CONTINUOUS MULTI-SPEED POWER TRANSFER FOR MULTI-ENGINE

Abstract

An electric powertrain includes a first electric motor having a continuous connection to a drive shaft of a vehicle. The electric powertrain further includes a second electric motor having an interruptible connection to the drive shaft. In one form, this interruptible connection includes a clutch. The electric powertrain further includes a first gear train in the form of a first planetary gear set and a second gear train in the form of a second planetary gear set. To provide a compact design, the first electric motor and second electric motor are arranged in centerline alignment with the drive shaft.

Description

[0001] The present invention relates to a powertrain system. GENERAL STATE OF THE ART

[0002] Given environmental and other concerns, there has been a recent trend to convert fossil fuel-powered vehicles to other forms of energy, such as electricity. Significant developments in electric motor technology have occurred predominantly in the passenger vehicle sector. However, heavy-duty vehicles have been slower in the transition from fossil fuels to electricity due to a number of factors, including the high torque requirements for such vehicles and concerns about vehicle range. The higher torques required to power such commercial vehicles require larger and heavier electric motors, which can tend to increase energy consumption. Retrofitting these electric powertrains into existing vehicle designs can also be challenging.

[0003] In this regard, DE 10 2012 220 970 B4, DE 10 2011 056 928 A1, DE 10 2011 056 046 A1, DE 10 2008 048 465 B4, DE 10 2008 006 581 B4 and US 2012 / 0221197 A1 are worth mentioning in relation to the state of the art.

[0004] Therefore, there is a need for improvement in this area. SUMMARY

[0005] This object is achieved by the features of patent claim 1. Advantageous embodiments thereof are specified in the dependent patent claims.

[0006] A system includes two or more electric motors that provide power to an output, such as a vehicle's driveshaft. One of the electric motors ("A"), referred to herein as the "first motor," is always connected to the output driveshaft to continuously provide power to propel the vehicle. In other words, the first electric motor (A) has a continuous connection to the output. In some cases, the first electric motor (A) is connected to the output via a planetary gear arrangement to reduce speed and increase output torque.

[0007] The system further includes a second electric motor ("B") that intermittently applies torque to the output shaft. In one variation, this intermittent connection between the second electric motor (B) and the output includes at least one clutch. The clutch engages and disengages the second electric motor (B) from the output shaft. With this arrangement, the second electric motor (B) is capable of providing additional torque or power to assist the first electric motor (A) as needed. Among other things, this multiple electric motor system allows for the use of smaller electric motors that may be less expensive than a comparably powered larger electric motor. For example, this system allows for the use of small automotive electric motors to power large, 40,000-pound or more vehicles.

[0008] A particular example concerns a dual-motor version that includes a dog clutch. In this example, both the first (A) and second (B) motors are high-speed motors (e.g., running at 10,600 rpm). The dog clutch, along with the gearbox, is used to transfer torque from the second electric motor (B) to the output shaft, which is also constantly driven by the first electric motor (A) through the gearbox. In other examples, other types of clutch arrangements may be used. For example, a single actuator may be used in conjunction with a selectable one-way clutch (SOWC). Various combinations of high- and low-speed motors may be used, along with various arrangements of motors, gearboxes, clutches, and drivelines.

[0009] Aspect 1 generally relates to a system comprising a first electric motor having an uninterruptible connection to an output and a second electric motor having an interruptible connection to the output.

[0010] Aspect 2 generally relates to the system of any previous aspect, wherein the continuous connection of the first electric motor includes a first gear train configured to reduce speed.

[0011] Aspect 3 generally relates to the system of any previous aspect, in which the interruptible connection of the second electric motor comprises a second gear train.

[0012] Aspect 4 generally relates to the system of any previous aspect, in which the first gear train comprises a planetary gear train.

[0013] Aspect 5 generally relates to the system of a previous aspect in which the second electric motor is connected to the output via a clutch.

[0014] Aspect 6 generally relates to the system of any previous aspect, in which the clutch comprises a dog clutch.

[0015] Aspect 7 generally relates to the system of any previous aspect, wherein the clutch comprises a wet disc clutch.

[0016] Aspect 8 generally relates to the system of any previous aspect, in which the clutch comprises an actuator and a selectable one-way clutch (SOWC).

[0017] Aspect 9 generally relates to the system of any previous aspect, wherein the clutch comprises a dry disc clutch.

[0018] Aspect 10 generally relates to the system of any previous aspect, wherein the interruptible connection comprises a clutch and a single planetary gear.

[0019] Aspect 11 generally relates to the system of any previous aspect, in which the first and second electric motors are low-speed motors having a maximum speed of less than 5,000 rpm.

[0020] Aspect 12 generally relates to the system of any previous aspect, in which the second electric motor is configured to supply power to the output via at least two planetary gears and a clutch.

[0021] Aspect 13 generally relates to the system of any previous aspect, in which the first and second electric motors are high-speed motors having a maximum speed of at least 5,000 rpm.

[0022] Aspect 14 generally relates to the system of any previous aspect, in which the output is configured to move a vehicle of 40,000 pounds or more.

[0023] Aspect 15 generally relates to a method of operating the system according to a previous aspect.

[0024] Further forms, objects, aspects, benefits, advantages and embodiments of the present invention will become apparent from a detailed description and drawings provided herein. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view of a vehicle. Fig. 2 is a schematic view of an example of an electric powertrain used in the vehicle of Fig. 1 can be used. Fig. 3 is a cross-sectional view of an example of the electric powertrain of Fig. 2. Fig. 4 is a flowchart illustrating a technique for switching the electric powertrain. Fig. 5 is a schematic view of the electric powertrain of Fig. 2 in a neutral position or shift configuration. Fig. 6 is a schematic view of the electric powertrain of Fig. 2 in a first position or range configuration. Fig. 7 is a schematic view of the electric powertrain of Fig. 2 in a second position or range configuration. Fig. 8 is a schematic view of another example of an electric powertrain used in the vehicle of Fig. 1 can be used. Fig. 9 is a schematic view of another example of an electric powertrain used in the vehicle of Fig. 1 can be used. Fig. 10 is a schematic view of the electric powertrain of Fig. 8 in a first position or range configuration. Fig. 11 is a schematic view of the electric powertrain of Fig. 8 in a neutral position or shift configuration. Fig. 12 is a schematic view of the electric powertrain of Fig. 8 in a second position or range configuration. DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

[0025] For a better understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific wording will be used to describe the same. It will, however, be understood that this is not to be construed as limiting the scope of the invention. All changes and further modifications to the described embodiments and all further applications of the principles of the invention as described herein are to be seen as would be normally known to one skilled in the art to which the invention relates. One embodiment of the invention is shown in more detail, although it will be appreciated by those skilled in the relevant art that some features not relevant to the present invention may not be shown for the sake of clarity.

[0026] The reference numbers in the following description have been organized to help the reader quickly identify the drawings where various components are first shown. In particular, the drawing in which an element first appears is typically indicated by the leftmost number(s) in the corresponding reference number. For example, an element indicated by a "100" series of reference numbers likely first appears in Fig. 1, an element indicated by a “200” series of reference numerals probably appears for the first time in Fig. 2 and so on.

