Inline electromechanical variable transmission system

A drive system includes a first planetary gear set coupled to a first electromagnetic device, a second planetary gear set coupled to a second electromagnetic device and directly coupled to the first planetary gear set, an engine directly coupled to the first planetary gear set with a connecting shaft, and an output shaft coupled to the first planetary gear set. The first and second electromagnetic devices include a first shaft and a second shaft, respectively. The connecting shaft extends through the second electromagnetic device and through the second planetary gear set to the first planetary gear set. The first shaft, the second shaft, the first planetary gear set, the second planetary gear set, the connecting shaft, and the output shaft are radially aligned, forming a straight-thru transmission arrangement.

BACKGROUND

Internal combustion engine vehicles, hybrid vehicles, and electric vehicles, among other types of vehicles, include transmissions. Traditional vehicle transmissions use gears and gear trains to provide speed and torque conversions from a rotating power source (e.g., an engine, a motor, etc.) to another device (e.g., a drive shaft, wheels of a vehicle, etc.). Transmissions include multiple gear ratios selectively coupled to the rotating power source with a mechanism. The mechanism may also selectively couple an output to the various gear ratios.

SUMMARY

One exemplary embodiment relates to a drive system for a vehicle. The drive system includes a first planetary gear set, a second planetary gear set directly coupled to the first planetary gear set, an engine directly coupled to the first planetary gear set with a connecting shaft, a first electromagnetic device coupled to the first planetary gear set, a second electromagnetic device directly coupled to the second planetary gear set, and an output shaft coupled to the first planetary gear set. The first planetary gear set, the second planetary gear set, and the connecting shaft are radially aligned. The first electromagnetic device includes a first shaft, and the second electromagnetic device includes a second shaft. The first shaft and the second shaft are radially aligned with the first planetary gear set, the second planetary gear set, and the connecting shaft. The connecting shaft extends through the second electromagnetic device and through the second planetary gear set to the first planetary gear set. The output shaft is radially aligned with the first planetary gear set, the second planetary gear set, and the connecting shaft to thereby form a straight-thru transmission arrangement.

Another exemplary embodiment relates to a drive system for a vehicle. The drive system includes a first gear set, a second gear set, a connecting shaft coupling an engine to the first gear set, a first electromagnetic device coupled to the first gear set, a second electromagnetic device coupled to the second gear set, and an output shaft. The first gear set includes a first sun gear, a first ring gear, a first plurality of planetary gears coupling the first sun gear to the first ring gear, and a first carrier rotationally supporting the first plurality of planetary gears. The second gear set includes a second sun gear, a second ring gear, a second plurality of planetary gears coupling the second sun gear to the second ring gear, and a second carrier rotationally supporting the second plurality of planetary gears. The first carrier is directly coupled to the second carrier. The output shaft is directly coupled to the first carrier and configured to transport power from the first electromagnetic device, the second electromagnetic device, and the engine to a tractive element of the vehicle. The output shaft is aligned with the connecting shaft, the first electromagnetic device, and the second electromagnetic device to thereby form a straight-thru transmission arrangement

Another exemplary embodiment relates to a vehicle that includes a multi-mode transmission, an engine, and a drive axle. The multi-mode transmission includes a first gear set including a planetary gear set having a planetary gear carrier, a second gear set, a first motor/generator coupled to the first gear set, a second motor/generator coupled to the second gear set, and an output shaft directly coupled to the planetary gear carrier of the first gear set and configured to selectively receive rotational mechanical energy from the first motor/generator and the second motor/generator. The planetary gear carrier and the second gear set are directly coupled. The engine is directly coupled to the first gear set and selectively coupled to the second gear set. The drive axle is coupled to the output shaft of the multi-mode transmission.

The invention is capable of other embodiments and of being carried out in various ways. Alternative exemplary embodiments relate to other features and combinations of features as may be recited herein.

DETAILED DESCRIPTION

According to an exemplary embodiment, a multi-mode inline electromechanical variable transmission is provided as part of a vehicle and is selectively reconfigurable between a plurality of operating modes. The vehicle may also include an engine and one or more tractive elements (e.g., wheel and tire assemblies, etc.). The multi-mode inline electromechanical variable transmission may include a first electromagnetic device and a second electromagnetic device. In one embodiment, at least one of the first electromagnetic device and the second electromagnetic device provides rotational mechanical energy to start the engine. In another embodiment, the engine provides a rotational mechanical energy input to both the first and second electromagnetic devices such that each operates as a generator to generate electrical energy. In still other embodiments, one of the first electromagnetic device and the second electromagnetic device are configured to receive a rotational mechanical energy output from the engine and provide an electrical energy output to power a control system and/or the other electromagnetic device. According to an exemplary embodiment, the multi-mode inline electromechanical variable transmission has a compact design that facilitates direct replacement of traditional inline transmissions (e.g., mechanical transmissions, transmissions without electromagnetic devices, etc.) used in front engine applications. Thus, the multi-mode inline electromechanical variable transmission may be installed during a new vehicle construction or installed to replace a conventional transmission of a front engine vehicle (e.g., as opposed to replacing a traditional midship transfer case, etc.). The multi-mode inline electromechanical variable transmission may additionally or alternatively be installed as part of a rear-engine vehicle (e.g., a bus, etc.).

According to the exemplary embodiment shown inFIGS. 1-2, a vehicle10includes an engine20coupled to a transmission, shown as transmission30. In one embodiment, engine20is configured to combust fuel and provide a mechanical energy input to transmission30. By way of example, engine20may be configured to provide a rotational mechanical energy input to transmission30. As shown inFIGS. 1-2, transmission30includes a first electrical machine, electromagnetic device, and/or motor/generator, shown as first electromagnetic device40, and a second electrical machine, electromagnetic device, and/or motor/generator, shown as second electromagnetic device50. According to an exemplary embodiment, vehicle10is configured as a rear engine vehicle and transmission30is configured as a multi-mode inline electromechanical transmission. In other embodiments, vehicle10is configured as a mid-engine vehicle or a front engine vehicle.

