U.S. patent application number 16/492717 was filed with the patent office on 2021-05-13 for pump assembly.
The applicant listed for this patent is GRUNDFOS HOLDING A/S. Invention is credited to Thomas BLAD.
Application Number | 20210140435 16/492717 |
Document ID | / |
Family ID | 1000005357533 |
Filed Date | 2021-05-13 |
United States Patent
Application |
20210140435 |
Kind Code |
A1 |
BLAD; Thomas |
May 13, 2021 |
PUMP ASSEMBLY
Abstract
A pump assembly includes an electric drive motor (4, 6), an
impeller, driven by the drive motor (4, 6), and a valve device (18)
situated in a flow path through the pump assembly, which is movable
between a first and a second switching position. The valve device
(18) is coupled to the drive motor via a first coupling such that a
movement of the drive motor (4, 6) is transmitted onto the valve
device (18) and the valve device is movable from the first into the
second switching position by rotation movement of the drive motor.
The first coupling is releasable by way of increasing the speed of
the drive motor (4, 6) and/or increasing the pressure at the outlet
side of the impeller and/or by way of slip, such that the coupling
between the drive motor (4, 6) and the valve device (18) is reduced
or lifted.
Inventors: |
BLAD; Thomas; (Bjerringbro,
DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GRUNDFOS HOLDING A/S |
Bjerringbro |
|
DK |
|
|
Family ID: |
1000005357533 |
Appl. No.: |
16/492717 |
Filed: |
March 12, 2018 |
PCT Filed: |
March 12, 2018 |
PCT NO: |
PCT/EP2018/056086 |
371 Date: |
September 10, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/4293 20130101;
F24D 3/105 20130101; F04D 13/0606 20130101; F04D 15/0066 20130101;
F24D 2220/0207 20130101; F04D 29/486 20130101 |
International
Class: |
F04D 13/06 20060101
F04D013/06; F04D 29/42 20060101 F04D029/42 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2017 |
EP |
17 160 834.2 |
Claims
1. A pump assembly comprising: an electric drive motor; at least
one impeller which is driven by the drive motor; and at least one
valve device which is situated in a flow path through the pump
assembly and which is movable at least between a first switching
position and a second switching position, wherein the valve device
is coupled to the drive motor via a first coupling such that a
movement of the drive motor is transmitted onto the valve device
and the valve device is movable from the first into the second
switching position by way of a rotation movement of the drive motor
and the first coupling is releasable by way of increasing the speed
of the drive motor and/or increasing pressure at the outlet side of
the impeller and/or by way of slip, such that the coupling between
the drive motor and the valve device is reduced or lifted.
2. A pump assembly according to claim 1, wherein a second
releasable coupling is provided between at least one movable part
of the valve device and a pump casing which surrounds the impeller,
said second releasable coupling being movable from a released,
first coupling position into a holding, second coupling position by
way of the pressure at the outlet side of the impeller.
3. A pump assembly according to claim 2, wherein the first and the
second coupling are configured such that the first coupling in a
first coupling released position has a lower holding force than the
second coupling in a second coupling holding position and the first
coupling in a first coupling coupled position has a greater holding
force than the second coupling in a second coupling released
position.
4. A pump assembly according to claim 1, wherein on operation of
the pump assembly, the drive motor produces a torque which is
larger than the holding force of the first coupling in a first
coupling coupled position.
5. A pump assembly according to claim 1, wherein the valve device
is configured as a switch-over valve which permits a switching-over
between two flow paths and/or is configured as a mixing device, in
which fluid is mixed from two flow paths, wherein the mixing device
is configured such that the mixing ratio is different in the two
switching positions.
6. A pump assembly according to claim 1, wherein the valve device
has a valve function in a flow path at the suction side of the
impeller and/or in a flow path at the delivery side of the
impeller.
7. A pump assembly according to claim 1, wherein the valve device
comprises at least one movable valve element as well as stop
elements which define the first and the second switching position
and of which at least one is position adjustable.
8. A pump assembly according to claim 1, wherein the valve device
comprises at least one movable valve element which interacts with
two valve openings such that in the first switching position of the
valve device, a first valve opening is covered by the valve element
to a greater extent than in the second switching position and in
the second switching position a second valve opening is covered to
a greater extent than in the first switching position.
9. A pump assembly according to claim 1, wherein the valve device
comprises a movable valve element which comprises at least one
sealing surface and a pressure surface, wherein the pressure
surface is connected to a delivery chamber which surrounds the
impeller, such that the valve element is pressed with the sealing
surface against a contact surface by way of the pressure which acts
upon the pressure surface, wherein the contact surface forms a
valve seat.
10. A pump assembly according to claim 1, wherein the valve device
comprises a rotatable valve element which via the first coupling is
releasably coupled to a rotor of the drive motor, wherein the
rotation axis of the valve element is aligned with the rotation
axis of the drive motor.
11. A pump assembly according to claim 1, wherein the drive motor
driveable in two rotation directions and the valve device is
configured such that the first switching position is achieved by
the drive of the drive motor in a first rotation direction and the
second switching position is reached by the drive of the drive
motor in a second rotation direction.
12. A pump assembly according to claim 2, wherein the first and/or
the second coupling is a friction coupling, a magnetic coupling
and/or a hydraulic coupling, which has slip.
13. A pump assembly according to claim 1, wherein the first
coupling comprises at least one coupling element which is movable
between a coupled and a released position, wherein the movement
direction between the coupled and the released position runs
transversely to a force direction of the force which is to be
transmitted by the coupling onto the valve device.
14. A pump assembly according to claim 13, wherein a valve element
of the valve device forms the movable coupling element.
15. A pump assembly according to claim 13, wherein the coupling
element is subjected to a biasing force via a biasing element, said
biasing force forcing the coupling element into the coupled
position.
16. A pump assembly according to claim 15, wherein the coupling
element comprises a pressure surface, the connection of said
pressure surface to a delivery chamber which surrounds the impeller
and the arrangement of said pressure surface being such that a
pressure acting upon the pressure surface produces a force which is
directed oppositely to the biasing force.
17. A pump assembly according to claim 13, wherein the coupling
element comprises a coupling surface which in the coupled condition
is in frictional contact with a counter coupling surface, and that
the coupling surface and the counter coupling surface are
configured and surrounded by a lubricant, such that a lubricant
film which overcomes the frictional contact forms between the
coupling surface and the counter coupling surface on increasing the
speed of the drive motor.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a United States National Phase
Application of International Application PCT/EP2018/056086 filed
Mar. 12, 2018, and claims the benefit of priority under 35 U.S.C.
.sctn. 119 of European Application 17 160 834.2, filed Mar. 14,
2017, the entire contents of which are incorporated herein by
reference.
TECHNICAL FIELD
[0002] The invention relates to a pump assembly, in particular to a
centrifugal pump assembly with an electric drive motor and with at
least one valve device which is situated in a flow path through the
pump assembly and which is movable at least between a first and a
second switching position.
TECHNICAL BACKGROUND
[0003] Pump assemblies which contain a valve device which permits
the switching between two possible flow paths, through which the
centrifugal pump assembly delivers, are known. Here, valve devices
which switch in a manner depending on the rotation direction of the
centrifugal pump assembly, which is to say lead to the flow into
different flow paths in a manner dependent on the rotation
direction are known. Such a pump assembly which comprises a
switch-over device, with the help of which one can switch between
two inlets of the pump assembly, in order to selectively suck fluid
from one of the two inlets is known for example from DE 9013992 U1.
The pump assembly which is disclosed there comprises a relatively
complicated mechanism which comprises an onflow element which is
situated at the delivery side and which is subjected to onflow by
the outlet-side flow produced by the pump assembly and which can be
moved into two different positions depending on the rotation
direction and therefore the flow direction. A valve element at the
suction side of the pump assembly is switched between the two
inlets via a lever system which is connected to the onflow
element.
SUMMARY
[0004] With regard to this state of the art, it is an object of the
invention to improve a pump assembly with an integrated valve
device to the extent that a simpler construction of the pump
assembly is achieved with a simultaneously increased reliability of
the switching function of the valve device.
[0005] With regard to the pump assembly according to the invention,
it is the case of a centrifugal pump assembly. The pump assembly
comprises an electrical drive motor which is preferably configured
as a wet-running electrical drive motor, i.e. as a canned motor.
The pump assembly according to the invention can be configured for
example for use as a circulation pump in a heating facility and/or
air-conditioning facility. In particular, the pump assembly is
configured for delivering water.
[0006] The pump assembly comprises at least one impeller which is
driven by the drive motor. A valve device is which is movable at
least between a first and a second switching position is moreover
integrated into the pump assembly. Here, the valve device is
preferably configured such that it provides a valve function for
the fluid flow which is delivered by the pump assembly.
