DE102019107517B3 - Drive device for a motor vehicle - Google Patents

Abstract

The invention relates to a 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), the first planetary gear stage (4) having a first planetary gear set with a plurality of planetary gears (7a), the planetary gears (7a) of the first planetary gear set being rotatably arranged on a first planetary gear carrier (8a) and with a first sun gear (9a) as well as 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 rotatable on a second planetary gear carrier (8b) are arranged and mesh with a second sun gear (9b) and with a second ring gear (10b), w the first sun gear (9a) and the second sun gear (9b) are connected to one another in a rotationally fixed manner and the drive shaft (2) is operatively connected to the two sun gears (9a, 9b), the first and the second ring gear (10a, 10b) being connected to one another in a rotationally fixed manner are connected and wherein the second planetary gear carrier (8b) is operatively connected to the differential stage (6), the first and second planetary gear stages (4, 5) having a double clutch device (11) with a first and a second powershiftable clutch (12a, 12b) are operatively connected, the first planet gear carrier (8a) being connected in a rotationally fixed manner to the housing (16) via the first clutch (12a), and the two ring gears (10a, 10b) being connected in a rotationally fixed manner to the housing (16) via the second clutch (12b) are connectable.

Description

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

From the DE 10 2011 088 668 A1 is a drive device with at least one electric drive machine, with at least a first planetary drive with a clutch and with a differential. A rotor shaft of the drive machine is rotatably coupled to a first connection shaft of the planetary drive formed from at least three connection shafts. A second connecting shaft of the first planetary drive can be fixed in rotation against a component of the drive device by means of a shift sleeve of the clutch. A third connection shaft of the first planetary gear is operatively connected to a sum wave of the differential. The shift sleeve can be moved in positive engagement either with the second connecting shaft of the first planetary gear or in a torque-transmitting operative connection with the sum shaft of the differential.

The DE 10 2014 215 156 A1 shows a group transmission of a motor vehicle, which comprises a main transmission and a drive group upstream or downstream of the main transmission, which is formed from two coupled planetary gear sets and has switchable gear ratios for a slow speed range, a fast speed range and a reverse speed range.

The object of the present invention is to further develop a drive device for a motor vehicle.

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 having two ring gears connected to one another in a rotationally fixed manner and two sun gears connected to one another in a rotationally fixed manner.

The gear 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 Tooth mesh, the second planetary gear stage having a second planetary gear set with a plurality of planet gears, the planet gears of the second planetary gear set being rotatably arranged on a second planet gear carrier and meshing with a second sun gear and with a second ring gear, the first sun gear and the second sun gear are connected to one another in a rotationally fixed manner, the drive shaft being operatively connected to both sun gears, the first and the second ring gear being connected to one another in a rotationally fixed manner, and the second planet gear carrier having the difference tialstufe is operatively connected, the first and the second planetary gear stage are operatively connected to a double clutch device with a first and a second power-shiftable clutch, the first planet gear carrier being rotatably connected to the housing via the first clutch, and the two ring gears being connected via the second clutch the housing is rotatably connectable.

The term “operatively connected” is to be understood to mean that two gear elements can be connected directly to one another, or that there are further gear elements between two gear elements, for example one or more shafts or gear wheels. Two gearwheels which mesh or mesh with one another are provided for transmitting a torque and a speed from one gearwheel to the other gearwheel. A gearwheel is understood to mean, for example, a sun, a ring gear and a planet of a planetary gear set.

The operative connection between the drive shaft or an output shaft and a sun gear arranged on the shaft can be formed in two ways. On the one hand, the sun gear or the toothing of the sun gear can have been introduced directly on the shaft, so that the sun gear and shaft are designed as one component. On the other hand, the sun gear can be present as a component separately formed from the shaft, the sun gear being or being mounted on the shaft in a torque-proof manner.

A double clutch device is to be understood as a device with two power shift clutches. Furthermore, the term “power shift clutch” is to be understood as 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.

In the closed state of the first clutch, the first planet gear carrier is connected to the housing in a rotationally fixed manner. The first planet carrier is thus fixed to the housing and can support a force. A torque from the drive shaft can now be passed on to the first ring gear via the first planetary gear set, the first and the second ring gear always being connected in a rotationally fixed manner, after which the torque finds its way into the second planetary gear stage and is finally delivered to the differential stage via the second planet gear carrier. When the first clutch is in the closed state, the second clutch is in the open state so that the interconnected ring gears can rotate around the sun gears.

