Spur gear differential for motor vehicle

Abstract

The invention relates to a transmission (10) for a motor vehicle having a spur gear differential (12) comprising a first sun gear (14) which is designed as a first output and a first spur gear of the spur gear differential (12) and has a first rolling circle diameter. The spur gear differential (12) comprises a second sun gear (16) arranged coaxially with the first sun gear (14), configured as a second follower and a second spur gear of the spur gear differential (12), and having a second rolling circle diameter different from the first rolling circle diameter. The spur gear differential (12) comprises at least one planetary gear set (26) by means of which the sun gears (14, 16) are coupled to one another in such a way that the sun gears (14, 16) can rotate in opposite directions, the planetary gear set (26) comprising a planet carrier (28). The planetary gear set (26) comprises a first differential planet gear (30) which meshes with the first sun gear (14), has a third rolling circle diameter, and is rotatably held on the planet carrier (28) about a first planet axis of rotation (32) with respect to the planet carrier (28).

Description

Technical Field

[0001] The present invention relates to a transmission for a motor vehicle as described in the preamble of claim 1. The present invention also relates to a motor vehicle, in particular a motor car having such a transmission. Background Art

[0002] DE 10 2014 203 522 A1 discloses a known spur gear differential transmission. In addition, DE 10 2015214 035B4 discloses an electric drive unit for a motor vehicle. In addition, DE 102018 128 836B3 discloses a transmission for a motor vehicle. Summary of the Invention

[0003] The object of the present invention is to provide a transmission for a motor vehicle and a motor vehicle having such a transmission, such that a particularly compact and weight - economical structure of the transmission and a particularly high torque density can be achieved.

[0004] This object is achieved by a transmission having the features of claim 1 and a motor vehicle having the features of claim 15. Advantageous designs with suitable improvements of the present invention are given in the remaining claims.

[0005] A first aspect of the present invention relates to a transmission for a motor vehicle, which is also simply referred to as a vehicle and is preferably configured as a motor car, in particular a passenger car. This means that the motor vehicle in its fully manufactured state has the transmission and can be driven via the transmission, in particular by means of the drive motor of the motor vehicle. In particular, for example, the wheels of the motor vehicle, also simply referred to as wheels, in particular the axles of the motor vehicle, also simply referred to as axles, can be driven by the transmission in order to drive the entire motor vehicle in this way.

[0006] The transmission has a spur gear differential, also known as a spur gear differential drive. Thus, the spur gear differential is a differential constructed as a spur gear differential, also simply referred to as a differential drive. For example, the wheels can be driven by a spur gear differential, in particular by the drive shaft of a motor vehicle. For example, the spur gear differential has functions well known from the prior art, namely distributing and transmitting the drive torque provided or available by the drive shaft to the wheels, in particular the side shafts by which the wheels can be driven. Furthermore, for example, the spur gear differential has the function of allowing different speeds of the wheels and thus the side shafts during a turn of the motor vehicle, such that the wheels on the outer side of the curve can rotate at a higher speed than the wheels on the inner side of the curve, in particular when the wheels are drivable or driven by the drive shaft via the spur gear differential. The side shafts can be, for example, components of the spur gear differential. In this case, a first wheel can be driven, for example, by a first side shaft, and a second wheel can be driven by a second side shaft. In particular, the side shafts can be arranged coaxially relative to each other. In particular, the wheels are arranged on vehicle sides opposite each other in the vehicle transverse direction of a motor vehicle (also simply referred to as "vehicle").

[0007] The spur gear differential has a first sun gear, which is constructed as a first driven member and a first spur gear of the spur gear differential. The first sun gear has a first pitch circle diameter. In particular, the first sun gear has a first pitch diameter. For example, the first sun gear is, in particular permanently, torsionally connected to the first side shaft, such that, for example, the first side shaft can be driven by the first sun gear, and such that, for example, the first wheel can be driven by the first sun gear via the first side shaft. The spur gear differential also has a second sun gear, which is constructed as a second driven member and a second spur gear of the spur gear differential. For example, the second sun gear is, in particular permanently, torsionally connected to the second side shaft, such that the second side shaft can be driven by the second sun gear. Thus, the second wheel can be driven by the second sun gear via the second side shaft. The sun gears are arranged coaxially relative to each other. In other words, for example, the second sun gear is arranged coaxially with the rotational axis of the first sun gear. In other words, for example, the first sun gear can rotate about the rotational axis of the first sun gear, in particular relative to the housing of the transmission. For example, the first sun gear is at least partially arranged in the housing. The second sun gear can, for example, rotate relative to the housing about the rotational axis of the second sun gear, for example, the second sun gear is at least partially arranged in the housing, whereby, due to the coaxial arrangement of the sun gears relative to each other, the sun gear rotational axes coincide. In particular, for example, the first side shaft is arranged coaxially with the first sun gear, and for example, the second side shaft is arranged coaxially with the second sun gear.

[0008] In the context of the present disclosure, the feature that two components are torsionally connected to each other can be understood as the two components being integrally formed with each other, thus formed from a single piece, and thus torsionally connected to each other, such that the two components integrally formed with each other form a whole, i.e., formed from a whole. In other words, the components integrally formed with each other are formed from a whole formed integrally and thus manufactured as a whole. In addition, it can be imagined that the two components torsionally connected to each other are constructed separately from each other and are torsionally connected to each other, in particular by means of a connection technique. The components torsionally connected to each other are rotatable or rotatable about a component rotation axis common to the components, in particular relative to a housing, in particular when the components are driven, such that the components are rotatable or rotatable about the component rotation axis together or simultaneously at the same angular velocity, in particular relative to the housing. In addition, relative rotation occurring between the components about the component rotation axis is prevented.

[0009] The second sun gear configured as a second spur gear has a second pitch circle diameter different from the first pitch circle diameter. Thus, for example, the first pitch circle diameter is greater than the second pitch circle diameter, and vice versa. In particular, the second sun gear has a second pitch circle diameter different from the first pitch circle diameter, such that, for example, the first pitch circle diameter is greater than the second pitch circle diameter, and vice versa.

[0010] The transmission further has a planetary gear set, which is also referred to as a planetary assembly or a rotating planetary assembly. By means of or via the planetary gear set, the sun gears are coupled to each other in such a way that the sun gears can rotate in opposite directions. This can be understood in particular as follows: The wheel is a ground contact element of a motor vehicle (also referred to as a vehicle), which can be supported or supported downward in the vehicle vertical direction of the motor vehicle on the ground, for example, on a road, via the ground contact element. If the wheel and thus the motor vehicle are driven such that the motor vehicle travels along the ground, and the motor vehicle is supported downward on the ground in the vehicle vertical direction via the ground contact element (wheel), the wheel rolls, in particular directly on the ground. For example, if the motor vehicle is now at least partially raised such that the wheel does not contact the ground and can be said to float in the air, and if, for example, the first wheel and thus the first side shaft and the first sun gear rotate about the first sun gear rotation axis in a first rotation direction, the second sun gear and the second side shaft are thus driven by the planetary gear set, as is well known from a conventional differential transmission, and are driven by the second side shaft in such a way that the second sun gear and thus, for example, the second side shaft rotate about the second sun gear rotation axis and thus about the first sun gear rotation axis in a second rotation direction opposite to the first rotation direction, and thus rotate in a direction opposite to the first sun gear.

[0011] The planetary gear set has a carrier, which is preferably arranged coaxially with the sun gear. The carrier can rotate, for example, relative to the housing about a carrier rotation axis, where the carrier can be at least partially arranged in the housing. In particular, it is conceivable that the carrier rotation axis coincides with the sun gear rotation axis, such that the carrier is preferably arranged coaxially with the sun gear. The planetary gear set also has at least one first differential planetary gear, which engages with a first sun gear and thus meshes with the first sun gear. The first differential planetary gear has a third pitch diameter. In particular, the first differential planetary gear has a third pitch circle diameter. For example, the planetary gear set has at least one additional or a plurality of additional first differential planetary gears, and the previous and subsequent statements regarding at least one first differential planetary gear can also be easily transferred to the corresponding additional first differential planetary gears, and vice versa. When the first differential planetary gear is mentioned above and below, unless otherwise specified, this is understood to be at least one first differential planetary gear. The first differential planetary gear is rotatably held on the carrier relative to the carrier about a first planetary rotation axis. The first planetary rotation axis preferably extends parallel to the corresponding sun gear rotation axis and / or parallel to the carrier rotation axis, where the first planetary rotation axis is preferably spaced apart from the corresponding sun gear rotation axis and / or from the carrier rotation axis.

[0012] The planetary gear set also includes at least one second differential planetary gear. It is conceivable that the planetary gear set has at least one additional second differential planetary gear or a plurality of additional second differential planetary gears, where the previous and subsequent statements regarding at least one second differential planetary gear can also be easily transferred to the corresponding additional second differential planetary gears, and vice versa. When the second differential planetary gear is mentioned above and below, unless otherwise specified, it is understood to be at least one second differential planetary gear. The second differential planetary gear meshes with a second sun gear. Thus, the second differential planetary gear is provided to engage with or mesh with the second sun gear. The second differential planetary gear is rotatably held on the carrier relative to the carrier about a second planetary rotation axis that extends parallel to the first planetary rotation axis and is spaced apart from the first planetary rotation axis. For example, the second planetary rotation axis extends parallel to the corresponding sun gear rotation axis and / or parallel to the carrier rotation axis, where preferably, the second planetary rotation axis is spaced apart from the corresponding sun gear rotation axis and / or the carrier rotation axis.