[0007] According to the invention, the valve device is configured
such that it is movable via the electrical drive motor of the pump
assembly, i.e. via the drive motor which drives the impeller. For
this, the valve device is coupled to the drive motor via a first
coupling in a manner such that the valve device is movable from the
first into the second switching position by way of a rotation
movement of the drive motor. This means that the movement of the
drive motor can be transmitted onto the valve device by the first
coupling, so that the valve device is directly or indirectly moved
by the drive motor. Inasmuch as the drive motor is configured such
that it can be driven in two rotation directions, according to a
preferred embodiment it would be possible to move the valve device
also back again from the second into the first switching position
via the respective rotation movement of the drive motor. According
to the invention, the first coupling is moreover configured such
that by way of increasing the speed of the drive motor and/or
increasing the pressure at the outlet side of the impeller and/or
slip, it is releasable in a manner such that the coupling effect
between the drive motor and the valve device can be reduced or
lifted. By way of this, it is possible to utilize the drive motor
in certain operating conditions in a targeted manner, in order to
move the valve device, whereas in other operating conditions, if
e.g. the increased pressure or the increased speed is provided, to
however not move the valve device. Usefully, the valve device is
thereby configured such that the coupling is released in the normal
operating condition of the pump assembly, i.e. when fluid is
delivered by the impeller in normal operation, so that in this
condition the valve element remains in an assumed switching
position.
[0008] According to a special embodiment of the invention, a gear
which changes or converts the movement direction and/or the
movement speed between the drive motor and the valve device can be
provided between the drive motor and the valve device. The gear can
be configured for example as a reduction gear which reduces a speed
of the valve device or of a valve element of the valve device, with
respect to the speed of the drive motor. Alternatively or
additionally, a rotation movement of the drive motor could be
converted into a linear movement of the valve element by a gear
such as a spindle drive.
[0009] The drive motor is preferably electrically controlled or
regulated so that it can be driven at different speeds and/or in
different rotation directions. A control device can be provided for
this, said control device regulating or controlling the drive motor
accordingly. In particular, the control device can be equipped with
a frequency converter for the speed change of the drive motor.
According to a further preferred embodiment of the invention, the
control device is configured such that it not only activates
(controls) the drive motor in a manner such that the drive motor
runs at different speeds, but also in a manner such that different
acceleration courses can be realized on accelerating and/or braking
the drive motor.
[0010] The configuration according to the invention has the
advantage that on the one hand one can make do without a separate
drive motor for the valve device, but that on the their hand one
can make do without complicated mechanisms for the transmission of
a force which is produced by the flow, onto a valve element. In
contrast, the force transmission can be effected by the first
coupling. The efficiency of the pump assembly can moreover be
improved since the valve device essentially does not compromise the
normal operation.
[0011] According to a preferred embodiment of the invention, at
least one stop can be provided, said stop holding the valve device
in a defined switching position, for example in the first or second
switching position. Further preferably, two stops can be provided,
wherein each of the two stops defines a switching position of the
valve device and the valve device is movable between the two
switching positions. This movement is effected via the first
coupling and by way of a suitable activation of the drive motor, in
particular via the described control device.
[0012] The valve device preferably comprises no further
electrically activated switching elements for switching and/or
holding the valve device. In contrast, the valve device is moved
between the switching positions solely by the drive motor.
[0013] According to a preferred embodiment of the invention, the
pump assembly comprises at least one second releasable coupling
between at least one movable part of the valve device and a valve
casing which surrounds the impeller. This second releasable
coupling is movable from a released first coupling position into a
holding coupling position by way of the pressure at the outlet side
of the impeller. Here, the at least one releasable coupling does
not need to engage on the pump casing in direct manner, but in
contrast can also engage on the pump casing in an indirectly
holding manner, by way of the coupling engaging with a component
which is connected to the pump casing. What is essential with the
embodiment of the second releasable coupling is the fact that in
its holding, second coupling position it prevents a movement of the
valve device. Here, preferably in one operation condition of the
pump assembly, the second releasable coupling comes into holding
engagement, i.e. into its holding, second coupling position, in
which the first coupling reaches its released position. One can
therefore succeed in the valve device being moved into a desired
switching position in one operating condition of the drive motor,
in particular in an operating condition with a lower speed and/or
lower acceleration, Subsequently, by way of a speed increase and/or
a particularly high acceleration of the drive motor, one can
succeed in the second releasable coupling coming into holding
engagement, so that the valve device remains and is held in the
reached switching position. Here, preferably the first coupling
simultaneously disengages or has a slip which permits the second
rotation of the drive motor with the impeller.
[0014] The first and the second coupling are preferably configured
in a manner such that in its released position, the first coupling
has a smaller holding force than the second coupling in its
holding, second coupling position. Conversely, the first coupling
in its coupled position preferably has a greater holding force that
the second coupling in its released, first coupling position. This
means that when it is engaged, the first coupling can transmit a
greater force or a greater torque that the second coupling in its
released, first coupling position. The valve element can therefore
be moved between two switching positions in this switch condition.
If the first coupling is located in its released position and the
second coupling in its holding coupling position, then the second
coupling can transmit a greater force or a greater toque than the
first coupling, so that the valve device is held in its reached
switching position and cannot be moved by the drive motor via the
first coupling.
[0015] Further preferably, the drive motor is configured such that
on operation of the pump assembly, it produces a torque which is
larger than the holding force of the first coupling in its coupled
position. By way of this, one prevents the first coupling from
preventing the rotation of the drive motor and thus of the impeller
in normal operation of the pump assembly.
[0016] The valve device can preferably be configured as a
switch-over valve which permits a switching between two flow paths.
Alternatively or additionally, the valve device can comprise a
mixing device, in which fluid from two flow paths is mixed, wherein
the mixing device is configured in a manner such that the mixing
ratio is different in the two switching positions of the valve
device. With the embodiment as a mixing device, the valve device
preferably comprises more than two switching positions and can be
movable in several steps or in a stepless manner, for example
between two switching positions which define the end positions. The
use as a switch-over valve can be used for example in a heating
facility, in which a switch-over valve is required, in order to
switch a heat transfer medium flow between a heat exchanger for
heating service water and at least one heating circuit for heating
a building. A mixing device can also be applied in a heating
facility, for example to reduce the temperature of a heat transfer
medium by way of admixing fluid from a return of the heating
facility. This can be useful e.g. for the use in a floor heating,
concerning which as a rule it is necessary to reduce the feed
temperature provided by a heating boiler, by way of admixing the
heat transfer medium from the return.
[0017] The valve device can preferably provide a valve function in
a flow path at the suction side of the impeller and/or a valve
function in a flow path at the delivery side of the impeller. The
valve device can therefore be arranged in particular as a
switch-over device at the suction side, so that the impeller sucks
fluid from a first or a second suction-side flow path depending on
the switching position of the valve device. Alternatively, a
switch-over device could be arranged at the delivery side, so that
the pump assembly delivers into a first or a second delivery-side
flow path depending on the switching position of the valve device.
If the valve device is configured as a mixing device, this can be
arranged at the delivery side for example such that two flow paths
in the mixing device run out at the delivery side into a mixing
point and that the mixing ratio between two flows is changed
depending on the switching position of the valve device. Here,
preferably one of the two flow paths runs through a heat exchanger
of a heating or cooling device, downstream of the pump assembly, in
order to control the temperature of fluid delivered by the pump
assembly, i.e. to heat or cool it. Fluid which is not
temperature-regulated is preferably located in the other flow path,
and this can then be mixed with the temperature-controlled fluid in
the mixing device. Alternatively, a mixing device could also be
arranged at the suction side of the pump assembly, so that the pump
assembly sucks e.g. a fluid which is mixed from two flow paths.
[0018] According to a further preferred embodiment, the valve
device comprises at least one movable valve element as well as stop
elements which define the first and the second switching position
and of which preferably at least one can be adjusted in its
position. It is possible to regulate the end positions or the
switching positions of the valve device by way of the ability to
adjust one or more stop elements. The stop elements prevent the
valve device or the valve element from being moved beyond the
desired switching position. The stop element therefore leads to a
positive engagement between the valve element and the stop element,
so that a further movement of the valve element is prevented.
[0019] According to a further preferred embodiment of the
invention, the valve device comprises at least one movable valve
element which interacts with two valve openings in a manner such
that in a first switching position of the valve device a first
valve opening is covered by the valve element to a greater extent
than in the second switching position and in the second switching
position a second valve opening is covered by the valve element to
a greater extent than in the first switching position. If the valve
element is configured as a switch-over valve, then in the first
switching position the second valve opening is opened and the first
valve opening is closed. Conversely then, in the second switching
position the second valve opening is closed and the first valve
opening is opened. Intermediate positions or intermediate switching
positions, in which both valve openings are simultaneously opened
but to a different extent are preferably possible in the case of
the configuration of the valve device as a mixing device. A mixing
ratio can therefore be changed by way of changing the openings
degrees of the two valve openings. Preferably, the at least one
movable valve element is configured such that when a valve opening
is opened by a certain amount, the other valve opening is
simultaneously closed by the same amount.
