U.S. patent application number 16/214795 was filed with the patent office on 2020-06-11 for stator having skewed mounting ears.
This patent application is currently assigned to GM Global Technology Operations LLC. The applicant listed for this patent is GM Global Technology Operations LLC. Invention is credited to Song He, Edward L. Kaiser, Pavan Kumar Patruni, Mithun Sunny.
Application Number | 20200185982 16/214795 |
Document ID | / |
Family ID | 70776439 |
Filed Date | 2020-06-11 |
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United States Patent
Application |
20200185982 |
Kind Code |
A1 |
Patruni; Pavan Kumar ; et
al. |
June 11, 2020 |
STATOR HAVING SKEWED MOUNTING EARS
Abstract
A stator for an electromagnetic machine includes a first
lamination stack defining a first cavity therein and having a
central longitudinal axis. The first lamination stack includes a
first plurality of mounting ears disposed opposite the first cavity
and each spaced apart from one another about the central
longitudinal axis. The stator further includes a second lamination
stack abutting the first lamination stack and defining a second
cavity therein aligned with the first cavity along the central
longitudinal axis. The second lamination stack includes a second
plurality of mounting ears disposed opposite the second cavity and
each spaced apart from the first plurality of mounting ears and
from one another about the central longitudinal axis. An
electromagnetic machine including the stator and a device including
the electromagnetic machine are also described.
Inventors: |
Patruni; Pavan Kumar;
(Karnatka, IN) ; He; Song; (Troy, MI) ;
Kaiser; Edward L.; (Orion, MI) ; Sunny; Mithun;
(Farmington Hills, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM Global Technology Operations LLC |
Detroit |
MI |
US |
|
|
Assignee: |
GM Global Technology Operations
LLC
Detroit
MI
|
Family ID: |
70776439 |
Appl. No.: |
16/214795 |
Filed: |
December 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K 1/185 20130101;
H02K 1/16 20130101 |
International
Class: |
H02K 1/16 20060101
H02K001/16; H02K 1/18 20060101 H02K001/18 |
Claims
1. A stator for an electromagnetic machine, the stator comprising:
a first lamination stack defining a first cavity therein and having
a central longitudinal axis, wherein the first lamination stack
includes a first plurality of mounting ears disposed opposite the
first cavity and each spaced apart from one another about the
central longitudinal axis; and a second lamination stack abutting
the first lamination stack and defining a second cavity therein
aligned with the first cavity along the central longitudinal axis,
wherein the second lamination stack includes a second plurality of
mounting ears disposed opposite the second cavity and each spaced
apart from the first plurality of mounting ears and from one
another about the central longitudinal axis.
2. The stator of claim 1, wherein the first lamination stack is
rotated with respect to the second lamination stack about the
central longitudinal axis.
3. The stator of claim 1, wherein the first plurality of mounting
ears do not contact the second plurality of mounting ears.
4. The stator of claim 1, wherein the first plurality of mounting
ears are spaced apart from one another by 120 angular degrees.
5. The stator of claim 4, wherein the second plurality of mounting
ears are spaced apart from one another by 120 angular degrees and
are each spaced apart from a respective one of the first plurality
of mounting ears by 60 annular degrees.
6. The stator of claim 1, wherein the first lamination stack has a
first height along the central longitudinal axis and the second
lamination stack has a second height along the central longitudinal
axis that is equal to the first height.
7. The stator of claim 1, wherein the first lamination stack has a
first external surface spaced opposite the first cavity and further
wherein the first plurality of mounting ears extend from the first
external surface away from the first cavity.
8. The stator of claim 7, wherein the first lamination stack is
welded to the second lamination stack on the first external
surface.
9. The stator of claim 1, wherein the first lamination stack has an
interface surface and is adhered to the second lamination stack at
the interface surface.
10. The stator of claim 1, wherein each of the first plurality of
mounting ears are configured to receive a respective one of a first
plurality of fasteners.
11. The stator of claim 10, wherein each of the second plurality of
mounting ears are configured to receive a respective one of a
second plurality of fasteners that are different from the first
plurality of fasteners.
12. The stator of claim 1, wherein the stator includes at least
three of the first plurality of mounting ears and at least three of
the second plurality of mounting ears.
13. The stator of claim 1, further including a third lamination
stack abutting the second lamination stack and defining a third
cavity therein aligned with the first cavity and the second cavity
about the central longitudinal axis, wherein the third lamination
stack includes a third plurality of mounting ears disposed opposite
the third cavity and each spaced apart from the second plurality of
mounting ears and from one another about the central longitudinal
axis.
