Planet carrier
By adopting independent spacer elements as rigid elements in the planet carrier and manufacturing separately from the cylindrical disk, the complex and expensive problems of existing planet carrier production are solved, simple and economical production is achieved, and the rigidity of the planet carrier is improved.
Patent Information
- Application Number
- CN202280099987.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-19
- Publication Date
- 2025-05-02
AI Technical Summary
The production of existing planetary carriers is complex and expensive, and rigid components require fine processing and difficult to manufacture separately, resulting in complex processing processes.
Independent spacer elements are used as rigid elements, respectively connected to the cylindrical disc, and connection and preloading are achieved through fastening devices, simplifying the production process.
The simple and economical production of the planet carrier is achieved, avoiding the need for fine machining of rigid components, and improving the torsion and bending rigidity of the planet carrier.
Smart Images
Figure CN119923536A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a planet carrier according to the generic part of claim 1 . Background Art
[0002] Planet carriers are used in planetary gear trains, especially precision gear trains, to support the planetary gears in the planetary gear train. The planet carrier may consist of two cylindrical disks, between which the rigid element is arranged. The rigid element serves to provide torsional and bending stiffness of the planet carrier. The rigid element forms an integral part of one or both disks and is also called cheek plate or jaw plate. Furthermore, in order to support the planetary gears in the planet carrier, holes are provided in the disks which can accommodate the planetary bearings.
[0003] In currently known planet carriers, the rigid elements are an integral part of one or both disks, requiring elaborate and expensive production, since the rigid elements must be cut out of the material of the planet carrier or of the disks of the planet carrier, for example by milling, or they must be molded onto the material of the disks, for example by welding. Furthermore, the rigid elements commonly used have an approximately triangular shape, making their machine production complex and expensive.
[0004] In order to ensure an accurately defined and correctly adjusted preload by the planet carrier within the planetary gear train, the rigid element must also have the correct length. This is achieved by grinding the outer surface of the rigid element together with the corresponding disk. However, this requires complex handling and machining of the parts of the planet carrier, because during this grinding process, the bearing seat or the already integrated bearing race that has been provided (especially in the disk) must not be damaged. Summary of the invention
[0005] It is therefore an object of the present invention to provide a planet carrier which is simple and economical to produce.
[0006] This object is achieved by a planet carrier according to claim 1 .
[0007] The planet carrier comprises a first and a second cylindrical disc arranged coaxially with respect to a common axis of rotation. These discs are spaced apart from each other and arranged with their respective bases or tops or front sides facing each other. The first and second discs each have a number of axial outer holes in their respective bases for supporting planetary gears, the outer holes extending parallel to the axis of rotation. The outer holes of the first and second discs are aligned with each other and are designed to accommodate planetary bearings for supporting planetary gears or supporting planetary shafts.
[0008] The outer ring of the planetary bearing can be inserted into the outer hole. Alternatively, the outer hole can take the form of an outer ring for the planetary bearing. In this case, the outer hole directly serves as an outer ring, and no additional outer ring is required. The rolling elements of the planetary bearing can roll along the surface of the outer hole used as a running surface, or the surface of the outer hole serves as a counter surface for a sliding bearing. Similarly, the outer hole can serve as a seat for the planet shaft, on which the planetary gear and its bearing arrangement then move.
[0009] Now, in order to connect the first and second cylindrical disks to each other while keeping them spaced apart, a spacing element is provided between the first and second disks, which takes the form of an element separate from the first and second disks and in contact with the first and second disks. The spacing element is designed to maintain a defined spacing between the first and second disks. However, the spacing element not only serves to maintain a defined spacing between the first and second disks, but also serves as a rigid element, such as is also provided in planet carriers known to date. With the help of such a rigid element, the support of the two disks is ensured while ensuring the torsional and bending rigidity of the planet carrier.
[0010] Due to the configuration of the spacing element as a separate element, the first and second disks as well as the spacing element can be produced separately in each case. This makes easy manufacturing possible, since the preferably geometrically simple elements, namely the two disks and the spacing element, can be manufactured separately from one another and can only be subsequently connected to one another. At the same time, the function of the spacing element continues to be provided, which corresponds to the function of the rigid elements used hitherto, namely to impart torsional and bending rigidity to the planet carrier.
[0011] Since the spacing element is manufactured separately from the disk, the bearing seat or the integrated bearing race which may have been arranged in the disk cannot be damaged during the manufacturing process of the spacing element, as was the case with the planet carriers used hitherto.
