WO2011009824A2

WO2011009824A2 - Starter drive having dry lubricant

Info

Publication number: WO2011009824A2
Application number: PCT/EP2010/060351
Authority: WO
Inventors: Thomas Botzenhard; Rainer Stoeckl
Original assignee: Robert Bosch Gmbh
Priority date: 2009-07-21
Filing date: 2010-07-16
Publication date: 2011-01-27
Also published as: DE102009027856A1; WO2011009824A3

Abstract

The invention relates to a system comprising an internal combustion engine and a starter (10) for turning over an internal combustion engine, wherein the starter (10) for turning over the internal combustion engine comprises at least one device for coupling tribologically interacting parts in the starter (10), wherein the device comprises a mechanism for coupling the tribologically interacting parts, having at least one drive part and at least one output part operationally tribologically connected to the drive part, wherein friction-reducing means are provided between the drive part and the output part for an operating mode, wherein the friction-reducing means are implemented as dry lubricants (300).

Description

description

title

The invention relates to a mechanism for coupling tribologically interacting parts in a starter motor for internal combustion engines according to the preamble of claim 1.

Furthermore, the invention relates to a starter motor for starting an internal combustion engine according to the preamble of claim 9.

In addition, the invention relates to a system comprising an internal combustion engine and a starter motor for starting an internal combustion engine according to the preamble of claim 10.

State of the art

The invention is based on a system with a starter or starter motor and a starter with internal reduction gear and a transmission for reducing the speed while increasing the torque for

Type of independent claims.

The present invention relates to starters for vehicles with internal combustion engines.

From the prior art, starters for vehicles with internal combustion engines are known, which usually comprise a DC electric motor for driving the internal combustion engine. In such starters or starter motors is responsible for a meshing or a hub in the ring gear, a relay fork lever system and a coarse thread. The stroke, also referred to as distance, or more precisely one

Single track movement is composed as follows: A magnetic relay pulls one Fork lever to the rear. At the same time a freewheel gear is pushed forward via a translation. When the relay is switched, an electric motor starts to turn. It is on a drive shaft, which can also be called depending on the convention as the output shaft, sitting coarse thread rotated and pushed a driver on flanks of the coarse thread forward. This axial and radial movement in conjunction with a Einspurfeder serves to facilitate finding tooth gaps in the sprocket. At the same time the coarse thread is used for power or torque transmission. This coarse thread is lubricated in known embodiments with a coarse thread grease.

Due to a large temperature difference in the application range of -40 ⁰ C and + 150 ⁰ C, it comes to hardening or leakage of the lubricant. Due to this phenomenon, higher friction forces occur in the coarse thread, which increases the switching times when engaging and disengaging from the ring gear. At a certain number of times, for example at two-thirds of the duration of a start-stop

Starters is no longer available lubricant and the coarse thread and the driving teeth begin to corrode, which leads, for example, to so-called grating. Types for starters are for example from GB 151454, US 1,594,825, JP

2002-257016, JP 2002-130097 and DE 102 90 004 T5.

DISCLOSURE OF THE INVENTION The mechanism according to the invention, the starter motor according to the invention and the system according to the invention having the features of the corresponding main claim or independent claim have the advantage that dry lubricants are used as friction-reducing agents. The volatile friction-reducing agents such as fats or oils used in the prior art have the disadvantage that they are consumed during operation or by the

Dusting entry of dust or dirt. This can lead to disturbing noises, increased wear or failure of the starter motor also called starter. The use of dry lubricants eliminates this risk of failure or is at least significantly reduced. In particular by a dry lubrication in the form of a hard coating with integrated

Solid lubricant or with an equivalent coating with appropriate Properties on the coarse thread and / or the driver teeth, in particular their running surfaces, a friction-minimized insertion and removal and at the same time a corrosion protection is achieved. The measures listed in the dependent claims are advantageous

Further developments and improvements of the predetermined in the independent and independent claims devices possible.

