Drive train arrangement for a work vehicle with one engine

Abstract

A powertrain assembly for a work vehicle having an engine, the powertrain assembly comprising a continuously variable power source (28d; 28e); an energy storage device (228; 262) configured to receive energy from the continuously variable power source (28d; 28e) for storage and to provide stored energy from the energy storage device (228; 262) to drive one or more components (232; 174e) of the continuously variable power source (28d; 28e); and a transmission (26d; 26e) configured to transmit power from the engine (24d; 24e) and from the one or more components (232; 174e) of the continuously variable power source (28d; 28e) to one or more components (24d; 262e) of the vehicle (20); and a controller (36) configured to: identify a transient power event during which the engine (24d;24e), while operating in a current operating state, provides insufficient power for one or more operations of the vehicle (20); and based on identifying the transient power event, to cause the energy storage device (228; 262) to provide stored energy from the energy storage device (228; 262) to drive the one or more components (232; 174e) of the continuously variable power source (26d; 26e); wherein the transmission (26d; 26e) receives power from the energy storage device (228; 262) via the one or more components (232; 174e) of the continuously variable power source (28d; 28e) during the transient power event such that the one or more operations of the vehicle (20) are performed at least in part using stored energy from the energy storage device (228;262), the powertrain assembly further comprising: a continuously variable transmission (26e) comprising: a double planetary gear set (178e) comprising a first input component (180), a second input component (182), and an output component (186); a first clutch (196); a second clutch (198); and a brake (200); wherein the first input component (180) is configured to receive a first mechanical power input to the double planetary gear set (178) from the engine (24e); wherein the first clutch (196) is configured to engage the first input component (180) to control a mechanical power transfer between the first input component (180) and the engine (24e);wherein the second input component (182) receives a second mechanical power input for the dual planetary gear set (178e) from the one or more components (174e) of the continuously variable power source (26e); and wherein the dual planetary gear set (178e) is configured to sum mechanical power from the engine (2eb) and the one or more components (174e) of the continuously variable power source (26e) and to provide the summed power to the output component (186), the output component (186) providing the summed power directly to the transmission (26e), whereby the transmission (26e) receives power from the energy storage device via the output component (186) during the transient power event, and the first input component comprises a first sun gear (180) and the second input component comprises a second sun gear (182);and wherein a first ring gear (190) of the double planetary gear set (178e) is formed integrally with a first planetary gear carrier (184) which supports one or more first planetary gears (192) which mesh with both the first sun gear (180) and a second ring gear (188) of the double planetary gear set (178e); and wherein the output component comprises a second planetary gear carrier (186) supporting one or more second planetary gears (194) that mesh with both the second sun gear (182) and the first ring gear (190) of the dual planetary gear set (178e), wherein the brake (200) is configured to engage the second ring gear (188) to stop rotation of the second ring gear (188), characterized in that the continuously variable power source (28d, 28e) comprises a plurality of a pair of electric machines (230, 232; 172e, 174e); and wherein the energy storage device (228;262) comprises one or more of an electrical storage device, and the second clutch (198) is configured to engage one or more of the second ring gear (188) and the first planetary gear carrier (184) to control relative movement of the second ring gear (188) and the first planetary gear carrier (184);

Description

[0001] The present invention relates to a drive train arrangement for a work vehicle having an engine, more particularly to a drive train arrangement for energy storage and delivery.

[0002] In a variety of environments, it may be useful to use both a conventional engine (e.g., an internal combustion engine) and a continuously variable power source (e.g., an electric or hydrostatic motor, a variable chain drive, etc.) to provide useful power. For example, a portion of the engine's power may be diverted to drive a first continuously variable machine (e.g., a first electric machine acting as a generator), which in turn may drive a second continuously variable machine (e.g., a second electric machine acting as a motor using electrical power from the first electric machine). In certain configurations, power from both types of sources (e.g., an engine and a continuously variable power source) may be used for the ultimate power output (e.g.,to a vehicle axle) via an infinitely variable transmission (“IVT”) or a finite ratio continuously variable transmission (“CVT”). This may be referred to as “split-mode” or “power-split mode” operation because the power transfer may be split between the mechanical path from the engine and the continuously variable path. Split-mode operation may be achieved in several known ways. For example, a planetary gear set may be used to sum rotary power from an engine and from an electric machine, with the summed power being transmitted downstream within an associated driveline. This may enable the delivery of power (e.g., to vehicle wheels) with a continuously variable effective gear ratio.However, several problems may arise, including limitations on the maximum achievable speed of adjustable power sources.

[0003] The operation of other transmission types, such as IVT or CVT transmissions, can introduce various other problems. For example, transmission shifts (e.g., transitions between different gear ratios) can cause vehicle shocks, hesitation, or other transient effects on the available power (e.g., at the vehicle's wheels or at a connected tool or device), or other adverse effects on system performance and the user experience.DE 10 2009 039 360 A1 discloses a hybrid drive train for a motor vehicle, comprising an internal combustion engine, a first, predominantly generator-operating electric machine, the rotor of which is connected to an output shaft of the internal combustion engine and the electrical output of which is connected to an electrical energy storage device, and a second, predominantly motor-operating electric machine, the electrical input of which is connected to the electrical energy storage device. At least one coupling element is provided, by means of which the first electric machine and / or the second electric machine can be coupled to a drive of the motor vehicle via a transmission stage. DE 10 2012 005 299 A1 and DE 10 2011 115 002 A1 disclose a drive train arrangement with the same features.

[0004] According to one aspect of the disclosure, a powertrain assembly for a work vehicle having an engine may include a continuously variable power source ("IVP"). An energy storage device may be configured to receive energy from the IVP for storage and to provide stored energy from the energy storage device to power one or more components of the IVP. A transmission may be configured to transfer power from the engine and one or more components of the IVP to other components of the vehicle. A transient power event may be identified during which a current operating condition of the engine does not provide sufficient power for work vehicle operations. The energy storage device may be caused to provide stored energy to power the one or more components of the IVP, thereby providing power to the transmission.

[0005] In certain embodiments, the transmission may also receive power from the engine during the transient power event, so that the work vehicle's operations may be performed at least partially using power from the engine and stored energy from the energy storage device. The transient power event may include a gear shift, an operation of a work vehicle tool, or an operation of the vehicle while the vehicle engine is off.

[0006] In certain embodiments, continuously variable transmissions of various configurations may be configured to receive power from one or more components of the continuously variable transmission. For example, a continuously variable transmission may include one or more planetary gear sets or dual planetary gear sets that may be configured to sum power from the engine and from the one or more components of the continuously variable transmission for delivery to the transmission.

[0007] According to another aspect of the invention, a method is disclosed for powering a work vehicle having an engine, an IVP, an energy storage device configured to receive energy from the IVP for storage and to provide stored energy from the energy storage device to power one or more components of the continuously variable power source, and a transmission configured to transfer power from the engine and from the one or more components of the continuously variable power source to one or more components of the vehicle.

[0008] The transient power event during which a current operating condition of the work vehicle's engine does not provide sufficient power for one or more work vehicle operations may be identified. The energy storage device may be caused to provide stored energy from the energy storage device to power the one or more IVP components. During the transient power event, the transmission may thereby receive power from the energy storage device via the one or more IVP components such that the one or more work vehicle operations may be performed at least partially using stored energy from the energy storage device.

[0009] The details of one or more implementations are set forth in the accompanying drawings and the following description. Other features and advantages will be apparent from the description, drawings, and claims.

