Planetary gear for a planetary gearbox and planetary carrier for such a planetary gear

Description

[0001] The present invention relates to a planetary gear for a planetary gear and a planetary carrier for such a planetary gear.

[0002] Planetary gear sets are particularly useful when high gear ratios need to be achieved in a small space. For example, modern vehicles have a large number of auxiliary drives, such as parking brake actuators, tailgate drives, sunroof drives, or seat adjustment mechanisms. Electric motors are almost exclusively used as torque sources, but these operate at comparatively high speeds and low torques. In these cases, planetary gear sets provide the necessary gear ratios in a compact space. Due to factors including the ability to produce high volumes at low cost and low noise levels, planetary gear sets, and especially the planetary gears themselves, are manufactured from plastic.Injection molding is a suitable option for this, although the constraints that must be observed during injection molding lead to designs, particularly of the planet carrier, that deviate significantly from conventional designs. Planet carriers and planet gears made of plastic are known, for example, from EP 3 722 641 A1, DE 10 2005 023 542 A1, DE 10 2015 119 803 A1, EP 3 527 846 A1, EP 3 486 523 A1, and WO 2014 / 095966 A1.

[0003] Further prior art documents include US 8 597 156 B2, EP 3 306 140 A1, DE 10 2019 104898 A1, US 2019 / 162293 A1, DE 10 2015 219455 A1 and CN 112 728 014 A.

[0004] Given their suitability for mass production, the quick and reliable assembly of such planetary gearboxes is an important additional consideration. Furthermore, in the applications mentioned above, these gearboxes are sometimes subjected to very high loads, making the fatigue strength, particularly of the planet gears, another crucial aspect, which occasionally conflicts with the requirements of injection molding.

[0005] The object of the present invention is to propose a planetary gear and a planetary carrier with which the requirements described above can be met and with which it is possible to create a planetary gear and a planetary carrier for a planetary gear using simple and cost-effective means, which are designed in such a way that the planetary gear can be easily manufactured and assembled and at the same time has a high fatigue strength or a high maximum transmissible misuse torque.

[0006] This object is achieved by the features specified in claims 1 and 10. Advantageous embodiments are the subject of the subclaims.

[0007] The invention relates to a planetary gear for a planetary gear, comprising a gear body with a first planetary gear end face and a second planetary gear end face, a planetary gear axis which o defines a planetary gear axis of rotation of the planetary gear and o comprises a first bearing section and o a second bearing section, wherein the first bearing section projects beyond the first planetary gear end face and the second bearing section projects beyond the second planetary gear end face, wherein at least one planetary gear bore running coaxially or parallel to the planetary gear axis of rotation at least partially passes through the planetary gear axis.

[0008] The proposed planetary gear comprises a first bearing section and a second bearing section, which are arranged outside the actual gear body and with which the planetary gear can be inserted into a first bearing recess and a second bearing recess of a planetary carrier, respectively. Due to the fact that the planetary gear has a planetary gear bore running coaxially to the planetary gear rotation axis, it is possible to insert a pin of an assembly tool into this planetary gear bore and, with this assembly tool, insert the planetary gear into the first bearing recess and the second bearing recess of the planetary carrier, respectively. As mentioned at the beginning, the proposed planetary gears and the proposed planetary carriers are suitable for being manufactured from plastic.However, this results in the situation that the functionally relevant surfaces, in particular the surfaces of the first bearing section and the second bearing section as well as the teeth of the gearing, are comparatively sensitive to external influences, so that damage to the functionally relevant surfaces cannot always be completely ruled out, particularly during assembly. The surfaces of the planetary gear bore, on the other hand, are not functionally relevant surfaces. In the event that they are damaged, for example, when the pin of the assembly tool is inserted into the planetary gear bore, this does not negatively affect the functionality of the planetary gear and consequently of the planetary gear unit. In this respect, the planetary gear unit with the proposed planetary gear units can be manufactured using a more stable manufacturing process than known manufacturing processes and consequently with a lower amount of scrap.

[0009] According to one embodiment, the planetary gear can have exactly one planetary gear bore which runs through the entire planetary gear. In order to introduce the above-mentioned pin of an assembly tool into the planetary gear bore, it is not absolutely necessary for the planetary gear bore to run through the entire planetary gear. However, the production of a planetary gear bore which runs through the entire planetary gear is usually easier than a planetary gear bore which only partially projects into the planetary gear, particularly due to the boundary conditions of the injection molding process. In addition, the elasticity of the entire planetary gear and in particular of the first bearing section and the second bearing section is increased, which is advantageous from an assembly point of view, in particular when the above-mentioned first bearing recesses and second bearing recesses of the planet carrier have first and second recesses.second locking projections, which in turn exhibit a certain degree of elasticity. This point will be discussed in more detail later.

[0010] In a further developed embodiment, the first bearing section has a first extension starting from the first planetary gear end face and the second bearing section has a second extension starting from the second planetary gear end face, wherein the first extension is not equal to the second extension.

[0011] As mentioned, the first bearing section and the second bearing section are inserted into corresponding first bearing recesses and second bearing recesses of the planet carrier, respectively. Again, particularly due to specifications resulting from the injection molding process, it may be necessary to design the first bearing recess and the second bearing recess with different lengths relative to the rotational axis of the planet carrier, especially if a separate insert is to be connected to the planet carrier. The different first extensions and second extensions of the first bearing section and second bearing section, respectively, allow the different extensions to be taken into account, so that a largely maximized contact area can be provided, which leads to a correspondingly lower surface pressure.It may be advisable to provide the first bearing recess and the second bearing recess with different fits for interaction with the first bearing section and the second bearing section, respectively, in order to take the different contact surfaces into account.

[0012] Since in this case attention must be paid to the correct alignment of the planetary gears during assembly, it may be advisable to additionally mark one of the bearing sections clearly, for example with a notch.

