Planet carrier
By setting up a lubricating channel on the planet carrier, the lubricant is transported from the central inner hole to the outer hole, which solves the problem that planetary bearings are difficult to achieve continuous lubrication in precision transmission devices, and achieves the reliable and continuous lubrication effect of planetary bearings.
Patent Information
- Application Number
- CN202380053558.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-20
- Filing Date
- 2023-07-05
- Publication Date
- 2025-02-28
AI Technical Summary
Existing planetary bearings are difficult to achieve continuous and reliable lubrication in compact precision transmissions, especially during immersion lubrication, where there are challenges in the integration of lubricant supply and delivery equipment.
A planetary carrier with lubricating channels is designed, which can be arranged on the inner shell surface or the outer shell surface section to form a lubricant channel from the central inner hole to the outer hole, and the lubricant is delivered to the planetary bearing using gravity and centrifugal force.
Continuous and reliable lubrication of planetary bearings is achieved, ensuring that lubricant can effectively flow to the operating surface of planetary bearings during operation, extending service life.
Smart Images
Figure CN119546883A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a planet carrier according to the preamble of patent claim 1. Background Art
[0002] Planetary bearings are used in planetary transmissions, especially precision transmissions, to mount the planets in the planet carrier. Planetary bearings of this type must be adequately lubricated in order to function correctly and achieve an adequate service life. Considering the compactness of planetary transmissions of this type, the integration of the lubricant supply and the integration of the equipment for delivering the lubricant into the planetary transmission are challenges.
[0003] Until now, planetary bearings have been lubricated by introducing lubricant into the planetary transmission by flood lubrication. It is relied upon here that during flood lubrication, due to the rotation of the planet carrier, a sufficient amount of lubricant flows to the planetary bearings, in particular the running surfaces. Summary of the invention
[0004] It is therefore an object of the present invention to provide a planet carrier which enables a continuous and reliable lubrication of the planet bearings.
[0005] This object is achieved by a planet carrier according to patent claim 1 .
[0006] The planet carrier has the shape of a cylindrical disk with an outer shell surface and an inner shell surface. Here, the inner shell surface defines a central inner hole, in which the sun gear of the planetary transmission can be arranged. In addition, a plurality of outer holes arranged around the central inner hole are provided in the disk. The planetary gears can be mounted in the outer holes, in particular using planetary bearings accommodated in the outer holes.
[0007] In order to achieve reliable and continuous lubrication compared with previous planetary transmissions, lubrication channels are provided on the inner shell surface at least in sections. The lubrication channel can be configured as a lubrication groove that is completely or partially circumferential. As an alternative, the lubrication channel can be configured as one (or more) lubrication tubes from the central inner hole to the outer hole. For example, the lubrication channel can be made into grooves in sections, rather than in a completely circumferential manner, such as by a side milling cutter, etc., wherein the inner shell surface is pierced only at the position of the outer hole. The depth of the piercing reaches here until the corresponding outer hole, thus forming a lubrication channel. Other embodiments are also possible, some of which will be explained in more detail below. In each case, the lubrication channel is configured to transport the lubricant introduced into the inner hole to the outer hole, and thus to the planetary bearing. This may occur during operation, so continuous lubrication of the planetary bearing is possible compared to immersion lubrication.
[0008] Alternatively or in addition, the lubrication channel can also be arranged at least in sections on the housing surface. This type of lubrication channel is configured to convey lubricant from the outside of the planet carrier to the outer hole. Just like the lubrication channel on the housing surface, the lubrication channel can be configured as a completely or sectionally circumferential lubrication groove. As an alternative, the lubrication channel can be configured as one (or more) lubrication pipes from the outside, that is to say from the housing surface, to the outer hole. Other embodiments are also possible, some of which will be explained in more detail below.
[0009] According to one embodiment, a plurality of circumferentially distributed lubrication channels may be provided on or in the inner shell surface. This type of circumferential distribution may ensure that the lubricant flows to all outer holes.
