Hybrid drive device

Abstract

Hybrid drive device (1) with an internal combustion engine (2), an electric machine (3) and a transmission, wherein the transmission has an input shaft (5) and at least two countershafts (12, 13), each with an output gear (14, 15), wherein the internal combustion engine (2) can be directly coupled to the input shaft (5) via a separating clutch (4), wherein at least six switchable gear pairs (17, 19, 21, 23, 25, 27) are provided, each with a gear arranged coaxially to the input shaft (5), wherein a first of the gear pairs (17) has a first gear designed as an idler gear (10) and arranged coaxially to the input shaft (5) and a second gear designed as an idler gear (16) and arranged coaxially to a countershaft (12, 13) of the two countershafts (12, 13), wherein the electric machine (3) is configured in such a way is connected to the first gear pair (17) that torques,starting from the electric machine (3) via the first gear pair (17) into the transmission, and wherein the first gear pair (17) is arranged in the last or penultimate gear plane in the axial direction (a) and as seen from the separating clutch (4), , wherein the electric machine (3) is arranged axially overlapping the separating clutch (4), characterized in that the separating clutch (4) and at least two output gears (14, 15) are arranged axially overlapping.

Description

The invention relates to a hybrid drive device having an internal combustion engine, an electric machine and a transmission of the type defined in more detail in the preamble of claim 1.DE 10 2010 030 572 A1, WO 2008 / 138 387 A1, DE 10 2017 102 943 A1 and DE 10 2016 002 863 A1 disclose hybrid drive devices having an internal combustion engine, an electric machine and a transmission.In relation to the more detailed prior art, DE 10 2019 202 955 A1, DE 10 2016 221 097 A1, DE 10 2013 210 013 A1, DE 10 2018 200 879 A1 and the generic US 2003 / 0 104 901 A1 each describe such a hybrid drive device in which the electric machine can be connected on the one hand to the input shaft of the transmission but on the side of a separating clutch facing away from the internal combustion engine, which is also referred to as a P2 connection, and also to a countershaft serving as an output shaft, which is in turn referred to as a P3 connection. The structure has four wheel planes for four individual gears. The electric machine is connected to two idler gears on the input shaft, which in turn form a wheel pair with a respective further idler gear on the countershaft. The electric machine can thus be coupled in the manner described above alternatively to the input shaft of the transmission or its countershaft or output shaft accordingly.Despite a comparatively few gear stages, the structure is relatively large, especially also in the axial direction, i.e. in the direction running along the input shaft of the transmission.The object of the present invention is to provide an improved hybrid drive device which, despite a plurality of gear stages, is very compact above all in the axial direction and which is moreover capable of shifting in the hybrid mode without complete interruption of the tractive force.According to the invention, this object is achieved by a hybrid drive device having the features in claim 1, and here in particular in the characterizing part of claim 1. Advantageous embodiments and developments of the hybrid drive device according to the invention are evident from the dependent claims dependent thereon.The hybrid drive device according to the invention therefore comprises, in addition to the internal combustion engine, an electric machine and a transmission. The transmission comprises an input shaft and at least two countershafts, each with an output wheel. In this case, at least six shiftable wheel pairings are provided, each with a gearwheel arranged coaxially with respect to the input shaft, wherein a first of the wheel pairings comprises two idler wheels, one on the input shaft and one on a countershaft of the two countershafts. The electric machine is connected to this first wheel pair in such a way that torques can be introduced into the transmission via the first wheel pair, starting from the electric machine. By configuring the first wheel pairing via two loose wheels, both a P2 connection and a P3 connection are possible. The first wheel pair is here the last or next to last wheel pair, as seen along the input shaft from the separating clutch. In a manner known per se, the electric machine overlaps the separating clutch in the axial direction. The overlapping arrangement in the sense of the invention means that the elements mentioned can lie in the same axial plane or, however, preferably project in the axial direction into the same axial plane. The axial plane is in this case in each case related to the input shaft, such that each axial plane is perpendicular to an axis of rotation of the input shaft and thus to the axial direction. According to the invention, the