[0013] It should be noted here that, depending on the design of the planetary carrier and the expected loads during operation, it is also possible to select the first extension to be the same as the second extension. From a manufacturing perspective, this has the advantage that the planetary gears do not have to be inserted into the planetary carrier in a specific orientation.

[0014] In a further developed embodiment, the planet gear axle can be formed by the wheel body. It is generally possible, for example, to provide a planet gear axle made of steel onto which the planet gear is mounted. This is the case, for instance, in WO 2014 / 095966 A1. In this embodiment, however, the planet gear axle is an integral part of the wheel body, so that the wheel body is designed as a single piece. This eliminates an additional assembly step. Furthermore, the number of components is reduced, which simplifies warehousing and keeps costs down.

[0015] According to the invention, the gear body comprises a gear rim with a first number of teeth and a second number of ribs, wherein the ribs run between the planet gear axis and the gear rim, and planet gear starting projections are arranged on the ribs and project beyond the gear rim along the planet gear rotation axis. The first number of teeth can be equal to the second number of ribs, but this is not absolutely necessary. The use of ribs has the advantage, among other things, that they can be arranged where the loads on the planet gear are highest. As a result, material can be saved without having to accept any significant disadvantages in the strength of the planet gear.The provision of planetary gear thrust bosses has the advantage of creating wear surfaces without the wear occurring there having a significant negative impact on the functionality of the planetary gear and, consequently, the planetary gear. The arrangement of the planetary gear thrust bosses on the ribs allows them to be positioned at a comparatively short distance from the planetary gear's axis of rotation. As a result, the circumferential speed of the planetary gear thrust bosses is reduced, so that their stress is kept correspondingly low. The provision of the planetary gear thrust bosses on the ribs is particularly suitable for spur gears, where the axial forces acting on them are lower than with helical gears.

[0016] An alternative according to the invention provides that the gear body can comprise a gear rim with a first number of teeth and a second number of ribs, wherein the gear body has at least one continuous planetary gear starting projection arranged between the ribs and the gear rim. Again, the first number can be the same as the second number or different from one another. Due to the fact that the planetary gear starting projections are continuous and therefore uninterrupted, continuous contact with the respective mating surfaces results. This allows alignment errors of the planetary gear rotation axes with respect to the planet carrier to be compensated for without noticeably increasing noise. The provision of a continuous planetary gear starting projection is particularly suitable for helical gears where high axial forces occur.

[0017] According to a further embodiment, the ribs have a concave curvature with a radius lying in a plane extending through the planetary gear rotation axis, a first end and a second end, wherein the curvature merges into the first bearing section or into the second bearing section in the region of the first end, and merges into the planetary gear starting projections in the region of the second end.

[0018] The provision of a curvature ensures a uniform stress distribution, thus avoiding stress peaks. The radius of the curvature can be constant or varying. The change in the radius can be selected such that a particularly uniform stress distribution results. For example, the radius can be smallest in an area in which a tangent to the curvature runs perpendicular to the axis of rotation, and increase towards the radially inner end and the radially outer end. The favorable stress distribution reduces the formation of stress peaks where the planet gear could fail during operation. Depending on the design of the curvature, it can also be approximated using a number of flat surfaces that are inclined relative to one another. The inclination of the surfaces relative to one another is flatter in the outer area of ​​the curvature and becomes steeper towards the center. However, the above statements apply equally to this type of design.

[0019] In another embodiment, it may be advantageous that The tooth ring has a tooth base between two adjacent teeth, and at least one rib is arranged radially aligned with one of the tooth bases.

[0020] It has been shown that the probability of a tooth breaking is highest at the tooth roots. The radial alignment of the ribs to the tooth roots ensures that the tooth roots are supported. This significantly reduces the probability of the gear failing at the tooth root.

[0021] According to a further embodiment, the first number can be greater than the second number. As mentioned, the first number refers to the teeth and the second number to the ribs. In this embodiment, a rib is not arranged in alignment at every tooth root. Rather, some tooth roots have no ribs. This results in the distance between two adjacent ribs in the circumferential direction being larger than that between two adjacent teeth. The pockets forming between two adjacent ribs are therefore larger than in a configuration in which the first number and the second number are the same. This results in injection molding advantages in that tight radii and material accumulations are avoided or at least kept to a minimum. These can lead to overheating during production of the planetary gear, which can cause shrinkage cavities to form.While this void formation can be corrected, it results in a longer and more complicated manufacturing process. Since material accumulation can be avoided in this design, the planetary gears can be manufactured faster and more cost-effectively.

[0022] In a further developed embodiment, the first number can be greater than the second number by an integer factor. This integer factor is particularly 2. However, it is also possible to choose, for example, 3 or 4 or larger as the integer factor. The pocket formed between two adjacent ribs can be chosen to be correspondingly large. The integer factor can be based, in particular, on the diameter of the planetary gear, whereby a larger integer factor can be applied for smaller diameters.

[0023] In a further developed embodiment, the ribs forming a first rib group with first ribs and a second rib group with second ribs, and the first ribs of the first planetary gear end face and the second ribs are arranged on the second planetary gear end face, wherein the first ribs are arranged rotated relative to the second ribs by an angle of rotation lying in a plane perpendicular to the planetary gear rotation axis.

[0024] For example, if the integer factor is 2, it is possible to select the angle of rotation such that it corresponds to the angle formed by two adjacent teeth with the planetary gear axis. Consequently, on the first planetary gear face, for example, each tooth root with an odd consecutive number is supported by a first rib and a second rib, respectively, and on the second planetary gear face, each tooth root with an even consecutive number is supported by a first rib and a second rib, respectively. Consequently, each tooth root is supported on a planetary gear face, ensuring uniform support of the tooth roots. This minimizes the likelihood of teeth breaking at the tooth roots.

