BR102022016970A2 - TRANSMISSION ASSEMBLY AND WORKING VEHICLE - Google Patents

Abstract

A transmission assembly for a single-engine work vehicle includes a variator operatively connected to the engine, a gear arrangement configured to provide a selective gear reduction for transmitting output power from the variator to an output shaft, and a drive unit. electric machine. The electrical machine unit further includes a main shaft operatively connected to the variator, a first rotor configured to rotationally drive a first shaft, a second rotor configured to rotationally drive a second shaft, and a clutch configured to selectively engage the first or second shaft. axis, or both the first axis and the second axis, to the main axis. The clutch, first rotor and second rotor are operable to control a rotational speed and direction of the mainshaft in providing rotational power to the variator.

Description

TRANSMISSION ASSEMBLY AND WORKING VEHICLE DESCRIPTION FIELD

[001] This description generally refers to powertrains for the operation of work vehicles for agricultural, forestry, construction and other applications.

FUNDAMENTALS OF DESCRIPTION

[002] It may be useful, in a variety of work vehicles, to use both a traditional engine (e.g., an internal combustion engine) and at least one electrical machine (engine/generator) to provide useful power to an output member . For example, a portion of the engine's power can be diverted to drive a first electrical machine which, in turn, can drive a second electrical machine. Motor and second electrical machine power can be delivered to the output member (for example, a vehicle wheel axle or other output shaft) in a parallel or dual path configuration. The engine, electrical machine(s) and output member may be operationally connected via an infinitely variable transmission (“IVT”) or continuously variable transmission (“CVT”).

DESCRIPTION SUMMARY

[003] A transmission assembly for a work vehicle with an engine includes a variator operatively connected to the engine, a gear arrangement configured to provide a selective gear reduction for transmitting output power from the variator to an output shaft, and an electrical machine unit. The electrical machine unit further includes a main shaft operatively connected to the variator, a first rotor configured to rotationally drive a first shaft, a second rotor configured to rotationally drive a second shaft, and a clutch configured to selectively engage the first or second shaft. axis, or both the first axis and the second axis, to the main axis. The clutch, first rotor and second rotor are operable to control a rotational speed and direction of the mainshaft in providing rotational power to the variator.

[004] In another implementation, a work vehicle includes an engine and a transmission assembly, with the transmission assembly additionally including a variator operatively connected to the engine, a gear arrangement configured to provide a selective gear reduction for power transmission variator output to an output shaft, and an electrical machine unit. The electrical machine unit further includes a main shaft operatively connected to the variator, a first rotor configured to rotationally drive a first shaft, a second rotor configured to rotationally drive a second shaft, and a clutch configured to selectively engage the first or second shaft. axis, or both the first axis and the second axis, to the main axis. The clutch, first rotor and second rotor are operable to control a rotational speed and direction of the mainshaft in providing rotational power to the variator.

[005] Details of one or more embodiments are shown in the attached drawings and in the following description. Other features and benefits will become apparent from the description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[006] At least one example of the present description will be described below in combination with the following figures:
FIG. 1 illustrates an exemplary work vehicle incorporating a transmission assembly that provides improved shift quality, in accordance with one embodiment;
FIG. 2 is a schematic diagram of an exemplary transmission assembly included in the working vehicle of FIG. 1, according to an embodiment;
FIG. 3 is a schematic diagram of an exemplary transmission assembly included in the working vehicle of FIG. 1, according to another modality;
FIG. 4 is a flowchart of a control scheme for shifting transmissions in a work vehicle during shifting between different speed modes or directional modes; It is
FIG. 5 is a flowchart of a control scheme for shifting transmissions on a work vehicle in response to a load accumulation event.

[007] Similar reference symbols in the various drawings indicate similar elements. For the sake of clarity and conciseness of illustration, descriptions and details of well known resources and techniques may be omitted to avoid unnecessarily obscuring the exemplary and non-limiting embodiments described in the subsequent Detailed Description. It should be further understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise indicated.

DETAILED DESCRIPTION

[008] The embodiments of the present description are shown in the attached figures of the drawings described briefly above. Various modifications to the exemplary embodiments can be contemplated by one skilled in the art without departing from the scope of the present invention, as presented in the appended claims.

OVERVIEW

[009] As previously noted, various types of work vehicles, such as backhoe loaders and tractors as examples, may include a powertrain with an IVT that transfers power from an engine and one or more electrical machines to an output member, such as an axle vehicle wheel or other output shaft. In the use of such work vehicles, it is understood that the IVT will operate in several modes determined by the specific operating conditions and parameters of the work vehicle, which can be generically identified as mode 1, mode 2, etc. The IVT modes control the speed and torque of the output shaft, for example, with the operation of various gears and clutches in the IVT, as well as the operation of electrical machines, being determined by the specified mode.

[0010] It is noticed that the electrical machines used in many current IVTs operate at very high speeds, such as speeds of up to 10,000 RPM, for example. In order to accommodate the high speed and torque produced by these electrical machines, the transmission must incorporate deeper gear sets that are capable of taking the electrical machine's output speed and torque and reducing it below a value necessary for transfer. to the output shaft for a desired drive application. The use of such deeper gear sets, however, results in a large amount of rotor inertia being transferred from the electrical machine to the transmission, i.e. a high “reflected inertia”. This reflected inertia is problematic when changing modes on the work vehicle, specifically for a parallel or dual path IVT, where engine power and electrical machine power are summed in the IVT variator for transfer to the output shaft. That is, in dual path IVT operation, the electrical machine needs to change its torque output from positive to negative to allow IVT operation in different modes. With a large amount of inertia reflected in the system, it is extremely difficult to achieve such torque reversal without significantly affecting the perceived shift quality in the work vehicle.

[0011] To allow better shifting quality in a dual path IVT, a transmission assembly is provided for a work vehicle in which the transmission assembly includes an electric machine unit with two separately and independently driven rotors (a first rotor and a second rotor) in it, along with a clutch that selectively couples the rotors' output speed to the variator in the transmission. Each of the rotors in the electric machine unit drives a respective shaft, and the clutch can engage either one of the shafts, or both shafts, to a main shaft that sends rotational power from the electric machine unit to the variator. The rotors can be driven in either the forward or reverse direction, so selective operation of the clutch and the two rotors can control both the speed and rotational direction of the mainshaft in providing rotational power to the drive.

[0012] In one embodiment, the operation of the electric machine unit is controlled by a controller to reduce the inertia in the transmission during switching between different operating modes. The controller is operatively connected to the transmission assembly and the electrical machine unit, with the controller selectively operating the transmission assembly in a first transmission mode or in a second transmission mode, and controlling the operation of the electrical machine unit and the clutch based on operation in the first transmission mode or the second transmission mode, or based on a shift that occurs between the first and second transmission modes. With the transmission assembly operating in the first transmission mode or the second transmission mode, the controller can operate the electric machine unit to drive the first rotor and second rotor in tandem in either the forward rotational direction or the reverse rotational direction. During a driving and shifting of the drive train from the first drive mode to the second drive mode, the controller can operate the electrical machine unit to drive the first rotor and the second rotor in opposition, with the first rotor driven in the rotational direction. forward and the second rotor driven in the reverse rotational direction.

[0013] When controlling the electric machine unit according to one modality, the controller operates to identify an upcoming change in the transmission set from the first transmission mode to the second transmission mode. Before shifting from the first transmission mode to the second transmission mode, the controller makes the second shaft clutch disengage from the main shaft and controls the electric machine drive to drive the second rotor and second shaft in the reverse rotational direction after disengagement of the second shaft from the main shaft. When subsequently changing from the first transmission mode to the second transmission mode, the controller then causes the clutch to re-engage the second shaft to the mainshaft and disengage the first shaft from the mainshaft, causing the mainshaft to be driven in the rotational direction. reverse. After disengaging the first shaft from the main shaft and after switching from the first transmission mode to the second transmission mode, the controller then controls the electric machine unit to drive the first rotor and first shaft in the reverse rotational direction and causes the clutch re-engage the first shaft to the mainshaft. Operating the electrical machine in this manner before and during shifting the transmission assembly from the first transmission mode to the second transmission mode reduces inertia in the electrical machine unit and transmission during the shift.