[0013] The planetary gear set also has at least one coupling planetary gear, which is arranged coaxially with the first differential planetary gear, torsionally connected to the first differential planetary gear and meshes with the second differential planetary gear, so as to engage with the second differential planetary gear or mesh with the second differential planetary gear, thereby coupling the differential planetary gears to each other, and having a fourth rolling circle diameter different from the third rolling circle diameter. In particular, the coupling planetary gear has a fourth pitch circle diameter different from the third pitch circle diameter. The first differential planetary gear and the second differential planetary gear form, for example, a differential planetary gear set. It is conceivable that a spur gear differential has at least one additional or multiple additional differential planetary gear sets. The statements about the front and back of the first differential planetary gear set can also be easily transferred to the corresponding other differential planetary gear set, and vice versa.

[0014] The coupling planetary gear and the first differential planetary gear form a differential stepped planetary gear, which is rotatably held on the planet carrier relative to the planet carrier about the first planetary rotation axis. The differential planetary gear and the coupling planetary gear are additional spur gears of the spur gear differential. The first differential stepped planetary gear has the first differential planetary gear as the first stepped planetary gear and the coupling planetary gear as the second stepped planetary gear. That is to say, the first differential planetary gear is also called the first stepped planetary gear, and the coupling planetary gear is also called the second stepped planetary gear. It is conceivable that a spur gear differential has at least one additional differential stepped planetary gear or multiple additional differential stepped planetary gears. Among them, the explanations about the front and back of the first differential stepped planetary gear can also be easily transferred to the corresponding additional differential stepped planetary gear, and vice versa.

[0015] The differential stepped planetary gear and the second differential planetary gear are arranged on different axes. This particularly means that the first planetary rotation axis and the second planetary rotation axis extend parallel to each other and are spaced apart from each other, especially in the radial direction of the planetary gear set and / or in the circumferential direction of the planetary gear set extending around the axis of the planetary gear set.

[0016] In order to be able to achieve a particularly compact, space-saving and weight-saving structure of the transmission and a particularly high torque density, according to the present invention, the first ratio between the first rolling circle diameter and the second rolling circle diameter and the second ratio between the third rolling circle diameter and the fourth rolling circle diameter are the same. For example, the first ratio is the first quotient, the first numerator of which has the first rolling circle diameter and the first denominator has the second rolling circle diameter. Very preferably, the second ratio is the second quotient, the second numerator of which has the third rolling circle diameter and the second denominator has the fourth rolling circle diameter. Therefore, according to the present invention, the providers are the same. The explanations about the rolling circle diameter in the front and below can also be transferred to the pitch circle diameter, and vice versa.

[0017] When the sun gear is mentioned hereinafter and in the following, unless otherwise specified, it is understood to be the first sun gear and the second sun gear. The first sun gear and the second sun gear are also collectively referred to as the driven device or the driven sun gear, wherein the first sun gear is the first of the driven sun gears and the second sun gear is the second of the driven sun gears.

[0018] The present invention makes it possible to divide the aforementioned drive torque, i.e., halve it, and distribute it to the driven sun gears and thus transmit it, so that a so-called 50:50 torque distribution can be achieved. For this purpose, the rolling circle diameters of the driven sun gears are slightly different, i.e., they have different sizes. However, adverse, extreme profile displacements and the resulting adverse effects on the load-bearing behavior of the teeth of the spur gear differential can be avoided. Therefore, the transmission can be designed to be particularly advantageous in terms of weight and structural space and can achieve a high torque density.

[0019] In order to be able to achieve a particularly compact structure, in one design of the present invention, the first differential planet gear includes a first tooth part having a first number of teeth and a first tooth part module, wherein the first tooth part meshes with the first sun gear. The first tooth part includes (a plurality of) first teeth having a corresponding first tooth height, wherein the first tooth height of (the plurality of first teeth) is preferably equal. The coupling planet gear includes a second tooth part having a second number of teeth and a second tooth part module, wherein the second tooth part meshes with the second differential planet gear. The second tooth part includes (a plurality of) second teeth having a corresponding second tooth height, wherein the second tooth height of (the plurality of second teeth) is preferably the same.

[0020] Preferably, the first differential planet gear meshes with the first sun gear, but preferably, the first differential planet gear does not mesh with the coupling planet gear, does not mesh with the second sun gear, and does not mesh with the second differential planet gear. In addition, preferably, the coupling planet gear meshes with the second differential planet gear, but preferably, the coupling planet gear does not mesh with the first differential planet gear, does not mesh with the first sun gear, and preferably, the coupling planet gear does not mesh with the second sun gear. In addition, preferably, the second differential planet gear meshes with the second sun gear and the coupling planet gear, wherein the second differential planet gear preferably does not mesh with the first sun gear and does not mesh with the first differential planet gear.

[0021] Another design of the present invention is characterized in that the first number of teeth and the second number of teeth are the same, wherein the first tooth part module and the second tooth part module are different from each other, and wherein the corresponding first tooth height and the corresponding second tooth height are different from each other. Therefore, the required structural space can be kept particularly low.

[0022] In order to enable a particularly compact structure, in another design of the present invention, the first tooth part and the second tooth part are rotationally oriented relative to each other, in particular about the first planetary rotation axis, such that the corresponding gaps (also called backlash) of the first tooth part are aligned with the corresponding gaps (also called backlash) of the second tooth part of the coupling planet. In other words, preferably, the backlash or all backlashes of the first tooth part are aligned with the backlash or all backlashes of the second tooth part, in particular axially of the differential stepped planetary gear, and thus when viewed along the first planetary rotation axis.

[0023] In another particularly advantageous design of the present invention, the first stepped planetary gear and the second stepped planetary gear are formed as a single entity with each other, and thus formed by a single entity. In other words, preferably, the first stepped planetary gear and the second stepped planetary gear are not constructed as components that are separated from each other and connected to each other, but preferably, the first stepped planetary gear and the second stepped planetary gear are constructed as an integral body with each other, such that the first stepped planetary gear and the second stepped planetary gear are constructed as a whole or formed by an integral structure. In other words, preferably, the first stepped planetary gear and the second stepped planetary gear are formed by an integral body manufactured as a single piece. Therefore, the required structural space, weight, and cost can be kept within a particularly low range.

[0024] Another design of the present invention is characterized in that when viewed axially of the first stepped planetary gear and the second stepped planetary gear, and thus when viewed along the first planetary gear rotation axis, a transition region is provided, formed, or arranged between the first stepped planetary gear having a first width extending axially of the first stepped planetary gear and the second stepped planetary gear having a second width extending axially of the second stepped planetary gear, wherein the transition region has a third width also called the transition width. In principle, it is conceivable that the first width and the second width are the same. In addition, it is conceivable that the first width and the second width are different from each other. In addition, the first width and the third width can be the same, or the third width and the first width can be different from each other. In addition, it is conceivable that the second width and the third width are the same, or the third width and the second width are different from each other. In particular, it is conceivable that the transition region has no tooth part, or a tooth part also called a transition tooth part is provided in the transition region, which can be integrally formed with the first tooth part and / or integrally formed with the second tooth part, for example.

[0025] For example, the tool outlet of the tooth cutting tool for manufacturing the first tooth part of the first differential planetary gear and / or for manufacturing the second tooth part of the coupling planetary gear is located in the transition region. Furthermore, it is preferably provided that the radial outer contour of the differential stepped planetary gear, in particular the radial outer contour, and thus the outer contour of the differential stepped planetary gear pointing outwards in the radial direction of the differential stepped planetary gear, is not less than the first addendum circle diameter of the second tooth part of the coupling planetary gear in the transition region, but rises or increases from the first addendum circle diameter of the second tooth part of the coupling planetary gear, in particular continuously rises or increases to the second addendum circle diameter of the first tooth part of the first differential planetary gear. Thus, for example, the second addendum circle diameter is greater than the first addendum circle diameter. The corresponding above-mentioned width extends axially between the first stepped planetary gear and the second stepped planetary gear, and thus axially in the differential stepped planetary gear, and thus extends along the first planetary gear rotation axis. In this way, a particularly compact structure can be ensured, especially axially in the differential stepped planetary gear and thus axially in the entire transmission.

[0026] In order to be able to achieve a particularly compact structure, especially axially in the transmission, in a further design of the present invention, it is provided that the third width of the transition region is significantly smaller than the first width of the first stepped planetary gear, in particular the first tooth part, and significantly smaller than the second width of the second stepped planetary gear, in particular the second tooth part. Preferably, the first width is the first tooth width of the first tooth part, and preferably, the second width is the second tooth width of the second tooth part. The feature that the third width is significantly smaller than the first width and significantly smaller than the second width should be particularly understood as, for example, when the first width and the second width are the same, the third width does not exceed 90% of the first width and the second width, in particular does not exceed 80%, in particular does not exceed 70%, in particular does not exceed 60%, and if the first width and the second width are different, the third width does not exceed 90% of the smaller of the first width and the second width, in particular does not exceed 80%, in particular does not exceed 70%, in particular does not exceed 60%. In particular, for example, the third width is less than 50% of the first width and the second width or the smaller of the first width and the second width, in particular less than 40%, very particularly less than 30%.

