WO2008145642A1

WO2008145642A1 - System comprising a starting device and an internal combustion engine, starting device, and internal combustion engine

Info

Publication number: WO2008145642A1
Application number: PCT/EP2008/056441
Authority: WO
Inventors: Sven Hartmann; Samuel Billot
Original assignee: Robert Bosch Gmbh
Priority date: 2007-05-27
Filing date: 2008-05-27
Publication date: 2008-12-04
Also published as: DE102007026078B4; DE102007026078A1

Abstract

The invention relates to a system comprising a starting device (10) and an internal combustion engine (252), wherein the starting device (10) comprises a starter pinion (22) suitable to be moved into a ring gear (25) of the internal combustion engine (252), wherein the ring gear (25) and the starter pinion (22) are each provided with a matching helical toothing. Means are provided on the starter pinion (22) and/or on the ring gear (25) that absorb axial forces acting between the ring gear (25) and the starter pinion (22) due to the helical toothing during the starting process.

Description

description

title

System of starting device and internal combustion engine, starting device and internal combustion engine

State of the art

The invention relates to a system comprising a starting device and an internal combustion engine, a starting device and an internal combustion engine, wherein the starting device has a starter pinion, which is suitable in a

Toothed ring of the internal combustion engine to be meshed. Both the ring gear of the internal combustion engine and the starting pinion of the starting device is each provided with a helical toothing, which is matched to the respective other gear (sprocket or starter pinion). From the British patent GB 151454, for example, a system of a starting device and a

Internal combustion engine known, in which the starting pinion and the ring gear of the internal combustion engine each have a coordinated helical toothing. The starter pinion is inserted there by means of an electromagnetically actuated slide in the ring gear of the internal combustion engine and is in the operating state at one

End shield of the starter. The axial forces acting during operation between the two gears are therefore transmitted on the one hand to the bearing plate and on the other hand to the internal combustion engine. The disadvantage here is that both the bearing plate and the pinion are exposed to increased friction, so that at this point increased wear is likely to occur. Furthermore, the load of the ring gear by the axial force leads to a bending moment in the ring gear and also to a moment load, for example in the nearest crankshaft bearing. US Pat. No. 1,594,825 likewise discloses a system comprising a starting device and an internal combustion engine (see FIGS. 3 and 5 there), wherein the starting device is an obliquely toothed starting pinion and also the toothed rim is helically toothed. To compensate for the axial forces acting between the two gears, it is provided on the part of the starting device that a "stop collar" prevents further movement of the starting pinion and, on the other hand, absorbs the axial force acting on the pinion As in the previously presented solution, this solution also leads to an additional burden on the mouth-like

Housing of the starting device, which here partially covers both the starter pinion and the ring gear.

Furthermore, in each case a starting device is known both from Japanese Patent Application Publication JP 2002-257016 and from JP 2002-130097, in which the axial force acting on the starter pinion is recorded by means of a stop collar. The same applies to the starting device known from the disclosure of DE 102 90 004 T5.

Disclosure of the invention

The proposed solution is intended that the axial forces acting between the starter pinion and the ring gear is not supported by the drive shaft, or the ring gear causes no bending moment on the crankshaft. In a system of starting device and

Internal combustion engine with the characterizing features of claim 1, there is the advantage that the disadvantages of the known solutions are avoided. The Axialkraftbelastung remains in the narrow range of their formation, namely in the starter pinion or directly adjacent to the starter pinion environment or in the ring gear and the helical toothing of the

Sprocket or its immediate surroundings. Ideally, the design of the system according to claim 1 means that only two components are loaded, namely the starter pinion with a thrust surface supporting the axial force of the ring gear and on the other hand, the ring gear. According to another embodiment of the invention according to claim 1, the Axial force of the pinion can be absorbed by a arranged on the sprocket surface. The proposed measures an axial force is thus avoided on the sprocket, whereby this sprocket or the flywheel (to which usually the sprocket is attached) will not be subjected to an additional bending load. Therefore, also a damaging effect on the bearing, which support the crankshaft or motor shaft, on which usually the flywheel or the ring gear is attached directly or indirectly. According to a further embodiment of the invention it is provided that the starting surface located on the side of the Andrehritzels is integrally connected to the starter pinion. This would mean that both the helical teeth of the piecing and the contact surface would be made in one piece. This is the case, for example, if the starter pinion with the contact surface were produced by a common sintering process. Another production method for a pinion with a contact surface would be extruding, for example. In both cases, there would be a one-piece part, which would be produced cost-effectively.

