Systems for a transmission system

Abstract

System, comprising: a first electric motor configured to deliver a first power to a power take-off (PTO) and a drive axle via a first two-speed gear arrangement; a second electric motor configured to deliver a second power to the drive axle via a second two-speed gear arrangement; and a control unit containing computer-readable instructions stored in a non-transferable memory which, when executed, cause the control unit to: to adjust the first power of the first electric motor depending on the second power.

Description

AREA

[0001] The present description relates generally to the design of a power take-off (PTO) in a transmission system of an at least partially electric vehicle. BACKGROUND AND OVERVIEW

[0002] Vehicles, including passenger cars, heavy-duty vehicles, off-road vehicles, and the like, are being equipped with electrified components to increase performance and reduce emissions. Vehicle electrification may require modifications to existing architectures designed to operate with an internal combustion engine. One example of a component that can be modified is the power take-off (PTO).

[0003] For example, electrified off-road vehicles can be equipped with one or two electric motors. In the example of a single electric motor, the motor is sized to deliver high torque at low speeds while achieving maximum vehicle speed. These comprehensive requirements may not be compatible with a single-speed transmission, so the weight and packaging savings from using a single electric motor may be mitigated by installing a multi-speed transmission. When using a single-speed transmission, the single electric motor can be oversized so that its size is comparable to or equal to that of two separate motors.

[0004] The problems described above may be addressed by a system including a first electric motor configured to provide a first power to a power take-off (PTO) and a drive axle via a first two-speed gearing arrangement, a second electric motor configured to provide a second power to the drive axle via a second two-speed gearing arrangement, and a controller including computer-readable instructions stored in a non-transferable memory thereof that, when executed, enable the controller to adjust the first power of the first electric motor based on the second power.

[0005] Note that the above summary is intended to introduce, in simplified form, a selection of concepts 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 an example of a vehicle system. Fig. Figure 2 shows a first example of a drive train with two electric motors and a two-speed transmission. The Fig. 3A and Fig. 3B show a second and third example of a powertrain with two electric motors and a two-speed transmission. The Fig. 4A, Fig. 4B, Fig. 4C and Fig. 4D show alternative embodiments of the first example with a power take-off (PTO) arranged at different locations. The Fig. 5A, Fig. 5B and Fig. 5C show alternative embodiments of the second and third examples in which the power take-off is arranged at different locations. The Fig. 6A, Fig. 6B and Fig. 6C show alternative embodiments of the second and third examples in which the power take-off is arranged at different locations. Fig. 7 shows a hydraulic system coupled to the power take-off. DETAILED DESCRIPTION

[0006] The following description refers to systems for a transmission system. The transmission system can be installed in an electric powertrain of a vehicle. Fig. 1 shows an example of a vehicle with the transmission system. Fig. Figure 2 shows a first example of a drivetrain with two electric motors and a two-speed transmission. Fig. 3A and Fig. 3B show a second and third example of a powertrain with two electric motors and a two-speed transmission. Fig. 4A, Fig. 4B, Fig. 4C and Fig. 4D show alternative embodiments of the first example with a power take-off (PTO) arranged at different locations. Fig. 5A, Fig. 5B and Fig. 5C show alternative embodiments of the second and third examples, in which the power take-off is arranged at different locations. Fig. 6A, Fig. 6B and Fig. 6C show alternative embodiments of the second and third examples in which the power take-off is arranged at different locations. Fig. 7 shows a hydraulic system coupled to the power take-off.

[0007] In one embodiment, the disclosure supports a system in which a power take-off is permanently connected to one of the two motors of a two-speed continuously variable transmission with two electric motors. The motor(s) can supply power to a vehicle hydraulic circuit and the vehicle driveline to provide propulsion. The motors can be equipped with an idle so that power can only be delivered to the hydraulic circuit when the vehicle speed is zero and a vehicle attachment, such as a bucket, forklift, or other equipment, is being operated. This allows the two motors to peak their power at different speeds, similar to a wheeled excavator, when the wheel loader drives its bucket into the pile.In the reach stacker example, one motor can be used for traction during low-speed maneuvers, while the second motor supplies the hydraulic circuit. At full load and full speed, the two motors can provide almost all available power for traction, while one of the two motors provides minimal hydraulic power for vehicle services. At shifting speeds, the need for hydraulic power to the vehicle's attachments is unlikely, and the motor driving the power take-off can assist the traction motor during gear changes, enabling seamless gear shifting and thus improving customer satisfaction and increasing transmission life.