[0014] In the control of the electric machine unit according to another modality, the controller operates to monitor the speed and torque parameters in the transmission assembly through a torque observer program. The controller identifies a build-up load condition based on the monitored speed and torque parameters and, in response to this, determines a next driveline downshift required to handle the build-up load condition. The controller then controls the clutch to selectively disengage either the first axle or the second axle, or both the first axle and the second axle, from the mainshaft prior to downshifting the driveline.

[0015] Examples of embodiments of a work vehicle with a transmission assembly and controller-operated electric machine unit that implement a transmission shift control scheme to reduce system inertia in the work vehicle are provided in FIGS. 1-4 according to that description. Notwithstanding the following examples, other types of work vehicles and other transmission configurations would also benefit from the electric machine unit and associated control scheme described below. It is, therefore, recognized that aspects of the invention are not intended to be limited solely to the specific embodiments described below.

EXAMPLES OF MODALITIES OF A TRANSMISSION ASSEMBLY WITH ELECTRIC MACHINE UNIT FOR BETTER QUALITY OF CHANGE

[0016] Referring initially to FIG. 1, a working vehicle 10 is shown which can implement details of one or more embodiments. In the illustrated example, the work vehicle 10 is represented as a backhoe and is therefore referred to below as "backhoe 10". It is understood, however, that other configurations may be possible, including configurations with the working vehicle as a mining machine, tractor, harvester, trailed forestry machine or one of several other types of working vehicles.

[0017] The backhoe loader 10 includes a chassis 12 and a ground engaging mechanism or ground drive member 14. The ground engaging mechanism 14 is capable of supporting the chassis 12 and propelling the chassis 12 through the ground. While the illustrated backhoe 10 includes wheels as the ground engaging mechanism 14, the backhoe 10 may include other ground engaging mechanisms, such as steel tracks, rubber mats, or other suitable ground engaging members.

[0018] The backhoe 10 further includes a loader assembly 16 and a backhoe assembly 22. As illustrated in FIG. 1, the loader assembly 16 includes a loader boom 18 and a work tool 20 in the form of a bucket. The work tool 20 may be capable of moving, digging, plowing or performing other material handling functions in a load such as dirt or other materials. Other suitable work tools include, for example, blades, pallet forks, bale lifters, augers, harvesters, plowers, mowers and grapples. The loader boom 18 is configured to move relative to the chassis 12 to move and operate the work tool 20. The backhoe assembly 22 of the backhoe 10 includes a backhoe boom 24 and a tool such as a backhoe bucket 26 with telehandler tool features. The backhoe boom 24 is attached to the frame 12 by a swing frame, with the backhoe boom 24 being pivotable with respect to the frame 12. The backhoe bucket 26 is in turn pivotally mounted on the backhoe boom 24 and extendable out of it through an extensible digging arm, so that the backhoe bucket 26 has more freedom of movement during operation.

[0019] An operator or autonomous control can operate the backhoe 10, including the ground engaging wheels 14, the loader assembly 16 and the backhoe assembly 22, from an operator station 28 on the backhoe 10. Although not shown in FIG. 1, it is seen that operator station 28 may include a human-vehicle interface 30 and various controls configured therein to receive operator input commands to control, for example, various electrical or hydraulic systems associated with actuation and control of loader assembly 16 and the backhoe assembly 22. The human-vehicle interface 30 may be configured in a variety of ways and may include input devices 32 which may include one or more levers, various switches or levers, one or more buttons, a touch screen interface touch that can be superimposed on a display, a keyboard, a loudspeaker, a microphone associated with a speech recognition system, or various other human-machine interface devices.

[0020] The backhoe 10 includes a controller 34 (or multiple controllers) to control various aspects of the operation of the backhoe 10. Generally, the controller 34 (or others) can be configured as a computing device with associated processor devices 34a and architectures of memory 34b, such as a wired computing circuit (or circuits), such as a programmable circuit, such as a hydraulic, electrical or electro-hydraulic controller, or otherwise. As such, controller 34 can be configured to perform various computational and control functionality with respect to backhoe loader 10. In some embodiments, controller 34 can be configured to receive input signals in various formats (e.g., as hydraulic signals, signals voltage signals, current signals, and so on) and output command signals in various formats (for example, as hydraulic signals, voltage signals, current signals, mechanical movements, and so on). In one embodiment, the controller 34 can be configured to receive input commands and interface with the operator via the human-vehicle interface 30.

[0021] Controller 34 may be in electronic, hydraulic, mechanical or other communication with various other systems or devices of the backhoe 10. For example, controller 34 may be in electronic or hydraulic communication with various actuators, sensors and other devices within (or outside) of the backhoe 10, including various devices described below. Controller 34 may communicate with other systems or devices (including other controllers) in a number of known ways, including via a CAN bus (not shown) from backhoe loader 10, via wireless or hydraulic communication, or otherwise. An exemplary location for controller 34 is shown in FIG. 1; however, it is understood that other locations on the backhoe loader 10 are possible.

[0022] As described in more detail below, the controller 34 can facilitate input of various types of operator commands and collection of various types of vehicle operating parameter data associated with the backhoe loader 10 as part of implementing a shift scheme transmission on the backhoe loader 10. As indicated above, operator commands can be entered into the controller 34 via the human-vehicle interface 30, while the vehicle operating parameter data can be in the form of raw data from the applicable sensors described below ( or other sources) or undergo some processing in the controller 34 to extract the desired features. The inputs and data received by the controller 34 are used to switch between different transmission modes in the backhoe 10 through the operation and control of a transmission 36 included in the backhoe 10, regarding which more detail will be provided below.

[0023] The backhoe loader 10 includes a propulsion source that, in an exemplary embodiment, is provided as a hybrid electric drive system that includes a motor 38 and a plurality of electric machine units 40, 42. The motor 38 and the electric machine units 40, 42 can power the transmission 36.

[0024] In one example, engine 38 is an internal combustion engine, such as a diesel engine, which is controlled by controller 34 to allow engine 38 to start, enable engine 38 to stop, disable engine 38 operation and/or modify some aspect of the operation of the engine 38 or associated system, for example, based on input received from the human-vehicle interface 30. The backhoe loader 10 may include an engine speed sensor 46 configured to determine the speed of the engine 38 during the operation.

[0025] In one example, the electrical machine units 40, 42 are AC motors, such as permanent magnet AC motors or induction motors. In one implementation, and as will be explained in more detail in FIG. 2, a first electrical machine unit 40 can receive mechanical power from the motor 38 and convert that power into electrical energy, with electrical energy from the first electrical machine unit 40 then being supplied to the second electrical machine unit 42. This electrical energy can then be reconverted by the second electrical machine unit 42 to mechanical output. The electrical machine units 40, 42 may be controlled by the controller 34 to control a speed and operating mode thereof, with the first electrical machine unit 40 operable in a "regenerative mode" to convert mechanical power into electrical energy and the second unit of electric machine 42 operable in “motor mode” to convert electrical energy into mechanical power.

[0026] The transmission 36 transfers power from the engine 38 and the second electric machine unit 42 to a suitable drive line (not shown) coupled to the ground engagement wheels 14 of the backhoe 10, which may include front and rear wheels, to allow the backhoe 10 to move. As described in more detail below with reference to FIG. 2, the transmission 36 can be configured as a hybrid electric transmission or IVT which combines the outputs of both the motor 38 and the second electric machine units 42 to provide a final power delivery (e.g. to a vehicle wheel axle) , more details of which will be provided below. Transmission 36 may include sensors 48 that measure one or more characteristics of transmission 36, such as transmission output speed, transmission torque and transmission gearing, for example.

