DE102019119953B4 - Drive device for a motor vehicle with a first planetary gear carrier connected in a rotationally fixed manner to the second sun gear and a second planetary gear carrier connected in a rotationally fixed manner to the first sun gear - Google Patents

Abstract

Drive device (1) for a motor vehicle, comprising an electric drive machine which is operatively connected to a transmission device (3) via a drive shaft (2), the transmission device (3) having at least one first and second planetary gear stage (4, 5) and a differential stage ( 6), wherein the first planetary gear stage (4) has a first planetary gearset with a plurality of planetary gears (7a), the planetary gears (7a) of the first planetary gearset being rotatably arranged on a first planetary gear carrier (8a) and having a first sun gear (9a) and mesh with a first ring gear (10a), the second planetary gear stage (5) having a second planetary gear set with a plurality of planetary gears (7b), the planetary gears (7b) of the second planetary gear set being rotatably arranged on a second planetary gear carrier (8b) and having a second sun gear (9b) and a second ring gear (10b) are in toothed engagement, the first and the second planetary gear set (4, 5) being operatively connected to a double clutch device (11) with a first and a second power-shiftable clutch (12a, 12b). are, characterized in that the first planetary gear carrier (8a) is non-rotatably connected to the second sun gear (9b) and the second planetary gear carrier (8b) is non-rotatably connected to the first sun gear (9a), the first planetary gear carrier (8a) and the second sun gear ( 9b) are operatively connected to the drive shaft (2) via the first clutch (12a), the second planet carrier (8b) and the first sun gear (9a) are operatively connected to the differential stage (6), the first ring gear (10a) via the second clutch ( 12b) is operatively connected to the drive shaft (2) and the second ring gear (10b) is fixed in a stationary manner in a housing (15).

Description

The invention relates to a drive device for a motor vehicle, in particular for an electrically driven motor vehicle, with an electric drive machine which is operatively connected to a transmission device via a drive shaft, the transmission device having at least a first and second planetary gear stage and a differential stage, the first planetary gear stage having a first planetary gearset with a plurality of planetary gears, the planetary gears of the first planetary gearset being rotatably arranged on a first planetary gear carrier and meshing with a first sun gear and with a first ring gear, with the second planetary gear set having a second planetary gearset with a plurality of planetary gears, with the planetary gears of the second planetary gearset are rotatably arranged on a second planetary gear carrier and mesh with a second sun gear and with a second ring gear, the first and the second planetary gear set being operatively connected to a double clutch device with a first and a second power-shiftable clutch.

Drive devices for motor vehicles are already known from the prior art. For example shows DE 10 2011 088 668 A1 a drive device with at least one electric drive machine, with at least one first planetary drive with a clutch and with a differential. A rotor shaft of the prime mover is coupled in a torque-proof manner to a first connecting shaft of the planetary drive formed from at least three connecting shafts. A second connection shaft of the first planetary drive can be fixed in a rotationally fixed manner against a component of the drive device by means of a shift sleeve of the shift clutch. A third connection shaft of the first planetary drive is operatively connected to a sum shaft of the differential. The shift sleeve can be shifted into positive engagement either with the second connecting shaft of the first planetary drive or into a torque-transmitting operative connection with the sum shaft of the differential.

Also shows the DE 10 2004 024 086 A1 a drive device for motor vehicles with a drive unit that acts on two output shafts via a differential gear, with a device being provided on the output shafts with the interposition of at least one superimposed gear, by means of which the output torque can be shifted from one output shaft to the other output shaft. In order to provide a drive device that is particularly effective in terms of control technology and function, it is proposed that the device be formed by at least one electric machine that can be switched as an electric motor and as a generator.

Also from the non-patent literature from OTT, A.: For the systematic synthesis of multi-gear planetary gear shift transmissions. ATZ, 1968, Vol.70, pp. 104-108, several transmission structures are known.

The U.S. 6,716,132 B1 shows a transmission scheme with several planetary gears, brakes and clutches.