[0010] For a full understanding of the objects, methods and structure of the invention, reference should be made to the following detailed description and the accompanying drawings: Fig. 1 is a side view of an exemplary work vehicle that may include a continuously variable transmission, Fig. 2 is a schematic view of a drive train of the vehicle of Fig. 1, Fig. 3 is a schematic view of a continuously variable transmission incorporated into the powertrain of Fig. 2 can be integrated, Fig. Figure 4 is a graphical representation of speeds of a continuously variable power source and speeds of vehicle wheels for different operating modes of the continuously variable transmission of Fig. 3, Fig. Figure 5 is a schematic view of another continuously variable transmission incorporated into the powertrain of Fig. 2 can be integrated, Fig. Figure 6 is a graphical representation of speeds of a continuously variable power source and speeds of vehicle wheels for different operating modes of the continuously variable transmission of Fig. 5, Fig. Figure 7 is a schematic view of another continuously variable transmission incorporated into the powertrain of Fig. 2 can be integrated, Fig. Figure 8 is a graphical representation of speeds of a continuously variable power source and speeds of vehicle wheels for different operating modes of the continuously variable transmission of Fig. 7, Fig. Figure 9 is a schematic view of a drive train similar to that of Fig. 3, with a power storage and delivery system, Fig. Figure 10 is a schematic view of a drive train similar to that of Fig. 7, with a power storage and delivery system, Fig. 11 is a diagrammatic view of a management history of a transient power event occurring in the powertrains of Fig. 9 and Fig. 10 can be used.

[0011] In the different drawings, the same reference symbols indicate the same elements.

[0012] The following describes one or more exemplary embodiments of the disclosed powertrain arrangement for energy storage and delivery, as shown in the accompanying drawing figures briefly described above. Various modifications to the exemplary embodiments may be contemplated by one skilled in the art.

[0013] In various known configurations, one or more planetary gear sets may be used to combine the power output of an IVP and a motor (e.g., an internal combustion engine). For example, in a planetary gear set, a first component of the gear set (e.g., a ring gear) may receive power from the motor, a second component of the gear set (e.g., a sun gear) may receive power from the IVP, and a third component of the gear set (e.g., a planetary gear carrier) may sum the power from the motor and the IVP at the output of the gear set. (For convenience of naming, "component" may be used herein, particularly in the context of a planetary gear set, to refer to an element for transmitting power, such as a sun gear, a ring gear, or a planetary gear carrier.)It is clear that such a configuration can enable an essentially infinite and continuously variable number of gear ratios for the planetary gear set. For example, for a given engine speed, a specific gear ratio can be set by varying the speed of the IVP with respect to the engine speed.

[0014] In certain cases, it may be useful to facilitate a zero-power mode for a vehicle (or other machine) in which the output speed of the vehicle's wheels (or other machine output) reaches zero speed without stopping the engine or releasing torque at the wheels. In this way, for example, vehicle power can be used to hold a vehicle stationary. Such a condition can be achieved, for example, with a planetary gear set configured as described above. For example, if an engine rotates a sun gear at a first positive speed, and an IVP (e.g., an electric motor driven by a generator) is commanded to rotate a ring gear at an equivalent negative speed, an associated planetary gear carrier (which may, for example, be connected to a differential input shaft) may not rotate at all.Furthermore, if the IVP provides output rotation at a slightly different (and opposite) speed than the engine, the vehicle may enter a "crawl" mode, where the vehicle moves very slowly but with high wheel torque. The zero-power and crawl modes are especially useful for heavy-duty work vehicles, such as the one shown in . Fig. 1, which are used in the agricultural, construction, and forestry industries. As wheel speed increases, the vehicle can then eventually enter a normal drive mode. In conventional configurations, each of these modes can be a power-split mode, in which the power delivery is split between a purely mechanical path from the engine and the mixed path through the IVP.

[0015] One issue with continuously variable powertrains may concern the relative efficiency of power transfer in different modes. For example, it is clear that mechanically transferring power from an engine to a gear set (i.e., mechanical transmission) may be a highly efficient mode of power transfer, whereas power transfer through an IVP may be less efficient (e.g., because the mechanical power must be converted into electrical or hydraulic power by a first machine, transferred to a second machine, and then converted back into mechanical power). Accordingly, there may be significant motivation to utilize the mechanical path more extensively than the IVP path (e.g., by increasing the engine's speed).However, this greater use of the mechanical path can also drive up the required IVP speed for zero-power and creep modes, as these modes may require a near or actual speed match between the IVP and engine speeds. This can lead to increased wear on associated gears and other parts (e.g., a planetary gear component receiving power from the IVP and associated bearings), even to the point of part failure. Furthermore, achieving suitable speeds may require a significant increase in the size and power of a relevant IVP from a preferred size and power. Among other advantages, the multimode continuously variable transmission ("MIVT") disclosed herein can address these issues.For example, by selectively utilizing clutches and / or brakes, an MIVT can allow greater use of a mechanical path while avoiding the need for excessive IVP speeds in zero-power and creep modes.

[0016] As will be apparent from the present discussion, an MIVT can be used advantageously in a wide variety of environments and with a wide variety of machines. For example, with reference now to Fig. 1 an MIVT may be included in the drive train 22 of a vehicle 20. In Fig. In Figure 1, the vehicle 20 is depicted as a tractor. However, it is understood that other configurations may be possible, including configuring the vehicle 20 as another type of tractor, a logging tractor, a road grader, or one of various other work vehicle types. Furthermore, it is understood that the disclosed IVT may also be used in non-work vehicles and non-vehicle applications (e.g., stationary powertrains).

[0017] As also noted above, an advantage of the disclosed MIVT is that it can enable operation of a vehicle in a variety of propulsion modes (e.g., zero-power mode, creep mode, and power-split mode) that utilize various combinations of engine and IVP power. For example, by utilizing various clutches and / or brakes associated with one or more planetary gear sets, an MIVT can enable engine power to be separated from an IVT output, even while the engine continues to operate.For example, if an IVP drives a first component of a planetary gear set and a motor drives a second component of the planetary gear set, in certain embodiments and modes, a clutch may disconnect the operating motor from the second component, and a brake may stop rotation of a third component of the gear set, allowing power to be delivered only from the IVP through the reduction gear of the planetary gear set. In this way, for example, only electric power (or hydraulic power, etc.) may be used to propel (or sustain) the vehicle 20 in certain modes, while combined electric and motor power may be used to propel (or sustain) the vehicle 20 in other modes.As such, among other advantages, an MIVT can avoid certain previous limitations on the power fraction that can be diverted from an engine through an electrical path (or hydraulic path, etc.).

[0018] With reference to Fig. 2, various components of an exemplary powertrain 22 are shown. For example, an engine 24 may supply mechanical power (e.g., via a rotating shaft) to an MIVT 26. The engine 24 may also supply mechanical power to an IVP 28, which may include one or more IVP machines (e.g., an electric motor and generator, or a hydrostatic machine with a hydrostatic motor and an associated pump). The MIVT 26 may additionally receive mechanical power from the IVP 28.

[0019] The MIVT 26 may include various clutches 30 and brakes 32, which may be controlled by various actuators 34. The actuators 34, in turn, may be controlled by a transmission control unit ("TCU") 36 (or other controller), which may receive various inputs from various sensors or devices (not shown) via a CAN bus (not shown) of the vehicle 20. The MIVT 26 may include one or more output shafts 38a for transmitting mechanical power from the MIVT 26 to various other components (e.g., a differential driveshaft). In certain embodiments, additional transmissions (e.g., a range transmission) may be disposed between the MIVT 26 and other parts of the vehicle 20 (e.g., a differential driveshaft). In certain embodiments, the IVP 28 may also provide power directly to other parts of the vehicle 20 (e.g., via a direct IVP driveshaft 38b).