[0027] Another design of the present invention is characterized in that the first differential planetary gear and the coupling planetary gear are constructed separately from each other and are especially torsionally connected to each other. Among the first stepped planetary gear and the second stepped planetary gear, one stepped planetary gear has a rolling circle diameter or a pitch circle diameter smaller than that of the other stepped planetary gear, and has a protrusion, for example designed as a pin, which is also called an extension section. The other stepped planetary gear among the first stepped planetary gear and the second stepped planetary gear is arranged and fixed on this protrusion. In other words, if the third rolling circle diameter is greater than the fourth rolling circle diameter, the first stepped planetary gear is the large planetary gear and the second stepped planetary gear is the small planetary gear. If the third rolling circle diameter is smaller than the fourth rolling circle diameter, the first stepped planetary gear is the small planetary gear and the second stepped planetary gear is the large planetary gear. In this case, a small planetary gear is provided with a protrusion, for example designed as a pin, which is also called an extension section, and the large planetary gear is arranged and fixed on this protrusion. For example, the large planetary gear has a hub, and at least one longitudinal region of the protrusion of the small planetary gear is arranged therein, such that the large planetary gear is arranged on the longitudinal region of the protrusion of the small planetary gear through its hub. In particular, the large planetary gear is torsionally fixed on the protrusion through the hub and is thus torsionally connected to the small planetary gear. Therefore, a structure that is particularly space-saving and cost-effective can be proposed.

[0028] In order to be able to keep the structural space requirement of the transmission particularly low, especially in the axial direction of the transmission, in another design of the present invention, it is provided that in the axial direction of the first stepped planetary gear and the second stepped planetary gear, and thus when observed along the first planetary gear rotation axis, the first stepped planetary gear and the second stepped planetary gear are directly or directly adjacent to each other.

[0029] In another design of the present invention, the first sun gear includes a third tooth part having a third number of teeth and a third tooth part module, wherein the third tooth part meshes with the first differential planetary gear, especially its first tooth part. The third tooth part includes (a plurality of) third teeth having a corresponding third tooth height, and preferably the third tooth height of (the plurality of third teeth) is the same. The second sun gear includes a fourth tooth part having a fourth number of teeth and a fourth tooth part module, wherein the fourth tooth part meshes with the second differential planetary gear, especially its fifth tooth part. The fourth tooth part includes (a plurality of) fourth teeth having a corresponding fourth tooth height, and preferably the fourth tooth height of (the plurality of fourth teeth) is equal. In order to achieve a structure that is particularly space-saving and lightweight, it has proven to be advantageous if the third number of teeth and the fourth number of teeth are different from each other, if the third tooth part module and the fourth tooth part module are the same, and if the corresponding third tooth height and the corresponding fourth tooth height are the same.

[0030] In the context of the present disclosure, ordinal numbers, also referred to as ordinal words, such as "first", "first", "second", "second", etc. do not necessarily serve to indicate or imply the quantity or number of elements to which the ordinal number refers, but rather serve to be able to unambiguously reference the element or term to which the ordinal number is assigned or to which the ordinal number refers.

[0031] In order to be able to keep the structural space requirements, costs and weight particularly low, in a further design variant of the invention, it is provided that all tooth parts of the spur gear differential are straight teeth and are thus designed or configured as straight teeth.

[0032] In order to be able to achieve a particularly high torque density in a particularly space-saving manner, in a further design variant of the invention, it is provided that a planetary gear set is provided in the transmission device - in particular in addition to the spur gear differential - which has at least one stepped planet gear provided in addition to the differential stepped planet gear, in particular in addition to the second differential planet gear, and preferably also in addition to the sun gear, and which is in particular rotatably held on the planet carrier relative to the planet carrier about a second planetary rotation axis, the stepped planet gear having a first planet gear and a second planet gear. The second planet gear is also referred to as the third stepped planet gear, and the second planet gear is also referred to as the fourth stepped planet gear. The third stepped planet gear and the fourth stepped planet gear are preferably spur gears. The third stepped planet gear and the fourth stepped planet gear are torsionally connected to each other. It is conceivable that the third stepped planet gear and the fourth stepped planet gear are integrally formed with each other and are thus formed from a single piece, or that the third stepped planet gear and the fourth stepped planet gear are formed separately from each other and are torsionally connected to each other.

[0033] In addition to the first sun gear and the second sun gear, and preferably also in addition to the differential stepped planet gear and also preferably in addition to the second differential planet gear and also preferably in addition to the stepped planet gear, the planetary transmission further has a third sun gear, which is a drive sun gear or also referred to as a drive sun gear. The third sun gear is preferably a spur gear. One planet gear of the stepped planet gear of the planetary transmission meshes, and thus meshes with the drive sun gear. Preferably, the first planet gear and the second planet gear, and thus the third stepped planet and the fourth stepped planet, have different sizes, in particular different rolling circle diameters and / or different pitch circle diameters from each other, such that for example the first planet gear has a fifth rolling circle diameter and / or a fifth pitch circle diameter, and such that for example the second planet gear has a sixth rolling circle diameter and / or a sixth pitch circle diameter. In this case, it is conceivable that the fifth rolling circle diameter and the sixth rolling circle diameter are different from each other. In particular, it is conceivable that the fifth pitch circle diameter and the sixth pitch circle diameter are different from each other. Thus, for example, the fifth rolling circle diameter or the fifth pitch circle diameter is greater than the sixth rolling circle diameter or the sixth pitch circle diameter. For example, one planet gear has a fifth rolling circle diameter or a fifth pitch circle diameter such that for example another planet gear of the stepped planet gear of the planetary transmission has a sixth rolling circle diameter or a sixth pitch circle diameter. Thus, one planet gear is preferably larger than another planet gear. In other words, preferably, one planet gear is the larger one among the planet gears, such that the other planet gear is the smaller one among the planet gears. Very preferably, the first planet gear is the said one planet gear, and very preferably, the other planet gear is the second planet gear. Thus, preferably, the larger planet gear of the stepped planet gear of the planetary transmission meshes with the drive sun gear.

[0034] The planetary transmission further has an annular gear, which is torsionally connected or connectable to the above-mentioned housing. In particular, the annular gear can be permanently torsionally connected to the housing. In particular, the annular gear is at least partially arranged in the housing. Another planet gear, in particular the smaller planet gear, meshes with the annular gear, and thus meshes into or engages with the annular gear. In particular, it is conceivable that the stepped planet gear of the planetary transmission, in particular permanently, is torsionally connected to the second differential planet gear, or that the stepped planet gear of the planetary transmission, in particular the rotation axis of the second planet gear, can rotate relative to the second differential planet gear. In particular, the stepped planet gear of the planetary transmission is coaxially arranged with the second differential planet gear. Thus, the stepped planet gear is preferably held on the planet carrier such that it can rotate relative to the planet carrier about the second planet rotation axis.

[0035] For achieving a particularly compact and lightweight structure, it has proven to be particularly advantageous if the second differential planetary gear adjoins the ring gear, a planetary gear of the planetary gear transmission, and another planetary gear meshing with the ring gear in a direction extending axially along the second differential planetary gear and thus parallel to or coinciding with the second planetary rotation axis, wherein, in the same direction, the ring gear and the other planetary gear of the planetary transmission adjoin the one planetary gear of the planetary transmission meshing with the drive sun gear, whereby, when viewed axially of the second differential planetary gear and thus along the second planetary rotation axis, the ring gear and the other planetary gear of the planetary transmission are arranged between the second differential planetary gear of the spur gear differential and the one planetary gear of the planetary transmission meshing with the drive sun gear. Thus, in particular in the axial direction of the transmission, a particularly compact structure can be presented.

[0036] Another design of the present invention is characterized in that the first rolling circle diameter of the first sun gear is greater than the second rolling circle diameter of the second sun gear, the second sun gear adjoins the first sun gear in an arrangement direction extending axially along the sun gear, wherein the first sun gear adjoins the third sun gear in the same arrangement direction. As a result, when viewed axially along the sun gear, the first sun gear is arranged between the second sun gear and the third sun gear, and thus when viewed along the corresponding sun gear rotation axis, as a result, in particular in the axial direction, the transmission can have a particularly compact structure.

[0037] In order to be able to maintain a particularly low structural space requirement, in another design of the present invention, in the axial direction of the planetary transmission and the spur gear differential and thus when viewed along the corresponding sun gear rotation axis, the planetary carrier walls of the planetary carrier are only located on the outside, bolts are fixed to the planetary carrier walls, in particular torsion-resistant, and the differential stepped planetary gear of the spur gear differential, the second differential planetary gear of the spur gear differential, and preferably the stepped planetary gear of the planetary transmission are rotatably held on the bolts, so as to be connected to the ring gear, the second differential planetary gear of the spur gear differential, the differential stepped planetary gear of the spur gear differential, and the sun gear of the spur gear differential on both sides, and preferably connected to the stepped planetary gear of the planetary transmission, such that the planetary carrier walls opposite each other in particular in the axial direction of the planetary carrier are arranged outside the planetary transmission and outside the spur gear differential when viewed in the axial direction of the transmission and thus along the corresponding sun gear rotation axis.

[0038] Furthermore, it has proven to be particularly advantageous if the first differential planetary gear is arranged in phase with the stepped planetary gear.

[0039] In a further design of the present invention, particularly in order to be able to maintain an especially low axial structural space requirement, when observed in the axial direction of the second differential planetary gear and thus along the second planetary rotation axis, the smaller planetary gears of the planetary transmission are arranged between the larger planetary gears of the planetary transmission and the second differential planetary gear of the spur gear differential, or preferably, axially to the second differential planetary gear of the spur gear differential, and thus when observed along the second planetary rotation axis, the larger planetary gears of the planetary transmission are arranged between the smaller planetary gears of the planetary transmission and the second differential planetary gear of the spur gear differential.

