Note: Descriptions are shown in the official language in which they were submitted.
ELECTRICAL ASSEMBLY HAVING A HEAT SINK THAT IS UNITARILY AND INTEGRALLY FORMED
WITH A LEAD OF A POWER SEMICONDUCTOR
FIELD
[0001] The present disclosure relates to an electrical assembly having a
heat sink that is
unitarily and integrally formed with a lead of a power semiconductor.
BACKGROUND
[0002] This section provides background information related to the present
disclosure
which is not necessarily prior art.
[0003] While there is increasing interest in the electrification of
vehicle drivelines, there
are significant issues that must be overcome before vehicles with electrified
drivelines
substantially displace vehicle drivelines that are powered solely by internal
combustion engines.
Some of these issues include the cost of the electrified driveline, the volume
of the electrified
driveline and its ability to be packaged into available space within a
vehicle, as well as the
robustness of the electronics that are employed to operate and control the
electrified driveline.
SUMMARY
[0004] This section provides a general summary of the disclosure, and is
not a
comprehensive disclosure of its full scope or all of its features.
[0005] In one form, the present disclosure provides an electrical assembly
that includes
a semiconductor die, a plurality of electrically conductive leads, a heat sink
and a case. The
semiconductor die includes a power semiconductor device having a plurality of
terminals. Each
of the electrically conductive leads is electrically coupled to an associated
one of the terminals
on the power semiconductor device. The heat sink is formed of an electrically
and thermally
conductive material and includes a base, a mount, and a plurality of fins. The
mount extends
from a first side of the base and is coupled to the semiconductor die. The
fins are fixedly coupled
to the base and extend from a second side of the base that is opposite the
first side of the base.
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Date Recue/Date Received 2022-06-17
The case is formed of a first electrically insulating material. A first one of
the plurality of leads is
integrally and unitarily formed with the mount.
[0006] In one form, each of the leads that is not unitarily and
integrally formed with the
mount is electrically coupled to its associated one of the terminals via a
bond wire. In one form,
the semiconductor die is coupled to the mount using at least one of a solder
material and a sinter
material. In one form, the plurality of fins are unitarily and integrally
formed with the base. In
one form, the electrically and thermally conductive material from which the
heat sink is formed
comprises at least one of copper and aluminum. In one form, the base and the
mount are
integrally formed. In one form, the power semiconductor device comprises a
field effect
transistor. In one form, the field effect transistor is a metal oxide silicone
field effect transistor.
In one form, at least a portion of each of the plurality of fins has a cuboid
shape. In one form, at
least a portion of each of the plurality of fins has a rod-like shape. In one
form, the plurality of
fins are orthogonal to the leads. In one form, the base of the heat sink has a
first side that has a
corrugated shape and a second side opposite the first side, where the second
side has a linear
shape. In one form, a length of the plurality of fins increases from a first
edge of the heat sink to
a second edge of the heat sink. In one form, the electrical assembly further
includes an inverter
mount and a plurality of bus bars, the inverter mount being formed of a second
electrically
insulating material and defining a mounting flange, where a portion of the
electrically conductive
leads are received through the mounting flange and are electrically and
mechanically coupled to
associated ones of the bus bars. In one form, the electrical assembly includes
a stator, the stator
having a motor winding, and wherein the heat sink is electrically coupled to
the motor winding.
[0007] In one form, the present disclosure provides a method for
fabricating a
semiconductor package that includes a plurality of leads. The method includes:
providing a heat
sink that is formed of an electrically and thermally conductive material, the
heat sink having a
base, a mount, and a plurality of fins, where the mount extends from a first
side of the base, the
plurality of fins are fixedly coupled to the base and extend from a second
side of the base that is
opposite the first side of the base, and where a first one of the plurality of
leads is integrally and
unitarily formed with the mount; attaching a semiconductor die that includes a
power
semiconductor device to the mount of the heat sink, the power semiconductor
device having a
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Date Recue/Date Received 2022-06-17
plurality of terminals; coupling each of the leads that is not unitarily and
integrally formed with
the mount to its associated one of the terminals via a bond wire; and
encapsulating the
semiconductor die and the mount with a case formed of a first electrically
insulating material.
[0008] Further areas of applicability will become apparent from the
description provided
herein. The description and specific examples in this summary are intended for
purposes of
illustration only and are not intended to limit the scope of the present
disclosure.