Referring again to the exemplary embodiment shown inFIG. 1, vehicle10includes a front axle, shown as front axle60, and a rear axle, shown as rear axle70. As shown inFIG. 1, front axle60includes a pair of tractive elements, shown as tires62, coupled to a front differential, shown as front differential64. Rear axle70includes a pair of tractive elements, shown as tires72, coupled to a rear differential, shown as rear differential74, according to an exemplary embodiment. According to the exemplary embodiment shown inFIG. 1, front differential64is coupled to transmission30with a front axle driveshaft66, and rear differential74is coupled to transmission30with a rear axle driveshaft76. While shown as coupled to tires62and tires72, front differential64and rear differential74may be coupled to various other types of tractive elements (e.g., tracks, etc.), according to alternative embodiments. As shown inFIG. 1, front axle driveshaft66and rear axle driveshaft76are configured to transport power from first electromagnetic device40, second electromagnetic device50, and engine20to tires62and tires72, respectively. Vehicle10may include a plurality of front differentials64that may be coupled and/or a plurality of rear differentials74that may be coupled, according to various alternative embodiments. In some embodiments, transmission30is selectively coupled (e.g., via a clutch mechanism, coupling mechanism, etc.) to at least one of the front axle driveshaft66and the rear axle driveshaft76(e.g., to reconfigure vehicle10into a front-wheel-drive configuration, a rear-wheel-drive configuration, an all-wheel-drive configuration, a four-wheel-drive configuration, etc.).

Engine20may be any source of rotational mechanical energy that is derived from a stored energy source. The stored energy source is disposed onboard vehicle10, according to an exemplary embodiment. The stored energy source may include a liquid fuel or a gaseous fuel, among other alternatives. In one embodiment, engine20includes an internal combustion engine configured to be powered by at least one of gasoline, natural gas, and diesel fuel. According to various alternative embodiments, engine20includes at least one of a turbine, a fuel cell, and an electric motor, or still another device. According to one exemplary embodiment, engine20includes a twelve liter diesel engine capable of providing between approximately 400 horsepower and approximately 600 horsepower and between approximately 400 foot pounds of torque and approximately 2000 foot pounds of torque. In one embodiment, engine20has a rotational speed (e.g., a rotational operational range, etc.) of between 0 and 2,100 revolutions per minute. Engine20may be operated at a relatively constant speed (e.g., 1,600 revolutions per minute, etc.). In one embodiment, the relatively constant speed is selected based on an operating condition of engine20(e.g., an operating speed relating to a point of increased fuel efficiency, etc.).

In one embodiment, at least one of first electromagnetic device40and second electromagnetic device50provide a mechanical energy input to another portion of transmission30. By way of example, at least one of first electromagnetic device40and second electromagnetic device50may be configured to provide a rotational mechanical energy input to another portion of transmission30(i.e., at least one of first electromagnetic device40and second electromagnetic device50may operate as a motor, etc.). At least one of first electromagnetic device40and second electromagnetic device50may receive a mechanical energy output from at least one of engine20and another portion of transmission30. By way of example, at least one of first electromagnetic device40and second electromagnetic device50may be configured to receive a rotational mechanical energy output from at least one of engine20and another portion of transmission30and provide an electrical energy output (i.e., at least one of first electromagnetic device40and second electromagnetic device50may operate as a generator, etc.). According to an exemplary embodiment, first electromagnetic device40and second electromagnetic device50are capable of both providing mechanical energy and converting a mechanical energy input into an electrical energy output (i.e., selectively operate as a motor and a generator, etc.). The operational condition of first electromagnetic device40and second electromagnetic device50(e.g., as a motor, as a generator, etc.) may vary based on a mode of operation associated with transmission30.

According to the exemplary embodiment shown inFIG. 2, a drive system for a vehicle, shown as drive system100, includes engine20, transmission30, first electromagnetic device40, and second electromagnetic device50. Transmission30may include first electromagnetic device40and second electromagnetic device50. As shown inFIG. 2, transmission30includes a first power transmission device or gear set, shown as power split planetary110, and a second power transmission device or gear set, shown as output planetary120. In one embodiment, power split planetary110and output planetary120are positioned outside of (e.g., on either side of, sandwiching, not between, etc.) first electromagnetic device40and second electromagnetic device50. As shown inFIG. 2, one or both of power split planetary110and output planetary120are disposed between (e.g., sandwiched by, etc.) first electromagnetic device40and second electromagnetic device50.

Referring to the exemplary embodiment shown inFIG. 2, power split planetary110is a planetary gear set that includes a sun gear112, a ring gear114, and a plurality of planetary gears116. The plurality of planetary gears116couple sun gear112to ring gear114, according to an exemplary embodiment. As shown inFIG. 2, a carrier118rotationally supports the plurality of planetary gears116. In one embodiment, first electromagnetic device40is directly coupled to sun gear112such that power split planetary110is coupled to first electromagnetic device40. By way of example, first electromagnetic device40may include or be coupled to a shaft (e.g., a first shaft, an input shaft, an output shaft, etc.) directly coupled to sun gear112.

Referring still to the exemplary embodiment shown inFIG. 2, output planetary120is a planetary gear set that includes a sun gear122, a ring gear124, and a plurality of planetary gears126. The plurality of planetary gears126couple sun gear122to ring gear124, according to an exemplary embodiment. As shown inFIG. 2, a carrier128rotationally supports the plurality of planetary gears126. In one embodiment, second electromagnetic device50is directly coupled to sun gear122such that output planetary120is coupled to second electromagnetic device50. By way of example, second electromagnetic device50may include or be coupled to a shaft (e.g., a second shaft, an input shaft, an output shaft, etc.) directly coupled to sun gear122. Carrier118is directly coupled to carrier128, thereby coupling power split planetary110to output planetary120, according to the exemplary embodiment shown inFIG. 2. In one embodiment, directly coupling carrier118to carrier128synchronizes the rotational speeds of carrier118and carrier128.