The DE 10 2009 028 668 A1 shows a multi-speed transmission in planetary design, in particular an automatic transmission for a motor vehicle.

It is therefore the object of the invention to further develop a drive device for a motor vehicle, the focus being on the simplest possible transmission structure with many identical parts and a suitable transmission ratio distribution or spread.

In the case of a generic device, this object is achieved according to the invention by the characterizing parts of independent claims 1 to 3 .

The three solutions have in common that the first planet carrier is non-rotatably connected to the second sun gear and the second planet carrier is non-rotatably connected to the first sun gear.

The first planetary gear carrier and the second sun gear can be operatively connected to the drive shaft, preferably via the first clutch. Alternatively, it is also conceivable that the first planetary gear carrier and the second sun gear are operatively connected to the differential stage via the first clutch.

In addition, it can be expedient if the second planetary gear carrier and the first sun gear are operatively connected to the differential stage directly or via the second clutch, or are fixed in place/stationary/rotatably fixed in a housing.

The first ring gear can be connected to the drive shaft in a torque-proof manner or can be operatively connected via the second clutch.

Furthermore, it is conceivable that the second ring gear can be fixed in place in the housing. There is also the possibility that the second ring gear is operatively connected to the differential stage.

The drive device according to the invention for a motor vehicle includes an electric Prime mover operatively connected to a transmission device via a drive shaft.

The transmission device has at least a first and second planetary gear stage and a differential stage, the first planetary gear stage having a first planetary gear set with a plurality of planetary gears, the planetary gears of the first planetary gear set being rotatably arranged on a first planetary gear carrier and having a first sun gear and a first ring gear in the meshing, the second planetary gear stage having a second planetary gear set with a plurality of planetary gears, the planetary gears of the second planetary gear set being rotatably arranged on a second planetary gear carrier and meshing with a second sun gear and with a second ring gear, and with the first and the second planetary gear stage are operatively connected to a dual clutch device having a first and a second power-shiftable clutch.

The term “operatively connected” is to be understood as meaning that two transmission elements for torque transmission can be connected directly to one another, or that there are further transmission elements between two transmission elements for torque transmission, for example a shaft or a plurality of shafts or gears. Two mutually meshing gears are provided for the transmission of a torque and a speed from one gear to the other gear. A gear is to be understood, for example, as a sun gear, a ring gear and a planet gear of a planetary gear set.

A dual clutch device is to be understood as meaning a device with two power-shiftable clutches. Furthermore, the term “power shiftable clutch” is to be understood as meaning a device which has at least one open and one closed state and can be switched between the at least two states under load. When open, the clutch does not transmit any torque.

Thus, the drive devices according to the invention allow great flexibility in the structural design of the transmission structure, which facilitates the adaptation of the desired translation and spread without unnecessarily complicating the transmission structure.

Advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

Furthermore, an advantageous embodiment can also be characterized in that an additional reduction gear is arranged in the torque flow between the electric drive machine and the differential stage. The reduction gear can be arranged on the input side between the electric drive machine and the first planetary gear set or on the output side between the second planetary gear set and the differential stage. The additional reduction gear increases the spread of the gear device and can be designed, for example, as a spur gear stage or as an additional planetary gear stage.

The first and second clutch of the double clutch device can preferably be designed as a friction clutch. Furthermore, the two clutches can preferably be arranged coaxially with one another. In particular, the respective clutch can be actuated by a respective actuator in order to initiate opening or closing of the respective clutch. The actuator can be designed to be actuated hydraulically, electromechanically, electromagnetically or, for example, pneumatically.

