Systems for an electric powertrain

Abstract

Multi-speed gearbox, comprehensive: a first input shaft, coupled with a first drive motor and a first motor gear; a second input shaft, coupled to a second drive motor and a second motor gear; a planet carrier coupled to a planet shaft which is engaged with a first clutch via a planet gear and a first clutch gear, or which is engaged with a second clutch shaft of a second clutch on which a second clutch gear is arranged; and an output shaft, wherein the first clutch gear is arranged on the output shaft, further comprising an output shaft gear which is arranged on the output shaft and meshes with the second clutch gear.

Description

TECHNICAL FIELD

[0001] The present description generally relates to a decoupling device of a transmission of an electric powertrain. BACKGROUND AND OVERVIEW

[0002] As vehicle electrification becomes more widespread, changes to vehicle components will be required to accommodate new vehicle designs. For example, transmissions designed for use with internal combustion engines may experience reduced performance and / or reduced durability when coupled with an electric motor. Electric motors can operate at higher speeds than internal combustion engines, which may result in increased stress on one or more transmission components. This increased stress may also lead to undesirable conditions for vehicle occupants, such as noise, vibration, and harshness (NVH).

[0003] Consequently, there is a need for a transmission configured to operate efficiently with an electric motor. In one example, the problems described above may be solved by a system comprising: a first input shaft coupled to a first prime mover and a first motor gear; a second input shaft coupled to a second prime mover and a second motor gear; a planetary carrier coupled to a planetary shaft engaged with a first clutch via a planetary gear and a first clutch gear or engaged with a second clutch shaft of a second clutch having a second clutch gear disposed thereon; and an output shaft, the first clutch gear disposed on the output shaft; further comprising an output shaft gear disposed on the output shaft and meshing with the second clutch gear.

[0004] It should be understood that the above summary is intended to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify critical or essential features of the claimed subject matter, as the scope of the claimed subject matter is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address disadvantages noted above or in any part of the disclosure. SHORT DESCRIPTION OF THE CHARACTERS

[0005] The foregoing and other advantages of the present disclosure will be readily apparent to one skilled in the art from the following detailed description when considered in light of the accompanying drawings in which: Fig. 1 is a schematic diagram of an exemplary vehicle powertrain according to an embodiment of the present disclosure; Fig. 2 is a first embodiment of a transmission of the vehicle powertrain according to an embodiment of the present disclosure; Fig. 3 is a second embodiment of a transmission of the vehicle powertrain according to an embodiment of the present disclosure; and Fig. 4 is a method for operating one or more clutches of the transmission based on the operation of one or more prime movers coupled to the transmission, according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0006] The following description relates to a transmission. In one example, the transmission is a two-speed transmission coupled to separate prime movers of a vehicle driveline, as shown in Fig. 1 shown. Fig. 2 illustrates a first operation of the transmission. Fig. 3 illustrates a second operation of the transmission. Fig. 4 shows a method for operating one or more clutches of the transmission based on the operation of one or more prime movers coupled to the transmission.

[0007] The Fig. 1-3 show example configurations with the positional relationship of the various components. Where such elements are shown as directly touching or directly coupled to one another, then they may be referred to as directly touching or directly coupled, respectively, in at least one example. Likewise, elements shown as being directly adjacent or contiguous to one another may be directly adjacent or adjacent to one another in at least one example. For example, components that are in surface contact with one another may be referred to as being in surface contact. In another example, elements that are positioned away from one another with only space and no other components between them may be referred to as such in at least one example. As yet another example, elements that are positioned above or below one another, on opposite sides of one another, or to the left or right of one another may be referred to as such.shown to the right of each other, may be referred to as such relative to each other. Further, as shown in the figures, in at least one example, a topmost element or a topmost point of an element may be referred to as a "top" of the component, and a bottommost element or a bottommost point of the element may be referred to as a "bottom" of the component. As used herein, top / bottom, upper / lower, over / under may refer to a vertical axis of the figures and may be used to describe a positioning of elements of the figures in relation to one another. Thus, in one example, elements shown above other elements are positioned vertically above the other elements. As yet another example, shapes of the elements depicted within the figures may be referred to as having those shapes (e.g.,circular, straight, flat, curved, rounded, beveled, angled, or the like). Further, elements shown as intersecting one another may be referred to as intersecting elements or as intersecting one another in at least one example. Further, an element shown inside another element or shown outside another element may be referred to as such in an example. It is understood that when one or more components are referred to as "substantially similar and / or identical," they differ from one another by manufacturing tolerances (e.g., within a 1% to 5% variation).

