EP3604791A1 - Starter for a combustion engine - Google Patents

Abstract

The invention relates to a starter device (3) for an internal combustion engine (2), which has a gear device (13) with at least two planetary gears (14, 15), which transmits a torque of an input shaft (9) of the starter device (3) to an output shaft ( 12) transmits the starting device (3). Reduced wear on the starter device (3) and / or increased efficiency are achieved in that planet gears (24, 25) of the planetary gears (14, 15) engage in a ring gear arrangement (30) of the gear device (13), which in the drive device ( The invention further relates to an internal combustion engine system (1) with an internal combustion engine (2) and such a starting device (3).

Description

The present invention relates to a starting device for an internal combustion engine, which has a drive motor and a transmission device. The invention further relates to an internal combustion engine system with an internal combustion engine with such a starting device.

The use of starting devices, also called starters or starters, for starting an internal combustion engine is well known from the prior art. It is also, for example from the US 2002/0123408 A1 , known to equip such a starter device with a gear device which, for starting the internal combustion engine, provides different transmission ratios between a drive motor and an output shaft which is operatively connected to the internal combustion engine. The different transmission ratios make it possible to carry out a corresponding starting phase of the internal combustion engine in an improved manner and / or to reduce the energy consumption and thus to increase the efficiency. During a starting phase of the internal combustion engine, it is regularly necessary and desirable to switch between the different gear ratios.

The EP 2 067 984 A2 . WO 2015/106739 A1 as well as the WO 2016/019952 A1 each show such starter devices that have a gear device with two planetary gears, the respective planetary gear can be connected to a drive motor in order to realize a corresponding transmission ratio and to transmit the torque provided by the drive motor accordingly to an output shaft, which for starting a associated internal combustion engine is connected or connectable to this. With these starter facilities, this shows each planetary gear has a gear shaft and associated planet gears, each of which engages in a ring gear arrangement surrounding it and drives it during operation. The ring gear arrangement is connected to the output shaft of the starter device and thus transmits the torque of the drive motor with the corresponding transmission ratio to the output shaft.

A disadvantage of such starting devices is the high wear, the starting device, which occurs in particular when switching between the gear ratios. In addition, it is desirable to improve the efficiency of the starting device.

The present invention is therefore concerned with the task of specifying improved or at least other embodiments for a starting device of the type mentioned at the beginning and for an internal combustion engine system with such a starting device and an internal combustion engine, which are characterized in particular by reduced wear and / or increased efficiency.

This object is achieved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea of equipping a starting device for an internal combustion engine for starting the internal combustion engine with a transmission device which has at least two planetary gears, and to attach a ring gear arrangement in which planet gears planetary gears engage in such a way that the planet gears run along during operation Comb the ring gear assembly and thus rotate it, but do not drive the ring gear assembly. The knowledge is used that the ring gear arrangement for the respective planetary gear has a larger diameter than other rotating or rotating components, so that by eliminating the rotation or rotation of the ring gear arrangement, corresponding moments of inertia in the drive device are reduced. In addition, the ring gear arrangement, in particular due to the dimensioning, has a higher mass compared to other components of the respective planetary gear, so that the moments of inertia are in turn reduced by the stationary arrangement of the ring gear arrangement. The reduction in the moments of inertia leads to reduced power transmissions, in particular between the planet gears and the ring gear arrangement, so that the wear on the planetary gears and thus the gear device and the starter device is reduced and the efficiency is increased.

According to the inventive concept, the starting device has a drive motor which drives a drive shaft of the starting device during operation. The starter device also has an output shaft for driving and thus starting the internal combustion engine, the drive shaft and output shaft being arranged rotatably, in particular mounted, relative to a structure of the starter device. A drive torque of the drive shaft is transmitted to the output shaft with the gear device, the gear device having at least two planetary gears of the aforementioned type, each of which has associated planet gears. The planet gears are each rotatable relative to the structure and engage in the ring gear arrangement, the ring gear arrangement surrounding the planet gears, such that the planet gears are arranged within the ring gear arrangement. For this purpose, the planet gears expediently have a tooth structure, and are in particular each configured as a gear wheel. The planetary gears expediently engage in a complementary tooth structure of the ring gear arrangement with which they mesh during operation. According to the invention, the ring gear arrangement is fixed to the structure in such a way that the planet gears move and move along the ring gear arrangement during operation thus rotate. The fixation of the ring gear arrangement to the structure leads in particular to the fact that the ring gear arrangement is rotationally fixed, preferably also rotationally fixed, with respect to the structure. This therefore leads to an arrangement which is stationary with respect to the structure and, in contrast to the planet gears.

