planetary gear

Abstract

A planetary gear (1) with 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) which are each mounted on the planet carrier (6) so as to be rotatable about a planet axis (8), and the planets (9) are each in meshing engagement with an inner side of the ring gear (5), is characterized 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 spaced from the axis of rotation (7) by a first radial distance (r1) and the second axial end (11) is spaced from the axis of rotation by a second radial distance (r2) (7) is removed,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 in amount from one another, so that the planetary axis (8) is tilted relative to the rotation axis (7).

Description

The invention relates to a planetary gear set according to the preamble of claim 1.To achieve simple assembly, planetary gears are usually designed with a slight play between the intermeshing gear wheel pairs (ring gear and planet, planet and sun). In particular in the case of higher-frequency alternating loads, this leads to acoustically disturbing rattle which arises as a result of the backlash-induced tooth exchange shocks when the direction of rotation of the gearwheel partners is reversed.In chassis technology, actively adjustable roll stabilizers are used, the actuator of which is often equipped with a multi-stage planetary transmission which is subjected to a (more or less) high-frequency alternating load during the operational use of a motor vehicle equipped therewith. This is because, when driving over rough roads, vibrations are generated at the vehicle wheels, which vibrations are introduced into the transmission of the associated actuator via the stabilizer sections of the roll stabilizer.In this connection, DE 10 2017 208 800 B3 discloses the use of a planetary gear divided into two partial gears within a planetary gear, wherein the partial gears are rotationally braced against one another by means of a spring element in the installed state in the planetary gear, in order to eliminate the gear backlash in this way. The production of such a divided planetary gear and its mounting within a multi-stage planetary gear are complicated. In addition, due to the increased friction, because of the present spring prestress, efficiency losses occur within the transmission.DE 10 2021 120 463 A1 in turn discloses a planetary gear for use on an actuator of an adjustable roll stabilizer, in which at least one bolt that accommodates a planetary gear is arranged on the planetary carrier in such an elastically tilted manner that in a load-free state of the planetary gear its planetary axis does not run axis-parallel to the common (central) rotational axis of the planetary gear. The elastic tilting of the bolt together with planet described there is intended to eliminate the play between the tooth flanks of planet and sun gear or planet and ring gear in an essentially load-free state of the planetary gearing and thus contribute to avoiding disruptive oscillations, in particular during the load change. From a constructional point of view, the bolt is connected with a first end section to the planet carrier in an elastically deformable manner and with a second end section is arranged radially displaceably on an elongated hole on the planet carrier. The elastic (thus also movable) mounting of the bolt in relation to the planetary carrier provided in this way is intended to ensure that, in a load-free state of the planetary gearing (=operation state of at most 10% of a rated load of the planetary gearing), the planet mounted on the bolt meshes with the ring gear or sun gear without play as a result of the elastic tilting in relation to the axis of rotation (compare FIG. 1 there) under prestress. The design implementation of the tilting described in DE 10 2021 120 463 A1 is complicated, in particular with regard to the mounting of the planetary gear relative to the planetary carrier. Moreover, disadvantageous friction losses arise due to the required prestress.It is an object of the present invention to provide a planetary gear of the type mentioned at the beginning which ensures freedom from play in an improved manner and thus avoids disadvantageous noise generation, in particular during the load change. At the same time, the planetary transmission should be low-friction under high load and therefore be operable efficiently and with a long service life. In addition, an actuator for an actively adjustable roll stabilizer is to be specified which achieves corresponding advantages.The object mentioned at the outset is initially achieved by a planetary gear set according to the features of claim 1. this is a planetary gear set, in particular for use on an actuator of an adjustable roll stabilizer for a motor vehicle, wherein the planetary gear set comprises a sun gear, a ring gear and a planetary carrier, which are arranged coaxially with respect to a common axis of rotation, wherein the sun gear is in meshing tooth engagement with a plurality of planets mounted on the planetary carrier in each case rotatably about a planetary axis, and the planets are in meshing tooth engagement with an inner side of the ring gear in each