PUMP ASSEMBLY

Abstract

A pump assembly includes pump casing (2), an impeller (14) rotatably arranged in the pump casing, a two rotation directions (A, B) electrical drive motor connected to drive the impeller and a valve arrangement (28) arranged in the pump casing to switch a flow path downstream of the impeller between two exits (24, 26) of the pump casing, depending on a rotation direction of the impeller. The valve arrangement includes a first movable valve element (34) at a first exit (24) and a second movable valve element (36) at a second exit (26). The first valve element partly closes the first exit in a closed position and is movable into an opened position by flow in the first rotation direction and the second valve element partly closes the second exit in a closed position and is movable into an opened position by flow in the second rotation direction (B).

Claims

1. A pump assembly comprising: a pump casing; an impeller rotatably arranged in the pump casing; an electrical drive motor connected to the impeller for selectively driving the impeller in two rotation directions; and a valve arrangement arranged in the pump casing and configured to switch a flow path downstream of the impeller between two exits formed in the pump casing, depending on a rotation direction of the impeller, the valve arrangement comprising a first movable valve element at a first of the two exits and a second movable valve element at a second of the two exits, wherein the valve elements in an idle position are each located in a closed position, in which the first valve element at least partly closes the first exit, and the second valve element at least partly closes the second exit, and the first valve element is movable into an opened position by way of a flow caused by the impeller in a first rotation direction, and the second valve element is movable into an opened position by way of a flow caused by the impeller in a second rotation direction.

2. A pump assembly according to claim 1, wherein the first valve element and the second valve element are movable independently of one another.

3. A pump assembly according to claim 1, wherein the first valve element and the second valve element are each configured as a flap which is pivotable about a pivot axis, between the opened position and the closed position.

4. A pump assembly according to claim 3, wherein the first valve element and the second valve element are pivotable about the same pivot axis.

5. A pump assembly according to claim 1, wherein the first valve element and the second valve element are arranged to be in contact with one another when one of the valve elements is located in the opened position.

6. A pump assembly according to claim 1, wherein the first valve element and the second valve element each comprise an opening, which permits a flow passage into the respective associated first exit and second exit even in a closed position of the respective the first valve element and the second valve element.

7. A pump assembly according to claim 6, wherein the opening in the first valve element and the opening in the second valve element are arranged offset to one another such that the opening in the first valve element is closed by the second valve element and the opening in the second valve element is closed by the first valve element, when the first valve element and the second valve element are in contact with one another.

8. A pump assembly according to claim 1, wherein the valve arrangement further comprises at least one restoring element and the first valve element and the second valve elements are subjected to force by way of the at least one restoring element, such that given a standstill of the impeller the first valve element and the second valve elements are each held in the closed position, and the first valve element and the second valve element are subjected to force by the at least one common restoring element arranged between the valve elements.

9. A pump assembly according to claim 1, wherein the first valve element and the second valve elements are each configured elastically or rigidly.

10. A pump assembly according to claim 1, wherein: the first valve element and the second valve elements each have an elastic seal arranged thereon; or a valve seat is provided lying opposite the first valve element and a valve seat is provided lying opposite the second valve element; or the first valve element and the second valve elements each have an elastic seal arranged thereon and a valve seat is provided lying opposite the first valve element and a valve seat is provided lying opposite the second valve element.

11. A pump assembly according to claim 1, wherein the pump casing comprises a receiving opening situated between the two exits and which is open to an interior of the pump casing and into which the two valve elements are inserted from an outer side of the pump casing, wherein the two valve elements are preferably mounted in a valve insert which is inserted into the receiving opening.

12. A pump assembly according to claim 11, wherein the two exits are situated in the receiving opening.

13. A pump assembly according to claim 1, wherein the two exits comprise valve seats which face an interior of the pump casing and which lie opposite one another, wherein the valve seats are aligned essentially parallel to one another.

14. A pump assembly according to claim 13, wherein the valve elements each comprise a sealing surface which is provided for contact on a valve seat and which extends angled to a radius with respect to the pivot axis of the respective valve element.

