Mechanically coupled electric drive unit

Abstract

Electric drive unit, comprising: a case; a first electric machine and a second electric machine, each arranged inside the housing; a first gearbox coupled to the first electric machine, and a second gearbox coupled to the second electric machine; and a separating device arranged between a shaft coupled to the first gearbox and a shaft coupled to the second gearbox, wherein the separating device is configured to mechanically couple the first gearbox and the second gearbox.

Description

TECHNICAL FIELD

[0001] This description relates generally to an electric drive unit adapted for use in an electric or hybrid vehicle. BACKGROUND AND SUMMARY

[0002] Electric and hybrid vehicles often use an electric drive unit (EDU) capable of regenerative braking, where one or more motors can act as a generator, transferring energy to a battery during braking and coasting to conserve energy that would otherwise be lost as heat. This energy recovery can power auxiliary vehicle functions such as heating / cooling and sound systems, and extend the range of the traction battery by increasing the amount of energy available in the traction battery for use by the vehicle's motor(s) during acceleration.

[0003] The inventors recognized the drawbacks of the regenerative braking system of existing EDUs, particularly twin systems where two electric machines operate as motors and / or generators. One problem is that energy is lost for each electric machine of an EDU during each switchover between generator and motor. Because both electric machines switch between generator and motor states simultaneously when a pedal is applied and released, energy is lost when the electric machine states are frequently switched. Because existing EDUs do not optimize energy consumption and regeneration across a full range of different operating states, the amount of energy saved by regenerative braking may not be sufficient to extend the drive's range.Another problem with non-mechanically coupled twin EDUs is that they require complex torque distribution calculations to account for the unequal frictional force between the vehicle's wheels. Therefore, driver control of the vehicle with a conventional EDU may be inadequate under certain driving conditions where the torque distribution is more extreme, such as off-road driving and starting from a standstill on rough terrain.

[0004] The inventors have developed a mechanically coupled EDU that can enable higher energy efficiency and better driver control than conventional EDUs by adapting to a wider range of driving conditions with more EDU modes. One embodiment may be an electric drive unit comprising: a housing; a first electric machine and a second electric machine, each disposed within the housing; a first transmission coupled to the first electric machine and a second transmission coupled to the second electric machine; and a disconnect device disposed between a shaft coupled to the first transmission and a shaft coupled to the second transmission, the disconnect device being configured to mechanically couple the first transmission and the second transmission.

[0005] In one embodiment, two motors and their respective transmissions can optionally be mechanically coupled via a dog clutch on auxiliary gears and shafts. This mechanical coupling creates the possibility for multiple operating modes not possible with conventional dual EDU architectures. Multiple EDU modes with different advantages and disadvantages can achieve an optimal balance between energy efficiency and function under different driving conditions. In other words, a greater variety of operating modes of a mechanically coupled EDU can expand the propulsion range of an electric or hybrid vehicle using the electric transmission and provide greater stability when needed.

[0006] Under certain driving conditions, such as idling on the highway, the mechanically coupled EDU can save more energy than conventional dual EDU systems by avoiding the inefficient switching of both motors between motor and generator mode each time the accelerator pedal is applied or released. Instead, the power of one motor can be sufficient to accelerate the vehicle when needed at idle, while the other electric machine continues to act as a generator, converting energy that is stored in a battery. This allows the states of the electric machines to switch between motor and generator less frequently under certain driving conditions, such as idling on the highway.Under other driving conditions, the torque distribution achieved by the mechanical coupling of the electric machines can result in one wheel experiencing greater torque than either motor when both electric machines operate as motors. For example, both electric machines can function as motors when the friction factors of the ground at each wheel vary locally. Using both electric machines as motors can increase the vehicle's performance on uneven ground while avoiding complicated torque distribution calculations in such driving conditions. Under other conditions, a dog clutch can also be disengaged so that the motors control each side of the vehicle independently, so that torque distribution can still be achieved at certain times, such as when the vehicle is cornering.In summary, the flexibility of the mechanically coupled EDU with multiple operating modes described here can offer advantages in terms of efficiency and function over other EDUs.

[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 an example vehicle with a mechanically coupled EDU. Fig. 2 shows an embodiment of the mechanically coupled EDU. Fig. 3 shows a table of the possible operating modes of the mechanically coupled EDU. Fig. Figure 4A shows the power flow of a first driving mode of the mechanically coupled EDU. Fig. Figure 4B shows the power flow of a second drive mode of the mechanically coupled EDU. Fig. Figure 4C shows the power flow of a third operating mode of the mechanically coupled EDU. Fig. Figure 4D shows the power flow of a fourth driving mode of the mechanically coupled EDU. Fig. Figure 4E shows the power flow of a fifth driving mode of the mechanically coupled EDU. Fig. 5 shows a flowchart of a method for selecting a driving mode of a mechanically coupled EDU depending on the driving conditions. Fig. Figure 6 shows a flowchart of a method for adapting between different mechanically coupled EDU modes. Fig. Figure 7 shows a timing diagram of an example of dynamic driving conditions in which the operating modes of a mechanically coupled EDU can be set. DETAILED DESCRIPTION

[0008] A mechanically coupled EDU is disclosed herein. The mechanically coupled EDU may be formed by two electric machines that can function as motors and / or generators, two gear trains, with one gear train adjacent to each electric machine, and a connection between the two gear trains via a disconnect device (e.g., a mechanical dog clutch with electrical actuation, an electrically actuated electromagnetic clutch, or an electrically actuated synchronizer) on auxiliary shafts. Thus, configuring an optional indirect connection between the two electric machines may provide greater flexibility for optimal operation under a wider variety of driving conditions than conventional EDUs, which lack this type of connection.

[0009] The Fig. 1-7 show various aspects of a mechanically coupled EDU and the functionality of the mechanically coupled EDU in a vehicle. Fig. 1 shows an example of how the mechanically coupled EDU can be integrated into a vehicle. Fig. 2 shows an exemplary embodiment of the mechanically coupled EDU. Fig. 3 shows different driving modes with possible combinations of states of the individual components of the mechanically coupled EDU, and Fig. Figure 4A-E shows an example of the power flow in the mechanically coupled EDU for each of the driving modes of Fig. 3. Fig. 5 shows a method for determining a mode depending on the driving conditions, and Fig. Figure 6 shows a method for adjusting the mechanically coupled EDU when switching between modes. Fig. Figure 7 shows an example of changing driving conditions and the corresponding operating modes that can be selected at different times.

[0010] The Fig. 1, Fig. 2 and Fig. 4A-E are schematic representations without any particular scale, and other relative dimensions may be used. For the sake of clarity of the descriptions and figures, the terms "left" and "right" refer to the relative orientation of the parts of a mechanically coupled EDU, as shown in the Fig. 1, Fig. 2 and Fig. 4A-E.