In the present sense, rotatable means rotatable about its own axis of rotation or axis. This means, for example, that the drive shaft rotates about its own axis relative to the structure during operation. In contrast, rotatable means a, in particular circular, rotational movement. The planet gears can therefore be rotated about their own axis and can also be rotated, in particular with their respective axis.

The respective planetary gear expediently represents or provides a transmission ratio between the input shaft and the output shaft. Accordingly, it can be provided that the planet gears of the different planetary gears each have different diameters.

The starter device advantageously has a clutch device with which switching between the planetary gears or the associated gear ratios is possible. For this purpose, the coupling device preferably couples the drive shaft optionally to the respective planetary gear. This means that the output shaft can be coupled to one of the planetary gears with the coupling device, so that the drive shaft drives this planetary gear. However, it is also conceivable to provide the clutch device on the output side in such a way that the clutch device optionally couples the output shaft to one of the planetary gears. It is thus possible to provide or tap the desired transmission ratio between the input shaft and the output shaft if required.

In principle, the coupling device can be of any design and / or can be operated as desired.

The clutch device is preferably designed as a friction clutch, which selectively and non-positively connects the drive shaft to the respective planetary gear. This makes it possible, in particular, to switch between different planetary gears and thus gears during operation of the starting device and during the starting process of the internal combustion engine. In particular, the friction clutch adjusts or synchronizes the speed differences between the pairs coupled to one another, in the present case between the drive shaft and the planetary gearbox coupled to it. This enables a particularly simple and efficient shift between the gears.

It proves to be advantageous if the friction clutch has several, that is to say at least two, preferably at least 3 or 4, friction pairs, in particular axially successive disks. The surface pressure per friction pair is thus reduced. As a result, the coupling device can be made radially smaller.

Embodiments in which the coupling device is configured electrically and / or electromagnetically are advantageous. This means that the clutch device can preferably be adjusted electrically or electromagnetically, the adjustment leading to shifting, in particular to the coupling between the drive shaft and the corresponding planetary gear. It is thus possible, in particular, to make the change between the different transmission ratios provided by the respective planetary gear, and thus switching, quickly and reliably, in the electromagnetic configuration also without contact.

Preferred variants provide that the clutch device for shifting between the different planetary gears is or can be shifted axially. This enables a simple and reliable design of the coupling device. It is in particular possible to provide the clutch device with a switching body which is connected to the drive shaft in a rotationally fixed manner and can be coupled to the respective planetary gear by an axial displacement. This means that the axial or translational displacement of the clutch body means that the drive shaft is optionally coupled to one of the planetary gears.

The switching body is advantageously electromagnetic and thus in particular axially displaceable or adjustable without contact. For this purpose, the coupling device can have at least one actuator, hereinafter also referred to as a switching actuator, which interacts electromagnetically with the switching body during operation. At least one such switch actuator is advantageously arranged on the respective axial side of the switch body. Switching can thus be carried out quickly and reliably.

Preferred embodiments provide that the transmission device is designed together with the clutch device as a double clutch transmission. This allows fast switching between the different gear ratios and / or leads to a reduced, interruption of the power transmission.

The respective planetary gear expediently has a gear shaft which is rotatably arranged with respect to the structure. The respective gear shaft is connected in a rotationally fixed manner to an associated sun gear of the associated planetary gear, such that the rotation of the gear shaft leads to a corresponding rotation of the sun gear. The sun gear is in engagement with the associated planet gears, such that rotation of the sun gear causes rotation of the planet gears and thus meshing of the planet gears Orbiting wheels along the ring gear arrangement surrounding them. The rotating and combing result in rotation of the planet gears along the ring gear assembly. It is preferred here if the gear shafts of at least two of the planetary gears are arranged coaxially. The gearbox can thus be simplified and / or compactly built.

