CN102869877A - Free wheel comprising an integrated damping system - Google Patents

Abstract

The present invention relates to an electric motor (10), particularly a starting device for an internal combustion engine. The electric motor (10) includes a rotary transmission mechanism (83), which is particularly implemented as a planetary gear transmission mechanism. The planetary gears (86) of the rotary transmission mechanism (83) are housed in a planetary gear carrier (98), which is supported in an annular drive member (197) by means of a damping element (200).

Description

Freewheel with integrated vibration damper

technical field

The invention relates to an electric machine, in particular a starting device for an internal combustion engine.

Background technique

Document DE 43 02 854 C1 relates to a starting device for internal combustion engines. The starting device includes a starter motor whose drive shaft is connected via a freewheel clutch to an axially displaceable starter pinion. The starter pinion meshes into the ring gear of the internal combustion engine. When rotating, especially in the drive direction, the spring accumulator acts in the drive train between the meshing pinion and the drive shaft of the starter motor, dampening the torque shocks between the meshing pinion and the drive shaft. The spring accumulator is arranged in the drive train with a preload torque acting in the drive direction of 15% to 50% of the short-circuit torque of the starter motor involved in the rotation of the pinion, wherein without spring accumulator In the case of a starter, the ratio of the torsional strength of the drive train from the starter motor to the engagement pinion to the short-circuit torque of the spring accumulator relative to the torsional strength acting on the engagement pinion is >4.

Document DE 196 16 666 A1 relates to a freewheel mechanism for starting devices for internal combustion engines. The freewheeling device has a cup-shaped entrainer assigned to the starter device, which has a pot-shaped lip and a pot-shaped bottom, wherein the pot-shaped lip cooperates via a clamping element with a hub assigned to the internal combustion engine. The pot edge has no mechanical connection to the pot bottom, at least in the region of the clamping part. The pot rim and the pot bottom are constructed in one piece, wherein the decoupling takes place via partial recesses.

In electric machines used today, in particular in starting devices for internal combustion engines, the vibration damper is usually mounted on the ring gear of the planetary gear in an epicyclic gear, especially in the form of a planetary gear. During operation of the electric machine, in particular of the internal combustion engine starter, the damper absorbs torque peaks that occur and additionally serves to minimize the noise of the electric machine.

Contents of the invention

According to the solution proposed according to the invention, in a starter device for starting an internal combustion engine, a vibration damper is proposed, which is integrated in particular into a freewheel mechanism which in turn is integrated into an epicyclic transmission of the starter device . According to the solution proposed according to the invention, for example, the sintered ring gear of the epicyclic transmission can be omitted, and on the other hand, the sintered ring gear can be integrated into the motor which is beneficial for the start-stop functionality and prolongs the service life of the starter. in the shock absorber.

For this purpose, the epicyclic gear of the starter device for starting the internal combustion engine is designed in particular as a planetary gear. The planetary gear interacts with a stationary 3-roller freewheel. The 3-roller freewheel is integrated into the carrier of the epicyclic transmission in a particularly advantageous and space-saving manner. A damping element is inserted between the planet carrier of the epicyclic transmission and the driver. The damping element can be designed, for example, as a spring profile, as a spring block, as a rubber decoupling element or most often as a vibration-damping material. In a particularly advantageous manner, the solution proposed according to the invention enables the integration of the freewheel mechanism into the entrainment, so that a very large Space-saving arrangement.

The epicyclic gear of a starter device proposed according to the invention for starting an internal combustion engine comprises a planetary carrier, in particular made of plastic or sintered material. Preferably, the plastic used is filled with glass fibers or carbon fibers or the like, so that a particularly stable mechanical stability of the component results.

By means of the solution proposed according to the invention, it is possible to decouple the epicyclic gear, which is designed in particular as a planetary gear, from impulses originating from the drive side, that is to say in this case originating from the starter pinion.

Furthermore, the angular balance achieved by the solution proposed according to the invention makes it possible to avoid obliquely running epicyclic gears, in particular designed as planetary gears, so that no occurrences which would negatively affect the service life of the epicyclic gears occur Or stable one-sided wear.

Description of drawings

The present invention will be described in detail below with reference to the accompanying drawings.

in:

Figure 1 shows a longitudinal sectional view of the starting device,

FIG. 2 shows a perspective view of the vibration damper integrated into the freewheel at the entrainment,

FIG. 3 shows a sectional view according to the sectional direction III-III shown in FIG. 4 , and

FIG. 4 shows a sectional view of a carrier with integrated freewheel and integrated vibration damping.

