Drive arrangement for a hybrid vehicle

Abstract

Drive arrangement for a hybrid vehicle, comprising an internal combustion engine (VM), an electric machine (EM), and a transmission (12) with at least one transmission input shaft (1, 10) and a transmission output shaft (11), wherein a first planetary gear set (PS1) and a second planetary gear set (PS2) and at least one switching element (K, I, J, L) are arranged upstream of the transmission (12), wherein a first element of the first planetary gear set (PS1) is rotationally fixed to a drive shaft (1A) of the internal combustion engine (VM) or to a second transmission input shaft (1), wherein a second element of the first planetary gear set (PS1) is fixedly connected to the housing (13), wherein a first element of the second planetary gear set (PS2) is rotationally fixed to the electric machine (EM), wherein a second element of the second planetary gear set (PS2) is connected to a first transmission input shaft (10) of the transmission (12), wherein a multiple switching element (K, I, L) is used as the switching element.J) is provided, and wherein in a first switching position (K) of the multiple switching element (K, I, J) the third element of the second planetary gear set (PS2) is connected to the third element of the first planetary gear set (PS1), in a second switching position (I) of the multiple switching element (I, J, K) the third element of the second planetary gear set (PS2) is connected to the drive shaft (1A) or to the second transmission input shaft (1) and in a third switching position (J) of the multiple switching element (K, I, J) the third element of the second planetary gear set (PS2) is connected to the second element of the first planetary gear set (PS1).

Description

[0001] The present invention relates to a drive arrangement for a hybrid vehicle with an internal combustion engine and an electric machine as well as a transmission with at least one transmission input shaft and one transmission output shaft, wherein a first planetary gear set and a second planetary gear set as well as at least one switching element are arranged upstream of the transmission.

[0002] Such a drive arrangement is described in the subsequently published German patent DE 10 2015 221 498 A1, in which reversing is made possible, particularly in hybrid mode, by providing drive torque also via the combustion engine. In this drive arrangement, a second element of the first planetary gear set and a third element of the second planetary gear set are each connected separately to a housing. This separate housing connection increases the manufacturing complexity.

[0003] The present invention is based on the objective of creating a drive arrangement of the type described above, which is structurally simple and cost-effective.

[0004] This problem is solved by the features of claim 1, with advantageous embodiments arising from the dependent claims, the description and the drawings.

[0005] A drive arrangement for a hybrid vehicle is thus proposed, comprising an internal combustion engine, an electric machine, and a transmission with at least one transmission input shaft and one transmission output shaft. A first planetary gear set and a second planetary gear set, as well as at least one shifting element, are arranged upstream of the transmission, wherein a first element of the first planetary gear set is rotationally fixed to a drive shaft of the internal combustion engine or to a second transmission input shaft of the transmission. A second element of the first planetary gear set is fixedly connected to the housing, and a first element of the second planetary gear set is rotationally fixed to the electric machine.A second element of the second planetary gear set is connected to a first transmission input shaft of the transmission, wherein a multiple switching element is provided as switching elements, in which in a first switching position the third element of the second planetary gear set is connected to the third element of the first planetary gear set, in a second switching position the third element of the second planetary gear set is connected to the drive shaft or the second transmission input shaft and in a third switching position the third element of the second planetary gear set is connected to the second element of the first planetary gear set.

[0006] In this way, a special arrangement of a nested housing connection is realized for the multi-stage switching element, allowing both the second element of the first planetary gear set and the third element of the second planetary gear set to be connected to the housing. In the third switching position, this enables the integrated starter-generator (ISG) function. In the second switching position, an electrodynamic starting element provides the forward function (EDA forward), while in the first switching position, the electrodynamic starting element provides the reverse function (EDA reverse). The shared housing connection of the first and second planetary gear sets results in a cost-effective and space-saving design.

[0007] In an advantageous embodiment of the invention, a positive-locking triple switching element may be provided as the multiple switching element, in which, for example, a sliding sleeve is movable between the three switching positions and a first neutral position located between the first switching position and the second switching position, as well as a second neutral position located between the second switching position and the third switching position. Due to the characteristics of the multiple switching element, it is designed as a claw switching element, which results in significant energy consumption advantages.

[0008] The proposed drive arrangement is fundamentally independent of the design of the downstream transmission. The transmission can, for example, be designed as a spur gear transmission, perhaps in a reduction gear configuration. It is also conceivable that the transmission is implemented in a planetary gear configuration. Furthermore, it is conceivable that it includes upstream and / or downstream gear sets. In one possible embodiment of the invention, the transmission may be assigned only one input shaft. However, it is also conceivable that two input shafts are provided, which could then be assigned, for example, to two sub-transmissions of the transmission. If, for example, only one input shaft is implemented in the proposed drive arrangement, an additional switching element, for example a simple switching element, is provided, with which the drive shaft of the internal combustion engine can be connected to the second element of the second planetary gear set or to the first input shaft.This additional switching element can preferably be designed as a friction-locking or force-locking switching element.

