Centrifugal pump assembly

Abstract

The invention relates to a centrifugal pump assembly comprising an electric drive motor (2), at least one impeller (14) driven by the electric drive motor (2) and a valve element (24; 24') rotatable between two valve positions, the valve element being driven by a fluid flow generated by the impeller (14), wherein the valve element (24; 24') comprises a cover plate (104; 104') extending perpendicular to an axis of rotation (X) of the impeller (14) and facing the impeller (14), wherein the valve element (24; 24') comprises a protrusion (102; 102') arranged on an outer surface side facing away from the impeller (14) such that a flow can act on the protrusion to drive the valve element (24; 24').

Description

Technical Field

[0001] The invention relates to a centrifugal pump assembly comprising a pump device and a valve element. The pump device is driven by an electric drive motor. Background Art

[0002] Especially in smaller buildings, compact heating systems are used to heat the building and provide domestic hot water. Those systems usually include a hydraulic valve arrangement for switching the flow of the heating medium between a heating circuit in the building and a heat exchanger for heating the domestic water.

[0003] From EP 3 376 049 it is known to integrate such a valve device into a circulating pump device such that a valve element of the valve device is moved between two possible valve positions or switching positions using the water flow generated by the pump. Summary of the Invention

[0004] The object of the present invention is to further improve a centrifugal pump assembly comprising a valve element driven by a fluid flow, such that a more reliable switching of the valve between two possible switching positions or valve positions can be achieved.

[0005] A centrifugal pump assembly according to the present invention comprises an electric drive motor and at least one impeller driven by the electric drive motor. The electric drive motor may have a rotor, preferably a permanent magnet rotor connected to the impeller via a rotor shaft. The electric drive motor may be, in particular, a wet-running electric drive motor with a rotor can disposed between a rotor space and a stator space containing the stator windings of the drive motor. In this design, the rotor space is filled with the liquid to be pumped (in particular, water). The impeller rotates within a pump housing having at least one inlet port and one outlet port. The centrifugal pump assembly also includes a valve device integrated into the centrifugal pump assembly. The valve device includes a valve element rotatable between two possible valve positions or switching positions. The valve element is moved between these valve positions by a fluid flow generated by the impeller (in particular, a fluid flow flowing circumferentially around the impeller). The valve element may be designed to selectively open two inlet ports of the centrifugal pump assembly or selectively open two outlet ports of the centrifugal pump assembly. Thus, the valve element can change the fluid flow, for example, between a heating circuit for heating a building and a heat exchanger for heating domestic water.

[0006] The valve element comprises a cover plate that extends perpendicularly to the impeller's axis of rotation and faces the impeller. Preferably, the cover plate extends parallel to the impeller's facing side, in particular the impeller's facing side that includes the suction port in the center of the impeller. The cover plate of the valve element preferably forms one of the walls that delimit a pump space within which the impeller is arranged. The cover plate preferably contacts the fluid flow on the outside of the impeller, in particular the fluid flow within the pump space in the direction of rotation.

[0007] According to the present invention, the valve element includes protrusions arranged on the outer surface side facing away from the impeller, so that the flow can act on these protrusions to drive the valve element. The fluid flow generated by the impeller can act on these protrusions, so that the protrusions constitute a force application surface. The force provided by the flow or fluid is applied to this force application surface, so that it generates a torque that acts on the valve element and rotates the valve element about its rotation axis. Because the protrusions are arranged on the surface of the valve element facing away from the impeller, the disturbance of the fluid flow in the area directly surrounding the impeller is reduced. As a result, the high efficiency of the centrifugal pump can be maintained. The hydraulic resistance generated by the valve element is minimized.

[0008] Preferably, the protrusions are provided on the outer circumference of the valve element, i.e., on the side of the outer surface of the valve element that forms the outer circumference of the valve element. Alternatively, the protrusions may be arranged on the rear side facing away from the impeller. Therefore, the protrusions are preferably not arranged on the surface facing the impeller, so that they are not arranged within the fluid flow in the immediate vicinity of the impeller. This minimizes hydraulic resistance.

[0009] According to another preferred embodiment, the protrusion extends in a radial direction relative to the rotation axis of the valve element. For example, the protrusion can extend in a radial direction from the outer peripheral surface of the valve element. Therefore, the protrusion can form a tooth-like structure substantially similar to a gear on the outer periphery of the valve element. The gap between the outer periphery of the valve element and the surrounding wall of the housing can be open toward the space containing the impeller, so that the fluid flow generated by the impeller can directly impact the protrusion arranged on the outer periphery of the valve element. According to another possible design, the protrusion can be tilted in the circumferential direction. The protrusion can form an inclined blade so that the fluid flow flowing parallel to the rotation axis of the valve element impacts the inclined surface of the protrusion, thereby generating a force in the circumferential direction (i.e., a torque acting on the valve element). The protrusion tilted in the circumferential direction is tilted relative to the rotation axis, that is, the angle between the axis parallel to the rotation axis of the valve element and the surface of the protrusion is between 0° and 90°, preferably between 0° and 60°. The protrusion can extend straight or curved to optimize the fluid flow and the torque acting on the valve element.

[0010] It is further preferred that the cover plate extends beyond the protrusion in the radial direction, that is, the diameter of the cover plate is preferably greater than the diameter of the circle along the radial outer end of the protrusion. This means that the cover plate covers the protrusion on the side facing the impeller. Therefore, the cover plate extends between the impeller and the protrusion. Therefore, the fluid flow acting on the protrusion needs to flow around the cover plate or through the gap around the cover plate. This flow can especially be a side flow generated by the impeller, rather than the main flow leaving the impeller towards the outlet port of the pump assembly. In particular, the side flow can be a side flow that only appears during the operating conditions of the movement of the valve element, rather than during the normal operation of the centrifugal pump. Thereby, the flow resistance during normal operation can be further reduced.

