Motor vehicle transmissions with planetary gear sets with the same fixed gear ratio

Abstract

Motor vehicle transmission for a hybrid powertrain, comprising the transmission elements: Gearbox housing (0), gearbox input shaft (1), a gearbox output shaft (2), first planetary gear set (PR1) with a first sun gear (S1), a first ring gear (H1) and a first web shaft (5) with a planet gear (P1) rotatably mounted on it, a second planetary gear set (PR2) with a second sun pinion (S2), a second ring gear (H2) and a second shaft (2a) with a planet gear (P2) rotatably mounted on it, and a third planetary gear set (PR3) with a third sun pinion (S3), a third ring gear (H3) and a third shaft (7) with a planet gear (P3) rotatably mounted on it, wherein two of the three sun gears (S1, S2, S3) are connected to each other in a rotationally fixed manner by a central shaft (3) and wherein the second web shaft (2a) is connected to the third ring gear (H3) in a rotationally fixed manner, where at least two of the three planetary gear sets are first, The second or third planetary gear set (PR1, PR2, PR3) must have the same fixed gear ratio and wherein the first sun gear (S1) and the second ring gear (H2) can each be selectively connected to the gearbox housing (0) in a rotationally fixed manner and wherein the second and third sun pinions (S2, S3) are connected to the central shaft (3) in a rotationally fixed manner and wherein the first ring gear (H1) is connected to the second and third sun pinions (S2, S3) in a rotationally fixed manner, characterized by the fact that in the gearbox housing (0) the gearbox input shaft (1) and the gearbox output shaft (2) are rotatably mounted about a central axis (ZA) and arranged concentrically to it and that the second web shaft (2a) is connected to the transmission output shaft (2) in a rotationally fixed manner and that the third web shaft (7) can be selectively connected to the transmission input shaft (1) in a rotationally fixed manner with a second coupling (K17) and that the transmission output shaft (2) is non-rotatably connected to the third ring gear (H3) and that the transmission input shaft (1) can be selectively connected to the first web shaft (5) in a rotationally fixed manner with a first clutch (K15) and that the central shaft (3) can be selectively connected to the first web shaft (5) in a rotationally fixed manner by means of a fourth coupling (K35).

Description

[0001] The invention relates to a motor vehicle transmission with three planetary gear sets according to the preamble of the first patent claim; such transmissions are known from the prior art, in particular from EP 1 396 369 A2.

[0002] The invention is described below using a passenger car hybrid drive train; this is not to be understood as a limitation of the invention.

[0003] Current hybrid transmissions are generally based on conventional automatic transmissions designed for a purely combustion engine drivetrain. For hybridization, an electromechanical energy converter is additionally integrated into the already limited installation space. This can result in the disadvantage that, due to the limited installation space, only limited electrification can usually be achieved, particularly with regard to the electrically deliverable drive power. This means that only relatively low drive / driving power is possible via the purely electric drive system. Furthermore, such a conventional automatic transmission, which has been further developed into a hybrid transmission, is not specifically designed for a hybrid drivetrain.

[0004] US 2007 0021258 A1 deals with an electrified motor vehicle transmission with planetary gear sets. US 2009 / 0275437 A1 deals with an electrified motor vehicle transmission for hybrid vehicles. US 7 396 305 B2 deals with an electrified motor vehicle transmission with three planetary gear sets. DE 11 2006 003 286 T5 deals with an electrically adjustable motor vehicle transmission with three planetary gear sets. DE 11 2005 003 356 T5 deals with an electrically adjustable motor vehicle transmission with three planetary gear sets. DE 10 2006 028 789 A1 deals with a multi-stage transmission. DE 10 2015 213 065 A1 deals with an automatic transmission.

[0005] EP 1 396 369 A2 proposes a hybrid transmission for coupling two electric motors and an internal combustion engine. The drive power provided by these drive motors is transmitted via an epicyclic gear train with multiple planetary gear sets, two sun gears of which are connected in a rotationally fixed manner. The proposed hybrid transmission also has at least one additional planetary gear set.

[0006] It is an object of the invention to provide a motor vehicle transmission for a hybrid drive with a small installation space requirement. This object is achieved by a motor vehicle transmission according to the first and second claims and by a motor vehicle drive train according to claim 10.

[0007] For the purposes of the invention, a motor vehicle transmission is understood to be a speed-change transmission having a transmission input shaft for receiving drive power from a prime mover, preferably an internal combustion engine and preferably a reciprocating piston internal combustion engine. This transmission further comprises a transmission output shaft configured to deliver the received drive power to one or preferably more drivable motor vehicle axles, preferably a front axle and preferably a rear axle, and particularly preferably to both.

[0008] The motor vehicle transmission is preferably designed as a shiftable transmission, and the drive power can be transmitted from the transmission input shaft to the transmission output shaft in different, preferably discrete, gear ratios. Such a gear ratio is to be understood in particular as a so-called gear or a so-called shift stage.

[0009] The motor vehicle transmission further comprises a transmission housing. This transmission housing is designed, in particular, to rotatably support the transmission input shaft and the transmission output shaft.

[0010] For the purposes of the invention, a planetary gear set is understood to be an epicyclic gear set comprising a sun pinion, a ring gear, and a planetary gear rotatably mounted on a carrier shaft. The planetary gear set preferably comprises a plurality of planetary gears. The planetary gear meshes, in particular, with both the ring gear and the sun pinion. Such an epicyclic gear set is known in the art as a so-called negative gear set.

