DE102008063599A1 - Drive strand for vehicle, has drive shaft coupled with combustion engine, and electric motor is coupled with drive shaft, where housing section is arranged in stationary manner - Google Patents

Abstract

The drive strand (1) has a drive shaft (2), which is coupled with a combustion engine. An electric motor is coupled with the drive shaft, where a housing section (10) is arranged in stationary manner. An antifriction bearing (9) is formed or arranged for mounting the drive shaft in the housing section. The antifriction bearing is formed as a grooved ball bearing.

Description

Field of the invention

The The invention relates to a drive train for a vehicle with a drive shaft which can be coupled to an internal combustion engine and / or is coupled, with an electric motor, which with the Drive shaft is coupled and / or coupled, with a housing section, which is arranged stationary, and with at least one Rolling, wherein the rolling bearing for the storage of Drive shaft disposed in the housing portion and / or is trained.

Of the Powertrain in a vehicle is primarily for transmission the drive torque from a motor than the driving torque generating unit on the driven wheels. Beside this However, the powertrain also has to function as a primary function be designed to have secondary functions, such as a change of the generating unit for the drive torque and / or the connection of a starter or a generator for generating of electrical energy, are possible. Due to the necessities To implement these secondary functions are drive trains übli cherweise Complex and set up in particular with regard to a long service life is a technical challenge.

The publication DE 10 2007 0311 09 A1 relates to a powertrain, in particular a drive train for a vehicle, and is probably the closest prior art. In this document, a drive train is described, which has a drive motor, a coupling device and an electric machine and, for example, as a hybrid drive, so as a combination of an internal combustion engine and an electric motor for driving the vehicle is formed. For storage in this document, a deep groove ball bearing between a pressure plate housing of the coupling device and an actuating means of the coupling device and a second, unspecified bearing disclosed, wherein the second bearing supports the drive shaft relative to a stationary housing.

description

Of the Invention has for its object to propose a drive train which has a long useful life. This task will by a powertrain for a vehicle having the features of claim 1 solved. Preferred or advantageous embodiments The invention will become apparent from the dependent claims, the following description and the accompanying figures.

The The invention relates to a drive train for a vehicle, in particular for a passenger car, which for transmission the drive torque for the drive of the vehicle suitable and / or trained. The powertrain includes a Drive shaft via which transmit the drive torque is and coupled with an internal combustion engine and / or coupled is. The internal combustion engine may be a conventional one Gasoline or diesel engine act. Furthermore, the drive train includes an electric motor which can also be coupled to the drive shaft and / or is coupled. The electric motor can in the simplest embodiment be designed as an electric starter, which allows the put the switched-off combustion engine into operation. More preferred However, if the electric motor for the regular Drive the vehicle suitable as an electric drive motor and / or is formed, so that the drive train is part of a Hybrid drive forms. Optionally complementary is the electric motor, ie in particular the electric starter or the electric drive motor, designed to be used as a power generator, wherein, for example, in Braking the vehicle reduces the kinetic energy of the vehicle electric current, especially for a later Use, is converted.

Further The drive train comprises a housing section, which stationary in the vehicle, but optionally sprung and / or damped, is arranged and, for example, a section forms a cover for the drive shaft.

to Storage of the drive shaft is a rolling bearing installed, wherein the rolling bearing the drive shaft directly or indirectly stored in the housing section. An immediate one Bearing is present when the rolling bearing on the drive shaft contacted is placed on. An indirect storage is given if between rolling bearing and drive shaft other components are interposed, which, however, rotatably with the drive shaft and preferably non-displaceably connected.

in the Under the invention, it is disclosed that the rolling bearing is designed as a deep groove ball bearing. The advantage of this training is that the deep groove ball bearing both loads in the main load direction, namely in the radial direction, as well as in the axial direction can record.

