DE102018111801B4 - Drive device with an electric machine - Google Patents

Abstract

Drive device for a motor vehicle, comprising an electric machine (1) which is operatively connected to a transmission device (3) via a drive shaft (2), the transmission device (3) having a planetary stage (4), a stepped planetary gear train (5) and a differential stage ( 6), wherein the planetary stage (4) has a planetary set with a plurality of planet gears (7a), the planet gears (7a) being rotatably arranged on a first planet carrier (8a) and having a first sun gear (9a) and a first ring gear ( 10a) are in toothed engagement, with the stepped planetary set (5) having a plurality of stepped planetary gears (7b), with each stepped planetary gear (7b) having a first and a second non-rotatably connected gear wheel (17a, 17b), with the stepped planetary gears (7b) being rotatable on a second planet carrier (8b) are arranged, wherein the first gear (17a) with a second sun gear (9b) and a second ring gear (10b) is in meshing engagement, and wherein the second gear (17b) meshes with a third ring gear (10c), the drive shaft (2) being non-rotatably connected to the first sun gear (9a), the first planet carrier (8a) being non-rotatably connected to the second sun gear (9b). is, and wherein the second planetary carrier (8b) is operatively connected to the differential stage (6), wherein further between the planetary stage (4) and the stepped planetary gear set (5) a double clutch device (11) with a first and second power-shiftable clutch (12a, 12b) is arranged, wherein the first ring gear (10a) can be connected to a housing (16) of the transmission device (3) via the first clutch (12a), and wherein the first ring gear (10a) can be connected to the second ring gear via the second clutch (12b). (10b) can be connected and the third ring gear (10c) is fixed in a stationary manner on the housing (16).

Description

The invention relates to a drive device with an electric machine, in particular for an electrically driven motor vehicle.

From the DE 10 2011 088 668 A1 discloses a drive device with at least one electric drive motor, 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.

The DE 10 2017 129 594 A1 shows a drive arrangement with an electromechanical drive device, a pre-stage transmission with a pre-stage input, which is coupled to the drive device and a first pre-stage output, a clutch device with a first clutch input, which is coupled to the first pre-stage output, and a first and a second clutch output, a reduction gear , with a first transmission input, which is coupled to the first clutch output of the clutch device, a second transmission input, which is coupled to the second clutch output of the clutch device, and a planet carrier, and a differential gear, with coupling planets, for branching the adjacent to the planet carrier of the reduction gear Drive power to a first and a second wheel drive shaft, wherein the reduction gear comprises a first sun gear with a first sun gear, which is driven via the first transmission input, the Redu ction transmission includes a second sun gear stage with a second sun gear that is driven via the second transmission input, the first sun gear stage is designed in such a way that it achieves a higher transmission ratio between the first sun gear and the first reduction planet than the second sun gear stage between the second sun gear and realizes the second reduction planet, and the planet carrier of the reduction gear carries the differential gear.

The DE 10 2018 101 267 A1 shows a drive device for a motor vehicle, comprising an electric machine which is operatively connected to a transmission device via a drive shaft, the transmission device having at least one planetary stage, at least one stepped planetary gearset and a differential stage, the planetary stage having a planetary gearset with a plurality of planetary gears, the planetary gears are rotatably arranged on a first planetary carrier and are in toothed engagement with a first sun gear and with a first ring gear, the stepped planetary gear set having a plurality of stepped planetary gears, each stepped planetary gear having a first and a second gear wheel non-rotatably connected to one another, the stepped planetary gears being rotatable on a second planetary carrier are arranged, wherein the first gear is in mesh with a second sun gear and a second ring gear, and wherein the second gear is in mesh with a third ring gear, wherein the The drive shaft is connected in a torque-proof manner to the first sun gear, the first planetary carrier being connected in a torque-proof manner to the second sun gear, and the second planetary carrier being operatively connected to the differential stage, a double clutch device with a first and second power-shiftable clutch also being arranged between the planetary stage and the stepped planetary gearset is, wherein the first ring gear can be connected to the second ring gear via the first clutch, and wherein the first ring gear can be connected to the second planet carrier via the second clutch.

The object of the present invention consists in further developing a drive device with an electric machine. The object is solved by the subject matter of patent claim 1. Preferred embodiments can be found in the dependent claims.