case. According to the invention, the planetary transmission is characterized in that each planet is assigned a first axial end lying on the planetary axis at a first point of the planet and a second axial end lying on the planetary axis at an opposite second side of the planet, wherein the first axial end is spaced apart from the rotational axis by a first radial distance and the second axial end is spaced apart from the rotational axis by a second radial distance, wherein the first radial distance and the second radial distance are invariable per se independently of a load state of the planetary transmission and also differ from one another in amount, so that the planetary axis is tilted with respect to the rotational axis. The tilting of the planetary axis provided according to the invention is accordingly not based on an elastic prestress (unlike in DE 10 2021 120 463 A1), but is structurally defined by constant radial distances. By tilting the planetary axes relative to the axis of rotation of the planetary gearing realized in this way, a play-free toothing within the planetary gearing is achieved at least in the load-free state of the planetary gearing in a manner still to be explained.Expediently, in all planets of the planetary gearing, the first radial distances are smaller than the second radial distances, so that imaginary extensions of the planetary axes preferably meet at a point lying on the rotational axis. Accordingly, all planets are tilted in the same direction in this case and in particular have a tilt of equal intensity with respect to the axis of rotation. The orientation of the (in the same direction) tilting of the planets is possible in principle in various ways. Thus, the first radial distances can face the drive side of the planetary gearing and the second radial distances face the driven side of the planetary gearing. In this case (planet carrier with the tilted planets forms a cone-like shape), the planet carrier with the tilted planets could be easily introduced into the ring gear in a joining direction directed to drive the planetary gear, which facilitates its assembly. Alternatively, conversely, the first radial distances could face the output side of the planetary gearing and the second radial distances could face the drive side of the planetary gearing. Such an alignment could prove to be advantageous with regard to the material stress, in particular since in this case the sun gear is subjected to more uniform load over its axial width.Advantageously, in a load-free state of the planetary gearing, a planetary axis and the rotational axis of the planetary carrier are each coplanar, i.e. they lie in an imaginary plane running through the rotational axis. In the context of the present application, a load-free state of the planetary transmission is to be understood as meaning a state in which the planetary transmission is loaded only slightly or not at all (below 10% of the rated load).In an advantageous manner, in at least one load-free state of the planetary gearing, a first region of the planetary gear dips deeply into the toothing of the sun gear, and a second region of the planetary gear dips deeply into the toothing of the ring gear, in order in this way to create a play-free drive connection within the planetary gearing-that is to say between sun gear and planet and between ring gear and planet-which, in particular, also exists during a load change of the planetary gearing.The tilting of the planetary axes advantageously ensures that a line contact is achieved in the case of a tooth engagement between planetary and sun gear and / or a tooth engagement between planetary and ring gear. In this case, the planets transmit a torque introduced into the planetary gear diagonally through the tooth surfaces concerned. In particular when the planetary gear is used within an adjustable roll stabilizer, disadvantageous acoustic noise generation (rattle) is prevented in this way due to the freedom from play achieved despite alternating torque introduction.With regard to the mounting of the planets, different constructions are conceivable. According to a preferred development of the planetary gear mechanism, a planet is in each case rotatably mounted on a bolt passing through it, wherein the bolt is in each case connected to the planetary carrier near the first axial end of the planetary gear mechanism and near the second axial end of the planetary gear mechanism, in particular is pressed into the planetary carrier. For the rotatable mounting of the planet relative to the bolt, a suitable rolling bearing, for example a needle bearing, or a plain bearing can be used.From a constructional point of view, an advantageous embodiment of the planetary gear set provides that the planet carrier comprises a housing body which twists about the axis of rotation under the influence of load, in particular in the form of a torque introduced into the planetary gear set, wherein the planets are mounted with respect to the housing body in such a way that the second axial ends of the planets are offset with respect to the first axial ends of the planets in the circumferential direction by the twisting of the housing