VARIABLE SPEED HYBRID ELECTRIC SUPERCHARGER ASSEMBLY AND
METHOD OF CONTROL OF VEHICLE HAVING SAME
RELATED APPLICATIONS
[0001] This application is being filed on 13 March 2013, as a PCT International
Patent application and claims priority to U.S. Patent Application Serial No.
61/617,152 filed on 29 March 2012, the disclosure of which is incorporated herein
by reference in its entirety.
TECHNICAL FIELD
[0002] The present teachings generally include a supercharger assembly that
includes a supercharger, an electric motor-generator, and a planetary gearing
arrangement.
BACKGROUND
[0003] Energy efficient engines of reduced size are desirable for fuel economy
and cost reduction. Smaller engines provide less torque than larger engines. A
supercharger is sometimes used to increase the torque available from an engine. At
low engine speeds, when higher torque is often requested by a vehicle operator by
depressing the accelerator pedal, the supercharger provides additional air to the
engine intake manifold, boosting air pressure and thereby allowing the engine to
generate greater torque at lower engine speeds.
SUMMARY
[0004] The present teachings generally include a supercharger assembly for an
engine. The engine has a crankshaft and an air intake manifold defining a plenum
through which air flow is provided to the engine. The supercharger assembly
includes a supercharger upstream of the plenum in the air flow to the engine. The
supercharger has a first rotor mounted on and rotatable with a first shaft and a
second rotor meshing with the first rotor and mounted on and rotatable with a
second shaft via rotation of the first shaft. The supercharger assembly also includes
an electric motor-generator that is selectively alternately operable as a motor and as
a generator, and planetary gearing arrangement. A first member of the planetary gear
set is operatively connected to be rotated by the electric motor-generator, a second
member of the planetary gear set is connectable to be rotated by the engine
crankshaft, and a third member of the planetary gear set is operatively connected for
rotation with the first shaft. The supercharger assembly has only two selectively
engageable torque-transmitting mechanisms including a clutch selectively
engageable to operatively connect the second member for rotation with the engine
crankshaft, and a brake selectively engageable to hold the first shaft stationary. A
control system is configured to control the electric motor-generator, the brake and
the clutch to achieve different operating modes. For example, if the engine is an
internal combustion engine with a throttle valve, the throttle valve and the
supercharger can be controlled so that throttling losses (i.e., the pressure drop that
occurs across the throttle due to the vacuum created by the reciprocating engine
cylinders) are selectively distributed across the throttle and/or the supercharger. The
pressure drop placed across the supercharger can create torque that is converted to
stored energy.
[0005] The above features and advantages and other features and advantages of
the present teachings are readily apparent from the following detailed description of
the best modes for carrying out the present teachings when taken in connection with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIGURE 1 is a schematic illustration in side view of a supercharger
assembly and an engine assembly, with a housing assembly of the supercharger
assembly partially removed, in accordance with an aspect of the present teachings.
[0007] FIGURE 2 is a schematic illustration in side view of the supercharger
assembly of Figure 1 within the housing assembly.
[0008] FIGURE 3 is a schematic illustration in cross-sectional view of the
supercharger assembly taken at lines 3-3 in Figure 2.
[0009] FIGURE 4 is a schematic illustration in cross-sectional view of the
supercharger assembly taken at lines 4-4 in Figure 3.
[0010] FIGURE 5 is a schematic illustration of a portion of the supercharger at
the area indicated in Figure 4.
[0011] FIGURE 6 is a schematic illustration in an end view of a gear cover
portion of the housing assembly.
[0012] FIGURE 7 is a schematic illustration in cross-sectional view taken at
lines 7-7 in Figure 6 of a portion of the supercharger assembly within the gear cover
portion.
[0013] FIGURE 8 is a schematic perspective illustration of the gear cover
portion.
[0014] FIGURE 9 is a schematic perspective illustration of an outlet housing
and outlet pipe of the housing assembly.
[0015] FIGURE 10 is a schematic plan view illustration of the outlet housing
and outlet pipe of the housing assembly.
[0016] FIGURE 11 is a schematic illustration in side view of the outlet housing
and outlet pipe of the housing assembly.
[0017] FIGURE 1 is a schematic illustration in cross sectional view of the
outlet housing and outlet pipe taken at the lines 12-12 in Figure 11.
[0018] FIGURE 13 is a schematic illustration in end view of the motor housing
portion.
[0019] FIGURE 14 is a schematic perspective illustration of the motor housing
portion.
[0020] FIGURE 15 is a schematic illustration in plan view of the motor housing
portion.
[0021] FIGURE 16 is a schematic illustration in end view of an inlet cover
portion of the housing forming a cavity for a brake.
[0022] FIGURE 17 is a schematic illustration in cross-sectional view of the inlet
cover portion taken at the lines 17- 17 in Figure 6.
[0023] FIGURE 18 is a schematic perspective illustration of the inlet cover
portion.
[0024] FIGURE 1 is a schematic perspective illustration of an oil slinger
mounted to a pulley shaft in Figure 3.
[0025] FIGURE 20 is a schematic illustration in an opposite end view of the
gear cover portion than shown in Figure 6.
[0026] FIGURE 2 is a schematic cross-sectional illustration of the rotor
housing portion with an outlet component having an outlet housing and an outlet
pipe in accordance with another aspect of the present teachings.
[0027] FIGURE 22 is a schematic perspective illustration of the outlet
component with the outlet housing and outlet pipe of Figure 21.
[0028] FIGURE 23 is a schematic illustration in bottom view of the rotor
housing of Figure 2.
[0029] FIGURE 24 is a schematic illustration in side view of a supercharger
assembly having the outlet component of Figures 2 1 and 22.
DETAILED DESCRIPTION
[0030] Referring to the drawings, wherein like reference numbers refer to like
components throughout the several views, Figure 1 shows an engine assembly 10
that includes a supercharger assembly 11 with a supercharger 2 placed in series
with a throttle valve, also referred to herein as a throttle 14, positioned in a throttle
body 16 of an engine 13. The throttle body 16 is in the air flow to the engine 3
upstream of a plenum 18 in an air intake manifold 20. Although the supercharger 12
is shown upstream of the throttle 14 in air flow to the engine 13, the supercharger 2
could instead be downstream of the throttle 14 in air flow to the engine 13. That is,
the throttle 14 could feed into an inlet 84 of the supercharger 12, and an outlet of the
supercharger 12 could flow directly to the plenum 8. It should be appreciated that
the supercharger 12 could also be used with an engine that does not have a throttle,
such as a diesel engine.
