DE102010040569A1 - Starter for drive chain for internal combustion engine for motor vehicle, comprises electric motor having stator, where rotor is arranged on starter shaft, and starter shaft is radially mounted at bearing in bearing shield - Google Patents

Abstract

The starter (14) comprises an electric motor having a stator (3), where a rotor (4) is arranged on a starter shaft (20). The starter shaft is radially mounted at a bearing (1) in a bearing shield (2), which is mechanically and electrically connected with the housing of an internal combustion engine (11).

Description

The present invention relates to a starter of the internal combustion engine of a motor vehicle according to the preamble of patent claim 1.

The starters known from the prior art comprise an electric motor with a stator and a runner arranged on a starter rotor, whose power supply via brushes, and a via a generally designed as a planetary gear starter gear to the starter shaft connected starter pinion, which axially is continuously displaceable to intervene prior to starting the internal combustion engine in the toothing of a connected to the crankshaft of the internal combustion engine starter ring gear.

During the starting process, currents in the order of magnitude of approximately 800 A, which are divided in proportion to the electrical resistances of the components, flow via the starter installed in a motor vehicle. The desired path of the current runs via the brushes, the starter end shield and the stator of the starter via the starter gear to ground.

Depending on the electrical resistance of the components of the starter, which may vary due to the series dispersion, the current through the starter shield, the radial near-radial mounting of the starter shaft in the bearing plate, the starter shaft, the rotor, the starter pinion and during the starting process with the starter pinion Run off the combing starter ring gear via the output shaft of the transmission of the vehicle and then over bearings and the gearbox housing to ground.

Depending on the resistances, it is also possible for the current to flow via the starter end shield, the radial radial bearing of the starter shaft in the end shield, the starter shaft, the rotor, the starter pinion and the starter ring meshing with the starter pinion during the starting operation via the crankshaft of the internal combustion engine. Bearing points and the engine drains to ground.

Thus, very high currents can flow into the gearbox and / or in the engine of the vehicle on the radial near-radial mounting of the starter shaft and the rotor, which can lead to damage in the transmission, for example on the parking brake and / or engine mounts in a disadvantageous manner or even EMC Problems in engine electronics and transmission electronics can cause.

From the DE 103 49 064 A1 a starter is known for an internal combustion engine of a motor vehicle, comprising a pair of angular contact ball bearings, which are used for radially supporting the rotor of the starter, wherein the angular contact ball bearings are arranged close to the opposite ends of a core of the rotor. In the known starter, the core has coils which form a commutator at one of the ends of the core, wherein one of the bearings is disposed within an inner peripheral edge of the commutator.

Furthermore, goes from the EP 0 911 516 B1 a starter for an internal combustion engine of a motor vehicle, comprising a starter motor for generating a rotational force, a rotor which is rotatable by the starter motor, a pinion moving body with a pinion gear, which can mesh with a ring gear of an engine, wherein the Rasi storage of the rotor via Plain bearing takes place, with a sliding bearing stock plate side is arranged.

In the starters known from the prior art, the radial bearing of the rotor is made electrically conductive.

The present invention has for its object to provide a starter of the internal combustion engine of a motor vehicle, in which on the transmission and / or the internal combustion engine flowing side streams are effectively prevented when starting the engine.

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 starter of the internal combustion engine of a motor vehicle comprising an electric motor with a stator and a runner arranged on a rotor, wherein the starter shaft is radially mounted via a bearing in a mechanically and electrically conductively connected to the combustion housing bearing plate, proposed in which the bearing plate side radial bearing the starter shaft is made electrically isolated.

Due to the conception according to the invention, a sidestream flow from the bearing plate of the starter via the bearing plate-side radial bearing of the starter shaft, the starter shaft, the rotor, the starter pinion and the starter ring meshing during the starting operation with the starter pinion is prevented by the transmission and / or the internal combustion engine.

The invention will be explained in more detail by way of example with reference to the attached FIGURE, which shows a schematic sectional view of a drive train of a motor vehicle with a starter comprising a bearing plate-side radial bearing designed in an electrically insulated manner.

Starters for internal combustion engines of motor vehicles are well known in the art, so that in the context of the following description of the figures only the components relevant to the invention are described and explained.

In the attached figure, the internal combustion engine is designated by the reference numeral 11 , the transmission with the reference numeral 12 , the transmission housing by the reference numeral 19 , the converter clutch with the reference numeral 13 , the crankshaft of the internal combustion engine with the reference numeral 10 and the drive shaft of the transmission by the reference numeral 9 Mistake; Further, the starter of the internal combustion engine 11 with the reference 14 designated.

The ignition 14 according to the attached figure comprises an electric motor with a stator 3 , which forms part of the housing of the starter and one on a starter shaft 20 arranged runners 4 , whose power supply via brushes 5 . 6 takes place, the brush 5 the plus pole and the brush 6 with the end shield 2 of the starter 14 electrically connected connected minus pole of the brushes. The starter shaft 20 is radial over bearings 1 in the bearing plate 2 stored. In addition to this brush-near bearing-side bearing is the starter shaft 20 over another, not shown bearing on the bearing plate 2 radially opposite end.

Furthermore, the starter includes 14 a starter gear designed as a planetary gear 15 and one over the starter gearbox 15 with the starter shaft 20 connected starter pinion 8th , which is axially continuously displaceable, before starting the internal combustion engine 11 in the teeth of one with the crankshaft 10 of the internal combustion engine 11 connected starter tooth ring 7 intervene.