[0009] Independently of the present invention, the two upstream planetary gear sets can be configured as negative or positive planetary gear sets. Where the binding permits, it is possible to convert one or more of the negative planetary gear sets into positive planetary gear sets by simultaneously swapping the link and ring gear connections and increasing the standard gear ratio by one. A negative planetary gear set, as is known, has planet gears rotatably mounted on the planet carrier, which mesh with the sun gear and the ring gear of this planetary gear set, such that, with the planet carrier fixed and the sun gear rotating, the ring gear rotates in the opposite direction to the direction of rotation of the sun gear.As is known, a plus planetary gear set has inner and outer planet gears rotatably mounted on its planet carrier and meshing with each other, with the sun gear of this planetary gear set meshing with the inner planet gears and the ring gear of this planetary gear set meshing with the outer planet gears, so that the ring gear rotates in the same direction as the sun gear when the planet carrier is fixed and the sun gear is rotating.

[0010] The present invention will now be explained in more detail with reference to the drawings. The drawings show: Fig. 1 a schematic view of a first embodiment of a drive arrangement according to the invention with a downstream gearbox having two gearbox input shafts; and Fig. 2 a schematic view of a second embodiment of the drive arrangement according to the invention with a downstream gearbox with a gearbox input shaft.

[0011] In the Fig. 1 and Fig. Figure 2 represents different embodiments of a drive arrangement according to the invention for a hybrid vehicle with an internal combustion engine VM and an electric machine EM, as well as with a transmission 12 of any design. A first planetary gear set PS1 and a second planetary gear set PS2, as well as at least one multiple switching element or triple switching element K, I, J, are connected upstream of the transmission or basic transmission 12.

[0012] Regardless of the specific design variant, the drive arrangement features a fixed connection between the second element of the first planetary gear set PS1 and the housing 13. This housing connection is also used to rigidly connect the third element of the second planetary gear set PS2 when the multi-switching element K, I, J is in the third switching position J. This creates a rotationally fixed connection between the third element of the second planetary gear set PS2, via the second element of the first planetary gear set PS1, and the housing 13. This specific housing connection of the two elements of the upstream planetary gear sets PS1 and PS2 is enabled in the third switching position J, where the so-called ISG function is implemented, effectively creating an integrated starter-generator.

[0013] At the in Fig. In the first embodiment shown in Figure 1, the downstream transmission 12 has a first transmission input shaft 10 and a second transmission input shaft 1, wherein in the Fig. In the second embodiment shown in Figure 2, a gearbox 12 is realized with only one first gearbox input shaft 10.

[0014] In both illustrated versions, a negative planetary gear set is shown as an example, representing the first planetary gear set PS1 and the second planetary gear set PS2. Accordingly, the first element in the second version is a sun gear 3 of the first planetary gear set PS1, connected to the drive shaft 1A. Fig. 2 or with the second transmission input shaft 1 in the first design variant according to Fig. 1. Furthermore, the second element is connected to the housing 13 as planet carrier 5 of the first planetary gear set PS1, and the third element, as ring gear 6 of the first planetary gear set PS1, is connected in the first switching position K of the multiple switching element K, I, J to the third element, designed as ring gear 8, of the second planetary gear set PS2. The second element, as planet carrier 14 of the second planetary gear set PS2, is connected to the first transmission input shaft 10, and the first element, as sun gear 9 of the second planetary gear set PS2, is connected to the electric machine EM. In the second embodiment according to Fig. 2 an additional simple switching element L is provided, with which the drive shaft 1A can be connected to the second element of the second planetary gear set PS2, which is designed as a planet carrier 14.

[0015] Regardless of the specific design variants, the housing connection between the planet carrier 5 of the first planetary gear set PS1 and the ring gear 8 of the second planetary gear set PS2 is provided by a sliding sleeve 7 of the multiple switching element K, I, J, designed as a positive-locking switching element, extending axially through the first planetary gear set PS1 to be rotationally fixed to the planet carrier 5 of the first planetary gear set PS1. This also connects the ring gear 8 of the second planetary gear set PS2 to the housing 13 via the planet carrier 5 of the first planetary gear set PS1. For this purpose, it is particularly simple in design for the sliding sleeve 7 to utilize a gap or housing window between the planet gears 4 supported by the planet carrier 5 to achieve the rotationally fixed connection with the planet carrier 5.This axial implementation is also possible because the planet carrier 5 of the first planet gear set RS1 is stationary due to the housing connection.

