U.S. patent application number 12/280366 was filed with the patent office on 2009-01-22 for motor centrifugal pump.
Invention is credited to Thomas Materne, Gunter Strelow.
Application Number | 20090022610 12/280366 |
Document ID | / |
Family ID | 37689441 |
Filed Date | 2009-01-22 |
United States Patent
Application |
20090022610 |
Kind Code |
A1 |
Materne; Thomas ; et
al. |
January 22, 2009 |
MOTOR CENTRIFUGAL PUMP
Abstract
The invention relates to a motor centrifugal pump having a
plastic-injection-moulded stator core of the electric motor,
wherein cooling channels are arranged in the plastic, through which
channels the conveying medium flows.
Inventors: |
Materne; Thomas;
(Ludinghausen, DE) ; Strelow; Gunter; (Bochum,
DE) |
Correspondence
Address: |
K.F. ROSS P.C.
5683 RIVERDALE AVENUE, SUITE 203 BOX 900
BRONX
NY
10471-0900
US
|
Family ID: |
37689441 |
Appl. No.: |
12/280366 |
Filed: |
November 29, 2006 |
PCT Filed: |
November 29, 2006 |
PCT NO: |
PCT/EP2006/011435 |
371 Date: |
August 22, 2008 |
Current U.S.
Class: |
417/423.7 ;
29/888.02 |
Current CPC
Class: |
Y10T 29/49236 20150115;
F04D 13/0626 20130101; H02K 11/33 20160101; F04D 13/064 20130101;
H02K 3/24 20130101; H02K 5/128 20130101; F04D 29/5806 20130101 |
Class at
Publication: |
417/423.7 ;
29/888.02 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 22, 2008 |
DE |
10 2006 008 423.3 |
Claims
1. A motor centrifugal pump having a plastic extrusion-coated
stator core for the electric motor wherein the plastic is formed
with cooling passages through which the pumping medium flows.
2. The pump according to claim 1 wherein the cooling passages
extend at least partly parallel to the motor axis.
3. The pump according to claim 1 wherein at least parts of the
cooling passages extend between the motor windings.
4. The pump according to claim 1 wherein the cooling passages are
connected via one, two, or more passages to the pump chamber
conducting the pumping medium.
5. The pump according to claim 1 wherein the cooling passages are
connected to one another.
6. The pump according to claim 1 wherein the cooling passages have
no connection to the pump chamber, and form a circuit inside the
motor.
7. The pump according to claim 1 wherein at least one cooling
passage extends past the electronics system of the motor in a
closed circuit.
8. The pump according to claim 1 wherein the plate for the motor
electronics system is mounted on the plastic, close to at least one
cooling passage.
9. The pump according to claim 1 wherein at least one cooling
passage on the side of the motor facing away from the pump impeller
is closed off and sealed by a lid-shaped element made of plastic or
metal.
10. The pump according to claim 9 wherein the plate for the motor
electronics system lies against the exterior of the lid-shaped
element for cooling.
11. The pump according to claim 1 wherein the plastic also forms
the split case.
12. The pump according to claim 1 wherein the plastic forms the
exterior of the motor.
13. The pump according to claim 1 wherein the housing for the
electronics system is fastened to the plastic.
14. A method of making a pump according to claim 1 wherein the
plastic is injected into gaps in the stator and forms the cooling
passages.
Description
[0001] The invention relates to a motor centrifugal pump having a
plastic extrusion-coated stator core for the electric motor.
[0002] Extrusion coating of the stator core of an electric motor
with plastic is known. One drawback of such extrusion coating is
that the plastic used represents a good thermal insulator. The
embedded stator is subjected to high thermal stress, and it is
difficult to release large amount of high heat to the surroundings
or to the coolant. Furthermore, the known wet rotor pumps for
heating water and service water are composed of numerous parts that
must be assembled. A large number of installation steps is
necessary in particular for assembly of the encapsulated electric
motor.
[0003] The object of the invention is to reduce the temperature of
the stator and in particular also of the motor electronics system
for motor centrifugal pumps of the above-described type, by use of
a simple design.
[0004] This object is achieved according to the invention by
forming the plastic with cooling passages through which the pumping
medium flows.
[0005] In this manner the high temperatures at the stator and the
electronics system needed for regulating and controlling the pump
are reduced by use of medium-filled cooling passages or chambers.