[0027] A vehicle 100 according to an example is in Fig. 1. As shown, the vehicle 100 includes at least one powertrain system 105, at least one controller 110, and at least one energy storage system ("ESS") 115 configured to provide power to the powertrain system 105. The powertrain system 105, the controller 110, and the ESS 115 are operably connected to communicate with each other via at least one controller area network ("CAN") 120. The controller 110 is configured to control the operation of one or more systems and / or other components of the vehicle 100, such as the powertrain system 105 and ESS 115. The powertrain system 105 has an output or driveshaft 125 that transmits mechanical power from the powertrain system 105 to a drive system 130.In the illustrated example, the propulsion system 130 includes one or more wheels 135, but in further examples, the propulsion system 130 may include other types of propulsion devices, such as track systems. One or more power cables 140 transmit electrical power between the powertrain system 105 and the ESS 115.

[0028] The powertrain system 105 is designed to efficiently electrically propel the vehicle 100. As explained in more detail below, the powertrain system 105 is designed to power commercial and / or military vehicles such as buses, refuse collection vehicles, fire trucks, and semi-trailers. The powertrain system 105 is designed to power vehicles 100 with a class group classification of at least four (4) according to the U.S. Department of Transportation Federal Highway Administration (FHWA) classification rules. In one form, the powertrain system 105 is configured to power at least 40,000 lb (18,144 kg) passenger vehicles such as buses.The powertrain system 105 has a unique, compact centerline design that allows for easy retrofitting of the powertrain system 105 into existing chassis designs and / or conventional powertrains with minimal changes to other parts of the vehicle 100, such as the braking and suspension systems. This, in turn, allows existing internal combustion vehicles to be easily retrofitted to fully electric vehicles. Furthermore, the centerline design of the powertrain system 105 reduces transmission and other power losses to make the vehicle 100 more power efficient, which in turn can improve range and / or reduce the weight of other components such as the ESS 115.

[0029] Fig. 2 shows a schematic representation of an example of an electric powertrain 200 used in the powertrain system 105 of Fig. 1 can be used. As shown, the electric powertrain 200 includes a continuous multi-motor power transmission 205. The transmission 205 of the electric powertrain 200 includes a first electric motor 210, sometimes referred to as "Motor A," and a second electric motor 215, sometimes referred to as "Motor B." In one example, the first electric motor 210 and second electric motor 215 are the same type of electric motor, so both motors generally provide the same speed and torque output within normal manufacturing tolerances. In one form, the first electric motor 210 and second electric motor 215 are both high-speed electric motors, and in another form, the first electric motor 210 and second electric motor 215 are both low-speed electric motors. In alternative variations, the first electric motor 210 and second electric motor 215 may be different types (e.g.,Permanent magnet motors, induction motors, switched reluctance motors, etc.) and / or have different designs / configurations (e.g., number of poles, winding patterns, etc.).

[0030] The transmission 205 of the electric powertrain 200 further includes a first gear train 220 located at an output end of the first electric motor 210 and a second gear train 225 located at the output end of the second electric motor 215. As can be seen, the first gear train 220 is located at the output end of the entire transmission 205, which is proximate the drive shaft 125. The second gear train 225 is located between the first electric motor 210 and the second electric motor 215. This configuration allows the electric powertrain 200 to have a compact design. In the illustrated example, the first gear train 220 is in the form of a first planetary gear train 230, and the second gear train 225 is in the form of a second planetary gear train 235.The first electric motor 210 and second electric motor 215 have a first output shaft 240 and a second output shaft 245, respectively, for providing rotating mechanical power. As shown in . Fig. 2, each of the first planetary gear set 230 and the second planetary gear set 235 includes a sun gear 250, one or more planetary gears 255 meshing with the sun gear 250, and a ring gear 260 surrounding and meshing with the planetary gears 255. The sun gear 250 of the first planetary gear set 230 is fixed to the first output shaft 240 of the first electric motor 210, and the sun gear 250 of the second planetary gear set 235 is fixed to the second output shaft 245 of the second electric motor 215. Both ring gears 260 of the first planetary gear set 230 and the second planetary gear set 235 are fixed to a housing 265 of the electric powertrain 200. The planetary gears 255 of the first planetary gear set 230 are supported by a first carrier 270. The first carrier 270 is configured to connect to the drive shaft 125 to transmit mechanical power from the transmission 205 to the drive system 130.The planet gears 255 of the second planetary gear 235 are carried by a second carrier 275.

[0031] As in Fig. 2, the electric powertrain 200 includes at least one clutch 280 that engages and disengages the second electric motor 215 from the first electric motor 210. The clutch 280 further enables the transmission 205 of the electric powertrain 200 to shift gears so that the speed and torque of the second electric motor 215 can be varied. The first electric motor 210 is permanently connected to the drive shaft 125 (i.e., there is no clutch), so that the first electric motor 210 is capable of providing continuous power to the drive shaft 125 and the drive system 130. In other words, the first electric motor 210 has a continuous connection to the drive shaft 125, and the second electric motor 215 has an interruptible connection to the drive shaft 125.This configuration of the electric drivetrain 200 facilitates powershifting, allowing power to always be provided to the wheels 135, even when a clutch 280 shift occurs. With a continuous provision of power, each shift can generally be unnoticeable to the driver and / or passengers. Furthermore, the acceleration performance of the vehicle 100 is improved, and the vehicle 100 is better able to maintain speed at higher speeds.

[0032] In the illustrated example, the electric powertrain 200 includes a single clutch 280, but in other examples, the electric powertrain 200 may include more than one clutch. In one variation, the clutch 280 is a dog clutch (e.g., 3-way dog ​​clutch), and in another, the clutch 280 includes a dog clutch (e.g., 2-way dog ​​clutch) along with a selectable one-way clutch (SOWC). In further variations, the clutch 280 includes a wet disc-type clutch or a dry disc-type clutch. The first output shaft 240 for the first electric motor 210 has a clutch engagement member 285 where the clutch 280 can engage the first output shaft 240. The second carrier 275 of the second planetary gear set 235 has a first range member 290 where the clutch 280 engages when it is in a first range position.When the clutch 280 is in the first range position, it connects the first range element 290 to the clutch engagement element 285 such that the speed (i.e., RPM) provided by the second electric motor 215 is decreased through the second gear train 225, and the torque provided by the second electric motor 215 to the first output shaft 240 is increased through the planetary gears 255 of the second planetary gear set 235. The second output shaft 245 of the second electric motor 215 has a second range element 295 where the clutch 280 engages when it is in a second range position. When the clutch 280 is in the second range position, it connects the second range element 295 to the clutch engagement element 285 such that the speed and torque of the second electric motor 215 are directly provided to the first output shaft 240 of the first electric motor 210.Compared to the first range position, the rotational speed of the second electric motor 215 provided for the first output shaft 240 of the first electric motor 210 is faster and the torque is lower.

[0033] The clutch 280 may further be positioned at a neutral position where the second electric motor 215 is not mechanically coupled to the first electric motor 210. In the neutral or shift position, the first electric motor 210 may provide the sole mechanical power for propelling the vehicle 100. Among other things, this ability to propel the vehicle 100 solely via the first electric motor 210 while the second electric motor 215 is disconnected from the first output shaft 240 allows the second electric motor 215 to synchronize speed with the first electric motor 210 to engage the clutch 280 without interrupting power to the vehicle 100 (e.g., when the clutch 280 is a dog clutch). This also allows the first electric motor 210 to operate at a more efficient point than when the output load is shared with the second electric motor 215.