[0025] Furthermore, the invention relates to a planet carrier for a planetary gear according to one of the previous embodiments, comprising a carrier body which extending along a planet carrier rotation axis, comprising a first disk-shaped body and a second disk-shaped body, wherein the first disk-shaped body and the second disk-shaped body are connected to each other by at least one connecting body, the first disk-shaped body having a first bearing recess, into which the first bearing section of the planet gear can be inserted, and which has at least one circumferentially extending first detent projection, and the second disk-shaped body having a second bearing recess, into which the second bearing section of the planet gear can be inserted, and which has at least one circumferentially extending second detent projection.

[0026] As mentioned earlier, the planet gears can be provided with a planet gear bore, which increases the elasticity of the planet gears, particularly in the first and second bearing sections. As also mentioned, during the assembly of the planetary gear set, the planet gears, with their first and second bearing sections, are inserted into the first and second bearing recesses of the planet carrier, respectively. The first and second locking lugs are briefly compressed elastically and then return to their original state. However, not only the first and second locking lugs are elastically deformed, but also the first and second bearing sections. The deformations are therefore distributed across both the first and second locking lugs and the first and second bearing sections.This reduces the probability of irreversible plastic deformation, especially of the locking projections, or prevents plastic deformation altogether.

[0027] Due to these processes taking place during assembly, a snap-fit, click-fit or clip connection is provided, which is characterized by particularly simple and quick assembly.

[0028] The first and second locking projections encircle the first and second bearing sections, respectively, radially outwards, thus providing a radially outward-acting undercut. This pre-fixes the planet gear inserted into the bearing recesses and prevents it from detaching from the planet carrier, even if the planet carrier and planet gears are not yet installed in a ring gear. Furthermore, this pre-fixation results in more stable operation of the planetary gear set. The first and second bearing recesses comprise approximately annular sector-shaped sections that guide and center the planet gears during insertion. Consequently, the surfaces of these annular sector-shaped sections enclose a recess angle.To minimize friction and consequently wear resulting from this contact, planetary gear sets are typically lubricated with oil or grease. The detent projections create a suction effect during operation, drawing the oil into the bearing recesses. This suction effect can be increased or decreased by selecting the correct recess angle. As a result, the engagement of the planet gears with the sun gear and ring gear is improved, thus reducing wear on the planetary gear set. Furthermore, noise generation is kept to a minimum.

[0029] The planet carrier according to the invention is designed such that On the first disc-shaped body, at least one first axial counter-running surface enclosing the first bearing recess and / or on the second disc-shaped body, at least one second axial counter-running surface enclosing the second bearing recess is provided, wherein the first axial counter-running surface and / or the second axial counter-running surface interacts with the planet gear thrust projections when the planet gear is inserted into the first bearing recess and the second bearing recess, wherein a first inclined surface adjoins the first axial counter-running surface towards the first bearing recess, which is inclined relative to the first axial counter-running surface at a first inclined surface angle and / or a second inclined surface adjoins the second axial counter-running surface towards the second bearing recess, which is inclined relative to the second counter-running surface at a second inclined surface angle.

[0030] As mentioned, the planet gears have planet gear thrusts. During operation, these thrusts come into contact with the first axial thrust surfaces or the second axial thrust surfaces of the planet carrier, thereby transferring axial forces acting on the planet gears to the planet carrier, which then absorbs them. To minimize friction and consequently wear resulting from this contact, planetary gears are typically lubricated with oil or grease, as previously mentioned. The first and / or second thrust surface creates a suction effect which, in conjunction with the rotational movement of the planet gear relative to the planet carrier, draws the oil or grease between the planet gear thrusts and the first or second axial thrust surface.This ensures that a sufficient amount of oil or grease is present to minimize the friction and associated wear described above.

[0031] Depending on the inclination of the first inclined surface and / or the second inclined surface, the suction effect is stronger or weaker.

[0032] According to a further developed design, the first axial counter-running surface transitions into the first inclined surface with a convex first inclined surface curvature, and the second axial counter-running surface transitions into the second inclined surface with a convex second inclined surface curvature. Together with the respective inclined surfaces, the inclined surface curvatures intensify the suction effect described above.

[0033] According to advanced training, the carrier body comprising at least one radially outer connecting body, at least one radially inner connecting body and at least one further connecting body arranged between the radially outer connecting body and the radially inner connecting body, wherein the radially outer connecting body, the radially inner connecting body and the further connecting body connect the first disk-shaped body to the second disk-shaped body.

[0034] All connecting elements establish a connection between the first disc-shaped body and the second disc-shaped body. Referring to the planet carrier shown in WO 2014 / 0095966 A1, it is noticeable that there the first disc-shaped body and the second disc-shaped body are connected to each other by only four connecting elements arranged around the outer circumference of the disc-shaped bodies. In contrast, the radially inner connecting element, the radially outer connecting element, and the other connecting element are distributed much more evenly over the entire planet carrier. This results in a correspondingly uniform force flow between the first disc-shaped body and the second disc-shaped body, which leads to increased stability of the carrier body overall.Since increased stability also leads to less deformation during the operation of the planetary gear, increased stability also results in less wear.

[0035] In a further design, the additional connecting body can be connected to both the radially outer and the radially inner connecting bodies. In this design, a closed force transmission between the radially outer and the radially inner connecting bodies is achieved by connecting the additional connecting body to both. This also increases the stability of the support body with the aforementioned technical effects.

[0036] An advanced design can specify that the radially outer connecting body and at least one other connecting body enclose a closed recess in the second disc-shaped body. By forming a closed recess with the radially outer connecting body and at least one other connecting body, material for the second disc-shaped body can be saved without significantly affecting its strength.

