WO2012123173A2

WO2012123173A2 - Drive device for driving a wheel of a torsion beam axle for an electrically drivable vehicle

Info

Publication number: WO2012123173A2
Application number: PCT/EP2012/051637
Authority: WO
Inventors: Jens Heimann; Martin Münster; Stephan Pollmeyer; Ulrich Mair; Karl-Hermann Ketteler
Original assignee: Zf Friedrichshafen Ag
Priority date: 2011-03-16
Filing date: 2012-02-01
Publication date: 2012-09-20
Also published as: DE102011005625A1; WO2012123173A3

Abstract

A drive device (11) for driving a wheel (7) of a torsion beam axle (1) for an electrically drivable vehicle is proposed, comprising an electric machine (12) and a transmission (13, 14) which is connected on the output side of the electric machine (12) when considered in the direction of force flux in the tractive mode, wherein the housing (26) of the electric machine (12) or the housing (16) of the transmission (13, 14) is screwed directly to the longitudinal link (2) of the vehicle axle or is integrated as a multi-part welded component into the longitudinal link (2).

Description

Drive device for driving a wheel of a torsion beam axle for an electrically driven vehicle

The present invention relates to a drive device for driving a wheel of a torsion beam axle for an electrically driven vehicle according to the preamble of patent claim 1.

In general, the arrangement of the drive train in electrically driven vehicles corresponds to the arrangement of the drive train in vehicles having a central drive, comprising an internal combustion engine. Here, a drive device comprising an electric machine, a transmission and a differential is fixed to the body in the center of the vehicle between the front or rear wheels arranged; The output torque is transmitted via side shafts to the driven wheels as in conventional central drives. In such an arrangement of the drive train, the suspension concept remains largely intact, with only modifications of the unit mounting and the subframe are required.

In electrically driven or driven vehicles, comprising a central drive, the battery housing represents a significant intervention in the vehicle structure. It is known, the battery in the subsoil, for example, under the rear seat or in the area taken in central drives with an internal combustion engine from the transmission tunnel was to integrate.

In the following, a torsion beam axle can generally be understood as meaning in general an axle which has at least one trailing arm per wheel. In particular, these may be a torsion beam axle, a trailing arm axle and / or a trailing arm axle. Radnahe electrical drives are also known in the prior art, which are understood by close to the wheel drives in further drives, which provide one or more electric motors per drive wheel of the vehicle. Thus, vehicles with two or more drive wheels are known, which have a corresponding number of drives, so two or more. In each case, an electric motor can act on exactly one drive wheel.

Under Radnahen drives but drives can be understood that are arranged handlebar-resistant and / or wheel.

Furthermore, known from the prior art radnahe electric drives for driving a wheel of a driven axle for electrically driven vehicles, which are integrated into the chassis of the vehicle, wherein, depending on the number of driven vehicle axles, for example, two or four electric drives are provided ,

Here, the electric drives can be arranged Radträgerfest; In this case, the electric drive springs directly with the respective wheel and the unsprung mass is directly influenced by the drive.

Another way of arranging the near-wheel electrical drives is to arrange this construction test. Here, the electric drives move out of the vehicle center out towards the wheels.

Further, the electric drives can be arranged handlebar fixed, in which case they are attached to the suspension arms, for example, the composite beam. This design reduces the unsprung mass by locating the electric drives close to the most advanced linkage point. From the applicant's DE 10 2007 039 059 A1, a driven vehicle axle designed as a torsion beam axle is known, in which an electric motor is provided for each wheel of the axle, which is arranged with the axis of rotation in the vehicle longitudinal direction, wherein its housing forms part of the longitudinal arm of the torsion beam axle ,

Near-wheel drives may be provided on four-wheel, front-wheel or rear-wheel drive vehicles, the axle types of the powered vehicle axles being conventional axle types, e.g. Strut or double wishbone axle types. Furthermore, wheel-near drives can be integrated into wheel-integrated running gears.

Furthermore, the near-wheel electric drives can have a transmission.

From EP 1 961 602 A1 a drive device for driving the wheel which can be integrated into a vehicle wheel is known, which has an electric motor and two planetary gears connected in series, which are arranged axially between the electric motor and the wheel.

