U.S. patent application number 11/848526 was filed with the patent office on 2008-03-06 for water pump for bodies of water containing suspended particles.
This patent application is currently assigned to OASE GMBH. Invention is credited to Christoph Bulter, Andreas Hanke, Martin Hottecke, Herbert Lambers.
Application Number | 20080056911 11/848526 |
Document ID | / |
Family ID | 38720708 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080056911 |
Kind Code |
A1 |
Hanke; Andreas ; et
al. |
March 6, 2008 |
Water Pump for Bodies of Water Containing Suspended Particles
Abstract
A water pump for bodies of water such as ponds, aquariums, or
fountains containing suspended particles has a housing with a pump
housing part provided with an intake opening and an exit opening,
in which housing part an impeller with a shaft is rotatably
supported, and a motor housing part in which an electric motor is
received. As an improvement, an electronically commutated motor is
used and the pump has a power input as well as power and control
electronics for the motor having an operating state detection
device with speed detection, processor and data storage device. The
processor can control an interrupt switch between the power input
and the motor. In the data storage device certain characteristic
lines in regard to normal operating states can be stored.
Inventors: |
Hanke; Andreas; (Osnabruck,
DE) ; Lambers; Herbert; (Horstel, DE) ;
Bulter; Christoph; (Horstel, DE) ; Hottecke;
Martin; (Greven, DE) |
Correspondence
Address: |
GUDRUN E. HUCKETT DRAUDT
SCHUBERTSTR. 15A
WUPPERTAL
42289
omitted
|
Assignee: |
OASE GMBH
Horstel-Riesenbeck
DE
|
Family ID: |
38720708 |
Appl. No.: |
11/848526 |
Filed: |
August 31, 2007 |
Current U.S.
Class: |
417/22 |
Current CPC
Class: |
F04D 7/04 20130101; F04D
13/0686 20130101; F04D 15/0088 20130101; A01K 63/047 20130101 |
Class at
Publication: |
417/22 |
International
Class: |
F04B 49/00 20060101
F04B049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 1, 2006 |
DE |
10 2006 041 317.2 |
Claims
1. A water pump for bodies of water containing suspended particles,
the water pump comprising: a housing comprises a pump housing part
provided with an intake opening and an exit opening and further
comprising a motor housing part; an impeller with a shaft arranged
in the pump housing part so as to be rotatable; an electric motor
arranged in the motor housing part, wherein the electric motor is
an electronically commutated motor; a power input; power and
control electronics for the electric motor comprising an operating
state detection device with speed detection, a processor, and a
data storage device.
2. The water pump according to claim 1, further comprising an
interrupt switch controlled by the processor and arranged between
the power input and the electric motor.
3. The water pump according to claim 1, wherein information in
regard to at least one normal operating state of the water pump are
stored in the data storage device.
4. The water pump according to claim 3, wherein the information
comprises at least one of a pump characteristic line and a speed
characteristic line.
5. The water pump according to claim 3, comprising a software that
carries out a nominal/actual value comparison between a stored
standard operating state data and an actual operating state of the
water pump detected by the operating state detection device,
wherein the software initiates a change of the actual operating
state when a preset difference for the nominal/actual value
comparison is surpassed.
6. The water pump according to claim 5, wherein the change of the
actual operating state consists of running a predetermined program
with speed change of the water pump.
7. The water pump according to claim 6, wherein, when the standard
operating state is reached again during the program pass, the
program is stopped.
8. The water pump according to claim 6, wherein the change of the
actual operating state resides in an activation of an interrupt
switch or in ending the program.
9. The water pump according to claim 1, wherein the power and
control electronics comprises governing electronics governing a
predetermined speed.
10. The water pump according to claim 1, wherein the power and
control electronics are arranged in the motor housing part and are
water-tightly potted.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a water pump for bodies of water
that contain principally not only pollution-free water but also
suspended particles, mud, leaves and pieces of algae or similar
materials. Such bodies of water are ponds, aquariums or fountains,
for example.
[0002] Pumps of the aforementioned kind as they are known in
practice have usually a thermoswitch as a safety device. This
switch switches off the pump when overheating occurs, for example,
as a result of an integrated or downstream filter being clogged by
suspended particles or as a result of clogging of a conduit in the
feed or outlet lines. Also, when the pump is operated without water
being actually conveyed, the pump will overheat so that after a
certain amount of time the overheating protection will
intervene.
[0003] There are also pumps that are provided alternatively or
additionally with a switch-off mechanism that immediately responds
when the pump conveys no water. This state is determined in such
pumps that operate with load-independent constant speed in such a
way that the load on the pump is measured. When the load is
extremely low, this means that the pump is running without water.
The pump is switched off immediately and, up to this point, has
often turned only one fourth of a revolution. When upon start-up
the pump is positioned, for example, in a pump sump that is only
filled minimally, it is not possible to start the pump permanently
because of the early power-off since the pump is not turning long
enough, despite taking in air, in order to suck in the required
water quantity into the pump sump for the pump to operate properly.