The deep groove ball bearing is preferably executed in a single row, wherein in the inner ring and in the outer ring in each case a groove is introduced, the radius of curvature preferably greater than the radius of the balls used as rolling elements is formed so that they are held in a nesting.

at a preferred structural design of the drive train has this at least one drive coupling device, which designed for coupling of the internal combustion engine with the drive shaft is. By this drive coupling device can thus connect for transmitting the drive torque between the drive shaft and internal combustion engine are opened or closed. Alternatively or additionally, the or a further drive coupling device for Coupling of the electric motor formed with the drive shaft. With This drive coupling device, it is thus possible the electric motor, in particular the rotor, mechanically from the drive shaft to decouple. In another, possible. alternative can the electric motor also be controlled such that a magnetic field is deactivated, so that the rotor in a decoupled state magnetic Passive and thus force and / or low friction with the drive shaft with turns and represents only an additional flywheel.

at a possible execution or training According to the invention, the drive train has a transmission coupling device for coupling the drive shaft with a transmission. The gear is preferably either as a manual transmission or as an automatic transmission educated. Particularly preferred is the coupling device as a double clutch device is formed, which is a switching of the transmission with no or little interruption of the drive torque implements.

at a preferred embodiment of the invention is at least one the coupling devices, so one of the drive coupling devices and / or the transmission coupling device as a dry clutch and / or designed as a friction clutch. Such couplings are due to the Low mechanical requirements prevalent in vehicles today used.

Especially when using a friction clutch, it is preferred that the Rolling a seal, which has the rolling bearing space seals against incoming dirt, especially abrasion. These Seal is advantageous because in the area of the deep groove ball bearing due the internal combustion engine a hot and due to the friction clutch, connected with clutch wear, dusty environment prevails, in which the deep groove ball bearing on the one hand requires its own lubrication and the other against the environmental influences must be protected.

Especially it is preferred if the seal is formed as a lip seal is, which in a possible development of the invention may have a reinforcing ring. The sealing lip is preferably arranged to be stationary with the outer ring of the deep groove ball bearing is arranged and the free lip portion in the direction of the inner ring of the deep groove ball bearing extends. In particular, the lip seal is only with a single lip fitted.

at A preferred embodiment of the invention is proposed that in a radial direction to the axis of rotation, the lip seal and the Inner ring of the deep groove ball bearing in an imaginary, relaxed Condition of the lip seal less than 0.2% of the pitch circle diameter of the deep groove ball bearing overlap or overlap. For the pitch diameter is in the context of the disclosure the circle is taken as the basis, which through the centers the balls of the deep groove ball bearing runs. In this training is proposed a low-contact seal, which However, the operating characteristics over a conventional trained, touching seal significantly improved. The improvements are reflected in particular by a reduction friction and thus a reduction in temperature during operation. On the other hand, the overlap seems sufficient Any installation tolerances between the drive shaft and the lip seal or the housing section.

at a development of the invention is even proposed, usually Touching lip seal to be dimensioned so that a Intermediate gap between sealing lip and inner ring is formed, which However, to the ingress of dirt or leakage of lubricant Avoid less than 0.03% of the pitch circle diameter is. The occurring in extreme cases gap is by itself from the Deep groove ball bearing sealed out by the grease. In particular preferred if the coverage is between 0.2% (positive coverage) and -0.03% (gap).

at a preferred realization of the invention with a pitch circle diameter the deep groove ball bearing between 50 mm and 60 mm, in particular of 55 mm, it is preferable if the sealing overlap between 115 μm (coverage) and -16 μm (Gap) at an average of 5 μm coverage is.

In an advantageous structural embodiment, the deep groove ball bearing is lubricated within the seal with a grease deposit. It is possible that the fat depot is filled with a normal filling, which is 50% of the undisturbed fat space in the deep groove ball bearing. The undisturbed fat space is the space between the seals of the deep groove ball bearing, which is not affected by the stationary or moving Wälz body is occupied or traversed with cage.

In an advantageous development, however, the deep groove ball bearing is equipped with an optimized filling, which is 25% smaller than the normal filling. The optimized filling is therefore less than 37.5% of the undisturbed fat space in the deep groove ball bearing. The lubricant used is a fat, based on ester oil, thickening agent polyurea having a base oil viscosity at 40 ° C. of 160 mm ² / s.

at a combination of measures, ie the use of a weakly touching or non-contact seal and an optimized filling, the temperature development the deep groove ball bearing and thus the tendency to wear so reduces that from a synergistic effect of these two measures to speak. It is assumed that this synergistic Effect is justified by the fact that by the reduced amount of grease the overlap of the seal and inner ring made less may be because of the retention of the seal Less is required than with a normal filling.

Further Features, advantages and effects of the invention will become apparent the following description of a preferred embodiment the invention and the accompanying figures. Showing:

1 a highly schematic representation of a drive train as an embodiment of the invention;

2 a detail from the 1 to illustrate the maximum allowable coverage of the seal and inner ring;

3 an illustration showing the possible gap dimension between seal and inner ring.