[0010] The depth of the lubrication channel or channels can preferably extend at least partially radially outwards to the outer bore. In this way, lubricant can be conveyed from the central inner bore via the lubrication channel / channels to the planetary bearing, that is to say to the outer bore. This means that the lubricant channel from the central inner bore to the outer bore is formed by this extension of the lubrication channel / channels. In particular, the lubrication channel or channels are in this case formed by a through hole from the central inner bore to the outer bore.
[0011] According to another embodiment, the lubrication channel on the inner shell surface comprises lubrication grooves arranged on the inner shell surface in the circumferential direction. In addition, the lubrication channel comprises at least one channel extending radially outwards to the outer hole so as to form a lubricant channel from the central inner hole to the outer hole. The channel is thus configured as a channel for the lubricant from the lubrication groove to the outer hole. In this case, the lubricant can be introduced into the central inner hole and then present in the lubrication groove. Starting from the lubrication groove, the lubricant can be transported to the outer hole via one or more channels. The channel is preferably arranged in the region of the outer hole or leads from the inner hole to the outer hole in the radial direction.
[0012] The lubricant can flow from the inner bore to the planetary bearings, in particular to their raceways, through lubricant channels which are formed due to the radial extent of the lubricant channel depth and / or due to the channels. Due to gravity and / or preferably due to centrifugal forces during the rotation of the planet carrier, the lubricant is conveyed from the inner bore into one or more lubricant channels. In particular, due to the centrifugal forces generated by the rotation of the planet carrier, the lubricant entering the inner bore of the planet carrier is accelerated outwards in the radial direction and is pressed into the lubricant channels and the channels leading to the outer bore.
[0013] This is particularly preferably a planet carrier that rotates at a rotational speed of more than 30 rpm, preferably about 200 rpm. This speed ensures that the lubricant moves to the outer bore during operation under the effect of centrifugal forces. In this way, reliable and continuous lubrication can also be achieved during operation.
[0014] As already described above, the lubrication channel can be configured as a lubrication groove and, in particular, as a completely circumferential lubrication groove. This enables particularly simple production of the lubrication groove, since this can be produced in a circumferential manner in the inner shell surface, for example by milling.
[0015] According to a further embodiment, the outer hole is configured as an outer ring of a planetary bearing. In this case, the outer hole is directly used as an outer ring, and no additional outer ring is required. The rolling elements of the planetary bearing can roll on the surface of the outer hole used as a running surface, or the surface of the outer hole is used as a counter surface of a sliding bearing.
[0016] As an alternative, the outer rings can be inserted into the outer holes. In this case, each outer ring has a lubricant channel, which is fluidically connected to a lubrication channel, such as a raceway.
[0017] According to a further embodiment, the planet carrier has a plurality of lubrication channels distributed circumferentially in sections on the housing surface. Due to these lubrication channels, not only the inner bores are fluidically connected to the outer bores, but also the outer sides can be fluidically connected to the outer bores. For example, the inner ring of a main bearing for mounting the planet carrier can be arranged on the housing surface. The main bearing can be lubricated via these lubrication channels in a manner similar to that described for the planet bearings. As already described above for the inner housing surface, the plurality of circumferentially distributed lubrication channels can achieve a particularly satisfactory delivery of lubricant to all outer bores.
[0018] According to one embodiment, the depth of one or more lubrication channels on the housing surface may extend at least partially radially inwards to the outer hole so as to form a lubricant channel from the outer side to the outer hole.
[0019] As has also been described for the inner housing surface, the lubrication channel on the outer housing surface can have in a similar manner a lubrication groove, which is arranged in the circumferential direction on the outer housing surface, and at least one channel, which extends radially inwards as far as the outer hole, in order to form a lubricant channel from the outside to the outer hole. Preferably, a plurality of channels are provided, each of which is arranged in the region of the outer hole. In this way, each outer hole can be supplied with lubricant via a channel.
[0020] Just like the lubrication channel in the inner shell surface, the lubrication channel in the outer shell surface can also be arranged circumferentially in sections, especially in the region from the channel to the outer hole, or completely circumferentially. This type of circumferential lubrication channel or lubrication groove can be manufactured particularly simply.
[0021] Further advantages and advantageous embodiments are detailed in the description, the drawings and the claims.Here, in particular, the combinations of features specified in the description and the drawings are purely exemplary, with the result that these features may also exist alone or in another combination.