[0008] Fig. 1 shows a vehicle 100 having a driveline 101 and a powertrain 103. The driveline includes a prime mover 106 and a transmission 108. The prime mover 106 may be, for example, an internal combustion engine or an electric motor and operates to provide rotational power to the transmission 108. The transmission 108 may be any type of transmission, such as a manual transmission, an automatic transmission, or a continuously variable transmission. The transmission 108 receives the rotational power produced by the prime mover 106 as input and outputs rotational power to the powertrain 103 according to a selected gear or setting.

[0009] In one example, the prime mover 106 is a first prime mover 106, and the vehicle 100 may further include a second prime mover 107. The first prime mover 106 may be different from the second prime mover 107. For example, the first prime mover 106 may be an electric machine, and the second prime mover 107 may be an internal combustion engine. Additionally or alternatively, the first prime mover 106 and the second prime mover 107 may both be an electric motor or an internal combustion engine, but a size and / or fuel source thereof may differ between the first and second prime movers 106, 107.If one of the first prime mover 106 or the second prime mover 107 is an internal combustion engine, in some examples, the internal combustion engine may additionally or alternatively be configured to combust multiple fuels with varying amounts of carbon, as well as carbon-free fuels. In one example, the vehicle 100 includes at least the first prime mover 106 and the second prime mover 107, with each of the prime movers delivering torque and / or power to a transmission system (e.g., the transmission 108).

[0010] Both the first prime mover 106 and the second prime mover 107 may be coupled to an energy storage device. The energy storage device may be a battery, a fuel tank, or a similar device. A charge of a fuel volume of the energy storage device may be monitored via a sensor or estimated based on vehicle operating conditions. In one example, one or more of the first prime mover 106 and the second prime mover 107 may be configured to replenish a charge of the energy storage device during generator operation.

[0011] The vehicle 100 may be a heavy-duty vehicle or an off-road vehicle. Additionally or alternatively, the vehicle 100 and / or one or more of its components may be used in industrial, railroad, and agricultural applications.

[0012] In some examples, such as Fig. 1, the powertrain 103 includes a first axle assembly 102 and a second axle assembly 112. The first axle assembly 102 may be configured to drive a first set of wheels 104, and the second axle assembly 112 may be configured to drive a second set of wheels 114. In one example, the first axle assembly 102 is disposed near a front of the vehicle 100 and thus includes a front axle, and the second axle assembly 112 is disposed near a rear of the vehicle 100 and thus includes a rear axle. The powertrain 103 is shown in a four-wheel drive configuration, but other configurations are possible. For example, the powertrain 103 may include a front-wheel drive, a rear-wheel drive, or an all-wheel drive configuration. Further, the powertrain 103 may include one or more tandem axle assemblies.Thus, the powertrain 103 may have other configurations without departing from the scope of this disclosure, and the configurations shown in . Fig. The configuration shown in Figure 1 is provided for illustrative purposes, not by way of limitation. Furthermore, the vehicle 100 may include additional wheels that are not coupled to the powertrain 103.

