Reduction gear, joint module and robot

Abstract

The present disclosure relates to the technical field of robots, in particular to a reducer, a joint module and a robot, which solves the problem that a reducer cannot consider both the speed reduction ratio and the axial size. The reducer comprises a primary sun gear, a plurality of primary planet gears, a fixed ring gear assembly, a primary planet carrier, a secondary sun gear, a plurality of double planet gears and a secondary planet carrier. The two-stage planetary rows of the reducer each have a speed reduction ratio, and the double planet gears also have a speed ratio difference, thereby improving the speed reduction ratio of the reducer. The orthogonal projection of the second planet gears along the radial direction of the primary sun gear on the primary sun gear overlaps the orthogonal projection of the primary planet gears along the radial direction of the primary sun gear on the primary sun gear, that is, the second planet gears of the double planet gears share the axial size of the reducer with the primary planet gears, thereby reducing the space occupation of the two-stage planetary rows in the axial direction of the reducer while ensuring the speed reduction ratio of the reducer, and reducing the axial size of the reducer.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of robots, in particular to a reducer, a joint module and a robot. BACKGROUND

[0002] The planetary reducer is widely applied to the joint module of a humanoid robot due to the advantages of strong bearing capacity, large speed ratio and compact structure. Since the space of the humanoid robot is limited, the axial size of the reducer of the joint module is required to be small. However, the humanoid robot needs strong power output, and the most convenient way to improve the power output is to use a reducer with a large speed ratio. At present, the NGW planetary transmission is the most commonly used planetary transmission mechanism, but the maximum speed ratio of the NGW planetary transmission is limited in the single-stage arrangement, and the speed ratio of 10 is already the limit, and the transmission stability and reliability problems are inevitably brought. If the speed ratio continues to increase, two-stage NGW planetary transmission in series arrangement needs to be used, which increases the axial size of the reducer. Even if other forms of planetary transmission, such as NW planetary transmission, WW planetary transmission and NGWN planetary transmission, are used, although the speed ratio can be increased, the axial size of the reducer is also increased. In other words, the reducer in the related art cannot balance the speed reduction ratio and the axial size. SUMMARY

[0003] Therefore, the embodiments of the present disclosure provide a reducer, a joint module and a robot, which solve the problem that the reducer in the related art cannot balance the speed reduction ratio and the axial size.

[0004] In a first aspect, embodiments of the present disclosure provide a reducer, comprising: a first sun gear capable of rotating around a central axis; a plurality of first planet gears respectively engaged with the first sun gear, so that the first sun gear can drive the plurality of first planet gears to rotate; a fixed ring gear assembly sleeved outside the plurality of first planet gears, the plurality of first planet gears respectively engaged with the fixed ring gear assembly, so that the plurality of first planet gears can revolve around the central axis under the drive of the first sun gear; a first carrier, to which the plurality of first planet gears are rotatably connected, the first carrier rotating around the central axis under the drive of the plurality of first planet gears; a second sun gear connected with the first carrier, the second sun gear rotating around the central axis under the drive of the first carrier; a plurality of double planet gears arranged around the second sun gear, the double planet gears comprising a first planet gear coaxially connected with a second planet gear, the first planet gear engaged with the second sun gear, so that the second sun gear can drive the plurality of double planet gears to rotate, the second planet gear engaged with the fixed ring gear assembly, so that the plurality of double planet gears can revolve around the central axis under the drive of the second sun gear, the diameter of the first planet gear being greater than the diameter of the second planet gear, wherein, in a case where at least one of the first planet gears and at least one of the double planet gears move to an aligned position, a projection of the second planet gear on the first sun gear along a radial direction of the first sun gear overlaps with a projection of the first planet gear on the first sun gear along the radial direction of the first sun gear, wherein, in the aligned position, an axis of the at least one of the first planet gears, an axis of the at least one of the double planet gears, and an axis of the first sun gear are coplanar; a second carrier, to which the plurality of double planet gears are rotatably connected, the second carrier rotating around the central axis under the drive of the plurality of double planet gears.

