DE102020005455A1 - Double clutch - Google Patents

Abstract

The invention relates to a double clutch transmission (6) with a first sub-transmission to which a first clutch (K1) and a first sub-transmission input shaft (8) are assigned, and a second sub-transmission to which a second clutch (K2) and a second sub-transmission input shaft (9) are assigned , a first countershaft (15) to which a first output gear (24) is permanently connected in a rotationally fixed manner, and a second countershaft (19) to which a second output gear (25) is permanently connected in a rotationally fixed manner, a first idler gear assigned to the first sub-transmission ( 14) and a second idler gear (20) assigned to the second sub-transmission are arranged coaxially to the first countershaft (15) and can be coupled to one another in a rotationally fixed manner by means of a bridge shift element (A), and a third idler gear (18) assigned to the first sub-gear and one the The fourth idler gear (23) assigned to the second sub-transmission is arranged coaxially with the second countershaft (19). The invention is characterized in that exactly four switching elements (A, B, C, D) are provided together with the bridge switching element (A), the bridge switching element (A) forming the first switching element (A), with a second switching element (B) for non-rotatably connecting the second idler gear (20) to the first countershaft (15), a third switching element (C) for non-rotatably connecting a third idler gear (18) to the second countershaft (19) and a fourth switching element (D) for non-rotatably connecting one fourth idler gear (23) with the second countershaft (19), and which is set up so that six forward gears can be formed.

Description

The invention relates to a double clutch transmission with a first sub-transmission, which is assigned a first clutch and a first sub-transmission input shaft, and with a second sub-transmission, which is assigned a second clutch and a second sub-transmission shaft, according to the type defined in more detail in the preamble of claim 1 The invention relates to a hybrid drive system with such a dual clutch transmission.

Double clutch transmissions are known in principle from the prior art. Purely by way of example, in this context the DE 10 2009 002 353 A1 to get expelled. The double clutch transmission with two double clutches described there shows a very complex structure with a large number of idler gears and fixed gears as well as a power shiftable winding gear, for which two of the idler gears can be connected via a bridge shift element, which in turn are each connected to a further clutch with the countershaft assigned to them can be.

All in all, this structure is relatively complex and requires a large number of components and thus a comparatively large installation space, especially in the axial direction, that is to say in the direction of the sub-transmission input shafts or countershafts.

The object of the present invention is to optimize a dual clutch transmission according to the type defined in more detail in the preamble of claim 1 in order to be able to implement this extremely efficiently with regard to its structural size, in particular the overall axial length.

According to the invention, this object is achieved by a dual clutch transmission with the features in claim 1, and here in particular in the characterizing part of claim 1. Advantageous refinements and developments of the double clutch transmission and of a hybrid drive system equipped with such a double clutch transmission emerge from the dependent claims.

The dual clutch transmission according to the invention is designed as a transmission with six forward gears. Together with the bridge switching element known in principle from the prior art, it comprises exactly four switching elements, the bridge switching element forming the first switching element, and a second switching element for non-rotating connection of the second idler gear with the first countershaft, a third switching element for non-rotating connection of a third idler gear is provided with the second countershaft and a fourth shifting element for rotationally fixed connection of the fourth idler gear to the second countershaft. The special feature of the invention is that the first and second idler gears, which are arranged coaxially to the first countershaft and can be connected by means of the bridge shift element, can then only be connected to the corresponding countershaft via the second shift element in the area of the second idler gear . The specialty is that there is no need for a further shift element in the area of the first idler gear. In the case of the dual clutch transmission according to the invention, this can no longer be connected directly to its countershaft, as is the case with the structure in the prior art mentioned at the beginning. This means that in the structure according to the invention to form a transmission gear, one and the same idler gear is connected to two shift elements at the same time, namely on one side, via the bridge shift element with the other idler gear and on the other side with the countershaft. This structure makes it possible to create a dual clutch transmission with six forward gears, which can be made extremely compact thanks to this “trick”. Above all, it can be made very short in the axial direction, i.e. in the direction of the central axes of the countershaft and the partial transmission input shafts, and is therefore ideally suited for installation in a vehicle transverse to the direction of travel.

The bridge shift element, which is designed to couple the first idler gear assigned to the first sub-transmission and the second idler gear assigned to the second sub-gearbox in a rotationally fixed manner or to connect them in a rotationally fixed manner, connects the first idler gear and the second idler gear to one another in a rotationally fixed manner, without these two idler gears mentioned at the same time to connect non-rotatably with the first countershaft. D. .H. that if the first idler gear is non-rotatably connected to the second idler gear by means of the bridge shift element, these two idler gears can still be rotated together with respect to the first countershaft as long as they are not rotatably connected to the first countershaft by means of another switching element.