A clutch body, with which the shift body of the clutch device couples for coupling with the associated planetary gear, can be attached in a rotationally fixed manner to the respective gear shaft.

It is advantageous if at least one of the gear shafts, together with the associated sun gear, is designed as a sun gear shaft. This reduces the assembly effort and leads to further reduced torque losses and / or to a further reduced wear.

The planet gears are preferably each designed as a planet gear. This means that the respective planet wheel can be rotated about an axis that runs parallel to the associated transmission axis and rotates around the transmission shaft during operation.

Advantageous embodiments provide that at least two transmission shafts are arranged concentrically. For this purpose, the radially outer gear shaft is expediently hollow, at least in sections. The concentric design of the gear shaft leads to a compact structure of the starting device and / or to a reduced weight.

Preferred embodiments provide a carrier of the transmission device that is rotatable relative to the structure. The planet gears of at least two of the planetary gears are rotatably mounted on the carrier such that the movement of the planet gears along the ring gear arrangement and thus the rotation the planet gears cause the carrier to rotate. The carrier is rotatably connected or connectable to the output shaft so that the torque is thus transmitted to the output shaft via the planetary gear and the carrier. The carrier expediently has at least two bearing shafts or bearing pins on which the planet wheels are rotatably mounted. It is preferred here if the carrier has a smaller diameter than the ring gear arrangement. This in particular reduces the moment of inertia of the transmission device and thus the starter device and thus the wear caused thereby.

In principle, the carrier and the output shaft can be manufactured separately and then connected to one another. It is also conceivable to manufacture the carrier with the output shaft in one piece, in particular monolithically.

The drive shaft and the transmission shafts are advantageously arranged coaxially. It is also preferred if the output shaft is arranged coaxially with the drive shaft and the transmission shafts. The drive shaft, the gear shafts and the output shaft can therefore be rotated about the same axis. As a result, the starting device can be constructed in a compact manner. This also reduces torque losses.

For at least two of the planetary gears, the ring gear arrangement can have an associated ring gear which is fixed relative to the structure, the ring gears being separate from one another and being axially spaced apart. In particular, the respective planetary gear can have its own ring gear of the ring gear arrangement.

It is also conceivable that the ring gear arrangement for at least two of the planetary gears, advantageously for all planetary gears, has a common ring gear. The ring gear arrangement can thus also have a single ring gear with which the planetary gears of all planetary gears are engaged. The ring gear advantageously has a single internal toothing, which has a number of teeth and a tooth pitch, with planet gears having external toothing, which are in engagement with this common internal toothing. The starting device can thus be produced inexpensively and in a simplified manner.

It is conceivable that the number of teeth of the planetary gears of different planetary gears differ. This means that different gear ratios can also be implemented.

In principle, the structure of the drive device can be any. It is particularly conceivable that the structure is a housing in which the planetary gears are arranged.

In principle, any transmission ratio between the input shaft and the output shaft can be realized with the respective planetary gear. In addition to a translation, a reduction is also conceivable. The different planetary gears preferably provide different gear ratios. A gear ratio between 2 and 6 is conceivable. In particular, one of the planetary gears can realize a gear ratio of 4 to 5, in particular 4.23, and the other planetary gear can implement a gear ratio between 3 and 4, in particular 3.33.

The starting device, in particular the clutch device, is advantageously designed in such a way that it performs the shifting between the different planetary gears and thus gears as a function of temperature. In particular, shifting into a gear with a lower gear ratio takes place faster when the temperature is higher. The temperature is in particular an ambient temperature of the starting device and / or the internal combustion engine or the temperature of a the internal combustion engine fluids, in particular from an engine oil or a coolant, or mixtures of these temperatures. The knowledge is used that the frictional resistance decreases with increasing temperatures, so that a lower torque is required for the drive. For temperature-dependent switching, the starting device can have corresponding temperature sensors or can communicate with them. A control of the clutch device or a control device of the starter device is designed in such a way that it carries out the switching in a temperature-dependent manner.