Detailed ways

FIG. 1 shows a starter device 10 in longitudinal section. For example, starter device 10 has a starter motor 13 and a pre-engagement actuator 16 , for example a relay or a starter relay. The starter motor 13 and the electric pre-engagement actuator 16 are fastened on a common drive end bearing shield 19 . The starter motor 13 serves to drive the starter pinion 22 when it meshes into a ring gear 25 of the internal combustion engine (not shown in FIG. 1 ).

The starter motor 13 has a pole tube 28 as housing, which carries pole shoes 31 on its inner circumference, which are each wound by an excitation winding 34 . The pole shoes 31 are used in the electrically activated starter 10 and the permanent magnets are used in the permanently excited starter 10 . The pole piece 31 , here the electro-active starter 10 , in turn encloses an armature 37 having an armature core 43 formed from a plurality of laminations 40 and an armature winding 49 arranged in slots 46 . The armature core 43 is pressed onto the drive shaft 44 . Furthermore, a commutator 52 is mounted on the end of the drive shaft 44 facing away from the starter pinion 22 , which is formed in particular from individual commutator segments 55 . The commutator laminations 55 are electrically connected to the armature winding 49 in a known manner, so that when the commutator laminations 55 are energized by the carbon brushes 58 a rotational movement of the armature 37 in the pole tube 28 occurs. A current lead 61 arranged between electrical drive 16 and starter motor 13 supplies carbon brushes 58 and field winding 34 with current in the switched-on state. The drive shaft 16 is supported on the commutator side via a journal 64 in a slide bearing 67 , which in turn is held stationary in a commutator bearing cover 70 . The commutator bearing cover 70 is in turn fastened in the drive end bearing cover 19 by means of tie rods 73 , for example screws (for example two, three or four), arranged in a distributed manner on the circumference of the pole tube 28 . In this case, the pole tube 28 is supported on the drive end bearing shield 19 and the armature bearing shield 70 is supported on the pole tube 28 .

Coupled to the armature 37 , viewed in the drive direction, is the sun gear 80 as part of an epicyclic gear, in particular a planetary gear 83 . The sun gear 80 is surrounded by a plurality of planet gears 86 , usually three planet gears 86 , which are supported on journals 92 by means of roller bearings 89 . The planet wheels 86 roll within a ring gear 95 , which is mounted on the outside in the pole tube 28 .

Coupled to the planet gears 86 in the direction of the output side is a planet gear carrier 98 in which journals 92 are accommodated. The planetary carrier 98 is in turn mounted in an intermediate bearing 101 and in a plain bearing 104 arranged therein. The intermediate bearing 101 is designed in the shape of a pot, so that both the planet carrier 98 and the planet gears 86 are accommodated therein. Furthermore, the ring gear 95 is arranged in a pot-shaped intermediate bearing 101 , which is finally closed off relative to the armature 37 by a cover 107 . Likewise, the intermediate bearing 101 is supported with its outer circumference on the inside of the pole tube 28 . At the end of the drive shaft 13 facing away from the commutator 52 , the armature 37 has a further journal 110 which is likewise accommodated in a slide bearing 113 . The slide bearing 113 is in turn accommodated in the central bore of the planet carrier 98 . The planet carrier 98 is integrally connected to the output shaft 116 . The output shaft is supported with its end 119 facing away from the intermediate bearing 101 in a further bearing 122 which is fastened in the drive end bearing cover 19 .

The output shaft 116 is divided into different sections: Following the section arranged in the plain bearing 104 of the intermediate bearing 101 is a section with a straight toothing 125 (internal toothing) which It is part of the shaft-hub connection 128 . In this case, the shaft-hub connection portion 128 enables the linear sliding of the driving member 131 along the axial direction. The driver 131 is realized as a sleeve-like projection which is connected in one piece with the freewheel 137 . The freewheel 137 (orientation brake) is accommodated in a drive ring 197 and includes a clamping body 138 . The clamping body 138 prevents the freewheel 137 from rotating in the second direction. In other words, the freewheel mechanism 137 achieves relative motion that is epicyclic in only one direction. The starter pinion 22 can alternatively also be embodied as a spur-meshing pinion. Instead of an electromagnetically excited pole shoe 31 with an excitation winding 34 , it is also possible to use permanently excited poles.

Furthermore, the electric pre-engagement actuator 16 or the armature 168 also has the task of moving a lever 190 , which is arranged rotatably in the drive end bearing bracket 19 . The lever 190, usually implemented as a forked lever, surrounds the two disks 193, 194 on its periphery with two "tines" not shown here, so that the Drive ring 197 is moved against freewheel 137 against the resistance of spring 200 and thereby engages starter pinion 22 into ring gear 25 of the internal combustion engine.