In the closed state of the second clutch, the two ring gears are non-rotatably connected to the housing. The ring gears are thus fixed to the housing and can support a force. A torque from the drive shaft can now be given to the second planetary gear set via the second sun gear and finally introduced to the differential stage via the second planetary gear carrier. The first planet gear carrier runs in "idle" mode due to the opened first clutch.

Alternatively, the second clutch can be operatively connected to the first planet gear carrier and the first clutch to the two ring gears.

The pitch circle of the two ring gears is advantageously the same, the pitch circles of the corresponding sun wheels being designed differently, so that a different transmission ratio of the two planetary gear stages can be formed. The pitch circle of the first sun gear is preferably smaller than the pitch circle of the second sun gear.

The respective clutch is designed in particular 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 designed to be hydraulically, electromechanically, electromagnetically or, for example, pneumatically actuated.

Opening both clutches at the same time can result in a power cut-off. Closing the first clutch and opening the second clutch realizes a first gear ratio, wherein closing the second clutch and opening the first clutch realizes a second gear ratio. In order to ensure a shift operation from one clutch to the other clutch that is largely without interruption in tractive force, one clutch opens in a temporal transition area while the other closes. Via the slip in the clutches designed as friction clutches, a torque-free switchover between two gear stages takes place, which is perceived by the operator of the drive device as a traction-free switchover mode between two gear stages, thus increasing the shifting comfort for the operator of the drive device.

The first gear ratio is preferably not the same as the second gear ratio. For example, the first gear ratio is larger than the second gear ratio. Alternatively, the first gear ratio is smaller than the second gear ratio.

The electric drive machine preferably has a stator and a rotor, the rotor being connected in a rotationally fixed manner to the drive shaft. The drive shaft can be designed as a rotor shaft or there is an axial offset between the drive shaft and the rotor shaft, a torque transmission device (transmission) being arranged between the two shafts.

Furthermore, the differential stage is preferably designed as a spur gear differential, the differential stage being intended to distribute drive power of 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, one of the two output shafts being guided axially through the drive shaft. The two output shafts are preferably arranged on a common drive axis.

Alternatively, the drive shaft is arranged axially parallel to the two output shafts, wherein axially parallel means that there is an axial offset between the drive shaft and the output shafts.

The differential stage has a first and a second planetary gear set, the planets of the first planetary gear set of the differential stage being in meshing engagement with a toothing on the first output shaft, wherein the planets of the second planetary gear set are in meshing engagement with a toothing on the second output shaft, and wherein the planets of both planetary sets mesh with each other in pairs.

Further measures improving the invention are shown below together with the description of a preferred embodiment of the invention with reference to the figures. The figures each show a simplified schematic illustration to illustrate the structure of a drive device according to the invention.

• 1 eine erste Ausführungsform der erfindungsgemäßen Antriebsvorrichtung in koaxialer Bauweise und
• 2 eine zweite Ausführungsform der erfindungsgemäßen Antriebsvorrichtung in achsparalleler Bauweise.

Show it:

• 1 a first embodiment of the drive device according to the invention in a coaxial design and
• 2nd a second embodiment of the drive device according to the invention in an axially parallel design.

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

The drive device according to the invention 1 For a motor vehicle - not shown here - has an electric drive machine and a transmission device (not shown here) 3rd on. The electric drive machine has a stator and a rotor. A drive power of the electric drive machine is via a drive shaft 2nd that between the electric drive machine and the gear device 3rd arranged and designed as a rotor shaft, in the transmission device 3rd initiated.

The gear device 3rd includes first and second planetary gear stages 4th , 5 as well as a differential stage 6 . The differential stage 6 can be designed as a spur gear differential. The differential stage is intended to provide drive power via the drive shaft 2nd on a first and second output shaft 15a , 15b to distribute. The drive shaft 2nd is coaxial to the two output shafts 15a , 15b arranged. Furthermore, the prime mover can be coaxial with the differential stage 6 be arranged.

