U.S. patent application number 10/168902 was filed with the patent office on 2004-04-01 for pump driven by an electromotor and method for producing a pump of this type.
Invention is credited to Heidrich, Torsten, Henschel, Matthias, Linde, Hansjuergen, Melzer, Frank, Neumann, Uwe, Pfetzer, Johannes, Rehklau, Andreas, Riehl, Guenther, Rocklage, Gerta, Schmitz, Matthias, Weigold, Thomas, Zierer, Gerald.
Application Number | 20040062664 10/168902 |
Document ID | / |
Family ID | 7660955 |
Filed Date | 2004-04-01 |
United States Patent
Application |
20040062664 |
Kind Code |
A1 |
Weigold, Thomas ; et
al. |
April 1, 2004 |
Pump driven by an electromotor and method for producing a pump of
this type
Abstract
The invention relates to a pump (10), having a pump head (12),
which has a pump chamber (11), and having an electric motor (14),
which drives the pump head (12) and has a stator (40) and a rotor
(38), the rotor (38) being connected to the pump head (12) and
being disposed in a rotor chamber (82) open toward the pump chamber
(11). It is proposed that the stator (40) is disposed radially
around the rotor chamber (82), and the rotor chamber (82) is sealed
off from the pump chamber (11) by a sealing wall (51) belonging to
the stator (40) and by at least one wall (64) of the pump housing
(18).
Inventors: |
Weigold, Thomas;
(Baden-Baden, DE) ; Zierer, Gerald; (Buehl,
DE) ; Pfetzer, Johannes; (Buehl, DE) ; Riehl,
Guenther; (Buehl, DE) ; Henschel, Matthias;
(Rheinmuenster, DE) ; Schmitz, Matthias; (Gifhorn,
DE) ; Rocklage, Gerta; (Bochum, DE) ;
Heidrich, Torsten; (Vaihingen/Enz, DE) ; Melzer,
Frank; (Stuttgart, DE) ; Linde, Hansjuergen;
(Coburg, DE) ; Neumann, Uwe; (Bamberg, DE)
; Rehklau, Andreas; (Coburg, DE) |
Correspondence
Address: |
Striker Striker & Stenby
103 East Neck Road
Huntington
NY
11743
US
|
Family ID: |
7660955 |
Appl. No.: |
10/168902 |
Filed: |
November 3, 2003 |
PCT Filed: |
September 20, 2001 |
PCT NO: |
PCT/DE01/03624 |
Current U.S.
Class: |
417/357 |
Current CPC
Class: |
F04C 15/008 20130101;
F04D 13/0686 20130101; F04D 13/064 20130101; F04D 29/5813 20130101;
F04D 13/0626 20130101; F04C 15/0061 20130101 |
Class at
Publication: |
417/357 |
International
Class: |
F04B 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 25, 2000 |
DE |
100 52 797.3 |
Claims
1. A pump, having a pump head (12), which has a pump chamber (11),
having an electric motor (14), which drives the pump head (12) and
has a stator (40) and a rotor (38), the rotor (38) being connected
to the pump head (12) and being disposed in a rotor chamber (82)
open toward the pump chamber (11), characterized in that the stator
(40) is disposed radially around the rotor chamber (82), and the
rotor chamber (82) is sealed off from the pump chamber (11) by a
sealing wall (51) belonging to the stator (40) and by at least one
wall (64) of the pump housing (18).
2. The pump of claim 1, characterized in that the pump head (12),
electric motor (14) and an electronic switch mechanism (16) for
controlling the electric motor (14) are disposed in a common, in
particular three-part pump housing (18).
3. The pump of claim 1 or 2, characterized in that at least one
wall (64) defining the rotor chamber (82) is embodied integrally
with a motor housing (34) of the electric motor (14).
4. The pump of claim 3, characterized in that the sealing wall (51)
defining the rotor chamber (82) radially and belonging to the
stator (40) seals off the rotor chamber (82) via elastic sealing
means (66).
5. The pump of one of the foregoing claims, characterized in that
the sealing wall (51) defining the rotor chamber (82) radially is
solidly connected to the stator (40).
6. The pump of claim 5, characterized in that the sealing wall (51)
is formed by a casing (50) of the stator (40), the casing being
completely closed in the circumferential direction of the rotor
chamber (82).
7. The pump of claim 6, characterized in that the casing (50) of
the stator (40), the casing being completely closed in the
circumferential direction of the rotor chamber (82), is of
plastic.
