EP3376037B1 - Centrifugal pump assembly - Google Patents

Description

The invention relates to a hydraulic structural unit with a centrifugal pump unit and at least one valve element which can be moved by a flow of liquid caused by the centrifugal pump unit.

Hydraulic assemblies with centrifugal pump units are known which have valve elements which are moved by the flow in the pump unit. Centrifugal pump units are known in which the flow inside the pump housing can be directed in two different directions by reversing the direction of rotation of the drive motor, so that a switching element can be moved between two outputs or two inputs of the centrifugal pump unit in order to selectively flow through one of these promote. Disadvantages of these known centrifugal pump units are relatively complex mechanics or the occurrence of efficiency losses due to the switching elements required in the flow path or the required reversal of the direction of rotation. Such centrifugal pump units are for example from U.S. 5,924,432 , DE 44 18 153 A1 , EP 0 394 140 A1 and EP 1 403 521 A1 known.

With regard to this problem, the object of the invention is to improve a hydraulic unit with a centrifugal pump unit and a valve element that can be moved via the flow generated by the centrifugal pump unit in such a way that reliable actuation of the valve element with a simple construction of the valve element and a high degree of efficiency is possible .

This object is achieved by a hydraulic assembly with the features specified in claim 1. Preferred embodiments emerge from the subclaims, the following description and the attached figures.

The hydraulic assembly according to the invention has a centrifugal pump unit which has an electric drive motor and at least one impeller which is driven in rotation by this. The electric drive motor is preferably a wet-running motor, that is to say a drive motor with a can or can between the stator and the rotor, so that the rotor can rotate in the liquid to be conveyed. In addition to this centrifugal pump unit, the hydraulic assembly according to the invention has at least one valve element which is arranged and configured such that it can be moved by a fluid flow caused by the impeller, in particular between at least two different switching positions. In addition to the centrifugal pump unit and the valve element, the hydraulic structural unit preferably includes at least those flow channels or flow paths that are required for connecting the centrifugal pump unit to external elements, for example pipelines of a heating circuit. More preferably, the hydraulic unit comprises at least some of the flow paths that are required for the connection between the centrifugal pump unit and the valve element, the valve element particularly preferably forming an integrated unit with the centrifugal pump unit. So z. B. the valve element in the pump housing, in which the impeller rotates, be arranged.

More preferably, the hydraulic unit is designed for use in a heating and / or air conditioning system, that is, the centrifugal pump assembly is preferably designed for use as a circulating pump assembly to use a liquid heat transfer medium such as in particular water to circulate in a circuit of a heating or air conditioning system. More preferably, the hydraulic unit can be designed as an integrated hydraulic unit for a heating system, in particular a compact heating system. Such integrated units usually include all essential flow paths and hydraulic components of the compact heating system. In particular, a secondary heat exchanger for heating domestic water can also be integrated into the hydraulic structural unit. Such a hydraulic assembly then essentially only has the connections for one or more heating circuits, for at least one heat source and, if necessary, an input for cold service water and an output for heated service water. Required valves, sensors and the centrifugal pump assembly are preferably integrated into the hydraulic structural unit, wherein at least some of the required flow paths can furthermore preferably be formed in one-piece cast components, in particular plastic injection molding.

According to the invention, at least a section of a wall delimiting a flow path in the hydraulic structural unit is designed to be movable. This is preferably a flow path through which the liquid conveyed by the centrifugal pump assembly flows. The liquid thus flows along the wall and thus also along the at least one movable section. This movable section of the wall is part of the valve element or is coupled or connected to the valve element for its movement. The movable wall can thus transmit force or kinetic energy directly to the valve element for its movement. The movable section is in turn movable by the liquid flow running along the wall. Thus, the liquid flow over the movable section of the wall can bring about a movement of the valve element coupled to this section of the wall. The transfer of kinetic energy from the flow to the movable section of the wall takes place according to the invention at least partially by means of frictional forces between the liquid flow and the wall. Particularly preferably, the entire force or energy transmission takes place by friction of the liquid flow on the movable section of the wall. Such a configuration has the advantage that essentially only a loss of energy is used for the movement of the valve element, which energy would occur in the interior of the flow path anyway due to the friction that occurs. Ideally, the surface of the movable section of the wall has a surface configuration or roughness which essentially does not deviate from the properties of the surfaces of the remaining wall of the flow path. Additional elements protruding into the flow and causing resistance are preferably not provided. Thus, essentially only the usual frictional losses occur on the movable section of the wall, and these can then be used to move the valve element. In this way, a very high degree of efficiency can also be achieved when the valve element is actuated, since hydraulic losses are minimized. In particular, after the movement of the valve element over the movable section of the wall, if it remains in an end position, essentially no additional flow losses occur during further operation of the centrifugal pump unit, as is the case, for example, with movable flaps or blades, which are used to move a valve element into the Current protrude that would be the case.