[0027] Referring to FIG. 2, an example of a hybrid electric transmission assembly 84 included in the backhoe loader 10 is illustrated which provides a more detailed discussion of the structure and arrangement of the engine 38, electric machine units 40, 42 and transmission 36 of the backhoe loader 10 and how the transmission 36 can be operated to reduce inertia in transmission 36 as part of a transmission shift scheme implemented by controller 34. It will be appreciated that transmission assembly 84 illustrated in FIG. 2 and described hereinafter is only an example and that transmissions with different arrangements or constructions could incorporate details of this description.

[0028] In the illustrated embodiment, the transmission assembly 84 includes the transmission 36, the first electrical machine unit 40 and the second electrical machine unit 42. The first electrical machine unit 40 and the second electrical machine unit 42 can be connected by a conduit 90. A power inverter 92 may be included and may be operatively connected to the first electrical machine unit 40 and/or to the second electrical machine unit 42. In some embodiments, the power inverter 92 can power and/or or receive power from a battery pack 93 (change in FIG. 2). Also, the power inverter 92 can supply and/or receive power from the transmission assembly 84. Additionally, in some embodiments, the power inverter 92 can dump power to an implement and/or other power discharging device (not showing ).

[0029] The transmission 36 transfers power from the engine 38 and the second electric machine unit 42 to an output shaft 94. As described below, the transmission 36 includes various gear, clutch and control assemblies to properly drive the output shaft 94 at different speeds and in multiple directions. Generally, in one example, the transmission 36 of the transmission assembly 84 may be any type of electrical infinitely variable transmission (eIVT) arrangement, it being recognized that alternatives to the transmission illustrated in FIG. 2 can be included in transmission set 84.

[0030] The motor 38 can provide rotational power via a motor output element, such as a flywheel, to a motor shaft 96 in accordance with commands from the controller 34 based on the desired operation. Shaft 96 may be configured to provide rotational power to a gear 98 and a gear 99. Gear 98 may be engaged with a gear 100, which may be supported on (e.g., attached to) a shaft 102. Shaft 102 may be substantially parallel to and spaced from motor shaft 96. Shaft 102 can support various drive train components 84 as will be discussed in detail.

[0031] The gear 99 can be engaged with a gear 104, which is supported on (e.g., attached to) a shaft 106. The shaft 106 can be substantially parallel and spaced from the motor shaft 96, and the shaft 106 can be connected to the first electrical machine unit 40. In this way, the mechanical power of the motor (i.e. engine power) can be transferred through the motor shaft 96 to the meshed gears 99, 104, to the shaft 106 and to the first electrical machine unit 40. The first electrical machine unit 40 can convert this power into electrical energy for transmission through conduit 90 to the second electrical machine unit 42. This converted and transmitted power can then be reconverted by the second electrical machine unit 42 for output along an axis 108. Various known control devices (not shown) can be provided to regulate such conversion, transmission, reconversion and so on. Furthermore, in some embodiments, shaft 108 can support a gear 110 (or other similar component). Gear 110 is meshable and can transfer power to a gear 112. Gear 110 is also meshable and can transfer power to a gear 114. Consequently, the power of the second electrical machine unit 42 can be split between gear 112 and gear 114 for transmission to other components as will be discussed in more detail below.

[0032] The transmission assembly 84 can additionally include a variator 116 that represents an example of an arrangement that allows an infinitely variable power transmission between the motor 38 and the second electrical machine unit 42 and the output shaft 94. embodiments, variator 116 may include at least two sets of planetary gears. In some embodiments, the planetary gearset can be interconnected and supported on a common shaft, such as shaft 102, and the planetary gearsets can be substantially concentric. In other embodiments, the different sets of planetary gears can be supported on separate respective shafts which are not concentric. The arrangement of planetary gear sets can be configured according to the space available inside the backhoe 10 to pack the transmission set 84.

[0033] As shown in the embodiment of FIG. 2, the variator 116 may include a first planetary gear set (i.e., a "low" planetary gear set) with a first sun gear 118, first planet gears and associated support 120, and a first ring gear 122. the variator 116 may include a second planetary gear set (ie, a "tall" planetary gear set) with a second sun gear 124, second planet gears and associated support 126, and a second ring gear 128. bracket 126 can be attached directly to first ring gear 122. Also, second planetary gears and bracket 126 can be attached directly to a shaft 130 having a gear 132 attached thereto. Furthermore, the second ring gear 128 can be attached directly to a gear 134. As shown, shaft 130, gear 132 and gear 134 can each receive and be substantially concentric with shaft 102. Although not specifically shown, it will be appreciated It is understood that the transmission assembly 84 can include several bearings to concentrically support these components. Specifically, shaft 130 can be rotationally attached via a bearing to shaft 102 and gear 134 can be rotationally attached via another bearing to shaft 130.

[0034] On the opposite side of the variator 116 (from left to right in FIG. 2), the gear 114 can be mounted (for example, fixed) on a shaft 136, which also supports the first and second sun gears 118, 124 In some embodiments, shaft 136 may be hollow and may receive shaft 102. A bearing (not shown) may rotationally support shaft 136 on shaft 102 substantially concentrically.

[0035] Furthermore, the first planetary gears and the associated support 120 can be attached to a gear 138. The gear 138 can be meshed with an ar gear 140, which is attached to a shaft 142. The shaft 142 can be substantially parallel and spaced from axis 102.

[0036] As noted above, the transmission assembly 84 can be configured to deliver power (from the motor 38 and the second electric machine unit 42) to the output shaft 94 through the transmission 36. The output shaft 94 can be configured to transmit that received power to the ground engaging mechanism 14 of the backhoe 10.

[0037] The transmission assembly 84 can operate in what can alternatively be described as a parallel path, dual path or split path mode, so that the power of the motor 38 and the second electrical machine unit 42 can be summed by the variator 116, with summed or combined power delivered to output shaft 94. Drive assembly 84 may also have different speed modes in split path mode and these different speed modes may provide different ranges of angular velocity to the output shaft 94. Furthermore, the transmission assembly 84 can have one or more forward modes for moving the backhoe 10 in a forward direction and one or more reverse modes for moving the backhoe 10 in a reverse direction. According to the embodiments, it is also possible for the transmission assembly 84 to operate in a direct drive mode where the power of the motor 38 can be transmitted to the output shaft 94, and the power of the second electrical machine unit 42 cannot be transmitted. be transferred to the output shaft 94, or in a series mode in which the power from the second electric machine unit 42 can be transmitted to the output shaft 94 and the power from the motor 38 cannot be transferred to the output shaft 94.

[0038] The transmission set 84 can switch between speed or directional modes (or from dual path mode to series or direct drive mode), for example, using a control set 144. The control set 144 may include one or more selectable transmission components. Selectable transmitting components can have first positions (engaged positions), in which the respective device transmits power from an input component to an output component. Selectable transmitting components can also have a second position (a disengaged position) in which the device prevents the transmission of power from the input component to the output component. The selectable transmission components of control assembly 144 may include one or more wet clutches, dry clutches, collar clutches, brakes, synchronizers, or other similar devices. Control assembly 144 may also include an actuator for actuating selectable transmission components between the first and second positions.