[0005] In some embodiments, the fixed ring gear assembly comprises: a ring gear, an inner ring of the ring gear having inner teeth, an outer ring of the ring gear having outer teeth, the first planet gears engaged with the ring gear through the inner teeth, the second planet gears engaged with the ring gear through the outer teeth.

[0006] In some embodiments, the reducer further comprises: a housing sleeved outside the double planet gears and the second carrier; wherein the fixed ring gear assembly further comprises: a connecting piece connecting the ring gear and the housing.

[0007] In some embodiments, the secondary planetary carrier has a first central hole, and the primary planetary carrier is arranged through the first central hole; wherein the speed reducer further comprises: a first bearing arranged between a first end of the primary planetary carrier and a first end of the secondary planetary carrier, the first end of the primary planetary carrier being close to an output end of the speed reducer, and the first end of the secondary planetary carrier being close to the output end of the speed reducer; and a second bearing arranged between the first end of the secondary planetary carrier and the housing.

[0008] In some embodiments, the speed reducer further comprises: a third bearing arranged between a second end of the secondary planetary carrier and the housing; and a fourth bearing arranged between a second end of the primary planetary carrier and the ring gear.

[0009] In some embodiments, the primary planetary carrier has a second central hole, and the primary sun gear is arranged through the second central hole; the speed reducer further comprises: a fifth bearing arranged between the primary planetary carrier and a first end of the primary sun gear, the first end of the primary sun gear being close to an input end of the speed reducer; and a sixth bearing arranged between the primary planetary carrier and a second end of the primary sun gear.

[0010] In some embodiments, the secondary sun gear has a third central hole, and the primary planetary carrier is arranged through the third central hole.

[0011] In some embodiments, the primary planetary carrier comprises: a plurality of first shaft portions, the plurality of first shaft portions being arranged around the primary sun gear, the first shaft portions being parallel to the central axis, and a plurality of the primary planetary gears being respectively sleeved on the plurality of first shaft portions and rotatably connected to the plurality of first shaft portions; wherein the speed reducer further comprises: a plurality of first wear pads sleeved on the plurality of first shaft portions and arranged between the primary planetary gears and the primary planetary carrier; and / or the secondary planetary carrier comprises: a plurality of second shaft portions, the plurality of second shaft portions being arranged around the secondary sun gear, the second shaft portions being parallel to the central axis, and a plurality of the double planetary gears being respectively sleeved on the plurality of second shaft portions and rotatably connected to the plurality of second shaft portions; wherein the speed reducer further comprises: a plurality of second wear pads sleeved on the plurality of second shaft portions and arranged between the double planetary gears and the secondary planetary carrier.

[0012] In a second aspect, embodiments of the present disclosure provide a joint module, comprising the speed reducer of the first aspect.

[0013] In a third aspect, embodiments of the present disclosure provide a robot, comprising the joint module of the second aspect.

[0014] The reducer provided by the embodiment of the present disclosure comprises a primary sun gear, a plurality of primary planet gears, a fixed ring gear assembly, a primary planet carrier, a secondary sun gear, a plurality of double planet gears and a secondary planet carrier. The primary sun gear, the plurality of primary planet gears, the fixed ring gear assembly and the primary planet carrier form a primary planetary set. The secondary sun gear, the plurality of double planet gears, the fixed ring gear assembly and the secondary planet carrier form a secondary planetary set. Both the primary planetary set and the secondary planetary set have a speed reduction ratio, and the double planet gears also have a speed ratio difference, thereby improving the speed reduction ratio of the reducer.

[0015] In the case that the at least one primary planet gear and the at least one double planet gear move to the aligned position, the orthogonal projection of the second planet gear of the double planet gear on the primary sun gear along the radial direction of the primary sun gear overlaps with the orthogonal projection of the primary planet gear on the primary sun gear along the radial direction of the primary sun gear, that is, the second planet gear of the double planet gear shares the axial dimension of the reducer with the primary planet gear, thereby reducing the space occupation of the two planetary sets in the axial direction of the reducer, and reducing the axial dimension of the reducer while ensuring the speed reduction ratio of the reducer. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. The drawings provided in the present disclosure are used to provide further understanding of the embodiments of the present disclosure and constitute a part of the specification, which serve to explain the present disclosure together with the embodiments of the present disclosure, but do not constitute a limitation to the present disclosure. In the drawings, the same reference numerals generally indicate the same components throughout the drawings.

