Planetary gear set with a planet carrier and a planet gear shaft

Abstract

Planetary gear set with a planet carrier (5) and a planet gear shaft (2), wherein one area of ​​the planetary support (5) is shaped as a first cheek, wherein the first cheek has an axially through recess into which the planet gear axis (2) is at least partially inserted, characterized by the fact that an axially directed threaded bore is provided in the end face of the planet gear shaft (2), wherein a screw (4) is screwed into the axially directed threaded bore, so that a spring element (6) is pre-tensioned, which secures the screw connection between screw (4) and planet gear shaft (2), wherein the area axially covered by the screw (4) overlaps at least with the axial area covered by the recess, wherein the spring element (6) is pre-tensioned and / or presses against the wall of the recess, wherein a planet gear (1) is rotatably mounted on the planet gear axis (2) by means of a bearing, wherein the planet gear (1) is positioned against a collar of the planet gear axle (2), wherein the screw (4) has a screw head, wherein the spring element (6) is arranged axially between the screw head and the end face of the planet gear shaft (2), wherein the spring element (6) is designed as a perforated disc, the axially covered area of ​​which shifts monotonically in the axial direction with increasing radial distance from the screw axis and / or central axis of the planet gear axis (2), wherein the outer edge of the perforated disc touches the wall of the recess and the inner edge of the perforated disc touches the screw (4), wherein the planet gear axle (2) has a collar with which it is positioned against the planet carrier (5), namely against an edge of the recess of the planet carrier (5).

Description

[0001] The invention relates to a planetary gear with a planet carrier and a planet gear axle.

[0002] It is generally known that a screw has a threaded section and a screw head that is radially widened relative to it.

[0003] US Patent 5,863,272 A describes a planetary gear as the closest state of the art.

[0004] A planetary gear with a single-walled planet carrier is known from DE 10 2014 225 340 A1.

[0005] Star disks are known from the publication by the authors WITTEL; MUHS; JANNASCH: Roloff / Matek Maschinenbauelemente. 21st edition. Wiesbaden: Springer Vieweg, 2013. pp. 405, 406. - ISBN 978-3-65802327-0.

[0006] The invention is therefore based on the objective of making a planetary gear easy to manufacture.

[0007] According to the invention, the problem is solved in the planetary gear according to the features specified in claim 1.

[0008] Important features of the invention in the planetary gear with a planet carrier and a planet gear shaft are that a region of the planet carrier is formed as a first cheek, wherein the first cheek has an axially through recess into which the planet gear shaft is at least partially inserted, wherein an axially directed threaded bore is provided in the end face of the planetary gear shaft, wherein a screw is screwed into the axially directed threaded bore, so that a spring element is pre-tensioned, which secures the screw connection between screw and planetary gear shaft, wherein the area axially covered by the screw overlaps at least with the axially covered area by the recess, wherein the spring element is pre-tensioned against and / or presses against the wall of the recess.

[0009] An advantage of this design is its ease of manufacture. The planetary gear axle can be inserted into the recess of the planet carrier with little or no force. After insertion, further tightening of the screw (i.e., screwing the screw further into the planetary gear axle) elastically deforms the spring element, thereby securing not only the screw connection between the screw and the planetary gear axle, but also the planetary gear axle axially within the planet carrier.

[0010] This allows for simple manufacturing, as well as simple non-destructive disassembly and reusability. The connection can be repeatedly disassembled and reassembled without causing irreversible deformation of the planet carrier recess and / or the planet gear shaft.

[0011] In an advantageous embodiment, a planet gear is rotatably mounted on the planet gear shaft by means of a bearing, in particular a needle bearing, wherein the planet gear is positioned against a collar on the planet gear shaft. It is advantageous that the collar provides an axially positive locking stop, and thus also a locking mechanism.

[0012] In an advantageous embodiment, the screw has a screw head, The spring element is arranged axially between the screw head and the end face of the planetary gear shaft. An advantage of this arrangement is that the spring element can be supported by the screw head.

[0013] In an advantageous embodiment, the spring element is designed as a perforated disc, the axially covered area of ​​which shifts monotonically in the axial direction with increasing radial distance from the screw axis and / or central axis of the planet gear axis, in particular is shifted monotonically in the axial direction.

[0014] In particular, the perforated disc has a constant wall thickness. A further advantage is that it can be manufactured simply.

[0015] In an advantageous embodiment, the outer edge region of the perforated disc touches the wall of the recess. and / or the inner edge of the perforated disc touches the screw. An advantage of this is that improved axial locking can be achieved.