[0040] The second aspect of the present invention relates to a motor vehicle, also simply referred to as a vehicle, which is preferably configured as an automobile, particularly a passenger car. The motor vehicle according to the second aspect of the present invention has a transmission according to the first aspect of the present invention. The advantages and advantageous designs of the first aspect of the present invention should be regarded as the advantages and advantageous designs of the second aspect of the present invention, and vice versa.

[0041] Other advantages, features, and details of the present invention will become apparent from the following description of the preferred embodiments and with reference to the drawings. Without departing from the scope of the present invention, the above-mentioned features and combinations of features mentioned in the description, as well as the features and combinations of features mentioned in the description of the drawings and / or shown individually in the drawings, can be used not only in the respective combinations but also in other combinations or individually. Description of the Drawings

[0042] In the drawings:

[0043] Figure 1 A schematic front view of a first embodiment of a transmission for a motor vehicle is shown;

[0044] Figure 2 A schematic side view of the first embodiment of the transmission is shown;

[0045] Figure 3 A schematic side view of a second embodiment of the transmission is shown;

[0046] Figure 4 A schematic front view of a first embodiment of the differential stepped planetary gear of the spur gear differential of the transmission is shown;

[0047] Figure 5 A second embodiment of the differential stepped planetary gear is shown;

[0048] Figure 6 A schematic front view of a third embodiment of the transmission is shown;

[0049] Figure 7Shows a schematic side view of a third embodiment of a transmission;

[0050] Figure 8 Shows a schematic front view of a fourth embodiment of a transmission;

[0051] Figure 9 Shows a schematic side view of a fourth embodiment of a transmission;

[0052] Figure 10 Shows a part of a schematic longitudinal sectional view of a third embodiment of a differential stepped planetary gear;

[0053] Figure 11 Shows a part of a schematic longitudinal sectional view of a fourth embodiment of a differential stepped planetary gear; and

[0054] Figure 12 Shows a part of a schematic longitudinal sectional view of a fifth embodiment of a differential stepped planetary gear.

[0055] In the figures, identical or functionally identical elements with the same reference numerals. Detailed Description

[0056] Figure 1 and Figure 2 The first embodiment of a transmission 10 for a motor vehicle is shown respectively in a schematic front view or a schematic and sectional side view. The motor vehicle is preferably configured as an automobile, in particular a passenger car, also simply referred to as a vehicle. In its fully manufactured state, the motor vehicle has, for example, at least or exactly two axles, which are arranged one after another in the vehicle longitudinal direction, also simply referred to as axles. The corresponding axles each have at least two or exactly two wheels, which are also simply referred to as wheels. The corresponding wheels of the corresponding axles are arranged on opposite sides of the motor vehicle in the vehicle transverse direction. The wheels are ground contact elements through which the motor vehicle can be supported or supported on the ground in the vehicle vertical direction of the motor vehicle. For example, the motor vehicle has at least one drive motor by means of which the wheels of at least one or exactly one axle can be driven via the transmission 10, whereby the motor vehicle can be driven as a whole. In particular, the drive motor can be an internal combustion engine or an electric motor, such that the motor vehicle is configured, for example, as a hybrid vehicle or an electric vehicle, in particular a battery electric vehicle (BEV). The wheels that can be driven by the transmission 10 are also referred to as drive wheels. Hereinafter, when referring to wheels or vehicle wheels, unless otherwise specified, it is understood to refer to the drive wheels of the motor vehicle.

[0057] The transmission device 10 has a spur gear differential 12, also known as a spur gear differential drive. The spur gear differential 12 is a differential configured as a spur gear differential drive, also simply referred to as a differential drive. In particular, the spur gear differential 12 is configured as a planetary differential. The spur gear differential 12 has a first sun gear 14, also known as the first sun gear. The first sun gear 14 is configured as the first driven member of the spur gear differential 12. In addition, the first sun gear 14 is configured as a first spur gear. In other words, the sun gear 14 is the first gear configured as a spur gear. The first sun gear 14 has a first rolling circle diameter. The spur gear differential 12 also has a second sun gear 16, which is configured as the second driven member of the spur gear differential 12. The second sun gear 16 is configured as a second spur gear. In other words, the second sun gear 16 is the second gear configured as a spur gear. From Figure 1 and Figure 2 it can be seen particularly clearly that the sun gears 14 and 16 are arranged coaxially relative to each other. The transmission device 10 has a housing 18, which is shown particularly schematically in Figure 1 and in which the spur gear differential 12 is at least partially arranged. The sun gears 14 and 16 can rotate relative to the housing 18 about a sun gear rotation axis common to the sun gears 14 and 16. The sun gear rotation axis 20 is also simply referred to as the rotation axis, wherein the rotation axis extends axially in the transmission device 10, and thus axially in the spur gear differential 12, particularly axially in the transmission device 10, and thus coincides axially in the spur gear differential 12. In particular, the axial direction of the transmission device 10 coincides with the axial direction of the spur gear differential 12, and the radial direction of the spur gear differential coincides with the radial direction of the transmission device 10. The second sun gear 16 is configured as the second driven member of the spur gear differential 12. The spur gear differential 12 can provide an output torque through its driven members, and thus through the sun gears 4 and 16, by means of which the drive wheels can be driven. In particular, the respective output torques provided or provided by the respective sun gears 14, 16 are generated by the drive torque that can be or is introduced into the spur gear differential 12. For example, the drive torque can be provided by a drive motor, or the drive torque is generated by another torque provided by a drive motor. In particular, the drive torque can be divided and distributed to the wheels by means of the spur gear differential 12, particularly in half. From Figure 2It can be seen that the first shaft configured as the first side shaft 22 can be driven by the first sun gear 14, and the second shaft configured as the second side shaft 24 can be driven by the sun gear 16. Among them, the first driving wheel can be driven by the side shaft 22, and the second driving wheel can be driven by the side shaft 24. In particular, in this case, the first sun gear 14, especially permanently, is torsionally resistant to the first side shaft 22, and alternatively or additionally, the second sun gear 16, especially permanently, is torsionally connected to the second side shaft 24. The second sun gear 16 has a second rolling circle diameter different from the first rolling circle diameter, where the second rolling circle diameter is smaller than the first rolling circle diameter. The second sun gear 16 is also referred to as the second sun gear, the small sun gear, or the smaller sun gear, and the sun gear 14 is also referred to as the first sun gear, the larger sun gear, or the large sun gear.

[0058] The spur gear differential 12 also has a planetary gear set 26. Through this planetary gear set 26, the sun gears 14 and 16 are coupled to each other in such a way that the sun gears 14 and 26 can rotate relative to the housing 18 in opposite directions, especially around the axis of rotation. The planetary gear set 26 has a planet carrier 28, which is also called a web and is coaxially arranged with the sun gears 14 and 16 in this example. The planet carrier 28 can rotate relative to the housing 18 around the axis of rotation (the sun gear axis of rotation 20). In addition, the planetary gear set 26 has a first differential planetary gear 30. In particular, the planetary gear set 26 has at least one additional or multiple additional first differential planetary gears. Among them, the following and previous embodiments regarding the first differential planetary gear 30 can also be easily transferred to the corresponding additional first differential planetary gears, and vice versa. The first differential planetary gear 30 meshes with the first sun gear 14, thus engaging with the first sun gear 14 or meshing with the first sun gear 14. In addition, the first differential planetary gear 30 is rotatably held on the planet carrier 28 relative to the planet carrier 28 around the first planetary axis of rotation 32. In addition, the first differential planetary gear 30 has a third rolling circle diameter. In the first embodiment, the first differential planetary gear 30 is assigned a first bolt 34, which is also called the first planetary bolt. In particular, the first differential planetary gear 30 is rotatably arranged on the bolt 34 relative to the bolt 34 and relative to the planet carrier 28 around the first planetary axis of rotation 32, especially supported on the bolt 34, where, for example, the bolt 34 is fixed to the planet carrier 28, especially torsionally fixed.

[0059] The planetary gear set 26 also has at least one second differential planetary gear 36. In particular, it is conceivable that the planetary gear set 26 has at least one additional second differential planetary gear or a plurality of additional second differential planetary gears, wherein the explanations regarding the front and back of the second differential planetary gear 36 can also be easily transferred to another second differential planetary gear and vice versa. The second differential planetary gear 36 meshes with the second sun gear 16, as Figure 2 shown by the dashed arrow 38 in. In other words, the second differential planetary gear 36 engages with the sun gear 16, or the second differential planetary gear 36 meshes with the second sun gear 16. Thus, the dashed arrow 38 represents "engagement". The second differential planetary gear 36 is rotatably held on the planet carrier 28 relative to the planet carrier 28 about the second planetary rotation axis 40. As can be seen from Figure 2 it, the second planetary rotation axis 40 extends parallel to the first planetary rotation axis 32 and is spaced apart from the planetary rotation axis 32. Furthermore, the planetary rotation axes 32 and 40 extend parallel to the rotation axis (sun gear rotation axis 20), and the planetary rotation axes 32 and 40 are each spaced apart from the rotation axis. In the first embodiment, a second bolt 42 is assigned to the second differential planetary gear 36, which is also referred to as the second planetary bolt. The second differential planetary gear 36 is rotatably arranged on the second bolt 42 relative to the bolt 42 and relative to the planet carrier 28 about the second planetary rotation axis 40, in particular supported on the second bolt 42. For example, the second bolt 42 is in turn fixed to the planet carrier 28, in particular torsionally fixed to the planet carrier 28.