According to a further embodiment of the invention, it is provided that the starting pinion with a tubular extension forms a seat for the inner ring of a freewheel of the starter. It is envisaged that the inner ring of

Freewheel is integrally formed with the contact surface. The inner ring of the freewheel thus forms with its sleeve-like shape with the contact surface a one-piece, integral part. The inner ring has a running surface for clamping body of the freewheel.

It is preferably provided that the hardness of the contact surface is between HRC 57 and 64.

The helical toothing of the starter pinion, that is the rolling surface, should have a hardness between HRC 57 and 64.

According to a further embodiment of the invention, a value range between 3.4 and 12, preferably between 4.2 and 8.3, ideally of 5.9 +/- 0 for the length ratio of the axial length of the helical gearing of Andrehritzels to axial length of the stop collar , 9 provided. This is so far from Advantage, as a result, that there is a good support of the axial forces between the two gears. These ratios are the result of a compromise between the shortest possible length of the starter and good or sufficiently good support of the axial forces.

According to a further embodiment of the invention, an aspect ratio of the axial length of the helical toothing of the starting pinion and a radial height of the starting collar standing over an engagement region of the helical toothing of the starting pinion is between 6.3 and 2, preferably between 4.2 and 2.5, ideally 3, 1 +/- 0.4 provided. This ratio is so far from

Meaning, as this is representative of a compromise between permissible axial pressure due to the axial forces and on the other hand, a maximum allowable bending moment in the starting collar. Furthermore, it plays a role to what extent the axial offset between starter pinion and ring gear is tolerated.

With respect to the Andrehritzels should between the teeth of its helical gearing, d. H. between these teeth and the transition region to the starting collar a conical transition surface (chamfer) be present. This transition surface also improves the bending load of Andrehritzels.

Ideally, the transition surface is inclined to the axis of Andrehritzels at an angle between 25 ° and 10 °, particularly preferred is a value of 15 °.

It is envisaged that the ring gear or its teeth have a tapered transition surface (chamfer) on its teeth matched to the conical transition surface (bevel). As a result, part of the axial force is transmitted in the vicinity of the tooth root of the twisting pinion. This is particularly important because in this area, the relative movement between sprocket and Andrehritzel particularly low and thus more potential

Wear can be largely avoided.

It is desirable according to a further embodiment of the invention that the starting collar is also flat radially within the pitch diameter of Andrehritzels, there are no radially aligned forces between sprocket and To create on-and-off pinions. Such forces would further deteriorate the already complex state of stress in the tooth roots of the piecing, so that the proposed design leads to an improved, less complex state of stress and thus the starter pinion with higher material usage at this point is higher loadable.

Advantageously, it is provided that the starting device has a drive shaft which carries no stop for the starting pinion.

Short descriptions of the drawings

The invention is explained in more detail below by way of example with reference to the figures:

Show it:

FIG. 1 shows a starting device in a longitudinal section,

Figure 2 is a partial enlargement of the drive end shield with the

Andrehritzel according to a first embodiment, Figure 3a a Ausspurgetriebe with a starter pinion after a second

embodiment,

Figure 3b, the starter pinion of Figure 3a with between the teeth and the

Transition area to start collar of conical transition surface (bevel),

FIG. 3c shows a one-piece starter pinion with a plane transition surface between the teeth and the transition region to the starting collar;

FIG. 4 shows a further exemplary embodiment, wherein the toothed rim is provided with a mounted start-up collar,

Figure 5 shows another embodiment, wherein the sprocket with a

Start-up collar is provided, which is integral with the helical gearing,

Figure 6 shows another embodiment, wherein the sprocket and the

Starting pinions are provided with a start-up collar,

Figure 7 shows another embodiment, wherein axial forces on the

Internal combustion engine are supported, Figure 8 is a schematic representation of a system of internal combustion engine and starting device.

Embodiments of the invention

FIG. 1 shows a starting device in a longitudinal section. FIG. 1 shows a starting device 10. This starting device 10 has, for example, a starter motor 13 and an engagement relay 16. The starter motor 13 and the engagement relay 16 are attached to a common drive bearing plate 19.

The starter motor 13 is functionally to drive a starter pinion 22 when it is meshed in the ring gear 25 of the internal combustion engine, not shown here.

