U.S. patent application number 11/407933 was filed with the patent office on 2007-02-01 for electric motor case with folded-out mounting brackets and economical motor-fan packaging.
This patent application is currently assigned to Siemens VDO Automotive Inc.. Invention is credited to Andrew Lakerdas, Paul Stephen McLennan, Attila Simofi-Ilyes, Stefan Zenon Smorowski, Ovidius Turcanu.
Application Number | 20070024135 11/407933 |
Document ID | / |
Family ID | 37693545 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070024135 |
Kind Code |
A1 |
Simofi-Ilyes; Attila ; et
al. |
February 1, 2007 |
Electric motor case with folded-out mounting brackets and
economical motor-fan packaging
Abstract
A cooling module 67 includes a motor assembly 42 having a motor
case 24 having at least one open end and including mounting
brackets 30 integral therewith. Each bracket has only a bottom
portion 32 connected with the motor case. An armature assembly is
disposed in the motor case and includes a rotatable shaft 46. A
brush card assembly 56 is associated with the armature assembly,
and an end cap 60 is disposed over the brush card assembly and
partially covers the open end of the motor case and thereby
defining a non end cap covered motor portion 63. A fan 64 is
coupled to an end of the shaft and has a hub substantially covering
one end of the motor assembly. A shroud 74 has a motor cover 76.
Fastening structure 78 is associated with the shroud and engaged
with the brackets thereby mounting the motor assembly to the
shroud, with the motor cover substantially covering the end cap and
the non end cap covered motor portion.
Inventors: |
Simofi-Ilyes; Attila;
(London, CA) ; Smorowski; Stefan Zenon; (London,
CA) ; Lakerdas; Andrew; (London, CA) ;
McLennan; Paul Stephen; (London, CA) ; Turcanu;
Ovidius; (London, CA) |
Correspondence
Address: |
SIEMENS CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
170 WOOD AVENUE SOUTH
ISELIN
NJ
08830
US
|
Assignee: |
Siemens VDO Automotive Inc.
London
CA
|
Family ID: |
37693545 |
Appl. No.: |
11/407933 |
Filed: |
April 21, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60702473 |
Jul 26, 2005 |
|
|
|
Current U.S.
Class: |
310/89 ; 310/239;
310/91; 417/423.7 |
Current CPC
Class: |
H01R 39/383 20130101;
H02K 5/06 20130101; H02K 7/14 20130101; H01R 39/385 20130101; Y10T
29/49963 20150115; H02K 5/00 20130101; F04D 29/646 20130101 |
Class at
Publication: |
310/089 ;
310/091; 310/239; 417/423.7 |
International
Class: |
H02K 5/00 20060101
H02K005/00; H01R 39/38 20060101 H01R039/38 |
Claims
1. A cooling module comprising: a motor assembly comprising: a
motor case defining a stator of generally cylindrical shape having
at least one open end, the motor case including a plurality of
mounting brackets integral therewith at the open end, each mounting
bracket having only a bottom portion connected with the motor case
with side portions of each bracket being separated from the motor
case by cut-out portions in the motor case, and an armature
assembly disposed in the motor case for rotation with respect to
the motor case, the armature assembly including a shaft that
rotates with the armature assembly, a brush card assembly
associated with the armature assembly, and an end cap disposed over
the brush card assembly and partially covering the open end of the
motor case and thereby defining a non end cap covered motor
portion, a fan coupled to an end of the shaft, the fan having a hub
substantially covering one end of the motor assembly, a shroud
having a motor cover, and fastening structure associated with the
shroud and engaged with the brackets thereby mounting the motor
assembly to the shroud, with the motor cover substantially covering
the end cap and the non end cap covered motor portion.
2. The module of claim 1, wherein the motor case defines a central
axis and each bracket is folded out so as to be generally
transverse with respect to the central axis.
3. The module of claim 2, wherein the motor assembly includes
permanent magnet structure mounted to the motor case in an interior
thereof.
4. The module of claim 3, wherein the permanent magnet structure
includes four permanent magnets, and at least three spaced brackets
are provided, a radial position of at least two of the brackets
with respect to the central axis being generally centered with
respect to an associated magnet.
