DE102024119051A1 - Powertrain for a motor vehicle and motor vehicle with such a powertrain - Google Patents

Abstract

The invention relates to a drive train (10) for a motor vehicle (K), comprising at least one drive motor (20) and at least one transmission (30), which is designed to translate a rotational speed provided by the at least one drive motor (20) and to transmit drive power provided by the at least one drive motor (20) to at least one drive wheel (70) of the motor vehicle (K). The transmission (30) has at least one helical first gear stage (40) and at least one second gear stage (50) with the same direction of rotation (12) as the at least one first gear stage (40). A further aspect of the invention relates to a motor vehicle (K) with a drive train (10).

Description

The invention relates to a drive train for a motor vehicle, comprising at least one drive motor and at least one transmission, which is designed to translate a rotational speed provided by the at least one drive motor and to transmit drive power provided by the at least one drive motor to at least one drive wheel of the motor vehicle. A further aspect of the invention relates to a motor vehicle with such a drive train.

From the DE 10 2009 001 147 A1 A motor vehicle drivetrain is known, comprising an internal combustion engine with a drive shaft, a stepped transmission with an input shaft connectable to the drive shaft of the internal combustion engine via a friction clutch, and an output shaft connected to the axle drive of a drive axle. The transmission also includes a hydrodynamic retarder arranged parallel to the output shaft on the output side of the stepped transmission, connected to the output shaft via a rotor shaft and a spur gear unit with a drive gear on the output shaft side and an output gear on the rotor shaft side. Essentially to increase the available maximum continuous braking power, but also to reduce fuel consumption and improve driving comfort, an electric machine with a stator and a rotor, operable as both a motor and a generator, is additionally provided. This electric machine is arranged coaxially on the output side of the stepped transmission, with a rotationally fixed connection of the rotor to a power take-off shaft connected to the output shaft of the stepped transmission.

The DE 10 2012 111 847 A1 Disclosing a high-speed transmission arrangement, comprising a drive shaft and a second shaft coupled to the drive shaft via a spur gear connection forming a first gear stage. Furthermore, the transmission arrangement includes a housing comprising a housing pot and a housing cover, wherein the drive shaft is supported in the housing pot, wherein the second shaft is supported at least indirectly in the housing pot, and wherein the housing pot further comprises a bearing receptacle for supporting a third shaft.

The object of the present invention is to provide a drive train of the type mentioned at the outset, in which a particularly demand-oriented propulsion of a motor vehicle is made possible, and to provide a motor vehicle with such a drive train.

This problem is solved by a drive train with the features of claim 1 and by a motor vehicle with the features of claim 6. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

A first aspect of the invention relates to a drive train for a motor vehicle, comprising at least one drive motor and at least one transmission, which is designed to translate a rotational speed provided by means of the at least one drive motor and to transmit drive power provided by means of the at least one drive motor to at least one drive wheel of the motor vehicle.

According to the invention, the transmission comprises at least one helical gear stage and at least one second gear stage with the same direction of rotation as the first gear stage. This is advantageous because the helical gearing of the first gear stage results in lower noise generation, thus achieving better acoustics, particularly at lower vehicle speeds of, for example, up to 80 km/h, compared to the spur gearing of the second gear stage, which, however, enables particularly efficient operation, especially at higher vehicle speeds of, for example, above 80 km/h. In other words, the helical gears of the first gear stage, meshing with each other, enable particularly quiet operation at lower speeds, where noise in the drivetrain is more noticeable, whereas the spur gears of the second gear stage, meshing with each other, enable particularly efficient operation at higher speeds. At these higher vehicle speeds, where the vehicle can be driven via second gear, the louder noises in the drivetrain associated with the straight-cut gears, for example due to wind noise, are less noticeable to the driver than at lower speeds, where the vehicle can be driven via first gear. Overall, the drivetrain enables particularly demand-oriented propulsion of the vehicle, since when driving via first gear at low speeds, where, for example, wind noise is minimal or barely audible, the helical gearing of first gear ensures particularly quiet operation. whereas the increased noise generated by the straight-cut gears of the second gear stage is hardly noticeable when driving at higher speeds, but energy-saving operation is made possible by the straight-cut gears of the second gear stage.

The term "driving in the same direction" means that the drive motor can specify drive speeds with a single drive direction. While both the first and second gears, when driven in the same direction, can produce different output speeds due to their different gear ratios, they rotate in the same direction. The opposite would be true, for example, if the first gear were the forward gear and the second the reverse gear, as is the case with conventional transmissions, since the reverse gear does not drive in the same direction as the forward gear, but in the opposite direction.

