Systems for a gearbox

Abstract

Arrangement, comprehensive: a first motor (102) which is arranged on a first shaft (104); a second motor (106) which is arranged on a second shaft (108); a first wet clutch (122) which is optionally coupled to the first shaft (104); a second wet clutch (124) which is optionally coupled to an output shaft (130); a third wet clutch (126) that meshes with the output shaft (130); a brake clutch (128) which is attached to a housing (190) of the arrangement; a planetary gear set (134) comprising a sun gear (136) arranged on the second shaft (108), a planet carrier (138) which meshes with the second wet clutch (124) and is optionally coupled with the third wet clutch (126), and a ring gear (140) which is optionally coupled with the brake clutch (128) and meshes with the first wet clutch (122); and a first one-way coupling (142) and a second one-way coupling (148) which is opposite to the first one-way coupling (142), wherein the first one-way coupling (142) and the second one-way coupling (148) are optionally coupled to the first shaft (104) and are engaged with a gear train (146, 150) to drive an auxiliary shaft (144).

Description

TECHNICAL FIELD

[0001] This description generally refers to systems for a transmission with two motors and two gears. GENERAL STATE OF THE ART AND OVERVIEW

[0002] Heavy-duty off-road vehicles may require higher (or lower) drive speed, traction, or PTO function depending on the application. Conventional heavy-duty off-road vehicles with internal combustion engines often combine PTO functionality and propulsion, with power being directed to the PTO, split between the drive shaft and PTO, or transmitted to the drive shaft only by engaging one or more clutches. In contrast, heavy-duty electric-powered off-road vehicles typically use separate motors for PTO function and propulsion.

[0003] The inventors have identified potential problems with such systems. Electrified transmissions with PTO functionality require energy management to ensure that sufficient energy is available to drive the PTO while also meeting the energy demands of the rest of the vehicle. This can be particularly challenging in heavy-duty applications where the PTO consumes a lot of power. Likewise, the power requirements to drive the PTO and the rest of the vehicle can vary depending on the application, e.g., loader, dozer, etc. For example, some applications may require high power for shorter periods of time. Another example is that some applications require relatively high load variability and load duration depending on the work.Configurations with a PTO motor separate from the drive motor may lack the flexibility to meet a variety of off-road and heavy-duty applications.

[0004] In one example, the problems described above may be solved by an assembly including a first motor on a first shaft, a second motor on a second shaft, a first wet clutch selectively coupled to the first shaft, a second wet clutch selectively coupled to an output shaft, a third wet clutch meshing with the output shaft, a brake clutch fixed to a housing of the assembly, a planetary gear set including a sun gear disposed on the second shaft, a planet carrier meshing with the second wet clutch and selectively coupled to the third wet clutch, and a ring gear selectively coupled to the brake clutch and engaged with the first wet clutch.The assembly further comprises a first one-way clutch and a second one-way clutch opposite the first one-way clutch, the first one-way clutch and the second one-way clutch being selectively coupled to the first shaft and meshing with a gear train for driving an auxiliary shaft. Thus, an electric transmission with three wet clutches and a brake clutch for shifting between two motors and / or two gears, as well as two one-way clutches for driving a power take-off shaft via the first motor, can be used for various applications.

[0005] It should be understood that the above outline is provided to introduce, in simplified form, a selection of concepts further described in the detailed description. It is not intended to identify critical or essential features of the claimed subject matter, the scope of which is defined only by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages noted above or elsewhere in this disclosure. Short description of the drawings

[0006] The present disclosure will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, which are set out below: Fig. 1 shows a dual-motor transmission with a power take-off (PTO); Fig. 2 shows a table of operating modes for the dual motor gearbox; Fig. 3 shows a first power path of the dual motor transmission in a first gear, in single motor mode; Fig. Figure 4 shows a second power path of the dual motor transmission in a second gear, in single motor mode; Fig. Figure 5 shows a third power path of the dual motor transmission in first gear, in dual motor mode; Fig. Figure 6 shows a fourth power path of the dual motor transmission in second gear, in dual motor mode; Fig. Figure 7 shows a first example of the power supply to the PTO and to the drive wheels in first gear forward mode, in dual motor mode; Fig. Figure 8 shows a second example of power transmission to the PTO and to the drive wheels in reverse first gear mode, in dual engine mode; Fig. 9 shows a configuration of the dual motor transmission with long gradient power take-off; Fig. 10 is a flowchart illustrating a first example method for operating mode and gear selection in a dual motor transmission; Fig. 11 is a flowchart illustrating an example method for transitioning between a first gear and a second gear in a single motor mode in a dual motor transmission; Fig. 12 is a flowchart illustrating an example method for transitioning between a single motor mode in first gear and a dual motor mode in first gear in a dual motor transmission; Fig. 13 is a flowchart illustrating an example method for transitioning between a single motor mode in a second gear and a dual motor mode in a second gear in a dual motor transmission; Fig. 14 is a flowchart illustrating an example method for transitioning between a first gear and a second gear in dual motor mode in a dual motor transmission; Fig. 15 is a flowchart illustrating an example of a method for setting a PTO mode and gear selection in a dual-motor transmission; Fig. 16 is a flowchart illustrating an example method for transitioning between a dual motor mode in a second gear and a single motor mode in a first gear, or between a single motor mode in a second gear and a dual motor mode in a first gear in a dual motor transmission; Fig. Figure 17 shows a timing diagram illustrating a first prophetic example of the operation of a dual motor transmission; Fig. 18 shows a timing diagram illustrating a second prophetic operation example of the disclosed dual motor transmission; Fig. Figure 19 is a diagram illustrating the relationship between torque, speed and power in an electric transmission; Fig. 20 is a diagram illustrating an operating example of the disclosed dual motor transmission; and Fig. 21 shows a table of shift modes for the dual motor transmission. Detailed description

[0007] The following description relates to systems and methods for an electric transmission. The electric transmission includes two electric motors, two gears with a planetary gear set, and a plurality of wet clutches for shifting between three operating modes and two gears. A first motor is provided for one or both of traction operation and power take-off operation, and a second motor is provided for traction operation. The two motors can be used together to achieve high tractive effort at low speeds (e.g., less than 5 km / h) or high speeds (e.g., in the range of 25 to 50 km / h) with relatively low tractive effort. In some applications, motor power can be reduced with pure electrification compared to motors used in transmissions with one or more internal combustion engines for driving drive wheels.In other applications, continuous engine power can be generated with similarly sized engines, e.g., by generating peak power over shorter periods of time from the first engine and high power over longer periods of time from both the first and second engines. This allows the system to reduce the conflict between the engine's peak power time and uncontrollable off-road operation.

[0008] An example of a dual motor transmission with power take-off (PTO) is shown in Fig. 1. The dual-motor transmission can be controlled in three modes and two gears. A table with the three operating modes, two gears, and clutches for selecting between the operating modes and gears is shown in Fig. 2. Depending on the operating mode and the selected gear, a power path runs from the first motor to a first shaft and from the second motor to a second shaft, via a planetary gear set and to a drive axle. In one example, a first mode (here also a normal mode and a single-motor drive mode) may include controlling the second motor to generate power for traction operation and controlling the first motor to generate power for PTO operation. The power path through the dual-motor transmission in a first gear of the first operating mode is shown in Fig. 3. The power path through the dual motor transmission in a second gear of the first mode is shown in Fig. 4. A second mode of operation may include controlling the first and second motors to generate power for high-traction propulsion and controlling the first motor to generate power for PTO operation. The power path through the dual-motor transmission in a first gear of the second mode is shown in Fig. 5. The power path through the dual motor transmission in a second gear of the second mode is shown in Fig. 6 shown. Fig. Figure 7 shows an example power path to the PTO and drive axle in first gear of dual motor mode to drive the dual motor transmission in the forward direction, and Fig. Figure 8 shows an example power path to the PTO and drive axle in first gear of the dual-motor mode to drive the dual-motor transmission in reverse. A third mode may include engaging clutches of the transmission to apply a parking brake. The dual-motor transmission may be used as a short downgrade, as shown in Fig. 1, or as a long gradient, as in Fig. 9 shown, be configured.

[0009] The dual motor gearbox can be controlled to switch between different operating modes. A table of switching modes is provided with reference to Fig. 21. An example of a control procedure for selecting operating modes and gears for the dual motor transmission is described in Fig. 10 shown. Fig. 11 shows an example method of operating the dual motor transmission to shift between first and second gears in single motor drive mode. Fig. 12 shows an example method of operating the dual motor transmission to switch between single motor drive and dual motor drive in first gear. Fig. 13 shows an example method of operating the dual motor transmission to switch between single motor drive and dual motor drive in second gear. Fig. 14 shows an example method of operating the dual motor transmission to shift between first and second gears in dual motor drive mode. Fig. 15 shows an example of a method for operating the dual motor transmission to adjust PTO operation. Fig. Figure 16 is a timeline illustrating a first prophetic operating example of the disclosed dual-motor transmission. In the first prophetic example, the dual-motor transmission is controlled to shift between first and second gears in the first operating mode and to actuate a power take-off device. Fig. Figure 17 is a timeline illustrating a second prophetic example of operation of the disclosed dual-motor transmission. In the second prophetic example, the dual-motor transmission is controlled to shift between single-motor drive and dual-motor drive in first gear and to actuate a power take-off device. Fig. Figures 19-20 are diagrams illustrating the advantages of the dual motor transmission.

[0010] The dual-motor transmission described here can represent a single package for an electrified transmission for off-highway vehicles, PTO, and charge pump. The two-speed options described here can receive power from the first motor (e.g., set up to generate power for the PTO) during dual-motor drive mode, which can be suitable for high power requirements in both gears. When the vehicle is stationary, the eVT mode described here releases the decoupling of the PTO motor (e.g., controlled by a first inverter) from the second motor (e.g., controlled by a second inverter). This allows the PTO motor (e.g., the first motor) to provide power to drive the traction force while the pumps can operate normally. In addition, the dual-motor transmission includes a bidirectional PTO transmission that provides unidirectional drive to the pump during PTO reversal to power the drive motor (e.g.,the second motor) which provides the required power during forward and reverse operation.

[0011] Fig. 1 shows an example configuration for a dual-motor transmission 100 for a vehicle 101. The vehicle 101 may be a heavy-duty vehicle, such as a bulldozer, loader, garbage truck, excavator, hay baler, and so on. In one example, the dual-motor transmission 100 includes a first motor 102 mounted on a first shaft 104 (e.g., a first motor output shaft) and a second motor 106 mounted on a second shaft 108 (e.g., a second motor output shaft). The speed and direction of the first motor 102 are controlled by a first inverter 110, and the speed and direction of the second motor 106 are controlled by a second inverter 112. The first motor 102 and the second motor 106 may include conventional components such as a stator, a rotor, a rotor shaft, and the like to enable the electric motors to generate mechanical power and electrical energy.The first motor 102 and the second motor 106 may be supplied with electrical energy from a battery 178 via the first inverter 110 and the second inverter 112, respectively, to transmit torque to a drive axle 130. In some examples, the first motor 102 and the second motor 106 may supply electrical energy to the battery 178, for example, when the first motor 102 and the second motor 106 are configured for regeneration. An axis of rotation 114 of the first motor 102, shown as dashed lines, is coaxial with the first shaft 104. An axis of rotation 116 of the second motor 106, shown as dashed lines, is coaxial with the second shaft 108. A rotation axis 115 of the drive axle 130 is shown in dashed lines. In one example, the rotation axis 114, the rotation axis 116 and the rotation axis 115 are arranged in parallel.

[0012] The dual-motor transmission 100 includes a plurality of clutches for switching between operating modes and speeds. The plurality of clutches includes a first wet clutch 122 disposed about and selectively coupled to the first shaft 104, a second wet clutch 124 disposed about and selectively coupled to the drive axle 130 (e.g., an output shaft), a third wet clutch 126 engaged with the drive axle 130, and a brake clutch 128 mounted to a housing 190.

[0013] The first motor 102 and the second motor 106 are selectively coupled to the drive axle 130 via a gear train 132 including a planetary gear set 134, a plurality of drive gears, and a plurality of output gears. The planetary gear set 134 includes a sun gear 136 on the second shaft 108, a planet carrier 138 engaged with the second wet clutch 124 and selectively coupled to the third wet clutch 126, and a ring gear 140 selectively coupled to the brake clutch 128 and engaged with the first wet clutch 122. The first wet clutch 122 is operable to selectively engage the first shaft 104 with the planetary gear set 134 via a first drive gear 154. The second wet clutch 124 can be actuated to selectively connect the drive axle 130 to the planetary gear set 134 via a second drive gear 160.The third wet clutch 126 is operable to selectively engage the second shaft 108 with the drive axle 130 via a gear set 157 including a third drive gear 156 and a first output gear 158. The brake clutch 128 is operable to selectively connect the second shaft 108 to the drive axle 130 via the planetary gear set 134 and the second wet clutch 124 or the third wet clutch 126. The drive axle 130 may be connected to the drive gears (not shown) via a first output flange 164.

[0014] Two opposing one-way clutches selectively couple an auxiliary shaft to the first shaft 104. In the dual-motor transmission 100 described here, the auxiliary shaft is a PTO shaft coupled to a power take-off shaft 152. A rotational axis 145 of the PTO shaft 144 is shown in dashed lines. A first one-way clutch 142 selectively couples the first shaft 104 to the PTO shaft 144 via a first gear train 146. A second one-way clutch 148 couples the PTO shaft 144 via a second gear train 150. The first one-way clutch 142 and the second one-way clutch 148 are arranged coaxially to the first shaft 104. The first motor 102 is selectively mechanically coupled to the PTO shaft 152 via the PTO shaft 144 by actuating either the first one-way clutch 142 or the second one-way clutch 148. The PTO shaft 152 can be driven clockwise or counterclockwise by the rotation of the first motor 102.In one example, when driven counterclockwise, the power path from the first engine 102 is from the first shaft 104 through the first one-way clutch 142 via the first gear train 146 to the PTO shaft 152. When driven clockwise, the power path from the first engine 102 is from the first shaft 104 through the second one-way clutch 148 via the second gear train 150 to the PTO shaft 152. The first gear train 146 includes a first PTO drive gear 168 engaged with a first PTO driven gear 170. The second gear train 150 includes a second PTO drive gear 172 connected to a second PTO drive gear 174 via an idler shaft 176.