The starter motor 13 has a housing as a pole tube 28 which at its

Inner circumference carries pole pieces 31, which are each wrapped by a field winding 34. The pole shoes 31 in turn surround an armature 37, which has an armature packet 43 constructed from fins 40 and an armature winding 49 arranged in grooves 46. The armature package 43 is pressed onto a drive shaft 44. At the starter pinion 22 remote from the end of the drive shaft 44, a commutator 52 is further attached, the u.a. composed of individual commutator fins 55. The commutator bars 55 are so electrically connected in a known manner with the armature winding 49, that upon energization of the commutator fins 55 by carbon brushes 58, a rotational movement of the armature 37 in the pole tube 28 results. One between the

Einspurrelais 16 and the starter motor 13 arranged power supply 61 supplies in the on state, both the carbon brushes 58 and the field winding 34 with power. The drive shaft 44 is commutator side supported with a shaft journal 64 in a sliding bearing 67, which in turn is held stationary in a commutator bearing cover 70. The commutator cover

70 in turn is by means of tie rods 73 which are arranged distributed over the circumference of the pole tube 28 (screws, for example, 2, 3 or 4 pieces) in the drive bearing plate 19 is attached. It supports the pole tube 28 on the drive bearing plate 19, and the commutator bearing cover 70 on the pole tube 28. In the drive direction, a so-called sun gear 80 connects to the armature 37, which is part of a planetary gear 83. The sun gear 80 is surrounded by a plurality of planet wheels 86, usually three planet wheels 86, which are supported by means of roller bearings 89 on journals 92. The planet gears 86 roll in a ring gear 95, which is mounted outside in the pole tube 28. Toward the

Output side connects to the planetary gears 86, a planet carrier 98, in which the stub axles 92 are added. The planet carrier 98 is in turn stored in an intermediate storage 101 and a slide bearing 104 arranged therein. The intermediate bearing 101 is designed cup-shaped, that in this both the planet carrier 98, and the planet wheels 86 are added. Furthermore, in the cup-shaped intermediate bearing 101, the ring gear 95 is arranged, which is ultimately closed by a cover 107 relative to the armature 37. Also, the intermediate bearing 101 is supported with its outer circumference on the inside of the pole tube 28. The armature 37 has on the end remote from the commutator 52 end of the drive shaft 44 another

Shaft 1 10 on, which is also included in a plain bearing 1 13, from. The slide bearing 1 13 in turn is received in a central bore of the planet carrier 98. The planet carrier 98 is integrally connected to the output shaft 1 16. This output shaft 1 16 is supported with its end facing away from the intermediate bearing 101 1 19 in a further bearing 122, which is fixed in the drive bearing plate 19, supported. The output shaft 1 16 is divided into several sections: Thus, the portion which is arranged in the sliding bearing 104 of the intermediate bearing 101, a portion with a so-called spur toothing 125 (internal teeth), which is part of a so-called shaft-hub connection. This shaft-hub connection 128 allows in this

Case the axially rectilinear sliding of a driver 131. This driver 131 is a sleeve-like extension which is integral with a cup-shaped outer ring 132 of the freewheel 137. This freewheel 137 (Richtgesperre) further consists of the inner ring 140 which is disposed radially within the outer ring 132. Between the inner ring 140 and the outer ring 132 are

Clamping 138 arranged. These clamp bodies 138, in cooperation with the inner and outer rings, prevent relative rotation between the outer ring and the inner ring in a second direction. In other words, the freewheel 137 allows a relative movement between inner ring 140 and outer ring 132 in one direction only. In this Embodiment, the inner ring 140 is formed integrally with the starter pinion 22 and the helical teeth 143 (external helical teeth).

For the sake of completeness, the single-track mechanism should be considered here. The push-in relay 16 has a bolt 150, which is an electrical contact and which is connected to the positive pole of an electric starter battery, which is not shown here. This bolt 150 is passed through a relay cover 153. This relay cover 153 terminates a relay housing 156, which is fastened by means of a plurality of fastening elements 159 (screws) on the drive end plate 19. In indenting relay 16, a pull-in winding 162 and a so-called holding winding 165 is further arranged. The pull-in winding 162 and the holding winding 165 each cause an electromagnetic field in the switched-on state, which flows through both the relay housing 156 (made of electromagnetically conductive material), a linearly movable armature 168 and an armature return 171. The armature 168 carries a push rod 174, which is moved in the direction of linear retraction of the armature 168 in the direction of a switching pin 177. With this movement of the push rod 174 to the switching pin 177 this is moved from its rest position in the direction of two contacts 180 and 181, so that attached to the contacts 180 and 181 end of the switching pin 177 contact bridge 184 connects both contacts 180 and 181 electrically. As a result, electrical power is conducted from the bolt 150 across the contact bridge 184 to the power supply 61 and thus to the carbon brushes 58. The starter motor 13 is energized.