[0012] According to one embodiment, the spacing element is already detachably fastened to the first and second discs. This fastening can be achieved, for example, by means of an adhesive or the like. Alternatively, the spacing element can be coupled to the first and second discs by fastening means. These fastening elements can be screws or bolts or the like, but they can also be any other type of clamping mechanism. The fastening elements can preferably pass through the spacing element and through the discs and in this way connect them to each other. For this purpose, the spacing element can, for example, have an inner hole, the fastening means extending through the corresponding inner hole of the spacing element and through the corresponding axial hole in the base surface of the first and second discs.
[0013] The holes in both disks may be through holes. Alternatively, the holes in one of the disks may be blind holes. Furthermore, some of the holes in one disk may be through holes and others may be blind holes, in which case the two corresponding holes in the first and second disks are respectively a through hole and a blind hole, so that the fastening element can pass through the through hole of one disk, through the corresponding spacing element and into the blind hole of the other disk. Furthermore, the holes or some of the holes may be provided with threads which can cooperate with corresponding threads of the fastening device.
[0014] By means of the fastening element, the two disks can be connected to each other and to the spacing element. In addition, by means of the fastening element, the desired clamping force is applied to the disk and the spacing element, and the corresponding preload of the planet carrier is generated thereby.
[0015] According to another embodiment, the fastening means are subjected to a tensile load and the spacing element is subjected to a compressive load. In this way, a defined preload state in the planet carrier is obtained, which preload state resists the operating loads.
[0016] As already explained, by means of the spacing element or rigidity element, the torsion of the two discs relative to each other is reduced and the rigidity of the planet carrier is increased. In addition, by means of the coupling of the discs, a preload by fastening means, for example by screws, is obtained, because the discs are supported together via the spacing element.
[0017] The spacer element may have a cylindrical shape. In particular, such a cylindrical spacer element may be used if the planet carrier is used in a planetary gear train in which the crossbeam is subjected to lower torques, since the requirements on torsional rigidity are lower here.
[0018] The advantage of this cylindrical shape is that the spacer elements can be easily manufactured, for example by cutting them from a rod or a hollow tube. In particular, this makes easy mass production possible. The spacer elements can also be produced by extrusion or similar methods instead of cutting them from a rod or a hollow tube. In order to make the spacer elements used in the planet carrier have the same length, a plurality of spacer elements can be clamped together in the machine and ground together to the same length.
[0019] The two disks each have a smooth, dimensionally stable surface at least on mutually opposing bases, preferably on both bases. If a spacing element that has been manufactured to the same length is then arranged between the disks, a precisely defined and uniform spacing can be provided between the two disks.
[0020] In another embodiment, the spacing element can have a polygonal shape, for example a triangular shape, such as has been provided in planet carriers known to date. Such a polygonal shape, for example a triangular shape, has the advantage that more material can be present in the outer region, as a result of which the torsional and bending stiffness of the planet carrier is further increased. However, compared to planet carriers known to date, even in the case of a polygonal shape of the spacing element, the planet carrier proposed here has the advantage that the disk and the spacing element are separate elements and can be manufactured separately, so that simpler and more economical production can be achieved.
[0021] The spacer elements can be made of various materials, for example metals (e.g. steel, aluminum, etc.), or of synthetic materials (e.g. polymers) or ceramics. The appropriate material can be selected depending on the application and the relevant requirements. For example, ceramics have the advantage that high preloads are possible, since ceramics constitute a very load-resistant material. When using synthetic materials, in particular, the weight of the planet carrier can be reduced, for example compared to metals.
[0022] Furthermore, the advantage of manufacturing the planet carrier from separate components is that different materials can be used for the disks and the spacer elements. The material of the spacer elements can thus be selected separately from the material of the disks and can be optimized according to the necessary functions. For planet carriers employed in high-torque planetary gear trains, materials that can withstand relatively high forces, such as steel, can be selected, while for planet carriers employed in planetary gear trains in hot environments, materials that can withstand high temperatures well, such as ceramics, can be selected.
[0023] The spacing elements themselves may also consist of different materials; for example, some spacing elements may consist of metal and some spacing elements may consist of a synthetic material.
[0024] According to another embodiment, each disk has an outer circumferential surface and an inner circumferential surface, the inner circumferential surface defining a central inner hole, and the outer hole is arranged between the inner circumferential surface and the outer circumferential surface. For example, a sun gear of a planetary gear train can pass through such a central inner hole.
