阅读说明：本技术 车辆的传动系统 (Transmission system of vehicle ) 是由 R·M·范德鲁滕 于 2018-04-18 设计创作，主要内容包括：用于车辆的传动系统具有被布置成用于连接到驱动源的输入和被布置成用于连接到负载的输出。该传动系统包括传动装置。传动装置包括第一输入轴杆、连接至输出的第一输出轴杆、以及连接第一输入轴杆和第一输出轴杆的第一变速挡位、以及第二输入轴杆、连接至输出的第二输出轴杆、以及连接第二输入轴杆和第二输出轴杆的第二变速挡位。传动装置包括第一耦合构件和第二耦合构件,第一耦合构件被布置成用于以第一速度比将输入耦合至第一输入轴杆,第二耦合构件被布置成用于以第二速度比将输入耦合至第二输入轴杆。该第一和第二变速挡位一起包括多个传动挡位,其中传动挡位被布置成使得通过交替地接合第一耦合构件和第二耦合构件来实现藉由相应的第一、第二、第三、第四、第五和第六挡位的连续换挡。(A driveline for a vehicle has an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, and a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The transmission comprises a first coupling member arranged for coupling the input to the first input shaft at a first speed ratio and a second coupling member arranged for coupling the input to the second input shaft at a second speed ratio. The first and second gear shift stages together comprise a plurality of transmission stages, wherein the transmission stages are arranged such that successive gear shifts by the respective first, second, third, fourth, fifth and sixth gear stages are achieved by alternately engaging the first coupling member and the second coupling member.)

1. A transmission system for a vehicle, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

a first coupling member comprising a first friction element, the first coupling member having a first section connected to the input and a second section connected to a first input shaft of the transmission, and

a second coupling member comprising a second friction element, the second coupling member having a third section connected to the input and a fourth section connected to a second input shaft of the transmission,

wherein the first and/or second transmission gear is axially positioned between the first friction element and the second friction element.

2. A transmission system according to claim 1, characterised in that the first friction element is arranged at a first end of the transmission and/or the second friction element is arranged at an opposite second end of the transmission, for example on one side of the drive source.

3. A transmission system according to claim 1 or 2, characterised in that the first and/or second coupling member comprises a friction clutch, such as a wet or dry disc friction clutch.

4. A transmission system as claimed in claim 1, 2 or 3, characterised in that the first and/or second coupling member comprises a planetary gear set comprising at least three rotational members and one friction brake.

5. A transmission system as claimed in claim 1, 2 or 3, characterised in that the first coupling member comprises a planetary gear set comprising at least three rotational members and one friction brake and the second coupling member comprises a clutch.

6. The transmission system of claim 5, wherein a second coupling member is positioned at a front end of the transmission on the drive source side, and the first coupling member is positioned on an opposite side of the transmission.

7. A transmission system according to any one of the preceding claims, characterised in that the first and/or second coupling member comprises a planetary gear set comprising at least four rotational members and two friction brakes.

8. A transmission system according to any one of claims 4 to 7, characterised in that the rotary members of the planetary gear sets are directly connected to the gear wheel of the first or second speed gear.

9. A transmission system according to any one of claims 4 to 8, characterised in that at least one rotary member of the planetary gear set is positioned at least partly inside a gear wheel of the first or second speed gear.

10. A transmission system according to any one of the preceding claims, characterised in that the first and second speed gears each comprise a radially offset input gear and output gear.

11. The transmission system of claim 10, wherein the first and second shift gears each include one or more transmission gears, each transmission gear including a radially offset input gear and an output gear, except for a reverse gear.

12. A transmission system according to any one of the preceding claims, wherein a further coupling member is located between the first and second input shafts.

13. The transmission system according to any one of the preceding claims, wherein the first gear shift stage comprises a reverse transmission stage.

14. A transmission system according to claim 13, characterised in that the first and/or second speed change gear comprises a transmission gear coupled to the reverse transmission gear, such as the second transmission gear.

15. A transmission system for a vehicle, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

wherein the first shift gear comprises a reverse gear, and

wherein the second shift gear comprises a gear coupled to the reverse gear, such as a second gear.

16. A transmission system according to any one of claims 13 to 15, characterised in that the first and/or second gear change steps comprise transmission steps coupled to the reverse transmission step, for example fourth and/or fifth transmission steps, so as to form additional transmission steps, such as the first and/or second transmission steps.