Advantageously, the use of radnahen electrical drives for driving a wheel of a driven axle results in the vehicle body in a high flexibility, since the elimination of the central drive in the vehicle center new degrees of freedom in the vehicle design, especially in the design of the vehicle interior, the battery housing and crash safety.

In addition, wheel-specific drive torques can be generated by radnahe electrical drives, which functions such as torque vectoring, ESP, ABS, ASR, etc. can be easily implemented. Due to the fast and more accurate controllability of electric drives, these can Functions are optimized compared to conventional brake-based control systems.

The present invention has for its object to provide a drive device for driving a wheel of a torsion beam axle for an electrically driven vehicle.

This object is solved by the features of patent claim 1. Further embodiments and advantages of the invention will become apparent from the dependent claims.

Accordingly, a drive device for driving a wheel of a torsion beam axle for an electrically driven vehicle is proposed, comprising an electric machine and a viewed in the direction of power flow in traction on the output side of the electric machine switched gear, the housing of the electric machine or the housing of the transmission directly to the trailing arm bolted to the torsion beam axle, integrated as a multi-part welding component in the trailing arm or executed in one piece with the trailing arm. The electric machine can be made high-revving, the transmission having a high gear ratio, resulting in a high power / weight ratio (kW / kg) of the drive device and a small size of the electric machine.

A translation is understood here as the ratio of the rotational speed of the output shaft of the transmission to the rotational speed of the drive shaft of the transmission.

A high ratio is understood to mean a ratio of greater than 1:10, preferably 1:10 to 1:20, particularly preferably 1:14 to 1:18, in particular 1:16. A high-speed machine is understood to mean a machine which has a maximum rotor rotational speed of more than 15,000 revolutions per minute, preferably between 19,000 and 25,000 revolutions per minute.

In a further embodiment, the electric machine and the transmission may have a common housing.

In a further development of the invention, the connection of the caliper and / or the damper and / or the spring are integrated into the housing of the transmission or in the housing of the electric machine of the drive device, wherein the connecting screws for fixing the caliper at the same time housing screws for fixing the Drive device on the trailing arm of the axis can represent.

In this way, a compact design is achieved and eliminates the need for separate components, resulting in a reduction in costs.

Preferably, the arrangement of the electric machine and the transmission is such that in the predominant operating position of the vehicle, the lubricant automatically flows back under the action of gravity from the electric machine in the oil sump in the gear compartment, for which purpose the housing of the electric machine is designed such that a sufficient lubrication of the bearings of the rotor shaft is ensured. This results in the advantage that eliminates the need to provide contacting or non-contacting seals, especially in fast-rotating shafts of the drive device, whereby lubricant losses and heat generation can be reduced. The gearbox connected on the output side of the electric machine preferably comprises two planetary gearboxes connected in series.

The two planetary gear is a large translation allows, the dimensions and weight of the electric machine and thus the unsprung mass can be kept low; For example, the obtainable by the two planetary gear ratio can assume a value that is greater than 10. Here, the distribution of the achievable translation on the two planetary gear can be done symmetrically or asymmetrically.

Advantageously, the combination of a low drive torque with a high speed utilization in total in conjunction with the high-ratio transmission of the drive device results in a high power / weight ratio (kW / kg). The electrical machine can thereby be dimensioned small, which allows or simplifies the integration of the electric machine in the trailing arm.

The considered in the power flow direction in the train operation on the drive side of the e- lectric machine switched gear can also be designed as a planetary gear, spur gear or as a combination of a planetary gear with a spur gear or with a bevel gear.

The invention will be explained in more detail below by way of example with reference to the attached figures in the case of a torsion beam rear axle, the same reference numerals being used for the same components. Show it:

Figure 1: A schematic plan view of a state of the

Technique carried out torsion beam rear axle; FIG. 2 shows a schematic sectional view of a first embodiment of a drive device according to the invention for an electrically drivable vehicle;

FIG. 3 shows a schematic sectional view of a second embodiment of a drive device according to the invention for an electrically drivable vehicle;

Figure 4 is a schematic perspective view of an embodiment of a drive device according to the invention for illustrating the connection of the damper in the housing of the electric machine and the attachment of the housing of the electric machine to the trailing arm for an electrically driven vehicle; and

Figure 5: A schematic plan view of an embodiment of a drive device according to the invention for illustrating the connection of the damper in the housing of e-lektrischen machine and the attachment of the housing of the electric machine to the trailing arm for an electrically driven vehicle.