It is expedient if both clutches can be opened at the same time to switch off the power. Closing the first clutch and opening the second clutch can realize a first gear ratio, whereas closing the second clutch and opening the first clutch can realize a second gear ratio. In order to ensure a largely uninterrupted shifting process from one clutch to the other clutch, one clutch can open in a transitional period while the other closes. The slip in the clutches, designed as friction clutches, can thus switch between two gear stages without torque interruption, which can be perceived by the operator of the drive device as a switch mode between two gear stages without interruption in traction, which in turn increases the shifting comfort for the operator of the drive device. Preferably, the first gear ratio is unequal to the second gear ratio. For example, the first gear ratio may be greater than the second gear ratio. Alternatively, the first gear ratio may be less than the second gear ratio.

Furthermore, the electric drive machine preferably has a stator and a rotor, the rotor being connected to the drive shaft in a torque-proof manner. The drive shaft can be designed as a rotor shaft or there is an axial offset between the drive and the rotor shaft, whereby a torque transmission device (reduction gear) can be arranged between both shafts.

Furthermore, the differential stage is preferably designed as a spur gear differential, the differential stage being provided for distributing drive power from the drive machine to a first and second output shaft.

The drive machine can be arranged coaxially or axially parallel to the differential stage. The drive shaft is preferably arranged coaxially with the two output shafts. In particular, the drive shaft is designed as a hollow shaft, with at least one of the two output shafts being guided axially through the drive shaft. The two output shafts are preferably arranged on a common drive axle. Alternatively, the drive shaft is arranged axially parallel to the two output shafts, with axially parallel meaning that there is an axial offset between the input shaft and the output shaft.

In other words, the invention relates to a two-speed gearbox for electric axles with sun-carrier double linkage. In the search for transmissions for two gears with an advantageous transmission ratio distribution in an axis-parallel and coaxial arrangement, the simplest possible transmission structure with many identical parts and suitable transmission ratio distribution or spread should be provided by a combination of two planetary gear stages with a spur gear stage and a shifting element designed as a double clutch or synchro unit, where the basic structure of the gear has a sun-carrier double bond. In a first possible coaxial or axis-parallel configuration with a switching element arranged on the input side, a moderate transmission ratio can be achieved with a moderate spread. Optionally, an additional spur gear stage, designed as a spur gear differential, for example, can be placed both upstream and downstream, which in turn increases the ratio that can be converted. A second coaxial or axially parallel configuration with an input-side shifting element and optional preceding or following spur gear stage enables a low gear ratio with a moderate spread. Here, too, the translation can be increased by possibly advancing or readjusting the spur gear stage. A third coaxial or axially parallel embodiment with an output-side shifting element and an optional preceding or following spur gear stage enables a moderate gear ratio with a high spread.

• 1 eine erste Ausführungsform einer erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise,
• 2 eine erste Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in koaxialer Bauweise,
• 3 eine zweite Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in achsparalleler Bauweise,
• 4 eine dritte Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in koaxialer Bauweise,
• 5 eine zweite Ausführungsform einer erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise,
• 6 eine erste Modifikation der Antriebsvorrichtung gemäß der zweiten Ausführungsform in achsparalleler Bauweise,
• 7 eine zweite Modifikation der Antriebsvorrichtung gemäß der zweiten Ausführungsform in koaxialer Bauweise,
• 8 eine dritte Ausführungsform einer erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise,
• 9 eine erste Modifikation der Antriebsvorrichtung gemäß der dritten Ausführungsform in achsparalleler Bauweise, und
• 10 eine zweite Modifikation der Antriebsvorrichtung gemäß der dritten Ausführungsform in koaxialer Bauweise.

Further measures improving the invention are presented in more detail below together with the description of preferred embodiments of the invention with reference to the figures. The figures each show a simplified schematic representation to illustrate the structure of drive devices according to the invention. Show it:

• 1 a first embodiment of a drive device according to the invention in a coaxial design,
• 2 a first modification of the driving device according to the first embodiment in coaxial construction,
• 3 a second modification of the drive device according to the first embodiment in paraxial design,
• 4 a third modification of the driving device according to the first embodiment in coaxial construction,
• 5 a second embodiment of a drive device according to the invention in a coaxial design,
• 6 a first modification of the drive device according to the second embodiment in paraxial design,
• 7 a second modification of the driving device according to the second embodiment in coaxial construction,
• 8th a third embodiment of a drive device according to the invention in a coaxial design,
• 9 a first modification of the drive device according to the third embodiment in the paraxial design, and
• 10 a second modification of the driving device according to the third embodiment in the coaxial type.

