U.S. patent application number 11/584134 was filed with the patent office on 2007-11-29 for motor-pump assembly.
This patent application is currently assigned to VOITH TURBO GMBH & CO. KG. Invention is credited to Franz Arbogast, Guenther Nagel, Stephan Schelp.
Application Number | 20070274848 11/584134 |
Document ID | / |
Family ID | 36950286 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070274848 |
Kind Code |
A1 |
Arbogast; Franz ; et
al. |
November 29, 2007 |
Motor-pump assembly
Abstract
The invention relates to a motor-pump assembly having an
electric motor, which has a rotor and a stator, and having a pump,
which pumps a liquid or a gas or a different pump medium. The pump
is in driven connection with the rotor of the electric motor. The
electric motor and the pump are enclosed in a common housing. The
housing has a casing, on the one end face of which is arranged a
motor-end cover and on the other end face of which is arranged a
pump-end cover. A non-rotating bearing axis is provided, fixed to
the housing, which is borne exclusively by the motor-end cover of
the housing and is mounted on the rotor of the electric motor. The
pump is arranged adjacent to the electric motor such that the pump
and the electric motor are aligned with each other.
Inventors: |
Arbogast; Franz;
(Heidenheim, DE) ; Schelp; Stephan;
(Herbrechtingen, DE) ; Nagel; Guenther;
(Steinheim, DE) |
Correspondence
Address: |
Charles N.J. Ruggiero;Ohlandt, Greeley, Ruggiero & Perle, L.L.P.
10th Floor
One Landmark Square
Stamford
CT
06901-2682
US
|
Assignee: |
VOITH TURBO GMBH & CO.
KG
|
Family ID: |
36950286 |
Appl. No.: |
11/584134 |
Filed: |
October 20, 2006 |
Current U.S.
Class: |
417/423.1 |
Current CPC
Class: |
F04B 17/03 20130101;
F04B 23/021 20130101 |
Class at
Publication: |
417/423.1 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2005 |
DE |
10 2005 050 737.9 |
Claims
1. A motor pump assembly, comprising: an electric motor having a
rotor and a stator; a pump for pumping a medium, said pump being in
driven connection with said rotor, said pump being arranged
adjacent to said electric motor so that said pump and said electric
motor are aligned with each other; and a common housing enclosing
said electric motor and said pump, said common housing having a
casing, said common housing comprising: a first end face and a
second end face; a motor-end cover being arranged on said first end
face; and a pump-end cover being arranged on said second end face;
and a non-rotating bearing axis borne exclusively by said motor-end
cover and mounted on said rotor.
2. The motor pump assembly of claim 1, wherein said medium is
selected from the group consisting of a liquid or a gas.
3. The motor pump assembly of claim 1, wherein said rotor is
mounted by a plurality of sliding bearings on said non-rotating
bearing axis.
4. The motor pump assembly of claim 3, wherein said plurality of
sliding bearings are formed from said non-rotating bearing
axis.
5. The motor pump assembly of claim 1, further comprising: a driver
plate being arranged in a rotationally resistant manner on said
rotor; and a shaft of said pump, said shaft being in driven
connection with said driver plate.
6. The motor pump assembly of claim 5, wherein said shaft has a
first end that is mounted at an opposite-lying end of said
non-rotating bearing axis so that said non-rotating bearing axis is
resistant to rotation or so that said non-rotating bearing axis is
supported against said shaft.
7. The motor pump assembly of claim 1, wherein said motor-end cover
has an inlet for said medium, and wherein said pump-end cover has
an outlet for said medium.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(a) of German Patent Application No. 10 2005 050 737.9,
filed Oct. 22, 2005, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a motor-pump assembly.
[0004] 2. Description of Related Art
[0005] Such pump assemblies and similar pump assemblies are known
from countless documents. See, for example, EP 0 611 887 A1 or WO
01/73295. In these assemblies, an electric motor and a hydrostatic
pump are enclosed in a single housing. The pump liquid flows
through the motor to cool it.
[0006] DE 197 28 802 A1 describes a motor-pump assembly provided
with a fixed bearing axis that is borne by a motor-end cover of a
housing.
[0007] DE 295 19 941 describes a motor-pump assembly having an
electric motor, comprising a rotor and a stator, and, in addition,
a pump that pumps a liquid or a gas. The pump is in driven
connection with the rotor of the electric motor. The electric motor
and the pump are enclosed by a common housing. The housing
comprises a casing as well as two face-end covers. Viewed in the
direction of the axis, the pump is arranged adjacent to the
electric motor such that the two are aligned with each other.
[0008] Assemblies of this type of design have the great advantage
that they are quiet and have a short structural length. However,
there is a serious drawback: The diameter of such assemblies is
relatively large.
BRIEF SUMMARY OF THE INVENTION
[0009] The invention is based on the problem of designing a
motor-pump assembly in such a way that the outer diameter is
smaller than in the known assemblies and that the noise produced is
also small.
[0010] The inventor has recognized the following:
[0011] In the known motor-pump assemblies, as described in EP 040
187 90, for example, the position of the rotor of the electric
motor is influenced by the hydrostatic pump. This can have the
result that the air gap between the rotor and the stator of the
electric motor is formed eccentrically. This leads to excessive
radial forces.
[0012] According to the invention, the electric motor and the pump
are not arranged radially in each other, but rather axially
adjacent to each other, so that the axes of the two are aligned
with each other. A non-rotating bearing axis is also essential in
accordance with the invention, and this axis is borne by the
motor-end cover of the housing and is mounted on the motor of the
electric motor.