It goes without saying that, in addition to the starting device, an internal combustion engine system with an internal combustion engine and the starting device also belong to the scope of this invention. Such an internal combustion engine system is used in particular in a motor vehicle.

The internal combustion engine system expediently has a connecting device which establishes a drive connection between the output shaft and the internal combustion engine, in particular a crankshaft of the internal combustion engine. In this case, the drive connection can be designed to be separable, so that it is produced as required, in particular in a starting phase of the internal combustion engine.

The connecting device advantageously has at least one component which is fixed in a rotationally fixed manner on the output shaft, that is to say which rotates with the output shaft. Said component can be a gear, in particular a pinion, this gear or pinion advantageously being part of the starting device.

The internal combustion engine system advantageously has a control device which is connected to the coupling device in such a way that it controls the Coupling device controls. With the control device it is therefore possible to switch between the different transmission ratios. The control device can also be connected to the connection device such that it controls the connection device. With the control device, the drive connection between the output shaft and the internal combustion engine can also be established and separated.

Further important features and advantages of the invention result from the subclaims, from the drawings and from the associated description of the figures with reference to the drawings.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, the same reference numerals referring to the same or similar or functionally identical components.

Fig. 1

einen stark vereinfachten Schnitt durch ein Brennkraftmaschinensystem mit einer Brennkraftmaschine und einer Anlasseinrichtung,

Fig. 2

die Ansicht aus Fig. 1 bei einem anderen Ausführungsbeispiel der Anlasseinrichtung,

Fig. 3

ein Diagramm zur Erläuterung von Schaltvorgängen der Anlasseinrichtung.

It shows, each schematically

Fig. 1

a greatly simplified section through an internal combustion engine system with an internal combustion engine and a starting device,

Fig. 2

the view Fig. 1 in another embodiment of the starting device,

Fig. 3

a diagram for explaining switching operations of the starting device.

An internal combustion engine system 1 as shown in Fig. 1 can be seen includes an internal combustion engine 2 and a starting device 3. The internal combustion engine 2 is shown in FIG Fig. 1 only indicated schematically and can be part of a vehicle 4, not shown, together with the starting device 3. The internal combustion engine 2 is started with the starter device 3 such that the starter device 3 functions as a starter. For this purpose, the starter device 3 is drive-connected to the internal combustion engine 2 via a connecting device 5. The connecting device 5 can loosen and establish the drive connection. In the example shown, a pinion 6 of the drive device 3 and a flywheel 7 of the internal combustion engine 2 work together to establish the drive connection.

The drive device 3 has a, in particular electrically operated, drive motor 8, which drives a drive shaft 9 during operation. The drive device 3 has a housing 10 which, in the example shown, forms a structure 11 with respect to or relative to which the drive shaft 9 is rotatably arranged. The housing 10 or the structure 11 is in Fig. 1 hinted at. The starter device 3 also has an output shaft 12 on which the pinion 6 is fixed in a rotationally fixed manner such that the pinion 6 rotates together with the output shaft 12. The output shaft 12 is also arranged rotatably relative to the structure 1. The starter device 3 also has a gear device 13 which transmits a torque of the drive shaft 9 to the output shaft 12 and also translates or reduces the rotation of the drive shaft 9, translations being possible in the present example.