[0020] Such a reciprocity of the closure of the two valve openings
can be realized with a valve element or however also with two valve
elements if these are mechanically coupled to one another.
[0021] According to a further preferred embodiment, the valve
device comprises a movable valve element which comprises at least
one sealing surface and a pressure surface, wherein the pressure
surface is connected to a delivery chamber which surrounds the
impeller, in a manner such that the valve element is pressed with
the sealing surface against a contact surface (bearing surface) by
way of the pressure acting upon the pressure surface, wherein the
contact surface preferably forms a valve seat. With such an
embodiment, the valve element together with the contact surface can
assume the function of the second coupling which is described
above. If the valve element is pressed against the contact surface
by way of pressure in the delivery chamber, then preferably such a
friction fit arises between the sealing surface and the contact
surface that the valve element is fixed in the reached switching
position. This friction fit could additionally be assisted by a
positive fit given a suitable configuration of the sealing surface
and the contact surface. A sealing is simultaneously achieved via
the bearing contact of the sealing surface if the bearing contact
is a valve seat. If the pressure in the delivery chamber is lower,
then the sealing surface preferably disengages from the contact
surface or preferably from a valve seat, so that an easy movability
of the valve element with a reduced friction is ensured. The valve
seats can preferably surround valve opening, as have been described
beforehand. A sealing of the flow paths to the outside is then
achieved by way of the bearing contact of the at least one sealing
surface. Moreover, a sealing surface can also be pressed against a
contact surface or a valve seat such that a sealing between the
suction chamber and the delivery chamber of the pump assembly is
achieved by the bearing contact. Several valve seats, on which one
or more sealing surfaces of the valve element can come to bear
given an adequately large pressure in the delivery chamber, can
therefore be provided, in order to achieve the necessary sealings
of the flow paths. A restoring element, for example a restoring
spring can preferably be provided, and this restoring element
disengages the valve element with the sealing surface from the
contact surface when the pressure in the delivery chamber falls
below a predefined valve, i.e. the force produced on the pressure
surface by the pressure in the delivery chamber is smaller than the
restoring force which is produced by the restoring element. An
easily movability of the valve element is thus ensured given a low
pressure.
[0022] The valve device can further preferably comprise a rotatable
valve element. I.e. the valve element is moved between the
switching positions by way of a rotating movement, wherein the
rotation axis further preferably is aligned with the rotation axis
of the impeller or of the drive motor, which permits a particularly
simple coupling without further gear means. The rotatable valve
element is preferably releasably coupled to a rotor of the drive
motor via the first coupling, wherein the coupling does not need to
engage on the actual magnet rotor but also on a component such as a
shaft or the impeller, which is connected to the magnet rotor. The
rotatable valve element is rotatingly co-moved via the rotor of the
drive motor when the first coupling is engaged.
[0023] The drive motor is preferably driveable in two rotation
directions and the valve device is configured in a manner such that
its first switching position can be reached by way of the drive of
the drive motor in a first rotation direction and its second
switching position by way of the drive of the drive motor in a
second rotation direction. A restoring means or a force generating
means which rotates the valve element back into a predefined
initial position or switching position on switching off the drive
motor can also be provided instead of a movement of the valve
element in two rotation directions by way of the drive motor. This
for example can be a magnetic restoring means, restoring means
acting by way of a spring force or one which acts by way of
gravity.
[0024] The first and/or the second coupling can preferably be a
frictional coupling, a magnetic coupling and/or a hydraulic
coupling which further preferably have a slip. If the first
coupling has slip, then after reaching a predefined switching
position when the valve element of the valve device or the valve
device is fixed in the switching position, this slip permits the
drive motor to be able to rotate further without becoming blocked
by the fixation of the valve device. A valve element for example
can therefore hit a stop, whereupon the coupling then slips
through, which is to say that the drive motor can rotate further
due to the slip in the coupling. Particularly preferably, a
hydraulic coupling can be realized via the fluid which is delivered
by the impeller. The fluid can hence be brought into rotation in
the rotation direction of the impeller by way of the impeller in
the inside of the pump casing and can drive the valve element via
the friction on a part of the valve device, in particular directly
on this valve element. The hydraulic flow flows further when the
valve element or the valve device reaches a switching position and
is fixed there, wherein the remaining hydraulic friction losses
only occur at the surfaces. I.e., the loss energy which is present
in any case and which is converted into a movement of the valve
device or of the valve element can therefore be used for moving the
valve device.
[0025] Further preferably, the first coupling comprises at least
one coupling element which is movable between a coupled and a
released position, wherein the movement direction between the
coupled and the released position preferably runs transversely to a
force direction of the force which is to be transmitted by the
coupling onto the valve device. In the coupled position, a
non-positive and/or positive engagement exists between the coupling
element and an opposite coupling surface. The coupling element is
movable such that it can disengage from the coupling surface, so
that the valve element can then no longer be moved or caught and
remains in its assumed switching position. The movement direction
between the coupled and released position preferably lies in a
direction which is different from the force transmission direction,
by which means it is ensured that the coupling element is not moved
out of engagement by the force to be transmitted. Particularly
preferably, the movement direction runs normally to the force
direction or a plane, in which the force direction runs. The latter
can be the case for example if the coupling serves for the
transmission of a torque. The movement direction then preferably
runs along the rotation axis and thus transversely and in
particular normally to the plane, in which the force is
transmitted.
[0026] Particularly preferably, a valve element of the valve device
can simultaneously form the movable coupling element. The valve
element can hence comprise a coupling surface which can engage with
an opposite coupling surface which is preferably arranged on the
rotor or impeller, in order to move the valve element, in
particular in a rotating manner. Here, a non-positive and/or
positive engagement can be envisaged. The coupling element can
further usefully be subjected to a biasing force via a biasing
element, said biasing force forcing the coupling element into the
coupled position. This means that the first coupling is in coupling
engagement in the idle position. This engagement is then preferably
made to disengage by way of the pressure occurring in the delivery
chamber or by way of a higher speed of the drive motor. If the
drive motor is switched off, then this force releasing the coupling
then drops again, so that the biasing force forces the coupling
back into the coupled position.
[0027] Further preferably, the coupling element comprises a
pressure surface, whose connection to a delivery chamber
surrounding the impeller and whose arrangement being such that
pressure acting upon the pressure surface produces a force which is
directed oppositely to the biasing force. The coupling element is
displaced if the pressure in the delivery chamber increases to such
an extent that the pressing force produced by the pressure surface
exceeds the biasing force, wherein the coupling element is arranged
such that it is moved into its released position given this
displacement, i.e. the first coupling disengages and the valve
element is not moved further by the drive motor, but remains in its
assumed switching position. If the pressure reduces, for example
when the pump assembly is switched off, then the pressing force
weakens and the biasing force again becomes the greater force, so
that the coupling is again moved into the coupled position. The
valve element or the valve device can then be moved again into
another switching position with the next start-up of the drive
motor.
[0028] According to a further preferred embodiment of the
invention, the coupling element can comprise a coupling surface
which in the coupled position is in frictional contact with a
counter coupling surface, wherein the coupling surface and the
counter coupling surface are configured and surrounded by a
lubricant such that a lubricant film which overcome or lifts the
frictional contact forms between the coupling surface and the
counter coupling surface on increasing the speed of the drive
motor. The fluid which is delivered by the pump assembly, for
example water is preferably applied as a lubricant. The coupling
then functions in the manner of a plain bearing. Given an
adequately high speed, a lubricant film forms between the coupling
surface and the counter coupling surface, so that the frictional
contact between the surfaces is lifted and these can slide on one
another in the manner of a plain bearing. A coupling which can be
disengaged by way of a speed increase can therefore be created.
I.e. if the drive motor is moved at a low speed, then the valve
element or the valve device is moved via the friction contact
between the coupling surface and the counter coupling surface which
is situated between the rotor and the valve device or the valve
element, so that the switching position can be changed. The drive
motor can subsequently be increased in its speed to such an extent
that the friction contact is lifted as has been described and the
valve device remains in the reached switching position.
[0029] If a purely hydraulic coupling between the drive motor and
the valve device is used, then the disengagement can be achieved by
way of hydraulic slip, wherein the valve device is then preferably
fixed in the second switching position by a second coupling in the
manner described above. Given a suitable acceleration of the drive
motor, with such a configuration it is also possible to hold the
valve element in its initial position without it being moved by the
hydraulic coupling. This can be achieved by way of the drive motor
being accelerated so rapidly that a pressure build-up which moves
the second coupling into the coupled coupling position is effected
so rapidly that the second coupling engages before a displacement
of the valve element and thus a change of the switching position of
the valve device occurs.
