Geared motor, comprising an electric motor and a gearbox

Description

[0001] The invention relates to a geared motor comprising an electric motor and a gearbox.

[0002] It is generally known that a geared motor has a gearbox that can be driven by an electric motor.

[0003] A kit for a series of geared motors is known from DE 103 12 941 A1.

[0004] From the DE 35 02 015 A1 The most readily available state of the art is a geared motor.

[0005] From the DE 44 01 164 A1 A gearbox that can be flanged to an electric motor is known.

[0006] From the DE 23 47 523 B1 A device for mounting an engine is known.

[0007] From the DE 103 12 941 A1 is a kit for a series of geared motors.

[0008] The invention is therefore based on the objective of further developing a geared motor that is easy to manufacture.

[0009] According to the invention, the problem is solved in the geared motor according to the features specified in claim 1.

[0010] Important features of the invention in the geared motor are that the geared motor comprises an electric motor and a gearbox, wherein the electric motor has a stator housing, a rotor shaft and a first bearing, in particular rolling bearings, in particular ball bearings, for supporting the rotor shaft, wherein a coupling sleeve is fitted onto the rotor shaft and is rotationally fixed to the rotor shaft, wherein an inner ring of a second bearing, in particular rolling bearings, in particular ball bearings, is fitted onto the coupling sleeve and the outer ring of the second bearing is received in an adapter ring which is rotationally fixed to a housing part of the gearbox, wherein the adapter ring is connected on its side facing away from the housing part to a ring-shaped round flange which is connected on its side facing away from the adapter ring to a round flange which is connected to the stator housing.

[0011] One advantage of this design is its simplified manufacturing process. In particular, it allows for direct mounting of the motor to the gearbox, enabling the gearbox's input-side bearing to be used as a second bearing for the rotor shaft. This results in a particularly compact geared motor. Furthermore, power loss can be reduced because fewer bearings are required. A disadvantage is that the rotor shaft cannot be fully supported during the motor's assembly. However, this can be overcome by using a temporary plain bearing bushing. This also allows for functional testing of the motor before it is mounted to the gearbox. After installation, the plain bearing bushing can wear down during operation of the electric motor or at least lose its bearing function, thus preventing power loss.

[0012] In a preferred embodiment, the rotor shaft, particularly during operation (i.e., after the electric motor has been attached to the gearbox), is supported by the first and second bearings. The advantage here is that a stable, load-bearing support is available during operation, and that the rotor shaft can be supported beforehand at least by the first bearing and the plain bearing bushing.

[0013] In an advantageous embodiment, a sun gear of the transmission has a pin-like extension that is inserted into the coupling sleeve, with the sun gear being rotationally fixed to the coupling sleeve. An advantage of this is that the sun gear, as the input gear of the transmission, can also be supported together with the rotor shaft. Thus, additional bearings are unnecessary.

[0014] In an advantageous embodiment, the first bearing is designed as a fixed bearing. An advantage of this is that the rotor shaft is permitted to exhibit thermal expansion in the area of ​​the second bearing, and axial movement relative to the coupling sleeve and / or the second bearing is also allowed. In this respect, the rotor shaft is already loosely supported in the area of ​​the second bearing via the sliding bearing bushing.

[0015] In an advantageous embodiment, the sun gear is spaced apart from the rotor shaft, The space between the sun gear and the rotor shaft contains lubricant, particularly grease, which is bounded by the coupling sleeve, the sun gear, and the rotor shaft. An advantage of this design is that the rotor shaft can expand axially due to thermal expansion and even shift relative to the coupling sleeve. Despite this, noise and wear are prevented. The lubricant in this space ensures lubrication of the rotor shaft's teeth. A sealing ring, particularly an O-ring, is located on the side facing away from this space, preventing lubricant from escaping into the interior of the electric motor. This ensures operational reliability, and both the sun gear and the rotor shaft can be supported by the coupling sleeve and the second bearing. The geared motor is therefore compact, cost-effective, and easy to manufacture.

[0016] In an advantageous embodiment, the sun gear is positively connected to the coupling sleeve in the circumferential direction, in particular wherein the sun gear has teeth that are pressed and cut into the material of the coupling sleeve. It is advantageous that the sun gear is spaced apart from the rotor shaft, yet the sun gear and the rotor shaft can still be supported together via the coupling sleeve and the second bearing.

