EP1556634A1

EP1556634A1 - Motor vehicle drive device

Info

Publication number: EP1556634A1
Application number: EP03810407A
Authority: EP
Inventors: Andreas Klaus; Tobias Ostertag
Original assignee: DaimlerChrysler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2002-11-02
Filing date: 2003-10-25
Publication date: 2005-07-27
Also published as: WO2004042257B1; JP2006504572A; WO2004042257A1; US20050265858A1; DE10251042A1; US7413417B2

Abstract

The invention relates to a motor vehicle drive device. An oil pump (6) which can only be driven by an electric motor (8) is provided for supplying oil to a drive gearbox (2) and optionally other drive elements. Preferably, a spacing region (14) is provided between the oil pump (6) and both the electric motor (8) and the drive motor (4), in which at least one torque transmission device (16), for example a hydrodynamic torque converter, a shiftable drive clutch and/or at least one electric motor can be positioned, in order to form a hybrid drive. A plurality of different drive devices can be formed by a standardised form of embodiment.

Description

Motor vehicle drive device

The invention relates to a motor vehicle drive device according to the preamble of claim 1.

DE 199 23 154 AI shows a motor vehicle drive device of this type, in which an oil pump is connected via a freewheel with an electric motor and another freewheel with a traction drive train. As a result, the oil pump is driven by either the electric motor or the traction drive train as a function of the rotational speed. In the engine compartment of motor vehicles there is very little installation space, so that it is difficult to accommodate the two freewheels and the electric motor.

From motor vehicle drive devices are known whose traction drive train (motor vehicle powertrain) axially one after the other an internal combustion engine and an automatic transmission, wherein the automatic transmission includes a hydrodynamic torque converter and a mechanical drive transmission containing planetary gear sets and switching elements for switching the planetary gear sets. The torque converter is located axially between the engine and the mechanical drive gear. For switching the switching elements (clutches and / or switching brakes) and for cooling the mechanical drive gear and oil supply to the torque converter, an oil pump is provided, which is drivable via a mechanical drive connection of the traction drive train. The oil pump is located axially between the torque converter and the mechanical drive gear and surrounds a drive shaft.

Due to increasing requirements of the consumption and emission reduction in the future start / stop operation of the internal combustion engine, for example at traffic lights in cities, can no longer be waived. To achieve a comfortable starting of the internal combustion engine, suitable starter / generators and various hybrid systems (traction drive systems containing at least two different traction motors, for example an internal combustion engine and at least one electric motor) are developed for this purpose.

The oil pump of the known automatic transmission is driven by the impeller of the torque converter, which is permanently coupled to the crankshaft of the engine. As a result, when the internal combustion engine is switched off, the oil pump can not be driven, so that when the internal combustion engine is switched off, the oil pressure for switching the shifting elements (clutches and optionally switching brakes) and for lubrication can not be maintained. As a result, a quick restart of the motor vehicle after a stop of the internal combustion engine is not possible. In this case, it is necessary to wait until the motor vehicle starts up until after the start of the internal combustion engine the oil system of the automatic transmission has filled and a sufficiently high oil pressure level has built up to actuate the switching elements. This is in contradiction to today's comfort claim. This comfort claim could be satisfied by the fact that the oil pump is driven in accordance with said DE 199 23 154 AI or an additional oil pump is provided, which is driven by an electric motor, if necessary, to maintain the oil supply and the oil pressure during the stoppage of the internal combustion engine. However, both solutions fail because most vehicles do not have sufficient space in them Is available and / or the existing components of the motor vehicle powertrain would have to be changed, which would be very expensive and would also be contrary to a series production of different vehicles using the same components or the same modules.

By the invention, the object to be achieved, the drive device in particular for passenger cars form such that immediately after starting the Fahrzeugantriebs- engine, which may be an internal combustion engine or an electric motor or another type of engine, -die for starting and driving the Motor vehicle required oil quantity and the required oil pressure in the motor vehicle drive gear is present without more or much more space is needed. Preferably, this object is to be achieved in such a way that the solution can also be used for various types of known vehicles produced in series, without requiring a great deal of technical or financial effort.