[0039] As shown in FIG. 2, the control assembly 144 may include a first clutch 146, a second clutch 148, a third clutch 150, a fourth clutch 152, and a fifth clutch 154. Also, the control assembly 144 may include a direct directional clutch 156 and a reverse directional clutch 158. In some embodiments, the first clutch 146 may be mounted and supported on a shaft 160. Also, the first clutch 146, in an engaged position, may engage gear 112 with shaft 160 for rotation as a unit. The first clutch 146, in a disengaged position, can allow gear 112 to rotate relative to shaft 160. Also, a gear 162 can be attached to shaft 160 and gear 162 can be meshed with gear 132 that is attached to shaft 130. Reverse directional clutch 158 may be supported on shaft 160 (ie, commonly supported on shaft 160 with first clutch 146). Reverse directional clutch 158 is engageable and alternatively disengages from gear 162 and a gear 164. Gear 164 is meshable with idler gear 166 and idler gear 166 is meshable with gear 168. Forward directional clutch 156 is meshable with be supported on gear 168 which in turn is supported on shaft 102 to selectively engage shaft 130. Thus, front directional clutch 156 may be concentric with either shaft 130 or shaft 102. Second clutch 148 may be supported on gear 168. supported on shaft 142. The second clutch 148 can engage and alternatively disengage shaft 142 and a gear 170. Gear 170 can be engaged with a gear 172. Gear 172 can be attached and mounted on a countershaft 174. The countershaft 174 can also support a gear 176. Gear 176 can be meshed with a gear 178, which is attached to output shaft 94.

[0040] The third clutch 150 can be supported on a shaft 180. The shaft 180 can be substantially parallel and spaced at a distance from the shaft 142. Also, a gear 182 can be attached and supported by the shaft 180. The gear 182 can be meshed with gear 134 as shown. Third clutch 150 can engage and alternatively disengage from gear 182 and a gear 184. Gear 184 can be engaged with gear 172. Fourth clutch 152 can be supported on shaft 142 (in common with second clutch 148). The fourth clutch 152 can engage and alternatively disengage from the shaft 142 and a gear 186. The gear 186 can be engaged and meshed with a gear 188, which is mounted and attached to the countershaft 174. In addition, the fifth clutch 154 can be supported on shaft 180 (in common and concentric with the third clutch 150). Fifth clutch 154 can engage and alternatively disengage shaft 180 and a gear 190. Gear 190 can be engaged with gear 188.

[0041] As previously indicated, the transmission assembly 84 is operable in various modes based on the selective operation of the transmission, including a split path mode in which the power of the motor 38 and the second electric machine unit 42 are combined. As introduced herein, controller 34 is coupled to control assembly 144 to control one or more actuators and, as a result, control movement of one or more selective transmission components within transmission 36, including first clutch 146, second clutch 148, third clutch 150, fourth clutch 152, fifth clutch 154, forward directional clutch 156, and reverse directional clutch 158. Generally speaking, controller 34 operates control assembly 144 as well as motor 38 and the second electrical machine unit 42, to implement the desired function, for example, to achieve the requested torque on the output shaft 94 for general control of the backhoe loader 10. This includes vehicle accelerations, stops, starts, changes between gear ratios, changes between directions and the like.

[0042] According to the embodiments, the transmission 36 and the second electrical machine unit 42 are operable to reduce the inertia in the transmission 36 (i.e., the various gears thereof) when the transmission assembly 84 is switching between modes of operation, such as when the transmission assembly 84 is switching between speed modes or forward and reverse modes during normal operation or when the transmission assembly 84 is forced to shift in response to a load build-up condition (i.e., introduction of a sudden large external load to the transmission assembly 84. As described below, the structure of the second electrical machine unit 42 and the operation thereof by the controller 34 reduces the amount of inertia transferred from the second electrical machine unit 42 to the transmission 36 (i.e. reflected inertia) during such a shift.

[0043] Referring further to FIG. 2, the second electrical machine unit 42 is shown as being configured as a split-rotor electrical machine that is housed within a unitary housing 192. The split-rotor electrical machine includes a first rotor portion 194 (here after "first rotor"). 194") and a second rotor portion 196 (here after "second rotor 196") which are separately and independently drivable. The first rotor 194 and the second rotor 196 are driven by means of electromagnetic interaction with a stator assembly 198 which, in the illustrated embodiment, is composed of a first stator 200 and a second stator 202 which are constructed separately, although it is understood that the assembly of stator 198 could instead be constructed as a single stator driving both rotors 194, 196. Through interaction with the first stator 200, the first rotor 194 rotationally drives a first shaft 204 coupled thereto and, accordingly, Likewise, the second rotor 196 rotationally drives a second shaft 206 coupled thereto through interaction with the second stator 202.

[0044] Also included in the second electrical machine unit 42 and within the unit housing 192 are gears 208 and a clutch arrangement 210. The clutch arrangement 210 is configured as a dual clutch configured to selectively engage and disengage each of the first axis 204 and the second axis 206 of the axis 108 (hereinafter referred to as the "main axis 108" of the second electric machine unit 42). Clutch arrangement 210 therefore allows mainshaft 108 to be driven by first shaft 204 only (via first rotor 194), second shaft 206 only (via second rotor 196), or both first shaft 204 and the second axis 206.

[0045] An alternative embodiment of the second electrical machine unit 42 is shown in FIG. 3, with the second electrical machine unit 42 being comprised of separate first and second electrical machines 212, 214 which are separately and independently actuable. The first electrical machine 212 includes a first rotor 194 and a first stator 200, while the second electrical machine 214 includes a second rotor 196 and a second stator 202. Through interaction with the first stator 200, the first rotor 194 rotationally drives a first shaft 204 coupled thereto and, similarly, the second rotor 196 rotationally drives a second shaft 206 coupled thereto through interaction with the second stator 202.

[0046] Gear 208 and a clutch arrangement 210 are also included in the second electric machine unit 42. The clutch arrangement 210 is configured to selectively engage and disengage each of the first shaft 204 and the second shaft 206 from the main shaft 108 of the second electric machine unit 42. The clutch arrangement 210 therefore allows the mainshaft 108 to be driven only by the first shaft 204 (via the first rotor 194), only by the second shaft 206 (via the second rotor 196) , either by the first axis 204 or by the second axis 206.

[0047] In each of the embodiments of the second electrical machine unit 42 shown in FIGS. 2 and 3, the controller 34 operates the second electrical machine unit 42 in a controlled manner to control a rotational direction and torque output thereof. The controller 34 can operate the second electrical machine unit 42 to provide a desired torque output to the variator 116 during operation of the transmission 36 in a specified operating mode. The controller 34 may also, as previously indicated, operate the second electrical machine unit 42 in accordance with a transmission shift scheme when it is determined that a transmission shift must occur for transmission 36, in order to reduce inertia in the transmission. 36 (i.e. the various gears thereof) during transmission shift. That is, it is noticed that during switching between different operational modes of the transmission assembly 84 (between speed modes or direct and reverse modes, for example), it may be necessary to change a direction of the torque output of the second electrical machine unit 42 (i.e. positive to negative or negative to positive). The second electrical machine unit 42 can therefore be selectively controlled by the controller 34 to reduce the inertia in the transmission 36 during alternation of the direction of torque output from the second electrical machine unit 42.

[0048] Referring now to FIG. 4, and continuing with reference to FIGS. 1-3, a flowchart of a method 220 for controlling the operation of the second electrical machine unit 42 during the operation of the transmission assembly 84 is provided in accordance with the present description, as may be performed by the controller 34. Generally, the method 220 is implemented during operation of the backhoe 10, with the transmission assembly 84 of the backhoe 10 operating in a particular mode or when it is necessary to switch between different modes.

[0049] Method 220 begins at step 222 with transmission assembly 84 operating in a current operating mode. During operation in this current mode, the controller 34 operates the control assembly 144 (i.e., selectable transmission components thereof), as well as the motor 38 and second electrical machine unit 42, to achieve the requested torque on the drive shaft. output 94 for general control of backhoe loader 10. Method 220 then continues to step 224 monitoring input commands from an operator and/or monitoring various operating characteristics or parameters of backhoe loader 10 and drive train 84. Monitoring of operating characteristics may usually be performed by sensors included in the backhoe loader 10 (e.g., sensors 48 in FIG. 1) that measure one or more characteristics of the drivetrain 84, such as transmission output speed, transmission torque, and transmission gearing, for example. .