14. An electromagnetic machine comprising: a motor housing defining
a chamber therein; a stator disposed within the chamber and
fastened to the motor housing, wherein the stator includes: a first
lamination stack defining a first cavity therein and having a
central longitudinal axis, wherein the first lamination stack
includes a first plurality of mounting ears disposed opposite the
first cavity and each spaced apart from one another about the
central longitudinal axis; and a second lamination stack abutting
the first lamination stack and defining a second cavity therein
aligned with the first cavity along the central longitudinal axis,
wherein the second lamination stack includes a second plurality of
mounting ears disposed opposite the second cavity and each spaced
apart from the first plurality of mounting ears and from one
another about the central longitudinal axis; a first plurality of
fasteners each disposed within a respective one of the first
plurality of mounting ears to thereby fasten the first lamination
stack to the motor housing; and a second plurality of fasteners
each disposed within a respective one of the second plurality of
mounting ears to thereby fasten the second lamination stack to the
motor housing.
15. The electromagnetic machine of claim 14, further including a
plurality of bosses disposed on the motor housing and each
configured for receiving a respective one of the second plurality
of fasteners.
16. The electromagnetic machine of claim 15, wherein each of the
first plurality of fasteners has a first length and each of the
second plurality of fasteners has a second length that is equal to
the first length.
17. The electromagnetic machine of claim 14, wherein each of the
second plurality of fasteners is longer than each of the first
plurality of fasteners.
18. A device comprising: a driven component; an electromagnetic
machine coupled to the driven component and including: a motor
housing defining a chamber therein; a stator disposed within the
chamber and fastened to the motor housing, wherein the stator
includes: a first lamination stack defining a first cavity therein
and having a central longitudinal axis, wherein the first
lamination stack includes a first plurality of mounting ears
disposed opposite the first cavity and each spaced apart from one
another about the central longitudinal axis; and a second
lamination stack abutting the first lamination stack and defining a
second cavity therein aligned with the first cavity along the
central longitudinal axis, wherein the second lamination stack
includes a second plurality of mounting ears disposed opposite the
second cavity and each spaced apart from the first plurality of
mounting ears and from one another about the central longitudinal
axis; and an output member disposed within the first cavity and the
second cavity and configured for driving the driven component.
19. The device of claim 18, wherein the first lamination stack is
rotated with respect to the second lamination stack about the
central longitudinal axis such that the first plurality of mounting
ears do not contact the second plurality of mounting ears.
20. The device of claim 18, wherein the stator further includes a
third lamination stack abutting the second lamination stack and
defining a third cavity therein aligned with the first cavity and
the second cavity about the central longitudinal axis; wherein the
third lamination stack includes a third plurality of mounting ears
disposed opposite the third cavity and each spaced apart from the
second plurality of mounting ears and from one another such that
the third lamination stack is rotated with respect to the second
lamination stack about the central longitudinal axis so that the
third plurality of mounting ears do not contact the second
plurality of mounting ears.
Description
INTRODUCTION
[0001] The disclosure relates to a stator, an electromagnetic
machine including the stator, and a device including the
electromagnetic machine.
[0002] Electromagnetic machines such as electric motors,
generators, and traction motors are useful for converting energy
from one form to another. Such electromagnetic machines often
include an element rotatable about an axis of rotation. The
rotatable element, i.e., the rotor, may be coaxial with a static
element, i.e., a stator, and energy may be converted via relative
rotation between the rotor and stator.
SUMMARY
[0003] A stator for an electromagnetic machine includes a first
lamination stack defining a first cavity therein and having a
central longitudinal axis. The first lamination stack includes a
first plurality of mounting ears disposed opposite the first cavity
and each spaced apart from one another about the central
longitudinal axis. The stator further includes a second lamination
stack abutting the first lamination stack and defining a second
cavity therein aligned with the first cavity along the central
longitudinal axis. The second lamination stack includes a second
plurality of mounting ears disposed opposite the second cavity and
each spaced apart from the first plurality of mounting ears and
from one another about the central longitudinal axis.
[0004] The first lamination stack may be rotated with respect to
the second lamination stack about the central longitudinal axis.
Further, the first plurality of mounting ears may not contact the
second plurality of mounting ears.
[0005] In one aspect, the first plurality of mounting ears may be
spaced apart from one another by 120 angular degrees. Further, the
second plurality of mounting ears may be spaced apart from one
another by 120 angular degrees and may each be spaced apart from a
respective one of the first plurality of mounting ears by 60
annular degrees.
[0006] The first lamination stack may have a first height along the
central longitudinal axis and the second lamination stack may have
a second height along the central longitudinal axis that is equal
to the first height.
[0007] The first lamination stack may also have a first external
surface spaced opposite the first cavity, and the first plurality
of mounting ears may extend from the first external surface away
from the first cavity.
[0008] In another aspect, the first lamination stack may be welded
to the second lamination stack on the first external surface. In a
further aspect, the first lamination stack may have an interface
surface and may be adhered to the second lamination stack at the
interface surface.