[0011] According to another possible embodiment of the present invention, the rotation axis of the valve element extends parallel to the rotation axis of the impeller, and preferably further extends along the rotation axis of the impeller. This allows for a compact arrangement of the impeller and the valve element in a single housing. Furthermore, the circumferential flow generated by the impeller also flows circulatory around the rotation axis of the valve element, thereby allowing for optimized hydraulic force or torque transmission between the impeller and the valve element via this fluid flow generated by the impeller.

[0012] According to another embodiment, the valve element is arranged inside a housing having a circular inner wall around the periphery of the valve element, with an annular gap between the periphery of the cover plate of the valve element and the inner wall. The fluid flow generated by the impeller can enter the gap so that it can act on the protrusions of the valve element, which are arranged on the outlet side of the gap, that is, on the side of the cover plate facing away from the impeller. According to another preferred embodiment, the cover plate, the valve element and the surrounding wall can be designed so that the gap is basically closed during normal operation, or so that during such normal operation, the fluid flow is blocked in another way through the gap to reduce the hydraulic resistance during normal operation. This can be achieved, for example, by linear movement of the valve element, which closes the gap and / or interrupts the flow path for the fluid side flow to enter the area where the protrusions are arranged through the gap.

[0013] Preferably, the protrusions are evenly distributed on the periphery of the valve element. Through this design, a uniform force or torque transmission on the valve element can be achieved.

[0014] According to a preferred embodiment, the protrusions have a tooth-like shape and preferably extend orthogonally to the cylindrical outer peripheral wall of the valve element, i.e., extend substantially radially to the center of the valve element. Thus, the valve element at least partially has the shape of a gear. The protrusions provide force application surfaces extending in the radial direction, so that the fluid flow in the circumferential direction impinges on these surfaces to generate a torque acting on the valve element for rotating the valve element between the possible valve positions.

[0015] According to another preferred embodiment, the protrusion is integrally formed with the peripheral wall of the valve element and / or the cover plate. For example, the valve element can be at least partially made of a plastic material, such as by injection molding. The protrusion is preferably formed in the part of the valve element formed of the plastic material. This allows for economical production of the valve element including the protrusion.

[0016] The cover plate of the valve element preferably includes a central outlet opening, which engages with the suction port of the impeller. In particular, the valve element can be a valve element that switches the flow on the suction side of the impeller between two possible flow paths (i.e., between two different suction ports). For example, one suction port can be connected to a heating circuit of a building, and the other suction port can be connected to a heat exchanger for heating domestic hot water. By changing the valve or switching position, one of the flow paths can be closed and the other opened. Preferably, both flow paths end in a central outlet opening, thereby forming a connection with the suction port of the impeller, so that a fluid flow between the suction port of the centrifugal pump assembly and the suction port of the impeller can be established by the valve element.

[0017] According to another preferred embodiment of the present invention, the valve element is supported on a central bearing column or pivot and is secured axially to the bearing column by an O-ring, wherein the O-ring preferably engages in a recess on the outer circumference of the bearing column. This embodiment can be implemented independently of the arrangement of the protrusions discussed above, that is, it can be implemented with a valve element that does not have such protrusions as described above. The O-ring performs the functions of a retaining ring or a spring lock washer, respectively. However, the arrangement of the O-ring has at least two advantages. If the valve element abuts against the O-ring, it provides a damping function in the axial direction. Furthermore, the O-ring can be easily installed without special tools, which allows for easy repair in the field. The O-ring forms an axial stop or abutment for the valve element, particularly if the valve element is axially movable, as described below. The bearing column may be provided with a circumferential recess or groove on its outer circumference, for example, near its free end. The O-ring is inserted into this recess so that it protrudes radially. The protruding portion of the O-ring then forms the abutment.

[0018] The bearing column is preferably attached to the inner surface of the pump housing and is preferably formed integrally with at least the inner surface of the pump housing. The pump housing can, for example, be made of a plastic material or metal. This allows the bearing column to be formed integrally with the pump housing. In an alternative embodiment, the bearing column can be inserted (for example in the form of a hole or a threaded hole) into a receiving portion formed in the inner surface of the pump housing. In such an embodiment, the bearing column can be pressed into or screwed into a hole in the bottom surface of the pump housing. The valve element is preferably slidably mounted on the bearing column so that a plane bearing is formed between the outer periphery of the bearing column and the inner periphery of the bearing hole inside the valve element.

[0019] According to another specific embodiment of the present invention, the valve element includes at least one sealing portion for selectively closing the first and second inlet ports, such that in the first valve position, the first inlet port is closed, and in the second valve position, the second inlet port is closed. In a specific embodiment, two sealing portions can be provided, one sealing portion for the first inlet port and one sealing portion for the second inlet port, such that in the first valve position, the first sealing portion closes the first inlet port, and in the second valve position, the second sealing portion closes the second inlet port, while the other inlet port is open. Preferably, the valve element allows the flow path between the two inlet ports to be changed, so as to selectively open one of the flow paths toward the inlet side of the impeller. For example, the valve element can be used to switch between a heating circuit and a heat exchanger for heating domestic water in a heating system.

