EP2472101B1 - Device for securing a pinion - Google Patents

Description

State of the art

DE 691 00 037 T2 relates to a starter assembly for an internal combustion engine. The starter assembly includes an electric motor housed in a motor housing. Furthermore, the starter assembly comprises a central support part which is attached coaxially to an end portion of the motor housing and delimits a cylindrical chamber. In this there is a planetary reduction gear unit between the central support part and an end plate of the motor housing. Furthermore, a pinion cover is provided which is attached to the same longitudinal end of the electric motor as the central support part and delimits a chamber in which an overrunning clutch is arranged. This has an input part connected to an output part of the planetary gear reduction gear unit and an output part carrying the pinion. One of the two parts, which are formed by an internal ring gear of the planetary reduction gear unit and the pinion cover, is provided with a projection which extends through an opening which is formed in the central support part. The projection engages in a recess which is provided in the other of the two parts which are formed by the inner ring gear of the planetary gear reduction unit and the pinion cover.

DE 38 08 673 A1 refers to a stop for the pinion of a starter. According to this solution, an area with an enlarged cross section by a predetermined length is formed on an inner circumferential surface of a pinion drive shaft. This delimits an annular space between the inner peripheral surface of the pinion drive shaft and the outer peripheral surface of a power output shaft. A shoulder is formed with an enlarged cross-section terminating end, a stop being provided in such a way that when the pinion drive shaft moves forward, the stop to limit the forward movement strikes the shoulder and in the Rest state, the stop is completely or partially received in the annulus.

U.S. 5,237,882 refers to a starting device. According to this solution, there is a coupling between a ring element which is let into a groove. The ring element is provided with sufficient radial dimensions so that it interacts with a driven coupling element.

FR 2 572 137 A1 and DE 197 01 968 A1 show as well as JP 4 060172 A a pinion which is rotatably connected to a roller collar by means of a coupling. For this purpose, the coupling has a toothing on the outer circumference of a shaft or an inner circumference of a hollow shaft or a roller collar.
JP 56 052568 A also has a coupling between a roller collar and a pinion shaft. FR 2 572 137 A1 shows an overload clutch that is used instead of a one-way clutch. In the event of overtaking, the clutch opens.

Presentation of the invention

According to the invention, it is proposed to couple the starter pinion and the roller collar of the freewheel with axial gears facing each other in the form of a claw clutch. The previously used snap ring and retaining ring components, with which a pinion, in particular a starting pinion of an electrical machine designed as a starting device, was previously secured, are dispensed with. Following the solution proposed according to the invention, a split retaining disk is placed in the undercut of the starter pinion and a roller collar separate from the pinion is used. In the solution proposed according to the invention, the starting pinion is fixed in the axial direction during assembly of the freewheel by the split retaining disk. A spring or a spring element which act on the starter pinion is protected from excessive centrifugal forces due to the internal installation. The starter pinion is a separate component compared to the roller collar, which can be displaced relative to one another within an axial play. In the solution proposed according to the invention, the torque is transmitted by means of a dog clutch.

Adapted to the application requirements, different materials can be used to produce the roller collar and to produce the starter pinion. For example, the roller collar can be made of a pressure-resistant material that withstands the Hertzian pressures that occur, while the starting pinion, which is a component separated from the roller collar, can be made from a sintered material or even from a plastic material. The two separate parts can come from different manufacturing and hardening processes and can therefore be optimally matched to the mechanical loads that occur in each case. For the creation of a new freewheel variant for use in the starting device with a different type of toothing, which may be application-dependent, the solution proposed according to the invention merely requires replacing the starting pinion.

Brief description of the drawing

The invention is described in more detail below with reference to the drawing.

• Figur 1 eine Startvorrichtung in einem Längsschnitt,
• Figur 2 eine getrennte Ausführung von Starterritzel und Rollenbund und
• Figur 3 die Klauenkupplung zwischen Andrehritzel und Rollenbund.

It shows:

• Figure 1 a starting device in a longitudinal section,
• Figure 2 a separate design of starter pinion and roller collar and
• Figure 3 the claw coupling between the starter pinion and the roller collar.

Embodiments of the invention

Figure 1 shows a starting device in a longitudinal section.