separating clutch and the at least two output wheels are arranged axially overlapping. This construction with a separating clutch which is very small in terms of its diameter can be achieved in particular by eliminating the startability of the separating clutch.The axial direction is identical to a direction of the axis of rotation of the input shaft.A loose wheel arranged on a shaft means a gearwheel arranged coaxially and rotatably with respect to this shaft, which gearwheel can be connected to the mentioned shaft in a rotationally fixed manner by means of an associated switching device. The associated switching device is also arranged coaxially to the shaft.By a fixed wheel, on the other hand, is meant a gear wheel which is arranged coaxially to a shaft and is permanently connected to this shaft in a rotationally fixed manner.A rotationally fixed connection of two rotatably mounted elements generally means that the two elements are arranged coaxially with respect to one another and are connected to one another in such a way that they rotate at the same angular speed.A wheel pairing is to be understood to mean exactly two mutually intermeshing gearwheels. The two gearwheels are arranged substantially in a common axial plane.By a first element being arranged axially overlapping with a second element, it is to be understood that at least a first part of the first element and a second part of the second element have the same axial extension range.By coaxial arrangement of an element with respect to another element is meant that one axis of rotation of the element and another axis of rotation of the other element are identical.In the above-mentioned manner, an extraordinarily compact construction of the hybrid drive device according to the invention is ensured, which enables a correspondingly compact construction at very low costs achieved by the special wheelset architecture. In addition, despite the simple construction, there is full functionality of six or more gear stages and high comfort in the shifting operations.For this purpose, the hybrid drive device according to the invention can preferably dispense with a disconnect clutch that can be started and in particular also with a mechanical reverse gear. As a result, the diameter of the separating clutch can be designed to be correspondingly small, so that it can be arranged in a space-saving manner overlapping the electric machine and overlapping the output gears on the countershafts.In a hybrid vehicle having the hybrid drive device according to the invention, it is then possible for it to be used together with a further purely electrically driven axle for driving an axle driven via the hybrid drive device. Starting processes and a reverse travel can then be implemented purely electrically with one or also both electric machines, that is to say the hybrid drive device according to the invention and the further purely electrically driven axle. The shifts within the transmission can take place without load interruption in the case of hybrid drive with the internal combustion engine and, if appropriate, with the electric machine, in that the electric machine compensates or supports the rotational speeds and torques accordingly in the P3 connection during the shift.According to a further very favorable embodiment of the hybrid drive device according to the invention in the above-described advantageous embodiment with two countershafts, it is provided that at least two dual gear planes are provided, which simplifies the construction of the gear sets and permits a very compact construction of the transmission in the axial direction.The term "dual-wheel plane" means two wheel pairings lying in an axial plane, wherein the two wheel pairings have a common gearwheel. The common gearwheel is arranged here coaxially with respect to the axis of rotation of the input shaft and meshes both with one wheel of the one wheel pair and with another wheel of the other wheel pair.Of the two provided dual-wheel planes, one of two of the 6 switchable wheel pairings is formed. The other is formed by two other of the 6 switchable wheel pairings. Thus, according to this further development 4 of the switchable wheel pairings are arranged in only 2 axial planes.The electric machine can be connected directly via a pinion connected to its rotor shaft in a rotationally fixed manner, i.e. rotating at the same rotational speed, or via a corresponding gear element, which can in principle be any type of gear element such as, for example, an intermediate gear, an intermediate gear, a chain drive or the like, to the first wheel pair. The connection can be made either in the second gearwheel of the first wheel pair or alternatively also on the first gearwheel of the wheel pair, i.e. either on the gearwheel of the first wheel pair arranged coaxially with the countershaft or on the gearwheel of the first wheel pair arranged coaxially with the input shaft of the transmission. This allows a further optimization with