[0008] In another embodiment, a transmission architecture and methodology for operating the transmission are provided. A first electric motor may be connected to an output shaft through a first transmission having a first reduction ratio or through a second transmission having a second reduction ratio less than the first reduction ratio. Selection between the two ratios may be accomplished by adjusting a first dog clutch. The dog clutch may provide a neutral state in addition to two engaged positions relative to the first reduction ratio and the second reduction ratio. The two reduction ratios may be achieved in one or more steps.A second electric motor may be connected to the output shaft through a third gearbox with a third reduction ratio or through a fourth gearbox with a fourth reduction ratio smaller than the third reduction ratio. Selection between the two additional gears can be achieved by adjusting a second dog clutch, which provides a neutral state in addition to the two engaged positions, and the two additional gears can be achieved in one or more stages. The power flowing from the first motor to the output shaft follows a different and independent path than the power transmitted from the second electric motor to the output shaft. The first shaft of the electric motor is permanently connected to a volumetric variable displacement pump via a power take-off directly connected to a pump shaft.The first electric motor, when disconnected from the output shaft, can supply power to the pump requested by the hydraulic circuit. The second electric motor, when connected to the output shaft via the third reduction ratio, can deliver the required power to the output shaft to achieve the required tractive effort of the vehicle. Furthermore, the second electric motor can be connected to the output shaft via the third reduction ratio to reach its maximum speed before or when the first electric motor, connected to the output shaft via the first reduction ratio, reaches its maximum speed.When the first electric motor is connected to the output shaft via the second reduction ratio and the second electric motor is connected to the output shaft via the fourth reduction ratio, the two motors, at their rated power, can reach a speed equal to or lower than the vehicle's maximum speed. A method may include connecting the first electric motor to the output shaft when a positive vehicle speed above a threshold occurs, and disabling the first electric motor below the threshold.When the first electric motor is connected to the output shaft, the method balances the traction power between the two electric motors so that the power delivered by the first electric motor to the hydraulic circuit and to the output shaft is a certain percentage of its rated power and the power delivered by the second electric motor to the output shaft is the same percentage of its rated power.

[0009] In a further embodiment, the motors are dimensioned such that the second electric motor, not connected to the hydraulic pump, is capable of delivering the maximum traction force of the vehicle alone when it is geared to the output shaft with the third reduction ratio, possibly for a limited period of time during which it reaches its peak power.

[0010] The motors are dimensioned so that the first electric motor connected to the hydraulic pump, when not connected to the output shaft, can provide the entire required hydraulic power alone, possibly for a limited period of time during which it reaches its peak power.

[0011] The motors are sized so that the power delivered by a single motor at full speed and full load with low equipment usage is not enough to maintain the vehicle speed indefinitely, while the use of two motors at rated power can maintain the vehicle speed.

[0012] Within the transmission, the two motors and their power electronics are identical in size, configuration, and output power. When both motors are connected to the drivetrain via a transmission, the drive power is split between the two motors, so that the second electric motor and the first electric motor deliver the same percentage of their rated power.

[0013] The transmission architecture of the present disclosure provides that reverse travel is achieved by reversing the rotation of the electric motor. Therefore, at low vehicle speeds below a lower limit speed, the first electric motor is not connected to the driveline. When traveling in the reverse direction, a pump with a reversing function can supply power to the hydraulic circuit. In such an example, the pump can be a hydrostatic axial piston unit with a swash plate. To make the pump configuration flexible, the first electric motor can be connected to the driveline so that the vehicle speed is non-zero and is positive.

[0014] Fig. 1 shows a schematic illustration of a vehicle 6 having a powertrain 8, which may include a prime mover 54 and a transmission 60. The vehicle 6 may be a passenger vehicle, a commercial vehicle, a heavy-duty vehicle, an off-road vehicle, an agricultural vehicle, an aircraft, a boat, or other vehicle system that utilizes lubricants.

[0015] The prime mover 54 may be electrically connected to an energy storage device 58 (e.g., one or more traction batteries, capacitors, fuel cells, combinations thereof, and the like). Furthermore, the prime mover 54 may be configured to operate as a generator under certain conditions, for example, to provide electrical energy to charge the energy storage device 58.

[0016] In some examples, vehicle 6 may include an internal combustion engine (ICE) configured to operate in combination with or independently of prime mover 54. Thus, in some examples, vehicle 6 may be configured as a hybrid vehicle.

[0017] In the illustrated example, the transmission 60 supplies mechanical power to a differential 62 of an axle assembly 53. However, it should be understood that the transmission 60 may additionally or alternatively supply mechanical power to the other axle 64 in the vehicle 6. In other examples, the transmission may be incorporated into one of the axles to form an electric axle assembly. In the electric axle example, in some cases, an internal combustion engine may supply mechanical power to the other axle.