A non-rotatable connection within the meaning of the invention is to be understood as a connection between rotating elements which connects them to one another in such a way that they rotate at the same angular speed.

Another aspect to further improve the compactness of the transmission according to an advantageous embodiment of the invention is that the first partial transmission comprises exactly two single gear planes, namely a single gear plane comprising the first idler gear and a second single gear plane. The second partial transmission includes likewise exactly two single gear planes, namely a third single gear plane comprising the second idler gear and a fourth single gear plane. According to a very advantageous development of this, the third idler gear can be assigned to the second single gear plane and the fourth idler gear can be assigned to the fourth single gear plane. Together with the omission of a shifting element, this guarantees a very compact design for one of the idler gears that can be connected via the bridge shift element between this idler gear and its countershaft. The exactly four single gear levels in combination with exactly four shifting elements enable the full functionality of a dual clutch transmission with six forward gears, namely a first gear, a second gear, a third gear, a fourth gear, a fifth gear and a sixth gear.

A further embodiment of the double clutch transmission according to the invention can provide that the fourth and the third shift element are implemented as a double shift element with a neutral position. This double switching element can be operated in particular via an actuator in order to make the structure even easier and more compact.

It can be provided that the third idler gear together with the first idler gear and the second idler gear contribute to the formation of the first gear. The fourth idler gear together with the first idler gear and the second idler gear can contribute to the formation of the sixth gear.

As already mentioned, it can be provided according to a very favorable embodiment that the dual clutch transmission according to the invention in an advantageous embodiment of the idea comprises exactly the six transmission gears, which are all designed as forward gears. This structure, which can be implemented without a mechanical reverse gear, has its decisive advantage when the dual clutch transmission is used in a hybrid drive system.

The hybrid drive system according to the invention for a vehicle provides this dual clutch transmission in addition to an internal combustion engine and an electric machine. It is so that the internal combustion engine is at least indirectly coupled or can be coupled to an input shaft of the double clutch transmission. In particular, on the side of the double clutch facing away from the partial transmissions in the power flow, the internal combustion engine can be coupled or can be coupled to the input shaft located there. Indirect in the sense of the claim means that further elements are provided between the internal combustion engine and the dual clutch transmission. Typically, these elements are devices for damping and absorbing torsional vibrations, so-called torsional vibration dampers, which, for example, via dual-mass flywheels, centrifugal pendulums or the like, dampen or eliminate the torsional vibrations emanating from a crankshaft of the internal combustion engine and at least partially keep them away from the dual clutch transmission.

The structure can be implemented as a classic parallel hybrid, for example as a so-called P2 hybrid. This means that the electric machine drives the input shaft of the dual clutch transmission together with the internal combustion engine, for example. For this purpose, a further separating clutch could be provided which, in particular, can be designed to be integrated into the double clutch in order to be able to couple or also decouple the electrical machine and / or the internal combustion engine as required.

According to an extremely favorable embodiment of the hybrid drive system according to the invention, however, it can also be provided that it is designed as a so-called P2.5 hybrid. Accordingly, a rotor of the electrical machine is at least indirectly coupled or can be coupled to one of the countershafts or to one of the sub-transmission input shafts. If necessary, the electric machine drives the dual clutch transmission virtually internally.

Another alternative or supplementary embodiment can also provide that the rotor of the electrical machine is coupled to one of the four idler gears in such a way that torques from the electrical machine can be introduced into the dual clutch transmission via one of the four idler gears. In particular, the coupling can take place with one of the idler gears, which can be coupled directly to their respective countershaft via one of the three shifting elements apart from the bridge shifting element. It is thus possible to achieve a highly flexible connection of the electrical machine to the power flow in the dual clutch transmission without an additional shift element or an additional clutch.

It is the case that the particular advantage of the hybrid drive system lies in the extremely compact design of the dual clutch transmission. Six forward gears can thus be shifted efficiently and sensibly, and the reverse gear, which is dispensable as a mechanical gear in the dual clutch transmission according to the invention, can be efficiently implemented by the electric machine.

Further advantageous configurations of the dual clutch transmission according to the invention also result from the exemplary embodiments, which are described in more detail below with reference to the figures.