[0034] By utilizing more than one electric motor, the powertrain system 105 is configured to use smaller, passenger vehicle electric motors to power larger commercial vehicles, such as those with an FHWA rating of four (4) or higher. For example, passenger vehicle electric motors may be used to move vehicles 100 that weigh 40,000 pounds (18,144 kg) or more. Typically, but not always, passenger vehicle electric motors are less expensive, lighter, and capable of higher speeds with higher torque compared to commercial vehicles. Furthermore, these passenger vehicle motors tend to be more power dense and energy efficient, so the range of the vehicle 100 between charges of the ESS 115 may be increased.

[0035] Due to high demand and high production volumes, improvements in electric motor technology tend to occur more rapidly in the passenger vehicle sector, so these advantages of passenger vehicle electric motors over commercial vehicle electric motors with lower demand are expected to become more pronounced in the future. However, there are still disadvantages to using these passenger vehicle electric motors for heavy-duty vehicles. Individual passenger vehicle electric motors tend to produce insufficient torque to properly move and / or accelerate heavy-duty vehicles such as buses and semi-trailers. There is also a trend to operate passenger vehicle electric motors at even higher speeds or revolutions per minute (RPM), which are undesirable for heavy-duty vehicles, which tend to operate at lower speeds and require higher torques.

[0036] To facilitate the use of these passenger vehicle electric motors in heavy-duty vehicle applications, the powertrain system 105 includes at least two electric motors (e.g., the first electric motor 210 and the second electric motor 215) to provide sufficient torque and power to the drive shaft 125 and the drive system 130. The powertrain system 105 further includes at least the first gear train 220 to reduce the speed and increase the torque provided by the first electric motor 210 and / or the second electric motor 215. As shown, the powertrain system 105 may include additional gear trains, such as the second gear train 225, to enhance the performance of the powertrain system 105.

[0037] This multiple-motor design can also use energy more efficiently. The power, speed, and / or torque provided by the first electric motor 210 and the second electric motor 215 can be adjusted so that the motors operate more efficiently under different operating conditions. For example, the clutch 280 can change the gear ratios of the second gear train 225 to adjust the output speed and / or torque provided by the second electric motor 215. The clutch 280 can further be used to disconnect the second electric motor 215 from the first electric motor 210 so that the first electric motor 210 provides all of the driving mechanical power to the drive shaft 125.At the same time, the second electric motor 215 may be turned off to conserve power and allow the first electric motor 210 to operate within an efficient power band, or the speed of the second electric motor 215 may be changed for shifting purposes. Once again, with the first electric motor 210 permanently connected to the driveshaft 125, power may always be applied to the drive system 130, so that any shift of the second gear train 225 via the clutch 280 may be unnoticeable to the driver and / or passengers of the vehicle 100. Because the first electric motor 210 continuously provides power to the wheels 135, the drive train system 105 can take the appropriate time during shifting to improve the efficiency and performance of the vehicle 100.The powertrain system 105 is capable of providing more than adequate time to address timing and synchronization issues between the first electric motor 210, second electric motor 215, second gear train 225, and / or clutch 280. By providing additional time to shift without interrupting power, better synchronization can occur prior to clutch engagement, which in turn extends the life of the clutch 280.

[0038] This unique dual-motor architecture further improves energy efficiency. For example, the controller 110 can set the torque of the first electric motor 210 to zero (0), so that only the second electric motor 215 powers the vehicle 100. For example, this can be done at low vehicle speeds, where the speed of the first electric motor 210 would be too slow for the first electric motor 210 to operate in a high-efficiency range, and at other times depending on the type and design of the two motors.

[0039] An example of the transmission 205 in the electric drive train 200 is shown in Fig. 3. As can be seen, the electric drive train 200 in this example has an electric motor transmission 300 which is arranged in a similar manner to that shown in Fig. 2. For example, the electric motor transmission 300 includes the first electric motor 210, second electric motor 215, first gear train 220, and second gear train 225 of the type previously described. The first gear train 220 is in the form of the first planetary gear set 230, and the second gear train 225 is in the form of the second planetary gear set 235. The first planetary gear set 230 is mounted to the first output shaft 240, and the second planetary gear set 235 is mounted to the second output shaft 245. The first output shaft 240 and second output shaft 245, as well as the rest of the components of the electric motor transmission 300, rotate about and are oriented along a longitudinal axis 305 to provide centerline alignment to the electric motor transmission 300.The centerline alignment allows the 1:1 ratio to be more efficient than a parallel motor countershaft architecture, which requires transmission engagement to provide power back to the initial centerline. There is no such transmission power loss for the 1:1 ratio in the illustrated centerline alignment. These power loss differences are further increased due to losses not only during propulsion but also during regenerative braking.

[0040] The components of the electric motor transmission 300 are housed inside the housing 265. As in Fig. 3, the first electric motor 210 and the second electric motor 215 each include a rotor 310 and a stator 315. The rotor 310 of the first electric motor 210 is fixed to the first output shaft 240, and the rotor 310 of the second electric motor 215 is fixed to the second output shaft 245. The stators 315 are, in turn, fixed to the housing 265. The rotors 310 are configured to rotate relative to the fixed stators 315. When rotating, the rotor 310 of the first electric motor 210 rotates the first output shaft 240, which in turn drives the first planetary gear set 230. The first planetary gear set 230 reduces the output speed of the first electric motor 210 and / or second electric motor 215, which is supplied to the drive shaft 125 via the first carrier 270. This speed reduction by the first gear train 220 can, in turn, facilitate the use of higher speed passenger car electric motors in heavy commercial vehicles.

[0041] The rotor 310 of the stator 315 rotates the second output shaft 245, which in turn drives the second planetary gear 235. Again, the second planetary gear 235 has the second carrier 275, which is designed to transmit mechanical power to the first output shaft 240 via the clutch 280. The clutch 280 in the Fig. 3 is a positive clutch 320 in the form of a dog clutch 325. The dog clutch 325 is actuated or moved by a clutch actuator 330. The clutch actuator 330 is operably connected to and controlled by the controller 110 via the CAN 120. In one form, the clutch actuator 330 comprises an electric motor or solenoid with connections that actuate the clutch 280 to engage or disengage the first range member 290 or second range member 295. The controller 110 is further operably connected to the first electric motor 210 and second electric motor 215 to control the speed, torque, and / or relative positions of the first electric motor 210 and second electric motor 215.

[0042] Because the positive clutch 320 utilizes an interface-type connection, the dog clutch 325 dramatically reduces power loss caused by slipping, which is commonly present in friction-type clutches such as wet and dry disc clutches. Wet and dry clutches also typically require high hydraulic pressures. On the other hand, dog clutches typically require only low lubrication pressures. Therefore, the dog clutch 325 lowers the pressure requirements for the hydraulic system in the electric motor transmission 300. The overall design of the electric powertrain 200 facilitates the use of the dog clutch 325.Because the first electric motor 210 is capable of providing continuous power to the drive shaft 125 on demand, the controller 110 can take the time to allow the second electric motor 215 to properly start or stop rotation to match the speed and relative position of the first range member 290 or second range member 295 with the clutch engagement member 285 of the first electric motor 210 to enable smooth engagement with minimal power loss.

[0043] As in Fig. 3, the second gear train 225 and clutch 280 are capable of being housed between the first electric motor 210 and second electric motor 215 to provide a compact configuration. Once again, this compact centerline configuration allows for easy retrofitting of the electric motor transmissions 300 into existing vehicle designs with minimal redesign of major systems such as the suspension, braking, and steering systems. While only two motors are illustrated, the electric powertrain 200 may include more than two motors. For example, this design is modular, so that additional motors, gear trains, and / or clutches may be connected in a closed chain to the end of the second electric motor 215 to provide additional mechanical power.

