Title of Invention	A POWERTRAIN WITH A TORQUE CONVERTER MOUNTED GENERATOR AND TO A METHOD OF ASSEMBLING POWERTRAINS
Abstract	A torque converter-mounted generator is provided that, along with power electronics, offers at least two types of electrical power output and may be attached to a transmission without impacting the axial length of a powertrain in comparison to a powertrain with an identical transmission and a torque converter not having a generator mounted thereto. Different torque-converter mounted generators and power electronics configurations providing different combinations of electrical power voltages may be offered for use with a given transmission type, thus allowing flexibility in meeting customer needs without unduly impacting assembly of the powertrains. A method of assembling transmissions is also provided.

Title of Invention

A POWERTRAIN WITH A TORQUE CONVERTER MOUNTED GENERATOR AND TO A METHOD OF ASSEMBLING POWERTRAINS

Abstract

A torque converter-mounted generator is provided that, along with power electronics, offers at least two types of electrical power output and may be attached to a transmission without impacting the axial length of a powertrain in comparison to a powertrain with an identical transmission and a torque converter not having a generator mounted thereto. Different torque-converter mounted generators and power electronics configurations providing different combinations of electrical power voltages may be offered for use with a given transmission type, thus allowing flexibility in meeting customer needs without unduly impacting assembly of the powertrains. A method of assembling transmissions is also provided.

