Assembly and production-optimized hybrid drive

Abstract

Drive train for a motor vehicle with a combined drive system with an internal combustion engine (ICE), which is arranged in the motor vehicle in a first end region, at least one electromechanical energy converter (EMW), at least one driven drive axle (HA), which is arranged in the motor vehicle in a second end region, a drive shaft (GW) for transmitting drive power from the internal combustion engine (ICE) to this drive axle (HA) and with an energy storage device for storing and providing electrical energy, said device having at least one first storage unit (GE.1), wherein the energy storage device has a second storage unit (GE.2), wherein the first and second storage units (GE.1, GE.2) are arranged along a rotation axis on opposite sides of the drive shaft (GW) and are arranged between the internal combustion engine (ICE) and the drive axle (HA) and, that the first and the second storage unit (GE.1, GE.2) can be connected to one another by means of a connecting device (VE), and wherein the connecting device (VE) is designed at least for transmitting electrical power and for transmitting a temperature control medium volume flow, and wherein the connecting device (VE) and at least one of the storage units (GE.1, GE.2) can be connected to one another by a plug / socket connection (VE.1, VE.2) and wherein the first and the second storage unit (GE.1, GE.2) can be connected to one another via the drive shaft (GW) by means of the connecting device (VE).

Description

[0001] The invention relates to a drive train for a hybrid vehicle according to the preamble of patent claim 1. Such a drive train is known from EP 1 316 694 A1.

[0002] The invention is described below in connection with a passenger car (PC) with a standard drive. For the purposes of the invention, a PC is understood to be a car with a front engine and rear-wheel drive; this is not to be understood as a limitation of the invention to such a drive configuration.

[0003] Compared to vehicles powered solely by internal combustion engines, hybrid vehicles require a number of additional features, not least an additional drive motor and its power supply system. Effective utilization of the available installation space is therefore particularly important for these vehicles.

[0004] EP 1 316 694 A1 discloses arranging the combustion engine in the front of the vehicle and driving the rear axle. For this purpose, the combustion engine and two electromechanical energy converters are connected to the drive axle via a drive shaft. The electrochemical energy storage device is arranged on one side of the drive shaft.

[0005] DE 10 2012 220 074 A1 deals with a body structure of a hybrid vehicle. DE 10 2013 203 333 A1 deals with a hybrid vehicle. DE 10 2011 012 447 A1 deals with a drive unit for a motor vehicle. US 2011 / 0 206 948 A1 deals with a power source device with electrical components arranged in the battery blocks.

[0006] It is an object of the invention to provide a drive train for a motor vehicle with a combined drive system with improved use of installation space.

[0007] The object is achieved by a device according to patent claim 1, preferred developments are the subject of the dependent claims.

[0008] For the purposes of the invention, a drive train is understood to be a device for providing and transmitting drive power to overcome driving resistance. Such a drive train comprises, in particular, drive shafts, drive shafts, transmission devices, and drive motors.

[0009] For the purposes of the invention, a motor vehicle is understood to mean a passenger car, in particular an automobile.

[0010] According to the invention, the energy storage device for supplying a drive motor of a combined drive system, in particular the electromechanical energy converter, comprises a first and at least one further, second storage unit. The first and second storage units are arranged along a rotational axis on opposite sides of a drive shaft and between the internal combustion engine and the drive axle. The drive shaft is understood to be a component for mechanically transmitting drive power, in particular from the internal combustion engine to the drive axle. The drive shaft preferably runs at least substantially in the longitudinal direction of the vehicle.Further preferably, the drive shaft divides the vehicle into a sub-area to the left of the drive shaft and a sub-area to the right of the drive shaft, with a first storage unit being arranged in one sub-area and the other storage unit being arranged in the other sub-area. The first and the second storage unit can be connected to one another via the drive shaft by means of a connecting device. In this case, the term "connection" within the meaning of the invention is to be understood as at least one electrically conductive connection and additionally a connection for conducting a temperature control medium volume flow. Furthermore, the connecting device is designed to transmit electrical power and to transmit a temperature control medium volume flow.

