Drivetrain with power take-off and reduction planetary gear set

Abstract

Powertrain system, which includes: a first drive motor; a reduction planetary gear set rotatably coupled to the first drive motor and a power take-off configured to connect to a work implement; and an input shaft that is rotatably coupled to the first drive motor and a gearbox; wherein the reduction planetary gear set has a fixed component.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a powertrain system, and more particularly to a powertrain system including a power take-off and a reduction planetary gear set. BACKGROUND AND SUMMARY

[0002] Electric drivetrains are used in certain vehicles because they are less complex and more compact. In addition, some vehicles, such as off-highway vehicles and other types of vehicles, are equipped with power take-offs used to drive work equipment. Electric drivetrain traction motors provide comparatively high input speeds to transmissions compared to transmissions that receive mechanical power directly from internal combustion engines. However, the high input speed delivered to the transmission may be higher than desired for the input to some power take-offs.

[0003] Attempts have been made to use a dedicated electric motor, separate from the traction motor, to supply mechanical power to a power take-off. However, using a separate motor to drive a power take-off increases the size and complexity of the electric drivetrain. Attempts have also been made to incorporate a power take-off into a hybrid drivetrain. For example, WO 2022 / 109644 A1 by Wiener et al. discloses a hybrid transmission that includes an internal combustion engine, electric motors, and a planetary gear set rotatably coupled to one of the electric motors and the engine. The planetary gear set enables Wiener's transmission to provide continuously variable speed in every gear range. Wiener's transmission also features a power take-off supplied with mechanical power by a ring gear of the planetary gear set.

[0004] The inventors have identified several disadvantages of the Wiener hybrid powertrain and other powertrains with built-in power take-offs. When the Wiener power take-off is driven solely by the electric motor, the input speed may be undesirable for certain implements. In general, the Wiener power take-off architecture may not be applicable to an all-electric powertrain. Powertrains with dedicated motors and inverters for power take-offs are complex and, in some cases, can pose manufacturing and installation challenges.

[0005] The inventors have recognized the aforementioned problems and developed a powertrain system. In one example, the powertrain system includes a first traction motor, a reduction planetary gear set rotatably coupled to the traction motor, and a power take-off configured to be connected to an implement. The powertrain system also includes an input shaft rotatably connected to the first traction motor and a transmission. The reduction planetary gear set includes a fixed component. For example, the planetary gear set may have a fixed ring gear. The planetary gear set therefore makes it possible to bring the high output speed of the motor into a range usable for a wider range of power take-offs. In this way, the capabilities of the system are expanded in a space-efficient manner.

[0006] To achieve a desired speed reduction, the reduction planetary gear set may, in one example, include a sun gear fixedly connected to the input shaft, a carrier rotatably connected to the power take-off, and a fixed ring gear. This achieves a desired gear ratio that can be used by a variety of power take-offs, further expanding the system's capabilities.

[0007] It should be understood that the above summary is intended to introduce, in simplified form, a selection of concepts that are further explained in the detailed description. It is not intended to identify the most important or essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages noted above or elsewhere in this disclosure. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 shows a section of an electric drive train with a traction motor and a power take-off in a vehicle. Fig. 2 and Fig. 3 show the mechanical power paths through the electric drive train from Fig. 1. Fig. 4 shows a diagram that compares the different operating modes of the electric drive train with the clutch positions in the electric drive train (see Fig. 1) in relation to. Fig. Figure 5 shows a second example of an electric drive train with two traction motors and a power take-off. Fig. 6 and Fig. 7 show the mechanical power paths through the electric drive train from Fig. 5. Fig. Figure 8 shows a diagram that compares the different operating modes of the electric drive train with the clutch positions in the electric drive train (see Fig. 5) in relation to. Fig. 9 shows a method for operating an electric drive train that includes a traction motor. Fig. 10 shows a method for operating an electric drive train that includes multiple traction motors. DETAILED DESCRIPTION

[0008] A powertrain system includes a reduction planetary gear set that supplies mechanical power to a power take-off from a traction motor within a desired speed range, allowing the power take-off to drive implements within a desired speed range.

[0009] Fig. 1 shows a vehicle 100 having an electric powertrain 102 with a system 103 (e.g., a powertrain system). The vehicle 100 is an electric vehicle (EV), e.g., a fully electric vehicle (e.g., a battery electric vehicle (BEV)). Fully electric vehicles may be used in particular due to their lower complexity and the associated lower number of potential component failures. However, in other examples, the vehicle may also be a hybrid electric vehicle (HEV) that includes an internal combustion engine.

[0010] The electric drivetrain 102 includes, among other things, a traction motor 104 rotatably coupled to a transmission 172 (e.g., an electric transmission). The traction motor 104 may include components such as a rotor and a stator that interact electromagnetically during operation to generate motive power. Furthermore, the traction motor may be a motor-generator that also generates electrical energy during regeneration operation.

