Speed reducer and robot

Abstract

The invention relates to the technical field of robots, in particular to a speed reducer and a robot, and solves the problem of how to reduce the size of the speed reducer while ensuring that the speed ratio and the torque are not reduced. The speed reducer comprises a shell, a bearing outer ring, a speed reduction assembly and a plurality of rolling pieces. The bearing outer ring is sleeved with the shell, the inner side face of the bearing outer ring is provided with a first annular roller path, an output piece in the speed reduction assembly is provided with a second annular roller path, rolling constraint can be provided for a rolling piece, in other words, the output piece has the function of the bearing inner ring at the same time, axial limiting structures such as a check ring and a gasket are reduced, and the cost is reduced. Therefore, the axial size of the speed reducer is reduced. In addition, according to the speed reducer, only the structure of the output piece is changed, the structure of the transmission assembly in the speed reduction assembly is not changed, namely the speed reduction ratio of the speed reduction assembly is not changed, and the size of the speed reducer is reduced while it is guaranteed that the speed ratio and the torque are not reduced.

Description

Technical Field

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

[0002] With the development of industrial automation and robotics, the performance requirements for reducers are getting higher and higher. With the compactness of machinery and equipment and the limitation of space, the reducer industry will pursue miniaturization and lightweight of products. This will help improve the efficiency and flexibility of equipment and reduce costs and occupied space. Miniaturization and lightweighting are not only about reducing size and weight, but also maintaining or improving the performance of the reducer, that is, reducing the size of the reducer while ensuring that the speed ratio and torque are not reduced. Summary of the invention

[0003] In view of this, the embodiments of the present disclosure provide a reducer and a robot, which solve the problem of how to reduce the size of the reducer while ensuring that the speed ratio and torque are not reduced.

[0004] In a first aspect, an embodiment of the present disclosure provides a reducer, comprising: a housing; a bearing outer ring, which is mounted in the housing, and the inner side surface of the bearing outer ring has a first annular raceway; a reduction assembly, comprising an input member, a transmission assembly and an output member, which are sequentially connected in transmission, and the output member is rotatable relative to the bearing outer ring, and the output member comprises an annular portion, and the outer side surface of the annular portion has a second annular raceway; a plurality of rolling members, part of the structure of the rolling members is arranged on the first annular raceway, and part of the structure is arranged on the second annular raceway, and when the output member rotates relative to the bearing outer ring, the rolling members roll in the first annular raceway and the second annular raceway.

[0005] In some embodiments, the inner side surface of the housing has a cycloidal tooth structure. The input member includes a crankshaft, which includes an input shaft section, a first eccentric shaft section, a second eccentric shaft section, and an output shaft section connected in sequence. The annular portion is rotatably connected to the output shaft section. The transmission assembly includes: a first cycloidal gear, rotatably connected to the first eccentric shaft section and partially meshed with the cycloidal tooth structure. The first cycloidal gear has a plurality of first connection holes penetrating through the first cycloidal gear in a first direction, and the first direction is parallel to the axial direction of the first cycloidal gear; a second cycloidal gear, rotatably connected to the second eccentric shaft section and partially meshed with the cycloidal tooth structure. The second cycloidal gear has a plurality of second connection holes penetrating through the second cycloidal gear in the first direction, and the plurality of second connection holes are arranged in one-to-one correspondence with the plurality of first connection holes; the output member further includes: a plurality of pin shaft portions, integrally formed with the annular portion, and the plurality of pin shaft portions are arranged in one-to-one correspondence with the plurality of first connection holes. The plurality of pin shaft portions respectively pass through the corresponding second connection holes and the first connection holes in sequence.

[0006] In some embodiments, the inner side surface of the outer ring of the bearing has a first sealing groove, and the first sealing groove is located at the end surface of the outer ring of the bearing away from the transmission assembly. The outer side surface of the annular portion has a second sealing groove, and the second sealing groove is located at the end surface of the annular portion away from the transmission assembly. The speed reducer further includes: a first sealing member, with a part of the first sealing member disposed in the first sealing groove and a part disposed in the second sealing groove.

[0007] In some embodiments, the shape of the radial cross-section of the first annular raceway includes a V shape, the shape of the radial cross-section of the second annular raceway includes a V shape, the shape of the rolling element includes a cylinder or a cone, and the axes of adjacent rolling elements are perpendicular to each other.

[0008] In some embodiments, the speed reducer further includes: a flange assembly, rotatably connected to the input shaft section; a second sealing member, which is elastic. The second sealing member includes a first annular sealing portion, a second annular sealing portion, and an annular connecting portion. The annular connecting portion connects the first annular sealing portion and the second annular sealing portion. Among them, the first annular sealing portion is sleeved on the outer side surface of the housing and is in interference connection with the outer side surface of the housing. The second annular sealing portion is sleeved on the outer side surface of the flange assembly and is in interference connection with the outer side surface of the flange assembly.