body. This circumferential offset corresponds to an additional rotation with respect to the axis of rotation.The circumferential offset arising under load advantageously causes an additional oblique position of the planetary axes relative to the axis of rotation, perpendicular to their tilting, which cancels the coplanarity of the axis of rotation and respective planetary axes, which is achieved in the load-free state. The axis of rotation and the planetary axes are thus in skew relationship to one another under load.For the conceptual distinction, in the context of the present application, "tilting" of the planetary axis is mentioned if the rotation of the planetary axis in a plane running through the rotational axis is meant, while the term "oblique position" of the planetary axis is used if an additional rotation of the planetary axis perpendicular thereto is meant due to the circumferential offset arising under load, as described above.The (additional) oblique position of the planetary axles under load-induced twisting of the planetary carrier advantageously ensures that, in the case of a toothed engagement between planetary and sun gear, and / or in the case of a toothed engagement between planetary and ring gear, surface contact is achieved which increases with increasing load. In other words, the position of the planetary axes within the planetary gearing advantageously changes as a result of the load-induced rotational deformation of the planetary carrier, as a result of which the geometry of the tooth engagement advantageously changes to the effect that the planetary and sun gear and / or planetary and ring gear contact one another in surface regions which increase with increasing load, which reduces, inter alia, operational wear.The described load-induced rotational twisting of the planetary carrier, which results in the oblique position of the planetary axes, advantageously takes place equally in both rotational directions of the planetary gearing. The effects of the inclination described above can be used accordingly for both rotational directions of the planetary gearing.According to an advantageous development of the planetary gearing, the planets have a crowning on their teeth formed thereon. In view of the rotational deformation of the planet carrier occurring under load, a spherical design of the teeth contributes to a more uniform loading of the teeth, whereby their wear is reduced.The additional oblique position of the planetary axles under load-induced twisting of the planetary carrier advantageously additionally ensures a freedom of play of the tooth engagement which increases with increasing twisting. This reduces friction inside the planetary gear under load, thereby achieving an efficiency gain of the planetary gear (less friction loss).It has been found that a higher efficiency can be achieved with a planetary gear set according to the invention than with conventional gears in which individual planets are prestressed by a spring mechanism in order to avoid acoustic noise generation. In the planetary transmission according to the invention, it is ensured that in operating situations there is freedom from load (including low loads), freedom from play. In particular, in the case of load changes within the planetary gearing, a noiseless tooth flank change takes place, whereby a disadvantageous noise generation is prevented. Under load, a line contact initially present during tooth engagement increasingly changes with increasing load to a surface contact, which reduces wear. A slight play which occurs advantageously only under load reduces the friction within the transmission, so that an increased efficiency can be achieved under high load.The object mentioned at the beginning is furthermore achieved by an actuator for an actively adjustable roll stabilizer according to the features of claim 12, which according to the invention has an electric motor and a transmission which can be brought into drive connection therewith in order to be able to rotate a stabilizer section of the roll stabilizer about an axis of rotation, wherein the transmission is constructed in particular in multiple stages and has a planetary transmission according to the features described above at least on one transmission stage, preferably on its output-side transmission stage.The invention is explained in more detail below with reference to the attached drawings. Other advantageous effects of the invention are also evident therefrom. The drawing shows: FIG. 1 shows an actively adjustable roll stabilizer in a simplified schematic view obliquely from above, FIG. 2 shows a partial sectional illustration of an actuator known from the prior art for illustrating the field of application of the invention, FIG. 3 is a partially sectional view of a planetary gear set according to the invention, simplified in the drawing, FIG. 4 shows a tooth of a planetary gear used on the planetary gear according to the invention in a simplified illustration to illustrate various contact situations, FIG. 5 shows a planet carrier of a planetary gear according to the invention in the no-load state, FIG. 6 shows a planet carrier of a planetary gear according