[0011] Furthermore, the traction motor 104 may be a multi-phase traction motor supplied with electrical power via an inverter 164. The inverter 164 is configured to convert direct current (DC) to alternating current (AC) and vice versa. Thus, the traction motor 104 may be an AC traction motor. For example, in one application, the traction motor and inverter may be three-phase devices. However, motors and inverters configured for operation with more than three phases are also conceivable. The electrical connection between the inverter 164 and the traction motor 104 is identified by electrical leads 166 (e.g., multi-phase wires). However, other suitable electrical connections may also be established between the motor and the inverter.

[0012] Inverter 164 may receive direct current from at least one electrical energy source 168 (e.g., an energy storage device such as a traction battery, a capacitor, combinations thereof, and the like, and / or an alternator). Arrows 170 indicate the flow of electrical energy between the energy source 168 and inverter 164.

[0013] The electric powertrain 102 further includes a power take-off assembly 106. The power take-off assembly 106 includes a power take-off 122 (e.g., a hydraulic power take-off unit such as a hydraulic pump) and may include a power take-off gear set 126. The power take-off may, in particular, be a hydraulic pump configured to supply hydraulic fluid to implements that perform functions of the vehicle, such as lifting, pushing, etc.

[0014] The power take-off gear set 126 may include a gear 130 and a gear 132 coupled to the power take-off input shaft 124 such that the gear 132 and the power take-off input shaft 124 rotate together. The number of gears in the power take-off gear set may be selected depending on the size of the power take-off. For example, the number of gears in the power take-off gear set may be increased if a larger power take-off is used in the system.

[0015] One or more power take-off devices 178 may be coupled to the power take-off 122, indicated by a hydraulic connection 179. The one or more power take-off devices 178 may be hydraulically driven devices. The power take-off gear set 126 is mechanically coupled to the traction motor 104 via a reduction planetary gear set 134. In this way, mechanical power is supplied to the power take-off 122 within a desired speed range, increasing the system's applicability and customer appeal.

[0016] The reduction planetary gear set 134 includes a sun gear 136, planetary gears 138, a ring gear 144, and a carrier 142 for the planetary gears. Thus, the planetary gear set can be a single planetary gear set, increasing the compactness of the power take-off arrangement. However, other types of planetary gear sets, such as multi-stage planetary gear sets, are also contemplated.

[0017] In the example shown, the sun gear 136 of the reduction planetary gear set 134 is rigidly coupled to an input shaft 108 for the transmission. The input shaft 108 can be directly coupled to the rotor shaft 135 of the traction motor.

[0018] In the reduction planetary gear set 134, the planet gears 138 mesh with the sun gear 136 and the ring gear 144. The carrier 142 is rotatably coupled to a gear 128. Thus, the sun gear 136 acts as the input of the planetary gear set 134, and the carrier 142 acts as the output of the reduction planetary gear set in the example shown. In this way, the planetary gear set can achieve a desired gear ratio. Furthermore, the ring gear 144 is fixed. More specifically, the ring gear 144 can be fixed by a gear housing 154. In this way, the housing fulfills a dual function, allowing the space utilization of the transmission to be increased, if desired.

[0019] The rotation of the planet gears 138 drives the rotation of the carrier 142. The carrier 142 is rotatably coupled to a gear 128 via a shaft 148. The shaft 148 has a central opening through which the input shaft 108 extends. In addition, bearings 160 (e.g., needle bearings or other suitable bearing types) may be connected to the shaft 148 and the input shaft 108 to allow these shafts to rotate independently of each other. Another bearing 162 may be coupled to the shaft 148. A bearing described herein may include inner races, outer races, and rolling elements (e.g., balls, cylindrical rollers, tapered cylindrical rollers, and the like).

[0020] Furthermore, in the illustrated example, gear 130 of power take-off gear set 126 meshes with gear 128. Furthermore, in the illustrated example, gear 128 is fixedly coupled or integrally formed with shaft 148 so that they rotate together, and gear 130 is fixedly connected to an idler shaft 149. Bearings 131 may be coupled to idler shaft 149 and allow its rotation. Furthermore, in the illustrated example, gear 130 meshes with gear 132. Gear 132 is fixedly coupled or integrally formed with power take-off input shaft 124. Bearings 133 are coupled to power take-off input shaft 124 in the illustrated example. Power take-off input shaft 124 provides a rotary input to power take-off 122.

[0021] When the traction motor 104 generates a rotary output, the mechanical power is transferred from the input shaft 108 through the reduction planetary gear set 134 to the gear 128, from the gear 128 to the power take-off gear set 126, and from the power take-off gear set 126 to the power take-off 122. The power take-off 122, driven by the traction motor 104, in turn drives the one or more power take-off devices 178. Furthermore, the ratio of the gears 130, 132 can be selected to drive the power take-off 122 within a desired torque / speed range. Although the power take-off gear set 126 includes two gears in the example shown, in other examples the power take-off gear set can include a different number of gears, as previously mentioned.

[0022] In the illustrated example, gear 128 may include an opening through which input shaft 108 extends. A bearing 146 and a bearing 158 may be coupled to input shaft 108 (e.g., at opposite ends) to permit rotation and support the shaft.

