Geared motor with gearbox which has at least one first planetary gear stage

Abstract

The invention relates to a geared motor with a gearbox which has at least one first planetary gear stage, wherein the first planetary gear stage has at least one first planet gear which is in engagement with the inner toothing of a first hollow gear and with the running toothing of a first sun gear, wherein the first sun gear has a plugging toothing which is spaced apart from the running toothing, wherein the plugging toothing has crowning.

Description

[0001] Geared motor with gearbox having at least a first planetary gear stage

[0002] Description:

[0003] The invention relates to a geared motor with a gearbox which has at least a first planetary gear stage.

[0004] It is generally known that a sun gear of a planetary gear stage has a running toothing which meshes with planetary gears which mesh with the internal toothing of a ring gear.

[0005] From JP 2007- 146 884 A, a transmission is known as the closest state of the art.

[0006] A drive device is known from DE 10 2021 115 043 A1.

[0007] A series of shafts is known from DE 103 16 155 A1.

[0008] A gearbox for a rolling mill drive is known from DE 10 2021 206 054 A1.

[0009] From DE 10 2019 216 427 A1 an axle drive assembly with a pivoting gear set is known.

[0010] A geared motor is known from DE 10 2004 012 022 A1.

[0011] The invention is therefore based on the object of designing a geared motor with an extended service life.

[0012] According to the invention, the object is achieved in the geared motor according to the features specified in claim 1.

[0013] Important features of the invention in the geared motor are that the geared motor has a gear that has at least a first planetary gear stage, wherein the first planetary gear stage has at least one first planet gear that is in engagement with the internal toothing of a first ring gear and with the running toothing of a first sun gear, wherein the first sun gear has a plug-in toothing that is spaced from the running toothing, wherein the plug-in toothing has a crowning.

[0014] The advantage of this design is that the crowning compensates for misalignment and thus evens out the load distribution among the planets. This improves the service life and / or durability of the gear.

[0015] Although the crowning reduces the contact area between the internal gearing of the adapter shaft and the spline, alignment deviations or misalignments can be compensated for by means of the crowning.

[0016] In particular, the first sun gear has a cylindrical region between the running gear and the spline gear, which is spaced from the running gear and adjoins a hyperbolic region, which at its end facing away from the cylindrical region adjoins a conical region which overlaps with the spline gear and radially delimits the spline gear, in particular so that the gearing is conically bevelled, in particular wherein the cone angle, in particular half the opening angle of the straight cone or cone, of the conical region is between 20° and 40°.

[0017] The advantage here is that the hyperbolic region, in contrast to an elliptical or parabolic region, provides improved stiffness and provides an improved transition between the cylindrical and conical region, especially with a lower probability of failure.

[0018] The aforementioned cone angle enables a long transition between the spline and the cylindrical area, thus resulting in high load capacity. Furthermore, the increased mass and / or moment of inertia improves synchronization, as rotational speed fluctuations of the first sun gear are better damped.

[0019] In an advantageous embodiment, the spline has a crowning, in particular a crowning and / or crowning. This is advantageous because it enables further improved compensation of misalignment.

[0020] In an advantageous design, the crowning is more than 100 pm. This is advantageous because the spline of the backlash-free splined shaft connection allows for compensation of large misalignments.

[0021] In an advantageous design, the crowning is between 100 pm and 300 pm. The advantage here is that large misalignments can be compensated for by means of the spline of the backlash-free splined shaft connection.

[0022] In an advantageous embodiment, the axial width of the first sun gear or the axial width of the spline is between 10 and 100 millimeters. This is advantageous because large misalignments can be compensated for by means of a backlash-free spline connection comprising a spline.

[0023] In an advantageous embodiment, the spline is designed as an involute spline. This is advantageous because it allows for simple manufacturing.

[0024] In an advantageous embodiment, the normal pressure angle of the spline, particularly the involute spline, is between 25° and 40°. This has the advantage of keeping the spline tooth height low, thus improving service life.

[0025] In an advantageous embodiment, the normal pressure angle of the spline, in particular the involute spline, is 30°. This has the advantage that the gear can be designed as compactly as possible because the spline can be designed with a very low tooth height. Furthermore, a cost-effective tool can be used to produce the spline. In an advantageous embodiment, the tooth thickness of each tooth of the spline of the first sun gear as a function of the axial position, in particular not has a parabolic curve, but rather a sinusoidal curve, in particular wherein for each tooth of the spline, the maximum tooth thickness is arranged axially centrally in the spline, with the axial direction being aligned parallel to the axis of rotation of the first sun gear. This has the advantage that a further improved load distribution between the planet gears can be achieved and thus also an improved service life.

