Transmission for a vehicle

Abstract

Transmission (2) for a vehicle (1), comprising: a first main shaft (24) and a second main shaft (26), wherein the first main shaft (24) is configured to connect to a first drive unit (4) and the second main shaft (26) is configured to connect to a second drive unit (6); an output wave (28); an intermediate shaft (32) which is connected to the first main shaft (24), the second main shaft (26) and the output shaft (28); a first gear pair (G1) which is connected to the first main shaft (24) and which can be detachably connected to the intermediate shaft (32) by a first coupling element (S1); a second gear pair (G2) which is connected to the second main shaft (26) and which can be detachably connected to the intermediate shaft (32) by a second coupling element (S2); a third gear pair (G3) which is connected to the intermediate shaft (32) and the output shaft (28); and a transfer case (34), comprising: a planetary gear (36) with a sun gear (38) which is connected to the output shaft (28); a ring gear (40) which can be detachably connected to a gear housing (24); and at least one planet gear (42) and one planet gear carrier (46) designed to connect to the drive wheels (16) of the vehicle (1); wherein the transmission (2) has a fourth gear pair (G4) which is connected to the first gear pair (G1) and which can be detachably connected to the planet carrier (46).

Description

TECHNICAL FIELD

[0001] The invention relates to a transmission for a vehicle, a vehicle, a method which is carried out by a control device for shifting gears in a vehicle transmission, a computer program and a computer-readable medium according to the appended claims. BACKGROUND

[0002] Heavy-duty vehicles, such as trucks and buses, can be powered by internal combustion engines. Hybrid powertrains have been developed to reduce fuel consumption and dependence on fossil fuels. A hybrid powertrain typically combines the use of a primary drive unit, such as an internal combustion engine, with a secondary drive unit, such as a battery-powered electric motor. To completely avoid the use of fossil fuels, all-electric vehicles have been developed. All-electric vehicles are powered by at least one electric machine / motor.

[0003] Heavy-duty vehicles powered by electric machines can also be equipped with a transmission in which rotational speed and torque can be transmitted and changed between the electric machines and drive shafts of the vehicle by engaging gears.

[0004] Conventional heavy-duty vehicles may be equipped with a transfer case (range transmission), which significantly increases the torque from the drive unit to the drive shafts. Such a transfer case doubles the number of gear shifts and typically features a planetary gear with a so-called lower and an upper gear, which divides the main transmission's gear shift options into a lower range position and an upper range position. In the lower range position, a gear reduction occurs via the planetary gear, while in the upper range position, the gear ratio via the planetary gear is 1:1.

[0005] The document WO 2016 / 053 171 A1 describes a hybrid powertrain with an internal combustion engine, first and second electric machines, a transmission and a transfer case. SHORT DESCRIPTION

[0006] Due to the diverse needs of heavy-duty vehicle users, the vehicle's drivetrain is often adapted to the specific requirements of the heavy-duty vehicle user. If the vehicle is used for commercial transport on roads such as highways, the transmission and drivetrain can be configured to propel the vehicle primarily at a constant, high speed. If the vehicle is used commercially in dense urban traffic with frequent deceleration and acceleration, the transmission and drivetrain can be designed for frequent braking and acceleration of the vehicle.

[0007] Heavy-duty vehicles may, under various circumstances and driving conditions, require specific torques to be transferred from the drive units to the drive shafts. However, if the drive units are electric machines, the vehicle's drivetrain may be equipped with a transmission and a transfer case (range transmission) that significantly upshifts the torque from the electric machine to the drive shafts. To avoid loss of speed and power in heavy-duty vehicles, shifting in such transmissions and transfer cases should be performed without interruption of torque in all driving and shifting situations, such as acceleration and braking, both forward and backward.

[0008] Heavy-duty vehicles may also require a large number of gears depending on the different circumstances and driving conditions in order to adapt the vehicle to different driving conditions.

[0009] Vehicles with hybrid powertrains and all-electric vehicles may require power takeoff for a power take-off (PTO) or for auxiliary components, such as air compressors or air conditioning systems. Depending on the user's requirements, such vehicles may have electric motors for propulsion that are also configured to provide the required, uninterrupted power output for consumers, such as power take-offs (PTOs) and auxiliary components. Such vehicles may also have a transmission and drivetrain adapted to the user's specific needs.

[0010] There is therefore a need to develop a transmission for a vehicle which is configured to drive the vehicle at a constant and high speed, which is further configured for frequent braking and acceleration of the vehicle, which further has a large number of gear shift steps which can be switched without interruption of the torque, and which, when switching, is capable of continuously supplying power to power consumers such as power take-offs and auxiliary components.

[0011] An object of the invention is therefore to develop a transmission for a vehicle which is designed to drive the vehicle at a constant and high speed.

[0012] Another object of the invention is to develop a transmission for a vehicle which is designed for frequent braking and acceleration of the vehicle.

[0013] Another object of the invention is to develop a transmission for a vehicle which has a large number of gear shift steps.

[0014] Another aim of the invention is to develop a transmission for a vehicle which can be shifted without interrupting the torque.

[0015] Another object of the invention is to develop a transmission for a vehicle which, when shifting, is capable of continuously supplying power to power consumers such as auxiliary drives or auxiliary components.

[0016] The objects stated herein are achieved with a transmission for a vehicle, a vehicle, a method carried out by a control device for shifting gears in a transmission for a vehicle, a computer program and a computer-readable medium according to the appended claims.

[0017] According to one variant of the invention, a transmission for a vehicle is provided. The transmission comprises: a first main shaft and a second main shaft, wherein the first main shaft is configured to be connected to a first drive unit and wherein the second main shaft is configured to be connected to a second drive unit; an output shaft; an intermediate shaft (countershaft) connected to the first main shaft, the second main shaft, and the output shaft; a first gear pair connected to the first main shaft and connectable to the intermediate shaft via a first coupling element; a second gear pair connected to the second main shaft and connectable to the intermediate shaft via a second coupling element; a third gear pair connected to the intermediate shaft and the output shaft;and a transfer case (range transmission) comprising: a planetary gear with a sun gear connected to the output shaft; a ring gear connectable to a transmission housing; and at least one planet gear and a planet gear carrier configured for connection to the drive wheels of the vehicle; wherein the transmission has a fourth gear pair connected to the first gear pair and connectable to the planet gear carrier. The term "gear" in this application and in the claims also includes "friction gear."

[0018] Such a transmission for a vehicle is designed to drive the vehicle at constant and high speeds. Such a transmission is also designed for frequent braking and acceleration of the vehicle. The transmission can have a large number of shift steps, which are shifted without interrupting torque transmission. This realizes modular design steps in a specialized dual-drive transmission to create multiple vehicle characteristics for different requirements.