[0009] In some embodiments, the second annular sealing portion includes: a sealing outer ring, connected to the annular connecting portion and in interference connection with the outer side surface of the flange assembly; a sealing inner ring, spaced from the sealing outer ring, connected to the annular connecting portion and in interference connection with the outer side surface of the flange assembly.

[0010] In some embodiments, the interference between the first annular sealing portion and the outer surface of the shell is 0.2-0.5 mm; and / or the interference between the second annular sealing portion and the outer surface of the flange assembly is 0.2-0.5 mm.

[0011] In some embodiments, the flange assembly includes: a flange body, rotatably connected to the input shaft segment; a baffle, connected to the flange body, the second annular sealing portion is sleeved on the outer side surface of the baffle and is interference connected to the outer side surface of the baffle, the baffle is configured to axially limit the first cycloid gear, wherein the material hardness of the baffle is greater than the material hardness of the flange body.

[0012] In some embodiments, the reducer also includes: a first bearing, which is arranged between the output member and the output shaft segment, the outer ring of the first bearing is connected to the output member, the inner ring of the first bearing is connected to the output shaft segment, the output member has a first limiting portion, and the first limiting portion is configured to axially limit the end face of the first bearing away from the second cycloid gear; and / or, a second bearing, which is arranged between the flange assembly and the input shaft segment, the outer ring of the second bearing is connected to the flange assembly, the inner ring of the second bearing is connected to the input shaft segment, and the flange assembly has a second limiting portion, and the second limiting portion is configured to axially limit the end face of the second bearing away from the first cycloid gear.

[0013] In a second aspect, an embodiment of the present disclosure provides a robot, comprising: the reducer mentioned in the first aspect.

[0014] The reducer provided by the embodiment of the present disclosure includes a housing, a bearing outer ring, a reduction assembly and a plurality of rolling elements. The bearing outer ring is mounted in the housing, and the inner side surface of the bearing outer ring has a first annular raceway. The reduction assembly includes an input element, a transmission assembly and an output element which are sequentially connected in transmission, the output element is rotatable relative to the bearing outer ring, the output element includes an annular portion, and the outer side surface of the annular portion has a second annular raceway. Part of the structure of the rolling element is arranged on the first annular raceway, and part of the structure is arranged on the second annular raceway. When the output element rotates relative to the bearing outer ring, the rolling element rolls in the first annular raceway and the second annular raceway.

[0015] In the related art, the inner ring of the bearing and the output member are separately arranged, and the inner ring of the bearing needs to be axially limited by axial limiting structures such as retaining rings and washers to limit the axial displacement of the inner ring of the bearing in the output member. However, the output member of the present application has a second annular raceway, which can provide rolling constraints for the rolling member, that is, the output member of the present application also has the function of the inner ring of the bearing, reducing the axial limiting structures such as retaining rings and washers, thereby reducing the axial size of the reducer.

[0016] In addition, the speed reducer of the present application can only change the structure of the output member without changing the structure of the transmission member in the speed reduction assembly, that is, without changing the reduction ratio of the speed reduction assembly. Therefore, while ensuring that the speed ratio and torque are not reduced, the size of the speed reducer is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features, and advantages of the present disclosure will become more apparent by describing the embodiments of the present disclosure in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation to the present disclosure. In the drawings, the same reference numerals generally represent the same components.

[0018] Figure 1 The following shows a schematic structural diagram of a speed reducer provided by an embodiment of the present disclosure.

[0019] Figure 2 The following shows a right view of a speed reducer provided by an embodiment of the present disclosure.

[0020] Figure 3 The following shows the Figure 2 cross-sectional view of the speed reducer shown in the A-A direction provided by an embodiment of the present disclosure.

[0021] Figure 4 The following shows the Figure 2 cross-sectional view of the speed reducer shown in the A-A direction provided by another embodiment of the present disclosure.

[0022] Figure 5 The following shows the Figure 4 partial enlarged view of the speed reducer shown in the B area provided by an embodiment of the present disclosure.

[0023] Figure 6 The following shows a schematic structural diagram of an outer bearing ring provided by an embodiment of the present disclosure.

[0024] Figure 7 The following shows the Figure 6 cross-sectional view of the outer bearing ring shown in the C-C direction provided by an embodiment of the present disclosure.

[0025] Figure 8 The following shows the Figure 7 partial enlarged view of the outer bearing ring shown in the D area provided by an embodiment of the present disclosure.