DRAWINGS
[0009] The drawings described herein are for illustrative purposes only
of selected
embodiments and not all possible implementations, and are not intended to
limit the scope of
the present disclosure.
[0010] Figures 1 and 2 are longitudinal section views of an exemplary
electric drive
module constructed in accordance with the teachings of the present disclosure;
[0011] Figures 3 and 4 are sections view of a portion of the electric
drive unit of Figure 1,
illustrating the construction of a motor assembly in more detail;
[0012] Figures 5 and 6 are partly sectioned views of the electric drive
unit of Figure 1;
[0013] Figure 7 is a perspective view of a portion of the motor assembly,
illustrating a
portion of an inverter in a see-through manner and in more detail;
[0014] Figures 8 and 9 are perspective views of a power semiconductor
package having a
plurality of rod-shaped fins and cuboid-shaped fins, respectively;
[0015] Figure 10 is a perspective view of a power semiconductor package
with a case
thereof removed for clarity;
[0016] Figure 11 is a perspective view of an inverter;
[0017] Figures 12 through 15 are partial cross-sectional views of a
busbar;
[0018] Figure 16 is a perspective view of the inverter shown with an end
plate;
[0019] Figure 17 is a sectional view of a portion of the electric drive
unit of Figure 1,
illustrating a sensor assembly having a TMR sensor that is mounted to a
control board and a
magnet that is coupled for rotation with a rotor of the motor assembly;
[0020] Figure 18 is a perspective view of the electric drive unit of
Figure 1;
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Date Recue/Date Received 2022-06-17
[0021] Figure 19 is a rear perspective view of a portion of a housing of
the electric drive
unit of Figure 1;
[0022] Figure 20 is a perspective view of a portion of the electric drive
unit of Figure 1
with the portion of the housing shown in Figure 18 removed;
[0023] Figure 21 is similar to that of Figure 19, but depicting the
electric drive unit with a
portion of a transmission and a differential assembly removed;
[0024] Figure 22 is similar to that of Figure 20, but depicting a further
portion of the
housing removed to better show a portion of the transmission;
[0025] Figure 23 is a sectional view of a portion of the electric drive
unit that is shown in
Figure 21; and
[0026] Figures 24 through 45 are section views of various portions of the
electric drive
unit of Figure 1, depicting the flow of cooling and lubricating oil through
various portions of the
electric drive unit.
[0027] Corresponding reference numerals indicate corresponding parts
throughout the
several views of the drawings.
DETAILED DESCRIPTION
[0028] With reference to Figures 1 and 2, an exemplary electric drive
module constructed
in accordance with the teachings of the present disclosure is generally
indicated by reference
numeral 10. The electric drive module 10 includes a housing assembly 12, an
electric motor 14,
a control unit 16, a transmission 18, a differential assembly 20, a pair of
output shafts 22a and
22b, a pump 24, a heat exchanger 26 (Fig. 5) and a filter 28.
[0029] The housing assembly 12 can house the motor 14, the control unit
16, the
transmission and the differential assembly 20. The electric motor 14 can be
any type of electric
motor and can have a stator 32 and a rotor 34. The stator 32 can include field
windings 36,
whereas the rotor 34 can include a rotor shaft 38 that can be disposed within
the stator 32 for
rotation about a first rotational axis 40.
[0030] The transmission 18 can include a planetary reduction 42, a shaft
44 and a
transmission output gear 46. The planetary reduction can have a sun gear,
which can be unitarily
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Date Recue/Date Received 2022-06-17
and integrally formed with the rotor shaft 38 to keep pitch line velocity as
low as possible, a ring
gear, which can be grounded to or non-rotatably coupled to the housing
assembly 12, a planet
carrier and a plurality of planet gears that can be journally supported by the
planet carrier and
which can be meshingly engaged with both the sun gear and the ring gear. The
sun gear, the ring
gear and the planet gears can be helical gears. The shaft 44 can be mounted to
a set of bearings
60 that support the shaft for rotation about the first rotational axis 40
relative to the housing
assembly 12. The transmission output gear 46 can be coupled to (e.g.,
unitarily and integrally
formed with) the shaft 44 for rotation therewith about the first rotational
axis 40.