Carrier118is directly rotationally coupled to an output with a shaft, shown as output shaft32, according to the exemplary embodiment shown inFIG. 2. Output shaft32may be coupled to at least one of rear axle driveshaft76and front axle driveshaft66. By way of example, output shaft32may be coupled to a transfer case and/or rear axle driveshaft76where transmission30is installed in place of a traditional, mechanical, straight-thru transmission. In another embodiment, the output is a PTO output, and output shaft32is coupled thereto. A clutch assembly may be engaged and disengaged to selectively couple at least one of front axle driveshaft66, a transfer case, and rear axle driveshaft76to output shaft32of transmission30(e.g., to facilitate operation of a vehicle in a rear-wheel-drive mode, an all-wheel-drive mode, a four-wheel-drive mode, a front-wheel-drive mode, etc.). As shown inFIG. 2, the transmission30includes an auxiliary shaft, shown as jack shaft34. In some embodiments, jack shaft34is offset (e.g., radially offset) from first electromagnetic device40, second electromagnetic machine50, power split planetary110, and/or output planetary120. As shown inFIG. 2, transmission30includes a shaft, shown as connecting shaft36. A clutch, shown as neutral clutch22is positioned to selectively couple engine20to connecting shaft36. Neutral clutch22may be a component of engine20or transmission30or a separate component. According to an exemplary embodiment, neutral clutch22and connecting shaft36directly couple engine20to power split planetary110. In one embodiment, neutral clutch22and connecting shaft36directly couple engine20with ring gear114of power split planetary110. According to an exemplary embodiment, power split planetary110is at least one of directly coupled to and directly powers a power takeoff (“PTO”) (e.g., a live PTO, etc.). By way of example, ring gear114and/or carrier118of power split planetary110may be at least one of directly coupled to and directly power the PTO. According to an alternative embodiment, neutral clutch22is omitted, and connecting shaft36is directly coupled to engine20.

As shown inFIG. 2, transmission30includes a first clutch, shown as input coupled clutch140. Input coupled clutch140is positioned to selectively couple second electromagnetic device50with engine20, according to an exemplary embodiment. Input coupled clutch140may thereby selectively couple engine20to output planetary120. As shown inFIG. 2, connecting shaft36extends from neutral clutch22, through input coupled clutch140and second electromagnetic device50, and through output planetary120to power split planetary110. Input coupled clutch140may selectively couple second electromagnetic device50with connecting shaft36. Accordingly, input coupled clutch140may selectively couple connecting shaft36to sun gear122of output planetary120. According to an exemplary embodiment, first electromagnetic device40and second electromagnetic device50(e.g., input/output shafts thereof, etc.) are aligned (e.g., radially aligned, etc.) with power split planetary110, output planetary120, connecting shaft36, and/or output shaft32(e.g., centerlines thereof are aligned, to thereby form a straight-thru or inline transmission arrangement, etc.).

Jack shaft34is rotationally coupled to carrier118of power split planetary110and thereby to output shaft32. According to the exemplary embodiment shown inFIG. 2, transmission30further includes a second clutch, shown as output coupled clutch150. Output coupled clutch150is positioned to selectively couple jackshaft34to ring gear124of output planetary120. In some embodiments, jack shaft34is rotationally coupled (e.g., selectively rotationally coupled, etc.) to one or more outputs, shown as PTO outputs80(e.g., to drive one or more hydraulic pumps, to power one or more hydraulic systems, to power one or more electrical power generation systems, to power one or more pneumatic systems, etc.). In other embodiments, the one or more outputs are used to power (e.g., drive, etc.) a vehicle with which transmission30is associated.

Transmission30may further include a third clutch, shown inFIG. 2as secondary output clutch42. In other embodiments, secondary output clutch42is omitted. Secondary output clutch42is positioned to selectively couple first electromagnetic device40with output shaft32, according to an exemplary embodiment. Secondary output clutch42may thereby selectively couple output shaft32and carrier118to sun gear112of power split planetary110. As shown inFIG. 2, output shaft32extends from power split planetary110, through first electromagnetic device40, and out through secondary output clutch42. In other embodiments, secondary output clutch42is omitted.

In some embodiments, neutral clutch22is biased into an engaged position (e.g., with a spring, etc.) and selectively disengaged (e.g., with application of pressurized hydraulic fluid, etc.). In some embodiments, input coupled clutch140is biased into a disengaged position (e.g., with a spring, etc.) and selectively engaged (e.g., with application of pressurized hydraulic fluid, etc.). In some embodiments, output coupled clutch150is biased into a disengaged position (e.g., with a spring, etc.) and selectively engaged (e.g., with application of pressurized hydraulic fluid, etc.). In some embodiments, secondary output clutch42is biased into a disengaged position (e.g., with a spring, etc.) and selectively engaged (e.g., with application of pressurized hydraulic fluid, etc.). In other embodiments, one or more of neutral clutch22, input coupled clutch140, output coupled clutch150, and secondary output clutch42are hydraulically-biased and spring released.

Referring again to the exemplary embodiment shown inFIG. 2, transmission30includes a brake, shown as output brake170. Output brake170is positioned to selectively inhibit the movement of at least a portion of output planetary120(e.g., ring gear124, etc.), according to an exemplary embodiment. In one embodiment, output brake170is biased into a disengaged position (e.g., with a spring, etc.) and selectively engaged (e.g., with application of pressurized hydraulic fluid, etc.). In other embodiments, output brake170is hydraulically-biased and spring released. In still other embodiments, the components of transmission30are still otherwise engaged and disengaged (e.g., pneumatically, etc.). By way of example, output brake170and output coupled clutch150may be engaged simultaneously, providing a driveline brake such that rotational movement of at least one of output planetary120(e.g., ring gear124, etc.), power split planetary110(e.g., carrier118, etc.), jack shaft34, and output shaft32are selectively limited.

