ELECTRIC ENERGY GENERATION USING VARIABLE SPEED HYBRID ELECTRIC SUPERCHARGER ASSEMBLY
An example method for selecting between modes of regeneration of an energy storage device of a vehicle includes: determining operating conditions of the vehicle; and when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device, including selecting between a nonperformance-impacting regeneration mode and a performance-impacting regeneration mode.
This application is being filed on 13 Mar. 2013, as a PCT International Patent application and claims priority to U.S. Patent Application Ser. No. 61/617,152 filed on 29 Mar. 2012, the disclosure of which is incorporated herein by reference in its entirety.
TECHNICAL FIELDThe present teachings generally include a supercharger assembly that includes a supercharger, an electric motor-generator, and a planetary gearing arrangement.
BACKGROUNDEnergy 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.
SUMMARYThe present teachings generally include a method for selecting between modes of regeneration of an energy storage device of a vehicle includes: determining operating conditions of the vehicle; and when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device, including selecting between a nonperformance-impacting regeneration mode and a performance-impacting regeneration mode.
In another example, a method for selecting between modes of regeneration of an energy storage device of a vehicle having a supercharger and an electric motor-generator includes: boosting an internal combustion engine of the vehicle using the supercharger; driving the vehicle using the electric motor-generator powered by the energy storage device; and selecting between regeneration operating modes to regenerate the energy storage device.
In yet another example, a method for regenerating an energy storage device of a vehicle using a supercharger includes: determining operating conditions of the vehicle; and when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device using the supercharger.
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.
Referring to the drawings, wherein like reference numbers refer to like components throughout the several views,
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
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 18. 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 12 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.
The supercharger assembly 11 includes a planetary gearing arrangement 41 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 41. The planetary gear set 41 is a simple planetary gear set. In other embodiments, a compound planetary gear set can be used.
As shown in
As shown in
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.
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.
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.
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 motor-generator 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.
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
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
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
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 13 to provide various operating modes, such as providing a desired intake air pressure to the engine cylinders, while allowing the supercharger 12 and the motor-generator 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.
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 61 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 41.
If vehicle operating conditions indicate that the engine 13 should be started, the engine assembly 10 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.
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. See
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
In other vehicle operating modes, the engine assembly 10 and the supercharger assembly 11 provide regeneration of the energy storage device 64. In these examples, the controller 65 is used to select an appropriate operating mode based upon vehicle operating conditions. If regeneration is appropriate, an operating mode involving regeneration is selected.
For example, referring now to
At operation 302, the controller 65 determines the current vehicle operating conditions. Factors such as vehicle speed, torque requirements, and state of charge of the energy storage device 64 are considered by the controller 65.
Next, at operation 304, the controller determines if regeneration is appropriate. If so, control is passed to operation 306, and the controller selects an appropriate operating mode for regeneration. If not, control is instead passed back to operation 302 for reevaluation of the vehicle operating conditions at a later point in time.
For example, if the controller 65 determines that the vehicle is accelerating rapidly and that boost is necessary, regeneration is not appropriate. So, the controller 65 would pass control back to operation 302 in that scenario. Conversely, if the vehicle is traveling at a constant rate of speed, such as on a highway, the controller 65 would pass control to operation 306 to select the appropriate mode for regeneration.
There are various regeneration operating modes that result in regeneration. Some of these regeneration operating modes are “nonperformance-impacting” in that the regeneration operating modes involve the recapture of energy that would otherwise be lost or otherwise does not appreciably impact the performance of the vehicle. See
Referring to
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 12 and control the throttle 14 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 12 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 13 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 41. All or a portion of the torque generated by the pressure drop across the supercharger 12 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.”
During an extended cruising period, when engine boost is not required, the throttling loss regeneration mode 310 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.
Referring to
The supercharger assembly 11 can also be controlled to capture energy during vehicle braking in the braking with supercharger locked regeneration mode 320. When vehicle braking slows the drive axle 21, 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 motor-generator functions as a motor. Reverse torque is thus applied to the crankshaft 48 through the planetary gearing arrangement 41 and electric energy generated by the electric motor-generator 50 is stored in the energy storage device 64. In this manner, energy from the braking of the vehicle is recaptured.
Referring to
Referring to
Finally, referring to
Referring again to
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 61 (shown in
As is apparent in
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
- 21 drive axle
- 22 transmission
- 24 set of rotors
- 26 first rotor
- 28 second rotor
- 30 first shaft
- 31 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
- 41 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
- 61 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 housing
- 196 cooling fins
- 198 bearing
- 200 snap ring
- 202 wave disc spring
- 204 stepped openings
- 300 method for regeneration
- 302 operation of the method
- 304 operation of the method
- 306 operation of the method
- 310 throttling loss regeneration mode
- 320 supercharger locked regeneration mode
- 330 supercharger unlocked regeneration mode
- 340 pumping regeneration mode
- 350 engine regeneration mode
A direction of oil
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.
Claims
1. A method for selecting between modes of regeneration of an energy storage device of a vehicle, the method comprising:
- determining operating conditions of the vehicle; and
- when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device, including selecting between a nonperformance-impacting regeneration mode and a performance-impacting regeneration mode.