In an advantageous embodiment of the invention, the at least one drive motor is designed as an electric motor. This is advantageous because the electric motor can be operated particularly efficiently and can generate its maximum drive torque even when accelerating a rotor shaft of the electric motor from a standstill.

In a further advantageous embodiment of the invention, the at least one transmission is designed as a spur gear transmission. This is advantageous because the spur gear transmission is particularly space-saving and can be manufactured with minimal production effort.

In a further advantageous embodiment of the invention, the at least one transmission is designed as a manual transmission and has a shifting device by means of which either the at least one helical gear stage or, alternatively, the at least one spur gear stage can be coupled to the at least one drive motor and the at least one drive wheel in a torque-transmitting manner. This is advantageous because the shifting device enables a particularly easy changeover between the first and second gear stages, i.e., it allows for particularly easy switching back and forth between the first gear stage (also referred to as first gear) and the second gear stage (also referred to as second gear). The transmission can generally be designed, for example, as a dual-clutch transmission in which the shifting device can perform clutch functions. Alternatively, the shifting device can also be designed as a dog clutch or as a clutch with synchronizing elements, for example, synchronizing rings, or synchro rings for short.

In a further advantageous embodiment of the invention, the at least one transmission comprises exclusively at least one helical-toothed first gear stage and at least one spur-toothed second gear stage. This is advantageous because, in this case, the transmission can have exactly two gear stages, namely the first gear stage and the second gear stage, so that further gear stages, such as a third and fourth gear stage, can be omitted, as can a reverse gear stage with a reversing direction (compared to the first and second gear stages) for reversing the vehicle. This makes the transmission particularly space-saving and easy to manufacture and maintain.

A second aspect of the invention relates to a motor vehicle with a drive train according to the first aspect of the invention. This motor vehicle can be operated in a particularly demand-oriented manner.

The preferred embodiments and their advantages presented with respect to one of the aspects apply accordingly to the other aspects of the invention and vice versa.

The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and/or shown in the figures alone, can be used not only in the combination specified in each case, but also in other combinations or on their own, without leaving the scope of the invention.

Further advantages, features and details of the invention will become apparent from the claims, the following description of preferred embodiments and the drawings.

• 1 eine schematische Darstellung eines Kraftfahrzeugs mit einem Antriebsstrang, dessen Getriebe eine schrägverzahnte erste Gangstufe und eine mit gleicher Drehrichtung wie die erste Gangstufe abtreibende zweite Gangstufe aufweist;
• 2 eine schematische Perspektivdarstellung der vereinzelt dargestellten ersten Gangstufe, deren jeweilige, in gegenseitigem Eingriff gezeigte, schrägverzahnte Zahnräder als Stirnräder ausgebildet sind; und
• 3 eine schematische Perspektivdarstellung der vereinzelt dargestellten zweiten Gangstufe, deren jeweilige, in gegenseitigem Eingriff gezeigte, geradverzahnte Zahnräder als Stirnräder ausgebildet sind.

The invention is explained below again using a specific embodiment. This is illustrated by:

• 1 a schematic representation of a motor vehicle with a drive train whose transmission has a helical first gear stage and a second gear stage driving in the same direction of rotation as the first gear stage;
• 2 a schematic perspective representation of the individually depicted first stage of the passage, whose respective, mutually interlocking The helical gears shown are designed as spur gears; and
• 3 a schematic perspective representation of the second gear stage shown in isolation, whose respective, mutually meshing, spur gears are designed as spur gears.

1 Figure 1 shows a schematic representation of a motor vehicle K with a drive train 10, by means of which the motor vehicle K can be driven.

The drive train 10 comprises a drive motor 20 designed as an electric motor and a gearbox 30, which is designed to translate a rotational speed provided by the drive motor 20 and to transmit drive power provided by the drive motor 20 to the respective drive wheels 70 of the motor vehicle K. The drive motor 20 is coupled to the gearbox 30 via a drive shaft 28. The drive shaft 28 can be coupled to a rotor shaft (not shown) of a rotor of the drive motor 20 (not shown) for torque transmission.

The gearbox 30, designed as a spur gear gearbox, has a low-noise first gear stage 40, which is helical-toothed, and an efficient second gear stage 50, which is straight-toothed.

A first helical gear 42 of the first gear stage 40 is rotatably mounted on the drive shaft 28. Furthermore, a first spur gear 52 of the second gear stage 50 is rotatably mounted on the drive shaft 28.

