Device for a motor vehicle with a dual clutch gearbox

Abstract

An apparatus having a dual clutch transmission includes: an input shaft connected to a power source of a vehicle; a first shaft carrying a plurality of first and fifth gears; a second shaft carrying a plurality of second gears; an output shaft connected to an axle of the vehicle and carrying a plurality of third gears engaged with the first gear, a plurality of fourth gears engaged with the second gear, and a sixth gear engaged with the fifth gear; a dual clutch connecting one of the first and second shafts with the input shaft; a first engagement device rotationally securing a relative one of the first engageable gears to the first shaft; a second engagement device rotationally securing a relative one of the second engageable gears to the second shaft; a third engagement device rotationally secures an opposing one of the third engageable gears to the output shaft. The apparatus also includes a motor generator having a rotor coupled to the fifth gear by a transmission.

Description

[0001] Cross - reference to related applications

[0002] This patent application claims priority to Italian Patent Application No. 102024000000330, filed on January 10, 2024, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] The present invention relates to a device for a motor vehicle having a dual - clutch transmission. Background art

[0004] It is known that some hybrid electric motor vehicles (i.e., equipped with an internal combustion engine and at least one electric generator for propulsion) are equipped with a dual - clutch transmission.

[0005] Generally, a dual - clutch transmission includes a countershaft or output shaft that defines the transmission output or is connected to at least one axle of the motor vehicle, and two main shafts that are respectively connected to the input end of the transmission by means of corresponding clutches arranged in parallel and defining a dual - clutch.

[0006] The two main shafts respectively carry a first gear and a second gear, which respectively determine a first set of gear mechanisms (usually an even number of gear mechanisms) and a second set of gear mechanisms (usually an odd number of gear mechanisms) by meshing with corresponding third gears carried by the countershaft.

[0007] For the engagement of one of the gear mechanisms, one of the two gears forming the gear mechanism to be engaged is rotated and fixed to the relative bearing shafts of the main shaft and the countershaft by means of an engagement device (such as a synchronizer), while the other of the two gears is itself configured to be rotationally fixed to the relative bearing shafts of the countershaft and the main shaft.

[0008] In some cases, the electric generator has a rotor that is connected to one of the gears carried by one of the main shafts and is rotatably attached to one of the main shafts by means of a relative engagement device.

[0009] In this way, by means of the rear engagement device, the electric generator can be selectively connected to the internal combustion engine to start the internal combustion engine or generate electrical energy by means of the power provided by the internal combustion engine.

[0010] However, with this transmission structure, the connection between the internal combustion engine and the electric generator also means transmitting torque to the wheels, because the gear mechanism including the gear connected to the rotor of the electric generator is inevitably engaged.

[0011] Therefore, a disadvantage associated with the above - mentioned structure is that when the wheels are not moving, the internal combustion engine and the electric generator cannot be connected.

[0012] Therefore, it is necessary to provide a dual-clutch transmission that does not have the above-mentioned disadvantages and at the same time avoids the structure of the transmission itself from being too complex.

[0013] The object of the present invention is to preferably meet the above requirements in a simple and reliable manner. Summary of the Invention

[0014] The present invention provides a device for a motor vehicle having a dual-clutch transmission, the dual-clutch transmission comprising: an input shaft connected to a power source of the motor vehicle; a first shaft carrying a plurality of first gears and a fifth gear, each of the first gears being carried in a fixed manner by the first shaft so as to define an element of a first rotationally fixed gear set, or being carried in a rotatable manner relative to the first shaft so as to define an element of a first engageable gear set;

[0015] - a second shaft carrying a plurality of second gears, each of the second gears being carried in a fixed manner by the second shaft so as to define an element of a second rotationally fixed gear set, or being carried in a rotatable manner relative to the second shaft so as to define an element of a second engageable gear set;

[0016] - an output shaft connected to an axle of the motor vehicle, the output shaft carrying a plurality of third gears meshing with the first gears to form a first gear mechanism, a plurality of fourth gears meshing with the second gears to form a second gear mechanism, and a sixth gear meshing with the fifth gear to form a third gear mechanism, wherein the third and fourth gears respectively meshing with the first and second engageable gears are carried in a fixed manner by the output shaft so as to define corresponding elements of a third rotationally fixed gear set, and wherein the third and fourth gears respectively meshing with the first and second rotationally fixed gears are rotatably carried relative to the output shaft so as to define corresponding elements of a third engageable gear set;

[0017] - a dual clutch selectively controllable to connect one of the first and second shafts to the input shaft;

[0018] - a first engaging device for each of the first engageable gears, the first engaging device being controllable to selectively rotationally fix a relative one of the first engageable gears to the first shaft;

[0019] - a second engaging device for each of the second engageable gears, the second engaging device being controllable to selectively rotationally fix a relative one of the second engageable gears to the second shaft;

[0020] - A third engaging device for each of said third engagable gears, said third engaging device being controllable to selectively rotationally fix a relative one of the third engagable gears to said output shaft;

[0021] The device further includes an electric generator having a rotor coupled to said fifth gear through a transmission such that rotation of the rotor can be transmitted to the fifth gear and vice versa,

[0022] wherein said fifth and sixth gears are rotatably carried relative to said first shaft and said output shaft respectively, thus forming part of said first and third engagable gear sets respectively.

[0023] In one embodiment, said third engaging device for said sixth gear is configured to engage only said sixth gear.