[0011] In particular, by distributing the storage device on two sides of the drive shaft, on the one hand, a particularly good utilization of the available installation space can be achieved, and on the other hand, a good assembly of the drive system can be achieved.

[0012] For the purposes of the invention, a combined drive system is understood to mean a drive device comprising at least a first and a second drive motor. These drive motors are, in particular, of different types. Preferably, one of the drive motors is designed as an internal combustion engine, preferably of reciprocating piston design, and the second drive motor is designed as an electromechanical energy converter. Such combined drive systems are often also referred to as hybrid drives. Preferably, the motor vehicle can be driven by one of the drive motors or by both simultaneously.

[0013] For the purposes of the invention, the arrangement of an internal combustion engine in a first end region of the motor vehicle means that it is arranged in front of or behind the geometric center of the vehicle in the direction of travel. In this case, "in front of" and "behind" refer to the main direction of travel (forward travel) of the motor vehicle. Furthermore, the end regions are preferably also identified by an axle of the vehicle (front axle, rear axle). The internal combustion engine is preferably arranged in the region of this front or rear axle, respectively.

[0014] For the purposes of the invention, an electromechanical energy converter is understood to be a device for converting electrical energy into mechanical energy or vice versa. An electromechanical energy converter is preferably an electric motor / generator. Such an energy converter is further preferably operable in multi-quadrant operation, preferably in four-quadrant operation. Further preferably, the electromechanical energy converter and the internal combustion engine are arranged coaxially with respect to their respective input / output shafts, or preferably axially parallel to each other.

[0015] For the purposes of the invention, a driven axle (drive axle) is understood to mean an axle of the motor vehicle that can be supplied with drive power by at least one of the two drive motors (internal combustion engine, electromechanical energy converter) to overcome driving resistance. This drive axle is arranged in particular in the second end region opposite the first end region with respect to the direction of travel.

[0016] Figuratively, this is preferably to be understood as meaning that if the internal combustion engine is positioned at the front relative to the main direction of travel of the motor vehicle, the drive axle is the rear axle of the motor vehicle (front engine, rear-wheel drive, or all-wheel drive), or vice versa (rear engine, front-wheel drive, or all-wheel drive). Furthermore, the motor vehicle preferably has two driven axles. This results in, in particular, in the possible combinations of front-engine rear-wheel drive, rear-engine front-wheel drive, or all-wheel drive with a mechanical connecting shaft between the driven axles. Particularly in the case of all-wheel drive, the positioning of the internal combustion engine is of secondary importance with respect to this invention.

[0017] In particular, due to the arrangement of the internal combustion engine and the driven axle in the first and second end regions of the motor vehicle, respectively, a drive shaft is necessary for transmitting the drive power to the axle in the vehicle's longitudinal direction. For the purposes of the invention, such a drive shaft is understood to be a mechanical shaft that extends in the longitudinal direction of the vehicle, relative to the direction of travel of the motor vehicle. In particular, the drive shaft is understood to be a universal joint or, preferably, a cardan shaft. The drive shaft can preferably be coupled directly to the internal combustion engine or the electromechanical energy converter, or preferably to at least one transmission device.

[0018] For the purposes of the invention, an energy storage device for storing and providing electrical energy is understood to mean a device that can be electrically connected to the electromechanical energy converter and provides electrical power to the converter for driving the vehicle or receives and stores electrical power from the converter. Such an energy storage device is preferably understood to be a rechargeable battery, preferably a lithium-ion rechargeable battery.

[0019] Such energy storage devices are often very heavy. Studies have shown that the positioning of additional mass in a motor vehicle is advantageously carried out in its geometric center. The drive configuration described here results in the special feature that a particularly favorable location for the arrangement of the energy storage device is already occupied by the drive shaft. According to the invention, the energy storage device is divided into two storage units, the first of which is arranged on one side of the drive shaft and the second storage unit is arranged on the opposite side of the drive shaft. Figuratively speaking, the energy storage device is thus divided, with respect to the direction of travel of the motor vehicle, into a left storage unit and a right storage unit (on the left and right sides of the drive shaft, respectively).

