阅读说明：本技术 用于混合动力车辆的、特别地用于临时四轮驱动的机动车辆的传动系 (Drive train for a hybrid vehicle, in particular for a temporary four-wheel-drive motor vehicle ) 是由 格哈德·霍弗 汉斯迪特尔·维德纳 斯特凡·蒂施林格 于 2018-04-03 设计创作，主要内容包括：一种用于混合动力车辆、特别地用于临时四轮驱动的机动车辆的传动系(1),其中,该传动系包括与主车桥(2)相关的第一部分传动系和与副车桥(3)相关的第二部分传动系,并且其中,第一部分传动系包括设计为内燃机的第一驱动单元(4)和设计为电机的第二驱动单元(5)以及变速箱(6),其中,混合动力传动系生产成本低廉、在运行中具有低的二氧化碳排放并且能够在临时四轮驱动机动车辆的传动系中使用。这是通过以下方式实现的：变速箱(6)包括输入轴(10)和输出轴(11),并且其中,第一驱动单元(4)经由变速箱(6)联接至主车桥(2),并且其中,第二驱动单元(5)经由变速箱(6)的输入轴(10)或输出轴(11)联接至主车桥(2),并且其中,该传动系还包括离合器装置(20),其中,副车桥(3)能够借助于离合器装置(20)以驱动的方式联接至主车桥(2)。(A drive train (1) for a hybrid vehicle, in particular for a temporary four-wheel-drive motor vehicle, wherein the drive train comprises a first partial drive train associated with a primary axle (2) and a second partial drive train associated with a secondary axle (3), and wherein the first partial drive train comprises a first drive unit (4) designed as an internal combustion engine and a second drive unit (5) designed as an electric machine and a gearbox (6), wherein the hybrid drive train is inexpensive to produce, has low carbon dioxide emissions in operation and can be used in the drive train of a temporary four-wheel-drive motor vehicle. This is achieved by: the gearbox (6) comprises an input shaft (10) and an output shaft (11), and wherein the first drive unit (4) is coupled to the primary axle (2) via the gearbox (6), and wherein the second drive unit (5) is coupled to the primary axle (2) via the input shaft (10) or the output shaft (11) of the gearbox (6), and wherein the drive train further comprises a clutch device (20), wherein the secondary axle (3) can be coupled in a driving manner to the primary axle (2) by means of the clutch device (20).)

1. A drive train (1) for a hybrid vehicle, in particular for a temporary four-wheel-drive motor vehicle, wherein the drive train comprises a first partial drive train which is assigned to a primary axle (2) and a second partial drive train which is assigned to a secondary axle (3), and wherein the first partial drive train comprises a first drive unit (4) which is configured as an internal combustion engine and a second drive unit (5) which is configured as an electric motor, and a gearbox (6), wherein the gearbox (6) comprises an input shaft (10) and an output shaft (11), and wherein the first drive unit (4) is coupled to the primary axle (2) via the gearbox (6), and wherein the second drive unit (5) is coupled to the primary axle (2) via the input shaft (10) or the output shaft (11) of the gearbox (6), and wherein a clutch device (20) is arranged between the first partial drive train and the second partial drive train, such that the secondary axle (3) can be drivingly coupled to the primary axle (2) by means of the clutch device (20).

2. Powertrain for a hybrid vehicle according to claim 1, characterized in that the second drive unit (5) is an electric machine based on 60 volt low voltage technology, preferably a 48 volt electric machine.

3. A drive train for a hybrid vehicle according to claim 1 or 2, characterized in that the main axle (2) comprises a first and a second half-axle and an axle differential (8), and that the drive torque from the first drive unit (4) and the second drive unit (5) can be distributed over the two half-axles via the axle differential (8).

4. A driveline for a hybrid vehicle according to any preceding claim, characterised in that the output shaft (11) of the gearbox (6) has a primary output (24) and a secondary output (19), and the primary output (24) is drivingly connected to the axle differential (8) via a spur gear stage (13) and a bevel gear (7).

5. A drive train for a hybrid vehicle according to any one of the foregoing claims, characterised in that the second drive unit (5) is drivingly connected to the secondary output (19) of the output shaft (11) via a gear stage with one or more gears, preferably via a spur gear stage, so that the second drive unit (5) is drivingly connected to the primary axle (2) both in the coupled and uncoupled state of the secondary axle (3).