The gear device 13 has at least two planetary gears 14, 15, in the example shown two planetary gears 14, 15, namely a first one Planetary gear 14 and a second planetary gear 15 are provided. The respective planetary gear 14, 15 has a gear shaft 16, 17, which is arranged rotatably relative to the structure 11. This means that the first planetary gear 14 has a first gear shaft 16 and the second planetary gear 15 has a second gear shaft 17, which in the example shown is separate from the first gear shaft 16. In the example shown, the first transmission shaft 16 is guided through the second transmission shaft 17. Accordingly, the second gear shaft 17 is hollow. The drive shaft 9, the transmission shafts 16, 17 and the output shaft 12 are arranged coaxially in the example shown and are thus rotatable about a common axis of rotation 18, which forms the common axis. For the rotatable arrangement of the drive shaft 9, the output shaft 12 and the transmission shafts 16, 17, bearings 19 can be provided in each case, which support the associated shaft 9, 12, 16, 17 rotatably relative to the structure 11 and about the axis of rotation 18. The respective planetary gear 14, 15 also has a sun gear 20, 21 connected to the associated gear shaft 16, 17 in a rotationally fixed manner. This means that the first planetary gear 14 has a first sun gear 20, which is attached to the first gear shaft 16 in a rotationally fixed manner, such that the first sun gear 20 rotates together with the first gear shaft 16 about the axis of rotation 18. In addition, the second planetary gear 15 has a second sun gear 21, which is attached to the second gear shaft 17 in a rotationally fixed manner such that the second sun gear 21 rotates together with the second gear shaft 17 about the axis of rotation 18. In the example shown, the first gear shaft 16 and the first sun gear 20 are designed as a sun gear shaft 22, hereinafter also referred to as the first sun gear shaft 22, and the second gear shaft 17 together with the second sun gear 21 are also designed as a sun gear shaft 23, hereinafter also referred to as the second sun gear shaft 23 , The respective planetary gear 14, 15 also has at least two planet gears 24, 25, which surround the associated sun gear 20, 21 and are in engagement with the latter via a tooth structure (not shown). That means that first planetary gear 14 has at least two first planetary gears 24, which are arranged radially on the outside of the first sun gear 20 and are in engagement with a complementary tooth structure of the sun gear shaft 20, not shown, via said tooth structure. Analogously to this, the second planetary gear 15 has at least two second planet gears 25, which are arranged radially on the outside of the second sun gear 21, the second sun gear 21 and the second planet gears 25 being in engagement via corresponding tooth structures. Here are in Fig. 1 two first planet gears 24 and two second planet gears 25 are shown. Of course, the respective planetary gear 14, 15 can also have more associated planet gears 24, 25, which are arranged, preferably evenly, distributed. The planet gears 24, 25 of both planetary gears 14, 15 are rotatably mounted on a carrier 26, the carrier 26 being connected in a rotationally fixed manner to the output shaft 12 such that the carrier 26 rotates together with the output shaft 12 about the axis of rotation 18. In the example shown, the carrier 26 is produced in one piece or monolithically with the output shaft 12. The carrier 26 has a base body 27, from which the output shaft 12 protrudes. On the side facing away from the output shaft 12 there are also bearing pins 28, 29 radially spaced from the base body 27 from the axis of rotation 18 or the output shaft 12, on which the respective associated planet gears 24, 25 are rotatably mounted. This means that the carrier 26 has first bearing pins 28, on which the first planetary gears 24 are rotatably mounted. In addition, the carrier 26 has second bearing pins 29, on which the second planet wheels 25 are rotatably mounted. The planet gears 24, 25 are surrounded by a ring gear arrangement 30, with which they engage via a corresponding tooth structure, not shown. The ring gear arrangement 30 is fixed relative to the structure 11, that is to say not rotatable and preferably also not rotatable. The respective planet gear 24, 25 can thus rotate around the associated bearing pin 28, 29 during operation and thus rotate along the ring gear arrangement 30. This rotation leads to a rotation of the carrier 26 and thus of the output shaft 12 about the axis of rotation 18 In the example shown, the ring gear arrangement 30 has a common ring gear 31 with a common internal toothing 51 for all planet gears 24, 25. The planet gears 24, 25 have external gears 52, 53 associated with the internal toothing 51, such that the planet gears 24, 25 are in engagement with the common internal toothing 51 of the common ring gear 31. Another gear ratio is realized with the respective planetary gear 14, 15. For this purpose, the sun gears 20, 21 and the planet gears 24, 25 of the different planetary gears 14, 15 are dimensioned radially differently in the example shown. In the example shown, the first sun gear 20 is radially smaller than the second sun gear 21. Accordingly, the first planet gears 24 are dimensioned radially larger than the second planet gears 25. Alternatively or additionally, the external toothing 52 of the first planetary gears 24, hereinafter also referred to as the first external toothing 52, have a different number of teeth, not shown, than the external teeth 53 of the second planetary gears 25, hereinafter also referred to as the second external teeth 53.

