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 one first countershaft (12) with a first output gear (14) arranged coaxially thereto, wherein the internal combustion engine (2) can be directly coupled to the input shaft (5) via a separating clutch (4), wherein at least four switchable gear pairs (17, 19, 21, 23, 25) are provided, each with a gear arranged coaxially to the input shaft, 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 the first countershaft (12), and wherein the electric machine (3) is connected to the first gear pair (17) in such a way that torques,starting from the electric machine (3) via the first gear pair (17) into the transmission, , wherein the electric machine (3) is arranged axially overlapping the separating clutch (4), characterized in that the electric machine (3) is arranged axially overlapping the first output gear (14) arranged coaxially with the first countershaft (12), wherein at least two countershafts (12, 13), namely the first countershaft (12) and a second countershaft (13), each with at least one output gear (14, 15), namely the first output gear (14) arranged coaxially with the first countershaft (12) and a second output gear (15) arranged coaxially with the second countershaft (13), are provided, wherein the separating clutch (4) and the at least two output gears (14, 15) are arranged axially overlapping.

Description

[0001] The invention relates to a hybrid drive device with an internal combustion engine, an electric machine and a transmission according to the type defined in more detail in the preamble of claim 1.

[0002] Hybrid drive systems are known, for example, from DE 10 2016 221 097 A1, DE 10 2016 108 124 A1, and DE 10 2019 003 780 B3. The arrangement of a separating clutch is known from DE 37 12 898 A1.

[0003] DE 10 2013 210 013 A1 discloses such a hybrid drive device, in which the electric motor 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 combustion engine (commonly referred to as a P2 connection), and, on the other hand, to a countershaft serving as the output shaft (commonly referred to as a P3 connection). The design features four gear planes for four individual gears. The electric motor is connected to two idler gears on the input shaft, which in turn form a gear pair with another idler gear on the countershaft. The electric motor can thus be coupled, as described above, alternatively to the input shaft of the transmission or its countershaft or output shaft.The structure is relatively large, especially in the axial direction, i.e., the direction running along the input shaft of the transmission. A hybrid drive device with a very similar structure is shown in JP 2011-235 748 A. The electric motor is arranged axially between the separating clutch and an end of the transmission facing away from the separating clutch. Here, too, the transmission has an input shaft and exactly one countershaft driving toward a differential gear.

[0004] US 2003 / 0 104 901 A1 discloses a hybrid drive system comprising an internal combustion engine, an electric motor, and a transmission with an input shaft and a precisely one countershaft driving toward a differential gear. A rotor shaft of the electric motor can be connected to the input shaft and the countershaft via two separate gear planes.

[0005] The object of the present invention is to provide an improved hybrid drive device which is very compact and which is also capable of switching in hybrid mode without a complete interruption of traction.

[0006] According to the invention, this object is achieved by a hybrid drive device having the features in claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments of the hybrid drive device according to the invention emerge from the dependent claims.

[0007] The hybrid drive device initially comprises, in a manner known per se, in addition to the internal combustion engine, an electric machine and a transmission. The transmission comprises an input shaft and at least one first countershaft with a first output gear arranged coaxially thereto. The internal combustion engine can be directly coupled to the input shaft via a separating clutch. At least four switchable gear pairs are provided, each with a gear arranged coaxially to the input shaft, wherein a first of the gear pairs comprises two loose gears, namely a first gear designed as a loose gear and arranged coaxially to the input shaft (5) and a second gear designed as a loose gear and arranged coaxially to the countershaft.The electric machine is connected to this first gear pair in such a way that torques originating from the electric machine or originating from a rotor of the electric machine can be introduced into the transmission via the first gear pair. By configuring the first gear pair with two loose gears, both a P2 connection and a P3 connection are possible. Furthermore, in a manner known per se, the electric machine is arranged so as to axially overlap the separating clutch. According to the invention, the electric machine is arranged so as to axially overlap the first output gear arranged coaxially with the first countershaft.Furthermore, according to the invention, at least two countershafts are provided, namely the first countershaft and a second countershaft, each with at least one output gear, namely the first output gear arranged coaxially to the first countershaft (12) and a second output gear arranged coaxially to the second countershaft. According to the invention, the separating clutch and the at least two output gears are arranged axially overlapping. The overlapping arrangement in the sense of the invention means that the said elements can lie in the same axial plane or, preferably, protrude into the same axial plane in the axial direction. The axial plane is in each case related to a rotational axis of the input shaft, so that each axial plane is perpendicular to the rotational axis of the input shaft and thus to the axial direction.

[0008] A gear pair is understood to mean exactly two meshing gears which are arranged in an axial plane.