17. A transmission system for a vehicle, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

wherein the first shift gear comprises a reverse drive gear, and

wherein the forward gear is formed using at least one gear of said reverse drive gear.

18. The transmission system of claim 17, wherein an additional forward gear is formed using at least one gear of a forward drive gear and at least one gear of the reverse drive gear.

19. A transmission system according to any one of claims 13 to 18, characterised in that the reverse gear is connected to the first input shaft and/or the first output shaft via a coupling member.

20. A transmission system according to any one of the preceding claims, including an initial coupling member positioned in an input of the transmission system to enable coupling of the transmission to the drive source or additional machine.

21. A transmission system according to claim 20, wherein an initial coupling member connects the input to the first or second coupling member.

22. A transmission system according to claim 20 or 21, wherein the additional machine is an electrical machine such as an electric motor or generator.

23. A transmission system according to any one of claims 20 to 22, characterised in that the additional machine is connected to the output of the initial coupling member and the input of the second coupling member.

24. A transmission system according to any one of claims 20 to 23, characterised in that the initial coupling member and/or the second coupling member are located axially within the additional machine.

25. The transmission system according to any one of claims 20 to 23, wherein the additional machine is positioned radially offset relative to the initial coupling member.

26. A transmission system according to any one of claims 20 to 25, wherein the initial coupling member is normally open.

27. A transmission system according to any one of the preceding claims, characterised in that the second coupling member is arranged for actuation via an axial thrust bearing.

28. A transmission system according to any one of the preceding claims, characterised in that the first and second speed changing gears together comprise a plurality of transmission gears, wherein the transmission gears are arranged such that by alternately engaging the first coupling member and the second coupling member, continuous gear shifting by means of the respective first, second, third, fourth, fifth and sixth gears is achieved.

29. A transmission system for a vehicle, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft;

a first coupling member arranged to couple the input to the first input shaft at a first speed ratio; and

a second coupling member arranged to couple the input to the second input shaft at a second speed ratio, wherein the first and second speed ratios are different;

wherein the first and second gear shift stages together comprise a plurality of transmission stages, wherein the transmission stages are arranged such that continuous gear shifting by the respective first, second, third, fourth, fifth and sixth gears is achieved by alternately engaging the first coupling member and the second coupling member.

30. A transmission system according to any one of the preceding claims, wherein the first and second speed change gears together comprise:

a set of transmission gears, each transmission gear comprising an input gear and an output gear, wherein the input gear is connected or connectable to the first or second input shaft and the output gear is connected or connectable to the first or second output shaft; and

a coupling gear comprising a first coupling gear rotationally coupled to a second coupling gear, wherein the first coupling gear meshes with a gear of a first transmission gear of the set of transmission gears and the second coupling gear meshes with a gear of a second transmission gear of the set of transmission gears.

31. A transmission system for a vehicle, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft;

a first coupling member arranged to couple the input to the first input shaft at a first speed ratio; and

a second coupling member arranged to couple the input to the second input shaft at a second speed ratio, wherein the first and second speed ratios are different;

wherein the first and second shift gears together comprise:

a set of transmission gears, each transmission gear comprising an input gear and an output gear, wherein

The input gear is connected or connectable to the first or second input shaft and the output gear is connected or connectable to the first or second output shaft; and

a coupling gear comprising a first coupling gear rotationally coupled to a second coupling gear, wherein the first coupling gear meshes with a gear of a first transmission gear of the set of transmission gears and the second coupling gear meshes with a gear of a second transmission gear of the set of transmission gears.

32. A transmission system according to any one of claims 28-31, characterised in that the first coupling gear meshes with the output gear of a first transmission gear of the set of transmission gears and the second coupling gear meshes with the output gear of a second transmission gear of the set of transmission gears, or

The first coupling gear meshes with an input gear of a first transmission gear of the set of transmission gears, and the second coupling gear meshes with an input gear of a second transmission gear of the set of transmission gears.

33. A transmission system according to claim 30, 31 or 32, wherein the first and second coupling gears are both mounted to a common coupling shaft.

34. A transmission system according to claim 30, 31, 32 or 33, characterised in that the first coupling gear meshes with the gear wheel of the first/second transmission gear and the second coupling gear meshes with the gear wheel of the fourth transmission gear.

35. A transmission system according to any one of the preceding claims, characterised in that the input and output gears of one of the set of transmission gears are radially offset.

