EP3376040B1 - Pump unit - Google Patents

Description

The invention relates to a pump unit with an electric drive motor, at least one of the electric drive motor rotatably driven impeller and a control device which drives the drive motor.

In modern pump units, it is known to drive the drive motor via a control device with a frequency converter, so that the drive motor can be adjusted in its speed and regulated. However, the speed range over which the speed is variable is limited.

US 2016/0268937 A1 discloses an electrically driven pump assembly in which prior to starting the electric motor determines the rotor position and the rotor is moved in a position that the poles are aligned in a defined manner to the stator.

DE 1958 277 discloses a pump unit with an integrated valve element in which the valve element can be rotated via a clutch from the motor shaft driving an impeller. This coupling can be brought into and out of engagement via an adjusting element, wherein at the same time a holding element for fixing the valve element in and can be brought out of engagement.

It is an object of the invention to improve a pump unit with an electric drive motor to the effect that the drive motor can be used in an improved way to drive other components.

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 an electric drive motor and at least one of this rotationally driven impeller. For this purpose, the impeller may be connected in a known manner with the rotor of the drive motor. The rotor is particularly preferably a permanent magnet rotor. Further preferred is the drive motor as a wet-running electric drive motor with a split tube or split pot, which separates the rotor space from the stator space formed. That is, the rotor preferably rotates in the fluid to be delivered by the pump unit. The pump unit may preferably be designed as a circulating pump unit and more preferably as a heating circulation pump unit.

According to the invention, the control device of the drive motor, which controls the drive motor and in particular controls the energization of stator coils in the stator of the drive motor, is designed such that it selectively drives the drive motor in at least one first or in a second operating mode. Here, the first mode is a conventional mode in which the drive motor is controlled by the controller such that the rotor of the drive motor rotates continuously over a plurality of revolutions. In this mode, the impeller is driven to produce the pressure and flow desired to operate the pump set. In the second operating mode, however, the control device controls the drive motor in such a way that the rotor of the drive motor is advanced only stepwise in at least one selected, in particular adjustable angular step, wherein these angular steps are preferably less than 360 degrees. This rotation in at least one selected angular step serves to rotate the rotor to a desired angular position. This makes it possible for the drive motor in the second operating mode to take on additional drive functions and, in particular, actuating functions, as might otherwise be assumed, for example, by stepper motors. This allows further fields of application. Thus, the drive motor in the pump unit in addition to the drive of the impeller other functions, in particular control functions for moving other components take over, which only need to be moved over smaller ways.

Preferably, the control device is designed so that the drive motor rotates in the first mode at a higher angular velocity than in the second mode. This is advantageous for drive and positioning functions in which smaller movements are to be carried out with greater accuracy.

The control device is further preferably designed such that in the first operating mode, the drive motor is adjustable in its speed and preferably adjustable. For this purpose, the drive motor in its control device preferably have a frequency converter, via which the speed of the drive motor is variable.

The control device is also preferably designed so that the drive motor is controlled in the second mode by the control device in an open loop, that is in the so-called open-loop operation, in which no position control is performed in the energization of the stator coils. In particular, the induced reverse voltage (back-EMF) is not used in the control or regulation in open loop operation. This control makes it possible to turn the drive motor at specific angles in a targeted manner by energizing the coils in the stator. The stator can be provided in a known manner with a plurality of stator poles and associated stator coils, which are designed for example for three-phase operation.

According to a further preferred embodiment, the control device is designed such that in the second operating mode, the drive motor is controlled by the control device with a frequency <10 hertz. That is, the stator coils are supplied with voltage or current with a frequency <10 Hertz. Alternatively or additionally, a higher motor current than in the first mode is used. Thus, in the operating mode, a motor current can be used or For example, the stator coils can be supplied with a current which corresponds to two to four times the nominal current for which the drive motor is designed. Optionally, the current may also be higher than four times the nominal current. It is essentially only limited by the fact that no demagnetization of the rotor may occur.

According to a further preferred embodiment, the control device is designed such that the number and / or the size of the individual angular steps in which the rotor is moved in the second operating mode are selectable. So it is possible to rotate the rotor targeted to a desired angular position. For this purpose, the control device selectively energizes the individual stator coils.

More preferably, the control device may be configured such that it controls the drive motor so that its direction of rotation in the second mode is opposite to the direction of rotation in the first mode. This makes it easier to use the different operating modes for different applications, because in addition to the impeller, for example, other components could be coupled to the rotor via a direction-dependent coupling, so that in one direction only the rotor is driven, while in the other direction of rotation, which preferably in the second mode is used, even another coupled component could be moved.