[0019] According to a further variant of the invention, a method is provided which is carried out by a control device for shifting gears in a transmission for a vehicle. The transmission has a first main shaft and a second main shaft, the first main shaft being adapted for connection to a first drive unit and the second main shaft being adapted for connection to a second drive unit; an output shaft; an intermediate shaft (countershaft) connected to the first main shaft, the second main shaft and the output shaft; a first gear pair connected to the first main shaft and connectable to the intermediate shaft by a first clutch element; a second gear pair connected to the second main shaft and connectable to the intermediate shaft by a second clutch element;a third gear pair connected to the intermediate shaft and the output shaft; and a transfer case (range transmission) comprising: a planetary gear with a sun gear connected to the output shaft; a ring gear connectable to a transmission housing; and at least one planet gear and a planet carrier configured to be connected to the drive wheels of the vehicle; wherein the transmission comprises a fourth gear pair connected to the first gear pair and connectable to the planet carrier; wherein the method comprises the following steps: synchronizing the rotational speed of the planet carrier and a fourth gear of the fourth gear pair; connecting the seventh gear of the fourth gear pair to the planet carrier; disconnecting the ring gear from the transmission housing; synchronizing the rotational speed of the sun gear and the planet carrier;and connecting the sun gear and the planet gear carrier.;

[0020] Such a method, executed by a control device, for shifting gears in a transmission for a vehicle is designed to drive the vehicle at constant and high speeds. The method results in a large number of shift steps being achieved, whereby the shifts can be carried out without interruption of the torque. This realizes modular execution steps in a transmission of a dual drive unit for generating multiple vehicle characteristics according to different requirements. The method includes a powershift function of the transfer case in a dual drive configuration. With the powershift, the gears are shifted without interruption of the torque through the transmission. The powershift function provides the transmission with additional gears.In high gear ranges in the transfer case, torque is not transmitted via the tooth flanks, which improves the robustness of the planetary gear and simplifies its design.

[0021] Additional objects, advantages, and novel features of the invention will become apparent to those skilled in the art from the following details and from practice of the invention. While the invention is described in more detail below, it is evident that the invention is not limited to the specific details described. One skilled in the art, having access to the teachings provided herein, will recognize additional applications, modifications, and uses in other fields, all of which are within the scope of the invention. BRIEF DESCRIPTION OF THE CHARACTERS

[0022] For a more complete understanding of the present invention, as well as further objects and advantages thereof, the following detailed description should be read in conjunction with the accompanying figures, in which like reference numerals indicate like components throughout the several figures: Fig. 1 schematically shows a side view of a vehicle with a transmission according to an embodiment; Fig. 2 shows a schematic view of a vehicle with a transmission according to an embodiment from above; Fig. 3 - 6 show schematically transmissions according to various embodiments; Fig. 7 shows a flowchart for a method according to an embodiment; and Fig. 8 schematically shows a control device or a computer according to an embodiment. DESCRIPTION OF DETAILS

[0023] The present description provides a transmission for a vehicle. The transmission comprises: a first main shaft and a second main shaft, wherein the first main shaft is configured to be connected to a first drive unit and wherein the second main shaft is configured to be connected to a second drive unit; an output shaft; an intermediate shaft connected to the first main shaft, the second main shaft, and the output shaft; a first gear pair connected to the first main shaft and connectable to the intermediate shaft via a first clutch element; a second gear pair connected to the second main shaft and connectable to the intermediate shaft via a second clutch element; a third gear pair connected to the intermediate shaft and the output shaft; and a transfer case comprising: a planetary gear set having a sun gear connected to the output shaft;a ring gear connectable to a transmission housing; and at least one planetary gear and a planetary gear carrier configured to connect to the drive wheels of the vehicle; wherein the transmission has a fourth gear pair connected to the first gear pair and connectable to the planetary gear carrier.

[0024] The transmission for the vehicle has gears that are arranged in gear pairs with a fixed ratio. The transmission is configured to transmit rotational speed and torque via the gears. The first main shaft and the second main shaft can be arranged coaxially or parallel to each other. The shafts can transmit rotational speed and torque to the gears in the transmission. The shafts can be rotatably arranged in the transmission by means of bearings. A lubricant can be provided in the transmission to reduce wear on the shafts, gears, and bearings in the transmission. The first drive unit and the second drive unit are connected to the first main shaft and the second main shaft, respectively. The first and second drive units can be of the same type or different types.One of the first and second drive units can be an electric machine that is supplied with electrical energy from an energy storage unit, such as an electric battery. The other drive unit can then be an internal combustion engine that is supplied with fuel from a fuel tank. The output shaft can transmit rotational speed and torque from the transmission directly to the drive shaft of the vehicle or via gears in the transmission. The intermediate shaft transmits rotational speed and torque from the main shafts to the output shaft or in the reverse direction. The first gear pair has two gears. A first gear is connected to the first main shaft and a second gear is connectable to the intermediate shaft. The first coupling element is configured to connect the second gear of the first gear pair to the intermediate shaft.The first clutch element may comprise splined portions disposed on the second gear and on the intermediate shaft, these portions cooperating with a first slidable sleeve that mechanically engages the splined portions of the second gear and the intermediate shaft. In the released state, relative rotation can occur between the second gear and the intermediate shaft. Alternatively, the first clutch element may comprise a friction clutch. The second gear pair comprises two gears. A third gear is connected to the second main shaft, and a fourth gear is connectable to the intermediate shaft. The second clutch element is configured to connect the fourth gear of the second gear pair to the intermediate shaft.The second clutch element may comprise splined portions formed on the fourth gear and the intermediate shaft, which portions cooperate with a second slidable sleeve that mechanically engages the splined portions of the fourth gear and the intermediate shaft. In the released state, relative rotation between the fourth gear and the intermediate shaft is possible. Alternatively, the second clutch element may also comprise a friction clutch. The third gear pair has two gears. A fifth gear is connected to the intermediate shaft, and a sixth gear is connected to the output shaft.

[0025] To shift up the torque and thus increase the torque of the transmission's output shaft, the transfer case is arranged in the transmission. The transfer case can be configured as a planetary gear, but can also be configured as one or more gear pairs. The transfer case can be configured as a planetary gear with a sun gear, a planet carrier on which a set of planet gears or at least one planet gear is mounted, and it can be provided with a ring gear. The set of planet gears interacts with the ring gear and the sun gear. The output shaft of the transmission is connected to the sun gear. The planet carrier is configured for connection to the drive wheels of the vehicle. An output shaft can be connected between the planet carrier and the drive wheels of the vehicle. The transmission housing is a non-rotating component.The transmission housing can be connected to the vehicle. To enable shifting in the lower range via the transfer case, the ring gear can be connected to the transmission housing. The fourth gear pair can include a seventh gear, which is rotatably mounted on the output shaft.

[0026] According to one example, the first gear pair and the fourth gear pair have a common gear.

[0027] The fourth gear pair may include the second gear of the first gear pair and the seventh gear. Torque and rotational speed generated by the first electric machine may be transmitted directly from the first electric machine to the planetary gear carrier of the transfer case via the first, second, and seventh gears.

[0028] According to one example, the common gear of the first and fourth gear pairs is connectable to the intermediate shaft and this connection can be canceled.

[0029] The second gear is rotatably mounted on the intermediate shaft. The second gear can also be released from the intermediate shaft using the first clutch element. Thus, the torque and rotational speed generated by the first electric motor can be directly transmitted from the first electric motor to the planetary gear carrier, independent of the rotational speed and torque of the intermediate shaft.

[0030] According to one example, the fourth gear pair is selectively connectable to the planetary gear carrier via a third clutch element.

[0031] The seventh gear is connectable to the planet carrier via the third clutch element. The third clutch element is thus configured to connect the seventh gear to the planet carrier. The third clutch element may comprise splined portions formed on the seventh gear and the planet carrier, wherein these portions cooperate with a third displaceable sleeve that mechanically engages the splined portions of the seventh gear and the planet carrier. In the released state, relative rotation between the seventh gear and the planet carrier is possible. Alternatively, the third clutch element may also comprise a friction clutch.

[0032] According to one example, the third clutch element is configured to connect and release the fourth gear pair with respect to the planetary gear carrier by means of a first actuator.