[0023] The reduction planetary gear set 134 can be specifically positioned adjacent (e.g., directly adjacent) to the traction motor 104 to increase the space efficiency of the electric powertrain 102, if desired. Furthermore, the reduction planetary gear set 134 can be a simple reduction planetary gear set, including only the sun gear 136, the ring gear 144, the planet gears 138, and the carrier 142. By using a simple planetary gear set, the compactness of the transmission is increased compared to more complex planetary gear sets, such as multi-stage planetary gear sets, Ravigneaux planetary gear sets, etc., and frictional losses are reduced. Consequently, the electric powertrain 102 can impose fewer space restrictions on other vehicle components, allowing the system's application possibilities to be expanded.Furthermore, losses in the electric drivetrain 102 are reduced when using a simple reduction planetary gear set, as opposed to more complex planetary gear sets, such as multi-stage planetary gear sets. However, in alternative examples, a multi-stage planetary gear set may also be used in the transmission, although this reduces the compactness of the system and increases losses.

[0024] The system 103 may include a transmission disconnect clutch 114 configured to selectively decouple the input shaft 108 from the transmission 172. Specifically, the transmission disconnect clutch 114 may be arranged coaxially with the input shaft 108 and configured to selectively rotatably couple a gear 110 (e.g., a clutch gear) to the input shaft 108. In particular, the transmission disconnect clutch 114 may be a friction clutch in one example. However, other types of clutches are also contemplated, such as a synchronizer or a dog clutch, in various examples. Further, in another example, the transmission disconnect clutch may be omitted from the electric powertrain. In such an example, the space efficiency of the electric powertrain may be increased at the expense of reduced functionality.

[0025] In the friction clutch example, the transmission disconnect clutch 114 may include a drum 116 rotatably connected to the input shaft 108 and a hub 117 rotatably connected to the gear 110. The drum 116 and the hub 117 each support a set of plates 118 (e.g., friction plates and intermediate plates). The hub 117 is rotatably coupled to the gear 110. The bearings 119 may be coupled to the hub 117 and the input shaft 108 such that they rotate independently of each other when the disconnect clutch is disengaged. Thus, when the transmission disconnect clutch 114 is engaged (i.e., closed), the gear 110 is coupled to the input shaft 108 such that they rotate together. In this way, when the transmission disconnect clutch 114 is engaged, mechanical power is transferred from the input shaft 108 to the gear 110.Conversely, the transmission of power between the input shaft 108 and the gear 110 is prevented when the transmission disconnect clutch 114 is disengaged (i.e., open).

[0026] A friction clutch as described herein may include two sets of plates configured to frictionally engage and disengage upon opening and closing of the clutch. This allows the torque transmitted through the clutch to be modulated depending on the degree of friction plate engagement. This allows the friction clutches described herein to operate with varying degrees of engagement (e.g., continuously across the clutch engagement range). In addition, the friction clutches described herein may be wet friction clutches through which a lubricant is passed to increase clutch life. However, in alternative examples, dry friction clutches may also be used. The transmission disconnect clutch 114 and the other friction clutches described herein may be adjusted using hydraulic, pneumatic, and / or electromechanical actuators. For example,Hydraulically actuated pistons are used to engage the friction clutches. However, in other examples, electromagnets can also be used for electromechanical actuation of the clutch.

[0027] Gear 110 may be rotatably coupled to transmission 172 via mechanical components 150 (e.g., gears, shafts, chains, joints, combinations thereof, etc.). Transmission 172 may, in turn, be mechanically coupled to one or more drive axle assemblies 174, each including a differential 175, which in turn is rotatably connected to drive gears 176.

[0028] The vehicle 100 also includes a control system 192 with a controller 193, as shown in Fig. 1. The controller 193 may include a microcomputer with components such as a processor 194 (e.g., a microprocessor unit), input / output ports, an electronic storage medium 195 for executable programs and calibration values ​​(e.g., a read-only memory chip, a read-only memory, a diagnostic memory, a data bus, and the like). The storage medium may be programmed with computer-readable data representing instructions that can be executed by the processor to perform the methods and control techniques described herein, as well as other variations that are expected but not explicitly listed.

[0029] The controller 193 may receive various signals from sensors 196 coupled to various areas of the vehicle 100, and in particular, the electric powertrain 102. Sensors 196 may include, for example, a pedal position sensor that detects the application of a driver-operated pedal such as an accelerator and / or brake pedal, a speed sensor on the transmission input shaft, a state of charge (SOC) sensor, clutch position sensors, etc. The motor speed may be determined from the electrical power supplied by the inverter to the traction motor. An input device 197 (e.g., accelerator pedal, brake pedal, drive mode selector, combinations thereof, and the like) may also provide input signals indicating the driver's intent for vehicle control.For example, buttons, switches, a touch interface, combinations thereof, and the like may be included in the vehicle to allow the driver to connect and disconnect the transmission 172 from the traction motor 104. However, in other examples, automated control strategies may also be used to connect and disconnect the transmission 172.