However, the engagement relay 16 or the armature 168 also has the task, with a tension member 187 to move the drive bearing plate 19 rotatably arranged lever. This lever 190, usually designed as a fork lever, surrounds with two "tines" not shown here on its outer circumference two discs 193 and 194 to move a trapped between these driver ring 197 for freewheel 137 towards the resistance of the spring 200 and thereby the starter pinion 22 einzuspuren in the ring gear 25. Figure 2 shows a detail of an enlargement of the drive bearing plate 19 with the starter pinion 22. Figure 2 shows the helical toothing 143, which is arranged on the toothed rim 25 facing the end of a sleeve-like extension 203. This sleeve-like extension 203 represents a kind of tube, which has a total of two sections. A first section is that on whose axial length the

Helical gear 143 is attached. The second section is that on which the inner ring 140 is pushed. This inner ring 140 in turn has three contours, which have different functions. Thus, on the one hand, there is a clamping surface or clamping web 210 which has a machined, preferably ground surface on which the clamping bodies 138 are clamped. In the direction of the helical gearing 143, a shoulder 213 can be seen, which separates the clamping track 210 from a starting collar 216.

The inner ring 140 is thereby pushed or shrunk onto the sleeve-like extension 203, so that a frictional connection between the sleeve-like extension 203 and the inner ring 140 is made. Under normal load conditions, this inner ring 140 of the sleeve-like extension 203 is not wegschiebbar. However, the inner ring 140 can also be fastened, for example, by material engagement (welding, soldering) or by means of a shaft-hub connection.

The starting collar 216 has the following function: If by means of the contact relay 16, the starter pinion 22 is pushed in the direction of the ring gear 25 and the helical toothing 22 adapted or coordinated helical toothing of the ring gear 25 is inserted in the

Andrehfall, so after transmitting a drive torque from the starter pinion 22 on the ring gear 25 causes an axial force between the ring gear 25 and the starter pinion 22. This axial force acts in such a way that the starting pinion 22 with its helical toothing 143 wants to be moved further in the direction of "meshing in." In the case of this left movement in FIG

Sprocket 25 comes with its face 220 on the start collar 216 and its contact surface 223 to the plant. This contact surface 223 or the start-up collar 216 then prevents further axial movement of the starting pinion 22 in the ring gear 25. It is thus a system of starting device 10 and internal combustion engine disclosed, wherein the starting device 10 is a starter pinion 22nd which is adapted to be meshed in a ring gear 25 of the internal combustion engine. Both the ring gear 25 and the starting pinion 22 are each provided with a coordinated helical teeth 143 and 240, respectively. On Andrehritzel 22 while a means (start-up collar 216, contact surface 223) is present, which at a starting process due to the

Helical teeth 143, 240 receives between the ring gear 25 and the starting pinion 22 acting axial forces.

In addition to the helical gearing 143 of the drive pinion 22 so that a contact surface 223 is present, which allows an investment of at least one tooth. By this contact surface 223 and this start-up collar 216 between the ring gear 25 and the starting pinion 22 acting axial forces are canceled such that these axial forces outside of the teeth or helical teeth 143 of Andrehritzels 22 and the helical gear 240 incl. A short radial portion below the helical teeth 240 of the

Sprocket 25 and the contact surface 223 and the start-up collar 216 are not effective. Only within this relatively narrow range are material stresses effective. In the case of the embodiment according to FIG. 2, that is to say with the configuration according to which the inner ring 140 is pushed onto the sleeve-like extension 203, these two sections are likewise encompassed by this statement. In other words, an axial force which acts on the starting collar 216 naturally leads to stresses in the joining surface between the inner ring 140 and the sleeve-like extension 203. The tensions do not continue otherwise. In the ring gear 25 caused by the axial force stresses act on the helical gear 240 and in a narrow radial

Area below the helical gearing 240.

As already mentioned, the starter pinion 22 and the contact surface 223 and the start-up collar 216 are mounted together, that is joined together.

