centrifugal pump unit

Description

[0001] The invention relates to a centrifugal pump unit with an electric drive motor, an impeller driven by it and a valve element.

[0002] Centrifugal pump units are known which have an integrated valve assembly that can be moved between two switching positions, for example, by different directions of rotation of the drive motor and thus different flow directions within a pump housing. These valve assemblies can very easily switch between two possible flow paths on the outlet side of the pump unit. Switching between two flow paths on the suction side of the pump unit, however, is only possible via a complex mechanism. US 2016 / 0258340 A1 discloses a cooling water pump with an integrated valve assembly for switching the flow path between branches of a cooling water circuit. The valve assembly has a rotatable valve element which is rotatable by a linearly movable pressure cylinder via a gear.The pressure cylinder can be pressurized via solenoid valves to cause movement of the pivoting valve element. US 5924432 A discloses another centrifugal pump assembly that is part of the prior art of the present invention.

[0003] With regard to this problem, the object of the invention is to improve a centrifugal pump unit with a valve element movable between at least two switching positions in such a way that, on the one hand, a simple design of the valve device and, on the other hand, a reliable movement of the valve element is ensured.

[0004] This problem is solved by a centrifugal pump unit with the features specified in claim 1. Preferred embodiments are described in the dependent claims, the following description, and the accompanying figures.

[0005] The centrifugal pump assembly according to the invention comprises an electric drive motor and at least one impeller that can be driven by this electric drive motor. The electric drive motor is preferably designed as a wet-running motor, i.e., as a motor with a canned tube between the stator and rotor. In such a motor, the rotor rotates in the fluid to be pumped. The centrifugal pump assembly, particularly with the use of a wet-running electric motor, can, for example, be used in a heating or air conditioning system. There, it can be used as a circulation pump assembly.

[0006] The centrifugal pump assembly according to the invention further comprises at least one valve element which can be moved directly or indirectly along a first path of motion between at least two switching positions by the electric drive motor that drives the impeller. Direct movement can be achieved, for example, by a suitable detachable coupling, in particular a magnetic or mechanical coupling, between the rotor or impeller of the drive motor and the valve element. Indirect movement can be caused, for example, by the fluid pumped by the impeller, by the fluid flow and / or the pressure of the fluid acting on the valve element in such a way that it can be moved. In this way, movement along a first path of motion between at least two switching positions is effected. The path of motion can be linear, curved, or rotary.

[0007] According to the invention, the at least one valve element is designed and arranged such that at least a part or section of the valve element, in addition to being movable along the first path of movement, is also movable along a second path of movement, which differs from the first path of movement. That is, movement of the valve element in at least two different directions, preferably angled relative to each other, is possible. Along the second path of movement, the valve element, or a part of the valve element, is movable between a released position, in which it is detached from and, in particular, spaced apart from at least one contact surface, and a pressed position, in which it is pressed against the at least one contact surface. In the released position, the valve element is movable, in particular along the first path of movement between the at least two switching positions.In the released position, the valve element can be spaced away from the contact surface or positioned so that it can easily slide along the contact surface. In the second, engaged position, however, the valve element rests so firmly against the contact surface that it is held in a previously assumed switching position, i.e., movement along the first path of motion is prevented. In the engaged position, the valve element is pressed against the contact surface so that the friction between the valve element and the contact surface is greater than in the released position. This allows the centrifugal pump unit to be operated in the conventional manner by running the electric drive motor, in particular to regulate the speed, without the valve element leaving its previously assumed switching position.To move the valve element to a different switching position, it is first moved along the second path of motion to the released position, so that it can then move to the other switching position, driven by the drive motor. The movement along the second path of motion is preferably also initiated directly or indirectly by the electric drive motor. This movement can be pressure-dependent, so that when a predetermined output pressure of the centrifugal pump unit is exceeded, the valve element is pressed into the closed position. If the centrifugal pump unit is operated at a lower pressure or differential pressure, movement of the valve element between switching positions is possible.

[0008] According to the invention, either the valve element as a whole can be movable along the second path of movement, or only a section of the valve element can be movable along the second path of movement, for example, an elastically deformable section of the valve element, such as an elastic seal. When this description refers to the movableness of the valve element along the second path of movement, this always expressly includes an embodiment in which only a part or a section of the valve element is movable along the second path of movement.

[0009] The at least one valve element is preferably mechanically and / or hydraulically coupled to the drive motor such that it can be moved by the drive motor along the first and / or the second path of motion. The movement along the first path of motion can be effected, for example, by a hydraulic flow generated by the impeller, whereby this flow acts on the valve element or drives it along in the direction of flow by friction. Alternatively, a mechanical or magnetic coupling can be provided, in particular a friction coupling. Such a coupling can preferably be designed so that it can be disengaged depending on the pressure, i.e., it disengages when a certain output pressure of the pump unit is reached, allowing the drive motor to continue rotating unhindered without moving the valve element further.Along the second path of movement, the valve element can, for example, be moved purely based on pressure. When a certain outlet pressure of the fluid conveyed by the impeller is reached, this pressure acts on the valve element in such a way that it is pressed against the contact surface and preferably held there by friction and / or positive locking, so that, in particular, a flow or other coupling cannot move the valve element further between the switching positions. The different flow velocities or pressures on the outlet side of the impeller can be set via a control device that controls the drive motor. The control device is preferably designed to adjust, in particular, the rotational speed and, more preferably, also the acceleration profiles of the drive motor.

[0010] The second path of motion preferably extends transversely to the first path of motion or transversely to a plane in which the second path of motion extends or runs. In particular, the planes in which the paths of motion run are perpendicular to each other. For example, the first path of motion can be a rotational motion about an axis of rotation, and the second path of motion can be a linear motion along this axis of rotation.

[0011] Preferably, the axis of rotation about which the valve element is rotatable along the first path of motion extends parallel to or in alignment with the axis of rotation of the impeller. This allows for a particularly simple coupling between the drive motor and impeller on the one hand and the valve element on the other.

[0012] The valve element is advantageously mounted rotatably such that, in the released position, it can rotate about a bearing, and in particular a central bearing, between the at least two switching positions, and is preferably held rotationally fixed to the contact surface in the second, engaged position. The central bearing is preferably designed such that, in the released position, the valve element rests primarily only against the bearing, making it particularly easy to rotate. Additionally, the valve element may optionally rest against a return element, which forces it into the released position. The bearing is preferably permanently lubricated or lubricated by the fluid being pumped, thus ensuring particularly smooth operation of the bearing.In the closed position, the valve element forms a force-locking and / or form-locking coupling with the contact surface, which prevents rotation and thus holds the valve element in the switched position.

[0013] The second path of motion is preferably a straight line, and more preferably a straight line extending parallel to or along the axis of rotation of the at least one valve element. The valve element can thus be mounted to rotate in its central region, the mounting preferably being designed to allow a certain linear movement along the axis of rotation in order to enable movement along the second path of motion.

[0014] The at least one contact surface is preferably at least one sealing surface. The sealing surface can, for example, be formed by a valve seat surrounding a valve opening of a flow path. By contacting this sealing surface with the valve element, a seal of the valve opening is simultaneously achieved. Additionally, the described frictional engagement to prevent movement of the valve element can be achieved through this contact. Alternatively or additionally, a sealing surface can also be arranged such that, when the valve element is located between the suction and pressure sides, it seals the suction side against the pressure side of the centrifugal pump assembly in its contact position.