to the invention with built-in bolts in the loaded state.FIG. 1 shows an actively adjustable roll stabilizer 3 for a motor vehicle, including wheel suspensions and wheels connected thereto, in a simplified schematic view. A left wheel 32a is rotatably mounted with respect to a wheel suspension 31a. Likewise, a right wheel 32 bis rotatably mounted with respect to a wheel suspension 31 b. In a manner known per se, the wheel suspensions 31 aand 31 bcan be mounted on a body of a motor vehicle (not shown for reasons of illustration).Each of the wheel suspensions 31 a, 31 bis coupled via a pendulum support, not designated in more detail here, to a wheel-side end of a stabilizer section 30 aand stabilizer section 30 b, respectively, wherein the stabilizer sections 30 aand 30 bare part of the roll stabilizer 3. In addition to the stabilizer sections 30 aand 30 b, the roll stabilizer 3 comprises an actuator 2, which is shown in simplified form as a cylindrical component and is arranged centrally between these and connects these rotatably with respect to one another about an axis of rotation 7.The actuator 2 has a housing 29 with a cylindrical basic shape, which extends substantially rotationally symmetrically to the axis of rotation 7. Inside the housing 29 there are accommodated an electric motor 16 and a gear 18, which are indicated only by reference numerals in FIG. 1. Electric motor 16 and transmission 18 can be brought into driving connection with one another in such a way that stabilizer section 30 bof adjustable roll stabilizer 3 can be rotated about axis of rotation 7 relative to stabilizer section 30 afixed to the housing.Due to the coupling with the wheel suspensions 31 aand 31 b, the roll stabilizer 3 can influence the roll behavior of a motor vehicle equipped therewith in this way; in particular, the adjustable roll stabilizer can specifically cause the vehicle body to roll or, for example, when cornering, can specifically counteract the vehicle body to roll. The transmission 18 used in the actuator 2 is advantageously designed as a multi-stage planetary transmission which is arranged coaxially with the electric motor 16 within the housing 29. An exemplary embodiment of such a transmission is described below with reference to FIG. 2.FIG. 2 shows a partial sectional illustration of an actuator, from which in particular the structure of the transmission contained therein is evident. Such a transmission can be used on an adjustable roll stabilizer 3, as shown with reference to FIG. 1, in a manner known per se.The transmission 18 shown in FIG. 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 merely by the reference sign in the illustration. The first planetary gear stage 21 is in driving connection with a second planetary gear stage 22, which in turn is in driving connection with a third, output-side planetary gear stage 23. A planet carrier 34 of the third planetary gear stage 23 is in driving connection via a clutch 38 acting as a vibration decoupling element with an output element 33, which is rotatably mounted with respect to the housing 29 via roller bearings 25. The output element 33 is connected in a rotationally fixed manner in the assembled state to a stabilizer section 30 b, which is indicated only by a reference sign in the drawing.With the transmission shown in FIG. 2, an input rotational speed provided by the electric motor 16 via the motor shaft 17 is transmitted or transmitted via the three planetary gear stages 21, 22 and 23 and the clutch 38 into an output rotational speed provided at the output element 33, whereby the stabilizer section 30 bcan be driven for rotation about the rotational axis 7.In the transmission 18 shown in FIG. 2, each of the planetary gear stages 21, 22, 23 comprises a combination of sun gear, ring gear, planetary carrier and planetary gears rotatably mounted thereon. The ring gears are designed as toothings at least for the second planetary gear stage 22 and the third planetary gear stage 23 on the housing 29 of the actuator, in particular on the inner side 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 designated).It is evident that axially divided planets 35 are used in the third planetary gear stage 23. These are planets which, as is known, for example, from DE 10 2017 208 800 B3, are prestressed in the installed state into the housing 29 by a spring acting between the partial gearwheels in order in this way to eliminate a gear play present within the gear 18 and thus, in particular during the change of direction, to avoid a noise development which is caused by a tooth flank change which is subject to play. In the transmission 18 shown in FIG. 2, the strained planets 35 cause additional friction during operation, which deteriorates the efficiency of the transmission in power transmission. In addition, the manufacture of the clampable planets 35 is complicated and their placement within the housing 29 requires greater axial installation space than even if simple planets were used on the third planetary gear stage (as on the first planetary gear stage 21 or the second planetary gear stage 22).FIG. 3 shows, in a partially simplified representation, essential areas of a