Planetary gear device assembly

Abstract

In a planetary gear device (5) having one sun gear (9), one internal gear (6), and one planetary gear carrier (7) provided with a plurality of, preferably three, planetary gears (8), the axial positions of two gear device members engaging with each other are defined by a magnetic preload. The planetary gear device (5) is characterized by this.

Description

Technical Field

[0001] The present invention relates to a planetary gear assembly comprising at least two planetary gear stages, each having one sun gear, one internal gear, and one planetary gear frame with a plurality of, preferably three, planetary gears.

Background Art

[0002] Such planetary gear assemblies are known and are used, for example, in actuating drives suitable for operating plugs or valves.

[0003] In order to achieve a desired transmission ratio, it is common to manufacture a planetary gear assembly with a plurality of gear stages arranged in series, where each gear stage is formed as one planetary gear device, and hereinafter, such a gear stage will also be referred to as a planetary gear stage.

[0004] Since planetary gear devices are compact and can be used in various ways, it is also common to preferably manufacture planetary gear devices, in which case a certain manufacturing error is tolerated.

[0005] In such preferably manufactured planetary gear devices, due to manufacturing errors, the axial backlash between individual meshing members, i.e., between gears, increases.

[0006] When such axial backlash between individual movable members becomes excessively large, an undefined operating state occurs, for example, only partial overlapping of meshing members with each other. This particularly leads to an increase in wear and needs to be avoided. Especially in a multi-stage planetary gear assembly, such axial backlash of individual planetary gear devices is amplified.

[0007] For this purpose, it is common to dimension the meshing members in the axial direction such that sufficient axial overlap is always maintained without causing partial axial overlap. However, this results in large dimensions and undesirably high costs. Summary of the Invention Problems to be Solved by the Invention

[0008] The problem of the present invention is to minimize the axial backlash between the gears of a compact planetary gear device and, nevertheless, enable inexpensive production. Means for Solving the Problems

[0009] This problem is solved by the planetary gear device assembly according to claim 1.

[0010] Thus, in particular, the planetary gear device assembly according to the present invention as a planetary gear device is characterized in that the axial positions of two gear device members engaging with each other are defined by a magnetic preload, and by this magnetic preload, at least the planetary gear frame of the first planetary gear device stage and the planetary gear frame of the second planetary gear device stage are held in position relative to each other in the axial direction (verspannt). In this way, the relative axial positions between two members engaging with each other are clearly preset and defined in advance. As a result, axial partial overlap and thus undefined operating states and higher wear are effectively eliminated. Therefore, it is also possible to compactly configure a planetary gear device that is inexpensively produced and thus has errors.

[0011] The magnetic preload has the further advantage that the relative axial position is defined without contact. This eliminates friction and wear.

[0012] In this case, it is not important whether both gear device members engaging with each other, for example, gears, are both movable or one gear device member is at least immovable in the axial direction. For example, in a planetary gear device, the internal gear may be immovable. In this case, the axial position may be defined between the internal gear and the planetary carrier and / or between the planetary carrier and the sun gear.

[0013] In this case, the axial position may be defined directly or indirectly between two gears engaging with each other. For example, it is also possible to define the axial position between gears that do not engage with each other, for example, between the sun gear and the internal gear. In this way, the axial positions of the gears engaging with each other are indirectly fixed.

[0014] The planetary gear device assembly may generally form a planetary gear device as a gear device, with or without, for example, a housing and / or another functional assembly, and / or may be a single-stage or multi-stage gear device.

[0015] In one configuration, the magnetic preload is defined for a gear device member coupled to the housing, particularly rotatably supported. In this way, there is an invariant reference point for the axial position, whereby the component errors hardly affect the relative and absolute positions of the individual gears.

[0016] In one configuration, due to the magnetic preload, at least the planetary gear carrier of the first gear device stage and the planetary gear carrier of the second gear device stage are held in position axially relative to each other. In this way, a plurality of gear device stages can be positioned axially relative to each other, and thus axial backlash can be prevented.

[0017] In one configuration, the planetary gear device has at least two permanent magnets arranged such that the same poles face each other. Due to the magnetic repulsion between the same poles, a force is generated that accurately defines the axial position. A further advantage is that the repulsive force increases significantly with a decrease in the distance. As a result, since the contact between both permanent magnets is actually eliminated, the position is reliably maintained.

[0018] In one configuration, the first permanent magnet is coupled to the planetary gear frame. Thus, the axial position of the planetary gear frame and hence the planetary gear can be defined. However, the first permanent magnet may be coupled to one of the other gears of the planetary gear device.