[0020] According to the invention, the storage units are addressed via a common interface; in particular, the electrical power for driving the motor vehicle can be drawn via this common interface. This is made possible by the fact that the first storage unit and the second storage unit can be connected to one another by means of a connecting device. Preferably, not only electrical power but also a temperature control medium volume flow can be transmitted between the two storage units. This configuration of the energy storage device advantageously allows the energy storage device to be addressed as a single unit and its mass to be distributed advantageously, at least substantially symmetrically, within the vehicle.In particular, this design of the energy storage device advantageously requires particularly few connecting cables to transmit the electrical drive power from the energy storage device to the electromechanical energy converter, and furthermore, this energy storage device can have a common heat balance for both storage units.

[0021] In a preferred embodiment, the housing device is designed to accommodate at least one electrochemical energy storage device, in particular an accumulator. The accumulator preferably has at least one, more preferably a plurality of, lithium-ion storage cells. The housing device preferably has at least one mounting opening. This mounting opening can be closed in particular by a mounting cover. During planned installation of the housing device in the motor vehicle, the mounting cover is preferably arranged on the underside of the housing device. The mounting opening is preferably geometrically designed such that the electrochemical energy storage device, preferably as a whole, can be inserted into the housing device through it.For this purpose, the mounting opening is preferably larger than the largest cross-sectional area of ​​the electrochemical energy storage device orthogonal to the direction in which it can be inserted into the housing. In particular, the positioning of the mounting cover on the underside of the housing, relative to the planned installation of the housing in the motor vehicle, enables particularly simple and thus less error-prone insertion of the energy storage device into the housing.

[0022] In a preferred embodiment, the mounting cover has a service opening. Preferably, the service opening is arranged, at least partially or preferably completely, within the mounting cover. Within the meaning of the invention, within the mounting cover is to be understood such that the service opening is surrounded by the mounting cover. In particular, the service opening is to be understood as a recess in the mounting cover. Further preferably, the service opening can be closed by a service cover. The service cover can preferably be removed, at least substantially, in the same direction as the mounting cover from the housing device. Preferably, the service cover can be connected to the mounting cover by means of a positive connection. Further preferably, the service cover can be connected to the mounting cover by means of a frictional connection.Further preferably, the service cover has a sealing device for sealing the service opening in the assembly cover. This sealing device is preferably designed as a permanently elastic seal, preferably as a sealing ring, and particularly preferably as a sealing strip. In particular, a positive connection between the service cover and the assembly cover represents a particularly simple and secure connection type.

[0023] In a preferred embodiment, a first storage unit is configured to accommodate the electrochemical energy storage device and to accommodate at least one control device. Preferably, the control device is configured at least to control the power draw from the electrochemical energy storage device. Further preferably, the control device is configured to draw power from the electrochemical energy storage device in the same housing device and to draw power from the electrochemical energy storage devices arranged in the other housing device. Further preferably, the housing device has a first section for accommodating the at least one control device and a second section for accommodating the electrochemical energy storage device. Further preferably, these two areas are separated from one another at least in sections by a housing wall or, preferably, a separating device.

[0024] For the purposes of the invention, such a control device is understood to be a power electronic device, preferably a control unit. Further preferably, this control device is configured to control the at least one electromechanical energy converter. Preferably, the same or a further control device is configured to control the power consumption of the electrochemical energy converter, in particular the charging process. In particular, by accommodating at least one of the control devices in the same housing as at least one electrochemical energy storage device, a particularly compact design is enabled, and, secondly, it is possible to cool both storage devices with only one coolant flow (temperature control medium volume flow).

[0025] In a preferred embodiment, the control device comprises a device for converting direct current to alternating current (inverter). In particular, the structural inclusion of the device for converting direct current to alternating current in the control device or in the storage unit enables a particularly compact design of the control device and thus of the drive train.

