DE102013227021B4 - Transmission for a motor vehicle - Google Patents

Abstract

Transmission (G) for a motor vehicle with a transmission input shaft (GW1) and a transmission output shaft (GW2), a main gearset (HRS), a Zusatzradsatz (ZRS), and an electric machine (EM) with a rotor (R) and a stator (S), the transmission (G) having at least one power path (L1, L2) between the transmission input shaft (GW1) and the main gearset (HRS), the main gearset (HRS) including first and second planetary gear sets (P1 , P2) with a total of four in speed order as first, second, third and fourth wave designated waves (W1, W2, W3, W4), wherein the at least one power path (L1, L2) via at least one switching element (A, B, D , E) is connectable to at least one of the four shafts (W1, W2, W3, W4) of the main gearset (HRS), the third shaft (W3) of the main gearset (HRS) being connected to the transmission output shaft (GW2), the Zusatzradsatz (ZRS) a planetary gear set (P4) with a first, second and third wave (W1P4 , W2P4, W3P4), and wherein the first shaft (W1P4) of the Zusatzradsatzes (ZRS) with the rotor (R) is permanently connected, characterized in that the second shaft (W2P4) of Zusatzradsatzes (ZRS) via a first additional switching element ( U) with the first shaft (W1) of the main gearset (HRS) and a second additional switching element (V) with the second or third shaft (W2, W3) of the main gearset (HRS) is connectable, wherein either the first additional switching element (U) or the second additional switching element (V) is closed, wherein - in the case that the second shaft (W2P4) of Zusatzradsatzes (ZRS) via the second additional switching element (V) to the second shaft (W2) of the main gearset (HRS) is connectable, the third Shaft (W3P4) of Zusatzradsatzes (ZRS) is constantly connected to the third or fourth shaft (W3, W4) of the main gearset (HRS), and- in the case that the second shaft (W2P4) of Zusatzradsatzes (ZRS) via the second additional switching element (V) with the third wave (W3) of the H the third shaft (W3P4) of the Zusatzradsatzes (ZRS) is constantly connected to the fourth shaft (W4) of the main gearset (HRS).

Description

The invention relates to a transmission having a transmission input shaft and a transmission output shaft, a main gearset, a Zusatzradsatz, and an electric machine having a rotor and a stator, wherein the transmission has at least one power path between the transmission input shaft and the main gear, wherein the main gearset having a first and a second planetary gear set with a total of four in speed order as the first, second, third and fourth waves, the at least one power path via at least one switching element with at least one of the four shafts of the main gear is connectable, wherein the third shaft the main gearset is connected to the transmission output shaft, and wherein the auxiliary gearset includes a planetary gear set having first, second and third shafts, the first shaft of the auxiliary gearset being connected to the rotor. The invention also relates to a drive train for a motor vehicle with a transmission.

A transmission referred to here in particular a multi-speed transmission in which a predefined number of gears, ie fixed gear ratios between a transmission input shaft and a transmission output shaft, is automatically switched by switching elements. The switching elements are, for example, clutches or brakes here. Such transmissions are mainly used in motor vehicles to adjust the speed and torque output capability of the drive unit to the driving resistance of the vehicle in a suitable manner.

From the patent application DE 10 2012 201 377 A1 The applicant is a transmission with a transmission input shaft and a transmission output shaft and two power paths between the transmission input shaft and a main gearset with two Einzelplanetenradsätzen with four in speed order as first, second, third and fourth wave known waves, wherein the third of the four shafts connected to the transmission output shaft is. An electric machine is connected via a planetary gear to the first shaft of the main gearset.

The patent application DE 10 2008 040 178 A1 teaches a power transmission system having a transmission section comprising four shafts arranged in order of speed and a differential section having three shafts associated with an internal combustion engine, an electric motor and an input shaft of the transmission section.

The object of the invention is to improve the load switching behavior of the transmission in selected gears.

Another object of the invention is to improve the range of use of the transmission so that the electric machine in each gear is capable of receiving or delivering mechanical power from the transmission output shaft.

The objects are achieved by the features of claim 1, wherein advantageous embodiments of the dependent claims, the description and from the figures.

The transmission comprises at least a transmission input shaft and a transmission output shaft, a main gearset, a Zusatzradsatz, and an electric machine with a rotor and a stator.

The main gearset has a first and a second planetary gear set with a total of four designated in speed order as the first, second, third and fourth wave waves. The main gearset is thus designed as a two-bar four-shaft gearbox. The Zusatzradsatz has a planetary gear set with a total of three designated as first, second, and third wave waves.

The first shaft of Zusatzradsatzes is permanently connected to the rotor. The third shaft of the main gearset is connected to the transmission output shaft.

Under a two-bridge four-shaft transmission is a planetary gear to understand that is formed of two over exactly two coupling shafts kinematically coupled to each other single planetary gear sets and in which four of its elements ("waves") are freely accessible to other transmission elements. A coupling shaft is defined as a permanent mechanical connection between an element - ie sun gear or web or ring gear - the first single planetary gear set with an element - ie sun gear or web or ring gear - the second single planetary gear set. The number of individual planetary gear sets and the number of free waves are not defined by the visual appearance of the transmission, but by its kinematics. In each gear of a two-land four-shaft transmission, two of the transmission shifting elements connected to elements of the two-land four-shaft transmission must be closed. For the graphical representation of the kinematics of the transmission usually a speed plan of the transmission is used, for example, the well-known from the Gauge Kutzbach plan. Known embodiments of such a two-bridge four-shaft transmission are the so-called Ravigneaux wheelset and the so-called Simpson wheelset.

A reduced two-bridge four-shaft transmission is a design of a two-bridge four-shaft transmission, in which an element - ie a sun gear, a bridge or a ring gear - of the transmission is saved, as another element of the Getriebes takes over its task without changing the kinematics thereby. The element which takes over the function of the saved element is thus at the same time one of the coupling shafts of the transmission. A known embodiment of this is the Ravigneaux wheelset, which has either two sun gears and only one ring gear or two ring gears and only one sun gear.

About at least one power path, the transmission input shaft via at least one switching element with at least one of the four shafts of the main gear is connectable. In a preferred embodiment, the at least one power path can be connected via two switching elements to two of the four shafts of the main gearset. By closing one of the switching elements thus a rotationally fixed connection between the at least one power path and one of the four shafts of the main gear is made, whereby torque from the transmission input shaft to the main gear is feasible. By at least one power path is meant that the transmission has one or more power paths between the transmission input shaft and the main gearset.

When used in a motor vehicle, the transmission input shaft is connected to a shaft of a drive unit or connectable via a coupling, so that mechanical power of the drive unit of the transmission input shaft can be fed. The drive unit can be designed both as an internal combustion engine and as an electrical machine. The transmission output shaft serves as an interface for transmitting mechanical power to the drive wheels of the motor vehicle.