Thus, the pump unit has a further movable component, which is coupled in addition to the at least one rotor via a releasable coupling with the rotor of the drive motor. In this case, the coupling can act directly on the rotor, on a rotor shaft connected to the rotor or on the impeller, which is arranged rotationally fixed on the rotor shaft. The at least one further movable component may for example be a valve element, wherein the valve element is preferably part of a mixing and / or switching valve. Such a switching valve may be, for example, a switching valve, which is used in a heating system to switch the flow path between a heating circuit and a hot water heat exchanger. A mixing valve may for example be a mixing valve, as used in a heating system for the application to regulate the flow temperature of the heating medium by mixing in cooled heating medium.

The coupling described for coupling the at least one further movable component is preferably detachable depending on the direction of rotation, so that in one direction of rotation the additional component can be moved in the manner described while in the opposite direction of rotation, which is preferably used in the first mode, the impeller in normal operation can rotate and undisturbed can perform a pumping function. The impeller may have blades, which are adapted to these preferred for normal operation direction of rotation.

Said coupling can be further preferably formed at a front end of the rotor shaft of the rotor. The component to be moved then has a corresponding mating coupling, which can engage with this coupling. In this case, the additional movable component is preferably also rotatable and more preferably rotatable about the same axis as the rotor shaft. The coupling at the front end of the rotor shaft may in particular have a sawtooth profile, that is to say have a sawtooth profile in a development in the circumferential direction. Preferably, this profile has two slopes whose axially projecting end edges extend transversely to the axis of rotation of the rotor shaft along a diameter line. Thus, engagement surfaces are preferably created starting from these end edges, which are in a plane parallel to the axis of rotation and the diameter of the rotor shaft extend. Facing away from these engagement surfaces, starting from the end edges of the profile, the bevels or wedge surfaces may extend, which in the opposite direction of rotation cause the clutch is pressed out of engagement. This disengagement occurs then by an axial displacement of the counter-coupling and / or the coupling to the rotor shaft.

According to a particularly preferred embodiment, the additionally rotationally moving component is a valve element, which is designed and arranged such that it can be moved in rotation between at least two switching positions. In this case, the axis of rotation of the valve element is preferably aligned with the axis of rotation of the drive motor. This allows a simple construction of the coupling described. The valve element is preferably additionally axially displaceable along its axis of rotation, wherein the axial displacement of the valve element, for example, a coupling, as described above, can be disengaged.

According to a further preferred embodiment, the valve element is arranged in the pump unit such that it has a pressure surface on which an output side of the at least one impeller prevails pressure. That is, the pressure surface preferably adjoins the pressure space in which the impeller rotates. Furthermore, the valve element is preferably movably mounted in a direction transverse to the pressure surface between an abutment position in which it bears against at least one abutment surface and a released position in which it is detached or spaced from the abutment surface. The movement path, along which the valve element is movable between the adjacent position and the released position, preferably differs from the movement path between the at least two switching positions of the valve element. Especially Preferably, the valve element is axially movable along the axis of rotation about which it is movable between the switching positions.

More preferably, a restoring or biasing element is provided, which generates a restoring force, which is directed opposite to the pressure force generated by the pressure on the pressure surface. Such a return element may for example be a spring. The return element is preferably arranged so that the restoring force generated presses the valve element in the released position. In the released position, the valve element is preferably substantially freely movable and in particular rotatable, so that it can be easily moved between its switching positions. In the adjacent position, however, the valve element is preferably held non-positively and / or positively on the contact surface, so that it is fixed in its assumed switching position.

The at least one contact surface may preferably be a sealing surface at the same time. In this way, the valve element is simultaneously sealed in the desired switching position, wherein the sealing surface preferably surrounds an input or switching opening and acts as a valve seat.

