Shaft-hub connection, in particular of a geared motor

Abstract

A shaft-hub connection, in particular of a geared motor, having a hollow shaft section acting as a hub, in particular of a rotor shaft of an electric motor, in particular which drives a gear mechanism, in particular of a planetary gear set, of the geared motor, wherein a shaft, in particular a sun gear shaft, is at least partly inserted into the hollow shaft section, wherein a spacer disc is arranged in the hollow shaft section, the spacer disc axially delimiting the shaft and being connected to the hub.

Description

[0001] Shaft-hub connection, especially of a geared motor

[0002] Description:

[0003] The invention relates to a shaft-hub connection, in particular of a geared motor.

[0004] It is generally known that in a shaft-hub connection, a shaft is connected to a hub in a rotationally fixed manner, in particular for the transmission of torque.

[0005] From US 2013 / 0 062 926 A1, the closest state of the art is a drive for a truck.

[0006] A gearbox with a flange arrangement is known from US 2021 / 0 071 646 A1.

[0007] A metal-ceramic composite body is known from DE 38 89 044 T2.

[0008] A planetary gear is known from DE 102022 003 275 A1.

[0009] The invention is therefore based on the object of developing a shaft-hub connection, in particular of a geared motor, whereby safe operation can be guaranteed.

[0010] According to the invention, the object is achieved in the shaft-hub connection according to the features specified in claim 1.

[0011] Important features of the invention in the shaft-hub connection, in particular of a geared motor, are that it has a hollow shaft section acting as a hub, in particular a rotor shaft of an electric motor, in particular which drives a gear, in particular a planetary gear, of the geared motor, wherein a shaft, in particular a sun gear shaft, is at least partially inserted into the hollow shaft section, wherein a spacer disk is arranged in the hollow shaft section, which spacer disk axially delimits the shaft and is connected to the hub. The advantage here is that the shaft is limited to its intended axial area and thus the shaft can be inserted and used in the intended manner. In this way, safe operation can be guaranteed by securing the axial working area of ​​the shaft.For example, the shaft is a sun gear shaft and is therefore mounted between planetary gears, where the running gear of the sun gear shaft engages with the planetary gears, in particular with the gears of the planetary gear of a geared motor. To prevent the running gear from axially drifting out of the engagement area with the planetary gears, the spacer washer according to the invention limits the shaft. By using spacers of different thicknesses, different positions can be achieved as limiting positions, in particular shafts of different lengths can be limited. In particular, when the thickness of the spacer washer is negligible, i.e. when the spacer washer is omitted, the shaft is limited by the bottom of the blind bore of the shaft.

[0012] Thus, depending on the axial length of the shaft and the area covered by the toothing of the planetary gears in the axial direction, the spacer disk can be dimensioned in such a way that the running toothing is in engagement with the planetary gears in this entire area.

[0013] In an advantageous embodiment, the hollow shaft section is formed by a blind hole formed in the hub, with the spacer being in contact with and / or secured to the bottom of the blind hole. It is advantageous that the spacer can be arranged in the blind hole.

[0014] In an advantageous embodiment, the spacer is integrally bonded to the hub, in particular to the hollow shaft section. This is advantageous because the spacer can be bonded using adhesive, thus facilitating simple production because the spacer is inserted into the blind hole and bonded in place after the adhesive has been applied.

[0015] In an advantageous embodiment, the spacer is positively connected to the hub, in particular to the hollow shaft section, in particular wherein a first screw protrudes through the spacer in the axial direction and is screwed into a threaded bore formed in the hub, in particular at the bottom of the blind bore, in particular wherein the screw head of the first screw presses the spacer against the hub, in particular against the bottom of the blind bore. Advantageously, the spacer is securely fastened.

[0016] In an advantageous embodiment, the spacer is designed as a perforated disk and / or the spacer is designed as a hollow cylinder. This is advantageous because it allows for simple manufacturing.

[0017] In an advantageous embodiment, the blind hole is designed as a stepped bore, and the spacer has an outer step on its outer circumference, with which the spacer rests against a step of the stepped bore and / or is centered and / or aligned. In particular, the spacer is designed as a rotating body and the maximum outer radius is a step function as a function of the axial position. It is advantageous that the spacer can be centered by means of the stepped bore.

[0018] In an advantageous embodiment, the axial direction is aligned parallel to the direction of rotation of the hub and / or the shaft, in particular, the radial direction being related to the direction of rotation of the hub and the circumferential direction also being related to the direction of rotation of the hub. It is advantageous that the hub and the shaft are coaxially aligned with each other and are connected to each other in a rotationally fixed manner.