[0017] In an advantageous embodiment, the rotor shaft is positively connected to the coupling sleeve in the circumferential direction, particularly wherein the coupling sleeve has a toothed section that is pressed and cut or formed into the material of the coupling sleeve. It is advantageous that the coupling sleeve can be connected in a rotationally fixed manner by means of a splined connection and, furthermore, that the second bearing functions as a bearing despite its distance from the rotor shaft.

[0018] In an advantageous embodiment, a sealing ring, in particular an O-ring, is fitted onto the rotor shaft between the rotor shaft and the coupling sleeve, especially on the side of the connection area between the rotor shaft and the coupling sleeve facing away from the sun gear. This sealing ring seals against the coupling sleeve and / or bears against the coupling sleeve, pre-centering the rotor shaft, in particular preventing lubricant from the surrounding area from entering the interior of the electric motor and / or sealing the surrounding area against the interior of the electric motor. An advantage of this is that the interior of the electric motor is protected from lubricant leakage.

[0019] In an advantageous embodiment, a sliding bearing bushing is fitted onto the rotor shaft, which is pressed and / or glued into a bore of the square flange, particularly for the auxiliary support of the rotor shaft during assembly. i.e., if the second bearing is still missing and / or if the second bearing is still missing support, where An annular gap exists between the plain bearing bushing and the rotor shaft, so that during operation, or at least after an initial period of operation, the bearing of the rotor shaft by the first and second bearings, in particular ball bearings, prevents frictional contact between the rotor shaft and the plain bearing bushing. An advantage of this design is that a temporary bearing for the rotor shaft can be used for functional testing during assembly, without having to install the gearbox and thus the second bearing. Furthermore, the rotor shaft's moment of inertia is minimized.

[0020] Alternatively, a sliding bearing bushing is fitted onto the rotor shaft, which projects into a bore of a square flange, particularly for the auxiliary support of the rotor shaft during assembly. especially if the second bearing is still missing and / or if the second bearing is still missing, wherein an annular gap is present between the sliding bearing bushing and the bore of the square flange, especially so that The rotor shaft is supported by the first and second bearings, particularly ball bearings, preventing frictional contact between the rotor shaft and the plain bearing bushing. An advantage of this design is that the moment of inertia is increased by the mass of the plain bearing bushing, resulting in smoother operation of the rotor shaft. If the two bearings are not yet installed, the plain bearing bushing can be used as a temporary or auxiliary support.

[0021] In an advantageous embodiment, the sun gear engages with planet gears, which engage with a hollow toothing of the housing part, in particular wherein the planet gears are rotatably mounted on bolts which are rigidly connected to a planet carrier, in particular which is rotationally fixed to the output shaft or functions as the output shaft. It is advantageous that the gearbox is coaxially designed. Thus, no lateral force is introduced via the sun gear. Therefore, the rotor shaft can be stably supported by the second bearing and is not subjected to lateral forces introduced from the side of the sun gear, in particular and / or caused to wobble.

[0022] In a preferred embodiment, a shaft seal is incorporated in the adapter ring, sealing against the coupling sleeve. The advantage here is that the coupling sleeve is not only supported in the adapter ring via the second bearing, but also sealed by the shaft seal. Alternatively, a labyrinth seal can be used instead of the shaft seal, which, in the case of grease lubrication, seals the gearbox interior.

[0023] In a preferred embodiment, the sliding bearing bushing is made of a sliding bearing material, in particular plastic. An advantage of this is that a sliding bearing is easy to manufacture.

[0024] In a preferred design, the coupling sleeve is made of steel. An advantage of this is that a high torque can be transmitted.

[0025] In an advantageous embodiment, the outer circumference of the square flange is cuboid and / or exhibits discrete rotational symmetry. The advantage here is that the square flange can be adapted to the stator housing of the electric motor, which is also cuboid and / or exhibits discrete rotational symmetry. Thus, an interface to the round flange can be provided within the square flange and does not need to be provided on the stator housing.

[0026] In an advantageous embodiment, the outer circumference of the round flange is round, circular, and / or exhibits discrete rotational symmetry. A further advantage is that the round flange can be adapted to the gear geometry of the coaxial gearbox. The interface to the square flange is therefore provided within the round flange and does not need to be provided within the gearbox itself.