[0017] Figure 1 Fig. 1 shows a structural schematic diagram of a reducer provided by an embodiment of the present disclosure.

[0018] Figure 2 Fig. 2 shows a front view of the reducer provided by an embodiment of the present disclosure.

[0019] Figure 3 Fig. 3 shows a schematic diagram of a primary sun gear, a primary planet gear and a double planet gear provided by an embodiment of the present disclosure. Figure 2 Fig. 4 shows a sectional view of the reducer in the A-A direction.

[0020] Figure 4 Fig. 5 shows a structural schematic diagram of the reducer in an aligned position provided by an embodiment of the present disclosure.

[0021] Figure 5 Fig. 6 shows an exploded view of the reducer provided by an embodiment of the present disclosure.

[0022] Figure 6 Fig. 7 shows a structural schematic diagram of a reducer provided by an embodiment of the present disclosure.

[0023] Figure 7The diagram shown is a structural schematic of a joint module provided in an embodiment of this disclosure.

[0024] Figure 8 The diagram shown is a structural schematic of a robot provided in one embodiment of this disclosure.

[0025] Figure label:

[0026] 1. Robot; 10. Joint module; 100. Reducer; 110. First-stage sun gear; 120. First-stage planetary gears; 130. Fixed gear ring assembly; 131. Gear ring; 132. Connector; 140. First-stage planetary carrier; 141. Second center hole; 142. First shaft; 210. Second-stage sun gear; 211. Third center hole; 220. Double planetary gear; 221. First planetary gear; 222. Second planetary gear; 230. Second-stage... Planetary carrier; 231, First center hole; 232, Second shaft; 310, Housing; 410, First bearing; 420, Second bearing; 430, Third bearing; 440, Fourth bearing; 450, Fifth bearing; 460, Sixth bearing; 510, First wear-resistant pad; 520, Second wear-resistant pad; 530, Bearing cap; 540, Sealing cap; 550, Outer ring pressure plate; 560, Inner ring pressure plate; L, Central axis; P, Alignment plane. Detailed Implementation

[0027] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0028] Figure 1 The diagram shown is a structural schematic of a speed reducer provided in an embodiment of this disclosure. Figure 2 The image shown is a front view of a speed reducer provided in an embodiment of this disclosure. Figure 3 The image shown is an embodiment of this disclosure. Figure 2 The speed reducer shown is a cross-sectional view along the AA direction. Figure 4 The diagram shown is a structural schematic of a speed reducer provided in an embodiment of this disclosure at the alignment position. Figure 5 The diagram shown is a schematic diagram of a primary sun gear, a primary planet gear, and a double planet gear according to an embodiment of this disclosure. Figure 6 The image shown is an exploded view of a speed reducer provided in an embodiment of this disclosure. Figures 1 to 6 As shown, the reducer 100 includes a first-stage sun gear 110, multiple first-stage planet gears 120, a fixed gear ring assembly 130, a first-stage planet carrier 140, a second-stage sun gear 210, multiple double-planet gears 220, and a second-stage planet carrier 230.

[0029] The primary sun gear 110, the plurality of primary planet gears 120, the fixed ring gear assembly 130, and the primary planet carrier 140 form a primary planetary set. The secondary sun gear 210, the plurality of double planet gears 220, the fixed ring gear assembly 130, and the secondary planet carrier 230 form a secondary planetary set. Both the primary planetary set and the secondary planetary set have a speed reduction ratio, and the double planet gears 220 also have a speed ratio step difference, which improves the speed reduction ratio of the speed reducer 100.

[0030] Specifically, the primary sun gear 110 can rotate around the central axis L. The plurality of primary planet gears 120 are respectively engaged with the primary sun gear 110, so that the primary sun gear 110 can drive the plurality of primary planet gears 120 to rotate. The fixed ring gear assembly 130 is sleeved outside the plurality of primary planet gears 120, and the plurality of primary planet gears 120 are respectively engaged with the fixed ring gear assembly 130, so that the plurality of primary planet gears 120 can revolve around the central axis L under the driving of the primary sun gear 110. The plurality of primary planet gears 120 are rotatably connected to the primary planet carrier 140, and the primary planet carrier 140 rotates around the central axis L under the driving of the plurality of primary planet gears 120.