The valve element can be, for example, a switch valve or a mixing valve. The valve element is preferably movable between two switching positions or end positions, it being able to be moved back and forth between these end positions by the flow. The reversal of direction can be achieved, for example, by changing the direction of the flow, for example, by changing the direction of rotation of the impeller. Alternatively, an additional restoring element, for example a spring or a weight, could be provided which, when the flow is switched off, ensures that the valve element moves back into a predetermined starting position.

The at least one movable section of the wall is preferably arranged in such a way that it can be moved parallel to the liquid flow running along the wall. This means that the flow can flow along this movable section of the wall as it does on adjacent wall parts, without being more strongly decelerated or impaired by the movable section of the wall. The flow takes the movable section of the wall with it, preferably solely through frictional forces in the flow direction, and thus moves the coupled valve element.

The at least one movable section of the wall can delimit a flow path extending from the centrifugal pump unit on the pressure side or a flow path extending from the centrifugal pump unit on the suction side. For example, a flow flowing towards the centrifugal pump unit on the suction side or a flow flowing away from the centrifugal pump unit on the pressure side can move the movable section and thus the valve element. It is also possible to drive the valve element both via a flow on the pressure side of the centrifugal pump assembly and a flow on the suction side of the centrifugal pump assembly. In this case, two movable sections are provided in two flow paths, which are both part of the valve element or are coupled to the valve element to drive it.

As already described above, the movable section of the wall is preferably designed and arranged in such a way that it can be moved together with the at least one valve element due to energy loss caused by the frictional forces on the wall of the flow path. There are essentially no losses in efficiency due to the valve element and its actuating elements, which move the valve element via the flow.

According to a further preferred embodiment, the at least one section of the wall is rotatably mounted in a pump housing and preferably rotatably mounted together with the at least one valve element in the pump housing. The impeller rotates in the pump housing. The impeller generates a rotating flow in the circumferential area. If the section of the wall and preferably also the valve element are rotatable, this rotating flow can very easily be converted into a movement of the valve element, since the rotating flow can move the rotatably movable section of the wall in the direction of flow by frictional forces. The axis of rotation of the at least one movable section of the wall is particularly preferably aligned with the axis of rotation of the drive motor and the at least one impeller. More preferably, the axis of rotation of a rotatable valve element is also aligned with the axis of rotation of the drive motor and the impeller.

The at least one movable section of the wall is expediently designed in such a way that the frictional forces acting on it through the liquid flow are greater than those frictional forces that occur in a bearing or the bearings of the movable section of the wall and the at least one valve element. This can be achieved, for example, by a correspondingly large surface area of the movable section of the wall will. The surface of the movable wall could also be structured in order to cause greater friction. It is essential that the design is such that the forces transmitted by the flow to the movable wall section are greater than the holding or frictional forces which act on the movable section of the wall and the at least one valve element. A movement of the valve element can thus be caused by the flow. In order to generate the greatest possible torque on a rotatable valve element, it is preferred to space at least part of the surface of the movable section as far as possible from an axis of rotation in order to generate the greatest possible torque. The movable section of the wall particularly preferably has a disk-shaped and, in particular, circular outer contour, the outer diameter of the disk preferably being at least as large as the diameter of the impeller in the pump housing.

According to the invention, a movable separating element is provided which separates a suction chamber inside a pump housing of the centrifugal pump unit from a pressure chamber surrounding the impeller, a surface facing the pressure chamber and / or a surface of the separating element facing the suction chamber forming or having the at least one movable section of the wall . Thus, the separating element can preferably be rotatable about an axis of rotation which is aligned with the axis of rotation of the impeller. More preferably, the separating element is formed directly from the valve element, that is, the separating element is part of the valve element. A direct drive of the valve element on a surface of the valve element which forms the movable section of the wall in the flow path can thus be caused.

More preferably, the separating element surrounds a suction mouth of the impeller in the shape of a ring, wherein the separating element can have a central opening which is aligned with the suction mouth, in particular is in sealing engagement therewith. The separating element thus forms a conventional deflector plate between the suction chamber and pressure chamber of the pump unit and is simultaneously movable in order to be able to drive the valve element when the separating element is moved by the flow acting on it or the flow flowing along it.

