DE102019119948B4 - Drive device for a motor vehicle with a sun wheel-ring wheel double bond - 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 with a second ring gear (10b) in meshing engagement, the first and the second e planetary gear set (4, 5) are operatively connected to a double clutch device (11) with a first and a second power-shiftable clutch (12a, 12b), the ring gear (10a, 10b) of one planetary gear set (4, 5) being non-rotatably connected to the sun gear ( 9a, 9b) of the other planetary gear set (4, 5), with• the first ring gear (10a) being non-rotatably connected to the second sun gear (9b),• the second ring gear (10b) being non-rotatably connected to the first sun gear (9a). • the first planet carrier (8a) is non-rotatably connected to one of the two clutches (12a, 12b) and the first ring gear (10a) is non-rotatably connected to the other of the two clutches (12a, 12b) and· the first sun gear ( 9a) and the second ring gear (10b) are fixed in place on a housing (15) and the second planet carrier (8b) is operatively connected to the differential stage (6) or the first sun gear (9a) and the second ring gear (10b) to the Differential stage (6) are operatively connected and the second planetary gear ger (8b) is fixed in place on the 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 gear set are rotatably arranged on a second planet carrier and are in meshing engagement with a second sun gear and with a second ring gear, the first and the second Planetary gear are operatively connected to a double clutch device with a first and a second power-shift 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.

It is 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 a generic device, this object is achieved according to the invention by the features of independent claim 1, the ring gear of one planetary gear set being non-rotatably connected to the sun gear of the other planetary gear set.

The drive device according to the invention for a motor vehicle comprises an electric drive machine which is 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 can be directly connected to one another, or that there are further transmission elements between two transmission elements, for example one or more 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.

According to the invention, the first ring gear can be connected to the second sun gear in a rotationally fixed manner. Furthermore, it can be advantageous if the second ring gear is connected to the first sun gear in a rotationally fixed manner. The non-rotatable connection between the first or second ring gear and the second or first ring gear can be embodied in any way, in particular via a welded connection. Alternatively, the respective ring gear can also be manufactured in one piece with the corresponding sun gear as an integral component. Regardless of the type of connection facilitates the invention Sun ring gear binding the assembly or assembly of the transmission device

According to the invention, the first planetary gear carrier can be non-rotatably connected to one of the two clutches and the first ring gear can be non-rotatably connected to the other of the two clutches, which makes it possible to transmit torque with two different gear ratios.

According to the invention, the first sun gear and the second ring gear or the second planetary gear carrier can be fixed in place on a housing, so that the transmission structure can be designed flexibly depending on the space required, while ensuring safe operation due to the different options for support / storage in the housing will.

In addition, it can be useful according to the invention if the second planetary gear carrier or the first sun gear and the second ring gear are operatively connected to the differential stage, since this also ensures a high degree of freedom in the design of the transmission structure on the output side.

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

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 shaft and the rotor shaft, with a torque transmission device (gear) being arranged between the two 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 an axis-parallel two-speed transmission for electric axes with a basic structure with a sun-ring gear double bond. In a first embodiment, the transmission is parallel to the axis with a shifting element arranged on the input side (double clutch direction), high gear ratio and moderate spread and can optionally be supplemented with a spur gear differential. As a further modification, an additional spur gear stage can also be placed in front. In a second embodiment, the transmission is paraxially designed with a shifting element arranged on the input side, a moderate transmission ratio and a moderate spread and can optionally be supplemented with a preceding spur gear stage.

• 1 eine erste Ausführungsform der erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise,
• 2 eine erste Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform,
• 3 eine zweite Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in achsparalleler Bauweise,
• 4 eine zweite Ausführungsform der erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise, und
• 5 eine erste Modifikation der Antriebsvorrichtung gemäß der zweiten Ausführungsform in achsparalleler 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 the drive device according to the invention in a coaxial design,
• 2 a first modification of the driving device according to the first embodiment,
• 3 a second modification of the drive device according to the first embodiment in paraxial design,
• 4 a second embodiment of the drive device according to the invention in a coaxial design, and
• 5 a first modification of the drive device according to the second embodiment in paraxial construction.