[0024] In one embodiment, said first engaging device for said fifth gear is axially carried by said first shaft between said fifth gear and another gear, said another gear being among said first engagable gears, said first engaging device for said fifth gear being configured to selectively rotationally fix one of said fifth gear and said another gear to said first shaft such that said another gear meshes with one of said third rotationally fixed gears.

[0025] In one embodiment, said third engaging device for said sixth gear is axially carried by said output shaft between one of said third rotationally fixed gears and said sixth gear, or wherein said sixth gear is axially arranged between said third engaging device for said sixth gear and said third and fourth gear sets.

[0026] In one embodiment, said first shaft extends along a straight axis.

[0027] In one embodiment, said dual clutch transmission further includes a reverse gear mechanism, said reverse gear mechanism including at least a seventh and an eighth gear, said seventh and eighth gears being carried in a fixed manner by a third shaft defined by one of said first and second shafts respectively and rotatably carried by said output shaft relative to said output shaft, or carried rotatably by said third shaft and carried in a fixed manner by said output shaft respectively, said dual clutch transmission further includes a fourth engaging device which is controlled to rotationally fix a gear rotatably carried between said seventh and eighth gears to a relevant bearing shaft between said third shaft and said output shaft.

[0028] In one embodiment, the gear mechanisms in the first gear mechanism and the other gear mechanisms in the first gear mechanism respectively form: a first gear mechanism group with the reverse gear mechanism; and a second gear mechanism group.

[0029] In one embodiment, the second gear mechanism group is arranged between the third gear mechanism and the first gear mechanism group according to the straight axis (B).

[0030] In one embodiment, the first gear mechanism group is arranged between the second gear mechanism group and the second gear mechanism according to the straight axis (B).

[0031] In one embodiment, the third gear mechanism, the first gear mechanism, and the second gear mechanism respectively include one gear mechanism, two gear mechanisms, and four gear mechanisms, which define seven corresponding transmission ratios. These transmission ratios are re - numbered in ascending order from the first transmission ratio to the seventh transmission ratio, so as to correspond to seven corresponding degrees of decrease in the angular input speed gradually decreasing from the first to the seventh gear ratio. Therefore, the gear ratios are divided into even ratios and odd ratios according to their numerical order.

[0032] In one embodiment, the third and first gear mechanisms define the even ratios, and the second gear mechanism defines the odd ratios.

[0033] In one embodiment, the third gear mechanism defines the fourth gear ratio.

[0034] In one embodiment, the first gear mechanism includes the fourth and fifth gear mechanisms, where:

[0035] - The fourth gear mechanism defines one of the fourth and sixth gear ratios, and is arranged between the third gear mechanism and the fifth gear mechanism according to the straight axis (B), and

[0036] - The fifth gear mechanism defines the second gear ratio, is part of the first gear mechanism group, and is preferably arranged between the reverse gear mechanism and the fourth gear mechanism according to the straight axis (B).

[0037] In one embodiment, the second gear mechanism includes the sixth, seventh, eighth, and ninth gear mechanisms, where:

[0038] - The sixth and seventh gear mechanisms form a third gear mechanism group and respectively define the seventh gear ratio and the fifth gear ratio;

[0039] - The eighth and ninth gear mechanisms form a fourth gear mechanism group and respectively define the third and first gear ratios;

[0040] - One of the third gear mechanism set and the fourth gear mechanism set is arranged between the first gear mechanism sets, and the other is arranged between the third gear mechanism set and the fourth gear mechanism set.

[0041] In one embodiment,

[0042] - The first gear of the fourth gear mechanism is carried in a rotatable manner about the first axis,

[0043] - The third gear of the fifth gear mechanism is carried in a rotatable manner about the output shaft, and

[0044] - The eighth gear of the reverse gear mechanism is carried in a rotatable manner about the output shaft.

[0045] In one embodiment,

[0046] - The second gears of the sixth and seventh gear mechanisms are carried in a rotatable manner about the second axis, and

[0047] - The fourth gears of the eighth and ninth gear mechanisms are carried in a rotatable manner about the output shaft.

[0048] In one embodiment, the third axis is defined by the first axis.

[0049] In one embodiment, the first and second axes are coaxial with each other.

[0050] In one embodiment, the third engagement device for the sixth gear includes a dog clutch configured to engage with the sixth gear on the output shaft. Description of the Drawings

[0051] Hereinafter, embodiments of the present invention will be described by way of non-limiting examples and with reference to the drawings in order to better understand the present invention, wherein:

[0052] Figure 1 is a perspective view of a motor vehicle, which includes a device with a dual clutch transmission according to the present invention; and

[0053] Figure 2 is a schematic cross-sectional view of the structure of the dual clutch transmission. Detailed Description of the Embodiments

[0054] In Figure 1 the reference numeral 1 is used to denote the entire motor vehicle.

[0055] The motor vehicle 1 includes four wheels 2, at least two of which are drive wheels and are coupled to each other by means of an axle of a known type, not shown for example.

[0056] The motor vehicle 1 further includes a power or torque source 3, in particular an internal combustion engine.

[0057] The motor vehicle 1 further includes a device which in turn includes another power or torque source, in particular an electric generator 4 and a dual clutch transmission 5.

[0058] The dual clutch transmission 5 includes an input shaft 6 connected to the source 3, i.e., the input shaft 6 is caused to rotate by the source 3. Specifically, the shaft 6 extends along an axis A, for example a straight axis.