Full Text	POWERTRAIN WITH TORQUE CONVERTER-MOUNTED GENERATOR FOR MULTIPLE VOLTAGE ELECTRICAL POWER AND METHOD FOR ASSEMBLING SAME TECHNICAL FIELD [0001] The invention relates to a powertrain with a torque converter-mounted generator and to a method of assembling powertrains. BACKGROUND OF THE INVENTION [0002] Motor vehicles, especially those of the military or commercial type, often include power take-off units or add-on devices connected with the vehicle engine and transmission for providing electrical power for external or "offboard" uses such as powering industrial equipment or tools. Such power take-off units and add-on devices require a significantly time-consuming installation process. Additionally, the overall axial length of the transmission is typically increased significantly with the incorporation of these devices into the vehicle powertrain. The application of a specific type of transmission by different customers varies widely, as does onboard and offboard power needs. SUMMARY OF THE INVENTION [0003] A torque converter-mounted generator is provided that, along with power electronics, offers at least two electrical power output voltages and may be attached to a transmission without impacting the axial length of a powertrain in comparison to a powertrain with an identical transmission and a torque converter not having a generator mounted thereto. Different torque-converter mounted generators and power electronics configurations providing different combinations of power output voltages may be offered for use with a given transmission type, thus allowing flexibility in meeting customer needs without unduly impacting assembly of the powertrains. [0004] Specifically, a powertrain within the scope of the invention includes a transmission housed within a transmission housing, and a torque converter operatively connected with the transmission and housed within a torque converter housing. The torque converter housing is secured to the transmission housing. A generator with a rotor is secured to the torque converter. The generator also has a stator that is secured to the torque converter housing. Power electronics are operatively connected with the generator. The generator and power electronics are configured to provide electrical power at multiple voltages. Voltage may be a relatively low voltage required for powering onboard vehicle accessories, while another voltage may be at a relatively high voltage for offboard power needs. As used herein, "onboard" refers to components normally connected with the vehicle at all times, including when the vehicle is in motion, while "offboard" components are those not integral with the vehicle and typically connected to the vehicle only when it is stationary. [0005] In some embodiments, the generator may generate electrical power at two or more different voltages, such as if the stator includes first and second sets of stator segments adapted to provide the two different electrical voltages. Alternatively, the generator may generate electrical power at only one voltage that is then converted to different voltages for electrical power output by different components of the power electronics. [0006] In one embodiment, the power electronics are configured to provide electrical power to the stator to drive the rotor, thereby operating the generator in a motoring mode for starting the engine and/or providing torque to the transmission in tandem with the engine. [0007] Within the scope of the invention, the design of the torque converter- mounted generator may vary widely. For example, the stator and rotor may be configured with a radial gap or an axial gap, in which case there may be two rotors concentrically arranged with the stator and axially spaced on either side of the stator. The stator may have windings and multi-phase power outputs. The rotor may include different sets of magnets. [0008' A method of assembling powertrains includes installing a first torque converter-mounted generator on a first transmission of a first type, and operatively connecting a first configuration of power electronics to the first torque converter- mounted generator. The first torque converter-mounted generator and the first configuration of power electronics provide electrical power at least two different voltages. The method further includes installing a second torque converter-mounted generator on a second transmission of the first type, wherein the first transmission and the second transmission are substantially identical. The method further includes operatively connecting a second configuration of power electronics to the second torque converter-mounted generator. The second torque converter-mounted generator and the second configuration of power electronics provide electrical power voltages different than the two voltages provided by the first torque converter-mounted generator and the first configuration of power electronics. Notably, only one of the voltages provided by each of the powertrain embodiments need be different in order for the two voltages provided by each to be considered different (e.g., the first torque converter-mounted generator and first configuration of power electronics may offer a low voltage power of 28 volts direct current, just as the second torque converter-mounted generator and second configuration of power electronics does, but different higher voltage power (e.g., 220 volts direct current versus 270 volts direct current) may be provided by the two embodiments. Preferably, the assembly of the transmissions with the different torque converters may occur on the same assembly line in a factory. Thus, customer needs for different types of electrical power may be addressed as the powertrains are assembled. [0009] The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIGURE 1 is a schematic illustration in partial cross-sectional side view of a first powertrain including a transmission, and engine, a torque converter with a first type of generator mounted thereon, and power electronics, providing electrical power at two different voltages; [0011] FIGURE 2 is a schematic cross-sectional illustration of the torque converter-mounted generator of Figure 1; [0012] FIGURE 3 is a schematic illustration in partial cross-sectional side view of a second powertrain including a transmission of the same type of the transmission of Figure 1, an engine of the same type as the ending of Figure 1, and a torque converter with a second type of generator mounted thereon, and power electronics, providing electrical power at voltages different than the voltages provided by the generator of Figures 1 and 2; and [0013] FIGURE 4 is a schematic illustration of a third powertrain including a transmission and an engine identical to those of Figure 3, and a torque converter without a gencrator mounted thereon. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0014] Referring to the drawings, wherein like reference numbers refer to like components, figure 1 shows a powertrain 10 that includes an engine 12, such as an internal combustion engine or a diesel engine. The powertrain 10 further includes a torque converter 14 housed within a torque converter housing 16 and a transmission 18 hou -d within a transmission housing 20. The engine crankshaft 22 is connected with an input shell 26 of the torque converter 14 via a flex plate 24 or other interface secured by bolts 28 or other fastening mechanisms to the torque converter input shell 26. As is known, the torque converter 14 forms a fluid coupling between the engine 12 and the transmission 18, providing torque multiplication via an impeller or pump portion rotating with the input shell 26 that forms a viscous coupling with a turbine portion rotating with torque-transmitting mechanisms, such as synchronizers, clutches and/or brakes, to esta! ish torque transmission at various speed ratios to a transmission output member 31. [0015] A torque converter-mounted generator 34 is provided that establishes, along with multiple sets of power electronics (discussed below) multiple power outputs for offboard and/or offboard power needs. The torque converter-mounted generator 34 includes a rotor 36 secured to the torque converter 14, specifically, to the torque converter input shell 26 for rotation therewith. The generator 34 further includes a stator 38 prented to the torque converter housing 16 such that the stator 38 remains stationary with the torque converter housing 16. The rotor 36 and stator 38 are concentrically arranged about an axis of rotation of the engine crankshaft 22 and the transmission input mender 30 and define a circumferential radial air gap 32 therebetween. The engine 12 includes an engine block 40 secured by bolts 42 or other fasteners to the torque converter housing 16 The torque converter housing 16 is also secured by bolts 44 or other fasteners to the transmission housing 20. The engine block 40, torque converter housing 16 and TRASMISSION housing 20 are stationary components. Preferably, the stator 38 is different than the first output voltage, as discussed below. The stator segments 46, 48 are bolted or otherwise secured to the torque converter housing 16 with bolts 54 as indicated. [0017] The rotor 36 of the torque converter-mounted generator 34 has magnets 56 circumferentially spaced therearound. The number of magnets 56 is selected to optimize the desired first and second output voltages. The rotor 36 is secured with bolts 58 or any other fastening method to the torque converter 14 so that it rotates with the torque converter 14. The bolts 58 are shown in an exemplary arrangement only, and may be of a different number, spacing, or location than that shown. The radial air gap 32 is shown between the stator segments 46 and 48, and