[0030] The invention is hereinafter described by way of example and
by way of the attached figures. The various features of novelty
which characterize the invention are pointed out with particularity
in the claims annexed to and forming a part of this disclosure. For
a better understanding of the invention, its operating advantages
and specific objects attained by its uses, reference is made to the
accompanying drawings and descriptive matter in which preferred
embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In the drawings:
[0032] FIG. 1 is an exploded view of a centrifugal pump assembly
according to a first embodiment of the invention;
[0033] FIG. 2 is a perspective view of the lower side of the valve
element of the centrifugal pump assembly according to FIG. 1;
[0034] FIG. 3 is a perspective view of the pump casing of the
centrifugal pump assembly according to FIG. 1 in the opened
condition;
[0035] FIG. 4 is a sectional view of the centrifugal pump assembly
according to FIG. 1;
[0036] FIG. 5 is a sectional view of the pump casing of the
centrifugal pump assembly according to FIG. 4 with the valve
element in a first switching position;
[0037] FIG. 6 is a sectional view according to FIG. 5 with the
valve element in a second switching position;
[0038] FIG. 7 is a schematic view of the hydraulic construction
with a heating facility with a centrifugal pump assembly according
to FIGS. 1 to 6;
[0039] FIG. 8 is an exploded view of a centrifugal pump assembly
according to a second embodiment of the invention;
[0040] FIG. 9 is a sectional view of the centrifugal pump assembly
according to FIG. 8 with the valve element in a first position;
[0041] FIG. 10 is a sectional view according to FIG. 9 with the
valve element in a second position;
[0042] FIG. 11 is an exploded view of the centrifugal pump assembly
according to a third embodiment of the invention;
[0043] FIG. 12 is a sectional view of the centrifugal pump assembly
according to FIG. 11 with the valve element in a first
position;
[0044] FIG. 13 is a sectional view according to FIG. 12 with the
valve element in a second position;
[0045] FIG. 14 is an exploded view of a pump assembly with a valve
element according to a fourth embodiment of the invention;
[0046] FIG. 15 is a sectional view of a centrifugal pump assembly
according to the fourth embodiment of the invention;
[0047] FIG. 16 is an exploded view of a centrifugal pump assembly
according to a fifth embodiment of the invention;
[0048] FIG. 17 is a sectional view of the centrifugal pump assembly
according to FIG. 16 with the valve element in a first
position;
[0049] FIG. 18 is a sectional view according to FIG. 17 with the
valve element in a second position;
[0050] FIG. 19 is an exploded view of a centrifugal pump assembly
according to a sixth embodiment of the invention;
[0051] FIG. 20 is a sectional view of the centrifugal pump assembly
according to FIG. 19;
[0052] FIG. 21 is a plan view of the opened pump casing of the
centrifugal pump assembly according to FIGS. 19 and 20 with the
valve element in a first switching position;
[0053] FIG. 22 is a plan view according to FIG. 21 with the valve
element in a second switching position;
[0054] FIG. 23 is an exploded view of a pump casing with a valve
element according to a seventh embodiment of the invention;
[0055] FIG. 24 is an exploded view of the pump casing with the
valve element according to the seventh embodiment seen from a
different side;
[0056] FIG. 25 is an exploded view of a centrifugal pump assembly
according to an eighth embodiment of the invention;
[0057] FIG. 26 is a sectional view of the centrifugal pump assembly
according to FIG. 25;
[0058] FIG. 27 is a plan view of the opened pump casing of the
centrifugal pump assembly according to FIGS. 25 and 26 with the
valve element in a first switching position;
[0059] FIG. 28 is a plan view according to FIG. 27 with the valve
element in a second switching position;
[0060] FIG. 29 is an exploded view of the centrifugal pump assembly
according to a ninth embodiment of the invention;
[0061] FIG. 30 is a perspective view of the centrifugal pump
assembly according to FIG. 29 with a removed pump casing and valve
element;
[0062] FIG. 31 is a perspective view of the motor shaft of the
centrifugal pump assembly according to FIGS. 29 and 30 as well as
of the coupling part of the valve element;
[0063] FIG. 32 is a sectional view of the centrifugal pump assembly
according to FIG. 29 with the valve element in a first
position;
[0064] FIG. 33 is a sectional view according to FIG. 32 with the
valve element in a second position;
[0065] FIG. 34 is a plan view upon the opened pump casing of the
centrifugal pump assembly according to FIGS. 29 to 33 with the
valve element in a first switching position;
[0066] FIG. 35 is a view according to FIG. 34 with the valve
element in a second switching position;
[0067] FIG. 36 is a view according to FIGS. 34 and 35 with the
valve element in a third switching position;
[0068] FIG. 37 is a schematic view of the hydraulic construction of
a heating facility with a centrifugal pump assembly according to
FIGS. 29 to 36;
[0069] FIG. 38 is an exploded view of a centrifugal pump assembly
according to a tenth embodiment of the invention;
[0070] FIG. 39 is a perspective view of the opened valve element of
the centrifugal pump assembly according to FIG. 38;
[0071] FIG. 40 is a perspective view of the closed valve element
according to FIG. 39;
[0072] FIG. 41 is a sectional view of the centrifugal pump assembly
according to FIG. 38 with the valve element in a first
position;
[0073] FIG. 42 is a sectional view according to FIG. 41 with the
valve element in a second position;
[0074] FIG. 43 is a plan view upon the opened pump casing of the
centrifugal pump assembly according to FIGS. 38 to 42 with the
valve element in a first switching position;
[0075] FIG. 44 is a view according to FIG. 43 with the valve
element in a second switching position;
[0076] FIG. 45 is a view according to FIGS. 43 and 44 with the
valve element in a third switching position;
[0077] FIG. 46 is a view according to FIGS. 43 to 45 with the valve
element in a fourth switching position; and
[0078] FIG. 47 is a schematic view of the hydraulic construction of
a heating facility with a centrifugal pump assembly according to
FIGS. 38 to 46.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0079] Referring to the drawings, the embodiment examples of the
pump assembly according to the invention, in the form of a
centrifugal pump assembly, which are described in the following
description, relate to applications in heating systems and/or air
conditioning systems, in which a fluid heat transfer medium, in
particular water, is circulated by the centrifugal pump
assembly.
[0080] The centrifugal pump assembly according to the first
embodiment of the invention comprises a motor casing 2, in which an
electrical drive motor is arranged. This in the known manner
comprises a stator 4 as well as 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 way of a can or a canned pot 10. This means that here it is the
case of a wet-running electrical drive motor. The motor casing 2 is
connected to a pump casing 12 at an axial end, in which pump casing
an impeller 14 which is connected to the rotor shaft 8 in a
rotationally fixed manner rotates.
[0081] An electronics casing 16 which contains control electronics
or a control device for the activation of the electrical drive
motor in the pump casing 2 is arranged at the axial end of the
motor casing 2 which is opposite to the pump casing 12. The
electronics casing 16 could also be arranged at another side of the
pump casing 2 in a corresponding manner.
[0082] A valve device with a movable valve element 18 is moreover
arranged in the pump casing 12. This valve element 18 is rotatably
mounted on a pivot 20 in the inside of the pump casing 12, and
specifically such that the rotation axis of the valve element 18 is
aligned with the rotation axis X of the impeller 14. The pivot 20
is fixed to the base of the pump casing 12 in a rotationally fixed
manner. The valve element 18 is not only rotatable about the pivot
20 but is movable in the longitudinal direction X by a certain
amount. This linear movability is limited in one direction by way
of the pump casing 12, upon which the valve element 18 hits or
butts with its outer periphery. In the opposite direction, the
movablility is limited by the nut 22, with which the valve element
18 is fastened on the pivot 20. It is to be understood that a
different axial fastening of the valve element 18 to the pivot 20
could also be selected instead of the nut 22.
[0083] In the pump casing 12, the valve element 18 separates a
suction chamber 24 from a delivery chamber 26. The impeller 14
rotates in the delivery chamber 26. The delivery chamber 26 is
connected to the delivery connection or delivery branch 28
(delivery nozzle) of the centrifugal pump assembly which forms the
outlet of the centrifugal pump assembly. Two suction-side inlets 28
and 30, of which the inlet 28 is connected to a first suction
branch 32 and the inlet 30 is connected to the second suction
branch 34 of the pump casing 12 run out into the suction chamber
24.