[0059] In addition, the transmission 5 includes two main shafts 7, 8, i.e., a first shaft 7 and a second shaft 8.

[0060] The shaft 7 specifically extends along an axis B (for example, a straight axis), in particular parallel to the axis a, and more particularly coincides with the axis a.

[0061] Preferably, the shaft 8 is coaxial with the shaft 7, i.e., the shaft 8 extends along an axis C parallel to and coinciding with the axis B. Alternatively, according to a variant not shown herein, the axis C may only be parallel to the axis B and not coincide with the axis B, or may not even be parallel to the axis B.

[0062] The shaft 7 carries a plurality of gears 9', 10', 11', each of which can be carried in a fixed manner by the shaft 7, i.e., can be attached to the shaft 7, or can be carried in a rotatable manner relative to the shaft 7 about the axis B, i.e., so as to be able to rotate about the axis B independently of the rotation of the shaft 7.

[0063] In this way, the gears among the gears 9', 10', 11' carried in a fixed manner define the elements of a first set of rotationally fixed gears, while the gears among the gears 9', 1', 11' carried in a rotatable manner define the elements of a first set of rotationally or engaging gears.

[0064] Similarly, the shaft 8 carries a plurality of gears 12', 13', 14', 15', each of which can be carried in a fixed manner by the shaft 8, i.e., can be attached to the shaft 8, or can be carried in a rotatable manner relative to the shaft 8 about the axis C, i.e., can rotate about the axis C independently of the rotation of the shaft 8.

[0065] In this way, the gears among the gears 12', 13', 14', 15' carried in a fixed manner define the elements of a second set of rotationally fixed gears, while the gears among the gears 12', 13', 14', 15' carried in a rotatable manner define the elements of a second set of rotationally or engaging gears.

[0066] In addition, the transmission 5 includes an output shaft or countershaft 16 connected to the axle or (driving) wheel 2, i.e., configured to transmit its rotation to the axle or wheel 2.

[0067] The output shaft 16 extends along an axis D (e.g., a straight axis), specifically parallel to axis B and also independently parallel to axis C.

[0068] The output shaft 16 carries a plurality of gears 9'', 10'', 11'', 12'', 13'', 14'', 15'' that respectively mesh with gears 9', 10', 11', 12', 13', 14', 15' to form corresponding gear mechanisms 9, 10, 11, 12, 13, 14, 15.

[0069] The gears 10'', 11'', 12'', 13'', 14'', 15'' that respectively mesh with the engaging gears are carried in a fixed manner by the shaft 16, thereby defining corresponding elements in the third set of rotationally fixed gears, while the gears 10'', 11'', 12'', 13'', 14'', 15'' that mesh with the rotationally fixed gears are carried in a manner rotatable about axis D relative to the shaft 16, thus defining corresponding elements in the third set of engaging gears.

[0070] In the embodiment shown herein, gear 10' and independently gears 12', 13' are engaging gears, i.e., they are respectively carried in a rotatable manner about axes B and C by shafts 7 and 8.

[0071] Thus, gears 10'', 12'', 13'' are rotationally fixed gears, i.e., they are carried in a rotationally fixed manner relative to the shaft 16 by the shaft 16.

[0072] Furthermore, gear 11' and independently gears 14', 15' are rotationally fixed gears, i.e., they are carried in a fixed manner relative to shafts 7 and 8 by shafts 7 and 8, i.e., they are respectively attached to shafts 7 and 8.

[0073] Thus, gears 11'', 14'', 15'' are engaging gears, i.e., they are carried in a rotatable manner about axis D relative to the shaft 16 by the shaft 16.

[0074] The gears 9', 9'' that mesh with each other to form gear mechanism 9 are both carried in a rotatable manner relative to shafts 7, 16 by corresponding shafts 7, 16, whereby gears 9', 9'' are both engaging gears, i.e., they respectively form part of the first and third sets of engaging gears, i.e., they define corresponding elements in the first set of engaging gears and the third set of engaging gears.

[0075] In order to engage the gear mechanisms 9, 10, 11, 12, 13, 14, 15, the gearbox 5 includes: a plurality of engaging devices, including the engaging device 17, which is configured or controllable to selectively connect one of the shafts 7 and 8 to the input shaft 6 so that the connecting shaft of the shafts 7, 8 rotates by the rotation of the shaft 6 or by the source 3; and engaging or selecting devices 18, 19, 20, 21, 22, which are configured or controllable to engage the engaging gears to, i.e., rotatably fix to, the relative bearing shafts of the shafts 7, 8, 16.

[0076] The equipment of the motor vehicle 1 includes a control unit ECU, which is configured to control each engaging device 17, 18, 19, 20, 21, 22.

[0077] In particular, the engaging device 17 is a dual clutch (e.g., of a known type, schematically shown in a rectangle in Figure 2 ), i.e., a device including two clutches, which are respectively configured or controllable to alternatively connect the shafts 7 and 8 to the shaft 6.

[0078] The engaging or selecting devices 18, 19, 20, 21, 22 can be dog clutches or synchronizers.

[0079] Preferably, the engaging device 20 is a dog clutch.

[0080] Furthermore, preferably, each of the engaging devices 18, 19, 21, 22 is a synchronizer.

[0081] Specifically, the engaging device 18 is configured or controllable to selectively engage to, i.e., rotatably fix to, one of the gears 9', 10' on the shaft 7 (i.e., one of the first engaging gears).