The meshing mechanism is explained below. The electric pre-engagement actuator 16 designed as a relay or starter relay has a bolt 150 which is an electrical contact and is coupled to the positive pole of the electric starter battery not shown in FIG. 1 when assembled in the vehicle place. The bolt 150 is guided through a cover 153 . The second screw 152 is a terminal for the starter motor 13 , which is powered via the current lead 61 (thick stranded wire). The cover part 153 closes a housing 156 made of steel, which is fastened to the drive end bearing shield 19 by means of a plurality of fastening elements 159 , which may be bolts, for example. Arranged in the electric pre-engagement actuator 16 are a push device 160 for exerting a tensile force on the fork lever 190 as well as a switching device 161 . The push device 160 has a coil 162 and the switch device 161 has a coil 165 . In the switched state, the coil 162 of the push device 160 and the coil 165 of the switching device 161 each generate an electromagnetic field, which flows through different components. Instead of being equipped with a straight-toothed toothing 125 , the shaft-hub connection 128 can also be equipped with a multi-threaded toothing. Combinations are possible here: a) the starter pinion 22 is helical and the shaft-hub connection 128 has a straight toothing 125; or b) the starter pinion 22 is helical and the shaft-hub connection 128 has a multi-start thread toothing; or c) the starter pinion 22 is spur toothed and the shaft-hub connection 128 is configured as a multi-threaded toothing.

The illustration according to FIG. 2 shows a perspective view of the solution proposed according to the invention, in which the freewheel integrated into the entrainment has a vibration damper.

As can be seen from the perspective illustration according to FIG. 2 , the output shaft 116 is mounted in the driver 197 by means of the freewheel 137 . The carrier 197 is substantially annular and has a first plurality of free spaces 204 and a plurality of second free spaces 206 . This first free space 204 is used to accommodate the freewheel 137 , which is in particular designed as a static 3-roller freewheel. Preferably, the freewheel 137 has three roller-shaped clamping bodies 138 which can be introduced into the first free space 204 . The roller-shaped clamping bodies 138 are each loaded by springs 202 which are respectively supported on the side walls of the first free space 204 . Preferably, the plurality of first free spaces 204 are arranged in a manner indexed by 120° relative to the inner circumference of the ring-shaped carrier 197 .

Furthermore, the ring-shaped carrier 197 includes a plurality of second free spaces 206 which are likewise arranged in a 120° graduation. The receptacle 208 of the planet carrier 98 is inserted into this second free space 206 of the ring-shaped entrainer 197 . In particular, the planet carrier 98 is made of a plastic material that is filled with glass fibers or carbon fibers or other fibers to increase the rigidity of the machine. The receptacles 208 are also introduced into the second free space 206 arranged in a 120°-gradient manner, so that each of the damping elements 200 can be accommodated laterally on the receptacles 208 . The receptacle 208 is thus supported on both sides in the damping element 200 . For example, the damping element 200 can be a spring or rubber decoupling element or a block-shaped material with elastic properties. The damping element 200 can likewise be configured as a hollow body in the form of a roller, cylindrical, etc. air cushion, which is introduced into the second free space 206 on both sides of the receptacle 208 . As a result, a compact vibration damping of the planet carrier 98 is achieved when it is mounted in the ring-shaped carrier 197 . Furthermore, the solution proposed according to the invention results in a compact mounting option for the freewheel 137 , which is designed in particular as a static 3-roller freewheel.

Preferably, the roller-shaped or cylindrical clamping body 138 of the freewheel 137 is designed such that its axial length does not exceed the thickness of the annular carrier 197 .

Due to the selected arrangement, the output shaft 116 is mounted in the drive ring 197 by means of the freewheel 137 , so that a rotation of the output shaft 116 in the direction of rotation is achieved.

FIG. 3 shows a cross-sectional view of the assembly shown in perspective in FIG. 2 , comprising the output shaft 116 , the driver 197 , the parts of the epicyclic gear and the planet carrier.

The illustration according to FIG. 3 shows a sectional view along the section line III-III shown in FIG. 4 . As can be seen from the illustration according to FIG. 3 , the toothing 125 on the periphery of the output shaft 116 is designed as a helical toothing or likewise as a helical toothing, however, it can also be designed as a straight toothing. Tooth, see illustration according to FIG. 1 .