[0031] Illustratively, the primary sun gear 110 can be connected with the output shaft of the motor, so that the output shaft of the motor drives the primary sun gear 110 to rotate around the central axis L. Illustratively, the primary sun gear 110 has external teeth, and the primary planet gears 120 have external teeth, and the primary planet gears 120 are externally engaged with the primary sun gear 110. Illustratively, the plurality of primary planet gears 120 are uniformly distributed along the circumference of the primary sun gear 110. Illustratively, the number of the primary planet gears 120 is 2, 3, 4, etc. Illustratively, the fixed ring gear assembly 130 includes two inner ring gears with internal teeth, and the two inner ring gears can be fixedly arranged opposite to each other. The primary planet gears 120 are internally engaged with one inner ring gear. The second planet gear 222 of the double planet gear 220 has external teeth, and the second planet gear 222 is internally engaged with the other inner ring gear.

[0032] The secondary sun gear 210 is connected with the primary planet carrier 140 and rotates around the central axis L under the driving of the primary planet carrier 140. The plurality of double planet gears 220 are arranged around the secondary sun gear 210. The double planet gear 220 includes a first planet gear 221 and a second planet gear 222 coaxially connected. The first planet gear 221 is engaged with the secondary sun gear 210, so that the secondary sun gear 210 can drive the plurality of double planet gears 220 to rotate. The second planet gear 222 is engaged with the fixed ring gear assembly 130, so that the plurality of double planet gears 220 can revolve around the central axis L under the driving of the secondary sun gear 210. The diameter of the first planet gear 221 is greater than the diameter of the second planet gear 222, i.e., the number of teeth of the first planet gear 221 is greater than the number of teeth of the second planet gear 222, so that the double planet gear 220 has a speed ratio step difference.

[0033] Exemplarily, the secondary sun gear 210 has external teeth, the first planetary gear 221 of the double planetary gear 220 has external teeth, and the secondary sun gear 210 is externally engaged with the first planetary gear 221. Exemplarily, a plurality of double planetary gears 220 are uniformly distributed along the circumference of the secondary sun gear 210. Exemplarily, the number of the double planetary gears 220 is 2, 3, 4, etc. Exemplarily, the number of the double planetary gears 220 is equal to or not equal to the number of the primary planetary gears 120.

[0034] In the case that the at least one primary planetary gear 120 and the at least one double planetary gear 220 move to the alignment position, the orthogonal projection of the second planetary gear 222 on the primary sun gear 110 along the radial direction of the primary sun gear 110 overlaps with the orthogonal projection of the primary planetary gear 120 on the primary sun gear 110 along the radial direction of the primary sun gear 110. In the alignment position, the axis of the at least one primary planetary gear 120, the axis of the at least one double planetary gear 220 and the axis of the primary sun gear 110 are coplanar.

[0035] Exemplarily, as shown in Figure 4 and Figure 5 , the axis of the one primary planetary gear 120, the axis of the one double planetary gear 220 and the axis of the primary sun gear 110 are all located in the alignment plane P, i.e. the axis of the one primary planetary gear 120, the axis of the one double planetary gear 220 and the axis of the primary sun gear 110 are coplanar. As shown in Figure 5 , the orthogonal projection of the second planetary gear 222 on the primary sun gear 110 along the radial direction of the primary sun gear 110 overlaps with the orthogonal projection of the primary planetary gear 120 on the primary sun gear 110 along the radial direction of the primary sun gear 110, i.e. there is an overlapping area Q in Figure 5 .

[0036] In the case that the at least one primary planetary gear 120 and the at least one double planetary gear 220 move to the alignment position, the orthogonal projection of the second planetary gear 222 on the primary sun gear 110 along the radial direction of the primary sun gear 110 overlaps with the orthogonal projection of the primary planetary gear 120 on the primary sun gear 110 along the radial direction of the primary sun gear 110, i.e. the second planetary gear 222 of the double planetary gear 220 shares the axial dimension of the speed reducer 100 with the primary planetary gear 120, which reduces the space occupation of the two-stage planetary gear set in the axial direction of the speed reducer 100, thereby reducing the axial dimension of the speed reducer 100.