• 1 ein Radsatzschema einer ersten möglichen Ausführungsform eines Hybridantriebssystems gemäß der Erfindung;
• 2 ein Schaltschema für das Doppelkupplungsgetriebe in dem Hybridantriebssystem gemäß 1;
• 3 eine erste alternative Ausgestaltung des Doppelkupplungsgetriebes in dem Hybridantriebssystem gemäß 2;
• 4 eine zweite alternative Ausgestaltung des Doppelkupplungsgetriebes in dem Hybridantriebssystem gemäß 2;
• 5 Schaltschema für das Doppelkupplungsgetriebe gemäß 4; und
• 6 eine vierte alternative Möglichkeit zur Ausgestaltung des Doppelkupplungsgetriebes in einem Hybridantriebssystem gemäß 1.

Show:

• 1 a wheelset scheme of a first possible embodiment of a hybrid drive system according to the invention;
• 2 a shift pattern for the dual clutch transmission in the hybrid drive system according to FIG 1 ;
• 3 a first alternative embodiment of the dual clutch transmission in the hybrid drive system according to FIG 2 ;
• 4th a second alternative embodiment of the dual clutch transmission in the hybrid drive system according to FIG 2 ;
• 5 Shift diagram for the dual clutch transmission according to 4th ; and
• 6th a fourth alternative possibility for designing the dual clutch transmission in a hybrid drive system according to FIG 1 .

In the representation of the 1 is a hybrid drive system 1 shown. It has an internal combustion engine 2 as well as an electric machine 3 . The internal combustion engine 2 drives via a device for absorbing and damping torsional vibrations such as a dual-mass flywheel 4th a designated 5 input shaft of a dual clutch transmission 6th at. A double clutch follows the input shaft 7th with the clutches K1 and K2 which in turn connect the input shaft 5 with a first partial transmission input shaft 8th and a second sub-transmission input shaft 9 enable. The two partial transmissions with the partial transmission input shafts 8th and 9 are then two single gear planes each 10 , 11 in the case of the first partial transmission input shaft 8th and single gear planes 12th , 13th in the case of the second partial transmission input shaft 9 assigned. The first single gear level 10 includes a first idler wheel 14th . This is coaxial with a first countershaft 15th arranged and meshes with a fixed gear 16 , which with the first partial transmission input shaft 8th is rotatably connected and arranged coaxially to this. The second single gear level 11 includes a fixed gear 17th , which is also coaxial and rotationally fixed to the first part of the transmission input shaft 8th is arranged as well as a third idler wheel 18th , which with a second countershaft input shaft 19th cooperates. It is arranged coaxially to this. The third single gear level 12th again includes a loose wheel 20th , namely the second idler gear, which is coaxial with the first countershaft 15th is arranged. The third single gear level 12th also includes a fixed gear 21 , which rotatably with the second part of the transmission input shaft 9 connected is. Also the fourth single gear level 13th includes a non-rotatable with the second part of the transmission input shaft 9 connected fixed gear 22nd , which with the fourth idler wheel 23 combs accordingly. The two countershafts 15th , 19th each have a non-rotatably connected output gear 24 , 25th , which is designed as a fixed gear, these two fixed gears 24 , 25th the countershafts 15th , 19th with another gear, which is not shown here, mesh to the power from the dual clutch transmission 6th submit. The further toothed wheel, not shown, is advantageously a differential wheel connected non-rotatably to a differential cage of an axle differential.

The extremely compact and efficient structure of the double clutch transmission 6th in the hybrid propulsion system 1 now includes six forward gears, namely a first gear G1 , a second gear G2 , a third gear G3 , a fourth gear G4 , a fifth gear G5 and a sixth gear G6 while the reverse gear is via the electric machine 3 can be realized. In addition to exactly four single gear levels 10 , 11 , 12th , 13th exactly four switching elements are provided for this. The first switching element is a bridge switching element A. , which is between the first idler wheel 14th and the second idler wheel 20th is arranged in such a way that there are these two idler gears 14th , 20th can connect if necessary. A switching element for directly connecting the first idler gear 14th with the first countershaft 15th is not provided for. The second idler wheel 20th can use a second switching element B. , possibly in addition to a connection between the two idler gears 14th , 20th with the first countershaft 15th get connected.

Two more switching elements C. and D. are in the area of the second countershaft 19th intended. The third switching element C. and the fourth switching element D. can be designed as a double switching element. This double switching element with the two switching elements C. , D. can now optionally use the third idler wheel 18th or the fourth idler wheel 23 with the second countershaft 19th or it can connect both idler gears in a neutral position 18th , 23 from the second countershaft 19th leave decoupled.