[0013] In such a constellation, the bearing of the rotor of the
electric motor, on the one hand, and the bearing of the rotor of
the pump, on the other hand, are uncoupled from each other. In no
way does the shaft on which the rotor of the pump rests influence
the position of the rotor of the electric motor. This leads to a
quiet running. Measurements have demonstrated a favorable noise
behavior.
[0014] Although the arrangement of the electric motor and the pump
radially adjacent to each other results in an increase in the axial
length of the structure, the outer diameter of the housing is
thereby reduced. Indeed, this is what is often important in
practice.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] The invention as well the prior art are described in greater
detail below on the basis of the drawing. Depicted in it, in
detail, is the following:
[0016] FIG. 1 shows a motor-pump assembly according to the
invention in an axial section.
[0017] FIG. 2 shows a motor-pump assembly according to DE 100 15
139 A1, likewise in an axial section.
[0018] The motor-pump assembly shown in FIG. 1 comprises an
electric motor 1 having a rotor 1.1 and a stator 1.2. The stator
has stator plates 1.2.1 and a winding 1.2.2. The rotor 1.1 is
pot-shaped and, in the axial section shown here, it is
U-shaped.
[0019] Provided axially adjacent to the electric motor 1 is a
hydrostatic pump 2. The axes of the electric motor 1 and the
hydrostatic pump 2 are aligned with each other.
[0020] The rotor 1.1 of the electric motor 1 is mounted on a
bearing axis 3. The bearing axis 3 is resistant to rotation and
rigid; that is, it does not turn. Here, a sliding bearing 3.1 is
provided between the bearing axis 3 and the rotor 1.1 of the
electric motor 1.
[0021] The electric motor 1 and the hydrostatic pump 2 are arranged
inside of a housing 4. The housing 4 has a cylindrical casing 4.1
and, in addition, a motor-end cover 4.2 and a pump-end cover 4.3.
The bearing axis 3 is fixed to the motor-end cover 4.2 by shrinkage
fitting. Other fastening possibilities are also conceivable.
[0022] The rotor 1.1 of the electric motor 1 is in driven
connection with the shaft 2.1 of the hydrostatic pump 2, namely,
via a driver plate 1.3, which is joined to the rotor 1.1 of the
electric motor 1 in a rotationally resistant manner.
[0023] The left end of the shaft 2.1 of the hydrostatic pump can
also be mounted on the opposite-lying face of the fixed bearing
axis. The bearing can be of any kind, for example, a sliding
bearing or a roller bearing. Thus, the bearing axis 3 could have an
open-edged, pot-like recess in its end region, in which engages the
left end, shown in the figure, of the shaft 2.1 of the pump 2.
[0024] The housing 4 has an inlet for medium 5 as well as a medium
outlet 6.
[0025] The arrows indicate the flow of the medium. This medium is
generally an oil. However, it can also be any other medium and
thus, for example, a different liquid.
[0026] FIG. 2 shows a motor-pump assembly according to the prior
art. It comprises an electric motor 1 having a rotor 1.1 and a
stator 1.2. The stator 1.2 has stator plates 1.2.1 and a winding
1.2.2. The rotor 1.1 has a pot shape and is U-shaped as viewed in
the axial section.
[0027] Arranged radially inside of the rotor 1.1 and of the stator
1.2 is a pump 2. As is seen, this pump 2 is completely enclosed by
the rotor 1.1 or the stator 1.2, respectively, of the electric
motor 1.
[0028] In order to create a driven connection between the rotor 1.1
and the pump shaft 2.1, the arm 1.1.1 of the rotor 1 has a bore
with inner teeth, which mesh with the outer teeth of the pump shaft
2.1. The pump shaft 2.1 has a pinion gear 2.2, which meshes with an
internal geared wheel 2.3, which is arranged eccentrically to the
pinion gear 2.2 inside of the rotor 1.1 of the electric motor 1.
Arranged axially on both sides of the internal geared wheel 2.3 are
side plates 2.4 and 2.5 of the pump 2, in which the pump shaft 2.1
is mounted on sliding bearings 2.4.1 and 2.5.1 so as to rotate.
[0029] Provided for supplying the pump medium is a pump medium
inlet 5 in an end face of the housing 4. Provided for discharging
the pump medium is a pump medium outlet 6 in the same end face of
the housing.
[0030] The medium drawn into the inlet 5 flows through the electric
motor 1 and thereby cools it. It then enters axially or radially
into the hydrostatic pump 2, flows through it, and is carried from
the outlet 6 to a consuming device.
[0031] The noise behavior of the pump is extremely favorable. In
operation, it is substantially quieter than known pumps.
[0032] The use of the rigid bearing axis 3 allows a reduction in
the outer diameter of the assembly by approximately 20%. Moreover,
it is possible, on account of the dimensions that thereby result,
to use a standard rotor with a standard rotor winding as the rotor
1.1, which leads to cost savings.
LIST OF REFERENCE NUMBERS
[0033] 1 electric motor [0034] 1.1 rotor [0035] 1.1.1 arm of the
rotor [0036] 1.2 stator [0037] 1.2.1 stator plates [0038] 1.2.2
winding [0039] 2 pump [0040] 2.1 pump shaft [0041] 2.2 pinion gear
[0042] 2.3 internal geared wheel [0043] 2.4 side plate [0044] 2.4.1
sliding bearing [0045] 2.5 side plate [0046] 2.5.1 sliding bearing
[0047] 3 bearing axis [0048] 3.1 sliding bearing [0049] 4 housing
[0050] 4.1 housing casing [0051] 4.2 motor-end cover [0052] 4.3
pump-end cover [0053] 5 medium inlet [0054] 6 medium outlet
* * * * *