Planetary gear reducer

Abstract

The utility model belongs to the technical field of speed reducers, and discloses a planetary gear speed reducer which comprises an inner-layer gear assembly and an outer-layer gear assembly, the inner-layer gear assembly comprises an inner-layer sun gear, a plurality of inner-layer planet gears, an inner-layer gear ring and an inner-layer planet carrier, and the plurality of inner-layer planet gears are installed on the inner-layer planet carrier; each inner-layer planet wheel is meshed with an inner-layer sun wheel and an inner-layer gear ring, and the inner-layer sun wheel is used for being connected with a driving source. The outer-layer gear assembly comprises an outer-layer sun gear, a plurality of outer-layer planet gears, an outer-layer gear ring and an outer-layer planet carrier, and the outer-layer planet gears are installed on the outer-layer planet carrier; each outer-layer planet wheel is meshed with the outer-layer sun wheel and the outer-layer gear ring, the outer-layer sun wheel is connected with the inner-layer planet carrier, the outer-layer planet carrier is used for outputting power, the inner-layer gear ring and the outer-layer gear ring are fixedly connected with an external support at the same time, and a gap is formed between the inner-layer gear ring and the outer-layer sun wheel. The planetary gear reducer is short in axial length, high in space utilization rate and high in bearing capacity.

Description

Technical Field

[0001] This utility model relates to the field of speed reducer equipment technology, and in particular to a planetary gear reducer. Background Technology

[0002] With the continuous development of science and technology, robots are increasingly being applied in production and daily life. Considering space constraints, miniaturization and lightweight design have become inevitable trends in robot development. Robots typically consist of multiple limbs and joint reducers connecting adjacent limbs. Currently, planetary gear reducers are commonly used as joint reducers in the field of robot technology. To improve the speed ratio of planetary gear reducers, existing technologies usually employ two-stage planetary gear reduction assemblies. This results in a relatively long overall planetary gear reducer, and each stage of the planetary gear reduction assembly suffers from a large speed ratio, but the sun gear of the planetary mechanism is too small, leading to insufficient overlap and thus weak load-bearing capacity. Utility Model Content

[0003] The purpose of this utility model is to provide a planetary gear reducer with a short axial length, high space utilization, and strong load-bearing capacity.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] This utility model discloses a planetary gear reducer, comprising: an inner gear assembly, the inner gear assembly including an inner sun gear, a plurality of inner planet gears, an inner ring gear, and an inner planet carrier, the plurality of inner planet gears being mounted on the inner planet carrier; each inner planet gear meshing with the inner sun gear and the inner ring gear, the inner sun gear being used to connect to a drive source; and an outer gear assembly, the outer gear assembly including an outer sun gear, a plurality of outer planet gears, an outer ring gear, and an outer planet carrier, the plurality of outer planet gears being mounted on the outer planet carrier; each outer planet gear meshing with the outer sun gear and the outer ring gear, the outer sun gear being connected to the inner planet carrier, and the outer planet carrier being used to output power; wherein, the inner ring gear and the outer ring gear are simultaneously fixedly connected to an external support, and there is a gap between the inner ring gear and the outer sun gear.

[0006] In some embodiments, the transmission ratio of the inner gear assembly is greater than the reduction ratio of the outer gear assembly.

[0007] In some specific embodiments, the transmission ratio of the inner gear assembly is less than or equal to 6, and the number of the inner planetary gears is greater than or equal to 3.

[0008] In some specific embodiments, the transmission ratio of the outer gear assembly is less than or equal to 4, and the number of the outer planetary gears is greater than or equal to 5.

[0009] In some more specific embodiments, the total transmission ratio of the planetary gear reducer is 9-25.

[0010] In some embodiments, the inner sun gear and the plurality of inner planet gears are all metal components.

[0011] In some embodiments, the outer sun gear and the plurality of outer planet gears are all made of plastic.

[0012] In some embodiments, the outer gear ring has a gear ring portion and a first groove portion, the gear ring portion meshing with the outer planetary gear, the first groove portion for accommodating the outer planetary carrier, and a first bearing provided between the outer planetary carrier and the sidewall of the first groove portion.