[0031]
The differential assembly 20 can include a final drive or differential input
gear 70
and a differential. The differential input gear 70 can be rotatable about a
second rotational axis
80 and can be meshingly engaged to the transmission output gear 46. In the
example provided,
the transmission output gear 46 and the differential input gear 70 are helical
gears. The
differential can be any type of differential mechanism that can provide rotary
power to the
output shafts 22a and 22b while permitting (at least in one mode of operation)
speed
differentiation between the output shafts 22a and 22b. In the example
provided, the differential
includes a differential case, which is coupled to the differential input gear
70 for rotation
therewith, and a differential gearset having a plurality of differential
pinions, which are coupled
to the differential case and rotatable (relative to the differential case)
about one or more pinion
axes that are perpendicular to the second rotational axis 80, and a pair of
side gears that are
meshingly engaged with the differential pinions and rotatable about the second
rotational axis
80. Each of the output shafts 22a and 22b can be coupled to an associated one
of the side gears
for rotation therewith. In the example provided, the output shaft 22b is
formed as two distinct
components: a stub shaft 90 and a half shaft 92. The stub shaft 90 is
drivingly coupled to an
associated one of the side gears and extends between an associated gear and
the half shaft 92
and is supported by a bearing 94 in the housing assembly 12 for rotation about
the second
rotational axis 80. Each of the output shaft 22a and the half shaft 92 has a
constant velocity joint
100 with a splined male stem. The splined male stem of the constant velocity
joint on the output
shaft 22a is received into and non-rotatably coupled to an associated one of
the side gears. The
Date Recue/Date Received 2022-06-17
splined male stem of the constant velocity joint on the half-shaft 92 is
received into and non-
rotatably coupled to the stub shaft 90.
[0032] In Figures 3 through 6, the control unit 16 includes a power
terminal 200, one or
more field capacitor 202, an inverter 204 and a controller 206. The power
terminal 200 can be
mounted to the housing assembly 12 and can have contacts or terminals (not
shown) that can be
fixedly coupled to a respective power lead 210 to electrically couple the
power lead 210 to the
control unit 16. It will be appreciated that the electric motor 14 can be
powered by multi-phase
electric AC power and as such, the power terminal 200 can have multiple
contacts or terminals
to permit the several power leads 210 to be coupled to the control unit 16.
[0033] Each field capacitor 202 electrically couples an associated one of
the power leads
210 to the inverter 204. In the example provided, each field capacitor 202 is
relatively small and
is disposed in an annular space between the inverter 204 and the housing
assembly 12. The
annular space can be disposed adjacent to an end of a body of the stator 32
from which the field
windings 36 extend. Each field capacitor 202 can be mounted to the inverter
204.
[0034] With reference to Figures 3, 4 and 7 through 15, the inverter 204
can be an annular
structure that can be mounted about the field windings 36 that extend from the
body of the
stator 32. In the example provided, the inverter 204 includes a power
semiconductor assembly
250 and a circuit board assembly 252. The power semiconductor assembly 250 can
comprise a
plurality of power semiconductor packages 262 and an inverter mount 264.
[0035] The power semiconductor package 262 has a semiconductor die 266
that includes
a power semiconductor device 268. The power semiconductor device 268 can be
any suitable
power semiconductor device, such as an insulated gate bipolar transistor
(IGBT). In the example
provided, the power semiconductor device is a field effect transistor 269,
which may be a metal
oxide silicone field effect transistor (MOSFET), or a junction field effect
transistor (JFET). The
power semiconductor package 262 has a plurality of terminals 270 and a
plurality of electrically
conductive leads 272a, 272b, 272c, 272d (collectively referred to hereinafter
as "electrically
conductive leads 272"). Each of the electrically conductive leads 272 is
electrically coupled to an
associated one of the terminals 270.
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Date Recue/Date Received 2022-06-17
[0036] The power semiconductor package 262 has a heat sink 274 that is
formed of an
electrically and thermally conductive material, such as copper or aluminum.
The heat sink 274
has a base 276, a mount 278, and a plurality of fins 280. The mount 278
extends from a first side
276a of the base 276 and is coupled to the semiconductor die 266. The
plurality of fins 280 are
fixedly coupled to the base 276 and extend from a second side 276b of the base
276 that is
opposite the first side 276a of the base 276. The base 276 and the mount 278
can be integrally
and unitarily formed.