[0026] In a preferred embodiment, the control device comprises a device for converting direct current into direct current (high voltage from the electrochemical storage device into the lower voltage of the vehicle's electrical system). In particular, the structural inclusion of the device for converting direct current into the control device or storage unit enables a particularly compact design of the control device and thus of the drive train.

[0027] In a preferred embodiment, the control device has a device for providing a high-voltage direct current (storage charger, on-board charger). This device is preferably designed to convert an alternating voltage into a direct voltage. Preferably, for converting an alternating voltage between 70 and 400 volts, preferably between 90 and 300 volts, and particularly preferably between 100 and 240 volts. A storage charger is designed in particular to distribute currents at high voltages, in particular to at least one or more electrochemical energy storage devices. In particular, the structural inclusion of the device for converting alternating current into direct current in the control device or in the storage unit enables a particularly compact design of the control device and thus of the drive train.

[0028] For the purposes of the invention, a high voltage or high voltage is understood to mean an electrical voltage which is greater than 60 volts, preferably greater than 90 volts and more preferably greater than 100 volts and particularly preferably greater than 200 volts and further less than 1500, preferably less than 700 volts, preferably less than 500 volts and particularly preferably less than 400 volts. Furthermore, for the purposes of the invention, a low voltage or an on-board network voltage is understood to mean a voltage which is less than 100 volts, preferably less than 60 volts, preferably less than 50 volts and particularly preferably less than 40 volts and further greater than 5 volts, preferably greater than 10 volts and preferably greater than 20 volts.

[0029] Further preferably, different high and low voltages from the aforementioned areas can be present in different areas of the drive train.

[0030] In a further preferred embodiment, this device for converting direct current to alternating current is arranged outside the energy storage device. Further preferably, the device for converting direct current to alternating current is to be understood as a structurally separate component that is independent of the energy storage device. In particular, the structural separation of the device for converting direct current to alternating current enables particularly simple adaptation of the energy storage device to different motor vehicle types and thus to different power requirements by using different devices for converting direct current to alternating current.

[0031] In a preferred embodiment, the connecting device can be connected to at least one of the storage units by a plug / socket connection. Preferably, the connecting device can be connected to both storage units by a plug / socket connection. Further preferably, the plug / socket connections on both sides of the connecting device are of identical design; this has the advantage that the connecting device can be installed particularly quickly and regardless of the installation position. Preferably, the plug / socket connections on both sides of the connecting device are of different geometric designs, such that the connecting device can only be used in a specific position between the storage units. In particular, a specific installation position of the connecting device between the storage units enables particularly good geometric adaptation of the connecting device.

[0032] In a preferred embodiment, the connecting device comprises electrical current transmission means and volume flow transmission means. Further preferably, these transmission means are surrounded, at least in sections, preferably completely in the radial direction, by a sheathing device. Further preferably, a sheathing device within the meaning of the invention is understood to be a bellows device, preferably a hose-like or particularly preferably a tube-like sheath for these transmission means. In particular, the fact that this connecting device has a certain elasticity, particularly in the axial direction of the transmission means, enables virtually tolerance-independent positioning of the storage units in the motor vehicle.

[0033] In a preferred embodiment, the storage capacity of the first storage device (SPK1) is lower than the storage capacity of the second storage device (SPK2). Preferably, SPK2 is > 1.1 SPK1, preferably > 1.2 SPK1, and particularly preferably ≥ 1.3 SPK1. Further preferably, SPK2 is < 2.5 SPK1, preferably < 1.75 SPK1, preferably < 1.5 SPK1, and particularly preferably < 1.35 SPK1.

[0034] A defined storage capacity can generally be assigned a specific installation space requirement. By selecting the proportions as described, it is possible to accommodate the control device for extracting power from the storage unit within the housing device. Furthermore, the housing device for the first and second storage devices is preferably at least substantially identical in construction, particularly despite their different storage capacities. In particular, this inventive design of the storage device enables a particularly cost-effective drive train construction.