[0020] According to another preferred embodiment, the valve element is additionally movable in a linear direction along its axis of rotation. This allows the valve element to perform further switching movements or actions, respectively. In particular, a switchable coupling or clutch can be implemented through this linear movement. For example, in a first axial position, the clutch can be engaged so that the valve element is fixed in its rotational direction. In a second axial position, the valve element can be released so that it is movable in the rotational direction to move between two possible valve positions. Preferably, the valve element is movable in a linear direction so that in the first axial position, at least one sealing portion is in sealing contact with the relative valve seat, and in the second axial position, the sealing portion is kept at a distance from the relative valve seat. Therefore, in the first axial position, the valve element is fixed in its rotational direction by engaging with the seal and possibly with another engaging surface, so that it cannot move in the rotational direction between the valve positions. In addition, a secure seal is ensured. In the second axial position, the valve element is released from the valve seat, so that engagement with the valve seat and possibly with another engagement surface is released, and the valve element is preferably freely rotatable about its rotational axis to be moved between valve positions by the flow generated by the impeller. By this axial movement, which is independent of the rotational movement between the valve positions, the sealing engagement and the change of the valve position are decoupled, with the advantage that no friction generated by the sealing engagement of the sealing portion needs to be overcome for movement between the valve positions. As a result, the torque or force required to move the valve element between the valve positions is reduced.

[0021] According to another embodiment, the valve element includes at least one inlet opening that is fluidically connected to the outlet opening of the valve element and is arranged such that in a first valve position, the inlet opening faces the second inlet port, and in a second valve position, the inlet opening faces the first inlet port. This means that in the first valve position, the inlet opening is open toward the second inlet port, and in the second valve position, the inlet opening is open toward the first inlet port, so that in the first valve position, a fluid flow is established from the second inlet port through the valve element toward the impeller. In the second valve position, a corresponding flow is established from the first inlet port toward the inlet side of the impeller. This allows the flow path between the two inlet ports to be varied by rotational movement of the valve element, thereby selectively drawing liquid or water from one of the two inlet ports.

[0022] In another embodiment, the valve element may include a sealing member that surrounds the inlet opening and is arranged so that in a first axial position of the valve element, the sealing member contacts the relative sealing surface or valve seat, and in a second axial position of the valve element, the sealing member keeps a distance from the sealing surface or valve seat respectively. In addition, preferably, the sealing member surrounding the inlet opening of the valve element is arranged on the periphery of the valve element. The sealing member provides a closed flow path that passes through the inlet opening and the valve element toward the impeller from one of the inlet ports. In addition, preferably, the sealing element closes the flow path around the valve element during normal operation of the pump. This can be a flow path of a side flow through the gap between the periphery of the valve element (particularly its cover plate) and the surrounding wall of the pump housing. If the valve element is in its axial position away from the sealing surface, a side flow from the impeller through the gap around the valve element toward the inlet opening of the valve element may occur. Due to the rotational movement of the impeller, the side flow has a rotation around the axis of rotation of the valve element acting on the protrusion to generate a torque acting on the valve element for its rotational movement. By changing the direction of rotation of the impeller, for example by means of a corresponding motor control of a drive motor, the direction of rotation can be changed so that the valve element can be moved into the opposite direction of rotation in order to move the valve element between two possible valve positions. In particular, by the pressure increase generated by the impeller, the valve element can be moved in the axial direction along the axis of rotation so that the sealing member contacts the opposite sealing surface and interrupts the side flow acting on the protrusion, so that the torque acting on the valve element is reduced. In addition, by the contact between the sealing member and the sealing surface, a frictional engagement that holds the valve element in the corresponding valve position can be achieved, preferably even if the direction of rotation of the impeller changes again. If the sealing member surrounding the inlet opening is arranged on the outer periphery of the valve element, a large radial distance between the frictional engagement area and the axis of rotation of the valve element can be achieved, resulting in a larger holding torque for fixing the valve element in its valve position.

[0023] Furthermore, a sealing member surrounding the inlet opening can be arranged at the axial end of the valve element opposite the axial end formed by the cover plate. In this way, pressure acting on the cover plate can cause the valve element to move in its axial direction, so that the sealing member is again pressed against a sealing surface, preferably a sealing surface provided on the bottom side of the pump housing. This enables frictional engagement to be achieved, thereby retaining the valve element in its respective valve position. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Hereinafter, the present invention will be described by way of example with reference to the accompanying drawings, in which:

[0025] Figure 1 is an exploded view of a centrifugal pump device according to the present invention,

[0026] Figure 2 is based on Figure 1 A top view of the centrifugal pump device on the axial end side of the electronics housing,

[0027] Figure 3 is based on Figure 1 and Figure 2 The centrifugal pump device is along Figure 2 sectional view along line III-III in FIG. 1 , wherein the valve arrangement is in its sealing position,

[0028] Figure 4 is similar to Figure 3 a sectional view of the valve device in its released and rotatable position,

[0029] Figure 5 is based on Figures 1 to 4 A top view of the opened pump housing of a centrifugal pump arrangement,

[0030] Figure 6 is based on Figures 1 to 5 sectional view of a valve arrangement in a centrifugal pump arrangement, wherein the valve element is in a first valve position,

[0031] Figure 7 is based on Figure 6 sectional view of a valve device, wherein the valve element is in the second valve position,

[0032] Figure 8 Is a centrifugal pump device along Figure 2 sectional view along line VIII-VIII in FIG. 1 , wherein the valve element is in its second valve position,

[0033] Figure 9 is based on Figures 1 to 8 A perspective view of a valve element in a centrifugal pump device,

[0034] Figure 10 is a plan view of the bottom side of the valve element including the sealing portion,

[0035] Figure 11 is a cross-sectional view of the valve element with the bypass valve in its closed position,

[0036] Figure 12 is based on Figure 11 a sectional view of the bypass valve in its open position,

[0037] Figure 13 Yes Figure 12 An enlarged cross section of the bypass valve 86 is shown,

[0038] Figure 14 is based on Figure 9 Exploded view of the valve components,

[0039] Figure 15 Based on what is seen from different directions Figure 9 Exploded view of the valve components,