[0037] The power semiconductor package 262 has a case 281 having a first
side 281a and
a second side 281b that is opposite the first side 281a of the case 281. The
case 281 is formed of
a first electrically insulating material, such as a resin material. The
semiconductor die 266 and the
mount 278 are encapsulated in the case 281 during, for example, an overmolding
process. The
plurality of fins 280 extend from the second side 281b of the case 281.
[0038] The plurality of fins 280 are fixedly coupled to (e.g., unitarily
and integrally formed
with) the base 276. The fins 280 can be disposed in any desired orientation,
such as orthogonal
to the electrically conductive leads 272. In one form, the first side 276a has
a corrugated shape,
and the second side 276b has a linear (or substantially linear) shape. It
should be understood that
the first side 276a and the second side 276b can have various shapes and are
not limited to the
examples described herein. The length of the base 276 can gradually (or
nongradually) increase
from the first side 276a to the second side 276b. Likewise, the length of the
fins 280 can gradually
(or nongradually) increase from the first side 276a to the second side 276b
(i.e., along the x-axis).
The power semiconductor packages 262 of the power semiconductor assembly 250
can be
arranged in an annular manner as shown in FIG. 7. If desired, the fins 280 of
a given power
semiconductor package 262 contact a second side 281b of the case 281 of a
circumferentially
adjacent power semiconductor package 262.
[0039] Each of the fins 280 on each heat sink 274 can be shaped as
desired. For example,
some or all of the fins 280 can be shaped as rods, such as the fins 280a shown
in FIG. 8, or could
have a cuboid shape, such as the fins 280b shown in FIG. 9. It should be
understood that the fins
280 may have other shapes in other forms and are not limited to the examples
described herein.
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Date Recue/Date Received 2022-06-17
[0040] The semiconductor die 266 is coupled to the mount 278 using a
bonding material
282, which may be at least one of a solder material and a sinter material. One
of the electrically
conductive leads 272 (e.g., the electrically conductive lead 272a) is
integrally and unitarily formed
with the mount 278. The remaining electrically conductive leads 272 (e.g.,
electrically conductive
leads 272b, 272c, 272d) that are not unitarily and integrally formed with the
mount 278 are
electrically coupled to an associated terminal 270 via a bond wire 284.
[0041] The power semiconductor package 262 has phase lead bosses 288,
which can
accept phase leads 294 (Fig. 3) of the field windings 36 (Fig. 3)
therethrough. The power
semiconductor package 262 can also have an oil inlet port 296 (Fig. 11).
[0042] A method for fabricating the power semiconductor package 262
includes
providing the heat sink 274 and attaching the semiconductor die 266 including
the power
semiconductor device 268 to the mount 278 of the heat sink 274. The method
includes coupling
each of the leads that is not unitarily and integrally formed with the mount
278 (e.g., electrically
conductive leads 272b, 272c, 272d) to an associated terminal 270 via the bond
wires 284 and
encapsulating the semiconductor die 266 and the mount 278 with the case 281
using an
overmolding process.
[0043] With reference to Figures 3, 4, 7, and 11 through 15, the inverter
mount 264 can
be formed of a second electrically insulating material that is different than
the first insulating
material of the case 281, such as a plastic material. The inverter mount 264
can define a mounting
flange 295 disposed circumferentially about the power semiconductor assembly
250. At least a
portion of the electrically conductive leads 272 can be received through the
mounting flange 295
and can be electrically and mechanically coupled to the circuit board assembly
252 via one or
more bus bars 297a, 297b, 297c, 297d (collectively referred to hereinafter as
"bus bars 297"),
such as a printed circuit board. The bus bars 297 can be stacked against
stacked against one
another and electrically coupled to the electrically conductive leads 272 as
well as to the phase
leads 294 of the field windings 36 of the stator 32. The quantity of printed
circuit boards is
dependent upon the thickness of the electrical traces or conductors on each of
the printed circuit
boards and the amount of current that is to pass through between each power
semiconductor
package 262 and an associated one of the field windings 36. The bus bars 297
may be electrically
8
Date Recue/Date Received 2022-06-17
insulated from each other via insulating spacers 298 such that each of the
electrically conductive
leads 272 is electrically and mechanically coupled to one of the bus bars 297.
[0044] With reference to Figure 17, the controller 206 is configured to
sense a rotational
position of the rotor 34 relative to the stator 32 (Fig. 1) and responsively
control the flow of
electric power from the inverter 204 (Fig. 3) to the field windings 36 (Fig.