As already explained for the description of the inner ring 140, this is integrally connected to the contact surface 223 and the start-up collar 216, wherein the inner ring 140 is a running surface or clamping surface or clamping track 210 for clamping body 138 of the freewheel 137 executed. The starter pinion 22 is resiliently supported by means of a plate spring or plate spring-like spring 139 relative to the outer ring 134.

For this invention it is provided that the starting device 10 has a drive shaft 1 16, which has no stop for the starter pinion 22.

FIG. 3a shows a second exemplary embodiment of the starting pinion 22 with the starting collar 216 or the contact surface 223. According to this exemplary embodiment, the starting pinion 22 is embodied in one piece such that it represents a one-piece combination of the starter pinion 22, starting collar 216 or contact surface 223 and clamping track 210.

For the contact surface 223 is - whether in one-piece or two-piece or multi-part design with the starter pinion 22 - a hardness value of at least HRC 57 to

64 provided. For the helical gearing 143 of the Andrehritzels 22 a hardness of HRC 57 to 64 is provided. The two mentioned hardness specifications refer both to the versions in one-piece design as well as to the versions in multi-part design. The hardness values also apply to the various designs of the ring gear 25, if hardening is required.

According to a further embodiment of the invention it is provided that with respect to the Andrehritzels 22 and the start-up collar 216 certain length ratios are met. For this example, it is required that the

Length ratio of axial length L-143 of the helical gearing 143 of the starting pinion 22 to the axial length \ -2 ^ Q of the starting collar 216 between 3.4 and 12, preferably between 4.2 and 8.3, ideally 5.9 +/- 0, 9 amounts to. Furthermore, an aspect ratio of axial length L-143 of the helical gear 143 of the Andrehritzels 22 and one on a

Engagement range of the helical gear 143 of Andrehritzels 22 standing radial height H216 of the stop collar 216 between 6.3 and 2, preferably between 4.2 and 2.5, ideally 3.1 +/- 0.4. FIG. 3b shows the starter pinion 22 according to FIG. 3a with a transitional surface 224 (bevel) which tapers between the teeth and the transition region to the starting collar 216. This transition surface also improves the bending load of Andrehritzels. Ideally, the transition surface is inclined to the axis 225 of Andrehritzels at an angle α between 25 ° and 10 °, particularly preferred is a value of 15 °.

It is envisaged that the ring gear or its teeth have a tapered transition surface (chamfer) on its teeth matched to the conical transition surface (bevel). That is, that directed to the starter pinion 22

Surface of the teeth is also conical. As a result, part of the axial force is transmitted in the vicinity of the tooth root of the twisting pinion. This is particularly important because in this area, the relative movement between sprocket and starter pinion particularly low and thus potential wear can be largely avoided. This area is therefore particularly advantageous usable.

It is desirable according to a further embodiment of the invention according to FIG. 3c, that the starting collar is also radially within the pitch circle diameter 280 of the Andrehritzels flat so as to produce there no radially aligned forces between sprocket and starter pinion.

Such forces would be the already complex state of tension in the

Tooth reasons of Andrehritzels further deteriorate, so that the intended

Design for an improved, less complex stress state and thus the starting pinion with less material used at this

Place is higher loadable.

If necessary, this configuration can also be applied in the opposite direction to the ring gear 25. This refers to the space between the teeth of the helical teeth of the ring gear 25 in the event that this

Start collar 243 has. Ie. The start-up collar is then so conical or just run.

In Figure 4, a drive pinion 22 of the starting device 10 and a ring gear 25 of the internal combustion engine is shown in fragmentary form. The ring gear 25 has, as also the starter pinion 22, the already mentioned helical gears 240. In contrast to the previous embodiments, however, the starting pinion here has no contact surface 223 or no start-up collar 216. Rather, in this case, the ring gear 25 takes over the support of the axial force with a start-up collar 243, which has a stop surface 246 in the axial

Direction is oriented and thus provides the engaged Andrehritzel 22 a support of the axial forces. The starting collar 243 can be attached to the sprocket 25 in a wide variety of ways. Thus, for example, in addition to cohesive manufacturing processes such as welding or soldering, for example, the fastening by means of bolts 244 (rivets,

Screws) in question.