[0020] With reference to Fig. 3, various internal components of MIVT 26 are shown as examples when MIVT 26a is shown. It should be noted that the schematic representations of the Fig. 3 shown gearbox (and also the one in Fig. 5 and Fig. 7) illustrate exemplary implementations in a simplified form for clarity and therefore cannot show all of the components associated with the illustrated transmission. The engine 24 may include an internal combustion engine 24a that can deliver mechanical power directly to a shaft S1. (A "direct" power transfer, as used herein, may include the transfer of power through a direct physical connection, a one-piece construction, or via a simple intervening element such as an impeller or planetary gear. In contrast, for example, a power transfer between a ring gear of a planetary gear set and a sun gear of the planetary gear set via a planetary gear carrier (and associated planetary gears) of the planetary gear set may not be considered "direct.") The IVP 28, shown exemplarily as IVP 28a, may include an electric generator 40 and electric motor 42. The electric generator 40 may receive mechanical power via a gear 46 and a gear 44 attached to the shaft S1, and may generate electrical power for transmission to an electric motor 42. The electric motor 42 may convert the received electrical power into mechanical power, thereby rotating the shaft S2.

[0021] Although specific terms such as "generator" and "motor" may be used herein to describe various example configurations, it is understood that these (and similar) terms may be used to generally refer to an electric machine capable of operating either as a generator or as a motor. For example, electric generator 40 may sometimes operate as an electric motor, and electric motor 42 may sometimes operate as a generator. Likewise, it is understood that the actual operating modes of other continuously variable power sources may similarly vary from those explicitly described herein.

[0022] In certain embodiments, the MIVT 26a may include a planetary gear set 48 and a dual planetary gear set 50. In certain embodiments, the planetary gear set 48 and the dual planetary gear set 50 may be configured to sum mechanical power from the engine 24a and the IVP 28a. Through the use of one or more associated clutches and / or brakes, the MIVT 26a may, in certain modes, provide an output using only power from the IVP 28a.

[0023] The planetary gear set 48 may, for example, include a planetary gear carrier 52 that supports planetary gears 54 that can mesh with a sun gear 56 and a ring gear 58. A drive clutch 60 may be configured to engage the planetary gear carrier 52 and the sun gear 56 (e.g., based on signals from the TCU 36) to control the power transfer between these gears. For example, in a fully engaged state, the drive clutch 60 may lock the planetary gear carrier 52 to the sun gear 56. As shown in Fig. 3, the motor 24a may directly drive the planetary gear carrier 52 via the shaft S1. Accordingly, engagement of the clutch 60 may effectively lock the sun gear 56 to the shaft S1 and the output of the motor 24a. A reversing brake 62 may be anchored to a fixed housing of the MIVT 26a (or other feature) and may be configured to engage to stop the rotation of the ring gear 58.

[0024] In certain embodiments, an output component of planetary gear set 48 may directly transmit power to an input component of dual planetary gear set 50. For example, sun gear 56 may be integrally connected to ring gear 64, thereby directly connecting an output of planetary gear set 48 (i.e., sun gear 56) to an input of dual planetary gear set 50 (i.e., ring gear 64).

[0025] The double planetary gear set 50 may also receive power input from the IVP 28a. For example, the electric motor 42 may drive the rotation of the shaft S2 in conjunction with an attached gear 66. The gear 66 may mesh with a gear 68 attached to the shaft S1, and the gear 68 may directly transmit power to (e.g., may be integrally formed with) the sun gear 70 of the double planetary gear set 50. The sun gear 70 may mesh with planetary gears 72 (one is shown), which may be directly connected to the planetary gears 74 (one is shown), with both sets of planetary gears 72 and 74 being carried by a planetary gear carrier 76. Each of the planetary gears 74 may mesh with one of several planetary gears 88, which in turn may mesh with a ring gear 78. The planetary gear carrier 76 can be connected to the ring gear 78 (e.g.via planetary gears 74 and 88) and a creep brake 80 may be anchored to a fixed housing of the MIVT 26a (or other feature) and configured to engage the ring gear 78 to stop rotation of that component.

[0026] The planetary gear carrier 76 may provide mechanical power output from the dual planetary gear set 50 for transmitting mechanical power to various parts of the vehicle 20. For example, the planetary gear carrier 76 may be integrally connected to an output gear 82 that may mesh with a gear along a idler shaft S3. In certain embodiments, an additional gear 84 (e.g., a range gear) may be disposed between the MIVT 26a and other parts of the vehicle 20 (e.g., a differential drive shaft ("DDS")) or may be included as part of the MIVT 26a. In this manner, for example, various gear shifts may be implemented via the continuously variable baseline gear ratio provided by the MIVT 26a.

[0027] In certain operating modes, the MIVT 26a (as shown in Fig. 3 configured) may provide zero-power and creep modes in which only power from the IVP 28a is delivered to the wheels of the vehicle 20. For example, the input clutch 60 may be released and the brake 80 engaged with the ring gear 78 (or, in certain configurations, with the ring gear 64 (not shown)). This may accordingly disengage the motor 24a from the dual planetary gear set 50 while providing a fixed gear (e.g., the ring gear 78) around which the components of the dual planetary gear set 50 can rotate. Mechanical power from the IVP 28a may be delivered to the sun gear 70, which may drive the planet carrier 76 around the ring gear 78. This, in turn, may cause rotation of the output gear 82, which is driven by the IVP 28a but not by the engine 24a, which may enable driving of the wheels of the vehicle 20 (e.g., via the gearshift 84) using only power from the IVP 28a.

[0028] To shift the vehicle out of this IVP-only mode, a reverse process to that described above may be performed. For example, clutch 60 may be engaged, connecting motor 24a to sun gear 56 and ring gear 64. Simultaneously (or nearly simultaneously), creep brake 80 may be released, allowing dual planetary gear set 50 to provide an output at gear 82 representing a sum of the power from IVP 28a and motor 24a. It will be appreciated that this selective use of two of a set of friction elements (e.g., clutches and brakes) may generally facilitate transition between different operating modes for vehicle 20.

[0029] In certain embodiments, it may be advantageous to effect a transition between modes (e.g., between an IVP-only creep mode and a combined drive mode) in different ways. For example, with clutch 60 engaged, it may be possible to rotate sun gear 70 (via IVP 28a) at a speed such that ring gear 78 substantially stops, even without the use of brake 80. To provide a more seamless shift between modes, it may be advantageous to transition between drive and creep modes at such a point. In this way, for example, brake 80 may be engaged and clutch 60 may be released, with minimal disruption to vehicle operation. A similar seamless shift point may also be obtained for shifting from creep to drive modes and may represent a target point for these (and other) shifts.However, it will be appreciated that in certain embodiments, ramp (or other) modulation of the clutch 60 (or other components) may be used.

[0030] In certain applications, it may be desirable to operate the vehicle 20 in reverse, whether in a crawl mode, drive mode, or another mode. In the MIVT 26a, as shown in Fig. 3, it may be possible, for example, to engage the reversing brake 62 for this purpose.

[0031] With reference to Fig. 4 is a graph of the relationship between the vehicle wheel speed (in kilometers per hour) and the speed of the electric motor 42 (in revolutions per minute) for the configuration of the MIVT 26a in Fig. 3. Various curves are presented for the operation of the vehicle 20, wherein various range gears (not shown) are engaged within the gearshift 84. It is clear that the Fig. 4 The sizes represented are only examples.

