Generator module for a serial hybrid drive train of a motor vehicle

Abstract

The present invention relates to a generator module (1) for a serial hybrid drive train (25) of a motor vehicle (3) and for direct connection (8) to an internal combustion engine (2), comprising a module housing (4), a stator (5) which is stationary relative to the module housing (4) and which is arranged within the module housing (4), a rotor (6) which can be rotated relative to the stator (5) about an axis of rotation (D), is arranged within the module housing (4) and is supported by a rotor carrier (7) which can be connected to the internal combustion engine (2) for conjoint rotation, wherein the module housing (4) has, for the input-side indirect or direct connection (8) of the rotor carrier (7) to a crankshaft (9) of the internal combustion engine (2), an inlet opening (10) through which the rotor carrier (7) extends in the axial direction (A) of the generator module (1) and through which the rotor carrier (7) is rotatably supported.

Description

[0001] Generator module for serial hybrid powertrain of a motor vehicle

[0002] The present invention relates to a generator module for a serial hybrid powertrain of a motor vehicle.

[0003] A serial hybrid powertrain comprises an electric machine configured as a generator module, which is connected to an internal combustion engine. The generator module comprises a power electronics unit that is electrically connected to a battery and, when the generator module is driven by the internal combustion engine, feeds electrical current into the battery. The battery is further electrically connected to a further power electronics unit of a further electric machine. The further electric machine draws power from the battery via the further power electronics unit and is configured as the traction motor of the serial hybrid powertrain, which drives the drive wheels of the motor vehicle.

[0004] Such a generator module, possibly together with the combustion engine to which it is connected, is typically referred to as a range extender, as it is capable of charging the battery of the electric vehicle while driving, thus increasing the range of the electric vehicle. The combustion engine can operate at its optimal operating point, i.e., convert the fuel used into rotational energy as efficiently as possible, allowing the generator module to maximize the yield of electrical energy from the fuel used.

[0005] The object of the present invention is to provide a functionally reliable, robust and cost-effective generator module.

[0006] According to the invention, this object is achieved by a generator module according to claim 1 for a serial hybrid drive train of a motor vehicle and for direct connection to an internal combustion engine, with a module housing, a stator which is stationary with respect to the module housing and is arranged within the module housing, a rotor which is rotatable about an axis of rotation relative to the stator, which rotor is arranged within the module housing and is carried by a rotor carrier which is rotatably connected to the internal combustion engine in a rotationally fixed manner, wherein the module housing has an inlet opening for the indirect or direct connection of the rotor carrier to a crankshaft of the internal combustion engine on the input side.

[0007] Since the rotor carrier extends in the axial direction of the generator module through the inlet opening, through which the rotor carrier is rotatably supported, a cost-effective and robust design is possible.

[0008] "Rotatably connected to the internal combustion engine" means that no relative rotation is possible between the internal combustion engine and the rotor carrier or rotor. In particular, this means that no torsional vibration damper, for example, in the form of a dual-mass flywheel, is arranged between the rotor carrier and the internal combustion engine. Thus, the generator module shown in particular does not have a torsional vibration damper within its module housing.

[0009] "Closed in the axial direction relative to the inlet opening" means that the generator module has no output side or rotary output side. Therefore, the generator module cannot be connected between an internal combustion engine and a transmission, but serves only to convert incoming rotational energy into outgoing electrical energy, and not to transmit or generate rotational energy using an electric motor. Such a generator module is commonly referred to as a range extender, as it is capable of charging the battery of an electric motor-driven vehicle while driving, thus increasing the range of the electric motor-driven vehicle. The internal combustion engine can be operated at its optimal operating point, i.e.convert the fuel used into rotational energy in the best possible way, whereby the generator module can maximize the yield of electrical energy from the fuel used.

[0010] Preferred embodiments of the friction clutch according to the invention are set forth in the dependent claims. The module housing preferably has a collar section that overlaps, in the axial direction, with rotor magnets fixedly arranged on the rotor carrier. This enables a cost-effective and robust construction of the generator module.