[0013] In some four-wheel drive configurations, such as Fig. 1, the powertrain 103 includes a transfer case 110 configured to receive rotary power output from the transmission 108. A first input shaft 113 is drivingly coupled to a first output 111 of the transfer case 110, while a second input shaft 122 is drivingly coupled to a second output 121 of the transfer case 110. The first input shaft 113 (e.g., a front driveshaft) transfers rotary power from the transfer case 110 to a first differential 116 of the first axle assembly 102 to drive the first set of wheels 104, while the second driveshaft 122 (e.g., a rear driveshaft) transfers the rotary power from the transfer case 110 to a second differential 126 of the second axle assembly 112 to drive the second set of wheels 114.For example, the first differential 116 is drivingly coupled to a first axle shaft set 118 coupled to the first set of wheels 104, and the second differential 126 is drivingly coupled to a second axle shaft set 128 coupled to the second set of wheels 114. Note that both the first axle shaft set 118 and the second axle shaft set 128 may be positioned within a housing.

[0014] The vehicle 100 may further include a control system 184. As shown, the control system 184 includes a controller 182 that receives information from a plurality of sensors 186 and sends control signals to a plurality of actuators 188. The controller 182 may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on an instruction or code programmed therein according to one or more routines. The plurality of sensors 186 may include speed sensors, temperature sensors, humidity sensors, location sensors, accelerometers, and the like. The plurality of sensors 188 may be actuators of one or more valves, motors, and other devices.

[0015] Fig. 2 shows this one transmission assembly 200. The transmission assembly 200 can be installed in the vehicle 100 by Fig. 1. In one example, the transmission assembly 200 is a non-limiting example of the transmission 108 of Fig. 1. The transmission assembly 200 may be a multi-speed transmission. In one example, the transmission assembly 200 is a two-speed transmission.

[0016] The transmission assembly 200 may include a first input shaft 202. The first input shaft 202 may transmit power from a first prime mover 210 to a first motor gear 204. In one example, the first prime mover 210 is an electric machine. The first prime mover 210 may be a non-limiting example of the first prime mover 106 of Fig. 1.

[0017] The transmission assembly 200 may further include a second input shaft 212. The second input shaft 212 may transmit power from a second prime mover 220 to a second motor gear 214. In one example, the second prime mover 220 is an electric machine. Additionally or alternatively, the second prime mover 220 may be an internal combustion engine. The second prime mover 220 may be a non-limiting example of the second prime mover 107 of Fig. 1.

[0018] In some examples, one or more of the first prime mover 210 and the second prime mover 220 may be configured as a motor / generator configured to propel the vehicle during a motoring mode and to replenish a charge of an energy storage device during a generating mode. Additionally or alternatively, one or more components may be powered during the generating mode.

[0019] The first motor gear 204 and the second motor gear 214 may be coupled to different portions of a planetary gear set. The first motor gear 204 may be in meshing engagement with a first gear 232. The meshing engagement may involve teeth of one gear crossing teeth of another gear, such that rotation of the gear results in rotation of the other gear.

[0020] The first gear 232 may be coupled to a first planetary gear 238 via a flange 239. The first planetary gear 238 is a ring gear of a planetary gear system. The second motor gear 214 may be coupled to a planetary carrier 236. In one example, the second motor gear 214 is a sun gear. The planetary carrier 236 may be disposed on a planetary shaft 234. The planetary carrier 236 supports the planetary gears connected to the second motor gear 214 and the first planetary gear 238. The planetary carrier 236 may be configured to transfer power from each of the first prime mover 210 and the second prime mover 220 to the planetary shaft 234.

[0021] A second gear 242 may mesh with a first clutch gear 246 of a first clutch 244. The planetary shaft 234 may be directly coupled to a second clutch 250. In one example, the first clutch 244 and the second clutch 250 may be identical clutches, such as wet clutches. Additionally or alternatively, the first clutch 244 and the second clutch 250 may be different types of clutches without departing from the scope of the present disclosure.

[0022] The first clutch 244 may control an output from the first clutch gear 246 to an output shaft 260. The second clutch 250 may control an output from a second clutch gear 248 to a first intermediate shaft gear 262 disposed on the intermediate shaft 260. In one example, the second clutch gear 248 is in meshing engagement with the first intermediate shaft gear 262. The second clutch gear 248 may be disposed on a second clutch shaft 249, which may be engaged with the planetary shaft 234 when the second clutch 250 is engaged.