3) to rotate the magnetic
field that is produced by the field windings 36 (Fig. 3). The controller 206
can include a second
circuit board assembly that can comprise a plurality of stacked printed
circuit boards. The second
circuit board assembly can have conventional hardware and control programming
for operating
the electric motor 14 (Fig. 1) and a TMR sensor 300 that is configured to
sense a rotational
position of a magnetic field of a magnet 302 that is fixedly coupled to the
rotor 34. The TMR
sensor 300 and the magnet 302 can optionally be used in place of a
conventional encoder or
resolver. Significantly, the controller 206 uses direct voltage traces on the
various printed circuit
boards and/or the electrically conductive leads 272 instead of resistors to
determine current
flow.
[0045] In Figure 18, the housing assembly 12 is shown to have a pump
mount 310, a heat
exchanger base 312 and a filter mount 314. The pump 24 can be mounted to the
pump mount
310 and can circulate an appropriate fluid about the electric drive module 10
to both lubricate
and/or cool various components. In the example provided the fluid is a
suitable dielectric fluid,
such as automatic transmission fluid. The heat exchanger 26 can be mounted to
the heat
exchanger base 312 and can be configured to receive a pressurized cooling
fluid, such as a water-
glycol mixture, from an external source and to facilitate the transfer of heat
from the dielectric
fluid circulated in the electric drive module 10 to the pressurized cooling
fluid. A suitable filer,
such as a spin-on oil filter 28, can be mounted to the filter base 314 and can
filter the dielectric
fluid that is circulated within the electric drive module.
[0046] With reference to Figures 19 through 21, an intake filter or
screen 400 can be
disposed in a portion of the housing assembly 12 that houses the differential
input gear 70. The
intake filter 400 can receive dielectric fluid that can be returned to the low-
pressure side of the
pump 24. A windage dam 402 can be integrated into a cover 404 and a main
housing portion
406 of the housing assembly 12 to shield the dielectric fluid that is being
returned to the intake
9
Date Recue/Date Received 2022-06-17
filter 400 from the differential input gear 70. More specifically, the windage
dam 402 can cause
dielectric fluid to accumulate in the vicinity of the intake filter 400 and
segregate the accumulated
fluid from the (rotating) differential input gear 70. It will be appreciated
that without the windage
dam 402, the rotating differential input gear 70 would tend to pull dielectric
fluid away from the
intake filter 2400, which could prevent sufficient dielectric fluid from being
returned to the low
pressure (intake) side of the pump 24. It will also be appreciated that
segregating the dielectric
fluid from the rotating differential input gear 70 can reduce drag losses that
would otherwise be
incurred from the rotation of the differential input gear through the
dielectric fluid. The cover
404 can also include a tubular feed pipe 410.
[0047] With reference to Figures 22 and 23, a deflector 420 can be
mounted to the planet
carrier PC and can shield the planetary reduction 42 from dielectric fluid
that is slung from other
rotating components and/or cause dielectric fluid to drain from the planetary
reduction 42 in a
desired manner.
[0048] In Figures 24 and 25, dielectric fluid is received into the intake
filter 400 and
transmitting to the low pressure (inlet) side of the pump 24. High pressure
dielectric fluid exits
the pump 24 and travels through an internal gallery 430 in the housing 12 to
an inlet passage of
the heat exchanger base 312, through the heat exchanger 26, into an outlet
passage of the heat
exchanger base 312, into an inlet passage of the filter base 314, through the
filter 28, into an
outlet passage in the filter base 314 and to another internal gallery 432 in
the housing 12.
[0049] In Figures 26 and 27, dielectric fluid exiting the internal
gallery 432 can travel
through a transfer tube 434 through the oil inlet port 296 in the end plate
290 and can enter an
annular cavity 440 that is located radially between a tubular central
projection 442 on the end
plate 290 and the field windings 36. The central projection 442 can carry a
seal that can be
sealingly engaged to the central projection 442 and to the field windings 36.
An annular gap 448
is formed between an axial end of the field windings 36 and an annular portion
of the end plate
290. As noted previously, the end plate 290 is fixedly and sealingly coupled
to the inverter mount
264.