[0026] In an advantageous embodiment, the first sun gear is tapered between the running gear teeth and the spline teeth. This allows for the integration of a predetermined breaking point into the first sun gear. This prevents overloading of the transmission.

[0027] In an advantageous embodiment, the first sun gear has a region between the running gear teeth and the spline teeth, the smallest outer diameter of which is smaller than the smallest outer diameter of the running gear teeth and / or the root diameter of the running gear teeth and / or the root diameter of the spline teeth and / or the smallest outer diameter of the spline teeth. This advantageously means that, in the event of overload, the region located between the spline teeth and the running gear teeth of the first sun gear fails first, thus acting as a sol-fracture point.

[0028] In an advantageous embodiment, the largest outer diameter of the running gear and / or the tip diameter of the running gear is smaller than the largest outer diameter of the spline and / or smaller than the tip diameter of the spline. This allows for a compact design.

[0029] In particular, only so little torque can be transmitted from the motor to the gearbox that the first sun gear does not yet fail. In an advantageous embodiment, the spline of the first sun gear is inserted into the internal gearing of an adapter shaft, which is rotationally connected to the rotor shaft of the electric motor, in particular by means of a keyway. The advantage here is that the spline can be used to compensate for misalignment.

[0030] In an advantageous embodiment, the planetary gear is rotatably mounted on a planetary carrier, which in particular has straight-flanked internal gearing. This is advantageous because the crowned spline rolls against the straight-flanked teeth of the internal gearing, thus compensating for misalignments.

[0031] In an advantageous embodiment, the transmission has a second planetary gear stage which has a second sun gear which has a running toothing and a spline toothing axially spaced from the running toothing, wherein the spline toothing of the second sun gear has a crowning, in particular which is between 100 pm and 300 pm, in particular wherein the axial width of the second sun gear or the axial width of the spline toothing of the second sun gear is between 10 and 100 millimeters, in particular wherein the normal pressure angle of the spline toothing, in particular the involute toothing, of the second sun gear is 30°. The advantage here is that alignment errors can be compensated for with a backlash-free splined shaft connection.

[0032] In an advantageous embodiment, the spline of the second sun gear is inserted into the internal toothing of the first planet carrier, in particular, the first planet carrier being connected to the second sun gear without or at least with minimal backlash. This is advantageous because misalignments can be compensated for by means of the spline.

[0033] In an advantageous embodiment, the transmission has a third planetary gear stage which has a third sun gear which has a running toothing and a plug-in toothing axially spaced from the running toothing, wherein the plug-in toothing of the third sun gear has a crowning, in particular which is between 100 pm and 300 pm, in particular wherein the axial width of the third sun gear or the axial width of the plug-in toothing of the third sun gear is between 10 and 100 millimeters, in particular wherein the normal pressure angle of the plug-in toothing, in particular the involute toothing, of the third sun gear is 30°. The advantage here is that the tooth height of the plug-in toothing can be provided to be low and thus the transmission can be constructed compactly.

[0034] In an advantageous embodiment, the spline of the third sun gear is inserted into the internal toothing of the second planet carrier, in particular wherein the second planet carrier is connected to the third sun gear in the circumferential direction without play or at least with little play, wherein the third planetary gear stage of the transmission has at least one third planet gear, which is in engagement with the internal toothing of a third ring gear and with the running toothing of a third sun gear. It is advantageous that

[0035] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art. The invention will now be explained in more detail with reference to schematic illustrations:

[0036] Figure 1 shows an oblique view of a gear motor according to the invention.

[0037] Figure 2 shows an enlarged section of Figure 1.

[0038] As shown in the figures, the geared motor comprises an electric motor 1, the rotor shaft of which is connected in a rotationally fixed manner to an adapter shaft 2, which drives a gear.

[0039] The first sun gear 3 has a running toothing and a plug-in toothing spaced from the running toothing, which is inserted into the adapter shaft 2, in particular into an internal toothing of the adapter shaft 2.

[0040] The spline has a width crowning and / or a height crowning, in particular tooth height crowning and / or crowning.

[0041] The crowning effect ensures that alignment deviations between the adapter shaft 2 and the first sun gear 3 can be compensated by the splined shaft connection formed by the internal toothing of the adapter shaft 2 and the spline toothing of the first sun gear 3.

[0042] Preferably, a large crown width of 100 to 200 pm is provided, wherein the axial width of the first sun gear 3 or at least of the spline of the first sun gear 3 is between 10 and 100 millimeters.

