Hybrid drive train device with centring means

Abstract

The invention relates to a hybrid drive train device (10) for a vehicle, for connection to an internal combustion engine of the vehicle, having an electric motor (12) comprising an electric motor housing (16) and a rotatable rotor shaft (24) which can be positioned offset and axially parallel to a crankshaft (22) of the internal combustion engine, a transmission (14) comprising a transmission housing (26) and a rotatable first transmission shaft (28) which is connected to the rotor shaft (24) in an at least torque-transmitting manner and to which a first gearwheel (30) is fastened, and a rotatable second transmission shaft (32) which can be connected to the crankshaft (22) at least for conjoint rotation and to which a second gearwheel (36) is fastened which is at least indirectly in toothed engagement with the first gearwheel (30) so as to form at least one gearwheel pair (34), wherein the first gearwheel (30) can be rotated about a first axis of rotation (38) in order to form the at least one gearwheel pair (34), wherein the rotor shaft (24) is centred with respect to the first axis of rotation (38) via centring means (48).

Description

[0001] Hybrid powertrain device with centering means

[0002] Description introduction

[0003] The invention relates to a hybrid powertrain device according to the preamble of claim 1.

[0004] DE 102018 106 987 A1 describes a hybrid module for the drive train of a motor vehicle, in which a crankshaft and an output shaft of an electric motor are connected in a torque-transmitting manner by an endless traction device, preferably a chain. An eccentric tensioner is arranged to tension the endless traction device.

[0005] DE 102018 111 410 A1 describes a hybrid module for a vehicle with two meshing gears for transmitting torque between an output shaft of an electric motor and a crankshaft of an internal combustion engine. The tolerance situation is accommodated by the geometry of the gears and finally adjusted via the gear pairing during assembly.

[0006] The object of the present invention is to reduce the noise and vibration of the hybrid powertrain device. Furthermore, the hybrid powertrain device should be designed to be cost-effective and robust.

[0007] At least one of these objects is achieved by a hybrid powertrain device having the features of claim 1. This allows imbalances in the hybrid powertrain device to be reduced. Furthermore, wear in the hybrid powertrain device can be reduced. The torque transmission capacity and the maximum speeds of the hybrid powertrain device are increased.

[0008] The vehicle can be a motor vehicle, a goods vehicle or a two-wheeled vehicle.

[0009] The hybrid powertrain device may be associated with a P2 hybrid arrangement. The electric motor and the internal combustion engine may individually or jointly output drive power to propel the vehicle.

[0010] The electric motor can have a stator fixed to the electric motor housing and a rotor rotatable relative to the stator. The rotor can be connected to the rotor shaft at least in a rotationally fixed manner, in particular fixedly. The electric motor housing can be designed in one piece or in multiple parts. The rotor shaft can be centered relative to the first axis of rotation by the centering means via the first gear shaft. The rotor shaft can be connected to the first gear shaft via a spline in a torque-transmitting manner. The spline can comprise an external toothing on the rotor shaft and an internal toothing in meshing engagement therewith on the first gear shaft, or vice versa. The spline can comprise an external toothing on the rotor shaft and an external toothing on the first gear shaft. The two external toothings can be connected to one another via a toothing sleeve with an internal toothing in a torque-transmitting manner.The spline can comprise an internal gear on the rotor shaft and an internal gear on the first gear shaft. The two internal gears can be connected to each other via a gear sleeve with an external gear in a torque-transmitting manner.

[0011] The rotor shaft can be axially movable or axially fixed relative to the first gear shaft.

[0012] The first gear and the first gear shaft may be formed as one piece. The first gear may be mounted concentrically to the first gear shaft.

[0013] The second gear can be mounted concentrically to the second gear shaft. The second gear can mesh directly with the first gear. The second gear can mesh indirectly with the first gear, i.e., via at least one other gear. The meshing can comprise spur gearing or helical gearing on the two gears.

[0014] The second gear and the second gear shaft can be designed as one piece.