[0030] After receiving the signals from the sensors 196 from Fig. 1, the controller 193 processes the received signals and deploys various vehicle component actuators 198 to adjust the components based on the received signals and the instructions stored in the memory of the controller 193. For example, the controller 193 may receive an accelerator pedal signal indicating a driver request for increased vehicle acceleration. The controller 193 may then command the operation of the inverters to adjust the traction motor power output and increase the power delivered by the traction motors to the transmission 172 and / or the power take-off 122. The controller 193 may be configured to send commands to the transmission disconnect clutch 114 to engage or disengage the clutch under certain operating conditions.For example, a control command may be sent to the transmission disconnect clutch 114, and in response to receiving the command, an actuator in the clutch may adjust the clutch based on whether to engage or disengage the clutch. The other controllable components in the vehicle, system, etc., may function in a similar manner, e.g., with respect to sensor signals, control commands, and actuator adjustment. Furthermore, a similar control system may also be included in the other electric powertrain embodiments described herein.

[0031] In some examples, the transmission 172 may be a multi-speed transmission. Thus, in various examples, the transmission 172 may be configured as a two-speed, three-speed, four-speed, etc. However, in other examples, the transmission may be configured as a single-speed transmission. Mechanical power paths through the transmission 172 of the vehicle 100 are described herein with respect to Fig. 2 and Fig. 3 is explained in more detail.

[0032] For reference, an axis system is Fig. 1 and in Fig. 2-7. The y-axis can be a vertical axis (e.g., parallel to a gravitational axis), the x-axis can be a lateral axis (e.g., a horizontal axis), and / or the z-axis can be a longitudinal axis. However, alternative axis orientations can be used in other examples.

[0033] Fig. 2 and Fig. 3 show various mechanical power paths through the system 103 of the electric drive train 102 in two different operating modes. In the operating mode in Fig. 2, mechanical power is delivered to the power take-off 122 and the transmission 172, where the power can then be distributed to one or more drive axle assemblies 174. In the operating mode in Fig. 3, the power take-off 122 is supplied with mechanical power, but not the transmission 172. The components of the electric drive train 102, which are Fig. 2 and Fig. 3 and which were previously referred to in Fig. 1 are similarly numbered, and redundant descriptions are omitted for clarity. It should be understood that clutch 114 can be engaged or disengaged to enable or disable power flow from the engine to the transmission.

[0034] As in Fig. 2, the transmission disconnect clutch 114 is engaged, thus enabling the transmission of power from the input shaft 108 to the transmission 172 via the gear 110 (e.g., the clutch gear). Fig. 2 a mechanical power path 200 (indicated by bold arrows) which includes a first branch which supplies power to the power take-off 122 and a second branch which supplies power to the transmission 172.

[0035] The first branch of the mechanical power path 200 is as follows: The mechanical power moves from the traction motor 104 to the sun gear 136, from the sun gear 136 to the planet gears 138, from the planet gears 138 to the carrier 142, from the carrier 142 to the shaft 148, from the shaft 148 to the gear 128, from the gear 128 to the gear 130, from the gear 130 to the gear 132, and from the gear 132 to the power take-off 122. The power take-off 122 can, in turn, deliver power (e.g., mechanically or hydraulically) to one or more power take-off devices 178.

[0036] The second branch of the mechanical power path 200 unfolds as follows: The mechanical power moves from the traction motor 104 to the transmission disconnect clutch 114, from the transmission disconnect clutch to the gear 110, from the gear 110 to the gear 172, from the gear 172 to the one or more axle assemblies 174.

[0037] In Fig. 3, the transmission disconnect clutch 114 is engaged, thus preventing the transmission of power from the input shaft 108 to the transmission 172 via the gear 110. The mechanical power path 300 (indicated by bold arrows) is as follows: The mechanical power moves from the traction motor 104 to the sun gear 136, from the sun gear 136 to the planet gears 138, from the planet gears 138 to the carrier 142, from the carrier 142 to the shaft 148, from the shaft 148 to the gear 128, from the gear 128 to the gear 130, from the gear 130 to the gear 132, and from the gear 132 to the power take-off 122.

[0038] Fig. 4 shows a diagram 400 relating the configurations of the transmission disconnect clutch 114 in the two operating modes of the electric powertrain shown in Fig. 2 and Fig. 3. As shown, in the mode in which both the power take-off and the transmission are supplied with mechanical power (this power path is shown in Fig. 2) the transmission disconnect clutch is engaged. Conversely, in the mode in which only the power take-off is supplied with mechanical power (this power path is shown in Fig. 3), the transmission clutch is disengaged and the power take-off is supplied with mechanical power exclusively from the traction motor.

[0039] Fig. 5 shows another example of an electric drivetrain 500 with a system 501. The electric drive 500 includes several components that overlap with the electric drivetrain 102, e.g., a first traction motor 502, a reduction planetary gear set 504, an inverter 506, an electrical power source 508, a power take-off 510, a power take-off input shaft 511, one or more implements 512, a gear 514 mechanically coupled to a transmission 516, a transmission disconnect clutch 518, an input shaft 520, one or more drive axle assemblies 522 with differential(s) 524 and drive gears 526, a gear 528 coupled to a carrier 530 of the planetary gear set 504, etc. These overlapping components have a similar structure and function to the corresponding component in Fig. 1-3 and have been described above. Therefore, redundant descriptions are omitted for the sake of brevity.