8. The pump of claim 6 or 7, characterized in that pole teeth (44)
of the stator (40) are injected into the casing (50) of the stator
(40).
9. The pump of claim 7 or 8, characterized in that the plastic
casing (50) of the stator (40) is shaped such that it serves as a
winding body (54) for stator windings (56).
10. The pump of one of the foregoing claims, characterized in that
the stator (40) is connected to the wall (64) of the motor housing
(34).
11. The pump of one of the foregoing claims, characterized in that
at least one wall (64) enclosing the switch mechanism (16) is
embodied integrally with the motor housing (34).
12. The pump of one of the foregoing claims, characterized in that
at least one electronic component (96) of the switch mechanism (16)
is disposed on a cooling wall (65) that is cooled by a pumping
medium.
13. The pump of claims 11 and 12, characterized in that the cooling
wall (65) is one wall (64) of the motor housing (34).
14. The pump of claim 12 or 13, characterized in that a volumetric
flow of the pumping medium flows from the compression side of the
pump head (12) past the cooling wall (65) to the intake side of the
pump head (12).
15. The pump of one of the foregoing claims, characterized in that
the electronic switch mechanism (16) is mounted on the opposite end
of the motor housing (34) from the pump head (12).
16. The pump of one of the foregoing claims, characterized in that
the shaft of the electric motor (14) is simultaneously the drive
shaft (20) of the pump head (12).
17. The pump of claim 16, characterized in that the pumping medium
flows through a conduit (92) in the drive shaft (20) of the motor
(14) to the intake side.
18. The pump of one of the foregoing claims, characterized in that
the electric motor (14) is an electronically commutated
direct-current motor.
19. The pump of one of the foregoing claims, characterized in that
the pump is water pump for use in motor vehicles.
20. A method for producing a pump (10), in particular a fluid pump
for the coolant or heating loop of a motor vehicle, in which the
pump (10) has a pump head (12) and an electric motor (14) with a
stator (40) and a rotor (38), characterized in that the stator (40)
of the electric motor (14) that drives the pump head (12) is
produced by spray-coating stator pole teeth (44), in particular
with a plastic; and that upon injection of the stator pole teeth
(44) into the plastic, the plastic casing (50) is shaped such that
the stator pole teeth (44) come to be seated in a manner secure
against relative rotation and firmly in the plastic casing (50);
the plastic casing (50) is shaped as a carrier (54) of the stator
windings (56); and the plastic casing (50) can seal off the stator
(40) from the rotor chamber (82) of the electric motor (14), which
rotor chamber is open toward the pumping medium.
Description
PRIOR ART
[0001] The invention is based on a motor pump having a pump head
and an electric motor that drives the pump head, as generically
defined by the preamble to claim 1, and to a method for producing
such a pump, as generically defined by the preamble to claim
20.
[0002] Such motor pumps serve to transport or increase the pressure
of a fluid and have long been used, for instance as water pumps in
heating circuits.
[0003] From European Patent EP-0 778 649 B1, a pump-motor unit is
known, which acts as a coolant pump of a motor vehicle internal
combustion engine. The pump-motor unit described in EP-0 778 649 B1
is a centrifugal pump, which is driven by an electronically
commutated direct-current motor. The centrifugal pump and the
direct-current motor are connected to one another via a radiator.
Fastened between the pump housing and the radiator is a split pot,
made of a suitable material, which separates the rotor of the
electric motor from the stator. A seal placed between the pump
housing and the split pot seals off the fluid-filled rotor chamber
from an outer stator chamber.
[0004] One disadvantage of the pump-motor unit described in EP-0
778 649 B1 and of all comparable motor pumps is the existing air
gap between the stator and the rotor of the electric motor, which
adversely affects the efficiency of a split tube motor of this
kind. Reducing the air gap by lessening the thickness of the
material of the split pot has the risk of mechanical instabilities
of the split pot. This can cause premature failure of the pump.
[0005] Cooling the power electronics of the control motor by means
of an additional passive radiator, as proposed in EP-0 778 649
B1-besides requiring one additional split pot increases the
complexity of such a pump.
[0006] In EP 0 713 282 B1, a split tube motor for pumps is
disclosed, with a split pot disposed between the rotor and the
stator. The rotor has a thin-walled, sleevelike and in particular
laminated base body. On its outside, this base body has radially
oriented ribs, which carry the stator winding, and with its
cylindrical inside, it rests at least partly on the outside of the
split tube. Once again, the complex assembly and sealing of the
additional split pot is a disadvantage. The split tube must be
built in and sealed off between the stator packet and the
rotor.