[0022] In the following, the present invention will be described in more detail based on the exemplary embodiments shown in the accompanying drawings. Here, the exemplary embodiments and the combinations shown in the exemplary embodiments are only examples and are not intended to limit the scope of protection of the present invention. This is only limited by the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In the attached picture:
[0024] Figure 1 shows a perspective view of a planet carrier according to one embodiment, and
[0025] Figure 2 Shows Figure 1 A cross-sectional view of the planet carrier.
[0026] In the following, identical or functionally identical active elements are denoted by the same reference numerals. DETAILED DESCRIPTION
[0027] Figure 1 and 2 A planet carrier 1 is shown which comprises a cylindrical disk 2. The disk 2 has an inner shell surface 3 which defines a central inner hole 4. A sun gear (not shown) of a planetary transmission can be arranged in the inner hole 4. Furthermore, the disk 2 has an outer shell surface 6 which can be connected to a housing, for example, via a main bearing (not shown). In the embodiment shown here, a flange 8 is provided on the outer shell surface 6. The flange can firstly be used to attach a drive device, such as another gear stage or an electric drive motor, or to attach an output device, such as another gear stage or a robot arm.
[0028] On the end side, the disk has an optional stiffening element 10 , via which two planet carriers can be connected.
[0029] The outer hole 12 is arranged around the inner hole 4. Four outer holes 12 are shown here as an example, but more or fewer outer holes 12 may be provided. Planetary gears (not shown) may be accommodated in the outer holes 12. For this purpose, a planetary bearing (not shown) for mounting the planetary gears in the planet carrier 1 may be arranged in the outer hole 12. Here, the outer ring of the planetary bearing may be accommodated in the outer hole 12, or the outer hole 12 may itself be used as the outer ring.
[0030] In order to be able to lubricate the planet bearings reliably and permanently compared to previous planet carriers or planetary gears, lubrication channels 14, 18 are provided in the planet carrier 1. One lubrication channel 14 is arranged on the inner housing surface 3, and the other lubrication channel 18 is arranged on the outer housing surface 6.
[0031] In the following, an embodiment is described in which the lubrication channels 14, 18 are each configured as a lubrication groove 14, 18 combined with a channel. However, it should be noted that different configurations of the lubrication channels 14, 18 are possible. For example, they can also be configured as through holes between the inner hole 4 and the outer hole 12 or between the outer side and the outer hole 12. In each case, a fluid connection is created between the inner hole 4 and the outer hole 12 or between the outer side and the outer hole 12 by the lubrication channels 14, 18, which will be explained in more detail below based on a specific embodiment. In addition, it is also possible to provide lubrication channels only in the inner shell surface or only in the outer shell surface.
[0032] exist Figure 1 and 2 In the embodiment shown, a lubrication groove 14 as part of a lubrication channel is at least partially arranged in the circumferential direction on the inner shell surface 3. In the embodiment shown, the lubrication groove 14 is arranged in a completely circumferential manner. However, it can also be present only in sections.
[0033] The lubricant introduced into the inner bore 4 can be transported to the outer bore 12 and thus to the planetary bearings through the lubrication groove 14. During operation, that is, during the rotation of the planet carrier 1, the lubricant in the inner bore 4 is pressed outward into the lubrication groove 14 by gravity and / or centrifugal force.
[0034] In order to convey the lubricant from the lubrication groove 14 further to the planetary bearing, that is to say to the outer bore 12, the depth of the lubrication groove 14 can at least partially extend radially outwards to the outer bore 12. In particular, in the region of the outer bore 12, the lubrication groove 14 can extend to the outer bore 12 or a channel can be provided so that the outer bore 12 is fluidically connected to the lubrication groove 14. Figure 1 and 2 As shown, a corresponding channel 16 is present in the outer bore 12 , which channel originates from a corresponding depth of the lubrication groove 14 or a channel between the lubrication groove 14 and the outer bore 12 .