[0084] The valve element 18 is configured in a disc-like manner and
simultaneously assumes the function of a common deflector plate
which separates the suction chamber 24 from the delivery chamber
26. The valve element 18 comprises a central suction opening 26
which comprises a projecting peripheral collar which is engaged
with the suction port 38 of the impeller 14 and is essentially in
sealing bearing contact with the suction port 38. Facing the
impeller 14, the valve element 18 is configured in an essentially
smooth manner. The valve element at the side which is away from the
impeller 14 comprises two annular sealing surfaces 40 which in this
embodiment example are situated on closed, tubular stubs
(connection pieces or nozzles). The two annular sealing surfaces 40
are arranged on the sealing element 18 at two diametrically
opposite positions with respect to the rotation axis X of this
element, so that they can come to sealing bear on the base of the
pump casing 12 in the peripheral region of the inlets 28 and 30, so
as to close the inlets 28 and 30. Support elements 42 are arranged
offset to the sealing surfaces 40 at an angular position of
90.degree. and can likewise come to bear on the peripheral region
of the inlets 28, 30, but are distanced to one another such that
they do not then close the inlets 28, 30. The inlets 28 and 30 do
not lie on the diameter line with respect to the rotation axis X,
but on a radially offset straight line, so that on rotation of the
valve element 18 about the rotation axis X into a first switching
position, the inlet 38 is closed by a sealing surface 40 whilst the
support elements 42 lie on the inlet 30 and open this. In a second
switching position, the inlet 30 is closed by a sealing surface 40
whilst the support elements 42 bear in the peripheral region of the
inlet 28 and open this. The first switching position, in which the
inlet 38 is closed and the inlet 30 is opened is represented in
FIG. 5. The second switching position, in which the inlet 30 is
closed and the inlet 28 is opened is represented in FIG. 6. This
means that one can switch between the two switching positions by
way of a rotation of the valve element about the rotation axis X by
90.degree.. The two switching positions are limited by a stop
element 44 which alternately hits two stops 46 in the pump casing
12.
[0085] In an idle position, which is to say when the centrifugal
pump assembly is not in operation, a spring 48 presses the valve
element 18 into released position, in which the outer periphery of
the valve element 18 does not sealingly bear on the pump casing 12
and the sealing surfaces 40 do not sealingly bear in the peripheral
region of the inlets 28 and 30, so that the valve element 18 can
rotate about the axis 20. If the drive motor is now brought into
rotation by the control device 17 in the electronics casing 16, so
that the impeller 14 rotates, then a peripheral flow which via the
friction co-rotates the valve element 18 in its rotation direction
is produced in the delivery chamber 26. I.e. a first hydraulic
coupling between the drive motor and the valve element is formed
via the rotating flow. The control device 17 is configured such
that it can drive the drive motor selectively in two rotation
directions. The valve element 18 can therefore likewise be moved in
two rotation directions about the rotation axis X depending in the
rotation direction of the impeller 14, via the flow which is
brought into rotation by the impeller 14, since the flow in the
peripheral region of the impeller 14 always runs in its rotation
direction. The valve element 18 can therefore be rotated between
the two switching positions which are limited by the stops 46.
[0086] If the impeller 14 rotates at a sufficient speed, then a
pressure builds up in the delivery chamber 26 and this pressure
produces a pressing force on the surface of the valve element 18
which surrounds the suction opening 36, said pressing force being
opposite to the spring force of the spring 48, so that the valve
element 18 is moved in the axial direction X against the spring
force of the spring 48 such that it comes to sealingly bear at its
outer periphery on an annular contact shoulder 50 on the pump
casing 12. Depending on the switching position, one of the sealing
surfaces 40 simultaneously comes to sealingly bear on the periphery
of one of the inlets 28 and 30, so that one of the inlets 28, 30 is
closed. The support elements 42 come to bear on the other inlet, so
that this inlet remains open and a flow path from this inlet 28, 30
to the suction opening 36 and from there into the inside of the
impeller 14 is given. A frictional contact between the valve
element 18 and the pump casing 12 is simultaneously created by way
of the bearing of the valve element 18 on the contact shoulder 50
and on the sealing surface 40 in the peripheral region of one of
the inlets 28, 30. This frictional contact forms a second coupling
which fixes the valve element. This frictional contact ensures that
the valve element 18 is held in the reached switching position.
This permits the drive motor to be briefly taken out of operation
and to be brought into operation again in the opposite rotation
direction without the valve element 18 being rotated. If the
switching-off and restarting operation of the motor are effected
rapidly enough, then the pressure in the delivery chamber 26 does
not reduce to the extent that the valve element 18 can again move
in the axial direction into its released position. This permits the
impeller to always be driven in its preferred rotation direction,
for which the blades are configured, on operation of the
centrifugal pump assembly and to only use the opposite rotation
direction for moving the valve element 18 in the opposite rotation
direction. The impeller 14 can rotate further when the valve
element 18 is in its bearing position, which is to say contacting
position, in which a frictional bearing contact is given and the
thus formed second coupling is engaged. The flow continues to run
in the delivery chamber 26 without co-rotating the valve element
18. This means that the hydraulic first coupling which is formed
between the impeller 14 and the valve element 18 disengages due to
slip.
[0087] The described centrifugal pump assembly according to the
first embodiment of the invention can be applied for example in a
heating system as is shown in FIG. 7. Such a heating system is
usually applied in apartments or houses and serves for heating the
building or for the provision of heated service water. The heating
facility comprises heat source 52, for example in the form of a gas
heating boiler. A heating circuit 54 which leads for example
through various radiators of a building is also present. A
secondary heat exchanger 56, via which service water can be heated
is moreover provided. A switch-over valve which selectively leads
the heat transfer medium flow through the heating circuit 54 or the
secondary heat exchanger 56 is usually required in such heating
facilities. Regarding the centrifugal pump assembly 1 according to
the invention, this valve function is assumed by the valve element
18 which is integrated into the centrifugal pump assembly 1. The
control is effected by the control device 17 in the electronics
casing 16. The heat source 52 is connected to the delivery branch
27 of the pump casing 12. A flow path 58 is connected to the
suction branch 32, whereas a flow path 60 through the heating
circuit 54 is connected to the suction branch 34. One can therefore
switch between the flow path 58 through the secondary heat
exchanger 56 and the flow path through the heating circuit 54
depending on the switching position of the valve element 18,
without a valve with an additional drive becoming necessary.
[0088] The second embodiment example according to FIGS. 8 to 10
differs from the first embodiment example in respect to the
construction of the valve element 18'. In this embodiment example
too, the valve element 18' separates the delivery chamber 26 from a
suction chamber 24 of the pump casing 12. The valve element 18
comprises a central suction opening 36', into which the suction
port 38 of the impeller 14 sealingly engages. Opposite the suction
opening 36, the valve element 18' comprises an opening 62 which can
be selectively brought to overlap with one of the inlets 28, 30
depending on the switching position of the valve element 18'. In
this embodiment example, the inlets 28', 30' with regard to shaping
differ from the inlets 28, 30 according to the preceding
embodiment. The valve element 18' comprises a central projection 64
which engages into a central hole 60 in the base of the pump casing
12 and is rotatingly mounted there about the rotation axis X. The
projection 64 in the hole 66 simultaneously permits an axial
movement along the rotation axis X, said movement being limited in
one direction by the base of the pump casing 12 and in the other
direction by the impeller 14. At its outer periphery, the valve
element 18' comprises a pin 68 which engages into a semicircular
groove 70 on the base of the pump casing 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 lies above the inlet 28' and in
the second switching position the opening 62 lies above the inlet
30' and the respective other inlet is closed by the base of the
valve element 18'. The rotation movement of the valve element 18'
between the two switching positions in this embodiment example is
also effected by the flow which is caused in the delivery chamber
26 by the impeller 14 and which forms a first hydraulic coupling.
The valve element 18' is provided with projections 72 which are
directed into the delivery chamber 26, in order to be able to
transmit this flow onto the valve element 18' in a better manner.
If the centrifugal pump assembly 1 is taken out of operation, the
spring 48 presses the valve element 18' into the released position
which is shown in FIG. 10 and in which it does not bear on the base
in the periphery of the inlets 28' and 30'. I.e. the second
coupling is released. In this position, the valve element 18' abuts
axially with a central pin 74 upon the face side of the motor shaft
8 and is limited in its axial movement by thus stop. If the
pressure in the delivery chamber 26 is adequately large, the valve
element 18' is pressed into the bearing (contacting) position which
is shown in FIG. 9 and in which the valve element 18' comes to bear
on the base of the pump casing 12 in the peripheral region of the
inlets 28' and 30', and the pin 74 is simultaneously lifted from
the face side of the rotor shaft 8. I.e. the second coupling is
engaged. In this position, the rotor impeller 14 then rotates in
normal operation of the centrifugal pump assembly. I.e. the
hydraulic first coupling disengages due to slip.