[0033] The third clutch element may include splined portions formed on the seventh gear and the planetary gear carrier, which portions cooperate with a third slidable sleeve that mechanically engages the splined portions of the seventh gear and the planetary gear carrier. The third clutch element may be axially slidable with the first actuator. The first actuator may be electrically, pneumatically, or hydraulically controlled. The first actuator may be connected to a first push or pull rod, which in turn is connected to a first sliding fork. The first sliding fork may be connected to the third clutch element.

[0034] According to one example, the output shaft is selectively connectable to the planetary gear carrier by means of a fourth coupling element.

[0035] The output shaft is selectively connectable to the planetary gear carrier via a fourth clutch element. The fourth clutch element is thus configured to connect the output shaft to the planetary gear carrier. The fourth clutch element may comprise splined portions on the output shaft and the planetary gear carrier, wherein these portions cooperate with a fourth slidable sleeve that mechanically engages the splined portions of the output shaft and the planetary gear carrier. In the released state, relative rotation between the output shaft and the planetary gear carrier is possible. Alternatively, the third clutch element may comprise a friction clutch.

[0036] According to one example, the fourth clutch element is configured to connect or release the output shaft with respect to the planetary gear carrier by means of a second actuator.

[0037] The fourth clutch element may include splined portions on the output shaft and the planetary gear carrier, which portions cooperate with a fourth displaceable sleeve that mechanically engages the splined portions of the output shaft and the planetary gear carrier. The fourth clutch element may be axially displaceable by the second actuator. The second actuator may be electrically, pneumatically, or hydraulically controlled. The second actuator may be connected to a second push-pull rod, which in turn is connected to a second sliding fork. The second sliding fork may be connected to the fourth clutch element.

[0038] According to one example, the ring gear is selectively connectable to the transmission housing via a fifth clutch element.

[0039] The ring gear is selectively connectable to the transmission housing via the fifth clutch element. The fifth clutch element is thus configured to connect the ring gear to the transmission housing. The fifth clutch element may comprise splined portions on the ring gear and the transmission housing, which portions cooperate with a fifth slidable sleeve that mechanically engages the splined portions of the ring gear and the transmission housing. In the released state, relative rotation between the ring gear and the transmission housing is possible. Alternatively, the fifth clutch element may also comprise a friction clutch.

[0040] According to one example, the fifth coupling element is configured to connect the ring gear to the transmission housing by means of a third actuator and to release this connection.

[0041] The fifth clutch element may have splined portions on the ring gear and the gear housing, which portions interact with a fifth displaceable sleeve that mechanically engages the splined portions of the ring gear and the gear housing. The fifth clutch element may be axially displaceable with the third actuator. The third actuator may be electrically, pneumatically, or hydraulically controlled. The third actuator may be connected to a third push-pull rod, which in turn is connected to a third sliding fork. The third sliding fork may be connectable to the fifth clutch element.

[0042] According to one example, the fifth clutch element is configured to connect the ring gear to the transmission housing via the second actuator and to release this connection.

[0043] On the other hand, the second actuator, which is configured to axially displace the fourth coupling element, can also axially displace the fifth coupling element. The second actuator is connected to the second push-and-pull rod, which in turn is connected to the second sliding fork. The second sliding fork is connected to the fourth coupling element. The third sliding fork, which is connected to the fifth coupling element, can also be connected to the second push-and-pull rod. The fourth and fifth coupling elements can also be displaced simultaneously by the second actuator. Thus, the total number of components can be kept low because only one actuator is required to displace the fourth and fifth coupling elements.

[0044] According to one example, the planetary gear carrier is configured for selective connection to the drive wheels of the vehicle via a sixth clutch element.

[0045] The planetary gear carrier is thus selectively connectable to the drive gears via the sixth clutch element. The sixth clutch element is thus configured to connect the planetary gear carrier to the drive gears. The sixth clutch element may comprise splined portions disposed on the planetary gear carrier and a drive shaft component, the latter being connected to the drive gears, and wherein said portions cooperate with a sixth displaceable sleeve, which mechanically engages the splined portions of the planetary gear carrier and the drive shaft component. In the released state, relative rotation between the planetary gear carrier and the drive gears is possible. Alternatively, the sixth clutch element may also comprise a friction clutch.

[0046] According to one example, the sixth clutch element is configured to connect the planetary gear carrier to the drive wheels via a fourth actuator and to release this connection.

[0047] The sixth clutch element may include splined portions on the planetary gear carrier and a drive shaft component connected to the drive shafts, these portions cooperating with a sixth slidable sleeve that mechanically engages the splined portions of the planetary gear carrier and the drive shaft component. The sixth clutch element may be axially displaceable by means of the fourth actuator. The fourth actuator may be electrically, pneumatically, or hydraulically controlled. The fourth actuator may be connected to a fourth push-pull rod, which in turn is connected to a fourth sliding fork. The fourth sliding fork may be connected to the sixth clutch element.

[0048] According to one example, the ring gear is configured for selective connection to the drive wheels via the sixth clutch element.

[0049] The ring gear is selectively connectable to the drive gears via the sixth clutch element. The sixth clutch element is thus configured to connect the ring gear to the drive gears. The sixth clutch element may include splined portions on the ring gear and a drive shaft component connected to the drive gears, wherein the portions cooperate with a sixth slidable sleeve that mechanically engages the splined portions of the ring gear and the drive shaft component. In the released state, relative rotation between the ring gear and the drive gears is enabled.

[0050] According to one example, a first power consumer is connected to the first main shaft and a second power consumer is connected to the second main shaft.

[0051] When shifting, the transmission is capable of continuously supplying power to power consumers, such as power take-offs and auxiliary components. The first and second power consumers can be disconnected from their respective main shafts.

[0052] According to one example, the first drive unit is a first electric machine and the second drive unit is a second electric machine.

[0053] The first and second electrical machines may be of the same type or different types. The first and second main shafts may be connectable via a connecting element, allowing the power of both electrical machines to be used simultaneously.

[0054] According to the present description, a vehicle is provided. The vehicle has the transmission described herein. Such a vehicle is configured for driving at constant and high speeds. The vehicle is further configured for frequent braking and acceleration. The transmission in the vehicle can have a large number of shift steps, which can be shifted without interrupting torque transmission. This realizes modular design steps of a special dual-drive transmission for generating multiple vehicle characteristics for different requirements.

[0055] According to the present description, a method is also provided, which is carried out by a control device, for shifting gears in a transmission for a vehicle. The transmission has a first main shaft and a second main shaft, the first main shaft being adapted for connection to a first drive unit and the second main shaft being adapted for connection to a second drive unit; an output shaft; an intermediate shaft connected to the first main shaft, the second main shaft, and the output shaft; a first gear pair connected to the first main shaft and connectable to the intermediate shaft via a first clutch element; a second gear pair connected to the second main shaft and connectable to the intermediate shaft via a second clutch element; a third gear pair connected to the intermediate shaft and the output shaft;and a transfer case comprising: a planetary gear set with a sun gear connected to the output shaft; a ring gear connectable to a transmission housing; and at least one planet gear and a planet gear carrier configured to connect to drive wheels of the vehicle; wherein the transmission has a fourth gear pair connected to the first gear pair and connectable to the planet gear carrier; wherein the method comprises the steps of: synchronizing the rotational speeds of the planet gear carrier and a seventh gear of the fourth gear pair; connecting the seventh gear of the fourth gear pair to the planet gear carrier; separating the ring gear from the transmission housing; synchronizing the rotational speeds of the sun gear and the planet gear carrier; and connecting the sun gear and the planet gear carrier.