A shaft is not to be understood below exclusively as an example cylindrical, rotatably mounted machine element for transmitting torque, but these are also general fasteners to understand that connect individual components or elements together, in particular connecting elements that connect a plurality of elements rotatably together.

A planetary gear set includes a sun gear, a land and a ring gear. Rotatably mounted on the web are planet gears, which mesh with the toothing of the sun gear and / or with the toothing of the ring gear. In the following, a negative gearset describes a planetary gear set with a web on which the planetary gears are rotatably mounted, with a sun gear and with a ring gear, wherein the toothing meshes with at least one of the planet gears both with the toothing of the sun gear and with the toothing of the ring gear whereby the ring gear and the sun gear rotate in opposite directions of rotation when the sun gear rotates at a stationary web.

Both sun gear and ring gear of a planetary gear set can also be divided into several segments. For example, it is conceivable that the planet gears mesh with two sun gears, which are not connected to each other. The speed ratios are of course identical on both segments of the sun gear, as if they were connected together.

A plus gear set differs from the negative planetary gear set just described in that the plus gear set has inner and outer planet gears rotatably supported on the land. The toothing of the inner planet gears meshes on the one hand with the teeth of the sun gear and on the other hand with the teeth of the outer planetary gears. The toothing of the outer planetary gears also meshes with the teeth of the ring gear. This has the consequence that rotate at a fixed land, the ring gear and the sun gear in the same direction.

The stationary gear ratio defines the speed ratio between the sun gear and ring gear of a planetary gear set with non-rotatable web. Since the direction of rotation between the sun gear and the ring gear is reversed in the case of a negative gearset with a non-rotatable web, the stationary gear ratio always assumes a negative value for a negative gearset.

The speed diagram shows the speed ratios of the individual shafts in the vertical direction. The horizontal distances between the waves result from the ratios between the waves, so that can be connected to a specific operating point speed ratios and torque ratios of the waves by a straight line. The transmission ratios between the shafts result from the stationary gear ratios of the planetary gear sets involved. The speed plan can be displayed, for example, in the form of a Kutzbach plan.

Four waves referred to as the first, second, third and fourth wave in the order of rotation are characterized in that the rotational speeds of these waves increase, decrease or become linear in the stated order. In other words, the speed of the first shaft is less than or equal to Speed of the second shaft. The speed of the second shaft is again less than or equal to the speed of the third shaft. The speed of the third shaft is less than or equal to the speed of the fourth shaft. This order is also reversible, so that the fourth shaft has the highest speed, while the first shaft assumes a speed which is less than or equal to the speed of the fourth shaft. There is always a linear relationship between the speeds of all four shafts.

The speed of one or more waves can also assume negative values, or even the value zero. The speed order is therefore always to refer to the signed value of the speeds, and not on the amount.

The speeds of the four shafts are then the same if two of these elements are connected to each other by the elements ring gear, web and sun of one of the planetary gear sets.

An electric machine consists at least of a non-rotatable stator and a rotatably mounted rotor and is configured in a motor operation to convert electrical energy into mechanical energy in the form of speed and torque, and in a regenerative operation mechanical energy into electrical energy in the form of To transform electricity and voltage.

By switching elements, depending on the operating state, a relative movement between two components allowed or made a connection for transmitting a torque between the two components. Under a relative movement, for example, to understand a rotation of two components, wherein the rotational speed of the first component and the rotational speed of the second component differ from each other. In addition, the rotation of only one of the two components is conceivable while the other component is stationary or rotating in the opposite direction. The switching elements are preferably designed in the present invention as claw-switching elements, which produce the connection by positive locking.

Two elements are referred to as being connected to one another, in particular, if a solid, in particular non-rotatable connection exists between the elements. Such connected elements rotate at the same speed. The various components and elements of said invention can be connected to one another via a shaft or via a closed switching element or a connecting element, but also directly, for example by means of a welding, pressing or other connection.

Two elements are hereinafter referred to as connectable if there is a releasable rotationally fixed connection between these elements. If the connection is made, such elements rotate at the same speed.

A switching operation is effected by closing a previously not lying in the power flow of the transmission switching element of the transmission and opening a previously lying in the power flow of the transmission switching element of the transmission. The shift operation can also be performed under load, that is to say without complete withdrawal of the torque at the transmission input shaft and the transmission output shaft. Such a switching operation is referred to below as a load circuit. A prerequisite for the load circuit in the use of jaw switching elements is that the switching element to be dissolved is guided before releasing in an at least almost no-load condition. The leadership in the virtually no-load condition is achieved in that the switching element is made largely free of torque, so that no or only a small torque is transmitted via the switching element. For this purpose, a torque is applied by the electric machine to that shaft, with which the switching element to be released establishes a connection.

According to the invention, the second shaft of the additional gearset can be connected to the first shaft of the main gearset via a first additional shift element and to the second or third shaft of the main gearset via a second additional shift element. If the second shaft of the Zusatzradsatzes connectable via the second additional switching element with the second shaft of the main gearset, the third wave of the Zusatzradsatzes is constantly connected to the third or fourth shaft of the main gearset. If the second shaft of the Zusatzradsatzes connectable via the second additional switching element with the third shaft of the main gearset, the third wave of Zusatzradsatzes is constantly connected to the fourth shaft of the main gearset.

In this case, either the first additional switching element or the second additional switching element is closed. During a switching phase between the first and second auxiliary switching element, at first one of the additional switching elements is opened, and only then the other additional switching element is closed. During this switching phase, therefore, neither of the two additional switching elements is closed at short notice.

By the first and second additional switching element, the position of the first wave of Zusatzradsatzes in the speed plan is selectively influenced.

If the first additional switching element is closed and the second additional switching element is open, the second shaft of the additional gearset is connected to the first shaft of the main gearset. In this position, the first and second auxiliary switching element is the first wave of the main gearset in the speed diagram between the first shaft of Zusatzradsatzes and the second shaft of the main gearset. This case is referred to below as the first operating state.

If the second additional switching element is closed and the first additional switching element is open, then the second shaft of the additional gearset is connected to the second or third shaft of the main gearset. This case is referred to below as the second operating state. In this position of the first and second auxiliary switching element, the position of the first shaft of Zusatzradsatzes changes in the speed plan compared to the first operating state. The ratio of the first shaft of Zusatzradsatzes to the third wave of the main gearset is reduced compared to the first operating state.