The valve element is preferably rotatably mounted on a central bearing, the axis of rotation of the valve element, as described, preferably extending in alignment with the axis of rotation of the drive motor. The central bearing has the advantage that the bearing diameter can be made very small, so that the friction losses on the bearing surfaces can be minimized. If the movable section of the wall is part of the valve element, it can also be located radially outside the bearing, preferably at a radial distance from the bearing, so that a greater torque for moving the valve element is caused by the flow acting on the movable section.

More preferably, the valve element can be moved between at least two switching positions, it being possible for these switching positions to be limited or defined by stops, for example. However, it is also conceivable that the valve element can assume more than two switching positions. According to a first embodiment of the invention, the valve element can act as a switchover valve between two flow paths, a first flow path then being opened and a second flow path being closed in a first switching position. Conversely, in a second switching position, the first flow path is closed and the second flow path is open. According to a In the second embodiment of the invention, the valve element can alternatively or additionally act as a mixing valve.

The valve element can preferably interact with at least two valve openings of two flow channels in such a way that the valve openings of the flow channels are opened differently depending on the switching position of the valve element. In the case of a switching valve, this means that the valve openings are either completely closed or completely open. When designed as a mixing valve, intermediate positions are also possible in which the valve openings are only partially open. When using the mixing valve, the valve element is preferably designed in such a way that, when it moves, it further closes one of the valve openings and at the same time further opens the other valve opening. This is preferably done to the same extent. It can be achieved in a particularly simple manner in that a one-piece valve element is provided which can cover both valve openings. According to the invention, however, a valve element is also to be understood as an arrangement of two valve elements which are coupled to one another in a suitable manner for common movement.

More preferably, the at least two valve openings each span a surface which extends parallel to a direction of movement of the valve element between the at least two switching positions. That is to say, the valve element for opening and closing the valve openings is preferably moved parallel to these or the surfaces spanned by the valve openings and is not moved closer to and away from the valve openings for opening and closing. This enables a very simple structural design of two valve openings to be opened and closed alternately by a valve element. Furthermore, preferably acts on the The pressure prevailing in the valve openings is not in the direction of movement of the valve element.

More preferably, the valve element is designed and arranged in such a way that it can be moved between at least two switching positions by the flow of liquid along a first movement path or a first movement path and, additionally, along a second movement path or along a second movement path as a result of a pressure generated by the impeller Force can be applied or moved, wherein the second movement path is angled to the first movement path. This enables the change between the switching positions to be carried out with very little friction, since in this state the valve element preferably does not rest against the necessary valve seats and / or contact surfaces or against these with relatively little friction. The pressure can apply force to the valve element in such a way that it comes into contact with the valve seats or is pressed against the valve seats and / or contact surfaces with greater force in a sealing manner. In this state, greater friction or holding force then occurs between the valve element and the valve seats or further contact surfaces, which can simultaneously serve to hold the valve element in the switching position that has been reached.

Thus, the valve element is preferably movable along the second movement path between a first released position in which the valve element can be moved between the at least two switching positions and an adjacent position in which it is in contact with at least one contact surface. This is to be understood as meaning that in the first position the valve element can optionally also rest against the contact surface, but in such a way that it can slide along the contact surface with relatively little friction. In the second position, however, the valve element is pressed against the contact surface in such a way that a stronger one Friction occurs between the valve element and the system, which generates a holding force which prevents further movement of the valve element over the liquid flow, as described above. Such a configuration makes it possible to move the valve element by appropriate drive of the drive motor and formation of a liquid flow, as long as such a liquid pressure is not reached that presses the valve element into contact with the contact surface. Such a pressure can be achieved by increasing the speed and, in particular, by increasing the speed of the drive motor very quickly, so that the valve element can then be specifically held in a switching position that has been reached. The pressure at which the valve element comes to rest on the contact surface is preferably selected such that it is lower than the lowest operating pressure during normal operation of the centrifugal pump assembly. The pressure can be adjusted by a return element such as a return spring, which is arranged to move the valve element into the released first position at a lower pressure.

The valve element and the contact surface are preferably designed in such a way that they come into force and / or form-fitting engagement with one another in the adjacent position, whereby a greater force can preferably be transmitted via this engagement than between the liquid flow and the at least one movable section of the wall. This ensures that the valve element, when it is in contact with the contact surface, is held in the switching position that has been reached and cannot be moved further by the flow of liquid. The liquid flow can then continue to flow along the movable section of the wall, this no longer being moved along with it.