[0040] However, as in Fig. 5, the electric drivetrain 500 includes a second traction motor 550 that is mechanically coupled to the transmission 516. More specifically, the system 501 may include another input shaft 552, which may have a gear 554 molded onto or fixedly connected thereto that meshes with a gear 556. The gear 556 may mesh with the gear 556. The gear 556 may be coupled to the transmission via one or more suitable mechanical components 558 (e.g., shafts, gears, chains, joints, combinations thereof, etc.). An inverter 560 may supply electrical power to the second traction motor 550. In addition, the inverter 560 may receive electrical power from the electrical power source 508 and / or another suitable power source. Arrows 562 indicate the flow of electrical power between the inverter 560 and the electrical power source 508.By using the second motor, the performance and adaptability of the system can be expanded.

[0041] The electric powertrain 500, in the illustrated example, further includes a power take-off clutch 564. The power take-off clutch may be a friction clutch in one case and another suitable clutch in other cases. When the power take-off clutch 564 is engaged, mechanical power is transferred from a gear 566 to gear 568. Conversely, when the power take-off clutch is disengaged, power transfer from gear 566 to gear 568 is prevented. In this way, losses in the system are reduced when power take-off operation is not desired. In the illustrated example, gear 566 meshes with gear 528. Furthermore, gear 568 may be fixedly coupled to or molded onto a shaft 570. In addition, the gear 568 meshes with a gear 572, which in the example shown is rigidly coupled to the power take-off input shaft 511 or is integrally formed therewith. The system architecture of Fig. 5 allows the performance of the system to be increased by using the power take-off clutch and the second drive motor.

[0042] Fig. 6 and Fig. 7 show various mechanical power paths 600, 602, and 700 through the system 501 of the electric powertrain 500 in various modes. The components of the electric powertrain 500 shown in Fig. 6 and which were previously referred to in Fig. 5 are numbered similarly and redundant descriptions are omitted for the sake of clarity.

[0043] In Fig. 6, the power take-off clutch 564 is engaged and the transmission disconnect clutch 518 is disengaged. The mechanical power path 600 (indicated by bold arrows) is as follows: Mechanical power moves from the traction motor 502 to the reduction planetary gear set 504, from the reduction planetary gear set 504 to the power take-off clutch 564, and from the power take-off clutch to the power take-off 510.

[0044] The mechanical power path 602 (indicated by bold arrows) is as follows: The mechanical power moves from the second traction motor 550 to the input shaft 552, from the input shaft 552 to the gear 554, from the gear 554 to the gear 556, and from the gear 556 to the transmission 516. In this way, the first traction motor 502 supplies exclusively mechanical power to the power take-off 510, and the second traction motor 550 supplies mechanical power to the transmission 516.

[0045] In one example, in the system operating mode in Fig. 6, the second traction motor 550 may be temporarily ramped up to reduce the degradation of driveline performance caused by the first traction motor driving only the power take-off and not the transmission. As described herein, ramping up the motor involves operating the motor at a power level above a power threshold, which indicates a power level beyond which the motor will be damaged if the high power level is maintained for an extended period of time.

[0046] In Fig. 7, the power take-off clutch 564 is disengaged and the transmission disconnect clutch is engaged. The mechanical power path 700 (indicated by bold arrows) unfolds as follows: In a first branch, the mechanical power moves from the traction motor 502 to the input shaft 520, from the input shaft to the disconnect clutch 518, from the disconnect clutch 518 to the gear 514, from the gear 514, from the gear 514 to the gear 556, and from the gear 556 to the transmission 516, and in a second branch, the mechanical power moves from the traction motor 550 to the input shaft 552, from the input shaft 552 to the gear 554, from the gear 554 to the gear 556, and from the gear 556 to the transmission 516. In this way, both traction motors supply mechanical power to the transmission while the power take-off is disconnected.

[0047] Fig. 8 shows a diagram 800 relating the configurations of the transmission disconnect clutch 518 and the power take-off clutch 564 in the electric powertrain 500 shown in Fig. 5. In each of the modes Fig. 8, the second traction motor is operating and generates rotational power that is transferred to the transmission. However, it should be understood that the system can also operate in modes where the second traction motor is deactivated.

[0048] As in Fig. As shown in Figure 8, in a first mode both clutches are engaged, so that the power is transferred from the first engine to the power take-off and from both engines to the transmission. In a second mode (which corresponds to the mechanical power path in Fig. 6), the separating clutch is disengaged and the power take-off clutch is engaged, so that the power is transferred from the first traction motor to the power take-off and from the second traction motor to the transmission. In a third mode (which corresponds to the mechanical power path in Fig. 7), the disconnect clutch is engaged and the power take-off clutch is disengaged, so that both motors mechanically drive the transmission, while the power take-off is disconnected from the first traction motor. In a fourth mode, the disconnect clutch is disengaged and the power take-off clutch is engaged, so that the second traction motor supplies mechanical power to the transmission.

[0049] Fig. 9 shows a method 900 for operating an electric powertrain system. In some examples, the method 900 may be performed via the electric powertrain 102 described above with reference to Fig. 1-4. Thus, the electric drivetrain may include a single traction motor that supplies mechanical power to the transmission. However, in other examples, method 900 may also be performed with other suitable electric transmission systems. The instructions for performing method 900 may be executed by a controller by executing instructions stored in a memory of the controller and in conjunction with signals received from sensors at the controller. The controller may employ actuators in various system components to implement the method steps described below.

