Gear motor comprising a gear mechanism driven by an electric motor

Abstract

The invention relates to a gear motor, comprising a gear mechanism driven by an electric motor, wherein the rotor shaft of the electric motor is conjointly connected to a hollow adapter shaft, wherein the adapter shaft is conjointly connected to a sun gear of the gear mechanism, wherein a multiple splining is incorporated into the rotor shaft, said multiple splining meshing with inner teeth of the adapter shaft, wherein the rotor shaft has an annular groove in which a sealing ring is arranged which bears against the adapter shaft.

Description

[0001] Geared motor, comprising a gearbox driven by an electric motor

[0002] Description:

[0003] The invention relates to a geared motor comprising a gear driven by an electric motor.

[0004] It is common knowledge that a geared motor has a gearbox driven by an electric motor.

[0005] From DE 102022 004 100 A1, a geared motor is known as the closest state of the art.

[0006] A coupling is known from DE 198 48 324 A1.

[0007] A compact connection between the gear shaft and pinion is known from DE 103 57 928 A1.

[0008] A lubricant supply is known from JP 2003 - 90 351 A.

[0009] From DE 102010 017 592 A1 a method for the non-cutting axial forming of a toothing on a workpiece is known.

[0010] From DE 199 29 639 B4 a shaft-hub connection with formed stop bevels in shaft splines is known.

[0011] The invention is therefore based on the object of achieving a long service life for a gear motor.

[0012] According to the invention, the object is achieved in the geared motor according to the features specified in claim 1.Important features of the invention in the geared motor, comprising a gearbox driven by an electric motor, are that the rotor shaft of the electric motor is connected in a rotationally fixed manner to a hollow adapter shaft, in particular an axially continuous one, wherein the adapter shaft is connected in a rotationally fixed manner to a sun gear of the gearbox, wherein a multi-spline toothing, in particular as an external toothing, is incorporated into the rotor shaft, which is in engagement with an internal toothing of the adapter shaft, in particular with a multi-spline toothing of the adapter shaft designed as an internal toothing corresponding to the multi-spline toothing, wherein the rotor shaft has an annular groove in which a sealing ring, in particular an O-ring, is arranged, which rests against the adapter shaft, in particular which is pressed against the adapter shaft, in particular wherein the sealing ring seals the rotor shaft against the adapter shaft.

[0013] The advantage here is that the sealing ring protrudes radially beyond the spline, thus reducing backlash. Even if the spline of the rotor shaft is flush with the corresponding internal spline of the adapter shaft, some backlash may still be present or may occur during operation under load or after extended service. The sealing ring reduces the backlash and, in any case, reduces any potential impacts that might otherwise occur between the flanks of the splines. This reduces wear and corrosion, thus increasing service life.

[0014] In an advantageous embodiment, the splined gearing is designed according to DIN 5480, wherein the root fillet is larger than in DIN 5480, in particular wherein the root fillet connects the right flank of a gap in the splined gearing with the left flank of the splined gearing, wherein the root fillet is continuously connected to the right flank and continuously connected to the left flank, in particular wherein the root fillet is designed as a radius in cross-section, in particular wherein the normal direction of the flat cross-sectional area is aligned parallel to the axis of rotation of the rotor shaft. The advantage here is that a high torque can be transmitted and that a long service life can be achieved.

[0015] In an advantageous embodiment, the sun gear has a running gear that meshes with planetary gears, in particular with the gears of planetary gears. This is advantageous because the sun gear meshes with the planetary gears on the one hand, thus keeping them centered, and is connected to the adapter shaft, which is supported by a bearing, on the other. This ensures that the sun gear is stable and rotatably mounted.

[0016] In an advantageous embodiment, the sun gear has a journal region inserted into the adapter shaft, which has knurled teeth cut into the adapter shaft, in particular so that the adapter shaft is sealed from the interior of the transmission, which is at least partially filled with lubricating oil, in particular wherein the maximum outer diameter of the running gear is larger than the maximum outer diameter of the journal region. It is advantageous that the journal region of the sun gear is aligned coaxially with the axis of rotation of the adapter shaft, and thus the sun gear is positioned and aligned as precisely as possible with respect to the adapter shaft by means of the journal region.

[0017] In an advantageous embodiment, a space is formed axially between the sun gear, in particular axially between the journal area of ​​the sun gear, and the rotor shaft, which is at least partially filled with lubricant, in particular grease, and which is sealed from the surroundings of the adapter shaft by means of the sealing ring and the sun gear. This advantageously involves applying lubricant to the splined gearing, thus reducing or preventing abrasion and / or corrosion.