The pump unit according to the invention makes it possible to drive the drive motor according to a novel method, which is also the subject of the invention. In this case, the essential process features from the foregoing description of the function of the pump unit. The second operating mode is preferably used to move an additional component, in particular a valve element in a desired position, in particular a desired angular position with respect to a rotational axis. For this purpose, the o-pen-loop operation is used in the control of the drive motor. At the same time is preferably between the rotor and the rotatable Valve element provided a direction of rotation dependent coupling, as described above. The coupling is designed so that it engages in at least one angular position, in the embodiment described above in two angular positions offset by 180 °. Since in normal operation in the first mode, the clutch in the manner described above by the pressure prevailing in the pressure chamber disengaged, when changing to the second mode is not sure that the valve element has not shifted slightly. In this respect, it is preferred that at the start of the second mode of operation, the drive motor is not rotated exactly in the angular position in which he was at the last time the end of the second mode of operation, but in an angular position moves, which is set back by a certain amount. At the beginning of the second mode of operation, therefore, this orientation of the rotor initially takes place in an angular position slightly before the angular position in which the rotor was located during the last decommissioning of the second operating mode. This ensures that in the further rotation, the clutch engages in any case and the valve element is moved in the desired manner.

Starting from the described starting position, the rotor is then rotated by the control device by corresponding energization of the stator coils in the manner described above in exactly the desired new angular position. This is preferably time-controlled in that the stator is supplied with a predetermined frequency for a period of time determined by the control device, the frequency preferably being in the very low range mentioned above. After reaching the desired angular position of the rotor is stopped and changed back to the first mode, in which the rotor is preferably rotated in the reverse direction, so that the clutch is disengaged and held by the pressure build-up in the pressure chamber in the manner described, the valve element in the switching position achieved becomes. By this method, the valve element can be Position very precisely so that various switching functions, such as switching functions, switching functions of a distributor valve and / or settings of a mixer valve can be made.

Fig. 1

eine Explosionsansicht des Kreiselpumpenaggregates gemäß einer ersten Ausführungsform der Erfindung,

Fig. 2

eine perspektivische Ansicht des Kreiselpumpenaggregates gemäß Fig. 1 mit abgenommenem Pumpengehäuse und Ventilelement,

Fig. 3

eine perspektivische Ansicht der Motorwelle des Kreiselpumpenaggregates gemäß Fig. 1 und 2 sowie des Kupplungsteils des Ventilelementes,

Fig. 4

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 1 mit dem Ventilelement in einer ersten Position,

Fig. 5

eine Schnittansicht gemäß Fig. 4 mit dem Ventilelement in einer zweiten Position,

Fig. 6

eine Draufsicht auf das geöffnete Pumpengehäuse des Kreiselpumpenaggregates gemäß Fig. 1 bis 3 mit dem Ventilelement in einer ersten Schaltstellung,

Fig. 7

eine Ansicht gemäß Fig. 6 mit dem Ventilelement in einer zweiten Schaltstellung,

Fig. 8

eine Ansicht gemäß Fig. 6 und 7 mit dem Ventilelement in einer dritten Schaltstellung,

Fig. 9

schematisch den hydraulischen Aufbau einer Heizungsanlage mit einem Kreiselpumpenaggregat gemäß Fig. 1 bis 8,

Fig. 10

eine Explosionsansicht eines Kreiselpumpenaggregates gemäß einer zweiten Ausführungsform der Erfindung,

Fig. 11

eine perspektivische Ansicht des geöffneten Ventilelementes des Kreiselpumpenaggregates gemäß Fig. 10,

Fig. 12

eine perspektivische Ansicht des geschlossenen Ventilelementes gemäß Fig. 11,

Fig. 13

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 10 mit dem Ventilelement in einer ersten Position,

Fig. 14

eine Schnittansicht gemäß Fig. 13 mit dem Ventilelement in einer zweiten Position,

Fig. 15

eine Draufsicht auf das geöffnete Pumpengehäuse des Kreiselpumpenaggregates gemäß Fig. 10 bis 14 mit dem Ventilelement in einer ersten Schaltstellung,

Fig. 16

eine Ansicht gemäß Fig. 15 mit dem Ventilelement in einer zweiten Schaltstellung,

Fig. 17

eine Ansicht gemäß Fig. 15 und 16 mit dem Ventilelement in einer dritten Schaltstellung,

Fig. 18

eine Ansicht gemäß Fig. 15 bis 17 mit dem Ventilelement in einer vierten Schaltstellung und

Fig. 19

schematisch den hydraulischen Aufbau einer Heizungsanlage mit einem Kreiselpumpenaggregat gemäß Fig. 10 bis 18.