[0040] Figure 16 The pump housing is along Figure 3 sectional view along line XIII-XIII in FIG. 1 , wherein the valve element is in the second valve position,

[0041] Figure 17 is based on Figure 18 sectional view of the valve element in a first valve position,

[0042] Figure 18 is a schematic diagram of a hydraulic circuit of a heating system including a centrifugal pump according to the present invention,

[0043] Figure 19 is an exploded view of a valve element according to a second embodiment, and

[0044] Figure 20 It includes Figure 19 A perspective view of the open pump housing showing the valve element. DETAILED DESCRIPTION

[0045] The centrifugal pump described as an example is a centrifugal pump provided for a heating system. The centrifugal pump device comprises a hydraulic valve device which can be used in a heating system to vary the flow of fluid between a heating circuit through a building and a heat exchanger for heating domestic water.

[0046] The centrifugal pump assembly includes an electric drive motor 2, which includes a motor housing 4, within which the stator and rotor are arranged. An electronics housing 6, containing control electronics 7 for the electric drive motor, is located at one axial end of the motor housing, along the longitudinal axis X. At the opposite axial end, the motor housing 4 is connected to a pump housing 8, which includes an outlet connection 10 connected to an outlet port 12 within the interior of the pump housing 8. The outlet port 12 is arranged on the periphery of the pump space, within which an impeller 14 is located. The pump housing 8 also includes two inlet connections 16 and 18. The first inlet connection is configured for connection to a building heating circuit, while the second inlet connection 18 is configured for connection to a heat exchanger used to heat domestic hot water. The first inlet connection 16 is fluidically connected to a first inlet port 20 within the pump housing 8. The second inlet connection 16 is connected to a second inlet port 22 within the pump housing 8. Inlet ports 20 and 22 are arranged in a flat plane perpendicular to the longitudinal axis, or axis of rotation X. The rotation axis X is the rotation axis of the impeller 14 and the valve element 24 , which will be described in more detail later. Seen in the longitudinal direction X, the first inlet port and the second inlet port are arranged in the bottom of the pump housing 8 .

[0047] The valve element 24 is arranged to switch the flow path between the two inlet connections 16 and 18 towards the impeller 14. Basically, the function of this hydraulic valve arrangement is similar to that disclosed in EP 3 376 049. The valve element 24 has a central outlet opening 26 which faces a suction opening 28 of the impeller 14 or engages with the suction opening 28 so that the fluid flows from this outlet opening 26 into the suction opening 28.

[0048] The valve element 24 is rotatable about an axis of rotation X, which corresponds to the axis of rotation X of the impeller 14. The valve element 24 is mounted on a pivot or bearing post 30 fixed in the bottom of the pump housing 8. In this embodiment, the pivot is molded into the material of the pump housing 8, for example, during an injection molding process. However, the bearing post can be fixed in the bottom of the pump housing 8 in a different manner, such as being screwed into a threaded hole or being integrally formed with the pump housing 8. The bearing post 30 extends from the bottom of the pump housing 8 into the interior of the pump housing 8 in the longitudinal direction X. The valve element 24 is rotatable about the longitudinal axis X and can move linearly along the longitudinal axis X on the bearing post 30 a specific distance. This specific distance is limited by an O-ring 32, which forms an axial stop or abutment for the valve element 24. The O-ring 32 engages in a circumferential groove or recess 34 located near the free distal end of the bearing post 30. The O-ring 32 forms a resilient axial stop and allows for easy assembly without special tools.

[0049] In this embodiment, the valve element 24 consists of two parts: a support member 36 and a cover member 38 connected by a snap fit. An engagement hook 40 is arranged on the inner surface of the cover member 38, which surrounds or engages an engagement shoulder or protrusion 42 inside the support member 36. The cover member 38 has a cover plate 104, a plate-like cover, and completely closes the central outlet opening 36. When arranged within the pump housing 8, the cover plate 104 of the cover member 38 forms one axial wall of the pump space 44, within which the impeller 14 rotates. The opposite axial wall of the pump space 44 is formed by a bearing plate 46, which holds a bearing for the rotor shaft 50. Opposite the cover member 38, a spring support 52 is connected to the support member 36. A helical compression spring 54 is arranged between the spring support 52 and the support member 36. One axial end of the spring 54 abuts the inner bottom surface of the spring support 52, while the opposite axial end of the spring 54 abuts a portion of the support member 36. The spring support 52 overlaps the resilient engagement hook 56, so that the engagement hook 56 engages with an opening or cutout 58 in the outer periphery of the spring support 52 from the interior of the spring support 2. The spring support 52 is thereby guided in the axial direction X on the outside of the leg of the engagement hook 56, allowing the spring support 52 to move in this axial direction on the outside of the leg of the engagement hook 56. Furthermore, a rib 60 is provided in the spring support 52 on the support member 38. The rib 60 and the slot 62 allow relative movement in the axial direction, but ensure torque transmission, so that the spring support 52 is connected to the support member 36 in a substantially torque-proof manner, except for a limited play between the rib 60 and the slot 62 in the circumferential direction. This play ensures the damping effect provided by the torsion of the compression spring 54, as the spring 54 is in the flux in the direction of rotation until the rib 60 abuts against one of the edges of the slot 62.

[0050] At the axial end opposite the support member 36, the spring support 52 includes a bearing portion 64 that is movably supported on the bearing column 30, that is, it slides on the outer circumference of the bearing column 30. Another bearing portion 66 that is in bearing contact with the bearing column 30 is formed in the support member 36. The bearing portion 66 includes a shoulder that protrudes in the radial direction. The axial end of the compression spring 54 abuts against this shoulder.

