DE102011005625A1 - Drive device for driving a wheel of a torsion beam axle for an electrically driven vehicle - Google Patents

Abstract

A drive device (11) is proposed for driving a wheel (7) of a torsion beam axle (1) for an electrically drivable vehicle, comprising an electric machine (12) and a transmission (viewed in the direction of force flow in pulling mode) switched on the output side of the electric machine (12). 13, 14), with the housing (26) of the electrical machine (12) or the housing (16) of the transmission (13, 14) screwed directly to the trailing arm (2) of the vehicle axle or as a multi-part welded component in the trailing arm (2) are integrated.

Description

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 DE 10 2007 039 059 A1 The applicant is known as a driven axle which is designed as a torsion beam axle, 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, the housing of which forms part of the longitudinal arm of the torsion beam axle.

Radnahe drives may be provided in vehicles with all-wheel, front or rear wheel drive, the axle types of the driven vehicle axles conventional axle types, such. B. strut or Doppelquerlenkerachstypen can be. Furthermore, wheel-near drives can be integrated into wheel-integrated running gears.

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

From the EP 1 961 602 A1 For example, there is known a drive apparatus for driving the wheel which can be integrated into a vehicle wheel and 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. The fast and more accurate controllability of electric drives enables these functions to be 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 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 electric machine connected transmission 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:

1 FIG. 2 is a schematic plan view of a prior art torsion beam rear axle; FIG.

2 : A schematic sectional view of a first embodiment of a drive device according to the invention for an electrically driven vehicle;

3 : A schematic sectional view of a second embodiment of a drive device according to the invention for an electrically driven vehicle;

4 : 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

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 the electric 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 1 includes a prior art torsion beam rear axle 1 two trailing arms 2 . 3 , which by a cross profile 4 connected to each other.

The torsion beam rear axle 1 is through two rubber mounts 5 . 6 bolted to the body of the vehicle. The wheels of the torsion beam rear axle 1 are in the figure with the reference numerals 7 respectively. 8th Mistake. Further, in the attached 1 With 9 a damper and with 10 a spring of the axle 1 designated.

At the in 2 shown embodiment of the invention is a drive device 11 to drive a wheel 7 a torsion beam axle 1 an electrically driven vehicle provided, which is an electrical machine 12 and two viewed in the direction of force flow in traction on the output side of the electric machine 12 connected in series planetary gear 13 . 14 includes. The first and the second planetary gear 13 . 14 are in the example shown on the wheel 7 facing side of the electric machine 12 arranged.

Here is the rotor of the electric machine 12 over a sun gear shaft 23 with the sun wheel 17 of the first planetary gear 13 rotatably connected, the web 18 of the first planetary gear 13 over another sun gear 27 with the sun wheel 19 of the second planetary gear 14 rotatably connected and wherein the output of the drive device 11 over the jetty 20 of the second planetary gear 14 and one with the jetty 20 rotatably connected shaft 24 done with the wheel hub 15 rotatably connected.

Furthermore, the ring gear 21 of the first planetary gear 13 and the ring gear 22 of the second planetary gear 14 fixed to the housing; they can attach to the case 16 the planetary gear 13 . 14 the drive device 11 coupled or integral with the housing 16 be executed. The ring gear 21 of the first planetary gear 13 and the ring gear 22 of the second planetary gear 14 can also be in the case 16 be pressed. In the event that a ring gear is integral with the housing 16 is executed, a radial shoulder may be provided to the diameter difference between the housing 16 and compensate the ring gear. Due to the design of a ring gear as einpressbarer in a cylindrical housing ring gear can be selected depending on the load of the material, which can result in a reduction in weight.

In a further development, the rotor of the electric. machine 12 integral with the sun gear shaft 23 of the first planetary gear 13 be executed; furthermore, the sun gear shaft 27 of the second planetary gear 14 with the jetty 18 of the first planetary gear 13 be executed in one piece.

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

Here is the helix angle of the sun gear 17 of the first planetary gear 13 opposite to the helix angle of the sun gear 19 of the second planetary gear 14 , In addition, advantageously, the directions of the helix angles of the sun gear 17 of the first planetary gear 13 and the sun wheel 19 of the second planetary gear 14 to choose so that the loads on the bearings of the drive device 11 , in particular on the bearings of the shaft 23 about which the Rotor with the sun gear 17 of the first planetary gear 13 is minimized. As a result, the friction losses are minimized and it is possible a smaller dimensioning of the bearings.