[0056] The process steps shift gears in the transfer case from lower to higher ranges. The first process step begins when the transfer case is in a lower gear position.

[0057] The gearbox has gears connected to form gear pairs with a fixed ratio. The gearbox is configured to transmit rotational speed and torque via the gears. The first main shaft and the second main shaft may be arranged coaxially or parallel to each other. The shafts may transmit rotational speed and torque to the gears in the gearbox. The shafts may be rotatably mounted in the gearbox with bearings. A lubricant may be provided in the gearbox to reduce wear on the shafts, gears, and bearings in the gearbox. The first drive unit and the second drive unit are connected to the first main shaft and the second main shaft, respectively. The first and second drive units may be of the same type or they may be of different types.One of these drive units can be an electric machine that is supplied with electrical power from an energy storage device, such as an electric battery. The other of these drive units can then be an internal combustion engine that is supplied with fuel from a fuel tank. The output shaft can transmit rotational speed and torque related to the transmission directly to the drive wheels of the vehicle via gears in the transmission. The intermediate shaft transmits rotational speed and torque from the main shaft to the output shaft or in the opposite direction. The first gear pair has two gears. A first gear is connected to the first main shaft and a second gear is connectable to the intermediate shaft. The first coupling element is configured to connect the second gear of the first gear pair to the intermediate shaft.The first clutch element can have splined portions on the second gear and the intermediate shaft, wherein the portions cooperate with a first displaceable sleeve that mechanically engages the splined portions of the second gear and the intermediate shaft. In the released state, relative rotation between the second gear and the intermediate shaft is possible. On the other hand, the first clutch element can also have a friction clutch. The second gear pair has two gears. A third gear is connected to the second main shaft, and a fourth gear is connectable to the intermediate shaft. The second clutch element is configured to connect the fourth gear of the second gear pair to the intermediate shaft.The second clutch element may comprise splined portions on the fourth gear and the intermediate shaft, these portions cooperating with a second slidable sleeve that mechanically engages the splined portions of the fourth gear and the intermediate shaft. In the released state, relative rotation between the fourth gear and the intermediate shaft is possible. The second clutch element, on the other hand, may comprise a friction clutch. The third gear pair has two gears. A fifth gear is connected to the intermediate shaft, and a sixth gear is connected to the output shaft.

[0058] The transfer case is provided in the transmission to shift up the torque and thus amplify the torque at the output shaft of the transmission. The transfer case can be designed as a planetary gear, but it can also be formed by a pair of gears or by several pairs of gears. The transfer case can also be designed as a planetary gear with a sun gear, a planet gear carrier on which a set of planet gears or at least one planet gear is mounted, and a ring gear. The set of planet gears interacts with the ring gear and the sun gear. The output shaft of the transmission is connected to the sun gear. The planet gear carrier is designed to be connected to the drive wheels of the vehicle. A drive shaft can be connected between the planet gear carrier and the drive wheels of the vehicle. The transmission housing is a non-rotating component.The transmission housing can be permanently connected to the vehicle. To enable shifting in the lower range via the transfer case, the ring gear can be connected to a transmission housing. The fourth gear pair can have a seventh gear, which is rotatably mounted on the output shaft.

[0059] The method step of synchronizing the rotational speeds of the planetary gear carrier and a seventh gear of the fourth gear pair may include increasing or decreasing the rotational speed of the planetary gear carrier to the same rotational speed as the seventh gear of the fourth gear pair. Alternatively, or in combination with this feature, this method step may include increasing or decreasing the rotational speed of the seventh gear to the same rotational speed as that of the planetary gear carrier.

[0060] The process step in which the seventh gear of the fourth gear pair is connected to the planet carrier causes the seventh gear and the planet carrier to rotate at the same speed.

[0061] The process step in which the ring gear is separated from the gear housing enables the ring gear to rotate independently of the gear housing. Before separating the ring gear from the gear housing, a torque balance should be created between the ring gear and the gear housing. To separate the ring gear and the gear housing, the first and / or second drive unit is controlled to achieve a torque balance between the ring gear and the gear housing. Once the torque balance is achieved, the ring gear is separated from the gear housing, so that the ring gear and the gear housing are no longer mechanically connected.

[0062] Torque balance refers to a condition in which a torque acts on the ring gear in the planetary gear train equal to the product of the torque acting on the planetary gear carrier and the planetary gear ratio, while at the same time a torque acts on the sun gear of the planetary gear train equal to the product of the torque acting on the planetary gear carrier (1 - the planetary gear ratio). If two of the components of the planetary gear train—the sun gear, the internal ring gear, or the planetary gear carrier—coupling device is used, this coupling device does not transmit torque between the parts of the planetary gear train when torque balance exists. Accordingly, the coupling device can be easily operated, and the components of the planetary gear train can be separated.

[0063] The method step of synchronizing the rotational speed of the sun gear and the planet gear carrier may include increasing or decreasing the rotational speed of the sun gear to match the rotational speed of the planet gear carrier. Alternatively, or in combination, this method step may also include increasing or decreasing the rotational speed of the planet gear carrier to match the rotational speed of the sun gear.

[0064] The process step of connecting the sun gear and the planet gear carrier results in the sun gear and the planet gear carrier rotating at the same speed.

[0065] According to one example, the step of synchronizing the rotational speeds of the planetary gear carrier and a seventh gear of the fourth gear pair includes synchronizing the rotational speeds of the planetary gear carrier and a seventh gear of the fourth gear pair by means of the first drive unit.

[0066] The rotational speed of the planetary gear carrier is determined by the rotational speed of the drive wheels and thus by the speed of the vehicle. By increasing or decreasing the speed of the first drive unit, the rotational speeds of the planetary gear carrier and a seventh gear can be synchronized depending on the respective rotational speed of the seventh gear and the planetary gear carrier. The rotational speed of the first drive unit is transmitted to the seventh gear via the first and second gears.

[0067] According to one example, the step of connecting the seventh gear of the fourth gear pair to the planetary gear carrier includes connecting the seventh gear of the fourth gear pair to the planetary gear carrier by means of a third coupling element.

[0068] The seventh gear is thus connectable to the planetary gear carrier by means of a third coupling element. The third coupling element is thus configured to connect the seventh gear to the planetary gear carrier. The third coupling element can have splined portions on the seventh gear and the planetary gear carrier, wherein these portions interact with a third displaceable sleeve that mechanically engages the splined portions of the seventh gear and the planetary gear carrier. In the released state, relative rotation between the seventh gear and the planetary gear carrier is possible. The third coupling element can also comprise a friction clutch. The third coupling element is configured to connect and disconnect the fourth gear pair with respect to the planetary gear carrier by means of a first actuator.The third clutch element may have splined portions on the seventh gear and the planetary gear carrier, which portions interact with a third displaceable sleeve that mechanically engages the splined portions of the seventh gear and the planetary gear carrier. The third clutch element may be axially displaceable with the first actuator. The first actuator may be electrically, pneumatically, or hydraulically controlled. The first actuator may be connected to a first push-pull rod, which is connected to a first shift fork (shift fork). The first shift fork may be connected to the third clutch element.

[0069] According to one example, the step of separating the ring gear from the transmission housing includes separating the ring gear from the transmission housing by controlling a fifth clutch element.