[0037] According to a further embodiment, at least one of the additional connecting bodies transitions into the first axial counter-running surface with a concave first curvature. For example, in the planet carrier shown in WO 2014 / 0095966 A1, the first axial counter-running surface and the additional connecting body abut directly and, at least theoretically, form an edge. At least, no curvature is provided with which the first axial counter-running surface transitions into the additional connecting body. In contrast, the concave first curvature ensures that stress peaks in the transition from the first counter-running surface to the additional connecting body are avoided or at least reduced. Similarly, the transition from at least one additional connecting body to the second axial counter-running surface can also be designed, whereby a concave second curvature may be provided.

[0038] In a further developed design, the concave first curvature has a radius, a first end, and a second end. At the first end, the first curvature transitions into the first axial counter-running surface, and at the second end, it transitions into the further connecting body, with the radius decreasing from both the first and second ends. This creates a particularly favorable stress distribution between the further connecting body and the first disk-shaped body. This favorable stress distribution prevents the formation of stress peaks where the support body could fail during operation. Depending on the design of the curvature, it can also be approximated by a number of flat surfaces inclined to each other. The inclination of the surfaces to each other is shallower in the outer area of ​​the curvature and becomes steeper towards the center. However, the above statements apply equally to such a design.

[0039] Furthermore, at least one of the additional connecting bodies can transition into the second axial counter-running surface with a concave second curvature, the radius of which changes in the same way as the radius of the first curvature. According to a further developed embodiment, the first disk-shaped body can form a first free planet carrier end face on which a number of stiffening ribs are arranged. In this embodiment, the torque is introduced into or removed from the planet carrier via the first disk-shaped body. Consequently, the first disk-shaped body is subjected to a significantly higher load compared to the second disk-shaped body. This load is absorbed by the stiffening ribs.

[0040] An advanced design can specify that the first bearing recess has a first extension along the planet carrier's axis of rotation and the second bearing recess has a second extension along the planet carrier's axis of rotation, with the first extension being larger than the second extension.

[0041] As mentioned, the insert serves to introduce torque into the support body, and in particular into the first disc-shaped body, or to dissipate torque from the support body, and in particular from the first disc-shaped body. To ensure reliable torque transmission between the insert and the support body, it is therefore necessary to provide the first disc-shaped body with a sufficient wall thickness. This is achieved by making the first dimension larger than the second dimension. It is not necessary to also provide the second disc-shaped body with an increased wall thickness. This prevents the dimensions of the support body and, consequently, the material consumption from being unnecessarily increased.

[0042] According to a further developed design, the planet carrier can have several primary bearing recesses and several secondary bearing recesses, and a number of planet carrier starting projections can be provided on the first disk-shaped body, arranged adjacent to the primary bearing recesses. The present planetary gear is primarily intended for use with spur gears, although helical gears up to a certain helix angle can also be considered. In the case of spur gears, the acting axial forces are theoretically zero or very small; however, in practice, for example due to gear defects within tolerances, the acting axial forces are so high that they must be taken into account. The planet carrier starting projections form wear surfaces when the planet carrier comes into contact with adjacent components.The wear occurring on the planet carrier's starting lugs has no effect, or at least a negligible one, on the functionality of the planetary gear set. As mentioned, the highest forces or torques are transmitted in the area of ​​the bearing recesses and, in particular, in the area of ​​the detent lugs between the carrier body and the planet gears. As also mentioned, the stiffening ribs therefore extend from the bearing recesses and especially from the area of ​​the detent lugs. This fact is used to absorb the forces that are transmitted to the carrier body of the planet carrier via the planet carrier's starting lugs.Compared to an arrangement of the planet carrier's leading edges approximately midway between two adjacent bearing recesses, the bending moments acting on the bearing recesses are kept low, thus minimizing the overall load on the carrier body. According to a further developed embodiment, an insert of the planet carrier can be connected to the first disk-shaped body, and the insert can comprise a fastening element with which the insert is connected to the carrier body. The fastening element has a radially outwardly projecting connecting surface that forms at least a radial extension and a toothed connection.

[0043] To reliably transmit the aforementioned torques between the carrier body and the insert, the insert's connecting element is equipped with a toothed connection. This toothed connection provides a large contact area between the insert and the carrier body, thus keeping the surface pressure correspondingly low. The radial extension further increases this contact area and reduces the surface pressure even more. Furthermore, the radial extension introduces a certain degree of eccentricity in certain sections, which positively influences torque transmission. This radial extension can give the insert a hypotrochoidal shape. The toothed connection should ideally feature a large number of small teeth with a large tooth tip radius. This also helps to avoid or minimize stress peaks.

[0044] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying drawings. Figure 1 is a perspective view of a planetary gear according to the invention, Figure 2 is a top view of the in Figure 1 The planetary gear shown in Figure 3 is a front view of the one in Figure 1 The planetary gear shown in Figure 4 is a sectional view along the axis shown in Figure 4. Figure 3 defined section plane CC, Figure 5 a front view of a planet carrier according to the invention with three in the Figures 1 to 4 The planetary gears shown in Figure 6 are a rear view of the gears shown in Figure 6. Figure 5 Planetary carrier according to the invention, Figure 7 a top view of the in Figure 5 depicted planetary carrier, Figure 8 a top view of the in Figure 5 The planetary carrier shown, without the planetary gears, Figure 9, a sectional view along the in Figure 8defined section plane AA, Figure 10 a section view along the in Figure 8 defined section plane BB, Figure 11, a perspective view of the in Figure 5 depicted planetary support, looking towards a second disc-shaped body, Figure 12 an enlarged representation of the in Figure 11 defined section X, Figure 13, a perspective view of the in Figure 5 depicted planetary carrier, looking at a first disc-shaped body, Figure 14 an enlarged representation of the in Figure 13 defined section Y, Figure 15 a principal enlarged representation of the radius marked in Figure 14, Figure 16 a perspective view of an insert, and Figure 17 a front view of the in Figure 16 shown insert.