As shown inFIG. 2, transmission30includes a gear set180that couples carrier118and carrier128to jack shaft34. In one embodiment, gear set180includes a first gear, shown as gear182, in meshing engagement with a second gear, shown as gear184. As shown inFIG. 2, gear182is rotatably coupled to carrier118and carrier128. By way of example, gear182may be fixed to a component (e.g., shaft, tube, etc.) that couples carrier118and carrier128. As shown inFIG. 2, gear184is rotatably coupled to jack shaft34. By way of example, gear184may be fixed directly to the jack shaft34.

According to an exemplary embodiment, transmission30includes a gear set, shown as gear set190, that couples output planetary120to jack shaft34. As shown inFIG. 2, gear set190includes a first gear, shown as gear192, coupled to ring gear124of output planetary120. Gear192is in meshing engagement with a second gear, shown as gear194, according to an exemplary embodiment. As shown inFIG. 2, gear194is coupled to a third gear, shown as gear196. Gear194may reverse the rotation direction of an output provided by gear192(e.g., gear194may facilitate rotating jack shaft34in the same direction as that of gear192, etc.). In other embodiments, gear192is directly coupled with gear196. By way of example, gear set190may not include gear194, and gear192may be directly coupled to (e.g., in meshing engagement with, etc.) gear196. As shown inFIG. 2, output coupled clutch150is positioned to selectively couple gear196with output shaft32when engaged. With output coupled clutch150disengaged, relative movement (e.g., rotation, etc.) may occur between gear196and jack shaft34. By way of example, output coupled clutch150may be engaged to couple ring gear124to jack shaft34. Output brake170is positioned to selectively limit the movement of gear192when engaged to thereby also limit the movement of ring gear124, gear194, and gear196.

According to the exemplary embodiment shown inFIG. 3, a control system200for a vehicle (e.g., vehicle10, etc.) includes a controller210. In one embodiment, controller210is configured to selectively engage, selectively disengage, or otherwise communicate with components of the vehicle according to various modes of operation. As shown inFIG. 3, controller210is coupled to engine20. In one embodiment, controller210is configured to selectively engage engine20(e.g., interface with a throttle thereof, etc.) such that an output of engine20rotates at a target rate. Controller210is coupled to first electromagnetic device40and second electromagnetic device50, according to an exemplary embodiment, and may send and receive signals therewith. By way of example, controller210may send command signals relating to at least one of a target mode of operation, a target rotational speed, and a target rotation direction for first electromagnetic device40and second electromagnetic device50. As shown inFIG. 3, first electromagnetic device40and second electromagnetic device50are electrically coupled (e.g., by an electrical power transmission system, etc.). By way of example, power generated by first electromagnetic device40may be utilized by second electromagnetic device50(e.g., to provide an output torque as a motor, etc.), or power generated by second electromagnetic device50may be utilized by first electromagnetic device40(e.g., to provide an output torque as a motor, etc.). Controller210is configured to selectively engage and selectively disengage neutral clutch22, secondary output clutch42, input coupled clutch140, output coupled clutch150, and output brake170directly or by interacting with another component (e.g., a pump, a valve, a solenoid, a motor, etc.).

According to an exemplary embodiment, the drive system100includes an energy storage device (e.g., a battery, etc.). In such embodiments, the battery may be charged and recharged by an electromagnetic device that is generating power. The battery may supply the electromagnetic device that is motoring the vehicle to propel the vehicle. In some embodiments, the battery may always be utilized as part of the drive system100. In other embodiments, the battery may be used only when excess generated power must be stored or excess power is required to motor the vehicle.

According to alternative embodiments, drive system100may be configured to operate with first electromagnetic device40and second electromagnetic device50, and no additional sources of electrical power. Additional sources of electrical power include, for example, a battery and other energy storage devices. Without an energy storage device, first electromagnetic device40and second electromagnetic device50may operate in power balance. One of the electromagnetic devices may provide all of the electrical power required by the other electromagnetic device (as well as the electrical power required to offset power losses). First electromagnetic device40and second electromagnetic device50may operate without doing either of (a) providing electrical power to an energy storage device or (b) consuming electrical power from an energy storage device. Thus, the sum of the electrical power produced or consumed by first electromagnetic device40, the electrical power produced or consumed by second electromagnetic device50, and electrical power losses may be zero. According to the embodiment ofFIGS. 1-3, two electromagnetic devices are shown. In other embodiments, the system includes three or more electromagnetic devices.

According to the exemplary embodiment shown inFIG. 3, control system200includes a user interface220that is coupled to controller210. In one embodiment, user interface220includes a display and an operator input. The display may be configured to display a graphical user interface, an image, an icon, or still other information. In one embodiment, the display includes a graphical user interface configured to provide general information about the vehicle (e.g., vehicle speed, fuel level, warning lights, etc.). The graphical user interface may be configured to also display a current mode of operation, various potential modes of operation, or still other information relating to transmission30and/or drive system100. By way of example, the graphical user interface may be configured to provide specific information regarding the operation of drive system100(e.g., whether neutral clutch22, secondary output clutch42, input coupled clutch140, output coupled clutch150, and/or output brake170are engaged or disengaged, a fault condition where at least one of neutral clutch22, secondary output clutch42, input coupled clutch140, output coupled clutch150, and/or output brake170fail to engage or disengage in response to a command signal, etc.).