[0018] The transmission 60 (e.g., a manual transmission) may be configured to receive torque from the prime mover 54 via a shaft (e.g., a driveshaft) and / or other suitable mechanical components. The transmission 60 may output torque to the differential 62. The output torque may be moderated based on selective adjustments of gear engagement on the transmission 60 to achieve a desired vehicle operation. The torque of the transmission 60 may rotate the differential 62, which in turn drives the axle shafts 66 that are rotationally connected to the vehicle wheels 55. The vehicle wheels 56 may rotate when the vehicle wheels 55 travel against a surface.

[0019] A controller 112 may form part of a control system 114. As illustrated, the control system 114 receives information from sensors 116 and sends control signals to actuators 181. Sensors 116 may include, for example, sensors such as a battery level sensor, a clutch activation sensor, one or more electric motor position sensors, etc. The controller 112 may receive input data from the sensors, process the input data via a processor, and trigger the actuators in response to the processed input data based on instructions or code programmed therein corresponding to one or more routines.

[0020] Fig. Figure 2 shows an example of a system 200 with an energy storage device 202 connected to a first inverter 204 and a second inverter 214. The first inverter 204 and the second inverter 214 may be controlled by the controller 112. Therefore, the previously introduced components may be numbered similarly in this and subsequent figures.

[0021] The inverters can be controlled to adjust the power of the respective electric motors. In particular, the first inverter 204 can be coupled to a first electric motor 206 and configured to control its operation. The second inverter 214 can be coupled to a second electric motor 216 and configured to control its operation.

[0022] A first shaft of the electric motor 208 may be coupled to the first electric motor 206 and configured to rotate in response to its operation. The first shaft of the electric motor 208 may extend parallel to a first axis. A first input gear 222 and a second input gear 224 are disposed on the first shaft of the electric motor 208. The first input gear 222 and the second input gear 224 may be configured to rotate when the first shaft of the electric motor 208 rotates. In one example, the first input gear 222 and the second input gear 224 are differently sized and may be included in a first two-speed gear arrangement.

[0023] A second shaft 218 of the electric motor may be coupled to the second electric motor 216 and configured to rotate depending on its operation. The second shaft of the electric motor 218 may be parallel to a second axis. In one example, the second axis is parallel to the first axis. A third input gear 226 and a fourth input gear 228 are arranged on the second shaft of the electric motor 218. The third input gear 226 and the fourth input gear 228 may be configured to rotate when the second shaft of the electric motor 218 rotates. In one example, the third input gear 226 and the fourth input gear 228 are differently sized and may be included in a second two-speed gear arrangement. The first two-speed gear arrangement and the second two-speed gear arrangement may include helical or spur gears and are free of planetary gear sets.

[0024] The first electric motor 206 may be configured to provide a first power, and the second electric motor 216 may be configured to provide a second power. In one example, an upper threshold for the first power may be equal to an upper threshold for the second power, where the upper thresholds for the first and second power are based on positive non-zero numbers corresponding to a maximum power of the electric motors. The first power and / or the second power may be adjusted based on the operating state of a vehicle including the system 200. In one example, the first power may be adjusted based on the second power.

[0025] A first intermediate shaft 230 may run parallel to a third axis. The third axis may run parallel to the first and second axes. The first intermediate shaft 230 may include a first clutch gear 232 and a second clutch gear 234. The first clutch gear 232 may mesh with the first input gear 222. The second clutch gear 234 may mesh with the second input gear 224. A first clutch 236 may be configured to control engagement and disengagement of the first clutch gear 232 and the second clutch gear 234 with the first intermediate shaft 230. The first intermediate shaft 230 may rotate when engaged with the first clutch gear 232 or the second clutch gear 234. In the disengaged state, the first intermediate shaft 230 must not rotate when the first clutch gear 232 and / or the second clutch gear 234 are disengaged.

[0026] A second intermediate shaft 240 may run parallel to a fourth axis. The fourth axis may run parallel to each of the first, second, and third axes. In this way, the shafts are parallel to each other without being coaxial, thereby reducing the packaging size of the system 200. The second intermediate shaft 240 may include a third clutch gear 242 and a fourth clutch gear 244. The third clutch gear 242 may mesh with the third input gear 226. The fourth clutch gear 244 may mesh with the fourth input gear 228. A second clutch 246 may be configured to control the engagement and disengagement of the third clutch gear 242 and the fourth clutch gear 244 with the second intermediate shaft 240. The second intermediate shaft 240 may rotate when engaged with the third clutch gear 242 or the fourth clutch gear 244.In the disengaged state, the second intermediate shaft 240 must not rotate in dependence upon the rotation of the disengaged third clutch gear 242 and / or the fourth clutch gear 244.

[0027] A first intermediate shaft output gear 238 may be configured to rotate in response to rotation of the first intermediate shaft 230. The first intermediate shaft output gear 238 may mesh with an output gear 270. The output gear 270 may mesh with an output shaft 272 coupled to a first rotating component 274 and a second rotating component 276. The first rotating component 274 and the second rotating component 276 may be connected to separate gears of a drive system.