Fig. 1

eine Explosionsansicht eines Kreiselpumpenaggregates gemäß einer ersten Ausführungsform der Erfindung,

Fig. 2

eine perspektivische Ansicht der Unterseite des Ventilelementes des Kreiselpumpenaggregates gemäß Fig. 1,

Fig. 3

eine perspektivische Ansicht des Pumpengehäuses des Kreiselpumpenaggregates gemäß Fig. 1 im geöffneten Zustand,

Fig. 4

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 1,

Fig. 5

eine Schnittansicht des Pumpengehäuses des Kreiselpumpenaggregates gemäß Fig. 4 mit dem Ventilelement in einer ersten Schaltstellung,

Fig. 6

eine Schnittansicht entsprechend Fig. 5 mit dem Ventilelement in einer zweiten Schaltstellung,

Fig. 7

schematisch den hydraulischen Aufbau mit einer Heizungsanlage mit einem Kreiselpumpenaggregat gemäß Fig. 1 bis 6,

Fig. 8

eine Explosionsansicht eines Kreiselpumpenaggregates gemäß einer zweiten Ausführungsform der Erfindung,

Fig. 9

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 8 mit dem Ventilelement in einer ersten Position,

Fig. 10

eine Schnittansicht entsprechend Fig. 9 mit dem Ventilelement in einer zweiten Position,

Fig. 11

eine Explosionsansicht eines Kreiselpumpenaggregates gemäß einer dritten Ausführungsform der Erfindung,

Fig. 12

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 11 mit dem Ventilelement in einer ersten Position,

Fig. 13

eine Schnittansicht entsprechend Fig. 12 mit dem Ventilelement in einer zweiten Position,

Fig. 14

eine Explosionsansicht eines Pumpengehäuses mit einem Ventilelement gemäß einer vierten Ausführungsform der Erfindung,

Fig. 15

eine Schnittansicht eines Kreiselpumpenaggregates gemäß der vierten Ausführungsform der Erfindung,

Fig. 16

eine Explosionsansicht eines Kreiselpumpenaggregates gemäß einer fünften Ausführungsform der Erfindung,

Fig. 17

eine Schnittansicht des Kreiselpumpenaggregates gemäß Fig. 16 mit dem Ventilelement in einer ersten Position, und

Fig. 18

eine Schnittansicht entsprechend Fig. 17 mit dem Ventilelement in einer zweiten Position.

The invention is described below by way of example with reference to the accompanying figures. In this shows:

Fig. 1

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

Fig. 2

a perspective view of the underside of the valve element of the centrifugal pump assembly according to FIG Fig. 1 ,

Fig. 3

a perspective view of the pump housing of the centrifugal pump assembly according to FIG Fig. 1 when open,

Fig. 4

a sectional view of the centrifugal pump assembly according to Fig. 1 ,

Fig. 5

a sectional view of the pump housing of the centrifugal pump assembly according to Fig. 4 with the valve element in a first switching position,

Fig. 6

a sectional view accordingly Fig. 5 with the valve element in a second switching position,

Fig. 7

schematically the hydraulic structure with a heating system with a centrifugal pump unit according to Figs. 1 to 6 ,

Fig. 8

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

Fig. 9

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 unit 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. 12 with 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 unit according to the fourth embodiment of the invention,

Fig. 16

an exploded view of a centrifugal pump unit 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, and

Fig. 18

a sectional view accordingly Fig. 17 with the valve element in a second position.

The exemplary 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 the centrifugal pump unit circulates a liquid heat transfer medium, in particular water.

The centrifugal pump unit according to the first embodiment of the invention has a motor housing 2 in which an electric drive motor is arranged. This 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 space which is separated from the stator space in which the stator 4 is arranged by a can or can 10. This means that 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 an impeller 14 that is non-rotatably connected to the rotor shaft 8 rotates.

At the axial end of the motor housing 2 opposite the pump housing 12, an electronics housing 16 is arranged, which contains control electronics or a control device 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 in a corresponding manner.

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 inside the pump housing 12, specifically 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 fixed in a rotationally fixed manner on the bottom of the pump housing 12. 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 In one direction, this linear mobility is limited by the pump housing 12 on which the valve element 18 strikes with its outer circumference. In the opposite direction, the mobility is limited by the nut 22 with which the valve element 18 is attached to the axis 20. It is to be understood that instead of the nut 22, another axial fastening of the valve element 18 on the axis 20 could also be selected.

The valve element 18 forms a separating element which 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 connection or pressure connection 28 of the centrifugal pump assembly, which forms the outlet of the centrifugal pump assembly. Two intake-side inlets 28 and 30 open into the suction chamber 24, of which the inlet 28 is connected to a first suction connection 32 and the inlet 30 is connected to a second suction connection 34 of the pump housing 12.