The operator input may be used by an operator to provide commands to at least one of engine20, transmission30, first electromagnetic device40, second electromagnetic device50, and drive system100or still another component of the vehicle. The operator input may include one or more buttons, knobs, touchscreens, switches, levers, or handles. In one embodiment, an operator may press a button to change the mode of operation for at least one of transmission30, and drive system100, and the vehicle. The operator may be able to manually control some or all aspects of the operation of transmission30using the display and the operator input. It should be understood that any type of display or input controls may be implemented with the systems and methods described herein.

Controller210may be implemented as a general-purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a digital-signal-processor (DSP), circuits containing one or more processing components, circuitry for supporting a microprocessor, a group of processing components, or other suitable electronic processing components. According to the exemplary embodiment shown inFIG. 3, controller210includes a processing circuit212and a memory214. Processing circuit212may include an ASIC, one or more FPGAs, a DSP, circuits containing one or more processing components, circuitry for supporting a microprocessor, a group of processing components, or other suitable electronic processing components. In some embodiments, processing circuit212is configured to execute computer code stored in memory214to facilitate the activities described herein. Memory214may be any volatile or non-volatile computer-readable storage medium capable of storing data or computer code relating to the activities described herein. According to an exemplary embodiment, memory214includes computer code modules (e.g., executable code, object code, source code, script code, machine code, etc.) configured for execution by processing circuit212. Memory214includes various actuation profiles corresponding to modes of operation (e.g., for transmission30, for drive system100, for a vehicle, etc.), according to an exemplary embodiment. In some embodiments, controller210may represent a collection of processing devices (e.g., servers, data centers, etc.). In such cases, processing circuit212represents the collective processors of the devices, and memory214represents the collective storage devices of the devices.

Referring next to the exemplary embodiments shown inFIGS. 4-12, transmission30is configured to operate according to a plurality of modes of operation. Various modes of operation for transmission30are identified below in Table 1. In other embodiments, a vehicle having transmission30is configured to operate according to the various modes of operation shown inFIGS. 4-12and identified below in Table 1.

As shown in Table 1, an “X” represents a component of drive system100(e.g., output brake170, input coupled clutch140, etc.) that is engaged or closed during the respective modes of operation. Secondary output clutch42is disengaged in each of the modes shown in Table 1.

In each of the modes shown in Table 1 andFIGS. 4-12, neutral clutch22is engaged. When engaged, neutral clutch22couples engine20to transmission30. When disengaged, neutral clutch22decouples engine20from transmission30. Accordingly, neutral clutch22may be used to isolate engine20from transmission30. Neutral clutch22may facilitate maintenance or towing of vehicle10. Further, with neutral clutch22disengaged, electromagnetic device40and/or electromagnetic device50may be used to drive output shaft32and/or jack shaft34(e.g., to drive one or more PTO outputs80) independent of engine20(e.g., without engine20running).

Throughout each of the modes shown in Table 1 andFIGS. 4-12, secondary output clutch42is disengaged. When engaged, secondary output clutch42limits rotation of output shaft32and carrier118relative to sun gear112, thereby preventing rotation of the planetary gears116about central axes thereof. Accordingly, secondary output clutch42limits the rotation of ring gear114relative relative to carrier118, such that rotation of connecting shaft36causes a corresponding rotation of output shaft32and electromagnetic device40. According to an exemplary embodiment, an energy flow path with only the neutral clutch22and the secondary output clutch42engaged includes: engine20providing a rotational mechanical energy input to connecting shaft36through the neutral clutch22; connecting shaft36conveying the rotational mechanical energy to ring gear114; ring gear114conveying the rotational mechanical energy to the plurality of planetary gears116; planetary gears116causing rotation of carrier118and sun gear112(e.g., planetary gears116may not rotate relative to carrier118or sun gear112because of the coupling caused by secondary output clutch42, etc.); sun gear112driving first electromagnetic device40such that it operates as a generator (e.g., generates electrical energy, etc.); and carrier118driving the output shaft32. With secondary output clutch42engaged, ring gear124and sun gear122may rotate freely such that second electromagnetic device50may rotate independently of engine20.

As shown inFIGS. 4 and 5, transmission30is selectively reconfigured into neutral/startup modes. The neutral/startup mode may provide a true neutral for transmission30. In one embodiment, at least one of first electromagnetic device40and second electromagnetic device50include and/or are coupled to an energy storage device (e.g., a capacitor, a battery, etc.) configured to store energy (e.g., electrical energy, chemical energy, etc.) associated with drive system100. In one embodiment, rotation of first electromagnetic device40rotates connecting shaft36to start engine20(e.g., with neutral clutch22, output coupled clutch150, and output brake170engaged, etc.). In another embodiment, rotation of second electromagnetic device50rotates connecting shaft36to start engine20(e.g., with neutral clutch22and input coupled clutch140engaged, etc.). First electromagnetic device40or second electromagnetic device50may be configured to use the stored energy to start engine20by providing a rotational mechanical energy input (e.g., a torque, etc.) to engine20through connecting shaft36.

In an alternative embodiment, engine20includes a traditional starting mechanism (e.g., a starter motor, etc.) configured to start engine20(e.g., in response to a vehicle start request, in response to an engine start request, etc.). The vehicle start request and/or the engine start request may include a directive to turn the engine “on” from an “off” state. The vehicle may include at least one of a pushbutton, a graphical user interface, an ignition, and another device with which a user interacts to provide or trigger the vehicle start request and/or the engine start request. Engine20may provide a rotational mechanical energy input to at least one of first electromagnetic device40and/or second electromagnetic device50. First electromagnetic device40and second electromagnetic device50may be brought up to a threshold (e.g., a threshold speed, a threshold speed for a target period of time, a threshold power generation, a threshold power generation for a target period of time, etc.) that establishes a requisite DC bus voltage for controlling first electromagnetic device40and/or second electromagnetic device50. Both first electromagnetic device40and second electromagnetic device50may thereafter be activated and controlled within and/or to desired states. The power electronics of control system200that control the motor-to-motor functions may be brought online during the neutral/startup mode.