[0011] Fig. 1 shows a schematic representation of an electric vehicle 100 with a mechanically coupled EDU 200 that generates motive power for vehicle propulsion. The electric vehicle 100 may be a light-duty, medium-duty, or heavy-duty vehicle. In one use case, the electric vehicle 100 may be a passenger vehicle, such as a truck, sedan, station wagon, or the like. However, in other examples, the electric vehicle 100 may also be an SUV or other type of vehicle. Furthermore, the electric vehicle 100 may be a battery electric vehicle (BEV), a series hybrid electric vehicle (HEV) with an internal combustion engine, or a fuel cell electric vehicle, to name a few examples.

[0012] In one embodiment, the electric vehicle 100 may be equipped with a mechanically coupled EDU 200. A reference axis 150 is provided for comparison with Fig. 2 in the further discussion below. The mechanically coupled EDU 200 may include a left electric machine 202 coupled to a left transmission 102 (e.g., a first transmission) and a right electric machine 204 coupled to a right transmission 104 (e.g., a second transmission). The arrows extending between the left and right electric machines 202 and 204 and their respective transmissions 102 and 104 indicate the mechanical power transfer capabilities of these components. The left and right electric machines 202 and 204 may be connected to a battery 230, e.g., for electrical coupling to the battery 230. Electrical energy may be transferred between components, features, and systems that are electrically coupled. In addition, the mechanically coupled EDU 200 may include a separator 220, wherein the separator 220 may optionally separate the left components (e.g.left transmission 102 and left electric machine 202) and the right components (e.g., right transmission 104 and right electric machine 204) via shafts 222. An arrow above the disconnector 220 indicates that mechanical power can be transferred between the left and right shafts 222 in either direction (e.g., left to right or right to left). In some embodiments, the shafts 222 may be connected to the gears of the left transmission 102 and the right transmission 104. In some examples, the disconnector 220 may be an electrically actuated dog clutch where the dogs engage to mechanically couple the shafts 222. In other examples, the disconnector 220 may be an electrically actuated friction clutch where friction drives the mechanical coupling of the shafts 222.In some examples, the disconnect device 220 may be an electrically actuated synchronizer. In other examples, the disconnect device 220 may be a combination of a dog clutch and a friction clutch and / or other suitable types of clutches. In some examples, the mechanically coupled EDU 200 may include two electric machines: electric machines 202 and 204 in a back-to-back configuration, with the electric machines 202 and 204 coaxially aligned and facing away from each other. The electric machines 202 and 204 may be traction motors. The electric machines 202 and 204 may be powered by the traction battery 230 to transfer torque to the front wheels of the vehicle 114. The front wheels of the vehicle 114 may include a first wheel 114a and a second wheel 114b.The electric machines 202 and 204 can also be operated as generators to provide electrical energy to charge the traction battery 230, e.g., during braking. The dashed arrows extending between the electric machines 202 and 204 and the battery 230 indicate the electrical power transmission options of these components. Furthermore, it should be noted that the configurations shown in . Fig. While the mechanically coupled EDU 200 shown in Figure 1 is mounted in a front-wheel drive configuration with input shafts facing the front axles, other configurations are also possible, such as using electric machines 202 and 204 in a center-axle configuration, a rear-axle configuration, or in a configuration that includes one or more EDUs. For example, one EDU may be equipped with rear-wheel drive and a second EDU with front-wheel drive.

[0013] The electric machines 202 and 204 may both be housed in a housing 118. In some embodiments, the housing may be 118a and enclose the disconnect device 220 and the shafts 222. In other embodiments, the housing may be 118b and not enclose the disconnect device 220 and the shafts 222. The housing 118 may be attached to the exterior of transmission housings. The transmission housings may each house a gear system 102 and 104. The transmissions may each include one or more shafts, gears, and clutches to transmit the mechanical power generated by the electric machines 202 and 204 downstream.A controller 120 may send a signal to the clutch actuator(s) to shift the respective positions of the clutches to shift gears for transmitting power from the electric machines 202 and 204 to the rear vehicle wheels 116 and / or the front vehicle wheels 114. The rear wheels 116 may include a third wheel 116a and a fourth wheel 116b.

[0014] The controller 122 may form part of a control system 120. The controller 122 may include a microcomputer with components such as a processor (e.g., a microprocessor unit), input / output ports, an electronic storage medium for executable programs and calibration values ​​(e.g., a read-only memory chip, random access memory, keep-alive memory, a data bus, and the like). The storage medium may be programmed with computer-readable data representing instructions executable by a processor to perform the methods and control techniques described herein, as well as other variations that are expected but not explicitly listed. As illustrated, a control system 120 receives information from a plurality of sensors 124 and sends control signals to a plurality of actuators 126.Sensors 124 may include, for example, a pedal position sensor that detects the depression of a driver-operated pedal such as an accelerator and / or brake pedal, a speed sensor on the transmission output shaft, a state of charge (SOC) sensor, clutch position sensors, and the like. Engine speed may be determined from the power delivered by the inverter to the electric machine. An input device (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. As another example, the actuators may include one or more clutches, etc.

[0015] After receiving the signals from the various sensors 124 of Fig. 1, the controller 122 processes the received signals and deploys various vehicle component actuators 126 to adjust the components based on the received signals and the instructions stored in the memory of the controller 122. For example, the controller 122 may receive an accelerator pedal signal indicating a driver request for greater vehicle acceleration. In response, the controller 122 may command the operation of inverters to adjust the electric machine output and increase the power delivered by the electric machine(s) to the transmissions. The controller 122 may be configured to send commands to clutches to engage and disengage clutch gears under certain operating conditions.For example, a control command can be sent to a clutch, and in response to the command, an actuator in the clutch can adjust the clutch engagement or disengagement based on the command. The other controllable components in the vehicle can function in a similar manner, e.g., with respect to sensor signals, control commands, and actuator adjustment.

[0016] The mechanically coupled EDU 200 can take various forms, one example of which is the mechanically coupled EDU 200 of Fig. 2. The reference axis 150 shows an orientation of the mechanically coupled EDU 200 in Fig. 2 (compared to an alignment of the mechanically coupled EDU 200 in Fig. 1). The mechanically coupled EDU 200 may include two electric machines; there may be a left electric machine 202 and a right electric machine 204. The electric machines 202 and 204 may be arranged coaxially, and the electric machines 202 and 204 may therefore have a common rotation axis 232. The two electric machines 202 and 204 may function as generators or motors and may be independently switched between generator and motor states. In other words, at certain times, the left electric machine 202 may operate as a generator, while the right electric machine 204 operates as a motor. At other times, the left electric machine 202 may operate as a motor and the right electric machine 204 may operate as a generator. At other times, both electric machines 202 and 204 may function as motors. At other times, both electric machines 202 and 204 may function as generators.In this way, both electric machines 202 and 204 may be able to draw energy from and transfer energy to the battery 230, as indicated by arrows extending between the electric machines 202 and 204 and the battery 230.