regard to the available installation space. By configuring the two gearwheels of the first wheel pair as idler wheels, both variants enable both a P2 and a P3 connection.Preferably, the electric machine can be connected to the last wheel pair viewed in the axial direction from the separating clutch, so that it extends in the axial direction along the very compact structure of the transmission and is arranged overlapping the separating clutch in the manner described at the beginning and, according to the described embodiments, preferably also overlapping the at least one output wheel in the axial direction.According to a further very advantageous embodiment, exactly six shiftable wheel pairings with a gearwheel arranged coaxially to the input shaft can be provided. Such a transmission allows the realization of six gear stages with the six wheel pairings in a very simple construction, in particular when the mechanical reverse gear is dispensed with as described above. In this case, the exactly six wheel pairings in the embodiment with two countershafts can be distributed, for example, to three double wheel planes or to two double wheel planes and two single wheel planes, in order to be able to realize the individual wheel planes and the required shift clutches in an optimum manner with respect to their arrangement in the axial direction and with the desired short design of the transmission in the axial direction.In the embodiment variant with two countershafts, it can furthermore be provided that at least two shiftable idler gears are arranged coaxially to each of the countershafts, preferably axially adjacent to each other. As a result of this construction, the actuator for the shift can be displaced between the two idler wheels adjacent to one another, which makes the construction even simpler and more compact with regard to the control and actuator system.A further very favorable embodiment of the hybrid drive device according to the invention can furthermore provide that at least two fixed wheels are arranged on the input shaft in the axial direction following the separating clutch, said fixed wheels forming corresponding wheel pairings, preferably each in a double wheel plane. This construction is extremely compact and efficient and can further support the compactness of the construction, in particular with the above-mentioned combination for connecting the electric machine to the last or next to last wheel pair as first wheel pair in the sense of the invention.Further advantageous embodiments and developments of the hybrid drive device according to the invention also result from the exemplary embodiments which are illustrated in more detail below with reference to the figures.The following are shown: FIG. 1 shows a first possible variant of the hybrid drive device according to the invention in a design with two countershafts; FIG. 2 shows a second possible variant of the hybrid drive device according to the invention in a design with two countershafts; FIG. 3 shows a third variant of the hybrid drive device according to the invention in a design with two countershafts; FIG. 4 shows a fourth possible variant of the hybrid drive device according to the invention in a design with two countershafts; FIG. 5 shows a fifth possible variant of the hybrid drive device according to the invention in a design with two countershafts; and FIG. 6 shows a sixth possible variant of the hybrid drive device according to the invention in a design with two countershafts.In the following figures, a hybrid drive device 1 in a design according to the invention is shown schematically. The wheelset plans which serve to represent the gearing installed therein are neither to scale nor are all components necessarily located in the plane of the blades in which they are represented. The orders of magnitude of the components with respect to one another also do not have to correspond to the real structure.FIG. 1 shows a hybrid drive device which, on the one hand, comprises an internal combustion engine 2, only a portion of which is indicated here. On the other hand, an electric machine 3 is provided. The internal combustion engine 2 is connected via a separating clutch 4 to an input shaft 5 of a transmission of the hybrid drive device 1. The direct connection can optionally comprise a device 6 for eliminating and / or damping torsional oscillations, for example a two-mass flywheel, between a crankshaft of the internal combustion engine 2 and the separating clutch 4, so that it is directly to be understood here that no further transmission elements such as clutches, transmission ratios or the like are arranged between the crankshaft of the internal combustion engine 2 and the separating clutch 4.Viewed from the separating clutch 4, coaxially to the input shaft 5, a first fixed gear 7, a second fixed gear 8, a first idler gear 9 and a second idler gear 10 follow in the axial direction a of the input shaft 5 and a shifting device 11 between these two idler