[0011] The epicyclic gear set preferably comprises a planetary gear and a positive planetary gear, preferably a plurality of such planetary gears and positive planetary gears, each of which is rotatably mounted on the carrier shaft and meshes with one another. In particular, the planetary gear meshes with the sun pinion, and the positive planetary gear meshes with the ring gear. Such an epicyclic gear set is known in the art as a so-called positive gear set / positive planetary gear set.

[0012] The motor vehicle transmission has three such planetary gear sets. The first planetary gear set accordingly has a first sun pinion, a first ring gear, and a first carrier shaft with a planetary gear or planetary gears rotatably mounted thereon. The second planetary gear set has a second sun pinion, a second ring gear, and a second carrier shaft with a planetary gear or planetary gears rotatably mounted thereon. The third planetary gear set has a third sun pinion, a third ring gear, and a third carrier shaft with a planetary gear or planetary gears rotatably mounted thereon.

[0013] Preferably, these three planetary gear sets are arranged concentrically to one another, in particular arranged concentrically to a common central axis, and further preferably, these three planetary gear sets are arranged axially spaced from one another along this central axis.

[0014] Preferably, all of these planetary gear sets are designed as so-called plus gear sets, preferably all of the planetary gear sets are designed as so-called minus gear sets and particularly preferably one of the planetary gear sets is designed as a so-called plus gear set and the other planetary gear sets are designed as so-called minus gear sets or vice versa.

[0015] Two of these three sun pinions (first, second, and third sun pinions) are preferably connected to each other in a rotationally fixed manner. Preferably, the second sun pinion is connected to the third sun pinion via a central shaft. In particular, this connection of the two sun pinions kinematically couples two of the three planetary gear sets, enabling power transmission from one to the other of these planetary gear sets.

[0016] Furthermore, the second carrier shaft, i.e. the carrier shaft of the second planetary gear set, can be selectively connected in a rotationally fixed manner to the third ring gear, i.e. the ring gear of the third planetary gear set, or is preferably connected in a rotationally fixed manner to the latter. Preferably, the second carrier shaft can be selectively connected in a rotationally fixed manner to the transmission housing by means of a brake. Further preferably, the second ring gear can be selectively connected in a rotationally fixed manner to the transmission housing by means of a brake. Further preferably, the second carrier shaft can be selectively connected in a rotationally fixed manner to the third ring gear by means of a clutch. Further preferably, the second carrier shaft can be selectively connected in a rotationally fixed manner to the third carrier shaft by means of a clutch.

[0017] In a preferred embodiment of the invention, the transmission input shaft can be selectively and non-rotatably connected to the first planetary gear shaft by means of a torque transmission device, in particular by means of a first clutch. In particular, this connection enables the power transmission from the transmission input shaft to the first planetary gear set and preferably allows selective control.

[0018] Further preferably, the transmission input shaft is rotationally fixedly connected to the third carrier shaft, i.e., the carrier shaft of the third planetary gear set. In a preferred embodiment of the invention, the transmission input shaft can be selectively rotationally fixedly connected to the third carrier shaft by means of a torque transmission device, in particular by means of a second clutch. In particular, this connection enables the power transmission from the transmission input shaft to the third planetary gear set, in particular selectively.

[0019] For the purposes of the invention, a rotationally fixed connection is understood to mean that when torque is transmitted from a first component to a second component, the second component has the same speed as the first component to which it is rotationally fixedly connected. Components that are rotationally fixedly connected to one another preferably contact one another directly or are indirectly connected to one another by means of a shaft and thus without any difference in speed during power transmission. For the selective rotationally fixed connection of the two components to one another (with regard to power transmission), a torque transmission device, preferably a brake, preferably a clutch and particularly preferably a synchronizer, is preferably arranged between them (with regard to power transmission). By means of such a torque transmission device, the possibility is created of selectively connecting the two components to one another in a rotationally fixed manner.

[0020] For the purposes of the invention, a selective connection of two components means that such a connection for torque transmission can be selectively established and then removed. Preferably, a torque transmission device of the aforementioned type, or a switching element, is provided to establish such a selective connection.

[0021] A torque transmission device is preferably understood to mean a clutch, a brake, or a synchronizer. A clutch, in particular, connects two rotatably mounted components to one another, while a brake, in particular, connects a rotatably mounted component and a permanently stationary component, in particular the transmission housing. This torque transmission device is preferably designed as a positive-locking or frictional-locking device, and preferably as a frictionally positive-locking device. A frictionally positive-locking device is particularly understood to mean a synchronizer or cone synchronizer. In particular, by means of such a selective connection, the motor vehicle transmission can be switched into different states, in particular different gear ratios and preferably different operating states, for power transmission.

[0022] Preferably, components connected to one another in a rotationally fixed manner share the same axis of rotation during power transmission. In particular, in the special case of a component connected to the gearbox housing in a rotationally fixed manner (the gearbox housing is stationary), the component connected to the gearbox housing is set to zero speed, the component is stationary, and power transmission is not possible.

[0023] Further preferably, the transmission output shaft is rotationally fixedly connected to the second carrier shaft, i.e., the carrier shaft of the second planetary gear set. Preferably, the transmission output shaft is rotationally fixedly connected to the second carrier shaft. In particular, this connection makes it possible to output the drive power transmitted to the motor vehicle transmission via the transmission output shaft and direct it toward a drivable motor vehicle axle.