[0025] According to another embodiment, the spacer element is arranged between the outer holes, in particular as close as possible to or adjacent to or adjacent to the outer circumferential surface. In particular, the advantage of this arrangement is that the planet carrier is supported and reinforced by the spacer element in its outer area, that is, on the base surface in the direction of the outer circumferential surface.
[0026] The planet carrier can have any number of external holes, for example an even or odd number. The spacing element is preferably always arranged between two external holes, although other types of arrangements are also possible, for example in each case two spacing elements between two external holes or in each case two external holes between one spacing element. Furthermore, the number of external holes and thus the number of planetary gears that can be accommodated and the number of spacing elements can be scaled arbitrarily.
[0027] According to another embodiment, the planet carrier has an additional fastening element, which is designed to couple the first disk and the second disk to each other. The additional fastening element extends through corresponding holes in the base surface of the first and second disks. In particular, the additional fastening element can be arranged adjacent to or as close as possible to the spacing element. With the help of such an additional fastening element, the connection of the two disks to each other can be improved. In addition, such an additional fastening element can also be arranged in a central area around the axis of rotation, in particular in an outer hole. In this way, an additional coupling of the two disks in the middle of them can be obtained, improving the coupling of the two disks to each other and increasing the overall stability. In this regard, the additional fastening element in the central area may actually have been arranged centrally. An eccentric arrangement, for example to compensate for an imbalance, is also possible.
[0028] Furthermore, it is possible to connect additional fastening elements to the spacing element and to provide not only a fastening element at the corresponding location but also, in addition, a spacing element through which the fastening element extends.
[0029] According to another embodiment, the first and second disks are identical to one another. In this way, not only the production of the spacing elements but also the production of the disks is simplified, since only one type of disk has to be manufactured and they can be arranged in a mirror-image manner relative to one another. Furthermore, the spacing elements can be identical to one another, as described above, with the result that here too production is simplified. In particular, in this way, individual elements can be produced in large quantities. Furthermore, various individual elements can be combined as desired, in particular with regard to material, number of holes, e.g. outer holes, etc. In this way, the same spacing element can be combined with various disks to realize various types of planet carriers.
[0030] Thus, the planet carrier described herein can be used for any type of planetary gear train in which the planet gears are to be guided and supported in planet bearings in the planet carrier or the planet shafts are to pass through the planet carrier or be pressed into it. Such a planet carrier can be used in a planetary gear train with a sun gear, in which case the disc has a central inner hole, but it can also be used in a planetary gear train without a sun gear, in which case such a central inner hole can be omitted. Furthermore, the number of outer holes, the number of spacing elements, the materials used, the length of the spacing elements, etc. can be adjusted according to the desired functionality.
[0031] Further advantages and advantageous embodiments are detailed in the description, the drawings and the claims.In particular, the combinations of features specified in the description and the drawings are purely exemplary, so that these features may also exist alone or in different combinations.
[0032] In the following, the present invention will be described in more detail based on the embodiment examples shown in the drawings. The embodiment examples and the combinations shown in the embodiment examples are merely exemplary and are not intended to establish the scope of protection of the present invention. The scope is limited only by the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 shows an exploded view of a planet carrier according to one embodiment;
[0034] Figure 2 Shows Figure 1 A plan view of the disk of the planet carrier shown;
[0035] Figure 3 According to another embodiment Figure 1 a perspective view of a disk of a planet carrier shown; and
[0036] Figure 4-6 According to a further embodiment, Figure 1 A plan view of each disk of the planet carrier is shown.
[0037] In the following, the same elements or elements having the same functional effect are marked with the same reference symbols. DETAILED DESCRIPTION
[0038] Figure 1 A planet carrier 1 consisting of two cylindrical disks 2, 2' is shown. The first and second disks 2, 2' have a common axis of rotation A and face each other with their base or top faces.
[0039] The two disks 2 , 2 ′ are preferably identical, so that only one of the disks 2 , 2 ′ will be described in detail below. Figure 2 A plan view of one of the trays 2 is shown. The features described apply analogously to both trays 2, 2', the reference symbol for the first tray 2 being marked with a "'" for the second tray 2'.