As shown inFIG. 4and Table 1, neutral clutch22, output coupled clutch150, and output brake170are engaged when transmission30is configured in the neutral/startup mode. According to an exemplary embodiment, engaging neutral clutch22, output brake170, and output coupled clutch150selectively limits the rotational movement of portions of both power split planetary110and output planetary120. By way of example, engaging output brake170may inhibit the rotational movement of ring gear124, gear192, gear194, and gear196such that each remains rotationally fixed. Engaging output coupled clutch150may inhibit rotational movement of jack shaft34such that jack shaft34remains rotationally fixed (e.g., since gear196is fixed and output coupled clutch150is engaged, etc.). With jack shaft34rotationally fixed, gear set180and carrier118become rotationally fixed, thereby isolating output shaft32from engine20, first electromagnetic device40, and second electromagnetic device50in the neutral/startup mode. Such isolation may substantially eliminate a forward lurch potential of the vehicle during startup (e.g., transmission30does not provide an output torque to tires62and/or tires72, etc.). Alternatively, as shown inFIG. 5, output coupled clutch150may be disengaged (e.g., before startup, during startup, after startup, etc.). However, disengaging output coupled clutch150may not prevent rotation of the jack shaft34and thereby output shaft32.

According to an exemplary embodiment, an energy flow path in the neutral/startup mode includes: first electromagnetic device40providing a rotational mechanical energy input to sun gear112that is received by the plurality of planetary gears116; the plurality of planetary gears116rotating about central axes thereof (e.g., planetary gears116may not rotate about sun gear112because carrier118may be rotationally fixed, etc.); the plurality of planetary gears116conveying the rotational mechanical energy to ring gear114; ring gear114transferring the rotational mechanical energy to the neutral clutch22through the connecting shaft36such that the rotational mechanical energy provided by first electromagnetic device40starts engine20.

An alternative energy flow path in the neutral/startup mode may include starting engine20with a traditional starting mechanism, engine20providing a rotational mechanical energy input to ring gear114that is received by the plurality of planetary gears116; the plurality of planetary gears116rotating about central axes thereof (e.g., planetary gears116may or may not rotate about sun gear112because carrier118may or may not be rotationally fixed, etc.); the plurality of planetary gears116conveying the rotational mechanical energy to sun gear112; and sun gear112conveying the rotational mechanical energy to first electromagnetic device40to bring first electromagnetic device40up to the threshold for establishing a requisite DC bus voltage and controlling first electromagnetic device40and/or second electromagnetic device50in a desired state. By way of example, the neutral/startup mode may be used to start engine20, establish a requisite DC bus voltage, or otherwise export power without relying on controller210to engage first electromagnetic device40and/or second electromagnetic device50. Transmission30may provide increased export power potential relative to traditional transmission systems.

As shown inFIG. 6, transmission30is selectively reconfigured into a low range mode of operation such that transmission30allows for a low output speed operation with a high output torque (e.g., in a forward direction of travel, etc.). The low range mode increases a vehicle's gradability (e.g., facilitates the vehicle maintaining speed on a grade, etc.). In one embodiment, engine20provides a rotational mechanical energy input to transmission30such that first electromagnetic device40generates electrical power and second electromagnetic device50uses the generated electrical power to provide a rotational mechanical energy output. As such, at least one of engine20and second electromagnetic device50provide a rotational mechanical energy input to drive at least one of tires62and tires72. In an alternative embodiment, first electromagnetic device40operates as a motor and second electromagnetic device50operates as a generator when transmission30is configured in the low range forward mode. In still another alternative embodiment, both first electromagnetic device40and second electromagnetic device50operate as a generator in the low range forward mode. In yet another embodiment, transmission30is not selectively reconfigurable into the low range mode of operation. In one such embodiment, transmission30does not include jack shaft34, does not include gear set190(e.g., gear192, gear194, gear196, etc.), and does not include output coupled clutch150. Transmission30may additionally or alternatively not include gear set180in embodiments where transmission30is not selectively reconfigurable into the low range mode of operation.

As shown inFIG. 6and Table 1, neutral clutch22and output coupled clutch150are engaged when transmission30is configured in the low range mode. As shown inFIG. 6, output coupled clutch150couples gear set190to jack shaft34. Accordingly, when engine20provides a rotational mechanical energy input to transmission30, at least one of engine20and second electromagnetic device50drive output shaft32through the interaction of connecting shaft36and jack shaft34with power split planetary110, respectively. According to the exemplary embodiment shown inFIG. 6, an energy flow path for the low range includes: engine20providing a rotational mechanical energy input to connecting shaft36through the neutral clutch22; connecting shaft36conveying the rotational mechanical energy to ring gear114; ring gear114causing the plurality of planetary gears116to rotate about central axes thereof, as well as about sun gear112such that carrier118and output shaft32rotate; and the rotation of the plurality of planetary gears116about a central axis causing a rotation of sun gear112, thus driving first electromagnetic device40such that it operates as a generator (e.g., generates electrical energy, etc.).

Referring still toFIG. 6, the rotation of carrier118drives both carrier128and gear set180. Carrier128drives the plurality of planetary gears126to rotate about sun gear122and about central axes thereof. In one embodiment, second electromagnetic device50receives electrical energy generated by first electromagnetic device40. Accordingly, second electromagnetic device50operates as a motor, providing a rotational mechanical energy input to sun gear122. The sun gear122conveys the rotational mechanical energy to the plurality of planetary gears126such that each further rotates about the central axis thereof. The plurality of planetary gears126drive ring gear124, and the rotation of ring gear124drives gear set190. According to the exemplary embodiment shown inFIG. 6, gear set180and gear set190transfer a torque to and from jack shaft34with output coupled clutch150engaged. As such, engine20and second electromagnetic device50move a vehicle at a low speed with a high output torque.