5. The module of claim 1, wherein each bracket includes a surface
defining a hole and wherein the fastening structure is a thread
forming screw engaged with an associated hole.
6. The module of claim 1, wherein the fastening structure is a
rivet.
7. The module of claim 1, wherein the end cap includes a bushing
assembly that supports an end of the shaft for rotation.
8. A method of mounting a motor assembly to a shroud, the method
including: providing a motor assembly having a motor case of
generally cylindrical shape having at least one open end, an end
cap partially covers the open end, the motor case defines a central
axis, the motor case includes a plurality of mounting brackets
integral therewith at the open end, each mounting bracket having
only a bottom portion connected with the case with side portions of
each bracket being separated from the motor case by cut-out
portions in the motor case, bending the mounting brackets about the
bottom portion thereof with respect to the motor case so as to be
generally transverse with respect to the central axis, providing a
shroud having a motor cover, and mounting the motor case and thus
the motor assembly to the shroud by engaging a fastener, associated
with the motor cover, with each of the brackets such that the motor
cover substantially covers the end cap and open end of the motor
case.
9. The method of claim 8, wherein each bracket includes a hole and
the fastener is a thread-forming screw, the method includes
engaging a thread-forming screw with an associated hole.
10. The method of claim 8, wherein the motor assembly includes: an
armature assembly disposed in the motor case for rotation with
respect to the motor case, the armature assembly including a shaft
that rotates with the armature assembly, a brush card assembly
associated with the armature assembly, and the end cap is disposed
over the brush card assembly and defines a non end cap covered
motor portion, wherein the step of providing shroud and motor cover
includes ensuring that the motor cover substantially covers the end
cap and the non end cap covered motor portion.
11. The method of claim 10, wherein the shaft has an end extending
from a second end of the motor case opposite the open end thereof,
the method further includes coupling a fan to the end of the shaft,
the fan having a hub constructed and arranged to substantially
cover the second end of the motor case.
12. A stator for a permanent magnet DC motor, the stator
comprising: a motor case of generally cylindrical shape having at
least one open end, the case including a plurality of mounting
brackets integral therewith at the open end, each mounting bracket
having only a bottom portion connected with the motor case with
side portions of each bracket being separated from the motor case
by cut-out portions in the motor case, each mounting bracket being
folded-out about the bottom portion thereof with respect to the
motor case for mounting the motor case to another object.
13. The stator of claim 12, wherein the motor case defines a
central axis and each bracket is folded out so as to be generally
transverse with respect to the central axis.
14. The stator of claim 13, further including permanent magnets
mounted to an interior of the motor case, a radial position of
certain brackets with respect to the central axis being generally
centered with respect to an associated magnet
15. The stator of claim 12, wherein four permanent magnets are
provided and at least three spaced brackets are provided, at least
two of the brackets define the certain brackets that are generally
centered with respect to an associated magnet.
16. The stator of claim 12, in combination with an armature
assembly disposed in the motor case, the motor case including
permanent magnet structure fixed with respect to an interior of the
motor case and associated with the armature assembly.
17. The combination of claim 16, in further combination with a
shroud, the shroud including a motor cover, wherein fastening
structure, associated with the motor cover, is engaged with the
brackets mounting the motor case to the shroud.
18. The combination of claim 17, wherein each bracket includes a
surface defining a hole receiving fastening structure in the form
of a thread-forming screw.
19. The combination of claim 17, wherein the fastening structure is
a rivet.
20. The stator of claim 12, wherein each bracket includes fastener
engagement structure constructed and arranged to engage fastening
structure.
Description
[0001] This application claims the benefit of the earlier filing
date of U.S. Provisional Application No. 60/702,473, filed on Jul.
26, 2005, which is incorporated by reference herein in its
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to Permanent Magnet Direct Current
(PMDC) motors for automotive applications such as engine
cooling.
BACKGROUND OF THE INVENTION
[0003] Electric motors used in engine cooling applications need
some type of mounting feature on the end cap or motor case (stator
assembly) to provide adequate fastening to a shroud. The stator
assembly is the stationary member of the electric motor. The two
most commonly used features are shown FIG. 1 and FIG. 2.