[0028] A second intermediate shaft output gear 248 may be configured to rotate based on rotation of the first intermediate shaft 240. The second intermediate shaft output gear 248 may mesh with the output gear 270. The second intermediate shaft driven gear 248 may mesh with a side of the output gear 270 opposite the first intermediate shaft output gear 238.

[0029] The controller 112 may adjust a position of the first clutch 236 and the second clutch 246 via a first active torque module 250 and a second active torque module 260, respectively. The first inverter 204 and the second inverter 214 may provide feedback to the controller 112 regarding the operation of the first motor 206 and the second motor 216, respectively. The controller 112 may then adjust the position of the first clutch 236 and / or the second clutch 246 to change the engagement / disengagement of one or more gears between the electric motor shafts and the intermediate shafts.

[0030] The Fig. 3A and Fig. 3B show alternative embodiments of a dual motor transmission. The embodiments of Fig. 3A and Fig. 3B include the battery 202, the first inverter 204, the second inverter 214, the first electric motor 206, and the second electric motor 216. Therefore, the previously introduced components are numbered similarly in this and the following figures.

[0031] Fig. 3A shows a first alternative embodiment 300 of a dual-motor transmission. The first electric motor 206 may include a first electric motor output shaft 302 with a first input gear 304. The first input gear 304 may mesh with the first electric motor output shaft 302 and be configured to rotate when the first electric motor output shaft 302 rotates. The first output shaft of the electric motor 302 is arranged along a first axis.

[0032] The second electric motor 216 may be equipped with a second electric motor output shaft 306. A second input gear 308 may mesh with the second shaft of the electric motor 306 and be configured to rotate when the second output shaft of the electric motor rotates. The second output shaft of the electric motor is arranged along a second axis that runs parallel to the first axis.

[0033] A first intermediate shaft 310 may mesh with a first intermediate shaft gear 312. The first intermediate shaft gear 312 may mesh with the first input gear 304. When the first input gear 304 rotates, the first intermediate shaft gear 312 may also rotate, thereby rotating the first intermediate shaft 310. A first clutch gear 314 and a second clutch gear 316 may be coupled to a first clutch 318 and configured to engage or disengage the first intermediate shaft 310. The first clutch 318 may be controlled via signals sent from the controller 112 to a first active torque module 340. The first intermediate shaft 310 is arranged along a third axis that is parallel to each of the first and second axes.

[0034] A second intermediate shaft 320 may mesh with a second intermediate shaft gear 322. The second intermediate shaft gear 322 may mesh with the second input gear 308. When the second input gear 308 rotates, the second intermediate shaft gear 322 may also rotate, thereby rotating the second intermediate shaft 320. A third clutch gear 324 and a fourth clutch gear 326 may be coupled to a second clutch 328 and configured to engage or disengage the second intermediate shaft 320. The second clutch 328 may be controlled via signals sent from the controller 112 to a second active torque module 342. The second intermediate shaft 320 may be arranged along a fourth axis that is parallel to each of the first, second, and third axes.

[0035] An output shaft 330 may be arranged along a fifth axis and parallel to each of the first electric motor output shaft 302, the second electric motor output shaft 306, the first intermediate shaft 310, and the second intermediate shaft 320. A first output gear 332 may mesh with the output shaft 330 via a plurality of internal teeth. The first output gear 332 may mesh with the first clutch gear 314 and the third clutch gear 324 having a plurality of external teeth. A second output gear 334 may mesh with the output shaft 330 via a plurality of internal teeth. The second output gear 334 may mesh with the second clutch gear 316 and the fourth clutch gear 326 having a plurality of external teeth. The output shaft 330 may rotate when the first output gear 332 or the second output gear 334 rotates. The output shaft 330 may be connected to a first rotating member 336 and a second rotating member 338, such as a gear.B. the wheels of a drive system.

[0036] Fig. 3B shows a second alternative embodiment 350 of the dual motor transmission. The second alternative embodiment 350 may be substantially identical to the first alternative embodiment 300, except that the second alternative embodiment 350 includes a third intermediate shaft 360. A first intermediate shaft gear 362 and a second intermediate shaft gear 364 may mesh with the third intermediate shaft 360 via a plurality of internal teeth. The first intermediate shaft gear 362 may mesh with the first clutch gear 314 and the third clutch gear 324 via a plurality of external teeth. The second intermediate shaft gear 364 may mesh with the second clutch gear 316 and the fourth clutch gear 326 via a plurality of external teeth.When the first gear 362 of the third intermediate shaft and / or the second gear 364 of the third intermediate shaft rotates, the third intermediate shaft 360 may also rotate, thereby rotating a third gear 366 of the third intermediate shaft.