In an advantageous embodiment, it is provided that the friction-reducing means are designed as non-volatile friction-reducing means. These may be formed for example in the form of a solid coating or the like. By training as a non-volatile friction-reducing agent, a maintenance or a Nachfüllaufwand is reduced. Moreover, it is advantageous if the non-volatile friction-reducing means comprise at least one friction-minimizing coating on the drive part and / or the driven part. As a result, the funds can be permanently applied by means of coating methods. In addition, the coating can save space, so that a size is not or only slightly influenced.

In an advantageous embodiment, it is provided that the coating is formed as a hard coating, in particular as a galvanic hard coating, for example by chrome plating, hard chrome plating or by electroplating with other materials such as with mixtures of chrome Teflon or the like. The hard coating comprises solid in one embodiment

Lubricants such as Teflon, MoS ₂ , possibly WS ₂ or graphite, which are still in solid form even at high temperatures, as they occur in operation, and a corresponding galvanic layer as a binding and carrier phase. In particular, the hard coating has no pasty components, so that dust is not bound, whereby a failure of the transmission is avoided by a possible blocking. Due to a high resistance to aging, failure can usually be ruled out. With suitable hard coatings, a toe-in path at low temperatures can be used without restrictions. The hard coatings of the invention are characterized in a preferred

Embodiment by a wide thermal range of use from about -50 ⁰ C to -A- greater about 400 ⁰ C from. Due to the almost constant viscosity even at temperatures below 0 ⁰ C, the friction properties can be optimally utilized and in particular reduce the generation of noise. In order to reduce the CO ₂ emissions of motor vehicles systems are increasingly used in which the internal combustion engine at standstill of the vehicle (eg at a red light) is switched off automatically (so-called start-stop systems). Especially with regard to start-stop systems, in which the vehicle for the driver to start almost unnoticed again, a low noise is of great importance. Even at high temperatures, there is an advantage of dry lubrication, for example compared with greases. The viscosity at a

Dry lubrication hardly drops when temperatures rise. For start-stop vehicles, a very large proportion of starts occur when the engine is hot. The dry lubricant remains at such temperatures at the applied location, so there is no lack of lubrication. In addition, dry lubrication can cope with the increasing power requirements of starters by aging less with correspondingly higher outputs. The fact that in a dry lubrication no paste occurs, such as greases, no dirt particles are bound, so a longer life is guaranteed even with starters with less space and increasing number of carbon brushes and associated increasing amounts of coal dust]

In an advantageous embodiment, it is provided that the hard coating is formed as a hard coating with integrated solid lubricant. By integrated in the hard coating solid lubricants is an advantageous

Lubrication feasible. In this case, a lubricant is realized by solid lubricant, which are integrated in the coating surface. An appropriate hard coating can save an additional, complicated curing process or at least reduce a hardening effort.

It is preferably provided that at least one of the interacting parts is formed as a coarse thread or includes a coarse thread. The coarse thread preferably has a dry lubricant. Preferably, at least one of the interacting parts comprises a dry lubricant. Preferably, both cooperating parts have a dry lubricant. By means of suitable

Dry lubrication can increase the performance of starter motors. In particular, the load on the individual parts is reduced, which leads to longer maturities. In a further advantageous embodiment of the invention it is provided that the other part of the cooperating parts, which cooperates with the coarse thread, as a driver toothing, in particular a ring gear is formed. The dry lubrication can be so effectively with existing

Use starter motors.

Not least is provided in a further advantageous embodiment that the friction-reducing means of one of the parts are at least partially different from the friction-reducing means of the other part. To this

In this way, tribologically optimized, co-operating friction pairings can be realized. For example, the coarse thread can be hard chrome plated with a solid lubricant. The driver toothing can then have a coating with a material such as hard chrome, bronze, silver or iron.