[0050] Operator commands and/or readings of the operating characteristics of the transmission assembly 84 are provided to the controller 34 and, in step 226, a determination by the controller 34 whether a change from a current transmission operating mode to another operating mode transmission is imminent. If controller 34 determines that no imminent change has been identified, as indicated at 228, then method 220 returns to step 222, with the transmission continuing to operate in its current operating mode and with continued monitoring for operator input commands and/or or operational characteristics of transmission set 84 at step 224. Alternatively, if the controller 34 determines that an imminent change in transmission set 84 is desired or necessary, as indicated at 230, then method 220 continues at steps 232-240, which may be collectively referred to as a transmission shift scheme whereby the transmission 36 and second electric machine unit 42 are operated to allow switching between operating modes. Specifically, the second electric machine unit 42 can be operated to control/change the amount and direction of the torque output thereof (to the variator 116), while the control assembly 144 is operated to control the transfer of power to the output shaft 94. This operational change is generally referred to hereinafter as being from a "first mode of transmission" to a "second mode of transmission", it being understood that it may refer to the change between any two operational modes during operation of transmission 36.

[0051] As shown in step 232 in the embodiment described, carrying out the transmission shift scheme by the controller 34 begins with the controller 34 actuating the clutch arrangement 210 (i.e., a second clutch 210b thereof) of the second machine unit 42 to cause the second shaft 206 to disengage from the mainshaft 108. The second shaft 206 is disengaged from the mainshaft 108 before the transmission 36 changes from the first transmission mode to the second transmission mode, with the second axle 206 and the second rotor 196 thereof being disengaged from the main shaft 108. Disengagement of the second shaft 206 from the main shaft 108 may occur while both the first shaft 204 and the second shaft 206 are being driven by the first rotor 194 and the second rotor 196, respectively , such as the first and second shafts 204, 206 being driven in tandem in a forward direction, for example.

[0052] After the second shaft 206 is disengaged from the main shaft 108, the controller 34 then controls the second electrical machine unit 42 to drive the second rotor 196 in a direction opposite to its current rotational direction at step 234. In the embodiment described , the second rotor 196 is thereby driven in the reverse direction at step 234. Driving the second rotor 196 in the reverse direction can be achieved by selectively supplying current to the second stator 202 to control the electromagnetic interaction between the second stator 202 and the second rotor 196 Driving the second rotor 196 in the reverse direction thus causes a corresponding rotation of the second shaft 206 in the reverse direction, with the second shaft 206 rotating in the reverse direction while the second shaft 206 remains disengaged from the main rod 108 and prior to the first mode change transmission to the second transmission mode.

[0053] Moving on to step 236, method 220 continues with the controller 34 actuating the clutch arrangement 210 (that is, first clutch 210a and second clutch 210b thereof) of the second electrical machine unit 42 to reengage the second shaft 206 with the mainshaft 108 and disengage the first shaft 204 from the mainshaft 108. The actuation of the clutch arrangement 210 at step 236 takes place in conjunction with the transmission 36 changing from the first transmission mode to the second transmission mode, including control of the selectable transmission components of the control assembly 144. The engagement of the second shaft 206 (which is rotating in the reverse direction via drive thereof by the second rotor 196) with the main shaft 108 and the disengagement of the first shaft 204 (which is rotating in the reverse direction) direct through its drive by the first rotor 194) of the main shaft 108 causes the main shaft 108 to be driven in the reverse rotational direction. Torque output from mainshaft 108 can thus be provided to variator 116 and summed to torque provided by motor shaft 96 for transfer (through transmission 36) to output shaft 94, in accordance with transmission operation in the second transmission mode.

[0054] According to one embodiment, additional steps 238, 240 are optionally performed as part of the transmission shift scheme, with steps 238, 240 being shown in dashed lines in FIG. 4. As shown in step 238, after the first shaft 204 is disengaged from the main shaft 108, the controller 34 then controls the second electric machine unit 42 to drive the first rotor 194 in a direction opposite to its current rotational direction. In the described embodiment, the first rotor 194 is thus driven in the reverse direction at step 238. Driving the first rotor 194 in the reverse direction can be achieved by selectively supplying current to the first stator 200 to control the electromagnetic interaction between the first stator 200 and the first stator. rotor 194. Driving the first rotor 194 in the reverse direction thus causes a corresponding rotation of the first shaft 204 in the rotational direction, with the first shaft 204 rotating in the reverse direction while the first shaft 204 remains disengaged from the main shaft 108. At step 240, the controller 34 actuates clutch arrangement 210 (ie, first clutch 210a) of second electric machine unit 42 to re-engage first shaft 204 to main shaft 108. Engagement of first shaft 204 (which is rotating in the reverse direction by actuation of the even by the first rotor 194) to the main shaft 108 causes additional torque to be provided to the main shaft 108 in addition to torque being provided by the second shaft 206.

[0055] In another embodiment, and alternatively to method 220 including steps 238, 240, upon actuation of the clutch arrangement 210 to re-engage the second shaft 206 to the main shaft 108 and disengage the first shaft 204 from the main shaft 108, the first shaft 204 can remain disengaged from mainshaft 108 after shifting transmission 36 from the first transmission mode to the second transmission mode. In such an embodiment, the first rotor 194 can remain idle during continuous operation of the transmission 36 in the second transmission mode. This maintenance of the first rotor 194 in an idle condition may be desirable in low load situations where torque from the first rotor 194 and first shaft 204 to the mainshaft 108 is not required as the idle speed of the first rotor 194 would eliminate the parasitic drag and wind resistance associated with its operation.

[0056] Upon completion of step 236 (and optional steps 238, 240), method 220 would return to step 222 while operating in the second transmission mode. Method 220 would then be rerun to identify if/when another imminent shift might occur in transmission set 84, whether shifting back to the first transmission mode or a third transmission mode, for example.

[0057] Referring now to FIG. 5, and with continued reference to FIGS. 1-3, a flowchart of another method 242 for controlling the operation of the second electrical machine unit 42 during the operation of the transmission assembly 84 is provided in accordance with the present description, as may be accomplished by the controller 34. Generally, the method 242 is implemented during operation of the backhoe 10, with the drivetrain 84 of the backhoe 10 operating in a particular mode and a "load buildup" (i.e., sharp increase in external load) is encountered that requires a downshift abrupt transmission.

[0058] Method 242 begins at step 244 with the transmission assembly 84 operating in a current operational mode. During operation in this current mode, the controller 34 operates the control assembly 144 (i.e., selectable transmission components thereof), as well as the motor 38 and second electrical machine unit 42, to achieve the requested torque on the drive shaft. output 94 for general control of backhoe loader 10. Method 242 then continues to step 246 monitoring external loads applied to backhoe loader 10, with such monitoring being performed by an observer algorithm stored and/or executed by controller 34. External load monitoring is obtained through feedback obtained regarding various characteristics or operating parameters of the backhoe loader 10 and drivetrain 84, with such feedback obtained by sensors included in the backhoe 10 (e.g., sensors 48 in FIG. 1) that measure one or more more transmission characteristics 36, such as transmission output speed and transmission torque. Specifically, in one embodiment, the output speed of the transmission can be monitored along with a torque being applied to the transmission 36 by the second electrical machine unit 42 and an inertia present in the system. For any changes in torque applied by the second electrical machine unit 42, the transmission output speed (and acceleration on changing that speed) is monitored and compared to a predicted transmission output speed (and acceleration) that should result from this application of torque. torque (and inertia in the system). If there is a difference between the actual monitored speed and/or acceleration versus the predicted speed and/or acceleration, then the observer determines that an external torque must be acting on the backhoe loader 10 – and this external torque is classified as an external load or condition. of “load accumulation” that is occurring or is about to occur.