36. The transmission system according to claim 35, wherein each transmission gear of said set of transmission gears includes a radially offset input gear and an output gear.

37. A transmission system according to any one of the preceding claims, characterised in that the first coupling member is arranged for coupling the input to the first input shaft while reducing the rotational speed in the coupled condition; and

the second coupling member is arranged for coupling the input to the second input shaft while maintaining a rotational speed in the coupled condition.

38. A transmission system according to any one of the preceding claims, characterised in that the first coupling member is arranged for reducing the rotational speed of the first input shaft by a factor between more than 1 and 2 relative to the rotational speed of the input, wherein the factor is preferably between 1.2 and 1.7, more preferably between 1.3 and 1.5.

39. A vehicle comprising a transmission system according to any one of claims 1 to 38.

40. A method for operating a driveline of a vehicle, the driveline having an input arranged for connection to a drive source and an output arranged for connection to a load, the driveline comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

a first coupling member comprising a first friction element, the first coupling member having a first section connected to the input and a second section connected to a first input shaft of the transmission, and

a second coupling member comprising a second friction element, the second coupling member having a third section connected to the input and a fourth section connected to a second input shaft of the transmission,

wherein the first and/or second transmission gear is axially positioned between the first friction element and the second friction element.

41. A method for operating a driveline of a vehicle, the driveline having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

wherein the first gear shift stage comprises a reverse gear,

the method includes forming a forward gear by driving a gear coupled with the gear of the reverse gear and connected with the first or second output shaft.

42. A method for operating a driveline of a vehicle, the driveline having an input arranged for connection to a drive source and an output arranged for connection to a load, and comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

wherein the first gear shift stage comprises a reverse drive stage,

the method includes forming a forward gear using at least one gear of the reverse drive gear.

43. A method for operating a driveline of a vehicle, the driveline having an input arranged for connection to a drive source and an output arranged for connection to a load, the driveline comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft,

a first coupling member arranged to couple the input to the first input shaft at a first speed ratio; and

a second coupling member arranged for coupling the input to the second input shaft at a second speed ratio, wherein the first and second speed ratios are different,

wherein the first and second gear shift stages comprise a plurality of transmission stages, wherein the transmission stages are arranged such that continuous gear shifting by the respective first, second, third, fourth, fifth and sixth gears is achieved by alternately engaging the first coupling member and the second coupling member,

the method includes effecting successive shifts by respective first, second, third, fourth, fifth and sixth gears by alternately engaging the first coupling member and the second coupling member.

44. A method for operating a driveline of a vehicle, the driveline having an input arranged for connection to a drive source and an output arranged for connection to a load, the driveline comprising:

a transmission device, the transmission device comprising

A first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft, an

A second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft;

a first coupling member arranged to couple the input to the first input shaft at a first speed ratio; and

a second coupling member arranged to couple the input to the second input shaft at a second speed ratio, wherein the first and second speed ratios are different;

wherein the first and second shift gears together comprise:

a set of transmission gears, each transmission gear comprising an input gear and an output gear, wherein the input gear is connected or connectable to the first or second input shaft and the output gear is connected or connectable to the first or second output shaft; and

a coupling gear comprising a first coupling gear rotationally coupled to a second coupling gear, wherein the first coupling gear meshes with a gear of a first transmission gear of the set of transmission gears and the second coupling gear meshes with a gear of a second transmission gear of the set of transmission gears.

Technical Field

The present invention relates to a transmission system for a vehicle having an input arranged for connection to a drive source and an output arranged for connection to a load.

Background

Transmission systems (such as automatic transmission systems for vehicles) are known. Such a transmission system typically has an input arranged for connection to a drive source, such as an internal combustion engine, and an output arranged for connection to a load, such as the driveline of a vehicle. One type of transmission system includes a transmission (transmission) that includes a first input shaft (draft), a first output shaft connected to the output, and a first gear shift stage (speed transforming gear) between the first input shaft and the first output shaft, and a second input shaft, a second output shaft connected to the output, and a second gear shift stage between the second input shaft and the second output shaft. Thus, different gears (such as first, second, third) may be associated with the first or second input shaft and may be individually selected.

WO2011/133033a1 describes a transmission system comprising: a first coupling member having a first section connected to the input and a second section connected to a first input shaft of the transmission; and a second coupling member having a third section connected to the input and a fourth section connected to the second input shaft of the transmission.