the rotor 36. [0018] When the engine crankshaft 22 turns, the input shell 26 and rotor 36 are turned. The magnetic flux of the rotating magnets 56 generates current flow in the windings 52 and 52A of stator 38. [0019] Referring again to Figure 1, the powertrain 10 incorporates power electronics; specifically, a first set of power electronics 60 in electrical communication with the first set of stator segments 46 as well as a second set of power electronics 62 in electrical communication with the second set of stator segments 48. Together, the first and second types of power electronics 60, 62 may be referred to as a first configuration of power electronics. The first set of stator segments 46 and the first set of power electronics 62 are configured to provide electrical power at a first voltage, such as a relatively low 28 volt direct current (VDC). The second set of stator segments 48 and the second set of power electronics 62 are configured to provide electrical power at a second voltage, such as a relatively high 270 volt direct current. The first set, or lower voltage, power electronics 60 includes a first power connection 64 connected with the first set of stator segments 52 which can function as a first power output, The first power connection 64 communicates power to a low voltage power module 66, which includes an inverter and electronic controller. The low voltage power module 66 is operable to convert the three-phase alternating current provided by the first set of stator segments 52 into power in the form of 28 volt direct current to be stored in a low voltage battery 68. The controller function of the power module 66 directs the battery 68 to provide energy to vehicle accessories 70 configured to function on power at the low voltage (e.g., 28 Volt) level. The vehicle accessories 70 may include air conditioning, audio systems, and any other onboard or offboard electrically-powered components designed to run on the low voltage power provided by the first set of power electronics. [0020] The second set of power electronics 62 includes a second power connection 72 that connects to the second set of stator segments 48 and functions as a second power output for the second, higher voltage, type of electrical power. The second power connection 72 communicates power to a high voltage rectifier and controller module 74 which functions as an export power rectifier and controller. The high voltage rectifier and controller module 74 is operable to convert the three-phase alternating current provided by the three-phase stator windings 52A into power in the form of 270 volt direct current that is provided to an external power load 76 under the control of the controller portion of the high voltage rectifier and controller module 74. The external power load 76 may include, for example, offboard industrial and utility equipment or tools, or an onboard load, such as refrigeration for a trailer in transit. [0021] Referring to Figure 3, a second embodiment of a powertrain 10A illustrates a second type of torque converter-mounted generator 34A utilized with an engine 12A and transmission 18A interconnected in the same manner as the corresponding components of Figure 1. In fact, the engine 12A is an identical type engine as engine 12 and the transmission 18A is an identical type transmission as the transmission 18. In the powertrain 10A however, the torque converter-mounted generator 34A is of a different configuration, providing different voltage outputs, than the torque converter-mounted generator 34. Thus, a transmission manufacturer can offer the transmission represented as 18 in Figure 1 and 18A in Figure 3, modified according to a customer's specific power output needs, by choosing one of the torque converter-mounted generators 34 or 34A, designed with customized low and high voltage outputs. Additionally, the transmission 18A may also be offered with a traditional torque converter 14B, i.e., one without a generator mounted thereon, as illustrated in Figure 4, as the traditional torque converter 14B and the torque converters with generators mounted thereon 14,14A, occupy essentially the same axial packaging space, with only a different torque converter housing required for each different design. [0022] The engine 12A includes an engine block 40A secured by bolts 42A or other fasteners to the torque converter housing 16A. The torque converter housing 16A is also secured by bolts 44A or other fasteners to the transmission housing 20A. The engine block 40A, torque converter housing 16A and transmission housing 20A are stationary components. [0023] Referring in more detail to Figure 3, the torque converter-mounted motor generator 34A is an axial gap air core generator that includes a stator 38A mounted to the torque converter housing 16A such that the stator 38A remains stationary with the torque converter housing 16A. The stator 38A includes multiple stator segments, circumferentially-spaced similar to those of Figure 3, allowing multiple stator segments for multiple voltage outputs at the same time with separate output terminals, as discussed below. The torque converter-mounted generator 34A also includes a first rotor 36A and a second rotor 36B secured to the torque converter HA, specifically, to the torque converter input shell 26A for rotation therewith. The rotors 36A, 36B and stator 38A are concentrically arranged about an axis of rotation of the engine crankshaft 22A and the transmission input member 30A, with the stator 38A sandwiched between the rotors 36A, 36B such that axial air gaps 32A, 32B are defined between each of the rotors 36A, 36B and the stator 38A, respectively. Each rotor has two sets of magnets 56 A and 56B spaced circumferentially therearound, each set being characterized by different strengths, inducing different current flow in the axial core windings of the stator 38A. Different voltage outputs associated with the magnets 56A, 56B are utilized to provide different types of power for onboard and/or offboard use, as described below. Those skilled in the art readily understand the construction of axial gap air core generators. [0024] The powertrain 10A incorporates a first set of power electronics 60A in electrical communication with the stator 38A via a first power connection 64A. The first set of power electronics 60A is configured for a first electrical power voltage, such as a lower voltage 24 volt direct current (VDC). The first set of power electronics 60A includes a low voltage power module 66A, including an inverter and an electronic controller, and a low voltage battery 68A operatively connected to vehicle accessories 70A. The components of the first set of power electronics 60A are configured and function similar to those like components of the first set of power electronics 60 of the powertrain 10 of Figure 2, except that the low voltage power module provides 24 volt direct current to the battery 68A. [0025] The powertrain 10A also incorporates a second set of power electronics 62A in electrical communication with the stator 38A via a second power connection 72A. Together the first and second sets of power electronics 60A, 62A, may be referred to as a second configuration of power electronics. The second set of power electronics 60A is configured for a second electrical power voltage, such as a higher voltage 220 volt direct current. The second power connection 72A communicates power to a high voltage rectifier and controller module 74A which functions as an export power rectifier and controller. The high voltage rectifier and controller module 74A is operable to convert three-phase 220 volt alternating current provided by the stator 38A into power in the form of 220 volt direct current that is provided to an external power load 76A under the control of the controller portion of the high voltage rectifier and controller module 74A. The external power load 76A may include, for example, offboard industrial and utility equipment of tools, or an onboard load, such as refrigeration for a trailer in transit. These components of the second set of power electronics 62A are configured and function similar to those like components of the second set of power electronics 62 of the powertrain 10 of Figure 1, except that the high voltage rectifier and controller module 74A provides power at 220V to the external power load 76A. [0026] The second set of power electronics 62A also includes componentry enabling the torque converter-mounted generator 34A to function as a motor to start the engine 12A or to provide power in tandem with the engine 12A to the transmission 18A, providing hybrid propulsion capability. Thus, the torque converter-mounted generator 34A may be referred to as a motor/generator. Specifically, the second set of power electronics 62A includes a high voltage alternating current to direct current power module 80A that functions as a power inverter and as an electronic controller to invert power from a high voltage alternating current, such as 220 volts alternating current, to a high voltage direct current, such as 220 volts direct current. The high voltage direct current is then stored in a high voltage battery 82A. A high voltage electronic controller 84A is configured to direct stored energy from the battery 82A to the stator 38A when operating conditions warrant starting the engine 12A, or when the engine 12A is already powering the transmission 18A and additional torque is required and may be provided by the motor/generator 34A. It should be appreciated that the direct current power module 80A, the battery 82A and the high voltage electronic controller 84A may also be employed on the powertrain 10 of Figure 2 such that the torque converter-mounted generator 34 could also function