gears 9, 10, with which the idler gears 9, 10 can each be connected to the input shaft 5 in a rotationally fixed manner. Rotationally fixed in the sense of the invention means that the elements rotate at the same speed.Two countershafts 12, 13 are arranged in parallel to the input shaft 5. Both countershafts 12, 13 have output wheels 14, 15 in an axial plane with the separating clutch 4, which in turn mesh, for example, with a differential not shown here directly or via at least one intermediate transmission element.The second idler gear 10, which represents the last gearwheel along the input shaft 5 in the axial direction a from the viewing direction of the separating clutch 4, forms a first wheel pair 17 with an idler gear 16 of the first countershaft 12. The first loose wheel 9 on or coaxial to the input shaft 5 forms a second wheel pair 19 with a fixed wheel 18. The second fixed gear 8 arranged in front of this first idler gear 9 of the second wheel pair 19 in the axial direction a in the direction of view from the separating clutch forms a third wheel pair 21 with one idler gear 20 on the first countershaft and a fourth wheel pair 23 with a further idler gear 22, this time on the other of the countershaft 13.A switching device 28 for the loose wheel 16 of the first wheel pair 17, i.e. for the second gear of the wheel pair 17, is arranged between the wheel plane of the first wheel pair 17 and the wheel plane of the second wheel pair 19, as seen in the axial direction a. Preferably, the shifting device 28 lies in an axial plane in the axial direction a with the shifting device 11, which is designed as a double shifting device between the two idler gears 9, 10 on the input shaft 5. An axial plane refers to a plane perpendicular to the axial direction a or to the input shaft 5.Between the two axial wheel planes, which are designed as double wheel planes and have the third and fourth wheel pairs 21, 23 or the fifth and sixth wheel pairs 25, 27, there are two further double switching devices 29, 30, which preferably lie again in an axial plane. In addition, as already mentioned, the two output wheels 14, 15 of the respective countershafts 12, 13 are situated in the same axial plane as the separating clutch 4.The connection of the electric machine 3 is now effected in such a way that a pinion 31, which is connected in a rotationally fixed manner to a rotor shaft 32 of the electric machine, is connected to the first wheel pair 17 via an optional intermediate wheel 33 in such a way that torque can be introduced from the electric machine 3 into the transmission. Depending on the position of the shifting devices 11, 28, a so-called P2 connection can be realized in which the electric machine 3 acts accordingly via the pinion 31, the intermediate gear 33, the loose gear 16 of the first wheel pair, which runs loosely on the first countershaft 12, and the loose gear 10 coupled to the input shaft via the shifting device 11, on the input shaft 5, namely on the side of the separating clutch 4 facing away from the internal combustion engine 2. Depending on the shift position within the transmission, the output then takes place via the first countershaft 12 and its output gear 14 or the second countershaft 13 and its output gear 15. Alternatively, the design is switched to a so-called P3 connection, in which, when the shift device 11 is open and the idler gear 10 rotating accordingly on the input shaft 5 and the idler gear 16 of the first wheel pair 17 coupled to the first countershaft 12 via the shift device 28, the first countershaft 12 and thus its output gear 14 is driven by the electric machine 3.The transmission of the hybrid drive device 1 can be designed, for example, in such a way that it is used as a six-speed transmission without a mechanical reverse gear. In this case, the first gear stage can be realized via the first wheel pair 17 and the second gear stage can be realized via the second wheel pair 19. The third gear stage can then be realized via the fifth wheel pair 25 and the fourth gear stage can be realized via the third wheel pair 21. In all these gear stages 1 to 4, the output is carried out accordingly via the first countershaft 12 and its output gear 14, which is connected as a fixed gear in a rotationally fixed manner to the first countershaft 12. The fifth and sixth gear stages can then be realized via the two further wheel pairings of the two double wheel planes around the fixed wheels 7, 8 on the input shaft 5, for example by the fifth gear stage being shifted via the sixth wheel pairing 27 and the fourth wheel pairing 23 being the sixth gear stage.Unlike the electric machine 3 shown in FIG. 1 and the subsequent figures, the electric machine 3 is arranged overlapping in the axial direction with respect to the separating clutch 4 and thus in particular also with respect to the drive wheels 14, 15 of the countershafts 12, 13. This enables an extraordinarily compact construction in which the electric machine ensures an