[0015] The dual motor transmission 100 may be electronically (e.g., wirelessly or wired) connected to a controller 180. The controller 180 may include a processor 182 operatively connected to a memory 184. The memory 184 may be a non-transitory, computer-readable medium and may be configured to store executable instructions (e.g., computer-executable code) that are processed by the processor 182 to perform one or more control methods, such as the Fig. 10 and additional methods related to the Fig. 11-16. Memory 184 may also be configured to store the data received from processor 182.

[0016] The controller 180 receives signals from a plurality of sensors 186 and deploys a plurality of actuators 188 to adjust system operation based on the received signals and the instructions stored in the controller's memory 184. The sensors 186 may include engine speed sensors, shaft and gear speed sensors, current sensors, temperature sensors, humidity sensors, etc., for monitoring the dual-motor transmission 100. As another example, an input device 199 (e.g., accelerator pedal, brake pedal, gear selector, joystick, combinations thereof, etc.) may further provide input signals indicating the driver's intent for vehicle control.

[0017] After receiving the signals from the sensors 186 from Fig. 1, the controller 180 processes the received signals and utilizes the actuators 188 of the vehicle components to adjust the components based on the received signals and the instructions stored in the memory 184 of the controller 180. For example, the controller 180 may receive a signal from the input device 199 indicating an operator request for a vehicle acceleration adjustment. The controller 180 may then command operation of the second motor 106 to increase the power delivered by the second motor 106 to the drive axle 130. The controller 180 may be configured to send commands to the plurality of clutches under certain operating conditions and, in response, to use clutch actuators to engage or disengage selected gears. For example, commands may be stored in the memory of the controller 180 that, when executed, cause the controller to select an operating mode, e.g.,an operating gear, and based on the selected operating mode, the controller may adjust one or more of the first wet clutch 122, the second wet clutch 124, the third wet clutch 126, or the brake clutch 128. The clutch actuators may include a first wet clutch actuator 122a for controlling a position of the first wet clutch 122, a second wet clutch actuator 124a for controlling a position of the second wet clutch 124, a third wet clutch actuator 126a for controlling a position of the third wet clutch 126, and a brake clutch actuator 128a for controlling a position of the brake clutch 128. The clutch actuators may further include a first one-way clutch actuator 142a for controlling a position of the first one-way clutch 142 and a second one-way clutch actuator 148a for controlling a position of the second one-way clutch 148.The controller 180 may determine the clutch position based on signals sent via a first wet clutch position sensor 122b for sensing the position of the first wet clutch 122, a second wet clutch position sensor 124b for sensing the position of the second wet clutch 124, a third wet clutch position sensor 126b for sensing the position of the third wet clutch 126, a brake clutch position sensor 128b for sensing the position of the brake clutch 128, a first one-way clutch position sensor 142b for sensing the position of the first one-way clutch 142, and a second one-way clutch position sensor 148b for sensing the position of the second one-way clutch 148. The other controllable components in the vehicle 101 may function in a similar manner, e.g., with respect to sensor signals, control commands, and actuator adjustment.As another example, the controller 180 may automatically adjust one or more clutch actuators based on signals from one or more traction sensors for monitoring wheel traction.

[0018] Fig. 2 shows a table 200 showing the operating modes of the disclosed transmission, such as the one with reference to Fig. 1. In one example, the clutches may be the same as or similar to the first wet clutch 122, the second wet clutch 124, the third wet clutch 126, and the brake clutch 128. The motors may be the first motor 102 and the second motor 106.

[0019] Table 200 illustrates example operating modes that may be implemented by engaging one or more clutches. In one example, the modes may use one or both motors to implement a first or second gear ratio. The first gear may drive an output shaft (e.g., drive axle 130) in a forward (F1) or reverse (R1) direction, and the second gear may drive the output shaft in a forward (F2) or reverse (R2) direction. The second gear ratio may be higher than the first. In one example, the modes include a first mode using a single motor to drive the drive axle and a second mode using two motors to drive the drive axle. The modes may also include a third mode in which a parking brake is engaged. In some embodiments, the third mode may not use either motor.A solid box indicates that the clutch is engaged with the corresponding shaft (e.g., first shaft 104, drive shaft 130) or housing (e.g., housing 190). An open box indicates that the clutch is disengaged from the corresponding shaft or housing.

[0020] The first mode of operation represents a single-motor drive configuration (e.g., normal) in which the second motor 106 generates the tractive effort for propulsion. In one example, the first mode of operation may be implemented in first gear by actuating the brake clutch 128 and the second wet clutch 124 to engage the second shaft 108 with the drive axle 130 via the planetary gear set 134 and the second drive gear 160. The first mode of operation in second gear may be implemented by actuating the third wet clutch 126 and the brake clutch 128 to connect the second shaft 108 with the drive axle 130 via the planetary gear set 134 and the gear pair 157. The second mode of operation is a dual-motor eVT mode and may operate in first or second gear.In one example, the second mode of operation may be implemented in first gear by actuating the first wet clutch 122 and actuating the second wet clutch 124 to engage the first shaft 104 and the second shaft 108 with the drive axle 130 via the planetary gear set 134 and the second drive gear 160. The second mode of operation in second gear may be implemented by actuating the first wet clutch 122 and the third wet clutch 126 to engage the first shaft 104 and the second shaft 108 with the drive axle 130 via the planetary gear set 134 and the gear set 157. In the third mode of operation, the parking brake is activated, which may prevent the drive wheels connected to the drive axle 130 from rotating. In one example, the third mode of operation includes actuating the second wet clutch 124 and the third wet clutch 126 to connect the drive axle 130 to the planetary gear set 134 and the third drive gear 160, respectively.to connect the second shaft 108 to the drive axle 130 via the gear pass 157.

[0021] Fig. 3 shows a first operation 300 of the dual motor transmission 100. The first operation 300 may be the same as or similar to the configuration of the first gear transmission in the first mode, which may be described with reference to the table 200 in Fig. 2. The first operation represents a single-motor drive configuration (e.g., normal), in which the second motor 106 generates the traction for driving in first gear. In the first operation 300 of the dual-motor transmission 100, the brake clutch 128 attached to the housing 190 is actuated to couple the ring gear 140 thereto. In addition, the second wet clutch 124, which engages the planetary carrier 138, is actuated to couple the drive axle 130 thereto. When the brake clutch 128 and the second wet clutch 124 are engaged, a power path 302 runs from the second motor 106 via the second shaft 108 and through the planetary gear set 134 to the drive axle 130 via the second drive gear 160. Specifically, the power path 302 runs from the sun gear 136 to the planet carrier 138, from the planet carrier 138 to the directly coupled second drive gear 160, and from the second drive gear 160 via the engagement of the second wet clutch 124 to the drive axle 130.

[0022] Fig. 4 shows a second operation 400 of the dual motor transmission 100. The second operation 400 may be the same as or similar to the configuration of the transmission in second gear of the first operating mode, which is described with reference to the table 200 in Fig. 2. The second operation 400 represents a single-motor drive configuration in which the second motor 106 generates the tractive power for driving in second gear. In the second actuation 400 of the dual-motor transmission 100, the brake clutch 128, which is fixedly connected to the housing 190, is actuated to couple the ring gear 140 thereto. Furthermore, the third wet clutch 126, which engages the drive axle 130 via the gear coupling 157, is actuated to couple the second shaft 108 thereto. With the brake clutch 128 and the third wet clutch 126 actuated, a power path 402 extends from the second motor 106 through the second shaft 108, through the planetary gear set 134, and via the gear coupling 157 to the drive axle 130.Specifically, the power path 402 runs from the sun gear 136 to the planet carrier 138, from the planet carrier 138 to the first driven gear 158 of the gear set 157 via the engagement of the third wet clutch 126, and from the first driven gear 158 to the drive axle 130 via the third drive gear 156.

[0023] Fig. 5 shows a third operation 500 of the dual motor transmission 100. The third operation 500 may be the same as or similar to the configuration of the transmission in first gear of the second mode, which can be determined with reference to the table 200 in Fig. 2. The third operation 500 represents a dual motor drive configuration in which the first motor 102 and the second motor 106 generate traction for first gear driving, also referred to herein as dual motor drive mode.

[0024] In the third operation 500 of the dual-motor transmission 100, the first wet clutch 122 is actuated to connect the first shaft 104 to the ring gear 140 of the planetary gear set 134. Additionally, the second wet clutch 124, which meshes with the planetary carrier 138, is actuated to couple the drive axle 130 thereto. When the first wet clutch 122 and the second wet clutch 124 are actuated, a power path 502 extends from the first motor 102 through the first shaft 104 and the planetary gear set 134. The power path 502 extends from the second motor 106 through the second shaft 108 and through the planetary gear set 134. From the planetary gear set 134, the power path 502 extends to the drive axle 130 via the second drive gear 160.Specifically, the power path 502 runs from the first motor 102 through the first shaft 104 and through the ring gear 140 via the engagement of the first wet clutch 122 into the first shaft 104 and via the first drive gear 154, which engages the ring gear 140 and the first wet clutch 122, and from the ring gear 140 to the planetary carrier 138. The power path 502 continues from the second motor 106 via the second shaft 108 to the sun gear 136 and from the sun gear 136 to the planetary carrier 138. The power path 502 continues from the planetary carrier 138 to the second drive gear 160, which is directly coupled thereto, and from the second drive gear 160 via the engagement of the second wet clutch 124 to the drive axle 130.

[0025] Fig. 6 shows a fourth operation 600 of the dual motor transmission 100. The fourth operation 600 may be the same or similar to the configuration of the transmission in the second mode in second gear, which is described with reference to the table 200 in Fig. 2. The fourth operation 600 represents a dual-motor drive configuration in which the first motor 102 and the second motor 106 generate traction for second-gear propulsion, also referred to herein as a dual-motor drive mode. In the fourth operation 600, the first wet clutch 122 is actuated to connect the first shaft 104 to the ring gear 140 of the planetary gear set 134. Further, the third wet clutch 126, which meshes with the drive axle 130 via the gear mate 157, is actuated to couple the second shaft 108 thereto. When the first wet clutch 122 and the third wet clutch 126 are engaged, a power path 602 runs from the first motor 102 through the first shaft 104 and through the planetary gear set 134. The power path 602 runs from the second motor 106 through the second shaft 108 and through the planetary gear set 134. The power path 602 leads from the planetary gear set 134 via the gear set 157 to the drive axle 130.Specifically, the power path 602 runs from the first motor 102 through the first shaft 104 and through the ring gear 140 via the engagement of the first wet clutch 122 with the first shaft 104 and via the first drive gear 154, which is engaged with the ring gear 140 and the first wet clutch 122, and from the ring gear 140 to the planetary carrier 138. The power path 502 continues from the second motor 106 via the second shaft 108 to the sun gear 136 and from the sun gear 136 to the planetary carrier 138. The power path 502 continues from the planetary carrier 138 to the first driven gear 158 of the gear set 157 via the engagement of the third wet clutch 126 and from the first driven gear 158 to the drive axle 130 via the third drive gear 156.

[0026] Fig. 7 and Fig. 8 show a first example 700 and a second example 800, respectively, illustrating the power paths to the PTO 152 and the drive axle 130 for the dual motor transmission 100. The first example 700 and the second example 800 both show a dual motor drive mode (e.g., the second mode) in a first gear, such as the eVT dual motor mode described with reference to FIG. Fig. 2 and Fig. 5 is described.

[0027] The first example 700 illustrates a configuration of a powertrain that allows the drive wheels coupled to the drive axle to rotate and propel the vehicle in a forward direction. For example, a first gear forward mode and a dual motor mode may be requested by user input and / or based on transmission operating conditions. To drive the drive axle 130 in a forward direction, the first inverter 110 may control the first motor 102 to rotate counterclockwise (CCW), and the second inverter 112 may control the second motor 106 to rotate clockwise (CW). When the first wet clutch 122 and the second wet clutch 124 are actuated, a power path 702 extends from the first motor 102 to the drive axle 130 via the engagement of the first shaft 104 with the planetary gear set 134 and the engagement of the planetary gear set 134 with the drive axle 130.The power path 702 continues from the second engine 106 to the drive axle 130 via the engagement of the second shaft 108 with the planetary gear set 134 and the engagement of the planetary gear set 134 with the drive axle 130. To operate the PTO 152 at a first power level, with the first engine 102 rotating counterclockwise, the first one-way clutch 142 is actuated. A power path 704 leads from the first engine 102 via the first one-way clutch 142 and the first gear train 146 to the PTO 152 and drives the PTO 144 and its connected PTO 152 in a clockwise direction.

[0028] The second example 800 shows a configuration of a power path that allows drive wheels coupled to the drive axle to rotate and propel the vehicle in the reverse direction (e.g., opposite to the direction shown in Fig. 7). For example, in dual-motor mode, first gear reverse may be requested by user input and / or based on transmission operating conditions. To drive drive axle 130 in the reverse direction, first inverter 110 may control first motor 102 to rotate clockwise, and second inverter 112 may control second motor 106 to rotate counterclockwise. When the first wet clutch 122 and the second wet clutch 124 are actuated, a power path 802 extends from the first motor 102 to the drive axle 130 via the engagement of the first shaft 104 with the planetary gear set 134 and the engagement of the planetary gear set 134 with the drive axle 130. The power path 802 continues from the second motor 106 to the drive axle 130 via the engagement of the second shaft 108 with the planetary gear set 134 and the engagement of the planetary gear set 134 with the drive axle 130.To operate the PTO 152 at a second power level while the first engine 102 rotates clockwise, the second one-way clutch 148 is actuated. A power path 804 extends from the first engine 102 through the second one-way clutch 148 and the second gear train 150 to the PTO 152, driving the PTO 144 and the connected PTO 152 in a clockwise direction.