[0031] The supercharger 12 can have a set of rotors 24 with a first rotor 26 that
can mesh with a second rotor 28 (the second rotor 28 being visible in Figure 3).
Each of the rotors 26, 28 has multiple lobes. The supercharger 12 can boost the air
pressure upstream of the plenum 18, forcing more air into engine cylinders, and thus
increasing engine power to power a drive axle 2 through a transmission 22.
[0032] The supercharger 12 can be a fixed displacement supercharger, such as a
Roots-type supercharger, that outputs a fixed volume of air per rotation. The
increased air output then becomes pressurized when forced into the plenum 8. A
Roots-type supercharger is a volumetric device, and therefore is not dependent on
rotational speed in order to develop pressure. The volume of air delivered by the
Roots-type supercharger per each rotation of the rotors 26, 28 is constant (i.e., does
not vary with speed). A Roots-type supercharger can thus develop pressure at low
engine and rotor speeds (where the supercharger is powered by the engine) because
the Roots-type supercharger functions as a pump rather than as a compressor.
Compression of the air delivered by the Roots-type supercharger takes place
downstream of the supercharger 12 by increasing the mass of air in the fixed volume
engine plenum 18. Alternatively, the supercharger 12 can be a compressor, such as a
centrifugal-type supercharger that compresses the air as it passes through the
supercharger 12, but with the compression and thus the volume of air delivered to
the throttle body 16 and air pressure in the plenum 18 being dependent on
compressor speed.
[0033] The supercharger assembly includes a planetary gearing arrangement
4 1 with a sun gear member 42, a ring gear member 44, and a carrier member 46 that
rotatably supports a set of pinion gears 47 that can mesh with both the ring gear
member 44 and the sun gear member 42. The sun gear member 42 is referred to as
the third member, the ring gear member 44 is referred to as the first member, and the
carrier member 46 is referred to as the second member of the planetary gear set 4 1.
The planetary gear set 4 1 is a simple planetary gear set. In other embodiments, a
compound planetary gear set can be used.
[0034] As shown in Figure 3, the first rotor 26 rotates on a first shaft 30 and has
multiple lobes that mesh via a set of intermeshing timing gears 34, 36 with multiple
lobes of the second rotor 28. It should be understood that the rotors 26, 28 mesh in
that their lobes interfit with one another when the rotors 26, 28 are rotating.
However, the lobes of the rotors 26, 28 do not contact one another. The second rotor
28 rotates on a second shaft 32. The second shaft 32 is driven by the first shaft 30
through the set of intermeshing timing gears 34, 36. Specifically, a first gear 34 is
mounted on the first shaft 30 to rotate with the first rotor 26. A second gear 36 is
mounted on the second shaft 32 to rotate with the second rotor 28. The first gear 34
meshes with the second gear 36.
[0035] As shown in Figure 1, the engine 13 has a crankshaft 48 that can be
operatively connected with the carrier member 46 through a belt drive 49 when an
electromagnetic clutch 55 is engaged to connect a pulley 57 mounted on the
crankshaft 48 for rotation with the crankshaft 48. The pulley 57 and crankshaft 48
are thereby drivingly connected through a belt 63 with a pulley 59 mounted to a
pulley shaft 6 1 to rotate with the pulley shaft 6 1. The pulley shaft 6 1 is connected to
rotate with the carrier member 46 at the same speed as the carrier member 46.
[0036] The clutch 55 is a normally closed clutch, in a normally engaged state in
which a clutch pack has a first set of plates 31 splined to the crankshaft 48 engaged
with a second set of plates 33 splined to a clutch housing 35 that is rigidly connected
for rotation with the pulley 57. A spring 37 biases an apply plate 38 toward the sets
of plates 31, 33 to maintain the clutch 55 in an engaged state. A coil 39 is energized
to create a magnetic force to move the plate 38 axially away from the clutch plates
31, 33, overcoming the biasing force of the spring 37, and thereby disengaging the
clutch 55. The coil 39 is selectively energized by a control system that includes a
system controller 65, such as an engine controller, operable to provide control
signals to clutch 55. The controller 65 is also operatively connected to the motor
controller 62, and to an electromagnetic brake, a bypass valve 70 and the throttle 14,
as discussed herein. Any other type of clutch, including a normally open clutch, can
be used in place of clutch 55.
[0037] An electric motor-generator/generator 50 can transfer torque to or receive
torque from the ring gear member 44 through a gear train that includes a first gear
member 53 that meshes with a second gear member 54. The motor-generator 50 has
a rotatable motor shaft 52 with the first gear member 53 mounted on the motor shaft
52. The first gear member 53 can mesh with the second gear member 54, which can
be a stepped gear member that meshes with the ring gear member 44. The sun gear
member 42 rotates with a shaft 56 that is connected to the first shaft 30 through a
semi-flexible coupling member 58 so that the sun gear member 42 rotates at the
same speed as the first rotor 26 of the supercharger 12. The coupling member 58
flexes to absorb torsional and axial vibrations between the first shaft 30 and a shaft
56 connected with the sun gear member 42. Rotation of the first rotor 26 causes
rotation of the second rotor 28 via the intermeshing gears 34, 36.
[0038] The electric motor-generator 50 has an integrated electronic motor
controller 62 that controls operation of the motor-generator 50 to function as a motor
or as a generator. When the motor-generator 50 functions as a motor, it receives
stored electrical energy from an energy storage device 64 such as a battery through
power cables 66. The controller 62 may include a power inverter to convert the
electrical energy from direct current to alternating current when energy flows from
the energy storage device 64 to the motor-generator 50, and from alternating current
to direct current when energy flows from the motor-generator 50 to the energy
storage device 64. The system controller 65 can be an engine controller, operatively
connected to the motor controller 62 via CAN bus or similar architecture, and is also
configured to control engagement of the clutch 55, engagement of a brake 68,
discussed herein, the position of the throttle 14, and the position of a bypass valve
70.
[0039] The belt drive 49 may be referred to as a front engine accessory drive
(FEAD). One or more vehicle accessories 78 can be driven by the engine crankshaft
48 via the belt 63 of the belt drive 49 when clutch 55 is engaged or by the motorgenerator
50 when the clutch 55 is not engaged, brake 68 is engaged to stop the sun
gear 42 and the engine 13 is off, such as during an engine start/stop mode discussed
herein. The vehicle accessories 78, such as an engine coolant pump or an air
conditioning compressor, are operatively connected to a shaft 79 that rotates with a
pulley 76 driven by the belt 63.