[0059] From the above-described observer monitoring, a determination is thus made by the controller 34 at step 248 whether a load accumulation condition is present or imminent that would require a downshift from a current transmission operating mode to another of lower transmission operation. If controller 34 determines that no pilefall condition is present or imminent, as indicated at 250, then method 242 returns to step 246, with controller 34 continuing to monitor external loads applied to backhoe 10. Alternatively, if the controller 34 determines that a load buildup condition is present or imminent, as indicated at 252, then the method continues with steps 254-258, which may be collectively referred to as a transmission shift scheme whereby the transmission 36 and the second electrical machine unit 42 are operated to allow a quick downshift in transmission 36 to address the load build-up condition. Specifically, the second electric machine unit 42 can be operated to selectively disengage one or both of the rotors 194, 196 thereof to decrease the torque output provided to the variator 116, thereby decreasing the inertia reflected in the transmission 36 during the downshift. gearing thereof (i.e., operating/actuating components of control assembly 144 to control power transfer to output shaft 94).

[0060] As shown in step 254 in the embodiment described, execution of the transmission shift scheme begins with the controller 34 actuating the clutch arrangement 210 (i.e. a second clutch 210b thereof) of the second electrical machine unit 42 to causing the second shaft 206 to disengage from the mainshaft 108. The second shaft 206 is disengaged from the mainshaft 108 before the transmission 36 downshifts to address the load accumulation condition, with the second shaft 206 and second rotor 196 thereof being disengaged from the main shaft 108. Disengagement of the second shaft 206 from the main shaft 108 can occur while both the first shaft 204 and the second shaft 206 are being driven by the first rotor 194 and the second rotor 196, respectively, as the first and second shafts 204, 206 being driven in tandem in a direct direction, for example.

[0061] In one embodiment, after the second shaft 206 is disengaged from the main shaft 108, the controller 34 then controls the second electric machine unit 42 to drive the second rotor 196 (and the second shaft 206) in an opposite direction of its current rotational direction at step 256. In the described embodiment, the second rotor 196 is thus driven in the reverse direction at step 256, with the second shaft 206 remaining disengaged from the main shaft 108 while driving the second rotor 196 is thus driven in the reverse direction. reverse direction. As noted above, this decoupling of the second shaft 206 from the main shaft 108 lowers the reflected inertia to the transmission 36 during transmission 36 downshifts, which allows an operator to more easily reach shift points or shift windows during shifting. transmission downshift 36, thereby providing a smoother downshift that minimizes wear or damage you may be inflicting on the transmission during fast downshifting.

[0062] Going to step 258, method 242 can continue with the controller 34 actuating the clutch arrangement 210 (that is, first clutch 210a and second clutch 210b thereof) of the second electric machine unit 42 to re-engage the second shaft 206 to mainshaft 108 and disengage first shaft 204 from mainshaft 108. Actuation of clutch arrangement 210 at step 258 occurs in conjunction with transmission 36 having reached the lowest transmission shift mode in which transmission 36 will operate to address the charge accumulation condition. Engagement of the second shaft 206 (which is rotating in the reverse direction through the drive thereof by the second rotor 196) to the main shaft 108 and disengagement of the first shaft 204 (which is rotating in the forward direction through the drive thereof by the first rotor 194) of the mainshaft 108 causes the mainshaft 108 to be driven in the reverse rotational direction. Torque output from mainshaft 108 can thus be provided to variator 116 and added to the torque provided by motor shaft 96 for transfer (through transmission 36) to output shaft 94, in accordance with the operation of transmission 36 in this low transmission shift mode.

[0063] Upon completion of step 258, method 242 can return to step 246 and continue to monitor the external loads applied to the backhoe 10.

[0064] Thus, the embodiments of this description provide a transmission set for a work vehicle that reduces the inertia in the transmission set during switching between different modes of operation. The transmission assembly includes an electric machine unit with two separately and independently driven rotors in it, together with a clutch that selectively couples the rotational output of the rotors to the variator in the transmission. The output torque of the rotors can be selectively engaged and disengaged from the variator through clutch operation to reduce the inertia reflected in the transmission when shifting between different operating modes. The rotors and clutch of the electric machine unit can be selectively controlled based on an identified imminent change in the driveline, whether that transmission shift is to change between different speeds or directions of operation during normal vehicle operation or to reduce gear in response to a state of vehicle charge accumulation.

NUMBERED EXAMPLES

[0065] The following examples are provided, which are numbered for ease of reference.

[0066] 1. A transmission assembly for a working vehicle with an engine includes a variator operatively connected to the engine, a gear arrangement configured to provide a selective gear reduction for transmission of output power from the variator to an output shaft , and an electrical machine unit. The electrical machine unit further includes a main shaft operatively connected to the variator, a first rotor configured to rotationally drive a first shaft, a second rotor configured to rotationally drive a second shaft, and a clutch configured to selectively engage the first or second shaft. axis, or both the first axis and the second axis, to the main axis. The clutch, first rotor and second rotor are operable to control a rotational speed and direction of the mainshaft in providing rotational power to the variator.

[0067] 2. The transmission assembly of example 1, wherein the electric machine unit is a split-rotor electric machine, with the first rotor being a first rotor portion, and the second rotor being a second rotor portion, and wherein the first rotor portion, the second rotor portion and the clutch are enclosed in a common unitary housing.

[0068] 3. The transmission assembly of example 1, wherein the electrical machine unit includes a first electrical machine and a second electrical machine, with the first electrical machine including the first rotor and the second electrical machine including the second rotor, and wherein the first shaft and the second shaft are selectively coupled to the main shaft through the clutch and gear.

[0069] 4. The transmission assembly of example 1, further including a controller, having a processor and memory architecture, in communication with the electric machine unit, the controller configured to control the operation of the electric machine unit for selective actuation and independently driving the first rotor and the second rotor in a forward rotational direction or a reverse rotational direction and controlling the clutch to selectively engage and disengage the first shaft and the second shaft from the main shaft.

[0070] 5. Transmission set according to claim 4, distinguished by the fact that the controller is configured to selectively operate the transmission set in a first transmission mode or a second transmission mode, controlling the operation of the transmission unit electric machine for driving the first rotor and the second rotor together in the forward rotational direction or in the reverse rotational direction during operation of the transmission assembly in the first transmission mode or in the second transmission mode, and controlling the operation of the electric machine unit to drive the first rotor and the second rotor in opposition, with the first rotor driven in the forward rotational direction and the second rotor driven in the reverse rotational direction, during a drive and drive train shift from the first drive mode to the second drive mode streaming.

[0071] 6. The transmission assembly of example 5, in which the controller is configured to control the electric machine unit to drive the first rotor and the second rotor, as well as the first shaft and the second shaft, in the forward rotational direction during first drive mode, identify a close shift in drive train from first drive mode to second drive mode, have clutch disengage second shaft from mainshaft before shifting from first drive mode to second transmission mode, control the electric machine unit to drive the second rotor and the second shaft in the reverse rotational direction after disengaging the second shaft from the main shaft and before switching from the first transmission mode to the second transmission mode, make the clutch reengages the second shaft to the mainshaft and disengages the first shaft from the mainshaft during shifting from the first transmission mode to the second transmission mode, thereby causing the mainshaft to be driven in the reverse rotational direction, control the unit of electric machine to drive the first rotor and the first shaft in the reverse rotational direction after disengaging the first shaft from the main shaft and after switching from the first transmission mode to the second transmission mode, and causing the clutch to re-engage the first shaft to the main axis.

[0072] 7. The transmission set of example 6, in which driving the first rotor and the second rotor in opposition before and during the shift of the transmission set from the first transmission mode to the second transmission mode reduces the inertia in the transmission unit electrical machine and transmission assembly during shifting.

[0073] 8. The transmission set of example 5, wherein, during operation of the transmission set in the first transmission mode or in the second transmission mode, the controller is configured to continue rolling operation of the electric machine unit to drive one of the first rotor or the second rotor in the forward rotational direction and idle the other of the first rotor or the second rotor.