[0037] The plurality of double planetary gears 220 are rotatably connected to a second planetary carrier 230. The second planetary carrier 230 rotates around the central axis L under the driving of the plurality of double planetary gears 220. Exemplarily, the second planetary carrier 230 can be connected with a motion structure to drive the motion structure to rotate. The motion structure can be a dexterous hand of a robot, an arm of a robot, a leg of a robot, etc.

[0038] In some embodiments, the fixed ring gear assembly 130 comprises a ring gear 131. The inner ring of the ring gear 131 has internal teeth, and the outer ring of the ring gear 131 has external teeth. The first planetary gears 120 are engaged with the ring gear 131 internally through the internal teeth, and the second planetary gears 222 are engaged with the ring gear 131 externally through the external teeth, i.e., the first planetary gears 120 and the second planetary gears 222 share the ring gear 131, without the need to use two internal ring gears, which simplifies the structure of the speed reducer 100 and reduces the weight of the speed reducer 100. In addition, the first planetary gears 120 and the second planetary gears 222 share the ring gear 131, without the need to use two internal ring gears, which also reduces the use of fasteners for fastening the internal ring gears, further saving the space occupation of the fixed ring gear assembly 130.

[0039] Exemplarily, the ring gear 131 is fixedly arranged opposite to the shell of the motor.

[0040] In some embodiments, the speed reducer 100 further comprises a housing 310. The housing 310 is sleeved outside the double planetary gears 220 and the second planetary carrier 230, i.e., the housing 310 accommodates other components of the speed reducer 100 except the housing 310. As Figure 3 shown, the fixed ring gear assembly 130 further comprises a connecting piece 132. The connecting piece 132 connects the ring gear 131 and the housing 310. Exemplarily, the connecting piece 132 is a circular ring structure, which can seal the space between the ring gear 131 and the housing 310, and reduce the contamination of components between the ring gear 131 and the housing 310.

[0041] Exemplarily, the ring gear 131 and the connecting piece 132 are integrally formed, which facilitates improving the coaxiality of the ring gear 131 and the connecting piece 132. Exemplarily, the ring gear 131 and the connecting piece 132 are separately arranged, which facilitates manufacturing. Exemplarily, the housing 310 is fixedly connected with the shell of the motor, and the ring gear 131 is fixedly connected to the housing 310 through the connecting piece 132, thereby realizing the fixation of the ring gear 131.

[0042] In some embodiments, as Figure 6 shown, the second planetary carrier 230 has a first central hole 231, and the first planetary carrier 140 is arranged through the first central hole 231, so that the second planetary carrier 230 and the first planetary carrier 140 share the axial dimension of the speed reducer 100, thereby reducing the axial dimension of the speed reducer 100.

[0043] The reducer 100 also includes a first bearing 410 and a second bearing 420. The first bearing 410 is disposed between the first end of the first-stage planetary carrier 140 and the first end of the second-stage planetary carrier 230. The first end of the first-stage planetary carrier 140 is close to the output end of the reducer 100. The first end of the second-stage planetary carrier 230 is close to the output end of the reducer 100. The second bearing 420 is disposed between the first end of the second-stage planetary carrier 230 and the housing 310.

[0044] For example, the first bearing 410 is a deep groove ball bearing, a roller bearing, etc. For example, the second bearing 420 is a crossed roller bearing, a combined bearing, etc.

[0045] The first bearing 410 and the second bearing 420 are used to support the end of the second-stage planetary carrier 230, thereby improving the stability of the second-stage planetary carrier 230.

[0046] In some embodiments, the reducer 100 further includes a third bearing 430 and a fourth bearing 440. The third bearing 430 is disposed between the second end of the second-stage planetary carrier 230 and the housing 310. The fourth bearing 440 is disposed between the second end of the first-stage planetary carrier 140 and the gear ring 131.