[0040] The sun gear member 42 is connected for common rotation with the first
rotor 26 by the shafts 56, 30 and through the coupling member 58. The brake 68 can
be controlled by the system controller 65, to selectively ground the first shaft 30 to a
stationary housing assembly 80 of the supercharger assembly 11. Specifically, the
brake 68 is an electromagnetic brake packaged in a cavity 69 (shown in Figure 4) of
an inlet cover portion 82 of the housing assembly 80 so that the inlet cover portion
82 supports the brake 68. The brake 68 is selectively actuated to ground the first
shaft 30 to the inlet cover portion 82, as further described with respect to Figure 4.
[0041] Air flows across the supercharger assembly 11, between the rotors 26,
28, from an air inlet 84 of an air inlet passage 85 in the inlet cover portion 82, shown
schematically in Figure 1, through an air inlet opening 84A (shown in Figure 21) of
the rotor housing portion 90, to an air outlet 86 (best shown in Figure 23) of an air
outlet passage 88 partially defined by a rotor housing portion 90 of the housing
assembly 80. The rotor housing portion 90 radially surrounds the rotors 26, 28 and
the shafts 30, 32. Shaft 30 extends out of an axial end of the rotor housing portion 90
into the inlet cover portion 82. A portion 92 of a bypass passage 94 is defined by the
inlet cover portion 82. The bypass passage 94 is also referred to as a bypass route.
The bypass valve 70 is supported within the bypass passage 94 and substantially
closes the bypass passage 94 when in the closed position shown in Figure . The
position of the bypass valve 70 is schematic, and is intended to represent a position
in which air flow through the passage 94 is completely blocked by the valve 70. The
bypass valve 70 can be controlled by the controller 65 to move to an open position
70A shown in phantom in Figure 1. When the bypass valve 70 is in the open
position 70A, air can flow from the air inlet portion 84 through the bypass passage
94 to the throttle body 16, bypassing the rotors 26, 28, such as when engine boost is
not desired.
[0042] Figures 2 and 4 show a gear cover portion 95 mounted to the rotor
housing portion 90 to surround and enclose the planetary gearing arrangement 4
and the gear members 53, 54. A motor housing portion 96 of the motor-generator 50
mounts to the gear cover portion 95. Both the gear cover portion 95 and the motor
housing portion 96 are portions of the stationary housing assembly 80. The housing
assembly 80 includes an inlet pipe 97 that attaches to the inlet cover portion 82 to
extend the inlet passage 85. The housing assembly 80 also includes an outlet pipe 98
attached to an outlet housing 99 that mounts to the rotor housing portion 90 to
extend the outlet passage 88. The outlet pipe 98 operatively connects to the throttle
body 16 shown in Figure 1 through an additional pipe extension (not shown)
connected to the outlet pipe 98.
[0043] Movement of pistons within the engine cylinders creates a vacuum that
pulls air through the plenum 18. When the throttle 14 is in the relatively closed
position shown in Figure 1, the vacuum created by the engine 13 creates a pressure
differential in the form of a pressure drop across the throttle 14. When the throttle 4
is moved to a relatively open position 14A, the pressure drop across the throttle 4 is
relieved. However, by controlling the motor-generator 50, the pressure differential
can be transferred to the rotors 26, 28, creating a torque on the rotors 26, 28 that can
be captured as. electrical energy in the energy storage device 64.
[0044] That is, a pressure differential is created across the supercharger 12 from
the air inlet 84 to the air outlet 86 upstream in air flow to the throttle 14 when the
throttle 14 is in the relatively open position 14A. As described below, the throttle 14
and the bypass valve 70 can be selectively controlled in conjunction with the engine
3 to provide various operating modes, such as providing a desired intake air
pressure to the engine cylinders, while allowing the supercharger 12 and the motorgenerator
50 to be used to provide regenerative electrical energy to the energy
storage device 64. The stored electric energy can be used to provide power to
vehicle electrical systems and devices in place of an alternator and/or for providing
torque at the crankshaft 48 when the motor-generator 50 is controlled to function as
a motor.
[0045] The engine assembly 10 with the supercharger assembly 11 enables a
variety of different operating modes that can be selected and commanded by the
controller 65 based on vehicle operating conditions such as engine torque
requirements, and the state of charge of the energy storage device 64. An engine-off
operating mode may be used to provide torque at the shaft 6 1 to power the auxiliary
vehicle components 78 when the engine 13 is off. As used herein, the engine 13 is
off when fuel and/or ignition is not provided for combustion in the engine 13. In the
engine-off operating mode, the controller 65 controls the motor-generator 50 to
function as a motor, engages the brake 68 and causes the clutch 55 to be disengaged.
Torque is transferred from the motor-generator 50 to the auxiliary components 78
through the planetary gear set 4 1.
[0046] If vehicle operating conditions indicate that the engine 13 should be
started, the engine assembly 0 can be transitioned from the engine-off operating
mode to an engine-start operating mode simply by engaging the clutch 55 while still
controlling the motor-generator 50 to function as a motor and keeping the brake 68
engaged. Torque from the motor-generator 50 will thus be applied to the crankshaft
48 to start the engine 13. Once the engine 13 is started, the motor-generator 50 can
freewheel, with the controller 65 neither directing electric energy from the energy
storage device 64 to the motor-generator 50, nor directing electric energy from the
motor-generator 50 to the energy storage device 64. The start/stop ability of the
motor-generator 50 allows the engine 13 to be shut off rather than idle, such as at
traffic lights, with an expected increase in fuel economy and reduction in carbon
dioxide emissions. Thus, fuel savings can be realized during the period that the
engine 13 is shutoff, and restarting the engine 13 can be accomplished with the
electric energy generated from recaptured energy stored in the battery.
[0047] Alternatively, once the engine 13 is started, the motor-generator 50 can
function either as a motor or as a generator. With the engine 13 on, engine boost,
brake regeneration and throttle loss regeneration modes described herein may be
used. An engine boost operating mode can be established by the controller 65 when
additional torque is required at the drive axle 21, such as for vehicle acceleration. To
establish the boost operating mode with the engine 13 on, the clutch 55 is engaged
and the brake 68 is disengaged. The motor-generator 50 is controlled to function as a
motor and the bypass valve 70 is in the closed position shown in Figure 1. The
engine 13 provides torque to drive the first shaft 30 through the belt drive system 49
and the carrier member 46. The motor-generator 50 provides torque to drive the first
shaft 30 through the intermeshing gears 53, 54 to the ring gear member 44. The
speed of the first shaft 30 is thus increased relative to the speed of shaft 6 1 using the
motor-generator 50 to adjust the speed of ring gear member 44 and, through the
planetary gearing arrangement 41, set the desired rotational speed of shafts 56 and
30, providing desired boost pressure.