Also, it is not possible to test the function of the pump without
water because switching off is taking place so quickly that it is
not possible to detect whether the motor turns at all.
SUMMARY OF THE INVENTION
[0004] It is therefore an object of the invention to provide a pump
that avoids the aforementioned problems.
[0005] This object is solved by a water pump wherein the motor is
an electronically commutated motor and the pump has a power input
as well as power and control electronics for the motor comprising
an operating state detection device with speed detection, processor
and data storage device.
[0006] The combined use of an electronically commutated motor (EC
motor) as well as the provision of power and control electronics
with an operating state detection device by means of speed sensing,
a processor, and a data storage device, the speed of the pump can
be detected, evaluated in the processor and can be utilized by
means of the power and control electronics for changing the pump
function. An--only imprecise--detection of the load on the pump is
no longer required, and an EC motor with load-dependent and
accordingly adjustable speed can be used.
[0007] The control electronics can thus lower as needed the speed
of the motor such that there is no risk of damaging it. Preferably,
the pump has also an interrupt switch between the power input and
the motor that, when certain defined operating states occur,
interrupts the power input so that the motor is stopped completely.
Of course, the pump can have additionally a conventional overheat
protection that switches off the pump, for example, by means of a
thermocouple and interrupt contact, when the pump is overheating
for whatever reason.
[0008] The speed detection required for operating state detection
can have a speed sensor that is designed for recognizing the rotor
position and the rotary frequency of the motor. This sensor can be,
for example, a Hall sensor. It is also possible, and realizable
without additional material expenditure by means of the
intelligence inherent in the pump, to configure the speed detection
without a sensor. In this connection, at any point in time at the
coil or coils momentarily not supplied with current and not
switched at the moment, the current flow induced by the magnet
rotor is measured and, based thereon, the rotor position is
determined. In this connection, the speed at which the coils that
generate an induced current flow change provides the rotary
frequency. Both pieces of information are evaluated by means of the
processor and can be utilized for control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further advantages and details result from the dependent
claims and the embodiments of the invention illustrated in the
drawings which will be explained in the following. It is shown
in:
[0010] FIG. 1 schematically a pump according to the invention;
[0011] FIG. 2 a diagram with pump characteristic lines and
operating states; and
[0012] FIG. 3 a diagram with speed characteristic lines of the
pump.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The water pump illustrated in FIG. 1 has a housing 1 that is
subdivided into a pump housing part 2 and a motor housing part 3.
The pump housing part 2 has an intake opening 4 functioning as a
water intake and an exit opening 5 serving as a water outlet. In
the pump housing part 2 an impeller 8 is arranged on a rotatable
shaft 9. The shaft 9 extends from the pump housing part 2 into the
motor housing part 3 and into an EC motor arranged therein. The EC
motor has a rotor 14 fixedly connected to the shaft 9 and a stator
12 surrounding the rotor. Preferably, the rotor 14 is of a two-pole
configuration and the stator 12 is of a six-pole configuration (or
a two-pole configuration with protective extra-low voltage). The
shaft 9 is supported in an end shield 10 that shields the motor
mechanically relative to the pump housing part 2 and the impeller
8.
[0014] In the pump housing 1 control and power electronics 16 are
provided which preferably are arranged also in the motor housing
part 3 and thus at a spacing from the water-conveying parts.
Included is also a schematically indicated microprocessor 17 that
can actuate an interrupt switch 21 by means of a control line
schematically indicated by arrow 19. In this way, the electric
supply between the electric power input 26 of the pump, that is
connected to a electric cable 36, and the power electronics 16 and
thus the motor can be interrupted. In FIG. 1, the interrupt switch
21 is illustrated in the activated position, i.e., current flow is
interrupted and the motor is switched off. The illustration of the
interrupt switch 21 is only schematic. Of course, not only a
mechanical switch but also in particular electronic switches can be
utilized.
[0015] The entire electronic device including power electronics 16,
microprocessor 17, and interrupt switch 21 can be potted so as to
be watertight for safety reasons. This holds true also for the
stator 12 of the motor. Inasmuch as stator 12 and rotor 14 are
separated by a so-called split cage, preferably the entire free
motor housing part can be potted to be watertight.
[0016] The pump according to the invention is utilizable in a
plurality of ways when in the date storage device information in
regard to a normal operating state of the pump is stored. This can
be in particular the conventional pump characteristic lines and/or
rotary speed characteristic lines. For an optimal control a
software is to be provided in the electronics which software
performs a nominal/actual value comparison between the stored
normal operating state data and the detected actual operating state
of the pump detected by the operating state detection device. Upon
surpassing a preset difference between these two values, which
preset difference is also stored within the data storage device, a
change of the operating state of the pump is to be initiated by
means of the control device. This change can be, for example,
lowering of the speed of the pump or switching off of the pump by
activation of the interrupt switch 21.