Figure 4 shows a detail of a system of starting device 10 and internal combustion engine, wherein the starting device 10 has a starting pinion 22 which is adapted to be meshed in a ring gear 25 of the internal combustion engine, wherein the ring gear 25 and the starting pinion 22 each with a coordinated Helical teeth 143, 240 are provided. In this embodiment, means (start-up surface 246, start-up collar 243) acting on a starting operation due to the helical gearing 143, 240 between the sprocket 25 and the starter pinion 22 on the sprocket 25

Absorb axial forces.

Accordingly, the ring gear 25 in addition to the helical teeth 240 a contact surface 246, which allows a system of at least one tooth of the Andrehritzels 22 and thereby between the ring gear 25 and the starter pinion 22 acting axial forces can be lifted.

Figure 5 shows a modification of the embodiment 4, a helical toothing 240, which is integrally formed with a start-up collar 243 and its contact surface 246. This one-piece part is the same as in FIG. 4 by means of

Screws, rivets or other manufacturing processes such as welding etc. connectable.

Figure 6 shows a combination of a ring gear 25 and a starter pinion 22, in which case both gears each have a start collar 216 and 243 have. The axial length of the ring gear 25 and the axial length of the Andrehritzels 22 are coordinated so that at least after the entry (slight wear) of both gears both start-up collar 216 and 243 respectively come to rest on the tooth of the other gear. In this case, then the bending load of the Auflaufkragens 216 both on the

Andrehritzel 22 and distributed to the start collar 243 of the ring gear 25.

The embodiment of Figure 6 thus shows a system of starting device 10 and internal combustion engine, wherein the starting device 10 has a starter pinion 22 which is adapted to a ring gear 25 of the

Internal combustion engine to be eingespurt, wherein both the ring gear 25 and the starting pinion 22 are each provided with a coordinated helical teeth 143, 240. It is in this case that both the starter pinion 22 and the ring gear 25 means (start-up collar 216 and 243), which in a starting operation due to the helical teeth 143,

240 receives between the sprocket 25 and the starter pinion 22 acting axial forces.

According to the embodiment of Figure 7 is provided in a further embodiment, that when Ausspuren between the two

Helical gears 143 and 240 acting axial forces are supported by means of an external bearing 249. This bearing 249 is then attached, for example, to an engine block of the internal combustion engine 252.

Figure 8 is a schematic representation of a system of internal combustion engine

252 with ring gear 25 and starter 10 with starter pinion 22.

The system according to the invention or the starting device or internal combustion engine 252 according to the invention has the advantage over the prior art that the axial force generated by the helical gearing, which acts on the

Drive train of the internal combustion engine 252 and the starting pinion 22 acts, is canceled, so that no costly changes to the unit, that is, the internal combustion engine, are necessary. The proposed solutions ensure a compact and flexible design of the helical gear depending on the available installation space and / or allowable stress on the Crankshaft. It is particularly advantageous that the helical teeth can be arbitrarily designed by the start-up collar 216 and 243, respectively, in order to achieve an optimum noise behavior of the toothing. Stress such as radial and tangential forces on the engine components need not be considered. A very expedient construction results by the

Support directly to the first gear (Andrehritzel 22 or ring gear 25) introduces and uses the end face of the second gear (sprocket 25 or Andrehritzel 22) as Gegenabstützfläche. This results in an ideal axial flow in a small space. From the tooth of the first gear, the axial force acts on the tooth of the mating gear, both contact surfaces, that is

Contact surfaces 223 and 246 cancel this axial force again. The stop on the drive shaft of the starter 10 may well be omitted.

The helix angle of the toothing is tuned to the sense of rotation of the starter 10 when turning the engine 252 so that the

Andrehritzel 22 when meshing on the sprocket 25 undergoes a forward axial force. That is, the tooth geometry favors the meshing.

It is envisaged that the system of internal combustion engine and starter is operated as a so-called start-stop system. This means that the

Internal combustion engine is turned off as often as possible or useful for consumption optimization, for example at traffic lights or railroad crossings or in traffic jams. For this purpose, the starter pinion 22 is already then eingespurt in the ring gear of the internal combustion engine, when the speed of the crank or drive shaft for Ausschaltens the

Internal combustion engine is reduced. The starter motor is only started when the start request is signaled by actuating an actuator (eg accelerator pedal).