The ratio of the first wave of Zusatzradsatzes to the third wave of the main gearset is greater in the first operating state than in the second operating state. By this enlarged in the first operating state ratio, the torque to be applied during the switching operation of the rotor is reduced, whereby the electric machine can be made smaller and lighter. In this way, the reduced electric machine can apply the required torque to the transmission input shaft even at a high torque at a load circuit, without resulting in an undesirably high torque reduction at the transmission output shaft. The enlarged ratio is also useful when the torque of the electric machine to be transmitted to the transmission output shaft, for example when using the transmission in a motor vehicle, whereby an electric driving operation of the motor vehicle is made possible. By so magnified translation starting up of the motor vehicle in a slope even with miniaturized electrical machine is possible. The increased ratio is additionally useful when transmitting torque from the electric machine to the transmission input shaft, for example when used to start an internal combustion engine connected to the transmission input shaft. Again, the enlarged translation causes the electrical machine can be smaller and thus easier to build.

By the arrangement according to the invention is also achieved that the rotor is even in a rotationally fixed fixing one of the shafts of the main gearset is able to assume a speed. The assumption of a speed is a prerequisite for receiving and delivering mechanical power by the electric machine. This makes it possible for the electric machine to be able to absorb or dispense mechanical power even in those gears in which, for example, the first shaft of the main gearset is fixed in a rotationally fixed manner or has no appreciable rotational speed. This is particularly advantageous when using the transmission in a motor vehicle, since kinetic energy of the motor vehicle can be recuperated by the regenerative operation of the electric machine in each gear of the transmission. If an internal combustion engine is connected to the transmission input shaft, then the load point of the internal combustion engine can be shifted by regenerative or engine operation of the electric machine in each gear. The transmission thus enables an increase in efficiency of the motor vehicle.

In the second operating state, the position of the first shaft of Zusatzradsatzes changes in the speed plan, the exact location of the stationary gear ratios of the planetary gear sets involved depends. Depending on the stationary gear ratio of the participating planetary gear sets is the first shaft of the main gearset in the speed plan in the second operating state between the first shaft of the Zusatzradsatzes and the second shaft of the main gearset, or the first wave of Zusatzradsatzes is located between the first and second shaft of the main gearset. If the second shaft of Zusatzradsatzes connected via the second additional switching element to the third shaft of the main gearset, the first wave of Zusatzradsatzes may be in the speed plan with closed second additional switching element between the second and third shaft of the main gear.

The ratio of the first wave of Zusatzradsatzes to the third wave of the main gearset is smaller in the second operating state than in the first operating state. Thereby, the rotational speed of the rotor of the electric machine, which is connected to the first shaft of the Zusatzradsatzes, are selectively reduced in selected gears. In low gears, with a high transmission ratio between the transmission input shaft and the transmission output shaft, the speed difference between the four shafts of the main gear and the rotor is comparatively low. In high gears, with a low transmission ratio between the transmission input shaft and the transmission output shaft, the speed difference between the four shafts of the main gearset and the rotor is significantly higher. In high gears, it may thus depending on the assignment of the switching elements to the worlds of the main gearset and depending on the stationary gear ratio of Planetary gear sets come to the limit speed of the rotor is achieved.

Due to the switching possibility according to the invention by means of the two additional switching elements, the ratio of the first shaft of Zusatzradsatzes to the third wave of the main gearset can be selectively influenced so that no compromise must be made in terms of the advantage of improved load switching behavior at low gears and the speed limit of the rotor in high gears.

The two additional switching elements are preferably actuated by a double-acting actuator. This reduces both the assembly costs and the manufacturing cost of the transmission.

Preferably, a sun gear of the planetary gear set of Zusatzradsatzes is a part of the first wave of the Zusatzradsatzes. In the case that the planetary gearset of Zusatzradsatzes is designed as minus wheelset, a bridge of the planetary gear set of Zusatzradsatzes is a part of the second shaft of the Zusatzradsatzes, and a ring gear of the planetary gear set of Zusatzradsatzes a part of the third wave of the Zusatzradsatzes. If the planetary gear set of Zusatzradsatzes designed as a plus-wheel, the assignment of ring gear and land is reversed, so that the ring gear of the planetary gearset Zusatzradsatzes is a part of the second shaft of the Zusatzradsatzes and the bridge of the planetary gear set of Zusatzradsatzes a part of the third wave of Zusatzradsatzes is. As a result, the speed of the second shaft of Zusatzradsatzes is always between the rotational speed of the first and third shaft of the Zusatzradsatzes, provided that said elements of the planetary gear set of Zusatzradsatzes do not rotate at the same speed.

When using a Plus wheel set, it must be taken into account that the amount of the stationary gear ratio must be increased by the value of one in order to achieve the same translation effect as with a minus wheel set.

Through this assignment of the elements of the planetary gearset of Zusatzradsatzes to the three waves of Zusatzradsatzes is ensured together with the inventive assignment of these three waves to the four shafts of the main gear that the first wave of the main gear always closed with the first additional switching element in the speed plan between the first wave Zusatzradsatzes and the second wave of the main gear is.

Due to the large number of offered possibilities of connection between rotor, additional gear and main gear, the invention is therefore particularly easy to adapt to different transmission variants and available space conditions.

Preferably, three of the four shafts of the main gearset rotate in the same direction of rotation as the transmission output shaft. The remaining wave of the four shafts of the main gearset either rotates in the same direction as the other waves of the main gearset or has no direction of rotation by the remaining shaft is set switchable rotatably. In other words, all four shafts of the main gear rotate in the same direction of rotation, unless one of the four waves is fixed by a switching element and thus has no speed, and thus no direction of rotation. There is thus no difference in the direction of rotation between the four shafts of the main gearset. If the connection of the rotor to additional gear set and main gear set chosen so that the rotor is in the speed plan with closed second additional switching element between the first and the second or third shaft of the main gear, it also happens between the four shafts of the main gear and the rotor to no reversal of direction. The rotor is thus always operated at a speed greater than zero except for a reverse gear realized by reverse rotation of the rotor. Since electrical machines are usually controlled or regulated by the rotor speed, a zero crossing of the speed at a dynamic change of direction a significant overhead in its control, or regulation. By the preferably selected stationary gear ratios of the planetary gear sets involved ensures that the Rotor in the forward gears during the second operating state undergoes no reversal of direction. With a suitable assignment of the switching elements and depending on the stationary gear ratio of the planetary gear sets involved can also be achieved that the rotor undergoes no change in direction in the forward gears even during the first operating state.

According to an advantageous embodiment, the stationary gear ratios of the planetary gearset of Zusatzradsatzes and the planetary gear sets of the main gearset are selected such that the first shaft of the Zusatzradsatzes in the speed plan with closed second auxiliary switching element and opened first additional switching element between the first and second shaft of the main gearset.