[0029] In this way, by operating one of the first one-way clutch 142 and the second one-way clutch 148, depending on the rotation direction of the first motor 102, the PTO shaft 152 of the first motor 102 can be rotated clockwise or counterclockwise. Furthermore, in the dual-motor drive mode of the first example 700 and the second example 800, where high tractive effort is required, some of the power of the first inverter 110 can be combined with the power of the second inverter 112, which can reduce the load on the second inverter 112 during high tractive effort. Furthermore, the dual-motor transmission configurations described herein allow for high tractive effort and high PTO power simultaneously, allowing the first motor 102 and the second motor 106 to briefly overload the first inverter 110.

[0030] Fig. 9 shows a second configuration example 900 for a dual-motor transmission. The second example configuration 900 may be an example configuration of the dual-motor transmission 100 for the vehicle 101 of Fig. 1. The double motor gearbox 100 from Fig. 1 shows a short-drop arrangement, and the second example configuration 900 includes elements of the dual-motor transmission 100 that are not repeated here for brevity. The second example configuration 900 is a long-drop arrangement in which the second wet clutch 124 is selectively coupled to a third axle 902 and the third wet clutch 126 engages the third axle 902 via the gear mate 157, which includes the third drive gear 156 and the first driven gear 158. The third axle 902 is coupled to a drive axle 904 via a second gear mate 906, which includes a fourth drive gear 908 and a second driven gear 910. The drive axle 904 may be coupled to drive gears (not shown) via a first output flange 912 and a second output flange 914. The long gradient arrangement described here can provide additional control of the power delivery to the drive wheels.Compared to the short-long drop arrangement where the drive gears are arranged coaxially with the second wet clutch 124, the additional gears (e.g., the fourth drive gear 908 and the second output gear 910) coupling the third axle 902 to the drive axle 904 can increase or decrease the gear ratio therebetween. Additionally or alternatively, in some embodiments, additional gears and / or clutches may be arranged on and / or selectively coupled to the drive axle 904 to further control the performance of the dual-motor transmission.

[0031] A dual motor gearbox can be a flexible platform in an integrated gearbox that can accommodate either a short case, as in Fig. 1, or a long slope, as in Fig. 9 described. Flexible shift modes can simplify complex control. Furthermore, not all clutches described here can be used in different vehicle applications. For example, the number of clutches or the number of operating modes may depend on the application and the tuning results of the transmission. Reducing the number of clutches to a minimum to achieve the gears and operating modes described here can increase the efficiency of the transmission. In some embodiments, the transmission may use an external rotor motor, such as a SUMO MD / HD torque motor, which operates at low speeds, resulting in lower drag torque, to further increase the efficiency of the transmission. Overall, the dual-motor transmission described here offers four shift modes in one integrated transmission (e.g.normal gear at the same power, gear change in eVT mode and gear change at the same power between normal and eVT mode) and two optional gradient arrangements (e.g., a short gradient and a long gradient).

[0032] The dual-motor transmission 100 may have a variety of shift modes. In one example, a first shift mode may include a normal powershift within the first mode (e.g., single-motor drive) between first and second gears. The transmission may provide increased traction in single-motor drive by shifting from second gear to first gear and increased speed in single-motor drive by shifting from first gear to second gear. A second shift mode may include a powershift to increase and / or decrease power in the high-traction gear (e.g., first gear). For example, the transmission may increase and / or decrease power by shifting between single-motor drive and dual-motor drive. A third shift mode may include a powershift to increase and / or decrease power in the high-speed gear (e.g., second gear).The third shift mode may, for example, include shifting between single-motor drive in second gear and dual-motor drive in second gear. A fourth shift mode may include a high-load shift in the second mode (e.g., dual-motor drive mode). For example, the transmission may provide more tractive effort in dual-motor drive by shifting from second to first gear and may provide more speed in dual-motor drive by shifting from first to second gear. A fifth shift mode may be a variable-power, variable-tractive effort shift mode, where the transmission can adjust both power and speed by shifting between dual-motor drive mode in first gear and single-motor drive mode in second gear, or between single-motor drive mode in first gear and dual-motor drive mode in second gear.

[0033] Table 2100 in Fig. Figure 21 contains a summary of the shift modes. The drive modes are listed as column and row headings, and the clutches that are applied during a shift therebetween are provided at an intersection of a column and a row. A corresponding number is provided in Table 2100 for each shift mode. For example, shifting between a first-gear single-motor drive mode and a second-gear single-motor drive mode involves the actuation of the second wet clutch, the third wet clutch, and the brake clutch, with the second wet clutch and the brake clutch engaged in the first-gear single-motor drive mode and the third wet clutch and the brake clutch engaged in the second-gear single-motor drive mode, as shown in Fig. 11. The blacked-out blocks include the switching modes shown elsewhere in Table 2100.

[0034] The disclosed transmission offers flexible shift modes (e.g., the first shift mode, the second shift mode, etc.) that can simplify control strategies. In the first shift mode, for example, the control strategy may include shifting between first and second gears in single-motor drive and vice versa, but not switching power. In some examples, the disclosed transmission may be configured to include the two wet clutches, the first wet clutch, and the brake clutch for most heavy-duty applications. In other examples, the disclosed transmission may include fewer clutches and be tailored to the particular vehicle application. In some examples, a smaller number of clutches may increase efficiency in certain applications. Example control strategies for the transmission described above are described in the Fig. 10-16 are described in more detail.

[0035] Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15 and Fig. 16 are flowcharts illustrating a method 1000, a method 1100, a method 1200, a method 1300, a method 1400, a method 1500, and a method 1600, respectively, for a dual motor transmission with a power take-off shaft. For example, method 1000 and the other methods described herein correspond to an operating method of the Fig. 1-9. The method 1000 shows an example strategy for transitioning between operating modes, such as those shown in Fig. 2. Methods 1100-1400 and 1600 describe example strategies for shifting between gears or power levels within shift modes, such as those described in Fig. 2. Method 1500 describes an example strategy for adjusting PTO operation. In some examples, methods 1000-1600 may be performed in an example of the disclosed transmission that implements the methods described with reference to Fig. 1, such as the first wet clutch 122, the second wet clutch 124, the third wet clutch 126, the brake clutch 128, the first one-way clutch 142, and the second one-way clutch 148 for the broadest applications. In other examples, the methods 1000-1600 may be performed by an example of the disclosed transmission that includes, for example, a subset of the above-mentioned clutches and is configured for a narrower application. Instructions for performing the method 1000 and the other methods described herein may be executed 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, such as those described above with reference to Fig. 1. The controller may use actuators of the vehicle system to adjust transmission operation according to the method described below. Examples of actuators are actuators 188, the first wet clutch actuator 122a, the second wet clutch actuator 124a, the third wet clutch actuator 126a, the brake clutch actuator 128a, the first one-way clutch actuator 142a, and the second one-way clutch actuator 148a described above with respect to Fig. 1 were described.

[0036] In Fig. 10 illustrates a general strategy for operating mode and gear selection in the disclosed dual-motor transmission in method 1000. At 1002, method 1000 determines the operating conditions. The operating conditions may include the position of the input device (e.g., shift lever position, accelerator pedal position, etc.), clutch configuration, vehicle speed, vehicle load, transmission load, engine speed, ambient temperature, etc. The operating conditions may be determined using sensor inputs, modeling, lookup tables, and / or other suitable techniques.In one example, a clutch configuration may be determined via inputs from one or more clutch sensors, such as the first wet clutch position sensor 122b, the second wet clutch position sensor 124b, the third wet clutch position sensor 126b, the brake clutch position sensor 128b, the first one-way clutch position sensor 142b, and the second one-way clutch position sensor 148b, described above with respect to . Fig. 1 were described.

[0037] At 1004, method 1000 determines whether an adjustment of the operating mode is desired. This determination may be made automatically based on engine speed, accelerator pedal position, brake pedal position, vehicle speed, vehicle load, etc. Alternatively, this determination may be made in response to operator interaction with a gear selector, such as the one described above with respect to Fig. 1 described input device 199.

[0038] If an adjustment of the operating mode is not desired, the method 1000 proceeds to 1022. If an adjustment of the operating mode is desired, the method 1000 proceeds to 1006. At 1006, the method 1000 selects an operating mode based on the operating conditions of the vehicle. For example, one of the three operating modes listed in table 200 in Fig. 2. For example, under conditions where more traction is desired, the transmission may shift to a mode in first gear, such as dual-motor first gear mode or normal first gear mode. In situations where higher vehicle speed is desired, the transmission may shift to a mode in second gear, such as dual-motor second gear mode or normal second gear mode. In situations where vehicle movement is not desired, the transmission may shift to parking brake mode.

[0039] At 1008, method 1000 relates to the clutch configuration for normal first gear: activating the brake clutch and the second wet clutch to connect the second motor to the drive axle via the planetary gear set. At 1010, method 1000 relates to the clutch configuration for normal second gear: activating the brake clutch and the third wet clutch to connect the second motor to the drive axle via the planetary gear set. At 1012, method 1000 relates to the clutch configuration for dual-motor first gear: activating the first wet clutch and the second wet clutch to connect the first motor and the second motor to the drive axle via the planetary gear set.At 1014, method 1000 relates to the clutch configuration for second gear with two motors: activating the first wet clutch and the third wet clutch to connect the first motor and the second motor to the drive axle via the planetary gear set. At 1016, method 1000 relates to the clutch configuration for the parking brake: activating the second wet clutch and the third wet clutch to connect the second motor to the drive axle via the planetary carrier. In one example, in each operating mode, only the active wet clutch is closed, and the other wet clutches of the transmission are open.

[0040] At 1017, method 1000 includes adjusting the first and / or second motor speed based on the selected mode. Transitioning from normal mode to a dual-motor drive mode, such as dual-motor first gear, may include, for example, increasing or decreasing the speed of the first motor up to a threshold speed of the second motor to equalize the speed of the first shaft and the second shaft when the shafts are connected to drive the drive axle. For example, the second motor may run at 900 rpm and the first motor may be increased to 900 ± 50 rpm.

[0041] At 1018, method 1000 includes adjusting the first wet clutch 122, the second wet clutch 124, the third wet clutch 126, and / or the brake clutch 128 based on the selected mode. Method 1000 may, for example, include transitioning between two operating modes. The adjustment may, for example, include switching from normal first gear mode to dual motor first gear mode. Transitioning from normal first gear mode to dual motor first gear mode may include adjusting the brake clutch to disengage from the housing and adjusting the first wet clutch to engage the first motor with the drive axle. Upon selection of the mode (e.g., automatically or driver selected), an electronic signal may be sent to the brake clutch actuator 128a to release the brake clutch 128 connecting the drive axle 130 to the second shaft 108 via the housing 190.At the same time, an electronic signal may be sent to the first wet clutch actuator 122a to cause the first wet clutch 122 to couple the first shaft 104 to the drive axle 130 via the planetary gear set 134. Methods for transitioning between operating modes within various exemplary shift modes are described with reference to FIGS. Fig. 11-16 are described in more detail.

[0042] At 1020, method 1000 includes setting the first motor and the second motor to a desired speed or torque and direction of rotation based on the selected mode. Transitioning from the normal first gear mode to the dual first gear mode may, for example, include ramping the first and second motors to a desired torque. In one example, a control signal may be sent to the first inverter 110 and the second inverter 112 to ramp the first motor 102 and the second motor 106, respectively, to a torque of 3000 Nm.

[0043] At 1022, method 1000 determines whether output power to an auxiliary component is desired. This determination may be made automatically based on signals from one or more sensors, e.g., for monitoring wheel traction, vehicle load, and the like. Alternatively, this determination may be made based on the driver's interaction with a control system interface. If output to an auxiliary component is not desired, the method continues to 1034.

[0044] At 1034, method 1000 includes maintaining the current operating mode of the transmission. For example, the transmission may remain in its current operating gear, and the clutches may thus remain in their current position. If an output to an auxiliary component is desired, the method continues to 1024.

[0045] In response to determining that output power is desired for an auxiliary component, method 1000 determines whether the first motor is rotating counterclockwise at 1024. If the first motor is rotating counterclockwise, method 1000 includes closing the first one-way clutch at 1026. For example, an electronic signal may be sent to the first actuator of the one-way clutch 142a to couple the first shaft 104 to the PTO shaft 144 via the first gear train 146 (e.g., Fig. 7). If the first motor is not rotating counterclockwise, the method 1000 includes closing the second one-way clutch at 1028. For example, an electronic signal may be sent to the second one-way clutch 148a to couple the first shaft 104 to the PTO shaft 144 via the second gear train 150 when the first motor is rotating clockwise or not rotating (e.g., Fig. 8).

[0046] At 1030, the method includes ramping up the first motor to drive the auxiliary device at the desired speed or torque. In one example, a control signal may be sent to the first inverter 110 to drive the first motor 102 to a speed of 2000 rpm. The first motor may power the PTO unit 152, for example, to rotate the PTO unit clockwise by rotating the first motor 102 clockwise or counterclockwise.

[0047] In Fig. 11, a method 1100 for transitioning between first gear and second gear in single-motor drive is illustrated. For example, method 1100 may be performed when dual-motor transmission 100 is controlled in the first mode (e.g., single-motor drive mode), with second motor 106 driving drive axle 130 and first motor 102 decoupled from drive axle 130 and selectively operable power take-off 152. As described herein, method 1100 may be performed as a transition between operation 300 of Fig. 3 and the process 400 of Fig. 4 and / or between the Fig. 7 and Fig. 8. Method 1100 further includes details of the transition between the single-motor drive mode and the parking brake mode.

[0048] At 1102, method 1100 includes determining that the transmission is operating in the normal shift mode. For example, a vehicle operator may select a shift mode via an interface by specifying a position (e.g., the position of the shift lever, the position of the accelerator pedal, and the like) via an input device. As another example, the shift mode may be determined based on operating conditions, including the position of the input device, the clutch configuration, the vehicle speed, the vehicle load, the transmission load, the engine speed, the ambient temperature, and the like. The shift mode may be determined via sensor inputs, modeling, lookup tables, and / or other suitable techniques indicative of the operating conditions and / or the vehicle operator's selection.