[0004] FIG. 1 shows an electric motor 10 where the motor mounting
features (to shroud) are conventional brackets 12 welded to the
motor case/stator assembly 14. An end cap (not shown) of the motor
is at the opposite side to the fan side A. With this configuration,
the function of the end cap is to provide coverage to the motor at
the opposite side of the fan and to hold a bearing/bushing assembly
(not shown) for supporting a motor shaft. However, the end cap does
not have structural function with regard to the motor mounting to
the shroud.
[0005] FIG. 2 shows another electric motor 10' that is functionally
the same as the motor 10 of FIG. 1. However, in FIG. 2, the
conventional mounting features to mount the motor 10' to the shroud
are flanges 15 integrated with the end cap 16 that covers an end of
the motor case/stator assembly 14.
[0006] Conventional motor to shroud attachments are illustrated in
FIG. 3 and FIG. 4. FIG. 3 shows the motor 10 to shroud 18
connection for motor 10 of FIG. 1. FIG. 4 shows the motor 10' to
shroud 18 connection for motor 10' of FIG. 2. In both
configurations, the fastening method is done with a screw fastener
19 or rivet. A conventional fan 22 is driven by the associated
motor 10, 10'.
[0007] The welded brackets 12 of motor 10 increase the overall cost
of the system due to the cost of three brackets and the cost of a
welding operation. The flanges 15 on the end cap of motor 10'
increase the overall system cost due to the cost of a larger and
thicker piece of material used to make the end cap having the
flanges.
[0008] Since there is a high demand to reduce the system cost of
the engine cooling module, there is a need to reduce the cost of
the attachment mechanism of a motor to a shroud.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to fulfill the need
referred to above. In accordance with the principles of the present
invention, this objective is obtained by providing a cooling module
including a motor assembly having a motor case defining a stator of
generally cylindrical shape having at least one open end. The motor
case includes a plurality of mounting brackets integral therewith
at the open end. Each mounting bracket has only a bottom portion
connected with the motor case with side portions of each bracket
being separated from the motor case by cut-out portions in the
motor case. An armature assembly is disposed in the motor case for
rotation with respect to the motor case. The armature assembly
includes a shaft that rotates therewith. A brush card assembly is
associated with the armature assembly. An end cap is disposed over
the brush card assembly and partially covers the open end of the
motor case, thereby defining a non end cap covered motor portion. A
fan is coupled to an end of the shaft and has a hub substantially
covering one end of the motor assembly. A shroud has a motor cover.
Fastening structure is associated with the shroud and engaged with
the brackets thereby mounting the motor assembly to the shroud,
with the motor cover substantially covering the end cap and the non
end cap covered motor portion.
[0010] In accordance with another aspect of the invention, a stator
is provided for a permanent magnet DC motor. The stator includes a
motor case of generally cylindrical shape having at least one open
end. The case includes a plurality of mounting brackets integral
therewith at the open end. Each mounting bracket has only a bottom
portion connected with the motor case with side portions of each
bracket being separated from the motor case by cut-out portions in
the motor case. Each mounting bracket is folded-out about the
bottom portion thereof with respect to the motor case for use in
mounting the motor case to a shroud.
[0011] In accordance with yet another aspect of the invention, a
method of mounting a motor assembly to a shroud provides a motor
assembly having a motor case of generally cylindrical shape having
at least one open end. An end cap partially covers the open end.
The motor case defines a central axis and includes a plurality of
mounting brackets integral therewith at the open end. Each mounting
bracket has only a bottom portion connected with the case with side
portions of each bracket being separated from the motor case by
cut-out portions in the motor case. The mounting brackets are bent
about the bottom portion thereof with respect to the motor case so
as to be generally transverse with respect to the central axis. A
shroud is provided having a motor cover. The motor case, and thus
the motor assembly, is mounted to the shroud by engaging a
fastener, associated with the motor cover, with each of the
brackets such that the motor cover substantially covers the end cap
and open end of the motor case.
[0012] Other objects, features and characteristics of the present
invention, as well as the methods of operation and the functions of
the related elements of the structure, the combination of parts and
economics of manufacture will become more apparent upon
consideration of the following detailed description and appended
claims with reference to the accompanying drawings, all of which
form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be better understood from the following
detailed description of the preferred embodiments thereof, taken in
conjunction with the accompanying drawings, wherein like reference
numerals refer to like parts, in which:
[0014] FIG. 1 is a view of a conventional electric motor assembly
where the motor mounting features for mounting a shroud are welded
to the motor case.