This object is achieved according to the invention by the features of claim 1.

Accordingly, there is the solution in a motor vehicle drive device, comprising a motor vehicle drive transmission with variable gear ratio for torque transmission in a drive train between a driving drive motor and at least one motor vehicle wheel, an oil pump for supplying the drive gear with pressurized oil for switching switching elements and / or for cooling the drive gear, an electric motor for driving the oil pump, characterized in that between the electric motor and the oil pump is a clutch-free, permanently closed drive connection and that neither the electric motor nor the oil pump have a mechanical drive connection to the torque transmission path of the traction drive train , According to the invention, the drive of the oil pump takes place only by an electric motor. The oil pump and its electric motor can be in the housing of the drive device, for. B. in the housing of an automatic transmission, consisting of hydrodynamic torque converter and mechanical transmission part integrated.

According to the invention, the oil pump used in today's passenger cars can be maintained. It is according to the invention no longer mechanically, -, but only, electrically driven. The electric motor is integrated in the housing so that little or no changes to the known drive device are required. Depending on the embodiment, a short extension of the converter housing to create an additional installation space may be required. However, no space for an additional external oil pump is needed.

Due to the direct integration of the oil pump and its electric motor in the drive train of the motor vehicle less space is required than if an additional, electrically driven oil pump would be used to the previous, only mechanically driven oil pump.

The sealing of the oil passages is also simplified. There are no cables to be laid. The oil exchange with the drive gear can, as in existing passenger cars ü over the already provided for this purpose channels.

In addition, it is possible to control the pump by the purely electric drive absolutely on demand. This makes effective fuel savings possible. In the conventional oil pump, the delivered Ölström depends solely on the speed of the engine. At high speeds, more oil is pumped than necessary. This overproduction will reduced by the electric drive, whereby the losses are significantly reduced.

According to a particular embodiment of the invention it is provided that the oil pump and its electric motor are arranged on the transmission input side of the drive gear, and that between the arrangement of the oil pump and its electric motor on the one hand and the traction drive motor on the other hand a distance range is provided for the positioning of at least one torque transmission device in Traction drive train, wherein ' ^• the torque transmission device has at least one of the elements switchable clutch, torque converter and / or at least one further electric machine and this element is positionable in the distance range. The further electric machine can be connected or connectable as an electric motor and as a generator with the traction drive train.

As a result, the drive device can be used in a modular system with which various motor vehicles, in particular passenger cars, can be equipped.

Further features of the invention are contained in the subclaims.

The invention will now be described by way of example with reference to the drawings of preferred embodiments. In the drawings show:

1 is a schematic side view of a motor vehicle drive device according to the invention,

Fig. 2 is a broken longitudinal section of a particular

Embodiment of the motor vehicle drive device according to the invention, Fig. 3 is a longitudinal section of yet another particular embodiment of a motor vehicle drive device according to the invention.

The drive device of the invention has particular advantages in passenger cars because there the space is particularly tight. However, the invention is also applicable to any other type of motor vehicle.

As shown in FIG. 1, the drive device of the invention includes a variable ratio motor vehicle drive transmission 2 for transmitting torque in a drive train between a traction drive motor 4 and at least one motor vehicle wheel. An oil pump 6 is for supplying the drive gear 2 with pressurized oil for switching switching elements of the drive gear and for cooling the drive gear 2 by an electric motor 8 driven.

The electric motor 8 of the oil pump 6 may be an internal rotor or an external rotor. In the embodiments shown in FIGS. 1, 2 and 3, it is an internal rotor which has a rotor 11 within a stationary stator 9.