[0050] In Figure 28, the dielectric fluid is shown to flow through the
annular gap 448,
through the fins 280 in the heat sinks 274 and into passages 450 formed
axially through the stator
Date Recue/Date Received 2022-06-17
32. While the fins 280 have been depicted herein as perpendicular projections,
it will be
appreciated that the fins 280 could be shaped differently (for example, as
diamond shaped
projections) to cause the flow of dielectric fluid passing through the fins
280 to move in both
tangential and axial directions. Flow in this manner may be beneficial for
rejecting more heat
from the heat sinks 274 into the dielectric fluid and/or to produce a desired
flow restriction that
can aid in the pressure balancing of the cooling flow to the rotor.
Accordingly, it will be
appreciated that dielectric fluid is introduced to the inverter 204, passes
through fins 280 on heat
sinks 274 that are electrically conductively coupled to the electrically
conductive leads 272 to
thereby cool the inverter 204, and thereafter enters the passages 450 in the
stator 32 to cool the
stator 32 as is shown in Figure 29.
[0051] In Figures 30 and 31, dielectric fluid exiting the stator 32 is
collected in an annular
cavity 460 on an opposite end of the stator 32 that permits the velocity of
the dielectric fluid to
slow. A portion of the dielectric fluid is returned to a sump (not shown) in
the housing assembly
12, while other portions of the flow are directed to lubricate various other
components. For
example, the annular cavity 460 can be in fluid communication with a worm
track 464.
[0052] With reference to Figures 32 through 34, the worm track 464 can
have an outlet
that can discharge the dielectric fluid into a bearing 470, which can support
the differential case
472 for rotation relative to the housing assembly 12, and/or onto the stub
shaft 92, where the
dielectric fluid can migrate to the opposite axial ends of the stub shaft 92
to lubricate the
differential gearing and the bearing 94. Thereafter, the dielectric fluid can
drain to the sump
where it can flow into the intake filter 400 (Fig. 23).
[0053] In Figures 35 and 36, the annular cavity 460 can be in fluid
communication with a
passage 480 that provides a flow of the dielectric fluid to a bearing 482 that
supports the rotor
shaft 38 relative to the housing assembly 12. Dielectric fluid that is
discharged from the bearing
482 can seep between the housing assembly 12 and the rotor shaft 38 and can
drain to the sump
in the housing assembly 12.
[0054] With reference to Figures 27, 28 and 37, a portion of the
dielectric fluid in the
annular cavity 440 can be discharged into a bypass tube 500. The amount of
fluid that is
discharged into the bypass tube 500 is based on pressure balancing between the
flow that is
11
Date Recue/Date Received 2022-06-17
directed through the bypass tube 500 and the portion of the flow that travels
through the
inverter 204 and the stator 32.
[0055] Figure 38 depicts the dielectric fluid as it is discharged from
the annular cavity 440
and transferred via the bypass tube 500 to the feed pipe 410 in the cover 404.
[0056] Figure 39 depicts the bypass flow exiting the bypass tube 500,
traveling through
the feed pipe 410 in the cover 404 and being fed into a heat exchanger 506
that is mounted
within the rotor shaft 38. The heat exchanger 506 receives the flow (inflow)
of dielectric fluid
along its rotational axis, and then turns the flow at the opposite end of the
rotor 34 so that the
flow of dielectric fluid flows concentrically about the inflow toward the end
of the rotor 34 that
received the inflow of the dielectric fluid.
[0057] In Figures 40 and 41, the outflow of the dielectric fluid that
exits the heat
exchanger 506 in the rotor shaft 38 can be at least partly employed to
lubricate the various
components (i.e., bearings, shafts, gear teeth) of the planetary reduction 42,
as well as the
bearings 60 that support the shaft 44 of the transmission. Note that the feed
pipe 410 in the
cover 404 is received through a bore in the shaft 44. In the example provided,
the feed pipe 410
is a discrete component that is assembled to the cover 404.
[0058] Figures 42 through 45 show various flows of dielectric fluid being
used to lubricate
various other components within the electric drive module.
[0059] The foregoing description of the embodiments has been provided for
purposes of
illustration and description. It is not intended to be exhaustive or to limit
the disclosure.
Individual elements or features of a particular embodiment are generally not
limited to that
particular embodiment, but, where applicable, are interchangeable and can be
used in a selected
embodiment, even if not specifically shown or described. The same may also be
varied in many
ways. Such variations are not to be regarded as a departure from the
disclosure, and all such
modifications are intended to be included within the scope of the disclosure.
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Date Recue/Date Received 2022-06-17