The electric machine 3 is in the hybrid drive system shown here as an example 1 integrated in such a way that it provides torque to the interior of the dual clutch transmission 6th can deliver. It is therefore a so-called P2.5 hybrid, as a parallel hybrid with a connection to the electrical machine 3 inside the gearbox, here the dual clutch gearbox 6th . One rotor 26th of the electric machine 3 is for it with its rotor shaft 27 with a gear 28 connected as a fixed gear, which in the one shown here Embodiment with the first idler gear 14th combs. It could just as well be done with another of the idler gears, for example with the second idler gear 20th , the third idler wheel 18th or the fourth idler wheel 23 comb. These modifications are familiar to the person skilled in the art, so that the electrical machine can use these alternative possibilities 3 into the dual clutch transmission 4th does not need to be discussed further.

Other alternative options, the electric machine 3 to be included would be a connection of the same directly or indirectly with the partial transmission input shafts, for example with one of the fixed gears of the four single gear planes 10 , 11 , 12th , 13th . Alternatively, a classic P2 hybrid with a connection to the double clutch would also be conceivable 7th could take place by means of a further separating clutch, ultimately as a connection in the area of the input shaft 5 .

The dual clutch transmission 6th of the hybrid drive system 1 can now shift six individual forward gears, and this with an extremely compact design, which, for example, can easily be installed in smaller passenger cars across the direction of travel. About the electric machine 3 a reverse gear can also be implemented, so that there is a mechanical reverse gear in the dual clutch transmission 6th can be dispensed with.

In the example of the double clutch transmission 6th in the representation of the 1 results in an in 2 The shift behavior shown is now from the corresponding shift matrix, which shows the six individual transmission gears in the first column G1 until G6 shows in the columns 2 and 3 the current state of the clutches K1 and K2 of the double clutch transmission 6th , whereby the coupling marked with X is closed accordingly. The same applies to the following four columns, which show the status of the respective switching elements A. , B. , C. and D. demonstrate.

The structure is now such that the first gear G1 with the clutch closed K2 and open clutch K1 with closed switching element A. and C. is realized. The power flow starts from the input shaft 5 so about the clutch K2 the double clutch 7th and the second sub-transmission input shaft 9 in the third single gear level 12th via the connected idler gears 14th and 20th without the first countershaft 15th is driven. Then the power flow goes over the first single gear level 10 and its fixed gear 16 on the first partial transmission input shaft 8th and from there over the second single gear level 11 and its third idler wheel 18th when the switching element is closed C. on the second countershaft 19th and via their output gear 25th to the output. It is a winding path in which both sub-transmissions are involved accordingly.

For a transition to second gear G2 become the clutches K1 , K2 the double clutch 7th then the switching element is changed A. solved.

For a transition to third gear G3 becomes the switching element B. between the second idler gear and the first countershaft input shaft, then the clutches are changed again, and finally the shifting element C. solved. Shift positions for the remaining transmission gears result analogously from the shift diagram shown in FIG 2 .

In the representation of the 3 is now an alternative embodiment of the dual clutch transmission 6th can be recognized, whereby only the differences will be discussed in more detail below. These essentially consist in the position of the respective switching elements A. , B. and C. , D. on their respective countershaft 15th , 19th is mirrored, whereby the corresponding single gear planes 10 , 11 ; 12th , 13th have mirrored and accordingly assigned to the other sub-transmission and with the other of the two sub-transmission input shafts 8th , 9 are connected. The circuit diagram, which is not shown here, is still analogous, however, with the two clutches K1 and K2 the double clutch 7th can now be shifted exactly the other way around, i.e. in the first gear G1 the coupling K1 is engaged in the second gear G2 the coupling K2 etc.

In the two gear set plans of the double clutch transmission 6th according to the 1 and 3 it is always the case that the fourth idler wheel 23 The second idler gear is involved in the fifth and sixth gear 20th into the third gear, the first idler gear 14th into the fourth gear and the third idler gear 18th in the first and second gear.

The two variants of the dual clutch transmission shown below 6th in the 4th and 6th , with a circuit diagram in the 5 vary this structure now. The first idler wheel 14th is now involved in the sixth gear G6 ', the one with it via the first shift element A. connectable second idler gear 20th , which via the second switching element B. at the same time as the first countershaft 15th can be coupled is involved in the fifth gear G5 '. The other two in the area of the second countershaft 19th coaxially arranged idler gears 18th and 23 are accordingly involved in the first and second or the third and fourth gear G4 '. Analogous to the description and representation in 2 this is made from the in 5 shown Switching matrix clearly. During the shift behavior for the first two transmission gears 1 and 2 is still unchanged, is used to implement the transmission gears 3 and 4th now no longer the second switching element B. , but instead the fourth switching element D. used, while to implement the fifth gear G5 'and the sixth gear G6' turn the second shift element B. instead of the fourth switching element D. is used, once again with the connection from the second idler wheel 20th to the first idler wheel 14th and once without, as is also the case above.