[0009] Each of the first plurality of mounting ears may be
configured to receive a respective one of a first plurality of
fasteners. Each of the second plurality of mounting ears may be
configured to receive a respective one of a second plurality of
fasteners that are different from the first plurality of
fasteners.
[0010] In one aspect, the stator may include at least three of the
first plurality of mounting ears and at least three of the second
plurality of mounting ears.
[0011] In an additional aspect, the stator may further include a
third lamination stack abutting the second lamination stack and
defining a third cavity therein aligned with the first cavity and
the second cavity about the central longitudinal axis. The third
lamination stack may include a third plurality of mounting ears
disposed opposite the third cavity and each spaced apart from the
second plurality of mounting ears and from one another about the
central longitudinal axis.
[0012] An electromagnetic machine includes a motor housing defining
a chamber therein and a stator disposed within the chamber and
fastened to the motor housing. The stator includes a first
lamination stack defining a first cavity therein and having a
central longitudinal axis. The first lamination stack includes a
first plurality of mounting ears disposed opposite the first cavity
and each spaced apart from one another about the central
longitudinal axis. The stator also includes a second lamination
stack abutting the first lamination stack and defining a second
cavity therein aligned with the first cavity along the central
longitudinal axis. The second lamination stack includes a second
plurality of mounting ears disposed opposite the second cavity and
each spaced apart from the first plurality of mounting ears and
from one another about the central longitudinal axis. The
electromagnetic machine further includes a first plurality of
fasteners each disposed within a respective one of the first
plurality of mounting ears to thereby fasten the first lamination
stack to the motor housing. In addition, the electromagnetic
machine includes a second plurality of fasteners each disposed
within a respective one of the second plurality of mounting ears to
thereby fasten the second lamination stack to the motor
housing.
[0013] The electromagnetic machine may further include a plurality
of bosses disposed on the motor housing and each configured for
receiving a respective one of the second plurality of
fasteners.
[0014] In one aspect, each of the first plurality of fasteners may
have a first length and each of the second plurality of fasteners
may have a second length that is equal to the first length.
[0015] In another aspect, each of the second plurality of fasteners
may be longer than each of the first plurality of fasteners.
[0016] A device includes a driven component and an electromagnetic
machine coupled to the driven component. The electromagnetic
machine includes a motor housing defining a chamber therein and a
stator disposed within the chamber and fastened to the motor
housing. The stator includes a first lamination stack defining a
first cavity therein and having a central longitudinal axis. The
first lamination stack includes a first plurality of mounting ears
disposed opposite the first cavity and each spaced apart from one
another about the central longitudinal axis. The stator also
includes a second lamination stack abutting the first lamination
stack and defining a second cavity therein aligned with the first
cavity along the central longitudinal axis. The second lamination
stack includes a second plurality of mounting ears disposed
opposite the second cavity and each spaced apart from the first
plurality of mounting ears and from one another about the central
longitudinal axis. The device also includes an output member
disposed within the first cavity and the second cavity and
configured for driving the driven component.
[0017] In one aspect, the first lamination stack may be rotated
with respect to the second lamination stack about the central
longitudinal axis such that the first plurality of mounting ears do
not contact the second plurality of mounting ears.
[0018] In another aspect, the stator may further include a third
lamination stack abutting the second lamination stack and defining
a third cavity therein aligned with the first cavity and the second
cavity about the central longitudinal axis. The third lamination
stack may include a third plurality of mounting ears disposed
opposite the third cavity and each spaced apart from the second
plurality of mounting ears and from one another such that the third
lamination stack is rotated with respect to the second lamination
stack about the central longitudinal axis so that the third
plurality of mounting ears do not contact the second plurality of
mounting ears.
[0019] The above features and advantages and other features and
advantages of the present disclosure will be readily apparent from
the following detailed description of the preferred embodiments and
best modes for carrying out the present disclosure when taken in
connection with the accompanying drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic illustration of an exploded
perspective view of a device including an electromagnetic machine
having a motor housing and a stator.
[0021] FIG. 2 is a schematic illustration of a perspective view of
the stator of FIG. 1.
[0022] FIG. 3 is a schematic illustration of a top view of the
stator of FIGS. 1 and 2.
[0023] FIG. 4 is a schematic illustration of a perspective view of
another embodiment of the stator of FIGS. 1-3.
[0024] FIG. 5 is a schematic illustration of a top view of the
motor housing of FIG. 1.
[0025] FIG. 6 is a schematic illustration of a top view of the
stator of FIGS. 1-3 fastened to the motor housing of FIGS. 1 and
5.