[0027] In an advantageous embodiment, the shaft seal, the adapter ring, the housing part, the driven shaft, and another shaft seal, which is received in the housing part and seals towards the driven shaft, define and, in particular, seal the interior of the gearbox, which is at least partially filled with lubricating oil. It is advantageous that a seal is established both towards the environment and towards the engine. Alternatively, a labyrinth seal can be provided instead of the shaft seal, which is particularly advantageous in the case of grease lubrication.

[0028] In an advantageous embodiment, the area covered by the second bearing, particularly with respect to the axis of rotation of the rotor shaft, overlaps at least partially with the area covered by the toothing of the coupling sleeve in the axial direction, especially wherein the areas are spaced axially from the plain bearing bushing. An advantage of this is that the rotor shaft can be supported as stably as possible, thus preventing vibrations of the rotor shaft during operation. Furthermore, the plain bearing bushing allows for auxiliary support during the manufacture of the motor. This means the electric motor can be operated even before the gearbox, including the adapter ring, second bearing, and coupling sleeve, is installed.

[0029] Further advantages arise from the dependent claims. The invention is not limited to the combination of features of the claims. For those skilled in the art, further meaningful combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent, in particular from the problem statement and / or the problem arising from a comparison with the prior art.

[0030] The invention will now be explained in more detail with reference to schematic illustrations: In the Figure 1 A geared motor, comprising a gearbox driven by an electric motor, is shown in cross-section. In the Figure 2 A section is shown enlarged. Figure 3 A square flange 2 and a round flange 3 are visible in oblique view. In the Figure 4 The two flanges are shown from a different perspective. In the Figure 5A series of geared motors according to the invention is shown schematically.

[0031] As shown in the figures, the geared motor has an electric motor connected via a square flange 2, which is connected to the preferably substantially cuboid stator housing 1 of the electric motor, and a round flange 3, which is connected on one side to an adapter ring 4, which is connected to a housing part 6 of the gearbox, and on the other side to the square flange 3.

[0032] The gearbox is designed as a coaxial gearbox, in particular as a planetary gearbox.

[0033] The rotor shaft 16 of the electric motor is rotatably mounted by means of a first bearing, which is housed in the stator housing 1 and is not shown in the figures, and indirectly rotatably mounted by means of a second bearing 5.

[0034] The first bearing is preferably designed as a fixed bearing.

[0035] The second bearing 5 is accommodated in an adapter ring 4, which is arranged between the round flange 3 and the housing part 6.

[0036] The inner ring of the second bearing 5 is mounted on a coupling sleeve 11, into which the rotor shaft 16 is inserted and into which a sun gear 9 is inserted.

[0037] For this purpose, the rotor shaft has a toothing 17, in particular a plug-in toothing, which is inserted into an internal toothing of the coupling sleeve 11, so that the rotor shaft 16 is positively connected to the coupling sleeve 11 in the circumferential direction, in particular in a rotationally fixed manner.

[0038] Furthermore, the sun gear 9, with its toothing 7, in particular its splined connection, is inserted into another internal cylindrical bore of the coupling sleeve 11. Upon insertion, the toothing 7 cuts into the material of the coupling sleeve 11, so that the sun gear 9 is positively connected to the coupling sleeve 11 in the circumferential direction, and in particular, is rotationally fixed.

[0039] The sun gear 9 is spaced apart from the rotor shaft 16, so that a space for lubricant is surrounded by the coupling sleeve 11. Since this space is bounded by the coupling sleeve 11, the sun gear 9 and the rotor shaft 16, the engagement area of ​​the teeth 17 is also exposed to the lubricant.

[0040] The adapter ring 4 accommodates a shaft seal 12, which seals against the coupling sleeve. For this purpose, the coupling sleeve has a sealing surface that contacts a sealing lip of the shaft seal 12. The sealing surface is particularly finely machined and cylindrical.

[0041] The rotor shaft 16 protrudes through a bore in the square flange. A sliding bearing bushing 15, preferably made of plastic and / or hollow cylindrical, is accommodated in this bore. The rotor shaft 16 extends through the hollow sliding bearing bushing 15. In this way, a temporary bearing arrangement for the rotor shaft is provided by means of the sliding bearing bushing 15 for assembly purposes. As long as the electric motor is not yet attached to the gearbox and the coupling sleeve 11 is not connected to the rotor shaft 16, the sliding bearing bushing 15 acts as a bearing for the rotor shaft 16. After the coupling sleeve 11 is fitted onto the rotor shaft 16 and inserted into the bearing 5 held in the adapter ring 4, the bearing 5 takes over the bearing function, and the sliding bearing bushing 15 becomes unnecessary.

