U.S. patent application number 10/958214 was filed with the patent office on 2006-04-06 for electric machine with power and control electronics integrated into the primary machine housing.
Invention is credited to William P. Stewart, Donald J. Williams.
Application Number | 20060072288 10/958214 |
Document ID | / |
Family ID | 36124108 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060072288 |
Kind Code |
A1 |
Stewart; William P. ; et
al. |
April 6, 2006 |
Electric machine with power and control electronics integrated into
the primary machine housing
Abstract
An electric machine includes a housing, a mount within the
housing, and power and control electronics coupled to the mount. An
interference fit is formed between the mount and the housing that
secures the mount within the housing independent of mechanical
fasteners. The electric machine can also include a segmented or
non-segmented stator within the housing.
Inventors: |
Stewart; William P.; (Saint
Peters, MO) ; Williams; Donald J.; (Pierron,
IL) |
Correspondence
Address: |
HARNESS, DICKEY, & PIERCE, P.L.C
7700 BONHOMME, STE 400
ST. LOUIS
MO
63105
US
|
Family ID: |
36124108 |
Appl. No.: |
10/958214 |
Filed: |
October 4, 2004 |
Current U.S.
Class: |
361/690 |
Current CPC
Class: |
H02K 1/148 20130101;
Y10T 29/49865 20150115; H02K 3/522 20130101; H02K 15/12 20130101;
H02K 15/022 20130101; Y10T 29/49009 20150115; Y10T 29/49696
20150115; H02K 11/33 20160101; Y10T 29/49011 20150115; Y10T
29/49012 20150115; Y10T 29/53143 20150115 |
Class at
Publication: |
361/690 |
International
Class: |
H05K 7/20 20060101
H05K007/20 |
Claims
1-9. (canceled)
10. An electric machine comprising a housing, a mount within the
housing, and power and control electronics coupled to the mount,
the mount and the housing forming an interference fit therebetween,
the interference fit securing the mount within the housing
independent of mechanical fasteners.
11. The machine of claim 10, wherein the mount abuts against an
internal stop defined within the housing.
12. The machine of claim 10, wherein the mount has a coefficient of
thermal expansion about equal to or greater than the housing's
coefficient of thermal expansion.
13. The machine of claim 10, wherein the mount and the housing have
coefficients of thermal expansion such that the interference fit is
maintained across an operating temperature range of the
machine.
14. The machine of claim 10, wherein the mount operates as a heat
sink for one or more of the electronics coupled thereto.
15. The machine of claim 10, wherein the housing includes one or
more external fins for increased heat dissipation from the
housing.
16. The machine of claim 10, wherein the interference fit between
the housing and the mount maintains good thermal conductivity
between the housing and the mount.
17. The machine of claim 10, further comprising a stator within the
housing.
18. An electric supercharger comprising the machine of claim
10.
19. A vehicle comprising the electric supercharger of claim 18.
20. An electric supercharger comprising a housing, a stator within
the housing, and power and control electronics integrated within
the housing.
21. A vehicle comprising the electric supercharger of claim 20.
Description
FIELD
[0001] The present invention generally relates to electric
machines, and more particularly (but not exclusively) to electric
machines with power and control electronics integrated into the
primary machine housing.
BACKGROUND
[0002] Electric machines and their power and control electronics
are commonly packaged separately within different housings or
enclosures. With this separate packaging, however, an interface is
created between the two discrete enclosures that must normally be
sealed from the outside environment in order to protect the various
machine components within the enclosures.
[0003] In addition, many applications require cooling features for
each of the separate housings. But the separate packaging can limit
the options available for the cooling features and/or compromise
the thermal efficiency of the cooling features depending on their
location and orientation.
[0004] Further, separately packing the machine from its power and
control electronics increases the number of component parts,
mechanical fasteners, and assembly steps. This, in turn, can
increase both time and costs associated with machine manufacture
and assembly. For example, one process involves bolting the machine
enclosure to the electronics enclosure. This bolted attachment,
however, requires additional components and processes and also
requires secondary features if the machine and electronics packages
are to be sealed from the outside environment.
SUMMARY
[0005] In one implementation, an electric machine includes a
housing, a mount within the housing, and power and control
electronics coupled to the mount. An interference fit is formed
between the mount and the housing that secures the mount within the
housing independent of mechanical fasteners. The electric machine
can also include a segmented or non-segmented stator within the
housing.
[0006] In another aspect, the present invention provides a method
that generally includes heating a housing of an electric machine to
thermally expand the housing, positioning within the housing a
mount for power and control electronics, and allowing the housing
to cool and thermally contract against the mount thereby forming an
interference fit between the housing and the mount. The
interference fit secures the mount within the housing.