[0026] Figure 9 The following shows a schematic structural diagram of an output member provided by an embodiment of the present disclosure.

[0027] Figure 10 The following shows a left view of an output member provided by an embodiment of the present disclosure.

[0028] Figure 11 Shown is a cross-sectional view of the output member provided in an embodiment of the present disclosure in the E-E direction. Figure 10 Shown is a cross-sectional view of the output member provided in an embodiment of the present disclosure in the E-E direction.

[0029] Figure 12 Shown is a schematic structural view of a housing provided in an embodiment of the present disclosure.

[0030] Figure 13 Shown is a schematic structural view of a crankshaft provided in an embodiment of the present disclosure.

[0031] Figure 14 Shown is a schematic structural view of a first cycloidal gear and a second cycloidal gear provided in an embodiment of the present disclosure.

[0032] Figure 15 Shown is a schematic structural view of a robot provided in an embodiment of the present disclosure.

[0033] Reference numerals:

[0034] 1, robot; 10, speed reducer; 100, housing; 110, cycloidal tooth structure; 200, outer bearing ring; 210, first annular raceway; 220, first sealing groove; 300, reduction assembly; 310, input member; 311, crankshaft; 3111, input shaft section; 3112, first eccentric shaft section; 3113, second eccentric shaft section; 3114, output shaft section; 320, transmission assembly; 321, first cycloidal gear; 3210, first connection hole; 322, second cycloidal gear; 3220, second connection hole; 330, output member; 331, annular portion; 3311, second annular raceway; 3312, second sealing groove; 332, pin shaft portion; 333, first limiting portion; 400, rolling element; 500, first seal; 600, flange assembly; 610, flange body; 620, baffle; 630, second limiting portion; 700, second seal; 710, first annular sealing portion; 720, second annular sealing portion; 721, sealing outer ring; 722, sealing inner ring; 730, annular connection portion; 810, first bearing; 820, second bearing; 910, rotor shaft sleeve; 920, pressing plate; 930, hollow sleeve; X, first direction. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0036] With the development of bipedal humanoid robots, the demand for joint reducers of robots is also increasing day by day. Precision reducers that are lightweight, have a large speed ratio, and high torque have become the basic requirements for bipedal humanoid robots. Currently, traditional reducers include planetary reducers, harmonic reducers, RV reducers, etc. The single-stage planetary reducer cannot meet the large speed ratio requirement, and the two-stage planetary reducer has a large axial dimension and weight, thus cannot optimally meet the requirements of humanoid robots. Harmonic reducers are mainly applied to light-load joints such as the robot's forearm, wrist, or hand. RV reducers are mainly applied to heavy-load joints such as the robot's base, upper arm, and shoulder. However, for the lower limbs of bipedal humanoid robots, harmonic reducers have low efficiency and weak stiffness, and RV reducers have a large weight, so they are not suitable for the lower limbs of bipedal robots. In other words, current reducers cannot reduce the size of the reducer while ensuring that the speed ratio and torque do not decrease, so as to meet the lightweight requirement.

[0037] To solve at least one of the above technical problems, this application is proposed. The output member of this application has a second annular raceway, which can provide rolling constraints for rolling elements. That is, the output member of this application simultaneously has the function of the inner ring of a bearing, reducing axial limiting structures such as snap rings and gaskets, thereby reducing the axial dimension of the reducer. In addition, the reducer of this application can only change the structure of the output member without changing the structure of the transmission components in the reduction assembly, that is, without changing the reduction ratio of the reduction assembly. Therefore, while ensuring that the speed ratio and torque do not decrease, the size of the reducer is reduced, meeting the lightweight requirement.

[0038] Figure 1 The following shows a schematic structural diagram of a reducer provided by an embodiment of the present disclosure. Figure 2 The following shows a right view of a reducer provided by an embodiment of the present disclosure. Figure 3 The following shows what is provided by an embodiment of the present disclosure Figure 2 A sectional view of the reducer shown in the A-A direction. Figure 4 The following shows what is provided by another embodiment of the present disclosure Figure 2 A sectional view of the reducer shown in the A-A direction. Figure 5 The following shows what is provided by an embodiment of the present disclosure Figure 4 A partial enlarged view of the reducer shown in the B area. Figure 6 The following shows a schematic structural diagram of an outer ring of a bearing provided by an embodiment of the present disclosure. Figure 7 The following shows what is provided by an embodiment of the present disclosure Figure 6 A sectional view of the outer ring of the bearing shown in the C-C direction. Figure 8 The following shows what is provided by an embodiment of the present disclosure Figure 7 A partial enlarged view of the outer ring of the bearing shown in the D area. Figure 9 The following shows a schematic structural diagram of an output member provided by an embodiment of the present disclosure. Figure 10Shown is a left side view of an output member provided by an embodiment of the present disclosure. Figure 11 The present invention provides an embodiment of the present invention. Figure 10 The output member is shown in a cross-sectional view in the EE direction. Figure 12 Shown is a schematic structural diagram of a shell provided in one embodiment of the present disclosure. Figure 13 Shown is a schematic structural diagram of a crank shaft provided in one embodiment of the present disclosure. Figure 14 Shown is a schematic structural diagram of a first cycloid gear and a second cycloid gear provided in an embodiment of the present disclosure. Figure 15 FIG. 1 is a schematic diagram of the structure of a robot provided by an embodiment of the present disclosure. Figures 1 to 15 As shown, the reducer 10 includes a housing 100 , a bearing outer ring 200 , a reduction assembly 300 and a plurality of rolling elements 400 .