A second helical gear 44 of the first gear stage 40 is mounted non-rotatably on an output shaft 68 of the transmission 30, which is arranged parallel to the input shaft 28. Furthermore, a second spur gear 54 of the second gear stage 50 is mounted non-rotatably on the output shaft 68. The output shaft 68 can be torque-transmittingly coupled to the drive wheels 70 via a differential gear of the drive train 10 (not shown).

A shifting device 60 of the transmission allows switching back and forth between first gear 40 and second gear 50 as needed, i.e., engaging either first gear 40 or second gear 50. To engage first gear 40, the shifting device 60 can establish a rotationally fixed connection between the first helical gear 42 and the drive shaft 28, while the first spur gear 52 can rotate relative to and around the drive shaft 28. To engage second gear 50, the shifting device 60 can establish a rotationally fixed connection between the first spur gear 52 and the drive shaft 28, while the first helical gear 42 can rotate relative to and around the drive shaft 28.

With the direction of rotation of the drive shaft 28, and thus of the rotor shaft of the drive motor 20, remaining constant, the first gear stage 40 and the second gear stage 50 each have the same direction of rotation 12 with respect to the drive shaft 68. In other words, the direction of rotation 12 of the drive shaft 68 is the same for both gear stages 40 and 50.

In summary, the switching device 60 can be used to selectively couple the helical first gear stage 40 or alternatively the spur gear second gear stage 50 with the at least one drive motor 20 and the drive wheels 70 in a torque-transmitting manner, wherein the first gear stage 40 and the second gear stage 50 have the same direction of rotation 12 with respect to the output shaft 68.

In this case, the transmission 30 has no further gears besides the first gear 40 and the second gear 50, in particular no reverse gear. In other words, the transmission 30 has only the helical first gear 40 and the spur gear second gear 50.

2 The first gear stage 40 is shown schematically again in isolated representations, in which the first helical gear 42 is in engagement with the second helical gear 44.

3 In contrast, the second gear stage 50 is shown schematically in isolated representations, in which the first straight-toothed gear 52 is in engagement with the second straight-toothed gear 54.

When considering the combination of 2 and 3 It is noticeable that the first gear (40) has a shorter gear ratio than the second gear (50). In other words, the second gear (50) has a longer gear ratio than the first gear (40).

Overall, the first gear stage 40, which can be described as the first short gear, enables quiet operation of the motor vehicle K with favorable acoustics due to its helical gearing (first helical gear 42, second helical gear 44). especially with low noise levels. In contrast to the first gear stage 40, the second gear stage 50, which can be described as the second long gear, enables more efficient driving of the motor vehicle K with lower losses but greater noise levels due to its straight-cut teeth (first straight-cut gear 52, second straight-cut gear 54).

The motor vehicle K can, for example, be designed as a sports car in which the second gear stage has a long ratio of 50 and is equipped with straight teeth, resulting in a higher range than with helical teeth in the second gear stage 50 due to the efficient driving operation.

Reference symbol list

10

Powertrain

12

Direction of rotation

20

drive motor

28

drive shaft

30

transmission

40

first gear

42

first helical gear

44

second helical gear

50

second gear

52

first straight-toothed gear

54

second straight-toothed gear

60

Switching device

68

Output shaft

70

drive wheel

K

motor vehicle

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 10 2009 001 147 A1 [0002]
• DE 10 2012 111 847 A1 [0003]

Claims (6)

Drive train (10) for a motor vehicle (K), comprising at least one drive motor (20) and at least one transmission (30), which is designed to translate a rotational speed provided by means of the at least one drive motor (20) and to transmit drive power provided by means of the at least one drive motor (20) to at least one drive wheel (70) of the motor vehicle (K), characterized in that the transmission (30) has at least one helical gear stage (40) and at least one second gear stage (50) driving with the same direction of rotation (12) as the at least one first gear stage (40). Powertrain (10) Claim 1 , characterized in that the at least one drive motor (20) is designed as an electric motor. Powertrain (10) Claim 1 or 2 , characterized in that the at least one transmission (30) is designed as a spur gear transmission. Drive train (10) according to one of the preceding claims, characterized in that the at least one transmission (30) is designed as a gearbox and has a shifting device (60) by means of which either the at least one helical gear stage (40) or alternatively the at least one spur gear stage (50) can be coupled to the at least one drive motor (20) and the at least one drive wheel (70) in a torque-transmitting manner. Drive train (10) according to one of the preceding claims, characterized in that the at least one transmission (30) exclusively comprises the at least one helical first gear stage (40) and the at least one spur gear second gear stage (50). Motor vehicle (K) with a drive train (10) according to one of the preceding claims.