Disclosure of Invention

It is an object to provide a transmission system which is more cost-effective than the known transmission systems. Alternatively or additionally, it is an object to provide a transmission system that allows smooth shifting through successive gears. Alternatively or additionally, it is an object to provide a transmission system that is flexible in selecting transmission gears.

More generally, it is an object to provide an improved or at least alternative transmission system.

According to one aspect, a transmission system for a vehicle, such as an automatic transmission system, is provided. The transmission system has an input arranged for connection to a drive source, such as an internal combustion engine and/or an electric motor. The transmission system has an output arranged for connection to a load, such as a wheel of a vehicle. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft.

In this context, the term gear shift is used to denote a combination of gears (e.g. gear pairs) that transforms the rotational speed at the respective input shaft to a (lower, equal or higher) rotational speed at the respective output shaft. The transmission system allows the vehicle to be operated in different gears, such as reverse, first, second, third, fourth, fifth, etc. Each shift gear is associated with one or more transmission gears. Herein, a transmission gear refers to a combination of gears (e.g., gear pair) that cause the transmission to operate in a predetermined gear. For example, a first transmission gear causes the transmission to operate in a first gear, a second transmission gear causes the transmission to operate in a second gear, and so on. It will be appreciated that different transmission gears may share one or more gears. For example, first/second transmission gear refers to a combination of gears (e.g., gear pairs) that cause the transmission to operate in either first or second gear, e.g., depending on the setting of the coupling member of the transmission system.

According to this aspect, the transmission system comprises a first coupling member comprising a first friction element, the first coupling member having a first section connected to the input and a second section connected to the first input shaft of the transmission. The transmission system comprises a second coupling member comprising a second friction element, the second coupling member having a third section connected to the input and a fourth section connected to a second input shaft of the transmission. The first and/or second transmission gear is positioned between the first friction element and the second friction element. The first and/or second transmission gear may be positioned between the first and second friction elements in an axial direction of the transmission system. The axial direction of the transmission system may be defined as the axial direction of the rotational axis of the first and/or second friction element. The first and/or second gear shift stage is preferably physically located between the first and second friction elements. The first and/or second gear shift positions may be positioned at one or more planes between the plane in which the first friction element extends and the plane in which the second friction element extends. This provides the advantage that the mechanical layout of the components of the transmission system can be simplified and/or made more compact.

Optionally, the first friction element is arranged at a first end of the transmission and/or the second friction element is arranged at an opposite second end of the transmission, e.g. at a side of the drive source.

Optionally, the first and/or second coupling member comprises (e.g. is) a friction clutch, such as a wet or dry disc friction clutch.

Optionally, the first and/or second coupling member comprises (for example) a planetary gear set (planetary gear set) comprising at least three rotational members and a friction element, such as a brake. The at least three rotating members may include a sun gear, a planet carrier, and a ring gear.

Optionally, the first coupling member comprises a planetary gear set. The first section of the first coupling member may be associated with a first rotating member of the planetary gear set. The second section of the first coupling member may be associated with a second rotating member of the planetary gear set. The third rotating member of the planetary gear set may be associated with a first friction element (such as a friction brake).

Optionally, the first and/or second coupling member comprises (for example is) a planetary gear set comprising at least four rotational members and two brakes. The first section of the first coupling member may be associated with a first rotating member of the planetary gear set. The second section of the first coupling member may be associated with a second rotating member of the planetary gear set. The third rotating member of the planetary gear set may be associated with a first friction element (such as a first friction brake). The fourth rotating member of the planetary gear set may be associated with another friction element (such as a second friction brake).

Optionally, the first coupling member comprises a planetary gear set and the second coupling member comprises a friction clutch. The friction clutch may be positioned on a drive source side of the transmission system, such as at a forward end of the transmission system, e.g., near an engine flywheel and/or an input shaft of the transmission, and the friction elements of the planetary gear sets may be positioned on an opposite side of the transmission system, e.g., at a rear end of the transmission system. Here, the rotary members of the planetary gear set may be axially positioned between the friction clutches and the friction brakes of the planetary gear set. The first and/or second transmission gear may be positioned between the rotational member of the planetary gear set and the friction brake in an axial direction of the transmission system. A first rotating member of the planetary gear set may be connected to the input. The second rotating member of the planetary gear set may be connected to the first input shaft. The third rotating member of the planetary gear set may be connected to the first friction element.