[0017] The electric machines 202 and 204 may each include a rotor shaft 206, via which each electric machine may be connected to a transmission. For example, the electric machine 202 may be connected to the left transmission 102, and the electric machine 204 may be connected to the right transmission 104. The two transmissions 102 and 104 may include one or more gears and one or more shafts, among other parts not shown for clarity. For example, the left and right transmissions 102 and 104 may each include a first gear 208 that may be coupled to the rotor shaft 206.The rotor shaft 206 may be coupled to a second gear 210, the second gear 210 may be coupled to a first shaft 214, the first shaft 214 may be coupled to a third gear 216, the third gear 216 may be coupled to a fourth gear 218, and the fourth gear 218 may be coupled to an output shaft 219. For any coupling between gears (e.g., third gear 216 and fourth gear 218), it can be assumed that the teeth of one gear may mesh (e.g., mesh) with the teeth of the other gear. Any connection (e.g., rotary coupling) between a shaft and a gear (e.g., first shaft 214 and second gear 210) can be made by gluing, pressing, set screws, keyways, involute gears, cross holes, and the like. The left gear 102 may also include other parts described in . Fig. 2 for brevity, such as one or more clutches, additional gears and shafts, and the like. Similarly, the right transmission 104 may include substantially the same components as listed for the transmission 102, including the Fig. 2, but with opposite orientations. In other embodiments, the right transmission 104 may have a different number of gears and / or shafts than the left transmission 102. Output shafts 219 may be coupled to one or more axles of a vehicle (e.g., vehicle 100) such that output shafts 219 may transfer mechanical power from the mechanically coupled EDU 200 to wheels of the vehicle (e.g., front wheels 114 and / or rear wheels 116 of the vehicle 100).

[0018] The auxiliary parts 106 may include two or more auxiliary gears and two or more auxiliary shafts. For example, auxiliary gears 212 may be coupled to the second gears 210, and auxiliary gears 212 may be coupled to auxiliary shafts 222. The auxiliary parts 106 may also include a disconnect device 220. The disconnect device 220 may be a dog clutch connected to the auxiliary shafts 222 via intermeshing teeth or dogs. The disconnect device 220 may also be frictionally connected to the auxiliary shafts 222, or a combination thereof. The disconnect device 220 may also be a synchronizer. The disconnect device 220 may be engaged or disengaged depending on driving conditions. When the separator 220 is in the engaged state, the separator 220 may be coupled to the auxiliary shafts 222 such that the separator 220 ensures that the auxiliary shafts 222 can rotate at the same speed.Thus, the left transmission 102 can be mechanically coupled to the right transmission 104 by engaging the disconnect device 220, with the mechanical coupling distributing the torque between the left and right transmissions 102 and 104, respectively. Conversely, when disengaged, the disconnect device 220 can be kept out of contact with the auxiliary shafts 222, allowing the auxiliary shafts 222 to rotate freely according to the torque of their respective transmissions without any interaction between the left and right transmissions 102 and 104, respectively. In this way, the disengagement of the disconnect device 220 can allow the torque to be controlled separately for each side of the vehicle.

[0019] To Fig. 3: Each of the five modes of a mechanically coupled EDU (e.g. the mechanically coupled EDU 200 from Fig. 2) shown in Table 300 may correspond to situations that may occur during the operation of a vehicle (e.g., vehicle 100 in Fig. 1), into which the mechanically coupled EDU may be installed. The different operating modes allow the mechanically coupled EDU to switch between the operating modes depending on the driving conditions, depending on which mode is most energy-efficient and functional. Therefore, greater overall energy efficiency of a vehicle can be achieved by saving energy in driving situations where energy was previously inefficiently recovered through EDUs and regenerative braking. Greater energy efficiency can increase the operating range of an electric or hybrid vehicle.

[0020] Table 300 shows possible combinations of a state of a disconnect device (column 302), which may be engaged or disengaged, and a state of two electric machines in a mechanically coupled EDU; a state of a left electric machine (column 304) and a state of a right electric machine (column 306), both of which may be in a motor state or a generator state. In one example, the state of the disconnect device may correspond to the disconnect device 220 of the mechanically coupled EDU 200, the state of the left electric machine may refer to the left electric machine 202 of the mechanically coupled EDU 200, and the state of the right electric machine may correspond to the right electric machine 204 of the mechanically coupled EDU 200.Additionally or alternatively, in another embodiment of a mechanically coupled EDU, the state of the isolating device and the states of the electrical machines may correspond to substantially the same components without departing from the scope of this disclosure.

[0021] When the disconnect device is engaged, the left and right electric machines may be mechanically coupled so that torque can be distributed across both transmission trains. When the disconnect device state is released, the electric machines may be disengaged so that each electric machine can individually deliver or receive torque to an adjacent transmission, allowing torque vectoring to occur. The change in the state of the disconnect device may be initiated by a controller (e.g., controller 122) and executed by an actuator (e.g., actuators 126). When the left electric machine state is motor, the left electric machine may deliver torque to a transmission. When the left electric machine state is generator, the left electric machine may receive torque from the transmission.Similarly, if the state of the right electric machine is "motor," the right electric machine applies torque to a transmission. If the state of the right electric machine is generator, the right electric machine may receive torque from the transmission. In other words, an electric machine in the motor state may be referred to as torque-producing, while an electric machine in the generator state may be referred to as torque-absorbing. Put another way, torque with respect to an electric machine may be considered positive when the electric machine is operating as a motor, and torque may be considered negative when the electric machine is operating as a generator. The change in the state of an electric machine may be initiated by a controller (e.g., controller 122 in FIG. Fig. 1). As already described, changing the state of an electrical machine from motor to generator and vice versa can lead to energy losses due to insufficient efficiency.

[0022] In one example, the two electric machines can be considered essentially identical. Thus, without considering redundancy with the left and right electric machine states, respectively, there can be six combinations of the disconnect device state, the left electric machine state, and the right electric machine state. However, there can be five modes of a mechanically coupled EDU when deployed in a vehicle, since torque can be distributed to both sides of the vehicle when the state of one electric machine is the generator state and, at the same time, the state of one electric machine is the motor state when the disconnect device state is engaged. Therefore, a combination of one electric machine in the generator state and another electric machine in the motor state with a disconnect device in the disengaged state is not discussed.

