DE102019119947A1 - Drive device for a motor vehicle with rotatably connected planetary wheel carriers and rotatably connected sun gears - Google Patents

Abstract

A drive device (1) for a motor vehicle has 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 set (4) having a first planetary gear set with several 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 meshing with a first ring gear (10a), the second planetary gear set (5) having a second planetary gear set with several planet gears (7b), the planet gears (7b) of the second planetary gear set being rotatably arranged on a second planetary gear carrier (8b) and with a second sun gear (9b) and with a second ring gear (10b) are in meshing engagement, the first and the z wide planetary gear stage (4, 5) are operatively connected to a double clutch device (11) with a first and a second power shiftable clutch (12a, 12b), and wherein the first planetary gear carrier (8a) rotatably with the second planetary gear carrier (8b) and the first sun gear ( 9a) rotatably connected to the second sun gear (9b).

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 having first planetary gear set with several planetary gears, wherein the planetary gears of the first planetary gear set are rotatably arranged on a first planetary gear carrier and are in meshing engagement with a first sun gear and with a first ring gear, the second planetary gear set having a second planetary gear set with several planetary gears, 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 a second ring gear, 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.

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 drive machine is coupled non-rotatably 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 a rotationally fixed manner against a component of the drive device by means of a shift sleeve of the 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 connection shaft of the first planetary drive or in a torque-transmitting operative connection with the sum shaft of the differential.

Also shows the DE 10 2013 225 519 A1 a planetary gear and a drive unit, especially for electric vehicles. The planetary gear has an input shaft forming a sun gear, a planetary gear carrier which carries a first set of planetary gears and a second set of planetary gears, a first ring gear which is assigned to the first set of planet gears, a second ring gear which is assigned to the second set of planet gears is assigned, a first locking means, by means of which the first ring gear can be locked and a second locking means, by means of which the second ring gear can be locked on.

However, the prior art has the disadvantage that, due to a complex gear structure, a large number of different parts and components are installed and therefore the production costs increase and assembly is made more difficult.

It is therefore the object of the invention to avoid or at least alleviate the disadvantages of the prior art. In particular, a drive device for a motor vehicle is to be further developed, the focus being on the simplest possible transmission structure with many identical parts and a suitable gear ratio distribution or spread.

In a device of the generic type, this object is achieved according to the invention in that the first planetary gear carrier is connected non-rotatably to the second planetary gear carrier and the first sun gear is non-rotatably connected to the second sun gear.

In other words, the object is achieved in a drive device according to the invention in that the first planet carrier and the second planet carrier are rigidly connected to one another to form a common planet carrier and the first sun gear and the second sun gear are rigidly connected to one another to form a common sun gear.

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 set as well as a differential stage, the first planetary gear set having a first planetary gear set with several planet gears, the planet gears of the first planetary gear set being rotatably arranged on a first planetary gear carrier and with a first sun gear and a first ring gear The second planetary gear set has a second planetary gear set with a plurality of planetary gears, the planetary gears of the second planetary gear set are rotatably arranged on a second planetary gear carrier and mesh with a second sun gear and a second ring gear, and the first and second planetary gear sets are operatively connected to a double clutch device with a first and a second power shiftable clutch.

The term “operatively connected” means that two transmission elements can be directly connected to one another, or that further transmission elements, for example one or more, are located between two transmission elements Shafts or gears. Two gearwheels that are in meshing engagement with one another are provided for transmitting a torque and a speed from one gearwheel to the other gearwheel. A gear is to be understood as meaning, for example, a sun gear, a ring gear and a planet gear of a planetary gear set.

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

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

According to the invention, the first planetary gear carrier and the second planetary gear carrier can preferably be formed in one piece, integrally and / or in one material. In other words, the first planet carrier and the second planet carrier can form a common planet carrier.

In addition, it is advantageous if the first sun gear and the second sun gear are non-rotatably connected to the drive shaft and in particular the drive shaft with the first sun gear and the second sun gear is designed as an integral component, so that the assembly of the transmission device can be facilitated.

In an embodiment according to the invention, the first planetary gear carrier and the second planetary gear carrier, i.e. the common planetary gear carrier, can preferably be fixed in a stationary / stationary / rotationally fixed manner in a housing via the first coupling. Alternatively, it is also conceivable that the first planetary gear carrier and the second planetary gear carrier are operatively connected to the differential stage.

Furthermore, the first ring gear can be fixed in a stationary manner in the housing, in particular via the first or second clutch.

In addition, according to the invention, the second ring gear can be fixed in place in the housing, preferably via the second clutch. In an alternative embodiment, however, the second ring gear can also be operatively connected to the differential stage.

In an advantageous development, the first planetary gear carrier and the second planetary gear carrier can be designed with identical planetary gear carrier diameters and identical planetary gear shaft diameters and the pitch circle diameters of the first sun gear and the second sun gear can be of different sizes. In other words, the planet gears of the first planetary gear set and the planet gears of the second planetary gear set can have a bearing bore with the same diameter and rotate at the same radial distance from the drive shaft.