Claims

claims

1 . System comprising starting device (10) and internal combustion engine (252), wherein the starting device (10) has a starting pinion (22) which is adapted to be meshed with a ring gear (25) of the internal combustion engine (252), both of which

Sprocket (25) and the starter pinion (22) are each provided with a coordinated helical toothing (143, 240), characterized in that the starter pinion (22) and / or on the sprocket means (216, 223; 243, 246) available are that take in a start operation due to the helical teeth (143, 240) between the sprocket (25) and the starter pinion (22) acting axial forces.

2. System according to claim 1, characterized in that in addition to the helical gearing (143) of the Andrehritzels (22) a thrust surface (223) is present, which allows an investment of at least one tooth of the sprocket (25) and thereby between the sprocket (25) and the Andrehritzel (22) acting axial forces can be canceled or compensated.

3. System according to claim 1, characterized in that in addition to the helical gearing (240) of the sprocket (25) has a stop surface (246) is provided, which allows a system of at least one tooth of Andrehritzels (22) and thereby between the sprocket (25). and the Andrehritzel (22) acting axial forces can be canceled or compensated.

4. System according to claim 2, characterized in that the contact surface

(223) is integrally connected to an inner ring (140) of a freewheel (137), wherein the inner ring (140) has a running surface (210) for clamping body (138) of the freewheel (137).

5. System according to claim 2 or 3, characterized in that the contact surface (223) of the Andrehritzels (22) integral with the starter pinion (22) and / or the contact surface of the ring gear (25) is integrally connected to the helical toothing (240).

6. System according to claim 2 or 3, characterized in that the starter pinion (22) and its start-up collar (216) and / or the ring gear (25) and its helical toothing (240) with its contact surface (246) are mounted together.

7. System according to one of claims 2 to 6, characterized in that the contact surface (223) has a hardness between HRC 57 and 64 and a hardness depth between 0.5 and 0.9 mm.

8. System according to one of claims 2 to 7, characterized in that the

Helical toothing (143) of the starter pinion (22) and / or the ring gear (25) has a hardness between HRC 57 and 64 and a hardness depth between 0.5 and 0.9 mm.

9. System according to one of claims 2 to 8, characterized in that an aspect ratio of axial length L22 of the helical gearing (143) of the

Andhrhritzels (22) to the axial length L216 of the start-up collar (216) between 3.4 and 12, preferably between 4.2 and 8.3, ideally 5.9 +/- 0.9.

10. System according to one of claims 2 to 9, characterized in that an aspect ratio of axial length L22 of the helical gearing (143) of the

Andrehritzels (22) and one over an engagement region of the helical gearing (143) of the Andrehritzels (22) standing radial height H216 of the stop collar (216) between 6.3 and 2, preferably between 4.2 and 2.5, ideally 3.1 + / -0.4.

1 1. A system according to any one of claims 2 to 10, characterized in that between the teeth of the helical gearing (143) of the Andrehritzels (22), ie between these teeth and the transition region to the starting collar (216) a conical transition surface (chamfer) is present , which ideally to the axis (225) of Andrehritzels (22) is inclined at an angle between 25 ° and 10 °, more preferably inclined at an angle of 15 °.

12. System according to claim 1 1, characterized in that the sprocket (25) or its helical toothing (240) on their teeth one on the conical

Transition surface (chamfer) matched tapered transition surface (chamfer) has.

13. System according to any one of claims 2 to 10, characterized in that the starting collar (216) is radially within a pitch circle diameter (280) of the helical gearing (143) of the Andrehritzels (22) flat to there no radially aligned forces between the ring gear (25 ) and Andrehritzel (22) to produce.

14. System according to any one of the preceding claims, characterized in that the starting device (10) has a drive shaft (1 16), which has no stop for the starter pinion (22).

15. Starting device (10) with a starter pinion (22) which is adapted to be meshed in a ring gear (25) of an internal combustion engine (252), wherein the starter pinion (22) is provided with a helical toothing (143), characterized in that means (216, 223) are provided on the starter pinion (22) which absorb axial forces acting during a starting operation on account of the helical toothing (143, 240).

16. Starting device according to claim 12, characterized by the features according to one of claims 2 and 4 to 1 1 and 13.

17. internal combustion engine (252) with a toothed rim (25), wherein the sprocket (25) has a helical toothing (240), characterized in that on the sprocket (25) means (243, 246) are present, the at a starting process due to accommodate the helical gearing (240) acting axial forces.

18. Internal combustion engine (252) according to claim 17, characterized in that this according to the features of claims 3 and / or 12 or the sprocket (25) concerned features of claims 5, 6, 7, 8 is configured