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

Fig. 1

an exploded view of the centrifugal pump assembly according to a first embodiment of the invention,

Fig. 2

a perspective view of the centrifugal pump assembly according to Fig. 1 with removed pump housing and valve element,

Fig. 3

a perspective view of the motor shaft of the centrifugal pump assembly according to Fig. 1 and 2 and the coupling part of the valve element,

Fig. 4

a sectional view of the centrifugal pump assembly according to Fig. 1 with the valve element in a first position,

Fig. 5

a sectional view according to Fig. 4 with the valve element in a second position,

Fig. 6

a plan view of the open pump housing of the centrifugal pump assembly according to Fig. 1 to 3 with the valve element in a first switching position,

Fig. 7

a view according to Fig. 6 with the valve element in a second switching position,

Fig. 8

a view according to 6 and 7 with the valve element in a third switching position,

Fig. 9

schematically the hydraulic structure of a heating system with a centrifugal pump assembly according to Fig. 1 to 8 .

Fig. 10

an exploded view of a centrifugal pump assembly according to a second embodiment of the invention,

Fig. 11

a perspective view of the open valve element of the centrifugal pump assembly according to Fig. 10 .

Fig. 12

a perspective view of the closed valve element according to Fig. 11 .

Fig. 13

a sectional view of the centrifugal pump assembly according to Fig. 10 with the valve element in a first position,

Fig. 14

a sectional view according to Fig. 13 with the valve element in a second position,

Fig. 15

a plan view of the open pump housing of the centrifugal pump assembly according to 10 to 14 with the valve element in a first switching position,

Fig. 16

a view according to Fig. 15 with the valve element in a second switching position,

Fig. 17

a view according to FIGS. 15 and 16 with the valve element in a third switching position,

Fig. 18

a view according to 15 to 17 with the valve element in a fourth switching position and

Fig. 19

schematically the hydraulic structure of a heating system with a centrifugal pump assembly according to 10 to 18 ,

The embodiments of the centrifugal pump assembly according to the invention described in the following description relate to applications in heating and / or air conditioning systems, in which of the centrifugal pump unit, a liquid heat carrier, in particular water, is circulated.

The centrifugal pump assembly according to both embodiments of the invention has a motor housing 2, in which an electric drive motor is arranged. This has in known manner a stator 4 and a rotor 6, which is arranged on a rotor shaft 8. The rotor 6 rotates in a rotor space, which is separated from the stator space in which the stator 4 is arranged by a split tube or a split pot 10. That is, it is a wet-running electric drive motor. At one axial end, the motor housing 2 is connected to a pump housing 12, in which a rotatably connected to the rotor shaft 8 impeller 14 rotates.

At the pump housing 12 opposite axial end of the motor housing 2, an electronics housing 16 is arranged, which has an electronic control system 17 for controlling the electric drive motor in the pump housing 2 includes. The electronics housing 16 could also be arranged in a corresponding manner on another side of the stator housing 2.

In addition, a movable valve element 18 is arranged in the pump housing 12. This valve element 18 is rotatably mounted on an axis 20 in the interior of the pump housing 12, in such a way that the axis of rotation of the valve element 18 is aligned with the axis of rotation X of the impeller 14. The axis 20 is rotatably fixed to the bottom of the pump housing 12. The valve element 18 is not only rotatable about the axis 20, but by a certain amount in the longitudinal direction X movable. In one direction, this linear mobility is limited by the pump housing 12, against which the valve element 18 abuts with its outer circumference.

The valve element 18 separates in the pump housing 12 a suction chamber 24 from a pressure chamber 26. In the pressure chamber 26 rotates the impeller 14. The pressure chamber 26 is connected to the pressure connection or discharge nozzle 27 of the centrifugal pump assembly, which forms the outlet of the centrifugal pump assembly.

In both embodiments shown, a mechanical coupling between the drive motor and the valve element is provided, wherein in these embodiments, the drive motor can be controlled by the control device 17 in two different operating modes or operating modes. In a first mode, which corresponds to the normal operation of the circulating pump unit, the drive motor rotates in a conventional manner with a desired, in particular adjustable by the control device 17, speed. In the second operating mode, the drive motor is activated in open-loop mode, so that the rotor can be gradually rotated in individual predetermined by the control device 17 angular steps, which are smaller than 360 °, can be rotated. Thus, the drive motor in the manner of a stepping motor can be moved in individual steps, which is used in these embodiments, the valve element targeted to move in small angular increments in a defined position, as will be described below.

In the first embodiment according to Fig. 1 to Fig. 9 is integrated in the pump housing 2, a mixing valve, as it can be used for example for temperature adjustment for underfloor heating.