The figures are only of a schematic nature and serve exclusively for understanding the invention. The same elements are provided with the same reference numbers. The features of the individual embodiments can be interchanged.

1 shows a first embodiment of the drive device 1 according to the invention in a coaxial design.

The drive device 1 according to the invention for a motor vehicle--not shown here--has an electric drive motor and a transmission device 3--not shown here. The electric drive machine has a stator and a rotor. A drive power (torque) of the electric drive machine is over a drive shaft 2, which is arranged between the electric drive machine and the transmission device 3 and is designed as a rotor shaft, is introduced into the transmission device 3.

The transmission device 3 comprises a first and second planetary gear stage 4, 5 and a differential stage 6. The first planetary gear stage 4 has a first planetary gear set with a plurality of planetary gears 7a, which are arranged rotatably on a first planetary gear carrier 8a and with a first sun gear 9a and with a first Ring gear 10a are in tooth engagement. Consequently, the planet gears 7a of the first planetary gear set mesh radially between the first sun gear 9a and the first ring gear 10a. The second planetary gear stage 5 has a second planetary gear set with a plurality of planetary gears 7b, which are rotatably arranged on a second planetary gear carrier 8b and mesh with a second sun gear 9b and with a second ring gear 10b. Consequently, the planet gears 7b of the second planetary gear set mesh radially between the second sun gear 9b and the second ring gear 10b.

Furthermore, a double clutch device 11 with a first clutch 12a and a second clutch 12b is provided. Closing the first clutch 12a and opening the second clutch 12b realizes a first gear ratio, with closing the second clutch 12b and opening the first clutch 12a realizing a second gear ratio. The first gear ratio is unequal to the second gear ratio. Power is switched off by opening both clutches 12a, 12b.

In other words, by shifting the dual clutch device 11, the torque transmitted from the electric drive motor via the transmission device 3 to the differential stage 6 can be optionally varied between the first and the second gear ratio. The torque thus transmitted is finally passed on from the differential stage 6 to output shafts 13a, 13b, which are connected, for example, to drive wheels of the motor vehicle. The transmission device 3 thus essentially enables two-gear operation of the motor vehicle.

In the drive device 1 according to the first embodiment, the dual clutch device 11 is arranged on the input side of the transmission device 3 . In particular, depending on the shifting of the dual clutch device 11, the first planetary gear carrier 8a and the second sun gear 9b, which is non-rotatably connected thereto, can be non-rotatably connected to the drive shaft 2 via the first clutch 12a or the first ring gear 10a via the second clutch 12b, which in turn means that the first or .second gear ratio can be implemented.

As described above, in the drive device 1 according to the first embodiment, the first planet carrier 8a is non-rotatably connected to the second sun gear 9b. In addition, the second planet carrier 8b is non-rotatably connected to the first sun gear 9a. The second ring gear 10b is fixed/accommodated/arranged in a fixed/non-rotatable/stationary manner in a housing 15 and thus supports the transmission arrangement in the housing 15 .

On the output side, the non-rotatable combination of the second planetary gear carrier 8b and the first sun gear 9a is operatively connected to the differential stage 6 and thus directs the torque of the electric drive machine to the differential stage 6, which distributes it to the two output shafts 13a, 13b. The differential stage 6 is designed as a spur gear differential in the first embodiment.

2 until 4 show modifications of the drive device 1 according to the invention according to the first embodiment. In the following, only the differences to the in 1 shown drive device 1 received according to the first embodiment.

At the in 2 illustrated, first modification of the drive device 1 according to the first embodiment, the differential stage 6 is designed as an additional planetary gear stage. A planetary gear carrier designed as a double planet is connected in a torque-proof manner to the second planetary gear carrier 8b. Two planetary gear sets are mounted on the double planetary gear and each mesh with a sun gear formed on the output shafts 13a, 13b.