[0024] Preferably, the first sun pinion, i.e., the sun pinion of the first planetary gear set, and the second ring gear, i.e., the ring gear of the second planetary gear set, are each selectively and rotationally fixedly connected to the transmission housing. This configuration thus allows the zero speed to be independently specified for both the first sun pinion and the second ring gear when connected to the transmission housing. This allows the transmission ratio between the transmission input shaft and the transmission output shaft to be changed in a particularly simple manner.

[0025] Furthermore, the first, second, and third planetary gear sets preferably have the same stationary gear ratio. Preferably, at least two, but preferably all three, planetary gear sets have identical components, in particular with regard to toothing components (sun pinion, ring gear, planet gear). In particular, by having the same stationary gear ratios for the planetary gear sets, it is possible to use a large number of identical parts for the planetary gear sets. This is particularly possible with the proposed transmission topology, since the three planetary gear sets are coupled to one another, or can be selectively coupled to one another, in such a way that a large number of different gear ratios can be realized with them, and that the step increments between these gear ratios are advantageous for driving a motor vehicle.

[0026] Preferably, the transmission input shaft is configured for selective, rotationally fixed connection to an internal combustion engine and the transmission output shaft is preferably configured for power output toward a drivable vehicle axle.

[0027] The second and third sun pinions are rotationally fixedly connected to the central shaft. In particular, such an embodiment of the invention provides a particularly simple means of transmitting power from the second to the third planetary gear set. In a further preferred embodiment, the first ring gear is rotationally fixedly connected to the second sun pinion and to the third sun pinion, in particular via the central shaft. In particular, such an embodiment of the invention provides a particularly simple means of transmitting power between the three planetary gear sets.

[0028] Furthermore, the second carrier shaft is connected to the transmission output shaft in a rotationally fixed manner. This design, in particular, enables particularly good gear ratio grading.

[0029] Further preferably, the transmission output shaft is connected to the third ring gear in a rotationally fixed manner. In a preferred embodiment of the invention, the transmission output shaft can be selectively connected to the third ring gear in a rotationally fixed manner, in particular by means of a third clutch. Such a clutch is preferably designed as a frictional, preferably as a positive, and particularly preferably as a frictional-formal torque transmission device. In particular, this connection enables the power transmission from the third ring gear to the transmission output shaft, in particular selectively.

[0030] Furthermore, the central shaft can be selectively connected to the first carrier shaft in a rotationally fixed manner, and a fourth clutch is provided to form this connection. The fourth clutch is thus configured, in particular, as a torque transmission device for selectively connecting two transmission elements of the first planetary gear set, or the first positive planetary gear set, in a rotationally fixed manner. The fourth clutch is thus to be understood, in particular, as a device that, together with the corresponding planetary gear set, enables power transmission without rolling power losses.

[0031] Such a clutch is preferably designed as a frictional, preferably as a positive, and particularly preferably as a frictional-positive torque transmission device. This connection enables the power transmission from the central shaft to the first ring gear, particularly selectively.

[0032] Furthermore, the third carrier shaft is connected to the transmission input shaft in a rotationally fixed manner, or the transmission input shaft can be selectively connected to the third carrier shaft in a rotationally fixed manner. Preferably, a torque transmission device is provided to form this selectively rotationally fixed connection; in particular, a second clutch is provided to form this connection. Such a clutch is preferably designed as a friction-locking, preferably as a form-locking, and particularly preferably as a friction-form-locking torque transmission device. In particular, such a configuration makes the transmission ratio of the transmission particularly easy to control.

[0033] In a preferred embodiment of the invention, the first sun pinion can be selectively connected to the transmission housing in a rotationally fixed manner by means of a torque transmission device, in particular by means of a first brake. Such a brake is preferably designed as a frictional, preferably as a positive, and particularly preferably as a frictional-positive torque transmission device. In particular, such an embodiment of the invention provides a particularly simple way of specifying a rotational speed for one of the transmission elements and thus influencing the transmission ratio.

[0034] In a preferred embodiment of the invention, the second ring gear can be selectively connected to the transmission housing in a rotationally fixed manner by means of a torque transmission device, in particular by means of a second brake. Such a brake is preferably designed as a frictional, preferably as a positive, and particularly preferably as a frictional-positive torque transmission device. In particular, such an embodiment of the invention provides a particularly simple way of specifying a rotational speed for one or more of the transmission elements and thus influencing the transmission ratio.

[0035] In a preferred embodiment of the invention, a first electromechanical energy converter, preferably an electric motor generator and preferably an electric motor, is provided for the motor vehicle transmission. This first electromechanical energy converter can preferably be connected to the first sun pinion, i.e., to the sun pinion of the first planetary gear set, in a torque-conducting manner. In a further preferred embodiment of the invention, the first electromechanical energy converter is connected in a rotationally fixed manner to the first sun pinion or can preferably be selectively connected in a rotationally fixed manner to the first sun pinion. Investigations have shown that, in particular, by means of such an embodiment of the invention, assistance of the internal combustion engine by the first electromechanical energy converter can be achieved particularly easily.

[0036] In a preferred embodiment of the invention, a second electromechanical energy converter is provided. The term "second" electromechanical energy converter does not necessarily imply that a first electromechanical energy converter must be present; rather, the term "first, second" electromechanical energy converter serves to differentiate between them. In particular, a first or a second electromechanical energy converter can be provided, and preferably, a first and a second electromechanical energy converter are provided.

[0037] Preferably, this second electromechanical energy converter is torque-conductingly connectable to at least one of the transmission shafts (transmission input shaft, transmission output shaft, central shaft) or preferably to one of the three ring gears for transmitting drive power (rotational speed, torque) or is connected to this or this in a rotationally fixed manner or is preferably selectively connectable to this or this in a rotationally fixed manner.