The motor housing 2 with the electronics housing 16 corresponds to the embodiment described above. The pump housing 12 has, in addition to the pressure port 27, two suction-side ports 32 and 34 which open at the bottom of the pump housing 12 in inputs 28 and 30, which are located in a plane transverse to the axis of rotation X.

The valve element 18 is drum-shaped and consists of a cup-shaped lower part 76, which is closed on its side facing the impeller 14 by a cover 78. In the central region of the lid 78, a suction opening 36 is formed. The suction opening 36 is in engagement with the suction mouth 38 of the impeller 14. The valve element 18 is rotatably mounted on an axle 20, which is arranged in the bottom of the pump housing 12. The axis of rotation of the valve element 18 corresponds to the axis of rotation X of the rotor shaft 8. The valve element 18 is also axially displaceable along the axis X and is by a spring 48 in the in Fig. 5 shown rest position, in which the valve element 18 is in a released position in which the lower part 76 is not applied to the bottom of the pump housing 12, so that the valve element 18 is substantially free to the axis 20 is rotatable. As an axial stop acting in the released position, the front end of the rotor shaft 8, which is designed as a coupling 108. The clutch 108 engages with a counter-coupling 110, which is arranged non-rotatably on the valve element 18 in engagement. The coupling 108 has tapered coupling surfaces which essentially describe a sawtooth profile along a circumferential line in such a way that torque transmission from the coupling 108 to the counterpart coupling 110 is possible only in one direction of rotation, namely in the direction of rotation A in FIG Fig. 3 , In the opposite direction of rotation B, however, the clutch slips through, resulting in an axial movement of the valve element 18. The direction of rotation B is the direction of rotation in which the pump unit is driven in normal operation. The direction of rotation A, however, is used for targeted adjustment of the valve element 18. That is, here is a direction of rotation dependent coupling is formed. In addition, however, the mating coupling 110 disengages from the coupling 108 by the pressure in the pressure chamber 26. If the pressure in the pressure chamber 26 increases, a pressure force acting on the cover 78, which is opposite to the spring force of the spring 48 and exceeds this, so that the valve element 18 is pressed into the applied position, which in Fig. 4 is shown. In this, the lower part 76 is located on the bottom side of the pump housing 12, so that on the one hand the valve element 18 is frictionally held and on the other hand, a tight system is achieved, which seals the pressure and the suction side in the manner described below against each other.

The suction port 32 opens at the inlet 28 and the suction port 34 opens at the inlet 30 in the bottom of the pump housing 12 in the interior, that is, the suction chamber 24 into it. The lower part 76 of the valve element 18 has in its bottom an arcuate opening 112, which extends substantially over 90 °. Fig. 6 shows a first switching position in which the opening 112 only the input 30 is covered, so that a flow path is given only from the suction port 34 to the suction port 36 and thus to the suction port 38 of the impeller 14. The second input 28 is sealed by the voltage applied in its peripheral region bottom of the valve element 18. Fig. 8 shows the second switching position in which the opening 112 covers only the input 28 while the input 30 is closed. In this switching position, only one flow path from the suction port 32 to the suction mouth 38 is opened. Fig. 7 now shows an intermediate position in which the opening 112 covers both inputs 28 and 30, the input 30 is only partially released. By changing the degree of release of the port 30, a mixing ratio between the flows from the inputs 28 and 30 can be changed. About the stepwise adjustment of the rotor shaft 8 and the valve element 18 can be adjusted in small steps to change the mixing ratio.

Such functionality can be found, for example, in a hydraulic system, as in Fig. 9 shown is used. There, the centrifugal pump assembly with the integrated valve, as described above, characterized by the dashed line 1. The hydraulic circuit has a heat source 114 in the form of, for example, a gas boiler, whose outlet opens into, for example, the suction port 34 of the pump housing 12. In this example, a floor heating circuit 116 connects to the pressure connection 27 of the centrifugal pump assembly 1, the return of which is connected both to the inlet of the heat source 114 and to the suction connection 32 of the centrifugal pump unit. Via a second circulating pump assembly 118, a further heating circuit 120 can be supplied with a heat carrier, which has the output-side temperature of the heat source 114. The floor heating circuit 116, however, can be regulated in its flow temperature in such a way that cold water from the return to the hot water output side the heat source 114 is mixed, and by changing the opening ratios of the inputs 28 and 30 in the manner described above, the mixing ratio by rotation of the valve element 18h can be changed.

