in its open position, is in the Fig. 6B and 8B shown.

Characterized in that the outputs 24 and 26 are substantially closed in the rest position of the valve elements 34 and 36, it is achieved that initially only a pressure and a flow in the interior 15 of the pump housing 2 build when commissioning the pump unit, which are used for this purpose to move one of the valve elements 34, 36 to its open position. In the systems adjoining the pressure ports 6 and 8, substantially no flow and no pressure are initially built up in this state, as a result of which water hammer during switching of the valve elements 34 and 36 is reduced. It can thus be achieved a very gentle switching. This is also facilitated by the pressure equalization through the openings 42, since so only a very small switching force for moving the valve elements 34 and 36 is required. The control device in the electronics housing 12 can also adjust the acceleration of the drive motor so that when commissioning initially just as much pressure and flow are built to one of the valve elements 34, 36 in the desired open position move and then the engine is then accelerated so that the desired final pressure or flow is established.

As in the Fig. 7 and 8B is shown, the interior 15 of the pump housing 2 is dimensioned so that it has a considerably larger diameter than the outer diameter of the impeller 14. Thus, a free annular space 47 remains in the peripheral region of the impeller 14, in which there is a rotating flow in the periphery of the impeller 14th can form, which then acts on the engagement surfaces of the valve elements 34 and 36 depending on the direction of rotation in order to move them into the open position can. Valve elements 34 and 36 are dimensioned such that their free ends 46 are spaced apart at any angular position during pivotal movement about pivot axis 32 from the outer periphery of impeller 34 such that valve elements 34 and 36 do not collide with impeller 14. More preferably, the distance between the ends 46 and the outer periphery of the impeller 14 is selected so that there is always a free space through which the annular or rotating flow can extend in the peripheral region of the impeller 14. In addition, the annular space 47 leads to an overall improved efficiency, especially when the impeller 14 has curved blades.

The receiving opening 22 is formed so that no undercuts are formed in a direction radial to the axis of rotation X of the drive motor. Thus, the receiving opening 22 can be formed by a core, which can be pulled out after the casting of the pump housing 2 in the radial direction to the outside. This allows a simple production of the receiving space 22nd

In the embodiment described above, the valve elements 34 and 36 are hinged to the pivot axis, that the Pivot axis 32 relative to the axis of rotation x of the impeller at the radially outer end of the valve elements 34, 36 is arranged, that is, the pivot axis 32 is maximally spaced from the impeller or the axis of rotation x in the radial direction. As in FIGS. 9 and 10 shown schematically, the pivot axis 32 'but could also be located at the radially inner end of the valve elements 34' and 36 '. Also in this arrangement, for example, in the direction of rotation A of the impeller 14 generates a flow in the same direction, which acts on the first valve member 34 'so that it pivots about the pivot axis 32' so that the first output 24 is released and simultaneously first valve element 34 'comes to rest on the second valve element 36'. Thus, the flow is directed into the first exit 24 while the second exit 26 remains closed. The remaining configuration of the valve elements 34 'and 36' may correspond to the embodiment described above. In particular, openings 42 may also be provided.

As described above, the circulating pump unit according to the invention is preferably used in a heating system, in particular in a gas boiler, which are also the subject of the invention. Such a heating system with a gas boiler 48 is shown schematically in FIG Fig. 11 shown. The gas boiler 48 includes a burner 50 with a primary heat exchanger 52, via which the water is heated in the heating circuit. About the pump unit 1, the water is conveyed through the heating circuit. Via the control device 12 of the pump unit 1, the direction of rotation is predetermined in the manner described above, whereby the valve arrangement formed by the valve elements 34, 36 valve arrangement is switched. The valve arrangement serves to switch over the flow path between a heating circuit 54, which runs through a building, and a secondary heat exchanger 55, which serves for the heating of service water. The heating circuit 54 passes through one or more radiators 56, wherein Within the meaning of this description, radiators are also considered to be circles of underfloor heating. Depending on the direction of rotation A, B, the flow either through the secondary heat exchanger 55 or the heating circuit 54. In the event that the impeller 14 should have curved blades to increase efficiency, the system is preferably designed so that the rotational direction in which the Heating water is directed through the heating circuit 54, which is the direction of rotation for which the curvature of the impeller blades is optimized. This ensures that the pump unit 1 works most of the operating time with the maximum efficiency, since the direction of rotation, at which the water is passed through the secondary heat exchanger 55, is usually used less frequently, since the operating times for hot water heating are usually lower as the operating hours for heating a building. The primary heat exchanger 52 with the burner 50, the pump unit 1 and the secondary heat exchanger 55 preferably form components of the gas boiler 48 and preferably the pump unit 1 and the secondary heat exchanger 55 in a hydraulic _Baueinheit, that is integrated a hydraulic block.