The second modification of the first embodiment is in 3 shown. As can be seen, on the output side there is an additional reduction gear 14 designed as a spur gear stage in the torque flow from the electric drive motor to the output shafts 13a, 13b between the second planetary gear stage 5, in the first embodiment the non-rotatable connection between the first sun gear 9a and the second planetary gear carrier 8b , and the differential stage 6 arranged.

Due to the reduction gear 14 arranged on the output side, the drive device 1 according to the second modification of the first embodiment has an axis-parallel basic structure/construction, i.e. the drive shaft 2 is arranged radially offset to the two output shafts 13a, 13b.

As in 4 can be seen, in the third modification of the drive device 1 according to the first embodiment, the reduction gear 14 is interposed on the input side between the electric drive machine and the transmission device 3, in particular the drive shaft 2, and is designed as a spur gear stage.

5 shows a second embodiment of the drive device 1 according to the invention in a coaxial design. In the following, the differences to the in 1 drive device 1 shown received.

In the drive device 1 according to the second embodiment, the dual clutch device 11 is arranged on the input side and optionally connects the first planet carrier 8a and the second sun gear 9b or the first ring gear 10a to the drive shaft 2 via the first clutch 12a or the second clutch 12b. The first sun gear 9a is non-rotatably connected to the second planetary gear carrier 8b and is fixed in place in the housing 15, i.e. the transmission device 3 is supported in the housing 15 via the first sun gear 9a and the second planetary gear carrier 8b. In the second embodiment, the second ring gear 10b is operatively connected to the differential stage 6, so that the torque is dissipated from the transmission device 3 to the differential stage 6 via the second ring gear 10b.

In the 6 and 7 are each a first and second modification of the drive device 1 shown according to the second embodiment. In the first modification of the second embodiment, the drive device 1 is designed with parallel axes and has the reduction gear 14 arranged between the second ring gear 10b and the differential stage 6 on the output side. The drive device 1 according to the second modification of the second embodiment is in turn designed coaxially, with the reduction gear 14 being interposed on the input side between the electric drive machine and the drive shaft 2 .

8th shows a third embodiment of the drive device 1 according to the invention in a coaxial design. In the following, only the differences to the in 1 drive device 1 shown received.

In the drive device 1 according to the third embodiment, the double clutch device 11 is arranged on the output side. On the input side, the drive shaft 2 is thus (directly) non-rotatably connected to the first ring gear 10a, so that the torque is always introduced into the transmission device 3 via the first ring gear 10a and the dual clutch device 11 allows the torque output to the differential stage 6 to be varied.

The first planetary gear carrier 8a is connected in a torque-proof manner to the second sun gear 9b and can also be operatively connected to the differential stage 6 via the first clutch 12a. The second planet carrier 8b is non-rotatably connected to the first sun gear 9a and can in turn be operatively connected to the differential stage 6 via the second clutch 12b. Consequently, in the first gear ratio, the torque is transmitted to the differential stage 6 via the non-rotatable combination of the first planetary gear carrier 8a and the second sun gear 9b, and in the second gear ratio via the non-rotatable combination of the second planetary gear carrier 8b and the first sun gear 9a.

Furthermore, in the drive device 1 according to the third embodiment, the second ring gear 10b is arranged stationarily in the housing 15, i.e. the transmission device 3 is supported in the housing 15 via the second ring gear 10b.

In the 9 and 10 a first and second modification of the drive device 1 according to the third embodiment are respectively shown. In the first modification of the third embodiment, the drive device 1 is designed with parallel axes and has the reduction gear 14 arranged between the dual clutch device 11 and the differential stage 6 on the output side. The drive device 1 according to the second modification of the third embodiment is in turn designed coaxially, with the reduction gear 14 being interposed on the input side between the electric drive machine and the drive shaft 2 .