The second embodiment according to Fig. 10 to 19 shows a centrifugal pump unit, which in addition to the above-described mixer functionality still has a switching functionality for additional supply of a secondary heat exchanger for domestic water heating.

The storage and the drive of the valve element 18i in this embodiment is the same as in the ninth embodiment. In contrast to the valve element 18, the valve element 18i in addition to the opening 112 on a passage 122 which extends from an opening 124 in the lid 78i to an opening in the bottom of the lower part 76i and thus connects the two axial ends of the valve element 18i together. Further, in the valve element 18i is still an only to the bottom, that is, to the bottom of the lower part 76i and thus open to the suction chamber 24 toward arcuate bridging opening 126 is formed, which is closed to the pressure chamber 26 through the lid 78i.

The pump housing 12 has, in addition to the pressure port 27 and the two previously described suction ports 34 and 32, a further port 128. The port 128 opens into an inlet 130 in the bottom of Umwälzpumpenaggregates 12 in addition to the inputs 28 and 30 in the suction chamber 24 into it. Based on 15 to 18 the various switching positions are explained, in which case the lid 78i of the valve element 18i is shown partially opened to illustrate the position of the underlying openings. Fig. 15 shows a first switching position in which the opening 112 facing the input 30, so that a flow connection from the suction port 34 to the suction port 38 of the impeller 14 is made. In the switching position according to Fig. 16 the opening 112 is located above the inlet 130 so that a flow connection is created from the connection 128 to the suction opening 36 and via this into the suction mouth 38 of the impeller 14. In another switching position, which Fig. 17 shows, the opening 112 is located above the input 30, so that in turn a flow connection from the suction port 34 to the suction port 38 of the impeller 14 is given. At the same time, a partial overlap of the opening 124 and the through hole 122 with the input 28 takes place, so that a connection between the pressure chamber 26 and the suction port 32 is made, which acts as a pressure port. At the same time, the bypass opening 126 concurrently covers the input 130 and a portion of the input 28, so that also a connection from the terminal 128 via the input 130, the bypass opening 126 and the input 28 to the terminal 32 is provided.

Fig. 18 shows a fourth switching position in which the passageway 122 completely covers the input 28, so that the terminal 32 is connected via the passage 122 and the opening 124 with the pressure chamber 26. At the same time, the bridging opening 126 only covers the entrance 130. The opening 112 also covers the entrance 30.

Such a centrifugal pump unit, for example, in a heating system, as in Fig. 19 is shown, find use. There, the dashed line limits the centrifugal pump unit 1, as it is just based on the 10 to 18 has been described. The heating system in turn has a primary heat exchanger or a heat source 114, which may be, for example, a gas boiler. On the output side, the flow path runs in a first heating circuit 120, which may be formed for example by conventional radiators or radiators. At the same time, a flow path branches off to a secondary heat exchanger 56 for heating service water. The heating system further includes a floor heating circuit 116. The returns of the heating circuit 120 and the floor heating circuit 116 open into the suction port 34 on the pump housing 12. The return from the secondary heat exchanger 56 opens into the port 128, which, as will be described below, offers two functionalities. The connection 32 of the pump housing 12 is connected to the flow of the underfloor heating circuit 116.

When the valve element 18i in the first in Fig. 15 is shown, the impeller 14 promotes liquid from the suction port 34 via the pressure port 27 through the heat source 140 and the heating circuit 120 and back to the suction port 34. Is the valve element 18i in the second switching position, which in Fig. 16 is shown, the plant is switched to domestic water operation, in this state, the pump assembly or the impeller 14 promotes liquid from the port 128, which serves as a suction port, through the pressure port 27, via the heat source 114 through the secondary heat exchanger 56 and back to the terminal 128. Is the valve element 18i in the third switching position, which in Fig. 17 is shown, the underfloor heating circuit 116 is additionally supplied. Via the suction connection 34, the water flows into the suction mouth 38 of the impeller 14 and is conveyed via the pressure connection 27 via the heat source 114 in the manner described by the first heating circuit 120. At the same time, the liquid emerges on the output side of the impeller 14 from the pressure chamber 26 into the opening 124 and through the through-passage 122 and thus flows to the connection 32 and via this into the underfloor heating circuit 116.