The oil pump 6 has a non-rotatably arranged pump housing 5 and a rotatably connected to the rotor 11 of the electric motor 8 by a permanently closed mechanical drive connection 10 pump rotor. 7

The traction drive motor 4 and the drive gear 2 are arranged along a theoretical axis of rotation 25 axially to each other and connected by an intermediate drive train 12 with each other drivingly connected or connectable.

The oil pump 6 and the electric motor 8 are located on the transmission input side of the transmission 2 about the axis of rotation 25 of the transmission 2. arranged drive internals 12 around. Between the arrangement of the oil pump 6 and its electric motor 8 on the one hand and the traction drive motor 4 on the other hand, a distance range 14 is provided for the positioning of at least one torque transmitting device 16 for torque transmission in the drive intermediate train 12. The torque transmitting device 16 has at least one of the elements switchable traction drive clutch, torque converter or at least a further electric machine, wherein this element in the distance region 14 is arranged. If the element is a hydrodynamic torque converter, then this can form an automatic transmission together with the drive gear 2. In this case, the drive gear 2 may have switching elements in the form of clutches and / or switching brakes for shifting gears. If the element is a switchable traction drive clutch, the drive gear 2 may be a manually shiftable transmission or an automatically shiftable transmission. Additionally or alternatively, the element may be or have at least one or more other electrical machines which is drivingly connected or connectable to the drive train 12. This further electric machine may be an electric motor to drive the drive gear 2 alone or in addition to the traction drive motor 4 or. Furthermore, the further electric machine can be designed such that it can also be operated as a generator for generating electricity, wherein it can be driven by the traction drive motor 4 or the vehicle wheels. Furthermore, the further electric machine can be designed as an electric starter motor for starting the driving drive motor 4, if this is an internal combustion engine.

The intermediate drive train 12, in which the torque transmitting device 16 is located, in the illustrated embodiment includes a transmission input shaft 22 between the torque transmitting device 16 and the drive gear 2, and an engine output shaft, for. Cranks Between the at least one of these shafts 22 and 24 on the one hand and the torque transmission device 16 on the other hand, a switchable coupling can be provided 18 or 20, depending on the type of drive device.

The oil pump 6 and / or the electric motor 8 extend around the intermediate drive train 12, preferably around the transmission input shaft 22.

According to preferred embodiments of the invention, the electric motor 8 has a larger outer diameter than the oil pump 6. As a result, they can be positioned at different radii. According to a preferred embodiment, the oil pump 6 is arranged at least partially or completely axially and radially within the electric motor 8.

These features take up very little space.

The embodiments of the invention according to FIGS. 2 and 3 can have all the features described above with reference to FIG. In Figs. 2 and 3, the parts of Fig. 1 corresponding parts with the same reference numerals.

2, the torque transmitting device 16 is a hydrodynamic torque converter, which is only partially shown and has, for example, a turbine wheel 26, an impeller 28 and a stator 30. The pump impeller 28 is connected to the crankshaft 24 of the traction drive motor 4, and the turbine wheel 26 is drivingly connected or connectable to the transmission input shaft 22 of the drive intermediate rail 12 of FIG. 1. The torque converter 16 may be provided with a switchable lock-up clutch that can be bridged. A drive housing may be formed in one piece or in two parts. It is formed in two parts in the illustrated embodiments of the invention and consists of a gear housing 32 containing the drive gear 2 and a header housing 34 containing the torque converter 16, the oil pump 6 and its electric motor 8. The two housings 32, 34 are on housing flanges 36 and 38 with each other screwed, as shown schematically by a screw 40.

The pump housing 5 of the oil pump 6 and the stator 9 of the electric motor 8 are arranged on the side facing away from the drive gear 2 side of the attachment housing flange 38 in the attachment housing 34 and secured to this flange 38.

The stator 9 of the electric motor 8 has an electromagnetically active part 9-1 which is housed in an electric motor housing 42 which is fixed to the flange 38 of the attachment housing 34.