[0023] The five modes of Table 300 are described below with reference to Fig. 3 and Fig. 4A-E. The power flow associated with each of the components listed in Table 300 of Fig. 3 shown modes is in Fig. 4A-E. The mechanically coupled EDU 200 is used as an example of an embodiment in which Fig. 4A operating mode 410, Fig. 4B the operating mode 420, Fig. 4C operating mode 430, Fig. 4D operating mode 440 and Fig. 4E shows the operating mode 450, however, similar directions of power flow may also occur in other embodiments. Each in the Fig. 4A-E, the left electric machine 202, the right electric machine 204, the separator 220 and the battery 230 as well as other parts of the mechanically coupled EDU 200, as shown in Fig. 2, which are not labeled for clarity and will not be reintroduced. In Fig. 4A-E, a solid arrow may indicate the direction of mechanical energy flow, while a dashed arrow may indicate the direction of electrical energy flow.

[0024] The Fig. Mode 410 shown in Figure 4A shows an example of mode 410 of Fig. 3. The state of the disconnect device 220 may be engaged, and the states of the electric machines 204 and 206 may both be motoring. As in Fig. 4A, electrical energy may be supplied from the battery 230 to the two electric machines 202 and 204, wherein the electrical energy may be converted into mechanical energy in the form of torque acting on the gear sets of the transmissions 102 and 104. Since the separator 220 may be engaged, the mechanical energy may be distributed in both directions via the shafts to which the separator 220 is coupled (e.g., the auxiliary shafts 222 of Fig. 2). In this way, the drive unit can be balanced and stable, with the torque being distributed to the wheels on both sides of the system in mode 410. This mode can be useful when high power is being transferred to the ground, while preventing torque vectoring provides stability, e.g., when the vehicle is climbing a hill and / or driving on loose surfaces and / or starting from a standstill, when the surface on which the vehicle is being driven imposes different frictional forces on the wheels (e.g., wheels 114 and / or 116 in vehicle 100 of Fig. 1). In this example, mode 410 may also result in one side experiencing higher torque than a single motor can deliver due to the distribution of torque, and the presence of such a mode is an advantage of a mechanically coupled EDU over other EDUs.

[0025] Mode 420 can provide another advantage of mechanically coupled EDUs (e.g. mechanically coupled EDU 200 of Fig. 2) demonstrate against other twin EDUs; the electrical machines can switch independently between generator and motor states. Fig. 4B shows an example of mode 420 of the mechanically coupled EDU 200, where the left electric machine 202 may be in the motor state and the right electric machine 204 may be in the generator state. In other examples of mode 420 of the mechanically coupled EDU 200, the left electric machine 202 may be in the generator state, while the right electric machine 204 may be in the motor state. A similar power flow may occur in both examples of mode 420. The battery 230 may supply the left electric machine 202 with electrical energy, which is converted into mechanical energy in the form of torque that is transferred to the transmission 102 via the rotor shafts, as described above with respect to Fig. 2. The state of the disconnect device 220 may be engaged so that the torque can be distributed throughout the drive unit of mode 420 to apply torque to the wheels. Because the disconnect device 220 may be engaged, the mechanical energy can be distributed in one direction across the shafts with which the disconnect device 220 is engaged (e.g., the auxiliary shafts 222 in Fig. 2). In this way, in mode 410, the torque can be distributed to both sides of the system by the left electric machine 202, but not by the right electric machine 204. Torque can also be absorbed by the right electric machine 204, which can convert the mechanical energy into electrical energy, which is then transferred from the electric machine 204 to the battery 230 for storage.

[0026] The power flow of mode 420 may be advantageous in driving situations where electric machines of conventional EDUs are repeatedly switched between generator and motor states. Additionally or alternatively, mode 420 may be useful when driving conditions do not require more power than a single motor (e.g., electric machine 202) can provide. Additionally or alternatively, mode 420 may be used at vehicle speeds where, due to the speed dependence of motor efficiency, it is more efficient for one motor to provide a given torque than for two motors each to provide half the torque. In this case, energy can be saved through greater efficiency of the motor function.For example, when coasting on the highway, conventional EDUs switch both electric machines from motors to generators when the accelerator pedal is released, and switch both electric machines back to motors when the pedal is applied again. As explained above, any transition of an electric machine from torque production to torque absorption results in energy losses. Since idling on the highway requires short periods of gentle acceleration to maintain a relatively similar speed over an extended period, constantly switching electric machines from motors to generators and vice versa can represent an inefficient use of energy.In contrast, mode 420 can be more energy efficient when idling on the highway because it is possible to use both a generator and a motor simultaneously, and the amount of energy required may be less than the maximum power of one motor. In mode 420, the states of the electrical machines can be adjusted less frequently because both a motor and a generator are available in this mode, resulting in less energy being lost adjusting the electrical machines from the motor to the generator and vice versa. In addition, because the efficiency of the motors is dependent on speed and torque, higher efficiency can be achieved by running one motor (e.g., mode 420) compared to two motors (e.g., mode 410).

[0027] A disadvantage of operating mode 420 is the energy loss between individual energy conversions, which leads to imperfect energy efficiency, even though the electric machine 204, as a generator, recovers some of the energy. In other words, since electric machines as motors or generators do not have perfect efficiency, every energy conversion from mechanical to electrical and vice versa results in energy losses. Therefore, when determining the states of electric machines, in addition to the energy losses due to switching between the states of electric machines, the energy losses due to energy conversion (e.g., efficiency of the motor and generator states) can also be taken into account. In other words, the efficiency of the continuous conversion of energy between mechanical and electrical energy in mode 420 can be compared to the efficiency of repeatedly switching between modes with two motors (e.g.,Modes 410 and 430) and dual-generator modes (e.g., modes 440 and 450) may be compared to determine when mode 420 is advantageous over other modes. Furthermore, mode 420 prevents torque splitting when disconnect device 220 is engaged, so mode 420 may not be desirable under driving conditions where torque splitting can increase vehicle performance according to road curvature. An example method for determining a mode based on driving conditions is discussed below with respect to [FIG. 1]. Fig. 5 discussed.

[0028] In mode 430, the disconnect device may be disengaged and the left and right electric machines may both be in the "Motor" state. As in Fig. 4C, the electrical energy from the battery 230 may be supplied to the two electric machines 202 and 204. The electric machines 202 and 204 may then convert the energy supplied by the battery 230 into mechanical energy by applying torque to their respective transmissions (e.g., transmissions 102 and 104 shown in Fig. 2). Since the isolating device 220 may be disengaged, the torque may rotate the auxiliary shafts, but as shown by the arrows indicating mechanical power flow, the torque is not transferred between the shafts on which the isolating device is mounted. This allows the shafts to rotate at different speeds. In other words, in mode 430, the maximum power of a single motor can be transferred separately to both transmissions, and torque vectoring can occur. Mode 430 may be useful when a vehicle is cornering. Additionally or alternatively, mode 430 may be advantageous when frictional forces from the ground are not applied evenly to each wheel, particularly when the right and left wheels experience different levels of frictional force.Additionally or alternatively, operating mode 430 may be used when high ground performance is required. For example, mode 430 may be selected when a vehicle (e.g., vehicle 100) with a mechanically coupled EDU (e.g., mechanically coupled EDU 200) is accelerating during a sharp turn and / or when the vehicle with the mechanically coupled EDU is accelerating on an uneven surface with varying friction in the wheel contact area.