[0039] The speed reducer 10 is applied to a robot 1. Exemplarily, the robot 1 is a collaborative robot, a humanoid robot, or the like.

[0040] The bearing outer ring 200 is sleeved in the housing 100 , and the inner side surface of the bearing outer ring 200 has a first annular raceway 210 .

[0041] The reduction assembly 300 includes an input member 310, a transmission assembly 320 and an output member 330 which are sequentially connected in transmission. The output member 330 is rotatable relative to the outer ring 200 of the bearing. The output member 330 includes an annular portion 331, and the outer side surface of the annular portion 331 has a second annular raceway 3311. Exemplarily, the reduction assembly 300 can be a reduction structure of a cycloid reducer, or a reduction structure of a harmonic reducer, a reduction structure of a planetary reducer, or a reduction structure of an RV reducer. Exemplarily, the input member 310 can be connected to the output shaft of the motor to transmit the power of the motor to the transmission assembly 320. Exemplarily, the rotation speed of the output member 330 is less than the reduction of the input member 310 to achieve the reduction effect of the reduction assembly 300.

[0042] Part of the rolling element 400 is arranged on the first annular raceway 210 , and part of the rolling element 400 is arranged on the second annular raceway 3311 . When the output element 330 rotates relative to the bearing outer ring 200 , the rolling element 400 rolls in the first annular raceway 210 and the second annular raceway 3311 .

[0043] In the related art, the inner ring of the bearing of the speed reducer is separately provided from the output member, and axial limiting structures such as snap rings and gaskets are required to axially limit the inner ring of the bearing to restrict the axial displacement of the inner ring of the bearing on the output member. However, the output member 330 of the present application has a second annular raceway 3311, which can provide rolling restraint for the rolling elements 400, that is, the output member 330 of the present application simultaneously has the function of the inner ring of the bearing, reducing axial limiting structures such as snap rings and gaskets, thereby reducing the axial dimension of the speed reducer 10. In addition, the speed reducer 10 of the present application can only change the structure of the output member 330 without changing the structure of the transmission component 320 in the speed reduction component 300, that is, without changing the reduction ratio of the speed reduction component 300. Therefore, while ensuring that the speed ratio and torque are not reduced, the size of the speed reducer 10 is reduced.

[0044] In some embodiments, the shape of the radial cross-section of the first annular raceway 210 includes a V shape, the shape of the radial cross-section of the second annular raceway 3311 includes a V shape, the shape of the rolling elements 400 includes a cylinder or a cone, and the axes of adjacent rolling elements 400 are perpendicular to each other. Exemplarily, the bearing outer ring 200, the plurality of rolling elements 400, and the annular portion 331 can form a crossed roller bearing. The crossed roller bearing can be a cylindrical crossed roller bearing or a tapered crossed roller bearing. The crossed roller bearing can withstand axial and radial forces and meet the axial and radial support requirements for the output member 330.

[0045] Specifically, when the crossed roller bearing is subjected to a radial load, point contact or line contact is formed between the rolling elements 400 and the first annular raceway 210 and the second annular raceway 3311, and the load is transmitted through the rolling elements 400 to the bearing outer ring 200 and the annular portion 331. Since the axes of adjacent rolling elements 400 are perpendicular to each other, that is, the rolling elements 400 are arranged crosswise, the load can be evenly distributed in different directions, thereby improving the load-bearing capacity of the crossed roller bearing. When the crossed roller bearing bears an axial load, the end faces of the rolling elements 400 contact the thrust surfaces of the bearing outer ring 200 and the annular portion 331, and the axial force is transmitted to the housing 100.