In the Figure 1 a starting device 10 is shown. This starting device 10 has, for example, a starter motor 13 and a toe-in actuator 16. The toe-in actuator can be designed as an engagement relay or relay, for example. The starter motor 13 and the toe-in actuator 16 are attached to a common drive end shield 19. The starter motor 13 is used 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 pole tube 28 as a housing, which carries pole shoes 31 on its inner circumference, each of which is wrapped by an excitation winding 34. The pole shoes 31 in turn surround an armature 37, which has an armature package 43 made up of lamellae 40 and an armature winding 49 arranged in grooves 46. The armature package 43 is pressed onto a drive shaft 44. At the end of the drive shaft 44 facing away from the starter pinion 22, a commutator 52 is also attached, which is made up of, among other things, individual commutator segments 55. The commutator segments 55 are electrically connected in a known manner to the armature winding 49 in such a way that when the commutator segments 55 are energized by carbon brushes 58, a rotary movement of the armature 37 in the pole tube 28 occurs. A power supply 61 arranged between the toe-in actuator 16 and the starter motor 13 supplies both the carbon brushes 58 and the excitation winding 34 with power in the switched-on state. The drive shaft 44 is supported on the commutator side with a shaft 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 shield 19 by means of tie rods 73 which are arranged distributed over the circumference of the pole tube 28 and can be designed, for example, as 2, 3 or 4 screws. The pole tube 28 is supported on the drive end shield 19 and the commutator bearing cover 70 on the pole tube 28.

A sun gear 80, which is part of an epicyclic gear, for example a planetary gear 83, adjoins the armature 37 in the drive direction. The sun gear 80 is surrounded by several planet gears 86, usually three planet gears 86, which are supported on axle journals 92 by means of roller bearings 89. The planet gears 86 roll in a ring gear 95 which is mounted on the outside in the pole tube 28. In the direction of the output side, the planet gears 86 are adjoined by a planet carrier 98 in which the axle journals 92 are received. The planet carrier 98 is in turn stored in an intermediate bearing 101 and a slide bearing 104 arranged therein. The intermediate storage 101 is configured in such a pot-shaped manner that in it both the Planet carrier 98 and the planet gears 86 are added. Furthermore, the ring gear 95 is arranged in the cup-shaped intermediate bearing 101, which is ultimately closed with respect to the armature 37 by a cover 107. The intermediate bearing 101 is also supported with its outer circumference on the inside of the pole tube 28. On the end of the drive shaft 44 facing away from the commutator 52, the armature 37 has a further shaft journal 110 which is also received in a slide bearing 113. The slide bearing 113 is in turn received in a central bore of the planet carrier. The planet carrier 98 is connected in one piece to the output shaft 116. The output shaft 116 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 shield 19. The output shaft 116 is divided into different sections: The section that is arranged in the sliding bearing 104 of the intermediate bearing 101 is followed by a section with a straight toothing 125 (internal toothing), which is part of a shaft-hub connection 128. In this case, this shaft-hub connection 128 enables a driver 131 to slide axially in a straight line. The driver 131 is designed as a sleeve-like extension which is designed in one piece with a cup-shaped outer ring 132 of the freewheel 137. This freewheel 137 (directional lock) also consists of an inner ring 140 which is arranged radially inside the outer ring 132. Clamping bodies 138 are arranged between the inner ring 140 and the outer ring 132. The clamping bodies 138, in cooperation with the inner ring 140 and the outer ring 132, prevent a relative rotation between the outer ring 132 and the inner ring 140 in a second direction. In other words: the freewheel 137 enables a relative movement between the inner ring 140 and the outer ring 132 only in one direction. In this exemplary embodiment, the inner ring 140 is made in one piece with the starter pinion 22 and its helical toothing 143 (external helical toothing). The starter pinion 22 can alternatively also be designed as a straight-toothed pinion. Instead of electromagnetically excited pole shoes 31 with excitation winding 34, permanently magnetically excited poles could also be used.

For the sake of completeness, the meshing mechanism is discussed here. The toe-in actuator 16 has a bolt 150 which represents an electrical contact and which is connected to the positive pole of an electrical contact Starter battery that is in Figure 1 is not shown, is connected. The bolt 150 is passed through a cover 153. The cover 153 closes off a housing 156 which is fastened to the drive end shield 19 by means of a plurality of fastening elements 159, for example screws. A winding 162 and a winding 165 are also arranged in the toe-in actuator 16. In the switched-on state, the winding 162 and the winding 165 both cause an electromagnetic field which flows through the housing 156 (made of an electromagnetically conductive material), a linearly movable armature 168 and an armature yoke 171. The armature 168 carries a push rod 74 which is moved in the direction of a switching pin 177 when the armature 168 is drawn in linearly. With this movement of the push rod 174 towards the switching pin 177, the latter is moved out of its rest position in the direction of two contacts 180 and 181, so that a contact bridge 184 attached to the contacts 180 and 181 at the end of the switching pin 177, both contacts 180 and 181 electrically connects to each other. As a result, electrical power is fed from the bolt 150 via the contact bridge 184 to the power supply 61 and thus to the carbon brushes 58. The starter motor 13 is energized.