[0032] For example, a line 90 may represent operation of the vehicle in a creep mode (e.g., using only electric power). It can be seen that at zero engine speed, the vehicle speed may be zero, with non-zero engine speed being directly proportional to vehicle speed. In creep mode (e.g., with the brake 80 engaged, the input clutch 60 disengaged, and an engaged A-range gear (not shown) in the transmission 84), the vehicle 20 may accelerate to a transition point. For example, as described above, the vehicle 20 may accelerate to a point where, based on the engine speed and relevant gear ratios, the ring gear 78 may be relatively stationary, even without engagement of the brake 80.At this (or another) point, the brake 80 may be released and the clutch 60 engaged, shifting the vehicle 20 relatively seamlessly into split-mode drive. The electric motor 42 may then begin to decelerate along a line 92, with the vehicle speed (now driven in power-split mode by both the electric motor 42 and the engine 24a) increasing even as the speed of the electric motor 42 changes direction (i.e., changes from positive rotation to negative rotation).

[0033] Continuing, the vehicle 20 may be shifted from the A-range gear in the gearshift 84 to a higher B-range gear (not shown). To continue accelerating the vehicle 20, it may now be appropriate to reverse the direction of rotation of the electric motor 42, thereby jumping from the negative rotation and line 92 to the positive rotation and a line 94. The electric motor 42 may then be slowed down again, followed by another shift to a higher C-range gear (not shown) in the gearshift 84 and a corresponding jump for the electric motor 42 from line 94 to a line 96. By modulating the rotation of the electric motor 42 in this manner, shifting between different range gears of the gearshift 84 can be achieved with the same reduction ratio at the start of the shift (e.g., at the end of A-range drive) as at the end of the shift (e.g., at the beginning of B-range drive).(It will be appreciated that a reduction ratio may be the product of the gear ratios of the planetary gear sets 48 and 50 and the engaged gear (e.g., the A-range gear) of the gearshift 84.)

[0034] Various benefits can be gained from configuring Fig. 3 (and others provided by this disclosure). For example, in the configuration of Fig. 3 (and other configurations), the transmission 84 may be located downstream of the planetary gear sets 48 and 50. This may enable the use of the full range of torques and speeds obtained at the output of the MIVT 26a (i.e., as they may result from various combinations of the power of the engine 24a and the electric motor 42) with any range or gear of the transmission 84. For example, an electric-only mode (or any of a variety of power-split modes) may be used with any range or gear of the transmission 84. This may provide significant flexibility during vehicle operation.

[0035] In addition, in the configuration of Fig. 3 (or in other configurations), a split-mode drive can be implemented using a relatively simple planetary path, which, among other advantages, can reduce wear, extend service life, and reduce costs for the MIVT 26a. This can be particularly useful, for example, for applications where a large portion of the operating time is expected to be spent in power-split mode (e.g., for various agricultural tasks performed by the vehicle 20). In power-split mode, for example, power from the engine 24a can be delivered through the clutch 60 to the ring gear 64, and power from the electric motor 42 can be delivered to the sun gear 70. These components (i.e.,The ring gear 64 and sun gear 70 can collectively cause the rotation of the planetary carrier 76 (via the planetary gears 72), which in turn can cause the rotation of the gear 82 and the corresponding transfer of power to the transmission 84. In contrast, in an electric-only mode, power can be delivered from the electric motor 42 to the sun gear 70 and then in turn to the planetary gears 72, planetary gears 74 (which can be directly connected to the gears 72 or formed integrally with them), and planetary gears 88. With the ring gear 78 locked by the brake 80, power can then flow from the planetary gears 72, 74, and 88 to the planetary carrier 76, and so on.In this way, it is clear that fewer gear meshes can be used in power split mode than in electric-only mode, which may represent a relative improvement in power transfer efficiency and may also lead to a relative reduction in part wear.

[0036] With reference to Fig. 5, another exemplary MIVT 26b is now presented. As in Fig. 5, an MIVT 26b may include a planetary gear set 98 and a dual planetary gear set 100. An internal combustion engine 24a may directly drive both a hydrostatic drive (e.g., a pump 102 and a motor 104) and a shaft S4, and the hydrostatic drive (e.g., via the motor 104) may drive a shaft S5. The planetary gear set 98 may include a sun gear 106, a planetary gear carrier 108, and a ring gear 110. A drive clutch 112 may be configured to engage the shaft S4 to connect the output of the motor 24b to the sun gear 106. A creep clutch 114 may be configured to engage both the planetary gear carrier 108 and the ring gear 110, potentially locking the planetary gear carrier 108 and the ring gear 110 together. A reversing brake 116 may be configured to engage the ring gear 110.Accordingly, in certain configurations, the reversing brake 116 may be used to reverse the output of the planetary gear set 98 with respect to the output of the motor 24b.

[0037] The planetary gear set 98 may include an output that is directly connected (e.g., directly meshed or integral with) an input of the double planetary gear set 100. For example, as shown in Fig. 5, the planetary gear carrier 108 may be an output component for the planetary gear set 98 and may mesh directly with a planetary gear carrier 122 of the dual planetary gear set 100 (i.e., via gears 118 and 120). Further, in certain configurations, this input to the dual planetary gear set 100 may rotate directly with another component of the dual planetary gear set 100. For example, the planetary gear carrier 122 may be formed as a single-piece component with a ring gear 124 such that both components rotate in unison.

[0038] The motor 104 may provide an additional input to the double planetary gear set 100. For example, the motor 104 may provide input power to both sun gears 126 and 128 via shaft S5. The double planetary gear set 100 may also include, for example, a ring gear 130 and planetary gear carrier 134.

[0039] In this configuration, similar to the discussion above regarding the embodiment of Fig. 3, various clutches and brakes associated with the MIVT 26b can be used to switch between different operating modes for the vehicle 20. For example, when the input clutch 112 is disengaged, no power can be transferred from the operating engine 24b to the planetary gear set 98 or the dual planetary gear set 100. Further, with the creep clutch 114 and the reversing brake 116 engaged, the gear 118 can be locked. Accordingly, the engagement of the creep clutch 114 and the reversing brake 116 can prevent rotation of both the ring gear 124 and the planetary gear carrier 122 (although the planetary gears 132 can continue to rotate around the carrier 122). In this manner, even though the motor 24b may be operating, the double planetary gear set 100 may only transmit power from the motor 104 to an output gear 140 (e.g., in either a forward or reverse creep mode).

[0040] In certain embodiments, additional power-transfer components may be provided to facilitate various types of vehicle operations and operating modes. For example, a lower clutch 136 and an upper clutch 138 may be included within the dual planetary gear set 100, with the upper clutch 138 configured to engage both the ring gear 130 and the output gear 140, and the lower clutch 136 configured to engage both the planetary gear carrier 134 and the output gear 140. Accordingly, in creep mode or other modes, the clutches 136 and 138 may be selectively activated to adjust the effective overall gear ratio of the two planetary gear sets 98 and 100.