[0018] In an advantageous embodiment, the inner ring of a bearing, in particular a rolling bearing, is placed onto the adapter shaft and the outer ring of the bearing is accommodated in a housing part of the geared motor, in particular wherein the inner ring bears with its first axial end region against a shaft collar formed on the adapter shaft and with its second axial end region against a retaining ring snapped into an annular groove of the adapter shaft, in particular wherein the outer ring is positioned against a second retaining ring accommodated in the housing part, wherein a spring assembly supported on a collar of the housing part presses the outer ring towards the retaining ring, in particular wherein the spring assembly has a stack of spring washers. The advantage here is that a simple and cost-effective bearing arrangement can be provided.

[0019] In an advantageous embodiment, to increase the spatial area, the sun gear has a conical bore at its end facing the rotor shaft, and the rotor shaft has another conical bore at its end facing the sun gear. This is advantageous because the lubricant reservoir is as large as possible.

[0020] In an advantageous embodiment, the root radius of the splined gear defines an axially continuous channel for lubricant, in particular lubricating grease. The root radius connects the right flank of a gap in the splined gear with the left flank of the splined gear, with the root radius being continuously connected to the right flank and continuously connected to the left flank. The advantage here is that the lubricant reservoir of the conical bores is connected to the splined gears via the channel, thus reliably ensuring an adhesive lubricant supply.

[0021] In an advantageous embodiment, an axially continuous channel or the axially continuous channel is at least partially filled with lubricant and delimited by a semi-cylindrical surface, in particular of the adapter shaft, in particular wherein the flanks of the externally toothed spline of the rotor shaft and the flanks of the internally toothed spline of the adapter shaft open into the channel, in particular so that the contact surfaces between the splines are adhesively coated and supplied with lubricant. In particular, wear and corrosion are thus reduced or prevented.

[0022] In an advantageous embodiment, an axially continuous channel, or the axially continuous channel, is at least partially filled with lubricant and is defined by a semi-cylindrical outer surface, in particular of the adapter shaft, wherein the contact gaps between the meshing tooth flanks of the splined and internal gearing open into the channel, in particular wherein the root radius of the splined gearing of the rotor shaft, together with the tip region of the internal gearing of the adapter shaft, define the channel. This is advantageous in that wear and corrosion are reduced or prevented.

[0023] In an advantageous embodiment, in the area covered by the splined gearing in the axial direction, the gap width of each tooth gap of the splined gearing is constant, i.e., independent of the axial position, and the root diameter of the gearing is also constant, i.e., independent of the axial position. The advantage here is that the externally toothed splined gearing of the rotor shaft and the correspondingly designed internally toothed splined gearing of the adapter shaft lie flat against one another, thus achieving a large-area contact of the tooth flanks. This allows for high torque transmission.

[0024] In an advantageous embodiment, a threading region, in particular a splined threading region having toothing corrections, adjoins the region covered by the splined toothing in the axial direction, in which the root circle diameter of the toothing decreases monotonically, in particular strictly monotonically, with increasing axial distance from the splined toothing, and on the side of the splined toothing axially remote from the threading region, a narrowing region adjoins the region covered by the splined toothing in the axial direction, wherein the gap width of the tooth gaps of the narrowing region, in particular of the splined threading region having toothing corrections, decreases monotonically, in particular strictly monotonically, with increasing axial distance from the splined toothing, in particular wherein half the root circle diameter equals the radial distance of the root circle to the axis of rotation of the rotor shaft.The advantage here is that when inserting the rotor shaft into the adapter shaft, the rotor shaft can be inserted without damage using the threading area. In addition, the constriction area reliably prevents it from being inserted too deeply.

[0025] In an advantageous embodiment, the annular groove is axially adjacent to the constriction area. This is advantageous because the seal seals the constriction area by being located at its axial end.

[0026] In an advantageous embodiment, the annular groove is incorporated into a cylindrical surface of the rotor shaft, in particular so that the sealing ring does not rest against a shaft step, but rather the rotor shaft has the same shaft diameter axially on both sides of the annular groove. This is advantageous because the sealing ring can be further deformed radially, thus providing the sealing ring with more space for expansion.

[0027] In an advantageous embodiment, the sealing ring closes the gaps in the toothing of the constriction area in the axial direction and / or seals them. It is advantageous that the sealing ring seals the channel on the motor side.