In the following, an exemplary embodiment is presented for a design of the stationary gear ratios. By way of example, a sun gear of the first planetary gearset of the main gearset is part of the first shaft of the main gearset. On The web of the first planetary gear set and a ring gear of the second planetary gear set of the main gearset is part of the second shaft of the main gearset. A ring gear of the first planetary gear set and a web of the second planetary gear set are components of the third wave of the main gearset. A sun gear of the second planetary gear set of the main gearset is part of the fourth wave of the main gearset. A sun gear of the planetary gear set of Zusatzradsatzes is an example of part of the first wave of Zusatzradsatzes. A bridge of the planetary gear set of Zusatzradsatzes is part of the second shaft of the Zusatzradsatzes, and a ring gear of the planetary gear set of Zusatzradsatzes is part of the third wave of the Zusatzradsatzes. All planetary gear sets are designed as minus wheelsets. In this exemplary embodiment, the second shaft of Zusatzradsatzes connected via the closed second additional switching element to the second shaft of the main gearset, and the third wave of Zusatzradsatzes connected to the third shaft of the main gearset, then the first wave of Zusatzradsatzes in the speed plan is only then between the first and second shafts of the main gearset when the amount of the stationary gear ratio of the planetary gearset of the Zusatzradsatzes is smaller than the amount of the stationary gear ratio of the first planetary gearset of the main gearset.

Is in this exemplary embodiment, the second shaft of Zusatzradsatzes connected via the closed second additional switching element to the third shaft of the main gearset, and the third wave of Zusatzradsatzes connected to the fourth shaft of the main gearset, the position of the first shaft of the Zusatzradsatzes in the speed plan is dependent from the stationary gear ratio of Zusatzradsatzes and the stationary gear ratios of the two planetary gear sets of the main gearset. The amount of the stationary gear ratio of the planetary gearset of Zusatzradsatzes must be smaller than the increased by the value of one amount of stationary gear ratio of the first planetary gearset of the main gearset, this sum must be divided by the amount of stationary gear ratio of the second planetary gearset of the main gearset.

The order of the four shafts of the main gearset in the speed diagram is dependent on the manner which waves are assigned to which components of the first and second planetary gearset of the main gearset, and which of the four shafts are interconnected. Examples are known in the prior art, but certain variants have been found to be particularly advantageous for the implementation in a transmission. These are particularly advantageous because of a geometrically favorable arrangement, because of a reduced component load and because of improved accessibility to switching elements.

According to a preferred variant, the first shaft of the main gearset is connected to a sun gear of the first planetary gear set of the main gearset. The second shaft of the main gearset is connected to a web of the first planetary gear set and a ring gear of the second planetary gear set of the main gearset. The third wave of the main gearset is connected to a ring gear of the first planetary gear set and to a land of the second planetary gear set of the main gearset. The fourth shaft of the main gearset is connected to a sun gear of the second planetary gear set of the main gearset. First and second planetary gear set are designed as minus wheelsets.

If the transmission has eight forward gears between the transmission input shaft and the transmission output shaft, the second additional shifting element is preferably closed in the fifth to eighth forward gear. The ratio between the first wave of Zusatzradsatzes and the third wave of the main gearset is reduced. When using the transmission in the drive train of a motor vehicle is to accept at these high gears a slight power dip at the transmission output shaft during the load circuit, since these high gears are usually used as a smooth response at high vehicle speeds. With a suitable choice of the stationary gear ratios of the participating planetary gear sets can be recuperated in these gears. In the first and second forward gear, the first additional switching element is preferably closed. In the first and second forward gear, the speed difference between the four shafts of the main gear is relatively low. Therefore, the limit speed of the rotor despite the enlarged when the first auxiliary switching element enlarged ratio between the first shaft of Zusatzradsatzes and the third wave of the main gearset is not reached. The advantage of the improved load circuit with closed first additional switching element can therefore be used in these corridors. In the engaged third or fourth forward gear is switched between the first and second auxiliary switching element.

The transmission according to the invention is preferably designed as a power shiftable eight-speed transmission. This eight-speed transmission has a first power path and a second power path between the transmission input shaft and the main gearset. First and second power path have a different gear ratio to the transmission input shaft. The first power path is via a first switching element with the fourth wave of the main gear and over a second switching element connectable to the second shaft of the main gearset. The second power path is connectable via a third switching element with the first shaft of the main gearset and a fourth switching element with the second shaft of the main gearset. The first wave of the main gearset is rotatably fixed by a fifth switching element. The fourth wave of the main gearset is rotationally fixed by a sixth switching element. By the fifth and sixth switching element is therefore a firm connection with a transmission housing of the transmission or with another rotatably fixed component of the transmission produced. This arrangement of the first to sixth switching elements causes a particularly advantageous division of the individual courses.

By selective pairwise engagement of the first to sixth switching element eight forward gears between the transmission input shaft and the transmission output shaft can be realized. A first forward speed results from closing the third switching element and the sixth switching element. A second forward speed results from closing the fourth switching element and the sixth switching element. A third forward speed results from closing the third switching element and the fourth switching element. A fourth forward speed is achieved by closing the fourth switching element and the first switching element. A fifth forward speed results from closing the third switching element and the first switching element. A sixth forward speed results from closing the second switching element and the first switching element. A seventh forward speed results from closing the third switching element and the second switching element. An eighth forward speed results from closing the fifth shift element and the second shift element.

Switching between the first and second additional switching element is particularly advantageous in the third forward gear, since the four shafts of the main gearset have the same speed when the third and fourth switching element is closed. An otherwise required when switching between the two additional switching elements synchronization of the waves involved eliminates this in a simple way.

According to a preferred embodiment of the eight-speed transmission two switching elements in each case can be actuated by a double-acting actuator. Third and fifth switching element can be actuated via a first double-acting actuator. Second and fourth switching element can be actuated via a second double-acting actuator. First and sixth switching element can be actuated via a third double-acting actuator. Each of the three double-acting actuators can assume three states. In a first switching state of the double-acting actuator, the first switching element assigned to the actuator is in a closed position, while the second switching element assigned to the actuator assumes an open position. In a second switching state of the actuator, the second switching element associated with the actuator is in a closed position, while the first switching element assigned to the actuator assumes an open position. In a third switching state, both switching elements assigned to the actuator assume the open position. Due to the design of the main gearset and the connection of the main gearset to the electric machine, this assignment of the first to sixth switching elements is made possible for only three double-acting actuators. This reduced number of actuators helps reduce the complexity of the transmission and reduces the manufacturing cost of the transmission.

The transmission may preferably be part of a hybrid drive train of a motor vehicle. The hybrid powertrain also has an internal combustion engine in addition to the transmission. The internal combustion engine is either directly or via a clutch connected to the transmission input shaft of the transmission, or connectable. The motor vehicle can be driven both by the internal combustion engine and by the electric machine of the transmission. Optionally, the hybrid powertrain on an additional electric machine, which is adapted to deliver a torque on the crankshaft of the internal combustion engine via its rotor and thus to start the internal combustion engine. This has the advantage that the internal combustion engine can be started by means of the additional electric machine, without having to influence a simultaneous electric driving operation, in which the motor vehicle is driven solely by the electric machine of the transmission. If the hybrid drive train has a clutch between the transmission and the internal combustion engine and an additional electric machine, the auxiliary electric machine is preferably arranged in the power flow between the internal combustion engine and the clutch. The coupling may have a variable transmission capability.