[0015] The gear housing can be a single-piece or multi-piece design. The first and second gears can be located within the gear housing.

[0016] The rotor shaft can be connected to the crankshaft exclusively via gears enclosing the first and second gears. An arrangement of belts and / or chains for torque transmission between the rotor shaft and the second gear shaft can be omitted.

[0017] In a preferred embodiment of the invention, it is advantageous if the centering means comprise a pilot bearing between the rotor shaft and the first gear shaft. The pilot bearing can comprise a centering projection in the rotor shaft and a centering opening in the first gear shaft that receives the centering projection. The pilot bearing can comprise a centering opening in the rotor shaft and a centering projection on the first gear shaft that is arranged in the centering opening. The centering projection can be arranged on an axial end face of the rotor shaft or first gear shaft, and the centering opening can be arranged correspondingly on an axially opposite end face of the first gear shaft or the rotor shaft. The pilot bearing can comprise a clearance fit, plain bearing, or roller bearing.

[0018] In an advantageous embodiment of the invention, the centering means comprise a spline between the rotor shaft and the first gear shaft. The spline can connect the rotor shaft to the first gear shaft in a torque-transmitting manner. The spline can be implemented directly between the rotor shaft and the first gear shaft or indirectly via a gear sleeve. The centering can be achieved by a tip or flank centering in the spline.

[0019] In a preferred embodiment of the invention, it is advantageous if the rotor shaft is mounted directly opposite the electric motor housing via at least one first bearing element, and the first transmission shaft is mounted directly opposite the transmission housing via at least one second bearing element. The first and / or second bearing element can comprise a rolling bearing, in particular a ball bearing. The rotor shaft is preferably mounted relative to the electric motor housing by at least two axially offset first bearing elements. The first transmission shaft is preferably mounted relative to the transmission housing by at least two axially offset second bearing elements.

[0020] In an advantageous embodiment of the invention, the first gear shaft is mounted directly opposite the gear housing via a single second bearing element. The second bearing element can be arranged axially opposite the rotor shaft with respect to the first gear. The second bearing element can be arranged axially overlapping the first gear at least in sections, in particular completely.

[0021] In a preferred embodiment of the invention, it is advantageous if the centering means comprise at least one centering seat between the electric motor housing and the transmission housing. The centering opening can comprise an axial projection on the electric motor housing and an axial recess receiving the axial projection, or vice versa. Centering can be carried out via an outer circumferential surface of the axial projection and an adjacent inner circumferential surface of the axial recess, or vice versa. In an advantageous embodiment of the invention, it is provided that the rotor shaft and the first transmission shaft are designed as one piece. This allows the hybrid drive train device to be designed more cost-effectively.

[0022] In a specific embodiment of the invention, it is advantageous if the first gear shaft is mounted relative to the gear housing exclusively via the rotor shaft. Direct mounting of the first gear shaft relative to the gear housing can be completely eliminated.

[0023] In a specific embodiment of the invention, it is advantageous if the electric motor can be positioned on the same axial side relative to the transmission as the combustion engine. This allows the axial installation space of the hybrid powertrain and combustion engine arrangement to be reduced.

[0024] In a specific embodiment of the invention, it is advantageous if the second transmission shaft can be positioned concentrically to the crankshaft. The second transmission shaft can be firmly connected to the crankshaft, in particular by screwing.

[0025] Further advantages and advantageous embodiments of the invention emerge from the description of the figures and the illustrations.

[0026] Character description

[0027] The invention is described in detail below with reference to the figures. They show in detail:

[0028] Figure 1: A cross-section of a hybrid powertrain device in a special

[0029] Embodiment of the invention.

[0030] Figures 2 and 3: A section of a cross section of a hybrid powertrain device, each in a further specific embodiment of the invention.

[0031] Figure 4: A cross-section of a hybrid powertrain device in another specific embodiment of the invention.

[0032] Figures 5 to 7: A section of a cross section of a hybrid drivetrain device, each in a further specific embodiment of the invention. Figure 8: A cross section of a hybrid drivetrain device in a further specific embodiment of the invention.