[0028] In an advantageous embodiment, the housing part is connected on the one hand to the gearbox housing, in particular to a bearing flange of the gearbox, and on the other hand to the motor housing, in particular to a bearing flange of the electric motor. In particular, the rotor shaft is rotatably mounted by means of a further bearing accommodated in the motor housing. It is advantageous that an adapter is interposed between the motor and the gearbox.

[0029] In an advantageous embodiment, the sun gear meshes with planetary gears rotatably mounted on a planetary carrier, which mesh with a ring gear that is connected to or enclosed by the transmission housing. Advantageously, the transmission is a planetary gear, and the sun gear is connected to the motor via the adapter, allowing tolerances to be compensated for by the splined gearing.

[0030] 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.

[0031] The invention will now be explained in more detail using schematic illustrations:

[0032] Figure 1 shows a longitudinal section through an adapter area of ​​a geared motor, which has an electric motor and a gear driven by the electric motor via an adapter.

[0033] Figure 2 shows a rotor shaft 2 of the electric motor, which has a splined toothing 21, and is shown in an oblique view.

[0034] Figure 3 shows a cross-section of the splined toothing 21.

[0035] As shown in the figures, the rotor shaft 2 with the splined toothing 21 is externally toothed and a correspondingly internally toothed adapter shaft 1, in particular a hollow shaft, is attached.

[0036] The splined toothing 21 has straight flanks in the cross-section shown in Figure 3, with a circular rounding with a radius R in the root area. Although the splined toothing 21 is designed according to DIN 5480, this radius R is larger than specified in DIN 5480. Preferably, the radius R is 20% to 30% larger than specified in DIN 5480. Surprisingly, this results in a higher load capacity of the rotor shaft 2, which is made of steel, and the adapter shaft 1, which is also made of steel.

[0037] Axially spaced from the rotor shaft 2 and coaxially aligned with the rotor shaft 2, a journal area of ​​a sun gear 11 is inserted into the adapter shaft 1. Preferably, the journal area of ​​the sun gear 11 has a knurled toothing for a rotationally fixed connection with the adapter shaft 1, which is cut into the material of the adapter shaft 1 when the journal area is pressed into the adapter shaft 1.

[0038] The running gear of the sun gear 11, which is axially spaced from the journal area, has a larger outer diameter than the journal area, so that a collar is formed on the sun gear 11, which bears against the adapter shaft 1 at the end face. The inner ring of a bearing 4, in particular a rolling bearing, is mounted on the adapter shaft. The outer ring of the bearing 4 is accommodated in a housing part 5 and axially delimited by a retaining ring, which is recessed in an annular groove of the housing part 5.

[0039] The inner ring of bearing 4 rests against a shaft collar of adapter shaft 1 and is delimited on the side axially remote from the shaft collar by another retaining ring, which is snapped into an annular groove of adapter shaft 1. Thus, the inner ring is axially fixed relative to adapter shaft 1. The outer ring of bearing 4 is pressed against the retaining ring connected to housing part 5 by spring washers supported on a collar of housing part 5.

[0040] A shaft sealing ring 9 accommodated in the housing part 5 has a sealing lip which seals against the adapter shaft 1.

[0041] The running gear teeth of sun gear 11 mesh with the gear teeth of planetary gears, which also mesh with an internally toothed ring gear. A planetary carrier, designed as an output shaft, rotatably supports the planetary gears.

[0042] The adapter shaft 1 is axially hollow throughout. However, since both the sun gear 11 and the rotor shaft 2 are inserted into the adapter shaft and are axially spaced from each other, a space for a lubricant, such as grease, is formed radially within the adapter shaft 1.

[0043] Lubricating oil is present inside the planetary gear, which lubricates the meshing between the planetary gears and the running gear of the sun gear 11 and also lubricates the meshing between the planetary gears and the ring gear.

[0044] The hollow adapter shaft 1 is sealed by inserting the journal portion of the sun gear 11 because the knurled teeth of the journal portion are cut into the material of the adapter shaft. Thus, the sun gear 11 is tightly connected to the adapter shaft 1.

[0045] Although the splined gearing 21 of the rotor shaft 2 contacts the corresponding flanks of the internal gearing of the adapter shaft 1, no seal is established, for example, in the base area. This is because the teeth of the splined gearing 21 extend in the axial direction. For sealing 1, a sealing ring 3, in particular an O-ring, is arranged in a circumferential annular groove of the rotor shaft. This sealing ring 3 contacts the adapter shaft 1 and is elastically deformed, in particular due to a corresponding oversize.