[0029] In mode 440, the disconnect device may be engaged, and the left and right electric motors may both be in the generator state. As in Fig. 4D, mechanical energy flows through transmissions (e.g., transmissions 102 and 104) to electric machines 202 and 204, where electrical energy may be generated by electric machines 202 and 204, and this energy may be transferred to battery 230. Mechanical energy may also be transferred between the left and right components via the auxiliary shafts (e.g., auxiliary shafts 222) because the disconnect device 220 may be engaged. In this way, torque may be distributed throughout the mechanically coupled EDU. Thus, mode 440 may correspond to a driving situation in which the vehicle is decelerating and torque shifting is not required. For example, a vehicle (e.g., vehicle 100) may be decelerating in a straight line in mode 440. If torque vectoring is not needed, engaging the disconnect device may increase vehicle stability and reduce the risk of malfunctions (e.g.,adjusting the wheels).

[0030] In operating mode 450, which is shown in Table 300 of Fig. 3, the states of the left and right electric motors can be generators, but the state of the separating device can be disengaged. As shown in Fig. 4E, the corresponding power flow may include mechanical energy directed to electric machines 202 and 204. In electric machines 202 and 204, the mechanical energy may be converted to electrical energy, which may be transferred to battery 230 for storage. Additionally, mechanical energy may be transferred to auxiliary gears and shafts (e.g., auxiliary gears 212 and auxiliary shafts 222). However, similar to mode 430, disengaging the disconnect device prevents energy from being transferred between the left and right auxiliary parts. In this way, the left and right electric machines may be controlled independently, and torque vectoring may occur. Therefore, a vehicle (e.g., vehicle 100) with a mechanically coupled EDU (e.g., mechanically coupled EDU 200) may use mode 450 during braking when torque vectoring may be required.Examples of such driving conditions include cornering while braking and / or braking on a surface with an uneven friction factor in the contact area with the vehicle's wheels.

[0031] In Fig. 5 is a method 500 for selecting a mode from Fig. 3-4E. For example, the method 500 may be performed by a mechanically coupled EDU as described above (e.g., mechanically coupled EDU 200 of Fig. 1 and Fig. 2). In other examples, the method 500 may be implemented by other embodiments of mechanically coupled EDUs. The method 500 may be executed by a controller (e.g., controller 122 in Fig. 1) according to instructions in the memory of the controller, which is communicatively coupled to the EDU, and from the vehicle sensors (e.g. sensors 124 in Fig. 1) received signals. Therefore, depending on the programming of the controller, methods other than method 500, including variants of method 500, may be used. In other words, method 500 is a non-limiting example of a method that may be used to determine the desired mode of a mechanically coupled EDU according to driving conditions. At any end of method 500, a state for a disconnect device and both electric machines of a mechanically coupled EDU has been selected. Therefore, in table 300 of Fig. 3 a corresponding mode that corresponds to the results of the method 500.

[0032] Method 500 begins at 502, where a torque is determined (e.g., calculated, estimated) from conditions such as pedal positions (e.g., accelerator pedal, brake pedal) and vehicle speed. A controller (e.g., controller 122) may perform the requested steps according to its internal non-transitory memory and signals from sensors (e.g., sensors 124) to output a particular torque. The determined torque may be the torque to be applied to the system by one or more electric machines in the mechanically coupled EDU. Accordingly, a positive torque may indicate that the electric machine(s) can apply torque to the transmission(s), while a negative torque may indicate that the electric machine(s) can accept torque from the transmission(s).

[0033] At 504, the method determines whether the determined torque is outside a threshold range. The threshold range may be limited by the maximum torque an electric machine of the mechanically coupled EDU can apply to a transmission and the maximum torque the electric machine can receive from a transmission. In this way, there may be a positive and a negative threshold, with the threshold range lying in between. The thresholds may be calculated by the controller from a variety of factors, including the characteristics of the electric machine and the speed of the vehicle. Since the efficiency of the electric machine depends on the speed of the vehicle, the thresholds may be a function of the vehicle speed.Because the thresholds can change dynamically with system conditions, the threshold can be calculated at each iteration of method 500. The thresholds can also be a constant predefined value programmed into the controller's memory.

[0034] If the magnitude of the determined torque is not outside a threshold range (NO), the method proceeds to 508 and selects the motor for a first electric machine state and the generator for a second electric machine state. Since the electric machines may be mechanically coupled to distribute torque to both sides of the vehicle when the electric machines are in different states (e.g., one electric machine in the generator state and another in the motor state), the method 500 then selects the "disengaged" state for a disconnect device at 510, and the method 500 ends. Thus, the corresponding mode may be mode 430.

[0035] Conversely, if the magnitude of the determined torque is outside a threshold range (YES), method 500 proceeds to 506, where the method assesses whether the determined torque is positive. As previously defined, a positive torque indicates that mechanical power is flowing from an electric machine to a transmission, while a negative torque indicates that mechanical power is flowing from a transmission to an electric machine. A controller (e.g., controller 122) may make this determination by examining the results of 502, in which the torque was determined.

[0036] If the torque is not positive (NO), i.e., negative or zero, method 500 proceeds to 512. Accordingly, at 512, the method selects the generator for both electric machine states of the mechanically coupled EDU. In this case, the vehicle may be decelerating (e.g., due to an applied brake pedal), and torque may be transferred from the transmissions (e.g., transmissions 102 and 104 of the mechanically coupled EDU 200) to the electric machines (e.g., electric machines 202 and 204), where the energy may be converted from mechanical to electrical energy and stored in a battery (e.g., battery 230 of the mechanically coupled EDU 200). Thus, this may correspond to mode 410 or 430.

[0037] If the torque is positive (YES), the method continues to 518, where method 500 selects the motor for both states of the mechanically coupled EDU's electric machines. Therefore, this may correspond to mode 440 or 450.

[0038] Next, at 514, method 500 determines whether the vehicle is traveling in a curve. This final decision narrows the selection of the operating mode for the driving conditions from two options, as described in steps 512 and 518, to a single operating mode. The controller (e.g., controller 122) may accept input from sensors (e.g., sensors 124) and / or input devices (e.g., steering wheel) to provide an output for 514.

[0039] Accordingly, if the vehicle is cornering (YES), method 500 selects the disengaged state for the disconnect device at 520. Disengaging the disconnect device enables torque distribution, which, as previously mentioned, can enhance the vehicle's cornering performance.

[0040] If the vehicle is not cornering (NO), method 500 selects the "engaged" state for the disconnect device at 510. As previously mentioned, in situations where torque vectoring is not practical, such as traveling in a straight line, engaging the disconnect device can stabilize the vehicle and enable greater performance on surfaces with uneven friction factors in the contact area with the vehicle's wheels.