[0045] Figure 1 shows a perspective view of a planetary wheel 10 according to the invention, Figure 2 a top view of the in Figure 1planet gear 10 shown, Figure 3 a front view and Figure 4 A sectional view of planet gear 10. Unless otherwise stated, the following explanations refer to the Figures 1 to 4 This planet gear 10 can be fitted into a planet carrier 44, which is used, among other things, in Figure 5 as shown, are used and together with a ring gear 13, which is only shown in principle, form a planetary gear 14.

[0046] The planet gear 10 has a gear body 16, which forms a first planet gear end face 18 and a second planet gear end face 20. Furthermore, the planet gear 10 includes a planet gear axis 22, which in the illustrated embodiment is formed by the gear body 16. In this respect, the planet gear axis 22 is an integral part of the planet gear 10. The planet gear axis 22 defines a planet gear rotation axis APR ( Figure 4), around which the planet gear 10 rotates during operation of the planetary gear 14. Furthermore, the planet gear shaft 22 forms a first bearing section 24 and a second bearing section 26, which are particularly important in Figure 2 as can be seen. The first bearing section 24 and the second bearing section 26 allow the planet gear 10 to be rotatably mounted in the planet carrier 44, which will be discussed in more detail later.

[0047] As from the Figure 2 As can be seen, the first bearing section 24 has a first extent x1 along the planet gear rotation axis APR and the second bearing section 26 has a second extent x2, also along the planet gear rotation axis APR, wherein the first extent x1 is greater than the second extent x2.

[0048] As can be seen in particular from the Figure 4As can be seen, the planetary gear 10 is provided with a planetary gear bore 28 that runs coaxially to the planetary gear's axis of rotation APR and passes completely through the planetary gear 10. The exact function of the planetary gear bore 28 will be discussed in more detail below. It should be noted here that for the planetary gear bore 28 to function, it is not absolutely necessary that it runs coaxially to the planetary gear's axis of rotation APR. Furthermore, it does not necessarily have to have a circular cross-section. The ratio of the first dimension x1 to the second dimension x2 also has no significant influence on the functionality of the planetary gear bore 28.

[0049] The planet gear 10 forms a toothed ring 30 with a first number n1 of teeth 31, wherein in the illustrated embodiment the first number n1 of teeth 31 is twenty-two (22), as can be seen in particular from the Figure 3This can be seen from the following. Furthermore, the planet gear 10 is provided with a second number n2 of ribs 32, which extend radially between the toothed ring 30 and the planet gear axis 22. From the Figure 3 It can be seen that the second number n2 of ribs 32 is eleven (11) and is therefore smaller than the first number n1. The tooth ring 30 forms a tooth root 34 between each pair of adjacent teeth 31, with a rib 32 being radially aligned with one of these tooth roots 34, which is particularly evident from the Figures 1 and 3 can be deduced.

[0050] As mentioned, the second number n2 of ribs 32 is half the number n1 of teeth 31. This means that not every tooth root 34, but only every second tooth root 34, is provided with a radially aligned rib 32 extending radially inwards. The ribs 32 arranged on the first planet gear end face 18 can be assigned to a first rib group 36, with the ribs 32 of the first rib group 36 being designated as first ribs 321. Similarly, a second rib group 38 can be defined, whose ribs 32 are designated as second ribs 322. From the Figure 4It can be seen that the first ribs 321 are arranged rotated relative to the second ribs 322 by an angle of rotation that lies in a plane perpendicular to the planet gear axis 22. This angle of rotation corresponds to the angle that two adjacent teeth 31 enclose in the previously defined plane. This ensures that each tooth root 34 is supported on either the first planet gear face 18 or the second planet gear face 20 by a first rib 321 or a second rib 322, respectively.

[0051] Each of the ribs 32 has a planet gear starting projection 40, which projects along the planet gear rotation axis APR beyond the toothed ring 30 (see in particular Figure 2 ). From the Figure 4 It can be seen that a concave curvature 42 extends radially inwards from the planet gear starting projections 40. Figure 4The curvature 42 has a constant radius R, although this radius R can also change to ensure the most uniform stress distribution possible and to avoid or at least reduce stress peaks. Consequently, the radius R can be chosen such that the stresses in the region of the curvature 42 are lower under the expected loads during operation than in the gear ring 30.

[0052] In Figure 3 An additional continuous planetary gear starting projection 41 is shown with dashed lines, which can be provided as an alternative or in addition to the planetary gear starting projections 40. The continuous planetary gear starting projection 41 is arranged radially outside the planetary gear starting projections 40 between the ribs 32 and the gear ring 30.

[0053] In the Figures 5 to 14A planet carrier 44 according to the present invention is shown in various views. Unless otherwise described, the following description refers to the Figures 5 to 14 The planet carrier 44 comprises a support body 46 extending along a planet carrier rotation axis APT, which is best positioned in the Figures 7 and 8 The support body 46 comprises a first disc-shaped body 48 and a second disc-shaped body 50, as can be seen in the Figure 5 on the first disc-shaped body 48 and in Figure 6 looking at the second disc-shaped body 50. The first disc-shaped body 48 and the second disc-shaped body 50 are connected to each other by a number of radially outer connecting bodies 52, a number of radially inner connecting bodies 54, and a number of further connecting bodies 56 arranged in between. Referring to the Figure 9It can be seen that a total of three radially outer connecting bodies 52 are provided, which are arranged in a ring shape. Correspondingly, three radially inner connecting bodies 54 are present, with the circumferentially outer ends of the radially outer connecting bodies 52 being the starting point of each of a further connecting body 56, which unite in the radially inner connecting body. While the radially outer connecting body 52 is convexly curved, the two further connecting bodies 56 are concavely curved. Due to this design, the radially outer connecting body 52 and the two further connecting bodies 56 enclose a recess 58 of the second disk-shaped body 50, which is particularly evident in Figure 6 can be viewed.