[0015] Preferably, at least one valve element has a pressure surface which is connected to a pressure side of the impeller in such a way that a pressure prevailing on the pressure side acts on the pressure surface and thus generates a pressure force acting on the valve element, wherein the pressure surface is positioned such that this pressure force is directed at least partially along the second path of movement of the valve element and, in particular, along the second path of movement towards the contact position. Thus, at sufficiently high pressure on the pressure side of the impeller, i.e.,in a pressure chamber of a pump housing surrounding the impeller, such a high pressure force is generated that it displaces the valve element or a section of the valve element from the released to the engaged position and presses it against the contact surface in order to hold the valve element there by force and / or friction and / or to ensure sufficient sealing when in contact with at least one sealing surface.

[0016] According to a further preferred embodiment, the valve element is coupled to at least one return element, in particular a return spring, which exerts a return force on the valve element along the second path of movement, particularly towards the released position. The return element ensures that when the pump unit is switched off, the valve element is moved to a starting position, which preferably corresponds to the released position. In this position, the valve element is then, as described above, preferably freely movable between the switching positions. If the drive motor is driven in this state, it is possible to move the valve element between the switching positions by appropriately controlling the drive motor.To move the valve element into the closed position, a force can be applied to it that overcomes the restoring force, thus moving the valve element into the closed position. This can be achieved, for example, by building up pressure on the outlet side of the impeller, as described above, which generates a pressure force on a contact surface of the valve element that is directed opposite to the described restoring force. If the pressure force is greater than the restoring force, the valve element is moved into the closed position.

[0017] According to another possible embodiment, the function of the return element can be achieved by the elastic deformability of a section of the valve element that is movable along the second path of movement. The return function is then performed by elastic return forces.

[0018] According to a further preferred embodiment, the centrifugal pump unit can include a force-generating means that exerts a force on the valve element in the direction of one of at least two switching positions, wherein the force is preferably a spring force, a magnetic force, and / or gravity. The switching position in the direction of which the force generated by the force-generating means is directed preferably constitutes a starting position or rest position. The force-generating means is preferably designed and arranged such that, when the centrifugal pump unit is at rest, it forces the valve element into this starting position or a predetermined switching position. From this position, the valve element can then be moved to another switching position by a suitable drive motor.However, if the valve element moves along the second path of motion first, and thus comes into contact with the contact surface, the valve element can be held in the switching position corresponding to its initial position even during operation of the centrifugal pump unit. This can be achieved, for example, by very rapid acceleration of the drive motor, which directly generates a pressure on the outlet side of the impeller that can act on the valve element against a pressure surface and press it against the contact surface.

[0019] The coupling between the drive motor and the valve element is particularly preferably hydraulically designed, wherein the at least one valve element is preferably configured such that it can be moved along the first path of motion by a fluid flow set in motion by the impeller. This fluid flow is particularly preferably a rotating fluid flow in the outlet region of the impeller, which surrounds the impeller as it rotates. This flow can, for example, act on the valve element by friction and move it along with it, especially if the valve element is designed such that it can be rotated between the switching positions about an axis of rotation that corresponds to the axis of rotation of the impeller.This hydraulic coupling has the advantage that, once the desired switching position is reached, the flow in the pump housing can continue unimpeded, while the valve element is held in the achieved switching position by a stop and / or contact with the mating surface. In this state, the flow on the surface of the valve element preferably only causes friction that corresponds to the normal friction inside the pump housing, so that the switching functionality essentially does not result in any additional power loss in the centrifugal pump unit.

[0020] According to a particular embodiment of the invention, the drive motor is designed, or can be controlled by a control device, such that it can be driven in two different directions of rotation. The impeller is further preferably designed such that, depending on its direction of rotation, it generates differently directed fluid flows, by which the at least one valve element can be moved in opposite directions along the first path of movement. Thus, by reversing the direction of rotation of the drive motor and therefore of the impeller, the valve element can be moved back and forth between the at least two switching positions.If, as described above, a force-generating device is provided to generate a force that moves the valve element back to an initial position, this reversal of the direction of rotation of the drive motor can be dispensed with, since the return movement of the valve element is then carried out by the force-generating device, while the movement from the initial position can be carried out by the drive motor in the manner described.

[0021] Particularly preferably, the drive motor has a control device which controls the drive motor in such a way that the speed and / or the acceleration and / or the direction of rotation of the drive motor can be specifically changed in order to achieve the processes described above.

[0022] According to a further preferred embodiment of the invention, the valve element is arranged and designed such that it can be moved along the first path of motion by a flow generated by the impeller and along the second path of motion by a fluid pressure generated at the impeller's outlet. The drive motor preferably has a control device configured such that the drive motor can be started with a first acceleration profile, in which the pressure builds up faster than the flow, and with a second acceleration profile, in which the flow builds up faster than the pressure. The first acceleration profile preferably corresponds to a stronger acceleration than the second acceleration profile.If sufficient pressure is reached quickly to force the valve element against a contact surface before a sufficient flow develops to move the valve element as described, the valve element can be held in the switching position corresponding to its initial position. However, if the acceleration is slower, a pressure high enough to move the valve element along the second path of movement into the contact position is not reached, and a flow can initially develop that moves the valve element to a different switching position as described. Thus, simply by controlling the drive motor, the valve element can be moved into a desired switching position and held there for the continued operation of the pump unit.The pressure at which the valve element comes into contact with the contact surface is preferably selected to correspond to a pressure that is lower than the usual operating pressure of the centrifugal pump unit, so that the normal operation of the centrifugal pump unit is not impaired after reaching the switching position.

[0023] According to a further preferred embodiment, the at least one valve element can be coupled to the impeller or a shaft driving the impeller of the drive motor, or directly to the rotor of the drive motor, via a coupling for its movement along the first path of motion. This coupling is preferably disengageable depending on pressure and / or speed and / or direction of rotation. This can be a mechanical coupling that transmits the rotary motion of the drive motor to the valve element in order to move it between the switching positions. The coupling can be designed such that it disengages when a certain fluid pressure is reached on the outlet side of the impeller.It can also be designed to disengage at a certain rotational speed, for example, by the formation of a lubricating film between the coupling elements, which essentially eliminates the frictional connection, allowing the coupling elements to then slide against each other like a plain bearing. The lubricating film can be formed, for example, by the fluid conveyed by the impeller. Water is particularly preferred as the fluid. Furthermore, a rotation-direction-dependent coupling is possible, which, for example, acts only in one direction of rotation, similar to a pawl or ratchet, while in the opposite direction of rotation the coupling elements slide against each other. For example,A direction of rotation of the drive motor, which preferably does not correspond to the normal direction of rotation of the impeller, is used to move the valve element into a desired switching position, while in the other direction of rotation, which preferably corresponds to the normal operating direction, the coupling is inactive, so that the valve element remains in the achieved switching position. Such a coupling can particularly preferably be used in combination with the force-generating device described above to generate a force that moves the valve element back to its initial position. Furthermore, a hydraulic coupling between the impeller and the drive motor is also possible, as described above.

[0024] According to a further preferred embodiment, the at least one valve element can be designed and arranged such that, within a pump housing surrounding the impeller, it separates a suction chamber connected to a suction side of the impeller from a pressure chamber connected to the pressure side of the impeller. The valve element can more preferably surround a suction inlet of the impeller in an annular manner. The arrangement of the valve element between the suction and pressure sides has the advantage that the differential pressure between the suction and pressure sides can be used to move the valve element along the second path of movement. The pressure-side pressure acts on one side of the valve element, while the suction-side pressure acts on the opposite side. Furthermore, it is possible that pressure can be applied to one or both sides of the valve element, i.e.,on the pressure side and / or the suction side, fluid flows are used to move the valve element along the first path of movement.