Extrusion coating of the electric stator greatly reduces the number
of individual parts, and thus minimizes manufacturing and
installation effort. Several functions are provided by the
extrusion coating.
[0006] Advantageous embodiments of the invention are given in the
dependent claims.
[0007] Four illustrated embodiments of the invention are
illustrated in the drawing and described in greater detail
below.
[0008] In the drawing:
[0009] FIG. 1 is an axial section of a first illustrated embodiment
of an electric motor with a pump impeller;
[0010] FIG. 2 is an axial section of a second illustrated
embodiment of an electric motor with a pump impeller;
[0011] FIG. 3 is an axial section of a third illustrated embodiment
of an electric motor with a pump impeller; and
[0012] FIG. 4 is a cross section of a fourth illustrated embodiment
of an electric motor.
[0013] The motor centrifugal pump has a motor shaft 1 having a
motor axis 2. The motor shaft 1 is supported in two radial bearings
3 and 4 and one axial bearing 5 inside the rotor compartment 6. On
the hydraulic side the motor shaft 1 projects from the electric
motor, and at this end carries the pump impeller 7 that is inside
the pump housing (not illustrated).
[0014] The rotor 8 is fixed to the shaft 1 in the rotor compartment
6, which in turn is surrounded by windings 9 and a stator core
10.
[0015] The rotor compartment 6, windings 9, and stator core 10 are
imbedded in a plastic mass 11 that is introduced, in particular
injected, between these parts in the form of a filling compound,
and that preferably forms the inner wall of the rotor compartment
6, so that an additional split case is not necessary since the
plastic forms the split case. In addition, it is not necessary for
the plastic mass to be surrounded by an external motor housing;
instead, the plastic itself may form the exterior of the motor.
[0016] Formed in the plastic mass 11, outside of and next to the
rotor compartment 6 and parallel to the motor axis 2, are cooling
passages or cooling chambers 12 that are preferably situated
between the windings 9 and connected to the pump chamber on the
hydraulic side via openings (not illustrated), so that the pumping
medium moved by the pump impeller 7 for cooling the motor flows
through the cooling passages 12.
[0017] As shown in the embodiment of FIG. 2, it is not absolutely
necessary for the cooling passages 12 to be connected to one
another; instead, sufficient medium exchange with the pump chamber
may occur within the cooling passage through the connecting opening
or openings in the cooling passage. In the illustrated embodiment
according to FIG. 1, however, the cooling passages 12 are connected
to one another via transverse passages or a transverse chamber 13
situated on the end of the motor facing away from the pump impeller
7, outside the rotor compartment 6. The transverse chamber 13 is
sealed off by a lid-shaped element 14, in particular made of
plastic, which separates the interior of an electronics housing 15
from the motor interior. The board 16 of the motor electronics
system lies against the outer side of this circular part 14 from
which the motor axis 2 extends perpendicularly, so that the
electronic parts are cooled by the liquid in the transverse chamber
13.
[0018] The electronics housing 15 is preferably fastened to the
plastic mass 11 by means of screws 17 extending parallel to the
motor axis 2. The electronics housing 15 is thus fastened on the
end of the motor facing away from the hydraulic area.
[0019] The transverse chamber 14 is connected to the rotor
compartment 6 via an opening, in particular a coaxial passage 18,
so that the pumped liquid flows through the cooling passages 12,
the transverse chamber 13, the passage 18, and the rotor
compartment 6, and back to the pump chamber via openings (not
illustrated). The illustrated embodiment according to FIG. 3 shows
that a design is also possible in which there is no connection
between the transverse chamber 13 and the rotor compartment 6.
Inside the rotor compartment 6, on the side facing away from the
pump impeller 7 and thus close to the transverse chamber 13,
coaxially molded onto the plastic mass 11 is a plastic collar 19 in
which the radial bearing 4 rests, so that the collar 19 forms a
secure seat for this bearing. In addition, the other bearings may
optionally or additionally be held by projecting parts of the
plastic mass 11.
[0020] FIG. 4 illustrates sections of the illustrated embodiments
according to FIGS. 1 through 3, and shows a triangular
cross-sectional shape of the cooling passages. In other designs not
illustrated, the cooling passages may have other cross-sectional
shapes, and may also be connected to one another via other
connecting passages (not illustrated) to form one, two, or more
circuits.
* * * * *