A clutch device 32 of the starter device 3 permits the optional coupling of the first gear shaft 16 or the second gear shaft 17 to the drive shaft 9, so that the drive shaft 9 drives the first gear shaft 16 or the second gear shaft 17. In the present case, the clutch device 32 is configured together with the transmission device 13 as a double clutch transmission 33. To couple the respective transmission shaft 16, 17 to the output shaft 9 via the coupling device 32, an associated coupling body 34, 35 is attached in a rotationally fixed manner to the respective transmission shaft 16, 17, the coupling bodies 34, 35 being axially spaced apart. This means that a first clutch body 34 is attached to the first gear shaft 16 and a second clutch body 35 axially spaced apart from the first clutch body 34 is attached to the second gear shaft 17. The coupling device 32 also has a switching body 36 which rotates with it is connected to the drive shaft 9 and is arranged axially with an intermediate body 37 between the coupling bodies 34, 35. The switching body 36 is axially displaceable, such that the intermediate body 37 can optionally be coupled to the first coupling body 34 or the second coupling body 35. The axial displacement of the shift body 36 thus allows switching between a first gear ratio or first gear provided by the first planetary gear 14 and a second gear ratio or second gear provided by the second planetary gear 15. The intermediate body 37 serves for the friction clutch between the shift body 36 and the respective transmission shaft 16, 17 or the clutch bodies 34, 35. This means that the clutch device 32 is designed as a friction clutch 50. The first transmission ratio is preferably greater, for example between 4 and 5, than the second transmission ratio, which can be between 3 and 4.

In the example shown, the axial displacement of the switching body 36 and thus the switching takes place with the aid of electromagnetic actuators 38, hereinafter also referred to as switching actuators 38, which enable a contactless displacement of the switching body 36 and thus a contactless switching. The switching actuators 38 are controlled by a controller 39, which is also referred to below as a switching controller 39. In this case, 36 switching actuators 38 are arranged on both axial sides of the switching body, in particular to enable fast switching.

The connecting device 5 has an actuator 40 for establishing and releasing the drive connection between the pinion 6 and the flywheel 7, which actuator is also referred to below as the connecting actuator 40. The connection actuator 40 and the switching control 39 are connected to a control device 41 such that the control device 41 controls the switching control 39 and the connection actuator 40, in particular can operate. It is thus possible to use the starting device 3 to start the internal combustion engine 2 in a starting phase of the internal combustion engine 2. It is also possible to switch between the first gear and the second gear during the starting phase.

In Fig. 2 Another exemplary embodiment of internal combustion engine system 1 or vehicle 4 is shown. This embodiment differs from that in Fig. 1 Example shown only in that the ring gear assembly 30 has two axially spaced, separate ring gears 31 for the respective planetary gear 14, 15. This means that the ring gear arrangement 30 has a first ring gear 31 ′ which is in engagement with the first planetary gears 24 of the first planetary gear 14. In addition, the ring gear arrangement 30 has a second ring gear 31 ″, which is separate from the first ring gear 31 ′ and with which the second planetary gears 25 of the second planetary gear 15 are in engagement. This makes it possible, in particular, for example by different dimensions of the ring gears 31, to provide gear ratios The first ring gear 31 'can also have an internal toothing 51', hereinafter also referred to as a first internal toothing 51 ', which differs from the internal toothing 51 "of the second ring gear 31", hereinafter referred to as a second internal toothing 51 ", for example with regard to the number of teeth not shown and / or the tooth pitch. This also makes different gear ratios of the two planetary gears 14, 15 possible.