[0051] The compression spring 54 forces the bearing portions 64 and 66 away from each other and forces the valve element 24 in the axial direction towards the motor housing 4. Under the compression of the spring 54, the valve element 24 can move towards the bottom side of the pump housing 8, that is, away from the impeller 14 and the motor housing 4. The two possible axial positions of the valve element 24 are Figure 3 and Figure 4 In Figure 4, the valve element 24 is in its first axial position, in which it abuts a circular shoulder 68 in the interior of the pump housing 8. The shoulder 68 extends in the radial direction from the inner periphery of the pump housing 8, which provides a circular sealing surface extending substantially perpendicularly to the longitudinal axis X. The valve element 24 is in sealing contact with this shoulder 68 via an elastic seal 70 on the outer periphery of the support member 36. This seal 70 ensures the sealing of the pump space 44 towards the suction side of the pump device. Figure 4 A second axial position of the valve element 24 is shown, in which the valve element 24 is moved toward the impeller 14 so that the seal 70 is no longer in contact with the shoulder 68 but is spaced apart from the shoulder 68. In this position, the valve element 24 is freely rotatable about the longitudinal axis X. However, if the seal 70 were in contact with the shoulder 68, the rotation of the valve element 24 would be inhibited due to the friction between the seal 70 and the shoulder 68. The shoulder 68 and the seal 70 thus act as a detachable coupling or clutch. The valve element 24 is moved to the second axial position by the spring force of the compression spring 54. Figure 4 In the released position shown. Figure 3 In the fixed position shown, in which the seal 70 is in contact with the shoulder 68, the valve element 24 is moved by the pressure generated by the impeller 14 and acting on the cover member 38 around the outlet opening 26. Thus, the valve element 24 can be selectively moved in the axial direction depending on the pressure generated by the pump on the outlet side of the impeller 14. This can be controlled by speed control and regulation performed by the control electronics 7 arranged in the electronics housing 6.

[0052] The valve element 24 includes two sealing portions 72 and 74, namely, a first sealing portion 72 and a second sealing portion 74. The two sealing portions 72 and 74 are arranged on the outer axial surface of the support member 36, that is, on the axial face side of the valve element 24 facing away from the impeller and opposite the first inlet port 20 and the second inlet port 22. The two sealing portions 72 and 74 are arranged in a common plane extending perpendicular to the rotation axis X. The two sealing portions 72 and 74 are positioned diametrically relative to the axis X, that is, in a position offset 180° around the rotation axis X. The two sealing portions 72 and 74 each include a resilient sealing member 76, 78, which in this embodiment is integrally formed with the seal 70 on the outer periphery of the support member. The seal 70 and the sealing members 76 and 78 can be formed as separate components or sealing devices connected to the support member 36 or connected to the support member 36 by an injection molding process.

[0053] The first seal 72 is provided to selectively close the first inlet port 20, and the second seal 24 is provided to selectively close the second inlet port 22. Between the two seals 72 and 74, an opening 80 is provided in the support member 36, which is in fluid connection with the outlet opening 26 and forms the inlet opening of the valve element 24.

[0054] In the direction of rotation about the longitudinal axis X, the valve element 24 can adopt two different valve positions. Figure 6 A first valve position is shown in which the first sealing portion 72 closes the first inlet port 20. In this first valve position, the second inlet port 22 is open to the opening 80 in the valve element 24, enabling a fluid flow from the inlet port 22 to the outlet opening 26 and into the suction port 28 of the impeller 24. Thus, in this first valve position, the impeller 14, and thus the entire pump, draws fluid through the first inlet connection 60 connected to the first inlet port 20. In this first valve position, when the valve element 24 is in the position shown Figure 3 In its engaged or sealing position shown, the first seal 72 with its sealing member 76 is pressed against a valve seat 82 formed by the surrounding circumference or edge of the inlet port 20. Thereby, the first inlet port 20 is fully closed.

[0055] In such Figure 7 In the second valve position shown, the first sealing portion 72 is rotated beside the first inlet port 20, so that the first inlet port 20 is open to the opening 80, thereby providing a flow path from the first inlet port 20 to the outlet opening 26 and the suction port 28 of the impeller 14. In this second valve position, the second sealing portion 24 is moved into its position covering the second inlet port 22, so that the second inlet port 22 is closed. In the engaged or sealing position of the valve element 24, the sealing member 78 of the second sealing portion 24 presses against a valve seat 84 formed on the outer periphery or edge of the second inlet opening 22.

[0056] Delayed from the first seal 76, the second seal 78 is not completely closed but comprises another valve in the form of a non-return valve forming a bypass valve 86, such as Figure 10-13 The bypass valve 86 has an opening 92 in the second sealing portion 74 that faces the second inlet port 22 in the second valve position, as shown. Figure 7As shown. Bypass valve 86 includes a bypass valve element 88 disposed between support member 36 and cover member 38 of valve element 24. Bypass valve element 88 is guided along a linear direction parallel to axis of rotation X on a guide element 90, which engages into bypass element 88. In its closed position, bypass valve element 88 abuts a valve seat formed by sealing member 78 surrounding opening 92 or by sealing member 78 defining opening 92 within second sealing portion 74. Bypass valve element 88 is retained in this closed or sealed position by a compression spring 94, which urges bypass valve element 88 into the illustrated sealed or closed position. Pressure acting on bypass valve element 88 causes bypass valve element 88 to move along guide element 90 against the force provided by compression spring 94 to open opening 92. The rear side of bypass valve element 88, facing away from outlet 92, contacts opening 80 and outlet opening 26—that is, the suction side of the pump and the flow path toward suction port 28 of impeller 14. Consequently, the pressure on the suction side of the pump acts on the rear side of bypass valve element 88. If the pressure difference between the two sides of bypass valve 86 or bypass valve element 88, respectively, exceeds a predetermined threshold value, which is defined by the dimensions of bypass valve element 88 and spring 94, bypass valve 86 opens, allowing fluid to flow from second inlet port 22 toward impeller 14, despite the closure of second inlet port 22 by second seal 74. This function can be used in a heating system when a heating circuit in a building is connected to first inlet connection 16. If all radiators in the heating circuit are closed, no fluid will flow through this first inlet connection 16. In this case, the pressure on the suction side of the impeller 14 and, therefore, the pressure on the rear side of the bypass valve element 88 will decrease to such an extent that the pressure difference across the bypass valve 86 exceeds a predetermined threshold value and the bypass valve 86 opens, thereby ensuring the flow of fluid through the second inlet port 22, to which, for example, a heat exchanger for heating domestic water can be connected. Thus, in a heating system, the flow of fluid through the boiler can be ensured, thereby avoiding overheating of the boiler.