[0025] Preferably, the at least one valve element is designed and arranged such that, within a pump housing surrounding the impeller, it separates a suction chamber connected to a suction side of the impeller from a pressure chamber connected to a pressure side of the impeller. In the pressure chamber, a flow generated by the impeller acts on the valve element, causing it to move along the first path of motion. The suction chamber is designed such that the flow prevailing there exerts no force on the valve element in the direction of the first path of motion. Thus, the valve element can be selectively driven or moved by the flow in the pressure chamber, preferably the flow surrounding the impeller, to move it between switching positions. On the suction side, less force or no force acts against this movement.Alternatively, it is also possible to design the suction-side flow paths in such a way that the flow prevailing there exerts a corresponding force on the valve element to move it.

[0026] According to a further particular embodiment of the invention, the centrifugal pump unit has at least two alternative flow paths, wherein the at least one valve element is arranged in these flow paths such that these flow paths are open differently in the at least two switching positions. For example, the valve element can function as a changeover valve by alternately opening the two flow paths. That is, in a first switching position, the first flow path is closed and the second flow path is open, while in a second switching position, the first flow path is open and the second flow path is closed. It is also possible to design the valve element as a mixing valve in which the flows from the two flow paths are mixed in variable proportions.In such a design, it is preferred that the valve element can assume more than two switching positions in which the flow paths are open to different degrees. The valve element is preferably designed such that, when it is moved, it closes one flow path by a certain amount while simultaneously opening the other flow path by the same amount.

[0027] The described flow paths are preferably located on the suction side of the impeller. This means that, for example, if the valve element acts as a diverter valve in the manner described, the impeller can draw fluid from one of the two flow paths depending on the position of the valve element. The diverter valve can be used, for example, in a heating system to selectively direct the circulation of the fluid pumped by the centrifugal pump unit either through a heat exchanger for domestic hot water production or through a heating circuit. However, particularly if the valve element operates as a mixing valve, it is also possible for the two flow paths to be located on the pressure side of the impeller. In this case, one of the flow paths preferably passes through a heat source or heat exchanger upstream of the mixing valve to temper the fluid, while the other flow path leads directly to the mixing valve.Thus, a temperature-controlled flow can be mixed with a non-temperature-controlled flow in the mixing valve. The invention is described below by way of example with reference to the accompanying figures. These show: . Fig. 1 is an exploded view of a centrifugal pump assembly according to a first embodiment of the invention, Fig. 2 is a perspective view of the underside of the valve element of the centrifugal pump assembly according to Fig. 1 , Fig. 3 a perspective view of the pump housing of the centrifugal pump unit according to Fig. 1 In the open state, Fig. 4 shows a sectional view of the centrifugal pump unit according to Fig. 1 , Fig. 5 a sectional view of the pump housing of the centrifugal pump unit according to Fig. 4 with the valve element in a first switching position, Fig. 6 a sectional view accordingly Fig. 5with the valve element in a second switching position, Fig. 7 schematically shows the hydraulic setup with a heating system with a centrifugal pump unit according to Figs. 1 to 6 Fig. 8 is an exploded view of a centrifugal pump assembly according to a second embodiment of the invention, Fig. 9 is a sectional view of the centrifugal pump assembly according to Fig. 8 with the valve element in a first position, Fig. 10 a sectional view accordingly Fig. 9 with the valve element in a second position, Fig. 11 an exploded view of a centrifugal pump assembly according to a third embodiment of the invention, Fig. 12 a sectional view of the centrifugal pump assembly according to Fig. 11 with the valve element in a first position, Fig. 13 a sectional view accordingly Fig. 12with the valve element in a second position, Fig. 14 an exploded view of a pump housing with a valve element according to a fourth embodiment of the invention, Fig. 15 a sectional view of a centrifugal pump assembly according to the fourth embodiment of the invention, Fig. 16 an exploded view of a centrifugal pump assembly according to a fifth embodiment of the invention, Fig. 17 a sectional view of the centrifugal pump assembly according to Fig. 16 with the valve element in a first position, Fig. 18 a sectional view accordingly Fig. 17 with the valve element in a second position, Fig. 19 an exploded view of a centrifugal pump assembly according to a sixth embodiment of the invention, Fig. 20 a sectional view of the centrifugal pump assembly according to Fig. 19 , Fig. 21 a top view of the opened pump housing of the centrifugal pump unit according to Fig. 19 and 20with the valve element in a first switching position, Fig. 22 a top view accordingly Fig. 21 with the valve element in a second switching position, Fig. 23 an exploded view of a pump housing with a valve element according to a seventh embodiment of the invention, Fig. 24 an exploded view of the pump housing with valve element according to the seventh embodiment seen from another side, Fig. 25 an exploded view of a centrifugal pump assembly according to an eighth embodiment of the invention, Fig. 26 a sectional view of the centrifugal pump assembly according to Fig. 25 , Fig. 27 a top view of the opened pump housing of the centrifugal pump unit according to Fig. 25 and 26 with the valve element in a first switching position, Fig. 28 a view according to Fig. 27with the valve element in a second switching position, Fig. 29 an exploded view of the centrifugal pump assembly according to a ninth embodiment of the invention, Fig. 30 a perspective view of the centrifugal pump assembly according to Fig. 29 with pump housing and valve element removed, Fig. 31 a perspective view of the motor shaft of the centrifugal pump unit according to Fig. 29 and 30 as well as the coupling part of the valve element, Fig. 32 a sectional view of the centrifugal pump unit according to Fig. 29 with the valve element in a first position, Fig. 33 a sectional view according to Fig. 32 with the valve element in a second position, Fig. 34 a top view of the opened pump housing of the centrifugal pump unit according to Figs. 29 to 33 with the valve element in a first switching position, Fig. 35 a view according to Fig. 34 with the valve element in a second switching position, Fig. 36 a view according to Figs. 34 and 35with the valve element in a third switching position, Fig. 37 schematically shows the hydraulic setup of a heating system with a centrifugal pump unit according to Figs. 29 to 36 Fig. 38 shows an exploded view of a centrifugal pump assembly according to a tenth embodiment of the invention, Fig. 39 shows a perspective view of the open valve element of the centrifugal pump assembly according to Fig. 38 , Fig. 40 a perspective view of the closed valve element according to Fig. 39 , Fig. 41 a sectional view of the centrifugal pump unit according to Fig. 38 with the valve element in a first position, Fig. 42 a sectional view according to Fig. 41 with the valve element in a second position, Fig. 43 a top view of the opened pump housing of the centrifugal pump unit according to Figs. 38 to 42 with the valve element in a first switching position, Fig. 44 a view according to Fig. 43 with the valve element in a second switching position, Fig. 45 a view according to Figs. 43 and 44with the valve element in a third switching position, Fig. 46 a view according to Figs. 43 to 45 with the valve element in a fourth switching position and Fig. 47 schematically the hydraulic setup of a heating system with a centrifugal pump unit according to Figs. 38 to 46 .

[0028] The embodiments of the centrifugal pump unit according to the invention described in the following description relate to applications in heating and / or air conditioning systems in which a liquid heat transfer medium, in particular water, is circulated by the centrifugal pump unit.

[0029] The centrifugal pump unit according to the first embodiment of the invention comprises a motor housing 2 in which an electric drive motor is arranged. This motor has, in a known manner, a stator 4 and a rotor 6, which is arranged on a rotor shaft 8. The rotor 6 rotates in a rotor chamber, which is separated from the stator chamber, in which the stator 4 is arranged, by a canned tube or a canned housing 10. This is a wet-running electric drive motor. At one axial end, the motor housing 2 is connected to a pump housing 12, in which an impeller 14, non-rotatably connected to the rotor shaft 8, rotates.