[0046] This seals off the space for the lubricant.

[0047] The adapter shaft 1 has an expansion 8 on the motor side, in particular so that the adapter shaft 1 can be easily threaded into the adapter shaft 1 when the rotor shaft 2 is inserted.

[0048] The widening 8 is designed such that with increasing axial distance from the sun gear 11, the clear inner diameter of the hollow adapter shaft 11 increases monotonically, in particular strictly monotonically.

[0049] The sealing ring 3 is arranged in the axial direction between the splined toothing 21 and the widening 8.

[0050] The rotor shaft is rotatably mounted via additional bearings in the stator housing of the electric motor, which is connected to the housing part 5 in a rotationally fixed manner.

[0051] In particular, the splined gear 21 features flat flank areas. This allows the internal gearing to rest flat against the external gearing, enabling high torque transmission.

[0052] The rotor shaft 2, the adapter shaft 1 and the sun gear 11 are made of metal, in particular steel.

[0053] The respective root radius of the splined gear 21 defines an axially continuous channel for lubricant, in particular lubricating grease. The respective channel, at least partially filled with lubricant, is axially continuous. The channel is defined by at least a half-cylindrical surface. This supports the lubricant distribution in the channel, so that the contacting flank areas of the splined gear 21 and their corresponding internal gearing of the adapter shaft 1 can also be easily supplied. As shown in Figure 2, the rotor shaft 2 has a threading area 20, which borders the area of ​​the splined gear 21, and a constriction area 22, which also borders the splined gear 21.

[0054] In particular, the area covered in the axial direction by the threading area 20 borders the area covered in the axial direction by the splined toothing 21, in particular, its first axial end. At the other axial end of the splined toothing 21, the area covered in the axial direction by the narrowing area 22 borders the area covered by the splined toothing 21.

[0055] The toothing of the splined toothing 21 thus also extends through the threading area 20 and the constriction area 22. However, the width of the tooth gaps decreases monotonically, in particular strictly monotonically, with increasing distance from the splined toothing. In the threading area 20, the root diameter of the toothing decreases monotonically, in particular strictly monotonically, with increasing distance from the splined toothing.

[0056] The annular groove receiving the sealing ring 3, in particular O-ring, is preferably introduced into a cylindrical surface of the rotor shaft 2.

[0057] In further embodiments according to the invention, a different type of toothing is used instead of the splined toothing, in particular an involute toothing.

[0058] List of reference symbols

[0059] 1 adapter shaft, especially hollow shaft

[0060] 2 rotor shaft

[0061] 3 Sealing ring, especially O-ring

[0062] 4 camps

[0063] 5 Housing part

[0064] 6 Flange part

[0065] 7 Stator housing

[0066] 8 Widening

[0067] 9 Shaft seal

[0068] 10 Internal gearing of the adapter shaft 1

[0069] 11 Sun gear

[0070] 20 threading area

[0071] 21 Splined gearing

[0072] 22 Constriction area

[0073] R radius, especially in the foot area

Claims

Patent claims:

1. Geared motor, comprising a gearbox driven by an electric motor, wherein the rotor shaft of the electric motor is rotationally connected to a hollow, in particular axially continuous, adapter shaft, wherein the adapter shaft is rotationally connected to a sun gear of the gearbox, characterized in that a multi-spline toothing, in particular as an external toothing, is incorporated into the rotor shaft, which is in engagement with an internal toothing of the adapter shaft, in particular with a multi-spline toothing of the adapter shaft designed as an internal toothing corresponding to the multi-spline toothing, wherein the rotor shaft has an annular groove in which a sealing ring, in particular an O-ring, is arranged, which rests against the adapter shaft, in particular which is pressed against the adapter shaft, in particular wherein the sealing ring seals the rotor shaft against the adapter shaft.

2. Geared motor according to claim 1, characterized in that the splined toothing is designed according to DIN 5480, wherein the root rounding is larger than in DIN 5480, in particular wherein the root rounding connects the right flank of a gap in the splined toothing with the left flank of the splined toothing, wherein the root rounding is continuously differentiable connected to the right flank and continuously differentiable connected to the left flank, in particular wherein the root rounding is designed as a radius in cross-section, in particular wherein the normal direction of the flat cross-sectional area is aligned parallel to the axis of rotation of the rotor shaft.

3. Geared motor according to one of the preceding claims, characterized in that the sun gear has a running toothing which engages with planetary gears, in particular with the toothings of planetary gears.