DETAILED DESCRIPTION
[0026] Referring to the Figures, wherein like reference numerals
refer to like elements, a device 10 including an electromagnetic
machine 12 is shown generally in FIG. 1. The device 10 and
electromagnetic machine 12 may be useful for applications requiring
excellent efficiency and minimal noise, vibration, and harshness
during operation. In particular, the electromagnetic machine 12 may
have excellent stiffness and stability and therefore may not suffer
from low-frequency whine and/or efficiency losses during operation.
In addition, the electromagnetic machine 12 and device 10 may be
economical in terms of manufacturing time and cost and may be
scalable to mass production manufacturing operations.
[0027] Accordingly, the device 10 and electromagnetic machine 12
may be useful for vehicular applications such as, but not limited
to, automobiles, buses, forklifts, motorcycles, bicycles, trains,
trams, trolleys, spacecraft, airplanes, farming equipment,
earthmoving or construction equipment, cranes, tanks and
transporters, boats, and the like. Alternatively, the device 10 and
electromagnetic machine 12 may be useful for non-vehicular
applications such as stationary power generation, residential
appliances, portable power generation, electronics, computers,
tools, and the like. More specifically, by way of a non-limiting
example, the device 10 and electromagnetic machine 12 may be useful
for electric traction motor applications for non-autonomous,
autonomous, or semi-autonomous vehicle applications. That is, the
device 10 may be a vehicle and the electromagnetic machine 12 may
be an electric motor.
[0028] More specifically, as described with reference to FIG. 1,
the electromagnetic machine 12 includes a motor housing 14 defining
a chamber 16 therein, and a stator 18 disposed within the chamber
16 and fastened to the motor housing 14. The motor housing 14 may
be configured for supporting and protecting components of the
electromagnetic machine 12 and may be formed from a comparatively
rigid, formable, and lightweight material such as steel or
aluminum. The motor housing 14 may have a generally square or
rectangular shape and the chamber 16 may be configured for
receiving the stator 18.
[0029] Referring now to FIG. 2, the stator 18 for the
electromagnetic machine 12 includes a first lamination stack 20
defining a first cavity 22 therein and having a central
longitudinal axis 24. The first lamination stack 20 may be formed
from a plurality of circular and concentric individual laminations
(not shown) formed from, for example, lamination steel and may have
a cylindrical shape. In addition, the first lamination stack 20 may
have a first height 26 along the central longitudinal axis 24.
[0030] Further, the first lamination stack 20 includes a first
plurality of mounting ears 28 disposed opposite the first cavity 22
and each spaced apart from one another about the central
longitudinal axis 24. More specifically, the first lamination stack
20 may have a first external surface 30 spaced opposite the first
cavity 22, and the first plurality of mounting ears 28 may extend
from the first external surface 30 away from the first cavity 22.
Each of the first plurality of mounting ears 28 may be configured
for receiving a respective one of a first plurality of fasteners 32
(FIG. 1) to thereby fasten the first lamination stack 20 to the
motor housing 14, as set forth in more detail below. That is, each
of the first plurality of mounting ears 28 may be shaped as a
protrusion or bump-out from the first external surface 30 and may
be arranged to receive the respective fastener 32, e.g., a bolt, so
as to secure the stator 18 within the chamber 16 during assembly of
the electromagnetic machine 12. In addition, the first plurality of
mounting ears 28 may carry a torque during operation of the
electromagnetic machine 12.
[0031] The stator 18 may include any number of the first plurality
of mounting ears 28. In one embodiment, the stator 18 may include
at least three of the first plurality of mounting ears 28 so as to
stably attach the stator 18 to the motor housing 14 and minimize
eccentric rotation of the stator 18 during operation. For example,
as shown in FIG. 2, the first lamination stack 20 may include three
of the first plurality of mounting ears 28. Alternatively, although
not shown, the stator 18 may include four or more of the first
plurality of mounting ears 28.
[0032] The first plurality of mounting ears 28 may be spaced apart
from one another by a suitable number of annular degrees. In one
non-limiting example, the first plurality of mounting ears 28 may
be spaced apart from one another by 120 angular degrees.
Alternatively, although not shown, the first plurality of mounting
ears 28 may be spaced apart from one another by 90 angular degrees
or by 72 angular degrees.
[0033] Referring again to FIG. 2, the stator 18 includes a second
lamination stack 34 abutting the first lamination stack 20 and
defining a second cavity 36 therein aligned with the first cavity
22 along the central longitudinal axis 24. The second lamination
stack 34 may also be formed from a plurality of circular and
concentric individual laminations (not shown) formed from, for
example, lamination steel and may also have a cylindrical shape. In
other words, the stator 18 may be split into multiple lamination
stacks 20, 34 that may be rotated or skewed with respect to one
another. Although set forth in more detail below, such rotation or
skewing may multiply a number of mounting ears 28, 38 for attaching
the stator 18 to the motor housing 14, which may increase stiffness
and decrease noise, vibration, and harshness without adding stator
mass and without changing a design or configuration of individual
laminations.