[0009] An idler gear mounted on a shaft is understood to be a gear arranged coaxially with the shaft and mounted for rotation relative to the shaft. A switching element is advantageously associated with the idler gear, which is particularly advantageously arranged coaxially with the idler gear and by means of which the idler gear can be connected to the shaft in a rotationally fixed manner.

[0010] A fixed gear as defined below is a gear arranged coaxially to a shaft and permanently connected to this shaft in a rotationally fixed manner.

[0011] The axial direction refers to the direction of the input shaft's rotational axis. The term "radial" used below also refers to the input shaft's rotational axis and denotes a direction perpendicular to the input shaft's rotational axis.

[0012] The above-mentioned features ensure an exceptionally compact design of the hybrid drive device according to the invention, which enables a correspondingly compact construction at very low costs thanks to the special gearset architecture. Furthermore, despite the simple design, full functionality and a high level of comfort during gearshifts are ensured.

[0013] The hybrid drive device according to the invention preferably dispenses with a startable separating clutch and, in particular, also with a mechanical reverse gear. This allows the diameter of the separating clutch to be designed to be correspondingly small, so that it can be arranged in a space-saving manner, overlapping the electric motor or its intermediate gear, and, according to an exceptionally advantageous development, overlapping at least one output gear on the at least one countershaft.

[0014] The design according to the invention with a separating clutch that is very small in terms of its diameter can be achieved in particular by dispensing with the starting capability of the separating clutch.

[0015] In a hybrid vehicle with the hybrid drive device according to the invention, it is particularly preferred that the hybrid drive device be connected to a first driven axle of the hybrid vehicle in a torque-transmitting manner, with a further driven axle of the hybrid vehicle being provided, which is connected to another electric motor in a torque-transmitting manner. Starting and reversing can then be realized purely electrically with one or both of the two electric motors.

[0016] In the case of a hybrid drive, gear shifts within the transmission can be carried out via the combustion engine and, if necessary, the electric motor without load interruption, for example, by the electric motor in the P3 connection compensating or supporting the speeds and torques accordingly during gear shifting. Particularly advantageously, the additional electric motor can be used to support gear shifts within the transmission, allowing the transmission of the hybrid drive system to be designed cost-effectively and relatively simply. In particular, friction shift elements can be dispensed with in favor of more cost-effective dog shift elements or a dual-clutch concept.

[0017] According to a further very advantageous embodiment of the hybrid drive device according to the invention in the above-described advantageous variant with two countershafts, it is further provided that at least two double gear planes are provided, which simplifies the construction of the gear sets and advantageously contributes to a very compact design of the transmission in the axial direction.

[0018] A double gear plane is defined as two gear pairs, each of which shares a common gear. This means that in a double gear plane, the common gear forms a gear pair with another gear, and the common gear forms another gear pair with yet another gear. The common gear, the other gear, and the yet another gear of the double gear plane are arranged in a common axial plane.

[0019] The rotor of the electric machine can now be directly connected or coupled to the first gear pair, so that, for example, a pinion on a rotor shaft of the electric machine meshes directly with one of the idler gears of the first gear pair. It would also be conceivable to use another gear element, such as an intermediate gear. An intermediate gear, within which the gear ratio is changed and which could be designed, for example, as a gear transmission, but also as a chain drive, belt drive, or the like, is also conceivable for connecting the electric machine or the pinion, which is non-rotatably arranged on its rotor shaft, to the first gear pair.Notwithstanding this manner of connecting the electric machine to the first gear pair, according to two independent advantageous embodiments of the hybrid drive device according to the invention, it can now be provided that the connection is made either to the second gear of the first gear pair or, alternatively, to the first gear of the gear pair, i.e., either to the gear of the first gear pair arranged coaxially to the countershaft or to the gear of the first gear pair arranged coaxially to the input shaft of the transmission. This enables further optimization with regard to the available installation space. By designing the two gears of the first gear pair as loose gears, both variants enable both a P2 and a P3 connection.

[0020] Preferably, the electric machine can be connected to the last gear pair as seen in the axial direction from the separating clutch, as the first gear pair, so that it extends in the axial direction along the very compact structure of the transmission and is preferably designed to overlap the separating clutch and / or the at least one output gear in the axial direction.

[0021] According to another very advantageous embodiment, exactly five selectable gear pairs can be provided, each with a gear arranged coaxially with the input shaft. Such a transmission then allows the five gear pairs to be used to realize five gear steps in a very simple and, above all, axially compact design, especially with the aforementioned omission of the mechanical reverse gear.

[0022] Further advantageous embodiments and developments of the hybrid drive device according to the invention also emerge from the exemplary embodiments which are presented in more detail below with reference to the figures.