[0054] In the Figures 5 to 7 The planet carrier 44 is shown in a state in which three planet gears 10, as described in the Figures 1 to 4are rotatably connected to the planet carrier 44. For this purpose, the first disc-shaped body 48 has a total of three first bearing recesses 60 and the second disc-shaped body 50 has a total of three second bearing recesses 62. The first bearing recesses 60 are provided with first locking projections 64 and the second bearing recesses 62 with second locking projections 66. As can be seen in particular from the Figures 7 and 8 As can be seen, the first bearing recess 60 has a first extent y1 and the second bearing recess 62 has a second extent y2 along the planet carrier rotation axis APT, wherein the first extent y1 is larger than the second extent y2. From the Figures 7 and 8 It is also apparent that an insert 68, which is in the Figures 16 and 17The insert 68 is shown separately and is connected to the first disk-shaped body 48, for example, by being overmolded. The first extent y1 is chosen such that the insert 68 can be integrated into the first disk-shaped body 48 as completely as possible. The insert 68 serves to introduce torque into or remove torque from the planet carrier 44.

[0055] The planetary gear 14 is assembled as follows: A pin of an assembly tool (not shown) is inserted into the planet gear bore 28, and then the planet gear 10 is inserted into one of the first bearing recesses 60 and one of the second bearing recesses 62 with a radially inward movement. During insertion, both the first bearing section 24 and the second bearing section 26 of the planet gear 10, as well as the first locking projections 64 and the second locking projections 66, deform elastically. Once the first bearing section 24 is fully inserted into the first bearing recess 60 and the second bearing section 26 is fully inserted into the second bearing recess 62, the elastic deformation is reversed.The first locking projections 64 and the second locking projections 66 form a radially outward-acting undercut with respect to the first bearing section 24 and the second bearing section 26 of the planet gear 10 and project circumferentially into the bearing recesses. As a result, a certain degree of pre-fixation of the planet gears 10 is achieved, preventing them from detaching from the planet carrier 44 even when the latter has not yet been inserted into the ring gear 13. Furthermore, the contact area between the bearing sections 24, 26 and the bearing recesses 60, 62 is increased, thus distributing wear more evenly.

[0056] The undercut formed by the locking projections 64, 66 also causes a suction effect of the lubricant into the bearing recesses 60, 62 during operation of the planetary gear 14. With particular reference to the Figure 9It can be seen that the bearing recesses 60, 62 comprise a circular section and an annular sector-shaped section, which merge into one another in the locking projections 64, 66. The annular sector-shaped sections enclose a recess angle β. By varying this recess angle β, the suction effect can be increased or decreased.

[0057] As mentioned, the annular sector-shaped sections transition into the circular sections in the area of ​​the locking projections 64, 66. The annular sector-shaped section is designed to transition into the circular section with a transition radius rv. The suction effect can also be influenced by the transition radius rv.

[0058] In Figure 5 Looking at a first free planetary support end face 70, on which a number of stiffening ribs 72 are arranged. In the Figures 5 , 6 and 9A planet gear rotation axis circle PDK is shown with dashed lines. The planet gear rotation axis circle PDK passes through the planet gear rotation axes APR when the planet gears 10 are inserted into the planet carrier 44 (see in particular Figure 9 If the stiffening ribs 72 are conceptually extended, they originate from the planet gear rotation axes APR when these are inserted into the planet carrier 44. In the illustrated embodiment, the stiffening ribs 72 extend slightly radially inwards on both sides of the first locking projections 64 from the first bearing recesses 60 and radially inwards towards the insert 68, such that at their radially inner end they run approximately tangentially to the tooth tip of the insert 68's toothing.

[0059] In addition, on the first free planet carrier end face 70, a total of six planet carrier starting projections 74 are arranged adjacent to the first locking projections 64.

[0060] As can be seen in particular from the Figures 11 , 13 and 14As can be seen, the first disc-shaped body 48 forms a first axial counter-running surface 76, which encloses the first bearing recess 60. Similarly, the second disc-shaped body 50 forms a second axial counter-running surface 78, which encloses the second bearing recess 62. During operation, the planet gear running projections 40 interact with the first counter-running surface 76 or the second counter-running surface 78. A first inclined surface 80 adjoins the first counter-running surface 76 towards the first bearing recess 60, and this first inclined surface 80 is inclined at a first inclined surface angle α1 relative to the first counter-running surface 76. The first inclined surface 80 transitions into the first axial counter-running surface 76 with a convex first inclined surface curvature 84.Accordingly, a second inclined surface 82 adjoins the second bearing recess 62, wherein the second inclined surface 82 is inclined at a second inclined surface angle α2 relative to the second counter-running surface 78. The second inclined surface 82 transitions into the second axial counter-running surface 78 with a second inclined surface curvature 86.

[0061] The first inclined surface 80 and the second inclined surface 82, together with the rotation of the planet gear 10, create a suction effect, which draws oil or grease lubricating the planetary gear 14 between the planet gear thrust projections 40 and the first axial counter-running surface 76 or the second axial counter-running surface 78. The suction effect is greater or lesser depending on the inclination of the first inclined surface 80 and the second inclined surface 82. Furthermore, certain misalignments of the planet gear axes of rotation APR relative to the planet carrier axis of rotation APR, or deformations due to the applied torque, can be compensated for without increasing noise or wear.