[0034] The second lamination stack 34 may have a second height 40
(FIG. 2) along the central longitudinal axis 24 that is equal to
the first height 26. That is, the first lamination stack 20 and the
second lamination stack 34 may be similarly sized. Alternatively,
although not shown, the first height 26 may be greater than or less
than the second height 40 such that the first lamination stack 20
and the second lamination stack 34 have different heights 26, 40.
The first height 26 and the second height 40 may be selected and
optimized to minimize noise, vibration, and harshness of the stator
18 during operation of the electromagnetic machine 12.
[0035] Further, the second lamination stack 34 includes a second
plurality of mounting ears 38 disposed opposite the second cavity
36 and each spaced apart from the first plurality of mounting ears
28 and from one another about the central longitudinal axis 24.
That is, as best shown in FIG. 2, the first lamination stack 20 may
be rotated with respect to the second lamination stack 34 about the
central longitudinal axis 24. Stated differently, the first
lamination stack 20 may be shifted or skewed or biased with respect
to the second lamination stack 34 about the central longitudinal
axis 24, as set forth in more detail below.
[0036] More specifically, as described with continued reference to
FIG. 2, the second lamination stack 34 may have a second external
surface 42 spaced opposite the second cavity 36, and the second
plurality of mounting ears 38 may extend from the second external
surface 42 away from the second cavity 36. Each of the second
plurality of mounting ears 38 may be configured for receiving a
respective one of a second plurality of fasteners 44 (FIG. 1) that
are different from the first plurality of fasteners 32 (FIG. 1) to
thereby fasten the second lamination stack 34 to the motor housing
14.
[0037] That is, one of the first plurality of fasteners 32 may not
extend through both a respective one of the first plurality of
mounting ears 28 and a respective one of the second plurality of
mounting ears 38. Similarly, one of the second plurality of
fasteners 44 may not extend through both a respective one of the
first plurality of mounting ears 28 and a respective one of the
second plurality of mounting ears 38. Instead, each of the first
plurality of mounting ears 28 may solely be configured to receive a
respective one of the first plurality of fasteners 32. Likewise,
each of the second plurality of mounting ears 38 may solely be
configured to receive a respective one of the second plurality of
fasteners 44.
[0038] Referring again to FIG. 2, each of the second plurality of
mounting ears 38 may be shaped as a protrusion or bump-out from the
second external surface 42 and may be arranged to receive the
respective fastener 44, e.g., a bolt, so as to secure the stator 18
within the chamber 16 during assembly of the electromagnetic
machine 12. In addition, the second plurality of mounting ears 38
may carry a torque during operation of the electromagnetic machine
12.
[0039] The stator 18 may include any number of the second plurality
of mounting ears 38. In one embodiment, the stator 18 may include
at least three of the second plurality of mounting ears 38 so as to
stably attach the stator 18 to the motor housing 14 and minimize
eccentric rotation of the stator 18 during operation. For example,
as shown in FIG. 2, the first lamination stack 20 may include at
least three of the first plurality of mounting ears 28 and the
second lamination stack 34 may include three of the second
plurality of mounting ears 38. Alternatively, although not shown,
the stator 18 may include four or more of the second plurality of
mounting ears 38.
[0040] The second plurality of mounting ears 38 may be spaced apart
from one another by a suitable number of annular degrees. In one
non-limiting example, the second plurality of mounting ears 38 may
be spaced apart from one another by 120 angular degrees.
Alternatively, although not shown, the second plurality of mounting
ears 38 may be spaced apart from one another by 90 angular degrees
or by 72 angular degrees.
[0041] As described with continued reference to FIG. 2, the first
lamination stack 20 may be rotated with respect to the second
lamination stack 34 about the central longitudinal axis 24 such
that the first plurality of mounting ears 28 do not contact the
second plurality of mounting ears 38. That is, the first plurality
of mounting ears 28 may not touch or abut the second plurality of
mounting ears 38 but may instead be shifted annularly with respect
to the second plurality of mounting ears 38 about the central
longitudinal axis 24. By way of a non-limiting example, the second
plurality of mounting ears 38 may be spaced apart from one another
by 120 annular degrees and may each be spaced apart from a
respective one of the first plurality of mounting ears 28 by 60
annular degrees. Alternatively, although not shown, in another
non-limiting example, the second plurality of mounting ears 38 may
be spaced apart from one another by 90 annular degrees and may each
be spaced apart from a respective one of the first plurality of
mounting ears 28 by 45 annular degrees. The number of angular
degrees or amount of rotation may be selected and optimized to
minimize noise, vibration, and harshness of the stator 18 during
operation of the electromagnetic machine 12.