The valve element 18 is disc-shaped and at the same time assumes the function of a conventional deflector plate which separates the suction chamber 24 from the pressure chamber 26. That is, it serves to guide the flow in the area of the pressure chamber and forms part of the wall of the pressure chamber 26. The valve element 18 has a central suction opening 36 which has a protruding circumferential collar which engages with the suction mouth 38 of the impeller 14 and is essentially in tight contact with the suction mouth 38. Facing the impeller 14, the valve element 18 is essentially smooth. On the side facing away from the impeller 14, the valve element has two ring-shaped sealing surfaces 40 which, in this exemplary embodiment, are located on closed tubular connections. The two annular sealing surfaces 40 are at two diametrically opposite positions on the sealing element 18 with respect to it Axis of rotation X arranged so that they can come into tight contact with the bottom of the pump housing 12 in the circumferential area of the inlets 28 and 30 in order to close the inlets 28 and 30. In an angular position offset by 90 ° to the sealing surfaces 40, support elements 42 are arranged, which can also come to rest on the circumferential area of the inlets 28, 30, but are spaced from one another so that they then do not close the inlets 28, 30. The inputs 28 and 30 do not lie on a diameter line with respect to the axis of rotation X, but on a radially offset straight line, so that when the valve element 18 is rotated about the axis of rotation X in a first switching position, the input 38 is closed by a sealing surface 40, while the support elements 42 lie at the input 30 and open it. In a second switching position, the inlet 30 is closed by a sealing surface 40, while the support elements 42 rest in the circumferential area of the inlet 28 and open it. The first switching position, in which the input 38 is closed and the input 30 is open, is in FIG Fig. 5 shown. The second switching position, in which the input 30 is closed and the input 28 is open, is in FIG Fig. 6 shown. This means that by rotating the valve element by 90 ° around the axis of rotation X, it is possible to switch between the two switching positions. The two switch positions are limited by a stop element 44 which alternately strikes two stops 46 in the pump housing 12.

In a rest position, that is, when the centrifugal pump unit is not in operation, a spring 48 pushes the valve element 18 into a released position in which the outer circumference of the valve element 18 is not close to the pump housing 12 and the sealing surfaces 40 are not close to the circumference of the inlets 28 and 30 rest so that the valve element 18 can rotate about the axis 20. If the drive motor is now set in rotation by the control device 17 in the electronics housing 16, so that the impeller 14 rotates, the pressure chamber 26 generates a circulating flow which, via friction on the end face of the valve element 18, rotates the valve element along in the direction of rotation of the flow. The valve element 18 thus forms a movable section of the wall of the pressure chamber 26, which is moved along by the flow. The control device 17 is designed so that it can optionally drive the drive motor in two directions of rotation. Thus, the valve element 18 can also be moved in two directions of rotation about the axis of rotation X depending on the direction of rotation of the impeller 14 via the flow set in rotation by the impeller 14, since the flow in the circumferential area of the impeller 14 always runs in its direction of rotation. The valve element 18 can thus be rotated between the two switching positions limited by the stops 46.

When the impeller 14 rotates at a sufficient speed, a pressure builds up in the pressure chamber 26, which on the surface of the valve element 18, which surrounds the suction opening 36, generates a pressure force that is opposite to the spring force of the spring 48, so that the valve element 18 is moved against the spring force of the spring 48 in the axial direction X in such a way that it comes into sealing contact with an annular contact shoulder 50 on the pump housing 12 on its outer circumference. At the same time, depending on the switching position, one of the sealing surfaces 40 comes to rest in a sealing manner around one of the inputs 28 and 30, so that one of the inputs 28, 30 is closed. The support elements 42 come to rest on the other inlet, so that this inlet remains open and a flow path is provided from this inlet 28, 30 to the suction opening 36 and from there into the interior of the impeller 14. As a result of the contact of the valve element 18 on the contact shoulder 50 and the sealing surface 40 in the peripheral area of one of the inlets 28, 30, a frictional contact between the valve element 18 and the pump housing 12 is created at the same time. This frictional contact ensures that the valve element 18 is held in the switch position that has been reached. This enables the drive motor to be taken out of operation again for a short time and put into operation again in the opposite direction of rotation without the valve element 18 being rotated. If the motor is switched off and started up again quickly enough, the pressure in the pressure chamber 26 does not decrease to such an extent that the valve element 18 can move again in the axial direction into its released position. This makes it possible to always drive the impeller during operation of the centrifugal pump unit in its preferred direction of rotation, for which the blades are designed, and to use the opposite direction of rotation only to move the valve element 18 in the opposite direction of rotation.