[0046] Exemplarily, the speed reducer 10 further includes a separator. Specifically, in order to maintain the correct position and spacing of the rolling elements 400 and prevent the rolling elements 400 from colliding and rubbing against each other, a separator can be installed in the crossed roller bearing. The separator is generally made of plastic or metal materials and has good wear resistance and self-lubricating properties.

[0047] In some embodiments, the speed reducer 10 further includes a pressing plate 920. The pressing plate 920 is connected to the housing 100 and abuts against the end face of the bearing outer ring 200 away from the transmission component 320 to press the bearing outer ring 200.

[0048] In some embodiments, such as Figures 3 to 5, Figure 12 As shown in the figure, the inner side surface of the housing 100 has a cycloid tooth structure 110. Exemplarily, the inner side surface of the housing 100 has a plurality of grooves arranged at intervals along the circumferential direction of the housing 100, and each groove is provided with a pin tooth, that is, the pin teeth are arranged at intervals along the circumferential direction of the housing 100 to form the cycloid tooth structure 110.

[0049] The input member 310 includes a crankshaft 311. As Figure 3 , Figure 4 and Figure 13 shown, the crankshaft 311 includes an input shaft section 3111, a first eccentric shaft section 3112, a second eccentric shaft section 3113, and an output shaft section 3114 that are connected in sequence.

[0050] Exemplarily, the crankshaft 311 is also called an eccentric shaft and includes two eccentrically arranged shaft sections. An eccentric shaft refers to a shaft whose axis is not at the center of the axis. When it rotates, it not only transmits self-rotation but also can transmit revolution. Exemplarily, the input shaft section 3111 and the output shaft section 3114 are coaxially arranged, and neither the first eccentric shaft section 3112 nor the second eccentric shaft section 3113 is coaxial with the input shaft section 3111, and the first eccentric shaft section 3112 and the second eccentric shaft section 3113 are generally symmetrically arranged at 180°. Exemplarily, the crankshaft 311 can be formed by installing two eccentric sleeves with a 180° offset on a single shaft. The two ends of this shaft respectively form the input shaft section 3111 and the output shaft section 3114, and the part where the two eccentric sleeves are installed forms the first eccentric shaft section 3112 and the second eccentric shaft section 3113.

[0051] The annular portion 331 is rotatably connected to the output shaft section 3114. The transmission assembly 320 includes a first cycloid gear 321 and a second cycloid gear 322. The first cycloid gear 321 is rotatably connected to the first eccentric shaft section 3112 and is partially engaged with the cycloid tooth structure 110. As Figure 14 shown, the first cycloid gear 321 has a plurality of first connection holes 3210 that penetrate the first cycloid gear 321 along the first direction X, and the first direction X is parallel to the axial direction of the first cycloid gear 321. The second cycloid gear 322 is rotatably connected to the second eccentric shaft section 3113 and is partially engaged with the cycloid tooth structure 110. The second cycloid gear 322 has a plurality of second connection holes 3220 that penetrate the second cycloid gear 322 along the first direction X, and the plurality of second connection holes 3220 are arranged in one-to-one correspondence with the plurality of first connection holes 3210.

[0052] Exemplarily, a needle roller bearing can be provided between the first eccentric shaft section 3112 and the first cycloid gear 321 to reduce the frictional force of the relative rotation between the first eccentric shaft section 3112 and the first cycloid gear 321. Exemplarily, a needle roller bearing can be provided between the second eccentric shaft section 3113 and the second cycloid gear 322 to reduce the frictional force of the relative rotation between the second eccentric shaft section 3113 and the second cycloid gear 322.

[0053] As Figure 3 , Figure 4 , Figures 9 to 11 shown, the output member 330 further includes a plurality of pin shaft portions 332. The plurality of pin shaft portions 332 are integrally formed with the annular portion 331, the plurality of pin shaft portions 332 are arranged in one-to-one correspondence with the plurality of first connection holes 3210, and the plurality of pin shaft portions 332 respectively pass through the corresponding second connection holes 3220 and the first connection holes 3210 in sequence.

[0054] The plurality of pin shaft portions 332 are integrally formed with the annular portion 331, reducing the connection structure between the pin shaft portions 332 and the annular portion 331. When the strength of the output member 330 is satisfied, the weight and size of the output member 330 can be reduced, thereby further reducing the weight and size of the speed reducer 10.

[0055] Exemplarily, when the input member 310 includes a crankshaft 311, the transmission assembly 320 includes a first cycloid gear 321 and a second cycloid gear 322, and the output member 330 includes an annular portion 331 and a plurality of pin shaft portions 332, the speed reducer 10 is a cycloid speed reducer. The reduction ratio of the cycloid speed reducer can be made relatively large, such as dozens, hundreds, or even thousands, and the torque of the cycloid speed reducer can also be made relatively large, such as hundreds, thousands, or even tens of thousands. Therefore, when the input member 310 includes a crankshaft 311, the transmission assembly 320 includes a first cycloid gear 321 and a second cycloid gear 322, and the output member 330 includes an annular portion 331 and a plurality of pin shaft portions 332, the speed reducer 10 can not only have a relatively large reduction ratio and torque, but also have a relatively small bearing size.