[0044] A technology for operating the Fig. 1, Fig. 2 and Fig. 3 will now be described with reference to a flowchart 400 shown in Fig. 4. This technique is described with respect to actuation of the dog clutch 325 in Fig. 3, but it should be understood that other types of clutches 280 may be controlled using this technique. Furthermore, other types of powertrain systems 105 may be controlled in a similar manner. Using this technique, controller 110 processes information from powertrain system 105 and sends control signals thereto to control the operation of first electric motor 210, second electric motor 215, and clutch 280.

[0045] In step 405 in the flowchart 400 of Fig. 4, the clutch 280 is positioned in a neutral / shift position, with the clutch 280 not engaging the first range element 290 and second range element 295. In step 410, the controller 110 determines whether the clutch 280 needs to be shifted, depending on a number of factors such as the operating conditions of the vehicle 100 and powertrain system 105. The controller 110 shifts the clutch 280 from the neutral position to the first range or shift position, where the clutch 280 engages the first range element 290 with the clutch engagement element 285, in step 415. At the first range position, both the first electric motor 210 and the second electric motor 215 provide power to the input shaft 125.Compared to the second range or shift position, in the first range position, the second electric motor 215 provides greater torque at a lower speed to the clutch engagement element 285 of the first output shaft 240. In step 420, the controller 110 shifts the clutch 280 back to the neutral position to maintain the clutch 280 in the neutral position so that no mechanical power is transmitted from the second electric motor 215 or to subsequently shift the clutch 280 to the second range position. In step 425, the controller 110 shifts the clutch 280 from the first range position to the neutral position of step 405.

[0046] Depending on the operating requirements and conditions of the vehicle 100, the controller 110 may shift the electric powertrain 200 to the second range position. When the controller 110 selects the second range position in step 410, the controller 110 shifts the clutch 280 from the neutral position to the second range position in step 430. At the second range position, the clutch 280 mechanically connects the second range member 295 to the clutch engagement member 285 of the first output shaft 240. While both the first electric motor 210 and the second electric motor 215 are in the second range position, they provide power to the drive shaft 125. Compared to the first range position, the second electric motor 215 in the second range position provides lower torque at a higher speed to the clutch engagement member 285 of the first output shaft 240.In step 435, the controller 110 switches the clutch 280 back to the neutral position to maintain the clutch 280 in the neutral position so that no mechanical power is transmitted from the second electric motor 215 or to subsequently switch the clutch 280 to the first range position. In step 440, the controller 110 switches the clutch 280 from the second range position to the neutral position of step 405.

[0047] Fig. 5 illustrates the state of the transmission 205 in the electric powertrain 200 when in the neutral or shift position of step 405 of the flowchart 400 of Fig. 4. As indicated by arrows 505 in Fig. 5, the only mechanical power to the drive shaft 125 of the vehicle 100 may be provided only by the first electric motor 210 via the first planetary gear set 230. While the arrows 505 are shown pointing in one direction toward the drive shaft 125, mechanical power may be sent the opposite way from the wheels 135 of the drive system 130 to the first electric motor 210 for regenerative braking purposes, where the first electric motor 210 serves as a power generator to charge the ESS 115. The first electric motor 210, when in this idle position, typically provides power to move the wheels 135. However, during a downhill descent, for example, the first electric motor 210 may be temporarily shut down to conserve energy or reused as a generator to recharge the ESS 115.

[0048] When the clutch 280 is in the neutral position, the second electric motor 215 may also be temporarily (or semi-permanently) deactivated to conserve energy. As shown in the flowchart 400 of Fig. 4, the controller 110 temporarily moves the clutch 280 to the neutral position when shifting between the first and second range positions. While in this neutral position during shifting, the speed and relative orientation of the output from the second electric motor 215 (i.e., at the first range element 290 or second range element 295) is changed to generally match the current speed and position of the first electric motor 210 when the positive clutch 320 such as the dog clutch 325 is used. Once the speed and position are generally matched, the clutch 280 can be shifted from the neutral position to the desired shift position or range.When the clutch 280 is a friction-based clutch such as a dry or wet disc clutch, the speeds and relative positions of the first electric motor 210 and second electric motor 215 do not need to be matched as closely as with the positive clutch 320.

[0049] Fig. Figure 6 shows the relative orientation of the clutch 280 when in the first shift or range position of stage 415 ( Fig. 4). When the dog clutch 325 is in the first range position, the dog clutch 325 connects the first range member 290 of the second carrier 275 to the clutch engagement member 285 of the first output shaft 240. As indicated by arrows 605 in Fig. 6, both the first electric motor 210 and the second electric motor 215 provide mechanical power to the drive shaft 125 of the vehicle 100. Once again, the first planetary gear set 230 reduces the speed of the resulting output from both the first electric motor 210 and the second electric motor 215. This, in turn, allows passenger vehicle engines, which tend toward high operating speeds, to be used in heavy-duty vehicles. While the arrows 605 are shown pointing in one direction toward the drive shaft 125, mechanical power may be sent the opposite way from the wheels 135 of the drive system 130 to the first electric motor 210 and / or second electric motor 215 for regenerative braking purposes, where the first electric motor 210 and / or second electric motor 215 serve as power generators to charge the ESS 115.

[0050] The second electric motor 215 is capable of supplementing or even replacing the torque provided by the first electric motor 210. When the clutch 280 is in the first range position, the second planetary gear set 235 reduces the speed and increases the torque output from the second electric motor 215 via the planetary gears 255. The speed of the first electric motor 210 and / or second electric motor 215 can be adjusted so that the dog clutch 325 is able to engage. While the second electric motor 215 provides supplemental (or primary) mechanical power, the first electric motor 210 can be smaller than required at peak load. This, in turn, allows electric motors designed for passenger vehicles to be used in larger commercial vehicles.Furthermore, the first electric motor 210 and second electric motor 215 can be selected based on the desired power and energy requirements for the vehicle 100. This, in turn, can increase the range of the vehicle 100 for a single charge of the ESS 115. Normally, both the first electric motor 210 and the second electric motor 215 provide power to the driveshaft 125 when in the first range position. However, under certain use cases, one of the motors can be turned off to conserve power. For example, the second electric motor 215 can be turned off so that the first electric motor 210 provides all power to the wheels 135. Alternatively, the first electric motor 210 can be turned off so that the second electric motor 215 provides all power to the wheels 135. This can help improve efficiency under general conditions, such as low-speed parking maneuvers.

[0051] Similarly, the second electric motor 215 is capable of supplementing the torque provided by the first electric motor 210 when in the second shift or range position of stage 430 ( Fig. 4). Fig. Figure 7 shows the relative position of clutch 280 when in the second range position. As can be seen, dog clutch 325 connects second range member 295 of second output shaft 245 to clutch engagement member 285 of first output shaft 240. Typically, but not always, controller 110 selects the second range position when vehicle 100 is traveling at higher speeds compared to the first range position. Normally, both first electric motor 210 and second electric motor 215 provide power to driveshaft 125 when in the second range position. However, under certain use cases, one of the motors may be turned off to conserve power. For example, second electric motor 215 may be turned off so that first electric motor 210 provides all power to wheels 135.Alternatively, the first electric motor 210 can be switched off so that the second electric motor 215 provides all the power to the wheels 135.