[0038] Preferably, the second electromechanical energy converter is connected to the transmission input shaft, preferably in a rotationally fixed manner. Preferably, the second electromechanical energy converter is connected to the transmission output shaft, preferably in a rotationally fixed manner.

[0039] In a preferred embodiment of the invention, the second electromechanical energy converter is provided and can be connected to the third ring gear in a torque-conducting manner, preferably connected to it in a rotationally fixed manner and preferably selectively connected to it in a rotationally fixed manner.

[0040] Preferably, the first electromechanical energy converter is connected to the first sun gear via an intermediate gear. In particular, an intermediate gear enables the adaptation of this electromechanical energy converter to the load requirement, thus enabling the hybridization of the motor vehicle transmission in a particularly simple manner.

[0041] Further preferably, the first electromechanical energy converter is connectable or torque-conductingly connected to one of the aforementioned transmission elements (transmission input shaft, transmission output shaft, central shaft or one of the three ring gears) by means of an intermediate transmission.

[0042] Such an intermediate gear is preferably designed as a traction drive and preferably as a gear drive. In particular, an intermediate gear enables the respective electromechanical energy converter to be adapted to the load requirement.

[0043] In particular, the arrangement or provision of the second electromechanical energy converter enables power cascading of the electrical drive power and the second electromechanical energy converter can be operated alone or in combination with the first electromechanical energy converter and, further preferably, a serial hybrid mode can be represented.

[0044] Furthermore, a motor vehicle drivetrain is provided which has the motor vehicle transmission explained above. Preferably, in this motor vehicle drivetrain, the transmission input shaft is connectable to an internal combustion engine, preferably selectively connectable in a rotationally fixed manner, and preferably the internal combustion engine is permanently connected to the transmission input shaft. Preferably, a so-called starting clutch and preferably a torque converter are provided for this selective connection. Further preferably, the internal combustion engine is permanently connected to the transmission input shaft for transmitting drive power, i.e., without a starting clutch or a torque converter being provided. Further preferably, the transmission output shaft is configured for transmitting power to a drivable motor vehicle axle.

[0045] In particular, a drivable motor vehicle axle is understood to mean the rear axle in a motor vehicle with rear-wheel drive, the front axle in a motor vehicle with front-wheel drive, and both the front axle and the rear axle in a motor vehicle with all-wheel drive. A drivable motor vehicle axle has, in particular, an axle drive, preferably a so-called differential gear, and at least one drive wheel, preferably two drive wheels, and half-shafts for transmitting the drive power from this axle drive to these drive wheels. Furthermore, this drive train preferably has at least one electromechanical energy converter, preferably two or more electromechanical energy converters.

[0046] In particular, the proposed motor vehicle drive train enables a particularly space-saving design of a hybrid drive train.

[0047] In a preferred embodiment of the invention, a further electromechanical energy converter is provided. In particular, this electromechanical energy converter is referred to as a third electromechanical energy converter and is intended to drive the motor vehicle drive train. This further electromechanical energy converter is preferably configured to transmit drive power (power transmission of rotational speed and torque) to the drivable motor vehicle axle or to another drivable motor vehicle axle.

[0048] Preferably, the construction of a motor vehicle drive train is made possible by means of the further electromechanical energy converter, in which drive power can be transmitted to the drivable motor vehicle axle by means of the motor vehicle transmission according to the invention and drive power can be transmitted to another, but also drivable, motor vehicle axle, in particular to the further drivable motor vehicle axle, by means of the further electromechanical energy converter.

[0049] In particular, the front axle of a motor vehicle can be driven by means of this additional electromechanical energy converter, and the rear axle can be driven via the motor vehicle transmission according to the invention, or vice versa. Such a configuration, in particular, provides a particularly simple way of achieving all-wheel drive in the form of a hybrid drive.

[0050] Furthermore, the additional electromechanical energy converter preferably enables a hybrid drivetrain configuration in which drive power can be transmitted to the same drivable motor vehicle axle both by means of the motor vehicle transmission according to the invention and by means of the additional electromechanical energy converter. In particular, such a configuration allows a particularly high drive power to be transmitted to a drivable motor vehicle axle, and furthermore, this drive power can be particularly well controlled by the electrical component of the drive power provided by this additional electromechanical energy converter.

[0051] As explained, the motor vehicle transmission shown can be used in a simple manner to create a hybrid drive, i.e. a drive in which both an internal combustion engine and another drive machine, in particular an electromechanical energy converter, are used to provide drive power.Due to the hybrid functionalities that can be realized by using an electromechanical energy converter as a drive machine in addition to an internal combustion engine, not as many gears are required for the internal combustion engine operation of the motor vehicle drive train as in a conventional drive train. As a result, a topology other than that known from conventional automatic transmissions can be used and, in particular, the proposed simple transmission topology can be selected and, preferably, the saved installation space can be used for the electrification, or for the greater electrification, of the motor vehicle drive train.

[0052] In addition, it is conceivable that certain driving ranges can be covered purely electrically, i.e. in a drive mode in which only one or more of the electromechanical energy converters are used to provide drive power (emission-free driving, electric gear).

[0053] In order to improve operational reliability in all operating conditions, the use of more than one electromechanical energy converter is preferred, preferably two and particularly preferably three or more electromechanical energy converters.

[0054] A combination of more than one electromechanical energy converter allows for a variety of transmission functions. In particular, it allows for further mechanical simplification of the motor vehicle transmission and, for example, the use of positive-locking torque transmission devices, especially brakes and clutches, without suffering a drop in traction during a gear shift.