The rotor 11 has a flat or plate-like curved rotor disk 44, which at least partially forms the permanently closed drive connection 10 between the rotor 11 and the pump rotor 7 of the oil pump 6. The rotor disk 44 carries at its radially outer end the electromagnetically active 11-1 part of the rotor 11 which cooperates electromagnetically with the electromagnetic part 9-1 of the stator 9 to drive the rotor 11.

The rotor disk 44 is rotatably connected at its radially inner end with a hollow shaft portion 48, or integrally formed, which extends from an annular disc portion 49 to the rear of the pump rotor 7, with which it is permanently connected rotationally fixed. The rearwardly projecting portion of the hollow shaft part 48 may be radially mounted on the pump housing 5 of the oil pump 6, either directly or through a bearing 46, for. B. a plain bearing. In the embodiment of Fig. 2, the electric motor housing 42 is provided with a stator 50 which is either integrally formed with the E lektromotorgehäuse 42 or non-rotatably attached to this and the electromagnetically active stator 9-1 either flat or plate-shaped curved according to extends inside toward the axis of rotation 25. The stator disk 50 is provided at its radially inner end with a forwardly extending from the pump housing 5 to the torque converter 16 toward hollow shaft portion 52. This hollow shaft part 52 extends axially forward each with a radial distance over an end portion of the hollow shaft part -48, which projects from the annular disc portion 49 to the front, and an opposite rearwardly extending hollow shaft portion 54 of the impeller 28 of the hydrodynamic torque converter 16. On the hollow shaft part 52nd the stator disc 50 is radially mounted via a bearing 56, the rotor disk 44 and the hollow shaft portion 48, radially mounted on a further bearing 58, the impeller 28 of the torque converter 16. Thus, the rotor disk 44 and thus the entire rotor 11 of the electric motor 8 both at the pump housing 5 of the oil pump 6 and on the stator 50 and thus on the stator 9 at least radially, if necessary, also axially supported.

According to another embodiment, the bearing 46 of the rotor disk 44 on the pump housing 5 can be omitted, and the rotor disk 44 are supported only on the stator disk 50.

According to another embodiment, the impeller 28, instead of the described embodiment, be rotatably mounted on the radially outer peripheral surface of the hollow shaft portion 52 of the stator 50, or on the hollow shaft portion 48 of the rotor disk 44 of the electric motor 8. Through all embodiments, a compact small construction is achieved ,

The electric motor housing 42 with the stator disk 50 on the one hand and the pump housing 5 of the oil pump 6 on the other hand bil- In the radially outer region of the Olkammer 60 are the electromagnetically active parts 9-1 and 11-1 of the stator 9 and the rotor 11. In the radially inwardly located region of the Olkammer 60, the rotor disc 44 extends between the pump housing 5 of the oil pump 6 and the stator 50 of the electric motor 8 each at a distance from these, so that in this area the oil chamber 60 is divided by the rotor disk 44 and a Hinströmweg and a Rückströmweg is formed for cooling oil. This oil for cooling the electric motor 8 is preferably the oil of the oil pump 6, which is supplied and discharged at suitable locations of the oil chamber 60.

From the oil pump 6, an oil passage 62 leads to the hydrodynamic torque converter 16 in order to supply it with oil. From this oil channel 62, a side channel or bypass 64 can be branched off, for example, at one or more locations, via which oil the oil pump 6 can flow through the oil chamber 60 of the electric motor 8.

The rotor disk 44 preferably extends substantially parallel to the pump housing 5 at a distance from this pump housing from outside to inside in the direction of the axis of rotation 25. The stator disk 50 preferably extends substantially parallel to the rotor disk 44 at a distance from this substantially from outside to inside in the direction of the axis of rotation 25 back.