[0060] The planetary gear set 26 also has at least one coupling planetary gear 44. In particular, the planetary gear set 26, especially each first differential planetary gear, has a corresponding coupling planetary gear, such as the coupling planetary gear 44. The first differential planetary gear 30, the second differential planetary gear 36, and the coupling planetary gear 44 are configured as spur gears, and thus are gears configured as spur gears. The coupling planetary gear 44 is arranged coaxially with the first differential planetary gear 30 and is, in particular, permanently and torsionally rigidly connected to the first differential planetary gear 30. The coupling planetary gear 44 meshes with the second differential planetary gear 36, with the result that the differential planetary gears 30 and 36 are coupled to each other via the coupling planetary gear 44, in particular for torque transmission. The coupling planetary gear 44 has a fourth pitch circle diameter different from the third pitch circle diameter of the first differential planetary gear 30. Furthermore, the first differential planetary gear 30 and its assigned coupling planetary gear 44 form a differential stepped planetary gear 46, also referred to as a differential stepped planet. Thus, the planetary gear set 26 has a differential stepped planetary gear 46. In particular, for example, the planetary gear set 26 has at least one additional or a plurality of additional differential stepped planetary gears, where the statements made above and below with respect to the differential stepped planetary gear 46 can also be easily transferred to the corresponding other differential stepped planetary gear, and vice versa. The differential stepped planetary gear 46 is rotatably held on the planet carrier 28 relative to the planet carrier 28 about a first planetary rotation axis 32. In this example, this is achieved by the differential stepped planetary gear 46 being arranged rotatably about the first planetary rotation axis 32 relative to the bolt 34 and relative to the planet carrier 28 on the bolt 34, in particular being supported on the bolt 34, such that the coupling planetary gear 44 is also arranged rotatably about the first planetary rotation axis 32 relative to the bolt 34 and relative to the planet carrier 28 on the bolt 34, in particular being supported on the bolt 34. The first differential planetary gear 30 is the first stepped planetary gear of the differential stepped planetary gear 46, or is also referred to as the first stepped planetary gear of the differential stepped planetary gear 46. Thus, the coupling planetary gear 44 is the second stepped planetary gear of the differential stepped planetary gear 46, or the coupling planetary gear 44 is also referred to as the second stepped planetary gear of the differential stepped planetary gear 46. In the first embodiment, the fourth pitch circle diameter of the coupling planetary gear 44 is smaller than the third pitch circle diameter of the first differential stepped planetary gear 46, such that the coupling planetary gear 44 is also referred to as a small stepped planetary gear or a smaller stepped planetary gear or a small planet gear, and such that the first differential planetary gear 30 is also referred to as a large stepped planetary gear or a larger stepped planetary gear or a large planet gear.

[0061] In order to achieve a particularly compact and weight-reduced structure of the transmission 10 and a particularly high torque density, it is provided that a first ratio between a first rolling circle diameter and a second rolling circle diameter and a second ratio between a third rolling circle diameter and a fourth rolling circle diameter are equal. In this case, the first differential planetary gear 30, for example, has a first tooth part with a first number of teeth and a first tooth part module, which meshes with the first sun gear 14, and a first tooth with a corresponding first tooth height. For example, the coupling planetary gear 44 has a second tooth part with a second number of teeth and a second tooth part module, which meshes with the second differential planetary gear 36, and a second tooth with a corresponding second tooth height. Furthermore, preferably, the first number of teeth and the second number of teeth are the same, and the first tooth part module and the second tooth part module are different from each other, such that the corresponding first connection and the corresponding second connection are different from each other.

[0062] Figure 4 A first embodiment of the differential stepped planetary gear 46 is shown in a schematic front view. In Figure 4 this, the first tooth part of the first differential planetary gear 30 is denoted by 48, and its first tooth is denoted by 50. The second tooth part of the coupling planetary gear 44 is denoted by 52 in Figure 4 and its second tooth is denoted by 54. It can be seen that the first tooth part 48 also has a first clearance 56, which is also referred to as a first backlash. In the circumferential direction of the tooth part 48 extending around the planetary rotation axis 32 and the differential planetary gear 30, a respective one of the clearances 56 is arranged between two directly adjacent teeth 50. The tooth part 52 has a second clearance 58, also referred to as a second backlash. In the circumferential direction of the coupling planetary gear 44 and the tooth part 52 extending around the planetary rotation axis 32, one of the second clearances 58 is arranged between two directly adjacent teeth 54. The respective clearance 56 is also referred to as a first backlash, and the respective clearance 58 is also referred to as a second backlash. In Figure 4 the first embodiment of the differential stepped planetary gear 46 shown, the tooth parts 48 and 52 are rotationally oriented with respect to each other around the planetary rotation axis 32 such that the respective first clearance 56 is aligned with the respective second clearance 58 axially of the differential stepped planetary gear 46 and thus when viewed along the first planetary rotation axis 32.

[0063] In Figure 1 and Figure 2 the first embodiment of the transmission 10 shown, the first differential planetary gear 30 and the coupling planetary gear 44 are separated from each other and connected to each other. In this case, the first differential planetary gear 30 and the coupling planetary gear 44 are directly adjacent to each other axially of the differential stepped planetary gear 46 and thus, when viewed along the first planetary rotation axis 32, in particular adjacent, such that, for example, the first differential planetary gear 30 and the coupling planetary gear 44 are in direct contact with each other axially of the differential stepped planetary gear 46. Figure 3A second embodiment of the transmission 10 is shown in a schematic and sectional side view. Also in the second embodiment, for example, the first differential planetary gear 30 and the assigned coupling planetary gear 44 are separated from each other and are in particular permanently and torsionally rigidly connected to each other. However, contrary to the first embodiment, when viewed axially from the differential stepped planetary gear 46, thus along the first planetary rotation axis 32, an intermediate region 60 is arranged between the first differential planetary gear 30 and the associated coupling planetary gear 44, which intermediate region 60 is also designated as a transition region or can be configured as a transition region. For example, the first differential planetary gear 30, in particular its tooth section 48, has a first width extending axially of the differential stepped planetary gear 46, by means of which tooth section 48, for example, it meshes with the sun gear 14. For example, the coupling planetary gear 44, in particular its tooth section 52, has a second width extending axially of the differential stepped planetary gear 46, in particular a second tooth width, by means of which tooth section 52, for example, it meshes with the differential planetary gear 36. The first width is also designated, for example, as b1, and the second width is also designated, for example, as b2. Furthermore, it is conceivable that the intermediate region 60 has a third width extending axially of the differential stepped planetary gear 46, which third width is also designated as b3.

[0064] Figure 5 A second embodiment of the differential stepped planetary gear 46 is shown in a schematic front view. In the second embodiment, when viewed on the first planetary rotation axis 32 of the differential stepped planetary gear 46, the tooth sections 48 and 52 are rotationally oriented relative to each other such that when viewed axially of the differential stepped planetary gear 46, a first gap 56 of the first tooth section 48 of the first differential planetary gear 30 is aligned with a second tooth 54 of the second tooth section 52 of the coupling planetary gear 44, and when viewed axially of the differential stepped planetary gear 46, a first tooth 50 of the first tooth section 48 of the first differential planetary gear 30 is aligned with a second gap 58 of the second tooth section 52 of the coupling planetary gear 44. Optionally, it is conceivable that although in Figure 4 the first embodiment of the differential stepped planetary gear 46 shown, the tooth sections 48 and 52 are precisely aligned axially of the differential stepped planetary gear 46, so that the tooth 50 is precisely aligned with the tooth 54 axially of the differential stepped planetary gear 46 and the gap 56 is precisely aligned with the gap 58, but in Figure 5 the second embodiment of the differential stepped planetary gear 46 shown, the tooth sections 48 and 52 are not aligned, but are offset or rotationally offset by an angle V relative to each other in the circumferential direction of the first planetary rotation axis 32 of the differential stepped planetary gear 46, such that, for example, at least a corresponding partial region of the tooth 50 and the gap 58 and at least a corresponding partial region of the gap 56 and the tooth 54, when viewed in the circumferential direction of the differential stepped planetary gear 46, the tooth 50 and the tooth 54 are at the same height or in the same rotational direction.

[0065] Preferably, in Figure 3 the second embodiment of the transmission 10 shown, the third width b3 of the intermediate region 60 is smaller than the first width b1 of the first stepped planet and smaller than the second width b2 of the second stepped planet. It is conceivable that the first width and the second width are the same, or that the first width and the second width can be different from each other.

[0066] Preferably, the first sun gear 14 has a third number of teeth and a third tooth module, has a third tooth engaging with the first differential planet gear 30, in particular its first tooth part 48, and has a third tooth with a corresponding third tooth height. The second sun gear 16 has, for example, a fourth number of teeth and a fourth tooth module, has a fourth tooth engaging with the second differential planet gear 36, in particular its fifth tooth part, and has a fourth tooth with a corresponding fourth tooth height. Preferably, the third number of teeth and the fourth number of teeth are different from each other, and the third tooth module and the fourth tooth module are preferably the same, such that the corresponding third tooth height and the corresponding fourth tooth height are preferably the same. Thus, preferably, all tooth parts of the spur gear differential 12 are straight teeth.