At least one of the rotating members of the planetary gear sets (e.g., the sun gear, the planet carrier, and the ring gear of the planetary gear set) may be positioned on one side of the transmission (e.g., the drive source side), and the friction elements of the planetary gear sets may be positioned on the opposite side of the transmission.

Optionally, a rotating member (such as a planet carrier) of the planetary gear set is directly connected to a gear of the first or second speed change gear. Thus, the number of components can be reduced. Optionally, the rotary member is directly connected to the gear wheel of the higher transmission gear (e.g. sixth or seventh gear or highest gear). Such gears in high gears may have a large radius compared to the gears of other transmission gears.

Optionally, at least one rotating member of the planetary gear set is positioned at least partially inside a gear of the first or second speed change gear. A compact construction can thus be achieved.

Optionally, the first and second gear shift positions comprise an input gear and an output gear, respectively, that are radially offset (i.e. have non-coincident shafts). Optionally, the first and second transmission gears each comprise one or more transmission gears. Optionally, each transmission gear includes a radially offset input gear and output gear in addition to the reverse gear. The reverse gear may include an input gear, an output gear, and an intermediate gear that are all radially offset.

Optionally, the first and second speed gears are free of planetary gear sets. Optionally, the first and second gear shift stages comprise gears mounted on shafts that are stationary relative to each other.

Optionally, a further coupling member (such as a further clutch) is located between the first and second input shafts. The further coupling member may then, for example, directly couple the first and second input shafts to each other without using further gear shift steps.

Optionally, the first and/or second transmission gear comprises a reverse gear. Optionally, the reverse gear does not reverse the direction of rotation between the first input shaft and the first output shaft of the transmission. The second shift gear may include a transmission gear directly coupled to the reverse gear, such as the second gear. Furthermore, the gear wheel of the reverse gear can mesh with the gear wheel of the directly coupled transmission gear. This allows a reduction in the number of components and/or a reduction in the number of larger gears and/or a compact construction.

According to one aspect, a transmission system for a vehicle, such as an automatic transmission system, is provided. The transmission system has an input arranged for connection to a drive source, such as an internal combustion engine and/or an electric motor. The transmission system has an output arranged for connection to a load, such as a wheel of a vehicle. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft.

According to this aspect, the transmission system comprises a first coupling member arranged for selectively coupling the input to the first input shaft at a first speed ratio. Thus, optionally, in addition to coupling the input to the first input shaft, the first coupling member may also transform the rotational speed at the input to a (lower, equal or higher) rotational speed at the first input shaft. The transmission system comprises a second coupling member arranged for selectively coupling the input to the second input shaft at a second speed ratio. Thus, optionally, in addition to coupling the input to the second input shaft, the second coupling member may also transform the rotational speed at the input to a (lower, equal or higher) rotational speed at the second input shaft. The first speed ratio is different from the second speed ratio. Hence, at least one of the first or second coupling members is arranged for transforming the rotational speed at the input into a (lower, equal or higher) rotational speed at the respective first or second input shaft.

The first and second gear shift stages together comprise a plurality of transmission stages. The transmission gears are arranged such that by alternately engaging the first coupling member and the second coupling member, a continuous shift by the respective first, second, third, fourth, fifth and sixth gears is achieved. This allows smooth shifting without switching the intermediate gear to the next gear while maintaining torque.

Optionally, the first and second shift gears together comprise a set of transmission gears. Each transmission gear of the set of transmission gears includes an input gear and an output gear. The input gear is connected or connectable to the first or second input shaft. The output gear is connected or connectable to the first or second output shaft. The first and second gear shift stages together comprise a coupling gear comprising a first coupling gear wheel rotationally coupled to a second coupling gear wheel. It will be appreciated that the linked gear may be comprised by the first gear shift stage, by the second gear shift stage or by both the first and second gear shift stages. The first coupling gear meshes with a gear of a first transmission gear of the set of transmission gears, and the second coupling gear meshes with a gear of a second transmission gear of the set of transmission gears.