[0048] The amount of boost pressure provided at the engine plenum 18 can thus
be varied during the engine boost operating mode in response to varying torque
demand. First, the controller 65 can vary the speed of the motor-generator 50 to
control the amount of boost pressure developed in the plenum 18 during the engine
boost operating mode. Alternately or in addition, the controller 65 can control the
position of the bypass valve 70, such as by moving the bypass valve 70 from the
closed position shown in Figure 1to the open position 70A. Air from the air inlet 84
can thus flow through the bypass passage 94, reducing the volume of air that will
flow through the rotor housing 90 past the rotors 26, 28 and thereby reducing the
pressure of air at the plenum in comparison to pressure that develops when air
flows through the rotors 26, 28. Operation of the bypass valve 70 by opening the
bypass valve 70 to the fully open position 70A can allow a relatively quick
adjustment in air pressure in the plenum 18 in comparison to a more gradual
adjustment achieved by changing the speed of the motor-generator 50. A more
modulated adjustment in boost pressure can be achieved by placing the bypass valve
70 in an intermediate position between the fully open position 70A and a fully
closed position. Control of both the speed of the motor-generator 50 and the position
of the bypass valve 70 allows a tailored engine boost in response to engine torque
demand. Because the boost pressure provided in the plenum 18 by the supercharger
12 is independent of engine speed, a relatively constant torque can be obtained at the
crankshaft 48 across the entire range of operating speeds of the engine 13.
Alternately, the torque at the crankshaft 48 can be tailored as desired across the
range of engine operating speeds.
[0049] When the engine 13 is on and engine boost is not required, such as
during vehicle cruising at a relatively steady vehicle speed, the controller 65 can
slow the speed of the supercharger 1 and control the throttle 1 so that the
throttling losses (i.e., the pressure drop associated with the vacuum created by the
moving engine cylinders) can be applied across both the throttle 14 and the
supercharger 1 with the bypass valve 70 closed. The position of the throttle 14 can
be balanced with the pressure drop desired across the supercharger 12 and air flows
through both the supercharger 12 and past the at least partially closed throttle 14 to
reach the engine cylinders. The bypass valve 70 can also be controlled during this
mode to allow air to bypass the supercharger 12 when a rapid change in air flow to
the engine 3 is required. The torque generated by the pressure drop across the
supercharger 12 will be applied to the sun gear member 42, and thus to the engine
crankshaft 48 and also to the motor-generator 50 (when controlled to operate as a
generator) via the torque split provided by the planetary gearing arrangement 4 1.
This operating mode can be referred to as a throttling loss regeneration mode. All or
a portion of the torque generated by the pressure drop across the supercharger 2 can
be converted to electric energy stored in the energy storage device 64 by controlling
the motor-generator 50 to function as a generator. The stored electric energy
generated from the pressure drop-induced torque is referred to as being from
"recaptured throttling losses."
[0050] During an extended cruising period, when engine boost is not required,
the throttling loss regeneration mode can be maintained until the energy storage
device 64 reaches a predetermined maximum state of charge. Then, the brake 68 can
be applied, the bypass valve 70 opened to position 70A, and the motor-generator 50
controlled to function as a motor to apply torque to the engine crankshaft 48 until the
energy storage device 64 reaches a predetermined minimum state of charge. This
cycling of charging and depleting the energy storage device 64 can continue
throughout the cruising period.
[0051] In one example, the pressure drop across the supercharger 12 is increased
an amount delta. This delta, which results in a larger pressure drop across the
supercharger 1 for all engine speeds, assures that the pressure drop does not
diminish to the point that the pressure differential is essentially zero. In one
example, the delta is applied at least at low engine speeds. In another example, the
delta is applied at all engine speeds. In this manner, continuous energy can be
captured through throttle loss regeneration, with only a marginal impact on fuel
economy.
[0052] In such an example, the control system is configured to control the
electric motor-generator to function as the generator and the throttle valve is
controlled to move to a relatively open position so that the pressure drop across the
supercharger is equal to or greater than the original throttle pressure drop such that
the electric motor-generator, through the planetary gearing arrangement, captures the
throttling as electric energy.
[0053] The supercharger assembly 1 can also be controlled to capture energy
during vehicle braking in a regenerative braking mode. When vehicle braking slows
the drive axle 1, the controller 65 is configured to engage the brake 68 and control
the electric motor-generator 50 to function as a generator with torque applied to the
electric motor-generator 50 in a reverse direction that is the opposite of the direction
of torque supplied by the electric motor-generator 50 when the electric motorgenerator
functions as a motor. Reverse torque is thus applied to the crankshaft 48
through the planetary gearing arrangement 4 and electric energy generated by the
electric motor-generator 50 is stored in the energy storage device 64.
[0054] Figure 1 shows an oil slinger 100 mounted to the pulley shaft 6 1 to rotate
with the pulley shaft 6 1. Figure 19 is a perspective view of the oil slinger 100
disconnected from the pulley shaft 61. The oil slinger 100 is an annular member
with a first end 102 that has a first inner diameter 104 configured to fit to the outer
surface of the pulley shaft 6 1. A second end 106 has a larger diameter so that the oil
slinger 100 fans out from the pulley shaft 6 1 toward the second end 106. The oil
slinger 100 is positioned on the pulley shaft 6 1 so that the second end 106 faces the
planetary gearing arrangement 41, as best shown in Figure 3. Figure 19 shows that
the oil slinger 100 is formed with a series of scooped portions 108 about a periphery
of the oil slinger 100 generally midway between the ends 102, 106. Each of the
scooped portions 108 has an opening 1 0, with each of the openings 0 facing the
same direction of rotation. Each scooped portion 108 tapers in an axial direction
between the larger end 106 and the smaller end 102. When the pulley shaft 6 1
rotates in a clockwise direction, the oil slinger 100 also rotates in a clockwise
direction and oil mist within the gear cover portion 95 will enter through the
openings 110 and be captured by the scooped portions 108. The oil mist will contact
the inner surface 12 of the scooped portion 108. Rotation of the oil slinger 100 will
cause the oil mist to travel toward the end 106 along an inner surface 114 of the oil
slinger 100 and be propelled from the oil slinger 100 in the direction of arrow A.
The oil will be strewn generally toward the planetary gear set 4 1 for lubrication of
the planetary gear set 4 1.