[0082] Thus, as described above, the gear 10'', i.e., one of the third rotationally fixed gears meshing with the gear 10', is carried in a fixed manner by the output shaft 16, particularly in a position adjacent to or facing the gear 9''.

[0083] Thus, the function of the engaging device 18 is shared by the gears 9', 10'; however, this should not be construed as a necessarily limiting example, since the engaging device 18 can be functionally regarded as two independent engaging devices, each dedicated to engaging the corresponding one of the gears 9', 10'. In fact, the engaging device 18 is controlled to alternatively engage the gear 9' or the gear 10', whereby it cannot engage the gears 9', 10' simultaneously. Furthermore, the engaging device 18 can also be replaced by two completely independent and separate engaging devices, and respectively dedicated to engaging the gears 9', 10'. Similar remarks also apply to the other engaging or selecting devices 19, 21, 22, and thus will not be repeated for the sake of brevity.

[0084] In particular, the engaging device 18 (i.e., the engaging device of gear 9') is axially carried between gears 9' and 10' (i.e., one of the first engagable gears) by shaft 7, and more particularly, is carried in an axially movable manner along axis B.

[0085] The engaging device 19 is configured or controllable to selectively engage, i.e., to be rotationally fixed to one of shaft 8, gears 12' and 13'.

[0086] In particular, the engaging device 19 is axially carried between gears 12' and 13' by shaft 8, and more particularly, is carried in an axially movable manner along axis C.

[0087] The engaging device 20 is configured or controllable to selectively engage, i.e., to be rotationally fixed to gear 9'' on shaft 16.

[0088] In particular, the engaging device 20 is axially carried between gears 9'' and 10'' by shaft 16, and more particularly, is carried in an axially movable manner along axis D.

[0089] In other words, since gear 10'' is particularly one of the rotationally fixed gears, the engaging device 20 is axially carried between one of the third engagable gears (gear 9'') and one of the third rotationally fixed gears by shaft 16.

[0090] Therefore, the engaging device 20 is independent or movable independently of any other engaging device among engaging devices 17, 18, 19, 20, 21, 22, or more generally, independent of any other engaging device.

[0091] In other words, the engaging device 20 is configured or controllable to only engage gear 9'', i.e., to engage gear 9'' in a dedicated manner, that is, it is arranged or configured not to control or be unable to control other gears except gear 9''.

[0092] Therefore, alternatively, gear 9'' is axially arranged between the engaging device 20 and all other gears carried by output shaft 16.

[0093] The engaging device 21 is configured or controllable to selectively engage, i.e., to be rotationally fixed to shaft 16, gear 11''.

[0094] In particular, the engaging device 21 is axially carried between gears 11'' and 12'' by shaft 16, and more particularly, is carried in an axially movable manner along axis D.

[0095] The engaging device 22 is configured or controllable to selectively engage, i.e., to be rotationally fixed to one of shaft 16, gears 14'' and 15''.

[0096] In particular, the engaging device 22 is axially carried between the gears 14'', 15'' by the shaft 16, and more particularly, is carried in an axially movable manner along the axis D.

[0097] In summary, the transmission 5 includes a first engaging device (here, the device 18) for each first engagable gear (here, the gears 9', 10'), a second engaging device (here, the device 19) for each second engagable gear (here, the gears 12', 13'), and a third engaging device (here, one of the devices 20, 21, 22) for each third engagable gear (here, the gears 9'', 11'', 14'', 15'').

[0098] Obviously, if the set of second engagable gears is an empty set, that is, for example, if none of the gears 12', 13', 14', 15' is carried in a rotatable manner relative to the shaft 8, the second engaging device would be redundant and thus does not exist.

[0099] The electric generator 4 includes a rotor (not shown) coupled or connected to the gear 9' through the transmission 23. The transmission 23, for example, includes a reduction gear unit or is defined by a reduction gear unit, such that the rotation of the rotor can be transmitted to the gear 9', and vice versa.

[0100] For example, the transmission 23 may include an engaging or clutch device (not shown) to selectively determine and interrupt the coupling or connection between the rotor and the gear 9'.

[0101] The gear mechanisms 9, 10, 11, 12, 13, 14, 15 define seven corresponding gear ratios or gears, which can be numerically reordered in ascending order from the first gear ratio or gear to the seventh gear ratio or gear, corresponding to seven corresponding decreasing degrees of the input angular velocity (the angular velocity of one of the shafts 7, 8) from the first to the seventh gear ratio. In other words, according to the corresponding gear ratio, the angular velocity of the shaft 16 is reduced relative to the input angular velocity by the gear mechanisms 9, 10, 11, 12, 13, 14, 15.

[0102] Here, the gear ratio is defined as a reduction ratio, and its value is less than or equal to the value obtained by the ratio between the angular velocity of the shaft 16 and the input angular velocity (the angular velocity of the shaft 7 or 8, depending on the engaged gear in the gear mechanisms 9, 10, 11, 12, 13, 14, 15).

[0103] The first gear ratio is the smallest, while the seventh gear ratio is the largest, that is, the closest to 1. Therefore, the gear ratios increase numerically from the first gear ratio to the seventh gear ratio.