The centrifugal pump unit described according to the first embodiment of the invention can be used, for example, in a heating system as shown in FIG Fig. 7 is shown. Such a heating system is usually used in apartments or houses and is used to heat the building and to provide heated service water. The heating system has a heat source 52, for example in the form of a gas boiler. There is also a heating circuit 54 which, for example, leads through various radiators in a building. In addition, a secondary heat exchanger 56 is provided, via which domestic water can be heated. In heating systems of this type, a changeover valve is usually required, which directs the heat transfer medium 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. The control takes place by the control device 17 in the electronics housing 16. The heat source 52 is connected to the pressure connection 27 of the pump housing 12. A flow path 58 is connected to the suction connection 32, while a flow path 60 through the suction connection 34 is connected Heating circuit 54 is connected. 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 the need for a valve with an additional drive.

The second embodiment according to Figs. 8-10 differs from the first embodiment in the structure of the valve element 18 '. In this embodiment too, the valve element 18 'as a separating element separates the pressure chamber 26 from a suction chamber 24 of the pump housing 12 and forms a movable section of the flow-guiding wall of the pressure chamber 26. The valve element 18 has a central suction opening 36' into which the suction mouth 38 of the Impeller 14 engages sealingly. 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 optionally be made to coincide with one of the inlets 28, 30. The inlets 28 ', 30' in this exemplary embodiment differ in their shape from the inlets 28, 30 according to the previous embodiment. The valve element 18 ′ has a central projection 64 which engages in a central hole 60 in the bottom of the pump housing 12 and is mounted there to rotate about the axis of rotation X. At the same time, the projection 64 in the hole 66 also allows an axial movement along the axis of rotation X, which is limited in one direction by the bottom of the pump housing 12 and in the other direction by the impeller 14. On its outer circumference, the valve element 18 ′ has a pin 68 which engages in a semicircular groove 70 on the bottom 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 ', wherein in a first switching position the opening 62 is above the input 28' and in a second switching position the opening 62 is above the input 30 'and the other entrance is closed by the bottom of the valve element 18 '. The rotary movement of the valve element 18 ′ between the two switching positions also takes place in this exemplary embodiment by the flow caused in the pressure chamber 26 by the impeller 14. In order to transfer this even better to the valve element 18 ′, it is provided with projections 72 directed in the pressure chamber 26. When the centrifugal pump unit 1 is taken out of operation, the spring 48 presses the valve element 18 'into the in Fig. 10 shown released position, in which it does not rest on the ground in the circumference of the entrances 28 'and 30'. In this it abuts axially with a central pin 74 on the end face of the motor shaft 8 and is limited in its axial movement by this stop. When the pressure in the pressure chamber 26 is sufficiently high, the valve element 18 'is in the Fig. 9 Depressed position shown, in which the valve element 18 'comes to rest on the bottom of the pump housing 12 in the circumferential area of the inlets 28' and 30 'and at the same time 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 assembly.

The third embodiment according to Figures 11 to 13 shows a further possible embodiment of the valve element 18 ". This embodiment differs from the previous embodiments in the structure of the valve element 18". This is designed as a valve drum. The pump housing 12 essentially corresponds to the structure shown in FIG Figs. 1 to 6 , wherein in particular the arrangement of the inputs 28 and 30 corresponds to the arrangement described with reference to the first exemplary 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 the suction mouth 38 of the impeller 14 with its axially directed collar The cover 78 thus forms a movable section the flow-guiding walls of the pressure chamber 26. On the opposite side, the bottom of the lower part 36 has an inlet opening 80 which, depending on the switching position, is brought into congruence with one of the inlets 28, 30, while the other inlet 28, 30 passes through the bottom of the Lower part 26 is closed. The valve element 18 ″ is rotatably mounted on an axis 20 which is fastened in the bottom of the pump housing 12, the axis of rotation defined by the axis 20 corresponding to the axis of rotation X of the impeller 14. In this exemplary embodiment, too, the valve element 18 ″ can be axially displaced by a certain amount along the axis 20, a spring 48 being provided here as well, which in the rest position moves the valve element 18 ″ into its in Fig. 13 shown released position presses. This axial position is also limited by the nut 22 in this exemplary embodiment. In the released position, the valve element 18 ″, as described above, can be rotated by the flow caused by the impeller 14, that is, a hydraulic coupling is established between the impeller 14 and the valve element 18 ″. In the adjacent position, which is in Fig. 12 is shown, one of the inputs 28, 30 is tightly closed depending on the switching position. On the other hand, there is also a seal between the suction chamber 24 and the pressure chamber 26 through the contact of the valve element 18 ″ on the contact shoulder 50.

In this exemplary embodiment, the mounting of the valve element 18 ″ on the axle 20 is furthermore encapsulated by two sleeves 82 and 84, so that these areas are protected from contamination by the conveyed fluid and, if necessary, can be lubricated beforehand. The aim is to ensure that the mounting is as smooth as possible in order to ensure the easy rotatability of the valve element 18 ″ by the flow caused by the impeller 14. It is to be understood that the mounting could also be encapsulated accordingly in the other exemplary embodiments described here.