[0015] FIG. 2 is a view of a conventional electric motor assembly
where the motor mounting features for mounting a shroud are
integrated into the end cap.
[0016] FIG. 3 is a sectional view of the conventional motor of FIG.
1 shown mounted to a shroud.
[0017] FIG. 4 is a sectional view of the conventional motor of FIG.
2 shown mounted to a shroud.
[0018] FIG. 5 is a perspective view of a motor case having
folded-out mounting tabs in accordance with the invention.
[0019] FIG. 6 is an exploded view of a motor assembly using the
motor case of FIG. 5.
[0020] FIG. 7 is a view of a fan mounted onto a shaft of the motor
of FIG. 6.
[0021] FIG. 8 shows the shroud side of the fan-motor assembly of
FIG. 7 mounted to a shroud.
[0022] FIG. 9 shows the fan side of a portion of the assembly of
FIG. 8.
[0023] FIG. 10 shows the motor of FIG. 6 mounted to a shroud, with
a fan not yet attached.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0024] With reference to FIG. 5, a motor case 24 is shown in
accordance with the principles of the present invention, for use in
a PMDC motor. The motor case 24 has a generally cylindrical wall
25, preferably a closed end 21, and an opposing open end 23,
defining an interior 27. With reference to FIG. 6, permanent magnet
structure 26 is mounted to the inside surface 28 of wall 25 within
the interior 27. In the embodiment, the magnet structure 26
includes four permanent magnets (only two are seen in FIG. 6),
although one or more magnets can be provided. This assembly defines
a stator assembly of a PMDC motor that receives a conventional
armature assembly (not shown in FIG. 5). The stator assembly is the
stationary member of the motor.
[0025] As shown in FIG. 5, the motor case 24 includes a plurality
(e.g., at least two) of folded out tabs or brackets 30 provided in
accordance with the principles of the invention for mounting the
motor case 24 to a shroud. The brackets 30 are made integral with
the wall 25 of the motor case 24 at the open end 23 thereof, with
only a bottom portion 32 of the bracket 30 being connected with the
motor case 24. Thus, the brackets 30, in an unfolded condition,
define part of the cylindrical wall 25 of the motor case 24 with
sides 34 of the brackets 30 being separated from the motor case 24
by cutout portions 36 in the motor case 24. Thus, the brackets 30
use existing material of the motor case. A cutout 38 is provided in
the motor case 24 for receiving a connector so as to reduce the
overall axial length of the motor. The motor case 24 defines a
central axis C of a motor assembly 42 (FIG. 6).
[0026] The brackets 30 are folded out (bent) about the bottom
portion 32 to extend from the motor case 24 (e.g., generally
transverse with respect to the central axis C) so as to provide
optimum structural support with minimum magnetic flux loss in the
motor. Each bracket 30 includes fastener engagement structure
preferably in the form of a through hole 40 receiving a fastener,
for securing the motor case 24 to a shroud, as will be explained
more fully below.
[0027] The preferred radial position (with respect to the central
axis C) for each bracket 30 is at the edge of the magnetic flux
circuit. This position typically would be at middle of a magnet 26
that is mounted to the inside of the motor case 24 as best shown in
FIG. 6. In the embodiment, since three evenly spaced brackets 30
are provided for a four-pole (four permanent magnets 26) motor,
only two brackets 30 are disposed with respect to the middle of an
associated magnet 26. It can be appreciated that the three brackets
30 can be unevenly spaced so to that each bracket 30 can be
disposed with respect to a middle of an associated magnet 26. Also,
four brackets 30 can be provided and disposed with respect to a
middle of an associated magnet of the four-pole motor. The
folded-out bracketing can be applied to motors having other than
four poles.