[0030] An electronics housing 16 is arranged at the axial end of the motor housing 2 opposite the pump housing 12. This electronics housing contains control electronics or a control unit for controlling the electric drive motor in the pump housing 2. The electronics housing 16 could also be arranged on another side of the stator housing 2.

[0031] Furthermore, a movable valve element 18 is arranged in the pump housing 12. This valve element 18 is rotatably mounted on an axis 20 inside the pump housing 12 such 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 fixed to the bottom of the pump housing 12 to prevent rotation. The valve element 18 is not only rotatable about the axis 20, but also movable to a certain extent in the longitudinal direction X. In one direction, this linear movement is limited by the pump housing 12, against which the valve element 18 abuts with its outer circumference. In the opposite direction, the movement is limited by the nut 22, with which the valve element 18 is fastened to the axis 20. It should be understood that instead of the nut 22, another axial fastening of the valve element 18 to the axis 20 could also be chosen.

[0032] The valve element 18 separates a suction chamber 24 from a pressure chamber 26 in the pump housing 12. The impeller 14 rotates in the pressure chamber 26. The pressure chamber 26 is connected to the pressure port or pressure nozzle 28 of the centrifugal pump unit, which forms the outlet of the centrifugal pump unit. Two suction-side inlets 28 and 30 open into the suction chamber 24, of which inlet 28 is connected to a first suction port 32 and inlet 30 to a second suction port 34 of the pump housing 12.

[0033] The valve element 18 is disc-shaped and simultaneously functions as a conventional deflector plate, separating the suction chamber 24 from the pressure chamber 26. The valve element 18 has a central suction opening 36 with a projecting circumferential collar that engages with the suction port 38 of the impeller 14 and is essentially in tight contact with it. The side facing the impeller 14 is essentially smooth. On the side facing away from the impeller 14, the valve element has two annular sealing surfaces 40, which in this embodiment are located on closed tubular nozzles.The two annular sealing surfaces 40 are arranged at two diametrically opposite positions on the sealing element 18 with respect to its axis of rotation X, so that they can come into tight contact in the circumferential region of the inlets 28 and 30 at the bottom of the pump housing 12 to close the inlets 28 and 30. Support elements 42 are arranged at an angle 90° offset from the sealing surfaces 40. These support elements can also come into contact with the circumferential region of the inlets 28 and 30, but are spaced apart from each other so that they do not close the inlets 28 and 30. The inlets 28 and 30 do not lie on a line of diameter with respect to the axis of rotation X, but on a radially offset line. Thus, when the valve element 18 is rotated about the axis of rotation X, in a first switching position, the inlet 38 is closed by a sealing surface 40, while the support elements 42 lie at the inlet 30 and open it.In a second switching position, the inlet 30 is closed by a sealing surface 40, while the support elements 42 bear against the circumference of the inlet 28 and open it. The first switching position, in which the inlet 38 is closed and the inlet 30 is open, is shown in . Fig. 5 shown. The second switching position, in which input 30 is closed and input 28 is open, is shown in Fig. 6 This means that by rotating the valve element 90° around the axis of rotation X, the two switching positions can be changed. The two switching positions are limited by a stop element 44, which alternately abuts two stops 46 in the pump housing 12.

[0034] In a rest position, that is, when the centrifugal pump unit is not in operation, a spring 48 presses the valve element 18 into a released position in which the outer circumference of the valve element 18 is not in tight contact with the pump housing 12 and the sealing surfaces 40 are not in tight contact with the circumferential area of ​​the inlets 28 and 30, so that the valve element 18 can rotate about the axis 20. When the control unit 17 in the electronic housing 16 sets the drive motor in motion, causing the impeller 14 to rotate, a circulating flow is generated in the pressure chamber 26, which, via friction, rotates the valve element 18 in its direction of rotation. The control unit 17 is designed to drive the drive motor in either of two directions of rotation.Thus, the valve element 18 can be moved about the axis of rotation X in two directions, depending on the direction of rotation of the impeller 14, by means of the flow set in rotation by the impeller 14, since the flow in the circumferential region of the impeller 14 always flows in its direction of rotation. In this way, the valve element 18 can be rotated between the two switching positions limited by the stops 46.

[0035] When the impeller 14 rotates at a sufficient speed, pressure builds up in the pressure chamber 26. This pressure generates a pressure force on the surface of the valve element 18, which surrounds the suction opening 36. This pressure force opposes the spring force of the spring 48, causing the valve element 18 to move axially in the direction X against the spring force of the spring 48. This movement brings its outer circumference into sealing contact with an annular contact shoulder 50 on the pump housing 12. Simultaneously, depending on the switching position, one of the sealing surfaces 40 around the circumference of one of the inlets 28 and 30 comes into sealing contact, thus closing one of the inlets 28, 30. At the other inlet, the support elements 42 come into contact, keeping this inlet open and allowing a flow path from this inlet 28, 30 to the suction opening 36 and from there into the interior of the impeller 14.By contacting the valve element 18 with the mounting shoulder 50 and the sealing surface 40 in the circumferential area of ​​one of the inlets 28, 30, a frictional connection is simultaneously created between the valve element 18 and the pump housing 12. This frictional connection ensures that the valve element 18 is held in the achieved switching position. This makes it possible to briefly switch off the drive motor and restart it in the opposite direction of rotation without rotating the valve element 18. If the motor is switched off and restarted quickly enough, the pressure in the pressure chamber 26 does not decrease to such an extent that the valve element 18 can move axially back to its released position.This makes it possible to always drive the impeller in its preferred direction of rotation, for which the blades are designed, when operating the centrifugal pump unit, and to use the opposite direction of rotation only to move the valve element 18 in the opposite direction of rotation.

[0036] The described centrifugal pump unit according to the first embodiment of the invention can, for example, be used in a heating system such as that found in Fig. 7As shown, such a heating system is typically used in apartments or houses and serves to heat the building and provide hot water. The heating system has a heat source 52, for example, in the form of a gas boiler. Furthermore, a heating circuit 54 is present, which, for example, runs through various radiators in a building. In addition, a secondary heat exchanger 56 is provided, via which hot water can be heated. In such heating systems, a diverter valve is usually required, which directs the heat transfer fluid flow either through the heating circuit 54 or the secondary heat exchanger 56. With the centrifugal pump unit 1 according to the invention, this valve function is taken over by the valve element 18, which is integrated into the centrifugal pump unit 1. Control is carried out by the control unit 17 in the electronic housing 16.The heat source 52 is connected to the pressure port 27 of the pump housing 12. A flow path 58 is connected to the suction port 32, while a flow path 60 through the heating circuit 54 is connected to the suction port 34. Thus, depending on the switching position of the valve element 18, it is possible to switch between the flow path 58 through the secondary heat exchanger 56 or the flow path 60 through the heating circuit 54 without requiring a valve with an additional actuator.