[0070] The ring gear is selectively connectable to the transmission housing via the fifth clutch element. The fifth clutch element is thus configured to connect the ring gear to the transmission housing. The fifth clutch element may comprise splined portions formed on the ring gear and the transmission housing, wherein these portions interact with a fifth displaceable sleeve that mechanically engages the splined portions of the ring gear and the transmission housing. In the released state, relative rotation between the ring gear and the transmission housing is enabled. The fifth clutch element may, on the other hand, also comprise a friction clutch. The fifth clutch element is configured to connect and disconnect the ring gear and the transmission housing by means of a third actuator.The fifth clutch element may have splined portions on the ring gear and the gear housing, which portions cooperate with a fifth displaceable sleeve that mechanically engages the splined portions of the ring gear and the gear housing. The fifth clutch element may be axially displaceable with the third actuator. The third actuator may be electrically, pneumatically, or hydraulically controlled. The third actuator may be connected to a third push-pull rod, which in turn is connected to a third sliding fork. The third sliding fork may be connected to the fifth clutch element.

[0071] According to one example, the step of synchronizing the rotational speeds of the sun gear and the planetary gear carrier includes synchronizing the rotational speeds of the sun gear and the planetary gear carrier by means of the second drive unit.

[0072] The rotational speed of the planetary gear carrier is determined by the rotational speed of the drive wheels and thus by the speed of the vehicle. By increasing or decreasing the speed of the second drive unit, depending on the respective rotational speeds of the sun gear and the planetary gear carrier, the rotational speed of the planetary gear carrier can be synchronized with that of the sun gear. The rotational speed of the second drive unit is transmitted to the sun gear via the second and third gear pairs.

[0073] According to one example, the step of connecting the sun gear and the planet gear carrier includes connecting the sun gear and the planet gear carrier by means of a fourth coupling element.

[0074] The sun gear is connected to the output shaft of the transmission. The sun gear, and thus also the output shaft, are selectively connectable to the planet gear carrier via a fourth clutch element. The fourth clutch element is thus configured to connect the output shaft to the planet gear carrier. The fourth clutch element may comprise splined portions formed on the output shaft and the planet gear carrier, said portions cooperating with a fourth displaceable sleeve which mechanically engages the splined portions of the output shaft and the planet gear carrier. In the released state, relative rotation between the output shaft and the planet gear carrier is possible. Alternatively, the clutch element may also comprise a friction clutch. The fourth clutch element is configured to connect and disconnect the output shaft with respect to the planet gear carrier by means of a second actuator.The fourth clutch element may include splined portions on the output shaft and the planetary gear carrier, which portions cooperate with a fourth displaceable sleeve that mechanically engages the splined portions of the output shaft and the planetary gear carrier. The fourth clutch element may be axially displaceable by means of the second actuator. The second actuator may be electrically, pneumatically, or hydraulically controlled. The second actuator may be connected to a second push or pull rod, which in turn is connected to a second sliding fork. The second sliding fork may be connected to the fourth clutch element.

[0075] The present description also relates to a computer program with instructions that, when executed by a computer, cause the computer to perform the methods described herein. The description further relates to a computer-readable medium with instructions that, when executed by a computer, cause the computer to perform the methods described herein.

[0076] The present description will now be explained in more detail by way of example with reference to the accompanying figures.

[0077] Fig. 1 schematically shows a side view of a vehicle 1 with a transmission 2 according to an example. The transmission 2 is arranged in a driveline 3 having first and second drive units 4, 6. The transmission 2 is connected to the drive units 4, 6 and a propeller shaft 8, which in turn is connected to the drive shafts 10 of the rear axle 12. The drive shafts 10 are connected to the propeller shaft 8 such that the propeller shaft 8 extends between the transmission 2 and the drive shafts 10. The drive units 4, 6 are arranged between the transmission 2 and the rear axle 12 in the longitudinal direction of the vehicle 1. An energy storage unit 14 is arranged in front of the driveline 3. The energy storage unit 14 is connected to the drive units 4, 6 and supplies power to the drive unit 4. The drive units 4, 6 are connected in series.If the drive units 4, 6 are electric motors, they can transmit electrical power to the energy storage unit 14. If the drive units 4, 6 are electric motors, they can supply electrical energy to each other. First and second power consumers 20, 22 are connected to the transmission 2. The vehicle 1 has rear drive wheels 16 and front wheels 18. The front wheels 18 can be steerable.

[0078] Fig. 2 schematically shows a plan view of a vehicle 1 with a transmission 2 according to an example. Two drive units 4, 6 are arranged in series in the drive train 3. The drive units 4, 6 can be first and second electric machines 4, 6, which together or individually deliver torque and power to propel the vehicle 1. The drive units 4, 6 and the propeller shaft 8 are connected in parallel to the transmission 2. The axial extent of the drive train 2 in the longitudinal direction of the vehicle 1, starting from the connection between the propeller shaft 8 and the drive shaft 10, corresponds to the common axial extent of the propeller shaft 8 and the transmission 2 in the longitudinal direction of the vehicle 1. The transmission 2 is accommodated in a transmission housing 64.

[0079] The Fig. 3 - 6 schematically show transmissions 2 according to various examples. The transmission 2 has a first main shaft 24 and a second main shaft 26. The first main shaft 24 is configured for connection to a first drive unit 4, and the second main shaft 26 is configured for connection to a second drive unit 6. The first and second main shafts 24, 26 can be connected to one another by a clutch device 25. By connecting the first and second main shafts 24, 26 by means of the clutch device, torque from both drive units 4, 6 can be input into the transmission 2. An output shaft 28 is provided. An intermediate shaft (countershaft) 32 is connected to the first main shaft 24, the second main shaft 26, and the output shaft 28. A first gear pair G1 is connected to the first main shaft 24 and is connectable to the intermediate shaft 32 via a first clutch element S1.A second gear pair G2 is connected to the second main shaft 26 and connectable to the intermediate shaft 28 via a second clutch element S2. A third gear pair G3 is connected to the intermediate shaft 32 and the output shaft 28. A transfer case (range transmission) 34 has a planetary gear 36. The planetary gear 36 has a sun gear 38 connected to the output shaft 28; furthermore, a ring gear 40 connectable to a transmission housing 64; and at least one planet gear 42 and a planet gear carrier 46 configured to connect to drive wheels 16 of the vehicle 1 (. Fig. 1). The transmission 2 has a fourth gear pair G4, which is connected to the first gear pair G1 and can be connected to the planetary gear carrier 46.

[0080] The first main shaft 24 and the second main shaft 26 are arranged coaxially with each other. The shafts 24, 26 transmit rotational speed and torque to the gears in the transmission 2. The shafts 24, 26 are rotatably arranged in the transmission 2. The first drive unit 4 and the second drive unit 6 are connected to the respective first main shaft and the second main shaft, respectively. The first and second drive units 4, 6 are electrical machines 4, 6, which are supplied with electrical power from the energy storage unit 14 ( Fig. 1 and Fig. 2).