If the pitch circle diameter of the first sun gear differs from the pitch circle diameter of the second sun gear, two different gear ratios can easily be implemented. The pitch circle diameter of the first sun gear can preferably be smaller than the pitch circle diameter of the second sun gear.

Alternatively, however, it would also be conceivable that the pitch circle diameters of the two sun gears are the same and the common planetary gear carrier is stepped, that is, that the first planetary gear carrier is arranged radially offset to the second planetary gear carrier and the planet gears of the first planetary gear set and the second planetary gear set are thus on circular paths with it different diameters revolve.

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 stage or on the output side between the second planetary gear stage and the differential stage. The additional reduction gear increases the spread of the transmission device and can be designed, for example, as a spur gear stage or as a further planetary gear stage.

The first and second clutch of the double clutch device can preferably be designed as a friction clutch. Furthermore, the two couplings can preferably be 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 implemented hydraulically, electromechanically, electromagnetically or, for example, also pneumatically.

It is useful here if opening both clutches can realize a power cut-off at the same time. 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 that the shifting process from one clutch to the other clutch is largely free of traction force interruption, one clutch can open in a transitional period while the other closes. Via the slip in the clutches, designed as friction clutches, a torque-free switchover between two gear stages can take place, which can be perceived by the operator of the drive device as a switchover mode between two gear stages without traction, which in turn increases the switching 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 can be greater than the second gear ratio. Alternatively, the first gear ratio can be smaller than the second gear ratio.

Furthermore, the electric drive machine preferably has a stator and a rotor, the rotor being non-rotatably connected 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 (gear) being arranged between the two shafts.

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

The drive machine can be arranged coaxially or axially parallel to the differential stage. The drive shaft is preferably arranged coaxially to the two output shafts. In particular, the drive shaft is designed as a hollow shaft, 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, axially parallel means that there is an axial offset between the drive shaft and the output shafts.

In other words, the invention relates to a two-speed transmission for electric axles with common planetary gear carriers and suns. In the search for transmissions for two gears with an advantageous gear ratio distribution in an axially parallel and coaxial arrangement, the aim is to provide the simplest possible gear structure with many identical parts and a suitable gear ratio distribution or spreading through a combination of two planetary gear stages with a spur gear stage and a shifting element designed as a double clutch or synchro unit, whereby the basic structure of the transmission has a common planet carrier and a common sun. In a first possible embodiment, the first ring gear or the common planetary gear carrier can optionally be set as a fixed element, whereas in a second embodiment the first ring gear or the second ring gear can be selected as a fixed element.

• 1 eine erste Ausführungsform einer erfindungsgemäßen Antriebsvorrichtung in achsparalleler Bauweise,
• 2 eine Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in koaxialer Bauweise, und
• 3 eine zweite Ausführungsform einer erfindungsgemäßen Antriebsvorrichtung in achsparalleler Bauweise,
• 4 eine Modifikation der Antriebsvorrichtung gemäß der ersten Ausführungsform in koaxialer Bauweise.

Further measures improving the invention are shown 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 an axially parallel construction,
• 2 a modification of the drive device according to the first embodiment in a coaxial construction, and
• 3 a second embodiment of a drive device according to the invention in an axially parallel construction,
• 4th a modification of the drive device according to the first embodiment in a coaxial construction.

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

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

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

The transmission device 3 comprises a first and second planetary gear set 4th , 5 as well as a differential stage 6 . The first planetary gear stage 4th has a first planetary gear set with several planetary gears 7a on which rotatable on a first planet carrier 8a are arranged and with a first sun gear 9a as well as with a first ring gear 10a are in mesh. So 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 second planetary gear stage 5 has a second planetary gear set with several planetary gears 7b on which rotatable on a second planet carrier 8b are arranged and with a second sun gear 9b as well as with a second ring gear 10b are in mesh. So the planet gears mesh 7b of the second planetary gear set radially between the second sun gear 9b and the second ring gear 10b .

There is also a double clutch device 11 with a first clutch 12a and a second clutch 12b intended. Closing the first clutch 12a and opening the second clutch 12b realizes a first gear ratio, with 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 shutdown is implemented.

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

In the drive device 1 according to the first embodiment is the double clutch device 11 on the input side of the transmission device 3 arranged. In particular, depending on the shifting of the double clutch device 11 optionally via the first coupling 12a the first planet carrier 8a and the second planet carrier connected to it in a rotationally fixed manner 8b or via the second coupling 12b the first ring gear 10a Fixed / stationary / non-rotatable in one housing 15th set / recorded / arranged, which in turn the first or second gear ratio can be implemented.

The first sun gear 9a and the second sun gear 9b are non-rotatable with the drive shaft 2 connected and conduct the torque of the electric drive machine in the transmission device 3 a. Here is the pitch circle diameter of the first sun gear 9a smaller than the pitch circle diameter of the second sun gear 9b .