[0016] In an advantageous embodiment, the screw head is radially widened relative to the threaded section of the screw. This has the advantage of allowing the spring element to be easily supported on the screw head.

[0017] In an advantageous embodiment, an internally polygonal, in particular internally hexagonal, recess is provided in the screw, especially in the end face facing away from the planet gear axis. An advantage of this is that simple operation of the screw is possible.

[0018] In an advantageous embodiment, the planet gear shaft has a collar with which it is positioned against the planet carrier, in particular against an edge of the recess in the planet carrier. An advantage of this is that an axial limit is achieved by positive locking.

[0019] 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.

[0020] The invention will now be explained in more detail with the help of illustrations: In the Fig. Figure 1 shows a cross-section of a single-sided planetary carrier arrangement of a planetary gear according to the invention, wherein a spring element 6 is relaxed. In the Fig. 2 is an excerpt of the Fig. 1 shown enlarged. In the Fig. Figure 3 shows the cross-section for the tensioned state of the spring element 6. In the Fig. 4 is an excerpt of the Fig. 3 shown enlarged. In the Fig. 5 is another excerpt of the Fig. 3 shown enlarged. In the Fig. Figure 6 shows a two-sided planet carrier arrangement of another embodiment according to the invention, instead of the one-sided one. In the Fig. Figure 7 shows the spring element 6 in oblique view. In the Fig. Figure 8 shows a spring element 6 of another embodiment according to the invention. In the Fig. Figure 9 shows a spring element 6 of a further embodiment according to the invention.

[0021] As in the Fig. As shown in Figures 1 to 5, the planetary gear has a planet carrier 5 on which a first cheek is formed, in particular in one piece, in particular in one part.

[0022] In the planet carrier 5 an axially continuous recess is provided in which a planet gear axle 2 is received, on which a bearing, in particular a needle bearing, is received, which in turn receives a planet gear 1 and is thus rotatably mounted towards the planet gear axle 2.

[0023] The teeth of planet gear 1 mesh with the internal teeth of a ring gear, which is rotationally fixed to a housing part of the gearbox.

[0024] The planet carrier is rotatably mounted via a rolling bearing, which is received in a recess of the housing part or a part that is non-rotatably connected to the housing part.

[0025] Furthermore, the teeth of the planet gear 1 mesh with the teeth of a sun gear, which is rotatably mounted in the housing via a bearing. The sun gear is non-rotatably connected to the input shaft, in particular a rotor shaft of an electric motor. The planet carrier 5 functions as the output shaft of the gearbox.

[0026] With its first axial end region, the planet gear shaft 2 is at least partially inserted into the axially through recess. An axially oriented threaded bore is provided in the axial end face of the planet gear shaft 2, into which a screw 4 is screwed with its threaded section, the screw head of which is widened, in particular radially wider with respect to the central axis or screw axis of the screw 4.

[0027] A spring element 6 is arranged between the screw head of screw 4 and the planet gear shaft 2. This spring element 6 is designed as a perforated disc, and screw 4 passes through this disc. In particular, the threaded section of the screw passes through the hole located centrally in the perforated disc.

[0028] As in Fig. 1 and Fig. As shown in Figure 7, the perforated disc 6 is curved or conical in shape.

[0029] The cross-section of the perforated disc 6 shows a constant wall thickness and is shaped in such a way that the axial position increases monotonically with increasing radial distance to the screw axis, i.e. also to the planet gear axis aligned coaxially to the screw 4.

[0030] Fig. Figure 1 shows the relaxed state of the spring element 6, i.e. the state when screw 4 is not fully screwed into the threaded hole.

[0031] Fig. Figure 3 shows the tensioned state of the spring element 6, i.e., the state when screw 4 is screwed in. In this state, the spring element 6 generates an axially directed restoring force and thus secures the screw connection. Furthermore, the spring element 6 is deformed in such a way that it presses radially outwards against the wall of the recess in the area of ​​the first cheek of the planet carrier 5.

[0032] As in Fig. 2 shown in more detail, is in the relaxed state, i.e. in the representation according to Fig. 1 and Fig. 2 a radial distance exists between the wall of the recess and the spring element 6, i.e. the perforated disc.

[0033] As in Fig. 3 together with Fig. As shown in Figure 5, in the tensioned state of the spring element 6, it actually protrudes radially and is thus deformed on the wall of the recess.