The electric machine is connected to a converter, via which the electric machine is connected to an energy store. For this purpose, any form of energy storage is suitable, in particular electrochemical, electrostatic, hydraulic and mechanical energy storage.

In a further embodiment, the transmission may also be part of a drive train of an electric vehicle. An electric vehicle is thereby alone by one or more Electric machines driven, and accordingly has no internal combustion engine. At the transmission input shaft in this case, a traction electric machine is connected. Due to the different gear ratios of the transmission, the traction electric machine can always be operated in an operating range with high efficiency, whereby the energy efficiency of the entire electric vehicle is improved.

• 1 zeigt schematisch ein Getriebe entsprechend einer ersten Ausführungsform der Erfindung.
• 2 zeigt einen Drehzahlplan des Getriebes.
• 3 zeigt ein Schaltschema des Getriebes.
• 4 zeigt schematisch ein Getriebe entsprechend einer zweiten Ausführungsform der Erfindung.
• 5 zeigt schematisch ein Getriebe entsprechend einer dritten Ausführungsform der Erfindung.
• 6 zeigt einen Hybridantriebstrang eines Kraftfahrzeugs.

Embodiments of the invention are described in detail below with reference to the accompanying figures.

• 1 schematically shows a transmission according to a first embodiment of the invention.
• 2 shows a speed plan of the transmission.
• 3 shows a circuit diagram of the transmission.
• 4 schematically shows a transmission according to a second embodiment of the invention.
• 5 schematically shows a transmission according to a third embodiment of the invention.
• 6 shows a hybrid powertrain of a motor vehicle.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names.

1 schematically shows a transmission G according to a first embodiment of the invention. The gear G has a Vorschaltradsatz VRS , a spare wheel set ZRS and a main gearset HRS on. The gearset VRS has a planetary gear set P3 on and the additional wheel set ZRS has a planetary gear set P4 on while the main gearset HRS a first planetary gear set P1 and a second planetary gear set P2 having. All planetary gear sets P1 . P2 . P3 . P4 are designed as minus wheelsets.

The representation of the transmission G essentially shows the connectable and connected elements of the transmission G , By in the representation of the transmission G selected distances can not be deduced on the gear ratios.

A transmission input shaft LV1 is with a sun wheel So-P3 of the planetary gear set P3 of the transfer gearset VRS connected while a ring gear Ho-P3 of the planetary gear set P3 of the transfer gearset VRS rotatably with the transmission housing GG of the transmission G , or with another rotatably fixed component of the transmission G connected is. In this way, a first and a second power path is established L1 . L2 formed by both the first power path L1 as well as through the second power path L2 Power from the transmission input shaft LV1 to the main gearset HRS can be transferred. The second performance path L2 It leads in comparison to the speed of the transmission input shaft LV1 changed speed to the main gearset HRS Continue by adjusting the speed at the transmission input shaft LV1 through the translation between the sun gear So-P3 and a jetty St-P3 of the planetary gear set P3 of the transfer gearset VRS is translated. The first performance path L1 directs the speed of the transmission input shaft LV1 without translation to the main gearset HRS continue. The sun wheel So-P3 of the planetary gear set P3 of the transfer gearset VRS is part of a first wave W1VS of the transfer gearset VRS connected to the transmission input shaft LV1 connected is. The jetty St-P3 of the planetary gear set P3 of the transfer gearset VRS is part of a second wave W2VS of the transfer gearset VRS , That component to which the ring gear Ho-P3 of the planetary gear set P3 of the transfer gearset VRS is supported in the following as a third wave W3VS of the transfer gearset VRS designated.

A first wave W1 of the main gearset HRS is with a sun wheel So-P1 of the first planetary gear set P1 of the main gearset HRS connected. A second wave W2 of the main gearset HRS is with a jetty St-P1 of the first planetary gear set P1 and with a ring gear Ho-P2 of the second planetary gear set P2 of the main gearset HRS connected. A third wave W3 of the main gearset HRS is with a ring gear Ho-P1 of the first planetary gear set P1 and with a jetty St-P2 of the second planetary gear set P2 of the main gearset HRS connected. A fourth wave W4 of the main gearset HRS is with a sun wheel So-P2 of the second planetary gear set P2 of the main gearset HRS connected. By this arrangement and connection between the individual components of the first and second planetary gear set P1 . P2 of the main gearset HRS becomes the arrangement of the first, second, third and fourth wave W1 . W2 . W3 . W4 of the main gearset HRS determined in the speed plan, the order of first, second, third, fourth wave W1 . W2 . W3 . W4 whose sequence corresponds to the speed plan. The third wave W3 is with a transmission output shaft GW2 connected. Alternatively, the third wave W3 also via an additional transmission gearbox with the transmission output shaft GW2 be connected. The sun wheel So-P2 of the second planetary gear set P2 of the main gearset HRS has two separate parts. This allows the connection of the transmission output shaft GW2 with the third wave W3 of the main gearset HRS which is between the two parts of the sun gear So-P2 is arranged. The speed ratios are of course on both parts of the sun gear So-P2 equal. As a result, below are both parts of the sun gear So-P2 as part of the same wave, specifically the fourth wave W4 of the main gearset HRS designated. In an alternative embodiment, not shown for clarity, the sun gear So-P2 of the second planetary gear set P2 of the main gearset HRS also be made in one piece, for example, in the event of use of the transmission in the motor vehicle in a transversely arranged to the direction of drive train, the transmission has an axially parallel output in this case.

The first performance path L1 is via a first switching element A with the fourth wave W4 of the main gearset HRS and a second switching element e with the second wave W2 of the main gearset HRS connectable. The second performance path L2 is via a third switching element B with the first wave W1 of the main gearset HRS and via a fourth switching element D with the second wave W2 of the main gearset HRS connectable. The first wave W1 of the main gearset HRS is by a fifth switching element C with the gearbox GG of the transmission G , or with another non-rotatable component of the transmission G connectable, so the first wave W1 of the main gearset HRS with the fifth switching element closed C can not accept any speed. The fourth wave W4 of the main gearset HRS is in the same way by a sixth switching element F rotationally fixable by the fourth shaft W4 through the sixth switching element F is connected to the transmission housing GG.

Two switching elements in each case can be actuated by a double-acting actuator. Third and fifth switching element B . C are actuated via a first double-acting actuator. Second and fourth switching element e . D are actuated via a second double-acting actuator. First and sixth switching element A . F are actuated via a third double-acting actuator.