4. Geared motor according to one of the preceding claims, characterized in that the sun gear has a pin region inserted into the adapter shaft, which has a knurled toothing which is cut into the adapter shaft, in particular so that the adapter shaft is sealed off from the interior of the gear unit which is at least partially filled with lubricating oil, in particular wherein the maximum outer diameter of the running toothing is larger than the maximum outer diameter of the pin region.

5. Geared motor according to one of the preceding claims, characterized in that axially between the sun gear, in particular axially between the journal area of ​​the sun gear, and the rotor shaft, a space area is formed which is at least partially filled with lubricant, in particular lubricating grease, in particular which is sealed from the environment of the adapter shaft by means of the sealing ring and the sun gear.

6. Geared motor according to one of the preceding claims, characterized in that the inner ring of a bearing, in particular a rolling bearing, is placed on the adapter shaft and the outer ring of the bearing is accommodated in a housing part of the geared motor, in particular wherein the inner ring rests with its first axial end region on a shaft collar formed on the adapter shaft and with its second axial end region on a retaining ring snapped into an annular groove of the adapter shaft, in particular wherein the outer ring is positioned against a second retaining ring accommodated in the housing part, wherein a spring assembly supported on a collar of the housing part presses the outer ring towards the retaining ring, in particular wherein the spring assembly has a stack of spring washers.

7. Geared motor according to one of the preceding claims, characterized in that, in order to enlarge the spatial area, the sun gear has a conical bore at its end facing the rotor shaft and the rotor shaft has a further conical bore coaxially aligned with the conical bore at its end facing the sun gear.

8. Geared motor according to one of the preceding claims, characterized in that the root rounding of the splined toothing of the rotor shaft together with the head region of the internal toothing of the adapter shaft delimits an axially continuous channel for lubricant, in particular lubricating grease, in particular wherein the root rounding connects the right flank of a gap of the splined toothing with the left flank of the splined toothing, wherein the root rounding is continuously differentiable connected to the right flank and continuously differentiable connected to the left flank.

9. Geared motor according to one of the preceding claims, characterized in that an axially continuous channel or the axially continuous channel is at least partially filled with lubricant and is delimited by a semi-cylindrical outer surface, in particular of the adapter shaft, wherein the contact gaps between the meshing tooth flanks of the splined toothing and internal toothing open into the channel, in particular wherein the root rounding of the splined toothing of the rotor shaft together with the head region of the internal toothing of the adapter shaft delimit the channel.

10. Geared motor according to one of the preceding claims, characterized in that in the area covered by the splined toothing in the axial direction, the gap width of each tooth gap of the splined toothing is constant, i.e. independent of the axial position, and the root circle diameter of the toothing is also constant, i.e. independent of the axial position.

11. Geared motor according to one of the preceding claims, characterized in that a threading region, in particular a multi-spline threading region having toothing corrections, adjoins the region covered by the splined toothing in the axial direction, in which the root circle diameter of the toothing decreases monotonically, in particular strictly monotonically, with increasing axial distance from the splined toothing, and on the side of the splined toothing axially remote from the threading region, a narrowing region adjoins the region covered by the splined toothing in the axial direction, wherein the gap width of the tooth gaps of the narrowing region, in particular of the multi-spline threading region having toothing corrections, decreases monotonically, in particular strictly monotonically, with increasing axial distance from the splined toothing, in particular wherein half the root circle diameter equals the radial distance of the root circle to the axis of rotation of the rotor shaft.

12. Geared motor according to one of the preceding claims, characterized in that the annular groove is axially adjacent to the constriction region, and / or that the annular groove is introduced into a cylindrical surface of the rotor shaft, in particular so that the sealing ring does not bear against a shaft step but the rotor shaft has the same shaft diameter axially on both sides of the annular groove.

13. Geared motor according to one of the preceding claims, characterized in that the sealing ring closes and / or seals the gaps in the toothing of the constriction region in the axial direction.

14. Geared motor according to one of the preceding claims, characterized in that the housing part is connected on the one hand to the gear housing, in particular to a bearing flange of the gear, and on the other hand to the motor housing, in particular to a bearing flange of the electric motor, in particular wherein the rotor shaft is rotatably mounted by means of a further bearing which is accommodated in the motor housing.

15. Geared motor according to one of the preceding claims, characterized in that the sun gear is in engagement with planetary gears rotatably mounted on a planetary carrier, which are in engagement with a ring gear which is connected to the gear housing or is encompassed by it.

Images