Reference List

1

drive device

2

drive shaft

3

gear device

4

first planetary gear stage

5

second planetary gear stage

6

differential stage

7a

first planet gear(s).

7b

second planet gear(s).

8a

first planet carrier

8b

second planet carrier

9a

first sun wheel

9b

second sun wheel

10a

first ring gear

10b

second ring gear

11

dual clutch device

12a

first clutch

12b

second clutch

13a, 13b

output shaft

14

reduction gear

15

Housing

Claims (8)

Drive device (1) for a motor vehicle, comprising an electric drive machine which is operatively connected to a transmission device (3) via a drive shaft (2), the transmission device (3) having at least one first and second planetary gear stage (4, 5) and a differential stage ( 6), wherein the first planetary gear stage (4) has a first planetary gearset with a plurality of planetary gears (7a), the planetary gears (7a) of the first planetary gearset being rotatably arranged on a first planetary gear carrier (8a) and having a first sun gear (9a) and mesh with a first ring gear (10a), the second planetary gear stage (5) having a second planetary gear set with a plurality of planetary gears (7b), the planetary gears (7b) of the second planetary gear set being rotatably arranged on a second planetary gear carrier (8b) and having a second sun gear (9b) and a second ring gear (10b) are in toothed engagement, the first and the second planetary gear set (4, 5) being operatively connected to a double clutch device (11) with a first and a second power-shiftable clutch (12a, 12b). are, characterized in that the first planetary gear carrier (8a) is non-rotatably connected to the second sun gear (9b) and the second planetary gear carrier (8b) is non-rotatably connected to the first sun gear (9a), the first planetary gear carrier (8a) and the second sun gear ( 9b) are operatively connected to the drive shaft (2) via the first clutch (12a), the second planet carrier (8b) and the first sun gear (9a) are operatively connected to the differential stage (6), the first ring gear (10a) via the second clutch ( 12b) is operatively connected to the drive shaft (2) and the second ring gear (10b) is fixed in a stationary manner in a housing (15). Drive device (1) according to the preamble of claim 1 , characterized in that the first planetary gear carrier (8a) is non-rotatably connected to the second sun gear (9b) and the second planetary gear carrier (8b) is non-rotatably connected to the first sun gear (9a), the first planetary gear carrier (8a) and the second sun gear (9b ) are operatively connected to the differential stage (6) via the first clutch (12a), the second planet carrier (8b) and the first sun gear (9a) can be operatively connected to the differential stage (6) via the second clutch (12b), the first ring gear (10a) is operatively connected to the drive shaft (2) and the second ring gear (10b) is fixed in a stationary manner in a housing (15). Drive device (1) according to the preamble of claim 1 , characterized in that the first planetary gear carrier (8a) is non-rotatably connected to the second sun gear (9b) and the second planetary gear carrier (8b) is non-rotatably connected to the first sun gear (9a), the first planetary gear carrier (8a) and the second sun gear (9b ) are operatively connected to the drive shaft (2) via the first clutch (12a), the second planet carrier (8b) and the first sun gear (9a) are fixed in a housing (15), the first ring gear (10a) via the second clutch ( 12b) is operatively connected to the drive shaft (2) and the second ring gear (10b) is operatively connected to the differential stage (6). Drive device (1) according to one of Claims 1 until 3 , characterized in that an additional reduction gear (14) is arranged in the torque flow between the electric drive machine and the differential stage (6). Drive device (1) after claim 4 , characterized in that the reduction gear (14) is arranged between the electric drive motor and the first planetary gear set (4). Drive device (1) after claim 4 , characterized in that the reduction gear (14) is arranged between the second planetary gear stage (5) and the differential stage (6). Drive device (1) according to one of the preceding claims, characterized in that the drive machine is arranged coaxially to the differential stage (6). Drive device (1) according to one of Claims 1 until 6 , characterized in that the drive machine is arranged offset parallel to the axis to the differential stage (6).

Images