as a motor. [0027] As indicated in Figures 2 and 3, different powertrains may be constructed with the same type of transmission and engine, but with different torque converter-mounted generators connected therebetween. The choice of torque converter-mounted generator in terms of the power outputs it is configured to provide may be driven by specific customer needs. Alternatively, if onboard or offboard power is not required for a specific powertrain implementation, a powertrain 10B, configured as shown in Figure 4, may be provided with an engine 12B, a transmission 18B and a torque converter 14B, within a torque converter housing 16B, that is not equipped with a generator. The engine 12B may be of the same type as engines 12 and 12A, and the transmission 18B may be of the same type as transmissions 18 and 18A. [0028] Preferably, the power outputs of the various generators 34, 34A are common and the power electronics 60, 62, 60A, 62A are common, so that the generators and power electronics can be used for various different types of transmissions as well. Various power electronic configurations, including those of the following electric power voltages, are preferably available for connection to the common power outputs of the generators 34, 34A: 600 Volts DC, 12 Volts DC, 42 Volts DC, 110/220 Volts (60 Hz) alternating current "AC", 220 Volts (50 Hz AC), 24 Volts DC and 270 Volts DC. [0029] Accordingly, a method of assembling powertrains, described with respect to the powertrain embodiments of Figures 1-4, includes installing a first torque converter-mounted generator 34 on a first transmission 18 of a first type. This may include attaching a torque converter housing 16 to a transmission housing 20. The method further includes operatively connecting a first configuration of power electronics 60, 62 to the first torque converter-mounted generator 34, The first torque converter-mounted generator 34 and the first configuration of power electronics 60, 62 provide electric power at at least two voltages (e.g., 28VDC and 270 VDC). [0030] The method also includes installing a second torque converter-mounted generator 34A on a second transmission 18A of the first type that is substantially identical to the first transmission 18. This may include attaching a different torque converter housing 16A to a transmission housing 20A that is identical to the transmission housing 20. The method then includes operatively connecting a second configuration of power electronics 60A, 62A, to the second torque converter-mounted generator 34A. The second torque converter-mounted generator 34A and the second configuration of power electronics 60A, 62A provide electric power at voltages different than the two voltages provided by the first torque converter-mounted generator 34 and the first configuration 60, 62 of power electronics. Within the scope of the method, a torque converter 14B that does not have a generator mounted thereon may be connected with a transmission 18B identical to the transmissions 18 and 18A and with an engine 12B identical to the engines 12 and 12A. Thus, the method enables a given transmission and engine combination to be connected with different torque converters (with different types of generators, a motor/generator, or no generator mounted thereto) and different power electronic configurations (or no power electronics in the case of a torque converter without a generator) to meet a customer's specific electrical power needs. [0031] While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. CLAIMS 1. A powertrain comprising: a transmission housed within a transmission housing; a torque converter operatively connected with the transmission and housed within a torque converter housing; wherein the torque converter housing is secured to the transmission housing; a generator having a rotor secured to the torque converter and a stator secured to the torque converter housing; power electronics operatively connected with the generator; and wherein the generator and power electronics are configured to provide electrical power at multiple voltage levels. 2. The powertrain of claim 1, wherein the generator generates electrical power at at least two different voltage levels. 3. The powertrain of claim 2, wherein the stator includes first and second sets of stator segments each adapted to provide a different one of the two different voltage levels. 4. The powertrain of claim 2, wherein the stator includes multi-phase power outputs. 5. The powertrain of claim 1, wherein the generator generates electrical power at only one voltage level; and wherein the power electronics include components configured to convert said one voltage level to one of said multiple voltage levels and other components configured to convert said one voltage level to another of said multiple voltage levels. 6. The powertrain of claim 1, further comprising: an engine operatively connected to the torque converter for powering the transmission; wherein said power electronics are configured to provide electrical power to said stator to drive said rotor, thereby operating the generator in a motoring mode for at least one of starting the engine and providing power to the transmission in tandem with the engine. 7. The powertrain of claim 1, wherein the rotor and the stator are concentrically arranged to define a radial gap therebetween. 8. The powertrain of claim 2, wherein the rotor and the stator are concentrically arranged to define an axial gap therebetween. 9. The powertrain of claim 8, wherein the rotor is a first rotor and the axial gap is a first axial gap, and further comprising: a second rotor concentrically arranged with the stator to define a second axial gap therebetween; wherein the stator is arranged axially between the first rotor and the second rotor. 10. A powertrain comprising: a transmission housed within a transmission housing; a torque converter operatively connected with the transmission and housed within a torque converter housing; wherein the torque converter housing is secured to the transmission housing; a generator having a rotor secured to the torque converter and a stator secured to the torque converter housing; wherein the rotor has magnets and the stator has windings; wherein the rotor and stator are concentrically arranged with a gap therebetween; power electronics operatively connected with the generator; and wherein the rotor and stator are configured to provide electrical power at multiple voltage levels to the power electronics; and wherein the power electronics are configured to provide electrical power at other multiple voltage levels corresponding with the multiple voltage levels provided by the rotor and the stator. 11. A method of assembling powertrains, comprising: installing a first torque converter-mounted generator on a first transmission of a first type; operatively connecting a first configuration of power electronics to the first torque converter-mounted generator; wherein the first torque converter-mounted generator and the first configuration of power electronics are configured to provide at least two voltage levels of electrical power; installing a second torque converter-mounted generator on a second transmission of the first type; wherein the first transmission and the second transmission are substantially identical; and operatively connecting a second configuration of power electronics to the second torque converter-mounted generator; wherein the second torque converter- mounted generator and the second configuration of power electronics are configured to provide electrical power at voltage levels different than the voltage levels provided by the first torque converter-mounted generator and the first configuration of power electronics. 12. The method of claim 11, wherein said first torque converter- mounted generator includes a first rotor operatively connected to a first torque converter and a first stator secured to a first torque converter housing; wherein the first transmission of the first type includes a first transmission housing; wherein said second torque converter-mounted generator includes a second rotor operatively connected to a second torque converter and a second stator secured to a second torque converter housing; wherein the second transmission of the first type includes a second transmission housing substantially identical to the first transmission housing; wherein said installing the first torque converter-mounted generator on the first transmission of the first type includes attaching the first torque converter housing to the first transmission housing; and wherein said installing the second torque converter-mounted generator on the second transmission of the first type includes attaching the second torque converter housing to the second transmission housing. 13. The method of claim 11, further comprising: installing a third torque converter on a third transmission of the first type; wherein the third torque converter is characterized by an absence of a torque-converter mounted generator. A torque converter-mounted generator is provided that, along with power electronics, offers at least two types of electrical power output and may be attached to a transmission without impacting the axial length of a powertrain in comparison to a powertrain with an identical transmission and a torque converter not having a generator mounted thereto. Different torque-converter mounted generators and power electronics configurations providing different combinations of electrical power voltages may be offered for use with a given transmission type, thus allowing flexibility in meeting customer needs without unduly impacting assembly of the powertrains. A method of assembling transmissions is also provided.