[0089] The third embodiment example according to FIGS. 11 to 13
shows a further possible embodiment of the valve element 18''. This
embodiment example differs from the preceding embodiment examples
with regard to the construction of the valve element 18''. This
valve element is configured as a valve drum. The pump casing 12
corresponds essentially to the construction according to FIGS. 1 to
6, wherein in particular the arrangement of the inlets 28 and 30
corresponds to the arrangement which is described by way of the
first embodiment example. The valve drum of the valve element 18''
consists of a pot-like lower part which is closed by a cover 78.
The cover 78 faces the delivery chamber 26 and comprises the
central suction opening 36 which engages with its axially directed
collar into the suction port 38 of the impeller 14. At the opposite
side, the base of the lower part 36 comprises an inlet opening 80
which is brought to overlap with one of thee inlets 28, 30
depending on the switching position, whilst the respective other
inlet 28, 30 is closed by the base of the lower part 26. The valve
element 18'' is rotatably mounted on a pivot 20 which is fastened
in the base of the pump casing 12, wherein the rotation axis which
is defined by the pivot 20 corresponds to the rotation axis X of
the impeller 14. In this embodiment example too, the valve element
18'' is axially displaceable along the pivot 20 by a certain
amount, wherein a spring 48 which in the idle position presses the
valve element 18'' into its released position which is shown in
FIG. 13 is present here too. Here too, a releasable second coupling
is therefore created for holding the valve element 18''. In this
embodiment example too, the released axial position is limited by
the nut 22. In the released position, the valve element 18'' is
rotatable by way of the flow which is created by the impeller 14,
as described previously, which is to say a hydraulic coupling
(first coupling) between the impeller 14 and the valve element 18''
is created, as has been described beforehand. In the bearing
position which is shown in FIG. 12, on the one hand one of the
inlets 28, 30 is sealingly closed depending on the switched
position. On the other hand, a sealing between the suction chamber
24 and the delivery chamber 26 is effected due to the valve element
18'' bearing on the contact shoulder 50.
[0090] In this embodiment example, the mounting of the valve
element 18'' on the pivot 20 is moreover encapsulated by two
sleeves 82 and 84, so that these regions are protected from
contamination by the delivered fluid and can be possibly
pre-lubricated. A very easy-motion mounting is sought after, in
order to ensure the easy rotatability of the valve element 18'' by
the flow which is caused by the impeller 14. It is to be understood
that the mounting can be encapsulated accordingly also in the case
of the other embodiment examples which are described here.
[0091] FIGS. 14 and 15 show a fourth embodiment example, concerning
which the construction of the pump casing 12 corresponds to the
construction of the pump casing 12 according to the first and the
third embodiment example. In this embodiment example, the rotation
movement of the valve element 18c is assisted by the suction-side
flow, which is to say the flow which enters into the suction port
38 of the impeller 14. Since the suction-side flow is also produced
by the centrifugal pump assembly in a circulation system, in which
a centrifugal pump assembly as is described here is applied, an
indirect coupling of the impeller 14 to the valve element 18c is
also created via the suction-side flow, said indirect coupling
representing a first hydraulic coupling. In this embodiment too,
the valve element 18c is configured in an essentially drum-like
manner and comprises a cover 28 which faces the delivery chamber 26
and which is with a central suction opening 36 which is engaged
with the suction port 38 as has been described beforehand. The
lower part 76b which is shown here comprises two entry openings 80
which can be brought to overlap with one of the inlets 28, 30
depending on the switching position, wherein the respective other
inlet 28, 30 is sealingly closed by the base of the lower part 46b,
as has been described with the preceding embodiment example. Guide
vanes 86 with blades, into which the flow enters radially from the
inlet openings 80 and exits axially to the central suction opening
36 are arranged between the lower part 76b and the cover 78. A
torque about the pivot 20 is also produced by the blades of the
guide vanes 86, by way of which torque the valve element 18c can be
moved between the switching positions. This functions essentially
as has been described previously. A spring 48, as has been
described previously, can additionally be provided, in order to
move the valve element 18c into a released position. With this
embodiment example, the restoring movement is effected by a weight
88, since a torque is always produced in the same direction
independently of the direction, in which the impeller 14 rotates,
on account of the shaping of the blades of the guide vanes 86. On
operation, the centrifugal pump assembly is always situated in the
installation position which is shown in FIG. 15 and in which the
rotation axis X extends horizontally. When the centrifugal pump
assembly is switched off, the valve element 18c always rotates
about the pivot 20 such that the weight 88 lies at the bottom. The
valve element 18c can be rotated against this restoring force which
is produced by the weight 88, by way of the torque produced by the
guide vanes 86, wherein a pressure can be built up in the delivery
chamber 26 in such a rapid manner by way of a very rapid starting
operation of the drive motor, that the valve element 18c gets into
its bearing position, as has been described above, in which
position it is non-positively held on the pump casing 12 in a
rotationally fixed manner without having to be moved out of its
idle condition. I.e., a second coupling as is described above is
also realized here. It is to be understood that a restoring of the
valve element by way of gravity or by way of another restoring
force independently of the drive could also be applied to the other
embodiment examples which are described here. If the valve element
18c is in the bearing position, then the first coupling which is
formed by the guide vanes 86 disengages due to slip, which is to
say that the flow continues to run through the guide vanes without
however being able to cause a rotation of the valve elements.
[0092] The fifth embodiment example according to FIGS. 16 to 18
differs from the preceding embodiment examples again in the
construction of the valve element. With regard to this embodiment
example, the valve element 18d is configured conically. The valve
element 18d comprises a conical, pot-like lower part 76d which is
closed by a cover 78d, wherein a central suction opening 36 which
is engaged with the suction port 38 of the impeller 14 in the
previously described manner is again formed in the cover 78d. Inlet
openings 90 which by way of rotating the valve element 18d can be
selectively brought to overlap with inlets which are connected to
the suction branches 32 and 34, in order to create a flow path
through the inside of the valve element 18d to the suction opening
36 are formed in the conical peripheral surface of the lower part
76b. Sealing surfaces 92 which can close the respective other inlet
are formed on the conical lower part between the inlet openings 90.
As also with the second embodiment example according to FIGS. 8 and
10, here the valve element 18d also comprises a pin-like projection
64 which engages in a recess on the base of the pump casing 12 and
there rotatably mounts the valve element 18d about the rotation
axis X. Here too, an axial movement is possible between a released
position, as is shown in FIG. 18 and a bearing (contacting)
position as is shown in FIG. 17, in order to form a releasable
second coupling. In the released position, the lower part 76d of
the valve element 18d essentially does not bear on the pump casing
12 so that it can be rotated by the flow in the delivery chamber 26
as a first hydraulic coupling, as has been described with regard to
the previously described embodiment examples. Here, a to-and-fro
movement of the valve element 18d can again be achieved in a manner
dependent on the rotation direction of the impeller, wherein here
too, the rotation movement of the valve element 18d can also be
limited by stops which are not shown. In the bearing position
according to FIG. 17, on the one hand a sealing bearing contact of
the valve element 18d is effected, and on the other hand it is
non-positively held, so that again, as long as the pressure in the
delivery chamber 26 is sufficiently large, it is not moved between
the switching positions even given a direction change of the
impeller 14.
[0093] The sixth embodiment example according to FIGS. 19 to 22 is
similar to the second embodiment example according to FIGS. 8 to
10. The pump casing 12 corresponds essentially to the construction
which is represented there and has been described. The motor casing
2 with the electronics casing 16 and the can 10 also correspond to
the construction according to the second embodiment example. The
valve element 18e has a construction which is very similar to the
construction of the valve element 18'. What is merely absent are
the projections 76 and pin 74. In contrast, the opening 62 is
formed in exactly the same manner. The suction opening 36e also
corresponds essentially to the construction of the suction opening
36'. The valve element 18e is rotatingly mounted on a hollow pivot
which is inserted into the hole 66 in the base of the pump casing
12. In this embodiment example, the spring 48 is arranged in the
inside of the hollow axis 94.
[0094] Depending on the switching position of the valve element
18e, the opening 62 either comes to lie over the inlet 28' or the
outlet 30', in order to either open a flow path from the suction
branch 32 to the impeller 14 or from the suction branch 34 to the
impeller 14. In this embodiment too, the valve element 18e is
additionally axially movable along the rotation axis X which is the
rotation axis of the impeller 14 and of the valve element 18e, in
order to from a second coupling. In an idle position, in which the
centrifugal pump assembly is not in operation, the valve element
18e is pushed by the spring 48 into a released position, in which
the surface of the valve element 18e which is away from the
impeller 14 is distanced to the base of the pump casing 12, so that
the valve element 18e can be rotated to and fro about the axis 94
in an essentially free manner between the stops which are formed by
the pin 68 and the groove 70. FIG. 21 shows the first switching
position, in which the opening 62 lies opposite the inlet 28' and
FIG. 22 shows the second switching position, in which the opening
62 lies opposite the second inlet 30'.