planetary gear 1 according to the invention. The planetary gear 1 shown in FIG. 3 can in principle, with structural adaptation, be used advantageously on an actuator 2 of a roll stabilizer 3 as explained with reference to FIG. 1, in particular alternatively to the third planetary gear stage 23 shown and explained as part of the transmission 18 in FIG. 2. The planetary transmission 1 according to the invention comprises, in a manner initially known per se, a sun wheel 4, a ring wheel 5 and a planetary carrier 6 (not shown in FIG. 3 for the sake of illustration, compare FIGS. 5 and 6 ) which are arranged coaxially with respect to one another with respect to a common rotational axis 7. In the completely assembled state, the sun wheel 4 is in meshing toothed engagement with a plurality of planets 9 mounted on the planet carrier 6 such that they can rotate about a planet axis 8, and the planets 9 are in meshing toothed engagement with an inner side of the ring gear 5. It should be noted that the ring gear 5, comparable to the configuration of the transmission 18 as explained with reference to FIG. 2, can advantageously be formed as part of the housing of the actuator.As can be seen with reference to FIG. 3, in the planetary gear 1 according to the invention, the planetary axis 8 of the planetary gear 9 is not parallel to the rotational axis 7 (of the planetary carrier 6 or the sun gear 4) but instead tilted with respect to the latter. Accordingly, the planet 9 is also tilted. This is explained as follows: As well as the other planets of the planetary gear 1 not shown in FIG. 3, a first axial end 10 lying on the planetary axis 8 is assigned to one side of the planet 9 and a second axial end 11 lying on the planetary axis 8 is assigned to an opposite second side of the planet 9. In this case, the first axial end 10 is at a first radial distance r 1 from the axis of rotation 7. The second axial end 11 is again at a second radial distance r 2 from the axis of rotation 7. Due to the mentioned tilting, the first radial distance r 1 is smaller than the second radial distance r 2, and accordingly the radial distances r 1 and r 2 differ from one another in terms of amount. The radial distances r1 and r2 are independent of a load state of the planetary gearing 1, since the planetary axle 8 is held on the planetary carrier 6 in radially immovable bores 40, 41 respectively. In this connection, reference is made to FIG. 5, from which the bores 40, 41 formed on the planet carrier 6 for receiving bolts 14 along the planet axis 8 are shown.In a planetary gear according to the invention, as partially shown with reference to FIG. 3, the first radial distances r 1 are smaller than the second radial distances r 2 in all planets, so that imaginary extensions of the planetary axes 8 of all planets 9 meet at a point lying on the rotational axis 7 (in FIG. 3, this point would lie far to the left of the drawing section). In the no-load state of the planetary gear 1, the planetary axles 8 and the rotational axle 7 of the planetary carrier 6 are each coplanar. This means that the planetary axis 8 of each planetary gear lies in an imaginary plane running through the rotational axis 7, which corresponds to the plane of the drawing in the example shown in FIG. 3.It can also be seen in FIG. 3 that in the no-load state of the planetary gear 1, caused by the tilting of the planetary gear 9, a first region 12 of the planetary gear 9 dips deeply into the toothing of the sun gear 4 and that a second region 13 of the planetary gear 9 dips deeply into the toothing of the ring gear 5. The first region 12 and the second region 13 are each illustrated in a simplified manner in the drawing; the actual shape of these regions can deviate therefrom. Due to the deep engagement at these regions 12 and 13 lying diagonally with respect to the planet 9, a play-free drive connection is created within the planetary gearing 1, which in particular also exists during a load change within the planetary gearing 1, whereby a disturbing flank strike during the load change within the planetary gearing is prevented. The tilting of the planetary axis 8 ensures that a linear contact is achieved in the case of the existing tooth engagement between planet 9 and sun wheel 4 and in the case of the tooth engagement between planet 9 and ring wheel 5.The structure of the planetary gear set according to the invention will be explained further below with reference to FIGS. 4, 5 and 6, which are all connected with FIG. 3 and serve to explain the effects and effects of the planetary gear set according to the invention.FIG. 5 shows a perspective illustration of a planet carrier 6 which is advantageously used in a planetary transmission according to the invention and has an output element 24 adjoining it. The planetary carrier 6 is an essentially rotationally symmetrical component, in contrast to which the output element 24, which is not to be explained in more detail here, has a five-beam star shape. Furthermore, the planet carrier 6 comprises a housing body 15 which is connected at an 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 which is suitable for accommodating four planets-not shown