Full Text

POWERTRAIN WITH TORQUE CONVERTER-MOUNTED GENERATOR FOR
MULTIPLE VOLTAGE ELECTRICAL POWER AND METHOD FOR ASSEMBLING
SAME
TECHNICAL FIELD
[0001] The invention relates to a powertrain with a torque converter-mounted
generator and to a method of assembling powertrains.
BACKGROUND OF THE INVENTION
[0002] Motor vehicles, especially those of the military or commercial type, often
include power take-off units or add-on devices connected with the vehicle engine and
transmission for providing electrical power for external or "offboard" uses such as
powering industrial equipment or tools. Such power take-off units and add-on devices
require a significantly time-consuming installation process. Additionally, the overall
axial length of the transmission is typically increased significantly with the incorporation
of these devices into the vehicle powertrain. The application of a specific type of
transmission by different customers varies widely, as does onboard and offboard power
needs.
SUMMARY OF THE INVENTION
[0003] A torque converter-mounted generator is provided that, along with power
electronics, offers at least two electrical power output voltages and may be attached to a
transmission without impacting the axial length of a powertrain in comparison to a
powertrain with an identical transmission and a torque converter not having a generator
mounted thereto. Different torque-converter mounted generators and power electronics
configurations providing different combinations of power output voltages may be offered
for use with a given transmission type, thus allowing flexibility in meeting customer
needs without unduly impacting assembly of the powertrains.
[0004] Specifically, a powertrain within the scope of the invention includes a
transmission housed within a transmission housing, and a torque converter operatively

connected with the transmission and housed within a torque converter housing. The
torque converter housing is secured to the transmission housing. A generator with a
rotor is secured to the torque converter. The generator also has a stator that is secured
to the torque converter housing. Power electronics are operatively connected with the
generator. The generator and power electronics are configured to provide electrical
power at multiple voltages. Voltage may be a relatively low voltage required for
powering onboard vehicle accessories, while another voltage may be at a relatively high
voltage for offboard power needs. As used herein, "onboard" refers to components
normally connected with the vehicle at all times, including when the vehicle is in
motion, while "offboard" components are those not integral with the vehicle and
typically connected to the vehicle only when it is stationary.
[0005] In some embodiments, the generator may generate electrical power at
two or more different voltages, such as if the stator includes first and second sets of
stator segments adapted to provide the two different electrical voltages. Alternatively,
the generator may generate electrical power at only one voltage that is then converted to
different voltages for electrical power output by different components of the power
electronics.
[0006] In one embodiment, the power electronics are configured to provide
electrical power to the stator to drive the rotor, thereby operating the generator in a
motoring mode for starting the engine and/or providing torque to the transmission in
tandem with the engine.
[0007] Within the scope of the invention, the design of the torque converter-
mounted generator may vary widely. For example, the stator and rotor may be
configured with a radial gap or an axial gap, in which case there may be two rotors
concentrically arranged with the stator and axially spaced on either side of the stator.
The stator may have windings and multi-phase power outputs. The rotor may include
different sets of magnets.
[0008' A method of assembling powertrains includes installing a first torque
converter-mounted generator on a first transmission of a first type, and operatively

connecting a first configuration of power electronics to the first torque converter-
mounted generator. The first torque converter-mounted generator and the first
configuration of power electronics provide electrical power at least two different
voltages. The method further includes installing a second torque converter-mounted
generator on a second transmission of the first type, wherein the first transmission and
the second transmission are substantially identical. The method further includes
operatively connecting a second configuration of power electronics to the second torque
converter-mounted generator. The second torque converter-mounted generator and the
second configuration of power electronics provide electrical power voltages different
than the two voltages provided by the first torque converter-mounted generator and the
first configuration of power electronics. Notably, only one of the voltages provided by
each of the powertrain embodiments need be different in order for the two voltages
provided by each to be considered different (e.g., the first torque converter-mounted
generator and first configuration of power electronics may offer a low voltage power of
28 volts direct current, just as the second torque converter-mounted generator and
second configuration of power electronics does, but different higher voltage power
(e.g., 220 volts direct current versus 270 volts direct current) may be provided by the
two embodiments. Preferably, the assembly of the transmissions with the different
torque converters may occur on the same assembly line in a factory. Thus, customer
needs for different types of electrical power may be addressed as the powertrains are
assembled.
[0009] The above features and advantages and other features and advantages of
the present invention are readily apparent from the following detailed description of the
best modes for carrying out the invention when taken in connection with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGURE 1 is a schematic illustration in partial cross-sectional side view of
a first powertrain including a transmission, and engine, a torque converter with a first

type of generator mounted thereon, and power electronics, providing electrical power at
two different voltages;
[0011] FIGURE 2 is a schematic cross-sectional illustration of the torque
converter-mounted generator of Figure 1;
[0012] FIGURE 3 is a schematic illustration in partial cross-sectional side view of
a second powertrain including a transmission of the same type of the transmission of
Figure 1, an engine of the same type as the ending of Figure 1, and a torque converter
with a second type of generator mounted thereon, and power electronics, providing
electrical power at voltages different than the voltages provided by the generator of
Figures 1 and 2; and
[0013] FIGURE 4 is a schematic illustration of a third powertrain including a
transmission and an engine identical to those of Figure 3, and a torque converter
without a gencrator mounted thereon.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Referring to the drawings, wherein like reference numbers refer to like
components, figure 1 shows a powertrain 10 that includes an engine 12, such as an
internal combustion engine or a diesel engine. The powertrain 10 further includes a
torque converter 14 housed within a torque converter housing 16 and a transmission 18
hou -d within a transmission housing 20. The engine crankshaft 22 is connected with an
input shell 26 of the torque converter 14 via a flex plate 24 or other interface secured by
bolts 28 or other fastening mechanisms to the torque converter input shell 26. As is
known, the torque converter 14 forms a fluid coupling between the engine 12 and the
transmission 18, providing torque multiplication via an impeller or pump portion rotating
with the input shell 26 that forms a viscous coupling with a turbine portion rotating with