[0052] As indicated by arrows 705 in Fig. 7, both the first electric motor 210 and the second electric motor 215 provide the mechanical power to the drive shaft 125 of the vehicle 100. In this case, the mechanical output of the second electric motor 215 bypasses the second gear train 225. Once again, the first planetary gear set 230 reduces the speed of the resulting output of both the first electric motor 210 and the second electric motor 215. It should again be appreciated that this configuration of the electric powertrain 200 allows passenger vehicle engines, which tend toward higher operating speeds, to be used in heavy-duty vehicles. While the arrows 705 in Fig. 7, in one direction toward the drive shaft 125, mechanical power may be sent in the opposite direction from the wheels 135 of the drive system 130 to the first electric motor 210 and / or second electric motor 215 for regenerative braking purposes, where the first electric motor 210 and / or second electric motor 215 serve as power generators to charge the ESS 115.

[0053] Fig. 8 shows a schematic representation of another example of an electric powertrain 800 used in the powertrain system 105 of Fig. 1 can be used. The electric drive train 800 shares a number of components and functions with those previously described (see, for example, Fig. 2 and Fig. 3). For the sake of brevity and clarity, these common features will not be described in detail below, but reference should be made to the previous discussion.

[0054] As shown, the electric powertrain 800 includes a continuous multi-motor power transmission 805. The transmission 805 of the electric powertrain 800 includes a first electric motor 810 with a first inverter 812 and a second electric motor 815 with a second inverter 817. The first inverter 812 is electrically connected between the ESS 115 and the first electric motor 810, and the second inverter 817 is electrically connected between the ESS 115 and the second electric motor 815. The first inverter 812 and second inverter 817 convert the direct current (DC) from the ESS 115 to alternating current (AC) to drive the first electric motor 810 and the second electric motor 815, respectively. The first electric motor 810 and second electric motor 815 may also serve as generators, such as during regenerative braking.In such a situation, the first inverter 812 and second inverter 817 convert the AC electrical power from the first electric motor 810 and second electric motor 815, respectively, to DC power that is supplied to the ESS 115. In one example, the first electric motor 810 and second electric motor 815 are the same type of electric motor, so both motors generally provide the same speed and torque output within normal manufacturing tolerances. In one form, the first electric motor 810 and second electric motor 815 are both high-speed electric motors, and in another form, the first electric motor 810 and second electric motor 815 are both low-speed electric motors. In alternative variations, the first electric motor 810 and second electric motor 815 may be different, such that one is a high-speed motor and the other is a low-speed motor, for example.

[0055] The transmission 805 of the electric powertrain 800 further includes a first gear train 820 and a second gear train 825, both located at an output end of the first electric motor 810 and the second electric motor 815.

[0056] As can be seen, the first gear train 820 is located at the output end of the overall transmission 805, which is near the input shaft 125. The second gear train 825 lies or is located between the second electric motor 815 and the first gear train 820. This configuration helps to dampen noise generated by the second gear train 825. In the illustrated example, the first gear train 820 is in the form of a first planetary gear set 830 and the second gear train 825 is in the form of a second planetary gear set 835. The first electric motor 810 and second electric motor 815 have a first output shaft 840 and a second output shaft 845, respectively, to provide rotary mechanical power. In the illustrated example, the second output shaft 845 is hollow so that the first output shaft 840 can extend concentrically through the second output shaft 845.Similar to the previous examples, the first planetary gear 830 has a first carrier 850 connected to the input shaft 125, and the second planetary gear 835 has a second carrier 855.

[0057] As in Fig. 8, the electric powertrain 800 includes at least one clutch 860 with a clutch actuator 862 that engages and disengages from the first electric motor 810 with the second electric motor 815. The clutch 860 further enables the transmission 805 of the electric powertrain 800 to shift gears so that the speed and / or torque of the second electric motor 815 can be changed. The first electric motor 810 is permanently connected to the drive shaft 125 (i.e., there is no clutch) so that the first electric motor 810 can provide continuous power to the drive shaft 125 and the drive system 130. In other words, the first electric motor 810 has a continuous connection to the drive shaft 125, and the second electric motor 815 has an interruptible connection to the drive shaft 125.This configuration of the electric powertrain 800 facilitates power shifting, whereby power can always be provided to the wheels 135, even when a shift of the clutch 860 is occurring. With power provided continuously, each shift can generally be unnoticeable to the driver and / or passengers.

[0058] In the illustrated example, the electric powertrain 800 includes a single clutch 860, but in other examples, the electric powertrain 800 may include more than one clutch. In one variation, the clutch 860 is a dog clutch, and in another, the clutch 860 is a selectable one-way clutch (SOWC). In further variations, the clutch 860 includes a wet disc-type clutch or a dry disc-type clutch. The first output shaft 840 for the first electric motor 810 has a clutch engagement element 865 where the clutch 860 can engage the first output shaft 840. The second carrier 855 of the second planetary gear set 835 includes a first range element 870 where the clutch 860 engages when in a first range position. When the clutch 860 is in the first range position, it connects the first range element 870 to the clutch engagement element 865 so that the speed (i.e.The speed (i.e., rpm) provided by the second electric motor 815 is decreased by the second gear train 825, and the torque provided by the second electric motor 815 to the first output shaft 840 is increased by the second planetary gear train 835. The second output shaft 845 of the second electric motor 815 includes a second range member 875 where the clutch 860 engages when in a second range position. When the clutch 860 is in the second range position, it connects the second range member 875 to the clutch engagement member 865 so that the speed and torque of the second electric motor 815 are directly provided to the first output shaft 840 of the first electric motor 810. Compared with the first range position, the rotational speed of the second electric motor 815 provided for the first output shaft 840 of the first electric motor 810 is faster and the torque is lower.The clutch 860 may further be positioned at a neutral position where the second electric motor 815 is not mechanically coupled to the first electric motor 810. In the neutral shift position, the first electric motor 810 may provide the sole mechanical power for propelling the vehicle 100.

[0059] By utilizing more than one electric motor, the powertrain system 105 is configured to allow the use of smaller passenger vehicle electric motors to power larger commercial vehicles, such as those with an FHWA rating of four (4) or higher and / or those capable of moving 40,000 pounds (18,144 kg) or more. Typically, but not always, passenger vehicle electric motors are less expensive, lighter, and capable of providing higher speeds compared to higher-torque commercial vehicle electric motors. Furthermore, these passenger vehicle motors tend to be more power dense and energy efficient, so that the range of the vehicle 100 between charges of the ESS 115 can be increased.

[0060] Again, this multiple-motor design can also use energy more efficiently. The power, speed, and / or torque provided by the first electric motor 810 and the second electric motor 815 can be adjusted so that the motors operate more efficiently under different operating conditions. For example, the clutch 860 can change the gear ratios of the second gear train 825 to adjust the output speed and / or torque provided by the second electric motor 815. The clutch 860 can also be used to disconnect the second electric motor 815 from the first electric motor 810 so that the first electric motor 810 provides all of the driving mechanical power to the drive shaft 125.At the same time, the second electric motor 815 may be turned off to conserve power and allow the first electric motor 810 to operate within an efficient power band, or the speed of the second electric motor 815 may be changed for shifting purposes. Once again, with the first electric motor 810 permanently connected to the driveshaft 125, power may always be applied to the drive system 130, so that any shift of the second gear train 825 via the clutch 860 may be unnoticeable to the driver and / or passengers of the vehicle 100. Given that the first electric motor 810 continuously provides power to the wheels 135, the drive train system 105 can take the appropriate time during shifting to improve the efficiency and performance of the vehicle 100.The powertrain system 105 is capable of providing more than adequate time to address timing and synchronization issues between the first electric motor 810, second electric motor 815, second gear train 825, and / or clutch 860.