The invention will be explained with reference to a torsion beam rear axle, as this represents the most common Hinterachskonzept. Referring to FIG. 1, a prior art compound link rear axle 1 constructed according to the prior art comprises two trailing links 2, 3, which are interconnected by a transverse section 4.

The torsion beam rear axle 1 is screwed by two rubber bearings 5, 6 with the body of the vehicle. The wheels of the torsion beam rear axle 1 are provided in the figure with the reference numerals 7 and 8 respectively. Further, in the attached Figure 1 with 9 a damper and 10 a spring of the axis 1 are designated.

In the embodiment of the invention shown in FIG. 2, a drive device 1 1 is provided for driving a wheel 7 of a torsion beam axle 1 of an electrically driven vehicle, which connects an electric machine 12 and two connected in series in the power flow direction in traction on the output side of the electric machine 12 Planetary gear 13, 14 includes. The first and the second planetary gear 13, 14 are arranged in the example shown on the wheel 7 side facing the electric machine 12.

Here, the rotor of the electric machine 12 via a sun gear shaft 23 rotatably connected to the sun gear 17 of the first planetary gear 13, wherein the web 18 of the first planetary gear 13 is rotatably connected via a further sun gear 27 with the sun gear 19 of the second planetary gear 14 and wherein the output of the drive device 1 1 via the web 20 of the second planetary gear 14 and a non-rotatably connected to the web 20 shaft 24 takes place, which is rotatably connected to the wheel hub 15.

Furthermore, the ring gear 21 of the first planetary gear 13 and the ring gear 22 of the second planetary gear 14 are arranged fixed to the housing; they may be coupled to the housing 16 of the planetary gear 13, 14 of the drive device 1 1 or be integral with the housing 16. The ring gear 21 of the first planetary gear 13 and the ring gear 22 of the second planetary gear 14 may also be pressed into the housing 16. In the event that a ring gear is formed integrally with the housing 16, a radial shoulder may be provided to compensate for the difference in diameter between the housing 16 and the ring gear. Due to the design of a ring gear as einpressbarer in a cylindrical housing Hohlrad- ring can be selected depending on the load of the material, which may result in a reduction of the weight.

As part of a development, the rotor of the electric machine 12 may be integral with the sun gear 23 of the first planetary gear 13; Furthermore, the sun gear 27 of the second planetary gear 14 may be integrally formed with the web 18 of the first planetary gear 13.

The teeth are preferably helical teeth, wherein the connection between the web 18 of the first planetary gear 13 and the sun gear 19 of the second planetary gear 14 is axially and radially supported by rolling bearings, plain bearings or thrust washers.

Here, the helix angle of the sun gear 17 of the first planetary gear 13 is opposite to the helix angle of the sun gear 19 of the second planetary gear 14. In addition, the directions of the helix angles of the sun gear 17 of the first planetary gear 13 and the sun gear 19 of the second planetary gear 14 are to be selected in an advantageous manner so the loads on the bearings of the drive device 1 1, in particular on the bearings of the shaft 23, via which the rotor is connected to the sun gear 17 of the first planetary gear 13, are minimized. As a result, the friction losses are minimized and it is possible a smaller dimensioning of the bearings.

The storage of the sun gear 23 of the first planetary gear 13 coincides with the bearing of the rotor of the electric machine 12, so that the need for separate storage is eliminated, the sun gear 17 of the first planetary gear 13 facing away from the bearing of the rotor of the electric machine 12 preferably by a spring element can be axially biased. Further, the storage of connected to the web 20 of the second planetary gear 14 shaft 24, ie the output of the drive device 1 1, formed by the wheel bearing of the wheel 7, which as a bearing of conventional design, for example, as a double-row roller bearing or bearing as two Einzelschrägrollenlager with a pressure angle between 15 ° and 60 ° can be executed. As a result, the number of bearings of the drive device can be reduced in an advantageous manner.