[0057] The threshold for opening the bypass through bypass valve 86 is preferably adjusted by replacing bypass valve element 88. Interchangeable bypass valve elements 88 can be provided in different sizes, in particular with different sizes of the rear surface on which the pressure on the suction side of the pump acts. Since the opposing surface is always defined by the cross-section of opening 92, the force acting on bypass valve element 88 in both directions can be adjusted by changing the size of the rear surface. Alternatively or additionally, the size of the surface closing opening 92 can also be adjusted by changing the diameter of the circular protrusion 93 on bypass valve element 88 that contacts the valve seat in sealing member 78.

[0058] Similar to what is known from EP 3 376 049, the valve element 24 is moved between two valve positions by the circulating flow generated by the impeller 14. If the speed of the electric drive motor is reduced or the motor is switched off by the control electronics 7, the pressure in the pump space 44 decreases, so that the compression spring 44 moves the valve element 24 into its release position, as shown in FIG. Figure 4 As shown in FIG. In this position, the valve element 24 can be rotated about the rotation axis X by the circulating fluid flow within the pump space 44. The direction of the fluid flow depends on the direction of rotation of the impeller 14. The two valve positions are each defined by an end stop. To this end, a circular recess 96 is provided in the bottom wall of the pump housing 8. This circular recess 96 does not define a complete circle, but rather has an interruption in the form of a web 98. The opposing surfaces of this web 98 define two end stops for the rotational movement of the valve element 24, that is, end stops that define two possible valve positions. The spring support 52 of the valve element 24 has an axial extension that forms a stop element 100. The stop element 100 is in the form of a finger that is offset relative to the rotation axis X and engages in the recess 96. The stop element 100 can abut against two opposing surfaces of the web 98 to define the two rotational positions corresponding to the possible valve positions described above. In this case, it is advantageous to arrange the stop element centrally, thereby allowing for a damping effect due to the elasticity of the components and, in particular, the torsion of the compression spring 54 as described above. Figure 13 Shown is the corresponding Figure 7 The stop element 100 is shown in the second valve position. Figure 14 Shown is the corresponding Figure 6 The stop element 100 is shown in the first valve position of the valve position. It can be seen that the valve element 24 is rotated by 270° in order to change the valve position.

[0059] In order to enhance the rotation of the valve element 24 during normal operation of the pump device without increasing the flow resistance, radial protrusions 102 are provided which are distributed over the entire periphery of the valve element 24. The protrusions 102 are arranged on the rear side of a cover plate 104 on the cover member 38, so that the cover member 36 has a cover plate 104 facing the impeller 14, which extends in the radial direction beyond these protrusions 102, so that the protrusions 102 are completely covered by the cover plate 104 on the side facing the impeller 14. Therefore, the protrusions 102 are arranged on the back side of the cover plate 104. The diameter of the cover plate 104 is smaller than the inner diameter of the pump housing 8, so that a circular gap 106 around the periphery of the cover plate 104 is provided. The gap 106 provides a flow connection between the pump space 44 and the area in which the protrusions 102 are arranged. If the valve element 24 is in a position such as Figure 3 In its sealed or engaged position as shown, substantially no fluid flow occurs through gap 106 because the flow path through gap 106 is closed by seal 70 on the opposite end. Figure 4 In its released position, shown, there is a gap between seal 70 and shoulder 68, which opens a flow path through gap 106 toward opening 80 of valve element 24 (i.e., on the suction side of valve element 24). Therefore, if impeller 14 rotates, a portion of the fluid flow exiting impeller 14 will enter gap 106 and flow around valve element 24 toward outlet opening 26, toward opening 80. Due to the rotation of impeller 14, this side flow through gap 106 causes a rotation in the direction of the impeller's rotation, acting on ribs or toothed projections 102, generating a torque on valve element 24 that rotates valve element 24 until stop element 100 abuts the end stop provided by web 98. If the speed of the impeller is now increased by control electronics 7, the pressure on the outside of impeller 14 also increases, causing valve element 24 to move into its sealing position, in which seal 70 contacts shoulder 68 and one of the sealing portions 72, 74 contacts the opposing valve seat 82, 84. In this operating state, the sealing valve position is reached. Thereafter, the impeller's rotational direction can be quickly changed without moving the valve element 24 out of its current valve position. To achieve this, the electric drive motor is rapidly accelerated due to corresponding control by the control electronics 7, causing the pressure outside the impeller 24 to generate an axial force that overcomes the spring force of the compression spring 54 before establishing a circulating flow that rotates the valve element 24 to the other valve position. This allows the valve element 24 to be selectively moved to the desired valve position and then the impeller 14's rotational direction to be changed again, ensuring that the impeller 14 can always rotate in the desired, optimized rotational direction during operation of the centrifugal pump device. The arrangement of the protrusions 102 on the rear side of the cover plate 104 has the following advantage: the protrusions are only active when the valve element 24 is in its released position. During normal operation, with the valve element in its sealed position, the protrusions 102 have little effect; in particular, they do not increase the hydraulic resistance in the pump chamber 44.