The inventive starter motor for starting an internal combustion engine, with at least one device for coupling tribologically cooperating parts in a starter motor for internal combustion engines, wherein the device comprises a mechanism for coupling the tribologically interacting parts, with at least one drive part and at least one with the drive part in tribologically operative connection Stripping part, wherein friction reducing means between the drive part and driven part are provided for operation and the friction reducing means are formed as a dry lubricant, over the prior art has the advantage that due to the dry lubrication life is increased and the starter for smaller spaces and larger

Loads is interpretable. The internal combustion engine is preferably an internal combustion engine. The starter motor can be configured as a star-excited or permanent-magnet starter motor. The inventive system comprising an internal combustion engine having at least one device for coupling tribologically cooperating parts in a starter motor for internal combustion engines, wherein the starter motor for starting the internal combustion engine comprises at least one means for coupling tribologically cooperating parts in the starter motor, the device having a mechanism for coupling the comprising tribologically cooperating parts, with at least one drive part and at least one with the drive part in tribologically operatively connected driven part, wherein friction reducing means between the drive part and driven part are provided for operation, wherein the friction reducing means are formed as dry lubricant, also has the advantages that due to the dry lubrication the maintenance intervals and the life are increased and the starter for smaller spaces and larger loads can be interpreted.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Show it:

Figure 1 is a starting device in longitudinal section and

Figure 2 shows an enlarged section of a starter in a side view.

Description of the embodiment

FIG. 1 shows a starting device in a longitudinal section. In the figure 1 is a starting device - or briefly a starter - 10 is shown. This starting device 10 has, for example, a drive or starter motor 13 and an engagement relay 16. Of the

Starter motor 13 and the engagement relay 16 are fixed to a common drive end plate 19. The starter motor 13 is functionally to a pinion - more precisely the starter pinion - 22 to drive when it is meshed in the ring gear 25 of the internal combustion engine, not shown here.

The starter motor 13 has a pole tube as a housing 28, which carries on its inner circumference 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. To the

Andrehritzel 22 remote from the end of the drive shaft 44, a commutator 52 is further attached, which among other things built up of individual commutator fins 55 is. 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. A arranged between the Einspurrelais 16 and the starter motor 13 power supply 61 supplies in the ON state, both the carbon brushes 58 and the

Excitation 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 fastened by means of tie rods 73, which are distributed over the circumference of the pole tube 28 (screws, for example, two, three or four pieces) in the drive end plate 19. 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 of several

Planetary wheels 86 surround, 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. Towards the output side, the planet wheels 86 are adjoined by a planetary carrier 98, in which the axle journals 92 are accommodated. The planet carrier 98 will turn in one

Intermediate bearing 101, which may be formed from planetary gear 83, and mounted therein a sliding bearing 104. 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 ultimately by a cover 107 relative to the

Anchor 37 is closed. 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 facing away from the commutator 52 end of the drive shaft 44 has a further shaft journal 110, which is also received in a sliding bearing 113, from. The sliding bearing 113 in turn is received in a central bore of the planet carrier 98. Of the

Planet carrier 98 is integrally connected to the output shaft 116. This output shaft 116 is supported with its end 119 facing away from the intermediate bearing 101 in a further bearing 122 which is fixed in the drive bearing plate 19. The output shaft 116 is divided into different sections. Thus, the section which is arranged in the sliding bearing 104 of the intermediate bearing 101, a section with a so-called spur toothing 125 (internal teeth) that follows in other Embodiments may also be designed as helical teeth, which is part of a so-called shaft-hub connection. This shaft-hub connection 128 in this case allows 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) consists of

Further, from the inner ring 140, which is arranged radially within the outer ring 132. Between the inner ring 140 and the outer ring 132 clamping body 138 are 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 its 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 are further arranged. The pull-in winding 162 and the holding winding 165 both cause each in the on state an electromagnetic field, which includes both the relay housing 156 (made of electromagnetically conductive material), a linearly movable armature 168 and a

Armature return 171 flows through. 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 shift pin 177 this is moved from its rest position towards two contacts 180 and 181, so that attached to the contacts 180 and 181 located end of the shift 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 drive 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, engages with two "tines", not shown here, on its outer circumference two discs 193 and 194 to a trapped between them driving ring

197 to move towards the freewheel 137 against the resistance of the spring 200 and thereby einzura the starter pinion 22 in the ring gear 25.