In Fig. 3 A diagram is shown with which a method for operating the internal combustion engine system 2 in a starting phase of the internal combustion engine 2 is explained by way of example. A power applied to the drive motor 8 or, analogously, the applied electric current is plotted along an abscissa 42. Along the in Fig. 3 the left ordinate 43 is the rotational speed of the carrier 26 and thus the output shaft 12 plotted while along the in Fig. 3 opposite, right ordinate 44 the torque is plotted by means of the carrier 26 and thus via the output shaft 12. Symbolized by crosses and connected to each other with the aid of a dashed line, the torque transmitted by the first planetary gear 14 is shown by a curve through a corresponding curve 45, which is also referred to below as the first torque curve 45. Symbolized by rectangles and connected by means of a dotted line, a further course 46 is shown, which shows the torque transmitted by the second planetary gear 15, this course 46 also being referred to below as the second torque course 46. Symbolized by triangles and connected with the aid of a dot-dash line, a further course 47 is shown, which shows the dependence of the rotational speed of the carrier 26 on the current applied when the carrier 26 is driven by the first planetary gear 14. This course 47 is therefore also referred to below as the first speed course 47. Again symbolized by rectangles and connected to one another with the aid of a dashed line, a further course 48 is shown, which shows the dependence of the rotational speed of the carrier 26 on the applied current when the carrier 26 is driven by the second planetary gear 15. This course 48 is therefore also referred to below as the second speed course.

To start the internal combustion engine 2, the starter device 3 starts in first gear, in which the first planetary gear 14 is connected to the drive shaft 9 by means of the clutch device 32 and is driven by the latter. The start of the operation of the starting device 3 and thus the starting phase of the internal combustion engine is in Fig. 3 symbolized with "T1" for the torque 26 provided. A drive connection between the carrier 26 and the internal combustion engine 2 is established with the aid of the connecting device 5. The inertia and the mechanical resistance of the internal combustion engine 2 cause the rotational speed to be zero lies. Overcoming the inertia and the mechanical resistance of the internal combustion engine 2 lead to a decrease in the torque and a simultaneous increase in the rotational speed. This can also be seen from the first torque curve 45 and the first speed curve 47. The starter device 3 is operated in first gear until the torque reaches the value labeled "T2" and the rotational speed reaches the value labeled "R2". When the torque "T2", which can be stored in the clutch device 32, in particular in the shift control 39 and / or in the control device 41, is reached, the clutch device 32 shifts into second gear, that is to say the second planetary gear 15 with the carrier 26 and consequently connected to the output shaft 12. This is in Fig. 3 by a jump between the value R2 in the first speed profile 47 to the value R2 'corresponding to the value R2' in the second speed profile 48, visible and indicated by a first arrow 49. At the same time, a shift from the value T2 in the first torque curve 45 to the value T2 ′ in the second torque curve 46 takes place due to the shifting into the second gear. Due to the still decreasing reduced mechanical resistance of the internal combustion engine 2 and the lack of ability of the second gear to provide the corresponding torque To make available, the torque initially drops the value T2 "in the second torque curve 46 while the rotational speed increases to the value R2" in the second speed curve 48. There follows a further decreasing torque, as can be seen from the course of the second torque curve 46, with a simultaneously increasing rotational speed, as can be seen from the second speed curve 48, until the internal combustion engine 2 is started, the drive connection between the starter device 3 and the internal combustion engine 2 then solved with the help of the connecting device 5 and the starting device is deactivated. The switching between the first gear and the second gear takes place during the starting process with the aid of the clutch device 32.

A freewheel element (not shown) can be arranged between the starting device 3 and the internal combustion engine 2 that can be driven thereby, which prevents the internal combustion engine 2 from driving the starting device 3 after the starting process has been completed. Thus, only a torque can be transmitted from the starting device 3 to the internal combustion engine 2, but not vice versa.

The starting device 3 is advantageously designed in such a way that it shifts from first to second in a temperature-dependent manner. Switching occurs earlier when the temperature rises. The temperature is the ambient temperature and / or the temperature of an engine oil supplied to the internal combustion engine. For this purpose, the switching controller 39 and / or the control device 41 is / are communicatively connected to at least one temperature sensor, not shown.