[0056] In some embodiments, the speed reducer 10 further includes a rotor shaft sleeve 910, and the rotor shaft sleeve 910 is connected to the input shaft section 3111. Exemplarily, the rotor shaft sleeve 910 is connected to the output shaft of the motor so that the motor drives the rotor shaft sleeve 910 to rotate, and the rotor shaft sleeve 910 drives the crankshaft 311 to rotate.

[0057] In some embodiments, as Figure 4As shown, the inner side surface of the outer bearing ring 200 has a first sealing groove 220, and the first sealing groove 220 is located at the end face of the outer bearing ring 200 away from the transmission assembly 320. The outer side surface of the annular portion 331 has a second sealing groove 3312, and the second sealing groove 3312 is located at the end face of the annular portion 331 away from the transmission assembly 320.

[0058] As Figure 4 shown, the speed reducer 10 further includes a first seal 500. The first seal 500 is partially disposed in the first sealing groove 220 and partially disposed in the second sealing groove 3312 to achieve sealing between the outer bearing ring 200 and the annular portion 331 of the output member 330.

[0059] Since the end face of the outer bearing ring 200 close to the transmission assembly 320 is adjacent to the cycloid tooth structure 110 of the housing 100, and the end face of the annular portion 331 close to the transmission assembly 320 is adjacent to the transmission assembly 320, and both the cycloid tooth structure 110 and the transmission assembly 320 are located within the housing 100, and the environment around the cycloid tooth structure 110 and the transmission assembly 320 is relatively clean, therefore, the first seal 500 can be provided only at the end face of the outer bearing ring 200 away from the transmission assembly 320 and the end face of the annular portion 331 away from the transmission assembly 320 to prevent the rolling elements 400 from being contaminated. In other words, the present application only performs single-sided sealing on the bearing structure formed by the outer bearing ring 200, the rolling elements 400, and the annular portion 331, which can reduce the space occupied by double-sided sealing and further reduce the axial dimension of the speed reducer 10.

[0060] In some embodiments, as Figure 3 shown, according to actual needs, double-sided sealing can also be performed on the bearing structure formed by the outer bearing ring 200, the rolling elements 400, and the annular portion 331.

[0061] In some embodiments, the speed reducer 10 further includes a flange assembly 600 and a second seal 700. The flange assembly 600 is rotatably connected to the input shaft section 3111.

[0062] The second seal 700 is elastic. Exemplarily, the material of the second seal 700 is an elastic material such as rubber or plastic. As Figure 5 shown, the second seal 700 includes a first annular seal portion 710, a second annular seal portion 720, and an annular connection portion 730. The annular connection portion 730 connects the first annular seal portion 710 and the second annular seal portion 720. The first annular seal portion 710 is sleeved on the outer side surface of the housing 100 and is in interference connection with the outer side surface of the housing 100. The second annular seal portion 720 is sleeved on the outer side surface of the flange assembly 600 and is in interference connection with the outer side surface of the flange assembly 600.

[0063] By making the second seal 700 with elasticity be interference - connected to the outer side surface of the housing 100 and the outer side surface of the flange assembly 600 respectively, the second seal 700 can be made relatively thin. Compared with a standard skeleton oil seal, the axial dimension of the second seal 700 can be shortened by more than 5 mm.

[0064] In some embodiments, the second annular seal portion 720 includes a seal outer ring 721 and a seal inner ring 722. The seal outer ring 721 is connected to the annular connection portion 730 and is interference - connected to the outer side surface of the flange assembly 600. The seal inner ring 722 is spaced from the seal outer ring 721, is connected to the annular connection portion 730, and is interference - connected to the outer side surface of the flange assembly 600. By using the seal outer ring 721 and the seal inner ring 722 to double - seal the flange assembly 600, the sealing effect of the second seal 700 is further improved.

[0065] Exemplarily, both the seal outer ring 721 and the seal inner ring 722 are annular structures, and the seal outer ring 721 and the seal inner ring 722 can be arranged in parallel or at an angle.