[0049] At 1104, method 1100 determines whether a higher value than a second threshold for traction or speed is indicated. For example, a first traction demand threshold and a larger, second traction demand threshold may be set as positive, non-zero values ​​for the vehicle. For example, the thresholds may be calibrated so that the transmission switches between single-motor and dual-motor drive settings when a sensor detects load, power output, or wheel slip. In one example, the first traction demand threshold may be 2000 kilograms (kg) and the second traction demand threshold may be 5000 kg of estimated load.Similarly, a first speed request threshold and a higher second speed request threshold may be positive non-zero thresholds specified for the vehicle. For example, the thresholds may be calibrated to cause the transmission to switch between single and dual motor drive based on inputs from a pedal position sensor. For example, the first speed request threshold may be a driver request indicating a vehicle speed greater than 10 km / h, and the second speed request threshold may be 25 km / h.

[0050] In response to an indication of a traction or speed request greater than the second threshold, method 1100 may adjust the operating mode at 1138. For example, the transmission may be switched to a dual-motor drive mode, where more power is transferred to the greater load or vehicle speed compared to the single-motor drive mode. In one example, method 1100 may directly refer to method 1000, where the operating mode may be selected and the transmission may be transitioned to the selected operating mode.

[0051] In response to an indication of a traction or speed request that is not greater than the second threshold, method 1100 includes determining at 1106 whether a traction request greater than the first threshold is indicated. In response to an indication of a traction request greater than the first traction request threshold, method 1100 includes determining at 1108 whether the second engine speed is equal to or less than the shift threshold. For example, the shift threshold may be a positive, non-zero threshold calibrated for the transmission to ensure smooth clutch engagement with minimal wear. In one example, the shift threshold may be an upper limit for engine speeds per minute (RPM), above which abrupt engagement, excessive wear, and / or transmission overload may occur.For example, the shift threshold may be 2000 rpm. In some examples, based on the specific configuration of the transmission, the method may proceed directly from 1106 to adjusting the second wet clutch and the third wet clutch at 1112 without determining whether the second engine speed is equal to or less than the shift threshold.

[0052] In response to an indication of a second motor speed greater than the switching threshold, method 1100 includes adjusting the current to the second motor to drive the switching threshold at 1110. For example, the controller may send a control signal to the second inverter indicating the desired motor speed (e.g., 2000 rpm). In response, the second inverter may adjust the current supply to the second motor to achieve the switching threshold. Method 1100 may return to 1108 to determine whether the second motor speed is less than or equal to the switching threshold.

[0053] In response to a second engine speed indication less than or equal to the shift threshold, method 1100 includes releasing the third wet clutch while engaging the second wet clutch at 1112. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to close the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to open the third wet clutch 126. In this way, in the first mode (e.g., in the single-motor drive mode), the transmission shifts from second to first gear, which may enable an increase in traction to respond to traction demand greater than the first threshold at 1106.

[0054] At 1114, method 1100 includes setting the current for the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position, a wheel slip signal, or an increased load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to drive forward or reverse.

[0055] Returning to 1106, in response to an indication of a traction request not greater than the first traction request threshold, method 1100 includes determining at 1116 whether there is an indication of a speed request greater than the first speed request threshold at 1116. In response to an indication that a vehicle speed request is greater than the first speed request threshold, method 1100 includes determining whether the second engine speed is equal to or less than the shift threshold at 1118. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear, e.g., the shift threshold may be 2000 rpm. In other examples, such asBased on the specific configuration of the transmission, the method may proceed directly to the adjustment of the second wet clutch and the third wet clutch at 1122.

[0056] In response to an indication of a second motor speed greater than the switching threshold, method 1100 includes adjusting the current to the second motor to drive the switching threshold at 1120. For example, as described above, the controller may send a control signal to the second inverter indicating the desired motor speed (e.g., 2000 rpm), and the second inverter may adjust the current to the second motor to achieve the switching threshold. Method 1100 may return to 1118 to determine whether the second motor speed is less than or equal to the switching threshold.

[0057] In response to an indication of the second engine speed less than or equal to the shift threshold, method 1100 includes engaging the third wet clutch while disengaging the second wet clutch at 1122. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to open the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to close the third wet clutch 126. In this way, in the first mode (e.g., in the single-motor drive mode), the transmission shifts from first to second gear, which may enable an increase in speed, in response to the speed request that is above the first threshold at 1116.

[0058] At 1124, the method includes adjusting the current for the second motor to a desired motor speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position, a wheel slip signal, or an increased load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to drive forward or reverse.

[0059] Returning to 1116, in response to an indication of the speed request not greater than the first threshold, method 1100 includes determining whether braking is required at 1132. In response to a braking request, method 1100 includes reducing the second engine speed at 1134. For example, the second engine speed may be reduced to achieve the shift threshold described above. In one example, the method may include determining whether the second engine speed is less than or equal to the shift threshold described above. In other examples, the method may proceed directly to engaging the second wet clutch and the third wet clutch at 1136 to activate the parking brake mode.

[0060] At 1136, the method includes actuating the second wet clutch and the third wet clutch to disconnect the second motor from the drive axle. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to engage the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to engage the third wet clutch 126. In this way, the transmission may operate in parking brake mode while simultaneously controlling the first motor to drive the PTO.

[0061] At 1126, method 1100 includes determining whether an adjustment of PTO operation is indicated. For example, the adjustment of PTO operation may be indicated based on inputs from the vehicle operator, e.g., via input device 199, or based on operating conditions, e.g., conditions of the first engine and / or the second engine, including speed, temperature, torque, etc. If PTO adjustment is indicated, method 1100 may include performing a control method for adjusting PTO operation at 1128. An example control method for adjusting PTO operation is described with reference to Fig. 15 described.

[0062] In response to the indication that PTO adjustment is not occurring, method 1100 includes maintaining the current operating mode of the transmission at 1130. For example, the transmission may remain in its current operating gear, and the clutches and PTO remain in their current positions.

[0063] In Fig. 12 illustrates a method 1200 for operating the featured transmission in a traction shift mode. For example, operation in the traction shift mode may include transitioning between the single-motor drive mode and the dual-motor drive mode, with both modes being in either first or second gear. For example, method 1200 may be performed when the dual-motor transmission 100 is controlled in the first operating mode, in which the second motor 106 drives the drive axle 130 via engagement of the brake clutch 128 and engagement of the second wet clutch 124, and in the second operating mode, in which the first motor 102 and the second motor 106 are coupled to the drive axle 130 via engagement of the first wet clutch 122 and the second wet clutch 124. The method 1200 may be performed as a transition between the process 300 of Fig. 3 and the process 500 of Fig. 5. In traction shift mode, the first engine can drive the PTO either in single-engine or dual-engine mode, as desired by the operator.

[0064] At 1202, method 1200 includes determining that the transmission is operating in traction shift mode. For example, a vehicle operator may select the shift mode via an interface by indicating the position of an input device (e.g., the position of the shift lever, the position of the accelerator pedal, and the like). As another example, the shift mode may be determined based on operating conditions, including the position of the input device, the clutch configuration, the vehicle speed, the vehicle load, the transmission load, the engine speed, the ambient temperature, and the like. The shift mode may be determined via sensor inputs, modeling, lookup tables, and / or other suitable techniques indicative of the operating conditions and / or the vehicle operator's selection.

[0065] At 1204, method 1200 includes determining whether there is an indication that a speed request is greater than the threshold. In one example, a speed request greater than the threshold may be a positive non-zero threshold set for the vehicle, which may be calibrated to transition the transmission out of the traction shift mode. In one example, the speed request greater than the threshold may be determined based on an input from a pedal position sensor, such as the driver request indicative of a vehicle speed of 10 km / h. In some examples, the transmission may shift gears upon exceeding one or more additional or alternative thresholds, such as one (e.g.,from traction shift mode by exceeding a gradient threshold (as measured by an accelerometer) or a load threshold indicating a lower load.

[0066] In response to an indication of a speed request above the threshold, method 1200 may adjust the operating mode at 1238. For example, the transmission may transition to a speed power shift mode, where more power is provided for the higher vehicle speed, or to the normal shift mode, where the single-motor drive may produce higher engine speeds. In one example, method 1200 may directly refer to method 1000, where the operating mode may be selected and the transmission may transition to the selected operating mode.

[0067] In response to an indication that a speed request is not greater than the speed threshold, method 1200 includes determining whether there is an indication that a traction request is greater than a traction request threshold at 1206. In one example, the traction request threshold may be a positive non-zero threshold for the vehicle, which may be calibrated to transition the transmission to dual motor drive. In one example, the traction request above the threshold may be determined based on inputs from a sensor that estimates, for example, load. In one example, the traction request threshold may be 5000 kg of the estimated load. In some examples, the transmission may transition to dual motor drive if one or more additional or alternative thresholds are exceeded, such as:a power output threshold, a wheel slip threshold, and a gradient threshold.

[0068] In response to an indication of a traction demand greater than the traction demand threshold, method 1200 includes, at 1208, determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold. For example, the shift threshold may be a positive non-zero threshold calibrated for the transmission to ensure smooth clutch engagement with minimal wear. In one example, the shift threshold may be an upper limit for engine speeds per minute (RPM), above which abrupt engagement, excessive wear, and / or transmission overload may occur. For example, the shift threshold may be 2000 RPM.Additionally or alternatively, the switching threshold may be a threshold for the speed difference between the first motor and the second motor, which is calibrated to synchronize the speeds of the first and second shafts before engagement of the clutch.

[0069] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1200 includes adjusting the current to one or both of the first motor and the second motor to achieve the switching threshold at 1210. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 RPM). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1200 may return to 1208 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0070] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1200 includes releasing the brake clutch while engaging the first wet clutch at 1210. For example, the controller may send a first control signal to the brake clutch actuator 128a to open the brake clutch 128 and a second control signal to the first wet clutch actuator 122a to close the first wet clutch 122. The transmission may be in first gear when the second wet clutch is engaged. The controller may further send a control signal to the second wet clutch actuator 124a of the second wet clutch 124 to maintain the transmission in first gear when transitioning between the single-motor drive mode and the dual-motor drive mode. In this way, the transmission in the first mode (e.g., single-motor drive mode) shifts to the second mode (e.g., dual-motor drive mode) while the gear (e.g.,first gear) is maintained, which can allow an increase in power to respond to traction requirements above the first threshold at 1206.

[0071] At 1214, method 1200 includes adjusting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position, a wheel slip signal, or an increased load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0072] Returning to 1206, in response to an indication that a traction demand is not greater than the traction demand threshold, method 1200 includes determining, at 1216, whether a power reduction is indicated. In some examples, the power reduction may be indicated based on one or more thresholds, such as a torque demand threshold, a threshold load, engine temperature, etc. In some examples, the power reduction may be indicated by an operator input signal.

[0073] In response to a power derating indication, method 1200 includes determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold at 1218. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear; for example, the shift threshold may be 2000 rpm. In other examples, such as based on the specific configuration of the transmission, the method may proceed directly to adjusting the brake clutch and the first wet clutch at 1222.

[0074] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1200 includes adjusting the current to one or both of the first motor and the second motor to achieve the switching threshold at 1220. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 RPM). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1200 may return to 1218 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0075] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1200 includes disengaging the first wet clutch while simultaneously engaging the brake clutch at 1222. For example, the controller may send a first control signal to the first wet clutch actuator 122a to open the first wet clutch 122 and a second control signal to the brake clutch actuator 128a to close the brake clutch 128. As described above, the transmission may be in either first gear when the second wet clutch is engaged or second gear when the third wet clutch is engaged. The controller may further send a control signal to an actuator of a corresponding wet clutch (e.g.,The second wet clutch actuator 124a of the second wet clutch 124 or the third wet clutch actuator 126a of the third wet clutch 126) may be transmitted to maintain the transmission in first or second gear when transitioning between the single-motor drive mode and the dual-motor drive mode. Thus, in the second mode (e.g., dual-motor drive mode), the transmission transitions to the first mode (e.g., single-motor drive mode) while maintaining the gear (e.g., first or second gear), which may allow for power reduction to respond to the requested power reduction at 1216.

[0076] At 1224, method 1200 includes adjusting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position, a wheel slip signal, or an increased load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0077] Returning to 1216, at 1232, in response to there being no indication of power reduction, method 1200 includes determining whether a braking request is indicated. In response to an indication that there is no braking request, method 1200 includes determining whether cessation of PTO operation is indicated at 1226. In response to a braking request, method 1200 includes reducing the first and second engine speeds based on the clutch configuration at 1234. For example, if the first wet clutch is engaged, the speeds of the first and second engines may be reduced. However, if the braking clutch is activated, the second engine speed may be reduced, but not the first engine speed.In one example, the method may include determining whether the first engine speed and the second engine speed, or only the second engine speed, are less than or equal to the switching threshold described above. In other examples, the method may proceed directly to opening the clutches at 1236.

[0078] At 1236, the method includes closing the second wet clutch and the third wet clutch. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to engage the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to engage the third wet clutch 126. In this way, the transmission may operate in parking brake mode while simultaneously controlling the first motor to drive the PTO.

[0079] At 1226, method 1200 includes determining whether a PTO adjustment is indicated. For example, the PTO adjustment may be indicated based on inputs from the vehicle operator, e.g., via input device 199, or based on operating conditions, e.g., conditions of the first engine and / or the second engine, including speed, temperature, torque, etc. If PTO adjustment is indicated, method 1200 may include performing a control method for adjusting PTO operation at 1228. An example control method for adjusting PTO operation is described with reference to Fig. 15 described.

[0080] In response to the no PTO adjustment message, method 1200 includes maintaining the current operating mode of the transmission at 1230. For example, the transmission may remain in its current operating gear, and the clutches and PTO remain in their current positions.

[0081] In Fig. 13 illustrates a method 1300 for operating the featured transmission in a speed-power shift mode. For example, in the speed-power shift mode, switching may occur between single-motor drive and dual-motor drive in second gear. For example, the method 1300 may be performed when the dual-motor transmission 100 is controlled in the first operating mode, in which the second motor 106 drives the drive axle 130 in second gear via the engagement of the third wet clutch 126 and the brake clutch 128, or in the second operating mode, in which the first motor 102 and the second motor 106 are coupled to the drive axle 130 in second gear via the engagement of the third wet clutch 126 and the first wet clutch 122. As described herein, the method 1300 may be performed as a transition between the process 400 of Fig. 4 and the process 600 of Fig. 6. In speed-power shift mode, the first engine can drive the PTO either in single-engine or dual-engine drive, as desired by the operator.