[0104] The gear ratios can be classified into even ratios and odd ratios according to their numerical order (the first, third, fifth, and seventh are odd ratios, while the second, fourth, and sixth are even ratios). Thus, the gear mechanisms 9, 10, 11, 12, 13, 14, 15 (each of which is associated with a corresponding gear ratio) can define an even gear mechanism 9, 10, 11, or can define an odd gear mechanism 12, 13, 14, 15, 16. Thus, the even gear mechanism 9, 10, 11 defines an even ratio, while the odd gear mechanism 12, 13, 14, 15 defines an odd ratio.

[0105] The gear mechanism 9 preferably defines the fourth gear ratio. In other words, the diameter of gear 9'' is greater than the diameters of three of the gears 10'', 11'', 12'', 13'', 14'', 15'' and less than the diameters of the other three of the gears 10'', 11'', 12'', 13'', 14'', 15'', i.e., the median diameter.

[0106] In addition, the gear mechanism 10 preferably defines the sixth gear ratio. In other words, the diameter of gear 10'' is less than the diameters of five of the gears 9'', 11'', 12'', 13'', 14'', 15'' and greater than the diameter of one of the gears 9'', 11'', 12'', 13'', 14'', 15''.

[0107] According to an alternative not shown herein, the gear mechanism 9 can define the sixth gear ratio, and in this case, the gear mechanism 10 will define the fourth gear ratio.

[0108] Thus, the gear mechanism 9 defines one of the fourth and sixth gear ratios, while the gear mechanism 10 defines the other of the fourth and sixth gear ratios.

[0109] In addition, the gear mechanism 11 preferably defines the second gear ratio. In other words, the diameter of gear 11'' is greater than the diameters of five of the gears 9'', 10'', 12'', 13'', 14'', 15'' and less than the diameter of one of the gears 9'', 10'', 12'', 13'', 14'', 15''.

[0110] The gear mechanism 10 is axially arranged between the gear mechanisms 9, 11 (according to axis B or axis D). Thus, one of the fourth and sixth gear ratios is axially arranged between the second gear ratio and the other of the fourth and sixth gear ratios.

[0111] Independently, the gear mechanism 11 is axially arranged between the gear mechanisms 10, 12 (according to axis B or D).

[0112] Independently, the gear mechanism 9 is axially arranged between the gear mechanism 10 (i.e., one of the other gear mechanisms) and the engagement device 17 (according to axis B or D).

[0113] The gear mechanism 12 preferably defines a seventh gear ratio. In other words, the gear 12'' has the smallest diameter relative to the other gears 9'', 10'', 11'', 13'', 14'', 15''.

[0114] Furthermore, the gear mechanism 13 preferably defines a fifth gear ratio. In other words, the diameter of the gear 13'' is greater than the diameters of two of the gears 9'', 10'', 11'', 12'', 14'', 15'' and less than the diameters of the other four of the gears 9'', 10'', 11'', 12'', 14'', 15''.

[0115] Furthermore, the gear mechanism 14 preferably defines a third gear ratio. In other words, the diameter of the gear 14'' is less than the diameters of two of the gears 9'', 10'', 11'', 12'', 13'', 15'' and greater than the diameters of the other four of the gears 9'', 10'', 11'', 12'', 13'', 15''.

[0116] Furthermore, the gear mechanism 15 preferably defines a first gear ratio. In other words, the diameter of the gear 15'' is the largest relative to the diameters of the gears 9'', 10'', 11'', 12'', 13'', 14''.

[0117] In particular, the gear mechanism 12 is axially arranged between the gear mechanisms 11 and 13 (according to axis C or axis D).

[0118] In particular, the gear mechanism 13 is independently axially arranged between the gear mechanisms 12 and 14 (according to axis B or D).

[0119] In particular, the gear mechanism 14 is independently axially arranged between the gear mechanisms 13 and 15 (according to axis B or D).

[0120] Therefore, according to the embodiments shown herein, the diameter of the gear 9'' is between the diameters of the gears 13'' and 14''.

[0121] The diameter of the gear 10'' is between the diameters of the gears 12'' and 13''.

[0122] The diameter of the gear 11'' is between the diameters of the gears 14'' and 15''.

[0123] The diameter of the gear 13'' is between the diameters of the gears 9'' and 10''.

[0124] The diameter of the gear 14'' is between the diameters of the gears 11'' and 9''.

[0125] In addition, more generally, two axially adjacent gear mechanisms among the gear mechanisms 9, 10, 11, 12, 13, 14, 15 define a corresponding gear ratio that astride (according to their numerical order) the gear ratio defined by another non - adjacent gear mechanism among the gear mechanisms 9, 10, 11, 12, 13, 14, 15. More specifically, if two axially adjacent gear mechanisms are even, then the other non - adjacent gear mechanism is odd, and vice versa (if two adjacent gear mechanisms are both odd, then the other non - adjacent gear mechanism is even).

[0126] Optionally, the gearbox 5 further includes a reverse gear mechanism 24, which includes at least two gears 24', 24'' carried by one of the shafts 7, 8 and the shaft 16 respectively.

[0127] Specifically, the gear 24'' is carried by the shaft 16 in a manner rotatable relative to its axis D, while the gear 24' is carried by one of the shafts 7, 8 in a fixed manner relative to it, that is, the gear 24' is attached to one of the shafts 7, 8. Alternatively, according to a variant not shown herein, the gear 24' can be carried by one of the shafts 7 or 8 in a manner rotatable relative to its axis B or C, while the gear 24'' can be carried by the shaft 16 in a fixed manner relative to it.