[0066] In some embodiments, the interference amount between the first annular seal portion 710 and the outer side surface of the housing 100 is 0.2 - 0.5 mm. Exemplarily, the interference amount between the first annular seal portion 710 and the outer side surface of the housing 100 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc. In some embodiments, the interference amount between the second annular seal portion 720 and the outer side surface of the flange assembly 600 is 0.2 - 0.5 mm. Exemplarily, the interference amount between the second annular seal portion 720 and the outer side surface of the flange assembly 600 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0067] Verified by experiments, the interference amount between the first annular seal portion 710 and the outer side surface of the housing 100 being 0.2 - 0.5 mm and the interference amount between the second annular seal portion 720 and the outer side surface of the flange assembly 600 being 0.2 - 0.5 mm are relatively appropriate interference amounts, which can make the starting torque of the second seal 700 account for a relatively low or even the lowest proportion, so as to reduce the increase in the starting torque of the reducer 10 caused by interference while ensuring the sealing effect.

[0068] In some embodiments, the flange assembly 600 includes a flange body 610 and a baffle 620. The flange body 610 is rotatably connected to the input shaft section 3111. The baffle 620 is connected to the flange body 610. The second annular seal portion 720 is sleeved on the outer side surface of the baffle 620 and is interference - connected to the outer side surface of the baffle 620. The baffle 620 is configured to axially limit the first cycloid gear 321. The material hardness of the baffle 620 is greater than the material hardness of the flange body 610.

[0069] Exemplarily, the baffle 620 is separately provided from the flange body 610, so that the baffle 620 with higher hardness can be used to contact the second annular seal portion 720, and the baffle 620 with higher hardness can be used to axially limit the first cycloidal gear 321. Since the baffle 620 has higher hardness and better wear resistance, by using the baffle 620 to contact the second annular seal portion 720, the wear of the second annular seal portion 720 on the baffle 620 can be reduced, and the service life of the baffle 620 can be improved. In addition, since the baffle 620 has higher hardness and better wear resistance, by using the baffle 620 to axially limit the first cycloidal gear 321, the wear of the first cycloidal gear 321 on the baffle 620 can also be reduced, further improving the service life of the baffle 620.

[0070] The flange body 610 does not need to have a limiting function, so it can be made of materials with lower hardness and smaller density to achieve the weight reduction effect.

[0071] Exemplarily, the material of the baffle 620 can be a wear-resistant material such as alloy steel. Exemplarily, the material of the flange body 610 can be aluminum alloy, iron, etc.

[0072] In some embodiments, the reducer 10 further includes a hollow sleeve 930 to facilitate wire routing. The crankshaft 311 has a through hole that penetrates the crankshaft 311 in the first direction, and the hollow sleeve 930 is disposed in the through hole. The hollow sleeve 930 can be connected to the output member 330 and rotate with the output member 330.

[0073] In some embodiments, the reducer 10 further includes a first bearing 810. The first bearing 810 is disposed between the output member 330 and the output shaft section 3114. The outer ring of the first bearing 810 is connected to the output member 330, and the inner ring of the first bearing 810 is connected to the output shaft section 3114. The output member 330 has a first limiting portion 333, and the first limiting portion 333 is configured to axially limit the end face of the first bearing 810 away from the second cycloidal gear 322, so that axial limiting structures such as snap rings and shaft shoulders are not required to axially limit the second cycloidal gear 322, reducing the axial limiting structures and further reducing the axial dimension of the reducer 10.

[0074] In some embodiments, the reducer 10 further includes a second bearing 820. The second bearing 820 is disposed between the flange assembly 600 and the input shaft section 3111. The outer ring of the second bearing 820 is connected to the flange assembly 600, and the inner ring of the second bearing 820 is connected to the input shaft section 3111. The flange assembly 600 has a second limiting portion 630, and the second limiting portion 630 is configured to axially limit the end face of the second bearing 820 away from the first cycloidal gear 321, so that axial limiting structures such as snap rings and shaft shoulders are not required to axially limit the first cycloidal gear 321, reducing the axial limiting structures and further reducing the axial dimension of the reducer 10.

[0075] Exemplarily, a wave washer may also be provided between the second limiting portion 630 and the end surface of the second bearing 820 away from the first cycloid gear 321 to improve the pressing effect of the second limiting portion 630 on the second bearing 820.

[0076] Exemplarily, a first needle bearing may be provided between the first eccentric shaft section 3112 and the first cycloid gear 321, and a gasket may be provided between the second bearing 820 and the first needle bearing. Exemplarily, a second needle bearing may be provided between the second eccentric shaft section 3113 and the second cycloid gear 322, and a gasket may be provided between the first bearing 810 and the second needle bearing.

[0077] Exemplarily, the first bearing 810 and the second bearing 820 may be ball bearings, roller bearings, etc. For example, both the first bearing 810 and the second bearing 820 may be deep groove ball bearings.