torque-transmitting mechanisms, such as synchronizers, clutches and/or brakes, to
esta! ish torque transmission at various speed ratios to a transmission output member 31.
[0015] A torque converter-mounted generator 34 is provided that establishes,
along with multiple sets of power electronics (discussed below) multiple power outputs
for offboard and/or offboard power needs. The torque converter-mounted generator 34
includes a rotor 36 secured to the torque converter 14, specifically, to the torque
converter input shell 26 for rotation therewith. The generator 34 further includes a stator
38 prented to the torque converter housing 16 such that the stator 38 remains stationary
with the torque converter housing 16. The rotor 36 and stator 38 are concentrically
arranged about an axis of rotation of the engine crankshaft 22 and the transmission input
mender 30 and define a circumferential radial air gap 32 therebetween. The engine 12
includes an engine block 40 secured by bolts 42 or other fasteners to the torque converter
housing 16 The torque converter housing 16 is also secured by bolts 44 or other
fasteners to the transmission housing 20. The engine block 40, torque converter housing
16 and TRASMISSION housing 20 are stationary components. Preferably, the stator 38 is

different than the first output voltage, as discussed below. The stator segments 46, 48 are
bolted or otherwise secured to the torque converter housing 16 with bolts 54 as indicated.
[0017] The rotor 36 of the torque converter-mounted generator 34 has magnets 56
circumferentially spaced therearound. The number of magnets 56 is selected to optimize
the desired first and second output voltages. The rotor 36 is secured with bolts 58 or any
other fastening method to the torque converter 14 so that it rotates with the torque
converter 14. The bolts 58 are shown in an exemplary arrangement only, and may be of a
different number, spacing, or location than that shown. The radial air gap 32 is shown
between the stator segments 46 and 48, and the rotor 36.
[0018] When the engine crankshaft 22 turns, the input shell 26 and rotor 36 are
turned. The magnetic flux of the rotating magnets 56 generates current flow in the
windings 52 and 52A of stator 38.
[0019] Referring again to Figure 1, the powertrain 10 incorporates power
electronics; specifically, a first set of power electronics 60 in electrical communication
with the first set of stator segments 46 as well as a second set of power electronics 62 in
electrical communication with the second set of stator segments 48. Together, the first
and second types of power electronics 60, 62 may be referred to as a first configuration of
power electronics. The first set of stator segments 46 and the first set of power
electronics 62 are configured to provide electrical power at a first voltage, such as a
relatively low 28 volt direct current (VDC). The second set of stator segments 48 and the
second set of power electronics 62 are configured to provide electrical power at a second
voltage, such as a relatively high 270 volt direct current. The first set, or lower voltage,
power electronics 60 includes a first power connection 64 connected with the first set of
stator segments 52 which can function as a first power output, The first power
connection 64 communicates power to a low voltage power module 66, which includes
an inverter and electronic controller. The low voltage power module 66 is operable to
convert the three-phase alternating current provided by the first set of stator segments 52
into power in the form of 28 volt direct current to be stored in a low voltage battery 68.
The controller function of the power module 66 directs the battery 68 to provide energy
to vehicle accessories 70 configured to function on power at the low voltage (e.g., 28

Volt) level. The vehicle accessories 70 may include air conditioning, audio systems, and
any other onboard or offboard electrically-powered components designed to run on the
low voltage power provided by the first set of power electronics.
[0020] The second set of power electronics 62 includes a second power
connection 72 that connects to the second set of stator segments 48 and functions as a
second power output for the second, higher voltage, type of electrical power. The second
power connection 72 communicates power to a high voltage rectifier and controller
module 74 which functions as an export power rectifier and controller. The high voltage
rectifier and controller module 74 is operable to convert the three-phase alternating
current provided by the three-phase stator windings 52A into power in the form of 270
volt direct current that is provided to an external power load 76 under the control of the
controller portion of the high voltage rectifier and controller module 74. The external
power load 76 may include, for example, offboard industrial and utility equipment or
tools, or an onboard load, such as refrigeration for a trailer in transit.
[0021] Referring to Figure 3, a second embodiment of a powertrain 10A
illustrates a second type of torque converter-mounted generator 34A utilized with an
engine 12A and transmission 18A interconnected in the same manner as the
corresponding components of Figure 1. In fact, the engine 12A is an identical type
engine as engine 12 and the transmission 18A is an identical type transmission as the
transmission 18. In the powertrain 10A however, the torque converter-mounted
generator 34A is of a different configuration, providing different voltage outputs, than the
torque converter-mounted generator 34. Thus, a transmission manufacturer can offer the
transmission represented as 18 in Figure 1 and 18A in Figure 3, modified according to a
customer's specific power output needs, by choosing one of the torque
converter-mounted generators 34 or 34A, designed with customized low and high voltage
outputs. Additionally, the transmission 18A may also be offered with a traditional torque
converter 14B, i.e., one without a generator mounted thereon, as illustrated in Figure 4, as
the traditional torque converter 14B and the torque converters with generators mounted
thereon 14,14A, occupy essentially the same axial packaging space, with only a different
torque converter housing required for each different design.

[0022] The engine 12A includes an engine block 40A secured by bolts 42A or
other fasteners to the torque converter housing 16A. The torque converter housing 16A
is also secured by bolts 44A or other fasteners to the transmission housing 20A. The
engine block 40A, torque converter housing 16A and transmission housing 20A are
stationary components.
[0023] Referring in more detail to Figure 3, the torque converter-mounted motor
generator 34A is an axial gap air core generator that includes a stator 38A mounted to the
torque converter housing 16A such that the stator 38A remains stationary with the torque
converter housing 16A. The stator 38A includes multiple stator segments,
circumferentially-spaced similar to those of Figure 3, allowing multiple stator segments
for multiple voltage outputs at the same time with separate output terminals, as discussed
below. The torque converter-mounted generator 34A also includes a first rotor 36A and a
second rotor 36B secured to the torque converter HA, specifically, to the torque
converter input shell 26A for rotation therewith. The rotors 36A, 36B and stator 38A are
concentrically arranged about an axis of rotation of the engine crankshaft 22A and the
transmission input member 30A, with the stator 38A sandwiched between the rotors 36A,
36B such that axial air gaps 32A, 32B are defined between each of the rotors 36A, 36B
and the stator 38A, respectively. Each rotor has two sets of magnets 56 A and 56B spaced
circumferentially therearound, each set being characterized by different strengths,
inducing different current flow in the axial core windings of the stator 38A. Different
voltage outputs associated with the magnets 56A, 56B are utilized to provide different
types of power for onboard and/or offboard use, as described below. Those skilled in the
art readily understand the construction of axial gap air core generators.
[0024] The powertrain 10A incorporates a first set of power electronics 60A in
electrical communication with the stator 38A via a first power connection 64A. The first
set of power electronics 60A is configured for a first electrical power voltage, such as a
lower voltage 24 volt direct current (VDC). The first set of power electronics 60A
includes a low voltage power module 66A, including an inverter and an electronic
controller, and a low voltage battery 68A operatively connected to vehicle accessories
70A. The components of the first set of power electronics 60A are configured and