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 of the electric drive machine is introduced into the gear device 3 via a drive shaft 2, which is arranged between the electric drive machine and the gear device 3 and is designed as a rotor shaft.

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 first embodiment, an additional reduction gear 14 designed as a spur gear stage is arranged on the input side between the electric drive motor and the transmission device 3 , in particular the drive shaft 2 , which enables an increased spread of the transmission device 3 . The drive shaft 2 is in turn connected to the double clutch device 11 at its end section facing away from the reduction gear 14 .

In the first embodiment, the first clutch 12a is connected in a torque-proof manner to the first ring gear 10a and the second sun gear 9b. the second clutch 12b in turn is rotatably connected to the first planet carrier 8a. The first sun gear 9a is accommodated in a stationary manner in a housing 15 and thus supports the first planetary gear set 4 and the second planetary gear set 5 in the housing 15 .

As described above, in the first embodiment, the first ring gear 10a is non-rotatably connected to both the first clutch 12a and the second sun gear 9b. The planet gears 7b of the second planetary gear set 5 roll on the one hand on the second sun gear 9b and on the other hand on the second ring gear 10b fixed to the housing. The second planet carrier 8b is operatively connected to the differential stage 6 and directs the torque from the electric drive machine to the differential stage 6, which in turn distributes it to the output shafts 13a, 13b.

If the first clutch 12a is now closed (first gear ratio), the torque is transmitted from the drive shaft 2 via the first clutch 12a to the first ring gear 10a and the second sun gear 9b. Although the first ring gear 10a drives the first planetary gear carrier 8a, whose planetary gears 7a roll on the first sun gear 9a fixed to the housing, no torque is transmitted and the first planetary gear set 4 is essentially non-functional. In other words, the first planetary gear stage 4 is operated in neutral at the first gear ratio.

The second sun gear 9b, on the other hand, drives the planetary gears 7b of the second planetary gear stage 5, which also roll on the second ring gear 10b fixed to the housing and thereby allow the second planetary gear carrier 8b to rotate in the same direction as the second sun gear 9b, in the form of a revolving transmission with the ring gear stationary. Thus, in the first gear ratio, the torque is transmitted from the drive shaft 2 via the first clutch 12a, the second sun gear 9b, the second planetary gear carrier 8b to the differential stage 6, where it is further distributed to the two output shafts 13a, 13b.

When the first clutch 12a is opened and the second clutch 12b is closed (second gear ratio), the torque is transmitted from the drive shaft 2 via the closed second clutch 12b to the first planet carrier 8a. The planet gears 7a of the first planetary gear set 4 roll on the first sun gear 9a fixed to the housing and thereby drive the first ring gear 10a and thus the second sun gear 9b. Due to the second ring gear 10b fixed to the housing, the second planetary gear set 5 is thus, similar to the first gear ratio, operated in two-shaft operation with the second sun gear 9b as the driving shaft, the second ring gear 10b as the stationary shaft and the second planetary gear carrier 8b as the driven shaft. In other words, in the second gear ratio, the torque is transmitted from the drive shaft 2 via the second clutch 12b, the first planetary gear carrier 8a, the first ring gear 10a, the second sun gear 9b, which is non-rotatably connected thereto, and the second planetary gear carrier 8b to the differential stage 6 , which finally distributes it to the two output shafts 13a, 13b.

2 and 3 each show a first and second modification of the drive device 1 according to the invention according to the first embodiment. Only the differences to the in 1 shown drive device 1 received according to the first embodiment.

At the in 2 shown modification, the differential stage 6 is designed as an additional double planetary gear 6, with a first planetary gear set 6a transmitting torque to the output shaft 13a and a second planetary gear set 6b torque to the output shaft 13b.