[0007] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0009] FIG. 1 is a perspective view showing an electronics mount
and power and control electronics aligned for positioning within a
housing according to an exemplary embodiment of the invention;
[0010] FIG. 2 is a perspective view showing the electronics mount
and power and control electronics installed within the housing
shown in FIG. 1;
[0011] FIG. 3 is an exploded view showing the electronics mount and
power and control electronics aligned for positioning within the
housing (cross-section) shown in FIG. 1 and also showing a
segmented stator and end shield within the housing;
[0012] FIG. 4 is an exploded perspective view showing the
electronics mount, power and control electronics, segmented stator,
and end shield aligned for positioning within the housing
(cross-section) shown in FIG. 3;
[0013] FIG. 5 is an exploded view showing the electronics mount,
power and control electronics, segmented stator, and end shield
aligned for positioning within the housing (cross-section) shown in
FIG. 4;
[0014] FIG. 6 is an inner perspective view of the housing shown in
FIG. 1;
[0015] FIG. 7 is an inner view of the housing shown in FIG. 6;
and
[0016] FIG. 8 is an exploded view of an electronics mount and power
and control electronics aligned for positioning within a housing
(cross-section) and also showing a non-segmented stator and end
shield within the housing according to an exemplary embodiment of
the invention.
[0017] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0018] The following description of the exemplary embodiments is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0019] An electric machine according to one aspect of the invention
generally includes a housing and a mount within the housing. Power
and control electronics can be coupled to the mount. An
interference fit is formed between the mount and the housing that
secures the mount within the housing independent of mechanical
fasteners. The electric machine can also include a segmented or
non-segmented stator within the housing. In yet other aspects, the
invention provides housings, mounts for power and control
electronics, and combinations thereof. Further aspects of the
invention include electric machines, electric motors, electric
superchargers, vehicles (e.g., automobiles, etc.), switched
reluctance motors, brushless permanent magnet (BPM) motors, and
induction motors that include housings and/or mounts for power and
control electronics of the present invention.
[0020] Accordingly, various implementations of the invention enable
the power and control electronics to be positioned within the same
primary housing as other machine components, such as the stator,
stator windings, end shield, and rotor. This, in turn, can
significantly improve the manufacturability of electric machines.
By eliminating the need for the separate packaging of the machine
from its power and control electronics, manufacture and assembly
can be streamlined with reductions in the number of discrete
components, fasteners, material, and tooling.
[0021] FIGS. 1 through 5 illustrate an exemplary housing 100 and a
mount 104 for power and control electronics in accordance with the
principles of this invention. The housing 100 is sized to receive
the mount 104 and the power and control electronics assembly 108
coupled to the mount 104. The housing 100 is also sized to receive
a stator 112 (including the stator windings 116, lead and exit ends
118 from the stator windings 116, and end caps 120) and an end
shield 124. Accordingly, the stator 112 and end shield 124 can be
positioned within the same primary housing 100 as the mount 104 and
electronics assembly 108.
[0022] As shown in FIG. 1, the end caps 120 can be configured so as
to position and maintain the position of the lead and exit ends 118
of the stator windings 116 for connection with corresponding
components of the electronics assembly 108. By way of example only,
the end caps 120 may comprise an end cap as described in U.S.
patent application Ser. No. ______ (Attorney Docket No.
5260-000186), filed on even date herewith, entitled "Stator End
Caps and Methods for Positioning the Lead and Exit Ends of the
Stator Windings", the entire disclosure of which is incorporated
herein by reference.
[0023] In various implementations, the housing 100 can also include
mounting and locating features for the mount 104. For example, and
as shown in FIGS. 1, 3, 6 and 7, the housing 100 can define an
internal stop or shoulder 128 configured to contact the mount 104.
While assembling the machine, the mount 104 and/or the housing 100
can be moved relatively towards one another until the mount 104
abuts against the stop 128 within the housing 100. At which point,
the stop 128 inhibits continued relative movement of the mount 104
into the housing 100.
[0024] As shown in FIG. 1, the mount 104 is configured in the shape
of a generally circular ring that defines a central circular
opening 130 therethrough. Alternatively, other shapes can be
employed for the mount depending on the particular configuration of
the housing in which the mount will be positioned. For example,
other embodiments can include a mount having a non-circular shape
(e.g., rectangular, triangular, ovular, among others) and/or a
solid or non-annular mount that does not define any openings
therethough.
[0025] The mount 104 can also define one or more recesses or
through-holes into which one or more electronic components (e.g.,
capacitors, etc.) extend. By having electronics components extend
into the recesses or through-holes defined by the mount 104, the
thickness of those electronics components can be accommodated
without having to otherwise increase the overall length of the
machine.