[0128] In addition, specifically, the gear 24'' can be selectively rotatably fixed to the shaft 16 by means of an engagement device, in particular by means of the engagement device 21. Here, the engagement device 21 is axially (according to the axis D or B) arranged between the reverse gear mechanism 24 and the gear mechanism 11, and more particularly, between the gears 24'', 11''. According to a variant not shown herein, the gear 24' can be selectively rotatably fixed to one of the shafts 7, 8 by means of an engagement device.

[0129] Therefore, the gear 24' can define an element in the first engagable gear set or the second engagable gear set according to whether it is carried by the shaft 7 or the shaft 8 respectively. Alternatively, the gear 24'' can define an element in the third engagable gear set.

[0130] In the embodiment shown herein, the gear 24' is carried by the shaft 7, and more particularly, fixedly carried by the shaft 7, whereby the gear 24'' is rotatably carried relative to the shaft 16, that is, it defines an element in the third engagable gear set.

[0131] The gear mechanism 11 and the reverse gear mechanism 24 form a gear mechanism group, which is different from the gear mechanism group formed by the gear mechanism 10 and possibly by the gear mechanism 9.

[0132] The gear mechanism groups 11, 24 are axially arranged between the gear mechanism groups 9, 10 and the gear mechanisms 12, 13, 14, 15 according to the axis B or C.

[0133] Therefore, according to a variant not shown herein, the gear mechanisms 11, 24 can be axially switched in position between them by the engaging device 21.

[0134] In the embodiment shown herein, the gear mechanisms 10, 11 (according to the axis B or D) are axially arranged between the gear mechanism 9 and the reverse gear mechanism 24, although according to a variant not shown herein, the reverse gear mechanism 24 can be axially arranged between the gear mechanisms 9, 10 and the gear mechanism 11.

[0135] Furthermore, in the embodiment shown herein, the reverse gear mechanism 24 is independently (according to the axis B or D) axially arranged between the gear mechanisms 10, 11 (possibly also including the gear mechanism 9) and the gear mechanisms 12, 13, 14, 15.

[0136] The gear mechanism 11 (according to the axis B or D) is axially arranged between the gear mechanism 10 and the reverse gear mechanism 24.

[0137] The gear mechanism 12 (according to the axis B or D) is axially arranged between the gear mechanism 13 and the reverse gear mechanism 24.

[0138] More generally, the gear mechanisms 12, 13 and the gear mechanisms 14, 15 form corresponding gear mechanism groups, and one gear mechanism can be arranged between another gear mechanism and the gear mechanism groups 11, 24. Herein, the gear mechanism groups 12, 13 are arranged between the gear mechanism groups 11, 24 and the gear mechanism groups 14, 15, although according to a variant, the gear mechanism groups 14, 15 can be arranged between the gear mechanism groups 12, 13 and the gear mechanism groups 11, 24. Furthermore, according to a variant not shown herein, the gear mechanisms 12, 13 and independently the gear mechanisms 14, 15 can be axially switched in position.

[0139] Furthermore, the gear mechanism 10 or its gear mechanism group is preferably arranged between the gear mechanism 9 and the gear mechanism groups 11, 24.

[0140] Optionally, the reverse gear mechanism 24 can be absent.

[0141] The above-mentioned engaging devices 17, 18, 19, 20, 21, 22 can be operated by corresponding actuators (not shown) controlled by the control unit ECU. The control unit ECU controls the engaging devices 17, 18, 19, 20, 21, 22 by sending electrical control signals to the engaging devices 17, 18, 19, 20, 21, 22.

[0142] The control unit ECU is configured to control the engaging devices 17, 18, 19, 20, 21, 22 either by a direct input command from the driver of the motor vehicle 1 or automatically in accordance with a shift control logic deployed in a specific software code, which can be stored in the control unit ECU.

[0143] The equipment of the motor vehicle 1 can set a dedicated control software code in the ECU of the transmission, and the ECU of the transmission is configured to: identify signals from sensors installed in the motor vehicle 1, such as the torque request at the output shaft 16 and the angular velocity of the input shaft 6; and automatically define gear shifts without any intervention from the driver.

[0144] Hereinafter, some operation modes of the equipment of the motor vehicle 1 will be described by way of example.

[0145] The first operation mode involves the motor vehicle 1 being parked, that is, the wheels 2 are not moving or rotating.

[0146] In this operation mode, the control unit ECU can control the engaging device 18 to rotationally fix the gear 9' to the shaft 7, and the shaft 7 is in turn connected to the shaft 6 through the engaging device 17. In addition, the control unit ECU controls the engaging device 20 such that the gear 9'' remains freely rotatable about the axis D relative to the shaft 16. In this way, the electric generator 4 and the source 3 are connected to each other, while neither of them is connected to the axle or the wheels 2. By doing so, the electric generator 4 can generate electrical energy or start the source 3 by means of the power provided by the source 3.

[0147] The second operation mode involves propulsion using the electric generator 4 or more generally using the connection between the wheels 2 or the axle and the electric generator 4 to move the motor vehicle 1.

[0148] In this operation mode, the control unit ECU can control the engaging device 18 to rotationally fix the gear 9' to the shaft 7. However, through the control of the engaging device 17 by the control unit ECU, the shaft 7 remains disconnected from the shaft 6.

[0149] By doing so, the electric generator 4 can transmit power to the shaft 7.