The first planetary gear stage 4th has a first planetary gear set with a plurality of planet gears 7a on, with the planet gears 7a of the first planetary gear set rotatable on a first planet gear carrier 8a are arranged and with a first sun gear 9a as well as with a first ring gear 10a mesh with teeth. Thus, the planet gears mesh 7a of the first planetary gear set radially between the first sun gear 9a and the first ring gear 10a . The drive shaft 2nd is rotatable with the first sun gear 9a connected.

Furthermore, the second planetary gear stage 5 a second planetary gear set with several planet gears 7b on, with the planet gears 7b of the second planetary gear set rotatable on a second planet gear carrier 8b are arranged and with a second sun gear 9b as well as with a second ring gear 10b mesh with teeth. Thus, the planet gears mesh 7b of the second planetary gear set radially between the second sun gear 9b and the second ring gear 10b . The drive shaft 2nd is also non-rotatable with the first sun gear 9a connected. Furthermore, the second planet gear carrier 8b with the differential stage 6 connected. The two ring gears 10a and 10b are rotatably connected to each other and have the same pitch circle diameter.

Furthermore, there is a double clutch device 11 with a first and second power shift clutch 12a , 12b intended. The first and the second ring gear 10a and 10b is about the second clutch 12b with the housing 16 connectable so that both ring gears 10a and 10b can be switched fixed to the frame or freely rotating. When closing the second clutch 12b becomes a non-rotatable connection between the first ring gear 10a , the second ring gear 10b and the housing 16 realized. Furthermore, the first planet carrier 8a about the first clutch 12a with the housing 16 connectable, making the first planet carrier 8a can be switched fixed to the frame or freely rotating. Closing the first clutch 12a and opening the second clutch 12b realizes a first gear ratio, whereby a closing of the second clutch 12b and opening the first clutch 12a realized a second gear ratio. The first gear ratio is not the same as the second gear ratio. By opening both clutches 12a , 12b a power cut-off is implemented, the drive machine being driven by the two output shafts 15a , 15b is decoupled.

The first gear ratio (closing the first clutch 12a) converts the first planetary gear stage 4th in a stationary transmission (two-shaft transmission) with a stationary transmission, the input torque via the first sun gear 9a initiated and the output torque via the first ring gear 10a is diverted. Because the first and the second ring gear 10a and 10b and also the first sun gear 9a and the second sun gear 9b one input torque each in the second planetary gear stage 5 Initiate as a three-shaft gearbox, the output torque is via the second planet carrier 8b given to the differential stage.

The second gear ratio (closing the second clutch 12b) leaves the first planetary gear stage 4th largely inoperative since the input torque from the drive shaft to the second sun gear 9b transferred and into the second planetary gear stage 5 is initiated. Through the second ring gear fixed to the frame 10b roll the planet gears 7b on the second ring gear 10b and turn the second planet carrier 8b directional with the sun gear 9b . The planetary gear stage becomes the second gear carrier 5 escaping torque is introduced into the differential stage and on to the output shafts 15a and 15b distributed.

The double clutch device 11 is in this embodiment on the drive side, that is at the input of the torque in the drive shaft 2nd arranged. Along the drive shaft 2nd then the first planetary gear stage 4th , the second planetary gear 5 and the differential stage in that order.

2nd shows a second embodiment of the drive device according to the invention 1 in axially parallel design. In the following it will only focus on the differences 1 received.

The double clutch device 11 is contrary to 1 no longer permanently on the housing 16 supported, but is on the transmission output side of the transmission device 3rd arranged or is by the input shaft 14 to the reduction gear 13 the differential stage 6 carried. Also, the double clutch device 11 on the of the drive shaft 2nd opposite side of the gear device 3rd arranged.

The first clutch 12a is now with the second planet carrier 8b connected. The first planet carrier 8a is permanently on the housing 16 supported, thus the first planetary gear stage 4th designed as a permanent stationary gear. The second planet gear or wheels 7b are smaller in diameter than the first planet gears 7a educated. Accordingly, the second sun gear 9b larger in diameter than the first sun gear 9a .

In the first gear ratio (closing the first clutch 12a) becomes the input torque of the drive shaft 2nd on both sun gears 9a , 9b transfer. In the function of the first planetary gear stage 4th the first ring gear is used as a stationary gear 10a rotated, which also the second ring gear 10b turns. The second planetary gear stage 5 acts as a three-shaft gear and receives a torque supply both via the second ring gear 10b as well as the second sun gear 9b . The second planet carrier 8b is by closing the first clutch 12a non-rotatable with the double clutch device 11 connected, which is connected to the input shaft 14 of the reduction gear 13 turns. A relative rotation remains in the second clutch 12b between the ring gear 10a , 10b and the double clutch device 11 .