Claims (18)

Starting device (3) for an internal combustion engine (2), - With a drive motor (8) which drives a drive shaft (9) of the starter device (3) during operation, and with an output shaft (12) for driving the internal combustion engine (2), the drive shaft (9) and output shaft (12) relative to a structure (11) of the starting device (3) is arranged rotatably, - With a gear device (13) which transmits a drive torque of the drive shaft (9) to the output shaft (12), - The transmission device (13) has at least two planetary gears (14, 15) for transmitting the drive torque between the drive shaft (9) and the output shaft (12), the respective planetary gear (14, 15) has associated planet gears (24, 25) which are rotatable relative to the structure (11) and which engage in a ring gear arrangement (30) of the gear device (13) surrounding them, characterized,
that the ring gear arrangement (30) is fixed to the structure (11). Starting device according to claim 1,
characterized,
that the starter device (3) has a clutch device (32) for selectively coupling the planetary gears (14, 15) to the drive shaft (9). Starting device according to claim 2,
characterized,
that the coupling device (32) is operated electrically, in particular electromagnetically. Starting device according to claim 2 or 3,
characterized,
that the transmission device (13) with the coupling device (32) is designed as a double clutch transmission (33). Starting device according to one of claims 2 to 4,
characterized,
that the clutch device (32) is designed as a friction clutch (50), in particular with a plurality of friction pairings. Starting device according to one of claims 1 to 5,
characterized,
that the respective planetary gear (14, 15) has a gear shaft (16, 17) and a sun gear (20, 21) attached to the gear shaft (16, 17) in a rotationally fixed manner, the sun gear (20, 21) with the associated planet gears (24 , 25) of the planetary gear (14, 15) is engaged. Starting device according to claim 6 and one of claims 2 to 5,
characterized, - that on the respective gear shaft (16, 17) a coupling body (34, 35) is attached in a rotationally fixed manner, the coupling bodies (34, 35) being axially spaced apart, - that a switching body (36) of the coupling device (32) is connected in a rotationally fixed manner to the drive shaft (9) and is at least partially arranged between the coupling bodies (34, 35), - That the coupling device (32) has at least one switching actuator (38) for axially adjusting the switching body (36) for optionally coupling the switching body (36) with the respective coupling body (34, 35). Starting device according to claim 7,
characterized,
that at least one switching actuator (38) is arranged axially on both sides of the switching body (36). Starting device according to claim 7 or 8,
characterized,
that the at least one switching actuator (38) for adjusting the intermediate body (37) cooperates electromagnetically with the switching body (36). Starting device according to one of claims 6 to 9,
characterized,
that the gear shafts (16, 17) are arranged concentrically. Starting device according to one of claims 1 to 10,
characterized, - That the gear device (13) has a carrier (26) which is rotatable relative to the structure (11), - that the planet wheels (24, 25) of at least two of the planetary gears (14, 15) are rotatably mounted on the carrier (26), - That the output shaft (12) is rotatably attached to the carrier (26). Starting device according to one of claims 1 to 11,
characterized,
that the ring gear arrangement (30) has a ring gear (31) with which the planet gears (24, 25) of at least two of the planetary gears (14, 15) are in engagement. Starting device according to claim 12,
characterized,
that the ring gear (31) has an internal toothing (51) and the planet gears (24, 25) of the at least two planetary gears (14, 15) each have an external toothing (52, 53), the internal toothing (51) of the ring gear (31) and the external teeth (52, 53) of the planet wheels (24, 25) belonging to the two planetary gears (14, 15) each have a different number of teeth but the same tooth pitch. Starting device according to claim 12 or 13,
characterized,
that the planet gears (24, 25) of the at least two planetary gears (14, 15) mesh with the same internal toothing (51) of the ring gear (31). Starting device according to one of claims 1 to 14,
characterized,
that the ring gear arrangement (30) has at least two spaced-apart ring gears (31), the planet gears (24) from one of the planetary gears (14) with one of the ring gears (31 ') and the planet gears (25) from another of the planet gears (15 ) are engaged with another of the ring gears (31 "). Starting device according to one of claims 1 to 15,
characterized,
that at least two of the planetary gears (14, 15) are designed such
that they provide different gear ratios between the drive shaft (9) and the output shaft (12). Starting device according to one of claims 1 to 16,
characterized,
that the starting device (3) is designed such that it performs a change between the clutch of one of the planetary gears (14) with the drive shaft (9) and another planetary gear (15) with the drive shaft (9) as a function of temperature. Internal combustion engine system (1), in particular a vehicle (4), with an internal combustion engine (2) and with a starting device (3) according to one of Claims 1 to 17 and with a connecting device (5) for drivingly connecting the output shaft (12) to the internal combustion engine ( 2).

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