here. For this purpose, four bores 40, 41 are respectively made in the housing body 15 and in the plate 20, which bores serve in pairs in each case for receiving a bolt 14 as shown in FIG. 6.FIG. 5 shows the planet carrier 6 in a load-free state, the planet carrier 6 is undeformed, corresponding to webs of the housing body 15 running in the axial direction extending parallel to the axis of rotation 7 toward the plate 20.In contrast, FIG. 6 shows the planet carrier 6 with bolts 14 mounted thereon in a load state.It should first be noted that FIG. 6 shows the same planetary carrier 6 as in FIG. 5, but in contrast four bolts 14 are pressed into the bores on the housing body 15 or the plate 20 (compare FIG. 5 ). In a completely assembled state of the planetary carrier 6, planets 9 would be rotatably mounted on the bolts 14. For the sake of illustration, no planets are drawn in FIG. 6, as a result of which an effect which sets under load can be explained better. If the planetary gear 1 is under load, then with increasing torque acting on the planetary gear, the interaction of the gear partners (sun gear, planetary, planetary carrier, ring gear) causes the housing body 15 to twist about the axis of rotation 7, indicated by a rotational direction arrow 19 and, visible in the drawing, by a profile of the webs of the housing body 15 which is oblique in comparison to the axis of rotation 7 and which are connected to the plate 20. In the deformed state of the housing body 15 shown in FIG. 6, the plate 20 is slightly rotated about the axis of rotation 7 with respect to the output element 24. Accordingly, the bores 40 formed on the plate 20 are also rotated about the axis of rotation 7 with respect to the bores 41 of the housing body 15. This has the consequence that the planetary axes 8 of the four planets have also been set obliquely in comparison with the rotational axis 7, and accordingly there is an "oblique position" illustrated in FIG. 6 between the planetary axis 8 and the rotational axis 7. The inclination shown in FIG. 6 is based on the load-dependent deformation of the housing body 15 and is to be distinguished from the load-independent "tilting" according to FIG. 3. It should be noted that the inclination of the planetary axis 8 taken place by using the housing body 15 in the circumferential direction 19 can also have an influence on the inclination according to FIG. 3 depending on the geometry.As a result of the inclination under the influence of load which additionally takes place in FIG. 6, the tooth engagement within the planetary gearing 1 also changes. FIG. 4 shows a simplified representation of an individual tooth 26 of a planet of a planetary gear according to the invention in a perspective representation in different engagement states. The tooth 26 is a tooth formed on the planet 9, which, as shown in FIG. 3, is in engagement with a ring gear 5.In the no-load state, i.e. when the housing body of the planet carrier is undeformed, the tooth 26 is in linear contact with the ring gear (not shown in FIG. 4 ) in the second region 13 shown in the drawing. This corresponds largely to the situation already explained with reference to FIG. 3, where the second region 13 is likewise illustrated as a region penetrating into the ring gear 5 on account of the tilting.As the load on the planetary gear mechanism increases and the deformation of the housing body 15 of the planetary carrier 6 thus begins, as already explained in particular with reference to FIG. 6, the contacting at the tooth 26 changes-indicated by the arrow-to the effect that the initially present line contacting 13 increasingly changes toward a surface contacting, represented by the region shown as surface contact 27. In this state, there is an oblique position of the planet, and thus also of the tooth 26, corresponding also to its tooth center 28, indicated by the dashed line, with respect 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 capacity of the tooth contact is increased. As the torque increases, the surface contact increases.This effect occurs equally also in the case of a reverse direction of rotation of the planetary gearing.With dynamically changing loading of the planetary gearing, there is in each case advantageously freedom from play within the transmission when the reversal point is reached, which leads to smooth, noise-free running of the transmission. The dimensioning of the planet carrier is advantageously to be adjusted in such a way that its torsional rigidity corresponds to the value which ensures, at higher torques introduced, that surface contact of the teeth is established again as a result of the twisting of the planet carrier.Reference numerals denote reference numerals1 Planetary transmission 2 Actuator 3 Actively adjustable roll stabilizer 4 Sun wheel 5 Ring gear 6 Planet carrier 7 Axis of rotation 8 Planetary axis 9 Planet 10 First axial end 11 Second axial end 12 First region 13 Second region 14 Bolt 15 Housing body 16 Electric motor 17 Motor shaft 18 Transmission 19 Circumferential direction 20 Plate 21 First planetary transmission stage 22 Second planetary transmission stage 23 Third planetary transmission stage 24 Output element 25 Rolling bearing 26 Tooth 27 Surface contact 28 Tooth center 29 Housing 30 aStabilizer section 30 bStabilizer section 31 a Radaufhängung 31 b Radaufhängung 32 aWheel 32 bWheel 33 Output element 34 Planet carrier 35 Planet 36 Sun wheel 37 Ring gear 38 Clutch 40 Bore 41 Bore r 1 First radial distance r 2 Second radial distanceReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2017 208 800 B3 [0004, 0031]DE 10 2021 120 463 A1 [0005, 0007]