[0040] The disk 2 has an outer circumferential surface 4, which can be connected to a housing, for example, via a main bearing (not shown). Alternatively, the planet carrier 1 can also be used without such a main bearing, that is, with a floating bearing arrangement. In the embodiment shown here, a flange 6 is already provided on the outer circumferential surface 4. On the one hand, the flange 6 can be used to connect a drive device, such as another gear stage or an electric motor, or for connecting an output device, such as another gear stage or a robot arm.
[0041] exist Figures 1 to 5 In the embodiment shown, the disc 2 also has an inner circumferential surface 8 defining a central bore 10. In the bore 10 a sun gear (not shown) of a planetary gear train may be positioned.
[0042] exist Figure 1 In the embodiment shown, the outer holes 12 are arranged around the inner hole 10 on the base surface of the disk 2. In an exemplary manner, four outer holes 12 are shown here, but more or fewer outer holes 12 can also be provided. Planetary gears (not shown) can be accommodated in the outer holes 12. For this purpose, planetary bearings (not shown) supporting the planetary gears in the planet carrier 1 can be arranged in the outer holes 12. In this case, the outer ring of the planetary bearing can be accommodated in the outer hole 12, or the outer hole 12 itself can serve as the outer ring. In this regard, it should be noted that the two disks 2, 2' or their outer holes 12, 12' are aligned with each other. In addition, the outer hole 12 can be used as a seat for a shaft on which the planetary bearing device and the planetary gear are already mounted.
[0043] Spacer elements or stiffening elements 14 have been arranged between the two base surfaces of the disks 2, 2'. These spacer elements 14 serve on the one hand to keep the two disks 2, 2' spaced apart, and on the other hand they serve to stiffen the two disks 2, 2' or the entire planet carrier 1. The spacer elements 14 take the form of separate elements. By means of this design as separate elements, both the disks 2, 2' and the spacer elements 14 can be produced in a simple manner, since each element can be manufactured separately. For example, Figure 1 As shown, the spacer element 14 may take the form of a cylindrical hollow body, which may be manufactured, for example, by truncating a hollow tube. Figure 1 As shown, the hollow cylindrical design constitutes only one possibility, and the spacing element 14 can also take the form of a solid cylinder or some other form.
[0044] The spacing element 14 may be coupled to the two plates 2, 2' by any type of clamping mechanism. For example, the spacing element 14 may have been connected to the two plates 2, 2' by fastening elements (not shown) extending through holes 16, 16' in the two plates 2, 2', such as screws or bolts. Figure 1 As shown by the dashed line 20 , the holes 16 , 16 ′ and the hole 18 in the spacing element 14 are aligned with each other so as to enable fastening between the disk 2 , 2 ′ and the spacing element 14 .
[0045] It should be noted that although Figure 1 1 , four spacing elements and four outer holes 12, 12' are shown, but any other number of spacing elements 14 and holes 12, 12' is possible. In addition, the inner hole 10 can also be omitted, and the planet carrier 1 can be used in a planetary gear train without a sun gear.
[0046] The spacing elements 14 and the corresponding holes 16 in the base surface of the disks 2, 2' are preferably arranged in the edge region of the base surface. This has the advantage that the two disks 2, 2' can be supported relative to each other via their base surfaces in a uniformly distributed manner by the spacing elements 14. In this case, it is particularly preferred that the spacing elements 14 are each arranged between the outer holes 12.
[0047] As mentioned above, the spacing element 14 may also have a different Figure 1 , 2 , 4 to 6. Figure 3 As shown, the spacer element 14 can have a triangular shape, for example. In this case, the spacer element 14 is arranged with its wide side 24 in the direction of the outside and its narrow side 22 in the direction of the inner hole 10. This has the advantage that more material is present in the outer region in order to provide better support and thus better torsional and bending stiffness there. Figure 3 In FIG. 2 , the spacing element 14 is shown already connected to the disc 2 , and a second disc 2 ′ (not shown) is likewise connected to the spacing element 14 .
[0048] In order to provide a better connection between the two plates 2, 2', in addition to the spacing element 14 and the associated fastening means, further fastening means may be provided. Figure 4 As shown, for example, the additional fastening means may be passed through the hole 26 which is located in the Figure 4 The spacer element 14 is already provided on both sides of the spacer element 14. This improves the coupling of the two disks 2, 2' and thus leads to a firm connection of the two disks 2, 2'.