[0081] The intermediate shaft 32 transmits rotational speed and torque from the main shafts 24, 26 to the output shaft 28. Rotational speed and torque can also be transmitted from the output shaft 28 to the main shafts 24, 26. The first gear pair G1 has two gears. A first gear 48 is connected to the first main shaft 24, and a second gear 50 is connectable to the intermediate shaft 32. The first clutch element S1 is configured to connect the second gear 50 of the first gear pair G1 to the intermediate shaft 32. The first clutch element S1 may include splined portions formed on the second gear 50 and the intermediate shaft 32, which portions cooperate with a first slidable sleeve 52 that mechanically engages the splined portions on the second gear 50 and the intermediate shaft 32.In the released state, relative rotation between the second gear 50 and the intermediate shaft 32 is possible. The second gear pair G2 has two gears. A third gear 54 is connected to the second main shaft 26, and a fourth gear 56 is connectable to the intermediate shaft 32. The second clutch element S2 is configured to connect the fourth gear 56 of the second gear pair G2 to the intermediate shaft 32. The second clutch element S2 may have splined portions formed on the fourth gear 56 and the intermediate shaft 32, which portions cooperate with a second slidable sleeve 58 that mechanically engages the splined portions of the fourth gear 56 and the intermediate shaft 32. The third gear pair G3 has two gears. A fifth gear 60 is connected to the intermediate shaft 32 and a sixth gear 62 is connected to the output shaft 28.

[0082] The transfer case 34 contains the planetary gear 36 with the sun gear 38, the planet gear carrier 46, on which planet gears 42 are mounted, and a ring gear 40. The planet gears 42 interact with the ring gear 40 and the sun gear 38. The output shaft 28 of the transmission 2 is connected to the sun gear 38. The planet gear carrier 46 is designed for connection to the drive wheels 16 of the vehicle 1. The cardan shaft 8 is connected between the planet gear carrier 46 and the drive wheels 16 of the vehicle 1. The transmission housing 64 is a non-rotatable component. The transmission housing 64 is fixedly connected to the vehicle 1. In order to enable shifts in the lower range by the transfer case 34, the ring gear 40 is connectable to the transmission housing 64. The fourth gear pair G4 includes a seventh gear 66 which is rotatably arranged with respect to the output shaft 28.

[0083] The first gear pair G1 and the fourth gear pair G4 share a common gear. The fourth gear pair G4 may include the second gear 50 of the first gear pair G1 and the seventh gear 66. Torque and rotational speed generated by the first electric machine 4 may be transmitted directly from the first electric machine 4 to the planetary gear carrier 46 of the transfer case 34 via the first, second, and seventh gears 48, 50, 66.

[0084] The common gear of the first and fourth gear pairs G1, G4 can be connected to and separated from the intermediate shaft 32. The second gear 50 is rotatably mounted on the intermediate shaft 32. The second gear 50 can be separated from the intermediate shaft 32 by the first clutch element S1. Thus, the torque and rotational speed generated by the first electric machine 2 can be transmitted directly from the first electric machine 2 to the planetary gear carrier 46, independent of the rotational speed and torque on the intermediate shaft 32.

[0085] The fourth gear pair G4 is selectively connectable to the planetary gear carrier 46 via a third coupling element S3. The seventh gear 66 is connectable to the planetary gear carrier 46 via the third coupling element S3. The third coupling element S3 is thus configured to connect the seventh gear 66 to the planetary gear carrier 46. The third coupling element S3 may have splined portions on the seventh gear 66 and the planetary gear carrier 46, these portions cooperating with a third displaceable sleeve 68, which mechanically engages the splined portions of the seventh gear 66 and the planetary gear carrier 46.

[0086] The third clutch element S3 is configured to connect and disconnect the fourth gear pair G4 and the planetary gear carrier 46 by means of a first actuator A1. The third clutch element S3 may have splined portions formed on the seventh gear 66 and the planetary gear carrier 46, these portions cooperating with a third displaceable sleeve 68 that mechanically engages the splined portions of the seventh gear 66 and the planetary gear carrier 46. The third clutch element S3 may be axially displaceable with the first actuator A1. The first actuator A1 may be electrically, pneumatically, or hydraulically controlled. The first actuator A1 is connected to a first sliding rod 70, which in turn is connected to a first sliding fork 72. The first sliding fork 72 is connected to the third clutch element S3.

[0087] The output shaft 28 is selectively connectable to the planetary gear carrier 46 via a fourth coupling element S4. The output shaft 28 is selectively connectable to the planetary gear carrier 46 via a fourth coupling element S4. The fourth coupling element S4 is thus configured to connect the output shaft 28 and the planetary gear carrier 46. The fourth coupling element S4 may include splined portions on the output shaft 28 and the planetary gear carrier 46, these portions cooperating with a fourth displaceable sleeve 74 that mechanically engages the splined portions of the output shaft 28 and the planetary gear carrier 46.

[0088] The fourth clutch element S4 is configured to connect and disconnect the output shaft 28 and the planetary gear carrier 46 by means of a second actuator A2. The fourth clutch element S4 can have splined portions on the output shaft 28 and the planetary gear carrier 46, which portions interact with a fourth displaceable sleeve 74 that mechanically engages the splined portions of the output shaft and the planetary gear carrier 46. The fourth clutch element S4 is configured to be axially displaced with the second actuator A2. The second actuator A2 can be electrically, pneumatically, or hydraulically controlled. The second actuator A2 is connected to a second sliding rod 76, which in turn is connected to a second sliding fork 78. The second sliding fork 78 is connected to the fourth clutch element S4.

[0089] The ring gear 40 is selectively connectable to the gear housing 64 via a fifth coupling element S5. The ring gear 40 is selectively connectable to the gear housing 64 via the fifth coupling element S5. The fifth coupling element S5 is thus configured to connect the ring gear 40 and the gear housing 64. The fifth coupling element S5 may include splined portions on the ring gear 40 and the gear housing 64, which portions cooperate with a fifth displaceable sleeve 80 that mechanically engages the splined portions of the ring gear 40 and the gear housing 64.

[0090] The fifth coupling element S5 is configured to connect and disconnect the ring gear 40 and the gear housing 64 via a third actuator A3. The fifth coupling element S5 may include splined portions on the ring gear 40 and the gear housing 64, which portions interact with a fifth displaceable sleeve 80 that mechanically engages the splined portions of the ring gear 40 and the gear housing 64. The fifth coupling element S5 is configured to be axially displaced via the third actuator A3. The third actuator A3 may be electrically, pneumatically, or hydraulically controlled. The third actuator A3 may be connected to a third sliding rod 82, which is connected to a third sliding fork 84. The third sliding fork 84 is connected to the fifth coupling element S5.

[0091] According to Fig. 4, the second gear 50 is provided with a secondary gear 50'. The secondary gear 50' has a reduced diameter compared to the second gear 50. The seventh gear is connected to the secondary gear 50'. The transmission ratio of the fourth gear pair G4 is thus increased compared to a connection of the seventh gear to the second gear 50.

[0092] According to Fig. 5, the fifth coupling element S5 is configured to connect and disconnect the ring gear 40 and the gear housing 64 by means of the second actuator A2. On the other hand, the second actuator A2, which is configured to axially displace the fourth coupling element S4, can also axially displace the fifth coupling element S5. The second actuator A2 is connected to the second sliding rod 76, which is connected to the second sliding fork 78. The second sliding fork 78 is connected to the fourth coupling element S4. The third sliding fork 84, which is connected to the fifth coupling element S5, can also be connected to the second sliding rod 76. The fourth and fifth coupling elements S4, S5 are configured to be displaced simultaneously by the second actuator A2. Thus, the total number of components can be kept low because only one actuator is required to displace the fourth and fifth coupling elements S4, S5.