[0019] In an advantageous design, the end face of the shaft rests against the spacer. The advantage here is that the spacer provides axial limitation when the shaft rests against the spacer.

[0020] In an advantageous embodiment, a further blind hole is made in the end face of the shaft, in particular facing the spacer disk, in which a damping disk is arranged, through which a further screw projects and is screwed into a further threaded hole made in the shaft, wherein the screw head of the further screw axially delimits the damping disk and wherein a spring element supported on the shaft, in particular a disc spring, presses the damping disk towards the screw head of the further screw. The advantage here is that the impact of the shaft on the spacer disk is dampened by means of the axially interposed damping disk and thus the service life is increased, thus enabling the longest possible reliable operation.

[0021] In an advantageous embodiment, the outer diameter of the damping disc, which is particularly designed as a rotating body, has a stepped profile as a function of the axial position. This is advantageous because centering at the step of the receiving stepped bore can be carried out easily and precisely.

[0022] In an advantageous embodiment, the shaft has a spline, in particular a spline external spline, which is inserted into a hollow spline, in particular a spline internal spline, of the hub or which is pressed into the blind hole, in particular plastically or at least elastically deforming. It is advantageous that the shaft and the hub are positively connected to one another in the circumferential direction, in particular, that they are connected to one another in a rotationally fixed manner.

[0023] In an advantageous embodiment, the area covered by the spring element in the axial direction is contained in or overlaps with the area covered by the damping disc in the axial direction. It is advantageous that the spring element can be arranged in the free space created by the step.

[0024] In an advantageous embodiment, the area covered by the spring element in the radial direction is contained in or overlaps with the area covered by the damping disc in the radial direction. It is advantageous that the spring element can be arranged in the free space created by the step.

[0025] In an advantageous embodiment, the spring element is positioned against one or the entire step of the damping ring. This is advantageous in that the spring element is supported on the shaft on one side and on the damping disc on the other. In an advantageous embodiment, the first screw is spaced apart from the other screw, in particular, in the axial direction, in particular, the first screw has a smaller external thread diameter than the other screw. This is advantageous in that the fastening elements, i.e., screws, do not damage each other.

[0026] In an advantageous embodiment, the spacer disc rests against the damping disc. The advantage here is that the damping disc can be made of a softer material than the spacer disc. This allows for damping of the impact shock.

[0027] Important features in the method for producing a variant of variants of a series of shaft-hub connections are that the kit comprises a hollow shaft section acting as a hub, in particular a rotor shaft of an electric motor, in particular which drives a gear, in particular a planetary gear, of the geared motor, a first shaft, in particular a sun gear shaft of the planetary gear, a second shaft, in particular a sun gear shaft of the planetary gear, a first spacer disk and a second spacer disk, wherein the second spacer disk has a larger axial extent, in particular in the direction of the disk axis of the spacer disk and / or in the direction of the rotational symmetry axis of the respective spacer disk, in particular wherein the maximum outer diameter, in particular of the sun gear toothing, of the second shaft is larger than the maximum outer diameter, in particular of the sun gear toothing, of the first shaft, wherein,To produce a first variant, the first spacer is inserted into the hollow shaft section and then the first shaft is at least partially inserted into the hollow shaft section and connected to the hollow shaft section, wherein the first spacer delimits the shaft axially, in particular in the axial direction, and To produce a second variant, the second spacer is inserted into the hollow shaft section and then the second shaft is at least partially inserted into the hollow shaft section and connected to the hollow shaft section, wherein the second spacer delimits the shaft axially, in particular in the axial direction.

[0028] The advantage here is that either the first or the second version can be manufactured. If the first version is to be manufactured, the first spacer is used; otherwise, the second version.

[0029] A third variant can be produced by not inserting any spacer into the hollow shaft section.

[0030] This means that a different variant can be created depending on the spacer disc.

[0031] Important features of the geared motor with a shaft-hub connection are that the shaft is a sun gear shaft of a planetary gear of the geared motor, wherein a rotor shaft of an electric motor, in particular acting as a hub, has the hollow shaft section, wherein the shaft has a running gear which engages with planet gears, and a plug-in external gear which is pressed and / or inserted into the hollow shaft section, in particular is pressed in in a plastic or at least elastically deforming manner, in particular wherein the hollow gear of the rotor shaft which is in engagement with the plug-in external gear covers an area in the axial direction which overlaps the area covered by the spacer disk in the axial direction.

[0032] The advantage here is that the spacer ensures that the running gear teeth remain fully engaged with the planetary gears, especially with the gear teeth of the planetary gears.