[0050] At 902, the method includes determining, more generally, the operating conditions in the system and / or the vehicle. Operating conditions may include traction motor speed, transmission input shaft speed, vehicle speed, clutch position, pedal position, transmission load, power take-off power demand, transmission power demand, etc. These conditions may be determined using sensors and / or modeling algorithms.

[0051] At 903, the method includes initiating operation of the traction motor and delivering mechanical power to the power take-off. For example, a command may be sent to an inverter that distributes electrical power to the traction motor, causing the traction motor to generate a rotary output. The rotary output, in turn, drives the reduction planetary gear set and the power take-off gear set connected to the power take-off input shaft. In this way, the power take-off can be driven within a desired speed range.

[0052] At 904, the method includes determining whether the transmission should be connected to an input shaft of the traction motor to receive power therefrom. The transmission connection determination may specifically include determining whether a desired transmission torque is greater than zero. However, additional or alternative factors may also be considered when determining whether or not to connect the transmission to the traction motor.

[0053] If it is determined that the transmission should not be connected to the traction motor (NO at 904), the method proceeds to 906. At 906, the method includes disengaging or maintaining disengagement of the disconnect clutch to disconnect or maintain disengagement of the traction motor from the transmission. For example, if the transmission was already disconnected from the traction motor (prior to step 906), the disconnect clutch disengagement is maintained. Conversely, if the transmission was connected to the traction motor (prior to step 906), the disconnect clutch may transition from an engaged state to a disengaged state. In this way, the traction motor may be used to drive the power take-off while the transmission is disconnected from the traction motor.

[0054] If it is determined that the transmission should be connected to the traction motor (YES at 904), the method proceeds to 908. At 908, the method includes engaging or maintaining engagement of the disconnect clutch to connect or maintain connection of the traction motor to the transmission. For example, if the transmission was already connected to the traction motor (prior to step 908), the disconnect clutch engagement is maintained. Conversely, if the transmission was disconnected from the traction motor (prior to step 908), the disconnect clutch transitions from a disengaged state to an engaged state. In this way, the traction motor is used to jointly drive the power take-off and the transmission.

[0055] Fig. 10 shows a method 1000 for operating an electric powertrain system. In some examples, the method 1000 may be performed via the electric powertrain 500 with two traction motors, as described above with reference to Fig. 5-8. However, in other examples, method 1000 may also be performed with other suitable electric powertrains. The instructions for performing method 1000 may be executed by a controller executing instructions stored in a memory of the controller and in conjunction with signals received from sensors at the controller. The controller may employ actuators in various system components to implement the method steps described below.

[0056] At 1002, the method includes determining the operating conditions in the system and, more generally, in the vehicle. Operating conditions may include traction motor speeds, transmission input shaft speed, vehicle speed, clutch position, pedal position, transmission load, power take-off (PTO) demand, transmission power demand, etc. These conditions may be determined using sensors and / or modeling algorithms.

[0057] At 1004, the method includes initiating or maintaining operation of the first traction motor. For example, a command may be sent to an inverter that distributes electrical power to the traction motor so that the traction motor produces a rotary output.

[0058] At 1006, the method includes determining whether to operate the system with the power take-off receiving power from the first traction motor but disconnected from the transmission and the second traction motor disabled.

[0059] If it is determined that the system should operate in PTO-only mode (YES at 1006), the method proceeds to 1008, where the method includes engaging (or maintaining engagement) the PTO clutch to connect (or maintain connection) the first traction motor and the PTO.

[0060] If, however, it is determined that the transmission should not operate in PTO-only mode (NO at 1006), the method proceeds to 1010. At 1010, the method includes determining whether the system should operate in a dual-engine mode. Such a determination may be made based on the demand for transmission power, the demand for PTO power, and the like. For example, if the demand for transmission power is greater than a threshold and / or the demand for PTO power is greater than a threshold, it may be determined that the system should operate in dual-engine mode.

[0061] If it is determined that the system should operate in dual-motor mode (YES at 1010), the method proceeds to 1012. At 1012, the method includes initiating or maintaining operation of the second traction motor. For example, a command may be sent to an inverter that distributes electrical power to the second traction motor so that the second traction motor produces a rotary output. Then, at 1014, the method includes engaging (or maintaining engagement) the disconnect clutch to connect (or maintain connection) the first traction motor to the transmission.

[0062] Conversely, if it is determined that the system should not operate in dual-motor mode (NO at 1010), the method proceeds to 1016. At 1016, the method includes initiating operation or maintaining operation of the second traction motor. For example, a command may be sent to an inverter that distributes electrical power to the second traction motor so that the second traction motor produces a rotary output. Then, at 1018, the method includes disengaging (or maintaining disengagement) the disconnect clutch to disconnect (or maintain the disconnection) of the first traction motor and the transmission.