[0082] At 1302, method 1300 includes determining that the transmission is operating in speed power shift mode. As described with reference to Fig. 11-12, in some examples, the determining may be performed in various ways, such as by a vehicle operator selection based on one or more operating conditions via sensor inputs, modeling, lookup tables, and / or other suitable techniques that may indicate operating conditions and / or the vehicle operator selection.

[0083] At 1304, method 1300 includes determining whether the traction demand is greater than the threshold. In one example, a traction demand greater than the threshold may be a positive non-zero threshold for the vehicle, which may be calibrated to transition the transmission out of the speed power shift mode. In one example, the traction demand greater than the threshold may be determined based on inputs from a sensor that estimates, for example, load. In one example, the traction demand threshold may be 2000 kg of the estimated load. In some examples, the transmission may transition out of the traction shift mode upon exceeding one or more additional or alternative thresholds, such as power output or wheel slip.

[0084] In response to an indication of a traction demand above the threshold, method 1300 may adjust the operating mode at 1338. For example, the transmission may transition to a traction shift mode, where more power is directed to the vehicle's higher traction demand, or to the normal shift mode, where the single-motor drive may alternate between higher speed demand and higher traction demand. In one example, method 1300 may directly refer to method 1000, where the operating mode may be selected and the transmission may transition to the selected operating mode.

[0085] In response to an indication that a tractive effort request is not greater than the tractive effort threshold, method 1300 includes determining whether there is an indication that a speed request is greater than a speed request threshold at 1306. In one example, a speed request greater than the threshold may be a positive non-zero threshold set for the vehicle, which may be calibrated to transition the transmission to dual motor drive. In one example, the speed request greater than a threshold may be determined based on a pedal position sensor input, e.g., the driver request indicating a vehicle speed of 25 km / h.

[0086] In response to an indication that a speed request is greater than a threshold, method 1300 includes determining, at 1308, whether the speeds of the first motor and the second motor are equal to or less than the shift threshold. The shift threshold may, for example, be a positive non-zero threshold calibrated for the transmission to ensure smooth clutch engagement with minimal wear. In one example, the shift threshold may be an upper limit on engine speeds per minute (RPM), above which abrupt engagement, excessive wear, and / or transmission overload may occur. The shift threshold may, for example, be 2000 RPM.Additionally or alternatively, the switching threshold may be a threshold for the speed difference between the first motor and the second motor, which is calibrated to synchronize the speeds of the first and second shafts before engagement of the clutch.

[0087] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1300 includes adjusting the current to one or both of the first motor and the second motor to achieve the switching threshold at 1310. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 rpm). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1300 may return to 1308 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0088] In response to an indication of the first and second engine speeds being less than or equal to the shift threshold, method 1300 includes releasing the brake clutch while engaging the first wet clutch at 1312. For example, the controller may send a first control signal to the brake clutch actuator 128a to open the brake clutch 128 and a second control signal to the first wet clutch actuator 122a to close the first wet clutch 122 while maintaining engagement of the third wet clutch 126. In this way, the transmission in the first mode (e.g., single-motor drive mode) and second gear shifts to the second mode (e.g., dual-motor drive mode) in second gear, which may allow for an increase in speed, in response to the speed request that is above the threshold at 1306.

[0089] At 1314, method 1300 includes setting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position or torque load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0090] Returning to 1306, in response to an indication of a speed request threshold not greater than the speed request threshold, method 1300 includes determining whether a power reduction is indicated at 1316. In some examples, a power reduction may be indicated based on one or more thresholds, such as a lower speed request threshold, engine temperature, etc. In some examples, the power reduction may be indicated by an operator input signal.

[0091] In response to a power derating indication, method 1300 includes determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold at 1318. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear; for example, the shift threshold may be 2000 rpm. In other examples, such as based on the specific configuration of the transmission, the method may proceed directly to adjusting the brake clutch and the first wet clutch at 1322.

[0092] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1300 includes adjusting the current to one or both of the first motor and the second motor to achieve the switching threshold at 1320. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 rpm). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1300 may return to 1318 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0093] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1300 includes disengaging the first wet clutch while maintaining engagement of the brake clutch at 1312. For example, the controller may send a first control signal to the first wet clutch actuator 122a to open the first wet clutch 122 and a second control signal to the brake clutch actuator 128a to close the brake clutch 128 while maintaining engagement of the third wet clutch 126. In this way, the transmission shifts from the second mode (e.g., dual motor drive mode) and second gear to the first mode (e.g., single motor drive mode) in second gear, which may allow for a power reduction to meet the requested power reduction at 1316.

[0094] At 1324, method 1300 includes setting the current for the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position or torque load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0095] Returning to 1316, at 1332, in response to there being no indication of power reduction, method 1300 includes determining whether a braking request is indicated. In response to an indication that there is no braking request, method 1300 includes determining whether cessation of PTO operation is indicated at 1326. In response to a braking request, method 1300 includes reducing the first and second engine speeds based on the clutch configuration at 1334. For example, if the first wet clutch and the second clutch are engaged, the speeds of the first and second engines may be reduced. However, if the brake clutch and the third wet clutch are engaged, the second engine speed may be reduced, but not the first engine speed.In one example, the method may include determining whether the first engine speed and the second engine speed, or only the second engine speed, are less than or equal to the switching threshold described above. In other examples, the method may proceed directly to opening the clutches based on the clutch configuration at 1336.

[0096] At 1326, method 1300 includes determining whether a PTO adjustment is indicated. For example, the PTO adjustment may be indicated based on inputs from the vehicle operator, e.g., via input device 199, or based on operating conditions, e.g., conditions of the first engine and / or the second engine, including speed, temperature, torque, etc. If PTO adjustment is indicated, method 1300 may include performing a control method for adjusting PTO operation at 1328. An example control method for adjusting PTO operation is described with reference to Fig. 15. In response to the no PTO adjustment message, method 1300 includes maintaining the current operating mode of the transmission at 1330. For example, the transmission may remain in its current operating gear, and the clutches and PTO remain in their current positions.

[0097] In Fig. 14 illustrates a method 1400 for operating the presented transmission in a high-load shift mode. The high-load shift mode may, for example, include switching between the first and second gears in dual-motor drive. The method 1400 may, for example, be performed when the dual-motor transmission 100 is controlled in the second operating mode in which the first motor 102 and the second motor 106 are coupled to the drive axle 130 via the engagement of the first wet clutch and the second wet clutch or the third wet clutch. As described herein, the method 1400 may be performed as a transition between the process 500 of Fig. 5 and the process 600 of Fig. 6. In high-performance shift mode, the first engine can selectively drive the PTO, depending on whether the driver operates the transmission in first or second gear.

[0098] At 1402, method 1400 includes determining that the transmission is operating in high power shift mode. As described in Fig. 11-13, in some examples, the determining may be performed in various ways, such as through a vehicle operator selection based on one or more operating conditions, via sensor inputs, modeling, lookup tables, and / or other suitable techniques that may be indicative of the operating conditions and / or the vehicle operator selection.

[0099] At 1404, method 1400 includes determining whether the first motor or the second motor is operating below a power threshold. In one example, the power threshold may be a positive non-zero threshold for the vehicle, which may be calibrated to transition the transmission out of the high-power shift mode. In one example, the power threshold may be determined based on inputs from a sensor, such as a thermal sensor detecting engine overheating, an accelerometer detecting vibration exceeding a threshold, or other means of detecting degradation of performance, such as poor acceleration and / or an inability to meet a speed or torque setpoint, an increase in the frequency of fuse blows, and so on.In one example, the power threshold may be an engine temperature indicating a temperature rise (e.g., above ambient temperature) of greater than 60°C. In response to indicating power below the threshold, method 1400 may adjust the operating mode at 1438. In one example, method 1400 may directly refer to method 1000, where the operating mode may be selected and the transmission may transition to the selected operating mode.

[0100] In response to an indication that performance is better than the threshold, method 1400 includes, at 1406, determining whether a traction demand greater than a traction demand threshold is indicated. In one example, the traction demand threshold may be a positive non-zero threshold for the vehicle, which may be calibrated to shift the transmission into first gear of the dual motor drive. In one example, the traction demand above the threshold may be determined based on inputs from a sensor that estimates, for example, load. In one example, the traction demand threshold may be 5000 kg of the estimated load. In some examples, the traction threshold may be set based on other operating parameters.In some examples, the transmission may switch to dual motor drive when one or more additional or alternative thresholds are exceeded, such as a power output threshold, a wheel slip threshold, and an uphill or downhill threshold.

[0101] In response to an indication of a traction demand greater than the traction demand threshold, method 1400 includes, at 1408, determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold. For example, the shift threshold may be a positive non-zero threshold calibrated for the transmission to ensure smooth clutch engagement with minimal wear. In one example, the shift threshold may be an upper limit for engine speeds per minute (RPM), above which abrupt engagement, excessive wear, and / or transmission overload may occur. For example, the shift threshold may be 2000 RPM.Additionally or alternatively, the switching threshold may be a threshold for the speed difference between the first motor and the second motor, which is calibrated to synchronize the speeds of the first and second shafts before engagement of the clutch.

[0102] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1400 includes adjusting the current to one or both of the first motor and the second motor to drive the switching threshold at 1410. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 rpm). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1400 may return to 1408 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0103] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1400 includes disengaging the third wet clutch and engaging the second wet clutch while maintaining the first wet clutch engaged at 1412. For example, the controller may send a first control signal to the second wet clutch actuator 124a to close the second wet clutch 124, a second control signal to the third wet clutch actuator 126a to open the third wet clutch 126, and a third control signal to the first wet clutch actuator 122a to maintain the first wet clutch 122 engaged. In this way, in the second gear mode (e.g., dual motor drive mode), the transmission shifts from second to first gear, which may enable an increase in power to respond to traction demand greater than the threshold of 1406.

[0104] At 1414, method 1400 includes adjusting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position or torque load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0105] Returning to 1406, in response to an indication that a traction request is not greater than the speed request threshold, method 1400 includes determining whether there is an indication that a speed request is greater than a speed request threshold at 1416. In one example, the speed request greater than a threshold may be a positive non-zero threshold set for the vehicle, which may be calibrated to shift the transmission into the second gear of the dual-motor drive. In one example, the speed request greater than a threshold may be determined based on an input from a pedal position sensor, e.g., the driver request indicating a vehicle speed of 25 km / h.In some examples, the speed limit may be set based on vehicle load or other operating parameters.

[0106] In response to a power derating indication, method 1400 includes determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold at 1418. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear; for example, the shift threshold may be 2000 rpm. In other examples, such as based on the specific configuration of the transmission, the method may proceed directly to adjusting the second wet clutch and the third wet clutch at 1422.

[0107] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1400 includes adjusting the current to one or both of the first motor and the second motor to drive the switching threshold at 1420. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 rpm). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1400 may return to 1418 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0108] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1400 includes disengaging the second wet clutch and engaging the third wet clutch while maintaining the first wet clutch engaged at 1414. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to open the second wet clutch 124, a second control signal to the third wet clutch actuator 126a to close the third wet clutch 126, and a third control signal to the first wet clutch actuator 122a to maintain the first wet clutch 122 open. In this way, in the second mode (e.g., in dual motor drive mode), the transmission shifts from first to second gear, which may allow for an increase in speed and thus respond to the speed request that is above the threshold at 1416.

[0109] At 1424, method 1400 includes setting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position or torque load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0110] Returning to 1416, if there is no indication of a speed request above the threshold, method 1400 includes determining whether there is an indication of a braking request at 1432. In response to an indication that there is no braking request, method 1400 includes determining whether discontinuing PTO operation is indicated at 1426. In response to a braking request, method 1400 includes reducing the first and second engine speeds at 1434. In one example, the method may include determining whether the first engine speed and the second engine speed are less than or equal to the shift threshold described above. In other examples, the method may proceed directly to opening the clutches at 1436.

[0111] At 1436, the method includes actuating the second wet clutch and the third wet clutch to disconnect the second motor from the drive axle. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to engage the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to engage the third wet clutch 126. In this way, the transmission may operate in parking brake mode while simultaneously controlling the first motor to drive the PTO.

[0112] At 1426, method 1400 includes determining whether an adjustment of PTO operation is indicated. For example, the adjustment of PTO operation may be indicated based on inputs from the vehicle operator, e.g., via input device 199, or based on operating conditions, e.g., conditions of the first engine and / or the second engine, including speed, temperature, torque, etc. If PTO adjustment is indicated, method 1400 may include performing a control method for adjusting PTO operation at 1428. An example control method for adjusting PTO operation is described with reference to Fig. 15 described.

[0113] In response to the indication that PTO adjustment is not occurring, method 1400 includes maintaining the current operating mode of the transmission at 1430. For example, the transmission may remain in its current operating gear, and the clutches and PTO remain in their current positions.

[0114] In Fig. 15, a method 1500 for operating the power take-off unit of the described transmission is illustrated. Operating the power take-off unit may include, for example, adjusting the power take-off, including, but not limited to, engaging and disengaging the power take-off unit, activating the first PTO clutch or the second PTO clutch (e.g., the first one-way clutch 142, the second one-way clutch 148), and adjusting the output of the first motor driving the PTO. In one example, the method 1500 may be performed in response to an instruction to adjust PTO operation, as described with reference to Fig. 11-14. At 1502, method 1500 determines whether PTO disengagement notification is desired. This determination may be made in response to operator interaction with a control system interface. For example, a vehicle operator may indicate a desire to disengage the PTO via input device 199. Alternatively, the determination may be made automatically based on signals from one or more sensors, e.g., for load monitoring and the like.

[0115] In response to a PTO disengagement indication, method 1500 includes determining whether the first engine speed is equal to or less than the shift threshold at 1504. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear; for example, the shift threshold may be 2000 rpm. In other examples, such as based on the specific configuration of the transmission, the method may proceed directly to opening the first and second PTO clutches at 1508.