[0041] In certain embodiments, a gearshift 142 may be arranged between the double planetary gear set 100 and other parts of the vehicle 20 (e.g., a DDS) and may include various gears (e.g., range gears). In certain embodiments, the gearshift 142 may also be arranged Fig. 5 may allow transition between fixed gear ratios within the transmission 142 (and in the context of the continuously variable gear ratio provided by the hydrostatic machine 102, 104) without necessarily changing the direction of rotation for the motor 104. For example, the vehicle 20 may begin operation at a zero speed with the motor 24b disengaged from the transmission (via the clutch 112) and the clutch 114 and brake 116 engaged. The motor 104 may accordingly provide the only power to the output gear 140 (and the transmission 142). The motor 104 may be started in the positive direction (for positive-direction creep mode operation) or in the negative direction (for negative-direction creep mode operation).Assuming, for example, an initial positive direction of motion, the rotation of the motor 104 (and thereby of the shaft S5) may accelerate in the positive direction, causing the sun gears 126, 128 to also accelerate. Initially, for example, the lower clutch 136 may be engaged, transferring power from the sun gear 128 via the planetary gear carrier 134 to the output gear 140. Within the gearshift 142, a first low-range gear may be engaged, completing the power transmission path from the motor 104 to other parts of the vehicle 20 (e.g., a differential drive shaft).

[0042] At a particular speed of the engine 104, depending on the particular associated gear ratios, the ring gear 110 may tend to be relatively stationary even when the brake 116 is not engaged. As also indicated above, this may provide a useful point at which to transition between operating modes (e.g., creep mode and power split mode) or different gears (e.g., range gears within the transmission 142). Accordingly, continuing the above example, once the engine 104 has accelerated through the creep mode to such a speed-matched point (or at various other times), the reversing brake 116 may be released and the input clutch 112 may be engaged. This may provide a mechanical transmission path for power from the engine 24b to the double planetary gear set 100.At the same time (or nearly so), the lower clutch 136 can also be released and the upper clutch 138 can be engaged. Due to the in . Fig. 5, it may not be necessary at this point to reverse the direction of rotation of the motor 104 in order to continue forward acceleration of the vehicle 20 (as is the case, for example, for the configuration shown in Fig. 3 may be the case). In certain embodiments, after engagement of clutch 112 (i.e., entry into a power split mode), the rotational speed of engine 104 may simply be slowed from the rotational speed at the time of the transition, with the vehicle 20 accelerating accordingly.

[0043] With reference to Fig. 6, for example, a graph of the relationship between the vehicle wheel speed (in kilometers per hour) and the speed of the engine 104 (in revolutions per minute) for the configuration of the MIVT 26b in Fig. 5. Various curves are shown for the operation of the vehicle 20, wherein various gears (e.g., range gears) are engaged within the transmission 142. It is clear that the Fig. 6 represented sizes are only examples.

[0044] For example, a line 150 may represent operation of the vehicle 20 in a creep mode (e.g., with hydrostatic power only). It can be seen that at zero engine speed, the vehicle speed may be zero, with non-zero engine speed being directly proportional to the vehicle speed. In creep mode (e.g., with the brake 116 and creep clutch 114 engaged, the drive clutch 112 disengaged, and an A-range gear (not shown) engaged in the transmission 142), the vehicle 20 may accelerate to a transition point. In certain embodiments, this may be a point where, based on the engine speed and relevant gear ratios, the ring gear 110 may be relatively stationary, even without engagement of the brake 116.At this (or another) transition point, the brake 116 may be released and the clutch 112 engaged, placing the vehicle 20 into split-mode drive. The engine 104 may then begin to decelerate along a line 152, with the vehicle speed (now driven by both the engine 104 and the engine 24b) increasing even as the speed of the engine 104 changes direction (i.e., changes from positive rotation to negative rotation).

[0045] Subsequently, the vehicle 20 may be shifted from the previous A-range gear in the transmission 142 to a higher B-range gear (not shown). To continue accelerating the vehicle 20, it may again be appropriate to switch the direction of acceleration of the rotation of the engine 104 (but not immediately the direction of rotation of the engine 104) and engage an appropriate range gear (with or without switching the clutches 136 and 138). The engine 104 may then accelerate along a line 154, with the vehicle 20 accelerating accordingly.

[0046] With reference to Fig. 7, an additional exemplary MIVT 26c is now presented. As in Fig. 7, an internal combustion engine 24c may provide mechanical power to an electric generator 172, which may provide electrical power to an electric motor 174 via a power cable 176. The electric motor 174 may drive (e.g., via direct gearing) the input rotation of a sun gear member 182 of the double planetary gear set 178. The double planetary gear set 178 may also be configured to receive mechanical power from the engine 24c via a shaft S7, with a drive clutch 196 configured to engage both the shaft S7 and another sun gear member 180. A planetary gear carrier 184, including planetary gears 192, may be directly connected to (e.g., integral with) a ring gear member 190, which itself may be configured to receive power from the sun gear member 182 via a planetary gear carrier 186 including planetary gears 194. A ring gear 188 can mesh with the planetary gears 192.Furthermore, the planetary gear carrier 186 may form an output component of the double planetary gear set 178 and may, for example, be directly connected to an input component of a gearshift 202 (e.g., formed integrally therewith).

[0047] As with other embodiments discussed herein, a number of clutches and brakes may be incorporated within the MIVT 26c (e.g., as shown in Fig. 7) may allow useful transition between various operating modes, including a creep mode co-driven by only the electric motor 174 and a power-split mode co-driven by both the electric motor 174 and the motor 24c. For example, the clutch 196 may engage the shaft S7 and the sun gear 180 to transfer power from the motor 24c to the dual planetary gear set 178. Likewise, a clutch 198 may engage both the ring gear 188 and the planetary gear carrier 184 to lock these components together. Finally, a reversing brake 200 may engage the ring gear 188 to stop rotation of this gear.

[0048] In this regard, it will be appreciated that the clutch 198, the brake 200, and the clutch 196 can be selectively engaged (and released) to provide various operating modes. For example, when the clutch 196 is released and both the clutch 198 and the reversing brake 200 are engaged, the vehicle 20 can be propelled using only the power of the electric motor 174. Likewise, other operating modes may be possible with various other configurations (e.g., various combinations in which two of the clutch 198, the brake 200, and the clutch 196 are engaged).

[0049] With reference to Fig. 8 also shows, for example, a graph of the relationship between the vehicle wheel speed (in kilometers per hour) and the speed of the electric motor 174 (in revolutions per minute) for the configuration of the MIVT 26c in Fig. 7. Various curves are presented for the operation of the vehicle 20, wherein various gears (e.g., range gears) are engaged within the transmission 202. It is clear that the Fig. 8 represented sizes are only examples.

[0050] For example, a line 212 may represent operation of the vehicle 20 in a creep mode (e.g., using only electric power). It can be seen that at zero engine speed, the vehicle speed may be zero, with non-zero engine speed being proportional to the vehicle speed. In creep mode (e.g., with the reversing brake 200 and clutch 198 engaged, the drive clutch 196 disengaged, and an A-range gear (not shown) engaged in the transmission 202), the vehicle 20 may accelerate to a transition point. For example, the vehicle 20 may accelerate to a point where, based on the engine speed and relevant gear ratios, the ring gear 188 may be relatively stationary, even without engagement of the brake 200. At this (or another) point, the clutch 198 may be disengaged and the clutch 196 engaged, thereby shifting the vehicle into splitter-mode drive.At this time (or nearly at this time), the electric motor 174 may then reverse its direction of rotation, transitioning from line 212 to a line 214. The vehicle 20 may accordingly continue to accelerate (now powered by both the electric motor 174 and the engine 24c), with the vehicle speed increasing, even while the speed of the electric motor 174 changes direction (i.e., changes from negative rotation to positive rotation). Similar shifts may also be effected, for example, to a B-range gear (not shown) from the A-range gear (not shown) by transitioning the electric motor 174 from line 214 to a line 216, etc.