[0019] In one configuration, the second permanent magnet is arranged on a gear device member that is particularly axially fixed and particularly other than the internal gear. Thus, it becomes possible to position different gear device members axially relative to each other or between different gear device stages.

[0020] In any case, the first and second permanent magnets are arranged such that the same poles face each other and the permanent magnets repel each other.

[0021] A combination where the first permanent magnet is coupled to the planetary gear frame and the second permanent magnet is coupled to a gear device member that is particularly immovable axially is particularly advantageous. In this case, the gear device member may be rotatable relative to the housing. Thus, a defined position of the planetary frame relative to the housing is ensured. For example, since the internal gear is also fixedly positioned relative to the housing, a defined axial position of the planetary gear frame relative to the internal gear, that is, of the planetary gear, is provided.

[0022] The permanent magnets may be shaped almost arbitrarily and may be arranged at appropriate locations.

[0023] In an advantageous configuration, the permanent magnets are each formed as annular magnets arranged coaxially with respect to the sun gear shaft. In this way, a simple arrangement becomes possible, and the repulsive force of the permanent magnets acts on the sun gear shaft in the axial direction. Therefore, no tilting moment is generated by the magnetic force, and thus there is no possibility of a negative influence on the gears in some cases.

[0024] In one configuration, the gear device has a housing portion in which both annular magnets are arranged inside. This housing portion simplifies the assembly and defines the positions of the magnets. Therefore, axial positioning of the gears becomes possible.

[0025] In one configuration, the planetary gear device has at least two gear device stages, each gear device stage being formed as a planetary gear device, and the axial position between both gear device stages being defined by a magnetic preload. Therefore, even when assembling a plurality of planetary gear devices in the axial direction, compensation for manufacturing errors can be performed, and axial backlash can be minimized.

[0026] In this way, additionally, for example, the axial position of the gears of the second gear device stage with respect to the gears of the first gear device stage can also be defined by a magnetic preload.

[0027] The present invention further includes a planetary gear device assembly having at least two planetary gear device stages, each gear device stage being formed as a planetary gear device, and both internal gear gears of the planetary gear device stages being axially coupled or couplable by locking coupling portions and / or screwing portions. In this way, by axially overlapping and / or screwing the individual planetary gear devices with each other, a multi-stage planetary gear device assembly can be composed of a plurality of simple planetary gear devices. This enables simple manufacturing and simple assembly.

[0028] The individual planetary gear units of the gear unit stage may preferably be identical, which thereby requires few additional different members or components. This makes production less expensive and additionally simplifies assembly.

[0029] In one configuration, the planet carrier of the first planetary gear unit stage has at least one locking tongue that is flexible in the axial direction. A groove extending over the entire circumference is arranged on the sun gear or the sun gear shaft of the second planetary gear unit stage, and the locking tongue engages in the groove when both planetary gear unit stages are coupled to each other.

[0030] During the coupling of both planetary gear unit stages, the sun gear or the sun gear shaft deflects the locking tongue in the axial direction to such an extent that the sun gear or the sun gear shaft passes through the opening of the locking tongue. Further introduced in the axial direction, as soon as the locking tongue reaches the groove, the locking tongue locks in the groove, thus forming an axial connection.

[0031] In one configuration, a magnetic preload as described above is formed between the planetary gear unit stages. Thereby, for example, the axial position of the groove with respect to the locking tongue can be defined so that no friction or contact occurs during operation.

[0032] The present invention will be described in detail below based on an embodiment with reference to the accompanying drawings. In this case, this embodiment merely serves as an example and in no way limits the present invention.

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0034] FIG. 1 shows a cross-sectional view of an operating drive device 1 including a drive motor 2, a planetary gear device assembly 3, a control electronic device 4, and a housing 10.

[0035] Since the drive motor 2 and the corresponding control electronic device 4 are not important for the present invention, they will not be described further in this specification. Therefore, the present invention is by no means limited to this embodiment.

[0036] The planetary gear device assembly 3 has three planetary gear device stages 5 each formed by a planetary gear device. Each planetary gear device 5 has one internal gear 6, one planetary gear frame 7 having three planetary gears 8, and one sun gear 9. The internal gear 6 is non-rotatably coupled to the housing 10 respectively. The sun gear 9 is the input body of each planetary gear device 5, and the planetary gear frame 7 is the output body.

[0037] The individual planetary gear devices 5 are arranged one behind the other in the axial direction. The sun gear 9 is hollow bored and arranged on the reporting shaft 11.