The 1 shows a highly schematic representation of a drive train 1 a vehicle, for example a passenger car. The powertrain 1 includes a drive shaft 2 , which on the left side of the 1 can be coupled and / or coupled with an internal combustion engine, not shown. The drive shaft 2 goes to a gearbox 3 , in particular a manual or automatic transmission. The drive shaft 2 can be formed in one or more pieces. At an intermediate piece of the drive shaft 2 between internal combustion engine and transmission 3 is a rotor 4 an electric machine, in particular an electric motor (not shown), with the drive shaft 2 coupled and / or coupled. The rotor 4 is rotationally fixed to the drive shaft in the embodiment shown 2 connected.

When in the 1 embodiment shown, the transmission 3 as a transmission clutch, a dual clutch device 5 on, which comprises two single clutches and when switching a nearly continuous transmission of the drive torque to a downstream automatic transmission 6 allowed.

In alternative embodiments of the powertrain 1 it is possible for a first drive coupling device 7 is provided, which is a coupling or uncoupling of the internal combustion engine from the drive shaft 2 allowed. Alternatively or additionally, another drive coupling device 8th provided that a coupling or uncoupling of the rotor 4 allows. These couplings are in the 1 shown as optional components by dashed lines.

The electric machine can be designed as a motor starter for the internal combustion engine or as a separate electric drive for the vehicle, so that the drive train 1 represents a hybrid drive for the vehicle. In both cases, it is optionally possible that the electric machine also works as a generator to energy-saving kinetic energy of the vehicle z. B. in a braking operation into electrical energy for storage or the like.

For storage of the drive shaft 2 is a deep groove ball bearing 9 integrated, which the drive shaft 2 against a housing section 10 rotatably supports. The housing section 10 is in the vehicle stationary - optionally damped or sprung - recorded. For example, the housing section 10 Part of a cover of the drive shaft 2 ,

The deep groove ball bearing 9 has an inner ring 11 and an outer ring 12 on, between which a plurality of bullets 13 in a cage 14 are stored rolling. inner ring 11 and outer ring 12 each have a circumferential groove, so that the balls 13 in the deep groove ball bearing 9 are arranged so that this record both radial forces and axial forces and from the drive shaft 2 in the housing section 10 can derive. In the deep groove ball bearing 9 is a rolling element room 15 formed, which laterally in the axial direction by seals 16 is limited.

That in the sectional view of 1 shown free volumes in the Wälzkörperraum 15 corresponds to an undisturbed fat space, which is defined as the volume that is between the seals 16 minus the space for bullets 13 and cage 14 in rotation results.

In conventional embodiments, this undisturbed fat space is about 50% filled with grease. This corresponds to a deep groove ball bearing 9 with a pitch circle diameter of d = 55 mm in about 3.5 to 4.0 g as a standard amount of fat. For example, the lubricant used is a fat-based ester oil with a covering agent polyurea and an intrinsic viscosity at 40 ° C of 160 mm ² / s.

A first measure to reduce the temperature during operation of the deep groove ball bearing 9 is to use an optimized filling instead of this normal filling quantity, which corresponds to less than 75% of the standard filling quantity. For the example mentioned only 2.5 g to 3.0 g of grease are thus filled. By reducing the amount of fat, a 15% lower temperature development than in the standard fat quantity was achieved in tests in operation.

A second measure for reducing the temperature development during operation is by a modification of the seals 16 to reach. The seals 16 are in the 2 and 3 shown enlarged again, the 2 and 3 in each case a detail and in addition an enlargement of the deep groove ball bearing 9 in the field of sealing 16 demonstrate. The seal 16 is designed as a lip seal, which by a circumferential support disk 17 z. B. is supported from metal. The seal 16 is in the outer ring 12 stationary or fixed and running with a circumferential sealing lip 18 in the area of the inner ring 11 out. sealing lip 18 is formed so that the reverse direction from the outside into the Wälzkörperraum 15 shows.

In order to achieve a further reduction in temperature during operation, it has emerged as a possible aspect of the invention that the sealing lip 18 only weak on the inner ring 11 as it is in the 2 is shown or even minimally spaced from the inner ring 11 is arranged, as in the 3 is illustrated. When measuring the overlap or the distance is always the undeformed seal 16 used, which, as it is in the 2 is shown, an overlap u of about 0.115 mm, based on the deep groove ball bearing 9 having a pitch diameter d of 55 mm. The maximum gap s, however, can be up to 0.016 mm. The average coverage in the radial direction is preferably 0.05 mm, so that the sealing lip 18 weakly touch the inner ring. Unless the deep groove ball bearing 9 is designed so that the sealing lip moves in a range from an overlap of 0.115 mm to a gap of 0.016 mm, ie a total of a tolerance range of 0.131 mm and also the amount of fat, as described above, is reduced, were in experiments 30th % lower temperature changes compared to standard seals.