[0049] Instead of providing additional fastening means only via the holes 26, further spacing elements 28 may also be present, such as Figure 5 In this case, the holes 26 are used not only for the fastening means, but also for the spacing element 28, in which respect the fastening means extend through the holes 26 in the two disks 2, 2' and through the spacing element 28, or through the holes through the spacing element 28, as already described with respect to the spacing element 14 and the holes 16.
[0050] An increase in torsional and bending stiffness can also be obtained by providing additional spacing elements in the middle of the disks 2, 2'. Figure 6 As shown, the planet carrier 1 as a whole can also be without the inner hole 10, in which case the additional spacing element 32 can be arranged in the middle around the axis of rotation A. As already described with respect to the spacing elements 14 and 28, here too the hole 30 is provided in the disk 2, 2' and the spacing element 32 is connected to the two disks 2, 2' via fastening means passing through the hole 30. Although in Figure 6 The inner hole 10 is not shown in the drawing, but a smaller inner hole 10 may be provided and / or the spacing element 32 may be arranged around the inner hole 10 .
[0051] By means of the planet carrier described here, it is thus possible to produce the individual components of the planet carrier easily and economically, which nevertheless provide sufficient torsional and bending stiffness of the planet carrier for a planetary gear train.
[0052] Reference numerals list
[0053] 1Planet carrier
[0054] 2. 2' plate
[0055] 4, 4' outer circumference surface
[0056] 6, 6' flange
[0057] 8, 8' inner circumference surface
[0058] 10, 10' internal bore
[0059] 12, 12' outer hole
[0060] 14 Spacer element
[0061] 16, 16' hole
[0062] 18 Through Holes
[0063] 20 Alignment
[0064] 22 Narrow side
[0065] 24 wide side
[0066] 26 holes
[0067] 28 Spacer element
[0068] 30 holes
[0069] 32 Spacer element
[0070] A Rotation axis
Claims
1. A planet carrier (1) comprising a first and a second cylindrical disk (2, 2') arranged coaxially with respect to a common rotation axis (A), wherein the first and the second disk (2, 2') have a plurality of axial outer holes (12, 12'), wherein the outer holes (12, 12') extend parallel to the rotation axis (A), wherein the outer holes (12, 12') of the first and the second disk (2, 2') are aligned with each other, and wherein the outer holes (12, 12') are designed to accommodate planetary bearings for supporting planetary gears or for supporting planetary shafts, It is characterized in that A spacing element (14) is arranged between the first and second plates (2, 2'), the spacing element (14) being in the form of an element separate from the first and second plates (2, 2') and in contact with the first and second plates (2, 2'), wherein the spacing element (14) is designed to maintain a defined spacing between the first and second plates (2, 2').
2. The planet carrier according to claim 1, wherein: The spacing element (14) is detachably fastened to the first and second plates (2, 2'), wherein the spacing element (14) is coupled to the first and second plates (2, 2'), in particular by fastening means.
3. The planet carrier according to claim 2, wherein: The fastening elements are subjected to tensile loads and wherein the spacing elements (14) are subjected to compressive loads, whereby a defined preload state in the planet carrier (1) is obtained which resists operating loads and operating stresses.
4. A planet carrier according to any one of the preceding claims, wherein: The spacer elements (14) each have an inner bore (18), wherein the fastening means extend through the respective inner bore (18) of the spacer element (14) and through the respective axial bores (16, 16') in the first and second disks (2, 2').
5. A planet carrier according to any one of the preceding claims, wherein: The spacer element (14) has a cylindrical or polygonal shape, in particular a triangular shape.
6. A planet carrier according to any one of the preceding claims, wherein: The spacing element (14) is arranged between the outer holes (12, 12'), in particular adjacent to the outer circumferential surfaces (4, 4') of the first and second disks (2, 2').
7. A planet carrier according to any one of the preceding claims, wherein: The planet carrier (1) has an additional fastening element which is designed to couple the first and second disks (2, 2') to one another, wherein the additional fastening element extends through corresponding holes (26, 30) in the first and second disks (2, 2'), wherein the additional fastening element is in particular arranged adjacent to the spacing element (14).
8. The planet carrier according to claim 7, wherein: The additional fastening element is arranged in a central region around the rotation axis (A).
9. A planet carrier according to any one of the preceding claims, wherein: The spacer element (14) is made of metal, in particular steel, a synthetic material, in particular a polymer, and / or ceramic.
10. A planet carrier according to any one of the preceding claims, wherein: The first and second plates (2, 2') are identical to one another and / or wherein the spacing elements (14) are identical to one another.