In the representation of the 6th is finally the structure according to 4th again along the axes of the two countershafts 15th , 19th mirrored single gear planes and shift elements, essentially a structure analogous to that in 3 , but with the different use of the individual idler gears 14th , 18th , 20th , 23 for the respective transmission gears as in 4th . Analogous to the representation in 3 a circuit diagram is also dispensed with here; this would again be in the same way as in 5 shown, with the individual transmission gears again only differing with respect to the shifting through the reverse use of the two clutches K1 and K2 the double clutch 7th result accordingly, as the corresponding single gear planes 10 , 11 ; 12th , 13th in turn to the respective other sub-transmission or its sub-transmission input shaft 8th , 9 assigned.

QUOTES INCLUDED IN THE DESCRIPTION

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

Patent literature cited

• DE 102009002353 A1 [0002]

Claims (10)

Double clutch transmission (6) with a first sub-transmission to which a first clutch (K1) and a first sub-transmission input shaft (8) is assigned, a second sub-transmission to which a second clutch (K2) and a second sub-transmission input shaft (9) is assigned, a first countershaft (15), with which a first output gear (24) is permanently connected in a rotationally fixed manner, a second countershaft (19), with which a second output gear (25) is permanently connected in a rotationally fixed manner, a first idler gear (14) assigned to the first sub-transmission and a the second idler gear (20) assigned to the second sub-transmission are arranged coaxially to the first countershaft (15) and can be coupled to one another in a rotationally fixed manner by means of a bridge shift element (A), a third idler gear (18) assigned to the first sub-transmission and a fourth idler gear assigned to the second sub-transmission (23) are arranged coaxially to the second countershaft (19), characterized in that overall gena u four switching elements (A, B, C, D) are provided, namely the bridge switching element (A), the second switching element (B), a third switching element (C) and a fourth switching element (D), the second switching element (B) is provided for the rotationally fixed connection of the second idler gear (20) to the first countershaft (15), the third shift element (C) is provided for the rotationally fixed connection of a third idler gear (18) with the second countershaft (19) and the fourth shift element (D) for the rotationally fixed connection of a fourth idler gear (23) to the second countershaft (19), whereby a first gear (G1, G1 '), a second gear (G2, G2'), a third gear (G3, G3 '), a fourth gear (G4, G4 '), a fifth gear (G5, G5') and a sixth gear (G6, G6 ') can be formed with the gear ratio falling in the order mentioned. Double clutch transmission (6) Claim 1 , characterized in that the first sub-transmission comprises exactly two single gear planes (10, 11), namely a first single gear plane (10) comprising the first idler gear (14) and a second single gear plane (11), and that the second sub-transmission comprises exactly two single gear planes (12 , 13), namely a third single gear plane (12) comprising the second idler gear (20) and a fourth single gear plane (13). Double clutch transmission (6) Claim 2 , characterized in that the third idler gear (18) is assigned to the second single gear plane (11) and the fourth idler gear (23) is assigned to the fourth single gear plane (13). Double clutch transmission (6) Claim 1 , 2 or 3 , characterized in that the third and fourth shifting elements (C, D) are implemented as double shifting elements with a neutral position. Dual clutch transmission (6) according to one of the Claims 1 until 4th , characterized in that exactly six transmission gears are included, all of which are designed as forward gears. Dual clutch transmission (6) according to one of the Claims 1 until 5 , characterized in that the first idler gear (14) and the second idler gear (20) are set up to form the first gear (G1, G1 '), the fourth gear (G4) and the sixth gear (G6, G6') to contribute. Dual clutch transmission (6) according to one of the Claims 1 until 6th , characterized in that the fourth idler gear (23) is set up to contribute to the formation of the fifth gear (G5, G5 ') and the sixth gear (G6, G6'). Hybrid drive system (1) for a vehicle, with an internal combustion engine (2), an electric machine (3) and a double clutch transmission (6) according to one of the preceding claims, characterized in that the internal combustion engine (2) with an input shaft (5) of the double clutch transmission (7) is at least indirectly coupled or can be coupled. Hybrid drive system (1) according to Claim 8 , characterized in that a rotor (26) of the electrical machine (3) is coupled or can be coupled at least indirectly to one of the countershafts (15, 19) or to one of the sub-transmission input shafts (8, 9). Hybrid drive system according to Claim 9 , characterized in that the rotor (26) of the electrical machine (3) is coupled to one of the four idler gears (14, 18, 20, 23) in such a way that torques originating from the electrical machine via one of the four idler gears (14, 18, 20, 23) can be introduced into the dual clutch transmission (6).

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