In the second gear ratio (closing the second clutch 12b) becomes the input torque of the drive shaft 2nd via the first planetary gear stage designed as a stationary gear 4th from the sun gear 9a on the ring gear 10a transfer. Because the second planet carrier 8b now through the opened first clutch 12a no torque to the input shaft 14 can only transmit the torque transmission from the first ring gear 10a on the second ring gear 10b due to the permanently non-rotatable connection between the two ring gears. The closed second clutch 12b can now apply this torque to the input shaft 14 pass on, causing the reducer 13 , the differential stage 6 and the two output shafts 15a and 15b to be set in motion.

Reference list

1

Drive device

2nd

drive shaft

3rd

Gear device

4th

first planetary gear stage

5

second planetary gear stage

6

Differential stage

7a

first planet gear / gears

7b

second planet gear

8a

first planet carrier

8b

second planet carrier

9a

first sun gear

9b

second sun gear

10a

first ring gear

10b

second ring gear

11

Double clutch device

12a

first clutch

12b

second clutch

13

Reduction gear

14

Input shaft

15a, 15b

Output shaft

16

casing

Claims (10)

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) comprising at least a first and second planetary gear stage (4, 5) and a differential stage ( 6), • the first planetary gear set (4) having a first planetary gear set with a plurality of planetary gears (7a), the planetary gears (7a) of the first planetary gear set being rotatably arranged on a first planet gear carrier (8a) and having a first sun gear (9a) as well as with a first ring gear (10a), • the second planetary gear stage (5) has a second planetary gear set with a plurality of planet gears (7b), the planet gears (7b) of the second Planetary gear set are rotatably arranged on a second planet gear carrier (8b) and mesh with a second sun gear (9b) and with a second ring gear (10b), • the first sun gear (9a) and the second sun gear (9b) being connected to one another in a rotationally fixed manner and the drive shaft (2) is operatively connected to the two sun gears (9a, 9b), • the first and the second ring gear (10a, 10b) being connected to one another in a rotationally fixed manner, • and the second planet gear carrier (8b) being connected to the differential stage (6 ) is operatively connected, • the first and the second planetary gear stage (4, 5) being operatively connected to a double clutch device (11) with a first and a second power shift clutch (12a, 12b), • the first planetary gear carrier (8a) being connected via the first Coupling (12a) with a housing (16) can be connected in a rotationally fixed manner, and the two ring gears (10a, 10b) can be connected in a rotationally fixed manner with the housing (16) via the second coupling (12b) or the first planet gear carrier (8a) is permanently attached to the housing (16), the second planet gear carrier (8b) can be connected to the differential stage (6) via the first clutch (12a) and the two ring gears (10a, 10b) via the second clutch (12b) are connectable to the differential stage (6). Drive device (1) after Claim 1 , characterized in that the pitch circle diameter of the two ring gears (10a, 10b) is the same size, the pitch circle diameter of the corresponding sun gears (9a, 9b) being of different sizes. Drive device (1) after Claim 1 or 2nd , characterized in that the pitch circle diameter of the first sun gear (9a) is smaller than the pitch circle diameter of the second sun gear (9b). Drive device (1) according to one of the preceding claims, characterized in that opening both clutches (12a, 12b) realizes a power cut-off. Drive device (1) according to one of the preceding claims, characterized in that a closing of the first clutch (12a) and the opening of the second clutch (12b) realizes a first gear ratio, wherein a closing of the second clutch (12b) and the opening of the first Coupling (12a) realized a second gear ratio. Drive device (1) after Claim 5 , characterized in that the first gear ratio is not the same as the second gear ratio. Drive device (1) according to one of the preceding claims, characterized in that the electric drive machine has a stator and a rotor, the rotor being connected in a rotationally fixed manner to the drive shaft (2). Drive device (1) 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 drive the drive power of the drive machine to a first and second output shaft (15a, 15b) to distribute. 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 the Claims 1 to 8th characterized in that the drive machine is arranged axially parallel to the differential stage (6).

Images