[0042] Such rotation or offset of the second plurality of mounting
ears 38 with respect to the first plurality of mounting ears 28 may
increase a stiffness and stability of the stator 18 and minimize
noise, vibration, and harshness of the stator 18 during operation
of the electromagnetic machine 12 without adding stator mass or
changing a design of individual laminations. That is, such rotation
may increase, e.g., at least double or triple, the number of
mounting ears 28, 38 of the stator 18. Such increased number of
mounting ears 28, 38 may ensure excellent attachment of the stator
18 to the motor housing 14, e.g., via the first plurality of
fasteners 32 (FIG. 1) and the second plurality of fasteners 44
(FIG. 2), and may therefore increase stiffness of the stator 18 and
stator 18--motor housing 14 connection.
[0043] Referring again to FIG. 2, the first lamination stack 20
abuts the second lamination stack 34. In one embodiment, the first
lamination stack 20 may be welded to the second lamination stack 34
on the first external surface 30. That is, the first lamination
stack 20 and the second lamination stack 34 may be welded together
along the first external surface 30 and the second external surface
42, e.g., along an exterior of the stator 18. Alternatively, the
first lamination stack 20 may have an interface surface 46 and may
be adhered to the second lamination stack 34 at the interface
surface 46. For example, an adhesive may be disposed along and
sandwiched between adjoining layers of the first lamination stack
20 and second lamination stack 34. That is, the adhesive may be
disposed between a top individual lamination steel of the first
lamination stack 20 and a bottom individual lamination steel of the
second lamination stack 34 to thereby adhere the first lamination
stack 20 to the second lamination stack 34. Alternatively, the
first lamination stack 20 and the second lamination stack 34 may be
formed from self-bonding lamination steel including a curable
coating configured for bonding together adjacent laminations. That
is, the first lamination stack 20 and the second lamination stack
34 may have interlinks between each adjacent individual
lamination.
[0044] Referring now to FIG. 4, the stator 118 may include more
than two lamination stacks 20, 34. The number of lamination stacks
20, 34 may be selected and optimized to minimize noise, vibration,
and harshness of the stator 118 during operation of the
electromagnetic machine 12. For example, the stator 118 may include
three lamination stacks 20, 34, 48 or four or more lamination
stacks (not shown).
[0045] In one non-limiting embodiment illustrated in FIG. 4, the
stator 118 may include a third lamination stack 48 abutting the
second lamination stack 34 and defining a third cavity 50 aligned
with the first cavity 22 and the second cavity 36 about the central
longitudinal axis 24. The third lamination stack 48 may also be
formed from a plurality of circular and concentric individual
laminations (not shown) formed from, for example, lamination steel
and may have a cylindrical shape.
[0046] The third lamination stack 48 may have a third height 52
(FIG. 4) along the central longitudinal axis 24 that is equal to
the first height 26 (FIG. 2) and the second height 40 (FIG. 2).
That is, the first lamination stack 20, the second lamination stack
34, and the third lamination stack 48 may be similarly sized.
Alternatively, although not shown, the first height 26 or the
second height 40 may be greater than or less than the third height
52 such that the first lamination stack 20, the second lamination
stack 34, or the third lamination stack 48 have different heights
26, 40, 52. The third height 52 may be selected to minimize noise,
vibration, and harshness of the stator 118 during operation of the
electromagnetic machine 12.
[0047] Further, the third lamination stack 48 may include a third
plurality of mounting ears 54 disposed opposite the third cavity 50
and each spaced apart from the second plurality of mounting ears 38
and from one another about the central longitudinal axis 24. That
is, as best shown in FIG. 4, the third lamination stack 48 may be
rotated with respect to the second lamination stack 34 about the
central longitudinal axis 24. Stated differently, the third
lamination stack 48 may be shifted or skewed or biased with respect
to the second lamination stack 34 about the central longitudinal
axis 24.
[0048] In particular, as described with continued reference to FIG.
4, the third lamination stack 48 may have a third external surface
56 spaced opposite the third cavity 50, and the third plurality of
mounting ears 54 may extend from the third external surface 56 away
from the third cavity 50. Each of the third plurality of mounting
ears 54 may be configured for receiving a respective one of a third
plurality of fasteners 58 that are different from the second
plurality of fasteners 44 (FIG. 1) to thereby fasten the third
lamination stack 48 to the motor housing 14. Stated differently,
one of the first plurality of fasteners 32 may not extend through
both a respective one of the third plurality of mounting ears 54
and a respective one of the second plurality of mounting ears 38.
However, one of the first plurality of fasteners 32 may extend
through both a respective one of the third plurality of fasteners
58 and a respective one of the first plurality of fasteners 32.
[0049] Referring again to FIG. 4, each of the third plurality of
mounting ears 54 may be shaped as a protrusion or bump-out from the
third external surface 56 and may be arranged to receive the
respective fastener 58, e.g., a bolt, so as to secure the stator
118 within the chamber 16 during assembly of the electromagnetic
machine 12. In addition, the third plurality of mounting ears 54
may carry a torque during operation of the electromagnetic machine
12.