[0037] The second embodiment according to Figs. 8 to 10This embodiment differs from the first embodiment in the construction of the valve element 18'. In this embodiment as well, the valve element 18' separates the pressure chamber 26 from a suction chamber 24 of the pump housing 12. The valve element 18 has a central suction opening 36' into which the suction port 38 of the impeller 14 engages in a sealing manner. Opposite the suction opening 36, the valve element 18' has an opening 62 which, depending on the switching position of the valve element 18', can be selectively aligned with one of the inlets 28, 30. The inlets 28', 30' differ in their shape in this embodiment from the inlets 28, 30 according to the preceding embodiment. The valve element 18' has a central projection 64 which engages in a central hole 60 in the base of the pump housing 12 and is mounted there to rotate about the axis of rotation X.Simultaneously, the projection 64 in the hole 66 also allows axial movement along the axis of rotation X, which is limited in one direction by the base of the pump housing 12 and in the other direction by the impeller 14. The valve element 18' has a pin 68 on its outer circumference, which engages in a semicircular groove 70 on the base of the pump housing 12. The ends of the groove 70 serve as stop surfaces for the pin 68 in the two possible switching positions of the valve element 18'. In the first switching position, the opening 62 is located above the inlet 28', and in the second switching position, the opening 62 is located above the inlet 30', with the other inlet being closed by the base of the valve element 18'. The rotational movement of the valve element 18' between the two switching positions is also effected in this embodiment by the flow generated by the impeller 14 in the pressure chamber 26.To transmit these forces even more effectively to the valve element 18', it is provided with projections 72 directed into the pressure chamber 26. When the centrifugal pump unit 1 is taken out of service, the spring 48 presses the valve element 18' into the recess. Fig. 10 The shown released position, in which it does not rest on the ground around the inlets 28' and 30', is shown. In this position, it abuts axially with a central pin 74 on the end face of the motor shaft 8, and its axial movement is limited by this stop. When the pressure in the pressure chamber 26 is sufficiently high, the valve element 18' is moved into the position shown. Fig. 9 The valve element 18' is pressed into the shown position, in which it comes into contact with the bottom of the pump housing 12 in the circumferential area of ​​the inlets 28' and 30', and simultaneously the pin 24 is lifted from the end face of the rotor shaft 8. In this position, the impeller 14 then rotates during normal operation of the circulating pump unit.

[0038] The third embodiment according to Figs. 11 to 13 Figure 1 shows another possible embodiment of the valve element 18". This embodiment differs from the preceding embodiments in the construction of the valve element 18". It is designed as a valve drum. The pump housing 12 essentially corresponds to the construction shown in Figure 1. Figs. 1 to 6, wherein in particular the arrangement of the inlets 28 and 30 corresponds to the arrangement described with reference to the first embodiment. The valve drum of the valve element 18" consists of a pot-shaped lower part, which is closed by a cover 78. The cover 78 faces the pressure chamber 26 and has the central suction opening 36, which engages with its axially directed collar in the suction mouth 38 of the impeller 14. On the opposite side, the bottom of the lower part 36 has an inlet opening 80, which, depending on the switching position, is aligned with one of the inlets 28, 30, while the other inlet 28, 30 is closed by the bottom of the lower part 26. The valve element 18" is rotatably mounted on an axis 20, which is fixed in the bottom of the pump housing 12, wherein the axis of rotation defined by the axis 20 corresponds to the axis of rotation X of the impeller 14.In this embodiment as well, the valve element 18" is axially displaceable along the axis 20 by a certain amount, and here too a spring 48 is provided which, in the rest position, holds the valve element 18" in its position. Fig. 13 The released position shown exerts pressure. This axial position is also limited in this embodiment by the nut 22. In the released position, the valve element 18", as described above, is rotatable by the flow caused by the impeller 14, i.e., a hydraulic coupling is established between the impeller 14 and the valve element 18". In the engaged position, which is shown in Fig. 12 As shown, depending on the switching position, one of the inputs 28, 30 is tightly closed. Furthermore, a seal is also created between the suction chamber 24 and the pressure chamber 26 by the contact of the valve element 18" with the system shoulder 50.

[0039] In this embodiment, the bearing of the valve element 18" on the shaft 20 is further encapsulated by two sleeves 82 and 84, so that these areas are protected from contamination by the pumped fluid and can be pre-lubricated if necessary. The aim is to achieve the smoothest possible bearing operation to ensure the easy rotation of the valve element 18" by the flow generated by the impeller 14. It should be understood that the bearing could also be similarly encapsulated in the other embodiments described here.

[0040] Fig. 14 and 15Figure 1 shows a fourth embodiment in which the design of the pump housing 12 corresponds to that of the pump housing 12 according to the first and third embodiments. In this embodiment, the rotary movement of the valve element 18c is assisted by the suction-side flow, that is, the flow entering the suction inlet 38 of the impeller 14. In this embodiment as well, the valve element 18c is essentially drum-shaped and has a cover 28 facing the pressure chamber 26 with the central suction opening 36, which engages with the suction inlet 38 as described above. The lower part 76b shown here has two inlet openings 80, which, depending on the switching position, can be covered by one of the inlets 28, 30, with the other inlet 28, 30 being tightly closed by the base of the lower part 46b, as described in the previous embodiment.A guide vane 86 is arranged between the lower part 76b and the cover 78. The flow enters radially from the inlet openings 80 into the guide vane and exits axially towards the central suction opening 36. The vanes of the guide vane 86 also generate a torque about the axis 20, which moves the valve element 18c between its switching positions. This functions essentially as described above. A spring 48, as described above, can also be provided to move the valve element 18c into a released position. Since the shape of the vanes of the guide vane 86 always generates a torque in the same direction, regardless of the direction of rotation of the impeller 14, the return movement in this embodiment is effected by a weight 88. During operation, the centrifugal pump unit is always in the installation position shown in [reference missing]. Fig. 15The figure shows the axis of rotation X extending horizontally. When the centrifugal pump unit is switched off, the valve element 18c always rotates about the axis 20 such that the weight 88 is at the bottom. The torque generated by the guide wheel 86 can rotate the valve element 18c against this restoring force generated by the weight 88. Very rapid activation of the drive motor allows pressure to build up so quickly in the pressure chamber 26 that the valve element 18c enters its closed position, as described above, in which it is held firmly against the pump housing 12 without being moved from its rest position. It should be understood that a return of the valve element by gravity or another restoring force, independent of the drive, could also be used in the other embodiments described here.

[0041] The fifth embodiment according to Figs. 16 to 18This embodiment differs from the preceding embodiments in the design of the valve element. In this embodiment, the valve element 18d is conical. The valve element 18d has a conical, pot-shaped lower part 76d, which is closed by a cover 78d. The cover 78d has a central suction opening 36, which engages with the suction inlet 38 of the impeller 14 as described above. In the conical circumferential surface of the lower part 76d, inlet openings 90 are formed. By rotating the valve element 18d, these inlets can be selectively aligned with the inlets connected to the suction ports 32 and 34 to create a flow path through the interior of the valve element 18d to the suction opening 36. Sealing surfaces 92 are formed on the conical lower part between the inlet openings 90, which can close the respective inlets.As well as embodiment 2 according to . Figs. 8 to 10 Here, the valve element 18d has a pin-shaped projection 64 which engages in a recess on the bottom of the pump housing 12 and mounts the valve element 18d there so that it rotates about the axis of rotation X. Here too, axial movement between a released position, as described in Fig. 18 shown, and an adjacent position, as shown in Fig. 17As shown, this is possible. In the released position, the lower part 76d of the valve element 18d is essentially not in contact with the pump housing 12, so that it can be rotated by the flow in the pressure chamber 26, as described in the previously described embodiments. Depending on the direction of rotation of the impeller 14, a back-and-forth movement of the valve element 18d can again be achieved, whereby the rotational movement of the valve element 18d can again be limited by stops (not shown). In the contact position according to Fig. 17 Firstly, the valve element 18d is tightly fitted, and secondly, it is held in a force-fit position so that, as long as the pressure in the pressure chamber 26 is sufficiently high, it is not moved between the switching positions even when the direction of rotation of the impeller 14 changes.

[0042] The sixth embodiment according to Figs. 19 to 22 is similar to embodiment 2 according to Figs. 8 to 10 The pump housing 12 essentially corresponds to the structure shown and described therein. The motor housing 2 with the electronics housing 16 and the canned tube 10 also correspond to the structure according to the second embodiment. The valve element 18e has a very similar structure to that of the valve element 18'. Only the projections 72 and the pin 74 are missing. The opening 62, however, is designed in the same way. The suction opening 36e also essentially corresponds to the structure of the suction opening 36'. The valve element 18e is rotatably mounted on a hollow shaft, which is inserted into the hole 66 in the base of the pump housing 12. In this embodiment, the spring 48 is arranged inside the hollow shaft 94.