[0042] Since the sun gear 9 is also inserted into the coupling sleeve 11 with the toothing 7 provided on the pin-like extension of the sun gear 9 and is thus connected in a rotationally fixed manner, the sun gear 9 is rotatably mounted by means of the bearing 5.

[0043] The sun gear 9 is engaged with planet gears which are rotatably mounted on bolts which are inserted into a planet carrier which is non-rotatably connected to the output shaft 8 or is made in one piece.

[0044] The driven shaft 8 is rotatably mounted via bearings housed in a housing part 6.

[0045] The housing part 6 of the gearbox is designed with a rounded outer circumference, so that the gearbox is designed as a coaxial gearbox.

[0046] The stator housing part 1 is cuboid in shape and connected to the square flange 2, which also has a substantially cuboid outer circumference. The round flange 3, connected to the gearbox housing part 6, is rounded to match the shape of the housing part 6.

[0047] Both the square flange 2 and the round flange 3 have an axially through bore, allowing a connecting screw to pass through and be screwed into a threaded bore of the adapter ring 4. Alternatively, the adapter ring 4 also has an axially through bore, allowing the connecting screw to pass through and be screwed into a threaded bore of the housing part 6. Thus, the two flanges (2, 3) and the adapter ring 4 are pressed together by the screw head of the screw, which rests against the square flange 2, and held together by this force against the housing part 6.

[0048] The toothing 7 of the sun gear 9 has a maximum outer diameter which is smaller than the clear inner diameter of the coupling sleeve 11 in the axial area covered by the toothing 17 and / or than the value of the largest maximum outer diameter of the toothing 17 of the rotor shaft 16.

[0049] In further embodiments of the invention, the coupling sleeve is internally toothed in the axial area covered by the toothing 17, and the rotor shaft is cylindrical, i.e., without the toothing 17. In this case, the toothing of the coupling sleeve 11 engages with the rotor shaft 16 when the coupling sleeve 11 is fitted onto the rotor shaft 16.

[0050] The sliding bearing bushing 15 is axially limited towards the motor by a shaft step formed on the rotor shaft 16 and towards the gearbox by a step formed on the bore receiving the sliding bearing bushing 15.

[0051] A sealing ring 14, in particular an O-ring, is fitted onto the rotor shaft 16 and rests against the coupling sleeve 11. Thus, the sealing ring 14 seals against the coupling sleeve 11. The sealing ring 14 is axially limited by a step formed on the rotor shaft 16.

[0052] In further embodiments of the invention, instead of the toothing 17, in particular a splined connection, a friction-fit connection is implemented, for example, a cylindrical end of the rotor shaft being pressed into the coupling sleeve. Likewise, the toothing 7, in particular a splined connection, can also be replaced by a friction-fit connection. While this allows for simpler manufacturing with less effort, only a lower torque can be reliably transmitted, since the friction-fit connection is less load-bearing than the positive-locking connection provided by the splined connection.

[0053] The adapter ring 4 has a centering collar that rotates circumferentially with respect to the axis of rotation of the rotor shaft 16, against which the radial inner wall, i.e. wall of a bore, of the round flange 3 rests.

[0054] The square flange 2 also has a circumferentially circumferential centering collar against which the radial inner wall, i.e., the wall of a bore, of the round flange 3 rests.

[0055] A modular system can be implemented using the adapter ring and the two flanges (2, 3). This allows for a large number of variants to be realized with a small number of different sized electric motors and gearboxes.

[0056] This shows Figure 5 three geared motors (50, 51, 52) which differ in that different sized gearboxes can be driven by the same electric motor and the connection is carried out by means of suitable dimensioning and selection of the adapter ring 4 and the two flanges (2, 3).

[0057] In particular, the gearbox is a planetary gearbox, which means that the sun gear 9 is engaged with several planet gears evenly distributed around its circumference. Therefore, no lateral force is essentially generated. Consequently, the sun gear 9 does not deflect the coupling sleeve 11, but rather provides additional stabilization. This results in smoother operation of the rotor shaft 16, which would otherwise be poorly supported by the bearing 5, dependent on a wobbling coupling sleeve 11.

[0058] Because the bearing 5 is spaced apart from the rotor shaft 16 and performs the bearing function only via the intermediate coupling sleeve 11.

[0059] Circumferential direction, radial direction and axial direction are always referred to the axis of rotation of the rotor shaft 16 and / or the sun gear 9 and / or the driven shaft 8.