[0041] After 520 or 510, method 500 proceeds to 522, which includes adapting to the selected states. The selected states include the states selected for each disconnect device and both electrical machines in the previous steps of method 500. A method for adapting states is described in Fig. 6. After the states are adjusted at 522, the method 500 ends.

[0042] After completion of method 500, the controller has selected the states of the separating device and the two electrical machines of the mechanically coupled EDU according to the driving conditions and, by method 600, Fig. 6 is set to a corresponding mode as shown in Fig. 3 and Fig. 4A-E shown.

[0043] The Fig. 6. The method 600 shown may be performed by a mechanically coupled EDU as described above (e.g., mechanically coupled EDU 200). Fig. The method 600 shown in Figure 6 may be executed by a controller (e.g., the controller 122 of Fig. 1) by employing actuators (e.g., actuators 126) to adjust the states of a disconnect device and / or electric machine(s) of a mechanically coupled EDU as needed. Method 600 is an example of how a vehicle may transition between operating modes of a mechanically coupled EDU, and a controller may use method 600 and / or variations of method 600 and / or other methods for similar purposes. The controller may continuously repeat method 600 at a certain interval. For example, with a one-second interval, the controller may initiate method 600 at a first time and respond as requested to achieve an end to method 600 before restarting the method one second after the first time, although other intervals may be used. In this way, a consistent assessment of driving conditions may be achieved.Additionally or alternatively, the controller may initiate method 600 in response to a particular signal from a sensor. For example, if the sensors detect that one or more driving conditions and / or input devices (e.g., pedal positions, steering wheel rotation, wheel friction, and vehicle speed) have changed, the controller may initiate method 600 in response to the change. In this way, adjustment of the states of the components of the mechanically coupled EDU may occur more quickly.

[0044] In 602, method 600 selects the states of the electrical machines and the disconnect device. The process the controller may use to determine the next states may be similar to method 500 of Fig. 5, which may result in the selected states of the disconnecting device and the electrical machines. Methods other than method 500 may also be used to achieve the same results.

[0045] After 602, at 604, method 600 compares the current states of the electrical machines and disconnect device to the selected states from 602. The current states may be retrieved from the controller's memory from a previous run of method 600. Additionally or alternatively, the controller may determine the current states from signals from one or more sensors. In one example, the sensors may indicate that the vehicle is cornering, after which the controller may select the state of the disconnect device to disengage through method 500 to enable torque splitting. The controller may then examine the current state of the vehicle to determine whether the disconnect device is currently engaged or disengaged and compare it to the selected disengaged state.

[0046] At 606, method 600 assesses whether the selected states match the current states. 606 may consider the comparison from 604. In particular, in this step, method 600 attempts to determine whether any of the current states do not match the next states determined in 602.

[0047] If at 606 the selected states match the current states (YES), method 600 proceeds to 620, where the current states of the electrical machines and the disconnect device are maintained. The controller may not adjust the states of the disconnect device or the electrical machines of the mechanically coupled EDU within the vehicle to achieve the selected states of 602. In other words, the current mode according to table 300 in Fig. 3 is the same as the selected mode. Therefore, no adjustments can be made to the mechanically coupled EDU to achieve optimal performance according to the current driving conditions. After 620, procedure 600 ends.

[0048] Or, if at 606 the selected states do not match the current states (NO), or in other words, the current mode according to table 300 in Fig. 3 does not match the selected mode of 602. Consequently, adjustments may be made to the mechanically coupled EDU (e.g., adjustments to the state of the disconnect device and / or one or more electric machines) to enhance vehicle performance. Method 600 proceeds to 608, where method 600 evaluates the current states of the electric machines and determines whether or not they are in the same state.

[0049] If, in a first case (608), the two electric machines are not in the same state (NO), the current states of the electric machines may be that the left electric machine is a motor and the right electric machine is a generator, or vice versa. Thus, the vehicle is currently in mode 420 of table 300 in Fig. 3, since no other modes contain unmatched states of the electrical machine. To switch to another mode, the state of one of the two electrical machines can be changed.

[0050] Thus, method 600 continues to 610, where the state of an electric machine is adjusted according to the comparison at 604. For example, if the right electric machine is in the generator state and the left electric machine is in the motor state (e.g., mode 420 in Fig. 3 and Fig. 4) and the selected mode includes two engines (e.g. Mode 410 and Mode 430 in Fig. 3 and Fig. 4), then the left electric machine may be set to motor. The adjustment between the states of the electric machine may include a controller (e.g., controller 122 in Fig. 1) sends a signal to change the direction of energy flow to or from the battery (e.g., battery 230).

[0051] Next, method 600 proceeds to 612, which involves disengaging the disconnect device. However, 612 is dependent on the comparison from 604. For example, since the current state of the disconnect device is engaged in mode 420, 612 may not be executed if the selected state of the disconnect device is also enabled. Conversely, the controller may adjust the disconnect device to be disengaged if the selected state of the disconnect device is disabled. After optionally adjusting the disconnect device, method 600 ends when the selected mode is reached, according to the selected states from 602.

[0052] Return to 608, alternatively, if for a second case, the two electric machines are currently in the same state (YES) and the method 600 proceeds to 614, wherein the torque is controlled to be the same or similar for both shafts coupled to the isolating device. In other words, the rotation of the shafts (e.g., the auxiliary shafts 222 in Fig. 2) is synchronized so that the difference in shaft speeds is zero and / or within an acceptable range. This step depends on the current state of the isolating device. If the isolating device is engaged, 614 cannot be executed because in this configuration the torque is already adequately distributed and the rotation of the shafts is synchronized. If the isolating device is disengaged, 614 can be executed to re-engage the isolating device. If the isolating device is not a synchronizing device (e.g., a dog clutch or equivalent electrically operated electromagnetic clutch), 614 can additionally be executed to ensure that the speed difference between the shafts is within the allowable range for smooth engagement of the isolating device.If the separating device is a synchronizing device, 614 cannot be executed either.

[0053] Method 600 continues to 622, which includes adjusting the EDU mode at 616 and / or 618. At 616, method 600 optionally includes changing the state of the disconnect device. For example, if the current state of the disconnect device is on and the next state of the disconnect device is disengaged as determined at 602, the state of the disconnect device is set to disengaged. In another example, step 616 is skipped if the current state of the disconnect device is engaged and the next state of the disconnect device is also enabled. In other words, step 616 is performed if the comparison at 604 determines that the current state of the disconnect device does not match the next state of the disconnect device. At 618, method 600 optionally includes changing the states of one or more electric machines.Similar to 616, 618 is executed if the comparison at 604 reveals that the current states of the electrical machines do not match the next states of the electrical machines. Method 600 ends.