[0013] In some embodiments, the outer planetary carrier has a second recess, a portion of the outer sun gear extends into the second recess, and a second bearing is provided between the portion of the outer sun gear extending into the second recess and the inner sidewall of the second recess.

[0014] In some embodiments, the inner sun gear has a connection portion for connection with the drive source, wherein the connection portion and the outer planetary carrier are located on opposite sides of the outer ring gear along its axial direction, and a third bearing is provided between the connection portion and the inner ring gear; the connection portion and the outer planetary carrier are located on one side of the outer ring gear along its axial direction, and a fourth bearing is provided between the connection portion and the outer planetary carrier.

[0015] The beneficial effects of this planetary gear reducer are as follows: Because the outer sun gear of this planetary gear reducer is connected to the inner planet carrier, a nested arrangement of the inner and outer gear assemblies is achieved. Specifically, the outer gear assembly is located radially outside the inner gear assembly, shortening the axial dimension of the entire planetary gear reducer. Compared to existing planetary gear reducers, the axial length of this embodiment is only 35% of that of existing novel gear reducers. Furthermore, in this embodiment, the inner gear assembly rotates at a higher speed and outputs relatively less torque, while the outer gear assembly rotates at a lower speed and outputs greater torque. The smaller size difference between the inner planetary gears and the inner gears improves space utilization. The relatively high overlap between the outer planetary gears and the outer sun gear enables a greater load-bearing capacity.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the planetary gear reducer according to Embodiment 1 of this utility model;

[0018] Figure 2 This is a cross-sectional view of the planetary gear reducer according to Embodiment 1 of this utility model;

[0019] Figure 3 This is a cross-sectional view of the planetary gear reducer according to Embodiment 1 of this utility model from another direction;

[0020] Figure 4 This is a cross-sectional view of the planetary gear reducer according to Embodiment 2 of this utility model.

[0021] Figure label:

[0022] 100. Inner gear assembly; 110. Inner sun gear; 111. Connecting part; 120. Inner planet gear; 130. Inner gear ring; 140. Inner planet carrier; 150. Inner shaft;

[0023] 200, outer gear assembly; 210, outer sun gear; 220, outer planet gear; 230, outer gear ring; 231, gear ring portion; 232, first groove portion; 240, outer planet carrier; 241, second groove portion; 242, perforation; 250, outer shaft;

[0024] 300, First bearing; 400, Second bearing; 500, Third bearing; 600, Fourth bearing; 700, Baffle. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0026] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0028] Example 1:

[0029] This utility model discloses a planetary gear reducer, see reference. Figure 1 and Figure 2 As shown, the planetary gear reducer includes an inner gear assembly 100 and an outer gear assembly 200. The inner gear assembly 100 includes an inner sun gear 110, multiple inner planet gears 120, an inner ring gear 130, and an inner planet carrier 140. The multiple inner planet gears 120 are mounted on the inner planet carrier 140. The inner planet carrier 140 is provided with multiple inner shafts 150, and each inner shaft 150 is fitted with an inner planet gear 120. Each inner planetary gear 120 meshes with an inner sun gear 110 and an inner ring gear 130. The inner sun gear 110 is used to connect to a drive source. The outer gear assembly 200 includes an outer sun gear 210, multiple outer planetary gears 220, an outer ring gear 230, and an outer planet carrier 240. The multiple outer planetary gears 220 are mounted on the outer planet carrier 240. The outer planet carrier 240 is provided with multiple outer shafts 250, and each outer shaft 250 is fitted with an outer planetary gear 220. Each outer planetary gear 220 meshes with an outer sun gear 210 and an outer ring gear 230. The outer sun gear 210 is connected to the inner planet carrier 140, and the outer planet carrier 240 is used to output power. The inner ring gear 130 and the outer ring gear 230 are simultaneously fixedly connected to an external support, and there is a gap between the inner ring gear 130 and the outer sun gear 210.