[0033] Figure 9: A section of a cross section of a hybrid powertrain device in another specific embodiment of the invention.

[0034] Figure 1 shows a cross-section of a hybrid drivetrain device in a specific embodiment of the invention. The hybrid drivetrain device 10 for a vehicle for connection to an internal combustion engine 11 of the vehicle comprises an electric motor 12 and a transmission 14. The electric motor 12 comprises an electric motor housing 16 in which a stator 18 and a rotor 20 rotatable relative to the stator 18 are arranged. The rotor 20 is at least rotationally fixedly connected to a rotatable rotor shaft 24 arranged offset and axially parallel to a crankshaft 22 of the internal combustion engine 11.

[0035] The transmission 14 comprises a transmission housing 26, which is connected to the electric motor housing 16, and a rotatable first transmission shaft 28, which is at least rotationally fixedly connected to the rotor shaft 24 and which receives a first gear 30, and a rotatable second transmission shaft 32, which is at least rotationally fixedly connected to the crankshaft 22 and which receives a second gear 36 that is in direct tooth engagement with the first gear 30 and thus forms a gear pair 34. The first and second gears 30, 36 are in direct tooth engagement, and the first gear 30 is rotatable about a first axis of rotation 38, and the second gear 36 is rotatable about a second axis of rotation 40. The second axis of rotation 40 is offset and arranged axially parallel to the first axis of rotation 38. The second transmission shaft 32 is arranged concentrically to the crankshaft 22 and, in particular, is screwed to it.

[0036] The electric motor 12 is arranged on the same axial side as the combustion engine 11 with respect to the transmission 14. The rotor shaft 24 is connected in a rotationally fixed manner to the first transmission shaft 28 via a spline 42 comprising an external spline 44 on the rotor shaft 24 and an internal spline 46 on the first transmission shaft 28. The rotor shaft 24 is centered relative to the first axis of rotation 38 via centering means 48. The centering of the rotor shaft 24 relative to the first axis of rotation 38 includes the first transmission shaft 28. The centering means 48 comprise a pilot bearing 50 between the rotor shaft 24 and the first transmission shaft 28. For this purpose, the rotor shaft 24 has a centering projection 52 which engages in a centering opening 54 in the first transmission shaft 28.

[0037] The rotor shaft 24 is mounted relative to the electric motor housing 16 via two first bearing elements 56, here ball bearings. The first gear shaft 28 is mounted relative to the gear housing 26 via two second bearing elements 58, here ball bearings, spaced apart along the first axis of rotation 38. The second gear shaft 32 is mounted relative to the gear housing 26 via a third bearing element 60.

[0038] The electric motor housing 16 is attached to the internal combustion engine 11 by first fastening means 62, here screw elements. The transmission housing 26 is attached to the internal combustion engine by second fastening means 64, here screw elements. The second fastening means 64 each comprise, in particular, a centering sleeve 66.

[0039] The assembly of the hybrid powertrain device 10 and the attachment to the internal combustion engine 11 can first comprise attaching the transmission housing 26 to the internal combustion engine 11 with the second attachment means 64 and then assembling the pilot bearing 50, by means of which the rotor shaft 24 and thus the electric motor 12 is centered relative to the first axis of rotation 38 and thus relative to the first gear 30 of the gear pair 34, and finally attaching the electric motor housing 16 to the internal combustion engine by means of the first attachment means 62.

[0040] Figures 2 and 3 show a section of a cross-section of a hybrid drive train device, each in a further specific embodiment of the invention. The centering means 48 in Figure 2 are designed as a pilot bearing 50 for centering the rotor shaft 24 relative to the first rotational axis 38, with a centering projection 52 formed concentrically on the rotor shaft 24 on the end face 68 of the rotor shaft 24 and a centering opening 54 formed concentrically on the first transmission shaft 28 in the axially opposite end face 70 of the first transmission shaft 28, into which the centering projection 52 engages.