[0055] Figure 2 shows the supercharger assembly 1 with the various portions
of the housing assembly 80 attached to one another. The inlet pipe 97 has openings
that align with openings 1 3 of the inlet cover portion 82, shown in Figure 18, so
that fasteners 115 can be used to attach the inlet pipe 97 to the inlet cover portion 82
over the air inlet 84. As used herein, a fastener can be any suitable component used
to attach two adjacent components, such as a bolt, a screw, or other suitable fastener.
[0056] Figure 3 shows an extension portion 116 of the first shaft 30 that has a
toothed end portion 118. A rotating member 120 with a flange 122 is splined to the
toothed end portion 118 and is supported at the inlet cover portion 82 by a bearing
124 to be rotatable relative to the inlet cover portion 82. The extension portion 116,
toothed end portion 118, rotating member 120 and flange 122 are within the cavity
69. An electromagnetic brake 68 is selectively actuatable by the controller 65 by
wires (not shown) that extend through a wire access opening 126 shown in Figure 18
to provide electric energy used to actuate a coil 128 within the brake 68 to hold the
flange 122 stationary relative to the inlet cover portion 82 via electromagnetic
attraction. The coil 128 is shown in Figure 3 not in Figure 18. A brake cover 130 is
attached to the inlet cover portion 82 with fasteners 132 that extend through
openings 134 in the inlet cover portion 82. As discussed with respect to Figure 1, the
inlet cover portion 82 also defines a portion 92 of the bypass passage 94. The
portion 92 is in fluid communication with the inlet 84 and extends through the inlet
cover portion 82. The portion 92 is shown over the brake cavity 69 and extending
out of a bottom of the inlet cover portion 82 in Figure 18. For illustrative purposes,
portion 92 is shown only above the brake 68 in Figure 1. Any suitable orientation of
the portion 92 in the inlet cover portion 82 may be used. The bypass passage 94 is
connected to the inlet cover portion 82 to be in communication with the portion 92
alternately bypass passage 94 may be attached upstream from inlet cover 82 and
inlet pipe 97 via a plumbing tee or the like.
[0057] Figure 2 shows a fastener 135 that is used to attach the inlet cover portion
82 to the rotor housing portion 90. Although only one fastener 135 is shown,
multiple additional fasteners 135 can be placed at various positions around the
interface of the rotor housing 90 and the inlet cover portion 82. Figure 3 shows that
when the inlet cover portion 82 is attached to the rotor housing portion 90, the first
shaft 30 extends from the rotor housing portion 90 into the inlet cover portion 82.
[0058] Figure 5 is a closer view of a portion of the supercharger assembly 1
that shows the planetary gearing arrangement 4 1 and its operative connection to the
first shaft 30. Specifically, the coupling member 58 is positioned within an opening
140 of the motor housing portion 96. The coupling member 58 includes a first
member 142 fit to the first shaft 30 and pinned to a flange 144 of the shaft 56 with
circumferentially positioned pins 146. The coupling member 58 absorbs torsional
vibrations that may be caused by pressure pulsation emanating from the
supercharger assembly 11 on shaft 30 or engine pulsation from shaft 61. A seal 148
seals the first shaft 30 to the rotor housing 90 to prevent leakage of air from within
the rotor housing 90.
[0059] Figures 6-8 show the gear cover portion 95 including a pattern of fastener
openings 150 that match a pattern of fastener openings 152 on the motor cover
portion 96, shown in Figure 13. Fasteners 157 (two shown in Figure 4) are used to
attach the gear cover portion 95 to the motor housing portion 96 through the aligned
openings 150, 152. Some of the fastener openings 150 are obscured in Figure 6 by a
mounting flange 154 of the gear cover portion 95. The mounting flange 154 has
fastener openings 156 though which fasteners are placed to mount the gear cover
portion 95, and thereby the entire supercharger assembly 11, to the engine 13 of
Figure 1.
[0060] The pulley 59 is shown with a hex screw 158 extending through an
opening in the pulley 59 to mount the pulley 59 to the pulley shaft 6 1 (shown in
Figure 4). The pulley shaft 6 1 extends through an opening in the gear cover portion
95. A washer 161 is positioned between the hex screw 158 and the pulley shaft 6 1.
Bearings 160A, 160B shown in Figure 4 permit the pulley shaft 6 1 and pulley 59 to
rotate relative to the gear cover portion 95. At least one passage 162 though the gear
cover portion 95 directs lubricating fluid through the gear cover portion 95 to the
bearings 160A, 160B. A seal 164 is positioned between the gear cover portion 95
and the pulley 59 at an opening in the gear cover portion 95 through which the shaft
6 extends. As best shown in Figure 7, a wave disc spring 166A is positioned
between the pulley 59 and the bearing 160A to stop the inner bearing race of bearing
160A from spinning relative to shaft 6 1 and manage stack-up tolerances. Another
wave disc spring 166B is positioned between the bearing 160B and a ledge of the
gear cover portion 95 to prevent the outer race of bearing 160B from spinning in
gear cover housing 95. Disc springs 166C, 166D are also used between the gear
cover portion 95 and motor gear 53 shaft and idler gear 54 shaft ends which ride on
needle bearings 168A and 168B housed in recesses 169 of the gear cover portion 95.
These disc springs provide wear surfaces and manage tolerance stack-up. Needle
bearing 168A allows gear 53 to rotate relative to and extend through the motor
housing portion 96. Gear 53 is splined to the motor shaft 52 (shown in Figure 4).
Needle bearings 168B and 188 allows the gear 54 to rotate relative to the gear
housing portion 95 and motor housing portion 96.
[0061] Figure 20 shows that the gear cover portion 95 has ribs 167A, 167B,
167C that strategically collect and direct oil within the gear cover portion 95. Ribs
167A and 167B generally form a V shape above the recesses 169 in which the
needle bearings 168A, 168B are housed. Oil droplets within the gear cover portion
95 will collect on the ribs 167A, 167B and drain to the recesses 169 to lubricate the
bearings 168A, 168B. Rib 167C forms a V shape that strategically directs oil in the
gear cover portion 95 to the passage 162. Oil drains through the passage 162 to a
space in the opening 151 between the bearings 160A, 160B to lubricate the bearings
160A, 160B.
[0062] Figures 9-12 show the outlet housing 99 with the outlet pipe 98
extending from the outlet housing 99. In this embodiment, the outlet pipe 98 and
outlet housing 99 are welded together. In the embodiment of Figures 21-22, an outlet
housing 99A and an outlet pipe 98A are a unitary, one-piece outlet component 101.