[0074] 9. The transmission assembly of example 4, in which the controller is configured to monitor the speed and torque parameters in the transmission assembly through a torque observer program, identify a load accumulation condition based on on the monitored speed and torque parameters, determine a close drivetrain downshift necessary to address the load build-up condition, and control the clutch to selectively disengage the first axle or second axle, or both the first axle and the second axle. second axle, from the main axle before the transmission assembly downshifts.

[0075] 10. A work vehicle includes an engine and a transmission assembly, with the transmission assembly additionally including a variator operatively connected to the engine, a gear arrangement configured to provide a selective gear reduction for output power transmission from the variator to an output shaft, and an electric machine unit. The electric machine unit further includes a main shaft operatively connected to the variator, a first rotor configured to rotationally drive a first shaft, a second rotor configured to rotationally drive a second shaft, and a clutch configured to selectively engage the first shaft or the second shaft. , or both the first axis and the second axis, to the main axis. The clutch, first rotor and second rotor are operable to control a rotational speed and direction of the mainshaft in providing rotational power to the variator.

[0076] 11. The work vehicle of example 10, further including a controller, having a processor and memory architecture, in communication with the electric machine unit, the controller configured to control the operation of the electric machine unit based on a current transmission operating mode or based on an imminent change of the current transmission operating mode, wherein in controlling the operation of the electrical machine unit the controller is further configured to control the electrical machine unit to actuate selectively and independently the first rotor and the second rotor in a forward rotational direction or a reverse rotational direction and control the clutch to selectively engage or disengage the first shaft and second shaft from the mainshaft to control their rotation in the forward rotational direction or in the forward direction. reverse rotation.

[0077] 12. The work vehicle of example 11, in which the controller configured to selectively operate the transmission assembly in a first transmission mode or a second transmission mode, controls the operation of the electrical machine unit to drive the first rotor and the second rotor in tandem in the forward rotational direction or in the reverse rotational direction during operation of the transmission assembly in the first transmission mode or in the second transmission mode, and controlling the operation of the electric machine unit to drive the first rotor and the second rotor in opposition, with the first rotor driven in the forward rotational direction and the second rotor driven in the reverse rotational direction, during a drive and changeover of the transmission assembly from the first transmission mode to the second transmission mode.

[0078] 13. The work vehicle of example 12, in which the controller is configured to control the electric machine unit to drive the first rotor and the second rotor, as well as the first axis and the second axis, in the forward rotational direction during first drive mode, identify a close shift in drive train from first drive mode to second drive mode, have clutch disengage second shaft from mainshaft before shifting from first drive mode to second transmission mode, control the electric machine unit to drive the second rotor and the second shaft in the reverse rotational direction after disengaging the second shaft from the main shaft, and before switching from the first transmission mode to the second transmission mode, make that the clutch reengages the second shaft from the mainshaft and disengages the first shaft from the mainshaft during shifting from the first transmission mode to the second transmission mode, thereby causing the mainshaft to be driven in the reverse rotational direction, controlling the electric machine unit for driving the first rotor and the first shaft in the reverse rotational direction after disengaging the first shaft from the main shaft and after switching from the first transmission mode to the second transmission mode, and causing the clutch to re-engage the first shaft to the main axis.

[0079] 14. The work vehicle of example 12, in which the controller is configured to control the operation of the electric machine unit to drive one of the first rotor or the second rotor in the forward rotational direction and idle the other of the first rotor or the second rotor, during operation of the transmission assembly in the first transmission mode or in the second transmission mode.

[0080] 15. The work vehicle of example 11, in which the controller is configured to monitor the speed and torque parameters in the transmission assembly through a torque observer program, identify a load accumulation condition based on on the monitored speed and torque parameters, determine a close driveline downshift necessary to address the load build-up condition, and control the clutch to selectively disengage the first axle or second axle, or both the first axle and the second axle. second axle, from the main axle before the transmission assembly downshifts.

CONCLUSION

[0081] The above provided a transmission assembly for a work vehicle that reduces the inertia in the transmission assembly during switching between different modes of operation. The transmission assembly includes an electric machine unit with two separately and independently driven rotors in it, together with a clutch that selectively couples the rotational output of the rotors to the variator in the transmission. The output torque from the rotors can be selectively engaged and disengaged from the variator via clutch operation to reduce inertia reflected in the transmission when switching between different operating modes. The rotors and clutch of the electric machine unit can be selectively controlled based on an identified imminent change in the driveline, whether that transmission shift is to change between different speeds or directions of operation during normal vehicle operation or to reduce gear in response to a vehicle load build-up condition.

[0082] As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (eg, “and”) and that are also preceded by the expression “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual list elements, or any combination thereof. For example, "at least one of A, B, and C" or "one or more of A, B, and C" indicates the possibilities of just A, just B, just C, or any combination of two or more of A, B and C (for example, A and B; B and C; A and C; or A, B and C). Also, the use of "one or more of" or "at least one of" in claims for certain elements does not imply that other elements are unique or have any other effect on the other elements of the claim.

[0083] Finally, as used herein, the singular forms “um”, “uma” and “o”, “a” are intended to include plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising", when used in this specification, specify the presence of feature, integers, steps, operations, elements and/or components declared, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

[0084] The description of the present description has been presented for the purpose of illustration and description, but it is not intended to be exhaustive or limited to the description in the form described. Many modifications and variations will be pointed out to those skilled in the art without departing from the scope and spirit of the description. Embodiments explicitly referenced in the present document have been chosen and described to better explain the principles of the description and their practical application and to allow others skilled in the art to understand the description and recognize the many alternatives, modifications and variations in the example(s) described( s). Accordingly, various embodiments and implementations other than those explicitly described are within the scope of the following claims.

Claims (15)