The electric motor 8 has in its radially outer end portion, where the electromagnetically active parts 9-1 and 11-1 of the stator 9 and the rotor 11, a larger diameter than the oil pump 6. This makes it possible, the oil pump 6 according to the 2 and 3 radially and axially completely within the electromagnetically active parts 9-1 and 11-1 of the rotor 11 and the stator 9 of the electric motor 8 to be arranged. The embodiment of FIG. 3 has the differences with respect to the embodiment of FIG. 2 that the electric motor housing 42, and hence the stator 9, does not have a stator disk 50 extending inwardly therefrom. There is no Olkammer 60 is provided, but the electric motor 8 is disposed in an oil-free air space 70. This is located between the flange 38 of the offset housing 34 and the torque converter 16th

The rotor 11 of FIG. 3 is provided with a rotor disk 144 which extends inwardly in the direction of the axis of rotation 25 from its electromagnetic active rotor part 11-1 and at least partially forms the drive connection 10. The rotor disk 144 has an annular disk part 149, at the radially inner region of which a hollow shaft part 148 extending axially to the rear to the pump rotor 7, which is connected in a rotationally fixed manner to the pump rotor 7, and a front hollow shaft part 152 extending axially in the opposite direction to the front is provided.

The rear hollow shaft part 148, which is connected in a rotationally fixed manner to the pump rotor 7, is mounted radially and, if necessary, also axially rotatable via one or more bearings 156 and 157 on the pump housing 5. These bearings 156 and 157 are located between an outer peripheral surface of the rear hollow shaft part 148 and an inner circumferential surface of the pump casing 5.

The annular disc part 149 and the two hollow shaft parts 148 and 152 are preferably together a one-piece molded part.

The impeller 28 of the hydrodynamic torque converter 16 is mounted radially on at least one bearing 158 at the front, in the direction of the torque converter 16 extending, hollow shaft portion 152 of the rotor disk 158 and axially rotatable if necessary. The bearing 158 is preferably located between an inner circumferential surface of the forward projecting Hohlwellenteils 152 and an outer peripheral surface of the rearwardly projecting hollow shaft part 54 of the impeller 28th

As far as no differences are described here, Fig. 3 corresponds to the embodiment of Fig. 2, so that in this regard, the description of Fig. 2 is correct.

As already mentioned with reference to FIG. 1, instead of a torque converter 16, a shiftable clutch may also be provided if the transmission 2 is not an automatic transmission but a manually shiftable or automatic transmission. For all embodiments, in the axial gap between the traction drive motor 4 (not shown in FIGS. 2 and 3) and the area in which the electric motor 8 and the oil pump 6 are arranged, also one or more electric machines may be arranged form a hybrid drive together with the traction drive motor 4 and / or can be used as a starter motor for starting the traction drive motor 4, if this is an internal combustion engine. The traction drive motor 4 could also be an electric motor according to another embodiment.

The invention is not limited to a particular type of bearings. These can be z. B. plain bearings, ball bearings, roller bearings, etc. be.

The electric motor 8 is independent of the traction drive train and its torques in all embodiments.

Claims

DaimlerChrysler AGPatent claims

Motor vehicle drive device comprising a motor vehicle drive transmission (2) with variable ratio for torque transmission in a drive train between a traction drive motor and at least one motor vehicle wheel, an oil pump (6) for supplying the drive gear (2) with pressurized oil for switching Switching elements and / or for cooling the drive gear (2), an electric motor (8) for driving the oil pump (6), characterized in that between the electric motor (8) and the oil pump (6) is a clutch-free, permanently closed drive connection (10) and that neither the electric motor (8) nor the oil pump (6) have a mechanical drive connection to the torque transmission path of the traction drive train.

Motor vehicle drive device according to claim 1, characterized in that the oil pump (6) and its electric motor (8) on the transmission input side of the drive gear (2) are arranged, and that between the arrangement of the oil pump (6) and its electric motor (8) on the one hand and the traction drive motor (4) on the other hand, a distance range (14) is provided for the positioning of at least one torque transmission device (16) for torque transmission between said torque transmitting device (16) and the traction drive train, wherein the torque transmitting device (16) at least one of the elements switchable clutch (18,20) torque converter and / or at least one further electric machine and this element in the distance range (14) is positionable or positioned.