[0116] In response to an indication of the first motor speed being greater than the switching threshold, method 1500 includes adjusting the current to the first motor to drive the switching threshold at 1506. For example, the controller may send a control signal to the first inverter indicating the desired motor speed (e.g., 2000 rpm). In response, the first inverter may adjust the current supplied to the first motor to achieve the switching threshold. Method 1500 may return to 1504 to determine whether the first motor is less than or equal to the switching threshold.

[0117] At 1508, the method includes opening the first and second PTO clutches. For example, a first control signal may be sent to the first one-way clutch actuator 142a to open the first one-way clutch 142, and a second control signal may be sent to the second one-way clutch actuator 148a to open the second one-way clutch 148. In this way, power flow from the first engine 102 to the PTO 144 is not transmitted through either the first gear train 146 or the second gear train 150.

[0118] In response to determining that a PTO disengagement indication is not desired, the method includes determining at 1510 whether a PTO engagement indication is desired. Similarly, this determination may be made in response to operator interaction with a control system interface, e.g., via input device 199, and additionally or alternatively, automatically based on signals from one or more sensors.

[0119] In response to an indication to engage the PTO, method 1500 includes determining at 1512 whether the first engine is rotating counterclockwise. If the first engine is rotating counterclockwise, the method closes the first PTO clutch at 1520. In one example, a first control signal may be sent to the first one-way clutch actuator 142a to close the first one-way clutch 142, and a second control signal may be sent to the second one-way clutch actuator 148a to open the second one-way clutch. If the first engine is not rotating counterclockwise, e.g., if the first engine is not rotating or if the first engine is rotating clockwise, the method includes closing the second PTO clutch at 1514.In one example, a first control signal may be sent to the second one-way clutch actuator 148a to close the second one-way clutch 148, and a second control signal may be sent to the first one-way clutch actuator 142a to open the first one-way clutch.

[0120] At 1516, the method includes ramping up the first motor to drive the PTO. For example, the controller may send a control signal to the first inverter specifying a desired motor speed or torque, e.g., a setpoint. For example, the desired motor speed or torque may be determined based on operating conditions determined, for example, via sensor inputs and / or operator inputs. The first inverter may then adjust the current supplied to the first motor to achieve the speed or torque setpoint at 1518.

[0121] In response to determining that PTO engagement is not desired, method 1500 includes setting the first motor to a desired PTO power at 1522. For example, the controller may send a control signal to the first inverter specifying a desired motor speed or torque, e.g., a setpoint. In response, the first inverter may adjust the current supplied to the first motor to achieve the speed or torque setpoint.

[0122] Fig. 16 shows a method 1600 for operating the featured transmission in a variable power speed traction shift mode. For example, method 1600 may be performed to transition between the dual motor drive mode in second gear and the single motor drive mode in first gear, as well as between the single motor drive mode in second gear and the dual motor drive mode in first gear. As described herein, method 1600 may be implemented as a transition between the process 600 of Fig. 6 and the process 300 of Fig. 3 and / or between the process 400 of Fig. 4 and the process 500 of Fig. 5 are shown.

[0123] At 1602, method 1600 includes determining that the transmission is operating in variable power speed traction shift mode. As described with reference to Fig. 11-14, in some examples, the determining may be performed in various ways, such as by a vehicle operator selection based on one or more operating conditions via sensor inputs, modeling, lookup tables, and / or other suitable techniques that may be indicative of the operating conditions and / or the vehicle operator selection.

[0124] At 1604, method 1600 includes determining whether a traction demand greater than a threshold is indicated. In one example, the traction demand threshold may be a positive non-zero threshold for the vehicle, which may be calibrated to shift the transmission into dual motor drive first gear. In one example, the traction demand above the threshold may be determined based on inputs from a sensor that estimates, for example, load. In one example, the traction demand threshold may be 5000 kg of the estimated load. In some examples, the traction demand threshold may be set based on other operating parameters. In some examples, the transmission may shift to dual motor drive when one or more additional or alternative thresholds are exceeded, such as:a power output threshold, a wheel slip threshold, and a gradient threshold.

[0125] In response to an indication of a traction demand greater than the threshold, method 1600 includes disengaging the third wet clutch and engaging the second wet clutch at 1606. For example, the controller may transmit a first control signal to the third wet clutch actuator 126a to open the third wet clutch 126 and a second control signal to the second wet clutch actuator 124a to close the second wet clutch 124.

[0126] Additionally, in response to indicating a speed demand greater than the threshold, method 1600 includes determining whether a power reduction is indicated at 1636. In some examples, an indication of a power reduction may be based on one or more thresholds, such as a speed demand below a threshold, an engine temperature, etc. In some examples, the power reduction may be indicated by an operator input signal.

[0127] In response to a power derating indication, method 1600 includes determining whether the speeds of the first motor and the second motor are equal to or less than the shift threshold at 1638. As described above, the shift threshold may be a positive, non-zero value calibrated for the transmission to ensure smooth clutch engagement with minimal wear; for example, the shift threshold may be 2000 rpm. In other examples, such as based on the specific configuration of the transmission, the method may proceed directly to adjusting the brake clutch and the first wet clutch at 1632.

[0128] In response to an indication that the speed of the first motor and the second motor is greater than the switching threshold, method 1600 includes adjusting the current to one or both of the first motor and the second motor to drive the switching threshold at 1640. For example, the controller may send a control signal to the first and second inverters indicating the desired motor speed (e.g., 2000 RPM). In response, the first inverter and the second inverter may adjust the current supply to the first motor and the second motor, respectively, to achieve the switching threshold. Method 1600 may return to 1638 to determine whether the speeds of the first motor and the second motor are less than or equal to the switching threshold.

[0129] In response to an indication of the first and second engine speeds less than or equal to the shift threshold, method 1600 includes disengaging the first wet clutch while simultaneously engaging the brake clutch at 1632. For example, the controller may send a first control signal to the first wet clutch actuator 122a to open the first wet clutch 122 and a second control signal to the brake clutch actuator 128a to close the brake clutch 128 while maintaining engagement of the second wet clutch 124. In this way, the transmission in the second mode (e.g., dual motor drive mode) and second gear shifts to the first mode (e.g., single motor drive mode) in first gear, which may allow for a reduction in power to respond to the requested power reduction at 1316 and an increase in traction to respond to the greater traction demand at 1604. In some examples, as described with reference to 。 Fig. 10-15, the method may include determining whether the first motor and the second motor are rotating at less than a switching threshold prior to engaging the clutches. Additionally or alternatively, the switching threshold may be a threshold for the speed difference between the first motor and the second motor calibrated to synchronize the speeds of the first and second shafts prior to clutch engagement.

[0130] At 1608, method 1600 includes adjusting the current for the first motor and the second motor to a desired speed or torque and a desired direction of rotation. The desired motor speed or torque may be based, for example, on an input signal such as a pedal position, a wheel slip signal, or an increased load. The direction of rotation (e.g., clockwise or counterclockwise) may be determined based on a command to move forward or reverse.

[0131] In response to indicating a traction demand not greater than the traction demand threshold 1604, or in response to not indicating a power reduction 1636, method 1600 includes determining whether a speed demand greater than a second speed demand threshold is indicated 1610. The second speed demand threshold and a lower first speed demand threshold may be non-zero, positive-value thresholds set for the vehicle. For example, the thresholds may be such that the transmission transitions between dual-motor drive and single-motor drive settings based on inputs from a pedal position sensor.For example, the second speed request threshold may be a driver request indicating a vehicle speed greater than 25 km / h, and the first speed request threshold may be greater than 10 km / h.

[0132] In response to an indication of a vehicle speed request greater than the second speed request threshold, method 1600 includes disengaging the second wet clutch while engaging the third wet clutch at 1612. For example, the controller may transmit a first control signal to the second wet clutch actuator 124a to open the second wet clutch 124 and a second control signal to the third wet clutch actuator 126a to close the third wet clutch 126. In some examples, as described with reference to Fig. 10-15, the method may include determining whether the first motor and the second motor are rotating at less than a switching threshold prior to engaging the clutches. Additionally or alternatively, the switching threshold may be a threshold for the speed difference between the first motor and the second motor calibrated to synchronize the speeds of the first and second shafts prior to clutch engagement.

[0133] After engaging the second clutch and releasing the first clutch at 1612, method 1600 proceeds to 1636 to determine if a power reduction is indicated. If a power reduction is indicated, method 1600 proceeds as described above. If no power reduction is indicated, the method returns to 1610 to determine if a speed demand greater than a second speed demand threshold is indicated. As described above, releasing the first clutch and engaging the second clutch may increase the speed such that the speed demand is not greater than the second threshold at 1610. Method 1600 proceeds to 1608 to adjust the current to the first motor and the second motor, as described herein.

[0134] At 1620, method 1600 includes determining whether a PTO adjustment is indicated. For example, the PTO adjustment may be indicated based on inputs from the vehicle operator, e.g., via input device 199, or based on operating conditions, e.g., conditions of the first engine and / or the second engine, including speed, temperature, torque, etc. If PTO adjustment is indicated, method 1600 may include performing a PTO adjustment control method at 1622. An example PTO adjustment control method is described with reference to Fig. 15. In response to the indication that PTO adjustment is not occurring, method 1300 includes maintaining the current operating mode of the transmission at 1630. For example, the transmission may remain in its current operating gear, and the clutches and PTO remain in their current positions.

[0135] Fig. 17 and Fig. 18 are timing diagrams illustrating a sequence of actions performed within a control method for operating the disclosed dual-motor transmission in a heavy-duty vehicle, such as a loader, including operation of the transmission to drive a power take-off device, such as a loader bucket. The control method for shaping the engine torque may be the same as or similar to the series of actions described above with reference to methods 1000, 1100, 1200, 1300, 1400, and 1500 in the Fig. 10-15. The double motor gearbox can be used in Fig. 1. Instructions for performing the control methods described in timing diagrams 1700 and 1800 may be executed by a controller (e.g., controller 180) based on instructions stored in a memory of the controller and in conjunction with sensory feedback received from components of a vehicle system (e.g., vehicle 101), including first engine speed sensors and second engine speed sensors, torque sensors, wheel speed sensors, load sensors, and a pedal position sensor (e.g.,, sensors 186), clutch sensors including the second wet clutch position sensor 124b, the third wet clutch position sensor 126b, the first wet clutch position sensor 122b, the brake clutch position sensor 128b, the first one-way clutch position sensor 142b, and the second one-way clutch position sensor 148b, described above with reference to . Fig. 1. In the prophetic examples, the controller determines whether operating conditions indicate a transition between gears and power levels, e.g., based on thresholds for traction demand and speed demand, and whether PTO operation is desired. When a transition is indicated, the controller can perform a gear shift (e.g., between first and second gear) or a power shift (e.g., between single motor, dual motor, or parking brake) based on the indicated demand being greater than the threshold. Fig. Figure 17 shows a scenario illustrating a control strategy with the vehicle in a normal shift mode (e.g., the transmission can be set between first drive gear and second drive gear in single-motor drive mode). Fig. Figure 18 shows a scenario illustrating a control strategy with the vehicle in traction switching mode. The horizontal (x-axis) denotes time, and the vertical markers t0-t9 indicate the relevant times for transmission control in the time diagrams 1700 and 1800 of the Fig. 17 and 18 respectively.

[0136] The time diagram 1700 in Fig. 17 shows curves 1702, 1704, 1706, 1708, 1710, 1712, 1714, 1716, and 1718, which represent the states of the components and / or the control settings of the vehicle system over time. Curve 1702 indicates a first engine torque. Curve 1706 indicates a second engine torque. The output torque of the first engine and the output torque of the second engine can be positive or negative. Curve 1704 indicates a first engine speed. A first shift threshold 1717 is indicated in curve 1704. The first shift threshold is a positive, non-zero value calibrated to smoothly apply the first PTO clutch or the second PTO clutch with minimal interference with the transmission (e.g., 2000 rpm). Curve 1708 indicates a second engine speed. A second switching threshold 1719 is indicated in curve 1708. The second switching threshold 1719 has the same speed as the first switching threshold (e.g.,2000 rpm) and is calibrated to apply the brake clutch or the second wet clutch evenly with minimal wear on the transmission. Curve 1710 indicates a speed request for vehicles. A first speed request threshold 1720 is indicated in graph 1710, which may be a non-zero positive threshold calibrated to shift the transmission from first gear to second gear, such as 10 km / h. A second speed request threshold 1722 is indicated in graph 1710, which may be a non-zero positive threshold calibrated to shift the transmission from the normal shift mode, in which the transmission can be set between the first traction gear and the second traction gear in single-motor drive, to another operating mode (e.g., a dual-motor drive mode) or another shift mode, such asthe traction shift mode, the speed powershift mode, or the high powershift mode. The second speed request threshold may be, for example, 25 km / h. Curve 1712 indicates a need for vehicle traction. Indicated in curve 1712 is a first traction request threshold 1724, which may be a positive non-zero threshold calibrated to shift the transmission from second to first gear, e.g., at a 2000 kg load. Indicated in curve 1712 is a second traction request threshold 1726, which may be a positive non-zero threshold calibrated to transition the transmission from the normal operating mode to another operating mode or another shift mode, e.g., at a 5000 kg load. Curve 1714 shows the position of a second gear clutch (e.g.the third wet clutch 126), which, when engaged, shifts the transmission into second gear. Curve 1716 indicates the position of a first gear clutch (e.g., the second wet clutch 124), which, when engaged, shifts the transmission into first gear. Curve 1718 shows the position of the first PTO clutch, which may be the first one-way clutch 142, and the second PTO clutch, which may be the second one-way clutch 148. In the embodiment shown in . Fig. 17, the brake clutch 128 may be engaged to enable shifting in single motor drive mode, as shown in Fig. 2 described.

[0137] At t0, the transmission is operating in second gear with the second gear clutch (e.g., the third wet clutch 126) engaged, as indicated by curve 1714, and the first gear clutch (e.g., the second wet clutch 124) disengaged, as indicated by curve 1716. The speed request for the vehicle is moderate in plot 1710 and is below the first speed request threshold 1720. The requested vehicle speed is in the forward direction, as indicated by a solid line. The traction demand in plot 1712 is low and is below the first traction demand threshold 1724. The second engine torque is low and positive, as indicated by curve 1706, and the second engine speed is higher, as indicated by curve 1708. The first engine is not operating.