Transmission assembly (84) for a work vehicle (10) having an engine (38), characterized in that the transmission assembly (84) comprises:
a variator (116) operatively connected to the motor (38);
a gear arrangement (98, 99, 100, 104, 110, 112, 114, 168, 170, 172, 176, 182, 184, 186, 188, 190) configured to provide a selective gear reduction for power transmission of output from the variator (116) to an output shaft (94); It is
an electrical machine unit (42) including:
a main shaft (108) operatively connected to the variator (116);
a first rotor (194) configured to drive
rotationally a first axis (204);
a second rotor (196) configured to drive
rotationally a second axis (206); It is
a clutch (210) configured to selectively couple the first shaft (204) or the second shaft (206), or both the first shaft (204) and the second shaft (206), to the main shaft (108);
wherein the clutch (210), the first rotor (194) and the second rotor (196) are operable to control a rotational speed and direction of the mainshaft (108) in providing rotational power to the variator (116). Transmission assembly (84) according to claim 1, characterized in that the electrical machine unit (42) comprises a split-rotor electrical machine, with the first rotor (194) comprising a first rotor portion (194) and the second rotor (196) comprising a second rotor portion (196), and wherein the first rotor portion (194), the second rotor portion (196) and the clutch (210) are enclosed in a common unitary housing (192). Transmission assembly (84) according to claim 1, characterized in that the electrical machine unit (42) comprises a first electrical machine (212) and a second electrical machine (214), with the first electrical machine (212 ) including the first rotor (194) and the second electrical machine (214) including the second rotor (196), and wherein the first shaft (204) and the second shaft (206) are selectively coupled to the main shaft (108) by clutch middle (210) and gear (208). Transmission assembly (84) according to claim 1, characterized in that it additionally comprises a controller (34), including a processor (34a) and memory architecture (34b), in communication with the electrical machine unit (42 ), the controller (34) configured to:
controlling operation of the electric machine unit (42) to selectively and independently drive the first rotor (194) and the second rotor (196) in a forward rotational direction or a reverse rotational direction; It is
controlling the clutch (210) to selectively engage and disengage the first shaft (204) and the second shaft (206) from the mainshaft (108). Transmission set (84) according to claim 4, characterized in that the controller (34) is configured to:
selectively operating the transmission assembly (84) in a first transmission mode or a second transmission mode;
controlling the operation of the electric machine unit (42) to drive the first rotor (194) and the second rotor (196) in tandem in the forward rotational direction or in the reverse rotational direction during operation of the transmission assembly (84) in the first mode of transmission or in the second mode of transmission; It is
controlling the operation of the electric machine unit (42) to drive the first rotor (194) and the second rotor (196) in opposition, with the first rotor (194) driven in the forward rotational direction and the second rotor (196) driven in the forward direction. reverse rotational direction, during a drive and change of the transmission assembly (84) from the first transmission mode to the second transmission mode. Transmission assembly (84) according to claim 5, characterized in that the controller (34) is configured to: control the electrical machine unit (42) to drive the
first rotor (194) and the second rotor (196), as well as the first shaft (204) and the second shaft (206), in the forward rotational direction during the first transmission mode;
identifying an upcoming change in the transmission set (84) from the first transmission mode to the second transmission mode;
causing the clutch (210) to disengage the second shaft (206) from the mainshaft (108) prior to shifting from the first transmission mode to the second transmission mode;
after disengaging the second shaft (206) from the main shaft (108), and before switching from the first transmission mode to the second transmission mode, control the electrical machine unit (42) to drive the second rotor (196) and the second axis (206) in the reverse rotational direction;
causing the clutch (210) to re-engage the second shaft (206) to the main shaft (108) and disengage the first shaft (204) from the main shaft (108) during shifting from the first transmission mode to the second transmission mode, for thereby causing the mainshaft (108) to be driven in the reverse rotational direction;
after disengaging the first shaft (204) from the main shaft (108), and after switching from the first transmission mode to the second transmission mode, control the electrical machine unit (42) to drive the first rotor (194) and the first shaft (204) in the reverse rotational direction; It is
cause the clutch (210) to re-engage the first shaft (204) to the mainshaft (108). Transmission assembly (84) according to claim
6, characterized in that driving the first rotor (194) and the second rotor (196) in opposition before and during shifting of the transmission assembly (84) from the first transmission mode to the second transmission mode reduces the inertia in the unit of electric machine (42) and in the transmission assembly (84) during the changeover. Transmission set (84) according to claim 5, characterized in that during operation of the transmission set (84) in the first transmission mode or in the second transmission mode, the controller (34) is configured to control the operating the electrical machine unit (42) to drive one of the first rotor (194) or the second rotor (196) in the forward rotational direction and idle the other of the first rotor (194) or the second rotor (196). Transmission set (84) according to claim 4, characterized in that the controller (34) is configured to: monitor speed and torque parameters in the transmission set (84) through a torque observer program;
identify a load accumulation condition based on the monitored speed and torque parameters;
determining a close downshift of the drivetrain (84) necessary to address the load build-up condition; It is
controlling the clutch (210) to selectively disengage the first shaft (204) or the second shaft (206), or both the first shaft (204) and the second shaft (206), from the mainshaft (108) before downshifting of the transmission assembly (84). Work vehicle (10), characterized by the fact that it comprises:
an engine (38); It is
a transmission assembly (84) comprising:
a variator (116) operatively connected to the motor (38);
a gear arrangement (98, 99, 100, 104, 110, 112, 114, 168, 170, 172, 176, 182, 184, 186, 188, 190) configured to provide a selective gear reduction for power transmission of variator output (116) to an output shaft (94); It is
an electrical machine unit (42) including:
a main shaft (108) operatively connected to the variator (116);
a first rotor (194) configured to drive
rotationally a first axis (204);
a second rotor (196) configured to drive
rotationally a second axis (206); It is
a clutch (210) configured to selectively couple the first shaft (204) or the second shaft (206), or both the first shaft (204) and the second shaft (206), to the main shaft (108);
wherein the clutch (210), the first rotor (194) and the second rotor (196) are operable to control a rotational speed and direction of the mainshaft (108) in providing rotational power to the variator (116). Work vehicle (10) according to claim 10, characterized in that it additionally comprises a controller (34), including a processor (34a) and memory architecture (34b), in communication with the electrical machine unit (42 ) and the transmission assembly (84), the controller (34) configured to control the operation of the electric machine unit (42) based on a current transmission operating mode or based on an imminent change of transmission operating mode. current transmission;
wherein, when controlling the operation of the electrical machine unit (42), the controller (34) is further configured to:
controlling the electric machine unit (42) to selectively and independently drive the first rotor (194) and the second rotor (196) in a forward rotational direction or a reverse rotational direction; It is
controlling the clutch (210) to selectively engage or disengage the first shaft (204) and the second shaft (206) from the main shaft (108) to control rotation thereof in the forward rotational direction or in the reverse rotational direction. Work vehicle (10) according to claim 11, characterized in that the controller (34) is configured to:
selectively operating the transmission assembly (84) in a first transmission mode or a second transmission mode;
controlling the operation of the electric machine unit (42) to drive the first rotor (194) and the second rotor (196) in tandem in the forward rotational direction or in the reverse rotational direction during operation of the transmission assembly (84) in the first mode of transmission or in the second mode of transmission; It is
controlling the operation of the electric machine unit (42) to drive the first rotor (194) and the second rotor (196) in opposition, with the first rotor (194) driven in the forward rotational direction and the second rotor (196) driven in the forward direction. reverse rotational direction, during a drive and change of the transmission assembly (84) from the first transmission mode to the second transmission mode. Work vehicle (10) according to claim 12, characterized in that the controller (34) is configured to:
controlling the electric machine unit (42) to drive the first rotor (194) and the second rotor (196), as well as the first shaft (204) and the second shaft (206), in the forward rotational direction during the first mode of streaming;
identifying an upcoming change in the transmission set (84) from the first transmission mode to the second transmission mode;
causing the clutch (210) to disengage the second shaft (206) from the mainshaft (108) prior to shifting from the first transmission mode to the second transmission mode;
after disengaging the second shaft (206) from the main shaft (108), and before switching from the first transmission mode to the second transmission mode, control the electrical machine unit (42) to drive the second rotor (196) and the second axis (206) in the reverse rotational direction;
causing the clutch (210) to re-engage the second shaft (206) to the main shaft (108) and disengage the first shaft (204) from the main shaft (108) during shifting from the first transmission mode to the second transmission mode, for thereby causing the mainshaft (108) to be driven in the reverse rotational direction;
after disengaging the first shaft (204) from the main shaft (108), and after switching from the first transmission mode to the second transmission mode, control the electrical machine unit (42) to drive the first rotor (194) and the first shaft (204) in the reverse rotational direction; It is
cause the clutch (210) to re-engage the first shaft (204) to the mainshaft (108). Work vehicle (10) according to claim 11, characterized in that the controller (34) is configured to:
monitoring speed and torque parameters in the transmission assembly (84) by means of a torque observer program;
identify a load accumulation condition based on the monitored speed and torque parameters;
determining a close downshift of the drivetrain (84) necessary to address the load build-up condition; It is
controlling the clutch (210) to selectively disengage the first shaft (204) or the second shaft (206), or both the first shaft (204) and the second shaft (206), from the mainshaft (108) before downshifting of the transmission assembly (84). Work vehicle (10) according to claim 12, characterized in that the electric machine unit (42) comprises both:
a split-rotor electric machine, with the first rotor (194) comprising a first rotor portion (194) and the second rotor (196) comprising a second rotor portion (196), and wherein the first rotor portion (194 ), the second rotor portion (196) and clutch (210) are enclosed in a common unitary housing; how much
a first electrical machine (212) and a second electrical machine (214), with the first electrical machine (212) including the first rotor (194) and the second electrical machine (214) including the second rotor (196), and wherein the first shaft (204) and the second shaft (206) are selectively coupled to the main shaft (108) by means of the clutch (210) and gear.

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