[0054] At each end of method 600, the selected mode is reached according to the results of 602, allowing the vehicle to operate optimally. The selected mode may become the current mode for the next iteration of method 600. The cycle may continue in this manner throughout the vehicle's operating time, as dictated by the controller at a regular interval and / or the sensed driving conditions.

[0055] In Fig. 7 is a timing diagram 700 (e.g., a timing diagram) for an example of driving conditions of a vehicle (e.g., vehicle 100) in which a mechanically coupled EDU (e.g., the mechanically coupled EDU 200 of Fig. 1 and Fig. 2) can switch between modes. The timing diagram 700 is an example of a series of dynamic driving conditions that can cause adjustments between the operating modes of a mechanically coupled EDU. However, the diagram 700 does not limit the order of operating modes in which a vehicle can be operated or the driving conditions that can cause an adjustment to a particular operating mode. The timeline diagram 700 shows a torque (e.g., that used in 502 of the method 500 of Fig. 5) with horizontal lines 702 and 704 marking the torque threshold values ​​+T and -T, and a horizontal line 706 marking zero torque. Thus, the values ​​between the horizontal lines 702 and 704 can lie within a threshold range (e.g., threshold range in 504 of the method 500 of Fig. 5). The thresholds +T and -T may be equal and opposite, or the thresholds may not be additive inverses of each other. The thresholds +T and -T may be constant values ​​that depend on the characteristics of the electrical machines (e.g., maximum output power, efficiency, size, etc.). For example, the threshold +T may be set according to the maximum torque capacity of a single electrical machine acting as a motor. Similarly, the threshold -T may be set according to the maximum torque absorption capacity of a single electrical machine acting as a generator. Additionally or alternatively, the thresholds +T and -T may be determined depending on dynamic factors such as the vehicle speed, in addition to the above-mentioned characteristics of the electrical machines.Therefore, the thresholds +T and -T may not be constant, unlike the horizontal lines 702 and 704, which are linear and show constant thresholds. M / G1 may correspond to the state of an electric machine (e.g., left electric machine 202 of the mechanically coupled EDU 200 of FIG. Fig. 1 and Fig. 2) and M / G2 may correspond to the state of a second electrical machine (e.g. right electrical machine 204 of the mechanically coupled EDU 200 of Fig. 1 and Fig. 2). The disconnect device as shown in timing diagram 700 may correspond to the state of the disconnect device 220 of the mechanically coupled EDU 200.

[0056] Between t0 and t1, the vehicle may accelerate because the torque is positive. As explained with respect to method 500, both electric machines M / G1 and M / G2 may be in the motoring state because the torque exceeds +T. In one example, the vehicle may be accelerating (e.g., from a standstill or at a relatively low speed) to a relatively high speed. In such an example, the vehicle may also be traveling on a route without sharp turns, where torque distribution is not helpful in steering the vehicle, so the disconnect device may be engaged. Thus, between t0 and t1, in mode 410, the mechanically coupled EDU may be Fig. 3 and Fig. 4A.

[0057] At t1, the torque falls back below the threshold +T. In this case, the vehicle may be idling on a highway where positive torque is needed to maintain the target speed, where the power of an engine may be sufficient to provide sufficient torque at the target speed. Therefore, an electric machine, M / G2, may be set to start at a particular time between t1 and t2 by method 600 of Fig. 6 functions as a generator, so that the mechanically coupled EDU can be switched from mode 410 to mode 420 from Fig. 3 and Fig. 4B can be set.

[0058] At t2, the torque becomes negative, and the vehicle can decelerate slightly while idling on a highway. The torque remains between the +T and -T thresholds, allowing the vehicle to remain in mode 420, reducing energy losses by half compared to switching both electric machines to generators as in conventional EDU systems. In this example, the energy supply to M / G1 from a battery (e.g., battery 230 of the mechanically coupled EDU 200) can be cut off, and M / G2 can absorb torque to transfer energy to the battery. If a higher positive torque is then required to maintain speed (e.g.,If the torque becomes positive again between t2 and t3, the power to M / G1 can be increased without requiring any adjustment of the electric machine states, as long as the requested torque does not exceed the maximum torque that a motor can provide to the system (e.g., threshold +T). If the torque becomes negative a second time between t2 and t3, M / G1 can no longer be fed by the battery, and M / G2 can continue to direct energy to the battery without energy losses due to adjustment states of the electric machines. This cycle can continue at idle, with one motor sufficient to provide the system with sufficient torque for the desired vehicle acceleration, and one generator sufficient for regenerative braking. In summary, when coasting on the highway, e.g.Between times t1 and t3, it is possible to remain in mode 420 even if the torque fluctuates between positive and negative. This allows energy to be saved because switching between the electric machine states is not as frequent as would be necessary in vehicles with EDUs other than a mechanically coupled EDU, as described here.

[0059] At t3, the torque exceeds +T, so M / G2 can be adjusted back to the motor, meaning the mode can be adjusted from 420 to 410 using method 600. For example, the vehicle may be climbing a hill that requires more drive power to propel the vehicle, so both motors are needed to achieve sufficient torque.

[0060] Finally, at t4 the mode can be changed from 410 to 450 from Fig. 3 and Fig. 4. Driving conditions that may require such an adjustment include the driver having to stop quickly due to external circumstances and / or braking while cornering, since torque vectoring may be activated when the disconnect device is disengaged.

[0061] The technical effect of the methods 500 and 600 disclosed herein for selecting and adjusting states of components of the mechanically coupled EDU is to increase the energy efficiency of a vehicle with the mechanically coupled EDU to expand the vehicle's driving range. Another technical effect of the mechanically coupled EDU described herein is to refine the vehicle's functionality through multiple modes that are more specific to a variety of driving conditions.

[0062] The disclosure also provides support for an electric drive unit comprising a housing, a first electric machine and a second electric machine, each disposed within the housing, a first transmission coupled to the first electric machine and a second transmission coupled to the second electric machine, and a disconnecting device disposed between a shaft coupled to the first transmission and a shaft coupled to the second transmission, wherein the disconnecting device is configured to mechanically couple the first transmission and the second transmission. In a first example of the system, the disconnecting device is disposed within the housing. In a second example of the system, optionally including the first example, the disconnecting device is disposed outside the housing.In a third example of the system, optionally comprising one or both of the first and second examples, the shaft of the first electric machine and the second electric machine are arranged within the housing. In a fourth example of the system, optionally comprising one or more or each of the first to third examples, the shaft of the first electric machine and the shaft of the second electric machine are located outside the housing. In a fifth example of the system, optionally comprising one or more or each of the first to fourth examples, the first electric machine and the second electric machine have a common axis of rotation.In a sixth example of the system, optionally comprising one or more or each of the first to fifth examples, the electric drive unit further comprises a controller including instructions stored in a non-transferable memory that, when executed, cause the controller to: select a mode of the electric drive unit and adjust the disconnect device between an engaged state and a disengaged state and adjust the first electric machine and the second electric machine between a generator state and a motor state based on the selected mode.