[0138] From t0 to t1, the vehicle speed demand, traction demand, second motor torque, and second motor speed are the same. The third wet clutch remains engaged, as indicated by curve 1714. At t1, a manual command is given via a button to engage the PTO to drive a loader bucket. Since the first engine is not operating, the first motor speed is below the first shift threshold and is not rotating counterclockwise. Consequently, from t1 to t2, the controller actuates the second PTO clutch actuator, as indicated by curve 1718, to drive the PTO connected to the loader bucket clockwise. However, since the brake clutch 128 is engaged and the first wet clutch 122 is disengaged, the first motor is not connected to the output shaft (e.g.,the drive axle 130) so that the transmission is in single-motor drive mode, with the first motor driving the PTO and the second motor driving the output shaft.

[0139] At t2, the second PTO clutch is engaged. From t2 to t3, the first motor current is adjusted to the desired torque for operating the loader bucket. The first motor torque and speed increase, as shown in curve 1702 and curve 1704, respectively, when the operator operates the loader bucket to move debris. Operating the loader bucket increases the vehicle load, resulting in an increased traction demand, as shown in curve 1712. The requested vehicle speed is constant, as shown in curve 1710. The second motor torque increases and the second motor speed decreases in response to the increased traction demand, as shown in curve 1706 and curve 1708, respectively.

[0140] At t3, the traction demand exceeds the first traction demand threshold. The second engine speed is below the second shift threshold. Consequently, from t3 to t4, the controller shifts the transmission from second gear to first gear. The controller sends a first control signal to the second transmission clutch actuator (e.g., the third wet clutch actuator 126a) to disengage the second transmission clutch (e.g., the third wet clutch 126), as illustrated in curve 1714, and a second control signal to the first transmission clutch actuator (e.g., the second wet clutch actuator 124a) to engage the first transmission clutch (e.g., the second wet clutch 124), as illustrated in curve 1716.

[0141] At t4, the first gear clutch is engaged. From t4 to t5, bucket operation continues with a high first engine torque and a low first engine speed, as shown in curve 1702 and curve 1704, respectively. Current to the second motor increases to produce increasing torque, as shown in curve 1706, in response to the increasing tractive effort demand resulting from bucket operation. Approaching t5, the vehicle speed drops precipitously as the operator comes to a stop. Subsequently, the second engine torque and speed decrease, as shown in curve 1706 and curve 1708, respectively. At the same time, the tractive effort demand drops precipitously as the load decreases in response to the bucket unloading. The first engine torque and speed decrease in response to the unloading, as shown in curve 1702 and curve 1704, respectively.

[0142] At t5, the commanded vehicle speed is reduced to zero as the driver prepares to reverse direction. To continue PTO operation, the controller prepares to swap the PTO clutches to allow the PTO to rotate continuously clockwise. The first engine speed is less than the first shift threshold. Consequently, from t5 to t6, the controller actuates the second PTO clutch actuator (e.g., the second actuator of one-way clutch 148a) to disconnect the PTO from the first engine via the second PTO clutch and the first PTO clutch actuator (e.g., the first actuator of one-way clutch 142a) to couple the PTO to the first engine via the first PTO clutch, as shown in curve 1718. In this way, PTO operation can continue while the vehicle is operating in reverse.

[0143] At t6, the first PTO clutch is engaged. From t6 to t7, the operator requests a higher speed in the reverse direction, as indicated by a dashed line in curve 1710. The second engine torque increases in a negative direction and the second engine speed increases toward the first speed request threshold. Traction demand is smooth and low, as shown in curve 1712. The first engine drives the PTO to the loader bucket with a low, constant torque and low engine speed, shown in curves 1702 and 1704, respectively.

[0144] At t7, the vehicle speed request exceeds the first speed request threshold. The second engine speed is below the second shift threshold. Consequently, from t7 to t8, the controller shifts the transmission into second gear. The controller sends a first control signal to the second wet clutch actuator to disengage the second wet clutch 124 and a second control signal to the third wet clutch actuator to engage the third wet clutch 126, illustrated in curves 1716 and 1714, respectively.

[0145] At t8, the third wet clutch 126 is engaged and the transmission is operating in second gear. From t8 to t9, current to the second motor increases to increase the second motor torque and the second motor speed in response to the increasing vehicle speed. As the second motor speed increases toward the second speed request threshold, the second motor torque simultaneously decreases, as shown in plots 1708 and 1706, respectively.

[0146] At t9, the vehicle speed request exceeds the second speed request threshold. The controller then determines that the operating mode setting is indicated. The timing diagram ends.

[0147] The example depicted in timing diagram 1700 illustrates a series of actions that may be performed during operation of the dual-motor transmission in the normal shift mode to shift between first and second gears, with the second motor driving the drive axle (e.g., second motor 106) and the first motor optionally driving the power take-off (e.g., first motor 102). A similar series of actions may be performed during operation of the dual-motor transmission in other shift modes, such as the high-load shift mode described with reference to Fig. 14, and in the variable power and traction mode described with reference to Fig. 16. In response to a traction demand that is above the threshold, the series of actions may include, for example, actuating the second gear clutch actuators (e.g., the third wet clutch actuator 126a) to disengage the second gear clutches (e.g., the third wet clutch 126) and actuating the first gear clutch actuator to engage the first gear clutch (e.g., the second wet clutch actuator 124a, the second wet clutch 124) while the first wet clutch 122 is engaged (e.g., in both first and second gears). In one example, the traction demand threshold may be the same as or similar to the second traction demand threshold (e.g., 5000 kg) or different from it (see, for example, the examples in Fig. 14). In response to a speed request greater than the threshold, for example, greater than the second speed request threshold (e.g., 25 km / h) or the first speed request threshold (e.g., 10 km / h), the series of actions may include shifting the transmission to second gear in dual-motor mode (e.g., the third operating mode) or shifting the transmission to second gear in single-motor mode (e.g., the second operating mode).

[0148] The time diagram 1800 in Fig. Figure 18 shows an example control strategy for the dual motor transmission with the traction shift mode as described with reference to Fig. 2 and Fig. 12. For example, the traction switching mode may include the transition between the single-motor drive mode and the dual-motor drive mode, with both modes being in either first or second gear. As shown in Fig. 18, the vehicle travels in first gear, optionally drives the drive axle with one or two motors, and optionally drives the power take-off shaft to drive a power take-off device.

[0149] Timing diagram 1800 shows curves 1802, 1804, 1806, 1808, 1810, 1812, 1814, 1816, and 1818, which represent the states of the components and / or the control settings of the vehicle system over time. Curve 1802 indicates a first engine torque. Curve 1806 indicates a second engine torque. The output torque of the first engine and the output torque of the second motor can be positive or negative. Curve 1804 indicates a first engine speed. A first shift threshold 1820 is indicated in curve 1804. In one example, the first shift threshold 1820 is a positive, non-zero threshold calibrated to smoothly engage clutches on the first engine output shaft (e.g., 2000 rpm) with minimal wear on the transmission. Curve 1808 indicates a second engine speed. A second switching threshold 1822 is indicated in curve 1808.The second shift threshold 1822 has the same speed as the first shift threshold (e.g., 2000 rpm) and is calibrated to apply the brake clutch 128 smoothly and with minimal wear on the transmission. Curve 1810 indicates a speed request for vehicles. Graph 1810 indicates a speed request threshold 1824, which may be a non-zero positive threshold calibrated to transition the transmission from traction powershift to another operating mode or shift mode, such as 10 km / h. Curve 1812 indicates a demand for vehicle traction. Curve 1812 indicates a traction request threshold 1826, which may be a non-zero positive threshold calibrated to transition the transmission from single-motor drive to dual-motor drive, such as 10 km / h. B. a load of 5000 kg.Curve 1814 indicates the position of a single-motor drive clutch (e.g., brake clutch 128) that, when engaged, shifts the transmission into single-motor drive mode. Curve 1816 indicates the position of a dual-motor drive clutch (e.g., first wet clutch 122) that, when engaged, shifts the transmission into dual-motor drive mode. Curve 1818 indicates a position of the first PTO clutch, which may be first one-way clutch 142, and the second PTO clutch, which may be second one-way clutch 148.

[0150] At t0, the loader is operating in single-motor drive with traction. The single-motor drive clutch (e.g., brake clutch 128) is engaged (see curve 1814), and the dual-motor drive clutch (e.g., first wet clutch 122) is disengaged at 1816. The loader is stationary with a low speed demand, shown in graph 1810, below speed demand threshold 1824. The traction demand is low and below the traction demand threshold 1826 shown in curve 1812. The second PTO clutch is engaged, see curve 1818, driving a loader bucket with low torque.

[0151] From t0 to t1, the loader carries debris in the bucket up an incline, causing the load to increase and the tractive effort requirement to increase, as shown in curve 1812. The torque output at the second motor increases, and the engine speed of the second motor is slightly reduced to meet the increasing tractive effort requirement, see curves 1806 and 1808, respectively. The output torque and engine speed of the first motor are the same, as shown in curves 1802 and 1804, respectively.

[0152] At t1, the second motor reaches its maximum output torque when the traction demand exceeds the traction demand threshold, as shown in curve 1812. The second motor speed is less than the second shift threshold, and the first motor speed is less than the first shift threshold, as indicated by curves 1808 and 1804, respectively. Additionally, the first shaft (e.g., coupled to the first motor) and the second shaft (e.g., coupled to the second motor) rotate at similar speeds. Consequently, the controller shifts the transmission from single-motor drive to dual-motor drive from t1 to t2. The controller sends a first control signal to the single-motor drive clutch actuator (e.g., the brake clutch actuator 128a) to disengage the single-motor drive clutch (e.g., the brake clutch 128) at curve 1814 and a second control signal to the dual-motor drive clutch actuator (e.g.,the actuator of the first wet clutch 122a) to engage the dual motor drive clutch (e.g., the first wet clutch 122).

[0153] At t2, the dual-motor drive clutch is engaged, as indicated by curve 1816. The loader operates in dual-motor drive, with the power of the first engine and the second engine being transferred to the drive axle. The second PTO clutch remains engaged, so that part of the power of the first engine also drives the PTO and the connected loader bucket.

[0154] From t2 to t3, the traction demand increases, as shown in curve 1812, as the loader climbs the slope. The second motor torque remains at the peak torque, shown in curve 1806. The power supply to the first motor increases the torque, as shown in curve 1802, to meet the increasing traction demand. At t3, the traction demand decreases as the loader reaches the top of the slope. The vehicle speed decreases as the operator decelerates to a stop. Subsequently, the torque of the first motor and the second motor decreases, as shown in curves 1802 and 1806.

[0155] At t3, the vehicle is stopped and the driver indicates that they want to decelerate the vehicle. The first motor speed is low, and the second motor speed is below the first switching threshold and the second switching threshold, respectively. Consequently, from t3 to t4, the dual-motor drive clutch is opened, decoupling the first motor from the drive axle.

[0156] At t4, the vehicle is decelerated. The second wet clutch and the third wet clutch are engaged to apply a parking brake. From t4 to t5, the operator drives the loader bucket while the vehicle is decelerated. Debris accumulated in the loader bucket increases the load. The first motor increases its output torque to operate the loader bucket at the increased load. The torque and speed of the second motor are maintained at a low level.

[0157] At t5, the vehicle's speed demand is indicated and signals the controller to disengage the second or third wet clutch and engage the brake clutch or the first wet clutch to enable driving. A traction demand below the threshold, represented by curve 1812, signals the controller to switch to single-motor drive. Consequently, from t5 to t6, the single-motor drive clutch is engaged to drive the drive axle with the second motor. At t6, the single-motor drive clutch is engaged, as represented by curve 1814.

[0158] From t6 to t7, the second motor ramps up to meet the traction demand and the increasing vehicle speed, see curve 1812 and curve 1810, respectively. The timing diagram ends at t7.

[0159] The example depicted in timing diagram 1800 illustrates a series of actions that may be performed during operation of the dual-motor transmission in traction shift mode to transition between single-motor drive and dual-motor drive in first gear. A similar series of actions may be performed during operation of the dual-motor transmission in another mode, such as speed power shift mode, to transition between single-motor drive and dual-motor drive in second gear. For example, in response to a vehicle speed request above the threshold, the series of actions may include maintaining engagement of the single-motor drive clutch (e.g., brake clutch 128) while actuating the dual-motor drive clutch actuator (e.g., first wet clutch actuator 122a) to engage the dual-motor drive clutch (e.g., first wet clutch 122).In one example, the speed request threshold may be the same as or similar to those described with reference to . Fig. 13 (e.g., 10 km / h). In response to an indication to reduce power, e.g., based on operator input or a sensor indicating a condition greater than the threshold, the series of actions may include actuating the dual-motor drive clutch actuator (e.g., the first wet clutch actuator 122a) to disengage the dual-motor drive clutch (e.g., the first wet clutch 122) while maintaining engagement of the single-motor drive clutch (e.g., the brake clutch 128).

[0160] Fig. Figure 19 is a curve 1900 illustrating the relationship between torque, power, and speed for an electric motor in a transmission, such as the dual-motor transmission 100. Curve 1908 shows the torque in Newton meters (Nm) with increasing speed in revolutions per minute (rpm) for an example main drive motor. Curve 1910 shows the power in watts (W) with increasing speed in revolutions per minute (rpm) for the example main drive motor. Three phases are indicated on curve 1900. A first phase from 0 to ~1000 rpm (e.g., before line 1902), a second phase from ~1000 to ~3400 rpm (e.g., between line 1902 and line 1904), and a third phase beyond ~3400 rpm (e.g., after line 1904).