[0030] It is understandable that, in this embodiment, the outer sun gear 210 is connected to the inner planet carrier 140, achieving a nested arrangement of the inner gear assembly 100 and the outer gear assembly 200. Specifically, the outer gear assembly 200 is located radially outside the inner gear assembly 100, shortening the axial dimension of the entire planetary gear reducer. Compared to planetary gear reducers in the prior art, the axial length of the planetary gear reducer in this embodiment is only 35% of the axial length of novel gear reducers in the prior art. Furthermore, in this embodiment, the inner gear assembly 100 rotates at a higher speed and outputs relatively less torque, while the outer gear assembly 200 rotates at a lower speed and outputs greater torque. The smaller size difference between the inner planet gear 120 and the inner ring gear 130 improves space utilization. The relatively high overlap between the outer planet gear 220 and the outer sun gear 210 enables a larger load-bearing capacity.

[0031] Optionally, the outer sun gear 210 and the inner planet carrier 140 can be connected by a connecting key, by adhesive bonding, or by other connection methods. No specific limitation is made here on the connection method between the outer sun gear 210 and the inner planet carrier 140.

[0032] Optionally, the inner planetary carrier 140 and the inner rotating shaft 150 are interference-fitted, and the inner rotating shaft 150 and the inner planetary gears 120 are connected by a flat key. Of course, the connection method between the inner planetary carrier 140 and the inner rotating shaft 150, and the connection method between the inner rotating shaft 150 and the inner planetary gears 120, can be adjusted according to actual needs.

[0033] Optionally, the outer planetary carrier 240 and the outer rotating shaft 250 are interference-fitted, and the outer rotating shaft 250 and the outer planetary gears 220 are connected by a flat key. Of course, the connection method between the outer planetary carrier 240 and the outer rotating shaft 250, and the connection method between the outer rotating shaft 250 and the outer planetary gears 220, can be adjusted according to actual needs.

[0034] Optionally, the planetary gear reducer also includes a baffle 700 that cooperates with the inner shaft 150 and the outer shaft 250, thereby protecting the inner planetary gear 120 and the outer planetary gear 220 and preventing them from moving in the circumferential direction.

[0035] Optionally, the transmission ratio of the inner gear assembly 100 is greater than the reduction ratio of the outer gear assembly 200. It is understood that a greater transmission ratio of the inner gear assembly 100 than the reduction ratio of the outer gear assembly 200 is beneficial for improving the overall load-bearing capacity of the planetary gear reducer.

[0036] Optionally, the transmission ratio of the inner gear assembly 100 is less than or equal to 6, and the number of inner planetary gears 120 is greater than or equal to 3. In this embodiment, the inner sun gear 110 has 9 teeth, the inner planetary gears 120 have 15 teeth, the inner ring gear 130 has 43 teeth, the transmission ratio of the inner gear assembly 100 is 5.78, and the number of inner planetary gears 120 is 4. Of course, in other embodiments of this utility model, the number of teeth of the inner sun gear 110, the number of teeth of the inner planetary gears 120, the number of teeth of the inner ring gear 130, the transmission ratio of the inner gear assembly 100, and the number of inner planetary gears 120 can be adjusted according to actual needs and are not limited to the examples above.

[0037] Optionally, the transmission ratio of the outer gear assembly 200 is less than or equal to 4, and the number of outer planetary gears 220 is greater than or equal to 5. In this embodiment, the outer sun gear 210 has 50 teeth, the outer planetary gears 220 have 24 teeth, the outer ring gear 230 has 100 teeth, the transmission ratio of the outer gear assembly 200 is 3, and the number of outer planetary gears 220 is 6. Of course, in other embodiments of this utility model, the number of teeth of the outer sun gear 210, the number of teeth of the outer planetary gears 220, the number of teeth of the outer ring gear 230, the transmission ratio of the outer gear assembly 200, and the number of outer planetary gears 220 can be adjusted according to actual needs and are not limited to the examples above.