[0034] In this way, a force-fit axial securing of the planet gear axis 2 in the first cheek is also achieved.

[0035] The planet gear shaft 2 has a flange, i.e., a diameter step, meaning its outer diameter tapers monotonically towards the planet carrier 5, with the planet carrier 5 bearing against the flange, i.e., the diameter step. This provides a positive-locking, axially controlled locking mechanism for the planet gear shaft 2, acting in the opposite direction to the axial direction.

[0036] The planet gear axle 2, which is pressed into the recess of the first cheek, is therefore secured by means of the spring element 6.

[0037] The spring element 6 is preferably made of a hardened sheet steel.

[0038] During assembly, the planetary gear shaft 2, pre-equipped with screw 4 and spring element 6, is pressed in until it stops against the collar and then held in place by further screwing screw 4 into the axially oriented threaded bore of the planetary gear shaft 2. This deforms the spring element 6, thus achieving the frictional locking mechanism.

[0039] The invention even allows the planetary gear shaft 2 to be inserted into the first web without interference or without significant interference. Thus, only a weak press fit or even a connection without pressing is possible, enabling easy disassembly, for which only the screw 4 needs to be unscrewed from the threaded bore.

[0040] In the Fig. Figures 1 to 5 depict a one-sided planetary support arrangement.

[0041] As in Fig. As shown in Figure 6, the invention can also be implemented with a two-sided planetary carrier arrangement.

[0042] A second web 60 is connected to the planet carrier 5. The planet gear shaft 2 is pressed into a recess in the second web with its end region facing away from the first web. There, the planet gear shaft 2 has an outer diameter d2 that is larger than the outer diameter d2 it has at its first axial end region, with which it is inserted into the recess of the first web.

[0043] As in Fig. As shown in Figure 7, the spring element 6 can also be designed as a perforated disc which has recesses on its outer circumference, in particular regularly spaced recesses in the circumferential direction, which are designed as radial cuts. Thus, anti-rotation protection can be easily implemented, in particular by corresponding toothing or knurling of the end face of the planet gear shaft 2 facing the spring element 6.

[0044] As in Fig. Figure 8 also shows that recesses can be provided on the inner wheel of the hole in the perforated disc, in particular regularly spaced recesses in the circumferential direction, which are designed as radial cuts. Thus, anti-rotation protection can be easily implemented, especially by corresponding toothing or knurling of the areas of the screw 4 facing the spring element 6, particularly the underside of the screw head of the screw 4. Reference symbol list 1 planetary gear 2 planetary gear axle 3 Sun wheel 4 screws 5 planetary carriers 6 spring element 60 second cheek

Claims

[1] Planetary gear with a planet carrier (5) and a planet gear shaft (2), wherein one area of ​​the planetary support (5) is shaped as a first cheek, wherein the first cheek has an axially through recess into which the planet gear axis (2) is at least partially inserted, characterized by , that an axially directed threaded bore is provided in the end face of the planet gear shaft (2), wherein a screw (4) is screwed into the axially directed threaded bore, so that a spring element (6) is pre-tensioned, which secures the screw connection between screw (4) and planet gear shaft (2), wherein the area axially covered by the screw (4) overlaps at least with the axial area covered by the recess, wherein the spring element (6) is pre-tensioned and / or presses against the wall of the recess, wherein a planet gear (1) is rotatably mounted on the planet gear axis (2) by means of a bearing, wherein the planet gear (1) is positioned against a collar of the planet gear axle (2), wherein the screw (4) has a screw head, wherein the spring element (6) is arranged axially between the screw head and the end face of the planet gear shaft (2), wherein the spring element (6) is designed as a perforated disc, the axially covered area of ​​which shifts monotonically in the axial direction with increasing radial distance from the screw axis and / or central axis of the planet gear axis (2), wherein the outer edge of the perforated disc touches the wall of the recess and the inner edge of the perforated disc touches the screw (4), wherein the planet gear axle (2) has a collar with which it is positioned against the planet carrier (5), namely against an edge of the recess of the planet carrier (5). [2] Planetary gear according to claim 1, characterized by that the perforated disc has a constant wall thickness. [3] Planetary gear unit according to claim 1 or 2, characterized by , that the screw head of the screw (4) is radially widened relative to the threaded section of the screw (4). [4] Planetary gears according to at least one of the preceding claims, characterized by , that an internal polygonal recess is provided in the screw (4), in particular in the end face facing away from the planet gear axis (2).

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