[0033] In an advantageous embodiment, a spring element supported on the shaft, in particular a disc spring, applies spring force generated by the spring element to the spacer disk in the axial direction, either directly or via a damping disk, particularly to preload a bearing that rotatably supports a planetary carrier onto which the shaft is pressed in the axial direction. The planetary carrier is either the planetary carrier that supports the planets meshing with the running gear of the sun gear shaft, or a planetary carrier of a subsequent stage of the two- or multi-stage planetary gear system.

[0034] 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.

[0035] The invention will now be explained in more detail using schematic illustrations:

[0036] Figure 1 shows a first embodiment of a shaft-hub connection of a geared motor according to the invention, wherein a spacer disk 1 is clamped in a hollow shaft 2.

[0037] Figure 2 shows a second embodiment, wherein the spacer disc 1 is connected to the hollow shaft 2 by means of a screw 20.

[0038] Figure 3 shows a third embodiment in which no spacer disc is present.

[0039] Figure 4 shows a fourth embodiment, wherein a further spacer disc 41 is used, the axial width of which is greater than the axial width of the spacer disc 1.

[0040] Figure 5 shows a fifth embodiment, wherein a damping disc 51 is provided on the end face of the shaft 10, axially opposite a spacer disc.

[0041] As shown in Figure 1, the shaft 10, in particular the sun gear shaft of a planetary gear, of the shaft-hub connection has a running gear 4 and a plug-in gear 9. Planetary gears rotatably mounted on a respective planet carrier pin 8 by means of a respective bearing engage with the running gear 4, which in turn engage with a ring gear of a housing part or a ring gear that is rotationally fixedly connected to a housing part.

[0042] With the spline 9, the shaft 10 is inserted into a spline 3, in particular internal spline, of a hollow shaft 2 acting as the hub of the shaft-hub connection, and is connected in a rotationally fixed manner.

[0043] The hollow shaft 2 is preferably not axially hollow throughout, but rather has only one hollow shaft section formed by an axially directed blind hole. The shaft 10 is inserted into the blind hole of the hollow shaft 2, with the spline 3 formed on the outer edge, in particular the radial outer edge, of the blind hole. The shaft 10 is mounted for axial movement between the planet gears 7. For axial limitation, a spacer disk 1 is arranged in the blind hole, in particular axially between the shaft 10 and the bottom of the blind hole.

[0044] The axial direction is aligned parallel to the rotational axis of the shaft 10. The radial direction and the circumferential direction are also each related to the rotational axis of the shaft 10.

[0045] The spacer disc 1 has such a radial oversize that it is clamped in the spline 3, in particular wherein elastically deformed regions of the spacer disc 1 bulge axially behind the spline in the radial direction and thus the spacer disc is axially limited at the axial end of the spline 3 itself, in particular is positioned against the teeth of the spline projecting radially inwards.

[0046] The spacer disc 1 is thus only pressed into the blind hole, in particular into the spline 3. Further fastening means are not used in the embodiment according to Figure 1.

[0047] The spacer disc 1 limits the axial clearance of the shaft 10. This ensures that the running gear 4 of the shaft 10, in particular the sun gear shaft, remains sufficiently engaged with the planet gears 7.

[0048] As can be seen in Figure 2, in the second exemplary embodiment, the spacer washer is fastened to the shaft 10, in particular to the bottom of the blind hole of the shaft 10, by means of a screw 20 which passes centrally through the spacer washer 1. The spacer washer preferably has a radial play with respect to the spline 3, so that force-free insertion of the spacer washer 1 into the blind hole is possible. In a further development, the spacer washer has a radial oversize, so that it is clamped in the spline 3. In this way, as in Figure 1, an axially secured clamping connection can be effected and, in addition, a positive locking is formed by means of the screw 20. This achieves increased safety. The shaft 10 is thus again axially limited by the spacer washer 1.A migration of the shaft 10 in the direction opposite to the axial direction is to be ensured by a thrust washer or another element, such as a second sun gear shaft of a second gear stage that is connected in a rotationally fixed manner to the planet carrier, wherein the thrust washer or the other element is arranged on the side of the shaft 10 axially facing away from the hollow shaft.

[0049] As shown in Figure 3, in a further development of the third embodiment, the shaft 10 can be designed to be axially long such that the shaft 10 extends to the bottom of the blind hole and is therefore axially limited by the bottom of the blind hole. Thus, no spacer washer is required. In this variant, the bottom of the blind hole itself forms the limit, with the bottom itself being conical. In particular, the bottom has a centrally arranged, axially directed threaded bore, in particular for receiving the screw 20 when using the axially shorter shaft 10 shown in Figure 2.