The drive device according to the invention for a motor vehicle comprises an electric machine, which is operatively connected to a transmission device via a drive shaft, the transmission device having at least one planetary stage, at least one stepped planetary gearset and a differential stage, the planetary stage having a planetary gearset with a plurality of planetary gears, the planetary gears being rotatable are arranged on a first planetary carrier and are in toothed engagement with a first sun gear and with a first ring gear, the stepped planetary gearset having a plurality of stepped planetary gears, each stepped planetary gear having a first and a second gear wheel non-rotatably connected to one another, the stepped planetary gears being rotatably arranged on a second planetary carrier are, wherein the first gear meshes with a second sun gear and a second ring gear, and wherein the second gear meshes with a third ring gear, where at the drive shaft is non-rotatably connected to the first sun gear, wherein the first planetary carrier is non-rotatably connected to the second sun gear, and wherein the second planetary carrier is operatively connected to the differential stage, a double clutch device with a first and second power-shiftable clutch also being arranged between the planetary stage and the stepped planetary gear set wherein the first ring gear can be connected to a housing of the transmission device via the first clutch, and wherein the first ring gear can be connected to the second ring gear via the second clutch, and the third ring gear is stationarily fixed to the housing. Consequently, the third ring gear is non-rotatably connected to the housing.

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 stepped planetary gear of a stepped planetary gear set, a sun gear, a ring gear and a planetary 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 respective clutch does not transmit any torque. Thus, the respective clutch transmits a torque between two shafts operatively connected to this respective clutch only in an at least partially closed state, the two shafts being connected to one another in a rotationally fixed manner in the closed state of this respective clutch. Consequently, in the closed state of the first clutch, the first ring gear and the housing are connected to one another in a rotationally fixed manner, with the first ring gear and the second ring gear being connected in a rotationally fixed manner to one another in the closed state of the second clutch. The second planet carrier is operatively connected to the differential stage. In particular, the second planet carrier is integrally connected to an output shaft of the second planetary stage, the output shaft of the second planetary stage being operatively connected to the differential stage. For example, the output shaft of the second planetary stage is designed to be non-rotatable with a drive shaft or a differential housing of the differential stage.

The respective clutch is designed as a friction clutch. Furthermore, the two clutches are preferably arranged coaxially to 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 hydraulically, electromechanically, electromagnetically or, for example, pneumatically operable.

The invention includes the technical teaching that opening both clutches implements a power shutdown. Closing the first clutch and opening the second clutch results in a first gear ratio, with closing the second clutch and opening the first clutch realizing a second gear ratio. Preferably, the first gear ratio is unequal to the second gear ratio. For example, the first gear ratio is greater than the second gear ratio. Alternatively, the first gear ratio is smaller than the second gear ratio.

The electrical machine preferably has a stator and a rotor, with the rotor being connected to the drive shaft in a torque-proof manner. Consequently, the drive shaft is designed as a rotor shaft.

Furthermore, the differential stage is preferably designed as a spur gear differential, the differential stage being provided for distributing a drive power of the electrical machine to a first and second output shaft of the transmission device. The differential stage has a first and a second planetary set with respective planet gears, the planetary gears of the first planetary set of the differential stage being in meshing engagement with a toothing on the first output shaft, and the planetary gears of the second planetary gear set being in meshing engagement with a toothing on the second output shaft , and the planetary gears of both planetary sets are in mesh with each other in pairs.

According to a preferred embodiment, the electrical machine is arranged coaxially to the differential stage. In particular, the electric machine is arranged coaxially to the two output shafts of the transmission device. The drive shaft is preferably designed as a hollow shaft, with the first output shaft being guided axially through the drive shaft. Alternatively, the second output shaft can also be guided axially through the drive shaft, which is designed as a hollow shaft. The two output shafts are preferably arranged on a common drive axle.

Further measures improving the invention are described below together with the Description of a preferred embodiment of the invention shown in more detail with reference to the single figure. The only figure shows a simplified schematic representation to illustrate the structure of a drive device according to the invention.

According to the single figure, the drive device according to the invention for a motor vehicle--not shown here--has an electric machine 1 and a transmission device 3. The electrical machine 1 is provided as a drive machine and has a stator 13 fixed to the housing and a rotor 14 . A drive power of the electrical machine 1 is introduced into the transmission device 3 via a drive shaft 2, which is arranged between the electrical machine 1 and the transmission device 3 and is designed as a rotor shaft. Consequently, a rotational speed and a torque for driving the motor vehicle are fed into the transmission device 3 via the drive shaft 2 .

The transmission device 3 comprises a planetary stage 4, a stepped planetary gear set 5 and a differential stage 6. The differential stage 6 is designed as a spur gear differential and is intended to distribute drive power from the electric machine 1 to a first and second output shaft 15a, 15b of the transmission device 3. The drive shaft 2 is arranged coaxially with the two output shafts 15a, 15b. The drive shaft 2 is designed as a hollow shaft, with the first output shaft 15a being guided through the drive shaft 2 . Furthermore, the electric machine 1 is arranged coaxially to the differential stage 6 .

The planetary stage 4 has a planetary gearset with a plurality of planetary gears 7a, the planetary gears 7a of the planetary gearset being rotatably arranged on a first planetary carrier 8a and meshing with a first sun gear 9a and a first ring gear 10a. Consequently, the planet gears 7a mesh radially between the first sun gear 9a and the first ring gear 10a. The drive shaft 2 is connected in a torque-proof manner to the first sun gear 9a. Due to the simplified schematic representation, only one planet wheel 7a of the planetary gear set is shown.