[0067] Figure 6 and 7 The third embodiment of the transmission 10 is shown in a schematic front view or a schematic and sectional side view, respectively. In the third embodiment, in addition to the spur gear differential 12, the transmission 10 further has a planetary gear drive 62, which will be explained in more detail below. In addition to one differential stepped planet gear 46, or in addition to a plurality of differential stepped planet gears 46, the planetary gear drive 62 has at least one stepped planet gear 64, and the stepped planet gear 64 is rotatably held on the planet carrier 28 relative to the planet carrier 28 about the second planetary rotation axis 40. In the third embodiment, the stepped planet gear 64 is rotatably arranged on the second bolt 42 relative to the bolt 42 and relative to the planet carrier 28, in particular supported on the second bolt 42. Thus, in the third embodiment, the stepped planet gear 64 is coaxially arranged with the second differential planet gear 36. In particular, the second differential planet gear 36 and the stepped planet gear 64 can rotate relative to each other about the second planetary rotation axis 40. For example, the planetary gear drive 62 can have at least one additional or a plurality of additional stepped planet gears, wherein the statements regarding the front and the back of the stepped planet gear 64 can be easily transferred to the corresponding further stepped planet gears, and vice versa. In particular, a corresponding stepped planet gear 64 is provided for each second differential planet gear 36.

[0068] The stepped planetary gear 64 has a first planetary gear 66 and a second planetary gear 68, wherein the planetary gears 66 and 68 are, in particular, permanently and torsionally rigidly connected to each other. The planetary gears 66 and 68 are spur gears. Thus, the planetary gears 66 and 68 are gears configured as spur gears. The planetary gears 66 and 68 are also preferably straight-toothed. The planetary gear 66 is also referred to as the third stepped planetary gear, and the planetary gear 68 is also referred to as the fourth stepped planetary gear. It can be seen that the planetary gears 66 and 68 have different sizes and thus have different rolling circle diameters and / or different pitch circle diameters. In this case, the planetary gear 66 has a fifth rolling circle diameter, and the planetary gear 68 has a sixth rolling circle diameter that is smaller than the fifth rolling circle diameter. Thus, the planetary gear 66 is also referred to as the large planetary gear or the larger planetary gear, and the planetary gear 68 is also referred to as the small planetary gear or the smaller planetary gear.

[0069] The planetary transmission 62 also has a third sun gear 70, which is arranged outside the first sun gear 14 and the second sun gear 16 and is also referred to as the drive sun gear or the drive sun. Preferably, the third sun gear 70 is also a spur gear and preferably has straight teeth. It can be seen that the large planetary gear, and thus in this case the planetary gear 66, meshes with the third sun gear 70. In other words, the large planetary gear meshes with the third sun gear 70. The planetary transmission 62 also has an annular gear 72, which, in the third embodiment, is in particular permanently and torsionally rigidly connected to the housing 18. In an alternative embodiment, it is conceivable to provide a shift element that can be switched between a coupled state and a decoupled state. For example, in the coupled state, the annular gear 72 is torsionally rigidly connected to the housing 18 by means of the shift element. In the decoupled state, for example, the shift element releases the annular gear 72 to rotate relative to the housing 18 about the axis of rotation (sun gear axis of rotation 20), such that the annular gear 72 can rotate relative to the housing 18 about the axis of rotation in the decoupled state. Thus, in the third embodiment, the planetary transmission 62 is coaxially arranged with the spur gear differential 12. In this case, the sun gear 70 is coaxially arranged with the sun gears 14 and 16 and can thus rotate relative to the housing 18 about the sun gear axis of rotation 20. Furthermore, it can be seen that the planet carrier 28 is a common planet carrier for the spur gear differential 12 and the planetary transmission 62, and the stepped planetary gear 64 is also held on the planet carrier in order to rotate about the second planetary axis of rotation 40. It can be seen that the small planetary gear, and thus in this case the planetary gear 68, meshes with the annular gear 72.

[0070] For example, the sun gear 70 can be driven by a drive motor so that the aforementioned drive torque can be provided, for example, via the planetary gear transmission 62 and introduced into the spur gear differential 12 via the planetary gear transmission 62, thereby driving the planet carrier 28 and thus driving the spur gear differential 12. Therefore, the planet carrier 28 is preferably configured as a driver of the spur gear differential 12, and the aforementioned drive torque of the spur gear differential 12 can be introduced through this driver.

[0071] In Figure 3 , the dashed arrow 74 represents "meshing", such that the dashed arrow 74 shows the sun gear 70 engaging with the large planet gear (planet gear 66) and thus meshing with the large planet gear.

[0072] In order to achieve a particularly compact structure, especially in the axial direction of the transmission 10, thus when viewed along the sun gear rotation axis 20, in the third embodiment, the second differential planet gear 36 abuts against the ring gear 72 and the planet gear 68 meshing with the ring gear 72 in a direction extending axially along the second differential planet gear 36 and thus parallel to or coinciding with the second planet rotation axis 40, as Figure 7 shown by the arrow 76 therein, wherein the ring gear 72 and the planet gear 68 meshing therewith abut against the planet gear 66 in the direction shown by the arrow 76, whereby the ring gear 72 and the planet gear 68 are arranged between the second differential planet gear 36 and the planet gear 66 in the axial direction of the second differential planet gear 36 and in this example also in the axial direction of the stepped planet gear 64 and thus when viewed along the second planet rotation axis 40.

[0073] Similar to the first and second embodiments of the transmission 10, in the third embodiment of the transmission 10, the first rolling circle diameter of the first sun gear 14 is also greater than the second rolling circle diameter of the second sun gear 16. In the second embodiment, the second sun gear 16 abuts against the sun gear 14 in the arrangement direction, which extends in the axial direction of the sun gears 14 and 16 and thus extends parallel to or coincides with the sun gear rotation axis 20, as Figure 3 shown by the arrow 78 therein, wherein, in this example, the arrangement direction shown by the arrow 78 corresponds to the direction shown by the arrow 76. The first sun gear 14 abuts against the third sun gear 70 in the arrangement direction (arrow 78), whereby the first sun gear 14 is arranged in the axial direction of the sun gears 14, 16, and 70, and thus when viewed along the sun gear rotation axis 20, the first sun gear 14 is arranged between the second sun gear 16 and the third sun gear 70.

[0074] It is also provided that, when viewed axially from the planetary gear unit 62 and the spur gear differential 12 and thus along the sun gear rotation axis 20, the planet carrier walls 80 and 82 of the planet carrier 28 are only located externally, and the bolts 34 and 42 are fixed to the planet carrier walls 80 and 82, in particular torsion-resistant, and thus abut the ring gear 72, the stepped planet gear 64, the second differential planet gear 36, the differential stepped planet gear 46 and the sun gears 14, 16 and 70 on both sides, and are thus arranged externally to the planetary gear unit 62 and the spur gear differential 12.

[0075] Figure 8 and 9 The fourth embodiment of the transmission 10 is shown in a schematic front view or a schematic and sectional side view, respectively. As in the third embodiment, the small planet gears (planet gears 68) mesh with the ring gear 72, and the large planet gears (planet gears 66) mesh with the third sun gear 70. However, in the fourth embodiment, when viewed axially from the second differential planet gear 36 and the stepped planet gear 64, the large planet gear (planet gear 66) is arranged between the second differential planet gear 36 and the small planet gear (planet gear 68), such that when viewed axially from the stepped planet gear 64 and the second differential planet gear 36, the planet gear 66 is arranged between the second differential planet gear 36 and the ring gear 72.

[0076] Figure 3 The third embodiment of the differential stepped planet gear 46 is shown. In the third embodiment, the differential planet gear 30 and the associated coupling planet gear 44 are constructed separately from each other and are torsion-resistantly connected to each other. In this case, the coupling planet gear 44 has a projection 84, which is formed in this example as a collar of the coupling planet gear 44 or is formed by the collar of the coupling planet gear 44. In this case, the differential planet gear 30 is arranged on the projection 84 and is in particular permanently, torsion-resistantly connected to the projection 84, whereby the differential planet gear 30 is in particular permanently, torsion-resistantly connected to the coupling planet gear 44. In this case, the differential planet gear 30 has a hub 36, and the projection 84 is arranged in the hub 36. Thus, the differential planet gear 30 is connected to the projection 84, and thus to the coupling planet gear 44, in particular permanently, torsion-resistantly via its hub 86.

[0077] Figure 11 The fourth embodiment of the differential stepped planet gear 46 is shown. In the fourth embodiment of the differential stepped planet gear 46, the first differential planet gear 30 and the associated coupling planet gear 44 are formed as one piece with each other, and are thus, in particular, permanently, torsion-resistantly connected to each other. In Figure 11 which, a region is denoted by B. From Figure 11It can be seen that the radial outer contour 88 of the differential stepped planetary gear 46 does not drop below the first addendum circle diameter k1 of the second tooth part 52 in the transition region (intermediate region 60), but rather rises from the first addendum circle diameter k1 to the second addendum circle diameter k2 of the first tooth part 48, in particular at least substantially continuously. In particular, the machining, in particular the manufacturing, of the tooth part 52 and / or the tooth part 48 is carried out, for example, in region B, in particular by means of a tooth part tool, such that region B is, for example, a tool exit region.

[0078] Figure 12 A fifth embodiment of the differential stepped planetary gear 46 is shown. From Figure 12 It can be seen that in the fifth embodiment, the intermediate region 60 (transition region) has no tooth part.