Claims

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 wheel (4), a ring wheel (5) and a planet carrier (6), which are arranged coaxially with respect to a common axis of rotation (7), wherein the sun wheel (4) is in meshing tooth engagement with a plurality of planets (9) mounted on the planet carrier (6) such that they can rotate about a planet axis (8) in each case, and the planets (9) are in meshing tooth engagement with an inner side of the ring wheel (5), characterized 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 spaced apart from the rotational axis (7) by a first radial distance (r1) and the second axial end (11) is spaced apart 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 per se independently of a load state of the planetary gearing (1) and also differ from one another in amount, so that the planetary axis (8) is tilted with respect to the rotational axis (7).Planetary gear according to claim 1, characterised in that in 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 planetary axes (8) meet preferably at a point lying on the rotational axis (7).Planetary transmission according to claim 1 or 2, characterised in that in a load-free state of the planetary transmission (1), a planetary axis (8) and the rotational axis (7) of the planetary carrier (6) are each coplanar, that is to say each lie in an imaginary plane running through the rotational axis (7).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 region (12) of the planetary gear (9) dips deeply into the toothing of the sun gear (4) and a second region (13) of the planetary gear (9) dips deeply into the toothing of the ring gear (5) in order to create a drive connection without play within the planetary gear (1), which drive connection in particular also exists during a load change of the planetary gear (1).Planetary gear according to one of the preceding claims, characterized in that the tilting of the planetary axes (8) ensures that a linear contact is achieved in the case of a toothed engagement between planetary gear (9) and sun gear (4) and / or a toothed engagement between planetary gear (9) and ring gear (5).Planetary gear according to one of the preceding claims, characterized in that a planet (9) is mounted rotatably on a bolt (14) passing through it, the bolt (14) being connected to the planet carrier (6), in particular pressed into the latter, in each case close to the first axial end (10) of the planet (9) and close to the second axial end (11) of the planet (9).Planetary gear according to one of the preceding claims, characterized in that the planet carrier (6) comprises a housing body (15) which twists about the axis of rotation (7) under the influence of load, in particular in the form of a torque introduced into the planetary gear (1), wherein the planets (9) are mounted with respect to the housing body (15) in such a way that the second axial ends (11) of the planets (9) are offset with respect to the first axial ends (10) of the planets (9) in the circumferential direction (19) as a result of the twisting of the housing body (15).Planetary gear according to claim 7, characterised in that the circumferential offset arising under load causes an additional oblique position of the planetary axes (8) relative to the rotational axis (7), perpendicular to their tilting, which cancels a respective coplanarity of the rotational axis (7) and planetary axes (8).Planetary gear according to claim 8 or 9, characterised in that the additional oblique position of the planetary axles (8) under load-induced twisting of the planetary carrier (6) ensures that in the case of a toothed engagement existing between planetary gear (9) and sun gear (4) and / or a toothed engagement existing between planetary gear (9) and ring gear (5), a surface contact (26) is achieved which increases with increasing load.Planetary gear according to one of the preceding claims, characterized in that teeth (25) formed on the planets (9) have a crowning.Planetary gear according to one of Claims 8 to 10, characterized in that the additional oblique position of the planetary axles (8) under load-induced twisting of the planetary carrier (6) ensures a freedom of play of the tooth engagement which increases with increasing twisting.Actuator (2) for an actively adjustable roll stabilizer (3), having an electric motor (16) and a transmission (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 an axis of rotation (7), wherein the transmission (18) is in particular of multistage design and has a planetary transmission (1) according to one of the preceding claims at least on one transmission stage (23), preferably on its output-side transmission stage (23).

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