Furthermore, the stepped planetary set 5 has a plurality of stepped planetary gears 7b, each stepped planetary gear 7b having a first and a second gear wheel 17a, 17b which are non-rotatably connected to one another. The stepped planet gears 7b are rotatably arranged on a second planetary carrier 8b. Due to the simplified schematic representation, only one stepped planet wheel 7b of the stepped planetary set 5 is shown. The first gear 17a meshes with a second sun gear 9b and a second ring gear 10b, with the first planet carrier 8a being connected in a torque-proof manner to the second sun gear 9b. On the other hand, the second gear wheel 17b meshes with a third ring gear 10c. The third ring gear 10c is fixed in a stationary manner on the housing 16 of the transmission device 3 and is thus connected to the housing 16 in a torque-proof manner. The second planet carrier 8b is operatively connected to the differential stage 6.

A double clutch device 11 with a first and second power-shiftable clutch 12a, 12b is arranged axially between the planetary stage 4 and the stepped planetary gearset 5. The first ring gear 10a can be connected to the housing 16 of the transmission device 3 via the first clutch 12a and can therefore be fixed in a stationary manner on the housing 16 . Furthermore, the first ring gear 10a can be connected to the second ring gear 10b via the second clutch 12b. Consequently, the dual clutch device 11 is in the power flow between the planetary stage 4 and the stepped planetary gearset 5.

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. By opening both clutches 12a, 12b, the power is switched off, the electric machine 1 thereby being decoupled from the two output shafts 15a, 15b.

Reference List

1

electric machine

2

drive shaft

3

gear device

4

planetary stage

5

stepped planetary set

6

differential stage

7a

planet wheel

7b

stepped planet wheel

8a, 8b

planet carrier

9a, 9b

sun gear

10a, 10b, 10c

ring gear

11

dual clutch device

12a, 12b

coupling

13

stator

14

rotor

15a, 15b

output shaft

16

Housing

17a, 17b

gear

Claims (8)

Drive device for a motor vehicle, comprising an electric machine (1) which is operatively connected to a transmission device (3) via a drive shaft (2), the transmission device (3) having a planetary stage (4), a stepped planetary gear train (5) and a differential stage ( 6), wherein the planetary stage (4) has a planetary set with a plurality of planet gears (7a), the planet gears (7a) being rotatably arranged on a first planet carrier (8a) and having a first sun gear (9a) and a first ring gear ( 10a) are in toothed engagement, with the stepped planetary set (5) having a plurality of stepped planetary gears (7b), with each stepped planetary gear (7b) having a first and a second non-rotatably connected gear wheel (17a, 17b), with the stepped planetary gears (7b) being rotatable on a second planet carrier (8b) are arranged, wherein the first gear (17a) with a second sun gear (9b) and a second ring gear (10b) is in meshing engagement, and wherein the second gear (17b) meshes with a third ring gear (10c), the drive shaft (2) being non-rotatably connected to the first sun gear (9a), the first planet carrier (8a) being non-rotatably connected to the second sun gear (9b). is, and wherein the second planetary carrier (8b) is operatively connected to the differential stage (6), wherein further between the planetary stage (4) and the stepped planetary gear set (5) a double clutch device (11) with a first and second power-shiftable clutch (12a, 12b) is arranged, wherein the first ring gear (10a) can be connected to a housing (16) of the transmission device (3) via the first clutch (12a), and wherein the first ring gear (10a) can be connected to the second ring gear via the second clutch (12b). (10b) can be connected and the third ring gear (10c) is fixed in a stationary manner on the housing (16). drive device claim 1 , characterized in that an opening of both clutches (12a, 12b) realizes a power shutdown. Drive device according to one of the preceding claims, characterized in that closing the first clutch (12a) and opening the second clutch (12b) implements a first gear ratio, with closing the second clutch (12b) and opening the first clutch (12a ) realized a second gear ratio. drive device claim 3 , characterized in that the first gear ratio is not equal to the second gear ratio. Drive device according to one of the preceding claims, characterized in that the electric machine (1) has a stator (13) and a rotor (14), the rotor (14) being non-rotatably connected to the drive shaft (2). Drive device according to one of the preceding claims, characterized in that the differential stage (6) is designed as a spur gear differential, the differential stage (6) being provided to transmit a drive power of the electrical machine (1) to a first and second output shaft (15a, 15b) to distribute. Drive device according to one of the preceding claims, characterized in that the electric machine (1) is arranged coaxially to the differential stage (6). drive device claim 7 , characterized in that the drive shaft (2) is designed as a hollow shaft and the first output shaft (15a) is guided through the drive shaft (2).

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