The connection of the connected to the web 20 of the second planetary gear 14 shaft 24 with the hub 15 can be done by means of a plug-in spline connection or a polygonal profile; Alternatively, the drive device 1 1 opposite end of the non-rotatably connected to the web 20 of the second planetary gear 14 shaft 24, the wheel hub 15 represent itself, whereby the assembly and manufacturing costs are reduced.

Referring to Figure 3, the electric machine 12 can be used as a hollow shaft motor, i. be designed as an electric machine with a rotor designed as a hollow shaft, wherein the first and the second planetary gear 13,

14 are arranged on the side facing away from the wheel 7 of the electric machine 12 and the output shaft of the drive device 1 1, which is formed by a rotatably connected to the web 20 of the second planetary gear 14 shaft 24 through the cavity of the rotor 25 of the electric machine 12th is guided to the wheel 7, where it is connected, for example via preferably a conventional splined shaft profile with the wheel hub 15 or the wheel hub

15 itself, as already explained.

Here, at the end remote from the electric machine 12 of the drive device 1 1 further storage (a first bearing is formed by the wheel bearing of the wheel 7, as already explained) provided with the web 20 of the second planetary gear 14 rotatably connected shaft 24 which is preferably arranged on a journal of the shaft 24. By interchanging the arrangement of the electric machine 12 and the first and second planetary gear 13, 14 in comparison to the embodiment of Figure 2, the advantage is achieved that in the region of the body longitudinal support space is provided, which is used in Einfe- countries in that the housing of the first and the second planetary gear 13, 14 with a smaller outer diameter is executable than the housing of the electric machine 12.

The electric machine 12 of the drive device 1 1 can be designed as an asynchronous machine, as a foreign-excited or permanent magnet synchronous machine or as a cross-field machine, which offers a high degree of flexibility.

Advantageously, the housing 26 of the electric machine 12 or the housing 16 of the planetary gear 13, 14 serve as a wheel or as part of the wheel carrier.

According to the invention, in particular in the case of an embodiment according to Figure 2, the housing 26 of the electric machine 1 2 or in particular in the case of an embodiment of Figure 3, the housing 16 of the planetary gear 13, 14 directly connected to the trailing arm 2 of the twist beam axis 1, preferably screwed. Alternatively, the housing 26 of the electric machine 12 or the housing 16 of the planetary gear 13, 14 may be integrated, for example, as a multi-part welding component in the trailing arm 2 or executed in one piece with the trailing arm 2. Further, the electric machine 12 can be inserted into the trailing arm 2 like a cartridge.

In a further development of the invention, the connection of the caliper (in the case of a disc brake) and / or the damper 9 and / or the spring 10 in the housing 16 of the planetary gear 13, 14 (preferably in an embodiment of Figure 3) or in the housing 26 of the electric machine 12 (preferably in an embodiment of Figure 2) of the drive device 1 1 integrated, the connecting screws for fixing the caliper can simultaneously represent housing screws for mounting the drive device 1 1 on the trailing arm 2 of the axle.

In Figures 4 and 5, the integration of the connection of the damper 9 in the housing 26 of the electric machine 12 and the direct attachment of the housing 26 of the electric machine 12 on the trailing arm 2 by means of connecting screws 28 is exemplified.

Due to the design according to the invention, a very compact design of the drive device can be realized with a low unsprung mass and high power / weight ratio (kW / kg).

The drive device presented here can also be combined with any axle types, for example, with a central link, Sword-arm, or trapezoidal link axle.

Furthermore, the drive device has a low number of bearings and good accessibility, and it can be integrated into the axle with little modification of an existing vehicle axle. For example, in the case of a torsion beam axle only the trailing arm has to be replaced by a modified part.

Further, the braking device of the wheels may be designed as a disc brake or drum brake; the drive device may be air-cooled or fluid-cooled, wherein the electric machine, the planetary gear transmission and the power electronics can have a common cooling. The power electronics can also be arranged radtragerfest or motor fixed.