As described above, the first planet carrier is 8a non-rotatably with the second planet carrier 8b connected. In particular, form the first planet carrier 8a and the second planet carrier 8b a common planet carrier. The first planet carrier 8a and the second planet carrier 8b the same / identical planetary gear carrier diameter, which describes the circular path on which the planets revolve. In addition, the first have planetary gear carriers 8a and the second planet carrier 8b same / identical planetary gear shaft diameter. The planet gear shaft diameter describes the diameter of the shaft on which the individual planet gears 7a , 7b are stored.

In other words, the common planetary gear carrier is designed in such a way that the planetary gear shafts have essentially no discontinuities such as a jump or offset in the axial direction.

The second ring gear 10b is via a reduction gear connected on the output side and designed as a spur gear stage 14th with the differential stage 6 effectively connected. Thus, the torque of the electric drive machine is via the drive shaft 2 into the transmission device 3 initiated, there depending on the circuit of the double clutch device 11 translated and via the second ring gear 10b , the reduction gear 14th on the differential stage 6 where it is finally passed on to the two output shafts 13a , 13b is distributed.

In the 2 The illustrated modification of the first embodiment is a drive device 1 in a coaxial design. The reduction gear 14th on the input side between the electric drive machine and the transmission device 3 , especially the drive shaft 2 , interposed so that the drive shaft 2 essentially coaxial with the two output shafts 13a , 13b is arranged. In particular, the drive shaft 2 here as a hollow shaft, which the two output shafts 13a , 13b records, executed.

3 shows a second embodiment of the drive device according to the invention 1 in coaxial design. The main differences to the one in 1 illustrated drive device 1 received.

In the drive device 1 according to the second embodiment, the first ring gear 10a over the first clutch 12a stationary in the housing 15th be determined. Via the second clutch 12b however, the second ring gear 10b stationary in the housing 15th be determined. Depending on the circuit of the double clutch device arranged on the input side 11 can thus optionally use the first ring gear for the first gear ratio 10a or the second ring gear for the second gear ratio 10b stationary in the housing 15th to be ordered.

The first planet carrier 8a and the second planet carrier 8b , ie the common planet carrier, are in the second embodiment via the reduction gear arranged on the output side 14th with the differential stage 6 effectively connected. The torque of the electric drive machine is consequently via the drive shaft 2 and the two sun gears 9a , 9b into the transmission device 3 initiated and via the common planet carrier and the reduction gear 14th to the differential stage 6 diverted.

In the 4th The illustrated modification of the first embodiment is a drive device 1 in a coaxial design. The reduction gear 14th on the input side between the electric drive machine and the transmission device 3 , especially the drive shaft 2 , interposed so that the drive shaft 2 essentially coaxial with the two output shafts 13a , 13b is arranged. In particular, the drive shaft 2 here as a hollow shaft, which the two output shafts 13a , 13b records, executed.

List of reference symbols

1

Drive device

2

drive shaft

3

Transmission device

4th

first planetary gear stage

5

second planetary gear stage

6th

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 gear

10a

first ring gear

10b

second ring gear

11

Double clutch device

12a

first clutch

12b

second clutch

13a, 13b

Output shaft

14th

Reduction gear

15th

casing

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102011088668 A1 [0002]
• DE 102013225519 A1 [0003]

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) having 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 several 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) and are in meshing engagement with a first ring gear (10a), the second planetary gear set (5) having a second planetary gear set with several planet gears (7b), the planet gears (7b) of the second planetary gear set being rotatably arranged on a second planetary gear carrier (8b) and with a second sun gear (9b) and a second ring gear (10b) are in meshing engagement, the first and the second e planetary gear stage (4, 5) are operatively connected to a double clutch device (11) with a first and a second power shiftable clutch (12a, 12b), characterized in that the first planetary gear carrier (8a) rotatably with the second planetary gear carrier (8b) and the first Sun gear (9a) is rotatably connected to the second sun gear (9b). Drive device (1) after Claim 1 , characterized in that the first sun gear (9a) and the second sun gear (9b) are rotatably connected to the drive shaft (2). Drive device (1) according to one of the Claims 1 or 2 , characterized in that the first planetary gear carrier (8a) and the second planetary gear carrier (8b) can be fixed (via the first clutch) in a stationary manner in a housing (15) or are operatively connected to the differential stage (6). Drive device (1) according to one of the Claims 1 to 3 , characterized in that the first ring gear (10a) (via the first or second clutch) can be fixed in a stationary manner in the housing (15). Drive device (1) according to one of the Claims 1 to 4th , characterized in that the second ring gear (10b) (via the second clutch) is stationary in the housing (15) or is operatively connected to the differential stage (6). Drive device (1) according to one of the Claims 1 to 5 , characterized in that the first planetary gear carrier (8a) and the second planetary gear carrier (8b) are designed with identical planetary gear carrier diameters and identical planetary gear shaft diameters and the pitch circle diameters of the first sun gear (8a) and the second sun gear (8b) are of different sizes. Drive device (1) according to one of the Claims 1 to 6 , 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 Claims 1 to 7th , 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) 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 preceding claims, characterized in that the drive machine is arranged offset axially parallel to the differential stage (6).

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