[0016] In the proposed drive arrangement, the drive shaft 1A or the second transmission input shaft 1 can be detachably or permanently connected to the internal combustion engine VM. The first planetary gear set PS1 serves as a reversing stage, with the sun gear 3 of the first planetary gear set PS1 being driven by the internal combustion engine VM, while the carrier or planet carrier 5 of the first planetary gear set PS1 is fixed to the housing. The ring gear 6 of the first planetary gear set PS1 rotates slowly in reverse. The ring gear 8 of the second planetary gear set PS2 can be connected in the three possible switching positions K, I, J either to the housing 13 or to the drive shaft 1A or to the second transmission input shaft 1 or to the reverse-rotating ring gear 6 of the first planetary gear set PS1.

[0017] Advantageously, only one actuator is required to operate the multiple switching element K, I, J, which can move to the three switching positions K, I, J as well as the two neutral positions. When the actuator moves the sliding sleeve 7 from right to left in the figures, the following switching position sequence is realized. In the first switching position K, the ring gear 8 of the second planetary gear set PS2 is connected to the reverse-rotating ring gear 6 of the first planetary gear set PS1, thus realizing the so-called EDA reverse function, which enables hybridized reverse driving. The first neutral position lies between the first switching position K and the second switching position I. This is required to synchronize the rotational speed of the switching element to be engaged with the electric machine EM.In the second shift position I, the EDA forward function is implemented, in which the ring gear 8 of the second planetary gear set PS2 is connected to the drive shaft 1A or to the second transmission input shaft 1 via a connection point 2, e.g., a fixed gear or the like, depending on the design variant. The EDA forward function enables the hybridized forward driving of the vehicle. Between the second shift position I and the third shift position J, there is a second neutral position, which is required to synchronize the rotational speed of the electric motor EM at the shift element to be engaged. In the third shift position J, the ring gear 8 of the second planetary gear set PS2 is connected to the housing 13 via the planet carrier 5 of the first planetary gear set PS1. This implements the ISG function and enables electric driving.

[0018] Before engaging the third shift position J, the rotational speed of the ring gear 8 of the second planetary gear set PS2 is brought to approximately zero or completely to a standstill by means of the electric machine EM. A suitable sensor detects whether the sliding sleeve 7 is facing a gap between the planet gears 4 of the first planetary gear set RS1 or a housing window on the circumference of the first planetary gear set PS1, without any planet gear 4 of the first planetary gear set PS1 obstructing it. Suitable sensors include angle detection on the drive shaft 1A, on the second transmission input shaft 1, and on the shaft supporting the sliding sleeve 7. However, a particularly simple option is relative angle detection, in which the sensor is located on the housing 13 and detects when the sliding sleeve 7 is facing it in the circumferential direction.

[0019] In principle, with the described drive arrangement, it is possible, for example, to change the connection of the second planetary gear set PS2, for example in such a way that the electric machine EM is located on the third element and the switchable connection between the drive shaft 1A or the second gearbox input shaft 1 and the housing 13 is located on the first element.

[0020] A further variant of the invention can be made possible by the fact that, particularly in the first embodiment according to Fig.1. A disconnect clutch or a starting clutch is provided for the internal combustion engine VM. For example, a brake on the shaft of the electric machine EM can also be provided as a conventional starting element for forward and reverse starting. This starting element supports or replaces the dynamic torque support provided by the electric machine EM in both the EDA forward and EDA reverse functions.

[0021] To obtain not only the EDA reverse function but also mechanical reverse gears without the necessary torque support from the electric motor EM, the second planetary gear set PS2 can be locked by an additional switching element, so that the three shafts of the elements of the third planetary gear set PS2 are forced to rotate at the same speed. Locking the second planetary gear set PS2 can be achieved by connecting any two of the three elements of the planetary gear set PS2. Such a lock-up clutch can also be designed as a friction clutch and serve as a conventional starting element for forward and reverse starts.

[0022] It is also possible that, for example, one of the planetary gear sets PS1, PS2 is designed as a Plus planetary gear set, since, as already mentioned, only the second and third elements of the respective planetary gear set PS1, PS2 are swapped. This means that in a Plus planetary gear set, the second element is designed as ring gear 6, 8 and the third element as planet carrier 5, 14. Based on this description, these other, not shown, design variants are also clearly revealed, in which at least one of the planetary gear sets PS1, PS2 is designed as a Plus planetary gear set.