[0060] In an advantageous embodiment, the rotor shaft 16 with its toothing 17 is inserted into an internal cylindrical bore of the coupling sleeve 11, wherein when the rotor shaft 16 is inserted the toothing 17 is cut into the material of the coupling sleeve 11, so that the rotor shaft 16 is positively connected to the coupling sleeve 11 in the circumferential direction, in particular in a rotationally fixed manner. Reference symbol list

[0061] 1 Stator housing 2 Square flange 3 Round flange 4 Adapter ring 5 Bearing 6 Housing part, in particular with ring gear or hollow teeth 7 Teeth, in particular splined teeth 8 Output shaft 9 Sun gear 10 Bearing, in particular angular contact bearing 11 Coupling sleeve 12 Shaft seal 13 Lubricant, in particular grease 14 Sealing ring, in particular O-ring 15 Plain bearing bushing, in particular hollow cylindrical 16 Rotor shaft 17 Teeth, in particular splined teeth 18 Further shaft seal 50 First geared motor 51 Second geared motor 52 Third geared motor

Claims

1. A geared motor (50), having an electric motor and a gear unit, wherein the electric motor has a stator housing (1), a rotor shaft (16) and a first bearing (15) for mounting the rotor shaft (16), wherein a coupling sleeve (11) is mounted on the rotor shaft (16) and is connected non-rotatably to the rotor shaft (16), wherein an inner ring of a second bearing (5), in particular rolling bearing, in particular ball bearing, is mounted on the coupling sleeve (11), and the outer ring of the second bearing is received in an adapter ring (4) which is connected non-rotatably to a housing part (6) of the gear unit, wherein the adapter ring (4) is connected on its side which faces away from the housing part (6) to a square flange (2) embodied in a ring-like manner which on its side which faces away from the adapter ring (4) is connected to a round flange (3) which is connected to the stator housing (1), characterised in that a sun wheel (9) of the gear unit has a trunnion-like extension which is inserted into the coupling sleeve (11), with the sun wheel (9) being connected non-rotatably to the coupling sleeve (11).

2. A geared motor (50) according to claim 1, characterised in that the rotor shaft (16) is borne by way of the first and the second bearing (15, 5).

3. A geared motor (50) according to one of the preceding claims, characterised in that the first bearing (15) is embodied as a fixed bearing.

4. A geared motor (50) according to one of the preceding claims, characterised in that the sun wheel (9) is spaced apart from the rotor shaft (16), with lubricant (13), in particular lubricating grease, being arranged in the spatial region between the sun wheel (9) and rotor shaft (16), with the spatial region being limited [by] the coupling sleeve (11), the sun wheel (9) and the rotor shaft (16).

5. A geared motor (50) according to one of the preceding claims, characterised in that the sun wheel (9) is connected in a form-fit to the coupling sleeve (11) in the peripheral direction, in particular with the sun wheel (9) having gearing (17) which is pressed and cut into the material of the coupling sleeve (11).

6. A geared motor (50) according to one of the preceding claims, characterised in that the rotor shaft (16) is connected in a form-fit to the coupling sleeve (11) in the peripheral direction, in particular with the coupling sleeve (11) having gearing (17) which is pressed and cut into the material of the coupling sleeve (11).

7. A geared motor (50) according to one of the preceding claims, characterised in that between the rotor shaft (16) and the coupling sleeve (11), in particular on that side of the connection region between the rotor shaft (16) and coupling sleeve (11) which faces away from the sun wheel (9), a sealing ring (14), in particular O-ring, is mounted on the rotor shaft (16), which sealing ring seals off towards the coupling sleeve (11) and / or lies against the coupling sleeve (11), in particular such that no lubricant (13) can pass out of the spatial region into the interior of the electric motor and / or such that the sealing ring (14) seals off the spatial region towards the interior of the electric motor.

8. A geared motor (50) according to one of the preceding claims, characterised in that a shaft sealing ring (12) which seals off towards the coupling sleeve (11) is received in the adapter ring (4).

9. A geared motor (50) according to one of claims 6 to 8, characterised in that the region covered in the axial direction by the second bearing (5), in particular relative to the axis of rotation of the rotor shaft (16), at least partly overlaps with the region covered in the axial direction by the gearing (17) of the coupling sleeve (11), in particular with the regions being spaced apart from the plain-bearing bushing (15) in the axial direction.