[0011] Furthermore, a rotor position sensor is preferably provided in an outer region of the collar section, which is arranged between the collar section and the rotor carrier. This enables a cost-effective and robust construction of the generator module.

[0012] It is advantageous if an outer ring of a rolling bearing rests against the inner wall of the collar section bordering the inlet opening, providing rotatable support for the rotor carrier. This enables a cost-effective and robust design of the generator module.

[0013] The rolling bearing preferably has a sealing ring. The rolling bearing is preferably secured in the axial direction, e.g., by a clamping nut or a retaining ring or grooved ring. The rolling bearing is preferably designed as a radial bearing.

[0014] According to another preferred embodiment, the rolling bearing overlaps the rotor position sensor in the axial direction. This enables a cost-effective and robust design of the generator module.

[0015] It is advantageous if the rotor carrier has a hub section that extends axially through the inlet opening for a non-rotatable connection to the combustion engine. This enables a cost-effective and robust design of the generator module.

[0016] Furthermore, it is advantageous if the hub section overlaps the collar section in the axial direction. This enables a cost-effective and robust design of the generator module.

[0017] Preferably, the module housing is closed by a module cover on a side opposite the inlet opening in the axial direction. This enables a cost-effective and robust construction of the generator module. It is advantageous if the module housing and the rotor carrier are each substantially U-shaped in a half-sectional view, with the openings of the U-shaped cuts of both components facing each other, so that the U-shaped cuts interlock on one of their respective limb sides. This enables a cost-effective and robust construction of the generator module.

[0018] Furthermore, it is advantageous if the module cover covers or overlaps the U-shaped cuts of both components in a half-sectional view in the radial direction of the generator module. This enables a cost-effective and robust construction of the generator module.

[0019] The present invention will be explained in more detail below using preferred embodiments in conjunction with the accompanying figures. These show:

[0020] Figure 1: a schematic representation of an embodiment of a serial hybrid drive train in a motor vehicle with a generator module, and

[0021] Figure 2: a half sectional view of an embodiment of a generator module that is or can be used in the serial hybrid powertrain shown in Figure 1.

[0022] Figure 1 schematically illustrates an embodiment of a serial hybrid drive train 25 in a motor vehicle 3. The serial hybrid drive train 25 has an electric machine designed as a generator module 1, which is directly connected to an internal combustion engine 2. In the illustrated embodiment, the internal combustion engine 2 is installed in a front-transverse design, i.e., arranged transversely to the longitudinal axis of the motor vehicle 3 between the front wheels 31 of the motor vehicle 3. The generator module 1 has a power electronics unit 39, which is electrically connected to a battery 26 and through which, when the generator module 1 is driven by the internal combustion engine 2, electrical current is fed into the battery 26. The battery 26 is also electrically connected to a further power electronics unit 28 of a further electric machine 27.The additional electric machine 27 draws power from the battery 26 via the additional power electronics unit 28 and is designed as the traction motor of the serial hybrid drive train 25. Via a differential 29 and connected drive shafts, the traction motor preferably drives the rear wheels 32 of the motor vehicle 3, with the traction motor preferably being arranged between the rear wheels 32, and the motor vehicle 3 preferably being designed with rear-wheel drive. Although not shown, the hybrid drive train 25 can also be integrated into a front-wheel drive or all-wheel drive motor vehicle 3.

[0023] A cooler unit 30 is fluidly connected to the generator module 1, more precisely to the power electronics unit 39 of the generator module 1, via a corresponding cooling circuit and is preferably likewise connected to the further electrical machine 27, more precisely to the further power electronics unit 28 of the further electrical machine 27, in order to cool the same during operation, ie to dissipate its heat.

[0024] Typically, such a generator module 1, possibly together with the internal combustion engine 2 to which it is connected, is also referred to as a range extender, since it is capable of charging the battery 26 of the electric motor-driven vehicle 3 while driving and thus increasing the range of the electric motor-driven vehicle 3. The internal combustion engine 2 can be operated at its optimal operating point, i.e., convert the fuel used into rotational energy in the best possible way, whereby the generator module 1 can maximize the yield of electrical energy from the fuel used.