The deep groove ball bearing 9 thus forms a support bearing for a hybrid drive concept, the training as deep groove ball bearings 9 it allows to absorb both axial and radial forces. By additional measures such as reducing the amount of grease and / or setting a defined coverage or gap, the temperature development during operation can be significantly reduced.

1

powertrain

2

drive shaft

3

transmission

4

rotor

5

Double coupling device

6

automatic transmission

7

Drive coupling device

8th

Drive coupling device (other)

9

Deep groove ball bearings

10

housing section

11

inner ring

12

outer ring

13

roll

14

Cage

15

Rolling room

16

seals

17

support ring

18

sealing lip

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102007031109 A1 [0003]

Claims (14)

Powertrain ( 1 ) for a vehicle with a drive shaft ( 2 ), which is coupled to an internal combustion engine and / or coupled to an electric motor ( 4 ), which with the drive shaft ( 2 ) is coupled and / or coupled, with a housing section ( 10 ), which is arranged stationary, and with at least one rolling bearing ( 9 ), the rolling bearing ( 9 ) for supporting the drive shaft ( 2 ) in the housing section ( 10 ) is arranged and / or formed, characterized in that the rolling bearing as a deep groove ball bearing ( 9 ) is trained. Powertrain ( 1 ) according to claim 1, characterized by a drive coupling device ( 7 . 8th ) for coupling the internal combustion engine and / or the electric motor ( 4 ) with the drive shaft. Powertrain ( 1 ) according to claim 1 or 2, characterized by a transmission coupling device ( 5 ) for coupling the drive shaft ( 2 ) with a gearbox. Powertrain ( 1 ) according to claim 3, characterized in that the transmission coupling device as a double clutch device ( 5 ) is trained. Powertrain ( 1 ) according to one of the preceding claims, characterized in that the drive coupling device ( 7 . 8th ) and / or the transmission coupling device ( 5 ) is designed as a friction clutch and / or dry clutch. Powertrain ( 1 ) according to one of the preceding claims, characterized in that the deep groove ball bearing ( 9 ) a seal ( 16 ), which has a rolling bearing space ( 15 ) seals against incoming dirt. Powertrain ( 1 ) according to claim 6, characterized in that the seal as a lip seal ( 16 ) with a sealing lip ( 18 ) is trained. Powertrain ( 1 ) according to claim 7, characterized in that the lip seal ( 16 ) in a relaxed state with the sealing lip ( 18 ) in the radial direction, in particular on average less than 0.2% of the pitch circle diameter (d) of the deep groove ball bearing ( 9 ) covered. Powertrain ( 1 ) according to claim 6 or 7, characterized in that the lip seal ( 16 ) in a relaxed state with the sealing lip ( 18 ) in the radial direction, in particular on average, a gap (s) with a gap size of up to 0.03% of the pitch circle diameter (d) of the deep groove ball bearing ( 9 ). Drive train according to one of the preceding claims 8 or 9, characterized in that the lip seal ( 16 ) in a relaxed state with the sealing lip ( 18 ) forms in the radial direction, in particular on average, an overlap or gap range between 0.115 mm as the maximum overlap and 0.016 mm as the maximum gap (s) for a pitch circle diameter (d) between 50 mm and 60 mm, in particular 55 mm. Powertrain ( 1 ) according to one of the preceding claims, characterized in that the deep groove ball bearing ( 9 ) is lubricated with a grease deposit. Powertrain ( 1 ) according to claim 11, characterized in that the fat depot in a possible normal filling 50% of the undisturbed fat space in the deep groove ball bearing ( 9 ) occupies. Drive train according to claim 11 or 12, characterized characterized in that the fat depot at an optimized filling at least 15% smaller than normal filling. Powertrain ( 1 ) according to one of the preceding claims, characterized in that the grease depot in the deep groove ball bearing ( 9 ) is formed with a pitch diameter (d) between 50 mm and 60 mm, in particular 55 mm, by a fat mass between 2.5 g and 3 g.