[0023] In summary, the aforementioned variants have been explained in such detail that they are readily implementable by the person skilled in the art and are sufficiently and clearly claimed by the present invention. Reference sign 1 second gearbox input shaft 1A Drive shaft 2 Connection point in the second switching position 3 Sun gear of the first planetary gear set 4. Planet gear of the first planet gear set 5 planetary gear carriers of the first planetary gear set 6 Ring gear of the first planetary gear set 7 sliding sleeve 8 Ring gear of the second planetary gear set 9 Sun gear of the second planetary gear set 10 first gearbox input shaft 11 Output shaft 12 gearboxes 13 cases 14 planetary gear carriers of the second planetary gear set VM internal combustion engine EM electric machine PS1 first planetary gear set PS2 second planetary gear set K,I,J Multiple switching element L Single switching element

Claims

[1] Drive arrangement for a hybrid vehicle, comprising an internal combustion engine (VM), an electric machine (EM), and a transmission (12) with at least one transmission input shaft (1, 10) and a transmission output shaft (11), wherein a first planetary gear set (PS1) and a second planetary gear set (PS2) and at least one switching element (K, I, J, L) are arranged upstream of the transmission (12), wherein a first element of the first planetary gear set (PS1) is rotationally fixed to a drive shaft (1A) of the internal combustion engine (VM) or to a second transmission input shaft (1), wherein a second element of the first planetary gear set (PS1) is fixedly connected to the housing (13), wherein a first element of the second planetary gear set (PS2) is rotationally fixed to the electric machine (EM), and wherein a second element of the second planetary gear set (PS2) is connected to a first transmission input shaft (10) of the transmission (12), and wherein the switching element is a multiple switching element. (K, I,J) is provided, and wherein in a first switching position (K) of the multiple switching element (K, I, J) the third element of the second planetary gear set (PS2) is connected to the third element of the first planetary gear set (PS1), in a second switching position (I) of the multiple switching element (I, J, K) the third element of the second planetary gear set (PS2) is connected to the drive shaft (1A) or to the second transmission input shaft (1) and in a third switching position (J) of the multiple switching element (K, I, J) the third element of the second planetary gear set (PS2) is connected to the second element of the first planetary gear set (PS1). [2] Drive arrangement according to claim 1, characterized by, that a positive-locking switching element (7) is provided as a multiple switching element (K, I, J) with a sliding sleeve (7) which moves between the three switching positions (K, I, J) and a first neutral position located between the first switching position (K) and the second switching position (I) and a second neutral position located between the second switching position (I) and the third switching position (J). [3] Drive arrangement according to claim 2, characterized by, that for the housing connection of the second element of the first planetary gear set (PS1) and the third element of the second planetary gear set (PS2) it is provided that the sliding sleeve (7) of the multiple switching element (K, I, J) designed as a positive locking switching element extends axially through the first planetary gear set (PS1) in order to be rotationally fixed to the second element of the first planetary gear set (PS1) in order to also connect the third element of the second planetary gear set (PS2) to the housing (13) via the second element of the first planetary gear set (PS1). [4] Drive arrangement according to claim 1, 2 or 3, characterized by , that a single switching element (L) is provided as a further switching element, with which the drive shaft (1A) can be connected to the second element of the second planetary gear set (PS2). [5] Drive arrangement according to claim 4, characterized by, that the simple switching element (L) is designed as a friction- or force-locking switching element. [6] Drive arrangement according to one of the preceding claims, characterized bythat the first planetary gear set (PS1) and the second planetary gear set are each designed as a negative planetary gear set, wherein the first element is a sun gear (3) of the first planetary gear set (PS1) connected to the drive shaft (1A) of the internal combustion engine (VM) or to the second transmission input shaft (1), wherein the second element is connected to the housing (13) as the planet carrier (5) of the first planetary gear set (PS1), and wherein the third element is connected to the third element as the ring gear (6) of the first planetary gear set (PS1) in the first switching position (K) of the multiple switching element (K, I, J), and wherein the second element is connected to the first transmission input shaft (10) as the planet carrier (14) of the second planetary gear set (PS2), and wherein the first element is connected to the electric machine as the sun gear (9) of the second planetary gear set (PS2). (EM) is connected. [7] Gear arrangement according to one of the preceding claims, characterized by , that the first element of the first and / or second planetary gear set (PS1, PS2) is a sun gear (3, 9) if the first and / or second planetary gear set (PS1, PS2) is designed as a plus planetary gear set, that the second element of the first and / or second planetary gear set (PS1, PS2) is a ring gear (6, 8) if the first and / or second planetary gear set (PS1, PS2) is designed as a plus planetary gear set, and that the third element of the first and / or second planetary gear set (PS1, PS2) is a planet carrier (5, 14) if the first and / or second planetary gear set (PS1, PS2) is designed as a plus planetary gear set.

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