[0050] As can be seen in Figure 4, in the fourth embodiment, an axially narrower spacer 41 is used than the spacer 1 according to Figure 2. Therefore, to fasten the spacer 41, an axially longer screw 40 is used compared to the screw 20, which presses the spacer 41 against the bottom of the blind hole.

[0051] As can be seen in Figure 5, in the fifth embodiment, a spacer disk 50 of stepped design is accommodated in the hollow shaft 2. In particular, the outer diameter of the spacer disk 50 exhibits a step change as a function of the axial position. The blind bore is designed as a stepped bore, so that the spacer disk 50 can be centered on the step of the stepped bore, particularly with its step change.

[0052] A further blind hole is formed in the shaft 10, in which a damping disk 51 is arranged, which is pressed towards the hollow shaft 2 by a spring element, in particular a disc spring 52, which is supported on the bottom of this further blind hole, wherein a further screw 53 protruding centrally through the damping disk 51 is screwed into a threaded hole in the shaft 10. The screw head of this further screw 53 axially limits the damping disk 51. When the shaft 10 now moves in the axial direction towards the hollow shaft 2, the damping disk 51 initially strikes the spacer disk 50, in particular so that the impact is dampened and the shaft is pushed back axially. For this purpose, the area covered by the damping disk 51 in the axial direction overlaps with the area covered by the shaft 10 in the axial direction. This is because the damping disk 51 protrudes axially from the shaft 10 towards the spacer disk 50.

[0053] A bearing of the hollow shaft 2 is accommodated in the housing of the gearbox and covers in the axial direction an area which also includes the area covered by the damping disc 51 and the spacer disc 50 in the axial direction or overlaps with the respective area.

[0054] The bearing is preferably designed as an angular contact bearing.

[0055] The hollow shaft 2 and the shaft 10 are coaxially aligned with each other. The damping disc 51 and the spacer disc 50 are also coaxially aligned with each other.

[0056] The maximum radial extension of the spacer disc 50 is greater than the maximum radial extension of the damping disc 51.

[0057] In further embodiments according to the invention, the damping disc 51 has a larger maximum outer diameter than the spacer disc 50.

[0058] In further embodiments according to the invention, the spacer disc is connected to the hub, in particular to the hollow shaft section, both in a materially bonded manner and in a form-fitting manner, in particular by means of the screw.

[0059] List of reference symbols

[0060] 1 spacer

[0061] 2 hollow shaft

[0062] 3 Spline teeth, especially internal teeth

[0063] 4 Running gear teeth of the sun gear, especially the sun gear shaft

[0064] 5 warehouses

[0065] 6 Bearing shield

[0066] 7 Planetary gear

[0067] 8 planet carrier bolts

[0068] 9 Spline, in particular external spline, of the sun gear, in particular of the sun gear shaft

[0069] 20 screw

[0070] 40 screw

[0071] 41 spacer

[0072] 50 spacer

[0073] 51 Damping disc

[0074] 52 disc spring

[0075] 53 additional screws

Claims

Patent claims:

1. Shaft-hub connection, in particular of a geared motor, comprising a hollow shaft section acting as a hub, in particular a rotor shaft of an electric motor, in particular which drives a gear, in particular a planetary gear, of the geared motor, wherein a shaft, in particular a sun gear shaft, is at least partially inserted into the hollow shaft section, characterized in that a spacer disk is arranged in the hollow shaft section, which spacer disk delimits the shaft axially, in particular in the axial direction, and is connected to the hub.

2. Shaft-hub connection according to claim 1, characterized in that the hollow shaft section is formed by means of a blind hole introduced into the hub, wherein the spacer disk rests against and / or is fastened to the bottom of the blind hole.

3. Shaft-hub connection according to one of the preceding claims, characterized in that the spacer disc is integrally connected to the hub, in particular to the hollow shaft section.

4. Shaft-hub connection according to one of the preceding claims, characterized in that the spacer washer is positively connected to the hub, in particular to the hollow shaft section, in particular wherein a first screw projects through the spacer washer in the axial direction and is screwed into a threaded bore made in the hub, in particular at the bottom of the blind hole, in particular wherein the screw head of the first screw presses the spacer washer against the hub, in particular against the bottom of the blind hole.

5. Shaft-hub connection according to one of the preceding claims, characterized in that the spacer disc is designed as a perforated disc and / or that the spacer disc is designed as a hollow cylinder.

6. Shaft-hub connection according to one of the preceding claims, characterized in that the blind hole is designed as a stepped bore and the spacer disk has an outer step on its outer circumference, with which the spacer disk rests against a step of the stepped bore and / or is centered and / or aligned, in particular wherein the spacer disk is designed as a rotational body and the maximum outer radius as a function of the axial position is a step function.