In the in Fig. 17 The switch position shown flows simultaneously via the bridging opening 126 liquid via the terminal 128 and the input 130 into the terminal 32. That is, here water flows through the heat source 114 through the secondary heat exchanger 26 and the terminal 128 to the terminal 32. Since in this heating operation on Secondary heat exchanger 56 is removed substantially no heat, so the port 32 hot water in addition to the cold water, which flows from the pressure chamber 26 via the passage 122 to the port 32, admixed. By varying the degree of opening via the valve position 18i, the amount of hot water mixed in at port 32 can be varied. Fig. 18 shows a switching position in which the admixture is turned off and the terminal 32 is exclusively in communication with the pressure chamber 26 directly. In this state, the water is conveyed in the floor circuit 116 without heat in a circle. It can be seen that by changing the switching positions of the valve element 18i in this embodiment, both a switching between heating and domestic water heating can be achieved and at the same time the supply of two heating circuits with different temperatures, namely a first heating circuit 120 with the output temperature of the heat source 114th and a floor heating circuit 116 having a reduced temperature via a mixing function.

Due to the fact that the clutch 108 and the counter-clutch 110 in the first mode during normal operation of the circulating pump unit, when the impeller 14 promotes fluid out of engagement, the problem arises when changing to the second mode, which requires a reversal of the direction Rotor 6 and the valve element 18, 18i again bring in a defined orientation with respect to their angular positions. The valve element 18, 18i should be held substantially in the position in which it was, as the pump unit by the controller 17 for the last time of the second mode changed to the first operating mode. At the same time, the controller 17 is aware of the position of the rotor 6, and the controller 17 is configured to store the rotor position. However, since it can not be completely ruled out that the valve element 18, 18i may have shifted by a small amount, the rotor 6 is preferably initially positioned when the second change of mode is performed again in such a way that the control device 17 rotates the rotor 6 by appropriate control of the stator 4 is not quite up to the stored angular position rotates, but preferably shortly before stops. Ie. In a first step, when the second operating mode is started, the rotor 6 is rotated into a previously stored angular position or into an angular position which is slightly ahead of the last stored angular position in the direction of rotation. Subsequently, the rotor can be rotated together with the valve element 18, 18i in a desired second angular position, wherein the control device 17 controls the stator 6 so that the rotor 6 rotates in this second mode exactly to the desired angle. During this rotation, the counter-coupling 110 is taken over the clutch 108, so that the valve element 18, 18i is then rotated to the desired angular position. In this, the rotor 6 is stopped and the control device 17 switches back to the first mode or the first operating mode and starts the rotor 6 in the opposite direction of rotation, so that the clutch 108 can disengage from the mating coupling 110 and the rest by the axial Displacement of the valve element 18, 18i by the pressure generated in the pressure chamber 26, the clutch 108 and the counter-coupling 110 completely disengage and the valve element 18, 18i is held by engagement with the bottom of the pump housing 12 in the achieved switching position.

The coupling 108 has two slopes or wedge surfaces 132, which extend from two end edges 134, which in Substantially in the diametrical direction with respect to the axis of rotation X run. On the side of the end edges 134 facing away from the wedge surfaces 132, engagement surfaces 136 which essentially run in a plane which is spanned by the rotation axis X and a diameter line to this rotation axis X extend. The counter-coupling 110 has a web-shaped projection 138 extending in the diameter direction with respect to the axis of rotation X, which protrudes in the axial direction and has two substantially mutually parallel side surfaces, which in turn extend in planes which are substantially of the diameter line and the rotation axis X or be clamped to these parallel axes. The side surfaces of the projection 138 engage the engagement surfaces 136 when the clutch is engaged. In the reverse direction of rotation D, the projection 138 slides on the wedge surfaces 137 under axial displacement. In this embodiment of the coupling 108 and the counter-coupling 110, there are exactly two positions offset by 180 ° from each other, in which the rotor 6 and the valve element 18, 18i can be coupled together.

In the embodiments described above, the pump housing 12 is integrally formed. However, it is to be understood that the pump housing can also be designed in several parts. In particular, a separate from the pump housing valve housing may be provided, in which the valve element described is arranged, while in the pump housing, only the impeller is arranged. Such a valve and pump housing can be connected to each other in a suitable manner.