[0038] Each planetary gear device 5 may be a planetary gear device that is simply and inexpensively manufactured. In this example, in order to compensate for any possible errors and axial backlash that may exist, the intermediate planetary gear device 5 has an axial magnetic preload. Naturally, a magnetic preload may also be applied to another or multiple planetary gear devices.

[0039] Figures 2 to 4 show the details of the intermediate planetary gear device 5. In the figure, the first permanent magnet 12 is coupled to the planetary gear frame 7 of the intermediate planetary gear device 5. This planetary gear frame 7 is non-rotatably coupled to the sun gear 9 of the planetary gear device 5 in the next gear device stage.

[0040] In this example, the first permanent magnet 12 is formed as an annular magnet disposed coaxially surrounding the sun gear 9.

[0041] The second permanent magnet 13 is also formed as an annular magnet and is disposed coaxially surrounding the sun gear 9. The second permanent magnet 13 is non-rotatably coupled to the gear device member 16. This gear device member 16 is fixed in position with respect to the housing 10 in the axial direction, but is rotatably disposed inside this housing 10. Both permanent magnets 12, 13 are separated by a gap 14, and in this case, like poles of the magnets are positioned facing each other. For this reason, the permanent magnets 12, 13 may be magnetized, for example, in the axial direction, and in this case, one end face is an N pole and the opposite end face is an S pole. In this way, the sun gear 9 together with the planetary gear frame 7 can be axially moved inside the gear device member 16 by magnetic force.

[0042] Both permanent magnets 12, 13 rotate, for example, within a housing 15 made of plastic. This housing 15 surrounds the outer circumferential surfaces of the permanent magnets 12, 13 and protects the permanent magnets 12, 13 against peripheral influences.

[0043] By arranging the same magnetic poles to face each other, a repulsive force that defines the axial relative position between the planetary gear frames 7 with respect to the gear device member 16 is generated in the axial direction. Since the internal gear 6 of the intermediate planetary gear device 5 is also fixedly coupled to the housing 10 against relative rotation, the axial position between the planetary gear 8 and the internal gear 6 of the intermediate planetary gear device 5 is indirectly defined.

[0044] In this example, the members of each planetary gear device 5 are axially coupled to each other by locking coupling portions 17. FIGS. 5 and 6 show one such locking coupling portion each.

[0045] In this example, the sun gear 9 is integrally formed with the sun gear shaft 18. In this case, the sun gear shaft 18 extends axially beyond the sun gear 9 on one side. The sun gear shaft 18 has an axial shaft hole 20 for accommodating the notification shaft 11. In the example of FIG. 5, the sun gear 9 has a larger diameter than the sun gear shaft 18.

[0046] As can be seen in FIG. 6, the sun gear 9 may have the same diameter as the sun gear shaft 18.

[0047] In this example, the planetary gear frame 7 is fixedly coupled to the sun gear shaft 18 against relative rotation. In this case, the sun gear 9 is included in the planetary gear device of the subsequent gear device stage. In this example, the planetary gear frame 7 is formed in a disk shape. The free end of the sun gear shaft 18, that is, the axial extension of the sun gear shaft 18, projects axially beyond the planetary gear frame 7.

[0048] In the region of the coupling to the sun gear shaft 18, the planetary gear frame has a pot-shaped recess 19. In this example, the sun gear shaft 18 has a tooth row 26 that can easily achieve a non-rotatable coupling with the planetary gear frame 7. For this purpose, the recess 19 has a corresponding tooth row. At the same time, this enables the planetary gear frame 7 to be axially placed over the sun gear shaft 18.

[0049] The planetary gear frame 7 further has a disk 21 disposed thereon, and this disk 21 has a coaxial opening 22. In any case, the diameter of this opening 22 is larger than the diameter of the sun gear shaft 18. The free end of the sun gear shaft 18 is guided through the opening 22 and projects axially beyond the disk 21. At the location of the opening 22, three locking tongue pieces 23 are distributed and arranged over the entire circumference at equal intervals. The locking tongue pieces 23 are directed radially and are formed as spring tongue pieces. In this example, the locking tongue pieces 23 are extended by slits 24 provided in the disk 21. Alternatively, the opening may have a larger diameter to extend the locking tongue pieces. Although the locking tongue pieces 23 are directed radially with respect to the opening in this example, other directions are possible in this case.

[0050] The sun gear shaft 18 has a locking groove 25 extending over the entire circumference, and when two such planetary gear devices are coupled to each other, the locking tongue pieces 23 engage within this locking groove 25.