[0023] When the intermediate shaft 260 rotates due to power transmitted from the planetary gear system through the first clutch 244 or the second clutch 250, a second intermediate shaft gear 264 may rotate and transmit power to a front and / or rear axle. In some examples, the second intermediate shaft gear 264 may additionally or alternatively be coupled to a power transfer case configured to transmit power to each of the front and rear axles.

[0024] In some examples, the second intermediate shaft gear 264 may additionally or alternatively be omitted, and the intermediate shaft 260 may provide output directly to a single axle of the vehicle.

[0025] Dashed lines 290 and 292 illustrate a direction of power through the transmission assembly 200 of the Fig. 2 or 3. A first operating mode is in Fig. 2. A second operating mode is shown in Fig. 3 illustrates.

[0026] During the first operating mode, the second clutch is disengaged and the first clutch is engaged. While the second clutch is disengaged, rotation, and therefore power, is not transferred from the planetary shaft 234 to the second clutch shaft 249. Power from each of the first prime mover 210 and the second prime mover 220 is transferred from the planetary shaft 234 through the first clutch gear 246, through the intermediate shaft 260, and to the front and / or rear axle. Thus, during the first mode, power does not flow through any of the second clutch 250, the second clutch shaft 249, the second clutch gear 248, and the first intermediate shaft gear 262.

[0027] Fig. 3 shows a direction of power flow via dashed lines 292 during the second operating mode. During the second operating mode, the first clutch 244 is disengaged and the second clutch 250 is engaged. When the first clutch 244 is disengaged, rotation of the first clutch gear 246 is not transmitted to the output shaft 260. Power from the first clutch gear 246 is not transmitted to the output shaft 260. Power flows from the first prime mover 210 and the second prime mover 220 through the second clutch shaft 249 via an engaged second clutch 250 to the planetary shaft 234. The second clutch shaft 249 rotates the second clutch gear 248, which is in meshing engagement with the first output shaft gear 262. The first output shaft gear 262 rotates the output shaft 260, on which the second output shaft gear 264 is disposed. The second output shaft gear 264 can transmit power to the differential 270.

[0028] Fig. 4 shows a method 400 for activating and deactivating clutches of a multi-speed transmission in response to operating conditions of one or more prime movers of a vehicle. Instructions for performing the method 400 may be provided by a controller based on instructions stored in a memory of the controller and in conjunction with signals received from sensors of the vehicle system, for example, the system described above with reference to Fig. 1 described in the vehicle system. The controller may use actuators of the vehicle system to adjust operation according to the method described below.

[0029] Method 400 begins at 402, which includes determining whether the vehicle is at a standstill. The vehicle may be at a standstill if a vehicle speed is zero, a brake pedal is depressed, and / or an accelerator pedal is released. If the vehicle is not at a standstill, method 400 may include engaging the second clutch at 404. In one example, the first clutch is disengaged when the second clutch is engaged.

[0030] At 406, method 400 may include flowing power from the first and second prime movers through the second clutch to the first output shaft gear and the differential and / or to a transfer case.

[0031] As shown at 402, if the vehicle is stationary, method 400 may include determining whether motion is requested at 408. Motion may be requested when the brake pedal is released and / or when the accelerator pedal is depressed.

[0032] If movement is not requested, method 400 may include maintaining the vehicle stationary at 410. Then, power is not transferred from the prime movers through the transmission assembly and to the vehicle's wheels.

[0033] If movement is requested, method 400 may include engaging the first clutch at 412. When the first clutch is engaged, the second clutch may be disengaged.

[0034] At 414, method 400 may include flowing power from the first prime mover through the first clutch, which is engaged, to the first clutch gear, to the output shaft, and to the differential / transfer case. In one example, the second prime mover is not outputting power.