[0093] The planetary gear carrier 46 is configured to be selectively connected to the drive wheels 16 of the vehicle 1 via a sixth coupling element S6. The planetary gear carrier 46 is selectively connectable to the drive wheels 16 via the sixth coupling element S6. The sixth coupling element S6 is thus configured to connect the planetary gear carrier 46 and the drive wheels 16. The sixth coupling element S6 can have splined portions on the planetary gear carrier 46 and a cardan shaft S8 connected to the drive wheels 16, wherein the portions cooperate with a sixth displaceable sleeve 86, which mechanically engages the splined portions of the planetary gear carrier 46 and the component of the cardan shaft 8.

[0094] According to Fig. 6, the sixth clutch element S6 is configured to connect and disconnect the planetary gear carrier 46 and the drive gears 16 by means of a fourth actuator A4. The sixth clutch element S6 may include splined portions on the planetary gear carrier 46 and a cardan shaft component 92 connected to the drive gears 16, wherein the portions cooperate with a sixth displaceable sleeve 86 that mechanically engages the splined portions of the planetary gear carrier 46 and the cardan shaft component 92. Displacing the sixth displaceable sleeve 46 into a position where the sixth displaceable sleeve 86 mechanically engages the splined portions on the ring gear 40 and the cardan shaft component 92 results in a reverse gear. The sixth clutch element S6 may be axially displaced by the fourth actuator A4. The fourth actuator A4 may be electrically, pneumatically, or hydraulically controlled.The fourth actuator A4 is connected to a fourth sliding rod 88, which in turn is connected to a fourth sliding fork 90. ​​The fourth sliding fork 90 is connected to the sixth clutch element S6. When reverse gear is engaged, the planetary gear carrier 46 is connected to the transmission housing 64 via the third clutch element S3.

[0095] The ring gear 40 is configured to be selectively connected to the drive wheels 16 via the sixth coupling element S6. The ring gear 40 is selectively connectable to the drive wheels 16 via the sixth coupling element S6. The sixth coupling element S6 is thus configured to connect the ring gear 40 and the drive wheels 16. The sixth coupling element S6 can have splined portions on the ring gear 40 and the cardan shaft component 92 connected to the drive wheels 16, these portions cooperating with a sixth displaceable sleeve 86 that mechanically engages the splined portions of the ring gear 40 and the cardan shaft component 92.

[0096] A first power consumer 20 is connected to the first main shaft 24, and a second power consumer 22 is connected to the second main shaft 26. During gear shifting, the transmission 2 is capable of continuously supplying power to the power consumers 20, 22, which may be, for example, power take-offs or auxiliary components. The first and second power consumers 20, 22 can be disconnected from the respective main shafts 24, 26.

[0097] The transmission 2 may include a control device 100 connected to the electric machines 4, 5, the actuators A1-A4, and sensors (not shown) that determine the rotational speed, torque, and positions of various components of the transmission 2.

[0098] Fig. Fig. 7 shows a flowchart for a method which is carried out with the control device 100 for shifting gears in a transmission 2 for a vehicle 1 according to an example. The method thus relates to the shifting of gears in the transmission 2 according to the Fig. 1 to 6. The transmission 2 has a first main shaft 24 and a second main shaft 26, wherein the first main shaft 24 is configured for connection to a first drive unit 4 and wherein the second main shaft 26 is configured for connection to a second drive unit 6. An output shaft 28 is provided. An intermediate shaft 32 is connected to the first main shaft 24, as well as to the second main shaft 26 and the output shaft 28. A first gear pair G1 is connected to the first main shaft 24 and can be connected to the intermediate shaft 32 via a first clutch element S1. A second gear pair G2 is connected to the second main shaft 26 and can be connected to the intermediate shaft 32 via a second clutch element S2. A third gear pair G3 is connected to the intermediate shaft 32 and to the output shaft 28. A transfer case 34 has a planetary gear 36.The planetary gear 36 has a sun gear 38 connected to the output shaft 28; further, a ring gear 40 connectable to a transmission housing 64; and at least one planet gear 42 and a planet gear carrier 46 configured for connection to drive wheels 16 of the vehicle 1. The transmission 2 has a fourth gear pair G4 connected to the first gear pair G1 and connectable to the planet gear carrier 46.

[0099] The method includes the steps of synchronizing (s101) the rotational speeds of the planetary gear carrier 46 and a seventh gear 66 of the fourth gear pair G4; connecting (s102) the seventh gear 66 of the fourth gear pair G4 to the planetary gear carrier 46; separating (s103) the ring gear 40 from the transmission housing 64; synchronizing (s104) the rotational speeds of the sun gear 38 and the planetary gear carrier 46; and connecting the sun gear 38 and the planetary gear carrier 46.

[0100] The method steps are designed to shift the gears of the transfer case 34 from lower gear positions to higher gear positions. The first method step begins when the transfer case 34 is shifted to lower gear positions.

[0101] According to one example, the step of synchronizing s101 the rotational speeds of the planet gear carrier 46 and the seventh gear 66 of the fourth gear pair G4 includes a synchronization of the rotational speed of the planet gear carrier 46 and a seventh gear 66 of the fourth gear pair G4 by means of the first drive unit 4. According to one example, the step of connecting s102 the seventh gear 66 of the fourth gear pair G4 to the planet gear carrier 46 includes a connection s102 of the seventh gear 66 of the fourth gear pair G4 to the planet gear carrier 46 by means of a third coupling element S3.

[0102] According to one example, the step of separating s103 between ring gear 40 and gear housing 64 includes separating the ring gear 40 from the gear housing 64 by controlling a fifth clutch element S5.

[0103] According to one example, the step of synchronizing s104 the rotational speed of the sun gear 38 and the planetary gear carrier 46 includes synchronizing the rotational speeds of the sun gear 38 and the planetary gear carrier 46 by means of the second drive unit 6.

[0104] According to one example, the step of connecting s105 the sun gear 38 and the planetary gear carrier 46 includes connecting the sun gear 38 and the planetary gear carrier 46 by means of a fourth coupling element S4.

[0105] Fig.8 shows an embodiment of a device 500. The control device 100, which carries out the method, can comprise the device 500 according to one embodiment. The device 500 contains a non-volatile memory 520, a data processing unit 510, and a read / write memory 550. The non-volatile memory 520 has a first memory element 530 in which a computer program, e.g., an operating system, is stored for controlling the functions of the device 500. The device 500 can further comprise a bus controller, a serial communication port, input / output devices (I / O), an analog / digital converter (A / D), a time and data input and transmission unit, an event counter, and an interrupt controller (not shown). The non-volatile memory 520 further comprises a second memory element 540.

[0106] A computer program P is provided with routines for securely executing the program. The program P can be stored in executable form or in compressed form in a memory 560 and / or in a read / write memory 550.

[0107] If the data processing unit 510 is described here as executing a specific function, this means that the data processing unit 510 implements a specific section of the program stored in the memory 560, or that a specific section of the program stored in the read / write memory 550 is executed.

[0108] The data processing device 510 can communicate with a data input 599 via a data bus 515. The non-volatile memory 520 is used for communication with the data processing unit 510 via a data bus 512. The separately provided memory 560 is used for communication with the data processing unit 510 via a data bus 511. The read / write memory 550 is configured for communication with the data processing unit 510 via a data bus 514.

[0109] If data is received at data input 599, it is temporarily stored in the second memory element 540. Once the received data has been temporarily stored, the data processing unit 510 is able to execute the code described above.

[0110] Parts of the methods described here can be implemented by the device 500 using the data processing unit 510, which executes the programs stored in the memory 560 or in the read / write memory 550. If the device 500 executes the programs, the methods described here are executed.