[0043] Depending on the switching position of the valve element 18e, the opening 62 comes to rest either above the inlet 28' or the outlet 30' in order to open a flow path either from the suction port 32 to the impeller 14 or from the suction port 34 to the impeller 14. In this embodiment as well, the valve element 18e is additionally movable axially along the axis of rotation X, which is the axis of rotation of the impeller 14 and the valve element 18e. In a rest position, in which the centrifugal pump unit is not in operation, the valve element 18e is pressed by the spring 48 into a released position in which the surface of the valve element 18e facing away from the impeller 14 is spaced from the bottom of the pump housing 12, so that the valve element 18e can rotate essentially freely back and forth about the axis 94 between the stops formed by the pin 68 and the groove 70. Fig. 21 shows the first switching position in which the opening 62 is opposite the input 28', Fig. 22 shows the second switching position, in which the opening 62 is opposite the second input 30'.

[0044] In this embodiment, the rotation of the valve element 18e is again effected via the impeller 14; however, a mechanical coupling is provided here, which is realized by the impeller 14, with its area surrounding the suction opening 38, frictionally engaging with the circumference of the suction opening 36e. Thus, the valve element 18e rotates with the impeller 14 until the pin 68 reaches a stop. At this point, the coupling disengages due to slippage. With increasing pressure in the pressure chamber 26, the valve element 18e is then moved axially into its engaged position, as described above, whereby the coupling disengages from the impeller 14, allowing the impeller 14 to rotate essentially without friction.

[0045] The seventh embodiment according to Fig. 23 and 24This embodiment differs from the sixth embodiment described above in that a tongue 96 extending into the pressure chamber 26 is arranged on the valve element 18f, serving as an additional valve element within the pressure chamber 26. The pump housing 12 has an additional pressure port 98, which opens into the pressure chamber 26 separately from the pressure port 27. Depending on the switching position of the valve element 18f, the tongue 96 can open either the pressure port 27 or the pressure port 28 and cover the other pressure port. Thus, in this embodiment, a pressure-side switching mechanism is provided on the pressure side of the impeller 14.A mixing function can be simultaneously implemented via inlets 28' and 30' by positioning the opening 92 such that, in a first switching position, it covers both inlets 28' and 30', allowing fluid from both inlets 28' and 30' to flow through the opening 62 and then through the suction port 38. In the second switching position, however, the opening 62 covers only inlet 28', while inlet 30' is closed by the base of the valve element 18f as described above. Simultaneously, the pressure port 27 is closed and the pressure port 98 is opened. The movement of the valve element 18f can be achieved, as described above, via the impeller 14 and a mechanical coupling, which disengages when the pressure in the pressure chamber 26 is sufficiently high due to axial displacement of the valve element 18f. In this embodiment, the valve element 18f is mounted on the rotor shaft 8.

[0046] The eighth embodiment according to Figs. 25 to 28This embodiment differs from the sixth embodiment in the design of the mechanical coupling between the rotor shaft 8 and the valve element 18g. In this embodiment, the valve element 18g is mounted directly on the rotor shaft 8, which is extended and reaches into the hole 66 in the base of the pump housing 12. Inside the valve element 18g, two ring segments 100 with sliding bearing properties, in particular made of ceramic, are arranged. The ring segments 100 are held together by a clamping ring 102 and pressed against the rotor shaft 8. In this example, the two ring segments 100 essentially form a 2 / 3 ring. In the area of ​​the missing ring segment for a complete ring, the valve element 18g engages with a projection 104 on its inner circumference, so that the two ring segments 100 are arranged rotationally fixed inside the valve element 18g.In the area of ​​the missing ring segment, i.e. adjacent to the projection 104, a passage 106 remains in the valve element 18g, which effects the valve function.

[0047] Passage 106 can be in a first switching position, which is in Fig. 27 as shown, opposite input 30' and in a second switching position, which is in Fig. 28 The valve element 18g is shown opposite inlet 28'. The other inlet is closed. According to the embodiments described above, the pressure prevailing in the pressure chamber 26 can press the valve element 18g axially against the base of the pump housing 2 surrounding inlets 28' and 30'.

[0048] The movement of the valve element 18g is effected by the drive of the impeller 14. At start-up, the rotor shaft 8 is positively engaged with the inner circumference of the ring segments 10 and rotates them, and thus the valve element 18g. Stops can be formed in the pump housing 12 for the two switching positions, as described above. If the valve element 18g reaches one of these stops, the pump shaft 8 slips inside the ring segments 100. As the rotational speed of the rotor shaft 8 increases, a lubricating film similar to that of a plain bearing can form between the outer circumference of the rotor shaft 8 and the inner surfaces of the ring segments 100, so that the rotor shaft 8 can then rotate essentially frictionlessly inside the ring segments 100.This means that, to adjust the valve element 18g between its two switching positions, the drive motor is preferably moved by the control device 17 at a lower speed than the speed at which the impeller 14 rotates during operation. To move the valve element 18g back and forth, the drive motor can be driven in two directions of rotation as described above, whereby, once the desired switching position is reached, a rapid increase in speed, as described above, ensures that the valve element 18g remains in the previously reached switching position due to the pressure in the pressure chamber 26 and its contact with the bottom of the pump housing 12.

[0049] In the ninth and tenth embodiments according to Figs. 29 to 37In figures 38 to 47, a mechanical coupling is also provided between the drive motor and the valve element. In these embodiments, the drive motor can be controlled by the control unit 17 in two different operating modes. In a first operating mode, which corresponds to the normal operation of the circulation pump unit, the drive motor rotates in the conventional manner at a desired speed, which can be set, in particular, by the control unit 17. In the second operating mode, the drive motor is controlled in open-loop operation, so that the rotor can be rotated stepwise in individual angular increments of less than 360°. Thus, the drive motor can be moved in individual steps, similar to a stepper motor. In these embodiments, this is used to move the valve element precisely in small angular increments to a defined position, as described below.

[0050] In the ninth embodiment according to Figs. 29 to 37 The pump housing 2 incorporates a mixing valve, which can be used, for example, to adjust the temperature of underfloor heating.

[0051] The motor housing 2 with the electronics housing 16 corresponds to the previously described design. The pump housing 12 is essentially constructed in the same way as the pump housing according to the first embodiment. Figs. 1 to 6Only the external configuration differs. In this ninth embodiment, the valve element 18h is also drum-shaped and consists of a pot-shaped lower part 76h, which is closed on its side facing the impeller 14 by a cover 78h. A suction opening 36 is formed in the central area of ​​the cover 78h. The valve element 18h is rotatably mounted on an axis 20, which is located in the base of the pump housing 12. As in the examples described above, the axis of rotation of the valve element 18h corresponds to the axis of rotation X of the rotor shaft 8h. The valve element 18h is also axially displaceable along the axis X and is held in position by a spring 48. Fig. 33The rest position shown is pressed, in which the valve element 18h is in a released position, in which the lower part 76h does not rest against the bottom of the pump housing 12, so that the valve element 18h is essentially free to rotate about the axis 20. In the released position, the end face of the rotor shaft 8h, which is designed as a coupling 108, acts as an axial stop. The coupling 108 engages with a mating coupling 110, which is arranged non-rotatably on the valve element 18h. The coupling 108 has chamfered coupling surfaces which, along a circumferential line, essentially describe a sawtooth profile such that torque transmission from the coupling 108 to the mating coupling 110 is only possible in one direction of rotation, namely in the direction of rotation A. Fig. 31In the opposite direction of rotation B, the clutch slips, resulting in axial movement of the valve element 18h. Direction of rotation B is the direction in which the pump unit is driven during normal operation. Direction of rotation A, on the other hand, is used for the targeted adjustment of the valve element 18h. This means that a direction-dependent clutch is designed here. Additionally, in this embodiment as well, the counter-clutch 110 disengages from the clutch 108 due to the pressure in the pressure chamber 26. If the pressure in the pressure chamber 26 increases, a compressive force acts on the cover 78h, which opposes and exceeds the spring force of the spring 48, so that the valve element 18h is pressed into the closed position, which is in Fig. 32As shown, the lower part 76h rests against the bottom side of the pump housing 12, so that on the one hand the valve element 18h is held in a force-fit manner and on the other hand a tight system is achieved which seals the pressure and suction sides against each other in the manner described below.