[0047] For example, the third bearing 430 is a deep groove ball bearing, roller bearing, etc. For example, the fourth bearing 440 is a deep groove ball bearing, roller bearing, etc.

[0048] The first bearing 410 and the second bearing 420 are used to support the first end of the second-stage planetary carrier 230, and the third bearing 430 and the fourth bearing 440 are used to support the second end of the second-stage planetary carrier 230, thereby achieving support at both ends of the second-stage planetary carrier 230 and further improving the stability of the second-stage planetary carrier 230.

[0049] In some embodiments, such as Figure 6 As shown, the first-stage planetary carrier 140 has a second central hole 141. The first-stage sun gear 110 passes through the second central hole 141, realizing the sharing of the axial dimension of the first-stage planetary carrier 140 and the first-stage sun gear 110 in the reducer 100, thereby reducing the axial dimension of the reducer 100.

[0050] The reducer 100 also includes a fifth bearing 450 and a sixth bearing 460. The fifth bearing 450 is disposed between the first end of the first-stage planetary carrier 140 and the first end of the first-stage sun gear 110. The first end of the first-stage sun gear 110 is close to the input end of the reducer 100. The sixth bearing 460 is disposed between the second end of the first-stage planetary carrier 140 and the first-stage sun gear 110, thereby providing bearing support for both ends of the first-stage planetary carrier 140 and improving the stability of the first-stage planetary carrier 140.

[0051] Exemplarily, the fifth bearing 450 is a deep groove ball bearing, a roller bearing, or the like. Exemplarily, the sixth bearing 460 is a deep groove ball bearing, a roller bearing, or the like.

[0052] In some embodiments, as shown, the second sun gear 210 has a third central hole 211. The primary planet carrier 140 is arranged through the third central hole 211. Figure 6

[0053] In the related art, the second sun gear is generally connected with the primary planet carrier through a shaft coupling, which occupies the axial dimension of the speed reducer, resulting in a large axial dimension of the speed reducer in the related art. The primary planet carrier 140 of the present disclosure is arranged through the third central hole 211, so that the connection between the second sun gear 210 and the primary planet carrier 140 can be achieved by means of interference fit, cementation, key connection, etc., without the use of a shaft coupling, further reducing the axial dimension of the speed reducer 100.

[0054] In some embodiments, the primary planet carrier 140 includes a plurality of first shaft portions 142. The plurality of first shaft portions 142 are arranged around the primary sun gear 110. The axis of the first shaft portion 142 is parallel to the central axis L. The plurality of primary planet gears 120 are respectively sleeved on the plurality of first shaft portions 142. The plurality of primary planet gears 120 are respectively rotatably connected with the plurality of first shaft portions 142. The speed reducer 100 further includes a plurality of first wear pads 510. The first wear pads 510 are sleeved on the plurality of first shaft portions 142 and arranged between the end portions of the primary planet gears 120 and the primary planet carrier 140, preventing the primary planet carrier 140 from being worn by the primary planet gears 120.

[0055] Exemplarily, the first shaft portion 142 is a planet pin. Exemplarily, a needle bearing is further arranged between the primary planet gear 120 and the first shaft portion 142 to reduce the friction between the primary planet gear 120 and the first shaft portion 142.

[0056] In some embodiments, the secondary planet carrier 230 includes a plurality of second shaft portions 232. The plurality of second shaft portions 232 are arranged around the secondary sun gear 210. The axis of the second shaft portion 232 is parallel to the central axis L. The plurality of double planet gears 220 are respectively sleeved on the plurality of second shaft portions 232, and the plurality of double planet gears 220 are respectively rotatably connected with the plurality of second shaft portions 232. The speed reducer 100 further includes a plurality of second wear pads 520. The second wear pads 520 are sleeved on the plurality of second shaft portions 232 and arranged between the end portions of the double planet gears 220 and the secondary planet carrier 230, preventing the secondary planet carrier 230 from being worn by the double planet gears 220.

[0057] Exemplarily, the second shaft portion 232 is a planet pin. Exemplarily, a needle bearing is further arranged between the double planet gear 220 and the second shaft portion 232 to reduce the friction between the double planet gear 220 and the second shaft portion 232.​

[0058] In some embodiments, the speed reducer 100 further comprises a bearing cover 530, a sealing cover 540, an outer ring pressing plate 550, and an inner ring pressing plate 560.