[0041] The rotor shaft 24 is connected to the first gear shaft 28 via a spline 42 for torque transmission. The spline 42 comprises an external toothing 44 on the rotor shaft 28, which meshes with an internal toothing 46 of the first gear shaft 28 to form the spline 42.

[0042] The centering means 48 in Figure 3 are designed as a pilot bearing 50 for centering the rotor shaft 24 relative to the first rotational axis 38, with a centering projection 52 concentrically formed on the rotor shaft 24 on the end face 68 of the rotor shaft 24 and a centering opening 54 concentrically formed on the first gear shaft 28 in the axially opposite end face 70 of the first gear shaft 28, into which the centering projection 52 engages. The rotor shaft 24 is connected to the first gear shaft 28 via a spline 42 for torque transmission.The spline 42 comprises an external toothing 44 on the rotor shaft 24 and an external toothing 72 on the first gear shaft 28, as well as a toothing sleeve 74 with an internal toothing 76, which is arranged axially overlapping the external toothing 44 of the rotor shaft 24 and the external toothing 72 of the first gear shaft 28 and thus connects the rotor shaft 24 to the first gear shaft 28 in a torque-transmitting manner.

[0043] Figure 4 shows a cross-section of a hybrid powertrain device in another specific embodiment of the invention. The structure of the hybrid powertrain device 10 is similar to that of Figure 1 except for the following differences. The electric motor housing 16 is directly connected to the transmission housing 26 via the first fastening means 62.

[0044] Figures 5 to 7 show a section of a cross-section of a hybrid drivetrain device, each in a further specific embodiment of the invention. The structure of the hybrid drivetrain device 10 in Figure 5 is similar to that of Figure 4 except for the following differences. The centering means 48 comprise exclusively a centering seat 78 between the electric motor housing 16 and the transmission housing 26. The centering seat 78 comprises, in particular, an axial projection 80 on the electric motor housing 16, which is received in an axial recess 82 in the transmission housing 26. An outer circumferential surface 84 of the axial projection 80 bears against an inner circumferential surface 86 of the axial recess 82 for centering purposes. The pilot bearing can therefore be omitted.

[0045] A second bearing element 58 is received in a recess 88 axially adjacent to the axial recess 82.

[0046] The structure of the hybrid drivetrain device 10 in Figure 6 is similar to that of Figure 4 except for the following differences. The centering means 48 are formed by the spline 42 itself, by means of a tip or flank centering in the spline 42.

[0047] The structure of the hybrid drive train device 10 in Figure 7 is similar to that in Figure 5 except for the following differences. The first transmission shaft 28 is mounted directly opposite the transmission housing 26 via only a second bearing element 58, here a ball bearing. The second bearing element 58 is arranged axially opposite the rotor shaft 24 with respect to the first gear 30. A possible axial offset between the rotor shaft 24 and the first transmission shaft 28 can be compensated for by skewing the first transmission shaft 28 within the tolerance of the bearing clearance of the second bearing element 58. Figure 8 shows a cross-section of a hybrid drive train device in a further specific embodiment of the invention. The structure of the hybrid drive train device 10 in Figure 8 is similar to that in Figure 7 except for the following differences.The first gear shaft 28 is constructed as a single piece with the rotor shaft 24 and is supported solely by the rotor shaft 24 relative to the gear housing 26. The second bearing elements are dispensable.

[0048] The centering means 48 for centering the rotor shaft 24 relative to the first axis of rotation 38 are formed exclusively by the centering seat 78 between the electric motor housing 16 and the gear housing 26.

[0049] Figure 9 shows a section of a cross-section of a hybrid powertrain device in another specific embodiment of the invention. The structure of the hybrid powertrain device 10 in Figure 9 is similar to that of Figure 8 except for the following differences.

[0050] The centering means 48 comprise, on the one hand, a second bearing element 58 which supports the first gear shaft 28, which is designed as one piece with the rotor shaft 24, relative to the gear housing 26, and, on the other hand, the one-piece design with the first gear shaft 28. The centering seat is omitted here.