LIST OF REFERENCE NUMBERS

1

pump unit

2

pump housing

4

Suction / suction

6.8

pressure port

10

stator

12

Electronics housing with control device

14

Wheel

15

inner space

16

rotor

18

camp

20

bearing plate

21

Slit pot or split tube

22

receiving opening

24

first exit

26

second exit

28

valve core

30

closing plate

32, 32 '

swivel axis

34, 34 '

first valve element

36, 36 '

second valve element

38

compression spring

40

sealing surface

42

opening

44

engaging member

46

Ends of the valve elements

47

annulus

48

gas water heater

50

burner

52

Primary heat exchanger

54

heating circuit

55

Secondary heat exchanger

56

radiator

A, B

directions

X

axis of rotation

Claims (15)

Pump unit with a pump housing (2), one in the pump housing (2) rotatably arranged impeller, one connected to the impeller (14) to its drive electric drive motor which is selectively driven in two directions of rotation (A, B), and one in the Pump housing (2) arranged valve assembly (28) which is designed such that, depending on the direction of rotation (A, B) of the impeller (14), a flow path downstream of the impeller between two in the pump housing formed outputs (24, 26), characterized in that
the valve assembly comprises a first movable valve member (34) at a first of the two outlets (24) and a second movable valve member (36) at a second of the two outlets (26),
the valve elements (34, 36) are each in a closed position in a rest position, in which the first valve element (34) at least partially closes the first outlet (24) and the second valve element (36) at least partially closes the second outlet (26) closes, and that
the first valve element (34) is movable into an open position by a flow caused by the impeller (14) in its first rotational direction (A), and the second valve element (36) is moved by one of the impeller (14) in its second rotational direction (B ) caused flow is movable to an open position. Pump unit according to claim 1, characterized in that the first and the second valve element (34, 36) are independently movable. Pump unit according to claim 1 or 2, characterized in that the first and the second valve element (34, 36) are each formed as a pivotable about a pivot axis (32) between the open position and the closed position flap. Pump unit according to claim 3, characterized in that the first and the second valve element (34, 36) about the same pivot axis (32) are pivotable. Pump unit according to one of claims 1 to 4, characterized in that the valve elements (34, 36) are arranged such that when one of the valve elements (34, 36) is in its open position, they are in contact. Pump unit according to one of the preceding claims, characterized in that the valve elements (34, 36) each have an opening (42) which has a flow passage into the associated outlet (24, 26) even in a closed position of this valve element (34, 36). allows. Pump unit according to claim 6, characterized in that the opening (42) in the first valve element (34) and the opening (42) in the second valve element (36) are offset from one another in such a way that the opening (42) in the first valve element (34) are closed by the second valve element (36) and the opening (42) in the second valve element (36) through the first valve element (34) when the two valve elements (34, 36) are in contact with each other. Pump unit according to one of the preceding claims, characterized in that the first and the second valve element (34, 36) are subjected to such a force by at least one return element (38) that they are held in each case in its closed position when the impeller (14), wherein preferably the first and the second valve element (34, 36) by a common return element (38), in particular by a spring arranged between the valve elements (38), are subjected to force. Pump unit according to one of the preceding claims, characterized in that the valve elements (34, 36) are each formed elastically or alternatively rigid. Pump unit according to one of the preceding claims, characterized in that in each case an elastic seal is arranged on the valve elements (34, 36) and / or these opposite valve seats. Pump unit according to one of the preceding claims, characterized in that the pump housing (2) has a receiving opening (22) located between the two outlets (24, 26) which is open towards the interior (15) of the pump housing (2) and into which of the outer side of the pump housing (2) forth the two valve elements (34, 36) are used, wherein the two valve elements (34, 36) are preferably mounted in a in the receiving opening (22) inserted valve insert (28). Pump unit according to claim 11, characterized in that the two outlets (24, 26) are located in the receiving opening (22). Pump unit according to one of the preceding claims, characterized in that the two outputs (24, 26) the valve body (15) of the pump housing (2) facing valve seats which face each other, wherein the valve seats are preferably aligned substantially parallel to each other. Pump unit according to one of the preceding claims, characterized in that the valve elements (34, 36) each have a provided for abutment on a valve seat sealing surface (40) which is angled relative to the pivot axis (32) of the respective valve element (34, 36). Pump unit according to one of the preceding claims, characterized in that it is designed as Umwälzpumpenaggregat, in particular for use in a heating system and preferably with a wet-running drive motor.

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