[0150] Accordingly, the control unit ECU can control one of the engaging devices 20, 21 to rotatably fix one of the gears 9'', 11'', 24'' to the shaft 16, thereby engaging one of the fourth gear ratio, the second gear ratio or the reverse gear mechanism respectively.

[0151] In this way, the electric generator 4 at least contributes to the propulsion of the motor vehicle 1.

[0152] In fact, in addition, the control unit ECU can control the engaging device 17 to connect the shaft 6 to the shaft 8, and control one of the engaging devices 19, 22 to disengage one of the odd-numbered gear ratios, so that the source 3 and the electric generator 4 contribute to the propulsion of the motor vehicle 1 in parallel.

[0153] For the above reasons, the advantages of the device according to the present invention are obvious.

[0154] The source 3 and the electric generator 4 can be connected to the parked motor vehicle 1.

[0155] In addition, since the electric generator 4 controls the rotation of the entire gear mechanism 9, the engaging device 20 can also be a simple claw clutch instead of a synchronizer. This results in a significant reduction in the radial dimension of the engaging device 20, so that the engaging device 20 can be placed at the same axial position as the engaging device 18 along the axes B, D.

[0156] In addition, the electric generator 4 can be used to propel the motor vehicle 1 at the most suitable gear ratio, that is, at the second gear ratio and the reverse gear mechanism (i.e., when the wheels 2 have a greater torque requirement), and to propel the motor vehicle 1 at the fourth gear ratio for suburban roads.

[0157] In addition, the reverse gear mechanism 24 is arranged in the middle between the gear mechanisms 9, 10, 11 and the gear mechanisms 12, 13, 14, 15, which is ideal for reducing the overall size of the transmission 5 without overly increasing the complexity of the transmission 5 itself.

[0158] Finally, the device according to the present invention can be changed and modified, but these changes and modifications do not exceed the scope of protection described in the appended claims.

[0159] In particular, the number, shape and arrangement of the components described and shown herein can be different.

[0160] In addition, each detail of the arrangement and dimensions of the gear mechanisms 9, 10, 11, 12, 13, 14, 15, 24 and the engaging devices 17, 18, 19, 20, 21, 22, 23 drawn in the drawings must be regarded as independent of other details.

[0161] Similarly, graphical representations of support elements, such as bearings for shafts 7, 8, 16 or other bearings shown schematically, are considered merely illustrative and are subject to change.

[0162] Finally, Figure 2 the illustration of is only schematic for a better understanding of the key aspects of the description and should not be understood as being entirely true.

Claims

1. An apparatus for a motor vehicle (1) having a dual clutch transmission (5), said dual clutch transmission (5) comprising: - an input shaft (6) connected to a power source (3) of the motor vehicle (1); - a first shaft (7) carrying a plurality of first gears (10', 11') and a fifth gear (9'), each of said first gears (10', 11') being carried in a fixed manner by the first shaft (7) so as to define an element of a first set of rotationally fixed gears, or being carried in a rotatable manner relative to the first shaft (7) so as to define an element of a first set of engageable gears; - a second shaft (8) carrying a plurality of second gears (12', 13', 14', 15'), each of said second gears (12', 13', 14', 15') being carried in a fixed manner by the second shaft (8) so as to define an element of a second set of rotationally fixed gears, or being carried in a rotatable manner relative to the second shaft (8) so as to define an element of a second set of engageable gears; - an output shaft (16) connected to an axle of the motor vehicle (1), said output shaft (16) carrying a plurality of third gears (10'', 11'') meshing with the first gears (10', 11') to form a first gear mechanism (10, 11), a plurality of fourth gears (12'', 13'', 14'', 15'') meshing with the second gears (12', 13', 14', 15') to form a second gear mechanism (12, 13, 14, 15), and a sixth gear (9'') meshing with the fifth gear (9') to form a third gear mechanism (9), wherein the third and fourth gears (10'', 11'', 12'', 13'', 14'', 15'') respectively meshing with the first and second engageable gears are carried in a fixed manner by the output shaft (16) so as to define corresponding elements of a third set of rotationally fixed gears, and wherein the third and fourth gears (10'', 11'', 12'', 13'', 14'', 15'') respectively meshing with the first and second rotationally fixed gears are carried rotatably relative to the output shaft (16) so as to define corresponding elements of a third set of engageable gears; - a dual clutch (17) selectively controllable to connect one of the first and second shafts (7, 8) to the input shaft (6); - first engaging means (18) for each of said first engageable gears, said first engaging means (18) being controllable to selectively rotationally fix a respective one of the first engageable gears to the first shaft (7); - second engaging means (19) for each of said second engageable gears, said second engaging means (19) being controllable to selectively rotationally fix a respective one of the second engageable gears to the second shaft (8); - third engaging means (20, 21, 22) for each said third engagable gear, said third engaging means (20, 21, 22) being controllable to selectively rotationally fix a respective one of the third engagable gears to said output shaft (16); The device further includes an electric generator (4) having a rotor coupled to said fifth gear (9') through a transmission (23) such that rotation of said rotor can be transmitted to said fifth gear (9'), and vice versa, characterized in that said fifth and sixth gears (9', 9'') are rotatably carried relative to said first shaft (7) and said output shaft (16) respectively, thereby forming part of said first and third engagable gear sets respectively.

2. The device according to claim 1, wherein, The third engaging means (20) for said sixth gear (9'') is configured to engage only said sixth gear (9'').