During the starting process, currents of about 800 A flow through the starter, which divide in proportion to the electrical resistances of the components. The desired path of the current in this case runs over the brushes 5 . 6 , the bearing shield 2 and the stator 3 the starter via the starter gearbox via a first ground connection 21 to the vehicle mass 23 ,

In the case of starters known from the prior art, a secondary current can flow over the brush forming the negative pole 6 electrically conductive end shield 2 , the near-radial radial bearing 1 the starter shaft 20 in the bearing plate 2 , the starter shaft 20 , the runner 4 , the starter pinion 8th and during cranking with the starter pinion 7 combing starter ring gear 7 over the drive shaft 9 of the gearbox and over bearings 16 . 17 and the case 19 of the transmission 12 via a second ground connection 22 to the vehicle mass 23 flow away.

Depending on the resistances of the components, it is also possible, as explained in the introduction, that a secondary flow over the end shield 2 , the near-radial radial bearing 1 the starter shaft 20 in the bearing plate 2 , the starter shaft 20 , the runner 4 , the starter pinion 8th and the starter sprocket meshing with the starter pinion during cranking 7 over the crankshaft 10 of the internal combustion engine 11 , Bearings 18 , the housing of the internal combustion engine 11 and the first ground connection 21 to the vehicle mass 23 flows.

The ignition 14 is with the starter gear 15 with the housing ("engine block") of the internal combustion engine 11 bolted so that the starter gear 15 the actual ground connection of the starter 14 forms on the engine block. Usually the stator is 3 of the starter 14 with the starter gear 15 connected via a plug connection, so that usually forms an electrical contact resistance, the current flow from the end plate 2 to the starter gear 15 and from the starter gear 15 prevents the engine block; For this reason, the secondary flow flows through the already described, the brush-near, bearing-shield side bearing 1 containing low-impedance paths and not on the on the bearing plate 2 opposite end of the starter shaft 20 arranged radial bearings.

To provide a sidestream flow through the brush-side bearing-side bearing 1 To prevent is proposed according to the invention, this camp 1 perform electrically isolated. As a result, bypass currents are avoided in a simple and cost-effective manner, which can lead to damage in the transmission, for example on the parking brake and / or damage to engine mounts and / or electrical control devices of the engine or transmission.

The warehouse 1 can be designed for example as a plain bearing or angular contact ball bearings.

As part of a development of the invention can also on the the bearing plate 2 opposite end of the starter shaft 20 be arranged bearings electrically isolated, for example, when the electrical contact resistance between the stator 3 and the starter gear 15 Due to the design is low.

In the context of another embodiment of the invention, in addition, the bearings 24 and 25 , about that with the starter shaft 20 mechanically connected starter pinion 8th on the starter housing 26 is rotatably mounted, and optionally further with the starter housing 26 be executed in connection with electrically isolated bearings so that in case of an electrically poor ground connection of the starter 14 to the housing of the internal combustion engine 11 an unwanted current flow through the starter housing 26 on the starter pinion bearing 24 . 25 and from there to the starter shaft 20 and the starter wreath 7 is prevented.

LIST OF REFERENCE NUMBERS

1

Shield bearing side of the starter shaft 20

2

end shield

3

stator

4

runner

5

brush

6

brush

7

Starter gear

8th

starter pinion

9

Drive shaft of the transmission

10

Crankshaft of the internal combustion engine

11

internal combustion engine

12

transmission

13

TCC

14

Starter

15

starter gear

16

camp

17

camp

18

camp

19

gearbox

20

starter shaft

21

first earth connection

22

second ground connection

23

vehicle mass

24

Bearing of the starter pinion

25

Bearing of the starter pinion

26

starter housing

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 10349064 A1 [0007]
• EP 0911516 B1 [0008]

Claims (4)

Starter ( 14 ) of an internal combustion engine ( 11 ) of a motor vehicle, comprising an electric motor with a stator ( 3 ) and one on a starter shaft ( 20 ) arranged runners ( 4 ), whereby the starter shaft ( 20 ) about a warehouse ( 1 ) in a bearing plate ( 2 ), which with a housing of the internal combustion engine ( 11 ) is mechanically and electrically conductively connected, is radially mounted, characterized in that the bearing plate side bearing ( 1 ) is designed electrically isolated. Starter ( 14 ) according to claim 1, characterized in that the power supply of the electric motor via brushes ( 5 . 6 ), whereby a brush ( 6 ) with the end shield ( 2 ) of the starter ( 14 ) electrically connected negative pole of the brushes ( 5 . 6 ). Starter ( 14 ) according to claim 1 or 2, characterized in that it is a with a housing of the internal combustion engine ( 11 ) bolted starter gearbox ( 15 ) and via the starter gear ( 15 ) with the starter shaft ( 20 ) connected axially continuously displaceable running starter pinion ( 8th ), wherein the stator ( 3 ) of the starter ( 14 ) with the starter gear ( 15 ) is connected via a plug connection. Starter ( 14 ) according to claim 1, 2 or 3, characterized in that a storage ( 24 . 25 ), about which with the starter shaft ( 20 ) mechanically connected starter pinions ( 8th ) of the starter ( 14 ) in a starter housing ( 26 ) is rotatably mounted, electrically isolated.

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