15. A pump assembly according to claim 1, wherein the pump assembly is configured as a heating facility circulation pump assembly with the electrical drive motor comprising a wet-running drive motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the drawings:

[0033] FIG. 1 is a perspective total view of a pump assembly according to the invention;

[0034] FIG. 2 is an exploded view of the pump assembly according to FIG. 1;

[0035] FIG. 3 is a perspective plan view of the pump casing, with a removed valve insert;

[0036] FIG. 4 is a perspective view of the arrangement of the valve elements;

[0037] FIG. 5 is a perspective view of the open pump casing, wherein the valve elements are located in a valve element idle position;

[0038] FIG. 6A is a view according to FIG. 5, in which the first valve element is located in a first valve element opened position;

[0039] FIG. 6B is a view according to FIG. 5, in which the second valve element is located in a second valve element opened position;

[0040] FIG. 7 is a sectioned view of the pump assembly, in which the valve elements are located in the valve element idle position;

[0041] FIG. 8A is a sectioned view according to FIG. 7, wherein the first valve element is located in the first valve element opened position;

[0042] FIG. 8B is a sectioned view according to FIG. 7, wherein the second valve element is located in the second valve element opened position;

[0043] FIG. 9 is a schematic view of an arrangement of the valve elements in the pump casing, according to a second embodiment of the invention, wherein the valve elements are located in the closed position;

[0044] FIG. 10 is a schematic view of an arrangement according to FIG. 9, in which one of the valve elements is located in the opened position; and

[0045] FIG. 11 is a block diagram of a heating facility with a pump assembly according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Referring to the drawings, the pump assembly 1, which is represented in the figures, is configured as a circulation pump assembly with a wet-running electrical drive motor. The pump assembly 1 comprises a pump casing 2 which can be configured as a molded component of metal or plastic. The pump casing 2 comprises a suction connection 4 and two delivery branches 6 and 8. A motor or stator casing 10, in which the electrical drive motor is arranged, is applied onto the pump casing 2. An electronics housing 12, in which a control and regulation device for the control of the electrical drive motor is arranged, is arranged on the axial end of the stator casing 10 which is away from the pump casing 2.

[0047] As can be recognized in the exploded view according to FIG. 2, an impeller 14 which is connected to the rotor 16 of the electrical drive motor in a rotationally fixed manner is arranged in the inside of the pump casing 2. The rotor 16 is rotatably held in a bearing 18, which is fixed on a bearing plate 20 in the pump casing 2. The stator of the electrical drive motor is arranged in the inside of the stator casing 10, and a canned pot 21 which separates the rotor space in which the rotor 16 is arranged, from the stator, so that the rotor space can be filled with fluid, is situated on the inner periphery of this stator. It is therefore the case of a wet-running drive motor.

[0048] A receiving opening 22 extends radially outwards, departing from the interior 15 of the pump casing 2, in which the impeller 14 rotates. The receiving opening 22 forms part of an exit-side flow path, through which the flow accelerated by the impeller 14 exits out of the pump casing 2. Thus two delivery branches 6 and 8 branch at a first exit 24 and a second exit 26 which are is situated in the inside of the receiver opening 22 (see FIG. 7).

[0049] A valve insert 28 which comprises a closure plate 30 closing the receiving opening 22 to the outside, is inserted into the receiving opening 22 from the outside. The closure plate 30 simultaneously serves as a carrier and holds a rotation pivot or simply pivot 32, on which a first valve element 34 and a second valve element 36 are pivotably mounted. A rotary spring 38 which forms a restoring element and in the assembled condition presses the first valve element 34 and the second valve element 36 apart, is moreover arranged on the pivot axis 32. The two valve elements 34 and 36 are configured identically and are merely arranged in a manner rotated to one another by 180.

[0050] FIG. 3 shows a valve insert 28 in the assembled condition before the insertion into the receiving opening 22 of the pump casing 2. The first and the second valve element 34, 36 are rotated by 180 to one another, and are arranged away from one another on the pivot 32, so that their outer surfaces 40 which are away from one another form sealing surfaces coming into sealing contact on the outer periphery of the exits 24 and 26 which forms a valve seat in each case, for the closure of these exits. Elastic sealing elements can be arranged on the outer periphery of the exits 24, 26 or on the sealing surfaces 40 for this. The flap-like valve elements 34 and 36 are configured such that an opening 42 extending transversely to the sealing surface 40, through the valve element 34, 36, is formed in the sealing surface 40 in each case. The opening 42 seen in the direction of the pivot axis 32 is arranged out-of-centre in the valve element 34, 36. The opening 42 is thereby arranged in one half in the sealing surface 40, seen in the direction of the pivot 32. The opening 42 in the first valve element 34 thus lies offset to the opening 42 in the second valve element 36, since the two valve elements 34 and 36 which are configured identically are arranged in a manner rotated to one another by 180. The opening 42 in the first valve element 34, in FIG. 4 lies in the upper half, whereas the opening 42 in the second valve element 36 lies in the lower half. The effect of this is that the openings 42 in the two valve elements 34 and 36 are not aligned or flush with one another when the two valve elements 34 and 36 come to bear on one another. In contrast, the valve elements 34 and 36 at their side which is away from the sealing surface 40, next to the opening 42 comprise an engagement element 44 which with regard to its shape corresponds to the opening 42 on the same side. The engagement element 44 of the first valve element 34 thus engages into the opening 42 of the second valve element 36 when the two valve elements come to bear on one another whilst overcoming the spring force of the rotary spring 38. The opening 42 of the second valve element 36 is thus closed by the first valve element 34 and its engagement element 44. The engagement element 44 can be configured elastically in the form of a seal. In a corresponding manner, the engagement element 44 of the second valve element 36 engages into the opening 42 of the first valve element 34 for its closure.