[0095] With this embodiment example, the rotation of the valve
element 18e is again effected via the impeller 14, but here a
mechanical coupling is provided as a first coupling, said coupling
being realized by way of the impeller 14 with its region which
surrounds the suction port 38 coming to frictionally bear on the
periphery of the suction opening 36e. The valve element 18e is
therefore co-rotated with the impeller 14 until the pin 68 reaches
a stop. The coupling then disengages due to slip. Then, with an
increasing pressure in the delivery chamber 26, the valve element
18e is moved axially into its bearing (contacting) position as
described above, in which position the second coupling is therefore
engaged and wherein the first coupling disengages from the impeller
14, so that the impeller 14 can then rotate in an essentially
frictionless manner.
[0096] The seventh embodiment example according to FIGS. 23 and 24
differs from the previously described sixth embodiment in that a
tongue 96 which extends into the delivery chamber 26 and which
serves as an additional valve element in the delivery chamber 26 is
arranged on the valve element 18f. The pump casing 12 comprises an
additional delivery branch 98 which runs out into the delivery
chamber 26 separately to the delivery branch 27. Depending on the
switching position of the valve element 18f, the tongue 96 can
release the delivery branch 27 or the delivery branch 28 and cover
the respective other delivery branch. With this embodiment example
therefore, a delivery-side switch-over is envisaged at the delivery
side of the impeller 14. A mixing function can be simultaneously
realized via the inlets 28' and 30', by way of the opening 92 being
positioned such that it covers both these inlets 28', 30' in a
first switching position, so that fluid can flow out of the both
inlets 28', 30' through the opening 62 and further through the
suction port 38. In contrast, in the second switching position the
opening 62 covers only the inlet 28', whereas the inlet 30' is
closed by the base of the valve element 18f in the manner described
above. The delivery branch 27 is simultaneously closed and the
delivery branch 98 released. The movement of the valve element 18f
can be realized in the manner described above via the impeller 14
and a mechanical coupling which disengages by way of the axial
displacement of the valve element 18f given a sufficiently high
pressure in the delivery chamber 26. The valve element 18f is
mounted on the rotor shaft 8 in this embodiment example.
[0097] The eighth embodiment according to FIGS. 25 to 28 differs
from the sixth embodiment with regard to the configuration of the
first mechanical coupling between the rotor shaft 8 and the valve
element 18g. Concerning this embodiment example, the valve element
18g is mounted directly on the rotor shaft 8 which is configured in
an extended manner and extends up to into the hole 66 in the base
of the pump casing 12. Two ring segments 100 with plain bearing
characteristics, in particular of ceramic are arranged in the
inside of the valve element 18g. The ring segments 100 are held
together by a clamping ring 102 and are pressed against the rotor
shaft 8. In this example, the two ring segments 100 form an
essentially 2/3 ring. The valve element 18g with a projection 104
on its inner periphery engages in the region of the ring segment
which is absent for a complete ring, so that the two ring segments
100 are arranged in the inside of the valve element 18g in a
rotationally fixed manner A passage 106 which effects the valve
function remains in the region of the absent ring segment, which is
to say adjacent to the projection 104.
[0098] In a first switching position which is shown in FIG. 27, the
passage 106 can lie opposite inlet 30' and in a second switch
position which is shown in FIG. 28 can lie opposite the inlet 28'.
The other inlet is closed in each case. For this, the valve element
18g can be pressed in the axial direction into bearing contact on
the base of the pump casing 2 which surrounds the inlets 28' and
30', by way of the pressure prevailing in the delivery chamber 26,
in accordance with the embodiments described above.
[0099] The movement of the valve element 18g is effected via a
first coupling by way of the drive of the impeller 14. At the
start, the rotor shaft 8 bears non-positively on the inner
periphery of the ring segments 10 and co-rotates these and thus the
valve element 18g. Stops for both switching positions can be formed
in the pump casing 12 in the manner described above.
[0100] When the valve element 18g reaches one of these stops, then
the pump shaft 8 slides through in the inside of the ring segments
100, i.e. the coupling disengages. Moreover, a lubrication film
forms between the outer periphery of the rotor shaft 8 and the
inner surfaces of the ring segments 100 in the manner of a plain
bearing, given an increasing speed of the rotor shaft 8, so that
the rotor shaft 8 can then rotate in an essentially frictionless
manner in the inside of the ring segments 100. This means that for
adjusting or actuating the valve element 18g between its two
switching positions, the drive motor is moved by the control device
17 preferably at a lower speed than the speed at which the impeller
14 is rotated on operation. The drive motor can be driven in two
rotation directions in the manner described above, for moving the
valve element 18g to and fro, wherein again after reaching the
desired switching position, by way of a rapid speed increase, one
can succeed in the valve element 18g remaining in the previously
reached switching position on account of the pressure in the
delivery chamber 26 and the bearing contact of the valve element on
the base of the pump casing 12, in the manner described above.
[0101] With regard to the ninth and tenth embodiment according to
FIGS. 29 to 37 as well as 38 to 47, a mechanical coupling is
likewise provided between the drive motor and the valve element,
wherein concerning these embodiments, the drive motor can be
activated in two different operational types or modes by way of the
control device 17. In a first operation mode which corresponds to
the normal operation of the circulation pump assembly, the drive
motor rotates in the conventional manner at a desired speed which
can be adjusted, in particular by the control device 17. In the
second operating mode, the drive motor is activated (controlled) in
open loop operation, so that the rotor can be rotated stepwise in
individual angular steps which are smaller than 360.degree.. The
drive motor can therefore be moved in individual steps in the
manner of a stepper motor, which concerning these embodiment
examples is used in order to move the valve element in small
angular steps into a defined position in a targeted manner, as is
described hereinafter.
[0102] With regard to the ninth embodiment according to FIGS. 29 to
37, a mixing valve as can be used for example for temperature
adjustment for a floor heating is integrated in the pump casing
2.
[0103] The motor casing 2 with the electronics casing 16
corresponds to the previously described embodiment. The pump casing
12 is constructed in essentially the same manner as the pump casing
according to the first embodiment according to FIGS. 1 to 6, and it
is only the outer configuration which is different. With this ninth
embodiment, the valve element 18h is likewise configured in a
drum-like manner and consists of a pot-like lower part 76h which at
its side which faces the impeller 14 is closed by a cover 78h. A
suction opening 36 is formed in the central region of the cover
78h. The valve element 18h is rotatably mounted on a pivot 20 which
is arranged in the base of the pump casing 12. Here, the rotation
axis of the valve element 18h corresponds to the rotation axis X of
the rotor shaft 8h, as is the case with the examples described
above. Here, for forming a second releasable coupling, the valve
element 18h is likewise axially displaceable along the axis X and
is pressed by a spring 48 into the idle position which is shown in
FIG. 33 and in which the valve element 18h is located in released
position, in which the lower part 76h does not bear on the base of
the pump casing 12, so that the valve element 18h is essentially
freely rotatable about the pivot 20. In the released position, the
face end of the rotor shaft 8h which is configured as a first
coupling 108 serves as an axial stop. The coupling 108 engages with
a counter coupling 110 which is arranged on the valve element 18h
in a rotationally fixed manner. The coupling 108 comprises beveled
(inclined) coupling surfaces which along a peripheral line
essentially describe a saw-toothed profile in a manner such that a
torque transmission from the coupling 108 onto the counter coupling
110 is only possible in one rotation direction, specifically in the
rotation direction A in FIG. 31. In contrast, the coupling slips
through in the opposite rotation direction B, wherein an axial
movement of the valve element 18h occurs. The rotation direction B
is that rotation direction, in which the pump assembly is driven in
normal operation. In contrast, the rotation direction A is used for
the targeted actuation of the valve element 18h. This means that a
rotation-direction-dependent first coupling is formed here.
However, concerning this embodiment too, the counter coupling 110
also disengages from the coupling 108 due to the pressure in the
delivery chamber 26. If the pressure in the delivery chamber 26
increases, then a pressing force which is opposed to the spring
force of the spring 48 and which exceeds this acts upon the cover
78h, so that the valve element 18h is pressed into the bearing
position as is shown in FIG. 32. In this position, the lower part
76h bears on the base side of the pump casing 12, so that on the
one hand the valve element 18h is non-positively held and on the
other hand a sealed bearing contact is achieved, said contact
sealing the delivery side and the suction side with respect to one
another in the subsequently described manner.