LIST OF REFERENCE NUMBERS

1

A centrifugal pump unit

2

motor housing

4

stator

6

rotor

8th

rotor shaft

10

canned

12

pump housing

14

Wheel

16

electronics housing

17

control device

18 18i

valve element

20

axis

24

suction

26

pressure chamber

27

pressure connection

28, 30

inputs

32.34

suction ports

38

saugmund

48

feather

76 76i

lower part

78, 78i

cover

108

clutch

110

counter-coupling

112

opening

114

heat source

116

Floor heating

118

circulation pump assembly

120

heating circuit

122

Through channel

124

opening

126

bridge opening

128

connection

130

entrance

132

wedge surfaces

134

front edges

136

engaging surfaces

138

head Start

X

axis of rotation

A, B

directions

Claims (16)

1. A pump assembly with an electrical drive motor, with at least one impeller (14) which is rotatingly driven by the electrical drive motor as well as with a control device (17) which activates the drive motor,
   wherein,
   the control device (17) is designed in a manner such that it selectively activates the drive motor in at least one first or a second operating mode, wherein in the first operating mode, the drive motor is activated by the control device (17) in a manner such that a rotor (6) of the drive motor continuously rotates for producing a flow and a pressure at the impeller, and in the second operating mode, the drive motor is controlled by the control device (17) in a manner such that the rotor (6) of the drive motor is moved further in a stepwise manner in at least one selected angular step of preferably smaller than 360° for reaching a certain angular position, characterised in that the rotor (6) of the drive motor, additionally to the at least one impeller (14), is coupled to at least one further movable component (18, 18i) via a releasable coupling (108, 110).
2. A pump assembly according to claim 1, characterised in that the control device (17) is designed in a manner such that the drive motor rotates at higher angular speed in the first operating mode than in the second operating mode.
3. A pump assembly according to claim 1 or 2, characterised in that the control device (17) is designed in a manner such that in the first operating mode, the drive motor in its speed is adjustable and in particular is closed-loop controllable.
4. A pump assembly according to one of the preceding claims, characterised in that the control device (17) is designed in a manner such that in the second operating mode, the drive motor is controlled by the control device (17) with an open-loop.
5. A pump assembly according to one of the preceding claims, characterised in that the control device (17) is designed in a manner such that in the second operating mode, the drive motor is activated by the control device (17) at a frequency < 10 Hertz and/or the motor current corresponds to twice to fourfold the rated amperage, for which the drive motor is designed.
6. A pump assembly according to one of the preceding claims, characterised in that the control device (17) comprises a frequency converter.
7. A pump assembly according to one of the preceding claims, characterised in that the control device (17) is designed in a manner such that the number and/or the size of the individual angular steps, in which the rotor (6) is moved in the second operating mode, is selectable.
8. A pump assembly according to one of the preceding claims, characterised in that the control device (17) is designed in a manner such that it activates the drive motor in a manner such that its rotation direction (A) in the second operating mode is opposite to the rotation direction (B) in the first operating mode.
9. A pump assembly according to one of the preceding claims, characterised in that the coupling (108, 110) is releasable in a rotation-direction-dependent manner such that in a first rotation direction (A) it is engaged and in the opposite second rotation direction (B) it is released.
10. A pump assembly according to one of the preceding claims, characterised in that the coupling (108) is formed at a face end of a rotor shaft (8) of the rotor and in particular has a saw-tooth profile.
11. A pump assembly according to one of the preceding claims 9, characterised in that the at least one further movable component is a valve element (18; 18i), wherein the valve element (18; 18i) is preferably part of a mixing valve and/or switch-over valve.
12. A pump assembly according to claim 11, characterised in that the valve element (18; 18i) is designed and arranged such that it is rotatingly movable between at least two switching positions, wherein a rotation axis (X) of the valve element (18; 18i) is preferably arranged in a manner aligned to the rotation axis (X) of the drive motor.
13. A pump assembly according to claim 11 or 12, characterised in that the valve element (18; 18i) is arranged in the pump assembly in a manner such that it comprises a pressure surface (78; 78i), upon which a pressure prevailing at the outlet side of the at least one impeller (14) acts, and the valve element (18; 18i) is movably mounted in a direction transverse to the pressure surface (78; 78i) between a bearing position, in which it bears on at least one contact surface, and a released position, in which it is released or distanced to the contact surface, wherein a restoring element (48) is preferably provided, said restoring element producing a restoring force which is directed oppositely to the pressing force which is produced by the pressure on the pressure surface (78; 78i).
14. A pump assembly according to claim 13, characterised in that the contact surface is a sealing surface.
15. A pump assembly according to claim 13, or 14, characterised in that a movement path (X) between the bearing position and a released position is different to the movement path between the at least two switching positions of the valve element (18; 18i).
16. A pump assembly according to one of the preceding claims, characterised in that it is designed as a circulation pump assembly and in particular as a heating circulation pump assembly.

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