[0007] The open- and closed-loop control electronics of the split
tube motor of EP-0 713 282 is embodied as a module and requires
complicated cooling. The electronic module rests with one side of
its housing by positive engagement on the stator winding. The heat
energy generated by the electronics is given off via the switch
housing to the motor housing, with the stator winding located
inside it. The stator winding in turn gives up the heat energy it
has absorbed to the pumping medium via the split pot.
ADVANTAGES OF THE INVENTION
[0008] The pump of the invention having the characteristics of
claim 1 has the advantage that in a simple way, it becomes possible
to seal off the rotor chamber, which is open toward the pumping
medium, from the stator chamber, and good cooling of the
electronics of the pump motor is achieved as well.
[0009] Because the sealing wall of the split pot belongs directly
to the stator, it is possible to dispense with a split tube as an
additional component. In the assembly and sealing off of the pump
of the invention, the assembly step of introducing the split tube
between the stator and the rotor is dispensed with, leading to a
corresponding simplification and cost reduction for the production
of the pump of the invention.
[0010] By the provisions recited in the dependent claims,
advantageous refinements of and improvements to the pump recited in
claim 1 are possible.
[0011] One advantageous feature of the pump of the invention is
obtained by providing that the pump head, the electric motor
driving this pump head, and an electronic switch mechanism that
serves to control the electric motor are disposed in common in a
housing. This housing can be a one-piece housing or can comprise
multiple components that are to be associated with the various
functions (pump, motor, switch mechanism) and are connected to one
another. The motor housing can thus be used simultaneously as a
housing part and as a radiator for the electronics.
[0012] A wall embodied integrally with the motor housing lends the
pump of the invention the requisite mechanical stability and can at
the same time contribute to sealing off the rotor chamber. In
particular, this wall can be produced of metal, which has
advantages in terms of strength and heat transfer. In principle, it
is thus possible to use only a single metal part for the pump
housing of the pump of the invention, which makes for a marked cost
reduction for such a pump.
[0013] A sealing wall solidly joined to the stator and defining the
rotor chamber radially averts the necessity of a split tube in the
form of an additional, separate component. For sealing between the
rotor and the stator, a separate part is accordingly no longer
necessary. In particular, this sealing wall can be embodied as a
casing of the stator that is completely closed in the
circumferential direction of the rotor chamber. This casing of the
stator can advantageous be produced from plastic or some other
suitable material.
[0014] Encasing the stator with a plastic furthermore offers the
advantage that the stator pole teeth, which can for instance be
formed by discrete sheet-metal lamination packets, can simply and
advantageously be injected directly into the plastic and thus
fixed. By means of the plastic casing, it is furthermore possible
for the sealing element between the rotor chamber and the stator
chamber to be assigned a number of additional functions, which a
separate split tube in its original sense cannot perform. Besides
sealing off the rotor chamber that carries the pumping medium from
the stator chamber, the stator lamination packets can be secured by
the injection and for instance secured against rotation. This means
a simple, secure fixation of the lamination packets. The
spray-coated stator also makes it possible for the requisite
winding bodies of the stator winding to be jointly embodied
directly in the injection-molding process. Contact pockets required
for connecting the stator winding can accordingly, like other
required retaining means on the stator, advantageously be formed
directly in the injection molding process. All of this makes the
structure and sealing of the stator simpler, reduces the number of
components, and thus facilitates the assembly of the pump of the
invention. With a split tube pump of the conventional design, this
is not feasible.
[0015] If the stator is connected to a motor housing wall, in
particular a metal wall, then this wall can absorb the incident
forces and moments. This metal wall, because of its thermal
conductivity, can then also expediently be used directly as a
radiator for the electronics of the pump motor. Good cooling of the
electronic switch elements is obtained if these elements are
mounted directly on the metal wall. A heat conduction foil can
optionally be placed between the component and the radiator as
well. It is conceivable for the power components of the electronics
to be pressed against the cooling surface by way of springs, or to
be coupled thermally directly with the cooling surface via an
electrically insulating adhesive. This assures good heat transfer
from the power component of the electronics into the metal motor
housing.