extraordinarily compact construction by the connection to the last or possibly also next to last wheel plane viewed in the axial direction a from the separating clutch 4 and its simultaneous axial overlap of the separating clutch 4, i.e. a protrusion into the wheel plane of the separating clutch 4 and in particular of the output wheels 14, 15.The structure of the hybrid drive device 1 in FIG. 2 now combines the two axial wheel planes of the first wheel pair 17 and of the second wheel pair 19 into a further dual wheel plane, which makes the structure even more compact, in particular in the axial direction a. The two loose wheels 9, 10 are replaced by a single loose wheel 10, which is arranged coaxially to the input shaft 5 and can be connected to the shifting device 11, which is now designed as a single shifting device, in a rotationally fixed manner to the latter. The first gear plane 17 is now formed from this idler gear 10 and the idler gear 16 with the shifting device 28 assigned to it, wherein, as a further difference, the idler gear 16 and the shifting device 28 are now arranged on the other, i.e. the second countershaft 3. The fixed gear 18 on the first countershaft 12 of the second wheel pair is now also replaced by a loose gear 34, which can be connected to the first countershaft 12 in a rotationally fixed manner via a switching device 35. The connection of the electric machine 3 to the first wheel pair 17 is also effected here via the idler wheel 16, i.e. its second gear, analogous to the illustration in FIG. 1, but is illustrated in the lower half. By using the idler gears 34, 10 and 16 in a gear plane and the possibility of connecting them to the associated shafts 12, 5, 13 in each case in a rotationally fixed manner, the P3 link now yields the possibility of realizing them both via the first countershaft 12 and its output gear 14 and also via the second countershaft 13 and its output gear 15.The gear stages can again be realized correspondingly analogously to the explanation of the hybrid drive device according to FIG. 1.In the illustration of FIG. 3, the structure of the hybrid drive device 1 shown in FIG. 2 is adopted again. The connection of the electric machine 3 is again effected here via the pinion 31 of the rotor shaft 32 and the intermediate gear 33 to the first wheel pair 17, but no longer to the idler gear 16 on one of the countershafts, here the second countershaft 13, but to the idler gear 10 on the input shaft 3. All other possibilities as well as the switching possibilities and the possibilities for connecting the electric machine 3 are again analogous to those in the hybrid drive device 1 according to FIG. 2.The connection of the electric machine via its pinion 31 or the intermediate gear 33, which is to be understood as optional here, could also be effected in the hybrid drive device 1 according to FIG. 1 in such a way that the connection to the first wheel pair 17 is effected not via its second gear, i.e. the loose gear 16, but via its first gear, i.e. the loose gear 10, accordingly, substantially thus analogously to the exemplary embodiment of FIG. 3 just described.In the embodiment variant in FIG. 4, it is now the case that the structure, as viewed in the axial direction from the internal combustion engine 2 or the separating clutch 4, along the input shaft 5 again corresponds to that of the hybrid drive device 1 according to the previous figures in the two first wheel planes with the fixed wheels 7, 8 and in the plane of the separating clutch 4 and the output wheels 14, 15 which axially overlap it and are preferably arranged in the same plane. In the further course in the axial direction, the first wheel pair 17 with the loose wheels 10 and 16 is now designed analogously to the variant embodiment of the hybrid drive device 1 according to FIG. 1, wherein the wheel plane with the first wheel pair 17 is here, as viewed from the separating clutch 4, not the last but the next-to-last wheel plane, as before. The connection of the electric machine 3 is again effected here via an intermediate wheel 33 and can be effected here, as is illustrated in dashed lines, via the second gearwheel of the first wheel pair 17, that is to say the loose gearwheel 16, or, as is illustrated in dash-dotted lines, via the first gearwheel of the wheel pair 17, that is to say here the loose gearwheel 10. A further wheel plane then adjoins along the input shaft 5, as seen in the axial direction a from the separating clutch 4. Unlike hitherto, it now comprises a fixed gear 36 on the input shaft 5 and a loose gear 37 with an associated shifting device 38 on one of the countershafts, here the second countershaft 13, while the first wheel pair 17 is again formed in a manner analogous to the illustration in FIG. 1 between the input shaft 5 and the first countershaft 12.In the illustration of FIG. 5, it is now the case that this structure illustrated in FIG. 4 has been interchanged with respect to the last and the next-to-last wheel