[0055] Preferably, the proposed motor vehicle transmission is designed as a 6-speed hybrid transmission, i.e. a transmission which can be coupled to an internal combustion engine and at least one electromechanical energy converter for power transmission and which can be switched in at least six discrete, different transmission ratios, based on the transmission ratio between the transmission input shaft and the transmission output shaft.

[0056] For this purpose, the motor vehicle transmission preferably has exactly three planetary gear sets and five torque transmission devices (two brakes and three clutches), thus providing appropriate installation space for at least one, preferably two, and particularly preferably several electromechanical energy converters. These electromechanical energy converters, or preferably at least one of them, are preferably integrated, at least partially or preferably completely, into the transmission housing of the motor vehicle transmission. At least one electromechanical energy converter(s) is / are preferably functionally integrated into the motor vehicle transmission.

[0057] Further preferably, a hybrid drivetrain is provided in which one or more electromechanical energy converters (further electromechanical energy converters) can be directly coupled to a drivable motor vehicle axle. In particular, the drive power delivered by this or these electromechanical energy converters is not transmitted through the proposed motor vehicle transmission, but is transmitted directly to the drivable motor vehicle axle.

[0058] In particular, the proposed configuration of the motor vehicle transmission makes it possible to integrate the first and the second electromechanical energy converter, preferably at least one of these two, into the motor vehicle transmission in such a way that they can represent not only hybrid driving functions but also transmission-related functions.

[0059] In particular, it is possible to use positive-locking torque transmission devices for at least some of the aforementioned torque transmission devices, which can offer advantages in terms of installation space and drag losses, or rather, actuation, compared to frictional torque transmission devices. Furthermore, the electromechanical energy converters make it possible to realize gear changes (switching from one gear ratio to another) without interrupting traction, despite at least one positive-locking torque transmission device, since speed synchronization during gear changes is achieved by means of the electromechanical energy converter(s).

[0060] The second electromechanical energy converter can be connected either to the transmission input shaft (drive side) or to the transmission output shaft (output side). Preferably, the second electromechanical energy converter is provided as the sole electromechanical energy converter of the hybrid transmission, preferably in combination with the first electromechanical energy converter and particularly preferably in combination with at least one further electromechanical energy converter.

[0061] If the connection of the second electromechanical energy converter is made on the output side, it is preferable to provide a further electromechanical energy converter for the hybrid drive train and to connect this to the further drivable motor vehicle axle via a separate tap, thereby providing all-wheel functionality, in particular without an extra transfer case.

[0062] In an alternative embodiment of the invention, at least one electromechanical energy converter can be coupled directly to a drivable motor vehicle axle, so that in particular this motor vehicle axle can be driven exclusively by the electromechanical energy converter(s), thus providing a particularly simple possibility for implementing an all-wheel drive.

[0063] Furthermore, a parking lock functionality can be easily implemented with this motor vehicle transmission, particularly via positive-locking torque transmission devices. The parking lock functionality is understood to mean a blocking of the motor vehicle transmission, so that at least the transmission output shaft is selectively secured relative to the transmission housing, particularly in a positive-locking manner, by means of this parking lock.

[0064] Preferably, the parking lock functionality is provided by a combination of the brake for selectively connecting the first sun pinion to the transmission housing in a rotationally fixed manner (first brake), the brake for selectively connecting the second ring gear to the transmission housing in a rotationally fixed manner (second brake), and the clutch for selectively connecting the central shaft to the first carrier shaft in a rotationally fixed manner (fourth clutch). Preferably, these torque transmission devices (first brake, second brake, fourth clutch) are simultaneously engaged or simultaneously held engaged, thus holding the transmission output shaft rotationally fixed relative to the transmission housing.Further preferably, these torque transmission devices (first brake, second brake, fourth clutch) are designed as positive-locking torque transmission devices and preferably, these torque transmission devices are designed as a “normally closed” clutch or brake or brakes, i.e. as a torque transmission device with which a torque can be transmitted in an unactuated state.

[0065] Further preferably, a serial driving mode or standby charging functionality can be realized by means of the clutches for selectively and non-rotatably connecting the transmission input shaft to the first carrier shaft (first clutch) and for selectively and non-rotatably connecting the first carrier shaft to the central shaft (fourth clutch). To provide these modes, in particular, the first clutch and the fourth clutch are closed and the remaining torque transmission devices are opened.

[0066] If a further electromechanical energy converter is provided, which is configured to drive one of the drivable motor vehicle axles, serial driving is particularly possible. Preferably, a first drivable motor vehicle axle and a further drivable motor vehicle axle are present. Preferably, the motor vehicle transmission is configured to drive one of these two axles, and the further electromechanical energy converter is configured to drive the other of these axles. Furthermore, the first and fourth clutches are preferably closed, allowing drive power to be directly transferred from the internal combustion engine to the first electromechanical energy converter.In the proposed configuration of the motor vehicle transmission, the transmission output shaft can be stationary, thus enabling stationary charging, i.e. charging of a motor vehicle energy storage device with electrical current while the vehicle is stationary, in which the first electromechanical energy converter is driven by the internal combustion engine in generator mode.

[0067] Furthermore, it is possible (serial driving operation), insofar as one of the drivable motor vehicle axles can be driven by the further electromechanical energy converter, not to use the electrical current which can be provided by the first electromechanical energy converter in generator mode, or only to use it partially, to charge the motor vehicle energy storage device, but to use it to drive one of the drivable motor vehicle axles via the further electromechanical energy converter.