[0025] Although it is not shown, it is also possible for the generator module 1 to supply the further electric machine 27 directly with power without the interposition of the battery 26.

[0026] Figure 2 shows an embodiment of the generator module 1 in half a

[0027] sectional view, which can equally be used in the serial hybrid drive train 25 described with reference to Figure 1. The said generator module 1 is designed for direct connection 8 to the internal combustion engine 2 of the motor vehicle 3, or directly connected to a crankshaft 9 of the internal combustion engine 2 of the motor vehicle 3. Preferably, the connection 8 is non-rotatably connected, in particular by screwing a rotor carrier 7 of the generator module 1 and / or a flexplate 20 of the generator module 1, preferably connected via a further flexplate 21, or a flywheel of the generator module 1, preferably connected via the further flexplate 21, to the crankshaft 9 of the internal combustion engine 2.

[0028] The generator module 1 is equipped with a module housing 4. The module housing 4 can be manufactured as a cast component made of light metal, for example, an aluminum or magnesium alloy. Furthermore, the module housing 4 can be screwed to an engine block of the internal combustion engine 2 in the final step of connecting the generator module 1 to the internal combustion engine 2 of the motor vehicle 3.

[0029] Furthermore, the generator module 1 has a stator 5 that is stationary relative to the module housing 4 and arranged within the module housing 4. Stator coils 35 of the stator 5, designed as electromagnets, are electrically contacted through a wall section of the module housing 4. A stator carrier 24 supports the stator 5, or more precisely, the stator coils 35, inside the module housing 4. Referring to Figure 2, the stator carrier 24 is connected, in particular screwed, to the module housing 4 from the left.

[0030] In addition, the generator module 1 has a rotor 6 which is rotatable about an axis of rotation D relative to the stator 5 and is arranged within the module housing 4 and is carried by the aforementioned rotor carrier 7, which can be connected in a rotationally fixed manner to the internal combustion engine 2. More precisely, in the illustrated embodiment, rotor magnets 16 are fastened to an outer wall of the essentially pot-shaped or collar-shaped rotor carrier 7. The generator module 1 is preferably designed as an internal rotor, i.e. the rotor 6 is arranged rotatably in the radial direction R of the generator module 1 within the stator 5. The module housing 4 further has an inlet opening 10 for the indirect or direct connection 8 of the rotor carrier 7 to the crankshaft 9 of the internal combustion engine 2 on the input side. The module housing 4 is closed in the axial direction A of the generator module 1 opposite the inlet opening 10 by a module cover 12.The module cover 12 extends essentially in the radial direction R and is screwed in its outer region to the module housing 4, more precisely to the wall section of the module housing 4, via a screw connection 36. The wall section of the module housing 4 extends essentially in the axial direction A.

[0031] In the half-sectional view shown in Figure 2, the module housing 4 and the rotor carrier 7 are each essentially U-shaped. Openings 33 of the U-shaped cuts of both components 4, 7 face each other, so that the U-shaped cuts engage with one another on one of their respective leg sides 34. More precisely, the radially inner leg side 34 of the module housing 4, which forms the collar section 11 of the module housing 4 to be explained below, engages with the radially outer leg side 34 of the rotor carrier 7, to which the rotor magnets 16 are attached. The module cover 12 covers or overlaps the U-shaped cuts of both components 4, 7 in the radial direction R, as viewed in the half-sectional view.More precisely, the U-shaped cut of the module housing 4 is open towards the module cover 12 so that the said opening 33 is covered by the module cover 12, and the U-shaped cut of the rotor carrier 7 is open away from the module cover 12 so that the said opening 33 is at least overlapped by the module cover 12 or at least overlaps with the module cover 12.