[0161] During the first phase, in which torque is held constant and speed increases, power increases. In the second phase, in which power is held constant and speed increases, torque decreases. In the third phase, in which speed approaches its peak, torque drops to 0 Newton meters (Nm) and power to 0 watts (W). In some transmission configurations, tractive effort can be limited during the first phase, e.g., the constant torque phase. By operating the dual-motor transmission in dual-motor drive high-traction mode (e.g., the third operation 500 in Fig. 5) The constant torque phase can extend to higher vehicle speeds and overlap with the constant power phase, as shown by the dashed line 1906. For some heavy vehicles, such as bulldozers and front loaders, high traction demands predominate. The PTO motor (e.g., the first motor 102) can provide additional power in dual-motor mode at the same gear ratio. With the described arrangement, when the transmission is controlled in dual-motor high-traction mode, the available power is increased in the maximum power range, and the higher the vehicle speed, e.g., the distance between lines 1902 and 1906, the more tractive effort is available. This allows the driver to increase vehicle speed while maintaining tractive effort.When the transmission is controlled in high-speed mode with two motors, the available power increases in the maximum power range, and more power is available as the vehicle speed increases.

[0162] The Fig. 20 illustrates the operating modes of the disclosed dual-motor transmission and an exemplary range for an electric motor. The curve includes traction force on the y-axis and vehicle speed on the x-axis. As described with reference to the graph 1900 in Fig. As described in Figure 19, the tractive effort generally decreases with increasing vehicle speed. Curve 2002 shows the operating range of an electric motor. The tractive effort is greatest at lower speeds in the peak torque range, represented by arrow 2012, and corresponds approximately to the first phase described with reference to Fig. 19. The vehicle speed is highest at lower torques in the maximum speed range, shown by the arrow 2016, and corresponds approximately to the Fig. 19. Between the peak torque area and the peak speed area lies the peak power area, which is represented by the arrow 2014 and roughly correlates with the second phase, which is described with reference to Fig. 19 is described.

[0163] Curve 2004 shows the operating range of the presented transmission with single-motor drive in first gear. The tractive effort is increased in the peak torque range. Curve 2006 shows the operating range of the presented transmission with single-motor drive in second gear. The vehicle speed is increased in the top speed range. Curve 2008 shows the operating range of the presented transmission in first gear with dual-motor drive. The tractive effort is further increased compared to the single-motor drive in first gear. Curve 2010 shows the operating range of the presented transmission in second gear with dual-motor drive. The vehicle speed is further increased compared to the single-motor drive in second gear.

[0164] The disclosure also supports a method for a transmission including a first motor selectively coupled to a power take-off (PTO) unit and a drive axle, and a second motor selectively coupled to the drive axle, the method comprising actuating both a second wet clutch and a brake clutch or both a third wet clutch and the brake clutch to change between a first operating mode and a second operating mode in the transmission, and actuating a first one-way clutch or a second one-way clutch opposite the first one-way clutch to drive the power take-off unit, the first operating mode comprising driving rotation of the drive axle with the second motor at a first gear ratio,and wherein the second operating mode comprises driving rotation of the drive axle with the second motor at a second gear ratio that is higher than the first gear ratio. In a first example of the method, operating the second wet clutch comprises setting the second wet clutch to the closed position to couple the second motor to the drive axle via a planetary gear set of a planetary gear set coaxial with the second motor.

[0165] Furthermore, the disclosure provides support for a method for a transmission including a first motor selectively coupled to a power take-off (PTO) unit and a drive axle, and a second motor selectively coupled to the drive axle, the method comprising actuating both a second wet clutch and a first wet clutch or both a third wet clutch and the first wet clutch to shift between a first operating mode and a second operating mode in the transmission, and actuating a first one-way clutch or a second one-way clutch opposite the first one-way clutch to drive the PTO unit, the first operating mode comprising driving rotation of the drive axle with the first motor and the second motor at a first gear ratio,and wherein the second operating mode comprises driving the rotation of the drive axle with the first motor and the second motor at a second gear ratio that is higher than the first gear ratio, and wherein the second wet clutch is coaxial with the drive axle, the third wet clutch is coaxial with a second motor output shaft, and the first wet clutch is coaxial with a first motor output shaft.

[0166] The disclosure further supports a method for a transmission including a first motor selectively coupled to a power take-off unit and a drive axle, and a second motor selectively coupled to the drive axle. The method includes adjusting both a second wet clutch and a brake clutch, or both the second wet clutch and a first wet clutch, to transition between a first operating mode and a second operating mode in the transmission, and adjusting a first one-way clutch or a second one-way clutch opposite the first one-way clutch to drive the power take-off unit.The first mode of operation includes driving, with the second motor, the rotation of the drive axle at a first gear ratio, and the second mode of operation includes driving, with the first motor and the second motor, the rotation of the drive axle at the first gear ratio. Setting the second wet clutch and the brake clutch includes setting the second wet clutch and the brake clutch to a closed position to couple the second motor to the drive axle via a planetary gear set of a planetary gear set coaxial with the second motor. The method further includes setting the second wet clutch and the brake clutch to the closed position in response to a request to reduce power.Adjusting the second wet clutch and the first wet clutch includes adjusting both the second wet clutch and the first wet clutch to a closed position to couple the first motor and the second motor to the drive axle via a ring gear of a planetary gear set arranged coaxially with the second motor, and closing the first wet clutch to couple the first motor to the drive axle via a ring gear of the planetary gear set. The method further includes adjusting the second wet clutch and the first wet clutch to the closed position in response to a request for increased power. Additionally, the method includes adjusting one of the first one-way clutch and the second one-way clutch based on an indication to deliver power to an auxiliary component, wherein the indication includes a direction of rotation of the first motor.

[0167] Furthermore, the disclosure supports a method for a transmission having a first engine selectively coupled to a power take-off unit and a drive axle, and a second engine selectively coupled to the drive axle, the method comprising adjusting at least two of a second wet clutch, a brake clutch, a third wet clutch, and a first wet clutch to shift between a first operating mode, a second operating mode, a third operating mode, and a fourth operating mode in the transmission, and adjusting a first one-way clutch or a second one-way clutch opposite to the first one-way clutch to drive the PTO unit.The first operating mode comprises driving, with the second motor, the drive axle to rotate at a first gear ratio. The second operating mode comprises driving, with the first motor and the second motor, the drive axle to rotate at a second gear ratio that is higher than the first gear ratio. The third operating mode comprises driving, with the first motor and the second motor, the drive axle to rotate at the first gear ratio. The fourth operating mode comprises driving, with the second motor, the drive axle to rotate at the second gear ratio. Adjusting the second wet clutch and the brake clutch comprises closing the second wet clutch and the brake clutch to connect the second motor to the drive axle.Adjusting the second wet clutch and the first wet clutch includes closing the second wet clutch and the first wet clutch to connect the first motor and the second motor to the drive axle. Adjusting the third wet clutch and the brake clutch includes closing the third wet clutch and the brake clutch to connect the second motor to the drive axle. Adjusting the third wet clutch and the first wet clutch includes closing the third wet clutch and the first wet clutch to connect the first motor and the second motor to the drive axle. The method further includes closing both the third wet clutch and the second wet clutch to decouple both the first motor and the second motor from the drive axle.

[0168] In this way, the systems and methods described herein increase the tractive effort and speed of heavy commercial vehicles. The transmission arrangement increases the upper threshold of tractive effort and the upper threshold of vehicle speed by coupling a second motor to the drive axle as needed. The transmission has two one-way clutches that can be engaged when the vehicle is moving forward, reverse, or stationary to drive a power take-off device. The transmission can be set between first and second gears, driven by one or two motors, and operation of the power take-off device by adjusting a plurality of clutches for a high degree of flexibility and ease of control.Furthermore, the disclosed systems and methods offer an adaptable solution for heavy-duty trucks, where a transmission can be built on the disclosed platform to contain fewer clutches and be tailored to the specific vehicle application. The technical effect of the presented transmission is an increased operating radius for heavy-duty vehicles.

[0169] Fig.1 and 3-9 show example configurations with the relative arrangement 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 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.In yet another example, elements shown above / below each other, on opposite sides of each other, or to the left / right of each other may be referred to as such in relation 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 "topmost" on the component, and a bottommost element or a bottommost point of the element may be referred to as "bottommost" on the component. As used herein, topmost / bottommost, 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 each other. Thus, elements shown above other elements are, in one example, positioned vertically above the other elements.As yet another example, shapes of elements depicted within the figures may be referred to as having those shapes (e.g., being 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. Furthermore, an element shown inside another element or shown outside another element may be referred to as such in one example.

[0170] In this way, a transmission arrangement has two wet clutches, a first wet clutch, and a brake clutch for shifting between two motors and / or two gears, with the first motor being able to drive a shaft via one of the two one-way clutches. The technical effect of the presented transmission is a flexible solution suitable for various heavy-duty applications.

[0171] It should be noted that the example control and estimation routines included herein may be used in various configurations of internal combustion engines and / or vehicle systems. The control methods and routines disclosed herein may be stored as executable instructions in non-transitory memory and may be executed by the control system, including the controller, in combination with the various sensors, actuators, and other hardware of the internal combustion engine. The specific routines described herein may be one or more of a variety of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. Thus, various illustrated actions, operations, and / or functions may be performed in the order illustrated, in parallel, or in some cases omitted.Accordingly, the order of processing is not required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for convenience of illustration and description only. One or more of the illustrated actions, operations, and / or functions may be performed repeatedly depending on the strategy used. Furthermore, the described actions, operations, and / or functions may graphically represent code to be programmed into the non-transitory memory of the computer-readable storage medium in the engine control system, wherein the described actions are carried out by execution of the instructions in a system including the various hardware components of the engine in combination with the electronic controller.

[0172] It should be understood that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments should not be considered in a limiting sense, as many variations are possible. For example, the technology described above may be applied to V-6, I-4, I-6, V-12, horizontally opposed 4-cylinder, and other engine types. Unless expressly stated otherwise, the terms "first," "second," "third," etc., are not intended to denote order, position, quantity, or importance, but are used merely to distinguish among the individual elements. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or characteristics disclosed herein.

[0173] The term “approximately” means plus or minus five percent of the range, unless otherwise stated.

[0174] 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 an equivalent thereof. These claims should be understood to include incorporation of one or more of such elements, but neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by presenting new claims in this or a related application. Such claims, whether broader, narrower, of the same or different breadth as the original claims, are also considered to be included within the subject matter of the present disclosure.

Claims

[1] Arrangement comprising: a first motor (102) disposed on a first shaft (104); a second motor (106) arranged on a second shaft (108); a first wet clutch (122) selectively coupled to the first shaft (104); a second wet clutch (124) selectively coupled to an output shaft (130); a third wet clutch (126) meshing with the output shaft (130); a brake clutch (128) attached to a housing (190) of the assembly; a planetary gear set (134) comprising a sun gear (136) arranged on the second shaft (108), a planet carrier (138) meshing with the second wet clutch (124) and selectively coupled to the third wet clutch (126), and a ring gear (140) selectively coupled to the brake clutch (128) and meshing with the first wet clutch (122); and a first one-way clutch (142) and a second one-way clutch (148) opposite to the first one-way clutch (142), the first one-way clutch (142) and the second one-way clutch (148) being selectively coupled to the first shaft (104) and engaging a gear train (146, 150) to drive an auxiliary shaft (144). [2] Arrangement according to one of the preceding claims, wherein the output shaft has at least one output flange which is coupled to a drive wheel. [3] Arrangement according to one of the preceding claims, in which the output shaft is in engagement with a drive axle via a gear pass, the drive axle having at least one output flange coupled to a drive wheel. [4] An arrangement according to any one of the preceding claims, further comprising a first inverter coupled to the first motor and a second inverter coupled to the second motor. [5] An arrangement according to any preceding claim, further comprising a controller having instructions that, when executed, cause the controller to select one of a plurality of operating modes and, based on the selected operating mode, to adjust one or more of the first wet clutch, the second wet clutch, the third wet clutch, and the brake clutch to deliver power from the first motor and / or the second motor to the output shaft. [6] The assembly of claim 5, wherein the plurality of operating modes include a single-motor drive mode in a first gear, the single-motor drive mode in a second gear higher than the first gear, a dual-motor drive mode in the first gear, the dual-motor drive mode in the second gear, and a parking brake mode, wherein the single-motor drive mode is configured to drive rotation of the output shaft with the second motor, the dual-motor drive mode is configured to drive rotation of the output shaft with the first motor and the second motor, and the parking brake mode is configured to stop driven rotation of the output shaft by at least one of the first motor and the second motor. [7] An arrangement according to any preceding claim, further comprising a controller having commands which, when executed, cause the controller to adjust either the first one-way clutch or the second one-way clutch based on an indication for delivering power to the auxiliary shaft, the indication comprising a direction of rotation of the first motor. [8] An arrangement according to any preceding claim, further comprising a controller having commands which, when executed, cause the controller to switch between shift modes, the shift modes comprising a normal shift mode in a single motor drive mode between a first gear and a second gear higher than the first gear, a traction power shift mode between the single motor drive mode and a dual motor drive mode in the first gear, a speed power shift mode between the single motor drive mode and the dual motor drive mode in the second gear, and a high power shift mode in the dual motor drive mode between the first gear and the second gear. [9] Transmission, comprising: a power take-off (PTO) unit (152); an output shaft (130); a first motor (102) selectively coupled to the power take-off shaft via a first one-way clutch (142) and a second one-way clutch (148) opposite to the first one-way clutch (142), the first motor (102) further being selectively coupled to the output shaft (130) via a first gear train including a first wet clutch (122), a planetary gear set (134), and a second wet clutch (124); and a second motor (106) selectively coupled to the output shaft (130) via a second gear train comprising the planetary gear set (134), the second wet clutch (124) and a third wet clutch (126). [10] The transmission of claim 9, wherein a ring gear of the planetary gear set is engaged with the first wet clutch. [11] A transmission according to claim 9 or 10, wherein a planet carrier of the planetary gear set is engaged with the second wet clutch and is selectively coupled to the third wet clutch. [12] Transmission according to one of claims 9 to 11, wherein a sun gear of the planetary gear set is arranged on a second motor output shaft (108) of the second motor. [13] The transmission of any one of claims 9 to 12, further comprising a brake clutch (128) secured to a housing of the transmission, the brake clutch being selectively coupled to a ring gear of the planetary gear set. [14] Transmission according to one of claims 9 to 13, wherein the first wet clutch is selectively coupled to a first engine output shaft (104) of the first engine and wherein the second wet clutch is selectively coupled to the output shaft (130). [15] Transmission according to one of claims 9 to 14, wherein the third wet clutch is engaged with the output shaft.

Images