3. Motor vehicle drive device according to one of the preceding claims, d a d u r c h e g e k e n e c e in that the oil pump (6) in a housing (32,34) is housed, which contains a part of the traction drive train.

4. The motor vehicle drive device according to claim 3, characterized in that the housing (32, 34) contains the drive gear (2).

5. The motor vehicle drive device according to claim 3 or 4, wherein a drive gear (2) is an automatic transmission and that the housing (32, 34) includes a torque converter (16) of the automatic transmission.

6. Motor vehicle drive device according to one of the preceding claims, d a d u r c h e c e n e z e c h e s that the oil pump (6) and its electric motor (8) surrounding a shaft (22) of the traction drive train.

7. Motor vehicle drive device according to claim 6, characterized in that the oil pump (6) and the electric motor (8) surrounding the transmission input shaft (22) of the drive gear (2).

8. Motor vehicle drive device according to one of the preceding claims, d a d u r c h e c e n e c i n e s in that the electric motor (8) is provided with a non-rotatably arranged electric motor housing (42).

9. Motor vehicle drive device according to claim 8, characterized in that the electric motor housing (42) with at least one bearing point (52) for supporting at least one rotatable relative thereto rotatable element (28,11) is formed.

10. Motor vehicle drive device according to claim 9, characterized in that a rotor (11) of the electric motor (8) is rotatably mounted at the bearing point (52) or at one of the bearing points of the electric motor housing (42).

11. Motor vehicle drive device according to claim 9 or 10, in that a rotational element (28) of a torque converter (16) is rotatably mounted at the bearing point (52) or at one of the bearing points.

12. Motor vehicle drive device according to one of the preceding claims, d a d u r c h e c e n e z e i c h e s that the oil pump (6) is a non-rotatable pump housing

(5).

13. Motor vehicle drive device according to claim 12, characterized in that the rotor (11) of the electric motor (8) is rotatably mounted on the pump housing (5).

14. Motor vehicle drive device according to one of the preceding claims, characterized in that the rotor (11) of the electric motor (8) in an oil chamber (60) is arranged, which is durchstrδmbar by the oil of the oil pump (6).

15. Motor vehicle drive device according to claim 14, characterized in that at least a part of the stator (9) of the electric motor (8) delimits the Olkammer (60), so that the oil of the oil pump (6) on this part of the stator (9) along flows.

16. A motor vehicle drive apparatus according to claim 14 or 15, wherein the oil chamber (60) of the electric motor housing (42) of claim 8 and of the pump housing (5) of claim 12 is limited and the rotor (11) of the electric motor

(8) extends between these two housings and is spaced from the two housings, so that between the rotor

(11) and the two housings each an oil passage is formed.

17. Motor vehicle drive device according to one of the preceding claims, characterized in that the electric motor (8) has a larger outer diameter than the oil pump (6) and that the oil pump (6) at least partially axially and radially within the electric motor 8 is arranged.

18. Motor vehicle drive device according to one of claims 14 to 17, characterized in that the oil supply of the oil chamber (60) of an oil path (62) is branched, which connects the oil pump (6) with the torque converter of claim 5.

19. Motor vehicle drive device according to claim 1, wherein the rotor of the electric motor is arranged in an oil-free air space.

20. Motor vehicle drive device according to claim 19, characterized in that the stator (9) of the electric motor (8) is provided with at least one cooling oil passage (60), through which oil from the oil pump (6) can flow for cooling the electric motor (8).

21. Motor vehicle drive device according to claim 19 or 20, characterized in that the rotor (11) of the electric motor (8) is rotatably mounted on the non-rotating arranged pump housing (5).

22. Motor vehicle drive device according to claim 21, characterized in that a rotational element (28) of a torque converter (16) on the rotor (11) of the electric motor (8) is rotatably mounted relative to it.