[0059] Exemplarily, the bearing cover 530 is detachably connected with the primary planetary carrier 140, for axially limiting the fifth bearing 450. Exemplarily, the sealing cover 540 is detachably connected with the secondary planetary carrier 230, and is sealingly connected, for sealing the first bearing 410. Exemplarily, the outer ring pressing plate 550 is detachably connected with the housing 310, for axially limiting the outer ring of the second bearing 420. Exemplarily, the inner ring pressing plate 560 is detachably connected with the secondary planetary carrier 230, for axially limiting the inner ring of the second bearing 420.

[0060] Figure 7 Fig. 1 shows a structural schematic diagram of a joint module according to an embodiment of the present disclosure. As shown in the figure, the joint module 10 comprises the speed reducer 100 in the above embodiment. Figure 7 Fig. 1 shows a structural schematic diagram of a joint module according to an embodiment of the present disclosure. As shown in the figure, the joint module 10 comprises the speed reducer 100 in the above embodiment.

[0061] Since the joint module 10 comprises the speed reducer 100, the joint module 10 has all the technical features and technical effects of the speed reducer 100, which will not be repeated here.

[0062] Figure 8 Fig. 1 shows a structural schematic diagram of a joint module according to an embodiment of the present disclosure. As shown in the figure, the joint module 10 comprises the speed reducer 100 in the above embodiment. Figure 8 Fig. 1 shows a structural schematic diagram of a joint module according to an embodiment of the present disclosure. As shown in the figure, the joint module 10 comprises the speed reducer 100 in the above embodiment.

[0063] Since the joint module 10 comprises the speed reducer 100, the joint module 10 has all the technical features and technical effects of the speed reducer 100, which will not be repeated here.

[0064] In the embodiments of the present disclosure, if the form of connection is not explicitly limited, the form of connection can be detachable connection forms such as bolt-nut, screw, buckle, magnetic attraction, etc. In some connections, if there is no special requirement for the form of non-detachable connection, the non-detachable connection can be achieved by welding, bonding, etc.

[0065] In the description, “one embodiment”, “an embodiment”, and the like indicate that the described embodiment can include a specific feature, structure, or characteristic, but not necessarily every embodiment. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure, or characteristic is described in combination with an embodiment, it is within the knowledge of those skilled in the art to realize such feature, structure, or characteristic in combination with other embodiments that are explicitly or implicitly described.

[0066] It should be understood that "on," "above," and "on top of" in the disclosure should be interpreted in the broadest context possible so that "on" means not only "directly on" but also includes the meaning of "on" with intervening features or layers therebetween, and "above" or "on top of" includes not only the meaning of "above" or "on top of" but also the meaning of "above" or "on top of" with no intervening features or layers therebetween (i.e., directly on).

[0067] In addition, spatially relative terms, such as "beneath", "below", "lower", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0068] It should be noted that, in the present document, the terms "comprising", "comprises" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0069] The preferred embodiments of the present disclosure have been described above with the purpose of enabling not only the best modes of practicing the disclosure but also of enabling others skilled in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, the above description is intended to be illustrative, but not restrictive, of the scope of the present disclosure. All modifications that can fall within the scope of the claims, and any equivalents thereof, are also included in the scope of the present disclosure.