[0051] List of reference symbols

[0052] 10 Hybrid powertrain device

[0053] 11 Combustion engine

[0054] 12 electric motor

[0055] 14 gearboxes

[0056] 16 electric motor housing

[0057] 18 Stator

[0058] 20 rotors

[0059] 22 Crankshaft

[0060] 24 Rotor shaft

[0061] 26 Gearbox housing

[0062] 28 first gear shaft

[0063] 30 first gear

[0064] 32 second transmission shaft

[0065] 34 gear pairing

[0066] 36 second gear

[0067] 38 first axis of rotation

[0068] 40 second axis of rotation

[0069] 42 spline

[0070] 44 external gearing

[0071] 46 internal gearing

[0072] 48 centering devices

[0073] 50 pilot storage

[0074] 52 Centering projection

[0075] 54 Centering opening

[0076] 56 first bearing element

[0077] 58 second bearing element

[0078] 60 third bearing element

[0079] 62 first fastening means second fastening means

[0080] Centering sleeve

[0081] front side

[0082] front side

[0083] external gearing

[0084] Gear sleeve

[0085] Internal gearing

[0086] Centering seat

[0087] axial projection

[0088] axial recess

[0089] Outer surface

[0090] inner surface

[0091] recess

Claims

Patent claims 1. A hybrid drive train device (10) for a vehicle for connection to an internal combustion engine of the vehicle, comprising an electric motor (12) with an electric motor housing (16) and a rotatable rotor shaft (24) that can be positioned offset and axially parallel to a crankshaft (22) of the internal combustion engine, a transmission (14) with a transmission housing (26) and a rotatable first transmission shaft (28) that is connected to the rotor shaft (24) at least in a torque-transmitting manner, to which a first gear (30) is fastened, and a rotatable second transmission shaft (32) that can be connected to the crankshaft (22) at least in a rotationally fixed manner, to which a second gear (36) is fastened that is at least indirectly in toothed engagement with the first gear (30) to form at least one gear pair (34), wherein the first gear (30) is rotatable about a first axis of rotation (38) to form the at least one gear pair (34), characterized in thatthat the rotor shaft (24) is centered relative to the first axis of rotation (38) via centering means (48).

2. Hybrid drive train device (10) according to claim 1, characterized in that the centering means (48) comprise a pilot bearing (50) between the rotor shaft (24) and the first transmission shaft (28).

3. Hybrid drive train device (10) according to claim 1 or 2, characterized in that the centering means (48) comprise a spline (42) between the rotor shaft (24) and the first transmission shaft (28).

4. Hybrid drive train device (10) according to one of the preceding claims, characterized in that the rotor shaft (24) is mounted directly opposite the electric motor housing (16) via at least one first bearing element (56) and the first transmission shaft (28) is mounted directly opposite the transmission housing (26) via at least one second bearing element (58).

5. Hybrid drive train device (10) according to claim 4, characterized in that the first transmission shaft (28) is mounted directly opposite the transmission housing (26) via only a second bearing element (58).

6. Hybrid drive train device (10) according to one of the preceding claims, characterized in that the centering means (48) comprise at least one centering seat (78) between the electric motor housing (16) and the transmission housing (26).

7. Hybrid drive train device (10) according to one of the preceding claims, characterized in that the rotor shaft (24) and the first transmission shaft (28) are designed as one piece with each other.

8. Hybrid drive train device (10) according to one of the preceding claims, characterized in that the first transmission shaft (28) is mounted relative to the transmission housing (26) exclusively via the rotor shaft (24).

9. Hybrid powertrain device (10) according to one of the preceding claims, characterized in that the electric motor (12) can be positioned on the same axial side with respect to the transmission (14) as the internal combustion engine.

10. Hybrid drive train device (10) according to one of the preceding claims, characterized in that the second transmission shaft (32) can be positioned concentrically to the crankshaft (22).

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