The outlet housing 99 of Figure 9 has a pattern of fastener openings 170 that
matches a pattern of fastener openings 77 (see Figure 23) at the rotor housing
portion 90 around the air outlet 86. One fastener 172 is shown in Figure 2
connecting the outlet housing 99 to the rotor housing 90. Figure 9 shows a flange
173 with an opening 174 that can be used to mount the outlet housing 99 to the
engine 13. An opening 103 of the outlet housing 99 is in fluid communication with
the air outlet 86 of the rotor housing portion 90. The outlet 176 of the outlet pipe 98
feeds into the throttle body 16 of Figure 1.
[0063] Figures 13-15 show the motor housing 96 with a mounting flange 180
with an opening 182 by which the motor housing 96 can be mounted to the engine
3 of Figure 1. The mounting flange 180 extends in the same direction as the flange
154 of the gear cover portion 95. A seal 185 is positioned in an opening 186 of the
motor housing 96 at which the motor shaft 52 is splined to the first gear member 53,
as shown in Figure 4. A needle bearing 88 is positioned in another opening 190 in
the motor housing portion 96 at which the second gear member 54 is supported for
rotation. The rotor housing 90 can be fastened to the motor housing portion 96
around the opening 140 with fasteners that extend through stepped openings 192.
Figure 14 shows that the motor housing portion 96 has openings 193 around a flange
at which the motor controller housing 194 of Figure 4 is mounted by fasteners
extending through the openings 193. The motor cover portion 96 includes integral
cooling fins 196 for cooling the motor-generator 50.
[0064] Figures 16-18 show the inlet cover portion 82 with the toothed end
portion 118 of the extension 116 extending into the cavity 69. Figure 17 shows a
bearing 198 supporting the end portion 116 for rotation relative to the inlet cover
portion 82. A snap ring 200 holds the bearing in a bore in the inlet cover portion 82.
A wave disc spring 202 absorbs axial thrust forces between the bearing 198 and the
inlet cover portion 82 keeping the outer race of bearing 198 from spinning in the
bore. Stepped openings 204 extend through the inlet cover portion 82 to allow the
inlet cover portion 82 to be mounted to the rotor housing portion 90 with fasteners
(not shown).
[0065] Figures 2 1 and 22 show a unitary, one-piece outlet component 101 that
includes an outlet housing 99A and an outlet pipe 98A. The outlet component 101
can be used in lieu of the outlet housing 99 and outlet pipe 98, as shown in the
supercharger assembly 11A of Figure 24, which is otherwise identical to
supercharger assembly 1 . An extension pipe 105 can be welded to the outlet pipe
98A to connect to the throttle body 16. The outlet housing 99A has an opening 103A
that is generally shaped like a pentagon. The opening 103A has a tapered, V-shaped
end, opposite a wider end. Figure 23 shows that the air outlet 86 of the rotor housing
portion 90 is also generally shaped like a pentagon and is generally the same shape
as the opening 103A. The outlet pipe 98A extends from the outlet housing 99A at a
45 degree angle. The generally pentagon shape of the opening 103A as well as the
angle at which the outlet pipe extends from the outlet housing 99A provide
beneficial air flow characteristics. Figure 24 shows the supercharger assembly 11A
like the supercharger assembly 11 of Figure 2 except with a housing assembly 80A
that includes the outlet component 101 in place of the outlet housing 99 and the
outlet pipe 98.
[0066] As is apparent in Figures 1 and 2, the housing assembly 80 is configured
so that the electric motor-generator 50 and the rotor housing portion 90 are on an
opposite side of the gear cover portion 95 than the pulley 59. Additionally, the air
inlet passage 85 and inlet pipe 97 are adjacent to the electric motor-generator 50 and
the air outlet passage 88 and outlet pipe 98 are on an opposite side of the rotor
housing portion 90 than the electric motor-generator 50. The housing assembly 80A
is arranged in a like manner. It should be appreciated that the throttle body 16 and
throttle 14 may be positioned upstream of the inlet pipe 97 in air flow to the engine
13, in which case the supercharger 12 would pull air through the throttle 14 and
would be operable to allow the same operating modes discussed herein.
[0067] The reference numbers used in the drawings and the specification along
with the corresponding components are as follows:
10 engine assembly
11 supercharger assembly
11A supercharger assembly
12 supercharger
13 engine
14 throttle
14A fully open position of throttle
16 throttle body
18 plenum
20 intake manifold
2 1 drive axle
22 transmission
24 set of rotors
26 first rotor
28 second rotor
30 first shaft
3 1 first set of plates
32 second shaft
33 second set of plates
34 first gear
35 clutch housing
36 second gear
37 spring
38 apply plate
39 coil
4 1 planetary gearing arrangement
42 sun gear member
44 ring gear member
46 carrier member
47 pinion gears
48 crankshaft
49 belt drive
50 electric motor-generator
52 motor shaft
53 first gear member
54 second gear member
55 clutch
56 shaft
57 pulley
58 semi-flexible coupling member
59 pulley
6 1 pulley shaft
62 motor controller
63 belt
64 energy storage device
65 system controller
66 power cables
68 brake
69 cavity
70 bypass valve
70A fully open position of bypass valve
76 pulley
79 shaft
78 vehicle accessories
80 stationary housing assembly
80A stationary housing assembly
82 inlet cover portion
84 air inlet of inlet cover portion
84A air inlet opening of rotor housing portion
85 air inlet passage
86 air outlet
88 air outlet passage
90 rotor housing portion
92 portion of bypass passage
94 bypass passage
95 gear cover portion
96 motor housing portion
97 inlet pipe
98 outlet pipe
98A outlet pipe
99 outlet housing
99A outlet housing
100 oil slinger
101 outlet component
102 first end of oil slinger
103 opening of outlet housing 99
103A opening of outlet housing 99A
104 first inner diameter
105 extension pipe
106 second end of oil slinger
108 scooped portion
110 opening
112 inner surface of scooped portions
113 opening of inlet cover portion
114 inner surface of oil slinger
115 fastener
116 extension portion of first shaft
118 toothed end portion
120 rotating member
122 flange
124 bearing
126 wire access opening
128 coil
130 brake cover
132 fastener
134 opening
135 fastener
140 opening of motor housing portion
142 first member of coupling
144 flange of shaft 56
146 pin
148 seal on first shaft
150 fastener openings on gear cover portion
151 opening
152 fastener opening in motor cover portion
154 mounting flange
156 fastener opening
157 fasteners
158 hex screw
160A bearing
160B bearing
161 washer
162 passage
164 seal
166A wave disc spring
166B wave disc spring
166C disc spring
166D disc spring
167A ribs
167B ribs
167C ribs
168A needle bearing
168B needle bearing
169 recess
170 fastener opening
172 fastener
173 flange
174 opening
176 outlet of outlet pipe
177 fastener opening
180 mounting flange
182 opening
185 seal
186 opening
188 needle bearing
190 opening
192 stepped opening
193 opening
194 motor controller housin;
196 cooling fins
198 bearing
200 snap ring
202 wave disc spring
204 stepped openings
A direction of oil
[0068] While the best modes for carrying out the many aspects of the present
teachings have been described in detail, those familiar with the art to which these
teachings relate will recognize various alternative aspects for practicing the present
teachings that are within the scope of the appended claims.