6. A driveline for a hybrid vehicle according to any preceding claim, characterised in that a clutch arrangement is arranged between the second drive unit (5) and the secondary output (19) of the output shaft (11).

7. A drive train for a hybrid vehicle according to any one of the preceding claims, characterised in that the second drive unit (5) has a reduction gear mechanism, preferably an epicycloidal gear mechanism.

8. a driveline for a hybrid vehicle according to any of the preceding claims, characterised in that the clutch device (20) is a friction clutch, wherein control means are assigned to the friction clutch, and wherein by actuating the clutch device, the force-fit connection between the output shaft (11) of the first partial driveline and the secondary axle (3) can be adjusted for distributing the drive torque from the first drive unit (4) and the second drive unit (5).

9. Driveline for a hybrid vehicle according to any of the preceding claims, characterised in that the driveline (1) further comprises a torque transferring element (21), preferably a propeller shaft, and wherein the electric machine is arranged parallel to the propeller shaft.

10. A driveline for a hybrid vehicle according to any of the preceding claims, wherein the gearbox (6) comprises a housing and the secondary drive unit (5) comprises a housing, and wherein the housing of the gearbox and the housing of the secondary drive unit may form a common housing.

11. A driveline for a hybrid vehicle according to any preceding claim, wherein the second partial driveline comprises an axle differential (16) and a clutch arrangement (17).

Technical Field

The present invention relates to a drive train for a hybrid vehicle, in particular for a temporary four-wheel-drive motor vehicle.

Background

Four-wheel drive vehicles, also referred to below as all-wheel drive vehicles, are known which are designed with both permanent and switchable four-wheel drive devices.

In motor vehicles with four-wheel drive, it is known to use a central differential gear to distribute the drive force between the front axle and the rear axle. Thus, the distribution of the drive torque between the front axle and the rear axle is predetermined constant.

In general, all-wheel drive vehicles are constantly improving, in part because of higher fuel consumption and increased compliance with emissions requirements. In particular, the emphasis here is on at least partial electrification of the drive of the motor vehicle. At least partial hybridization of the drive of a motor vehicle is a compromise between reduced fuel consumption, sufficient travel and good performance.

From the prior art, drive trains for motor vehicles are known which are equipped in design with an electric machine in addition to an internal combustion engine (hybrid vehicles). Here, the electric machine is integrated with the internal combustion engine in the drive train. Furthermore, in the known embodiment, in addition to the primary front wheel drive unit with permanent front axle drive, a separate electric rear axle is used as secondary axle. However, such a drive with an electric rear axle is not considered to be a true all-wheel drive system, since the maximum torque is limited and the availability of torque at the secondary axle is limited in terms of heat or energy.

Hybrid vehicles do meet the requirements of regulated emission standards and can significantly reduce carbon dioxide emissions, but such a powertrain is costly. This is mainly because the function of the electric machine is achieved by voltages above the 60V limit and therefore requires a correspondingly large technical complexity in terms of safety.

Disclosure of Invention

The object of the present invention is to improve a drive train for a hybrid vehicle such that it is inexpensive to produce, has low carbon dioxide emissions in operation and can be used in the drive train of a temporary four-wheel-drive motor vehicle.

This object is achieved by the features given in claim 1.

Since the design of the drive train according to the invention has the internal combustion engine as the main drive unit and the electric machine as the additional drive unit, different operating modes can be achieved, such as all-wheel drive, disconnection (i.e. if no all-wheel drive is required, part of the drive train of the secondary axle is switched off), recuperation (conducting all braking energy into the electric machine operating as a generator), propulsion (accelerating the motor vehicle by means of positive drive torque from both the internal combustion engine and the electric machine), and electric-only drive. In this way, an efficient and variable all-wheel drive system can be achieved. In particular, by using a powerful electric machine based on low-voltage technology, a drive train with lower production costs can be achieved, since no safety-related measures are required.

A further advantage of the hybrid drive train for a motor vehicle according to the invention is that both the main drive unit and the electric machine in the overall drive train of the vehicle are assigned to the permanently driven axle. The electric machine is arranged as a second drive unit between the main transmission (gearbox) and a part of the drive train of the auxiliary axle. According to the invention, the partial drive train can be decoupled by means of a clutch device. In the "uncoupled" state, the motor remains connected to the main axle. The secondary axle is only engaged in "all-wheel drive" operation.