[0016] A further marked improvement in cooling of the elements of
the control electronics can be attained if the metal cooling wall
is in turn additionally cooled actively. In the motor pump of the
invention, some of the fluid to be pumped is therefore carried past
the cooling wall toward the motor. Such cooling is possible because
the expected coolant temperatures of the internal combustion engine
come to be below the ambient temperatures. For cooling the metal
wall, an opening on the compression side is provided in the pump
head; via a conduit in the common shaft of the electric motor, this
opening together with the pump wheel creates a communication with
the intake side of the pump. Thus via the rotor the full pressure
difference of the pump is applied, so that a secondary flow of the
fluid to be pumped, which is moved precisely past the cooling face
of the motor housing, has been achieved.
[0017] Advantageously, the electric motor is disposed between the
switch mechanism having the power electronics and the pump head.
This makes a compact, space-saving construction of the motor pump
of the invention possible. An electronically commutated
direct-current motor, which can drive the pump, assures exact
regulation of the coolant flow rate, for instance in a cooling or
heating circuit of a motor vehicle with an internal combustion
engine. This in turn makes a precisely adapted heat dissipation
possible, and thus among other effects also enables optimal
efficiency and fuel consumption of the vehicle engine.
DRAWING
[0018] In the drawing, one exemplary embodiment of the invention is
shown, which is described in further detail in the ensuing
description.
[0019] Shown are:
[0020] FIG. 1, a longitudinal section through an
electric-motor-driven pump of the invention;
[0021] FIG. 2, a cross section through the stator of the electric
motor of the electric-motor-driven pump of the invention; and
[0022] FIG. 3, a detail of the stator of the electric-motor-driven
pump of the invention.
DESCRIPTION OF THE EXEMPLARY EMBODIMENT
[0023] The exemplary embodiment, shown in longitudinal section in
FIG. 1, of an electric-motor-driven pump 10 of the invention
comprises a pump head 12, which is driven by a brushless,
electronically commutated electric motor 14, and a switch mechanism
16 for controlling the electric motor 14.
[0024] The pump head 12 has a pump housing 18, in which an impeller
22, secured to a drive shaft 20, is located in a pump chamber 11.
The impeller 22 is provided with vanes 24 for transporting and
increasing the pressure of a fluid to be recirculated. An opening
26 for aspirating the fluid in the direction of the arrow 28 leads
into the pump housing 18. The pump housing also has an outlet
opening 30, not completely shown in FIG. 1, on the compression side
of the pump. The intake opening 26 discharges at the vanes 24 of
the impeller 22 of the pump 10. In the exemplary embodiment of the
motor pump 10 of the invention shown, the pump housing 18 is
connected via a flange 32 to the motor housing 34 and sealed off
via an O-ring 36, which is located between the two housing parts.
For stable connection of the pump head 12 to the motor housing 30,
various fastening options are conceivable, of which only screwing,
riveting and adhesive bonding will be named here as examples.
[0025] The electric motor 14 of the pump 10 of the invention has a
rotor 38, disposed in the motor housing 34, and a stator 40,
radially surrounding the rotor 38. The stator 40 comprises a
plastic carrier part 42, into which a plurality of soft iron teeth
44 forming the stator poles are injected directly. These soft iron
teeth are embodied for instance in the form of sheet-metal
lamination packets 46--as suggested in FIG. 1.
[0026] FIG. 2 shows a cross section through the stator 40. The
plastic carrier part 42 and the pole teeth 44 injected into it can
be seen. The plastic carrier part 42, on its inside 48 oriented
toward the rotor 38 (not shown in FIG. 2 for the sake of
simplicity), forms a completely closed plastic casing 50 of the
stator 40. The plastic casing 50 is designed such that it seals off
the rotor 38 located on the inside, that is, in the interstice 52
of the plastic carrier part 42, from the stator 40. The plastic
casing 50 of the stator pole teeth 44 serves not only as a sealing
wall 51 for the stator but also as a carrier form and winding body
54 for the windings 56 of the stator coils 58.
[0027] FIG. 3 in a detail shows one possible embodiment of the
carrier form 54 for the windings 56 of the stator 40. The plastic
casing 50 of the pole teeth 44 is shaped such that a stable
receptacle is obtained for the windings 56 of the coil 58.
Additional contact pockets 60 for the winding wire 62 can--as shown
in FIG. 3--be formed--just like other required retaining
means--directly on the plastic carrier part 42 of the stator 40 by
a shaping process.