The toe-in actuator 16 and the armature 168 also have the function of using a tension element 187 to move a lever 190 which is rotatably arranged on the drive end shield 19. The lever 190, which is usually designed as a fork lever, engages with two prongs (not shown here) on its outer circumference two disks 193 and 194 in order to move a driver ring 197 clamped between these for the freewheel 137 against the resistance of the spring 200 and thereby the starter pinion 22 to mesh with the ring gear 25 of the internal combustion engine.

Figure 2 shows an embodiment of the solution proposed according to the invention, in which a starter pinion and a roller collar represent separate components.

According to the representation Figure 2 it can be seen that the starting pinion 22 and a freewheel 137 are designed in such a way that these components represent components that are separated from one another. The starter pinion 22 is provided with an external toothing not shown in detail. Figure 2 also shows that the Freewheel 137 has a roller collar 246 and clamping body 138. These are enclosed by the cup-shaped outer ring 132 of the freewheel 137. From the representation according to Figure 2 It can be seen that the separate components, ie the roller collar 246, of the freewheel 137 and the starting pinion 22 separated therefrom are connected to one another via a claw coupling 228 shown in the closed state 250. To illustrate the claw coupling 228, both the starter pinion 22 and the roller collar 246 have axial toothings 232 and 236 on their respective facing end faces. As a result, a torque corresponding to the driving direction of the freewheel 137 can be transmitted to the starter pinion 22 from the roller collar 246 of the cup-shaped outer ring 132 of the freewheel 137 receiving the clamping bodies 138. From the representation according to Figure 2 It can also be seen that an inner spring 230 is enclosed by the axial toothings 232 or 236 of the starter pinion 22 and the roller collar 246. This represents a protection for the inner spring 230, since the inner spring 230 can be protected from excessive centrifugal forces due to its internal installation. The inner spring 230, which is supported on the end faces of the starter pinion 22 and roller collar 246, ensures that the two named components are pretensioned against one another, but are designed to be movable, in particular displaceable, in the axial direction.

The axial fixation of the starting pinion 22 with respect to the freewheel assembly 137 is carried out by a retaining disk 240, which is in particular divided into two parts. The retaining disk 240, which is particularly divided into two parts, is at an undercut, cf. Figure 3 , and has an axial play 242, which is in Figure 2 The illustrated engaged state 250 of the dog clutch 228 is "pushed out" due to the action of the inner spring 230, but is present to compensate for displacements. In particular, the split retaining disk 240 is formed on the undercut 244 on the outside of the axial toothing 232 of the starter pinion 22. When the freewheel 137 is stamped, the split retaining disk 240 protects guide disks made of plastic from excessive forces or distributes the forces that occur over a relatively large area. The split retaining disk 240 is in particular hardened or made of pre-tempered Material made or made with a lubricious coating, such as bonded varnish, which have the required material properties.

According to the representation Figure 2 it can also be seen that the cup-shaped configured outer ring 132 of the freewheel 137, which surrounds the clamping bodies 138, is acted upon by a spring 200 which is supported on a contact plate 224. According to the representation Figure 3 it can also be seen that the roller collar 246 is secured in the cup-shaped outer ring 132 of the freewheel 137 by a ring 226. Finally goes out Figure 2 shows that the cup-shaped inner ring is provided on the side facing away from the starter pinion 22 with internal teeth, which are designed here as helical teeth. In this here in the exemplary embodiment according to Figure 2 The toothing formed as a helical toothing on the cup-shaped outer ring 132 of the freewheel 137 engages the toothing that is at the output end of the planetary carrier 98 according to the epicyclic gear 83 according to FIG Figure 1 is trained.

Figure 3 shows the intermeshing axial teeth of the starter pinion and roller collar.