[0068] In particular, such a configuration (stationary charging function) can improve the operational safety or driving comfort (serial driving operation) of the motor vehicle drive train, or both.

[0069] In a further preferred embodiment, an electric drive mode is provided. To provide the electric drive mode, the brake for selectively connecting the second ring gear to the transmission housing in a rotationally fixed manner (second brake) and the clutch for selectively connecting the first carrier shaft to the central shaft in a rotationally fixed manner (fourth clutch) are preferably provided and closed for this drive mode. In particular, when these torque transmission devices are closed, direct drive of the drivable motor vehicle axle via the transmission output shaft by the first electromechanical energy converter is enabled, and in particular, this drive is enabled without the need for a further electromechanical energy converter.

[0070] Individual features and embodiments of the invention are explained in more detail below with reference to the partially schematic figures, in which: Fig. 1: a longitudinal section of a first motor vehicle transmission without electromechanical energy converter, Fig. 2: a longitudinal section of the first motor vehicle transmission with the first electromechanical energy converter, Fig. 3: a longitudinal section of a second motor vehicle transmission without electromechanical energy converter, Fig. 4: a longitudinal section of the second motor vehicle transmission with the first electromechanical energy converter, Fig. 5: a longitudinal section through a motor vehicle transmission with two planetary gear sets with the same stationary ratio, Fig. 6: a circuit diagram for some of the illustrated motor vehicle transmissions, Fig. 7: a longitudinal section of a hybrid powertrain, Fig. 8: a longitudinal section of a hybrid drive train in an all-wheel drive variant

[0071] In Fig. Figure 1 shows a longitudinal section of a motor vehicle transmission for a hybrid drive. The motor vehicle transmission has a transmission housing 0, in which the transmission input shaft 1 and the transmission output shaft 2 are rotatably mounted about the central axis ZA and arranged concentrically thereto.

[0072] The three planetary gear sets PR1, PR2, and PR3 are also arranged concentrically to the central axis ZA. The first planetary gear set PR1 has a first sun pinion S1, a first ring gear H1, and a first carrier shaft 5, on which the planet gear P1 of this planetary gear set PR1 is rotatably mounted.

[0073] The second planetary gear set PR2 has a second sun pinion S2, a second ring gear H2 and a second carrier shaft 2a on which the planet gear P2 of this planetary gear set PR2 is rotatably mounted.

[0074] The third planetary gear set PR3 has a third sun pinion S3, a third ring gear H3 and a third carrier shaft 7 on which the planet gear P3 of this planetary gear set PR3 is rotatably mounted.

[0075] The two sun pinions S2 and S3 are connected to each other via the central shaft 3. Furthermore, the second carrier shaft 2a is connected to the transmission output shaft 2.

[0076] The first sun pinion S1 is selectively and non-rotatably connected to the transmission housing 0 by means of the first sun pinion shaft 4 via the first brake B04. The first carrier shaft 5 is selectively and non-rotatably connected to the transmission input shaft by means of the first clutch K15 and selectively and non-rotatably connected to the central shaft 3 by means of the fourth clutch K35. The third ring gear H3 is selectively and non-rotatably connected to the transmission output shaft 2 by means of the third clutch K27. The third carrier shaft 7 is non-rotatably connected to the transmission input shaft 1.

[0077] In Fig. 2 shows a further embodiment of the motor vehicle transmission, as this is already partly shown in the Fig. 1, the essential differences between these embodiments are discussed below.

[0078] In the Fig. The motor vehicle transmission shown in Figure 2 features the first electric motor generator EMA, which is non-rotatably connected to the first sun pinion S1, i.e., the sun pinion of the first planetary gear set PR1, by means of the first sun pinion shaft 4. The first electromechanical energy converter, designed as an electric motor generator EMA, enables particularly simple hybridization of the motor vehicle transmission.

[0079] In Fig. 3 shows a further embodiment of the motor vehicle transmission, as this is already partly shown in the Fig. 1, the main differences between these embodiments are discussed below.

[0080] In the Fig. 3, an additional clutch, i.e. the second clutch K17, is provided, but the third clutch K27 is omitted. Unlike the Fig. In the embodiment of the invention shown in Figure 1, the transmission output shaft 2 or the second carrier shaft 2a is connected in a rotationally fixed manner to the third ring gear H3.

[0081] In Fig. 4 shows a further embodiment of the motor vehicle transmission, as this is already partly shown in the Fig. 1, the essential differences between these embodiments are discussed below.

[0082] In the Fig. 4 is, as in the case of the motor vehicle transmission shown in Fig. 3, the second clutch K17 is provided, whereas the third clutch K27 is omitted.

[0083] Furthermore, the Fig. The first electromechanical energy converter, i.e., the electric motor generator EMA, is provided in the motor vehicle transmission shown in Figure 4. The electric motor generator EMA is rotationally fixedly connected to the first sun pinion S1 via the first sun pinion shaft 4. The first sun pinion shaft 4 can be selectively rotationally fixedly connected to the transmission housing 0 by means of the first brake B04.

[0084] In Fig. 5 shows a longitudinal section through another motor vehicle transmission, which differs from the one shown in Fig. 1 shown motor vehicle transmission, therefore the essential differences to the one shown in Fig. 1 illustrated motor vehicle transmission.

[0085] This embodiment of the motor vehicle transmission has a first planetary gear set, which is designed as a so-called positive gear set and is referred to as the first positive planetary gear set PR1'. The first positive planetary gear set PR1' replaces the planetary gear set designed as a negative gear set, as shown in Fig. 1 is shown.