[0063] The disclosure also provides support for a method of operating an electric drive unit of a vehicle, comprising: selecting a first mode of the electric drive unit, the electric drive unit comprising a first electric machine and a second electric machine disposed in a housing, the first electric machine mechanically coupled to the second electric machine via a clutch, and in response to selecting the first mode, adjusting the clutch to an engaged state, the first electric machine to a motoring state, and the second electric machine to a generator state. In a first example of the method, the method further comprises: selecting the first mode in response to determining a torque within a threshold range.In a second example of the method, optionally including the first example, the method further comprises: selecting a second mode of the electric drive unit in response to determining positive torque outside a threshold range and the vehicle is not cornering, and in response to selecting the second mode, adjusting the first electric machine and the second electric machine to the engine state and the clutch to the engaged state.In a third example of the method, optionally comprising one or both of the first and second examples, the method further comprises: selecting a third mode of the electric drive unit in response to determining positive torque outside a threshold range and the vehicle is cornering, and in response to selecting the third mode, adjusting the first electric machine and the second electric machine to the engine state and the clutch to a disengaged state.In a fourth example of the method, optionally comprising one or more or each of the first to third examples, the method further comprises: selecting a fourth mode of the electric drive unit in response to determining negative torque outside a threshold range and the vehicle is not cornering, and in response to selecting the fourth mode, adjusting the first electric machine and the second electric machine to the generator state and the clutch to the engaged state.In a fifth example of the method, optionally comprising one or more or each of the first to fourth examples, the method further comprises: selecting a fifth mode of the electric drive unit in response to determining negative torque outside a threshold range and the vehicle is cornering, and in response to selecting the fifth mode, adjusting the first electric machine and the second electric machine to the generator state and the clutch to a disengaged state.

[0064] The disclosure also provides a support for a vehicle comprising: a first wheel and a second wheel, an electric drive unit having a first transmission coupled to the first wheel and a second transmission coupled to the second wheel, a first electric machine coupled to the first transmission and a second electric machine coupled to the second transmission, the first electric machine coupled to the second electric machine via shafts and a disconnect device, and a controller including instructions stored in a non-transitory memory that, when executed, cause the controller to determine a torque of the vehicle, selecting a mode of the electric drive unit, the mode including a state of the first electric machine,a state of the second electric machine and a state of the disconnect device in response to the determined torque, and adjusting states of the first electric machine, the second electric machine, and the disconnect device according to the selected mode. In a first example of the system, the controller adjusts the state of the first electric machine and the second electric machine between a motor state and a generator state in response to a sign of the determined torque and the determined torque compared to a threshold range. In a second example of the system, optionally including the first example, the instructions further cause the controller to determine whether the vehicle is cornering, and the controller adjusts the state of the disconnect device between engaged and disengaged,depending on the magnitude of the determined torque compared to the threshold range and based on whether the vehicle is cornering or not. In a third example of the system, optionally comprising one or both of the first and second examples, the instructions further comprise selecting a mode of the electric drive unit in which the first electric machine and the second electric machine are in different states in response to the determined torque within a threshold range. In a fourth example of the system, optionally comprising one or more or each of the first to third examples, the electric drive unit further includes a housing, and the first electric machine and the second electric machine are disposed in the housing. In a fifth example of the system, optionally comprising one or more or each of the first to fourth examples,The first electric machine is coupled to the second transmission when the disconnect device is in an engaged state. In a sixth example of the system, optionally including one or more or each of the first through fifth examples, the electric drive unit mode selection instructions further include determining whether the torque is positive or negative and determining whether the vehicle is cornering.

[0065] In an alternative embodiment, a method for operating an electric drive unit of a vehicle comprises: determining a torque of the vehicle, selecting a mode of the electric drive unit in response to the torque within a threshold range, wherein a first electric machine of the electric drive unit is in a motoring state and a second electric machine of the electric drive unit is in a generator state, and adjusting the electric drive unit to the selected mode. In a first example of the method, the method further comprises: in response to the torque within the threshold range, selecting the mode of the electric drive unit in which a disconnect device of the electric drive unit is in an engaged state.In a second example of the method, optionally including the first example, the method further comprises: in response to the torque being outside the threshold range, determining whether the torque is positive, and in response to determining that the torque is positive, selecting a mode of the electric drive unit in which the first electric machine and the second electric machine are in the motor state. In a third example of the method, optionally including one or both of the first and second examples, the method further comprises: in response to determining that the torque is negative, selecting a mode of the electric drive unit in which the first electric machine and the second electric machine are in the generator state.In a fourth example of the method, optionally comprising one or more or each of the first to third examples, the method further comprises: determining whether the vehicle is cornering, and in response to determining that the vehicle is cornering, selecting a mode of the electric drive unit in which a disconnect device of the electric drive unit is in a disengaged state. In a fifth example of the method, optionally comprising one or more or each of the first to fourth examples, in response to determining that the vehicle is not cornering, selecting a mode of the electric drive unit in which the disconnect device is in an engaged state.

[0066] The Fig. 1, Fig. 2 and Fig.4A-E show example configurations with relative positioning 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. Thus, 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 the like). 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.

[0067] 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] Electric drive unit, comprising: a housing; a first electric machine and a second electric machine, each arranged within the housing; a first transmission coupled to the first electric machine and a second transmission coupled to the second electric machine; and a separating device arranged between a shaft coupled to the first transmission and a shaft coupled to the second transmission, the separating device being configured to mechanically couple the first transmission and the second transmission. [2] Electric drive unit according to claim 1, wherein the separating device is arranged within the housing. [3] Electric drive unit according to one of the preceding claims, wherein the separating device is arranged outside the housing. [4] Electric drive unit according to one of the preceding claims, wherein the shaft of the first electric machine and the shaft of the second electric machine are arranged within the housing. [5] Electric drive unit according to one of the preceding claims, wherein the shaft of the first electric machine and the shaft of the second electric machine are located outside the housing. [6] Electric drive unit according to one of the preceding claims, wherein the first electric machine and the second electric machine have a common axis of rotation. [7] An electric drive unit according to any one of the preceding claims, wherein the electric drive unit further comprises a controller including instructions stored in a non-transferable memory which, when executed, cause the controller to: select a mode of the electric drive unit; and adjust the disconnect device between an engaged state and an engaged state and adjust the first electric machine and the second electric machine between a generator state and a motor state based on the selected mode. [8] The electric drive unit of claim 7, wherein the selected mode includes the first electric machine and the second electric machine being in different states. [9] An electric drive unit according to any preceding claim, wherein the electric drive unit is included in a vehicle, the vehicle further comprising a first wheel connected to the first transmission and a second wheel connected to the second transmission.

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