According to one aspect, a transmission system for a vehicle is provided, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The transmission system comprises a first coupling member arranged for selectively coupling the input to the first input shaft at a first speed ratio. The transmission system comprises a second coupling member arranged for selectively coupling the input to the second input shaft in a second speed ratio, wherein the first and second speed ratios are different. The first and second gear shift stages together comprise a set of transmission stages, each transmission stage comprising an input gear and an output gear, wherein the input gear is connected or connectable to a first or second input shaft and the output gear is connected or connectable to a first or second output shaft. The first and second shift gears together comprise a coupling gear comprising a first coupling gear rotationally coupled to a second coupling gear. The first coupling gear meshes with a gear of a first transmission gear of the set of transmission gears, and the second coupling gear meshes with a gear of a second transmission gear of the set of transmission gears.

Optionally, the first coupling gear meshes with an output gear of a first transmission gear of the set of transmission gears, and the second coupling gear meshes with an output gear of a second transmission gear of the set of transmission gears. Optionally, the first coupling gear meshes with the input gear of a first transmission gear of the set of transmission gears, and the second coupling gear meshes with the input gear of a second transmission gear of the set of transmission gears.

Optionally, the first transmission gear of the set of transmission gears is a forward gear and the second transmission gear of the set of transmission gears is a forward gear. Alternatively, the first transmission gear of the set of transmission gears is a forward gear and the second transmission gear of the set of transmission gears is a reverse gear.

Optionally, both the first coupling gear and the second coupling gear are mounted to a common coupling shaft.

Optionally, the first coupling gear meshes with the gear of the first/second transmission gear and the second coupling gear meshes with the gear of the fourth transmission gear.

Optionally, the input gear and the output gear of one of the set of transmission gears are radially offset.

Optionally, each transmission gear of the set of transmission gears comprises a radially offset input gear and output gear.

Optionally, the first coupling member is arranged for coupling the input to the first input shaft while reducing the rotational speed in case of coupling. Optionally, the second coupling member is arranged for coupling the input to the second input shaft while maintaining the rotational speed in the coupled condition. The first coupling member may be arranged for reducing the rotational speed of the first input shaft by a factor between more than 1 and 2 relative to the rotational speed of the input. Optionally, the factor is between 1.2 and 1.7. Optionally, the factor is between 1.3 and 1.5.

According to one aspect, a transmission system for a vehicle, such as an automatic transmission system, is provided. The transmission system has an input arranged for connection to a drive source, such as an internal combustion engine and/or an electric motor. The transmission system has an output arranged for connection to a load, such as a wheel of a vehicle. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The first shift gear includes a reverse gear. The second gear shift stage includes a stage coupled (e.g., directly coupled) to the reverse gear, such as the second gear. Furthermore, the gear wheel of the reverse gear can mesh with the gear wheel of the directly coupled transmission gear.

Optionally, the second gear shift stage comprises a gear wheel directly coupled to the reverse gear (e.g. of the fifth gear) for forming an additional gear, e.g. the second gear.

Optionally, the first and/or second gear shift positions comprise (e.g. forward) transmission gears (e.g. fourth and/or fifth transmission gears) which are coupled to the reverse transmission gears so as to form additional (e.g. forward) transmission gears, such as the first and/or second transmission gears.

According to one aspect, a transmission system for a vehicle is provided, the transmission system having an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The first shift gear comprises a reverse drive gear. The forward gear is formed using at least one gear of the reverse transmission gear.

Optionally, additional (e.g. forward) gears are formed using at least one gear of the forward drive gear and at least one gear of the reverse drive gear. Optionally, the additional gears are formed using one or more additional gears mounted on an additional shaft that is mounted radially offset from the first and second input shafts and/or the first and second output shafts.

Optionally, the reverse gear is connected to the first input shaft and/or the first output shaft via a coupling member.

Optionally, the transmission system comprises a first gear, a second gear, a fourth gear and a fifth gear, wherein the gears of the first and second gears are mounted on a common shaft.

Optionally, the transmission system includes an initial coupling member, such as a friction element, connected between the input of the transmission system and the second coupling member. Additional machines may be connected to the output of the initial coupling member and the input of the second coupling member. The initial coupling member enables coupling of the transmission to the drive source and/or additional machines. The drive source may be, for example, an internal combustion engine. The additional machine may be an electric machine, such as an electric motor or generator. Thus, the initial coupling member may for example enable selection of an internal combustion engine, or an electric machine (e.g. an electric motor), or both.

Optionally, the initial coupling member and/or the second coupling member are located axially within the additional machine. For example, the motor may be arranged concentrically with the initial coupling member.