In the representation according to Figure 3 the inner spring 230, via which the starter pinion 22 and the roller collar 246 located in the interior of the freewheel 137 are preloaded against one another, has been omitted for the sake of illustration. According to the representation Figure 3 it can be seen from this that the axial toothings 232 and 236, in the engaged state 250 of the claw coupling 228, mesh with one another according to their axial extent. The axial teeth 232 and 236, which represent the coupling partners of the claw coupling 228, cause a coupling between the roller collar 246 and the starting pinion 22 in such a way that a torque can be transmitted to the starting pinion 22. This applies in the event that the freewheel 137 is operated in the driving direction and the clamping bodies 138 are located between the cup-shaped outer ring 132, see illustration in FIG Figure 2 , and clamp the roller collar 246 so that a torque can be transmitted to the starter pinion 22. From the representation according to Figure 3 It can also be seen that the roller collar 246 is secured in the freewheel 137 by the ring 226 is. The axial fixation between the starter pinion 22 and the roller collar 246 of the freewheel 137 is carried out by the holding disk 240, which is in particular divided into two parts and which is received on a receptacle 244 at its inner radius. This receptacle 244 is located in the exemplary embodiment according to Figure 3 on the outside, ie the lateral surface of the axial toothing 232 formed on the starter pinion 22. Individual teeth 238 of the axial toothing 236, which is formed on the roller collar 246, are complementary to this. Due to the axial fixation with the formation of the axial play 242 as shown in FIG Figure 2 What is achieved is that a continuous component in the form of a pinion shaft, on which the starting pinion 22 and the roller collar 246 would otherwise have to be received, can be dispensed with, since the axial securing of the starting pinion 22 in relation to the freewheel assembly 137 is taken over by the retaining disk 240, which is in particular split becomes. The transmission of a torque from the roller collar 246, which is part of the freewheel 137, to the starting pinion 22 in the state engaged in the ring gear 25 of the internal combustion engine takes place via the dog clutch 228 when it is in Figure 2 shown engaged state 250 is.

This in Figure 2 The axial play 242 shown depends on the length of the individual teeth 234 or 238, which extends in the axial direction, of the axial toothings 232 or 236, which represent the claw coupling 228. Furthermore, the axial play 242 according to the illustration in FIG Figure 2 depending on the dimension, which the split retaining disk 240 is designed to recede in a corresponding groove which is formed on the end face of the cup-shaped outer ring 132 of the freewheel 137.

The axial play 242 and the resilience between the components of the axial toothings 232, 236 of the starting pinion 22 and the roller collar 246 is limited by the displacement of the claw-like individual teeth 234 and 238 in the axial direction with respect to one another. In an alternative embodiment variant not shown in the drawing, the starter pinion 22 and the roller collar 246 can have different bearing diameters. In this case, for example, the starting pinion 22 is mounted directly on a shaft and the roller collar 246, for example, with a bushing. Alternatively, could the roller collar 246 can be mounted directly on the shaft and the starting pinion 22 can be mounted by means of a bushing.

Claims (9)

1. Electrical machine (10), in particular starter device for an internal combustion engine, having a starter pinion (22) which engages a gear rim (25) of an internal combustion engine and which is driven via a freewheel (137), wherein the starter pinion (22) and a roller collar (246) of the freewheel (137) are designed as separate components which can be moved relative to each other, wherein the starter pinion (22) has a end face and the roller collar (246) has an end face facing the end face of the starter pinion, characterized in that the starter pinion (22) has an axial toothing (232) on its end face which corresponds to an axial toothing (236) of the roller collar (246) in order to represent a claw coupling for transmitting a torque.
2. Electrical machine (10) according to the preceding claim, characterized in that the starter pinion (22) and the roller collar (246) are arranged concentrically with respect to each other and are preloaded against each other via an internally arranged spring element (230).
3. Electrical machine (10) according to claim 2, characterized in that the internally arranged spring element (230) is encapsulated on the outside by at least one of the axial toothings (232, 236) on the starter pinion (22) or on the roller collar (246).
4. Electrical machine (10) according to any one of the preceding claims, characterized in that a seat (244) for a retaining washer (240), in particular a divided retaining washer, is formed on the starter pinion (22) or on the roller collar (246).
5. Electrical machine (10) according to the preceding claim, characterized in that the seat (244) is formed in the region of the respective axial toothing (232, 236) of the starter pinion (22) or the roller collar (246).
6. Electrical machine (10) according to any one of claims 4 or 5, characterized in that the divided retaining washer (240) has an axial clearance (242) with respect to a cup-shaped outer ring (132) of the freewheel (137).
7. Electrical machine (10) according to any one of claims 4 to 6, characterized in that the divided retaining washer (240) engages in an undercut on the roller collar (246), in particular in a seat on the outside of the axial toothings (232, 236) of the starter pinion (22) or of the roller collar (246).
8. Electrical machine (10) according to any one of claims 4 to 7, characterized in that the divided retaining washer (240) is made of a hardened material, or of pre-tempered material, or of a material to which a slidable coating, such as sliding lacquer, is applied.
9. Starter device for an internal combustion engine having a starter pinion (22) and a roller collar (246) of a freewheel (137) according to any one of the preceding claims.

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