7. Shaft-hub connection according to one of the preceding claims, characterized in that the axial direction is aligned parallel to the direction of rotation of the hub and / or the shaft, in particular wherein the radial direction is related to the direction of rotation of the hub and the circumferential direction is also related to the direction of rotation of the hub.

8. Shaft-hub connection according to one of the preceding claims, characterized in that the end face of the shaft rests against the spacer disk, and / or that a spring element supported on the shaft, in particular a disc spring, applies spring force to the spacer disk in the axial direction, in particular for preloading a bearing which rotatably supports another shaft, in particular a planet carrier, which is pressed by the shaft in the axial direction.

9. Shaft-hub connection according to one of the preceding claims, characterized in that a further blind hole is made in the end face of the shaft, in particular facing the spacer disk, in which a damping disk is arranged, wherein a spring element, in particular a disc spring, supported on the shaft, presses the damping disk towards the spacer disk and / or that a further blind hole is made in the end face of the shaft, in particular facing the spacer disk, in which a damping disk is arranged, through which a further screw projects, which is screwed into a further threaded bore which is made in the shaft, wherein the screw head of the further screw axially delimits the damping disk and wherein a spring element, in particular a disc spring, supported on the shaft presses the damping disk towards the screw head of the further screw.

10. Shaft-hub connection according to one of the preceding claims, characterized in that the outer diameter of the damping disc, which is designed in particular as a rotary body, has a stepped profile as a function of the axial position.

11. Shaft-hub connection according to one of the preceding claims, characterized in that the shaft has a spline, in particular a spline external spline, which is inserted into a hollow spline, in particular a spline internal spline, of the hub or which is pressed into the blind hole, in particular in a plastic or at least elastically deforming manner.

12. Shaft-hub connection according to one of the preceding claims, characterized in that the area covered by the spring element in the axial direction is contained in the area covered by the damping disc in the axial direction or overlaps therewith, and / or that the area covered by the spring element in the radial direction is contained in the area covered by the damping disc in the radial direction or overlaps therewith, and / or that the spring element is positioned against one or the step of the damping ring.

13. Shaft-hub connection according to one of the preceding claims, characterized in that the first screw is spaced from the further screw, in particular is spaced in the axial direction, in particular wherein the first screw has a smaller external thread diameter than the further screw, and / or that the spacer washer rests against the damping washer.

14. A method for producing a variant of variants of a series of shaft-hub connections, in particular according to one of the preceding claims, from a modular system, wherein the modular system comprises a hollow shaft section acting as a hub, in particular a rotor shaft of an electric motor, in particular which drives a gear, in particular a planetary gear, of the geared motor, a first shaft, in particular a sun gear shaft of the planetary gear, a second shaft, in particular a sun gear shaft of the planetary gear, a first spacer disk and a second spacer disk, wherein the second spacer disk has a larger axial extent, in particular in the direction of the disk axis of the spacer disk and / or in the direction of the rotational symmetry axis of the respective spacer disk, in particular wherein the maximum outer diameter, in particular of the sun gear toothing, of the second shaft is larger than the maximum outer diameter,in particular the sun gear toothing, of the first shaft, characterized in that, to produce a first variant, the first spacer disc is inserted into the hollow shaft section and then the first shaft is at least partially inserted into the hollow shaft section and connected to the hollow shaft section, wherein the first spacer disc limits the shaft axially, in particular in the axial direction, and that, to produce a second variant, the second spacer disc is inserted into the hollow shaft section and then the second shaft is at least partially inserted into the hollow shaft section and connected to the hollow shaft section, wherein the second spacer disc limits the shaft axially, in particular in the axial direction.

15. Geared motor with a shaft-hub connection according to one of the preceding claims, characterized in that the shaft is a sun gear shaft of a planetary gear of the geared motor, wherein a rotor shaft of an electric motor, in particular acting as a hub, has the hollow shaft section, wherein the shaft has a running gear which engages with planet gears, and a plug-in external gear which is pressed and / or inserted into the hollow shaft section, in particular is pressed in in a plastic or at least elastically deforming manner, in particular wherein the hollow gear of the rotor shaft which is in engagement with the plug-in external gear covers an area in the axial direction which overlaps the area covered by the spacer disk in the axial direction, in particular wherein a spring element supported on the shaft, in particular a disc spring,the spacer disc is loaded directly or via a damping disc with spring force generated by the spring element in the axial direction, in particular for preloading a bearing of a planet carrier, rotatably mounted on which the shaft is pressed in the axial direction.

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