[0035] At 416, method 400 may include determining whether a threshold speed is reached. In one example, the threshold speed may be based on a speed at which powertrain efficiency is increased by operating each of the first and second prime movers. Additionally or alternatively, the threshold speed may be based on a speed at which vibrations generated by activating the second prime mover are less than a predetermined value, such that a vehicle occupant may not perceive the vibration.

[0036] If the threshold speed is not reached, method 400 may include maintaining the first clutch engaged and the second clutch disengaged at 418. Additionally or alternatively, only the first prime mover may deliver power to the transmission assembly.

[0037] The disclosure provides support for a multi-speed transmission comprising: a first input shaft coupled to a first prime mover and a first motor gear; a second input shaft coupled to a second prime mover and a second motor gear; a planetary carrier coupled to a planetary shaft via a planetary gear and a first clutch gear meshing with a first clutch, or with a second clutch shaft of a second clutch on which a second clutch gear is disposed; and an output shaft, the first clutch gear disposed on the output shaft, further comprising an output shaft gear disposed on the output shaft and meshing with the second clutch gear. A first example of the transmission further includes the first clutch being engaged when only the first prime mover is operating.A second example of the transmission, optionally comprising the first example, further comprises the second clutch being engaged when the first prime mover and the second prime mover are operating. A third example of the transmission, optionally comprising one or more of the preceding examples, further comprises the first prime mover and the second prime mover being electric machines. A fourth example of the system, optionally comprising one or more of the preceding examples, further comprises the multi-speed transmission being a two-speed transmission. A fifth example of the transmission, optionally comprising one or more of the preceding examples, further comprises the output shaft directly driving a differential of a front axle or a rear axle.

[0038] The disclosure provides additional support for a system comprising: a transmission system coupled to two motors via a first input shaft and a second input shaft, a planetary gear set comprising a plurality of gears, a carrier and a planetary shaft, and a pair of clutches configured to adjust power flow through the transmission system to different ends of an output shaft, wherein a first clutch transfers power from a gear of the planetary gear set to the output shaft and a second clutch transfers power from the planetary shaft to an output shaft gear.A first example of the system further includes a controller having instructions stored in a memory thereof that, when executed, enable the controller to engage the first clutch and disengage the second clutch when a vehicle including the transmission system is moving from a stop, the instructions further enabling the controller to operate only a first motor coupled to the first input shaft. A second example of the system, optionally including the first example, further includes the instructions further causing the controller to engage the second clutch and disengage the first clutch when the vehicle is moving at a threshold speed, the instructions further enabling the controller to operate the first motor coupled to the first input shaft and a second motor coupled to the second input shaft.A third example of the system, optionally including one or more of the preceding examples, further includes where the transmission system is a multi-speed transmission system. A fourth example of the system, optionally including one or more of the preceding examples, further includes where the output shaft is the sole output of the transmission system. A fourth example of the system, optionally including one or more of the preceding examples, further includes where the pair of clutches are wet clutches. A fifth example of the system, optionally including one or more of the preceding examples, further includes where the first clutch includes a first clutch gear in meshing engagement with the gear of the planetary gear set, and wherein the first clutch gear is disposed on the output shaft.A sixth example of the system, optionally including one or more of the preceding examples, further includes the second clutch including a second clutch gear disposed on a second clutch shaft, the second clutch shaft being directly coupled to the planetary shaft and the second clutch gear in a meshing coupling with the output shaft gear. A seventh example of the system, optionally including one or more of the preceding examples, further includes only one of the first clutch and the second clutch being engaged when power is being transferred to the output shaft.