[0037] The third gear 366 of the third intermediate shaft can mesh with an output gear 372 via a plurality of external teeth. The output gear 372 can mesh with an output shaft 370 that is rotationally coupled to a first rotational component 374 and a second rotational component 376 and can be configured to rotate.

[0038] The following figures and descriptions refer to various locations of the power take-off (PTO) in a dual-motor transmission arrangement. The power take-off can be used to drive a hydraulic circuit, as shown in Fig. 7. It is clear that the shafts of the double motor gearbox in each of the examples are in the Fig. 2-7 run parallel to each other without being coaxial.

[0039] In Fig. 4A, an embodiment 400 is shown showing a first example configuration of the system 200 with a power take-off 410. The battery, inverters, controller, and active torque modules are omitted for brevity. The power take-off 410 may be directly connected to the first shaft of the electric motor 208. In this way, when the vehicle is stationary and a vehicle implement such as a bucket, fork, or other implement is to be used, substantially all of the power of the first electric motor 206 may be used to drive the power take-off. The first clutch 236 may be actuated to disconnect both the first clutch gear 232 and the second clutch gear 234 from the first intermediate shaft 230 when substantially all of the power of the first electric motor 206 is being delivered to the power take-off 410 and no tractive effort is requested from the first electric motor 206.

[0040] Fig. 4B shows an embodiment 425 illustrating a second example configuration of the system 200 with a power take-off 430. The second example configuration may differ from the first example configuration of Fig. 4A in that the power take-off 430 is coupled to a power take-off shaft 432. A power take-off shaft gear 434 can mesh with the first input gear 222 disposed on the first shaft of the electric motor 208. In this way, the power take-off shaft gear 434 can rotate when the first input gear 222 rotates, thereby rotating the power take-off shaft 432 and driving the power take-off 430.

[0041] Fig. 4C shows an embodiment 450 illustrating a third example configuration of the system 200 with a power take-off 460. The power take-off 460 may be coupled to a power take-off shaft 462 including a power take-off shaft gear 464. The third example configuration may differ from the second example configuration of Fig. 4B in that the power take-off shaft gear 464 is coupled to a fifth input gear 466 disposed on the first electric motor output shaft 208.

[0042] In Fig. 4D, an embodiment 475 is shown illustrating a fourth example configuration of the system 200 with a power take-off 480. The power take-off 480 may be coupled to a power take-off shaft 482 that meshes with a power take-off shaft gear 484. A first idler gear 492 may be disposed on a first idler gear shaft 494 and mesh with the second input gear 224. A second idler gear 496 may be disposed on a second idler gear shaft 498 and mesh with the first idler gear 492 and the power take-off shaft gear 484. Thus, power flows from the first electric motor 206 via the first electric motor output shaft 208, the second input gear 224, the first idler gear 492, the second idler gear 496, the power take-off shaft gear 484, the power take-off shaft 482, and the power take-off 480.

[0043] Fig. 5A shows an embodiment 500 illustrating a first example configuration of the system 300 with a power take-off 510. The battery, inverters, controller, and active torque modules are omitted for brevity. The power take-off 510 may be directly connected to the first output shaft of the electric motor 302. In this way, when the vehicle is stationary and a vehicle implement such as a bucket, fork, or other implement is to be used, substantially all of the power of the first electric motor 206 may be used to drive the power take-off. The first clutch 318 may be actuated to disconnect both the first clutch gear 314 and the second clutch gear 316 from the first intermediate shaft 310 when substantially all of the power of the first electric motor 206 is being delivered to the power take-off 510 and no tractive effort is requested from the first electric motor 206.

[0044] Fig. 5B shows an embodiment 525 illustrating a second example configuration of the system 300 with a power take-off 530. The second example configuration may differ from the first example configuration of Fig. 5A in that the power take-off 530 is coupled to the first intermediate shaft 310. In this way, the power take-off 530 is driven to rotate via the first intermediate shaft 310. The operation of the first and second example configurations may be similar, so that the instructions stored in the memory of a controller configured for operating the dual-motor transmission need not be changed for a vehicle having the first example configuration or the second example configuration.

[0045] Fig. 5C shows an embodiment 550 illustrating a third example configuration of the system 300 with a power take-off 560. The third example configuration may differ from the first and second example configurations of Fig. 5A and 5B, respectively, in that the power take-off 560 is coupled to a power take-off shaft 562. A power take-off shaft gear 564 can mesh with the power take-off shaft 562 and the first input gear. When the first input gear 304 rotates, the power take-off shaft gear 564 can also rotate, thereby rotating the power take-off shaft 562 and transmitting power to the power take-off 560.