[0026] A wide range of electronic components can be coupled to the
mount 104 using any suitable means including adhesives, clips,
mechanical fasteners, among others. In various implementations, the
mount 104 is positioned within the housing 100 before any
electronics are coupled to the mount 104. After the mount 104 is
within the housing 100, electronics assembly 108 is then positioned
within the housing 100 and coupled to the mount 104. Alternative
implementations, however, can include coupling electronics (e.g.,
as an assembly 108) to the mount 104, and then positioning the
mount 104 and the electronics thereon into the housing 100.
[0027] To retain the mount 104 within the housing 100, an
interference fit can be formed between a sidewall 132 of the mount
104 and a surface 136 of the housing 100. With this interference
fit, the mount 104 can thus be engaged and retained within the
housing 100 independent of mechanical fasteners. The interference
fit can also help maintain good thermal conductivity between the
housing 100 and the mount 104 (e.g., there is little to no
impediment to heat transfer at the mated surfaces). Integrating the
electronics into the primary machine housing 100 eliminates an
interface (and consequently a potential ingress for moisture) that
is usually present in existing applications between the separate
housings for the electronics and the machine (e.g., stator and
rotor). The single unit electronics enclosure can also work to
contain electromagnetic interference (EMI) fields.
[0028] A description will now be provided of an exemplary method
for forming the interference fit between the mount's sidewall 132
and the housing's surface 136. First, the housing 100 can be heated
(e.g., induction heated, etc.) to thermally expand the housing 100.
The mount 104 and/or housing 100 can then be moved relative to one
another so as to position the mount 104 within the thermally
expanded housing 100. That is, the mount 104 can be moved towards
the housing 100 as the housing 100 remains stationary, or the
housing 100 can be moved towards the mount 104 as the mount 104
remains stationary, or both the mount 104 and the housing 100 can
be moved towards each other. In any event, the relative movement
between the housing 100 and the mount 104 can continue until the
mount 104 abuts against the stop 128 within the housing 100. The
housing 100 is allowed to cool and thermally contract against the
mount's sidewall 132, thereby forming an interference fit between
the housing 100 and the mount 104. Allowing the housing 100 to cool
can include either or both passively allowing the housing 100 to
cool and/or actively cooling the housing 100.
[0029] Alternatively, other implementations can form the
interference fit by thermally contracting the mount (e.g., by
actively cooling the mount), moving the mount and/or housing
relative to one another so as to position the thermally contracted
mount within the housing, and then allowing the mount to thermally
expand against the housing (e.g., by actively heating and/or
passively allowing the mount to return to ambient temperate). In
further implementations, the interference fit between the housing
and the mount can be formed by using other suitable methods, such
as axial press fitting and thermally conductive adhesives.
[0030] A wide range of materials can be used for the housing 100
and the mount 104. In preferred implementations, the housing 100
and the mount 104 are formed from materials such that the housing
100 and mount 104 have coefficients of thermal expansion for
maintaining the interference fit therebetween across an operating
temperature range of the machine. This, in turn, allows the mount
104 to be retained within the housing 100 independent of mechanical
fasteners. The selection of materials for the housing 100 and mount
104 can also depend at least in part on the thermal conductivity
properties of the materials being considered.
[0031] In one exemplary embodiment, the housing 100 and the mount
104 are formed from the same material, such as aluminum or an
aluminum alloy, among other suitable materials. In which case, the
housing 100 and mount 104 can have about equal coefficients of
thermal expansion and thus thermally expand at about the same rate.
Alternatively, the housing 100 and mount 104 can be formed from
different materials yet still have coefficients of thermal
expansion for maintaining the interference fit across an operating
temperature range of the machine.
[0032] Various implementations can also include thermal management
features incorporated into the machine. For example, the housing
100 and the mount 104 can all be formed from materials having good
thermal conductivity properties. In addition to material selection,
the interference fit between the housing 100 and the mount 104 can
also help maintain good thermal conductivity between the housing
100 and the mount 104. Accordingly, these features can allow heat
to be relatively efficiently transferred from the mount 104 to the
housing 100 and/or to allow the mount 104 to operate as a heat sink
for the electronics assembly 108, such as the power electronics of
the assembly 108.
[0033] The housing 100 can also include one or more external fins
140 for increased heat dissipation from the housing 100. In the
illustrated embodiment, the housing 100 includes eight fins 140
each circumferentially disposed entirely around the housing 100.