FIG. 2 shows an enlarged detail of a starter 10 in a side view. The starter 10 essentially corresponds to the starter 10 according to FIG. 1 and identical reference symbols are used for identical or similar components. A thread formed on the drive shaft or, depending on the designation of the output shaft, is formed as a coarse thread SG. The coarse thread SG is meshing with a driver toothing MV on a driver 131 in engagement. In this case, at least running surfaces of the driving teeth MV as

Hard coating trained dry lubricant 300 on. By a rotational movement of the output shaft 116 and a Oszillationshub, represented by the arrows R and H, a meshing of Andrehritzels 22 takes place in the sprocket 25. For this purpose, a magnetic relay (not shown here) pulls a fork also not shown here backwards. At the same time the starter pinion 22 is pushed forward over a translation. When the relay is switched, the starter motor 13 starts to rotate. The seated on the output shaft 116 steep thread SG is rotated and the driver 131 pushed over flanks forward. This axial and rotational movement (arrows R, H) in conjunction with a Einspurfeder serve to facilitate finding tooth gaps in a ring gear. At the same time that will

Steep thread SG used for power or torque transmission.

Through the use of dry lubricants Einspurvorgang is improved because by a dry lubrication in the form of a hard coating with integrated solid lubricant or with an equivalent coating with appropriate properties on the coarse thread and / or the driver teeth, in particular their treads, a friction-minimized input and output and simultaneously achieved a corrosion protection.

Claims

claims

1. Mechanism for coupling tribologically co-operating parts in a starter (10) for internal combustion engines, comprising at least one drive part and at least one with the drive part in tribological operative connection standing

Abtriebsteil, wherein friction reducing means between the drive part and driven part are provided for operation, characterized in that

the friction-reducing means are designed as dry lubricants (300).

2. Mechanism according to claim 1, characterized in that

the friction reducing agents comprise non-volatile friction reducing agents.

3. Mechanism according to claim 1 or 2, characterized in that the non-volatile friction reducing means at least one

friction-minimizing coating on the drive part and / or driven part.

4. Mechanism according to one of claims 1 to 3, characterized in that

the coating is formed as a hard coating.

5. Mechanism according to one of claims 1 to 4, characterized in that

the hard coating is designed as a hard coating with integrated solid lubricant.

6. Mechanism according to one of claims 1 to 5, characterized in that

at least one of the cooperating parts is formed as a coarse thread (SG).

7. Mechanism according to one of claims 1 to 6, characterized in that

the other of the parts, which cooperates with the coarse thread (SG), as a driver toothing (MV), in particular a sprocket, is formed.

8. Mechanism according to one of claims 1 to 7, characterized in that

the friction-reducing means of one of the parts are at least partially different from the friction-reducing means of the other part.

9. starter (10) for starting an internal combustion engine, with at least one device for coupling tribologically cooperating parts in a starter (10) for internal combustion engines, characterized in that

the device has a mechanism for coupling the tribological

comprising cooperating parts, with at least one drive part and at least one standing with the drive part in tribologically operative connection driven part, wherein friction reducing means between the drive part and driven part for a

Operation are provided, the friction reducing means as

Dry lubricant (300) are formed, the friction reducing means are designed as non-volatile friction-reducing means.

10. System comprising an internal combustion engine and a starter (10) for

Turning on an internal combustion engine, characterized in that the starter (10) for starting the internal combustion engine comprises at least one device for coupling tribologically cooperating parts in the starter (10), wherein the

Device comprises a mechanism for coupling the tribologically cooperating parts, with at least one drive part and at least one with the

Drive part in tribologically operative connection driven part, wherein

friction reducing means between the drive part and driven part are provided for operation, wherein the friction reducing means as

Dry lubricant (300) are formed.