[0063] At 1020, the method includes determining whether to operate the power take-off. This determination may consider the power take-off's power demand and operator input via an input device indicating an operator's desire to use the power take-off. For example, an operator may trigger the input device to initiate power take-off operation. In other examples, the determination of power take-off operation may occur automatically, for example, when an implement is attached to the power take-off.

[0064] If it is determined that the power take-off should be operated (YES at 1020), the method proceeds to 1008. Conversely, if it is determined that the power take-off should not be operated (NO at 1020), the method proceeds to 1022, where the method includes disengaging (or maintaining disengagement) the power take-off clutch to disconnect (or maintain disconnection) the first traction motor and the power take-off. Method 1000 enables various powertrain operating modes to be implemented in the electric transmission system to expand the capabilities of the system.

[0065] The technical effect of the electric powertrain system and operating methods described herein is to expand the power take-off capabilities of the system and, in particular, to enable simultaneous operation of the power take-off and transmission without limiting the capabilities of the transmission or the power take-off, if desired.

[0066] Fig.1-7 show example configurations with the relative arrangement of the various components. When these elements are in direct contact with each other or are directly coupled, they may be referred to as being in direct contact or directly coupled, respectively, at least in one example. Similarly, elements shown side by side or adjacent to each other may be adjacent to each other or adjacent to each other, at least in one example. For example, components that are in surface-to-surface contact with each other may be referred to as being in surface-to-surface contact. As another example, in at least one instance, elements that are separated from each other with only a space between them and that do not have any other components may be referred to as such.In yet another example, elements depicted above / below, on opposite sides, or to the left / right of each other may be referred to as such, relative to each other. Further, in at least one example, as depicted in the figures, a topmost element or point of an element may be referred to as a "top" of the component, and a bottommost element or point of the element may be referred to as a "bottom" of the component. As used herein, the terms top / bottom, upper / lower, above / below may refer to a vertical axis of the figures and may be used to describe the positioning of elements of the figures relative to each other. For example, in one example, elements displayed above other elements are arranged vertically above the other elements.As a further example, the shapes of the elements depicted in the figures may be referred to as such (e.g., circular, straight, flat, curved, rounded, beveled, angled, or similar). Furthermore, in one example, elements that are coaxial with one another may be referred to as such. Furthermore, in at least one example, the depicted elements that intersect one another may be referred to as intersecting elements or as intersecting elements. Furthermore, an element depicted inside or outside another element may be referred to as such. In other examples, elements that are offset from one another may also be referred to as such. Elements that are arranged coaxially or parallel to one another may also be referred to as such.

[0067] The invention is further described in the following paragraphs. In one aspect, a powertrain system is provided that includes a first traction motor; a reduction planetary gear set rotatably coupled to the first traction motor and a power take-off configured to be connected to a work implement; and an input shaft rotatably coupled to the first traction motor and a transmission; wherein the reduction planetary gear set includes a fixed component.

[0068] Another aspect is a method of operating a powertrain system that includes selectively disconnecting a power take-off from a first traction motor by actuating a power take-off clutch; the powertrain system including the power take-off clutch, the first traction motor, a reduction planetary gear set rotatably coupled to the first traction motor and a power take-off configured to be connected to an implement, and an input shaft rotatably coupled to the first traction motor and coupled to a transmission. The method may further include, in one example, selectively disconnecting the first traction motor from the transmission by actuating a transmission disconnect clutch while a second traction motor rotatably coupled to the transmission is operating.

[0069] In another aspect, an electric vehicle powertrain system is provided that includes a first traction motor; an input shaft rotatably coupled to the first traction motor and a transmission; and a reduction planetary gear set including a sun gear rotatably coupled to the input shaft and a carrier rotatably coupled to a power take-off clutch; wherein the power take-off clutch is configured to selectively disconnect the reduction planetary gear set from a power take-off configured to connect to an implement; wherein the reduction planetary gear set includes a fixed component.

[0070] In any one or combination of aspects, the powertrain system may further include a power take-off clutch configured to selectively disconnect the power take-off from the reduction planetary gear set.

[0071] In any one or combination of aspects, the powertrain system may further include a controller including instructions that, when executed during operation of the first traction motor, cause the controller to selectively disengage the power take-off clutch based on operating conditions.

[0072] In one of the aspects or combinations of the aspects, the power take-off clutch may be a friction clutch.

[0073] In one of the aspects or combinations of the aspects, the working device may be a hydraulic pump.

[0074] In one of the aspects or combinations of the aspects, the reduction planetary gear set may be a simple reduction planetary gear set.

[0075] In any one aspect or combination of aspects, the reduction planetary gear set may include a sun gear fixedly coupled to an input shaft; a carrier rotatably coupled to the power take-off; and a ring gear that is fixed.

[0076] In one of the aspects or combinations of the aspects, the ring gear may be fixed by a gear housing.

[0077] In any one aspect or combination of aspects, the powertrain system may further include a second traction motor rotatably coupled to the transmission.

[0078] In any one or combination of aspects, the powertrain system may further include a transmission disconnect clutch configured to selectively disconnect the first traction motor from the transmission.

[0079] In one of the aspects or combinations of the aspects, the transmission may be a multi-speed transmission.

[0080] In one of the aspects or combinations of the aspects, the power take-off clutch may be a wet friction clutch.