[0038] Optionally, the total transmission ratio of the planetary gear reducer is 9-25. Specifically, the total transmission ratio of the planetary gear reducer can be 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3; 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12, 12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12. 8, 12, 9, 13, 13.1, 13.2, 13.3, 13.4, 13.5, 13.6, 13.7, 13.8, 13.9, 14, 14.1, 14.2, 14.3, 14.4, 14.5, 14.6, 14.7, 14.8, 14.9, 15, 15.1, 15.2, 15.3, 15.4, 15.5, 15.6, 15.7, 15.8, 15.9, 16, 16.1, 16.2, 16.3, 16.4, 16.5, 16.6, 16.7, 16.8, 1 6.9, 17, 17.1, 17.2, 17.3, 17.4, 17.5, 17.6, 17.7, 17.8, 17.9, 18, 18.1, 18.2, 18.3, 18.4, 18.5, 18.6, 18.7, 18.8, 18.9, 19, 19.1, 19.2, 19.3, 19.4, 19.5, 19.6, 19.7, 19.8, 19.9, 20, 20.1, 20.2, 20.3, 20.4, 20.5, 20.6, 20.7, 20.8, 20.9 21, 21.1, 21.2, 21.3; 11.4, 21.5, 21.6, 21.7, 21.8, 21.9, 22, 22.1, 22.2, 22.3, 22.4, 22.5, 22.6, 22.7, 22.8, 22.9, 23, 23.1, 23.2, 23.3, 23.4, 23.5, 23.6, 23.7, 23.8, 23.9, 24, 24.1, 24.2, 24.3, 24.4, 24.5, 24.6, 24.7, 24.8, 24.9, 25. Other values ​​within the range of 9-25 can also be selected based on actual needs, and are not limited to the examples listed above.

[0039] Optionally, the inner sun gear 110, the multiple inner planet gears 120, and the inner ring gear 130 are all metal components. It is understood that the inner sun gear 110 and the multiple inner planet gears 120 are relatively small in size; using metal components ensures their load-bearing capacity, thereby improving the load-bearing capacity of the planetary gear reducer in this embodiment. Further optionally, the inner sun gear 110 and the multiple inner planet gears 120 can be structural components made of stainless steel, powder alloy, or other metals, depending on actual needs.

[0040] Optionally, the outer sun gear 210 and the multiple outer planet gears 220 are all made of plastic. It is understood that the outer sun gear 210 and the multiple outer planet gears 220 are relatively large in size and have relatively good load-bearing capacity; therefore, using lighter plastic parts helps to reduce the overall weight of the planetary gear reducer. Further optionally, the outer sun gear 210 and the multiple outer planet gears 220 can also be manufactured from other materials according to actual needs.

[0041] Optionally, the outer gear ring 230 has a gear ring portion 231 and a first groove portion 232. The gear ring portion 231 meshes with the outer planetary gear 220, and the first groove portion 232 is used to accommodate the outer planetary carrier 240. A first bearing 300 is provided between the outer planetary carrier 240 and the sidewall of the first groove portion 232. It is understood that accommodating the outer planetary carrier 240 within the first groove portion 232 of the outer gear ring 230 can, on the one hand, protect the outer planetary carrier 240, and on the other hand, further shorten the axial dimension of the entire planetary gear reducer. The first bearing 300 provided between the outer planetary carrier 240 and the sidewall of the first groove portion 232 provides good support for the outer planetary carrier 240, ensuring stable rotation while reducing wear.

[0042] Optionally, the outer planetary carrier 240 has a second recess 241, into which a portion of the outer sun gear 210 extends. A second bearing 400 is provided between the portion of the outer sun gear 210 extending into the second recess 241 and the inner wall of the second recess 241. It is understood that accommodating the outer sun gear 210 within the second recess 241 of the outer planetary carrier 240 helps to further shorten the axial dimension of the entire planetary gear reducer. The second bearing 400 between the portion of the outer sun gear 210 extending into the second recess 241 and the inner wall of the second recess 241 provides good support for the outer sun gear 210, ensuring stable rotation while reducing wear.

[0043] Optionally, the inner sun gear 110 has a connecting portion 111 for connection to a drive source. The connecting portion 111 and the outer planetary carrier 240 are located on opposite sides of the outer ring gear 230 along its axial direction. A third bearing 500 is provided between the connecting portion 111 and the inner ring gear 130. It is understood that the third bearing 500 between the connecting portion 111 and the inner ring gear 130 provides good support for the inner sun gear 110, ensuring stable rotation while reducing wear.