[0060] The electric motor in the motor housing 4 is a wet-running electric motor having a rotor sleeve 108 forming a rotor space in which a rotor shaft 50 with a rotor 110 rotates. This rotor space is filled with the liquid to be pumped (i.e., preferably water). A stator 112 is arranged on the outside of the rotor sleeve 108 in a dry stator space within the motor housing 4.

[0061] Figure 18 An example of the use of the aforementioned centrifugal pump device 114 is shown. The centrifugal pump device includes the aforementioned features (i.e., the valve element 24 and the bypass valve 86 are formed by Figure 18). The centrifugal pump device 114 includes a centrifugal pump 116 having an electric drive motor 2 and an impeller 14. A valve element 24 forming a switching valve is arranged on the suction side of the centrifugal pump 116, thereby allowing the flow path to be switched between two possible inlet connections (a first inlet connection 16 and a second inlet connection 18). On the pressure side, the centrifugal pump 116 is connected to an outlet connection 10. In this example, the outlet connection 10 is connected to a boiler 118 that heats a liquid (in particular water) in a heating circuit. On the outlet side of the boiler 118, the heating circuit branches into a first branch and a second branch. The first branch forms the circuit of a central heating CH, which can include, for example, several radiators 120 or one or more floor heating circuits, and the second branch is used to heat domestic hot water DHW. The second branch includes a heat exchanger 122 for heating domestic hot water (DHW). As can be seen, a bypass valve is connected to the second branch (i.e., the branch including the heat exchanger 122). When valve element 24 is in a valve position in which the flow path through central heating circuit CH is open, bypass valve 86 can prevent overheating of boiler 118. In this valve position, if radiator 120 is closed, the flow of fluid through central heating circuit CH is interrupted. In this case, bypass valve 86 can open due to the pressure difference that overcomes the biasing force of compression spring 94, so that the flow path through heat exchanger 122 is opened, and water is circulated through the second branch of the heating system (i.e., through heat exchanger 122) by centrifugal pump 116, thereby distributing the heat generated by boiler 180 within the system to prevent overheating of boiler 118.

[0062] Figure 19 A second embodiment of a valve element 24' is shown. In this embodiment, the support member 36 including the bypass valve 86 is essentially the same as described above. In this second embodiment, the cover member 38' of the valve element 24' has a different design. In this embodiment, the projections 102' extend from the outer peripheral surface 124 in the radial direction. Furthermore, the projections 102' are inclined in the circumferential direction so that they form inclined blades on the outer peripheral surface 124 of the valve element. In this embodiment, the cover plate 104' does not extend beyond the periphery of the circumferential wall 124, i.e. does not cover the axial end sides of the projections 102'. Consequently, by using this valve element 24', the gap 106' or the annular space between the outer peripheral wall 124 of the valve element and the inner peripheral wall 126 of the pump housing 8' is open towards the space containing the impeller 14, as Figure 20 As can be seen in FIG. 1 . Thus, the fluid flow generated by the impeller 14 can directly impinge on the protrusions 102 ′. Due to their inclination, the protrusions 102 ′ generate a greater torque acting on the valve element 24 ′ about the axis of rotation X. Figure 20 The pump housing 8' shown with the valve element 24' can be connected to a pump housing such as Figure 1The electric drive motor 2 is shown and described above. Otherwise, the impeller 14 may be the same as that shown in the first embodiment.

[0063] Reference Signs List

[0064] 2 electric drive motors

[0065] 4Motor housing

[0066] 6 Electronic device housing

[0067] 7. Control electronics

[0068] 8, 8' pump casing

[0069] 10 outlet connectors

[0070] 12 export ports

[0071] 14 impeller

[0072] 16, 16' first inlet connection piece

[0073] 18, 18' second inlet connection piece

[0074] 20First entry port

[0075] 22 Second entry port

[0076] 24, 24' valve element

[0077] 26 exit openings

[0078] 28 suction ports

[0079] 30 pivot, bearing column

[0080] 32O-ring

[0081] 34 notches

[0082] 36 Support members

[0083] 38, 38' cover member

[0084] 40 engagement hooks

[0085] 42 Engage the shoulders

[0086] 44 pump spaces

[0087] 46 bearing plate

[0088] 48 bearings

[0089] 50 rotor shaft

[0090] 52, 52' spring support

[0091] 54 compression spring

[0092] 56 engagement hooks

[0093] 58 incision

[0094] 60 ribs

[0095] 62 slots

[0096] 64 bearing part

[0097] 66 bearing department

[0098] 68 Shoulders

[0099] 70 seals

[0100] 72 first sealing part

[0101] 74 second sealing portion

[0102] 76, 78 sealing components

[0103] 80 openings

[0104] 82, 84 valve seats

[0105] 86 bypass valve

[0106] 88 bypass valve element

[0107] 90 guide element

[0108] 92 openings

[0109] 93 protrusions

[0110] 94 compression spring

[0111] 96 grooves

[0112] 98 belly plate

[0113] 100 stop elements

[0114] 102, 102' protrusion

[0115] 104, 104' cover

[0116] 106, 106' gap

[0117] 108 rotor sleeve

[0118] 110 rotor

[0119] 112 stator

[0120] 114 centrifugal pump device

[0121] 116 centrifugal pump

[0122] 118 boiler

[0123] 120 radiator

[0124] 122 heat exchanger

[0125] 124 outer wall

[0126] 126 inner wall

[0127] CH Central Heating

[0128] DHW domestic hot water

[0129] X rotation axis

Claims

1. A centrifugal pump assembly comprising an electric drive motor (2), at least one impeller (14) driven by the electric drive motor (2), and a valve element (24; 24') rotatable between two valve positions, the valve element being driven by a fluid flow generated by the impeller (14), wherein: The valve element (24; 24') comprises a cover plate (104; 104') extending perpendicularly to the axis of rotation (X) of the impeller (14) and facing the impeller (14), It is characterized by: The valve element (24; 24') comprises a protrusion (102; 102') which extends radially from an outer peripheral surface (124) of the valve element (24; 24'), the protrusion being arranged on the outer surface side facing away from the impeller (14) so ​​that a flow can act on the protrusion to drive the valve element (24; 24').