[0032] The previously mentioned power electronics unit 39 of the generator module 1 is firmly connected to the module housing 4 on an outer side of the module housing 4, i.e., radially outside. The power electronics unit 39 is electrically connected at least to the stator 5 through the respective wall section of the module housing 4. The electrical connection is made, for example, via a three-phase connection that penetrates the respective wall section 13 of the module housing 4 in the radial direction R. Alternatively or additionally, it is possible for the power electronics unit 39 of the generator module 1 to be arranged axially outside the module cover 12 on an outer wall of the module cover 12 and to be firmly connected to it.

[0033] The rotor carrier 7 extends through the inlet opening 10 of the module housing 4 in the axial direction A. The rotor carrier 7 is rotatably supported on the module housing 4 through the inlet opening 10. For this purpose, the rotor carrier 7 has a hub section 23 which extends through the inlet opening 10 in the axial direction A for the rotationally fixed connection 8 to the internal combustion engine 2.

[0034] The module housing 4 has the previously mentioned collar section 11, which overlaps in the axial direction A with the rotor magnets 16 fixedly arranged on the rotor carrier 7. A rotor position sensor 15 is provided in an outer region of the collar section 11 and is arranged between the collar section 11 and the rotor carrier 7. The previously mentioned hub section 23 overlaps with the collar section 11 in the axial direction A.

[0035] A rotating part of the rotor position sensor 15, in particular a sensor plate, is attached to a bottom portion of the rotor carrier 7 within the module housing 4, and a non-rotating part of the rotor position sensor 15, in particular a detector, is attached to the collar portion 11 of the module housing 4. The rotor position sensor 15 is designed to detect the angular position of the rotor 6, for example, optically or inductively.

[0036] On an inner wall delimiting the inlet opening 10 in the radial direction R

[0037] An outer ring 17 of a rolling bearing 14 rests against the collar portion 13 of the collar portion 11, by which the rotor carrier 7 is rotatably supported. An inner ring 18 of the rolling bearing 14 rests on the hub portion 23 of the rotor carrier 7, more precisely, on an outer wall of said hub portion 23.

[0038] In the illustrated embodiment, the said rolling bearing 14 is the only bearing by which the rotor carrier 7 or the entire rotor 6 is mounted and rotatably supported with respect to the module housing 4. In particular, the rolling bearing overlaps

[0039] 14 with the rotor position sensor 15 in the axial direction A. Furthermore, the rolling bearing 14 is arranged further inward in the radial direction R than the rotor position sensor 15. Between the inner ring 18 of the rolling bearing 14 and the outer ring 17 of the rolling bearing 14, rolling elements 22 are arranged, distributed in the circumferential direction of the generator module 1, preferably cage-guided, preferably running in grease, wherein the space between the inner ring 18 and the outer ring 17 is closed off on both sides by sealing rings 19, preferably in the axial direction A. The generator module 1 is thus sealed on the side of the engine block of the internal combustion engine 2 against, for example, dirty water without further sealing elements.

[0040] The rolling bearing 14 is preferably designed as a radial bearing for transmitting radial and axial forces. Furthermore, the rolling bearing 14 is preferably secured in the axial direction A, e.g., by a clamping nut 37 on the inner ring 18 and / or by a grooved ring 38 on the outer ring 17.

[0041] The preceding exemplary embodiments relate to a generator module 1 for a serial hybrid drive train 25 of a motor vehicle 3 and for direct connection 8 to an internal combustion engine 2, comprising a module housing 4, a stator 5 which is stationary with respect to the module housing 4 and arranged within the module housing 4, a rotor 6 which is rotatable about an axis of rotation D relative to the stator 5, which rotor 6 is arranged within the module housing 4 and is carried by a rotor carrier 7 which is rotatably connected to the internal combustion engine 2, wherein the module housing 4 has an inlet opening 10 for the indirect or direct connection 8 of the rotor carrier 7 to a crankshaft 9 of the internal combustion engine 2 on the input side, through which the rotor carrier 7 extends in the axial direction A of the generator module 1 and through which the rotor carrier 7 is rotatably supported, and wherein the inlet opening 10 is formed in particular by at least one sealing ring 19 of the single,The rotor carrier 7 is sealed by a roller bearing 14 rotatably mounted on it. Furthermore, the preceding embodiments relate to a serial hybrid drive train 25 for a motor vehicle 3, comprising a generator module 1 directly connected to an internal combustion engine 2, and a further electric machine 27 for driving the motor vehicle 3. List of reference symbols,