Fig. 14 and 15th show a fourth exemplary embodiment in which the structure of the pump housing 12 corresponds to the structure of the pump housing 12 according to the first and third exemplary embodiments. In this exemplary embodiment, the rotary movement of the valve element 18c is supported by the flow on the suction side, that is, the flow entering the suction mouth 38 of the impeller 14. In this embodiment too, 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 mouth 38, as described above. The lower part 76b shown here has two inlet openings 80 which, depending on the switching position, can be brought to overlap with one of the inputs 28, 30, the respective other input 28, 30 being tightly closed by the bottom of the lower part 46b, as in the previous one Embodiment has been described. Between the lower part 76b and the cover 78 there is arranged a stator 86 with blades, into which the flow enters radially from the inlet openings 80 and exits axially to the central suction opening 36. The stator 86 is a flow-guiding component which, with its walls, serves to guide the flow and can be moved along with the flow as a movable part of the flow-guiding walls. The blades of the stator 86 also generate a torque about the axis 20, by means of which the valve element 18c can be moved between the switching positions. This works essentially as described above. A spring 48, as described above, can also additionally be provided in order to move the valve element 18c into a released position. Since the shape of the blades of the stator 86 always generates a torque in the same direction, regardless of the direction in which the impeller 14 rotates, in this exemplary embodiment the return movement is effected by a weight 88. The centrifugal pump assembly is in operation always in the installation position, which in Fig. 15 is shown in which the axis of rotation X extends horizontally. When the centrifugal pump unit is switched off, the valve element 18c always rotates about the axis 20 so that the weight 88 is below. Due to the torque generated by the stator 86, the valve element 18c can be rotated against this restoring force generated by the weight 88, whereby by very quickly starting up the drive motor in the pressure chamber 26, a pressure can be built up so quickly that the valve element 18c is in its adjacent position occurs, as described above, in which it is held non-rotatably on the pump housing 12 without being moved out of its rest position. It is to be understood that resetting of the valve element by gravity or another resetting force could also be used in the other exemplary embodiments described here, independently of the drive.

The fifth embodiment according to Figures 16-18 again differs from the preceding exemplary embodiments in the construction 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, with a central suction opening 36 being formed in the cover 78d which engages with the suction mouth 38 of the impeller 14 in the manner described above. The cover 78d adjoins the pressure chamber 26 and there forms a movable section of the flow-guiding wall. In the conical circumferential surface of the lower part 76b, inlet openings 90 are formed, which, by rotating the valve element 18d with inlets which are connected to the suction connections 32 and 34, can optionally be brought to overlap in order to create a flow path through the interior of the valve element 18d to the suction opening 36 to manufacture. Between the inlet openings 90 are on the conical lower part sealing surfaces 92 formed which can close the other input. As also the embodiment 2 according to Figs. 8-10 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 there the valve element 18d rotates about the axis of rotation X. Here, too, there is an axial movement between a released position, as shown in Fig. 18 and an abutting position as shown in Fig. 17 shown is possible. In the released position, the lower part 76d of the valve element 18d does not essentially lie against the pump housing 12, so that it can be rotated by the flow in the pressure chamber 26, as was described in the exemplary embodiments described above. Here, depending on the direction of rotation of the impeller 14, a back and forth movement of the valve element 18d can again be achieved, the rotational movement of the valve element 18d being again limited by stops, not shown. In the adjacent position according to Fig. 17 on the one hand there is a tight fit of the valve element 18d, on the other hand it is held non-positively 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.

In the exemplary embodiments described, the pump housing 12 serves as a combined valve and pump housing which is in one piece is trained. It is to be understood, however, that the pump housing 12 could be designed in a corresponding manner in several parts.

List of reference symbols

1

Centrifugal pump unit

2

Motor housing

4th

stator

6th

rotor

8th

Rotor shaft

10

Can

12

Pump housing

14th

Wheel

16

Electronics housing

17th

Control device

18,18 ', 18 ", 18c, 18d

Valve element

20th

axis

22nd

mother

24

Suction chamber

26th

Printing room

27

Pressure connection

28, 30

Entrances

28 ', 30'

Entrances

32, 34

Suction connections

36, 36 '