2. The method of claim 1, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- opening a throttle to an engine of the vehicle;
- allowing a pressure drop across a supercharger to spin the supercharger; and
- applying torque from the supercharger to an electric motor-generator to charge the energy storage device.
3. The method of claim 2, further comprising opening a bypass valve to allow fluid to bypass the supercharger when a rapid change in fluid flow to the engine is required.
4. The method of claim 1, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- locking a supercharger of the vehicle; and
- applying negative torque from an electric motor-generator to an engine of the vehicle to support braking of the vehicle; and
- allowing the negative torque applied to the electric motor-generator to charge the energy storage device.
5. The method of claim 1, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- controlling a throttle of an engine of the vehicle to increase pressure downstream of a supercharger to cause the supercharger to brake;
- applying negative torque from an electric motor-generator to the engine of the vehicle to support braking of the vehicle; and
- allowing the negative torque applied to the electric motor-generator to charge the energy storage device.
6. The method of claim 1, wherein selecting the performance-impacting regeneration mode further comprises:
- opening a throttle to an engine of the vehicle;
- allowing a pressure drop across a supercharger to spin the supercharger;
- allowing the supercharger to apply a negative torque to the engine as the supercharger spins; and
- applying a torque from the supercharger to an electric motor-generator to charge the energy storage device.
7. The method of claim 1, wherein selecting the performance-impacting regeneration mode further comprises:
- stopping a supercharger; and
- applying torque from an engine of the vehicle to an electric motor-generator to charge the energy storage device.
8. A method for selecting between modes of regeneration of an energy storage device of a vehicle having a supercharger and an electric motor-generator, the method comprising:
- boosting an internal combustion engine of the vehicle using the supercharger;
- driving the vehicle using the electric motor-generator powered by the energy storage device; and
- selecting between regeneration operating modes to regenerate the energy storage device.
9. The method of claim 8, wherein selecting between the regeneration operating modes further comprises:
- determining operating conditions of the vehicle; and
- when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device, including selecting between a nonperformance-impacting regeneration mode and a performance-impacting regeneration mode.
10. The method of claim 9, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- opening a throttle to the engine of the vehicle;
- allowing a pressure drop across the supercharger to spin the supercharger; and
- applying torque from the supercharger to the electric motor-generator to charge the energy storage device.
11. The method of claim 10, further comprising opening a bypass valve to allow for an increase in air flow when a rapid change in a speed of the engine is required.
12. The method of claim 9, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- locking the supercharger of the vehicle;
- applying negative torque from the electric motor-generator to the engine of the vehicle to support braking of the vehicle; and
- allowing the negative torque applied to the electric motor-generator to charge the energy storage device.
13. The method of claim 9, wherein selecting the nonperformance-impacting regeneration mode further comprises:
- controlling a throttle of the engine of the vehicle to increase pressure downstream of the supercharger to cause the supercharger to brake;
- applying negative torque from the electric motor-generator to the engine of the vehicle to support braking of the vehicle; and
- allowing the negative torque applied to the electric motor-generator to charge the energy storage device.
14. The method of claim 9, wherein selecting the performance-impacting regeneration mode further comprises:
- opening a throttle to the engine of the vehicle;
- allowing a pressure drop across the supercharger to spin the supercharger; and
- allowing the supercharger to apply a negative torque to the engine as the supercharger spins; and
- applying a torque from the supercharger to the electric motor-generator to charge the energy storage device.
15. The method of claim 9, wherein selecting the performance-impacting regeneration mode further comprises:
- stopping the supercharger; and
- applying torque from the engine of the vehicle to the electric motor-generator to charge the energy storage device.
16. A method for regenerating an energy storage device of a vehicle using a supercharger, the method comprising:
- determining operating conditions of the vehicle; and
- when regeneration is appropriate based upon the operating conditions, regenerating the energy storage device using the supercharger.
17. The method of claim 16, wherein regenerating the energy storage device further comprises:
- opening a throttle to an engine of the vehicle;
- allowing a pressure drop across the supercharger to spin the supercharger; and
- applying torque from the supercharger to an electric motor-generator to charge the energy storage device.
18. The method of claim 17, further comprising opening a bypass valve to allow for an increase in air flow when a rapid change in a speed of the engine is required.
19. The method of claim 16, wherein regenerating the energy storage device further comprises:
- locking the supercharger of the vehicle;
- applying negative torque from an electric motor-generator to an engine of the vehicle to support braking of the vehicle; and
- allowing the negative torque applied to the electric motor-generator to charge the energy storage device.
20. The method of claim 16, wherein regenerating the energy storage device further comprises:
- opening a throttle to an engine of the vehicle;
- allowing a pressure drop across the supercharger to spin the supercharger; and
- allowing the supercharger to apply a negative torque to the engine as the supercharger spins; and
- applying a torque from the supercharger to an electric motor-generator to charge the energy storage device.
Type: Application
Filed: Mar 13, 2013
Publication Date: Mar 5, 2015
Inventors: Robert P. Benjey (Dexter, MI), Vasilios Tsourapas (Northville, MI)
Application Number: 14/388,527
International Classification: B60L 11/18 (20060101); B60K 6/485 (20060101); F02B 33/38 (20060101);