[0035] The following figures show preferred embodiments and features of a drive train according to the invention in a partially schematic representation. Fig. 1: a) a plan view of a drive train according to the invention, b) a sectional view along AA, Fig. 2: a perspective view of a storage unit and the connecting device, Fig. 3: a perspective view of a second storage unit, Fig. 4: an exploded view of a first and second storage unit, as well as the connecting device, Fig. 5: a sectional view of the connecting device and the cardan shaft, Fig. 6: Sectional views of the housings of the storage devices and the assembly and service covers, Fig. 7: a perspective sectional view of the assembly cover and the service cover.

[0036] In Fig. Figure 1 shows a plan view of the drive train according to the invention. The drive train comprises an internal combustion engine VKM, a transmission device Get, and an electromechanical energy converter ENW. The drive power is transmitted to the rear axle via a drive shaft GW, which is designed as a cardan shaft. A first storage unit is arranged on the left side (relative to the main direction of travel FR), and a second storage unit is arranged on the right side, i.e., opposite one another. The storage units GE1 / GE2 are each enclosed by a housing. Control electronics in the form of a power electronic control unit LE are arranged in the first housing. This power electronics LE is configured to control the power extraction from the storage units.Inverter IV, which controls the electromechanical energy converter ENW, is located directly on the gearbox Get. Inverter IV can be connected to the storage units GE.1 / GE.2 via an electrical cable EL.

[0037] The arrangement of the storage units GE.1, GE.2 in relation to the cardan shaft is particularly clear in Fig. 1b. The drive shaft is located above the exhaust system AGA. The two housing units are connected to each other via the connecting device VE, which runs above the drive shaft. The connection between the housing units includes both an electrically conductive connection and a connection that allows the flow of a temperature control medium. The first housing unit has an interface EL.1 for connection to the electrical line EL.

[0038] The Fig. Figure 2 shows the connecting device VE as it can be connected to the first housing device via the interface VE.1. The housing device has a service opening SO. This service opening SO is located in the mounting cover MD. The mounting cover MD can be removed from the housing device downwards.

[0039] Fig. 3 shows a second housing device. In this embodiment, the second housing device is essentially structurally identical to the first housing device. The mounting cover MD can also be removed downwards in the second housing device. The second housing device has a second interface VE.2 for connection to the connecting device (not shown). Connections for transmitting the temperature control medium, in particular a coolant, are arranged within the interface; these are marked with A. Furthermore, a vent line C is arranged in the interface VE.2. For transmitting the electrical power, low-voltage transmission means D and high-voltage transmission means B are arranged in the interface VE.2.

[0040] In Fig. Figure 4 shows an exploded view of the two housing assemblies and the connecting device VE. The connecting device VE is elastically deformable in the axial direction AB. This elastic deformability in the direction AB enables virtually tolerance-free positioning of the two housing assemblies. The two interfaces VE.1 and VE.2 are designed identically, so that the connecting device VE is particularly easy to install and can be used to connect the ports A to D.

[0041] In Fig. Figure 5 shows a sectional view through the housing device and the connecting device VE as well as the universal joint shaft. The universal joint shaft is surrounded by a virtual envelope curve GWH. This envelope curve GWH specifies the distance that the connecting device VE must maintain from the universal joint shaft. The connecting device VE has a bellows as a casing VE.H. The bellows VE.H surrounds the lines that run from one storage unit to the other storage unit. A temperature control medium line A is shown as an example of these lines. The temperature control medium line A can be connected using a plug-in connection (A.1, A.2). The housing-side connection A.1 is designed as a socket and the connecting device-side connection A.2 as a plug. The connecting device VE is elastically deformable in the AB direction.

[0042] Fig. Figure 6 shows sectional views of the mounting cover and the housing assembly. Fig. 6a shows the connection of the mounting cover MD to the housing assembly by means of a positive connection, in this case a screw connection. The mounting cover can be removed downwards. Fig. Figure 6b shows the connection between the mounting cover MD and the service cover SD. The service opening SO can be closed using the service cover SD. The service cover SD can be connected to the mounting cover MD via a positive connection, in this case a screw connection. The service cover can have additional devices SD.1 for accommodating electrical components.