These fins 140 serve to increase the surface area from which heat
can be dissipated from the housing 100. As shown in FIG. 3, the
housing 100 includes four upper fins 140 adjacent the stator 112,
and four lower fins 140 adjacent the mount 104 and electronics
assembly 108. Accordingly, the housing 100 thus includes fins 140
for both the electronics assembly 108 and the other machine
components like the stator 112, the end shield 124, and a rotor
(not shown).
[0034] In various implementations, the fins 140 can be arranged to
optimize heat dissipation from the housing 100 for air flow in a
single direction that is generally perpendicular to the axis of
rotation of the rotor assembly. For example, the housing 100 can be
subject to forced convention. The preferred airstream velocity can
be dependent on the cooling demands of the particular
application.
[0035] Alternative implementations, however, can include a housing
with more or less than eight fins and/or fins that do not
circumferentially extend completely around the housing.
[0036] To further help with thermal management, the end shield 124
can also be coupled to the housing 100 by an interference fit
formed between a sidewall of the end shield 124 and an inner
surface of the housing 100. This interference fit can help maintain
good thermal conductivity between the housing 100 and the end
shield 124. The end shield 124 is also preferably formed of one or
more materials (e.g., aluminum, aluminum alloy, etc.) having good
thermal conductivity properties so that heat can be relatively
efficiently transferred from the end shield 124 to the housing
100.
[0037] A description will now be provided of an exemplary method
for forming the interference fit between the end shield 124 and the
housing 100. First, the housing 100 can be heated (e.g., induction
heated, etc.) to thermally expand the housing 100. The end shield
124 and/or housing 100 can then be moved relative to one another so
as to position the end shield 124 within the thermally expanded
housing 100. That is, the end shield 124 can be moved towards the
housing 100 as the housing 100 remains stationary, or the housing
100 can be moved towards the end shield 124 as the end shield 124
remains stationary, or both the end shield 124 and the housing 100
can be moved towards each other. The housing 100 is allowed to cool
and thermally contract against a sidewall of the end shield 124,
thereby forming an interference fit between the housing 100 and the
end shield 124. Allowing the housing 100 to cool can include either
or both passively allowing the housing 100 to cool and/or actively
cooling the housing 100.
[0038] Alternatively, other implementations can form the
interference fit by actively cooling the end shield to thermally
contract the end shield, moving the end shield and/or housing
relative to one another so as to position the thermally contracted
end shield within the housing, and allowing the end shield to
thermally expand against the housing (e.g., by actively heating
and/or passively allowing the end shield to return to ambient
temperate). In further implementations, the interference fit
between the housing and the end shield can be formed by using other
suitable methods.
[0039] FIGS. 3 through 5 show the circumferentially segmented
stator 112 having six stator segments. Alternative embodiments,
however, can include segmented stators having more or less than six
stator segments depending on the particular application. Indeed,
some embodiments include a non-segmented or full round stator. For
example, FIG. 8 illustrates an exemplary housing 200, a mount 204,
and power and control electronics assembly 208 being used in
conjunction with a non-segmented stator 212.
[0040] In another form, the present invention provides a method
that generally includes heating a housing of an electric machine to
thermally expand the housing, positioning within the housing a
mount for power and control electronics, and allowing the housing
to cool and thermally contract against the mount thereby forming an
interference fit between the housing and the mount. The
interference fit secures the mount within the housing and also can
maintain good thermal conductivity between the housing and the
mount. In addition, the mount can also operate as a heat sink for
the power electronics coupled thereto.
[0041] The mount and the housing preferably have coefficients of
thermal expansion such that the interference fit therebetween is
maintained across an operating temperature range of the machine.
For example, the mount preferably has a coefficient of thermal
expansion about equal to or greater than the housing's coefficient
of thermal expansion.
[0042] The method can also include mounting power and control
electronics to the mount either before, after, or as the mount is
being positioned within the housing. In various implementations,
positioning the mount within the housing can include abutting the
mount against an internal stop defined within the housing. The
method can further include positioning a segmented or non-segmented
stator within the housing.
[0043] Accordingly, various implementations enable power and
control electronics to be positioned within the same primary
housing as other machine components, such as the stator, stator
windings, end shield, and rotor. This, in turn, can significantly
improve the manufacturability of electric machines. By eliminating
the need to separately package the machine from its power and
control electronics, manufacture and assembly can be streamlined
with reductions in the number of discrete components, fasteners,
material, and tooling.
[0044] Various aspects of the present invention can be used in a
wide range of electric machines, electric motors, electric
superchargers, switched reluctance motors, brushless permanent
magnet (BPM) motors, and induction motors. Accordingly, the
specific references to electric machine herein should not be
construed as limiting the scope of the present invention to only
one specific form/type of electric machine.
[0045] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the gist of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention.
* * * * *