[0086] The first positive planetary gear set PR1' has, in addition to the first planetary gear P1, a first positive planetary gear P1', which meshes with both the first planetary gear P1 and the first ring gear H1. The first planetary gear P1 meshes with this first positive planetary gear P1' and the first sun pinion S1.

[0087] The first planetary gear P1 and the positive planetary gear P1' are rotatably mounted on the first carrier shaft 5. The KPR1 clutch is provided for locking the positive planetary gear set PR1'. The KPR1 clutch selectively connects the first ring gear to the first carrier shaft in a rotationally fixed manner. Furthermore, this transmission has a K1PR1 clutch for selectively connecting the transmission input shaft to the first positive planetary gear set PR1', in particular to the first ring gear H1.

[0088] The central shaft 3 is connected in a rotationally fixed manner to the first carrier shaft 5, thereby compensating for the reversal of the direction of rotation associated with the introduction of the first positive planetary gear set PR1', with respect to the stationary ratios of the first planetary gear set (PR1) and the first positive planetary gear set PR1'. The couplings of the second planetary gear set PR2 and the third planetary gear set PR3 can, as in the Fig. 1 known embodiment of the motor vehicle transmission.

[0089] In Fig. 6 shows a circuit diagram for motor vehicle transmissions with three planetary gear sets PR1 - PR3 with the same stationary gear ratio for switching the different gear ratios (1 to 6).

[0090] An "X" means that the corresponding torque transmission device (clutch K15, K35, K17, K27 or brake B04, B06) is closed; otherwise, the torque transmission device is open. This logic also shows additional operating modes of the vehicle transmission, into which the vehicle transmission and thus the hybrid powertrain can be switched by actuating the corresponding clutches and brakes.

[0091] In Fig. Figure 7 shows a schematic hybrid drive train with a HyG motor vehicle transmission as described in the previous Fig. 1 to 5.

[0092] The motor vehicle transmission HyG can be selectively and non-rotatably connected to the internal combustion engine (ICE) via the separating clutch AK, allowing drive power from the internal combustion engine (ICE) to be selectively supplied to the transmission input shaft 1. The first electric motor generator (EMA) can be supplied with electrical power via the power supply (EV), or the electrical power provided by the first electric motor generator (EMA) can be stored in this power supply (EV).

[0093] Drive power from the motor vehicle transmission HyG can be delivered to the drivable rear axle HA via the transmission output shaft 2. The drivable rear axle HA has an axle drive 10 for distributing the drive power, with which the provided drive power can be distributed to the drive wheels AR.

[0094] In Fig. Figure 8 shows another schematic hybrid drive train with a HyG motor vehicle transmission, as described in the previous Fig. 1 to 4. This hybrid drivetrain features all-wheel drive, as it provides two drivable vehicle axles (front and rear axles). This configuration, in particular, enables the described serial driving mode.

[0095] The motor vehicle transmission HyG can be selectively and non-rotatably connected to the internal combustion engine (ICE) via the separating clutch AK, allowing drive power from the internal combustion engine (ICE) to be selectively supplied to the transmission input shaft 1. The first electric motor generator (EMA) and the second electric motor generator (EMC) can be supplied with electrical power via the power supply (EV), or the electrical power provided by these electric motor generators (EMA and EMC) can be stored in the power supply (EV).

[0096] Drive power is delivered to the drivable front axle (VA) via the transmission output shaft 2. The drivable rear axle (RA) is driven by the additional electric motor generator (EMC). The provided drive power is transferred to the roadway via the drive wheels (AR). To distribute the drive power to the drive wheels (AR), the drivable vehicle axles (VA and HA) each have an axle drive 10. List of reference symbols: 0 Gearbox housing 1 transmission input shaft 2 gearbox output shaft 2a second web wave 3 Central shaft 4 first sun pinion shaft 5 first bridge wave 7 third bridge wave 10 axle gears B04 first brake B06 second brake K15 first clutch K17 second clutch K27 third clutch K35 fourth clutch KPR1 clutch for selectively connecting two elements of the first positive planetary gear set with each other K1PR1 clutch for selectively coupling the transmission input shaft with the first positive planetary gear set PR1 first planetary gear set S1 first sun pinion P1 planetary gear of the first planetary gear set H1 first ring gear PR1' first positive planetary gear set P1' first positive planetary gear PR2 Second planetary gear set S2 second sun pinion P2 planetary gear of the second planetary gear set H2 second ring gear PR3 Third planetary gear set S3 third sun pinion P3 planetary gear of the third planetary gear set H3 third ring gear EMA first electromechanical energy converter EMC further electromechanical energy converter ZA central axis