[0051] As is to be seen in FIG. 7, the first and the second exit 24 and 26 in the receiving opening 22 lie opposite one another, wherein valve seats formed by the edge of the exits 24 and 26 are situated in planes which are parallel to one another. If the valve insert 34 is inserted into receiving opening 22, the first valve element 34 and the second valve element 36 are pressed by the rotary spring 38 functioning as a restoring element, into their idle position which represents a closed position, in which the first valve element 34 covers the first exit 24 and the second valve element 36 covers the second exit 26. The first exit and the second exit are thus essentially closed by the first valve element 34 and the second valve element 36, i.e. closed with the exception of the flow passage through the openings 42. As can be recognized in FIGS. 5, 6, 7 and 8, the valve elements 34 and 36, in a direction transverse to the pivot axis 32 are configured so long, that their ends 46 distanced to the pivot axis 32 extend into the interior 15 and thus into an annular space surrounding the impeller 14. The surfaces which are adjacent the ends 46, in the extension of the sealing surfaces 40 of the valve elements 34, 36 form engagement surfaces, upon which the flow rotating in the interior 15 acts on rotation of the impeller 14.

[0052] The control device which is arranged in the electronics housing 12 is configured such that it can activate the electrical drive motor in two different rotation directions A and B in a targeted manner. This can be effected for example via a frequency converter which subjects the coils in the stator to current in a targeted manner. The valve device in the valve insert 28 is configured such that it guides the flow into the first exit 24 and thus to the first delivery branch 6 or into the second exit 26 and thus to the second delivery branch 8, depending on the rotation direction A, B. The heating circuit of a heating for a building for example can connect to the first delivery branch 6, whereas a heat exchanger for heating service water connects to the second delivery branch 8.

[0053] On starting operation of the pump assembly therefore, the rotation direction is first set by the control device 12, in order to set one of the two exits 24 or 26, through which the fluid is to be delivered. If now the first exit 24 with the connecting delivery branch 6 is to be used, the pump assembly is set into movement such that the impeller rotates in the first rotation direction A. The exits 24 and 26, with the exception of the flow passages through the openings 42 are essentially closed in the idle position shown in FIGS. 5 and 7. The openings 42 effect a pressure compensation between both sides of the valve elements 34 and 36, so that the valve elements 34 and 36 on starting operation of the pump assembly are not pressed against the exits 24 and 26 by the pressure forming in the interior 15. This means that the valve elements 34 and 36 are held in their position essentially merely by the rotary spring 38. A rotating flow in the peripheral region of the impeller is produced in the interior 15 of the pump casing 2, on rotation of the impeller in the direction A. The flow thereby likewise rotates in the rotation direction A and this acts upon the engagement surface of the first valve element 34. The flow therefore produces a force on the first valve element 34 and this force counteracts the spring force of the rotary spring 38 and thus moves the first valve element 34 out of the closed position into its opened position, in which the valve element 34 bears on the second valve element 36. Thereby, the first valve element 34 closes the opening 42 in the second valve element 36. The second exit 26, on which the second valve element 36 remains in contact, is now completely closed. The first exit 24 is completely opened, so that the flow flows through this exit 24 into the delivery branch 6. The pressure prevailing in the interior 15 now simultaneously acts upon the sealing surface 40 of the first valve element 34, and this first sealing element via the contact on the second valve element 36 presses this into additional sealing contact with the valve seat surrounding the second exit 26. This condition, in which the first valve element 34 is opened and thus a flow path through the first exit 24 to the delivery branch 6 is therefore opened, is represented in FIG. 6A and 8A.

[0054] If the drive motor is formed by the control device, then the impeller 14 comes to a standstill and the flow as well as the pressure in the interior 15 disappears. The first valve element 34 is thereupon brought again into its idle position by way of the rotary spring 38, in which idle position it essentially closes the first exit 24. If the pump assembly is operated in the opposite rotation direction B, then accordingly the second valve element 36 will move into an opened position, in which it comes to bear on the first valve element 34 and thus completely closes the opening 42 in the first valve element 34, and thus the first exit 24. The second exit 26 is simultaneously opened and the flow can flow through this exit into the second delivery branch 8. This condition, in which the second valve element 36 is in its opened position, is represented in FIG. 6B and 8B.