[0039] The disclosure further provides support for a method of operating clutches of a two-speed transmission, comprising: activating a first clutch of the two-speed transmission and flowing power from only a first motor to a planetary shaft of a planetary gear set, to a planetary gear, to a first clutch gear meshing with the planetary gear, and to an output shaft on which the first clutch gear is disposed during a first operation, and activating a second clutch of the two-speed transmission and deactivating the first clutch during a second operation, further comprising flowing power from each of the first motor and a second motor to the planetary shaft of the planetary gear set, to a second clutch shaft coupled to the planetary shaft, to a second gear disposed on the second clutch shaft, and to an output shaft gear disposed on the output shaft.A first example of the method further includes where the first operation includes moving a vehicle including the two-speed transmission from a stop. A second example of the method, optionally including the first example, further includes where the second operation includes moving a vehicle including the two-speed transmission at a threshold speed. A third example of the method, optionally including one or more of the preceding examples, further includes where flowing power further includes flowing power to a differential on an axle with wheels coupled to extreme ends of the axle. A fourth example of the method, optionally including one or more of the preceding examples, further includes where the first motor is an electric machine.

[0040] As used herein, the term “approximately” shall mean plus or minus five percent of the range unless otherwise specified.

[0041] 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 understood as encompassing inclusion of one or more such elements, not as requiring or 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 presenting new claims in this or a related application. Such claims, whether broader, narrower, covering the same or different scope as the original claims, are also considered to be included within the subject matter of the present disclosure.

Claims

[1] Multi-speed gearbox, comprising: a first input shaft coupled to a first prime mover and a first motor gear; a second input shaft coupled to a second prime mover and a second motor gear; a planetary carrier coupled to a planetary shaft which is engaged with a first clutch via a planetary gear and a first clutch gear or which is engaged with a second clutch shaft of a second clutch on which a second clutch gear is arranged; and an output shaft, wherein the first clutch gear is arranged on the output shaft, further comprising an output shaft gear arranged on the output shaft and meshing with the second clutch gear. [2] A multi-speed transmission according to claim 1, wherein the first clutch is engaged when only the first prime mover is operating. [3] A multi-speed transmission according to any one of the preceding claims, wherein the second clutch is engaged when the first prime mover and the second prime mover are operating. [4] Multi-speed transmission according to one of the preceding claims, wherein the first drive machine and the second drive machine are electric machines. [5] Multi-speed transmission according to one of the preceding claims, wherein the multi-speed transmission is a two-speed transmission. [6] Multi-speed transmission according to one of the preceding claims, wherein the output shaft directly drives a differential of a front axle or a rear axle. [7] System comprising: a transmission system coupled to two motors via a first input shaft and a second input shaft; a planetary gear set comprising a plurality of gears, a carrier, and a planetary shaft; and a pair of clutches configured to adjust power flow through the transmission system to different ends of an output shaft, a first clutch transmitting power from a gear of the planetary gear set to the output shaft and a second clutch transmitting power from the planetary shaft to an output shaft gear. [8] The system of claim 7, further comprising a controller having instructions stored in a memory thereof that, when executed, enable the controller to engage the first clutch and disengage the second clutch when a vehicle including the transmission system is moved from a standstill, the instructions further enabling the controller to operate only a first motor coupled to the first input shaft. [9] The system of claim 8, wherein the instructions further cause the controller to engage the second clutch and disengage the first clutch when the vehicle is moving at a threshold speed, wherein instructions further enable the controller to operate the first motor coupled to the first input shaft and a second motor coupled to the second input shaft. [10] System according to one of claims 7 to 9, wherein the transmission system is a multi-speed transmission system. [11] A system according to any one of claims 7 to 10, wherein the output shaft is the sole output of the transmission system. [12] A system according to any one of claims 7 to 11, wherein the pair of clutches are wet clutches. [13] The system of any one of claims 7 to 12, wherein the first clutch comprises a first clutch gear in meshing engagement with the gear of the planetary gear set, and wherein the first clutch gear is disposed on the output shaft. [14] The system of any one of claims 7 to 13, wherein the second clutch comprises a second clutch gear disposed on a second clutch shaft, the second clutch shaft being directly coupled to the planetary shaft and the second clutch gear being in meshing engagement with the output shaft gear. [15] A system according to any one of claims 7 to 14, wherein only one of the first clutch and the second clutch is engaged when power is transmitted to the output shaft.

Images