[0051] In certain embodiments, including with respect to various transmission configurations discussed above, it may be useful to provide a powertrain arrangement with energy storage and delivery ("ESD") capability for driving vehicle systems, in addition to (or as an alternative) to a conventional engine. For example, with respect to the vehicle 20, it may be useful to provide one or more electrical, hydraulic, or other energy storage devices as part of the powertrain 22 (or in communication therewith). Energy from the engine 24 may be received for storage at these devices (e.g., energy provided by the engine 24 in mechanical form and then converted to non-mechanical forms for storage). The energy may then be transferred in various advantageous ways from storage to delivery to various vehicle components (e.g.,to a transmission or other drivetrain arrangement).

[0052] In certain embodiments of the disclosed powertrain arrangement, an ESD system may be used to reduce the adverse effects of transient power events for the vehicle 20. A transient power event may include events in which the available power from the engine 24 (at least under the current operating condition of the engine 24) is insufficient for one or more existing (or requested) operations. For example, a transient power event may occur when a driven operation is requested by an operator, but the available (i.e., excess) power from the engine 24 (at least under the current operating conditions) is insufficient to complete the operation without adverse effects (e.g., without reducing the power supply to other vehicle systems). For example, while the engine 24 is powering various vehicle systems (e.g.,A vehicle actively driving a vehicle (e.g., a set of drive wheels) may request an operation that requires additional power beyond that currently available from engine 24. In certain embodiments, an ESD system may be used to supplement (or replace) available engine power for such an operation while avoiding various problems (e.g., power lag, inefficient engine operation, jarring of vehicle 20, etc.).

[0053] For example, a transient power event may also occur when an engine is not providing power to the corresponding powertrain. In certain embodiments, an ESD system may be used to provide power to various vehicle systems when an engine is in a turned-off state or otherwise not operating.

[0054] In certain embodiments, a component of an IVP (e.g., an electric generator or a hydraulic pump) may be configured to receive mechanical power from the motor 24 and convert the power into another form (e.g., electrical power or hydraulic pressure / flow). A portion of the converted power may be directed to an energy storage device (e.g., a battery or accumulator) for storage. When needed (e.g., during a particular transient power event), stored energy may then be released from the energy storage device to a component of the IVP (e.g., an electric motor or a hydraulic motor) for conversion back to mechanical power. This mechanical power may then be directed throughout the vehicle 20 as needed.For example, an MIVT may be configured to receive power from the IVP to supplement mechanical power received directly from the engine 24.

[0055] In certain implementations, an ESD system may be used in the disclosed powertrain assemblies to provide shift smoothing. During certain shift events of a transmission of the vehicle 20 (e.g., during the transition from a first range or gear of a multi-speed transmission to a second range or gear of the multi-speed transmission), more power may be requested at an input to the transmission than is available from the engine 24 (i.e., a transient power event may occur). For example, one or more clutches of the transmission may slip as the transmission begins to accept a load (e.g., an increased load) after the shift event. This slipping may result in power dissipation within the transmission itself (e.g., due to energy loss when the clutch slips), even while power is being transferred through the transmission to the transmission output.Therefore, the power required at the transmission input can be significantly greater than the power available at the transmission output.

[0056] As a result of this power loss (or other factors), various adverse events may occur with respect to the engine 24, the transmission, or other vehicle systems. For example, due to the excessive power demand at the transmission input, the engine 24 may temporarily "stall" or suffer other reduced performance, which may be perceived by a user as hesitation of the vehicle 20 (or the engine 24). Similarly, the transmission may perform a non-ideal shift, which may be perceived by a user as a judder, stutter, or even stalling of the vehicle 20.

[0057] Smooth shifting, such as that provided by an ESD system, can help solve these (and other) problems. For example, during stationary (or other) operation of the vehicle 20, a portion of the power from the engine 24 can be directed to the ESD system (e.g., via an IVP) for storage (e.g., as stored electrical, hydraulic, kinetic, or other energy). During a shift event, as appropriate, the ESD system can then deliver a portion of the stored energy to the corresponding transmission (e.g., via the IVP) to supplement the power provided directly by the engine 24. In this manner, power delivery from the ESD system can allow for relatively smooth shifts, even when a shift event causes a power demand on a transmission that exceeds the (current) power output of the engine 24.This can be useful, for example, to avoid the need to increase engine speed during shifting. Furthermore, the use of an ESD system for shift smoothing can reduce the need for complex transmission designs (and controls) that might otherwise be necessary to provide smooth shifts across a variety of shift events.

[0058] An ESD system may provide various other benefits in addition to (or as an alternative to) smoothing shifting. In certain embodiments, an ESD system may be used for load balancing, where increases in power demand during operations other than shifting events may be met (at least in part) with stored energy from the ESD system rather than with increased power delivery from the engine 24. In certain implementations, this may allow the engine 24 to operate at a relatively constant load and a relatively constant speed during a large number of operations of the vehicle 20, which in turn results in more efficient use of a given configuration of the engine 24. Likewise, an ESD system may be used to power operation of the vehicle 20 (or a subsystem thereof) without continuous power delivery from the engine 24.For example, in a “pure” electric (or hydraulic) mode, where the engine 24 may not provide power to operate the vehicle 20, an ESD system may drive the operation of various vehicle systems using previously stored energy.

[0059] In certain embodiments, an ESD system may be included in or otherwise overlap with an IVP of the vehicle 20. For example, an IVP of the vehicle 20 may include a first IVP machine configured as an electric generator or a hydraulic pump, which may be configured to receive mechanical power from the engine 24 and convert the power into an electrical or hydraulic (or other) form accordingly. A battery or accumulator (or other energy storage device) may be in communication with the first IVP machine such that a portion (i.e., some or all) of the converted power may be directed to the battery or accumulator for storage. A second IVP machine of the IVP (e.g.,an electric motor or a hydraulic motor) may be configured to receive power from the battery or accumulator (or directly from the first IVP machine) and to convert the received power into a mechanical form for downstream components of the vehicle powertrain 22.

[0060] An ESD system can be controlled in various ways. In certain embodiments, the routing of power to and from an ESD system can be regulated using a controller configured as a computing device of various designs (e.g., a processor and memory architecture, a programmable electronic circuit, etc.). In certain embodiments, the operation of an ESD system (as part of the disclosed powertrain arrangement) can be regulated, for example, by the TCU 36, or it can be regulated by another controller (not shown).An ESD system can be controlled based on various inputs, including inputs from speed sensors (not shown) for the engine and other vehicle components, inputs from sensors (not shown) related to gear shifting, vehicle power consumption or demand, or inputs from various other devices (not shown).

[0061] Also with reference to Fig. 9, an exemplary powertrain arrangement including an ESD system is shown. The powertrain of Fig. 9 is configured to transmit mechanical power from an internal combustion engine 24d to various vehicle components and systems. As illustrated, mechanical power from the engine 24d is transmitted along a shaft S8 to a planetary gear set 48d and a double planetary gear set 50d, as well as to an electric generator 230. (It will be appreciated that in other configurations, a different IVP machine may be used instead of, or in addition to, the electric generator 230.) The electric generator 230 is in communication with a battery 234 (or other electrical energy storage device) and with an electric motor 232.Together, the electric generator 230 and the electric motor 232 may be considered an IVP 28d that is in communication with an ESD system 228 that includes the battery 234 (or batteries 234, as appropriate), as well as various other components (not shown), including various power electronics, controls, etc.