In the 3 The second modification shown represents a drive device 1 in an axially parallel design. In contrast to the in 1 shown drive device 1 in a coaxial design here the drive shaft 2 is offset axially parallel to the two output shafts 13a, 13b.

4 shows a second embodiment of the drive device 1 according to the invention in a coaxial design. Only the differences to the in 1 shown drive device 1 received according to the first embodiment.

In the second embodiment, the first clutch 12a is connected in a torque-proof manner to the first planet gear carrier 8a. The second clutch 12b in turn is non-rotatably connected to the first ring gear 10a and the second sun gear 9b. The first sun gear 9a is non-rotatably connected to the second ring gear 10b and operatively connected to the differential stage 6 . The second planetary gear carrier 8b is stationary in the housing 15, so that the first planetary gear set 4 and the second planetary gear set 5 are supported in the housing 15 via the second planetary gear carrier 8b.

Now, when the first clutch 12a is closed (first gear ratio), the torque of the drive shaft 2 is transmitted via the closed, first clutch 12a to the first planet carrier 8a, which when rolling off the Pla netenräder 7a drives the first ring gear 10a and the first sun gear 9a. Due to the non-rotatable connection of the first ring gear 10a with the second sun gear 9b, this rotates in the same direction as the first ring gear 10a, as a result of which the planetary gears 7b roll on the second ring gear 10b and thus transmit the torque via the differential stage 6 to the output shafts 13a, 13b.

When the first clutch 12a is opened and the second clutch 12b is closed (second gear ratio), the torque of the drive shaft 2 is introduced via the closed, second clutch 12b to the first ring gear 10a and the second sun gear 9b connected thereto. The planet gears 7a roll on the first ring gear 10a, but without transmitting torque, so that the first planetary gear set 4 is essentially non-functional in the second gear ratio. The second sun gear 9b allows the planetary gears 7b mounted on the second planetary gear carrier 8b, which is fixed to the housing, to roll off the second ring gear 10b, which thus transmits the torque to the differential stage 6. This in turn distributes the torque to the two output shafts 13a, 13b.

In the 5 The first modification shown represents a drive device 1 with an axially parallel construction. In contrast to the in 1 In the illustrated drive device 1 in a coaxial design, the drive shaft 2 is here offset axially parallel to the two output shafts 13a, 13b.

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 gear

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 (5)

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 with a second ring gear (10b) in meshing engagement, the first and the second e planetary gear set (4, 5) are operatively connected to a double clutch device (11) with a first and a second power-shiftable clutch (12a, 12b), the ring gear (10a, 10b) of one planetary gear set (4, 5) being non-rotatably connected to the sun gear ( 9a, 9b) of the other planetary gear set (4, 5) is connected, wherein • the first ring gear (10a) is non-rotatably connected to the second sun gear (9b), • the second ring gear (10b) is non-rotatably connected to the first sun gear (9a), • the first planet carrier (8a) is non-rotatably connected to one of the two clutches (12a, 12b) and the first ring gear (10a) is non-rotatably connected to the other of the two clutches (12a, 12b) and the first sun gear (9a) and the second ring gear (10b) are fixed in place on a housing (15) and the second planet carrier (8b) is operatively connected to the differential stage (6) or · the first sun gear (9a) and the second ring gear (10b) are operatively connected to the differential stage (6) and the second planet carrier (8b) is fixed in place on the housing (15). Drive device (1) after claim 1 , characterized in that in the torque flow between the electric drive machine and an additional reduction gear (14) is arranged in the differential stage (6). Drive device (1) after claim 2 , characterized in that the reduction gear (14) is arranged on the input side between the electric drive motor and the first planetary gear stage (4). Drive device (1) after claim 2 , characterized in that the reduction gear (14) is arranged on the output side 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 offset axially parallel or arranged coaxially to the differential stage (6).

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