[0046] Fig. 6A shows an embodiment 600 illustrating a first example configuration of the system 350 with a power take-off 610. The battery, inverters, controller, and active torque modules are omitted for brevity. The power take-off 610 may be directly connected to the first output shaft of the electric motor 302. In this way, when the vehicle is stationary and a vehicle implement such as a bucket, fork, or other implement is to be used, substantially all of the power of the first electric motor 206 may be used to drive the power take-off. The first clutch 318 may be actuated to disconnect both the first clutch gear 314 and the second clutch gear 316 from the first intermediate shaft 310 when substantially all of the power of the first electric motor 206 is being delivered to the power take-off 610 and no tractive effort is requested from the first electric motor 206.

[0047] Fig. 6B shows an embodiment 625 illustrating a second example configuration of the system 350 with a power take-off 630. The second example configuration may differ from the first example configuration of Fig. 6A in that the power take-off 630 is coupled to the first intermediate shaft 310. In this way, the power take-off 630 is rotated via the first intermediate shaft 310. The operation of the first and second example configurations may be similar.

[0048] Fig. 6C shows an embodiment 650 illustrating a third example configuration of the system 350 with a power take-off 660. The third example configuration may differ from the first and second example configurations of the Fig. 6A and 6B, respectively, in that the power take-off 660 is coupled to a power take-off shaft 662. A power take-off shaft gear 664 can mesh with the power take-off shaft 662 and the first input gear. When the first input gear 304 rotates, the power take-off shaft gear 664 can also rotate, thereby rotating the power take-off shaft 662 and transferring power to the power take-off 660.

[0049] In Fig. 7, an embodiment 700 is shown showing a hydraulic system 710 coupled to the power take-off 410 of embodiment 400 of the system 200. The hydraulic system 710 may include a pump 712 driven by the power take-off 410. An accumulator 714 may be configured to store and / or pressurize the fluid delivered by the pump 712. A pressure relief valve 718 may be disposed between the pump 712 and an actuator 716. The actuator 716 may be configured as a basket, fork, loader, or other device. The pump 712, the pressure relief valve 718, and the actuator 716 are each connected to a reservoir 719 in which hydraulic fluid may be stored.

[0050] In one example, the pressure of the hydraulic circuit depends on a flow rate and a circuit resistance, where the circuit resistance is proportional to the user load (e.g., the driver's demand). Adjusting the power of the first motor must not affect the pressure in the circuit. The pressure in the hydraulic circuit can be adjusted by varying the speed of pump 712.

[0051] The following presents a real-world operating example of embodiment 700. Embodiment 700 is a wheel loader, but other vehicles may be used and operated in a similar manner. The process describes a wheel loader entering a pile at an upper threshold torque and operating the attachments to fill the bucket, reverse to retract from the pile, and oscillate to accelerate to its maximum speed under full load.

[0052] When approaching the pile, at low vehicle speed, the first electric motor 206 is in a neutral state with respect to the transmission, such that neither the first input gear 222 nor the second input gear 224 are engaged and rotating to energize the hydraulic circuit via the power take-off 410. During this phase, the first electric motor 206 supplies power to the vehicle functions (e.g., temperature control) and the boom and bucket cylinders connected to the hydraulic system 710. The second motor 216 is connected to the second electric motor output shaft 218, with the fourth input gear 228 engaged, thus achieving maximum vehicle traction, which may include a power peak from the second electric motor 216.During this phase, the second electric motor 216 may drive the vehicle to push the bucket further into the pile while the first electric motor 206 is used to actuate the bucket.

[0053] Once the bucket is fully loaded, the vehicle is instructed to reverse. During this phase, the first electric motor 206 provides hydraulic power for the vehicle's services, while the second electric motor 216 accelerates in the reverse direction.

[0054] When commuting, the second electric motor 216 may reduce its speed to zero to move in a forward direction, with the first electric motor 206 providing its power for vehicle services rather than vehicle propulsion.

[0055] The vehicle now increases its speed in a positive direction, and during a threshold-crossing event, e.g., falling below a lower threshold speed or exceeding an upper threshold speed, the first electric motor 206 may change its speed to synchronize the second output gear 224 with the first electric motor output shaft 208. The pump displacement may follow the speed change of the first electric motor 206 to meet a hydraulic circuit demand, i.e., increasing its displacement when the second electric motor 216 slows down, or conversely, decreasing the pump displacement when the second electric motor 216 speeds up, with the accumulator buffering any detected imbalances in pump performance.Upon synchronization, the controller may engage the second input gear 224 by actuating the first clutch 236, shifting a portion of the traction load originally required only by the second electric motor 216 to the first electric motor 206. During this process, the vehicle continues to increase speed seamlessly, so the switch is unnoticeable to a vehicle operator.