[0050] The stator 118 may include any number of the third plurality
of mounting ears 54. In one embodiment, the stator 118 may include
at least three of the third plurality of mounting ears 54 so as to
stably attach the stator 118 to the motor housing 14 and minimize
eccentric rotation of the stator 118 during operation. That is, as
shown in FIG. 4, the first lamination stack 20 may include three of
the first plurality of mounting ears 28, the second lamination
stack 34 may include three of the second plurality of mounting ears
38, and the third lamination stack 48 may include three of the
third plurality of mounting ears 54. Alternatively, although not
shown, the stator 118 may include four or more of the third
plurality of mounting ears 54.
[0051] The third plurality of mounting ears 54 may be spaced apart
from one another by a suitable number of annular degrees. In one
non-limiting example, the third plurality of mounting ears 54 may
be spaced apart from one another by 120 angular degrees.
Alternatively, although not shown, the third plurality of mounting
ears 54 may be spaced apart from one another by 90 angular degrees
or by 72 angular degrees.
[0052] As described with continued reference to FIG. 4, the third
lamination stack 48 may be rotated with respect to the second
lamination stack 34 about the central longitudinal axis 24 such
that the third plurality of mounting ears 54 do not contact the
second plurality of mounting ears 38. That is, the third plurality
of mounting ears 54 may not abut or touch the second plurality of
mounting ears 38 but may instead be shifted annularly with respect
to the second plurality of mounting ears 38 about the central
longitudinal axis 24. By way of a non-limiting example, the third
plurality of mounting ears 54 may be spaced apart from one another
by 120 annular degrees and may each be spaced apart from a
respective one of the second plurality of mounting ears 38 by 60
annular degrees. Alternatively, although not shown, in another
non-limiting example, the third plurality of mounting ears 54 may
be spaced apart from one another by 90 annular degrees and may each
be spaced apart from a respective one of the second plurality of
mounting ears 38 by 45 annular degrees.
[0053] Such rotation or offset of the third plurality of mounting
ears 54 with respect to the second plurality of mounting ears 38
may increase a stiffness and stability of the stator 118 and
minimize noise, vibration, and harshness of the stator 118 during
operation of the electromagnetic machine 12 without adding stator
mass or changing a design of individual laminations. That is, such
rotation may in effect increase, e.g., at least double or triple,
the number of mounting ears 28, 38, 54 of the stator 118. Such
increased number of mounting ears 28, 38, 54 may ensure excellent
attachment of the stator 118 to the motor housing 14, e.g., via the
first plurality of fasteners 32 (FIG. 1), the second plurality of
fasteners 44 (FIG. 1), and the third plurality of fasteners 58
(FIG. 4), and may therefore increase stiffness of the stator 118
and stator 118--motor housing 14 connection.
[0054] Referring now to FIGS. 1, 3, and 6, the electromagnetic
machine 12 also includes the first plurality of fasteners 32 each
disposed within a respective one of the first plurality of mounting
ears 28 to thereby fasten the first lamination stack 20 to the
motor housing 14. In addition, the electromagnetic machine 12
includes the second plurality of fasteners 44 each disposed within
a respective one of the second plurality of mounting ears 38 to
thereby fasten the second lamination stack 34 to the motor housing
14. In addition to fastening or attaching the stator 18 and the
motor housing 14, the first plurality of fasteners 32 and the
second plurality of fasteners 44 may also provide additional heat
sinks or thermal paths to dissipate thermal energy and cool the
stator 18 during operation of the electromagnetic machine 12.
Further, in one embodiment described with reference to FIG. 1, each
of the second plurality of fasteners 44 may be longer than each of
the first plurality of fasteners 32. In another embodiment
described with reference to FIG. 6, each of the first plurality of
fasteners 32 may have a first length 60 and each of the second
plurality of fasteners 44 may have a second length 62 that is equal
to the first length 60.
[0055] That is, referring now to FIG. 5, the electromagnetic
machine 12 may further include a plurality of bosses 64 disposed on
the motor housing 14 and each configured for receiving a respective
one of the second plurality of fasteners 44. Each of the plurality
of bosses 64 may be a protruding feature formed on or disposed in
the motor housing 14. Additionally or alternatively, each of the
plurality of bosses 64 may include or be configured as an
additional bracket disposed on the motor housing 14.