The clutch device provided in the region of the torque transmission element between the partial drive train of the front axle and the partial drive train of the rear axle is designed as a multiplate clutch. The design of the multiplate clutch allows torque to be variably distributed between the front and rear axles.

Another advantage of using a hybrid powertrain for a temporary four-wheel drive motor vehicle is that the mode of operation of the "hybrid" can be adjusted independently of the mode of operation of the "all-wheel drive" and vice versa. This allows the hybrid mode to be adjusted in a manner that is beneficial for fuel efficiency, and the all-wheel drive mode to be adjusted or controlled in a manner that is beneficial for improved performance and driving dynamics.

The hybrid powertrain for a motor vehicle according to the invention can be used as a hybrid module for both all-wheel-drive motor vehicles and front-wheel-drive motor vehicles. This is possible because the electric machine as the second drive unit is assigned to a part of the drive train of the front axle and only then is the clutch device arranged in the region of the torque transmission element in the direction of the rear axle. The electric machine is drivingly connected to a secondary output of the main transmission. By means of this design, the partial drive train of the front axle, including the hybrid drive, can also be used in the vehicle structure of a conventional two-wheel-drive motor vehicle, so that the platform strategy can be implemented. When the first partial drive train is used in a two-wheel-drive motor vehicle, the clutch device for the drive connection between the primary axle and the secondary axle can be omitted.

With respect to the present invention, it should be noted that a "drive" connection refers to a direct or indirect connection between two rotatable components that are held in a fixed rotational relationship with respect to each other. If an element is "connectable" or "couplable," this refers to a connection that may also optionally be a separable connection (e.g., an indirect connection between two elements via a clutch or switching element).

Advantageous embodiments of the invention are given in the dependent claims.

Drawings

The invention is described below with reference to exemplary embodiments schematically illustrated in the drawings.

Shown in the attached drawings:

Fig. 1 is a schematic view of a hybrid powertrain of an all-wheel drive motor vehicle according to the present invention.

Detailed Description

Fig. 1 shows a hybrid drive train 1 of a temporary four-wheel-drive motor vehicle, wherein the front axle is configured as a primary axle 2 and the rear axle is configured as a selectively engageable secondary axle 3. The hybrid drive is formed here by a first drive unit 4 in the form of an internal combustion engine and a second drive unit 5 in the form of an electric motor. The second drive unit 5 is designed as a motor based on the 60V low-voltage technology.

The first drive unit 4 and the second drive unit 5 are distributed to a first part of the drive train of the primary axle 2. As is evident from the schematic representation in fig. 1, the first drive unit 4 is permanently connected to the front axle of the motor vehicle, including a front axle differential 8, via a main transmission configured as a gearbox 6 and a bevel gear 7, so that the front wheels 9 located on the front axle 2 are permanently driven by the first drive unit 5.

Differential gears are known per se, and in this arrangement, the differential gear on the front axle is also described as an axle differential which compensates for the difference in rotational speed between the two output elements when the motor vehicle is travelling around a curve. The output element is connected in a rotationally fixed manner to the two half shafts of the front axle 5. Furthermore, the drive torque from the hybrid drive unit is distributed over the two half-shafts via a differential gear.

The gearbox 6 has an input shaft 10 and an output shaft 11 arranged spaced apart from and parallel to each other. The input shaft 10 and the output shaft 11 are drivingly connected together via a plurality of gear stages 12 in order to realize a plurality of selectable gear stages. In this regard, a more detailed description of the gearbox is not required, as gearboxes are generally known to those skilled in the art. The input shaft 10 is coupled to an output shaft of the first drive unit. The output shaft 11 has a first end region 11a and a second end region 11 b. The first end region 11a as the main output 24 is connected to the angular gear 7 via the spur gear stage 13. The second drive unit 5 is connected to the front axle 2 via a second end region 11b as a secondary output 19 of the output shaft 11 and via a spur gear stage 14 (gear stage). In a development, the gear stage can also be provided with a plurality of gears. The drive connection between the output shaft 11 and the bevel gear 7 or the main axle 2 can also be realized via an angularly arranged shaft and bevel teeth.