[0061] Fig. 9 shows an electric drive train 900 which is a variation of the electric in Fig. 8. As can be seen, the electric drive train 900 contains the same components and is constructed in the same way as the drive train 800 shown in Fig. 8. For example, the electric drive train 900 includes the first electric motor 810, first inverter 812, second electric motor 815, second inverter 817, second gear train 825, second planetary gear 835, first output shaft 840, second output shaft 845, second carrier 855, clutch 860, and clutch actuator 862 of the type described above for the electric drive train 800 in Fig. 8. However, the electric powertrain 900 has a transmission 905 in which the first gear train 820 (i.e., the first planetary gear set 830) has been omitted. This configuration of the electric powertrain 900 is beneficial in situations where the first electric motor 810 and second electric motor 815 are both low-speed motors, such that the first gear train 820 is not necessary to reduce the speed of the output from the electric powertrain 900.

[0062] The electric drivetrain 800 in Fig. 8 and electric drivetrain 900 in Fig. 9 work in a similar way to the one previously described in relation to Fig. 4. A technique for operating the electric powertrain 800 in Fig. 8 will now be discussed with reference to Fig. 4, Fig. 10, Fig. 11 and Fig. 12. It should be obvious that the electric drivetrain 900 in Fig. 9 operates in the same manner, except that the output power is not routed through the first planetary gear 830 to reduce the output speed of the electric drive train 900. Otherwise, the electric drive train 900 operates in Fig. 9 in the same way as described below.

[0063] Fig. Figure 10 shows the electric drive train 800 with the clutch 860 in a first range or shift position (i.e., stage 415 in Fig. 4). The controller 110 moves the clutch 860 via the clutch actuator 862 to the first range, where the clutch 860 connects the first range element 870 of the second carrier 855 with the clutch engagement element 865 of the first output shaft 840. As indicated by arrows 1005 in Fig. 10, the torque or power from the first electric motor 810 is transmitted via the first output shaft 840 to the first planetary gear set 830 of the first gear train 820. The mechanical power from the second electric motor 815 is transmitted via the second output shaft 845 to the second planetary gear set 835 of the second gear train 825. In the second planetary gear set 835, the power is transmitted through the clutch 860 from the first range member 870 of the second planetary gear set 835 to the clutch engagement member 865 of the first output shaft 840. It should also be apparent that the second planetary gear set 835 increases the torque and decreases the speed of the output from the second electric motor 815. The torque of both the first electric motor 810 and the second electric motor 815 is combined and transmitted through the first planetary gear set 830 to the input shaft 125.The direction of the arrows 1005 shows the power being transferred to the drive shaft 125, but in other operating modes, such as during regenerative braking, this direction may be reversed.

[0064] Fig. 11 shows the electric drive train 800 with the clutch 860 in the neutral or shift position of stage 405 in Fig. 4. As can be seen by arrows 1105, the clutch 860 is in an idle position where the first range element 870 and second range element 875 of the second electric motor 815 are separated from the clutch engagement element 865 of the first electric motor 810. When in the Fig. 77, the controller 110 may position the clutch 860 in the neutral position via the clutch actuator 862 so that the second electric motor 815 may be temporarily deactivated to conserve energy and / or otherwise disconnected so that it is unable to supply mechanical power to the first output shaft 840 of the first electric motor 810. The clutch 860 may also be in this position when switching between the first and second range positions to provide sufficient time for the relative speeds and positions of the first electric motor 810 and the second electric motor 815 to generally match each other. As indicated by the arrows 1105 in Fig. As shown in Figure 11, only the first electric motor 810 is capable of providing mechanical power to the drive shaft 125 via the first planetary gear set 830 and the first output shaft 840 when the clutch 860 is in the neutral position. Once again, the direction of the arrows 1105 indicates the power being transferred to the drive shaft 125, but in other operating modes, such as during regenerative braking, this direction may be reversed.

[0065] Fig. 12 shows the electric drive train 800 with the clutch 860 in a second range or shift position of stage 430 in Fig. 4. The controller 110 moves the clutch 860 via the clutch actuator 862 to the first range, where the clutch 860 connects the second range element 875 of the second output shaft 845 with the clutch engagement element 865 of the first output shaft 840. As indicated by arrows 1205 in Fig.12, the torque or power from the first electric motor 810 is transmitted to the first planetary gear set 830 of the first gear train 820 via the first output shaft 840. The mechanical power from the second electric motor 815 bypasses the second planetary gear set 835 of the second gear train 825 and is transmitted directly from the second output shaft 845 via the second range member 875 to the clutch engagement member 865. With this arrangement, the speed and torque supplied to the first output shaft 840 from the second electric motor 815 are the same (i.e., are not changed). The torque of both the first electric motor 810 and the second electric motor 815 are combined and transmitted through the first planetary gear set 830 to the input shaft 125.The direction of the arrows 1205 shows the power being transferred to the drive shaft 125, but in other operating modes, such as during regenerative braking, this direction may be reversed. Glossary of terms

[0066] The language used in the claims and description is intended to have only its usual and ordinary meaning, except as expressly defined below. The words in these definitions are intended to have only their usual and ordinary meaning. This usual and ordinary meaning includes all common dictionary definitions from the most recently published Webster Dictionaries and Random House Dictionaries. As used in the claims and description, the following definitions apply to these terms and common variations thereof, which are defined below.

[0067] "Coupling" generally refers to a device that engages and disengages mechanical power transmission between two or more rotating shafts or other moving components. In one example, one shaft is typically attached to a prime mover, motor, or other power source, serving as the driving member, while the other shaft (i.e., the driven member) provides output power for work. While the given motions are usually rotary, linear couplings are also used to engage or disengage components that move with a linear or near-linear motion. The coupling components can be engaged or disengaged by, for example, mechanical, hydraulic, and / or electrical actuation. The couplings can include positive-type clutches and friction-type clutches.Wet clutches are typically immersed in a cooling lubricant or other fluid, while dry clutches are not immersed in such fluids. Some non-limiting examples of clutches include cone clutches, centrifugal clutches, torque limiting clutches, axial clutches, disc clutches, jaw clutches, and rim clutches, to name a few.

[0068] "Controller" generally refers to a device that uses mechanical, hydraulic, pneumatic, electronic techniques, and / or a microprocessor or computer to monitor and physically change the operating conditions of a particular dynamic system. As a non-limiting example, the controller may include an Allen Bradley brand programmable logic controller (PLC). A controller may include a processor for performing calculations to process input or output. A controller may include memory for storing values ​​to be processed by the processor or for storing the results of previous processing. A controller may also be configured to accept input and output from a variety of input and output devices for receiving or sending values.Such devices include other computers, keyboards, mice, visual displays, printers, industrial equipment, and systems or machinery of all types and sizes. For example, a controller may control a network or a network interface to perform various network communications on demand. The network interface may be part of the controller or characterized as separate and remote from the controller. A controller may be a single, physical computing device, such as a desktop computer or a laptop computer, or may be composed of multiple devices of the same type, such as a group of servers operating as one device in a networked cluster, or a heterogeneous combination of different computing devices operating as one controller and interconnected by a communications network.The communications network connected to the controller may also be connected to a wider network, such as the Internet. Therefore, a controller may include one or more physical processors or other computing devices or circuits, and may also include any suitable type of memory. A controller may also be a virtual computing platform with an unknown or fluctuating number of physical processors and memories or storage devices. Thus, a controller may be physically located in one geographical location or physically dispersed across multiple widely distributed locations, with multiple processors interconnected by a communications network to operate as a single controller. Multiple controllers or computing devices may be configured to communicate with each other or with other devices via wired or wireless communications links to form a network.Network communications can pass through various controllers acting as network devices, such as switches, routers, firewalls, or other network devices or interfaces, before passing through other larger computer networks, such as the Internet. Communications can also pass through the network as wireless data transmissions, carried via electromagnetic waves through transmission lines or free space. Such communications involve the use of Wi-Fi or another wireless local area network (WLAN) or a cellular transceiver to transmit data.