[0035] As described above, the lubricant is pressed into the lubrication groove 14 by gravity and / or centrifugal force, and then from the lubrication groove 14 into the channel 16 and then into the planetary bearing. If the outer rings are accommodated in the outer bore 12, they can also have lubricant channels, such as grooves, in order to convey the lubricant into the interior space of the planetary bearing, in particular onto the running surface.
[0036] like Figure 1 and 2 As shown, a further lubrication groove 18 can be provided in the circumferential direction in the housing surface 6. By means of this further lubrication groove 18, not only the inner bore 4 but also the outer side can be fluidically connected to the outer bore 12.
[0037] In addition to the channel 16 for fluid connection with the inner bore 4, the outer bore 12 may have further channels or trenches 20, such as Figure 2 As shown. Via these channels 20, the outer bore 12 is fluidically connected to the lubrication groove 18 in the housing surface 6 and thus to the outside. In this way, lubricant present via the inner bore 4 or in the inner bore 4 can be conveyed not only to the outer bore 12 but also to the housing surface 6 and, for example, to the main bearing arranged there. Just like a planetary bearing, a main bearing of this type can have corresponding channels in order to convey lubricant into the interior space of the main bearing.
[0038] Overall, the planet carrier described here enables simple and reliable lubrication of the planet bearings, which lubrication can be maintained continuously, ie can also be maintained precisely during operation of the planet carrier.
[0039] Reference numerals list
[0040] 1Planet carrier
[0041] 2 plates
[0042] 3 Inner shell surface
[0043] 4 inner holes
[0044] 6 Shell surface
[0045] 8 Flange
[0046] 10 Rigid components
[0047] 12 external holes
[0048] 14 Lubrication groove
[0049] 16 channels
[0050] 18 Lubrication groove
[0051] 20 channels
Claims
1. A planet carrier (1) having a cylindrical disk shape with an outer shell surface (3) and an inner shell surface (6), wherein the inner shell surface (3) defines a central inner hole (4), wherein the planet carrier (1) has a plurality of outer holes (12) arranged around the central inner hole (4) for mounting planetary gears, and further wherein the outer holes (12) are configured to receive planetary bearings for mounting the planetary gears, It is characterized in that The lubrication channels (14, 18) are arranged at least in sections on the inner shell surface (3) and / or the outer shell surface (6).
2. The planet carrier according to claim 1, wherein: Preferably, a plurality of lubrication channels (14) distributed circumferentially are provided on the inner shell surface (3).
3. The planet carrier according to claim 2, wherein: The depth of one or more lubrication channels (14) on the inner shell surface (3) extends at least partially radially outward to the outer hole (12) to form a lubricant channel (16) from the central inner hole (4) to the outer hole (12).
4. A planet carrier according to any one of the preceding claims, wherein: The lubrication channel on the inner shell surface (3) comprises a lubrication groove (14) arranged on the inner shell surface (3) in a circumferential direction, and at least one channel extending radially outward from the central inner hole (4) to the outer hole (12), so as to form a lubricant channel (16) from the central inner hole (4) to the at least one outer hole (12).
5. A planet carrier according to any one of the preceding claims, wherein: The outer hole (12) is configured for the outer ring of the planetary bearing.
6. A planet carrier according to any one of the preceding claims, wherein: Outer races are inserted into the outer bore (12), wherein the outer races each have a lubricant channel fluidly connected to the lubrication channel (14).
7. A planet carrier according to any one of the preceding claims, wherein: A plurality of lubrication channels distributed circumferentially are arranged on the shell surface (6).
8. The planet carrier according to claim 7, wherein: The depth of one or more lubrication channels (18) on the housing surface (6) at least partially extends radially inward to the outer hole (12) so as to form a lubricant channel (20) from the outside to the outer hole (12).
9. The planet carrier according to claim 7 or 8, wherein: The lubrication channel (18) on the housing surface (6) comprises lubrication grooves (18) arranged on the housing surface (6) in the circumferential direction, and at least one channel extending radially inwardly to the outer hole (12) so as to form a lubricant channel (20) from the outside to one of the outer holes (12).
10. A planet carrier according to any one of the preceding claims, wherein: The lubrication channels (14, 18) on the inner shell surface (3) and / or the outer shell surface (6) are arranged completely circumferentially.