[0028] The stator 40 with its plastic carrier part 42 is secured in
the axial direction, in a manner fixed against rotation, on one
wall 64 of the motor housing 34 and is additionally sealed off from
the motor housing 34 via sealing elements 66. The wall 64, remote
from the pump head 12, of the motor housing 34 is embodied, in the
exemplary embodiment shown, integrally with the motor housing 34
and has a plurality of retainers--embodied in this exemplary
embodiment as pegs 68--for fixation of the stator 40. The housing
wall 64 furthermore has a number of leadthroughs 70 for one or more
electrical connections 72 connecting the electric motor 14 to the
switch mechanism 16. The housing wall 64 can preferably--like the
motor housing 34--be made of metal, so as to better absorb the
forces and moments of the motor and to guarantee a secure fastening
of the stator 40. For heat transfer reasons as well, a metal wall
is an attractive option for the cooling wall 65. The housing wall
64 additionally has a retainer 74--embodied integrally in the
exemplary embodiment--into which a first bearing 76 of the motor
shaft 20 is placed.
[0029] According to the invention, the interior 52, encased by the
plastic carrier part 42, of the stator 40 and the correspondingly
covered region of the housing wall 64 of the motor housing 34 form
a cup-shaped chamber 78, in which the rotor 38 of the electric
motor 14 rotates. The rotor 38 is seated firmly on a shaft, which
in this exemplary embodiment is also the drive shaft 20 of the pump
impeller 22. The rotor 38 has permanent magnets 80 in the axial
direction, which are distributed uniformly over its entire
circumference. The cup-shaped chamber 78 forming a rotor chamber 82
is precisely large enough radially that the parts of the rotor
remote from the axis revolve in the immediate vicinity of the
inside 48 of the plastic casing 50 of the stator 40 but do not
touch it. As a result of the plastic casing 50 of the invention on
the stator 40, it is possible for the gap between the stator and
the rotor 38 of the electric motor 14 to be kept very slight.
[0030] Toward the pump head 12, the rotor chamber 82 is closed off
by a wall 84 and sealing elements 86. The wall 84 of the rotor
chamber 82 carries a second bearing 88 for the drive shaft 20 of
the pump 10. In addition, the wall 84 toward the pump head has an
opening 90 toward the compression side of the pump 10.
[0031] Through the opening 90 on the compression side of the rotor
chamber wall 84 toward the pump head, some of the fluid to be
pumped can reach the rotor chamber 82 and both bathe and cool the
rotor 28 and especially the bearings 76 and 88 of the drive shaft
20. The fluid that reaches the rotor chamber 82 also flows along
the motor housing wall 64 toward the switch mechanism and cools it
as well. Through a conduit 92 in the common drive shaft 20 of the
motor 14 and pump head 12, the fluid then flows out of the rotor
chamber 82 again in the direction of the arrow 94 and into the
region of the intake-side opening 90 of the pump head 12.
[0032] The switch mechanism 16 for controlling and regulating the
pump 10 of the invention is located on the side of the motor
housing 34 remote from the pump head 12. In the exemplary
embodiment shown, the switch mechanism 16 is joined integrally to
the motor housing 34 and advantageously shares the housing wall 64
with it. On the side of the housing wall 64 remote from the motor
14, power elements 96 of the switch electronics 98 of the electric
motor 14 are secured. These power elements 96, which can for
instance be transistors, are mounted directly on the housing wall
64, in this exemplary embodiment, resulting in good thermal
conductivity between these electrical components of the switch
mechanism 16 and the wall 64. The heat produced by the electronics
98 can be given up quickly to the housing wall 64--which in the
exemplary embodiment is of metal. However, it is also conceivable
for the components of the switch element 16 that are to be cooled
to be pressed against the housing wall 64 via springs instead.
Direct adhesive bonding, with an electrically insulating adhesive,
for thermal coupling of the electronic components 98 to the cooling
wall 64 is also possible.
[0033] The housing wall 64 is furthermore bathed at least in part,
toward the motor, by the fluid to be recirculated, so that
according to the invention, a substantially improved heat
dissipation is obtained for the components of the switch mechanism
16.
[0034] The switch mechanism 16 itself is to be closed via a lid
100, which in the exemplary embodiment is mounted directly on the
motor housing 34 of the pump 10. The lid 100 can be slipped on,
screwed on, riveted, adhesively bonded, or fastened securely and
optionally reversibly by some other suitable technique to the motor
housing 34. In the exemplary embodiment shown, the lid 100 of the
switch mechanism 16 has a terminal 102 for externally supplying
voltage to the motor pump 10 of the invention.
[0035] The invention is not limited to the exemplary embodiment of
an electric-motor-driven pump described.
[0036] In particular, a sealing wall joined integrally to the
stator can advantageously be employed as well.
* * * * *