[0069] "Controller Area Network" or "CAN" generally refers to a vehicle bus standard designed to allow microcontrollers, sensors, and / or other devices to communicate with each other in applications without necessarily requiring a host computer. CAN systems feature a message-based protocol originally designed for multiplexed electrical wiring in automobiles, but are also used in many other contexts. A vehicle with a CAN system typically, but not always, includes multiple electronic control units (ECUs), also called nodes.These ECUs may include engine control modules (ECMs) and transmission control modules (TCMs), as well as other control units such as those for airbags, anti-lock brakes / ABS, cruise control, electric power steering, audio systems, power windows, doors, mirror adjustment, battery, and / or hybrid / electric charging systems, to name a few. A CAN comprises a multi-master serial bus standard for interconnecting ECUs. The complexity of the ECU or node can range from a simple input / output (I / O) device to an embedded computer with a CAN interface and software. The ECU or node can also serve as a gateway, allowing a general-purpose computer to communicate with the devices on the CAN network through an interface such as a USB and / or Ethernet port.Each ECU typically, but not always, includes a central processing unit, a CAN controller, and transceivers. CAN systems can include, for example, low-speed CAN (128 kbps) under the ISO 11898-3 standard, high-speed CAN (512 kbps) under the ISO 11898-2 standard, CAN FD under the ISO 11898-1 standard, and single-wire CAN under the SAE J2411 standard.

[0070] "Dog clutch" generally refers to a type of positive coupling that couples and uncouples at least two rotating shafts or other rotating mechanical components through an interface-like connection. The two parts of the clutch are designed so that one pushes the other, causing both to rotate at the same speed with no (or very little) slippage. Typically, but not always, one part of the dog clutch has a series of teeth or other projections designed to mate with another part of the dog clutch that has corresponding recesses to receive the teeth or projections. Unlike friction clutches, which allow slipping, dog clutches are used where slipping is undesirable and / or the clutch is not used to control torque. Without slipping, dog clutches are not subject to wear in the same way as friction clutches.

[0071] "Electric motor" generally refers to an electrical machine that converts electrical energy into mechanical energy. Typically, but not always, electric motors operate by the interaction between one or more magnetic fields within the motor and winding currents to produce power in the form of rotation. Electric motors can be powered by direct current (DC) sources, such as batteries, motor vehicles, and / or rectifiers, or by alternating current (AC) sources, such as a power grid, inverters, and / or electrical generators. An electric generator may (but not always) be mechanically identical to an electric motor but operate in the opposite direction, accepting mechanical energy and converting the mechanical energy into electrical energy.

[0072] An "energy storage system" (ESS) or "energy storage unit" generally refers to a device that captures energy generated at one time for use at a later time. The energy can be supplied to the ESS in one or more forms, including, for example, radiation, chemicals, gravitational potential, electric potential, electricity, elevated temperature, latent heat, and kinetic energy. The ESS converts energy from forms that are difficult to store into more practical and / or economical forms.As non-limiting examples, techniques for harvesting energy in the ESS may include: mechanical capture techniques, such as compressed air storage, flywheels, gravitational potential energy devices, springs, and hydraulic accumulators; electrical and / or electromagnetic capture techniques, such as the use of capacitors, supercapacitors, and superconducting magnetic energy storage coils; biological techniques, such as the use of glycogen, biofuel, and starch storage media; electrochemical capture techniques, such as the use of flow batteries, rechargeable batteries, and ultrabatteries; thermal capture techniques, such as the use of eutectic systems, molten salt storage, phase-change materials, and vapor accumulators; and / or chemical capture techniques, such as the use of hydrated salts, hydrogen, and hydrogen peroxide. Common ESS examples include lithium-ion batteries and supercapacitors.

[0073] "Geartrain" generally refers to a system of gears that transmit power from one mechanical component to another. For example, a geartrain may include a combination of two or more gears mounted on rotating shafts to transmit torque and / or power. As a non-limiting example, the geartrain may include, for example, a planetary gear set.

[0074] “High-speed engine” generally refers to an engine that has a maximum output speed of at least 5,000 rpm (revolutions per minute) without the use of gear trains or other similar devices to increase the speed.

[0075] "Interruptible connection" generally refers to a mechanical connection between two mechanical components that has the capability of breaking continuity during normal operation, allowing the components to be mechanically disconnected and reconnected at will. When disconnected, the components are unable to provide mechanical power to each other. The interruptible connection may include multiple components, such as multiple shafts and gears, that mesh with each other. The interruptible connection includes at least one mechanism, such as a clutch, designed to disconnect and reconnect the mechanical connection between the components during normal operation.

[0076] “Longitudinal” generally refers to the length or longitudinal dimension of an object, rather than the transverse dimension.

[0077] “Low-speed engine” generally refers to an engine that has a maximum output speed of less than 5,000 rpm (revolutions per minute) without the use of gear trains or other similar devices to increase the speed.

[0078] "Planetary gear" or "planetary gear set" generally refers to a system of at least two gears mounted so that the center of at least one gear rotates about the center of the other. In other words, the planetary gear set comprises a system of epicyclic gears in which at least one gear axis rotates about the axis of another gear. In one example, a carrier connects the centers of the two gears and rotates to support one gear, called a planetary gear, around the other, commonly called a sun gear. Typically, but not always, the planet and sun gears mesh so that their pitch circles roll without slippage. A point on the planet gear's pitch circle usually follows an epicycloid curve. In a simplified case, the sun gear is stationary, and the one or more planet gears roll around the sun gear.In other examples, an epicyclic gear train can be assembled so that the planetary gear rolls on the inside of the pitch circle of a stationary outer gear ring or ring gear, sometimes referred to as an annular gear. In this case, the curve traced by a point on the planetary gear's pitch circle is a hypocycloid. A planetary gear train is typically used to transmit large torque loads in a compact form.

[0079] "Positive clutch" generally refers to a type of clutch designed to transmit torque without slipping. Some examples of positive clutches include jaw clutches (e.g., square or spiral clutches) and dog clutches.

[0080] "Powertrain" generally refers to devices and / or systems used to convert stored energy into kinetic energy for propulsion purposes. The powertrain may include multiple power sources and may be used in non-wheel-based vehicles. As non-limiting examples, the stored energy sources may include chemical, solar, nuclear, electrical, electrochemical, kinetic, and / or other possible energy sources. For example, in a motor vehicle, the powertrain includes the devices that generate power and deliver the power to the road surface, water, and / or air. These devices in the powertrain include prime movers, engines, transmissions, drive shafts, differentials, and / or final drive components (e.g., drive wheels, tracks, propellers, thrusters, etc.).