[0023] Showing: Fig. 1 a first possible variant of the hybrid drive device according to the invention in a construction with two countershafts; and Fig. 2 a second possible variant of the hybrid drive device according to the invention in a design with two countershafts.

[0024] The following figures schematically depict a hybrid drive device 1 in a design according to the invention. The gear set diagrams, which serve to illustrate the transmission installed therein, are neither to scale nor do all components necessarily lie in the plane of the page in which they are depicted. The relative dimensions of the components do not necessarily correspond to the actual design.

[0025] Fig. 1 shows a hybrid drive device 1, which on the one hand comprises an internal combustion engine 2, of which only a section 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 of a transmission of the hybrid drive device 1. The direct connection can optionally comprise a device 6 for absorbing and / or damping torsional vibrations, for example a dual-mass flywheel, between a crankshaft of the internal combustion engine 2 and the separating clutch, so that "direct" is to be understood here in the sense 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.

[0026] In the axial direction a of the input shaft 5, seen from the separating clutch 4, there follows a first fixed gear 7, a second fixed gear 8 and an idler gear 10 with a switching element 11, with which the idler gear 10 can be connected in a rotationally fixed manner to the input shaft 5, wherein rotationally fixed in the sense of the invention means that the connected elements rotate at the same speed.

[0027] Two countershafts 12, 13 are arranged parallel to the input shaft 5. Both countershafts 12, 13 have output gears 14, 15 in an axial plane with the separating clutch 4, namely a first output gear 14 and a second output gear 15, which in turn mesh, for example, with a differential (not shown here) directly or via at least one intermediate transmission element.

[0028] The idler gear 10 is arranged in a final axial plane or gear plane in the axial direction a, viewed from the direction of the separating clutch 4, along the input shaft 5. Such an axial plane is a plane that is perpendicular to the axial direction a and thus ultimately to the input shaft 5. In this final gear plane, the idler gear 10 forms a first gear pair 17 together with an idler gear 16 on the first countershaft 12. A second gear pair 19 is formed between the fixed gear 7 and an idler gear 20 on the second countershaft 13. Adjacent to this in the axial direction a is a third gear pair 21 between the second fixed gear 8 and an idler gear 22, which is also arranged coaxially on the second countershaft 13. A fourth gear pair 23 is in turn formed by the fixed gear 7 and an idler gear 24 located coaxially on the first countershaft 12.A fifth gear pair 25 is formed by the second fixed gear 8 on the input shaft 5 and a loose gear 26, which in turn is arranged on the first countershaft 12.

[0029] The aforementioned idler gear 16 of the first gear pair 17 is also located coaxially with the first countershaft 12. Via a switching element 28, the idler gear 16 can be connected in a rotationally fixed manner to the first countershaft 12 and thus ultimately to the first output gear 14 arranged thereon as a fixed gear.

[0030] The idler gears 26 and 24 of the two gear pairs 23 and 25 enclose between them a shifting element 29 designed as a double shifting element; the second gear pair 19 and the third gear pair 21 enclose a corresponding analogous double shifting element 30 in the area of ​​the second countershaft 13. The two double gear planes with the second and fourth gear pairs 19, 23 on the one hand and the third and fifth gear pairs 21, 25 on the other hand enclose between them, in a further axial plane, the double shifting elements 29, 30 for the respective idler gears 20, 22, 24, 26 on the respective countershaft 12, 13. The shifting elements 11 and 28 for the two idler gears 10 and 16 of the first gear pair 17 are located in a further axial plane.

[0031] The connection of the electric machine 3 itself to the first gear pair 17 is now established via a pinion 31, which is rotationally fixedly connected to a rotor shaft 32 of the electric machine 3. The pinion 31 is connected to the idler gear 16, i.e., the second gear of the first gear pair 17, and can transmit torque to the transmission in this way if necessary. The rotor shaft 32 is rotationally fixedly connected to a rotor of the electric machine 3.

[0032] Depending on the position of the shift elements 11, 28, a so-called P2 connection can be realized, in which the electric motor 3 acts on the input shaft 5 via the pinion 31 and the idler gear 16 of the first gear pair 17, which rotates loosely on the first countershaft 12, and the idler gear 10, which is coupled to the input shaft 5 via the shift element 11, specifically on the side of the separating clutch 4 facing away from the combustion engine 2. Depending on the shift position within the transmission, the output is then via the first countershaft 12 and its first output gear 14 or the second countershaft 13 and its second output gear 15.Alternatively, the structure is switched to a so-called P3 connection, in which the first countershaft 12 and thus its first output gear 14 are driven when the switching element 11 is open and the idler gear 10 is rotating accordingly on the input shaft 5 and the idler gear 16 of the first gear pair 17 is coupled to the first countershaft 12 via the switching element 28.