[0081] In any one of the aspects or combinations of the aspects, the reduction planetary gear set may include a ring gear secured by a gear housing.

[0082] In any one aspect or combination of aspects, the powertrain system may further include a second traction motor rotatably coupled to the transmission; a transmission disconnect clutch configured to selectively disconnect the first traction motor from the transmission; and a controller including instructions that, when executed during operation of the first and second traction motors, cause the controller to disengage the transmission disconnect clutch and engage the power take-off clutch.

[0083] In one of the aspects or combinations of the aspects, the transmission disconnect clutch may be a wet friction clutch.

[0084] In one of the aspects or combinations of the aspects, the working device may be a hydraulic pump.

[0085] In one of the aspects or combinations of the aspects, the electric vehicle powertrain system may be a powertrain system for a pure electric vehicle.

[0086] In another representation, a two-motor electric drive is provided, which comprises a first traction motor, a power take-off which is selectively rotatably coupled to the first traction motor via a power take-off clutch, a transmission which is selectively rotatably coupled to the first traction motor via a disconnect clutch, and a second traction motor which is rotatably coupled to the transmission.

[0087] It should be noted that the example control and estimation routines contained herein may be used with various powertrain, electric drive, and / or driveline system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non-volatile memory and executed by the control system, including the controller, in combination with the various sensors, actuators, and other transmission and / or vehicle hardware, in combination with the electronic controller. Thus, the described actions, operations, and / or functions may graphically represent code programmed into the non-volatile memory of the computer-readable storage medium in the vehicle and / or powertrain control system.The various actions, operations, and / or functions illustrated may be performed in the order shown, in parallel, or in some cases, omitted. Accordingly, the order of processing is not required to achieve the features and advantages of the examples described herein, but is provided for convenience only. One or more of the actions, operations, and / or functions illustrated may be performed repeatedly depending on the strategy used. One or more of the process steps described herein may also be omitted if desired.

[0088] Although various embodiments have been described above, they are to be considered as examples and not as limitations. Those skilled in the art will appreciate that the disclosed subject matter may be embodied in other specific forms without departing from the spirit of the subject matter. The embodiments described above are, therefore, to be considered in all respects as illustrative and not restrictive. Thus, the configurations and routines disclosed herein are exemplary, and the specific examples are not to be considered as limiting, as numerous variations are possible. For example, the technology described above may be applied to powertrains that include various types of power sources, including various types of traction motors, internal combustion engines, and / or transmissions.The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions and / or properties disclosed herein.

[0089] The term “substantially” means, unless otherwise specified, plus or minus five percent of the range.

[0090] The following claims particularly point out certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims are to be construed as including the inclusion of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope than the original claims, are also to be considered included within the subject matter of the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2022 / 109644 A1

[0003]

Claims

[1] Powertrain system that includes: a first traction motor; a reduction planetary gear set rotatably coupled to the first traction motor and a power take-off configured to be connected to a work implement; and an input shaft rotatably coupled to the first traction motor and a transmission; wherein the reduction planetary gear set has a fixed component. [2] The powertrain system of claim 1, further comprising a power take-off clutch configured to selectively disconnect the power take-off from the reduction planetary gear set. [3] The powertrain system of claim 2, further comprising: a controller with instructions which, when executed during operation of the first traction motor, cause the controller to: selective disengagement of the power take-off clutch based on operating conditions. [4] A powertrain system according to claim 2 or 3, wherein the power take-off clutch is a friction clutch. [5] A drive train system according to any one of the preceding claims, wherein the working device is a hydraulic pump. [6] A drive train system according to any one of the preceding claims, wherein the reduction planetary gear set is a simple reduction planetary gear set. [7] The drivetrain system of claim 6, wherein the reduction planetary gear set includes: a sun gear that is rigidly coupled to the input shaft; a carrier rotatably coupled to the power take-off; and a ring gear that is fixed. [8] The drive train system of claim 7, wherein the ring gear is secured by a transmission housing. [9] A powertrain system according to any preceding claim, further comprising a second traction motor rotatably coupled to the transmission. [10] The powertrain system of claim 9, further comprising a transmission disconnect clutch configured to selectively disconnect the first traction motor from the transmission. [11] Powertrain system according to one of the preceding claims, wherein the transmission is a multi-speed transmission. [12] A drive train system according to any preceding claim, wherein the reduction planetary gear set includes a ring gear secured by a transmission housing. [13] A powertrain system according to any one of the preceding claims, further comprising: a power take-off clutch configured to selectively disconnect the power take-off from the reduction planetary gear set; a second drive motor rotatably coupled to the transmission; a transmission disconnect clutch configured to selectively disconnect the first traction motor from the transmission; and a controller having instructions which, when executed during operation of the first traction motor and the second traction motor, cause the controller to: Disengaging the transmission disconnect clutch; and Engaging the power take-off clutch. [14] A powertrain system according to claim 13, wherein: the transmission clutch is a wet friction clutch; and / or the power take-off clutch is a wet friction clutch. [15] A powertrain system according to any one of the preceding claims, wherein the powertrain system is a fully electric powertrain system.

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