Suction opening

38

Suction mouth

40

Sealing surfaces

42

Support elements

44

Stop element

46

attacks

48

feather

50

Contact shoulder

52

Heat source

54

Heating circuit

56

Secondary heat exchanger

58, 60

Flow paths

62

opening

64

head Start

66

hole

68

pen

70

Groove

72

Ledges

74

Cones

76, 76b, 76d

Lower part

78, 78d

cover

80

Inlet opening

82, 84

Pods

86

Idler

90

Weight

90

Inlet opening

92

Sealing surfaces

X

Axis of rotation

Claims (16)

1. A hydraulic construction unit with a centrifugal pump assembly which comprises an electrical drive motor (4, 6) as well as at least one impeller (14) which is driven by this, as well as with at least one valve element (18) which is arranged in a manner such that it is movable by way of a fluid flow which is created by the impeller (14),
   wherein
   at least one section (18; 78) of a wall delimiting a flow path in the hydraulic construction unit is designed in a movable manner,
   this movable section (18; 78; 86) of the wall is part of the valve element (18) or is connected to the valve element (18) for its movement, and
   this movable section (18; 78; 86) is movable in a manner at least partly effected by friction forces of the fluid flow running along the wall, characterised by a movable separating element (18; 78) which separates a suction chamber (24) in the inside of a pump casing (12) of the centrifugal pump assembly from a delivery chamber (26) which surrounds the impeller (14), wherein a surface of the separating element (18; 78) which faces the delivery chamber (26) and/or a surface of the separating element which faces the suction chamber (24) forms the at least one movable section of the wall.
2. A hydraulic construction unit according to claim 1, characterised in that the at least one movable section (18; 78; 86) of the wall is arranged in a manner such that it is movable parallel to the fluid flow which runs along the wall.
3. A hydraulic construction unit according to claim 1 or 2, characterised in that the at least one movable section (18; 78) of the wall delimits a flow path (26) which extends from the centrifugal pump assembly at the delivery side.
4. hydraulic construction unit according to one of the preceding claims, characterised in that the at least one movable section of the wall delimits a flow path (86) which extends from the centrifugal pump assembly (1) at the suction side.
5. A hydraulic construction unit according to one of the preceding claims, characterised in that the movable section (18; 78; 86) of the wall is designed and arranged in a manner such that it is movable together with the at least one valve element (18) by way of the energy loss which is caused by the frictional forces on the wall of the flow path.
6. A hydraulic construction unit according to one of the preceding claims, characterised in that the at least one section (18; 78; 86) of the wall is rotatably mounted in a pump casing (12) and preferably together with the at least one valve element (18) is rotatably mounted in the pump casing (12).
7. A hydraulic construction unit according to claim 6, characterised in that the at least one movable section (18; 78; 86) is designed in a manner such that the friction forces which act upon it by way of the fluid flow are larger than those friction forces which occur in a mounting of the movable section (18; 78; 86) and of the at least one valve element (18).
8. A hydraulic construction unit according to one of the preceding claims, characterised in that the separating element (18; 78) annularly surrounds a suction port (38) of the impeller (14).
9. A hydraulic construction unit according to one of the preceding claims, characterised in that the separating element (18; 78) is formed by the valve element (18).
10. A hydraulic construction unit according to claim 9, characterised in that the valve element (18) is rotatably mounted on a central bearing (20), wherein the rotation axis (X) of the valve element (18) extends in manner preferably aligned to the rotation axis (X) of the drive motor (4, 6).
11. A hydraulic construction unit according to one of the preceding claims, characterised in that the valve element (18) is movable between at least two switching positions.
12. A hydraulic construction unit according to one of the preceding claims, characterised in that the valve element (18) interacts with at least two valve openings (28, 30) of two flow channels in a manner such that the valve openings (28, 30) of the flow channels are opened to a different extent depending on the switching position of the valve element (18).
13. A hydraulic construction unit according to claim 12, characterised in that the at least two valve openings (28, 30) each span a surface which extends parallel to a movement direction of the valve element (18) between the at least two switching positions.
14. A hydraulic construction unit according to one of the preceding claims, characterised in that the valve element (18) is designed and arranged in a manner such that it is movable along a first movement path between at least two switching positions by way of the fluid flow and additionally can be subjected to force or is movable, along a second movement path, by way of a pressure which is produced by the impeller (14), wherein the second movement path runs in an angled manner to the first movement path.
15. A hydraulic construction unit according claim 14, characterised in that the valve element (18) is movable along the second movement path between a first released position, in which the valve element (18) is movable between the at least two switching positions, and a bearing position, at which it bears upon at least one contact surface.
16. A hydraulic construction unit according to claim 15, characterised in that valve element (18) and the contact surface are designed in a manner such that they non-positively and/or positively engage with one another in the bearing position, wherein preferably a greater force can be transmitted via this engagement than between the fluid flow and the at least one movable section (18; 78; 86) of the wall.

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