As shown inFIG. 7, transmission30is selectively reconfigured into a mid range mode of operation. In the mid range mode of operation, transmission30may facilitate a mid range output speed operation (e.g., in a forward direction of travel, etc.). The speed range associated with the mid range mode of operation may be larger than that of traditional transmissions (i.e., transmission30may provide increased coverage in the mid range, etc.). The mid range mode may improve low output speed torque and high output speed power. In one embodiment, engine20provides a rotational mechanical energy input such that first electromagnetic device40generates electrical power, and second electromagnetic device50uses the generated electrical power to provide a rotational mechanical energy output. Second electromagnetic device50thereby provides a rotational mechanical energy input to drive at least one of tires62and tires72. In an alternative embodiment, second electromagnetic device50operates as a generator while first electromagnetic device40operates as a motor when transmission30is configured in the mid range mode. In still another alternative embodiment, both first electromagnetic device40and second electromagnetic device50operate as a generator in the mid range mode.

As shown inFIG. 7and Table 1, neutral clutch22and output brake170are engaged when transmission30is configured in the mid range mode. As shown inFIG. 7, output brake170inhibits the rotation of gear set190(e.g., gear192, gear194, gear196, etc.). Output brake170thereby rotationally fixes ring gear124. In one embodiment, engaging output brake170substantially eliminates a power dip between output and input modes of transmission30. According to the exemplary embodiment shown inFIG. 7, an energy flow path for the mid range forward mode includes: engine20providing a rotational mechanical energy input to connecting shaft36that is conveyed to ring gear114; ring gear114driving the plurality of planetary gears116to rotate about central axes thereof, as well as about sun gear112such that both carrier118and sun gear112rotate; and the rotation of carrier118driving the output shaft32.

With ring gear124fixed by output brake170, second electromagnetic device50may operate as a motor. In one embodiment, second electromagnetic device50receives electrical energy generated by first electromagnetic device40. First electromagnetic device40operates as a generator, removing a rotational mechanical energy from sun gear112. The sun gear122conveys rotational mechanical torque from the second electromagnetic device50to the plurality of planetary gears126such that each further rotates about sun gear122(e.g., at an increased rotational speed, etc.). The rotation of the plurality of planetary gears126(e.g., effected by sun gear122, etc.) drives carrier128and thereby carrier118. Carrier118drives output shaft32at a mid range output speed and may thereby drive a vehicle at a mid range output speed.

As shown inFIG. 8, transmission30is selectively reconfigured into a high range mode of operation such that transmission30allows for a high output speed operation (e.g., in a forward direction of travel, etc.). In one embodiment, engine20provides a rotational mechanical energy input such that second electromagnetic device50generates electrical power while first electromagnetic device40uses the generated electrical power to provide a rotational mechanical energy output. As such, at least one of engine20and first electromagnetic device40provide rotational mechanical energy to drive at least one of tires62and tires72. In an alternative embodiment, first electromagnetic device40operates as a generator and second electromagnetic device50operates as a motor when transmission30is configured in the high range mode.

As shown inFIG. 8and Table 1, neutral clutch22and input coupled clutch140are engaged when transmission30is configured in the high range mode. As shown inFIG. 8, the engagement of input coupled clutch140with connecting shaft36rotationally couples engine20and second electromagnetic device50. By way of example, engine20may provide a rotational mechanical energy input to connecting shaft36such that second electromagnetic device50generates electrical energy. In one embodiment, first electromagnetic device40receives the electrical energy generated by second electromagnetic device50. First electromagnetic device40operates as a motor, providing a rotational mechanical energy input to sun gear112that drives the plurality of planetary gears116and carrier118.

Referring still toFIG. 8, power from engine20is transferred to ring gear114and the plurality of planetary gears116. The plurality of planetary gears116are driven by at least one of engine20(e.g., via ring gear114, etc.) and first electromagnetic device40(e.g., via sun gear112, etc.). Carrier118rotates, which drives output shaft32such that the rotational mechanical energy provided by engine20and first electromagnetic device40drives a vehicle at a high range speed.

As shown inFIG. 9, transmission30is selectively reconfigured into an intermediate shift mode of operation that facilitates transitioning transmission30(i.e., shifting, changing modes, etc.) between the mid range mode of operation and the high range mode of operation. According to the embodiment shown inFIG. 9, neutral clutch22, input coupled clutch140, and output brake170are engaged when transmission30is selectively reconfigured into the intermediate shift mode of operation. According to an exemplary embodiment, the intermediate shift mode provides a smooth and robust shifting strategy that functions reliably even in a wide variety of operating conditions, when using various types of oil for the components of transmission30, and when experiencing valve nonlinearities that may be present in one or more valves of transmission30. The intermediate shift mode may provide a zero inertia shift through and across two or more overlapping ranges (e.g., the mid range and the high range, etc.). According to the exemplary embodiment shown inFIGS. 7-9, the intermediate shift mode eliminates the need to simultaneously disengage output brake170and engage input coupled clutch140to shift from the mid range mode to the high range mode, or vice versa. The intermediate shift mode reduces jerking sensations associated with simultaneously disengaging output brake170and engaging input coupled clutch140to shift from mid range to high range, providing a smoother ride.

During operation, the intermediate shift mode may be used to shift from mid range mode to high range mode or from high range mode to mid range mode. In one embodiment, when shifting between the mid range mode and the high range mode, both input coupled clutch140and output brake170are engaged for a period of time prior to disengaging input coupled clutch140or output brake170. Transmission30may be selectively reconfigured into the intermediate shift mode in response to one or more inputs reaching a predetermined threshold condition, the inputs including a rotational speed of second electromagnetic device50and a rotational speed of connecting shaft36and/or engine20. One or more sensors may be positioned to monitor the rotational speed of at least one of engine20, connecting shaft36, a portion of second electromagnetic device50, or still another component. A controller (e.g., controller210, etc.) may reconfigure transmission30into the intermediate shift mode in response to sensing signals provided by the one or more sensors.