[0042] Generator module

[0043] combustion engine

[0044] motor vehicle

[0045] Module housing

[0046] stator

[0047] rotor

[0048] rotor carrier

[0049] Connection

[0050] crankshaft

[0051] Entrance opening

[0052] collar section

[0053] Module cover

[0054] inner wall

[0055] Rolling bearings

[0056] Rotor position sensor

[0057] rotor magnet

[0058] outer ring

[0059] inner ring

[0060] seal

[0061] Flexplate additional Flexplate

[0062] Rolling elements

[0063] Hub section

[0064] Stator carrier serial hybrid powertrain

[0065] Battery further electrical machine further power electronics unit

[0066] differential

[0067] cooler unit

[0068] Front wheel 32 Rear wheel

[0069] 33 Opening

[0070] 34 thigh side

[0071] 35 Stator coil

[0072] 36 screw connection

[0073] 37 clamping nut

[0074] 38 Grooved ring

[0075] 39 Power electronics unit

[0076] A axial direction

[0077] D axis of rotation

[0078] R radial direction

Claims

Patent claims 1. Generator module (1) for a serial hybrid drive train (25) of a motor vehicle (3) and for direct connection (8) to an internal combustion engine (2), comprising a module housing (4), a stator (5) which is stationary with respect to the module housing (4) and arranged within the module housing (4), a rotor (6) which is rotatable about an axis of rotation (D) relative to the stator (5), which rotor is arranged within the module housing (4) and is carried by a rotor carrier (7) which is rotatably connected to the internal combustion engine (2), wherein the module housing (4) has an inlet opening (10) for the indirect or direct connection (8) of the rotor carrier (7) to a crankshaft (9) of the internal combustion engine (2) on the input side, through which opening the rotor carrier (7) extends in the axial direction (A) of the generator module (1) and by which the rotor carrier (7) is rotatably supported.

2. Generator module (1) according to claim 1, wherein the module housing (4) has a collar portion (11) which overlaps in the axial direction (A) with rotor magnets (16) fixedly arranged on the rotor carrier (7).

3. Generator module (1) according to claim 2, wherein a rotor position sensor (15) is provided in an outer region of the collar portion (11), which is arranged between the collar portion (11) and the rotor carrier (7).

4. Generator module (1) according to claim 2 or 3, wherein an outer ring (17) of a rolling bearing (14) rests against an inner wall (13) of the collar section (11) delimiting the inlet opening (10), by means of which the rotor carrier (7) is rotatably supported.

5. Generator module (1) according to claim 4 in conjunction with claim 3, wherein the rolling bearing (14) overlaps with the rotor position sensor (15) in the axial direction (A).

6. Generator module (1) according to one of claims 1 to 5, wherein the rotor carrier (7) has a hub section (23) which extends in the axial direction (A) for rotationally fixed connection (8) to the combustion engine (2) extends through the inlet opening (10).

7. Generator module (1) according to claim 6 in conjunction with one of claims 2 to 5, wherein the hub portion (23) overlaps with the collar portion (11) in the axial direction (A).

8. Generator module (1) according to one of claims 1 to 7, wherein the module housing (4) is closed by a module cover (12) on a side opposite the inlet opening (10) in the axial direction (A).

9. Generator module (1) according to one of claims 1 to 8, wherein the module housing (4) and the rotor carrier (7) are each substantially U-shaped in a half sectional view, wherein the openings (33) of the U-shaped cuts of both components (4, 7) face each other, so that the U-shaped cuts engage with each other on one of their leg sides (34).

10. Generator module (1) according to claim 9 in conjunction with claim 8, wherein the module cover (12) covers or overlaps the U-shaped cuts of both components (4, 7) in a half sectional view in the radial direction (R) of the generator module (1).

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