[0033] The transmission of the hybrid drive device 1 according to Fig. 1 can, for example, be designed to be used as a five-speed transmission without a mechanical reverse gear. The first gear stage can be realized via the first gear pair 17, and the second gear stage via the second gear pair 19, etc.

[0034] The electric machine 3 is different than in Fig. 1 and the following Fig. 2, in the construction according to these figures, it is arranged so as to overlap in the axial direction with the separating clutch 4 and thus in particular also with the drive wheels 14, 15 of the countershafts 12, 13. This enables an extremely compact construction in which the electric machine is ensured by its connection to the last or possibly also the penultimate wheel plane in the axial direction as seen from the separating clutch 4 and its simultaneous axial overlap with the separating clutch 4, i.e. by projecting into the wheel plane of the separating clutch 4 and in particular the output wheels 14, 15, an extremely compact construction.

[0035] The representation of the Fig. 2 essentially shows an analogous structure as already described above in the explanation of the hybrid drive device 1 according to Fig. 1 has been described in detail. Therefore, only the difference will be discussed in more detail below. In contrast to the structure according to Fig. 1, the pinion 31, which there meshed directly with the idler gear 16, is connected here via an intermediate gear 33. This intermediate gear 33 now meshes not with the idler gear 16, i.e. the second gear of the first gear pair 17, but with the idler gear 10 as the first gear of the gear pair 17. In principle, this construction would also be conceivable without the intermediate gear 33, just like the construction of the Fig. 1 can be realized with an intermediate gear 33. The structure differs in the hybrid drive device 1 according to Fig. 2 essentially by the type of connection of the electric machine to the first wheel pair 17. Regardless of the changed connection, both a P2 and a P3 connection can be realized here via the position of the switching elements 11, 28.

[0036] The transmission of the hybrid drive device 1 according to Fig. 2 is also a five-speed gearbox like the one in the design of the hybrid drive device 1 according to Fig. 1. Unlike there, not every gear pair 17, 19, 21, 23, 25 is assigned to the corresponding gear step in its numbering. Rather, the structure can be Fig. 2, in particular, be used such that the fourth gear pair 23 is used to form the first gear, while the second gear pair 19 is used to form the second gear. The first gear pair 17 would then be used to implement the third gear stage, the fifth gear pair 25 to implement the fourth gear stage, and the remaining third gear pair 21 to implement the second gear stage.

[0037] Otherwise, the structure is in accordance with the Fig. 1 and Fig.2, the electric motor 3 is arranged overlapping both the separating clutch 4 and the two output gears 14, 15. The two structures have the same axial gear planes and are therefore of comparable size in the axial direction a.

Claims

[1] 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 one first countershaft (12) with a first output gear (14) arranged coaxially thereto, wherein the internal combustion engine (2) can be directly coupled to the input shaft (5) via a separating clutch (4), wherein at least four switchable gear pairs (17, 19, 21, 23, 25) are provided, each with a gear arranged coaxially to the input shaft, 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 the first countershaft (12), and wherein the electric machine (3) is connected to the first gear pair (17) in such a way that torques,starting from the electric machine (3) via the first gear pair (17) into the transmission, wherein the electric machine (3) is arranged axially overlapping the separating clutch (4), characterized by , that the electric machine (3) is arranged axially overlapping the first output gear (14) arranged coaxially with the first countershaft (12), wherein at least two countershafts (12, 13), namely the first countershaft (12) and a second countershaft (13), each with at least one output gear (14, 15), namely the first output gear (14) arranged coaxially with the first countershaft (12) and a second output gear (15) arranged coaxially with the second countershaft (13), are provided, wherein the separating clutch (4) and the at least two output gears (14, 15) are arranged axially overlapping. [2] Hybrid drive device (1) according to claim 1, characterized bythat at least two double wheel levels are provided. [3] Hybrid drive device (1) according to one of claims 1 or 2, characterized by that the electric machine (3) is connected to the first gear pair (17) in such a way that torques originating from the electric machine (3) at the second gear of the first gear pair (17) can be introduced into the transmission. [4] Hybrid drive device (1) according to one of claims 1 or 2, characterized by that the electric machine (3) is connected to the first gear pair (17) in such a way that torques originating from the electric machine (3) can be introduced at the first gear wheel (10) of the first gear pair (17). [5] Hybrid drive device (1) according to one of claims 1 to 4, characterized by that the electric machine (3) is connected to the last wheel pair (17) seen in the axial direction (a) and from the separating clutch (4).

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