[0028] FIG. 6 is an exploded view of a permanent magnet DC brush
motor assembly, generally indicated at 42, using the motor case 24
of FIG. 5 with folded out brackets 30. The motor assembly 42
includes an armature assembly having a lamination stack 44
(armature windings 61 shown in FIG. 7) for rotating a shaft 46. A
bearing 48 supports an end of the shaft 46 for rotation and a
bearing retainer 50 holds the bearing 48 in the motor case 24. A
commutator 52 of the armature assembly is associated with the
armature stack 44 for delivering electric current from brushes 54
of a brush card 56 to the armature windings in the conventional
manner. The link windings of the commutator 52 are not shown but
are the type disclosed in U.S. Pat. No. 6,694,599, the contents of
which is hereby incorporated by reference into this specification.
A connector 58 for powering the motor assembly 42 is mounted to the
brush card 56 so current can be supplied to the brushes 54. A
portion of the connector 58 is received in the cutout 38 (FIG. 5)
of the motor case 24. An end cap 60 covers the brush card 56 and
thus closes and partially covers the open end of the motor case 24.
With reference to FIG. 7, since the end cap 60 does not completely
cover the open end of the motor case 24, a portion of the windings
61 are exposed in a non end cap covered motor portion 63 to aid in
cooling of the motor assembly 42. The end cap 60 includes a bushing
assembly 62 that supports the other end of the shaft 46 for
rotation.
[0029] FIG. 7 shows a fan, generally indicated at 64, mounted onto
the shaft 46 (e.g., pressed on) of the motor assembly 42 of FIG. 6
to define a fan-motor assembly 65. The fan 64 includes a fan hub
66. A plurality of fan blades 68 extending from the hub 66 with
tips of the blades 68 being joined by an outer ring 70. The hub 66
includes cooling fins 72 that aid cooling the motor assembly
42.
[0030] FIG. 8 shows the fan-motor assembly 65 of FIG. 7 mounted
onto a shroud 74 to define a cooling module, generally indicated at
67. In the figure, the motor assembly 42 is hidden (sandwiched
between the fan hub 66 and a motor cover 76 that is part of the
shroud 74. Fasteners, preferably in the form of thread-forming
screws 78 secure the motor-fan assembly 65 to the shroud 74. More
particularly, each screw 78 forms a thread in an associated hole 40
of a bracket 30 of the motor case 24 (FIG. 7). Rivets 78' or other
fasteners can be used instead of the screws 78 to engage the
brackets 30. FIG. 9 shows a portion of the fan side of the module
67.
[0031] With reference to FIGS. 8 and 9, the motor assembly 42 (only
connector 58 seen in FIGS. 8 and 9) is packaged/sandwiched with
respect to the shroud cover 76 and fan hub 66 such that the motor
assembly 42 is barely visible. In a conventional motor
configuration, the motor case and end cap are painted for
esthetic/appearance purposes. Since the motor assembly 42 is barely
visible, there is an opportunity to further reduce the system cost
by choosing a more economical surface protection for motor case 24
and end cap 60 or even not applying any type of protection. Also,
the back of the motor assembly 42 (end cap 60 and non end cap
covered motor portion 63 of FIG. 7) is protected/shielded by the
shroud motor cover 76 from heat and/or splashing liquids.
Therefore, a smaller end cap 60 can be used, resulting in lower
cost. More importantly, the end cap 60 is not used for motor
mounting. Thus, thin material can be used to make the end cap 60,
which also further reduces the overall cost of the product.
[0032] Instead of mounting the shroud 74 to the motor-fan assembly
as in FIG. 8, FIG. 10 shows that the motor assembly 42 also can be
mounted/fastened (the fasteners are not shown) to the shroud 74
first, then the fan 64 can be attached thereafter. However, a hole
will be required in the middle of the motor cover 76 to support the
shaft 46 at the motor cover side during a fan press-on operation.
In this embodiment, a fan adapter (not shown) is insert-molded into
the center part of the fan hub. However, the fan adapter also can
be pressed on to the motor shaft 46 prior to fan attachment for
other types of fan attachment configurations.
[0033] The foregoing preferred embodiments have been shown and
described for the purposes of illustrating the structural and
functional principles of the present invention, as well as
illustrating the methods of employing the preferred embodiments and
are subject to change without departing from such principles.
Therefore, this invention includes all modifications encompassed
within the spirit of the following claims.
* * * * *