[0111] The above description of examples is provided for illustrative and explanatory purposes. It is not exhaustive and does not limit the examples to the variants presented. Numerous modifications and variations will be apparent to those skilled in the art. The examples were chosen and described in detail to best illustrate the principles and practical applications and thus enable a person skilled in the art to understand examples in their various embodiments and with the respective modifications according to the desired use. The above components and features can be combined within the scope of the examples from the individual given embodiments.

Claims

[1] Transmission (2) for a vehicle (1), comprising: a first main shaft (24) and a second main shaft (26), wherein the first main shaft (24) is adapted to be connected to a first drive unit (4) and the second main shaft (26) is adapted to be connected to a second drive unit (6); an output shaft (28); an intermediate shaft (32) connected to the first main shaft (24), the second main shaft (26) and the output shaft (28); a first gear pair (G1) which is connected to the first main shaft (24) and which is detachably connectable to the intermediate shaft (32) by a first coupling element (S1); a second gear pair (G2) which is connected to the second main shaft (26) and which is detachably connectable to the intermediate shaft (32) by a second coupling element (S2); a third gear pair (G3) connected to the intermediate shaft (32) and the output shaft (28); and a transfer case (34) comprising: a planetary gear (36) with a sun gear (38) which is connected to the output shaft (28); a ring gear (40) which is detachably connectable to a gear housing (24); and at least one planetary gear (42) and one planetary gear carrier (46) arranged to be connected to the drive wheels (16) of the vehicle (1); wherein the transmission (2) has a fourth gear pair (G4) which is connected to the first gear pair (G1) and which is detachably connectable to the planetary gear carrier (46). [2] Transmission (2) according to claim 1, wherein the first gear pair (G1) and the fourth gear pair (G4) have a common gear. [3] Transmission (2) according to claim 2, wherein the common gear of the first and fourth gear pair (G1, G4) is detachably connectable to and separable from the intermediate shaft (32). [4] Transmission (2) according to one of the preceding claims, wherein the fourth gear pair (G4) is selectively detachably connectable to the planetary gear carrier (46) by a third coupling element (S3). [5] Transmission (2) according to claim 4, wherein the third clutch element (S3) is arranged to connect and disconnect the fourth gear pair (G4) and the planetary gear carrier (46) by means of a first actuator (A1). [6] Transmission (2) according to one of the preceding claims, wherein the output shaft (28) is selectively detachably connectable to the planetary gear carrier (46) by a fourth coupling element (S4). [7] Transmission (2) according to claim 6, wherein the fourth clutch element (S4) is arranged to connect and disconnect the output shaft (28) and the planetary gear carrier (46) by means of a second actuator (A2). [8] Transmission (2) according to one of the preceding claims, wherein the ring gear (40) is selectively detachably connectable to the transmission housing (24) by a fifth coupling element (S5). [9] Transmission (2) according to claim 8, wherein the fifth clutch element (S5) is arranged to connect and disconnect the ring gear (40) and the transmission housing (64) by a third actuator (A3). [10] Transmission (2) according to claims 7 and 8, wherein the fifth clutch element (S5) is arranged to connect and disconnect the ring gear (40) and the transmission housing (64) by the second actuator (A2). [11] Transmission (2) according to one of the preceding claims, wherein the planetary gear carrier (46) is arranged to be selectively connected to the drive wheels (16) of the vehicle (1) by a sixth coupling element (S6). [12] Transmission (2) according to claim 11, wherein the sixth clutch element (S6) is arranged to connect and disconnect the planetary gear carrier (46) and the drive gears (16) by a fourth actuator (A4). [13] Transmission (2) according to one of claims 11 or 12, wherein the planetary gear carrier (46) is arranged to be selectively connected to the ring gear (40) by a sixth coupling element (S6). [14] Transmission (2) according to one of the preceding claims, wherein a first power consumer (20) is connected to the first main shaft (24) and a second power consumer (22) is connected to the second main shaft (26). [15] Transmission (2) according to one of the preceding claims, wherein the first drive unit (4) is a first electric machine and the second drive unit (6) is a second electric machine. [16] Vehicle (1) comprising a transmission (2) according to one of the preceding claims. [17] Method, carried out by a control device (100), for shifting gears in a transmission (2) for a vehicle (1), the transmission (2) comprising: a first main shaft (24) and a second main shaft (26), wherein the first main shaft (24) is adapted to be connected to a first drive unit (4) and wherein the second main shaft (26) is adapted to be connected to a second drive unit (6); an output shaft (28); an intermediate shaft (32) connected to the first main shaft (24), the second main shaft (26) and the output shaft (28); a first gear pair (G1) which is connected to the first main shaft (24) and which is detachably connectable to the intermediate shaft (32) by a first coupling element (S1); a second gear pair (G2) which is connected to the second main shaft (26) and which is detachably connectable to the intermediate shaft (32) by a second coupling element (S2); a third gear pair (G3) connected to the intermediate shaft (32) and the output shaft (28); and a transfer case (34) comprising: a planetary gear (36) with a sun gear (38) which is connected to the output shaft (28); a ring gear (40) which is detachably connectable to a gear housing (24); and at least one planetary gear (42) and one planetary gear carrier (46) arranged to be connected to the drive wheels (16) of the vehicle (1); wherein the transmission (2) has a fourth gear pair (G4) which is connected to the first gear pair (G1) and which is detachably connectable to the planetary gear carrier (46); the method comprising the following steps: Synchronizing (s101) the rotational speeds of a planetary gear carrier (46) and a seventh gear (66) of the fourth gear pair (G4); Connecting (s102) the seventh gear (66) of the fourth gear pair (G4) to the planet carrier (46); Separating (s103) the ring gear (40) from the gear housing (64); Synchronizing (s104) the rotational speeds of the sun gear (38) and the planet gear carrier (46); and Connecting (s105) the sun gear (38) and the planet gear carrier (46). [18] Method according to claim 17, wherein the step of synchronizing (s101) the rotational speeds of the planetary gear carrier (46) and the seventh gear (66) of the fourth gear pair (G4) includes synchronizing the rotational speeds of the planetary gear carrier (46) and a seventh gear (66) of the fourth gear pair (G4) by means of the first drive unit (4). [19] Method according to one of claims 17 and 18, wherein the step of connecting (s102) the seventh gear (66) of the fourth gear pair (G4) to the planetary gear carrier (46) includes a connection (s102) of the seventh gear (66) of the fourth gear pair (G4) to the planetary gear carrier (46) by means of a third coupling element (S3). [20] The method according to any one of claims 17-19, wherein the step of separating (s103) the ring gear (40) from the gear housing (64) includes separating the ring gear (40) from the gear housing (64) by controlling a fifth clutch element (S5). [21] Method according to one of claims 17-20, wherein the step of synchronizing (s104) the rotational speeds of the sun gear (38) and the planetary gear carrier (46) includes synchronizing the rotational speeds of the sun gear (38) and the planetary gear carrier (46) by means of the second drive unit (6). [22] The method according to any one of claims 17-21, wherein the step of connecting (s105) the sun gear (38) and the planetary gear carrier (46) includes connecting the sun gear (38) and the planetary gear carrier (46) by a fourth coupling element (S4). [23] Computer program (P) with instructions which, when the program is executed in a computer (100; 500), cause the computer (100; 500) to carry out the method according to one of claims 17-22. [24] A computer-readable medium comprising instructions which, when executed by a computer (100; 500), cause the computer (100; 500) to perform the method according to any one of claims 17-22.

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