[0062] The planetary gear set 48d and the double planetary gear set 50d, as well as the IVP 28d are configured to operate in a similar manner to the planetary gear set 48, the double planetary gear set 50 and the IVP 28a from Fig. 3 (as discussed in detail above) to provide an MIVT 26d that has similar functionality to the MIVT 26a. However, the MIVT 26d may exhibit various differences. For example, in Fig. 9 that a shaft S16 is configured to receive power from the shaft S8 via the drive gear for the electric generator 230 to drive rotation of an auxiliary drive pulley 250. Similarly, a shaft S10, driven by a gear 44d of the shaft S8 (which also supplies power to the electric generator 230), may supply power to a transmission control, a suction pump, or other pump.

[0063] During operation, power from the engine 24d may be routed in various ways through the MIVT 26d to a transmission 84d (e.g., configured as a controllable gearbox) to provide continuously variable multi-mode power transmission to various vehicle systems. For example, as shown, an output gear 82d of the dual planetary gear set 50d is configured to mesh with input gears 236 and 238 of the transmission 84d. Accordingly, through selective operation of the clutches 252, the output gear 82d may drive rotation of one of the transmission shafts S11 and S13, respectively. Selective control of various other clutches 254 may be used to shift the transmission 84d into various range gears 240, 242, 244, 246, and 248, respectively, which may correspond to ranges A through E for the transmission 84d. In this way, power from the motor 24d as well as from the electric motor 232 can be directed to a differential drive shaft S12a.As shown, a brake 256 and a clutch 258 may also be controlled to transfer power from the transmission 84d for mechanical front-wheel drive to a drive shaft S12b. (It is understood that the illustrated configuration of the various gears of the transmission 84d is presented only as an example. An ESD system may also be used with respect to other configurations of the transmission 84d.)

[0064] Other devices and functionalities may also be provided. For example, it can be seen that gear 44d of shaft S8 is configured to rotate an impeller 68d on shaft S12a, as well as to provide power to electric generator 230. In turn, gear 68d may drive rotation of a PTO shaft S14, and in certain configurations, a front PTO shaft S15.

[0065] As regulated by a suitable controller (not shown), a portion of the power received at the electric generator 230, once converted to an electrical form, may be directed to an ESD 228 for storage in the battery 234. In certain embodiments, power from the electric generator 230 may be continuously directed to the battery 234 as long as the engine 24d is running and the battery 234 is not fully charged. In certain implementations, power from the electric generator 230 may be more selectively directed to the battery 234. For example, in certain control strategies, power from the electric generator 230 may only be directed to the battery 234 when it has been detected (e.g., by various engine or other sensors (not shown)) that the engine 24d is producing excess power relative to the current power demands of vehicle operation.

[0066] As needed, energy can be released from the battery 234 to drive operation of the electric motor 232. As described above with respect to the electric motor 42 of Fig. 3, power from the electric motor 232 may then be routed through the dual planetary gear set 50d to supplement (or replace) power from the engine 24d. This may be useful, for example, to ensure that adequate power is provided to the various systems and devices of the vehicle 20, even while maintaining the engine 24d at an ideal and relatively constant operating speed.

[0067] In certain implementations, power from the battery 234 may be used via the electric motor 232 for smooth shifts. For example, during (or before or after) a shift from the A-range gear 240 to the B-range gear 242, an appropriate controller may identify that additional power may be required at the transmission 84d to ensure a smooth shift and, in certain embodiments, to avoid the need to increase engine speed or power. Accordingly, for the A-to-B shift event (and other shift events), energy may be released from the battery 234 to the electric motor 232 so that the electric motor 232 can provide additional power to the transmission 84d (i.e., via the dual planetary gear set 50d).

[0068] A smooth shift as in the example described above may be implemented based on a variety of factors. For example, in certain implementations, a signal from the TCU 36 (or other device) may indicate that a shift between gears of the transmission 84d will soon occur (or is currently occurring, or has recently occurred). If such a shift event is identified (or expected) to result in a transient power event, power may be diverted from the ESD 228 accordingly. In certain implementations, engine sensors, shaft speed sensors, or other sensors (not shown) may detect indications of a lack of power at the transmission 84d (e.g., due to clutch slipping within the transmission 84d during a shift). Routing power from the ESD 228 to the transmission 84d may then be implemented accordingly.

[0069] In certain implementations, power from the battery 234 may be used for other operations. For example, when operation of the motor 24d is not possible or practical (e.g., during operation of the vehicle 20 within an enclosed space), energy from the battery 234 may be used to implement electric-only operation of the vehicle 20. In certain implementations, electric-only operation may be implemented automatically (e.g., based on receiving a drive or other command when the vehicle is started but the motor 24d is off). In certain implementations, electric-only operation may be implemented based on other factors (e.g., based on an operator actuating a particular switch, button, or lever).

[0070] As another example, where the use of a particular tool of the vehicle requires increased power from the vehicle 20, energy from the battery 234 may be used to ensure that adequate power is available at the tool without significant adverse effects on other vehicle systems (e.g., the vehicle drive wheels) or a significant increase in engine speed. For example, if a mechanical tool (e.g., a baler, seed drill, soil conditioner, cutting blade, etc.) is driven by the PTO shaft S14, or a hydraulic tool (e.g., a loader bucket, dump truck pad, excavator arm, soil conditioner, etc.) is driven using power from the front PTO shaft S15 or another shaft (i.e.,as converted by a suitable hydraulic pump (not shown)), the drivetrain of the vehicle 20 may be subject to increased power demands. Accordingly, in certain embodiments, during operation of such a tool, energy from the battery 234, as converted into mechanical energy by the electric motor 232, may be used to supplement (or replace) power from the engine 24d with respect to the corresponding tool (or vehicle system).

[0071] In certain implementations, power from battery 234 may be automatically used whenever any tool of the vehicle (or any tool of the vehicle of a particular configuration) is operated. In certain embodiments, power from battery 234 may be used more selectively. For example, engine sensors, shaft speed sensors, or other sensors (not shown) may detect indications of a lack of power due to tool operation, and power may be drawn from battery 234 accordingly.

[0072] Also referring to Fig. 10 is another exemplary MIVT 26e similar to the MIVT 26c from Fig. 7. An internal combustion engine 24e supplies mechanical power via a shaft S17 to a double planetary gear set 178e and to an electric generator 172e (or other IVP machine) contained within an IVP 28e. The electric generator 172e converts the mechanical power from the engine 24e into electrical power, which is sent via a power cable 176e to an electric motor 174e. The electric motor 174e then converts the electrical power into mechanical power, which is also sent to the double planetary gear set 178e. In this way, the MIVT 26e can be used via the double planetary gear set 178e to combine power from the engine 24e and the IVP 28e to provide continuously variable power with a limited gear range to a transmission 202e.

[0073] In the illustrated embodiment, the electric generator 172e is in electrical communication with a battery 260 (or other electrical energy storage device), as well as with the electric motor 174e. Together, the electric generator 172e and the electric motor 174e may be considered an IVP 28e that is in communication with an ESD system 262 that includes the battery 260 (or batteries 260, as appropriate), as well as various other components (not shown), including various power electronics, controls, etc. In this manner, mechanical energy from the motor 24e may be stored as electrical energy in the battery 260 and released, as appropriate, via the electric motor 174e to provide power to the double planetary gear set 178e. As with respect to the configuration of Fig. 9, energy from the battery 260 may be used to provide circuit smoothing, to operate the vehicle 20 in an electric-only mode, to power operation of a tool of the vehicle 20 (or to power other vehicle systems during operation of such a tool), etc.