[0043] The spline is preferably designed as an involute spline, in particular with a normal pressure angle of 30°. With this unusual value of the normal pressure angle, a particularly low tooth height is sufficient to transmit the intended torque from the adapter shaft 2 to the first sun gear 3. The installation space is thus used as efficiently as possible. Furthermore, the running gear meshes with first planetary gears 6, which also mesh with the internal gearing of a first ring gear 5. The planetary gears 6 are rotatably mounted in a first planetary carrier 6.

[0044] By means of the crowning, the load distribution on the first planet gears 6 is evened out.

[0045] The internal gearing of adapter shaft 2 is straight-flanked, i.e., without crowning. In particular, this internal gearing is also designed as an involute gearing.

[0046] An optional additional crowning feature allows for even better compensation of misalignment. The addendum height and / or the maximum radial distance of the spline exhibits a single maximum as a function of the axial position. Thus, the tooth height initially increases and then decreases again in the axial direction.

[0047] In the circumferential direction, the spline is inserted into the internal toothing of the adapter shaft 2 without backlash or at least with minimal backlash. Thus, the torque generated by the electric motor can be transmitted to the gearbox without backlash or at least with minimal backlash.

[0048] In particular, the transmission is designed with multiple stages. For this purpose, the first planet carrier 6 also has internal gearing, into which a plug-in gearing of the second sun gear 7 is inserted, which is axially spaced from a running gearing of the second sun gear 7.

[0049] This spline toothing of the second sun gear 7 also has a width crowning and / or a height crowning, wherein the internal toothing of the first planet carrier 6 is designed with straight flanks, i.e. without width crowning and without a height crowning.

[0050] The running gear of the second sun gear 7 engages with second planet gears 8, which are rotatably mounted in a second planet carrier 10 and engage with the internal gearing of a second ring gear 9. Internal gearing, in particular a straight-flanked internal gearing, is also formed in the second planet carrier 10, into which a plug-in gearing of a third sun gear 11 is inserted, which is axially spaced from a running gearing of the third sun gear, which engages with third planet gears 13, which in turn engage with the internal gearing of a third ring gear 12.

[0051] The spline of the third sun gear 11 is also designed as an involute spline and again has a crowning and / or crowning.

[0052] The third planetary gears 13 are rotatably mounted in a third planetary carrier 14, which acts as the output shaft of the transmission.

[0053] The first sun gear 3 is tapered in the region axially arranged between the spline teeth of the first sun gear 3 and the running teeth of the first sun gear 3. Thus, the smallest outer diameter of this region is smaller than the root diameter and / or smallest outer diameter of the running teeth of the first sun gear 3 and smaller than the root diameter and / or smallest outer diameter of the spline teeth of the first sun gear 3.

[0054] By specifying the smallest outer diameter of this area, the gearbox can be protected from overloading, since in the event of an overload the tapered area will fail first.

[0055] The largest outer diameter of the spline of the first sun gear 3 is larger than the largest outer diameter of the running gear of the first sun gear 3. Thus, a large torque can be transmitted from the electric motor to the gearbox via the adapter shaft 2.

[0056] If the first sun gear 3 fails, it can be replaced with minimal effort. All that's required is to remove the gearbox from the electric motor, including the adapter shaft 2, and then replace the first sun gear 3.

[0057] In particular, a sinusoidal profile of the crowning improves compensation of misalignment and thus improves service life. In particular, the first sun gear 3 has a cylindrical region between the running gear and the spline gear, which is spaced from the running gear and borders a hyperbolic region. At its end facing away from the cylindrical region, this region borders a conical region that overlaps the spline gear and radially delimits the spline gear, in particular so that the gearing is conically chamfered, in particular wherein the cone angle of the conical region is between 20° and 40°.In further embodiments according to the invention, instead of the three-stage transmission, the transmission is designed only as a single-stage or two-stage planetary transmission or as a transmission with the first planetary transmission stage and further transmission stages which are designed as spur gear stages.