[0052] The pump housing 12 has two suction ports 32 and 34, of which suction port 32 opens into an inlet 28h and suction port 34 into an inlet 30h in the base of the pump housing 12, i.e., into the suction chamber 24. The lower part 76h of the valve element 18h has an arc-shaped opening 112 in its base, which extends substantially over 90°. Fig. 34Figure 1 shows a first switching position in which the opening 112 merely covers the inlet 30h, so that a flow path exists only from the suction port 34 to the suction opening 36 and thus to the suction mouth 38 of the impeller 14. The second inlet 28h is tightly closed by the base of the valve element 18h, which rests against its circumference. Fig. 36 The second switching position is shown, in which the opening 112 only covers the inlet 28h, while the inlet 30h is closed. In this switching position, only one flow path is open, from the suction port 32 to the suction nozzle 38. Fig. 35The diagram now shows an intermediate position in which opening 112 covers both inlets 28h and 30h, with inlet 30h only partially open. By changing the degree to which inlet 30h is open, the mixing ratio between the flows from inlets 28h and 30h can be altered. The valve element 18h can also be adjusted in small steps by gradually moving the rotor shaft 8h to change the mixing ratio.

[0053] Such functionality can be found, for example, in a hydraulic system, such as those found in Fig. 37The centrifugal pump unit with the integrated valve, as described above, is shown in the diagram. The hydraulic circuit has a heat source 114, for example a gas boiler, whose outlet leads to, for example, the suction port 34 of the pump housing 12. In this example, a floor heating circuit 116 is connected to the pressure port 37 of the centrifugal pump unit 1, the return of which is connected to both the inlet of the heat source 114 and the suction port 32 of the centrifugal pump unit. A second circulation pump unit 118 can supply another heating circuit 120 with a heat transfer fluid that has the outlet temperature of the heat source 114.The underfloor heating circuit 116, on the other hand, can have its flow temperature regulated in such a way that cold water from the return is mixed with the hot water on the outlet side of the heat source 114, whereby the mixing ratio can be changed by rotating the valve element 18h by changing the opening conditions of the inlets 28h and 30h in the manner described above.

[0054] The tenth embodiment according to Figs. 38 to 47 The diagram shows a centrifugal pump unit which, in addition to the mixing functionality described above, also has a switching functionality for the additional supply of a secondary heat exchanger for domestic hot water heating.

[0055] The bearing and drive of the valve element 18i are carried out in this embodiment in the same way as in the ninth embodiment. In contrast to the valve element 18h, the valve element 18i has, in addition to the opening 112, a through-channel 122 which extends from an opening 124 in the cover 78i to an opening in the base of the lower part 76i and thus connects the two axial ends of the valve element 18i. Furthermore, the valve element 18i also has an arc-shaped bridging opening 126, open only towards the underside, i.e., towards the base of the lower part 76i and thus towards the suction chamber 24, which is closed towards the pressure chamber 26 by the cover 78i.

[0056] 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. Port 128 opens into the suction chamber 24 via an inlet 130 in the base of the circulating pump unit 12, in addition to inlets 28h and 30h. Based on the Figs. 43 to 46 The different switching positions are explained, with the cover 78i of the valve element 18i shown partially open in these figures to illustrate the position of the openings underneath. Fig. 43 This shows a first switching position in which the opening 112 is opposite the inlet 30h, so that a flow connection is established from the suction port 34 to the suction opening 38 of the impeller 14. In the switching position according to Fig. 44The opening 112 is located above the inlet 130, thus creating a flow connection from the connection 128 to the suction opening 36 and via this to the suction mouth 38 of the impeller 14. In a further switching position, which Fig. 45 As shown, opening 112 lies above inlet 30h, thus establishing a flow connection from suction port 34 to the suction opening 38 of the impeller 14. Simultaneously, opening 124 and through-hole 122 partially overlap inlet 28h, creating a connection between pressure chamber 26 and suction port 32, which here functions as a pressure port. At the same time, bridging opening 126 covers inlet 130 and part of inlet 28h, thus also creating a connection from port 128 via inlet 130, bridging opening 126, and inlet 28h to port 32.

[0057] Fig. 46This shows a fourth switching position in which the through channel 122 completely covers input 28h, so that connection 32 is connected to pressure chamber 26 via the through channel 122 and the opening 124. At the same time, the bridging opening 126 only covers input 130. The opening 112 continues to cover input 30h.

[0058] Such a centrifugal pump unit can be used, for example, in a heating system, as is the case in Fig. 47 The dashed line defines the centrifugal pump unit 1, as shown by the... Figs. 38 to 46The heating system has a primary heat exchanger or heat source 114, which can be, for example, a gas boiler. On the outlet side, the flow path leads to a first heating circuit 120, which can consist of conventional radiators, for example. Simultaneously, a flow path branches off to a secondary heat exchanger 56 for heating domestic hot water. The heating system also has an underfloor heating circuit 116. The return lines of the heating circuit 120 and the underfloor heating circuit 116 open into the suction port 34 on the pump housing 12. The return line from the secondary heat exchanger 56 opens into the connection 128, which, as described below, offers two functionalities. The connection 32 of the pump housing 12 is connected to the supply line of the underfloor heating circuit 116.

[0059] If the valve element 18i is in the first in Fig. 43In the switching position shown, the impeller 14 pumps fluid 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. If the valve element 18i is in the second switching position, which is shown in Fig. 44 As shown, the system is switched to domestic hot water operation. In this state, the pump unit or impeller 14 pumps liquid from connection 128, which serves as the suction connection, through pressure connection 27, via the heat source 114, through the secondary heat exchanger 56, and back to connection 128. If the valve element 18i is in the third switching position, which is shown in Fig. 45As shown, the underfloor heating circuit 116 is also supplied. Water flows through the suction port 34 into the suction inlet 38 of the impeller 14 and is conveyed through the first heating circuit 120 via the heat source 114 and the pressure port 27 as described. Simultaneously, the fluid exits the pressure chamber 26 of the impeller 14 into the opening 124 and through the passage 122, flowing to the connection 32 and then into the underfloor heating circuit 116.

[0060] In the Fig. 45In the switch position shown, fluid simultaneously flows through the bypass opening 126, via port 128 and inlet 130, into port 32. This means that water flows from the heat source 114 through the secondary heat exchanger 26 and port 128 to port 32. Since essentially no heat is drawn from the secondary heat exchanger 56 during this heating operation, hot water is mixed into port 32 in addition to the cold water flowing from the pressure chamber 26 through the through channel 122 to port 32. The amount of hot water mixed into port 32 can be varied by changing the valve opening via position 18i. Fig. 46Figure 1 shows a switching position in which the mixing is switched off and connection 32 is exclusively in direct contact with the pressure chamber 26. In this state, the water in the underfloor heating circuit 116 is circulated without heat input. It can be seen that, by changing the switching positions of the valve element 18i in this embodiment, both switching between heating and domestic hot water heating can be achieved, as well as simultaneously supplying two heating circuits with different temperatures: a first heating circuit 120 with the output temperature of the heat source 114 and an underfloor heating circuit 116 with a temperature reduced by a mixing function.