Optionally, the additional machine is positioned radially offset relative to the initial coupling member. The additional machine may be coupled to the initial coupling member, for example, via one or more gears.

Optionally, the initial coupling member is normally open, so that the drive source does not engage with the unactuated initial coupling.

Optionally, the second coupling member is arranged for actuation via an axial thrust bearing.

The planetary gear set may be present in a space between a transmission housing of the transmission and a partition (partition) attached to the outside of the transmission housing. Preferably, however, the planetary gear set is not present in a space between the transmission housing and a partition attached to the outside of the transmission housing. The planetary gear set may be located inside the transmission housing, where the planetary gear set may be located in a subspace separated from the transmission by a partition (if any). The planetary gear sets may also be located outside of the transmission housing in separate wet or dry spaces.

The gear ratios of the planetary gear set and the transmission may be selected such that the lowest forward gear of the transmission system may be achieved by closing the friction elements of the planetary gear set.

Optionally, the first and second rotational members of the planetary gear set are directly coupled to each other by means of the second coupling member and a further coupling member connected in series therewith, such as a further friction clutch, without the use of further gear steps. The further coupling member may then be located in the transmission between the first and second input shafts. The further coupling member may then directly couple the first and second input shafts to each other without using further gear shift steps.

According to one aspect, a vehicle is provided comprising a transmission system as described above.

According to one aspect, a method for operating a driveline of a vehicle is provided. The transmission system has an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The transmission system comprises a first coupling member arranged for coupling the input to the first input shaft at a first speed ratio. The transmission system comprises a second coupling member arranged for coupling the input to the second input shaft at a second speed ratio. The first and second speed ratios are different. The first and second shift gears include a plurality of transmission gears. The transmission gears are arranged such that by alternately engaging the first coupling member and the second coupling member, a continuous shift by the respective first, second, third, fourth, fifth and sixth gears is achieved. The method includes effecting successive shifts by respective first, second, third, fourth, fifth and sixth gears by alternately engaging the first coupling member and the second coupling member.

According to one aspect, a method for operating a driveline of a vehicle is provided. The transmission system has an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The transmission system comprises a first coupling member arranged for coupling the input to the first input shaft at a first speed ratio. The transmission system comprises a second coupling member arranged for coupling the input to the second input shaft at a second speed ratio. The first and second speed ratios are different. The first and second gear shift stages together comprise a set of transmission stages, each transmission stage comprising an input gear and an output gear, wherein the input gear is connected or connectable to a first or second input shaft and the output gear is connected or connectable to a first or second output shaft. The first and second gear change steps together comprise a coupling step comprising a first coupling gear wheel rotationally coupled to a second coupling gear wheel, wherein the first coupling gear wheel meshes with a gear wheel of a first transmission step of the set of transmission steps and the second coupling gear wheel meshes with a gear wheel of a second transmission step of the set of transmission steps.

According to one aspect, a method for operating a driveline of a vehicle is provided. The transmission system comprises an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The transmission system includes a first coupling member including a first friction element, the first coupling member having a first section connected to the input and a second section connected to a first input shaft of the transmission. The transmission system comprises a second coupling member comprising a second friction element, the second coupling member having a third section connected to the input and a fourth section connected to a second input shaft of the transmission. The first and/or second gear shift stage is axially positioned between the first and second friction elements.

According to one aspect, a method for operating a driveline of a vehicle is provided. The transmission system comprises an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The first shift gear includes a reverse gear. The method includes forming a forward gear by driving a gear coupled with a gear of a reverse gear and connected with the first or second output shaft.

According to one aspect, a method for operating a driveline of a vehicle is provided. The transmission system comprises an input arranged for connection to a drive source and an output arranged for connection to a load. The transmission system includes a transmission. The transmission includes a first input shaft, a first output shaft connected to the output, and a first shift gear connecting the first input shaft and the first output shaft. The transmission includes a second input shaft, a second output shaft connected to the output, and a second shift gear connecting the second input shaft and the second output shaft. The first shift gear comprises a reverse drive gear. The method includes forming a forward gear using at least one gear of the reverse drive gear.

It will be appreciated that any one or more of the above-described aspects, features and options may be combined. It will be appreciated that any one option described in view of one of the aspects may be equally applied to any other aspect. It will also be apparent that all aspects, features and options described in view of the transmission system apply equally to the vehicle and method.