[0043] Fig.7 shows a perspective sectional view of the service cover SD and the mounting cover MD. It can be seen that the mounting cover MD surrounds the service cover SD like a type of frame-like component. The service opening SO can be closed by means of the service cover SD. The service cover SD is arranged in the mounting cover MD in such a way that an at least essentially flat surface is created. The mounting cover MD is arranged on an edge of the housing device. To install the storage units in the housing device in the mounting direction MR, the mounting cover MD is removed from the housing device. After installation, the housing device is closed using the covers MD and SD. If maintenance of the storage units becomes necessary at a later date, the smaller service cover SD can then be removed from the mounting cover MD.This offers the advantage that the relatively large MD mounting cover can be securely connected to the housing using a material-to-material seal. Any necessary service work on the storage unit can still be performed by removing the SD service cover.

Claims

[1] Drive train for a motor vehicle with a combined drive system with an internal combustion engine (ICE), which is arranged in the motor vehicle in a first end region, at least one electromechanical energy converter (EMW), at least one driven drive axle (HA), which is arranged in the motor vehicle in a second end region, a drive shaft (GW) for transmitting drive power from the internal combustion engine (ICE) to this drive axle (HA) and with an energy storage device for storing and providing electrical energy, said device having at least one first storage unit (GE.1), wherein the energy storage device has a second storage unit (GE.2), wherein the first and second storage units (GE.1, GE.2) are arranged along a rotation axis on opposite sides of the drive shaft (GW) and are arranged between the internal combustion engine (ICE) and the drive axle (HA) and, that the first and the second storage unit (GE.1, GE.2) can be connected to one another by means of a connecting device (VE), and wherein the connecting device (VE) is designed at least for transmitting electrical power and for transmitting a temperature control medium volume flow, and wherein the connecting device (VE) and at least one of the storage units (GE.1, GE.2) can be connected to one another by a plug / socket connection (VE.1, VE.2) and wherein the first and the second storage unit (GE.1, GE.2) can be connected to one another via the drive shaft (GW) by means of the connecting device (VE). [2] Drive train according to claim 1, characterized by , that at least one of these storage units (GE.1, GE.2) has a housing device, that the housing device is designed to accommodate at least one electrochemical energy storage device, that the housing device has a mounting opening, that the mounting opening can be closed by a mounting cover (MD), that the mounting cover (MD) is arranged on the underside of the housing device in the motor vehicle when it is installed as planned. [3] Drive train according to claim 2, characterized by that the assembly cover (MD) has a service opening (SO), that this service opening (SO) can be closed by a service cover (SD). [4] Drive train according to claim 3, characterized by that the service cover (SD) can be connected to the assembly cover (MD) by means of a form-fitting connection. [5] Drive train according to one of the preceding claims, characterized by , that a first storage unit (GE.1) is arranged to accommodate the electrochemical energy storage device and to accommodate a control device, that the control device is designed at least to control the power extraction from the electrochemical energy storage device. [6] Drive train according to claim 5, characterized by that the control device has a device (IV) for converting direct current into alternating current (inverter). [7] Drive train according to one of claims 5 or 6, characterized by that the control device has a device for converting direct current. [8] Drive train according to one of claims 5 to 7, characterized by that the control device has a device for converting alternating current into direct current and is designed to charge the electrochemical energy storage device. [9] Drive train according to claim 5, characterized bythat the device (IV) for converting direct current into alternating current (inverter) is arranged outside the energy storage device. [10] Drive train according to one of the preceding claims, characterized by that the connecting device (VE) has electric current transmission means (D, B) and volume flow transmission means (A, C) and that these are surrounded at least in sections by an enclosing device (VE.H). [11] Drive train according to one of the preceding claims, characterized by that the storage capacity of the first storage device (SPK1) is less than the storage capacity of the second storage device (SPK2).

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