[0079] It can be seen that the spur gear differential 12 particularly includes a planet carrier 28 and two sun gears 14 and 16 of different sizes, which simultaneously represent the two output parts of the spur gear differential 12 and are also referred to as driven parts. In addition, the spur gear differential 12 includes differential stepped planet gears 46 or preferably includes a set of identical differential stepped planet gears 46, wherein the set includes at least two or more identical differential stepped planet gears 46. The differential stepped planet gears 46 are preferably arranged to be evenly distributed in the circumferential direction extending around the sun gear rotation axis 20 of the spur gear differential 12, particularly on the respective circumferences of the corresponding sun gears 14, 16. In addition, the spur gear differential 12 includes second differential planet gears 36 or preferably includes a set of identical differential planet gears 36, wherein, preferably, a plurality of differential planet gears 36 are arranged to be evenly distributed in the circumferential direction extending around the sun gear rotation axis 20 of the spur gear differential 12. In particular, a corresponding second differential planet gear 36 is provided for each differential stepped planet gear 46. The differential stepped planet gears 46 and the second differential planet gears 36 are rotatably supported on their respective associated bolts 34 and 42. For example, rolling bearings and / or sliding bearings can be used for this purpose. The bolts 34 and 42 are fixed to the planet carrier 28, particularly in the planet carrier 28, particularly torsionally resistant. The planet carrier 28 can be one or more parts and is thus designed as one or more parts. The planet carrier 28 is mounted, for example, directly or indirectly relative to the single-piece or multi-piece housing 18, particularly rotatably supported, and the single-piece or multi-piece housing is configured, for example, as a gearbox or a drive housing. For example, the direct support between the planet carrier 28 and the housing is achieved by at least or exactly two bearings, which are configured, for example, as sliding bearings or rolling bearings, particularly in such a way that the planet carrier 28 is rotatably supported on the housing 18 by means of the bearings, particularly in such a way that the planet carrier 28 can rotate relative to the housing 18 about the rotation axis. The second differential planet gears 36 engage with the second smaller sun gear 16 and a coupling planet gear 44 that is smaller than the first differential planet gear 30, particularly directly in each case, and preferably do not engage with any other gears. The first differential planet gear 30 engages, for example, specifically with the first larger sun gear 14. In order to apply the same torque to the two sun gears 14 and 16, so that the driving torque can be strongly and thus evenly distributed on the sun gears 14 and 26 and the side shafts 22, 24, the ratio between the rolling circle diameters of the sun gears 14 and 16 and the stepped planets (differential planet gears 30 and coupling planet gear 44) of the differential stepped planet gears 46 is the same, such that:

[0080] WS1 / WS2 = WSP1 / WSP2

[0081] Here, WS1 represents the first rolling circle diameter of the first sun gear 14, WS2 represents the second rolling circle diameter of the second sun gear 16, WSP1 represents the third rolling circle diameter of the first differential planetary gear 30, and WSP2 represents the fourth rolling circle diameter of the coupling planetary gear 44. As described above, the first rolling circle diameter is greater than the second rolling circle diameter, and the third rolling circle diameter is greater than the fourth rolling circle diameter.

[0082] All tooth portions of the spur gear can be straight teeth or helical teeth. Straight teeth are preferred. As Figure 4 shown, if the tooth portions 48 and 52 are rotationally oriented relative to each other such that tooth 50 is precisely aligned with tooth 54, such that gap 56 is precisely located over gap 58, and tooth 50 is precisely located on tooth 54, then the tool exit of the tooth tool for manufacturing the smaller tooth portion 52 can, for example, project into the gap of the larger tooth portion 48 without removing material in the region of the larger tooth portion 48. The reference numeral 90 denotes a journal, by means of which the particularly wide bearing base of the stepped planetary gear 64 can be shown.

[0083] In this way, the unusable intermediate region 60 between the tooth portions 48 and 50 can be kept small or short axially in the differential stepped planetary gear 46. The smaller the difference between the third rolling circle diameter and the fourth rolling circle diameter, the more advantageously the intermediate region 60 that cannot be used for the tooth portions also becomes smaller or shorter.

[0084] If the differential planetary gear 30 and the associated coupling planetary gear 44 are constructed separately from each other and are torsionally connected to each other, the torsional connection between the differential planetary gear 30 and the associated coupling planetary gear 44 can be achieved by press fit, inserted tooth portions, weld seams, combinations of these connections, or other means. An advantage here is that the differential planetary gear 30 and the associated coupling planetary gear 44 can be directly adjacent axially, i.e., without an intermediate region 60, with the result that a particularly short axial structure can be presented.

[0085] However, the intermediate region 60 with a width of B3 is preferably arranged between the differential planetary gear 30 and the coupling planetary gear 44, and thus between the tooth portions 48 and 52. In the intermediate region 60, for example, it is the tool outlet of the tooth portion tool for manufacturing the tooth portion 52 of the coupling planetary gear 44. The tooth portion tool, also simply called the tool, even enters the region of the tooth portion 48 of the differential planetary gear 30, but only enters the gap 56 of the tooth portion 48, so that the tooth portion 48 will not be damaged, machined or otherwise impaired by the tooth portion tool for manufacturing the tooth portion 52. In the intermediate region 60, the teeth 54 of the tooth portion 52 grow from the second rolling circle diameter or the addendum circle diameter k1 to the first rolling circle diameter or the addendum circle diameter k2. Therefore, the radial outer contour 88 of the differential stepped planetary gear 46 in the intermediate region 60 is not smaller than the addendum circle diameter k1 of the coupling planetary gear 44 of the first differential planetary gear 30. Preferably, the difference between the first rolling circle diameter of the differential planetary gear 30 and the second rolling circle diameter of the coupling planetary gear 44 is selected to be as small as possible, because the width b3 of the intermediate region 60 can thus be kept small. The advantages of this design are especially that:

[0086] The differential stepped planetary gear 46 can be designed as an integral or single-piece, and as a result, the cost can be kept particularly low.

[0087] By immersing the tooth portion tool for manufacturing the tooth portion 52 into the tooth portion 48, the width b3 can be kept small, which represents the distance between the differential planetary gear 30 and the coupling planetary gear 44 extending in the axial direction of the differential stepped planetary gear 46.

[0088] - The tooth root strength is higher than that of the saw teeth.

[0089] Finally, as Figure 12 shown, in the fifth embodiment, it can be imagined that an intermediate region 60 with a width of b3 exists between the two tooth portions 48 and 52, or between the differential planetary gear 30 and the associated coupling planetary gear 44, when observed in the axial direction of the differential stepped planetary gear 46, wherein, in Figure 12 the fifth embodiment shown, within the intermediate region 60, the outer diameter of the differential stepped planetary gear 46 is significantly smaller than the addendum circle diameter k1 of the tooth 54 or the tooth portion 52, which is smaller compared to the addendum circle diameter k2 of the tooth 50 or the tooth portion 48. The outer diameter is denoted by a in Figure 12 . In this intermediate region 60, the outer diameter a can even be designed to be equal to or smaller than the root circle diameter of the tooth portion 52. It can be imagined, for example, that the tooth portion tool for manufacturing the tooth portion 52 does not enter the region or gap 56 of the tooth portion 48. In this case, it is advantageous not to axially align the teeth 50 and 54 of the tooth portions 48 and 52, but as Figure 5As shown, the tooth portions 48 and 52 are rotated relative to each other about the planetary rotation axis 32. This rotational alignment or rotation of the tooth portions 48 and 52 can be freely selected at least, but for all differential stepped planetary gears 46, they should have the same dimensions so that the advantageous assembly ability of the spur gear differential 12 can be demonstrated. Therefore, in this specific embodiment, the tooth portions 52 and 48 do not necessarily have the same number of teeth. The disadvantage of doing so may be the large width b3 between the tooth portions 48 and 52. However, this can be classified as acceptable. The resulting benefits may be:

[0090] Integral or one-piece design

[0091] Simple manufacturing process

[0092] It is conceivable that the number of teeth in the tooth portions 48 and 52 is the same. For example, as provided by the first embodiment shown, the teeth 50 and 54 of the two tooth portions 48 and 52 are axially aligned in the differential stepped planetary gear 46. As an alternative, it is conceivable that, as shown, when viewed in the circumferential direction of the differential stepped planetary gear 46, the tooth portions 48 and 52 are rotationally arranged relative to each other instead of being aligned relative to each other. Figure 4 As provided by the first embodiment shown, the teeth 50 and 54 of the two tooth portions 48 and 52 are axially aligned in the differential stepped planetary gear 46. As an alternative, it is conceivable that, as shown, when viewed in the circumferential direction of the differential stepped planetary gear 46, the tooth portions 48 and 52 are rotationally arranged relative to each other instead of being aligned relative to each other. Figure 5 As shown, when viewed in the circumferential direction of the differential stepped planetary gear 46, the tooth portions 48 and 52 are rotationally arranged relative to each other instead of being aligned relative to each other.

[0093] In particular, the transmission 10 can achieve the following advantages:

[0094] In a conventional bevel gear differential, during torque transmission, high axial expansion forces are generated between the bevel gears, and these forces must be absorbed by a solid housing usually made of gray cast iron. In the case of the transmission 10, significantly less axial force is advantageously generated in the housing 18. Thus, the structural space requirement in the axial direction can be kept particularly low, and the planet carrier 28 can be designed to be much lighter than the gray cast iron housing of the bevel differential.

[0095] In a conventional solution, the disadvantage may be that a significant axial gap must exist between the two sun gears 14 and 26, in which two wide planetary gears engage with each other,

[0096] without engaging with the tooth portion of one of the two suns in this area. In contrast, in the case of the transmission 10, the axial structural space requirement can be kept particularly low, and the weight and material cost can be kept particularly low.