In another embodiment, the second drive unit 5 may be provided with a reduction gear mechanism for reducing the rotation speed and increasing the torque. The reduction gear mechanism may be configured as an epicycloidal gear mechanism. As a further alternative, the reduction gear mechanism may be integrated in the gear stage. The reduction gear mechanism may be configured as a selectable gear mechanism and thus allow more than one transmission ratio.

The second gear unit 5 can be built in its own housing on the housing of the main transmission. Alternatively, the second gear unit 5 may be arranged in a common housing comprising the second drive unit 5, the gear stage 14 and the clutch device 20.

The part-drive train 15 of the rear axle 3 comprises a rear axle differential 16, a clutch device 17 and rear wheels 18.

The rear axle 3 forming the auxiliary axle in the hybrid drive train 1 may be driven by a hybrid other than the front axle 2, if desired.

For this purpose, a clutch device 20 is provided on the auxiliary output 11b for selectively "connecting" or "disconnecting" the output shaft 11 of the gearbox 12 relative to the rear axle 3. The clutch device 20 includes a friction clutch (multi-plate clutch) and an actuator for actuating the friction clutch. The actuator is controlled by a control device (not shown). The clutch device 20, i.e. the friction clutch, has a first clutch element 25 and a second clutch element 26 which can be coupled to the first clutch element 25. Here, the first clutch element 25 comprises a clutch hub carrying a plurality of first clutch plates. The clutch hub is connected to the output shaft 11 in a rotationally fixed manner. The second clutch element 26 comprises a clutch retainer, which is connected in a rotationally fixed manner to the torque transmission element 21 via a carrier coupling (carrier driver), and the second clutch element 26 also comprises a plurality of second clutch plates. The first clutch plates are engaged in the intermediate spaces of the second clutch plates in an alternating arrangement. When the clutch device is actuated, the flaps move axially and press against one another; the output shaft carries a torque transmitting element. The clutch device 20 can be switched mechanically, hydraulically, pneumatically or electromagnetically.

By corresponding actuation of the multiplate clutch and axial displacement of the plates, a force-fitting connection can be established between the output shaft 11 and the torque transmission element 21, and a torque distribution between 0% and 100% between the primary axle and the secondary axle can be achieved.

The output of the clutch device 20 is connected to one end of a torque transfer element 21, e.g. a propeller shaft. The torque-transmitting element 21 is connected at its other end region to a bevel gear 22, which bevel gear 22 meshes with a ring gear 23 connected to a differential carrier of the rear differential 16.

The function of the rear differential 16 corresponds to the function described for the front differential 8.

In order to prevent an unnecessary rotation of the torque transfer element 21 and the differential cage of the rear axle differential 16 and thus to consume energy, the clutch 17 is configured as a disengaged clutch during travel when the clutch device 20 is disengaged, i.e. in a "pure front-wheel drive" operating mode.

If it is desired to switch to an "all-wheel drive" mode of operation during travel, the fixed torque-transmitting element 21 is first set to rotate again. For this purpose, the clutch device 17 is first engaged again, and starting from the rear axle 3, which rotates as a result of the advancing movement, the torque transmission element 21 is accelerated by means of the rear axle differential 16. Then, by actuating the clutch device 20, a friction-fit connection is established between the torque transmitting element 21 and the output shaft 11 in order to transmit torque. The vehicle is now operating in all-wheel drive mode.

In a further alternative embodiment (not shown), a further clutch device is provided between the second drive unit 5 and the input shaft 10 or the output shaft 11. In this embodiment, both the secondary axle 3 and the second drive unit 5 can be decoupled from the primary axle 2 independently of one another.

List of reference numerals:

1 hybrid powertrain

2 main axle

3 auxiliary vehicle bridge

4 first drive unit

5 second drive unit

6 speed changing box

7 oblique bevel gear

8 front axle differential mechanism

9 front wheel

10 input shaft

11 output shaft

12 gear stage

13 spur gear stage

14 spur gear stage

15-part drive train

16 rear axle differential mechanism

17 Clutch device

18 rear wheel

19 pairs of outputs

20 Clutch device

21 torque transmitting element

22 bevel gear

23 Ring gear

24 main output

25 first clutch element

26 second clutch element