Claims

1. A speed reducer characterized by, The application relates to a reducer, which comprises the following components: a primary sun gear capable of rotating around a central axis; a plurality of primary planet gears respectively engaged with the primary sun gear so that the primary sun gear can drive the plurality of primary planet gears to rotate; a fixed ring gear assembly sleeved outside the plurality of primary planet gears, wherein the plurality of primary planet gears are respectively engaged with the fixed ring gear assembly so that the plurality of primary planet gears can revolve around the central axis under the driving of the primary sun gear; a primary planet carrier, wherein the plurality of primary planet gears are rotatably connected to the primary planet carrier, and the primary planet carrier rotates around the central axis under the driving of the plurality of primary planet gears; a secondary sun gear connected to the primary planet carrier and rotating around the central axis under the driving of the primary planet carrier; a plurality of double planet gears arranged around the secondary sun gear, wherein the double planet gears comprise coaxially connected first planet gears and second planet gears, the first planet gears are engaged with the secondary sun gear so that the secondary sun gear can drive the plurality of double planet gears to rotate, the second planet gears are engaged with the fixed ring gear assembly so that the plurality of double planet gears can revolve around the central axis under the driving of the secondary sun gear, and the diameter of the first planet gears is greater than that of the second planet gears, wherein, in the case that at least one of the primary planet gears and at least one of the double planet gears move to an aligned position, the orthographic projection of the second planet gears on the primary sun gear along the radial direction of the primary sun gear overlaps with the orthographic projection of the primary planet gears on the primary sun gear along the radial direction of the primary sun gear, and in the aligned position, the axis of at least one of the primary planet gears, the axis of at least one of the double planet gears and the axis of the primary sun gear are coplanar; a secondary planet carrier, wherein the plurality of double planet gears are rotatably connected to the secondary planet carrier, and the secondary planet carrier rotates around the central axis under the driving of the plurality of double planet gears. The fixed ring gear assembly comprises: a ring gear, wherein the inner ring of the ring gear is provided with internal teeth, the outer ring of the ring gear is provided with external teeth, the primary planet gears are engaged with the ring gear internally, and the second planet gears are engaged with the ring gear externally.

2. The speed reducer according to claim 1, characterized by The reducer further comprises: a housing sleeved outside the double planet gears and the secondary planet carrier; The fixed ring gear assembly further comprises: a connecting piece connecting the ring gear and the housing.

3. The speed reducer according to claim 2, characterized by The secondary planet carrier is provided with a first central hole, and the primary planet carrier passes through the first central hole; The reducer further comprises: a first bearing arranged between the first end of the primary planet carrier and the first end of the secondary planet carrier, wherein the first end of the primary planet carrier is close to the output end of the reducer, and the first end of the secondary planet carrier is close to the output end of the reducer; a second bearing arranged between the first end of the secondary planet carrier and the housing.

4. The speed reducer according to claim 3, characterized by The reducer further comprises: a third bearing arranged between the second end of the secondary planet carrier and the housing; a fourth bearing arranged between the second end of the primary planet carrier and the ring gear.

5. The speed reducer according to claim 3, characterized by The primary planetary carrier has a second central hole, and the primary sun gear is arranged in the second central hole; The speed reducer further comprises: A fifth bearing is arranged between the primary planetary carrier and a first end of the primary sun gear, and the first end of the primary sun gear is close to the input end of the speed reducer; A sixth bearing is arranged between the primary planetary carrier and a second end of the primary sun gear.

6. The speed reducer according to any one of claims 1 to 5, characterized by The secondary sun gear has a third central hole, and the primary planetary carrier is arranged in the third central hole.

7. The speed reducer according to any one of claims 1 to 5, wherein The primary planetary carrier comprises: A plurality of first shaft portions are arranged around the primary sun gear, the axis of the first shaft portion is parallel to the central axis, a plurality of the primary planetary gears are respectively sleeved on the plurality of first shaft portions, and the plurality of primary planetary gears are respectively rotatably connected with the plurality of first shaft portions; The speed reducer further comprises: A plurality of first wear pads are sleeved on the plurality of first shaft portions and arranged between the end of the primary planetary gear and the primary planetary carrier; And / or The secondary planetary carrier comprises: A plurality of second shaft portions are arranged around the secondary sun gear, the axis of the second shaft portion is parallel to the central axis, a plurality of the double planetary gears are respectively sleeved on the plurality of second shaft portions, and the plurality of double planetary gears are respectively rotatably connected with the plurality of second shaft portions; The speed reducer further comprises: A plurality of second wear pads are sleeved on the plurality of second shaft portions and arranged between the end of the double planetary gear and the secondary planetary carrier.

8. An articulating module, comprising: The speed reducer comprises: The speed reducer according to any one of claims 1 to 7.

9. A robot, characterized in that The joint module comprises: The joint module according to claim 8.

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