[0058] List of reference symbols

[0059] I Electric motor 2 Adapter shaft

[0060] 3 first sun gear

[0061] 4 first planetary gear

[0062] 5 first ring gear

[0063] 6 first planet carrier 7 second sun gear

[0064] 8 second planetary gear

[0065] 9 second ring gear

[0066] 10 second planet carrier

[0067] II third sun gear 12 third ring gear

[0068] 13 third planet gear

Claims

Patent claims:

1. A geared motor with a gearbox having at least a first planetary gear stage, wherein the first planetary gear stage has at least one first planetary gear that meshes with the internal toothing of a first ring gear and with the running toothing of a first sun gear, characterized in that the first sun gear has a spline toothing that is spaced apart from the running toothing, wherein the spline toothing has a crowning, in particular wherein the first sun gear has a cylindrical region between the running toothing and the spline toothing, which is spaced apart from the running toothing and borders on a hyperbolic region, which, at its end facing away from the cylindrical region, borders on a conical region that overlaps with the spline toothing and radially delimits the spline toothing, in particular so that the toothing is conically beveled,in particular, the cone angle of the conical area is between 20° and 40°., 2. Geared motor according to claim 1, characterized in that the plug-in toothing has a crowning, in particular tooth height crowning and / or crowning.

3. Geared motor according to one of the preceding claims, characterized in that the crowning is more than 100 pm and / or that the crowning is between 100 pm and 300 pm.

4. Geared motor according to one of the preceding claims, characterized in that the axial width of the first sun gear or the axial width of the spline between 10 and 100 millimeters.

5. Geared motor according to one of the preceding claims, characterized in that the plug-in toothing is designed as an involute toothing.

6. Geared motor according to one of the preceding claims, characterized in that the normal pressure angle of the plug-in toothing, in particular the involute toothing, is between 25° and 40°.

7. Geared motor according to one of the preceding claims, characterized in that the normal pressure angle of the plug-in toothing, in particular the involute toothing, is 30°.

8. Geared motor according to one of the preceding claims, characterized in that the tooth thickness of each tooth of the spline of the first sun gear as a function of the axial position, in particular does not have a parabolic profile, but rather a sinusoidal profile, in particular wherein for each tooth of the spline the maximum tooth thickness is arranged axially centrally in the spline, wherein the axial direction is aligned parallel to the axis of rotation of the first sun gear.

9. Geared motor according to one of the preceding claims, characterized in that the first sun gear is tapered between the running gear and the plug-in gear and / or that the first sun gear has a region between the running gear and the plug-in gear, the smallest outer diameter of which is smaller than the smallest outer diameter of the running gear and / or than the root circle diameter of the running gear and / or than the root circle diameter of the plug-in gear and / or than the smallest outer diameter of the plug-in gear.

10. Geared motor according to one of the preceding claims, characterized in that the largest outer diameter of the running gear teeth and / or the tip diameter of the running gear teeth is smaller than the largest outer diameter of the plug-in gear teeth and / or smaller than the tip diameter of the plug-in gear teeth.

11. Geared motor according to one of the preceding claims, characterized in that the plug-in toothing of the first sun gear is inserted into an internal toothing of an adapter shaft which is rotationally connected to the rotor shaft of the electric motor, in particular by means of a key connection.

12. Geared motor according to one of the preceding claims, characterized in that the planetary gear is rotatably mounted on a planetary carrier which has, in particular, straight-flanked internal teeth.

13. Geared motor according to one of the preceding claims, characterized in that the transmission has a second planetary gear stage which has a second sun gear which has a running toothing and a plug-in toothing axially spaced from the running toothing, wherein the plug-in toothing of the second sun gear has a crowning, in particular which is between 100 pm and 300 pm, in particular wherein the axial width of the second sun gear or the axial width of the plug-in toothing of the second sun gear is between 10 and 100 millimeters, in particular wherein the normal pressure angle of the plug-in toothing, in particular the involute toothing, of the second sun gear is 30 °.

14. Geared motor according to one of the preceding claims, characterized in that the plug-in toothing of the second sun gear is inserted into the internal toothing of the first planet carrier, in particular wherein the first planet carrier is connected to the second sun gear without play or at least with little play.

15. Geared motor according to one of the preceding claims, characterized in that the transmission has a third planetary gear stage which has a third sun gear which has a running toothing and a plug-in toothing axially spaced from the running toothing, wherein the plug-in toothing of the third sun gear has a crowning, in particular which is between 100 pm and 300 pm, in particular wherein the axial width of the third sun gear or the axial width of the plug-in toothing of the third sun gear is between 10 and 100 millimeters, in particular wherein the normal pressure angle of the plug-in toothing, in particular the involute toothing, of the third sun gear is 30 °.

16. Geared motor according to one of the preceding claims, characterized in that the plug-in toothing of the third sun gear is inserted into the internal toothing of the second planet carrier, in particular wherein the second planet carrier is connected to the third sun gear in the circumferential direction without play or at least with little play, wherein the third planetary gear stage of the transmission has at least one third planet gear which is in engagement with the internal toothing of a third ring gear and with the running toothing of a third sun gear.

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