[0097] The above problems can be solved, for example, by using at least partially teeth with extreme profile shifts. However, this may be disadvantageous for the operating strength and specific load-carrying capacity of the affected profile-shifted gears and must be compensated for by a significant widening of the profile-shifted tooth flanks. In addition, extreme profile shifts have an adverse effect on the rolling behavior and thus on the noise radiation of the profile-shifted tooth flanks. These disadvantages and problems can be avoided in the transmission 10. As a result, a smaller axial structural space requirement, a lighter weight, and lower material costs can be achieved. In addition, at relative rotational speeds, lower mechanical excitation (noise radiation) can be exhibited within the tooth flanks.

[0098] List of Reference Signs

[0099] 10 Transmission

[0100] 12 Spur gear differential

[0101] 14 First sun gear

[0102] 16 Second sun gear

[0103] 18 Housing

[0104] 20 Sun gear axis of rotation

[0105] 22 First side shaft

[0106] 24 Second side shaft

[0107] 26 Planetary gear set

[0108] 28 Planet carrier

[0109] 30 First differential planetary gear

[0110] 32 First planetary axis of rotation

[0111] 34 Bolt

[0112] 36 Second differential planetary gear

[0113] 38 Dashed arrow

[0114] 40 Second planetary axis of rotation

[0115] 42 Bolt

[0116] 44 Coupling planetary gear

[0117] 46 Differential stepped planetary gear

[0118] 48 First tooth flank

[0119] 50 First tooth

[0120] 52 Second tooth part

[0121] 54 Second tooth

[0122] 56 First gap

[0123] 58 Second gap

[0124] 60 Intermediate region

[0125] 62 Planetary drive

[0126] 64 Step planetary gear

[0127] 66 First planetary gear

[0128] 68 Second planetary gear

[0129] 70 Third sun gear

[0130] 72 Ring gear

[0131] 74 Dotted arrow

[0132] 76 Arrow

[0133] 78 Arrow

[0134] 80 Planet carrier wall

[0135] 82 Planet carrier wall

[0136] 84 Protrusion

[0137] 86 Hub

[0138] 88 Outer contour

[0139] 90 Journal

[0140] b1 First width

[0141] b2 Second width

[0142] b3 Third width

[0143] B Region

[0144] V Offset angle

[0145] a Outer diameter

[0146] k1 First addendum circle diameter

[0147] k2 Second addendum circle diameter

Claims

1. A transmission device (10) for a motor vehicle, the transmission device having a spur gear differential (12), the spur gear differential comprising: a first sun gear (14), the first sun gear being configured as a first driven member and a first spur gear of the spur gear differential (12), and having a first pitch circle diameter; - a second sun gear (16) coaxially arranged with the first sun gear (14), the second sun gear being configured as a second driven member - and a second spur gear of the spur gear differential (12), and having a second pitch circle diameter different from the first pitch circle diameter; and at least one planetary gear set (26), by means of which the sun gears (14, 16) are coupled to each other in such a way that the sun gears (14, 16) can rotate in opposite directions, wherein the planetary gear set (26) comprises: ○ a planet carrier (28); ○ at least one first differential planetary gear (30), the at least one first differential planetary gear meshing with the first sun gear (14), having a third pitch circle diameter, and being rotatably held on the planet carrier (28) relative to the planet carrier (28) about a first planetary rotation axis (32); ○ at least one second differential planetary gear (36), the at least one second differential planetary gear meshing with the second sun gear (16), and being rotatably held on the planet carrier (28) relative to the planet carrier (28) about a second planetary rotation axis (40) extending parallel to and spaced apart from the first planetary rotation axis (32); and ○ at least one coupling planetary gear (44), the at least one coupling planetary gear being coaxially arranged with the first differential planetary gear (30), torsionally connected to the first differential planetary gear (30) and meshing with the second differential planetary gear (36), thereby coupling the differential planetary gears (30, 36) to each other, the at least one coupling planetary gear having a fourth pitch circle diameter different from the third pitch circle diameter, and forming a differential stepped planetary gear (46) with the first differential planetary gear (30), which is rotatably held on the planet carrier (28) relative to the planet carrier (28) about the first planetary rotation axis (32), the first differential planetary gear (30) serving as a first stepped planetary gear and the coupling planetary gear (44) serving as a second stepped planetary gear; characterized in that a first ratio between the first pitch circle diameter and the second pitch circle diameter and a second ratio between the third pitch circle diameter and the fourth pitch circle diameter are equal.

2. The transmission device (10) according to claim 1, characterized in that the first differential planetary gear (30) comprises a first tooth portion (48) having a first number of teeth and a first tooth module, the first tooth portion meshing with the first sun gear (14), and having a first tooth (50) with a corresponding first tooth height; and The coupling planetary gear (44) includes a second tooth part (52) having a second number of teeth and a second tooth part module, the second tooth part meshing with the second differential planetary gear (36) and having teeth (54) with a corresponding second tooth height.

3. The transmission device (10) according to claim 2, wherein, - the first number of teeth and the second number of teeth are equal; - the first tooth part module and the second tooth part module are different from each other; and - the corresponding first tooth height and the corresponding second tooth height are different from each other.

4. The transmission device (10) according to claim 2 or 3, wherein, the first tooth part (48) and the second tooth part (52) are rotationally oriented relative to each other such that a corresponding clearance (56) of the first tooth part (48) of the first differential planetary gear (30) is aligned with a corresponding clearance (58) of the second tooth part (52) of the coupling planetary gear (44).

5. The transmission device (10) according to any one of the preceding claims, wherein, the stepped planetary gears are integrally formed with each other.

6. The transmission device (10) according to claim 5 and any one of claims 2 to 4, wherein, in the axial direction of the respective stepped planetary gears, a transition region (60) having a third width (b3) is provided between the first stepped planetary gear having a first width (b1) and the second stepped planetary gear having a second width (b2), wherein the radially outer contour (88) of the differential stepped planetary gear (46) does not drop below a first addendum circle diameter (k1) of the second tooth part (52) in the transition region (60), but rises from the first addendum circle diameter (k1) to a second addendum circle diameter (k2) of the first tooth part (48).

7. The transmission device (10) according to claim 6, wherein, the third width (b3) of the transition region (60) is less than the first width (b1) of the first stepped planetary gear and less than the second width (b2) of the second stepped planetary gear.

8. The transmission device (10) according to any one of claims 1 to 4, wherein, the first differential planetary gear (30) and the coupling planetary gear (44) are formed separately from each other and connected to each other, wherein a rolling circle diameter of one of the stepped planetary gears among the first stepped planetary gear and the second stepped planetary gear is less than a rolling circle diameter of the other stepped planetary gear among the first stepped planetary gear and the second stepped planetary gear, and the one stepped planetary gear has a protrusion (84) and the other stepped planetary gear is fixed to the protrusion.

9. The transmission device (10) according to claim 8, wherein, the stepped planetary gears are directly adjacent to each other in the axial direction of the respective stepped planetary gears.

10. The transmission device (10) according to any one of the preceding claims, wherein, The first sun gear (14) includes a third tooth portion having a third number of teeth and a third tooth module of the tooth portion, the third tooth portion meshes with the first differential planet gear (30), and has a third tooth with a corresponding third tooth height; - The second sun gear (16) includes a fourth tooth portion having a fourth number of teeth and a fourth tooth module of the tooth portion, the fourth tooth portion meshes with the second differential planet gear (36), and has a fourth tooth with a corresponding fourth tooth height; - The third number of teeth and the fourth number of teeth are different from each other; - The third tooth module and the fourth tooth module are the same; and - The corresponding third tooth height and the corresponding fourth tooth height are the same.

11. The transmission device (10) according to any one of the preceding claims, characterized in that all tooth portions of the spur gear differential (12) are straight teeth.

12. The transmission device (10) according to any one of the preceding claims, characterized in that the transmission device (10) includes a planetary transmission (62), which includes: ○ At least one stepped planet gear (64) provided in addition to the differential stepped planet gear (46), the at least one stepped planet gear is rotatably held on the planet carrier (28), which has a first planet gear (66) as the third stepped planet gear and is torsionally connected to a second planet gear (68) as the fourth stepped planet gear, ○ A third sun gear (70) as a driving sun gear provided in addition to the first sun gear (14) and the second sun gear (16), which meshes with one of the planet gears (66, 68); and ○ An annular gear (72), the annular gear is torsionally connected or connectable to the housing (18) of the transmission device (10), and the other one of the planet gears (66, 68) of the stepped planet gear (64) meshes with the annular gear (72).

13. The transmission device (10) according to claim 12, characterized in that The second differential planet gear (36) abuts against the annular gear (72), one of the planet gears (66) of the planetary transmission (62), and the other planet gear (68) in a direction (76) extending along the axis of the second differential planet gear (36), the annular gear (72) and the other planet gear (68) abut against one of the planet gears (66) of the planetary transmission (62) in the direction (76), whereby, when viewed axially of the second differential planet gear (36), the annular gear (72) and the other planet gear (68) are located between the second differential planet gear (36) of the spur gear differential (12) and one of the planet gears (66) of the planetary transmission (62).

14. The transmission device (10) according to claim 12 or 13, characterized in that The first rolling circle diameter of the first sun gear (14) is greater than the second rolling circle diameter of the second sun gear (16). The second sun gear is adjacent to the first sun gear (14) in an arrangement direction (78) extending axially along the first sun gear (14) and the second sun gear (16). The first sun gear is adjacent to the third sun gear (70) in the arrangement direction (78). Thus, when viewed axially from the first sun gear (14) and the second sun gear (16), the first sun gear (14) is disposed between the second sun gear (16) and the third sun gear (70).

Images