3. The device according to claim 1, wherein, The first engaging means (18) for said fifth gear (9') is axially carried between said fifth gear (9') and another gear (10') by said first shaft (7), said another gear (10') being between said first engagable gears, the first engaging means (18) for said fifth gear (9') being configured to selectively rotationally fix one of said fifth gear (9') and said another gear (10') to said first shaft (7) such that said another gear (10') meshes with one of said third rotationally fixed gears.

4. The device according to claim 1, wherein, The third engaging means (20) for said sixth gear (9'') is axially carried between one of said third rotationally fixed gears and said sixth gear (9'') by said output shaft (16), or wherein said sixth gear (9'') is axially disposed between the third engaging means (20) for said sixth gear (9'') and said third and fourth gear sets.

5. The device according to claim 1, wherein Said first shaft (7) extends along a straight axis (B).

6. The device according to claim 5, wherein Said dual clutch gearbox (5) further includes a reverse gear mechanism (24), said reverse gear mechanism (24) including at least seventh and eighth gears (24', 24''), said seventh and eighth gears (24', 24'') being carried in a fixed manner by a third shaft defined by one of said first and second shafts (7, 8) respectively and being carried rotatably relative to said output shaft (16) by said output shaft (16), or being carried rotatably relative to said third shaft and being carried in a fixed manner by said output shaft (16) respectively, said dual clutch gearbox (5) further including a fourth engaging means (21) which is controlled to rotationally fix a gear rotatably carried between said seventh and eighth gears (24', 24'') to a relevant bearing shaft between said third shaft and said output shaft (16).

7. The apparatus according to claim 6, wherein, The gear mechanism (11) in the first gear mechanism (10, 11) and the other gear mechanisms (10) in the first gear mechanism (10, 11) respectively form: a first gear mechanism group (11, 24) formed with the reverse gear mechanism (24); and a second gear mechanism group (10) is formed.

8. The device according to claim 7, wherein The second gear mechanism group (10, 11) is arranged between the third gear mechanism (9) and the first gear mechanism group (11, 24) according to the straight axis (B).

9. The device according to claim 7, wherein The first gear mechanism group (11, 24) is arranged between the second gear mechanism group (10, 11) and the second gear mechanism (12, 13, 14, 15) according to the straight axis (B).

10. The device according to claim 9, wherein, The third gear mechanism (9), the first gear mechanism (10, 11) and the second gear mechanism (12, 13, 14, 15) respectively include one gear mechanism, two gear mechanisms and four gear mechanisms, which define seven corresponding transmission ratios. These transmission ratios are numerically reordered in ascending order from the first transmission ratio to the seventh transmission ratio, so as to correspond to seven corresponding decreasing degrees of the angular input speed gradually decreasing from the first to the seventh gear ratio. Therefore, the gear ratios are divided into even ratios and odd ratios according to their numerical order.

11. The device according to claim 10, wherein, The third and first gear mechanisms (9, 10, 11) define the even ratios, and the second gear mechanism (12, 13, 14, 15) defines the odd ratios.

12. The device according to claim 10, wherein, The third gear mechanism (9) defines the fourth gear ratio.

13. The apparatus according to claim 10, wherein, The first gear mechanism (10, 11) includes the fourth and fifth gear mechanisms (10, 11), wherein: - The fourth gear mechanism (10) defines one of the fourth and sixth gear ratios, and is arranged between the third gear mechanism (9) and the fifth gear mechanism (11) according to the straight axis (B), and - The fifth gear mechanism (11) defines the second gear ratio, is a part of the first gear mechanism group (11, 24), and is preferably arranged between the reverse gear mechanism (24) and the fourth gear mechanism (10) according to the straight axis (B).

14. The device according to claim 10, wherein, The second gear mechanism (12, 13, 14, 15) includes the sixth, seventh, eighth and ninth gear mechanisms (12, 13, 14, 15), wherein: - The sixth and seventh gear mechanisms (12, 13) form a third gear mechanism group (12, 13), and respectively define the seventh gear ratio and the fifth gear ratio; - The eighth and ninth gear mechanisms (14, 15) form a fourth gear mechanism group (14, 15), and respectively define the third and first gear ratios; - One of the third gear mechanism group (12, 13) and the fourth gear mechanism group (14, 15) is arranged between the first gear mechanism group (11, 24), and the other is arranged between the third gear mechanism group (12, 13) and the fourth gear mechanism group (14, 15).

15. The device according to claim 13, wherein, - The first gear (10') of the fourth gear mechanism (10) is carried in a rotatable manner about the first shaft (7), - The third gear (11') of the fifth gear mechanism (11) is carried in a rotatable manner about the output shaft (16), and - The eighth gear (24'') of the reverse gear mechanism (24) is carried in a rotatable manner about the output shaft (16).

16. The device according to claim 14, wherein - The second gears (12', 13') of the sixth and seventh gear mechanisms (12, 13) are carried in a rotatable manner about the second shaft (8), and - The fourth gears (14', 15') of the eighth and ninth gear mechanisms (14, 15) are carried in a rotatable manner about the output shaft (16).

17. The apparatus according to claim 6, wherein, The third shaft is defined by the first shaft (7).

18. The device according to claim 1, wherein, The first and second shafts (7, 8) are coaxial with each other.

19. The device according to claim 1, wherein, The third engaging device (20) for the sixth gear (9'') includes a claw clutch configured to engage with the sixth gear (9'') on the output shaft (16).

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