function similar to those like components of the first set of power electronics 60 of the
powertrain 10 of Figure 2, except that the low voltage power module provides 24 volt
direct current to the battery 68A.
[0025] The powertrain 10A also incorporates a second set of power electronics
62A in electrical communication with the stator 38A via a second power connection 72A.
Together the first and second sets of power electronics 60A, 62A, may be referred to as a
second configuration of power electronics. The second set of power electronics 60A is
configured for a second electrical power voltage, such as a higher voltage 220 volt direct
current. The second power connection 72A communicates power to a high voltage
rectifier and controller module 74A which functions as an export power rectifier and
controller. The high voltage rectifier and controller module 74A is operable to convert
three-phase 220 volt alternating current provided by the stator 38A into power in the form
of 220 volt direct current that is provided to an external power load 76A under the control
of the controller portion of the high voltage rectifier and controller module 74A. The
external power load 76A may include, for example, offboard industrial and utility
equipment of tools, or an onboard load, such as refrigeration for a trailer in transit. These
components of the second set of power electronics 62A are configured and function
similar to those like components of the second set of power electronics 62 of the
powertrain 10 of Figure 1, except that the high voltage rectifier and controller module
74A provides power at 220V to the external power load 76A.
[0026] The second set of power electronics 62A also includes componentry
enabling the torque converter-mounted generator 34A to function as a motor to start the
engine 12A or to provide power in tandem with the engine 12A to the transmission
18A, providing hybrid propulsion capability. Thus, the torque converter-mounted
generator 34A may be referred to as a motor/generator. Specifically, the second set of
power electronics 62A includes a high voltage alternating current to direct current
power module 80A that functions as a power inverter and as an electronic controller to
invert power from a high voltage alternating current, such as 220 volts alternating
current, to a high voltage direct current, such as 220 volts direct current. The high
voltage direct current is then stored in a high voltage battery 82A. A high voltage

electronic controller 84A is configured to direct stored energy from the battery 82A to
the stator 38A when operating conditions warrant starting the engine 12A, or when the
engine 12A is already powering the transmission 18A and additional torque is required
and may be provided by the motor/generator 34A. It should be appreciated that the
direct current power module 80A, the battery 82A and the high voltage electronic
controller 84A may also be employed on the powertrain 10 of Figure 2 such that the
torque converter-mounted generator 34 could also function as a motor.
[0027] As indicated in Figures 2 and 3, different powertrains may be
constructed with the same type of transmission and engine, but with different torque
converter-mounted generators connected therebetween. The choice of torque
converter-mounted generator in terms of the power outputs it is configured to provide
may be driven by specific customer needs. Alternatively, if onboard or offboard power
is not required for a specific powertrain implementation, a powertrain 10B, configured
as shown in Figure 4, may be provided with an engine 12B, a transmission 18B and a
torque converter 14B, within a torque converter housing 16B, that is not equipped with
a generator. The engine 12B may be of the same type as engines 12 and 12A, and the
transmission 18B may be of the same type as transmissions 18 and 18A.
[0028] Preferably, the power outputs of the various generators 34, 34A are
common and the power electronics 60, 62, 60A, 62A are common, so that the
generators and power electronics can be used for various different types of
transmissions as well. Various power electronic configurations, including those of the
following electric power voltages, are preferably available for connection to the
common power outputs of the generators 34, 34A: 600 Volts DC, 12 Volts DC, 42
Volts DC, 110/220 Volts (60 Hz) alternating current "AC", 220 Volts (50 Hz AC), 24
Volts DC and 270 Volts DC.
[0029] Accordingly, a method of assembling powertrains, described with
respect to the powertrain embodiments of Figures 1-4, includes installing a first torque
converter-mounted generator 34 on a first transmission 18 of a first type. This may
include attaching a torque converter housing 16 to a transmission housing 20. The

method further includes operatively connecting a first configuration of power
electronics 60, 62 to the first torque converter-mounted generator 34, The first torque
converter-mounted generator 34 and the first configuration of power electronics 60, 62
provide electric power at at least two voltages (e.g., 28VDC and 270 VDC).
[0030] The method also includes installing a second torque converter-mounted
generator 34A on a second transmission 18A of the first type that is substantially
identical to the first transmission 18. This may include attaching a different torque
converter housing 16A to a transmission housing 20A that is identical to the
transmission housing 20. The method then includes operatively connecting a second
configuration of power electronics 60A, 62A, to the second torque converter-mounted
generator 34A. The second torque converter-mounted generator 34A and the second
configuration of power electronics 60A, 62A provide electric power at voltages
different than the two voltages provided by the first torque converter-mounted generator
34 and the first configuration 60, 62 of power electronics. Within the scope of the
method, a torque converter 14B that does not have a generator mounted thereon may be
connected with a transmission 18B identical to the transmissions 18 and 18A and with
an engine 12B identical to the engines 12 and 12A. Thus, the method enables a given
transmission and engine combination to be connected with different torque converters
(with different types of generators, a motor/generator, or no generator mounted thereto)
and different power electronic configurations (or no power electronics in the case of a
torque converter without a generator) to meet a customer's specific electrical power
needs.
[0031] While the best modes for carrying out the invention have been described
in detail, those familiar with the art to which this invention relates will recognize various
alternative designs and embodiments for practicing the invention within the scope of the
appended claims.