The gear G has an electric machine EM on, being a stator S rotatably with the transmission housing GG of the transmission G or with another non-rotatable component of the transmission G connected so that the stator S can not accept any speed. A rotatably mounted rotor R is with a sun wheel So-P4 of the planetary gear set P4 of additional wheel set ZRS connected. The sun wheel So-P4 of the planetary gear set P4 of additional wheel set ZRS is part of a first wave W1P4 of additional wheel set ZRS , A jetty St-P4 of the planetary gear set P4 of additional wheel set ZRS is part of a second wave W2P4 of additional wheel set ZRS , The second wave W2P4 of additional wheel set ZRS is via a first additional switching element U with the first wave W1 of the main gearset HRS , and via a second additional switching element V with the second wave W2 of the main gearset HRS connectable. A ring gear Ho-P4 of the planetary gear set P4 of additional wheel set ZRS is part of a third wave W3P4 of additional wheel set ZRS and is with the third wave W3 of the main gearset HRS connected.

2 shows a speed plan of the transmission G while in 3 a circuit diagram of the transmission G is shown. In 2 are the vertical speeds of the four waves W1 . W2 . W3 . W4 of the main gearset HRS and the first wave W1P4 of additional wheel set ZRS in relation to the speed n the transmission input shaft LV1 applied. A maximum occurring speed n the transmission input shaft LV1 is normalized to the value one. The distances between the four waves W1 . W2 . W3 . W4 of the main gearset HRS and the first wave W1P4 of additional wheel set ZRS result from the stationary gear ratios of the first and second planetary gear set P1 . P2 of the main gearset HRS and the stationary gear ratio of the planetary gear set P4 of additional wheel set ZRS , Speed ratios associated with a particular operating point can be connected by a straight line.

Is the first additional switching element U closed, so is the first wave W1 of the main gearset HRS in the speed plan between the first shaft W1P4 of additional wheel set ZRS and the second wave W2 of the main gearset HRS , Is the second additional switching element V closed, so is the first wave W1P4 of additional wheel set ZRS between the first wave W1 of the main gearset HRS and the second wave W2 of the main gearset HRS ,

If two shafts are connected, these connected shafts rotate at the same speed. For the sake of clarity, such connected shafts in the speed plan can be shown horizontally separated from each other, for example, the speed transmission from the transfer gear VRS over the first or second power path L1 . L2 to the main gearset HRS better to clarify. The selected in the speed schedule horizontal distance between the connected waves is arbitrary. The translation between such connected waves is of course the value one, regardless of the horizontal distance selected in the speed plan.

If two of these elements are connected to each other by ring gear, web and sun of a planetary gear set, the ring gear, land and sun of this planetary gear set rotate at the same speed. In this state, the translation between the named elements assumes the value one. For the sake of clarity, the horizontal arrangement of the waves connected to these elements is not shifted in the speed plan. As a result, this condition can be recognized in the speed diagram by a horizontal straight line connecting the shafts involved.

3 shows a circuit diagram of the transmission G according to the first embodiment. Through the wiring diagram in 3 and the speed plan in 2 will the functioning of the transmission G clear. The closed switching elements A . B . C . D . e . F and additional switching elements U . V are in 3 indicated by circles. The shift pattern, the respective translations of the individual gear ratios and the gear ratios to be determined from the next higher gear can be exemplified, the transmission G has such a spread of 10.1. The translations result from the stationary gear ratios of the planetary gear sets P1 . P2 . P3 . P4 , With sequential switching mode, double circuits or group circuits can be avoided since two adjacent gear stages share a switching element. The gears of the transmission G are shown in the different lines of the wiring diagram. In a column of the wiring diagram is further specified whether the electric machine EM in the gear in question is capable of mechanical power to the transmission output shaft GW2 to give or receive from this.

A first forward speed 1VM between the transmission input shaft LV1 and the transmission output shaft GW2 results from closing the third switching element B and the sixth switching element F , a second forward gear 2VM by closing the fourth switching element D and the sixth switching element F , a third forward speed 3VM by closing the third switching element B and the fourth switching element D , a fourth forward gear 4VM by closing the fourth switching element D and the first switching element A , a fifth forward gear 5VM by closing the third switching element B and the first switching element A , a sixth forward speed 6VM by closing the second switching element e and the first switching element A , a seventh forward gear 7VM by closing the third switching element B and the second switching element e , and an eighth forward gear 8VM by closing the fifth switching element C and the second switching element e ,

In the first and second forward gear 1VM . 2VM is the first additional switching element U closed. Either in third or fourth forward 3VM . 4VM becomes the first additional switching element U opened and the second additional switching element V closed, or vice versa. In the fifth to eighth forward speed 5VM-8VM is the second additional switching element V closed.

In a first electrical gear 1EM will torque alone from the electric machine EM to the transmission output shaft GW2 transferred, wherein the first, second, third, fourth switching element A . e . B . D is open and thus no torque-conducting connection between the transmission input shaft LV1 and the transmission output shaft GW2 consists. The first additional switching element U and the sixth switching element F are closed. The fifth switching element C it is open. In a second electrical gear 2em is instead of the first additional switching element U the second additional switching element V closed.

In a first and second start mode 1S . 2S becomes the transmission input shaft LV1 Torque supplied, depending on the position of the sixth switching element F Torque only from the electric machine EM or also from the transmission output shaft GW2 the transmission input shaft LV1 can be fed. Is the sixth switching element F closed, and gives the electric machine EM no moment off, so can the transmission input shaft LV1 Torque also exclusively from the transmission output shaft GW2 be supplied. This is especially true when using the transmission G in the motor vehicle relevant to such a on the transmission input shaft LV1 connected internal combustion engine VKM to start. Is this the sixth switching element F open, so must the transmission output shaft GW2 be fixed in rotation by a parking brake. The first additional switching element U is closed.

In the following, a load switching operation will be described by way of example. In second forward, the second and fourth wave form W2 . W4 of the main gearset HRS one differential wave each, while the third wave W3 of the main gearset HRS represents a total wave. In a shift from the second forward gear 2VM in the third forward gear 3VM remains the fourth switching element D closed. The sixth switching element F is opened, then the third switching element B closed. Is the sixth switching element F designed as a claw-switching element, so must the sixth switching element F be made largely free of torque before opening, so that the sixth switching element F No or only a small torque transfers. This load release of the sixth switching element F is through a regenerative moment of the electric machine EM causes. In this case, at least a portion of the previously remains at the third wave W3 of the main gearset HRS received torque, causing it to the transmission output shaft GW2 does not come to a complete torque dip. Is the sixth switching element F open, so will the second wave W2 of the main gearset HRS to the sum wave, while the first wave W1P4 of additional wheel set ZRS and the third wave W3 of the main gearset HRS each form a differential wave. By the electric machine EM Now a generator torque is applied to a speed synchronization between the second shaft W2VS of the transfer gearset VRS and the first wave W1 of the main gearset HRS to reach. This will cause the third switching element to close B allows, with at least a portion of the previously on the third wave W3 of the main gearset HRS applied torque is maintained. Is the third switching element B closed, so will the first wave W1 of the main gearset HRS to the differential shaft, the switching process is completed. This ensures that during the switching process part of the power flow from the transmission input shaft LV1 to the transmission output shaft GW2 can be maintained. This mode of action applies to all embodiments.