[0056] The plurality of bosses 64 may be configured to locate the
second plurality of fasteners 44 within the motor housing 14 and
reduce attachment tolerances that may otherwise exist due to
different attachment planes for the first plurality of fasteners 32
and the second plurality of fasteners 44. That is, for the
embodiment in which each of the second plurality of fasteners 44
has the same length as each of the first plurality of fasteners 32,
the electromagnetic machine 12 may include the bosses 64 or inserts
to anchor the second plurality of fasteners 44 to the motor housing
14. For this embodiment, the second plurality of fasteners 44 may
extend through the second plurality of mounting ears 38 and attach
to the bosses 64.
[0057] Although not shown, a method of forming the stator 18, 118
may include welding together the first lamination stack 20 and the
second lamination stack 34 at the first external surface 30 (FIG.
2) and the second external surface 42 (FIG. 2). That is, the first
lamination stack 20 may be stacked adjacent to the second
lamination stack 34 in a welding fixture (not shown) and welded at
the first external surface 30 and the second external surface
42.
[0058] In another embodiment, the method may include adhering
together the first lamination stack 20 and the second lamination
stack 34, for example with adhesive or a self-bonding lamination
steel including a curable coating. Individual laminations of the
first lamination stack 20 and the second lamination stack 34 may be
stamped, stacked, and cured to adhere the first lamination stack 20
and second lamination stack 34.
[0059] In a further embodiment, the method may include first
stamping a blank (not shown) within a die (not shown) to form the
first lamination stack 20 and first plurality of mounting ears 28.
The method may then include rotating the stamped first lamination
stack 20 within the die about the central longitudinal axis 24
before again stamping the stamped first lamination stack 20 to
thereby form the second lamination stack 34 and second plurality of
mounting ears 38.
[0060] The method may also include selecting or optimizing at least
one of a number or quantity of lamination stacks 20, 34, 48, a
number of annular degrees rotation of the second plurality of
mounting ears 38 with respect to the first plurality of mounting
ears 28 about the central longitudinal axis 24, and a height 26,
40, 52 of the lamination stacks 20, 34, 48 to minimize noise,
vibration, and harshness of the stator 18, 118 during operation of
the electromagnetic machine 12. Although the method may initially
increase assembly time and cost, the rotated second plurality of
mounting ears 38 with respect to the first plurality of mounting
ears 28 about the central longitudinal axis 24 may increase
stability of the stator 18, 118 and decrease vibration, noise, and
harshness of the electromagnetic machine 12 during operation.
[0061] Referring again to FIG. 1, the device 10 includes a driven
component 68 and an output member 66 disposed within the first
cavity 22 (FIG. 2) and the second cavity 36 (FIG. 2) and configured
for driving the driven component 68. Further, the electromagnetic
machine 12 may be coupled to the driven component 68. That is, the
electromagnetic machine 12 may provide power to the driven
component 68 through the output member 66. For example, for
vehicular applications, the driven component 68 may be a
driveshaft, a transmission linkage, or a plurality of wheels.
Further, the output member 66 may be a rotor (shown generally in
FIG. 1) concentric with the stator 18 and disposed within the first
cavity 22 and the second cavity 36.
[0062] During operation, the rotor or output member 66 may rotate
within the first cavity 22 and the second cavity 36 to thereby
generate electric current, which may in turn drive the driven
component 68. As such, the stator 18 may be concentric with the
output member 66 and may not vibrate unnecessarily during
operation. That is, the skewed second plurality of mounting ears 38
with respect to the first plurality of mounting ears 28 about the
central longitudinal axis 24 may provide the stator 18 with
excellent stiffness and dampen vibration, noise, and harshness of
the rotating output member 66 and static stator 18 within the motor
housing 14. Further, the configuration and spacing of the plurality
of mounting ears 28, 38 may increase motor housing 14-to-stator 18
stiffness, increase concentricity of the stator 18, and decrease an
airgap (not shown) between the stator 18 and the output member 66.
As such, the electromagnetic machine 12 may not exhibit high noise
at comparatively low speeds since twisting of the stator 18 and
motor housing 14 may be minimized.
[0063] Therefore, the device 10 and electromagnetic machine 12 may
be useful for applications requiring excellent efficiency and
minimal noise, vibration, and harshness during operation. In
particular, the electromagnetic machine 12 may have excellent
stiffness and therefore may not suffer from low-frequency whine
and/or efficiency losses during operation. Further, the
electromagnetic machine 12 and device 10 may be economical in terms
of manufacturing time and cost and may be scalable to mass
production manufacturing operations. That is, rotation or skewing
of the mounting ears 28, 38 with respect to one another may
multiply the number of mounting ears 28, 38 for attaching the
stator 18 to the motor housing 14, which may increase stiffness and
decrease noise, vibration, and harshness without adding stator mass
or changing a design or configuration of individual
laminations.
[0064] While the best modes for carrying out the disclosure have
been described in detail, those familiar with the art to which this
disclosure relates will recognize various alternative designs and
embodiments for practicing the disclosure within the scope of the
appended claims.
* * * * *