It follows from the illustration according to FIG. 3 that the receptacle 208 in which the journal 92 for the planetary gear 86 is supported is supported in the second free space 206 , which is configured in the form of a ring-shaped drive on the inner circumference of piece 197. The journals 92 each carry a planetary gear 86 which itself meshes with the sun gear 80 of the epicyclic gear 83 , which is designed in particular as a planetary gear.

FIG. 4 results from the section curve III-III shown in FIG. 3 . It can be seen from the plan view according to FIG. 4 that the plurality of first free spaces 204 and the plurality of second free spaces 206 are each configured as 120° graduations, wherein the 120° graduations and the plurality of first free spaces 204 are formed therein. A 120° index offset with the second free space 206 is implemented therein. It can be seen from FIG. 4 that the roller-shaped or cylindrical clamping body 138 is each loaded by a spring 202 , which brings the roller-shaped or cylindrical clamping body 138 into abutment. On the confining wall of the first free space 204 .

It can be seen from the illustration according to FIG. 4 that the damping elements 200 formed on both sides of the receptacle 208 of the planetary carrier 98 are designed as thin-walled hollow bodies, so that the receptacle 208 is elastically mounted on a ring-shaped In the driving part 197. In each receptacle 208 (see in particular FIG. 2 ), a journal 92 is respectively accommodated, which respectively accommodates a planetary wheel 86 , see the perspective view according to FIG. 2 and the sectional view according to FIG. 3 .

In the illustration according to FIG. 4 , the damping element 200 is shown as a hollow body with a thin-walled wall. If the hollow body is filled with air, a certain degree of compressibility is imparted to the damping element 200 , which has a favorable influence on its damping properties. Instead of the damping element 200 configured as a hollow body, it is also possible to use a spring or rubber decoupling element made of solid or hollow material in the form of a block, roller or cylinder, etc., which can be mounted in the receptacle 208 Both sides are accommodated in the second free space 206 . Through the solution proposed according to the invention, which can be advantageously implemented in particular on a dual mass flywheel, it is possible on the one hand to achieve vibration damping of the planetary carrier 98 of the epicyclic transmission 83 and, on the other hand, it can be configured integrally The freewheel 137 of the stationary 3-roller freewheel enables an extremely space-saving and compact design of the electric machine for the internal combustion engine, in particular the starter. In particular, the solution according to the invention also makes it possible to dispense with a vibration damper in the ring gear 95 , since it is accommodated in the freewheel 137 . The ring gear 95 made of sintered material can thus be dispensed with cost-effectively and it can be made of plastic material.

Claims (11)

1. Electric motors, in particular starters for internal combustion engines, with epicyclic gears (83), especially planetary gears, the planetary gears (86) of which are accommodated in planetary gear carriers (98) , characterized in that the planet carrier (98) is supported in an annular carrier (197) by means of a damping element (200). 2. The electric machine as claimed in the preceding claims, characterized in that the planet carrier (98) is made of plastic filled with glass fibers or carbon fibers. 3. The electric machine as claimed in any one of the preceding claims, characterized in that the planet carrier (98) is located in the receptacle (208) for the journal (92) of the planet gear (86). It is supported in the second free spaces (206) of the annular carrier (197) in the region. 4. According to the electric machine according to any one of the preceding claims, it is characterized in that the annular carrier (197) has a plurality of first free spaces (204) in which free spaces are accommodated. Components of the wheel mechanism (137). 5. The electric machine as claimed in any one of the preceding claims, characterized in that the freewheel (137) is a fixed 3-roller freewheel with separate passages arranged at 120° graduations. Spring (202) loaded clamping body (138). 6 . The electric machine as claimed in claim 1 , characterized in that the damping element ( 200 ) is formed as a spring, as a rubber decoupling element, as a hollow body or as a block from an elastic material. 7. The electric machine as claimed in claim 1, characterized in that the receptacle (208) for the journal (92) is introduced into the second free space of the annular carrier (197) (206). 8. The electric machine as claimed in claim 1, characterized in that the receptacle (208) is mounted on both sides in a second free space (206) in the damping element (200) middle. 9. The electric machine as claimed in claim 1, characterized in that the damping element (200) is formed as a hollow body in the shape of a block or cylinder. 10. The electric machine according to any one of the preceding claims, characterized in that the ring-shaped entrainer (197) is configured in a ring, and the first free space (204) and the second free space ( 206 ) is formed on the inner circumference of the annular carrier. 11. The electric machine according to any one of the preceding claims, characterized in that the first free space (204) is arranged at 120° graduations and the second free space (206) is arranged at 120° graduations arrangement, wherein the 120° graduation of the first free space (204) is staggered relative to the 120° graduation of the second free space (206).

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