[0104] The pump casing 12 comprises two suction branches 32 and 34,
of which the suction branch 32 runs out at an inlet 28h and the
suction branch 34 at an inlet 30h, in the base of the pump casing
12 into the interior of this, which is to say into the suction
chamber 24. The lower part 76h of the valve element 18h in its base
comprises an arched opening 112 which extends essentially over
90.degree.. FIG. 34 shows a first switching position, in which the
opening 112 only overlaps the inlet 30h, so that a flow path only
from the suction branch 34 to the suction opening 36 and therefore
to the suction port 38 of the impeller 14 is given. The second
inlet 28h is sealingly closed by the base of the valve element 18h
which bears in the peripheral region of this second inlet. FIG. 36
shows the second switching position, in which the opening 112 only
overlaps the inlet 28h, with the inlet 30h closed. In this
switching position, only a flow path from the suction branch 32 to
the suction port 38 is opened. FIG. 35 now shows an intermediate
position, in which the opening 112 overlaps both inlets 28h and
30h, wherein the inlet 30h is only partly released. A mixing ratio
between the flows from the inlets 28h and 30h can be changed by way
of changing the degree of release of the branch 30h. The valve
element 18h can also be adjusted or actuated in small steps via the
stepwise actuation of the rotor shaft 8h, in order to change the
mixing ratio.
[0105] Such a functionality can be applied for example in a
hydraulic system as is shown in FIG. 37. There, the centrifugal
pump assembly with the integrated valve as has been described above
is characterized by the dashed line 1. The hydraulic circuit
comprises a heat source 114 in the form of a gas heating boiler for
example, the outlet of which running out for example into the
suction branch 34 of the pump casing 12. In this example, a floor
heating circuit 116 whose return is connected to the inlet of the
heat source 114 as well as to the suction branch 32 of the
centrifugal pump assembly 114 connects onto the delivery branch 37
of the centrifugal pump assembly 1. A further heating circuit 120
can be supplied with a heat transfer medium which has the
outlet-side temperature of the heat source 114, via a second
centrifugal pump assembly 118. The floor heating circuit 116 in
contrast can be regulated in its feed temperature in a manner such
that cold water from the return is admixed to the hot water at the
outlet side of the heat source 114, wherein the mixing ratio can be
changed by way of changing the opening ratios of the inlets 28h and
30h in the manner described above by way of rotating the valve
element 18h.
[0106] The tenth embodiment example according to FIGS. 38 to 47
shows a centrifugal pump assembly which additionally to the
previously described mixing function yet comprises a switch-over
functionality for the additional supply of a secondary heat
exchanger for the heating of service water.
[0107] Concerning this embodiment, the mounting and drive of the
valve element 18i is effected just as with the ninth embodiment. In
contrast to the valve element 18h, the valve element 18i
additionally to the opening 112 comprises a through-channel 122
which extends from an opening 124 in the cover 78i to an opening in
the base of the lower part 76i and therefore connects the two axial
ends of the valve element 18i to one another. An arched bridging
opening 126 is moreover yet formed in the valve element 18i and
this opening is closed to the delivery chamber 28 by the cover 78i
and is only open to the lower side, which is to say to the base of
the lower part 76i and thus to the suction chamber 24
[0108] The pump casing 12 comprises a further branch 128, apart
from the delivery branch 27 and both previously described suction
branches 34 and 32. The branch 128 runs out into an inlet 130 in
the base of the centrifugal pump assembly 12 additionally to the
inlets 28h and 30h into the suction chamber 24. The various
switching positions are explained by way of FIGS. 43 to 46, wherein
the cover 78i of the valve element 18i is shown in a partly opened
manner in these figures, in order to clarify the position of the
openings which lie therebelow. FIG. 43 shows a first switching
position, in which the opening 112 lies opposite the inlet 30h, so
that a flow connection from the suction branch 34 to the suction
port 38 of the impeller 14 is created. In the switching position
according to FIG. 44, the opening 112 lies over the inlet 130, so
that a flow connection from the branch 128 to the suction opening
36 and via this into the suction port 38 of the impeller 14 is
created. In a further switching position which is shown in FIG. 45,
the opening 112 lies over the inlet 30h, so that again a flow
connection from the suction branch 34 to the suction port 38 of the
impeller 14 is given. A partial overlapping of the opening 124 and
of the through-hole 122 with the inlet 28h simultaneously takes
place, so that a connection between the delivery chamber 26 and the
suction branch 32 which functions here as a delivery branch is
created. The bridging opening 126 simultaneously overlaps the inlet
130 and a part of the inlet 28h, so that a connection from the
branch 128 to the branch 32 is likewise created via the inlet 130,
the bridging opening 126 and the inlet 28h.
[0109] FIG. 46 shows a fourth switching position, in which the
through-channel 122 completely overlaps the inlet 28h, so that the
branch 32 is connected to the delivery chamber 26 via the
through-channel 122 and the opening 124. Simultaneously, the
bridging opening 126 continues to cover only the inlet 130. The
opening 112 continues to cover the inlet 30h.
[0110] Such a centrifugal pump assembly can be applied for example
in a heating system as is shown in FIG. 47. Here, the dashed line
delimits the centrifugal pump assembly 1, as has just been
described by way of FIGS. 38 to 46. The heating system again
comprises a primary heat exchanger or a heat source 114 which for
example can be gas heating boiler. At the outlet side, the flow
path runs into a first heating circuit 120 which can be formed for
example by way of conventional radiators. A flow path
simultaneously branches to a secondary heat exchanger 56 for
heating service water. The heating system moreover comprises a
floor heating circuit 116. The returns of the heating circuit 120
and of the floor heating circuit 116 run out into the suction
branch 34 on the pump casing 12. The return from the secondary heat
exchanger 56 runs out into the branch 128 which provides two
functionalities as is described hereinafter. The branch 32 of the
pump casing 12 is connected to the feed of the floor heating
circuit 116.
[0111] When the valve element 18i is located in the first switching
position represented in FIG. 43, the impeller 14 delivers fluid
from the suction branch 34 via the delivery branch 27 through the
heat source 140 and the heating circuit 120 and back to the suction
branch 34. If the valve element 18i is located in the second
switching position which is shown in FIG. 44, the facility is
switched over to service water operation and in this condition the
pump assembly or the impeller 14 delivers fluid from the branch 128
which serves as a suction branch, through the delivery branch 27,
via the heat source 114 through the secondary heat exchanger 56 and
back to the branch 128. The floor heating circuit 116 is
additionally supplied if the valve element 18i is located in the
third switching position which is shown in FIG. 45. The water flows
into the suction port 38 of the impeller 14 via the suction branch
34 and is delivered via the delivery branch 27 through the first
heating circuit 120 via the heat source 114 in the described
manner. The fluid at the outlet side of the impeller 14
simultaneously exits the delivery chamber 26 into the opening 124
and through the through-channel 122 and thus flows to the branch 32
and via this into the floor heating circuit 116.
[0112] Fluid simultaneously flows via the bridging opening 126 into
the branch 32 via the branch 128 and the inlet 130, in the
switching position which is shown in FIG. 45. This means that here
water flows via the heat source 114 through the secondary heat
exchanger 26 and the branch 128 to the branch 32. Since essentially
no heat is taken at the secondary heat exchanger 56 in this heating
operation, hot water is admixed to the branch 32 additionally to
the cold water which flows out of the delivery chamber 26 to the
branch 32 via the through-channel 130. The quantity of the admixed
warm water at the branch 32 can be varied by way of changing the
degree of opening via the valve position 18i. FIG. 46 shows a
switching position, in which the admixing is switched off and the
branch 32 is exclusively in direct connection with the delivery
chamber 26. In this condition, the water in the floor heating
circuit 116 is delivered in the circuit without any supply of heat.
It is to be recognized that with this embodiment, a switching
between the heating and service water heating as well as
simultaneously the supply of heating circuits with two different
temperatures, specifically of a first heating circuit 120 with the
exit temperature of the heat source 114 and of a floor heating
circuit 116 with a temperature which is reduced via a mixing
function can also be achieved by way of the change of the switching
positions of the valve element 18i.
[0113] It is to be understood that the various previously described
embodiments can be combined with one another in a different manner.
Thus the different described drive modes of the valve element can
be essentially arbitrarily combined with different geometric
configurations of the valve element as have likewise been described
above. The different valve functionalities (for example mixing and
switching-over) can likewise be realized and combined with
different drive modes. These different combination possibilities
which are to be derived from the preceding embodiment examples are
expressly encompassed by the invention.
[0114] Concerning the described examples, the valve element with
the impeller is always arranged in a common pump casing, which
therefore forms a combined valve and pump casing. It is to be
understood that this pump casing can also be configured of several
parts.
[0115] 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.
* * * * *