[0061] It is understood that the various embodiments described above can be combined with one another in different ways. For example, the different described drive types of the valve element can be combined with various geometric configurations of the valve element, as also described above, essentially at will. Likewise, the various valve functionalities (for example, mixing and switching) can also be implemented and combined with different drive types. These various combination possibilities, which result from the preceding exemplary embodiments, are therefore expressly included in the invention. In all illustrated exemplary embodiments, the valve element is arranged directly in the pump housing; that is, the pump housing forms a combined pump and valve housing.However, it is understandable that the pump housing could also be designed in multiple parts. In particular, the valve element could also be arranged in a housing separate from the pump housing, which is connected to the pump housing, in which the impeller rotates, only via suitable connecting channels or pipes. Reference symbol list

[0062] 1 Centrifugal pump unit 2 Motor housing 4 Stator 6 Rotor 8 Rotor shaft 10 Slotted tube 12 Pump housing 14 Impeller 16 Electronic housing 17 Control unit 18, 18', 18", 18c, 18d, 18e, 18f, 18g, 18h, 18i Valve element 20 Shaft 22 Nut 24 Suction chamber 26 Pressure chamber 27 Pressure connection 28, 30 Inlets 28', 30', 28h, 30h Inlets 32, 34 Suction connections 36, 36', 36e Suction opening 38 Suction nozzle 40 Sealing surfaces 42 Support elements 44 Stop element 46 Stops 48 Spring 50 System shoulder 52 Heat source 54 Heating circuit 56 Secondary heat exchanger 58, 60 Flow paths 62 Opening 64 Projection 66 Hole 68 Pin 70 Groove 72 Projections 74 Tenon 76, 76b, 76dm 76h, 76i Lower part 78, 78d, 78h, 78i Cover 80 Inlet opening 82,84 Sleeves 86 Guide wheel 88 Weight 90 Inlet opening 92 Sealing surfaces 94 Axle 96 Tongue 98 Pressure connection 100 Ring segment 102 Tension ring 104 Projection 106 Passage 108 Coupling 110 Counter coupling 112 Opening 114 Heat source 116 Underfloor heating circuit 118 Circulating pump unit 120 Heating circuit 122 Passage channel 124 Opening 126 Bridging opening 128 Connection 130 Inlet X Rotation axis A, B Directions of rotation,

Claims

1. A centrifugal pump assembly having an electric drive motor (4, 6), an impeller (14) which is driven by this drive motor and also at least one valve element (18) which can directly or indirectly be moved by the electric drive motor (4, 6) along a first movement path between at least two switching positions, characterized in that at least a part of the valve element (18) can additionally be moved along a second movement path, which is different from the first movement path, between a released position, in which the valve element is spaced from at least one bearing surface, and a bearing position, in which the valve element bears against the at least one bearing surface, wherein it is pushed against the bearing surface such that the friction between valve element and bearing surface is greater than in the released position, and the movement along the first movement path is suppressed.

2. The centrifugal pump assembly according to Claim 1, characterized in that the at least one valve element (18) is mechanically and / or hydraulically coupled with the drive motor (4, 6) in such a manner that it can be moved along the first and / or the second movement path by means of the drive motor (4, 6).

3. The centrifugal pump assembly according to Claim 1 or 2, characterized in that the second movement path runs transversely to the first movement path or transversely to a plane in which the second movement path extends.

4. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) can be rotated along the first movement path about an axis of rotation (X), wherein the axis of rotation (X) preferably extends parallel to or along the axis of rotation (X) of the impeller (14).

5. The centrifugal pump assembly according to Claim 4, characterized in that the at least one valve element (18) is mounted in a rotatable manner such that, in the released position, it can be rotated about a bearing and in particular a central bearing between the at least two switching positions and preferably, in the second bearing position, is held on the bearing surface in a rotationally fixed manner.

6. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the second movement path is a straight line (X).

7. The centrifugal pump assembly according to any one of Claims 4 to 6, characterized in that the second movement path runs parallel to or along the axis of rotation (X) of the at least one valve element (18).

8. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one bearing surface is a sealing surface.

9. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) has a pressure surface which is connected to a pressure side (26) of the impeller (14) in such a manner that a pressure prevailing on the pressure side (26) acts on the pressure surface and thus generates a pressure force acting on the valve element (18), wherein the pressure surface is located such that the pressure force is directed at least partially along the second movement path of the valve element (18) and in particular is directed along the second movement path towards the bearing position.

10. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) is coupled with at least one restoring element (48), particularly a restoring spring, which exerts a restoring force on the valve element (18) along the second movement path, particularly towards the released position.

11. The centrifugal pump assembly according to any one of the preceding claims, characterized by a force generating means which exerts a force on the valve element in the direction of one of the switching positions, wherein the force is preferably a spring force, a magnetic force and / or gravity.

12. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) is configured in such a manner that it can be moved along the first movement path by a fluid flow that is set moving by the impeller (14).

13. The centrifugal pump assembly according to Claim 12, characterized in that it is configured in such a manner that the impeller (14) generates differently directed fluid flows depending on its direction of rotation, by means of which fluid flows the at least one valve element (18) can be moved in opposite directions along the first movement path.

14. The centrifugal pump assembly according to any one of the preceding claims, characterized in that it has a control device (17) which activates the electric drive motor (4, 6) in such a manner that the rotational speed and / or direction of rotation of the drive motor (4, 6) is variable.

15. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) can be moved along the first movement path by a flow generated by the impeller (14) and can be moved along the second movement path by a fluid pressure generated by the impeller (14) and the drive motor (4, 6) preferably has a control device (17) which is configured in such a manner that the drive motor (4, 6) can be started with a first acceleration curve, in which the pressure builds up faster than the flow, and with a second acceleration curve, in which the flow builds up faster than the pressure.

16. The centrifugal pump assembly according to any one of the preceding claims, characterized in that, the at least one valve element (18), for its movement along the first movement path, is coupled by means of a coupling with the impeller (14) or a shaft (8) of the drive motor (4, 6), which drives the impeller (14), which coupling is preferably releasable in a pressure- and / or rotational-speed- and / or direction-of-rotation-dependent manner.

17. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) is formed and arranged in such a manner that, in a pump housing (12) surrounding the impeller (14), it separates a suction chamber (24), which is connected to a suction side (24) of the impeller (14), from a pressure chamber (26), which is connected to a pressure side of the impeller (14).

18. The centrifugal pump assembly according to any one of the preceding claims, characterized in that the at least one valve element (18) is formed and arranged in such a manner that, in a pump housing (12) surrounding the impeller (14), it separates a suction chamber (24), which is connected to a suction side of the impeller (14), from a pressure chamber (26), which is connected to a pressure side of the impeller (14), wherein, in the pressure chamber (26), a flow generated by the impeller (14) acts on the valve element (18) for the movement thereof along the first movement path and the suction chamber (24) is configured in such a manner that the flow prevailing there exerts no force on the valve element (18) in the direction of the first movement path.

19. The centrifugal pump assembly according to any one of the preceding claims, characterized in that it has at least two alternative flow paths, wherein the at least one valve element (18) is arranged in these flow paths in such a manner that these flow paths are opened differently in the at least two switching positions.

20. The centrifugal pump assembly according to Claim 19, characterized in that the two flow paths are located on the suction side of the impeller (14).