4 schematically shows a transmission G according to a second embodiment of the invention. In contrast to the first embodiment, the third wave W3P4 of additional wheel set ZRS not with the third wave anymore W3 of the main gearset HRS connected. Instead, the third wave W3P4 of additional wheel set ZRS with the fourth wave W4 of the main gearset HRS connected. To have the same translation effect between the first wave W1P4 of additional wheel set ZRS and the four waves W1 . W2 . W3 . W4 of the main gearset HRS to achieve as in the first embodiment of the transmission G must the stationary gear ratio of the planetary gear set P4 of additional wheel set ZRS be adjusted accordingly.

5 schematically shows a transmission G according to a third embodiment of the invention. In contrast to the second embodiment, the second shaft W2P4 of additional wheel set ZRS in this third embodiment via the second additional switching element V not with the second wave anymore W2 of the main gearset HRS connectable. Instead, the second wave W2P4 of additional wheel set ZRS over the second additional switching element V now with the third wave W3 of the main gearset HRS connectable. The third wave W3P4 of additional wheel set ZRS is with the fourth wave W4 of the main gearset HRS connected.

The speed plan in 2 and the schematic in 3 apply also to the second and third embodiment, provided that the stationary gear ratios of the planetary gear sets are selected accordingly.

6 schematically shows a hybrid powertrain of a motor vehicle. The transmission contained therein G corresponds to the first embodiment of the transmission G although this is to be considered as an example only. A rotatable rotor R2 an additional electric machine SG is with the transmission input shaft LV1 connected while the stator S2 the auxiliary electric machine SG rotatably on the gear housing GG of the transmission G or at another non-rotatable component of the transmission G is connected. About a rotational vibration damper RD is an internal combustion engine VKM with the transmission input shaft LV1 connected. The transmission output shaft GW2 is with a axle drive AG connected. From the axle drive AG starting from the torque that is applied to the transmission output shaft GW2 rests on wheels W of the motor vehicle distributed. In motor operation of the electric machine EM becomes the stator S via an inverter INV electrical power supplied. In generator operation of the electric machine EM leads the stator S the inverter INV electric power too. The inverter INV converts the DC voltage of a battery BAT in one for the electric machine EM suitable alternating voltage, and vice versa. The additional electric machine SG can also do this via the inverter INV be supplied with electrical power. Alternatively, the additional electric machine SG be connected to another power supply, for example, to a low-voltage electrical system of the motor vehicle.

LIST OF REFERENCE NUMBERS

G

transmission

LV1

Transmission input shaft

GW2

Transmission output shaft

n

Speed of the transmission input shaft

HRS

main gear

ZRS

Zusatzradsatz

VRS

gearset

EM

Electric machine

R

Rotor of the electric machine

S

Stator of the electric machine

SG

Additional electric machine

R2

Rotor of auxiliary electric machine

S2

Stator of auxiliary electric machine

RD

rotational vibration

VKM

Internal combustion engine

INV

inverter

BAT

battery

K0

clutch

P1

First planetary gear set of the main gearset

P2

Second planetary gear set of the main gearset

P3

Planetary gear set of the transfer gearset

P4

Planetary wheel set of additional wheelset

W1

First wave of the main gearset

W2

Second wave of the main gearset

W3

Third wave of the main gearset

W4

Fourth wave of the main gearset

W1VS

First wave of the transfer gearset

W2VS

Second wave of the transfer gearset

W3VS

Third wave of the transfer gearset

W1P4

First wave of additional wheel set

W2P4

Second wave of Zusatzradsatzes

W3P4

Third wave of Zusatzradsatzes

A

First switching element

e

Second switching element

B

Third switching element

D

Fourth switching element

C

Fifth switching element

F

Sixth switching element

U

First additional switching element

V

Second additional switching element

So-P1

Sun gear of the first planetary gear set of the main gearset

St-P1

Bridge of the first planetary gear set of the main gearset

Ho-P1

Ring gear of the first planetary gear set of the main gearset

So-P2

Sun gear of the second planetary gear set of the main gearset

St-P2

Bridge of the second planetary gear set of the main gearset

Ho-P2

Ring gear of the second planetary gear set of the main gearset

So-P3

Sun gear of the planetary gear set of the transfer gearset

St-P3

Bridge of the planetary gear set of the transfer gearset

Ho-P3

Ring gear of the planetary gear set of the transfer gearset

So-P4

Sun gear of the planetary gear set of additional wheelset

St-P4

Bridge of the planetary gear set of Zusatzradsatzes

Ho-P4

Ring gear of the planetary gear set of Zusatzradsatzes

L1

First performance path

L2

Second performance path

1 VM-8VM

First to eighth forward

1 EM

First electric gear

2em

Second electric gear

1S

First startup mode

2S

Second start mode

AG

transaxles

W

wheel

Claims (15)