[0056] As the shift speed is approached, the traction load on the second electric motor 216 is zero, and the entire load is taken up by the first electric motor 206. At the shift point, the implement's consumption may be zero, and the load on the hydraulic circuit and the first electric motor 206 may equal the combined load on the traction system and the hydraulic pump(s). At zero load, the fourth input gear 228 is disengaged by actuating the second clutch 246 based on a command from the controller 112 to the second active torque module 260, and the second electric motor 216 is in a neutral state with respect to the driveline. The second electric motor is therefore decelerated to synchronize the driven gear of the third input gear 226 with its shaft.Once synchronization is achieved, the second clutch controller can signal, via the second active torque control module, to engage the third input gear 226. This shifts a portion of the traction load originally provided only by the first electric motor 206 to the second electric motor 216. During this process, the vehicle continues to increase speed seamlessly.

[0057] Similar to the second electric motor 216 circuit described above, where the traction load is met only by the second electric motor 216. At zero traction load, the second input gear 224 is disengaged and the first electric motor 206 is in a neutral state with respect to the driveline. The second electric motor is therefore decelerated to synchronize the first input gear 222 with the first electric motor's output shaft 208, and the pump 712 can adjust its displacement to compensate for the speed change of the first electric motor 206, with the accumulator 714 ultimately buffering the hydraulic load. Upon synchronization, the controller can engage the first input gear 222 so that a portion of the traction load met only by the second electric motor 216 is also met by the first electric motor 206. During this process, the vehicle continues to increase speed seamlessly.

[0058] When the two motors are engaged with the high-gear ratio gears (e.g., the first input gear 222 and the third input gear 226), the vehicle continues to increase speed, eventually utilizing the peak power of the motors. From this point on, any cruising speed, including the vehicle's top speed, can be maintained indefinitely by the motors without overloading them.

[0059] The real-life example serves to demonstrate the use of the architecture. Additionally, a deceleration ramp can be performed in a similar manner, in reverse order of the operations.

[0060] The disclosure also provides support for a system comprising: a first electric motor configured to provide a first power to a power take-off (PTO) and a drive axle via a first two-speed gearing arrangement; a second electric motor configured to provide a second power to the drive axle via a second two-speed gearing arrangement; and a controller including computer-readable instructions stored in a non-transferable memory thereof that, when executed, enable the controller to adjust the first power of the first electric motor based on the second power. In a first example of the system, the power take-off is permanently connected to a shaft of the first electric motor.In a second example of the system, optionally including the first example, the power take-off is permanently coupled to a gear of the first two-speed gear arrangement. In a third example of the system, optionally including one or both of the first and second examples, the power take-off drives a pump of a hydraulic circuit. In a fourth example of the system, optionally including one or more or each of the first to third examples, the hydraulic circuit includes an accumulator that adjusts a pressure of the hydraulic circuit when the first power is adjusted. In a fifth example of the system, optionally including one or more or each of the first to fourth examples, the first electric motor and the second electric motor are identical. In a sixth example of the system, optionally including one or more or each of the first to fifth examples, the power take-off is coupled only to the first electric motor.

[0061] The disclosure also provides support for a powertrain comprising: a first electric motor configured to provide first power to a power take-off (PTO) and a drive axle via a first two-speed gearing arrangement, wherein a first clutch is configured to engage or disengage the first two-speed gearing arrangement with the first electric motor, a second electric motor configured to provide second power to the drive axle via a second two-speed gearing arrangement, wherein a second clutch is configured to engage or disengage the second two-speed gearing arrangement with the second electric motor, and a controller including computer-readable instructions stored in a non-transferable memory thereof that, when executed,enabling the controller to adjust the first power output of the first electric motor based on the operation of a vehicle with the drivetrain. In a first example of the system, the first clutch and the second clutch are dog clutches. In a second example of the system, optionally including the first example, the reduction ratios of the first two-speed gearing arrangement are identical to the reduction ratios of the second two-speed gearing arrangement. In a third example of the system, optionally including one or both of the first and second examples, the power take-off is coupled to a power take-off shaft, with a power take-off gear meshing with the power take-off shaft and a gear of the first two-speed gearing arrangement. In a fourth example of the system, optionally including one or more or each of the first to third examples,The power take-off operates a pump of a hydraulic circuit. In a fifth example of the system, optionally including one or more or each of the first to fourth examples, the hydraulic circuit comprises a pressure accumulator and an actuator configured to operate an auxiliary device. In a sixth example of the system, optionally including one or more or each of the first to fifth examples, the drive axle is coupled to wheels of an off-road vehicle. In a seventh example of the system, optionally including one or more or each of the first to sixth examples, the first power and the second power are each equal percentages of the total power of the first electric motor and the second electric motor.