[0062] In the Figure 11Looking at the first axial counter-running surface 76, a transition from the first axial counter-running surface 76 to a further connecting body 56 is observed, forming a first bulge 871. In the Figure 14 Looking at the second axial counter-running surface 78 and one of the further connecting bodies 56, it can be seen that the further connecting body 56 transitions into the second axial counter-running surface 78 with a second bulge 872. The first bulge 871 and the second bulge 872 are shown schematically in Figure 15 The first bulge 871 and the second bulge 872 each have a changing radius R. In comparison, in Figure 15A comparative curvature 88 is also shown with a dashed line, which has a constant radius R. The first curvature 871 and the second curvature 872 have a first end 90 and a second end 92. The radius R of the first curvature 871 and the second curvature 872 decreases from the first end 90 and the second end 92 towards the center, so that where in Figure 15 The first curvature 871 or the second curvature 872 and the reference curvature 88 touch, and the curvature has the smallest radius R. This design of the first curvature 871 or the second curvature 872 ensures a particularly uniform stress distribution.

[0063] In the Figures 16 and 17The previously mentioned insert 68 is shown separately. The insert 68 comprises a mounting body 94, with which the insert 68 can be connected to the carrier body 46. The mounting body 94 has a radially outwardly projecting connecting surface 96, which forms a connecting toothing 100. Furthermore, the connecting surface 96 forms three radial extensions 98, so that the connecting toothing 100 exhibits a certain eccentricity in sections. The three radial extensions 98 give the mounting body 94 a hypertrochoidal shape. The number of eccentric extensions 98 corresponds to the number of planet gears 10 of the planetary gear set 14, with the maximum radius of an eccentric extension 98 being located between two adjacent planet gears 10. The number and shape of the eccentric extensions 98 can be selected such that the acting stresses are kept low.The design of the eccentric extensions 98 includes, among other things, their size and geometric shape. As mentioned, the radial extensions 98 are based on a hypotrochoid. By appropriately selecting the relevant parameters, the radial extensions 98 can be designed so that the shape of the mounting body 94 approximates that of a polygon, in this case a triangle, or a circle. As mentioned, the insert 68 is enclosed by the first disk-shaped body 48 in the area of ​​the mounting body 94. The course of the stiffening ribs 72 is chosen such that a large portion of the forces is introduced approximately tangentially into the insert 68 and, in particular, into the tooth heads arranged in the radial extensions 98. Consequently, a torque can be transmitted between the insert 68 and the planet carrier 44. List of reference symbols

[0064] 10 Planetary gear 13 Ring gear 14 Planetary gear set 16 Gear body 18 First planetary gear face 20 Second planetary gear face 22 Planetary gear axle 24 First bearing section 26 Second bearing section 28 Planetary gear bore 30 Ring gear 31 Teeth 32 Ribs 321 First ribs 322 Second ribs 34 Tooth root 36 First rib group 38 Second rib group 40 Planetary gear leading edge 42 Curvature 44 Planetary carrier 46 Carrier body 48 First disc-shaped body 50 Second disc-shaped body 52 Radially outer connecting body 54 Radially inner connecting body 56 Further connecting body 58 Recess 60 First bearing recess 62 Second bearing recess 64 First 66 Second locking projection 68 Insert 70 First free planet carrier end face 72 Stiffening rib 74 Planet carrier leading projection 76 First axial counter-running surface 78 Second axial counter-running surface 80 First inclined surface 82 Second inclined surface 84 First inclined surface curvature 86 Second inclined surface curvature 871 First curvature872 Second curvature 88 Comparison curvature 90 First end 92 Second end 94 Fastening body 96 Connecting surface 98 Radial extension 100 Connecting toothing APR planetary wheel axis of rotation APT planetary carrier axis of rotation n1 first number n2 second number R radius x1 first extent x2 second extent y1 first extent y2 second extent α1 first inclined surface angle α2 second inclined surface angle βRecess angle

Claims

1. Planetary gear (10) for a planetary transmission, comprising - a gearwheel body (16) having a first planetary gear end face (18) and a second planetary gear end face (20), - a planetary gear axle (22) which o defines a planetary gear axis of rotation (APR) of the planetary gear (10) and o comprises a first mounting section (24) and o a second mounting section (26), wherein o the first mounting section (24) extends over the first planetary gear end face (18) and the second mounting section (26) extends over the second planetary gear end face (20), - wherein at least one planetary gear bore hole (28), which extends coaxially or parallel to the planetary gear axis of rotation (APR), extends at least partially through the planetary gear axle (22), characterized in that the gearwheel body (16) comprises - a gear rim (30) having a first plurality (n1) of teeth (31) and - a second plurality (n2) of ribs (32), wherein - the ribs (32) extend between the planetary gear axle (22) and the gear rim (30), wherein - planetary gear abutment protrusions (40) are arranged on the ribs (32) which extend over the gear rim (30) along the planetary gear axis of rotation (APR), or wherein - the gearwheel body (16) comprises at least one continuous planetary gear abutment protrusion (41) which is arranged between the ribs (32) and the gear rim (30).

2. Planetary gear (10) in accordance with claim 1, characterized in that the planetary gear (10) comprises exactly one planetary gear bore hole which extend through the entire planetary gear (10).

3. Planetary gear (10) in accordance with claim 1 or 2, characterized in that - the first mounting section (24) comprises, beginning from the first planetary gear end face (18), a first extension (x1) and in that - the second mounting section (26) comprises, beginning from the second planetary gear end face (20), a second extension (x2), wherein - the first extension (x1) is not equal to the second extension (x2).

4. Planetary gear (10) in accordance with any of the preceding claims, characterized in that the planetary gear axle (22) is formed by the gearwheel body (16).

5. Planetary gear (10) in accordance with any of the preceding claims, characterized in that - the ribs (32) comprise a concave curvature (42) o with a radius (R) which lies in a plane extending through the planetary gear axis of rotation (APR), o comprising a first end (90) and a second end (92), and - the curvature (42) o transitions, in the region of the first end (90), into the mounting section (24) or into the second mounting section (26) and, in the region of the second end (92), into the planetary gear abutment protrusions (40).

6. Planetary gear (10) in accordance with any of the preceding claims, characterized in that - the gear rim (30) comprises a tooth base (34) between two adjacently arranged teeth (31), and - at least one rib (32) is arranged radially in alignment with one of the tooth bases (34).

7. Planetary gear (10) in accordance with any of the preceding claims, characterized in that the first plurality (n1) is greater than the second plurality (n2).

8. Planetary gear (10) in accordance with claim 7, characterized in that the first plurality (n1) exceeds the second plurality (n2) by an integer factor.

9. Planetary gear (10) in accordance with any of the preceding claims, characterized in that the ribs (32) - form a first rib group (36), having first ribs (321), and a second rib group (38), having second ribs (322), wherein - the first ribs (321) are arranged on the first planetary gear end face (18) and the second ribs (322) are arranged on the second planetary gear end face (20), wherein - the first ribs (321) are arranged turned to the second ribs (322) at a rotation angle which is in a plane extending vertically to the planetary gear axis of rotation (APR).

10. Planetary gear carrier (44) for a planetary gear (10) in accordance with any of the preceding claims, comprising a carrier body (46), which - extends along a planetary gear carrier axis of rotation (APT), - includes a first disc-shaped body (48) and - a second disc-shaped body (50), wherein - the first disc-shaped body (48) and the second disc-shaped body (50) are connected to each other by means of at least one connection body (52, 54, 56) and - the first disc-shaped body (48) comprises a first mounting recess (60), o into which the first mounting section (24) of the planetary gear (10) can be inserted, and o which comprises at least one first latching projection (64) extending in circumferential direction, and - the second disc-shaped body (50) comprises a second mounting recess (62), o into which the second mounting section (26) of the planetary gear (10) can be inserted, and o which comprises at least one second latching projection (66) extending in circumferential direction characterized in that - at least one first axial counter rotation surface (76) which surrounds the first mounting recess (60) is provided on the first disc-shaped body (48) and / or - at least one second axial counter rotation surface (78) which surrounds the second mounting recess (62) is provided on the second disc-shaped body (50), wherein - the first axial counter rotation surface (76) and / or the second axial counter rotation surface (78) interact(s) with the planetary gear abutment protrusions (40) when the planetary gear (10) has been inserted into the first mounting recess (60) and the second mounting recess (62), wherein - the first axial counter rotation surface (76) adjoins, in the direction of the first mounting recess (60), a first inclined surface (80), which is inclined at a first inclined surface angle (α1) in relation to the first axial counter rotation surface (76) and / or - the second axial counter rotation surface (78) adjoins, in the direction of the second mounting recess (62), a second inclined surface (82), which is inclined at a second inclined surface angle (α2) in relation to the second axial counter rotation surface (78).

11. Planetary gear carrier (44) in accordance with claim 10, characterized in that - the first axial counter rotation surface (76) transitions into the first inclined surface (80) over a first convex inclined surface curvature and / or - the second axial counter rotation surface (78) transitions into the second inclined surface (82) over a second convex inclined surface curvature.

12. Planetary gear carrier (44) in accordance with either of claims 10 or 11, characterized in that the carrier body (46) comprises - at least one radial out connection body (52), - at least one radial inner connection body (54), as well as - at least one further connection body (56) arranged between the radial outer connection body (52) and the radial inner connection body (54), wherein - the radial outer connection body (52), the radial inner connection body (54) and the further connection body (56) connect the first disc-shaped body (48) to the second disc-shaped body (50).

13. Planetary gear carrier (44) in accordance with claim 12, characterized in that the further connection body (56) is connected to the radial outer connection body (52) and to the radial inner connection body (54).

14. Planetary gear carrier (44) in accordance with either of claims 12 or 13, characterized in that the radial outer connection body (52) and the at least one further connection body (56) surround a closed recess (58) of the second disc-shaped body (50).

15. Planetary gear carrier (44) in accordance with any of claims 12 to 14, characterized in that - at least one of the further connection bodies (56) transitions into the first axial counter rotation surface (76) over a first concave curvature (871).

16. Planetary gear carrier (44) in accordance with claim 15, characterized in that - the first concave curvature (871) comprises o a radius (R), as well as o a first end (90) and a second end (92), and - the first curvature (871) transitions into the first axial counter rotation surface (76) in the region of the first end (90) and transitions into the further connection bodies (56) in the region of the second end (92), wherein - the radius (R) declines beginning at the first end (90) and at the second end (92).

17. Planetary gear carrier (44) in accordance with any of claims 10 to 16, characterized in that the first disc-shaped body (48) forms a first free planetary gear carrier end face (70) on which a plurality of stiffening ribs (72) is arranged.

18. Planetary gear carrier (44) in accordance with any of claims 10 to 17, characterized in that - the first mounting recess (60) comprises a first extension (y1) along the planetary gear axis of rotation (APT), and - the second mounting recess (62) comprises a second extension (y2) along the planetary gear axis of rotation (APT), wherein - the first extension (y1) is larger than the second extension (y2).

19. Planetary gear carrier (44) in accordance with any of claims 10 to 18, characterized in that the planetary gear carrier comprises a plurality of first mounting recesses and a plurality of second mounting recesses, wherein, on the first disc-shaped body (48), a plurality of planetary gear abutment protrusions (74) are provided which are arranged adjacently to the first mounting recesses (60).

20. Planetary gear carrier (44) in accordance with any of claims 10 to 19, characterized in that - an insert (68) of the planetary gear carrier (44) is connected to the first disc-shaped body, and in that the insert (68) - has an attachment body (94), by means of which the insert (68) is connected to the carrier body (46), wherein - the attachment body (94) comprises a connection surface which faces radially outwards and which o forms at least one radial expansion (98) and o a connection toothing (100).