Transmission (G) for a motor vehicle with a transmission input shaft (GW1) and a transmission output shaft (GW2), a main gearset (HRS), a Zusatzradsatz (ZRS), and an electric machine (EM) with a rotor (R) and a stator (S), the transmission (G) having at least one power path (L1, L2) between the transmission input shaft (GW1) and the main gearset (HRS), the main gearset (HRS) including first and second planetary gear sets (P1 , P2) with a total of four in speed order as first, second, third and fourth wave designated waves (W1, W2, W3, W4), wherein the at least one power path (L1, L2) via at least one switching element (A, B, D , E) is connectable to at least one of the four shafts (W1, W2, W3, W4) of the main gearset (HRS), the third shaft (W3) of the main gearset (HRS) being connected to the transmission output shaft (GW2), the Zusatzradsatz (ZRS) a planetary gear set (P4) with a first, second and third wave (W1P4 , W2P4, W3P4), and wherein the first shaft (W1P4) of the auxiliary wheel set (ZRS) is permanently connected to the rotor (R), characterized in that the second shaft (W2P4) of the Zusatzradsatzes (ZRS) via a first additional switching element (U) with the first shaft (W1) of the main gearset (HRS) and a second additional switching element (V) with the second or third shaft (W2, W3) of the main gearset (HRS) is connectable wherein either the first additional switching element (U) or the second additional switching element (V) is closed, wherein - in the case that the second shaft (W2P4) of Zusatzradsatzes (ZRS) via the second additional switching element (V) with the second wave (W2) of the Main gearset (HRS) is connectable, the third shaft (W3P4) of the additional gearset (ZRS) is permanently connected to the third or fourth shaft (W3, W4) of the main gearset (HRS), and - in the case of the second shaft (W2P4) the Zusatzradsatzes (ZRS) via the second additional switching element (V) to the third shaft (W3) of the main gearset (HRS) is connectable, the third wave (W3P4) of Zusatzradsatzes (ZRS) constantly with the fourth wave (W4) of the main gearset (HRS ) connected is. Transmission (G) to Claim 1 characterized in that a sun gear (So-P4) of the planetary gear set (P4) of the Zusatzradsatzes (ZRS) is a component of the first wave (W1P4) of Zusatzradsatzes (ZRS), and - in the case that the planetary gear set (P4) of the Zusatzradsatzes (ZRS) is designed as a minus wheel set, a web (St-P4) of the planetary gear set (P4) of Zusatzradsatzes (ZRS) is a part of the second wave (W2P4) of Zusatzradsatzes (ZRS) and a ring gear (Ho-P4) of Planetenradsatzes (P4) of the Zusatzradsatzes (ZRS) is a part of the third wave (W3P4) of the Zusatzradsatzes (ZRS), and - in the case that the planetary gear set (P4) of the Zusatzradsatzes (ZRS) is designed as a plus gear set, the ring gear ( Ho-P4) of the planetary gear set (P4) of Zusatzradsatzes (ZRS) is a component of the second shaft (W2P4) of Zusatzradsatzes (ZRS) and the web (St-P4) of the planetary gear set (P4) of Zusatzradsatzes (ZRS) is a part of the third Shaft (W3P4) of Zusatzradsatzes (ZRS) is. Transmission (G) to Claim 1 or Claim 2 characterized in that upon rotation of the transmission output shaft (GW2) at least three of the four shafts (W1, W2, W3, W4) of the main gearset (HRS) have the same direction of rotation as the transmission output shaft (GW2), the remaining shaft of the four shafts (W1, W2, W3, W4) of the main gearset (HRS) has either the same direction of rotation as the transmission output shaft (GW2) or switchable rotationally fixed fixed. Transmission (G) according to one of Claims 1 to 3 , characterized in that the stationary gear ratios of the planetary gear set (P4) of the Zusatzradsatzes (ZRS) and the first and second planetary gear set (P1, P2) of the main gearset (HRS) are selected so that when the second auxiliary switching element (V) closed, the first wave (W1P4 ) of the additional gear set (ZRS) lies in the speed diagram between the first shaft (W1) and the second shaft (W2) of the main gearset (HRS). Transmission (G) according to one of Claims 1 to 4 , characterized in that a sun gear (So-P1) of the first planetary gear set (P1) of the main gearset (HRS) is part of the first wave (W1) of the main gearset (HRS), wherein a web (St-P1) of the first planetary gear set (P1 ) of the main gearset (HRS) and a ring gear (Ho-P2) of the second planetary gearset (P2) of the main gearset (HRS) are components of the second shaft (W2) of the main gearset (HRS), wherein a ring gear (Ho-P1) of the first planetary gearset (P1) of the main gearset (HRS) and a web (St-P2) of the second planetary gearset (P2) of the main gearset (HRS) are components of the third shaft (W3) of the main gearset (HRS), and wherein a sun gear (So-P2) of the second planetary gear set (P2) of the main gearset (HRS) is part of the fourth wave (W4) of the main gearset (HRS). Transmission (G) to Claim 1 , characterized in that the first additional switching element (U) and the second additional switching element (V) can be actuated by a double-acting actuator. Transmission (G) according to one of Claims 1 to 6 , characterized in that the transmission (G) has eight forward gears (1VM-8VM), wherein at least in the first and second forward gear (1VM, 2VM), the first additional switching element (U) is closed, and wherein at least in the fifth to eighth forward gear (5VM -8VM), the second additional switching element (V) is closed. Transmission (G) to Claim 7 , characterized in that in the third or fourth forward gear (3VM, 4VM) either the first additional switching element (U) or the second additional switching element (V) is closed. Transmission (G) to Claim 7 or Claim 8 characterized in that the transmission (G) comprises a first power path (L1) and a second power path (L2) between the transmission input shaft (GW1) and the main gearset (HRS), the first power path (L1) via a first switching element (A) with the fourth shaft (W4) of the main gearset (HRS) and via a second switching element (E) with the second shaft (W2) of the main gearset (HRS) is connectable, wherein the second power path (L2) via a third switching element ( B) with the first shaft (W1) of the main gearset (HRS) and a fourth switching element (D) with the second shaft (W2) of the main gearset (HRS) is connectable, wherein the first shaft (W1) of the main gearset (HRS) a fifth switching element (C) rotatably fixed, and wherein the fourth shaft (W4) of the main gearset (HRS) by a sixth switching element (F) is rotatably fixable. Transmission (G) to Claim 9 , characterized in that by selective pairwise engagement of the six switching elements (A, B, C, D, E, F) eight forward gears (1VM-8VM) can be realized, wherein the first forward gear (1VM) by closing the third switching element (B ) and the sixth shift element (F), the second forward speed (2VM) by closing the fourth shift element (D) and the sixth shift element (F), the third forward speed (3VM) by closing the third shift element (B) and the fourth shift element (FIG. D), the fourth forward speed (4VM) by closing the fourth shift element (D) and the first shift element (A), the fifth forward speed (5VM) by closing the third shift element (B) and the first shift element (A), the sixth forward speed (6VM) by closing the second switching element (E) and the first switching element (A), the seventh forward speed (7VM) by closing the third switching element (B) and the second switching element (E), and the eighth Vo reverse (8VM) by closing the fifth switching element (C) and the second switching element (E) results. Transmission (G) according to one of Claims 9 to 10 characterized in that the third and fifth switching elements (B, C) are operable by a first double-acting actuator, the second and fourth switching elements (E, D) being operable by a second double-acting actuator, and wherein the first and sixth switching elements (B, C) A, F) is actuated by a third double-acting actuator. Hybrid powertrain for a motor vehicle, wherein the hybrid powertrain at least one internal combustion engine (VKM), characterized in that the hybrid powertrain a transmission (G) according to one of Claims 1 to 11 having. Hybrid powertrain after Claim 12 , characterized in that the hybrid powertrain at least one with the internal combustion engine (VKM) directly or via a transmission connected additional electric machine (SG) which is adapted to start the internal combustion engine (VKM). Hybrid powertrain after Claim 12 or Claim 13 , characterized in that the power flow between the internal combustion engine (VKM) and the transmission input shaft (GW1) is interruptible by a clutch. Drive train for an electric vehicle, characterized in that the drive train is a transmission (G) according to one of Claims 1 to 11 having.

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