CLAIMS
1. A powertrain comprising:
a transmission housed within a transmission housing;
a torque converter operatively connected with the transmission and housed
within a torque converter housing; wherein the torque converter housing is secured to the
transmission housing;
a generator having a rotor secured to the torque converter and a stator
secured to the torque converter housing;
power electronics operatively connected with the generator; and
wherein the generator and power electronics are configured to provide
electrical power at multiple voltage levels.
2. The powertrain of claim 1, wherein the generator generates
electrical power at at least two different voltage levels.
3. The powertrain of claim 2, wherein the stator includes first and
second sets of stator segments each adapted to provide a different one of the two different
voltage levels.
4. The powertrain of claim 2, wherein the stator includes multi-phase
power outputs.
5. The powertrain of claim 1, wherein the generator generates
electrical power at only one voltage level; and wherein the power electronics include
components configured to convert said one voltage level to one of said multiple voltage
levels and other components configured to convert said one voltage level to another of
said multiple voltage levels.

6. The powertrain of claim 1, further comprising:
an engine operatively connected to the torque converter for powering the
transmission;
wherein said power electronics are configured to provide electrical power
to said stator to drive said rotor, thereby operating the generator in a motoring mode for
at least one of starting the engine and providing power to the transmission in tandem with
the engine.
7. The powertrain of claim 1, wherein the rotor and the stator are
concentrically arranged to define a radial gap therebetween.
8. The powertrain of claim 2, wherein the rotor and the stator are
concentrically arranged to define an axial gap therebetween.
9. The powertrain of claim 8, wherein the rotor is a first rotor and the
axial gap is a first axial gap, and further comprising:
a second rotor concentrically arranged with the stator to define a second
axial gap therebetween; wherein the stator is arranged axially between the first rotor and
the second rotor.
10. A powertrain comprising:
a transmission housed within a transmission housing;
a torque converter operatively connected with the transmission and housed
within a torque converter housing; wherein the torque converter housing is secured to the
transmission housing;

a generator having a rotor secured to the torque converter and a stator
secured to the torque converter housing; wherein the rotor has magnets and the stator has
windings; wherein the rotor and stator are concentrically arranged with a gap
therebetween;
power electronics operatively connected with the generator; and
wherein the rotor and stator are configured to provide electrical power at
multiple voltage levels to the power electronics; and wherein the power electronics are
configured to provide electrical power at other multiple voltage levels corresponding with
the multiple voltage levels provided by the rotor and the stator.
11. A method of assembling powertrains, comprising:
installing a first torque converter-mounted generator on a first
transmission of a first type;
operatively connecting a first configuration of power electronics to the
first torque converter-mounted generator; wherein the first torque converter-mounted
generator and the first configuration of power electronics are configured to provide at
least two voltage levels of electrical power;
installing a second torque converter-mounted generator on a second
transmission of the first type; wherein the first transmission and the second transmission
are substantially identical; and
operatively connecting a second configuration of power electronics to the
second torque converter-mounted generator; wherein the second torque converter-
mounted generator and the second configuration of power electronics are configured to
provide electrical power at voltage levels different than the voltage levels provided by the
first torque converter-mounted generator and the first configuration of power electronics.
12. The method of claim 11, wherein said first torque converter-
mounted generator includes a first rotor operatively connected to a first torque converter

and a first stator secured to a first torque converter housing; wherein the first transmission
of the first type includes a first transmission housing;
wherein said second torque converter-mounted generator includes a
second rotor operatively connected to a second torque converter and a second stator
secured to a second torque converter housing; wherein the second transmission of the
first type includes a second transmission housing substantially identical to the first
transmission housing;
wherein said installing the first torque converter-mounted generator on the
first transmission of the first type includes attaching the first torque converter housing to
the first transmission housing; and
wherein said installing the second torque converter-mounted generator on
the second transmission of the first type includes attaching the second torque converter
housing to the second transmission housing.
13. The method of claim 11, further comprising:
installing a third torque converter on a third transmission of the first type;
wherein the third torque converter is characterized by an absence of a torque-converter
mounted generator.

A torque converter-mounted generator is provided that, along with power electronics, offers at least two types of electrical power output and may be attached to a transmission without impacting the axial length of a powertrain in comparison to a powertrain with an identical transmission and a torque converter not having a generator mounted thereto. Different torque-converter mounted generators and power electronics configurations providing different combinations of electrical power voltages may be
offered for use with a given transmission type, thus allowing flexibility in meeting
customer needs without unduly impacting assembly of the powertrains. A method of assembling transmissions is also provided.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=7Bq3TGa9qgz11FX4B4mWaA==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

271350

Indian Patent Application Number

1369/KOL/2008

PG Journal Number

08/2016

Publication Date

19-Feb-2016

Grant Date

17-Feb-2016

Date of Filing

14-Aug-2008

Name of Patentee

GM GLOBAL TECHNOLOGY OPERATIONS, INC.

Applicant Address

300 GM RENAISSANCE CENTER, DETROIT,MICHIGAN 48265-3000

Inventors:

#	Inventor's Name	Inventor's Address
1	ROBERT FRANKLIN COMBS	9750 WEST COUNTRY ROAD 800, NORTH MULBERRY, IN 46058
2	LEROY K. JOHNSON	4188 STONERIDGE DRIVE BROWNSBURG, IN 46112
3	DAVID J. SAGARS	7710 WARBLER DRIVE INDIANAPOLIS, IN 46256

PCT International Classification Number

H02P15/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	11/856,755	2007-09-18	U.S.A.