[0074] It is understood that the various storage devices of an ESD system (e.g., batteries 234 and 260) may receive and store energy from motors other than the relevant ones (e.g., motors 24d and 24e). For example, in certain implementations, regenerative systems (e.g., systems for capturing energy from braking) may be configured to direct power to an ESD system for later use (e.g., smoothing shifting, electric-only operation, etc.), or they may form part of an ESD system. Likewise, it is understood that an ESD system may be used with powertrains and transmissions (including MIVTs) other than those specifically illustrated. In certain embodiments, an ESD system (not shown) may be described, for example, with reference to the system described in Fig. 5 shown drive train via a hydraulic accumulator 264 (see Fig. 5, hydraulic connections not shown) or with respect to various other drivetrain configurations (not shown).

[0075] Several of the processes described above (and others) can be implemented as part of a Transitional Performance Event Management (“TPEM”) process. Also referring to Fig. 11, for example, a TPEM method 300 for the vehicle 20 may be implemented by various controllers (e.g., the TCU 36) or other devices.

[0076] The TPEM method 300 may include identifying 302 a transient power event. For example, a controller may identify through an engine speed sensor, various shaft speed sensors, other sensors, or devices that a current (or upcoming) operating condition of the subject vehicle has resulted in (or is likely to result in) a power deficiency. For example, a shift 304 (e.g., a recent, current, or upcoming shift 304) may be identified during which a transmission may require more power from an engine (e.g., due to clutch slipping) than may be available from the engine (at least in the current operating condition). For example, due to clutch slipping during a shift, more power may be required from the engine at the input to a transmission than is available from the engine at the current engine speed.Similarly, an operation 306 of a tool (e.g., an ongoing or pending operation 306 of the tool) may be identified during which the power requirements of the tool (e.g., in combination with other power requirements for other vehicle systems) may exceed the available power from the engine. In certain implementations, identifying 302 a transient power event may include identifying 302 operation of the vehicle (or a subsystem thereof) while the engine is in a turned-off (or otherwise unpowered) state 308. For example, a drive operation or operation of a tool of the vehicle (e.g., a current or pending drive or tool operation) may be identified while the engine is in a turned-off state 308.

[0077] The TPEM method 300 may further include causing 320 an energy storage device (e.g., such as may form part of a larger ESD system) to supply stored energy to a component of an IVP (e.g., an IVP machine). For example, the TPEM method 300 may be used to cause energy to be supplied from a battery to an electric motor, to cause energy to be supplied from a hydraulic accumulator to a hydraulic motor, etc. (In certain implementations, it will be understood that this is preceded by the TPEM method 300 causing energy to be stored in the IVP. In certain implementations, energy may be stored in the IVP in other ways.)

[0078] The TPEM method 300 may then include providing 330 power from the IVP component (e.g., an IVP motor) to a transmission. For example, the TPEM method 300 may include providing power from an electric or hydraulic motor to an MIVT of various configurations, to a transmission with fixed gear ratios, or to other transmissions included in the subject powertrain.

[0079] In certain implementations, the TPEM method 300 may further include providing 340 power from the engine to the transmission. For example, when the engine is not in a shut-down state 308, an MIVT (or other device) may be used to sum the power received from the engine and the IVP, respectively, so that power from both the engine and the IVP may be provided to the respective transmission.

[0080] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It is further understood that any use of the terms "comprises" and "comprising" in this specification specifies the presence of said features, integers, steps, acts, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, acts, elements, components, and / or groups thereof.

Claims

[1] A powertrain assembly for a work vehicle having an engine, the powertrain assembly comprising a continuously variable power source (28d; 28e); an energy storage device (228; 262) configured to receive energy from the continuously variable power source (28d; 28e) for storage and to provide stored energy from the energy storage device (228; 262) to drive one or more components (232; 174e) of the continuously variable power source (28d; 28e); and a transmission (26d; 26e) configured to transfer power from the engine (24d; 24e) and from the one or more components (232; 174e) of the continuously variable power source (28d; 28e) to one or more components (24d; 262e) of the vehicle (20); and a controller (36) configured to: identify a transient power event during which the engine (24d;24e), while operating in a current operating state, provides insufficient power for one or more operations of the vehicle (20); and based on identifying the transient power event, to cause the energy storage device (228; 262) to provide stored energy from the energy storage device (228; 262) to drive the one or more components (232; 174e) of the continuously variable power source (26d; 26e); wherein the transmission (26d; 26e) receives power from the energy storage device (228; 262) via the one or more components (232; 174e) of the continuously variable power source (28d; 28e) during the transient power event such that the one or more operations of the vehicle (20) are performed at least in part using stored energy from the energy storage device (228;262), the powertrain assembly further comprising: a continuously variable transmission (26e) comprising: a double planetary gear set (178e) comprising a first input component (180), a second input component (182), and an output component (186); a first clutch (196); a second clutch (198); and a brake (200); wherein the first input component (180) is configured to receive a first mechanical power input to the double planetary gear set (178) from the engine (24e); wherein the first clutch (196) is configured to engage the first input component (180) to control a mechanical power transfer between the first input component (180) and the engine (24e);wherein the second input component (182) receives a second mechanical power input for the dual planetary gear set (178e) from the one or more components (174e) of the continuously variable power source (26e); and wherein the dual planetary gear set (178e) is configured to sum mechanical power from the engine (2eb) and the one or more components (174e) of the continuously variable power source (28e) and to provide the summed power to the output component (186), the output component (186) providing the summed power directly to the transmission (26e), whereby the transmission (26e) receives power from the energy storage device via the output component (186) during the transient power event, and the first input component comprises a first sun gear (180) and the second input component comprises a second sun gear (182);and wherein a first ring gear (190) of the double planetary gear set (178e) is formed integrally with a first planetary gear carrier (184) supporting one or more first planetary gears (192) that mesh with both the first sun gear (180) and a second ring gear (188) of the double planetary gear set (178e); and wherein the output component includes a second planetary gear carrier (186) supporting one or more second planetary gears (194) that mesh with both the second sun gear (182) and the first ring gear (190) of the double planetary gear set (178e), the brake (200) being configured to engage the second ring gear (188) to stop rotation of the second ring gear (188); characterized byin that the continuously variable power source (28d, 28e) comprises a plurality of a pair of electric machines (230, 232; 172e, 174e); and wherein the energy storage device (228; 262) comprises one or more of an electrical storage device, and the second clutch (198) is configured to engage one or more of the second ring gear (188) and the first planetary gear carrier (184) to control relative movement of the second ring gear (188) and the first planetary gear carrier (184). [2] Drive train arrangement according to claim 1, characterized by that the transmission (26d) also receives mechanical power from the engine (24d) during the transient power event, such that the one or more operations of the vehicle (20) are performed at least partially using mechanical power from the engine (24d) and stored energy from the energy storage device (228). [3] Drive train arrangement according to claim 1 or 2, characterized by that the transient power event comprises a shift; and wherein a power requirement to perform the one or more operations of the vehicle (20) during the shift at the transmission (26d) exceeds the power provided by the engine (24d) in the current operating state. [4] Drive train arrangement according to at least one of claims 1 to 3, characterized by that the transient power event comprises operation of a tool of the vehicle (20); and wherein a power requirement for operation of the tool exceeds the power available from the engine (24d) in the current operating state of the engine (24d) for operation of the tool. [5] Drive train arrangement according to claim 1, characterized bythat the engine (24d) is switched off in the current operating state, so that no power is provided by the engine (24d) to the vehicle (20) during the transient power event.

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