[0062] The disclosure also provides support for a system comprising: a first electric motor configured to provide first power to a power take-off (PTO) and a drive axle via a first two-speed gearing arrangement, wherein a first clutch is configured to engage or disengage the first two-speed gearing arrangement with the first electric motor, a second electric motor configured to provide second power to the drive axle via a second two-speed gearing arrangement, wherein a second clutch is configured to engage or disengage the second two-speed gearing arrangement with the second electric motor, a hydraulic circuit including a pump coupled to the power take-off, and a controller including computer-readable instructions stored in a non-transitory memory thereof that, when executed, cause the controller toadjust the first power output of the first electric motor based on the operation of a vehicle with the powertrain. In a first example of the system, each shaft of the system is parallel and not coaxial. In a second example of the system, optionally including the first example, the gears of the first two-speed gear arrangement and the second two-speed gear arrangement are helical or spur geared. In a third example of the system, optionally including one or both of the first and second examples, the first electric motor supplies power to the power take-off during all active operating states of the first electric motor. In a fourth example of the system, optionally including one or more or each of the first through third examples, the instructions cause the controller to make one or more of the following adjustments: adjusting the power output of the first electric motor, the second electric motor,a position of the first clutch and a position of the second clutch to adjust the operating conditions.

[0063] Fig.2 to 7 show example configurations with relative positioning of the various components. Where these elements are shown directly touching or directly coupled to one another, such elements may be referred to as directly touching or directly coupled, respectively, at least in one example. Similarly, elements shown adjacent to or juxtaposed with one another may be adjacent to or adjacent to one another, at least in one example. For example, components that are in surface-to-surface contact with one another may be referred to as being in surface-to-surface contact. As another example, in at least one instance, elements that are separated from one another 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. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As another 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 the like). Further, in at least one example, depicted elements that intersect each other may be referred to as intersecting elements or as intersecting elements. Furthermore, an element depicted inside another element or outside another element may be referred to as such. It is understood that one or more components described as "substantially similar and / or identical" may vary from one another according to manufacturing tolerances (e.g., within 1-5% variation).

[0064] 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.

Claims

[1] System comprising: a first electric motor configured to deliver a first power to a power take-off (PTO) and a drive axle via a first two-speed gear arrangement; a second electric motor configured to deliver a second power to the drive axle via a second two-speed gear arrangement; and a control unit containing computer-readable instructions stored in a non-transferable memory which, when executed, cause the control unit to: to adjust the first power of the first electric motor depending on the second power. [2] The system of claim 1, wherein the power take-off is permanently coupled to the shaft of the first electric motor. [3] A system according to any one of the preceding claims, wherein the power take-off is permanently coupled to a gear of the first two-speed gear arrangement. [4] A system according to any one of the preceding claims, wherein the power take-off drives a pump of a hydraulic circuit. [5] The system of claim 4, wherein the hydraulic circuit comprises an accumulator. [6] A system according to any one of the preceding claims, wherein the first electric motor and the second electric motor are identical. [7] System according to one of the preceding claims, wherein the power take-off is coupled only to the first electric motor. [8] Powertrain, comprising: a first electric motor configured to provide a first power to a power take-off (PTO) and to a drive axle via a first two-speed gear arrangement, wherein a first clutch is configured to engage or disengage the first two-speed gear arrangement with the first electric motor; a second electric motor configured to supply a second power to the drive axle via a second two-speed gear arrangement, wherein a second clutch is configured to engage or disengage the second two-speed gear arrangement with the second electric motor; and a control unit containing computer-readable instructions stored in a non-transferable memory which, when executed, cause the control unit to: to adjust the first power of the first electric motor depending on the operation of a vehicle containing the powertrain. [9] The drive train of claim 8, wherein the first clutch and the second clutch are dog clutches. [10] A drive train according to claim 8 or 9, wherein the reduction ratios of the first two-speed gear arrangement are identical to the reduction ratios of the second two-speed gear arrangement. [11] Drive train according to one of claims 8 to 10, wherein the power take-off is coupled to a power take-off shaft, wherein a power take-off gear meshes with the power take-off shaft and a gear of the first two-speed gear arrangement. [12] Drive train according to one of claims 8 to 11, wherein the power take-off actuates a pump of a hydraulic circuit. [13] Drive train according to claim 12, wherein the hydraulic circuit comprises a pressure accumulator and an actuator arranged to actuate an auxiliary device. [14] Drive train according to one of claims 8 to 13, wherein the drive axle is coupled to wheels of an off-road vehicle. [15] A powertrain according to any one of claims 8 to 14, wherein the first power supplied by the first motor and the second power supplied by the second motor are each equal percentages of the total power of the first electric motor and the second electric motor, respectively.

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