2. The centrifugal pump assembly according to claim 1, characterized in that The protrusion (102') is inclined in the circumferential direction.

3. The centrifugal pump assembly according to claim 1, wherein: The projection (102; 102') extends in a radial direction relative to the rotation axis (X) of the valve element (24; 24'), and the cover plate (104; 104') extends beyond the projection (102; 102') in the radial direction.

4. The centrifugal pump assembly according to claim 1, wherein: The rotation axis (X) of the valve element (24; 24') extends parallel to the rotation axis (X) of the impeller (14).

5. The centrifugal pump assembly according to claim 4, characterized in that The rotation axis (X) of the valve element (24; 24') extends along the rotation axis (X) of the impeller (14).

6. The centrifugal pump assembly according to claim 1, wherein: The valve element (24; 24') is arranged inside a housing (8; 8'), which has a circular inner wall surrounding the outer periphery of the valve element (24; 24'), and an annular gap (106; 106') is provided between the outer periphery of the cover plate (104; 104') and the inner wall.

7. The centrifugal pump assembly according to claim 1, wherein: The protrusions (102; 102') are evenly distributed on the outer circumference of the valve element (24; 24').

8. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The protrusion (102; 102') has a tooth-like shape.

9. The centrifugal pump assembly according to claim 8, wherein: The protrusion (102; 102') extends orthogonally to the cylindrical outer peripheral wall of the valve element (24; 24').

10. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The protrusion (102; 102') is formed integrally with the outer peripheral wall of the valve element (24; 24') and / or the cover plate (104; 104').

11. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The cover plate (104; 104') of the valve element (24; 24') includes a central outlet opening (26) that engages with a suction port (28) of the impeller (14).

12. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The valve element (24; 24') is supported on a central bearing column (30) and is fixed in the axial direction on the central bearing column (30) by an O-ring (32).

13. The centrifugal pump assembly according to claim 12, wherein: The O-ring (32) engages in a recess (34) on the outer circumference of the central bearing column (30).

14. The centrifugal pump assembly according to claim 12, wherein: The central bearing column (30) is attached to the inner surface of the pump housing (8; 8').

15. The centrifugal pump assembly according to claim 14, wherein: The central bearing column (30) is formed integrally with at least the inner surface of the pump housing (8; 8').

16. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The valve element (24; 24') comprises at least one sealing portion (70, 72, 74) for selectively closing a first inlet port (20) and a second inlet port (22), such that in a first valve position the first inlet port (20) is closed and in a second valve position the second inlet port (22) is closed.

17. A centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The valve element (24; 24') is additionally movable in a linear direction along the axis of rotation (X) of the valve element (24; 24').

18. The centrifugal pump assembly according to claim 17, wherein: The valve element (24; 24') is movable in a linear direction such that in a first axial position at least one sealing portion (70, 72, 74) is in sealing contact with an opposing valve seat (68, 82, 84), and in a second axial position the sealing portion (70, 72, 74) is spaced apart from the opposing valve seat (68, 82, 84).

19. The centrifugal pump assembly according to any one of claims 1 to 7, characterized in that The valve element (24; 24') comprises at least one inlet opening (80) which is in flow connection with an outlet opening (26) of the valve element (24; 24') and is arranged such that in a first valve position the inlet opening (80) faces the second inlet port (22) and in a second valve position the inlet opening (80) faces the first inlet port (20).

20. The centrifugal pump assembly of claim 17, wherein: The valve element (24; 24') comprises a sealing member which surrounds an inlet opening (80) and is arranged such that in a first axial position of the valve element (24; 24') the sealing member is in contact with an opposing sealing surface and in a second axial position of the valve element (24; 24') the sealing member is spaced apart from the sealing surface.

21. The centrifugal pump assembly of claim 20, wherein: The sealing member surrounding the inlet opening (80) of the valve element (24; 24') is arranged on the outer circumference of the valve element (24; 24').

22. The centrifugal pump assembly of claim 19, wherein: The valve element (24; 24') comprises a sealing member which surrounds the inlet opening (80) and is arranged such that in a first axial position of the valve element (24; 24') the sealing member is in contact with an opposing sealing surface and in a second axial position of the valve element (24; 24') the sealing member is spaced apart from the sealing surface.

23. The centrifugal pump assembly of claim 22, wherein: The sealing member surrounding the inlet opening (80) of the valve element (24; 24') is arranged on the outer circumference of the valve element (24; 24').

24. The centrifugal pump assembly of claim 20, wherein: The sealing member surrounding the inlet opening (80) is arranged between the valve element (24; 24') and the cover plate (104; 104') is formed on the axial end opposite to the axial end.

25. The centrifugal pump assembly of claim 22, wherein: The sealing member surrounding the inlet opening (80) is arranged between the valve element (24; 24') and the cover plate (104; 104') is formed on the axial end opposite to the axial end.

Images