What is claimed is:
1. A supercharger assembly for an engine having a crankshaft
and an air intake manifold defining a plenum through which air flow is provided to
the engine, the supercharger assembly comprising:
a supercharger upstream of the plenum in the air flow to the engine,
wherein the supercharger has a first rotor mounted on and rotatable with a first
shaft and a second rotor meshing with the first rotor and mounted on and rotatable
with a second shaft via rotation of the first shaft;
an electric motor-generator selectively operable as a motor and as a
generator;
a planetary gearing arrangement having a first member operatively
connected to be rotated by the electric motor-generator, a second member
connectable to be rotated by the engine crankshaft, and a third member operatively
connected for rotation with the first shaft;
two selectively engageable torque-transmitting mechanisms including
a clutch selectively engageable to operatively connect the second member for
rotation with the engine crankshaft, and a brake selectively engageable to hold the
first shaft stationary; and
a control system configured to control the electric motor-generator,
the brake and the clutch to achieve different operating modes.
2. The supercharger assembly of claim , wherein at least one
vehicle component is operatively connected to the second member; and wherein the
control system is configured to disengage the clutch when the engine is off, and
control the electric motor-generator to function as a motor to power said at least
one vehicle component in an engine-off operating mode.
3. The supercharger assembly of claim , wherein the control
system is configured to engage both the brake and the clutch and control the
electric motor-generator to function as a motor to start the engine through the
planetary gearing arrangement in an engine-start operating mode.
4. The supercharger assembly of claim 1, wherein the control
system is configured to engage only the clutch when the engine is on and control
the electric motor-generator to function as a motor, both engine torque and electric
motor-generator torque thus driving the supercharger in an engine boost operating
mode.
5. The supercharger assembly of claim 4, wherein the control
system is configured to vary a speed of the electric motor-generator to control
engine boost provided by the supercharger based on engine torque demand during
the engine boost operating mode.
6. The supercharger assembly of claim 4, wherein the
supercharger assembly further comprises:
a bypass passage configured to permit air to flow from an inlet of the
supercharger to the plenum, bypassing the first and second rotors; and
a bypass valve operable to control airflow through the bypass
passage;
wherein the control system is configured to control a position of the
bypass valve during the engine boost operating mode to adjust a pressure of air in
the plenum as engine torque demand varies.
7. The supercharger assembly of claim , wherein the engine has
a throttle body and a throttle valve in the throttle body; wherein the plenum is
downstream of the throttle body in air flow to the engine; wherein the supercharger
is in series with the throttle valve in air flow to the engine and further comprising:
an energy storage device operatively connected to the electric motorgenerator
for supplying electric power to the electric motor-generator when the
electric motor-generator functions as a motor and for receiving electric power from
the electric motor-generator when the electric motor-generator functions as the
generator;
wherein the control system is configured to control the electric
motor-generator to function as the generator, and to move the throttle valve to a
relatively open position so that torque due to a throttling pressure drop across the
supercharger is provided from the supercharger to the electric motor-generator
through the planetary gearing arrangement, throttling losses thus being captured as
electric energy in the energy storage device.
8. The supercharger assembly of claim 7, wherein the control
system is configured to alternately control the electric motor-generator to function
as a motor, engage the brake, open a bypass valve, and position the throttle valve to
a relatively closed position managing the throttling pressure drop, when a state of
charge of the energy storage device reaches a predetermined maximum so that the
motor-generator drives the crankshaft until the state of charge of the energy storage
device reaches a predetermined minimum, and then control the electric motorgenerator
to function as the generator, move the throttle valve to the relatively open
position so that torque due to the throttling pressure drop across the supercharger is
provided from the supercharger to the electric motor-generator through the
planetary gearing arrangement.
9. The supercharger assembly of claim 1, wherein the control
system is configured to engage the brake and control the electric motor-generator to
function as the generator with torque applied to the electric motor-generator in a
reverse direction than a direction of torque supplied by the electric motor-generator
when the electric motor-generator functions as a motor, thereby applying reverse
torque to the crankshaft and storing electric energy generated by the electric motorgenerator
in an energy storage device.
10. The supercharger assembly of claim 1, further comprising:
a housing assembly having:
a rotor housing portion configured to radially surround the first
and second rotors; and
an inlet cover portion configured to attach to the rotor housing
portion such that the first shaft extends from within the rotor housing portion into
the inlet cover portion and is supported by the inlet cover portion; wherein the inlet
cover portion at least partially defines an air inlet passage through which air is
provided to the rotors; and wherein the inlet cover portion further defines a cavity
and supports the brake within the cavity.
11. The supercharger assembly of claim 10, wherein the inlet
cover portion partially defines a bypass passage configured to divert air from the air
inlet passage to a throttle body, bypassing the rotors; and
a bypass valve positioned in the bypass passage and operable to
control airflow through the bypass passage.
. The supercharger assembly of claim 1, further comprising:
a coupling member operatively connecting the third member with the
first shaft;
a housing assembly having:
a rotor housing portion configured to radially surround the first
and second rotors;
a motor housing portion that has an opening aligned with an
end of the rotor housing portion; and
a gear cover portion that mounts to the motor housing portion
such that the first shaft extends from within the rotor housing portion to the coupling
member at the opening in the motor housing portion; and wherein the gear cover
portion is configured to house the planetary gearing arrangement.
13. The supercharger assembly of claim 12, wherein the motor
housing portion is configured to be attached to the electric motor-generator; and
further comprising a gear train positioned within the gear cover portion and having a
first gear member connected for rotation with the electric motor-generator and a
second gear member connected for rotation with the first member of the planetary
gearing arrangement, the gear train thereby transferring torque between the planetary
gearing arrangement and the electric motor-generator.