plane, as seen in the axial direction a along the input shaft 5, as seen from the separating clutch 4, so that the fixed wheel 36 therefore adjoins the fixed wheels 7 and 8 on the input shaft 5 in the axial direction a and the first wheel pairing 17 with the idler wheel 10 and the idler wheel 16 again forms the last wheel plane. Here too, the connection of the electric machine 3 to the idler gear 10 or 16 can be made as desired, depending on how it is more suitable with regard to the structural design.The structure according to FIG. 6 then again corresponds to the structure of FIG. 5, wherein the second wheel pair 19 again comprises the idler wheel 9 on the input shaft 5 and a fixed wheel 39. Analogously to the illustration in FIG. 1, this design is then merely modified in such a way that the fixed gear 39 travels from the first countershaft 12 to the second countershaft 13 here, unlike the fixed gear 18 in the illustration in FIG. 1. The electric machine 3 can in turn be integrated via the loose wheel 16 or the loose wheel 10 of the first wheel pair 17, which has already been described in the explanation of the illustration in FIG. 1, even if it is not explicitly shown there.All variants of the hybrid drive device 1 according to FIGS. 1 to 6 allow six gears to be realized without a mechanical reverse gear. The hybrid drive device 1 can preferably be used for driving a first driven axle of a vehicle, in which a second driven axle is driven purely electrically. The vehicle could then in principle have further driven or non-driven axles, wherein the structure as a passenger car typically provides two axles. Such a hybrid car is the preferred, but not exclusive, use of the hybrid drive device 1.

Claims

Hybrid drive device (1) having an internal combustion engine (2), an electric machine (3) and a transmission, wherein the transmission has an input shaft (5) and at least two countershafts (12, 13) each having an output wheel (14, 15), wherein the internal combustion engine (2) can be coupled directly to the input shaft (5) via a separating clutch (4), wherein at least six shiftable wheel pairings (17, 19, 21, 23, 25, 27) are provided each having a gearwheel arranged coaxially to the input shaft (5), wherein a first of the wheel pairings (17) has a first gearwheel designed as a loose wheel (10) and arranged coaxially to the input shaft (5) and a second gearwheel designed as a loose wheel (16) and arranged coaxially to a countershaft (12, 13) of the two countershafts (12, 13), wherein the electric machine (3) is connected to the first wheel pairing (17) in such a way that torques, Transmission starting from the electric machine (3) via the first wheel pair (17), and wherein the first wheel pair (17) is arranged in the axial direction (a) and, as viewed from the separating clutch (4), in the last or next-to-last wheel plane, wherein the electric machine (3) is arranged axially overlapping with the separating clutch (4), characterized in that the separating clutch (4) and the at least two output wheels (14, 15) are arranged axially overlapping.Hybrid drive device (1) according to Claim 1, characterized in that at least two double-wheel planes are provided.Hybrid drive device (1) according to either of Claims 1 and 2, characterized in that the electric machine (3) is connected to the first wheel pair (17) in such a way that torques, starting from the electric machine (3), can be introduced at the second gearwheel (16) of the first wheel pair (17).Hybrid drive device (1) according to either of Claims 1 and 2, characterized in that the electric machine (3) is connected to the first wheel pair (17) in such a way that torques, starting from the electric machine (3), can be introduced at the first gearwheel (10) of the first wheel pair (17).Hybrid drive device (1) according to one of Claims 1 to 4, characterized in that the electric machine (3) is connected to the last wheel plane (27), as seen in the axial direction from the separating clutch (4).Hybrid drive device (1) according to one of Claims 1 to 5, characterized in that exactly six switchable wheel pairings (17, 19, 21, 23, 25, 27) are provided, each with a gearwheel arranged coaxially with respect to the input shaft (5).Hybrid drive device (1) according to Claim 1, characterized in that at least two shiftable idler gears (20, 24; 22, 26) are arranged coaxially with each of the countershafts (12, 13), in each case axially adjacent.Hybrid drive device (1) according to one of Claims 1 to 7, characterized in that the electric machine (3) is connected directly or indirectly via an intermediate wheel (33) or an intermediate transmission to the first wheel pair (17).Hybrid drive device (1) according to Claim 2, characterized in that, following the separating clutch (4) in the axial direction (a), at least two fixed wheels (7, 8) are arranged coaxially with respect to the input shaft (5), which are each part of a double-wheel plane.

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