The bearing of the sun gear shaft 23 of the first planetary gear 13 coincides with the bearing of the rotor of the electric machine 12 together, eliminating the need for separate bearings, taking the sun gear 17 of the first planetary gear 13 remote storage of the rotor of the electric machine 12 may preferably be biased axially by a spring element.

Furthermore, the storage of the bridge with the 20 of the second planetary gear 14 connected shaft 24 , ie the output of the drive device 11 , through the wheel bearing of the wheel 7 formed, which can be designed as a bearing of conventional design, for example, as a double-row roller bearing or as a bearing comprising two Einzelschrägroßenlager with a pressure angle between 15 ° and 60 °. As a result, the number of bearings of the drive device can be reduced in an advantageous manner.

The connection of the bridge 20 of the second planetary gear 14 connected shaft 24 with the wheel hub 15 can be done by means of a plug-in splined connection or a polygonal profile; Alternatively, that of the drive device 11 opposite end of the bridge 20 of the second planetary gear 14 rotatably connected shaft 24 the wheel hub 15 represent themselves, whereby the assembly and manufacturing costs are reduced.

Referring to 3 , can the electric machine 12 as a hollow shaft motor, ie be designed as an electric machine with a designed as a hollow shaft rotor, wherein the first and the second planetary gear 13 . 14 at the wheel 7 opposite side of the electric machine 12 are arranged and the output shaft of the drive device 11 going through a with the jetty 20 of the second planetary gear 14 rotatably connected shaft 24 is formed, through the cavity of the rotor 25 the electric machine 12 to the wheel 7 is guided, where, for example, preferably via a conventional splined shaft profile with the wheel hub 15 is connected or the wheel hub 15 represents itself, as already explained.

Here is on the electric machine 12 remote end of the drive device 11 another storage (a first storage is through the wheel bearing of the wheel 7 formed, as already explained) with the web 20 of the second planetary gear 14 rotatably connected shaft 24 provided, preferably on a journal of the shaft 24 is arranged.

By interchanging the arrangement of the electric machine 12 and the first and second planetary gear 13 . 14 compared to the embodiment according to 2 the advantage is achieved that in the area of the longitudinal body of the vehicle space is provided, which is used during compression, since the housing of the first and the second planetary gear 13 . 14 smaller outer diameter is executable as the housing of the electric machine 12 ,

The electric machine 12 the drive device 11 can be implemented as an asynchronous machine, as a third-excited or permanent magnet synchronous machine or as a cross-field machine, which offers a high degree of flexibility.

Advantageously, the housing 26 the electric machine 12 or the housing 16 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 2 , the case 26 the electric machine 12 or in particular in the case of an embodiment according to 3 the housing 16 the planetary gear 13 . 14 directly with the trailing arm 2 the torsion beam axle 1 connected, preferably screwed. Alternatively, the housing 26 the electric machine 12 or the housing 16 the planetary gear 13 . 14 For example, as a multipart welding component in the trailing arm 2 be integrated or with the trailing arm 2 be executed in one piece. Furthermore, the electric machine 12 like a cartridge in the trailing arm 2 be inserted.

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 case 16 the planetary gear 13 . 14 (Preferably in an embodiment according to 3 ) or in the housing 26 the electric machine 12 (Preferably in an embodiment according to 2 ) of the drive device 11 integrated, wherein the connecting screws for fixing the caliper at the same time housing screws for fastening the drive device 11 on the trailing arm 2 can represent the axis.

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

In 4 and 5 exemplifies the integration of the connection of the damper 9 in the case 26 the electric machine 12 as well as the direct attachment of the housing 26 the electric machine 12 on the trailing arm 2 by means of connecting screws 28 illustrated.

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 and the power electronics may have a common cooling. The power electronics can also be arranged Radträgerfest or motor-fixed.