14. The supercharger assembly of claim 12, further comprising:
a pulley having a pulley shaft supported by the gear cover portion;
wherein the pulley shaft is connected for rotation with the second member; wherein
the pulley is operatively connected to the crankshaft; and
an oil slinger mounted to the pulley shaft and opening toward the
planetary gearing arrangement and configured to direct fluid within the gear cover
portion onto the planetary gearing arrangement.
15. The supercharger assembly of claim 1, further comprising:
a gear cover portion configured to house the planetary gearing
arrangement;
a pulley having a pulley shaft; and
bearings supporting the pulley shaft for rotation relative to the gear
cover portion; wherein the pulley shaft is connected for rotation with the second
member; wherein the pulley is operatively connectable to the crankshaft;
wherein the gear cover portion has integral ribs and a passage;
wherein the ribs are positioned to collect lubricating oil and direct the lubricating oil
to the bearings through the passage.
16. The supercharger assembly of claim 1, further comprising:
a rotor housing portion configured to radially surround the first and
second rotors and at least partially defining an air inlet and an air outlet; and
an outlet component including an outlet opening; wherein the outlet
component is configured to attach to the rotor housing portion with the outlet
opening in fluid communication with the air outlet; and wherein the air outlet and
the outlet opening both have a substantially identical pentagon shape.
17. A supercharger assembly for an engine defining a plenum
through which air flows to the engine; the supercharger assembly comprising:
a supercharger in series with the plenum in the air flow to the engine,
wherein the supercharger has a first rotor mounted on and rotatable with a first
shaft and a second rotor meshing with the first rotor and mounted on and rotatable
with a second shaft via rotation of the first shaft;
a bypass passage operatively connecting an air inlet to a throttle
body;
a bypass valve positioned in the bypass passage to selectively permit
air flow through the bypass passage between the air inlet and the throttle body and
bypassing the first and second rotors;
an electric motor-generator selectively alternately operable as a motor
and as a generator;
an energy storage device operatively connected to the electric motorgenerator
for supplying electric power to the electric motor-generator when the
electric motor-generator functions as a motor and for receiving electric power from
the electric motor-generator when the electric motor-generator functions as the
generator;
a planetary gearing arrangement having a first member operatively
connected to be rotated by the electric motor-generator, a second member, and a
third member operatively connected for rotation with the first shaft;
a pulley configured to be operatively connectable to a crankshaft and
having a pulley shaft connected for rotation with the second member;
a gear train having a first gear member connected for rotation with
the electric motor-generator and a second gear member connected for rotation with
the third member of the planetary gearing arrangement, the gear train thereby
transferring torque between the planetary gearing arrangement and the electric
motor-generator;
two selectively engageabie torque-transmitting mechanisms including
an electromagnetic clutch selectively engageabie to operatively connect the second
member for rotation with the engine crankshaft, and an electromagnetic brake
selectively engageabie to hold the first shaft stationary; and
a control system configured to control the electric motor-generator,
the bypass valve, the brake and the clutch to achieve different operating modes.
18. The supercharger assembly of claim 17, further comprising:
a housing assembly having:
a rotor housing portion configured to radially surround the
first and second rotors and having a rotor housing air inlet opening and a rotor
housing air outlet at least partially defining an air outlet passage;
an inlet cover portion configured to attach to the rotor housing
portion such that the first shaft extends into and is supported by the inlet cover
portion; wherein the inlet cover portion at least partially defines an air inlet passage
through which air is provided to the rotor housing air inlet opening;
a motor housing portion that has an opening aligned with the
first and second shafts in the rotor housing portion; wherein the motor housing
portion is configured to support the electric motor-generator; and
a gear cover portion that mounts to the motor housing portion
with a coupling member positioned at the opening of the motor housing portion such
that the first shaft operatively connects to the third member via the coupling
member; wherein the gear cover portion is configured to house the planetary gearing
arrangement and support the pulley and the pulley shaft;
wherein the housing assembly is configured so that the electric
motor-generator and the rotor housing portion are on an opposite side of the gear
cover portion than the pulley, the air inlet passage is adjacent to the electric motorgenerator
and the air outlet passage is on an opposite side of the rotor housing
portion than the electric motor-generator.
19. A supercharger assembly for an engine having a crankshaft, a
throttle body, an air intake manifold defining a plenum downstream of the throttle
body, and a selectively positionable throttle valve in the throttle body controlling
air flow to the engine; the supercharger assembly comprising:
a Roots-type supercharger in series with the throttle valve upstream
of the throttle body in the air flow to the engine; wherein the supercharger has a
first rotor mounted on and rotatable with a first shaft and a second rotor meshing
with the first rotor and mounted on and rotatable with a second shaft via rotation of
the first shaft;
a housing assembly defining an air inlet to the supercharger;
a bypass passage operatively connecting the air inlet to the throttle
body;
a bypass valve positioned in the bypass passage to selectively permit
air flow through the bypass passage between the air inlet and the throttle body and
bypassing the first and second rotors;
an electric motor-generator selectively alternately operable as a motor
and as a generator;
an energy storage device operatively connected to the electric motorgenerator
for supplying electric power to the electric motor-generator when the
electric motor-generator functions as a motor and for receiving electric power from
the electric motor-generator when the electric motor-generator functions as the
generator;
a planetary gearing arrangement having a first member connected to
be rotated by the electric motor-generator, a second member connectable to be
rotated by the engine crankshaft, and a third member connected for rotation with
the first shaft;
only two selectively engageable torque-transmitting mechanisms
including a clutch selectively engageable to operatively connect the second member
for rotation with the engine crankshaft, and a brake selectively engageable to hold
the first shaft stationary; and
at control system configured to control the electric motor-generator,
the throttle valve, the bypass valve, the brake and the clutch to achieve an operating
mode in which the electric motor-generator starts the engine, an operating mode in
which the engine is on and the electric motor-generator varies a speed of the rotors
via the planetary gearing arrangement to control air pressure in the plenum, and an
operating mode in which air flows to the engine bypasses the rotors through the
bypass passage.
20. The supercharger assembly of claim 19, wherein the control
system is configured to control the electric motor-generator to function as the
generator and the throttle valve is controlled to move to a relatively open position so
that torque due to a throttling pressure drop across the supercharger is provided from
the supercharger to the electric motor-generator through the planetary gearing
arrangement, throttling losses thus being captured as electric energy, and wherein
the control system is configured to control the electric motor-generator to function
as the generator and the throttle valve is controlled to move to a relatively open
position so that the pressure drop across the supercharger is equal to or greater than
the original throttle pressure drop such that the electric motor-generator, through the
planetary gearing arrangement, captures the throttling as electric energy.