Claims

[1] Motor vehicle transmission for a hybrid drive train, comprising the transmission elements: Gearbox housing (0), gearbox input shaft (1), a gearbox output shaft (2), first planetary gear set (PR1) with a first sun pinion (S1), a first ring gear (H1) and a first carrier shaft (5) with a planet gear (P1) rotatably mounted thereon, a second planetary gear set (PR2) with a second sun pinion (S2), a second ring gear (H2) and a second carrier shaft (2a) with a planetary gear (P2) rotatably mounted thereon, and with a third planetary gear set (PR3) with a third sun pinion (S3), a third ring gear (H3) and a third carrier shaft (7) with a planetary gear (P3) rotatably mounted thereon, wherein two of the three sun pinions (S1, S2, S3) are connected to a central shaft (3) in a rotationally fixed manner, and wherein the second web shaft (2a) is connected to the third ring gear (H3) in a rotationally fixed manner, wherein at least two of the three planetary gear sets are first, second or third planetary gear set (PR1, PR2, PR3) have the same stationary ratio and wherein the first sun pinion (S1) and the second ring gear (H2) are each selectively rotatably connected to the transmission housing (0) and wherein the second and third sun pinion (S2, S3) are connected to the central shaft (3) in a rotationally fixed manner, and wherein the first ring gear (H1) is connected to the second and third sun pinion (S2, S3) in a rotationally fixed manner, characterized by , that in the gearbox housing (0) the gearbox input shaft (1) and the gearbox output shaft (2) are rotatably mounted about a central axis (ZA) and arranged concentrically thereto and that the second carrier shaft (2a) is connected to the gearbox output shaft (2) in a rotationally fixed manner and that the third carrier shaft (7) can be selectively connected to the transmission input shaft (1) in a rotationally fixed manner by means of a second clutch (K17) and that the transmission output shaft (2) is connected in a rotationally fixed manner to the third ring gear (H3) and that the transmission input shaft (1) can be selectively connected to the first carrier shaft (5) in a rotationally fixed manner by means of a first clutch (K15) and that the central shaft (3) can be selectively connected in a rotationally fixed manner to the first web shaft (5) by means of a fourth coupling (K35). [2] Motor vehicle transmission for a hybrid drive train, comprising the transmission elements: Gearbox housing (0), gearbox input shaft (1), a gearbox output shaft (2), first planetary gear set (PR1) with a first sun pinion (S1), a first ring gear (H1) and a first carrier shaft (5) with a planet gear (P1) rotatably mounted thereon, a second planetary gear set (PR2) with a second sun pinion (S2), a second ring gear (H2) and a second carrier shaft (2a) with a planetary gear (P2) rotatably mounted thereon, and with a third planetary gear set (PR3) with a third sun pinion (S3), a third ring gear (H3) and a third carrier shaft (7) with a planetary gear (P3) rotatably mounted thereon, wherein two of the three sun pinions (S1, S2, S3) are connected to a central shaft (3) in a rotationally fixed manner, and wherein the second carrier shaft (2a) is selectively connected to the third ring gear (H3) in a rotationally fixed manner, wherein at least two of the three planetary gear sets are first, second or third planetary gear set (PR1, PR2, PR3) have the same stationary ratio and wherein the first sun pinion (S1) and the second ring gear (H2) are each selectively rotatably connected to the transmission housing (0) and wherein the second and third sun pinion (S2, S3) are connected to the central shaft (3) in a rotationally fixed manner, and wherein the first ring gear (H1) is connected to the second and third sun pinion (S2, S3) in a rotationally fixed manner, characterized by , that in the gearbox housing (0) the gearbox input shaft (1) and the gearbox output shaft (2) are rotatably mounted about a central axis (ZA) and arranged concentrically thereto and that the second web shaft (2a) is connected to the gearbox output shaft (2) in a rotationally fixed manner that the third carrier shaft (7) is connected in a rotationally fixed manner to the transmission input shaft (1) and that the transmission input shaft (1) can be selectively connected to the first carrier shaft (5) in a rotationally fixed manner by means of a first clutch (K15) and that the central shaft (3) can be selectively connected in a rotationally fixed manner to the first web shaft (5) by means of a fourth coupling (K35). [3] Motor vehicle transmission according to claim 2, characterized bythat the transmission output shaft (2) can be selectively connected in a rotationally fixed manner to the third ring gear (H3) by means of a third clutch (K27). [4] Motor vehicle transmission according to one of the preceding claims, characterized by that the first sun pinion (S1) can be selectively connected in a rotationally fixed manner to the gear housing (0) by means of a first brake (B04). [5] Motor vehicle transmission according to one of the preceding claims, characterized by that the second ring gear (H2) can be selectively connected in a rotationally fixed manner to the transmission housing (0) by means of a second brake (B06). [6] Motor vehicle transmission according to one of the preceding claims, characterized by that a first electromechanical energy converter (EMA) is provided, that this first electromechanical energy converter (EMA) is connected to the first sun pinion (S1) in a torque-conducting manner. [7] Motor vehicle transmission according to claim 6, characterized bythat the first electromechanical energy converter (EMA) is non-rotatably connected to the first sun pinion (S1). [8] Motor vehicle transmission according to one of the preceding claims, characterized by that a second electromechanical energy converter (EMB) is provided, that the second electromechanical energy converter (EMB) can be connected in a torque-conducting manner to one of the three transmission shafts, transmission input shaft (1), transmission output shaft (2) or central shaft (3), or is connected in a rotationally fixed manner to one of these three transmission shafts (1, 2, 3). [9] Motor vehicle transmission according to one of claims 1 to 7, characterized by that a second electromechanical energy converter (EMB) is provided, that this second electromechanical energy converter (EMB) is connected in a rotationally fixed manner to the third ring gear (H3). [10] Motor vehicle drive train with a motor vehicle transmission according to one of the preceding claims, characterized bythat an internal combustion engine (ICE) can be selectively connected in a rotationally fixed manner to the transmission input shaft (1) and that the transmission output shaft (2) is designed to transmit power to a drivable motor vehicle axle. [11] Motor vehicle drive train according to claim 10, characterized by that a further electromechanical energy converter (EMC) is provided, that this further electromechanical energy converter (EMC) is designed to transmit power to the drivable motor vehicle axle or to a further drivable motor vehicle axle.

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