[0051] When fitting the planetary gear frame 7 over the sun gear shaft 18, the locking tongue pieces 23 are deflected axially by the free end of the sun gear shaft 18 to such an extent that the sun gear shaft 18 can be moved along the locking tongue pieces 23. As soon as the locking tongue pieces 23 reach the locking groove 25, the locking tongue pieces 23 lock into the locking groove 25.

[0052] Preferably, the free end of the sun gear shaft 18 has a chamfer or rounding that can facilitate insertion.

[0053] The locking coupling part 17 enables easy coupling of a plurality of planetary gear devices axially to each other, and thus a multi-stage planetary gear device can be obtained. In this case, the individual sun gear shafts 18 and planetary gear frames 7 of the individual gear device stages may be fitted over the input shaft 11 in sequence, and in this case, they are coupled axially to each other by the locking coupling part 17.

[0054] In this embodiment, a magnetic preload and a locking coupling portion are shown in combination with each other. However, both concepts can be used and applied independently on their own. That is, for example, it is quite possible to use a magnetic preload in a single-stage planetary gear device. Also, it is possible to apply an axial locking coupling portion without a magnetic preload.

Explanation of Reference Signs

[0055] 1 Actuating drive device 2 Drive motor 3 Planetary gear device assembly 4 Control electronics 5 Planetary gear device, gear device stage, planetary gear device stage 6 Internal gear 7 Planetary gear frame 8 Planetary gear 9 Sun gear 10 Housing 11 Shaft, notification shaft 12 First permanent magnet 13 Second permanent magnet 14 Gap 15 Receiving portion 16 Housing member, gear device member 17 Locking coupling portion 18 Sun gear shaft 19 Recess 20 Axial hole 21 Disk 22 Opening 23 Locking tongue 24 Slit 25 Locking groove

Claims

1. A planetary gear assembly (3) comprising at least two planetary gear stages (5), each having one sun gear (9), one internal gear (6), and one planetary gear carrier (7) with a plurality of, preferably three, planetary gears (8). The planetary gear assembly (3) is characterized in that the axial positions of two engaging gear members relative to each other are defined by a magnetic preload, and by this magnetic preload, the planetary gear carrier (7) of at least the first planetary gear stage (5) and the planetary gear carrier (7) of the second planetary gear stage (5) are held in position relative to each other in the axial direction.

2. The planetary gear assembly (3) according to claim 1, characterized in that the magnetic preload is defined for a gear member (16) coupled to the housing (10), in particular rotatably supported.

3. The planetary gear assembly (3) according to claim 1 or 2, characterized in that the planetary gear (3) has at least two permanent magnets (12, 13) arranged such that the same poles face each other.

4. The first permanent magnet (12) is coupled to the planetary gear carrier (7) and / or the second permanent magnet (13) is coupled to a gear member (16) other than the internal gear (6), in particular axially fixed in position. The planetary gear assembly (3) according to claim 3.

5. The planetary gear assembly (3) according to claim 3 or 4, characterized in that the permanent magnets (12, 13) are each formed as annular magnets arranged coaxially with the sun gear shaft (18).

6. The planetary gear assembly (3) according to claim 5, characterized in that the planetary gear (3) has a receiving portion (15) in which both of the annular magnets (12, 13) are arranged inside.

7. The planetary gear assembly (3) according to the preamble of claim 1 or any one of claims 1 to 6, characterized in that at least both of the planetary gear stages (5) are axially coupled or couplable by a locking coupling portion (17).

8. The planetary gear frame (7) of the first gear unit stage (5) has at least one locking tongue piece (23) that is flexible in the axial direction, and a locking groove (25) extending over the entire circumference is arranged on the sun gear (9) or the sun gear shaft (18) of the second planetary gear unit stage (5). The planetary gear unit assembly (3) according to claim 7, characterized in that the locking tongue piece (23) engages in the locking groove (25) when the two planetary gear unit stages are coupled to each other.

9. The planetary gear unit assembly (3) according to claim 7 or 8, characterized in that the locking tongue piece (23) is arranged at or can pass through an opening (22) coaxial with the sun gear (9) or the sun gear shaft (18) that it has passed through.

10. The planetary gear unit assembly (3) according to any one of claims 7 to 9, characterized in that three locking tongue pieces (23) are arranged at the opening (22), and in particular, the locking tongue pieces (23) are evenly distributed over the entire circumference of the opening (22).

11. An operating drive device (1) comprising the planetary gear unit assembly (3) according to any one of claims 1 to 10.

Images