[0055] On starting operation of the pump assembly, one succeeds in firstly only a pressure and flow which is utilized for moving one of the valve elements 34, 36 into its opened position, being built up in the interior 15 of the pump casing 2, due to the fact that the exits 24 and 26 are essentially closed by the valve elements 34 and 36 in the idle position. In this condition, at first, essentially no flow and no pressure is built up in the systems connecting to the delivery branches 6 and 8, by which means water hammers are reduced when switching the valve elements 34. Thus a very gentle or smooth switching can be achieved. This is also encouraged by the pressure compensation via the openings 42, since only a very low switching force is thus necessary for moving the valve elements 34 and 36. The control device in the electronics housing 12 can moreover adapt the acceleration of the drive motor such that at first, on starting operation, only so much pressure and flow are built up, so as to move one of the valve elements 34, 36 into the desired opened position, and only subsequently is the motor accelerated, so that the desired final pressure or flow is built up.

[0056] The interior 15 of the pump casing 2 is dimensioned such that it has a significantly larger diameter than the outer diameter of the impeller 14, as is represented in the FIGS. 7 and 8B. A free annular space 47 thus remains in the peripheral region of the impeller 14, in which a rotating flow can form in the periphery of the impeller 14, which then acts upon the engagement surfaces of the valve elements 34 and 36, depending on the rotation direction, in order to be able to move these into the opened position. The valve elements 34 and 36 are dimensioned such that their free ends 46, at every angular position during the pivot movement about the pivot axis 32, are distanced to the outer periphery of the impeller 34 such that the valve elements 34 and 36 do not collide with the impeller 14. Further preferably, the distance between the ends 46 and the outer periphery of the impeller 14 is selected such that a free space always remains, through which the annular or rotating flow can run in the peripheral region of the impeller 14. The annular space 47 additionally leads to an overall improved efficiency, particularly if the impeller 14 comprises arcuate blades.

[0057] The receiving opening 22 is configured such that no undercuts are formed in a direction radially to the rotation axis X of the drive motor. The receiving opening 22 can thus be formed by a core, which can be pulled out to the outside in the radial direction after the molding of the pump casing 2. This permits a more simple manufacture of the receiving space 22.

[0058] With the previously described embodiment example, the valve elements 34 and 36 are articulated on the pivot such that the pivot or pivot axis 32 with respect to the rotation axis X of the impeller is arranged on the radially outer end of the valve elements 34, 36, which is to say the pivot or pivot axis 32 is distanced maximally from the impeller or the rotation axis X in the radial direction. As is schematically represented in FIGS. 9 and 10, the pivot axis 32′ however could also be situated on the radially inner end of the valve elements 34′ and 36′. With this arrangement too, a flow would be produced in the same direction for example in the rotation direction A of the impeller 14, and this flow acts upon the first valve element 34′ such that this pivots about the pivot axis 32′ such that the first exit 24 is released and simultaneously the first valve element 34′ comes to bear on the second valve element 36′. The flow is therefore guided into the first exit 24, whilst the second exit 26 remains closed. The remaining design of the valve elements 34′ and 36′ can thereby correspond to the design described above. In particular, openings 42 can likewise be provided.

[0059] As described above, the circulation pump assembly according to the invention is preferably applied into a heating facility, in particular into a gas heater, which is likewise the subject matter of the invention. Such a heating facility with a gas heater 48 is represented schematically in FIG. 11. The gas heater 48 comprises a combustor 50 with a primary heat exchanger 52, via which the water is heated in the heating circuit. The water is delivered through the heating circuit via the pump assembly 1. The rotation direction of the pump assembly 1 is set via the control device 12 of this pump assembly in the described manner, by which means the valve arrangement formed by the valve elements 34, 36 is switched over. The valve arrangement serves for switching over the flow path between a heating circuit 54 which runs through a building, and a secondary heat exchanger 55 which serves for heating service water. The heating circuit 54 runs through one or more radiators 56, wherein circuits of a floor heating can also be considered as a radiator in the context of this description. The flow either runs through the secondary heat exchanger 55 or the heating circuit 54, depending on the rotation direction A, B. In the case that the impeller 14 is to comprise arcuate blades for increasing the efficiency, then the facility is preferably configured such that that rotation direction, with which the heating water is led through the heating circuit 54, is that rotation direction, for which the curvature of the impeller blades is optimized. It is therefore ensured that the pump assembly 1 operates at maximum efficiency for the most part of the operating time, since the rotation direction, with which the water is led through the secondary heat exchanger 55, as a rule is used more seldom, since the operating times for service water heating as a rule are less than the operating times for heating a building. The primary heat exchanger 52 with the combustor 50, the pump assembly 1 as well as the secondary heat exchanger 55 preferably form constituents of the gas heater 48, and the pump assembly 1 and the secondary heat exchanger 55 are preferably integrated into a hydraulic construction unit which is to say into a hydraulic block.

[0060] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.