[0081] "Rotor" generally refers to a part or section in a machine that rotates in or around a stationary part, commonly referred to as a stator. The rotor is the moving or rotating part of a rotating system, such as those found in power generators, electric motors, sirens, mud motors, turbines, and / or biological rotors. In one specific non-limiting example, the rotor comprises the rotating portion of a power generator and / or motor, particularly an induction motor.

[0082] "Stator" generally refers to a stationary part or section in a machine in or around which a rotating part, commonly referred to as a rotor, rotates. The stator is the stationary part of a rotating system, such as those found in power generators, electric motors, sirens, mud motors, turbines, and / or biological rotors. In one specific, non-limiting example, the stator comprises the stationary section of a power generator and / or motor, particularly an induction motor.

[0083] "Transmission" generally refers to a power system that provides controlled application of mechanical power. The transmission uses gears and / or gear trains to provide speed, direction, and / or torque conversion from one rotating power source to another device.

[0084] "Continuous connection" generally refers to a mechanical connection between two mechanical components without a break in continuity, so that mechanical power can be transmitted on a continuous basis as desired. The continuous connection does not require a uniform connection, so the continuous connection may have multiple components, such as multiple shafts and gears, that are in mesh with each other. The continuous connection lacks mechanisms or other structures, such as clutches, designed to disconnect and reconnect the mechanical connection between the components during normal operation. It should be apparent that the continuous connection may occasionally have random interruptions that separate the components, but the design of the continuous connection is not designed to facilitate such interruptions and the resulting separations.

[0085] "Vehicle" generally refers to a machine that transports people and / or cargo. General types of vehicle can include land-based vehicles, amphibious vehicles, watercraft, aircraft, and spacecraft. As non-limiting examples, land-based vehicles can include wagons, carts, scooters, bicycles, motorcycles, automobiles, buses, trucks, semi-trailers, trains, trolleys, and streetcars. Amphibious vehicles can include, for example, hovercraft and duck boats, and watercraft can include ships, boats, and submarines, to name a few. General forms of aircraft include airplanes, helicopters, autogyros, and balloons, and spacecraft can include, for example, rockets and rocket-powered aircraft. The vehicle can have numerous types of power sources.For example, the vehicle can be human-powered, electrically powered, chemically combustion powered, nuclear-powered, and / or solar-powered. The direction, speed, and operation of the vehicle can be human-controlled, autonomously controlled, and / or semi-autonomously controlled. Examples of autonomously or semi-autonomously controlled vehicles include automated guided vehicles (AGVs) and drones.

[0086] The term “or” is inclusive, meaning “and / or”.

[0087] It should be noted that the singular forms "a," "an," "an," "the," "the," and the like, as used in the description and / or claims, include the plural forms unless expressly stated otherwise. For example, if the description and / or claims refer to "a device" or "the device," they include one or more such devices.

[0088] It should be noted that directional terms such as "upwardly", "downwardly", "top", "bottom", "laterally", "longitudinally", "radially", "circumferentially", "horizontally", "vertically", etc. are used herein only for the convenience of the reader to enable the reader to better understand the illustrated embodiments, and the use of these directional terms is not intended to limit the described, illustrated and / or claimed features to any particular direction and / or orientation.

[0089] While the invention has been fully illustrated and described in detail in the drawings and the foregoing description, it is to be considered as illustrative and not restrictive, it being understood that only the preferred embodiment has been shown and described and that all changes, equivalents, and modifications which come within the spirit of the inventions are intended to be protected by the following claims. All publications, patents, and patent applications cited in this specification are incorporated herein by reference as if each individual publication, patent, or patent application were specifically and particularly indicated to be cited herein by reference and set forth in its entirety. Reference symbol 100 vehicles 105 Powertrain system 110 controllers 115 ESS 120 CAN 125 drive shaft 130 drive system 135 wheels 140 power cables 200 electric drivetrain 205 gearbox 210 first electric motor 215 second electric motor 220 first transmission train 225 second transmission train 230 first planetary gear 235 second planetary gear 240 first output shaft 245 second output shaft 250 sun gear 255 planetary gears 290 first area element 295 second area element 300 electric motor gearboxes 305 Longitudinal axis 310 rotor 315 Stator 320 positive clutch 325 claw coupling 330 clutch actuator 400 Flowchart 405 level 410 level 415 level 420 level 425 level 430 level 435 level 440 level 505 arrows 605 arrows 820 first gear train 825 second transmission train 830 first planetary gear 835 second planetary gear 840 first output shaft 845 second output shaft 850 first carrier 855 second carrier 860 clutch 862 clutch actuator 865 clutch engagement element 870 first area element 875 second area element 900 electric drivetrain 905 gearbox 260 ring gear 265 housings 270 first carrier 275 second carrier 280 clutch 285 Clutch engagement element 705 arrows 800 electric drivetrain 805 gearbox 810 first electric motor 812 first converter 815 second electric motor 817 second converter 1005 arrows 1105 arrows 1205 arrows

Claims

[1] Powertrain system (105), comprising: an exit; a first electric motor (210, 810) having a continuous connection to the output; a second electric motor (215, 815) having an interruptible connection to the output; and wherein the interruptible connection comprises a clutch (280, 860) and a single planetary gear configured to engage the clutch (280, 860), the clutch being configured to disconnect and reconnect the interruptible connection, the interruption being effected by the clutch (280, 860) between the single planetary gear and the output. [2] The powertrain system (105) of claim 1, wherein the first and second electric motors (210, 810, 215, 815) are low-speed motors having a maximum speed of less than 5,000 rpm. [3] The powertrain system (105) of claim 1, wherein the first and second electric motors (210, 810, 215, 815) are high-speed motors having a maximum speed of at least 5,000 rpm. [4] The powertrain system (105) of any preceding claim, wherein the uninterrupted connection of the first electric motor (210, 810) includes a first gear train (220, 820) configured to reduce speed. [5] The drive train system (105) of any preceding claim, wherein the interruptible connection of the second electric motor (215, 815) comprises a second gear train (225, 825). [6] The drive train system (105) of any preceding claim, wherein the first gear train (220, 820) comprises a first planetary gear train (230, 830). [7] The powertrain system (105) of any preceding claim, wherein the second electric motor (215, 815) is connected to the output via the clutch (280, 860). [8] The drive train system (105) of any preceding claim, wherein the clutch (280, 860) comprises a dog clutch (325). [9] The powertrain system (105) of any preceding claim 1-7, wherein the clutch (280, 860) comprises a wet disc clutch. [10] The powertrain system (105) of any preceding claim, wherein the clutch (280, 860) includes an actuator (330) and a selectable one-way clutch (SOWC). [11] The powertrain system (105) of any preceding claim 1-7, wherein the clutch (280, 860) comprises a dry disc clutch. [12] The powertrain system (105) of claim 1, wherein the first and second electric motors (210, 810, 215, 815) are low-speed motors having a rated operating speed of less than 5,000 rpm. [13] The powertrain system (105) of any preceding claim, wherein the second electric motor (215, 815) is configured to supply power to the output via at least two planetary gears (230, 830, 235, 825) and a clutch (280, 860). [14] The powertrain system (105) of claim 1, wherein the first and second electric motors (210, 810, 215, 815) are high-speed motors having a rated operating speed of at least 5,000 rpm. [15] The powertrain system (105) of any preceding claim, wherein the output is configured to move a vehicle (100) of 40,000 pounds or more.

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