Designation composite beam rear axle

Trailing arm

cross Section

Rubber bearing

wheel

damper

feather

driving device

electric machine

first planetary gear

second planetary gear

wheel hub

Housing of the planetary gear 13, 14th

Sun gear of the first planetary gear 13

Bridge of the first planetary gear 13

Sun gear of the second planetary gear 4

Web of the second planetary gear 14

Ring gear of the first planetary gear thirteenth

Ring gear of the second planetary gear 14th

Sun gear shaft of the first planetary gear 13

with the web 20 of the second planetary gear 14 rotatably connected shaft

Rotor of the electric machine 12

Housing of the electric machine 12

Sun gear shaft of the second planetary gear 14th

connecting bolts

Claims

claims

1 . Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically drivable vehicle, comprising an electric machine (12) and a transmission (13, 14) connected on the output side of the electric machine (12) in the direction of force flow in traction mode ), characterized in that the housing (26) of the electric machine

(12) and / or the housing (16) of the transmission (13, 14) screwed directly to the trailing arm (2) of the vehicle axle, integrated as a multi-part welding component in the trailing arm (2) and / or integral with the trailing arm (2) are.

Second drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim

1, characterized in that the connection of the caliper and / or the damper (9) and / or the spring (10) in the housing (16) of the transmission or in the housing (26) of the electric machine (12) of the drive device ( 1 1) is integrated.

Third drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim

2, characterized in that connecting means (28) for fixing the caliper simultaneously connecting means for the attachment of the drive device (1 1) on the trailing arm (2) of the axis (1),

4. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 1, 2 or 3, characterized in that the housing (26) of the electric machine (12) and / or the housing (16) of the transmission (13, 14) serves as a wheel carrier or as part of the wheel carrier.

5. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 1, 2, 3 or 4, characterized in that the transmission (13, 14) two in the direction of force flow in Zugbetrieb considered on the output side of the electric machine (12) connected in series planetary gear (13, 14).

6. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim

5, characterized in that the rotor (25) of the electric machine

(12) via a sun gear (23) rotatably connected to the sun gear (17) of the first planetary gear (13), that the web (18) of the first planetary gear (13) via a further sun gear (27) with the sun gear (19) the second planetary gear (14) is rotatably connected, that the ring gear (21) of the first planetary gear (13) and the ring gear (22) of the second planetary gear (14) are fixed to the housing and that the output of the drive device (1 1) via the web (20) of the second planetary gear (14) and with the web (20) rotatably connected to the shaft (24) takes place, which is rotatably connected to the wheel hub (15).

7. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim

6, characterized in that the rotor (25) of the electric machine (12) integral with the sun gear (23) of the first planetary gear (13) is executed.

8. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 6 or 7, characterized in that the sun gear shaft (27) of the second planetary gear (14) with the web ( 18) of the first planetary gear (13) is made in one piece.

9. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 6, 7 or 8, characterized in that the bearing of the web (20) of the second planetary gear ( 14) connected to the shaft (24) which forms the output of the drive device (1 1), by the wheel bearing of the wheel (7) is formed.

10. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 6, 7, 8 or 9, characterized in that the connection with the web (20) of the second Planetary gear (14) connected shaft (24) to the wheel hub (15) by means of a plug-in spline connection or a polygonal profile or that the drive device (1 1) facing away from the end connected to the web (20) of the second planetary gear (14) shaft ( 24) represents the wheel hub (15) itself.

1 1. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 6, 7, 8, 9 or 10, characterized in that the first and the second planetary gear (13, 14) on the wheel (7) facing side of the electric machine (12) are arranged.

12. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to claim 6, 7, 8, 9 or 10, characterized in that the first and the second planetary gear (13, 14) on the side facing away from the wheel (7) of the electric machine (12) are arranged, wherein the electric machine (12) is designed as a hollow shaft motor and the output shaft of the drive device (1 1) by the with the web (20). the second planetary gear (14) rotatably connected shaft (24) is formed, through the cavity of the rotor (25) of the electric machine (12) to the wheel (7) is guided.

13. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to at least one of the preceding claims, characterized in that the transmission (13,14) has a high gear and the electric Machine (12) is designed high-revving.

14. Drive device (1 1) for driving a wheel (7) of a torsion beam axle (1) for an electrically driven vehicle, according to at least one of the preceding claims, characterized in that the electrical machine is aligned with its longitudinal axis transverse to the longitudinal axis of the trailing arm.