[0017] As a result of the speed detection, the pump cannot only
comprise control electronics but also governing electronics without
significant further material expenditure which governing
electronics ensure by a closed-loop control circuit that the target
speed of the pump is indeed achieved and maintained. In this
connection, the speed is continuously detected, compensated, and
possibly adjusted. This is done, for example, in that the
permissible and preset difference for the nominal/actual value
comparison between normal operating state and actual operating
state is set to be very low.
[0018] The application possibilities and the function of the pump
according to the invention can be explained particularly well with
the aid of the diagrams of FIGS. 2 and 3.
[0019] FIG. 2 shows the water flow rate in liters/minute plotted
against the pressure or the height in meters that must be overcome
by the water with the aid of the pump. The light-colored line 61 is
the characteristic line 61 (state 1) provided by the manufacturer
for the height plotted against flowrate on which characteristic
line the pump operates in the normal operating state. However, the
pump is also able or capable of providing higher power up to a
maximum characteristic line 62 (state 2). Additionally, FIG. 2
illustrates two device characteristic lines 63, 64. The lower
device characteristic line 63 represents the proper use of the pump
in a normal device in which the pump is usually utilized and for
optimal free conduits and filters, i.e., for a device that as a
whole is clean. The pump then operates generally at the operating
state point A.
[0020] The upper steeper device characteristic line 64, on the
other hand, shows possible operating points of the total device
when filters are clogged, the device as a whole is soiled or higher
pressures must be overcome for other reasons. In this case or, for
example, in the case of a clogged filter, the operating state of
the pump moves from point A along the normal characteristic line 61
to the operating state point C. In this connection, the pump no
longer achieves the desired flow rate Q; the flow rate drops. By
means of the software-supported pump control in such a case the
operating state of the pump is moved upwardly along the device
characteristic line 64 until the initial and desired flow rate is
reached. This is the case at the illustrated operating state point
A'. The flow rate of the pump can be increased maximally until the
maximum characteristic line 62 is reached.
[0021] The pump therefore can automatically adjust the desired
operating state and maintain the flow rate Q at a constant rate,
for example, in the case of a filter that slowly becomes clogged,
over a long period of time without the operator of the pump having
to continuously adjust the pump operation himself.
[0022] The control is optimized in that in the data storage device
different pump characteristics lines and speed characteristics
lines are stored already at the time of delivery of the pump. The
pump can therefore automatically react to changes of the device
characteristic line and perform a readjustment to the set
output.
[0023] In analogy to the determination of the flow rate based on
the diagram of FIG. 2, the speed of the pump in different operating
states can be taken from the diagram of FIG. 3. Numeral 61
indicates again the standard characteristic line and 62 indicates
the maximum pump characteristic line.
[0024] The described operating state detection technology is
utilized also for dry running and blocking protection. In the case
of dry running of the pump, i.e., when the pump takes in no water,
the pump has no resistance and therefore rotates at very high speed
without any flow; this is indicated by operating state point T. The
point T is above the maximum characteristic line 62. This is
recognized by the pump by means of the speed detection and the
interrupt switch 21 will be activated. However, in order to prevent
in the case of a brief period of dry running, for example, if not
enough water is present in the pump sump, an immediate power-off of
the pump, the software comprises a predetermined program that first
causes one or several speed changes of the pump before the pump is
switch off. Such a program can lower the engine speed, for example,
once or several times, to the operating point P. An example of such
a program course is as follows:
[0025] 2 seconds operating point T. 2 seconds operating point P 2
seconds operating point T. 2 seconds operating point P, 2 seconds
operating point T. power off.
[0026] During the course of this program pass, the pump has the
possibility, for example, if the pump sump is not filled
sufficiently, to take in the required quantity of water for its
operation. In this way, there is a flow rate Q and the operating
point moves on the standard characteristic line 61. When during the
program pass it is detected that the standard operating state is
reached, the software is to be designed such that the program is
stopped because switching off of the pump is no longer
required.
[0027] Such a program can advantageously be used also as a
self-test of the pump. When at the time of purchase the pump is
connected to a power supply without water being present, the pump
runs the afore described program and powers off at the end of the
program. The buyer can therefore hear that the motor of the pump is
intact.
[0028] When the pump is blocked, for example, in the case of a
complete clogging, the opposite of a dry run occurs. In the case of
blockage, the speed is reduced to zero at the indicated operating
point B. This operating point B is significantly below the minimal
desired nominal characteristic line 61 so that this state is
detected by the electronic device as a blockage and the pump is
switch off.
[0029] The pump according to the invention can therefore be used in
different operating states without the operator having to perform
his own adjustments. As described, an automatic self-test can be
provided so that even at the time of purchase the function of the
pump can be demonstrated plausibly.
[0030] The specification incorporates by reference the entire
disclosure of German priority application 10 2006 041 317.2 having
a filing date of Sep. 1, 2006.
[0031] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *