Planetary gear mechanism

Abstract

The invention relates to a planetary gear mechanism (1) having a sun gear (4), a ring gear (5) and a planet carrier (6), which are arranged coaxially to one another in relation to a common axis of rotation (7), wherein the sun gear (4) is in meshing engagement with a plurality of planets (9) each mounted rotatably about a planet axis (8) on the planet carrier (6), and the planets (9) are each in meshing engagement with an inner side of the ring gear (5), characterised in that each planet (9) is assigned a first axial end (10) lying on the planet axis (8) on a first side of the planet (9) and a second axial end (11) lying on the planet axis (8) on an opposite second side of the planet (9), wherein the first axial end (10) is at a first radial distance (r1) from the axis of rotation (7) and the second axial end (11) is at a second radial distance (r2) from the axis of rotation (7), wherein the first radial distance (r1) and the second radial distance (r2) are invariable independently of a load state of the planetary gear mechanism (1) and also differ from one another in amount, so that the planet axis (8) is tilted relative to the axis of rotation (7).

Description

[0001] Planetary gear

[0002] The invention relates to a planetary gear according to the preamble of claim 1. In addition, the invention relates to an actuator for an actively adjustable roll stabilizer according to claim 12.

[0003] To ensure easy assembly, planetary gears are typically designed with a slight backlash between the meshing gear pairs (ring gear and planet, planet gear and sun gear). Particularly under high-frequency alternating loads, this leads to acoustically disturbing rattling caused by the backlash-related tooth change shocks when the direction of rotation of the gear partners reverses.

[0004] Actively adjustable roll stabilizers are used in chassis technology. Their actuators are often equipped with a multi-stage planetary gear, which is subjected to (more or less) high-frequency alternating loads during operational use of a vehicle equipped with them. When driving over uneven road surfaces, vibrations are generated at the vehicle wheels, which are transmitted via the stabilizer sections of the roll stabilizer into the gear of the associated actuator.

[0005] In this context, DE 102017 208 800 B3 discloses the use of a planetary gear divided into two component gears within a planetary gear train. When installed in the planetary gear train, the component gears are rotationally clamped against each other by a spring element to eliminate gear backlash. The manufacture of such a split planetary gear train and its assembly within a multi-stage planetary gear train is complex. In addition, the increased friction caused by the spring preload results in efficiency losses within the transmission.

[0006] DE 102021 120463 A1, in turn, discloses a planetary gear for use in an actuator of an adjustable roll stabilizer, in which at least one pin accommodating a planet is elastically tilted on the planet carrier such that, in a load-free state of the planetary gear, its planetary axis is not axially parallel to the common (central) rotational axis of the planetary gear. The elastic tilting of the pin together with the planet described therein is intended to eliminate the play between the tooth flanks of the planet and sun gear or planet and ring gear in a substantially load-free state of the planetary gear, thus contributing to the prevention of disruptive vibrations, particularly during load changes. From a structural point of view, the pin is elastically deformably connected to the planet carrier by a first end section and is arranged radially displaceably on an elongated hole on the planet carrier by a second end section.The elastic (and thus also movable) mounting of the pin relative to the planetary carrier provided in this way is intended to ensure that, when the planetary gear is unloaded (= operating condition of no more than 10% of the planetary gear's nominal load), the planet mounted on the pin meshes with the ring gear or sun gear without backlash due to the elastic tilting relative to the rotational axis (see Figure 1 therein) under preload. The structural implementation of the tilting described in DE 10 2021 120 463 A1 is complex, particularly with regard to the mounting of the planet relative to the planetary carrier. In addition, the required preload causes adverse friction losses.

[0007] It is an object of the present invention to provide a planetary gear of the type mentioned above that provides improved backlash-free operation and thus avoids adverse noise development, particularly during load changes. At the same time, the planetary gear should operate with low friction under high loads and thus be efficient and have a long service life. In addition, an actuator for an actively adjustable roll stabilizer should be provided that achieves corresponding advantages.

[0008] The object mentioned at the outset is firstly achieved by a planetary gear according to the features of claim 1. This is a planetary gear, in particular for use on an actuator of an adjustable roll stabilizer for a motor vehicle, wherein the planetary gear comprises a sun gear, a ring gear and a planet carrier, which are arranged coaxially to one another with respect to a common axis of rotation, wherein the sun gear is in meshing tooth engagement with a plurality of planets, each of which is mounted on the planet carrier so as to be rotatable about a planetary axis, and the planets are each in meshing tooth engagement with an inner side of the ring gear.According to the invention, the planetary gear is characterized in that each planet is assigned a first axial end located on the planetary axis at a first location on the planet and a second axial end located on the planetary axis at an opposite second side of the planet, wherein the first axial end is spaced from the axis of rotation by a first radial distance and the second axial end is spaced from the axis of rotation by a second radial distance, wherein the first radial distance and the second radial distance are invariable independently of a load state of the planetary gear and also differ from one another in amount, so that the planetary axis is tilted relative to the axis of rotation. The tilting of the planetary axis provided according to the invention is therefore not based on an elastic preload (unlike in DE 10 2021 120 463 A1), but is structurally determined by constant radial distances.By tilting the planetary axes relative to the rotational axis of the planetary gear thus achieved, a backlash-free toothing within the planetary gear is achieved in a manner to be explained below, at least in the load-free state of the planetary gear.

[0009] For all planets in the planetary gear set, the first radial distances are expediently smaller than the second radial distances, so that imaginary extensions of the planetary axes preferably meet at a point on the rotation axis. Accordingly, in this case, all planets are tilted in the same direction and, in particular, have an equal degree of tilt relative to the rotation axis. The orientation of the (same direction) tilt of the planets is, in principle, possible in various ways. For example, the first radial distances can face the input side of the planetary gear set, and the second radial distances can face the output side of the planetary gear set. In this case (the planetary carrier with the tilted planets forms a cone-like shape), the planet carrier with the tilted planets could be easily inserted into the ring gear in a joining direction directed towards the drive of the planetary gear set, which facilitates its assembly.Alternatively, the first radial distances could be positioned toward the output side of the planetary gear, and the second radial distances could be positioned toward the input side of the planetary gear. Such an alignment could prove advantageous in terms of material stress, particularly since the sun gear is subjected to more even stress across its axial width.

[0010] In a load-free state of the planetary gear, a planetary axis and the rotational axis of the planet carrier are advantageously coplanar, i.e., they lie in an imaginary plane passing through the rotational axis. In the context of this application, a load-free state of the planetary gear is understood to mean a state in which the planetary gear is not loaded or is barely loaded (below 10% of the nominal load).

[0011] Advantageously, in at least one load-free state of the planetary gear, a first region of the planet engages deeply into the toothing of the sun gear, and a second region of the planet engages deeply into the toothing of the ring gear, in order to create a backlash-free drive connection within the planetary gear - i.e. between the sun gear and the planet and between the ring gear and the planet - which exists in particular even during a load change of the planetary gear.

[0012] Advantageously, the tilting of the planetary axes ensures that a linear contact is achieved when the planets and sun gear mesh, and / or the planets and ring gear mesh. The planets transmit the torque introduced into the planetary gear diagonally through the affected tooth surfaces. Particularly when the planetary gear is used within an adjustable roll stabilizer, this eliminates adverse acoustic noise (rattling) despite the alternating torque introduction.

[0013] Different designs are conceivable for the bearing of the planets.

[0014] According to a preferred development of the planetary gear, each planet is rotatably mounted on a pin penetrating the planetary gear. The pin is connected to the planet carrier, in particular pressed into it, near the first axial end of the planet and near the second axial end of the planet. A suitable rolling bearing, such as a needle bearing or a plain bearing, can be used to rotatably support the planet relative to the pin.

[0015] From a design perspective, an advantageous embodiment of the planetary gear system provides that the planet carrier comprises a housing body that twists around the rotational axis under the influence of load, in particular in the form of a torque introduced into the planetary gear system. The planets are mounted relative to the housing body in such a way that the second axial ends of the planets are offset in the circumferential direction relative to the first axial ends of the planets due to the twisting of the housing body. This circumferential offset corresponds to an additional twist relative to the rotational axis.

[0016] The circumferential offset occurring under load advantageously causes an additional inclination of the planetary axes relative to the axis of rotation, perpendicular to its tilt, which eliminates the coplanarity of the axis of rotation and the respective planetary axes achieved in the unloaded state. Thus, the axis of rotation and the planetary axes are skewed to each other under load.

[0017] For the purpose of conceptual differentiation, in the context of the present application, the term "tilting" of the planetary axis is used when the rotation of the planetary axis in a plane passing through the axis of rotation is meant, while the term "inclined position" of the planetary axis is used when an additional rotation of the planetary axis perpendicular to this is meant due to the circumferential offset occurring under load, as described above.

[0018] The (additional) inclination of the planetary axes under load-induced torsion of the planetary carrier advantageously ensures that, when the planetary gear and sun gear mesh, and / or when the planetary gear and ring gear mesh, surface contact is achieved that increases with increasing load. In other words, the load-induced rotational deformation of the planetary carrier advantageously changes the position of the planetary axes within the planetary gear set, thereby advantageously changing the geometry of the tooth engagement such that the planetary gear and sun gear and / or the planetary gear and ring gear contact each other over a surface area that increases with increasing load. This, among other things, reduces operational wear.

[0019] The described load-induced rotational distortion of the planet carrier, which results in the skewed position of the planetary axes, advantageously occurs equally in both directions of rotation of the planetary gear. The previously described effects of the skewed position can be utilized for both directions of rotation of the planetary gear.

[0020] According to an advantageous development of the planetary gear, the planets have a crowned design on their teeth. Given the rotational deformation of the planet carrier that occurs under load, a crowned design of the teeth contributes to a more even load on the teeth, thereby reducing their wear.

[0021] The additional inclination of the planetary axes under load-induced torsion of the planetary carrier also advantageously ensures that the backlash of the tooth meshing increases with increasing torsion. This reduces friction within the planetary gear under load, resulting in increased efficiency of the planetary gear (less friction loss).

[0022] It has been shown that with a planetary gear train described in the invention, a higher level of efficiency can be achieved than with conventional gear trains in which individual planets are preloaded by a spring mechanism to prevent acoustic noise. The planetary gear train according to the invention ensures that there is no backlash in operating situations under no load (including low loads). In particular, during load changes within the planetary gear train, a silent tooth flank change takes place, thus preventing adverse noise development. Under load, the line contact that is initially present during tooth meshing increasingly changes to surface contact with increasing load, which reduces wear. A slight backlash that advantageously only occurs under load reduces friction within the gear train, thus allowing increased efficiency to be achieved under high load.

[0023] The object mentioned at the outset is further achieved by an actuator for an actively adjustable roll stabilizer according to the features of claim 12. According to the invention, this actuator has an electric motor and a gear that can be brought into drive connection therewith in order to be able to rotate a stabilizer section of the roll stabilizer about a rotation axis, wherein the gear is in particular constructed in several stages and has at least on one gear stage, preferably on its output-side gear stage, a planetary gear according to the features described above.

[0024] The invention is explained in more detail below with reference to the accompanying drawings. Further advantageous effects of the invention are also apparent from these drawings. The drawing shows:

[0025] Figure 1 shows an actively adjustable roll stabilizer in a simplified schematic view from above,

[0026] Figure 2 is a partial sectional view of an actuator known from the prior art to illustrate the field of application of the invention,

[0027] Figure 3 is a partial sectional view of a planetary gear according to the invention, simplified in drawing,

[0028] Figure 4 shows a tooth of a planetary gear used in the planetary gear according to the invention to illustrate various contact situations in a simplified representation, Figure 5 shows a planet carrier of a planetary gear according to the invention in the load-free state,

[0029] Figure 6 shows a planet carrier of a planetary gear according to the invention with installed bolts in the loaded state.

[0030] Figure 1 shows a simplified schematic view of an actively adjustable roll stabilizer 3 for a motor vehicle, including the associated wheel suspensions and wheels. A left wheel 32a is rotatably mounted relative to a wheel suspension 31a. Similarly, a right wheel 32b is rotatably mounted relative to a wheel suspension 31b. The wheel suspensions 31a and 31b can be mounted to a body of a motor vehicle (not shown for illustrative reasons) in a manner known per se.

[0031] Each of the wheel suspensions 31a, 31b is coupled via a pendulum support (not further described here) to a wheel-side end of a stabilizer section 30a or stabilizer section 30b, respectively, wherein the stabilizer sections 30a and 30b are part of the roll stabilizer 3. In addition to the stabilizer sections 30a and 30b, the roll stabilizer 3 comprises an actuator 2, shown simplified as a cylindrical component, which is arranged centrally between them and connects them so that they can rotate relative to one another about a rotation axis 7.

[0032] The actuator 2 has a housing 29 with a cylindrical basic shape, which extends essentially rotationally symmetrically to the rotation axis 7. An electric motor 16 and a gear 18, which are only indicated by reference numerals in Figure 1, are housed within the housing 29. The electric motor 16 and gear 18 can be drivenly connected to one another in such a way that the stabilizer section 30b of the adjustable roll stabilizer 3 can be rotated about the rotation axis 7 relative to the stabilizer section 30a fixed to the housing.

[0033] Due to its coupling to the wheel suspensions 31a and 31b, the roll stabilizer 3 can thus influence the roll behavior of a motor vehicle equipped therewith. In particular, the adjustable roll stabilizer can specifically cause the vehicle body to roll or—for example, when cornering—specifically counteract the roll of the vehicle body. The gear 18 used in the actuator 2 is advantageously designed as a multi-stage planetary gear, which is arranged coaxially with the electric motor 16 within the housing 29. An exemplary embodiment of such a gear is described below with reference to Figure 2.

[0034] Figure 2 shows a partial sectional view of an actuator, showing in particular the structure of the gear mechanism contained therein. Such a gear mechanism can be used in a known manner on an adjustable roll stabilizer 3, as shown in Figure 1.

[0035] The transmission 18 shown in Figure 2 has three planetary gear stages, of which a first planetary gear stage 21 can be driven by a motor shaft 17 of an electric motor 16, indicated only by the reference numeral in the illustration. The first planetary gear stage 21 is drive-connected to a second planetary gear stage 22, which in turn is drive-connected to a third, output-side planetary gear stage 23. A planet carrier 34 of the third planetary gear stage 23 is drive-connected via a clutch 38 acting as a vibration-decoupling element to an output element 33, which is rotatably mounted relative to the housing 29 via roller bearings 25. In the assembled state, the output element 33 is rotationally fixedly connected to a stabilizer section 30b, indicated only by a reference numeral in the drawing.

[0036] With the transmission shown in Fig. 2, a drive speed provided by the electric motor 16 via the motor shaft 17 is translated or transmitted via the three planetary gear stages 21, 22 and 23 and the clutch 38 into an output speed provided at the output element 33, whereby the stabilizer section 30b can be driven to rotate about the rotation axis 7.

[0037] In the transmission 18 shown in Figure 2, each of the planetary gear stages 21, 22, 23 comprises a combination of a sun gear, a ring gear, a planet carrier, and planets rotatably mounted thereon. The ring gears, at least for the second planetary gear stage 22 and the third planetary gear stage 23, are formed as gears on the housing 29 of the actuator, in particular on the inside of the housing 29. In the case of the first planetary gear stage 21, the ring gear is formed by a separately inserted component (not further designated).

[0038] It is noticeable that axially split planets 35 are used in the third planetary gear stage 23. These planets are preloaded by a spring acting between the component gears when installed in the housing 29, as is known, for example, from DE 10 2017 208 800 B3. This eliminates any backlash within the gear 18 and thus prevents noise, particularly during direction changes, caused by backlash-affected tooth flank changes. In the gear 18 shown in Figure 2, the preloaded planets 35 cause additional friction during operation, which impairs the efficiency of the gear in power transmission.In addition, the manufacture of the clampable planets 35 is complex, and their placement within the housing 29 requires greater axial installation space than if simple planets were also used on the third planetary gear stage (as on the first planetary gear stage 21 or the second planetary gear stage 22).

[0039] Figure 3 shows, in a partial, simplified representation, essential areas of a planetary gear 1 according to the invention. The planetary gear 1 shown in Figure 3 can, in principle - with structural adaptation - be used advantageously on an actuator 2 of a roll stabilizer 3 as explained with reference to Figure 1, in particular as an alternative to the third planetary gear stage 23 shown and explained in Figure 2 as part of the transmission 18. The planetary gear 1 according to the invention comprises, in a manner initially known per se, a sun gear 4, a ring gear 5 and a planet carrier 6 (not shown in Figure 3 for reasons of illustration, compare Figures 5 and 6), which are arranged coaxially to one another with respect to a common axis of rotation 7.In the fully assembled state, the sun gear 4 meshes with several planets 9, each mounted on the planet carrier 6 for rotation about a planetary axis 8, and the planets 9 mesh with an inner side of the ring gear 5. It should be noted that the ring gear 5, comparable to the design of the transmission 18 as explained with reference to Figure 2, can advantageously be formed as part of the actuator housing.

[0040] As can be seen from Figure 3, in the planetary gear 1 according to the invention, the planetary axis 8 of the planet 9 is not parallel to the axis of rotation 7 (of the planet carrier 6 or the sun gear 4), but is tilted relative to it. The planet 9 is also tilted accordingly. This can be explained as follows: The planet 9 - as well as the other planets of the planetary gear 1 not shown in Figure 3 - is assigned a first axial end 10 lying on the planetary axis 8 on one side of the planet 9 and a second axial end 11 lying on the planetary axis 8 on an opposite second side of the planet 9. The first axial end 10 is spaced from the axis of rotation 7 by a first radial distance r1. The second axial end 11 is in turn spaced from the axis of rotation 7 by a second radial distance r2.Due to the aforementioned tilting, the first radial distance r1 is smaller than the second radial distance r2; accordingly, the radial distances r1 and r2 differ in magnitude from one another. The radial distances r1 and r2 are independent of the load condition of the planetary gear 1, since the planetary axis 8 is held on the planet carrier 6 in radially immovable bores 40, 41. Reference is made to Figure 5, which shows the bores 40, 41 formed on the planet carrier 6 for receiving bolts 14 along the planetary axis 8.

[0041] In a planetary gear according to the invention, as partially shown in Figure 3, the first radial distances r1 for all planets are smaller than the second radial distances r2, so that imaginary extensions of the planetary axes 8 of all planets 9 meet at a point lying on the axis of rotation 7 (in Figure 3 this point would be far to the left of the drawing section). When the planetary gear 1 is not under load, the planetary axes 8 and the axis of rotation 7 of the planet carrier 6 are each coplanar. This means that the planetary axis 8 of each planet lies in an imaginary plane running through the axis of rotation 7; in the example shown in Figure 3 this corresponds to the drawing plane.

[0042] Furthermore, Figure 3 shows that when the planetary gear set 1 is not under load, due to the tilting of the planet 9, a first region 12 of the planet 9 engages deeply into the toothing of the sun gear 4 and a second region 13 of the planet 9 engages deeply into the toothing of the ring gear 5. The first region 12 and the second region 13 are each shown in a simplified manner; the actual shape of these regions may differ. Due to the deep engagement in these regions 12 and 13, which are diagonally opposite to one another with respect to the planet 9, a backlash-free drive connection is created within the planetary gear set 1. This connection also exists in particular during a load change within the planetary gear set 1, thus preventing disruptive flank knocking during a load change within the planetary gear set.The tilting of the planetary axis 8 ensures that a line contact is achieved during the existing tooth engagement between planet 9 and sun gear 4 and during the tooth engagement between planet 9 and ring gear 5.

[0043] The structure of the planetary gear according to the invention will be further explained below with reference to Figures 4, 5 and 6, which are all related to Figure 3 and serve to explain the effects and effects of the planetary gear according to the invention.

[0044] Figure 5 shows a perspective view of a planetary carrier 6, which is advantageously used in a planetary gear according to the invention, with an adjoining output element 24. The planet carrier 6 is a substantially rotationally symmetrical component; in contrast, the output element 24, which will not be explained in detail here, has a five-pointed star shape. The planet carrier 6 also comprises a housing body 15, which is connected at one axial end of the planet carrier 6 to a substantially circular plate 20, wherein the housing body 15 and plate 20 form a cage-like structure suitable for accommodating four planets (not shown here). For this purpose, four bores 40, 41 are each made in the housing body 15 and in the plate 20, which bores serve in pairs to accommodate a bolt 14 as shown in Figure 6.

[0045] In Figure 5, the planet carrier 6 is shown in a load-free state, the planet carrier 6 is undeformed, and accordingly, webs of the housing body 15 extending in the axial direction extend parallel to the rotation axis 7 towards the plate 20.

[0046] In contrast, Figure 6 shows the planet carrier 6 with bolts 14 attached to it in a load state.

[0047] First, it should be noted that Figure 6 shows the same planet carrier 6 as in Figure 5, but with four bolts 14 pressed into the holes on the housing body 15 or the plate 20 (see Figure 5). In a fully assembled state of the planet carrier 6, planets 9 would be rotatably mounted on the bolts 14. For illustrative purposes, no planets are shown in Figure 6, which allows for a better explanation of an effect that occurs under load.

[0048] If the planetary gear unit 1 is under load, the housing body 15 is twisted about the rotation axis 7 as the torque acting on the planetary gear unit increases and the gear partners (sun gear, planet, planet carrier, ring gear) interact. This is indicated by an arrow 19 indicating the direction of rotation and is graphically visible by the oblique course of the webs of the housing body 15, which are connected to the plate 20, compared to the rotation axis 7. In the deformed state of the housing body 15 shown in Figure 6, the plate 20 is slightly twisted about the rotation axis 7 relative to the output element 24. Accordingly, the bores 40 formed on the plate 20 are also twisted about the rotation axis 7 relative to the bores 41 of the housing body 15.This has the consequence that the planetary axes 8 of the four planets are also inclined in relation to the rotational axis 7, accordingly there is an “inclined position” between the planetary axis 8 and the rotational axis 7, as shown in the drawing in Figure 6. The inclined position shown in Figure 6 is due to the load-induced deformation of the housing body 15 and is to be distinguished from the load-independent “tilting” according to Figure 3. In other words, in the loaded state shown in Figure 6 there is an inclined position as shown, and at the same time there is also a tilt as shown in Figure 3. It should be noted that the inclined position of the planetary axis 8 in the circumferential direction 19 caused by the use of the housing body 15 can, depending on the geometry, also have an influence on the tilt according to Figure 3.

[0049] As a result of the additional inclination under load shown in Figure 6, the tooth meshing within the planetary gear 1 also changes. This is explained in more detail with reference to Figure 4. Figure 4 shows a simplified illustration of a single tooth 26 of a planet of a planetary gear according to the invention in perspective view in different engagement states. Tooth 26 is a tooth formed on the planet 9, which, as shown in Figure 3, meshes with a ring gear 5.

[0050] In the load-free state, i.e., when the housing body of the planet carrier is undeformed, tooth 26 is in linear contact with the ring gear (not shown in Figure 4) in the second region 13 shown in the diagram. This largely corresponds to the situation already explained with reference to Figure 3, where the second region 13 is also shown as a region that dips into the ring gear 5 due to the tilting.

[0051] With increasing load on the planetary gear, and the resulting deformation of the housing body 15 of the planet carrier 6, as already explained in particular with reference to Figure 6, the contact at tooth 26 changes - indicated by the arrow - in such a way that the initially existing line contact 13 increasingly changes into a surface contact, represented by the area drawn as surface contact 27. In this state, the planet, and thus also tooth 26, and accordingly its tooth center 28, indicated by the dashed line, are inclined relative to the axis of rotation 7. By changing the line contact present in the load-free state to a surface contact 27 under the influence of load, the load-bearing capacity of the tooth contact increases. With increasing torque, the surface contact increases. This effect also occurs when the direction of rotation of the planetary gear is reversed.

[0052] When the planetary gear is subjected to dynamically changing loads, the reversal point is reached, resulting in a beneficial absence of backlash within the gear, resulting in smooth, noiseless operation. The dimensioning of the planetary carrier should be adjusted so that its torsional rigidity corresponds to the value that ensures that, at higher applied torques, surface contact between the teeth is restored due to the torsion of the planetary carrier.

[0053] Reference symbol

[0054] planetary gear

[0055] Actuator actively adjustable roll stabilizer

[0056] sun gear

[0057] ring gear

[0058] planet carrier

[0059] rotation axis

[0060] planetary axis

[0061] Planet first axial end second axial end first area second area

[0062] bolt

[0063] Housing body

[0064] electric motor

[0065] Motor shaft

[0066] Gearbox

[0067] circumferential direction

[0068] Plate first planetary gear stage second planetary gear stage third planetary gear stage

[0069] Output element

[0070] Rolling bearings

[0071] Tooth

[0072] Surface contact

[0073] Tooth center

[0074] Housing a Stabilizer section b Stabilizer section 1a Wheel suspension 1 b Wheel suspension 2a Wheel 2b Wheel 3 Output element 4 Planet carrier 5 Planet 6 Sun gear 7 Ring gear 8 Clutch 0 Bore 1 Bore r1 First radial distance r2 Second radial distance

Claims

Patent claims 1. Planetary gear (1), in particular for use on an actuator (2) of an adjustable roll stabilizer (3) for a motor vehicle, wherein the planetary gear (1) comprises a sun gear (4), a ring gear (5), and a planet carrier (6), which are arranged coaxially with one another with respect to a common axis of rotation (7), wherein the sun gear (4) is in meshing engagement with a plurality of planets (9), each rotatably mounted on the planet carrier (6) about a planetary axis (8), and the planets (9) are each in meshing engagement with an inner side of the ring gear (5), characterized in that each planet (9) is assigned a first axial end (10) lying on the planetary axis (8) on a first side of the planet (9) and a second axial end (11) lying on the planetary axis (8) on an opposite second side of the planet (9).wherein the first axial end (10) is spaced from the rotational axis (7) by a first radial distance (r1) and the second axial end (11) is spaced from the rotational axis (7) by a second radial distance (r2), wherein the first radial distance (r1) and the second radial distance (r2) are invariable independently of a load condition of the planetary gear (1) and also differ from one another in terms of amount, so that the planetary axis (8) is tilted relative to the rotational axis (7).

2. Planetary gear according to claim 1, characterized in that for all planets (9) of the planetary gear (1) the first radial distances (r1) are smaller than the second radial distances (r2), so that imaginary extensions of the planet axes (8) preferably meet at a point lying on the rotation axis (7).

3. Planetary gear according to claim 1 or 2, characterized in that in a load-free state of the planetary gear (1), a planetary axis (8) and the rotational axis (7) of the planet carrier (6) are each coplanar, that is to say each lie in an imaginary plane passing through the rotational axis (7).

4. Planetary gear according to one of the preceding claims, characterized in that at least in a load-free state of the planetary gear (1) a first Area (12) of the planet (9) is deeply immersed in the toothing of the sun gear (4) and a second area (13) of the planet (9) is deeply immersed in the toothing of the ring gear (5) in order to create a play-free drive connection within the planetary gear (1), which is particularly effective during a load change of the planetary gear (I) exists.

5. Planetary gear according to one of the preceding claims, characterized in that the tilting of the planetary axes (8) ensures that a line contact is achieved in the case of a tooth engagement between the planet (9) and the sun gear (4) and / or a tooth engagement between the planet (9) and the ring gear (5).

6. Planetary gear according to one of the preceding claims, characterized in that a planet (9) is rotatably mounted on a bolt (14) penetrating it, wherein the bolt (14) is connected to the planet carrier (6) near the first axial end (10) of the planet (9) and near the second axial end (11) of the planet (9), in particular is pressed into the latter.

7. Planetary gear according to one of the preceding claims, characterized in that the planet carrier (6) comprises a housing body (15) which twists around the rotational axis (7) under the influence of a load, in particular in the form of a torque introduced into the planetary gear (1), wherein the planets (9) are mounted relative to the housing body (15) in such a way that the second axial ends (II ) the planets (9) are offset relative to the first axial ends (10) of the planets (9) by the twisting of the housing body (15) in the circumferential direction (19).

8. Planetary gear according to claim 7, characterized in that the circumferential offset occurring under load causes an additional inclination of the planetary axes (8) relative to the rotational axis (7), perpendicular to their tilting, which cancels out any coplanarity of the rotational axis (7) and the planetary axes (8).

9. Planetary gear according to claim 8 or 9, characterized in that the additional inclined position of the planet axes (8) under load-induced twisting of the planet carrier (6) ensures that in the case of a tooth engagement between the planet (9) and the sun gear (4), and / or a tooth engagement between the planet (9) and the ring gear (5), a surface contact (26) is achieved which increases with increasing load.

10. Planetary gear according to one of the preceding claims, characterized in that teeth (25) formed on the planets (9) have a crowning.

11. Planetary gear according to one of claims 8 to 10, characterized in that the additional inclination of the planetary axes (8) under load-induced torsion of the planetary carrier (6) ensures a backlash of the tooth engagement which increases with increasing torsion.

12. Actuator (2) for an actively adjustable roll stabilizer (3), comprising an electric motor (16) and a gear (18) which can be brought into drive connection therewith in order to be able to rotate a stabilizer section (30b) of the roll stabilizer (3) about a rotation axis (7), wherein the gear (18) is in particular constructed in several stages and has a planetary gear (1) according to one of the preceding claims at least on one gear stage (23), preferably on its output-side gear stage (23).

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