LIST OF REFERENCE NUMBERS

1

Torsion beam rear axle

2

Trailing arm

3

Trailing arm

4

cross Section

5

Rubber bearing

6

Rubber bearing

7

wheel

8th

wheel

9

damper

10

feather

11

driving device

12

electric machine

13

first planetary gear

14

second planetary gear

15

wheel hub

16

Housing of the planetary gear 13 . 14

17

Sun gear of the first planetary gear 13

18

Bridge of the first planetary gear 13

19

Sun gear of the second planetary gear 14

20

Bridge of the second planetary gear 14

21

Ring gear of the first planetary gear 13

22

Ring gear of the second planetary gear 14

23

Sun gear shaft of the first planetary gear 13

24

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

25

Rotor of the electric machine 12

26

Housing of the electric machine 12

27

Sun gear shaft of the second planetary gear 14

28

connecting bolts

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007039059 A1 [0011]
• EP 1961602 Al [0014]

Claims (14)

Drive device ( 11 ) to drive a wheel ( 7 ) a torsion beam axle ( 1 ) for an electrically driven vehicle, comprising an electric machine ( 12 ) and viewed in the direction of force flow in traction on the output side of the electric machine ( 12 ) switched gear ( 13 . 14 ), characterized in that the housing ( 26 ) of the electric machine ( 12 ) and / or the housing ( 16 ) of the transmission ( 13 . 14 ) directly with the trailing arm ( 2 ) bolted to the vehicle axle, as a multi-part welding component in the trailing arm ( 2 ) and / or with the trailing arm ( 2 ) are made in one piece. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ( 11 ) is integrated. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ( 11 ) on the trailing arm ( 2 ) of the axis ( 1 ), Drive device ( 11 ) to drive a wheel ( 7 ) 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. Drive device ( 11 ) to drive a wheel ( 7 ) 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 viewed in the direction of force flow in traction on the output side of the electric machine ( 12 ) connected in series planetary gear ( 13 . 14 ). Drive device ( 11 ) to drive a wheel ( 7 ) 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 shaft ( 23 ) with the sun wheel ( 17 ) of the first planetary gear ( 13 ) is rotatably connected, that the bridge ( 18 ) of the first planetary gear ( 13 ) via another sun gear shaft ( 27 ) with the sun wheel ( 19 ) of 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 ( 11 ) over the jetty ( 20 ) of the second planetary gear ( 14 ) and one with the bridge ( 20 ) rotatably connected shaft ( 24 ), which is connected to the wheel hub ( 15 ) is rotatably connected. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ) in one piece with the sun gear shaft ( 23 ) of the first planetary gear ( 13 ) is executed. Drive device ( 11 ) to drive a wheel ( 7 ) 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 bridge ( 18 ) of the first planetary gear ( 13 ) is made in one piece. Drive device ( 11 ) to drive a wheel ( 7 ) a torsion beam axle ( 1 ) for an electrically driven vehicle, according to claim 6, 7 or 8, characterized in that the storage of the with the web ( 20 ) of the second planetary gear ( 14 ) connected shaft ( 24 ), which the output of the drive device ( 11 ), through the wheel bearing of the wheel ( 7 ) is formed. Drive device ( 11 ) to drive a wheel ( 7 ) a torsion beam axle ( 1 ) for an electrically driven vehicle, according to claim 6, 7, 8 or 9, characterized in that the connection of the with the web ( 20 ) of the second planetary gear ( 14 ) connected shaft ( 24 ) with the wheel hub ( 15 ) by means of a plug-in splined connection or a polygonal profile or that of the drive device ( 11 ) facing away from the end with the bridge ( 20 ) of the second planetary gear ( 14 ) connected shaft ( 24 ) the wheel hub ( 15 ) represents itself. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ) at the wheel ( 7 ) facing side of the electric machine ( 12 ) are arranged. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ) at the wheel ( 7 ) facing away from the electrical machine ( 12 ), wherein the electric machine ( 12 ) is designed as a hollow shaft motor and the output shaft of the drive device ( 11 ), which by the with the bridge ( 20 ) of 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 ) to be led. Drive device ( 11 ) to drive a wheel ( 7 ) 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 ratio and the electric machine ( 12 ) is executed high-revving. Drive device ( 11 ) to drive a wheel ( 7 ) 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.

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