As shown inFIG. 10, transmission30is selectively reconfigured into a low speed reverse mode of operation. In one embodiment, engine20provides a rotational mechanical energy input to transmission30such that first electromagnetic device40generates electrical power and second electromagnetic device50uses the generated electrical power to provide a rotational mechanical energy input to transmission30. As such, at least one of engine20and second electromagnetic device50provide rotational mechanical energy to drive at least one of tires62and tires72in a reverse direction (e.g., backwards, etc.). In an alternative embodiment, first electromagnetic device40operates as a motor and second electromagnetic device50operates as a generator when transmission30is configured in the low range reverse mode.

As shown inFIG. 10and Table 1, neutral clutch22and output coupled clutch150are engaged when transmission30is configured in the low speed reverse mode. As shown inFIG. 10, the low speed reverse mode is substantially similar to the low range mode ofFIG. 6in that output coupled clutch150couples gear set190to output shaft32. In the low speed reverse mode, second electromagnetic device50may provide a rotational mechanical energy input to transmission30in an opposite direction as compared to the low range mode ofFIG. 6.

As shown inFIG. 11, transmission30is selectively reconfigured into a mid speed reverse mode of operation such that transmission30allows for a mid reverse output speed operation. In one embodiment, engine20provides a rotational mechanical energy input such that first electromagnetic device40generates electrical power, and second electromagnetic device50uses the generated electrical power to provide a rotational mechanical energy input to transmission30. As such, at least one of engine20and second electromagnetic device50provides a rotational mechanical energy input to drive at least one of tires62and tires72in a reverse direction (e.g., backwards). In an alternative embodiment, second electromagnetic device50operates as a generator and first electromagnetic device40operates as a motor when transmission30is configured in the mid speed reverse mode. In still another alternative embodiment, both first electromagnetic device40and second electromagnetic device50operate as a generator in the mid speed reverse mode.

As shown inFIG. 11and Table 1, neutral clutch22and output brake170are engaged when transmission30is configured in the mid speed reverse mode. As shown inFIG. 11, output brake170inhibits the rotation of gear set190(e.g., gear192, gear194, gear196, etc.). Output brake170thereby rotationally fixes ring gear124. According to the exemplary embodiment shown inFIG. 11, an energy flow path for the mid speed reverse mode includes: engine20providing a rotational mechanical energy input to connecting shaft36that is conveyed to ring gear114; and ring gear114driving the plurality of planetary gears116to rotate about central axes thereof, as well as about sun gear112such that both carrier118and sun gear112rotate.

Referring still toFIG. 11, the rotation of carrier118drives carrier128, which rotates the plurality of planetary gears126about central axes thereof, as well as about sun gear122. With ring gear124fixed by output brake170, second electromagnetic device50may operate as a motor. In one embodiment, second electromagnetic device50receives electrical energy generated by first electromagnetic device40. Accordingly, first electromagnetic device40operates as a generator, removing a rotational mechanical energy from sun gear112. Second electromagnetic device50receives electrical energy from first electromagnetic device40, applying a rotational mechanical torque to sun gear122. The sun gear122conveys the rotational mechanical torque to the plurality of planetary gears126such that each further rotates about sun gear122(e.g., at an increased rotational speed, etc.). The rotation of the plurality of planetary gears126(e.g., effected by sun gear122, etc.) drives carrier128and thereby carrier118. Carrier118drives output shaft32at a mid reverse output speed and may thereby drive a vehicle at a mid reverse output speed.

As shown inFIG. 12, transmission30is selectively reconfigured into a power generation mode such that rotation of connecting shaft36rotates first electromagnetic device40and second electromagnetic device50to generate electrical power. In one embodiment, the electrical power is stored for future use. In another embodiment, the electrical power is used to power internal devices (e.g., control system200, components of the vehicle, etc.) and/or external devices. As shown inFIG. 12and Table 1, neutral clutch22and input coupled clutch140are engaged when transmission30is configured in the power generation mode.

According to an exemplary embodiment, engine20provides a rotational mechanical energy input to connecting shaft36, which drives both first electromagnetic device40and second electromagnetic device50. As shown inFIG. 12, second electromagnetic device50is rotationally coupled to engine20via the engagement of input coupled clutch140with connecting shaft36such that second electromagnetic device50generates electrical power. According to the exemplary embodiment shown inFIG. 12, an energy flow path for the power generation mode includes: connecting shaft36provides rotational mechanical energy to ring gear114of power split planetary110; ring gear114conveys the rotational mechanical energy from connecting shaft36to the plurality of planetary gears116; the plurality of planetary gears116rotate about central axes thereof, thereby transferring rotational mechanical energy to sun gear112; sun gear112provides the rotational mechanical energy from engine20to first electromagnetic device40via the shaft of first electromagnetic device40such that first electromagnetic device40generates electrical power. In some embodiments, a brake is applied to front axle60and/or rear axle70to prevent movement of the vehicle10in the power generation mode.

According to an alternative embodiment, engine20does not provide a rotational mechanical energy input to drive a vehicle. By way of example, first electromagnetic device40, second electromagnetic device50, and/or another device may store energy during the above mentioned modes of operation. When sufficient energy is stored (e.g., above a threshold level, etc.), at least one of first electromagnetic device40and second electromagnetic device50may provide a rotational mechanical energy output such that the vehicle is driven without an input from engine20(e.g., an electric mode, etc.).

It should be noted that the terms “exemplary” and “example” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).