[0044] Example 2:

[0045] refer to Figure 4 As shown, the structure of the planetary gear reducer in this embodiment is largely the same as that in Embodiment 1. The difference is that the outer planet carrier 240 has a through hole 242 for the connecting part 111 to pass through. The connecting part 111 and the outer planet carrier 240 are located on one side of the outer gear ring 230 along its axial direction. A fourth bearing 600 is provided between the connecting part 111 and the outer planet carrier 240. It can be understood that the fourth bearing 600 between the connecting part 111 and the outer planet carrier 240 can provide good support for the inner sun gear 110, ensuring its stable rotation while reducing wear.

[0046] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A planetary gear reducer, characterized in that, include: An inner gear assembly (100) includes an inner sun gear (110), a plurality of inner planet gears (120), an inner ring gear (130), and an inner planet carrier (140). The plurality of inner planet gears (120) are mounted on the inner planet carrier (140). Each inner planet gear (120) meshes with the inner sun gear (110) and the inner ring gear (130). The inner sun gear (110) is used to connect to a drive source. An outer gear assembly (200) includes an outer sun gear (210), a plurality of outer planet gears (220), an outer ring gear (230), and an outer planet carrier (240). The plurality of outer planet gears (220) are mounted on the outer planet carrier (240). Each outer planet gear (220) meshes with the outer sun gear (210) and the outer ring gear (230). The outer sun gear (210) is connected to the inner planet carrier (140), and the outer planet carrier (240) is used to output power. The inner gear ring (130) and the outer gear ring (230) are simultaneously fixedly connected to the external bracket, and there is a gap between the inner gear ring (130) and the outer sun gear (210).

2. The planetary gear reducer according to claim 1, characterized in that, The transmission ratio of the inner gear assembly (100) is greater than the reduction ratio of the outer gear assembly (200).

3. The planetary gear reducer according to claim 2, characterized in that, The transmission ratio of the inner gear assembly (100) is less than or equal to 6, and the number of the inner planetary gears (120) is greater than or equal to 3.

4. The planetary gear reducer according to claim 2, characterized in that, The transmission ratio of the outer gear assembly (200) is less than or equal to 4, and the number of the outer planetary gears (220) is greater than or equal to 5.

5. The planetary gear reducer according to any one of claims 2-4, characterized in that, The total transmission ratio of the planetary gear reducer is 9-25.

6. The planetary gear reducer according to claim 1, characterized in that, The inner sun gear (110) and the plurality of inner planet gears (120) are both metal parts.

7. The planetary gear reducer according to claim 1, characterized in that, The outer sun gear (210) and the plurality of outer planet gears (220) are made of plastic.

8. The planetary gear reducer according to claim 1, characterized in that, The outer gear ring (230) has a gear ring portion (231) and a first groove portion (232). The gear ring portion (231) meshes with the outer planetary gear (220). The first groove portion (232) is used to accommodate the outer planetary carrier (240). A first bearing (300) is provided between the outer planetary carrier (240) and the side wall of the first groove portion (232).

9. The planetary gear reducer according to claim 1, characterized in that, The outer planetary carrier (240) has a second groove (241), a portion of the outer sun gear (210) extends into the second groove (241), and a second bearing (400) is provided between the portion of the outer sun gear (210) extending into the second groove (241) and the inner wall of the second groove (241).

10. The planetary gear reducer according to claim 1, characterized in that, The inner sun gear (110) has a connection portion (111) for connection with the drive source, wherein, The connecting part (111) and the outer planetary carrier (240) are located on both sides of the outer gear ring (230) along its axial direction, and a third bearing (500) is provided between the connecting part (111) and the inner gear ring (130); The connecting part (111) and the outer planetary carrier (240) are located on one side of the outer gear ring (230) along its axial direction. The outer planetary carrier (240) is provided with a through hole (242) for the connecting part (111) to pass through. A fourth bearing (600) is provided between the connecting part (111) and the outer planetary carrier (240).

Images