[0078] The inventor made a comparative analysis of the reducer 10 of the present application and a traditional two-stage planetary reducer. The specific comparison parameters are shown in Table 1.

[0079] Table 1 Comparative analysis of the reducer 10 of the present application and a traditional two-stage planetary reducer

[0080]

[0081] As can be seen from Table 1, compared with the traditional two-stage planetary reducer, under the same speed ratio and the same rated load, the axial dimension of the reducer 10 is shortened by 8.2 mm, the weight is reduced by 236 g, the hollow diameter is 15 mm. At the same time, the usage amount of ball bearings is reduced by half, and the usage amount of needle bearings is reduced to 2.

[0082] Figure 10 The following shows a schematic structural diagram of a robot provided by an embodiment of the present disclosure. As Figure 10 shown, the robot 1 includes the reducer 10 in the above embodiment.

[0083] Since the robot 1 includes the reducer 10, the robot 1 has all the technical features and technical effects of the reducer 10, which will not be elaborated here.

[0084] In the embodiments of the present disclosure, if the form of connection is not clearly defined, the form of connection may be a detachable connection form such as bolt and nut, screw, buckle, magnetic attraction, etc. In some connections, if there is no special requirement for the form of non-detachable fit, non-detachable connection can be carried out by welding, bonding, etc.

[0085] As used in the specification, phrases such as "an embodiment" and "embodiments" mean that the described embodiments may include specific features, structures, or characteristics, but not every embodiment necessarily includes such specific features, structures, or characteristics. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a specific feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether explicitly or implicitly described.

[0086] It should be understood that the terms "on", "above", and "over" in this disclosure should be construed in the broadest manner, such that "on" not only means "directly on something", but also includes the meaning of "on something" with intermediate features or layers therebetween, and "above" or "over" not only include the meaning of "above" or "over something", but may also include the meaning of "above" or "over something" with no intermediate features or layers therebetween (i.e., directly on something).

[0087] In addition, for ease of description, spatial relative terms may be used in this document, such as "below", "beneath", "under", "above", "over", etc., to describe the relationship of one component or feature to another as shown in the figures. Spatial relative terms are intended to encompass different orientations of the components in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0088] It should be noted that in this document, the term "comprise", "include", or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0089] The above are only the preferred embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent replacements, etc. made within the spirit and principles of this disclosure shall be included within the protection scope of this disclosure.

Claims

1. A speed reducer, characterized in that, Comprising: A housing; An outer race of a bearing, sleeved in the housing, and an inner side surface of the outer race of the bearing has a first annular raceway; A speed reduction assembly, including an input member, a transmission assembly, and an output member that are sequentially drivingly connected. The output member is rotatable relative to the outer race of the bearing. The output member includes an annular portion, and an outer side surface of the annular portion has a second annular raceway; A plurality of rolling elements, a part of the structure of the rolling elements is arranged in the first annular raceway, and a part of the structure is arranged in the second annular raceway. When the output member rotates relative to the outer race of the bearing, the rolling elements roll in the first annular raceway and the second annular raceway.

2. The speed reducer according to claim 1, wherein The inner side surface of the housing has a cycloidal tooth structure. The input member includes a crankshaft, and the crankshaft includes an input shaft section, a first eccentric shaft section, a second eccentric shaft section, and an output shaft section that are sequentially connected. The annular portion is rotatably connected to the output shaft section; The transmission assembly includes: A first cycloidal gear, rotatably connected to the first eccentric shaft section and partially meshed with the cycloidal tooth structure. The first cycloidal gear has a plurality of first connection holes penetrating through the first cycloidal gear along a first direction, and the first direction is parallel to the axial direction of the first cycloidal gear; A second cycloidal gear, rotatably connected to the second eccentric shaft section and partially meshed with the cycloidal tooth structure. The second cycloidal gear has a plurality of second connection holes penetrating through the second cycloidal gear along the first direction, and the plurality of second connection holes are arranged in one-to-one correspondence with the plurality of first connection holes; The output member further includes: A plurality of pin shaft portions, integrally formed with the annular portion, the plurality of pin shaft portions are arranged in one-to-one correspondence with the plurality of first connection holes, and the plurality of pin shaft portions respectively pass through the corresponding second connection holes and the first connection holes in sequence.

3. The speed reducer according to claim 1, wherein, The inner side surface of the outer race of the bearing has a first sealing groove, the first sealing groove is located at an end surface of the outer race of the bearing away from the transmission assembly, and the outer side surface of the annular portion has a second sealing groove, the second sealing groove is located at an end surface of the annular portion away from the transmission assembly; The speed reducer further includes: A first sealing member, part of the first sealing member is arranged in the first sealing groove and part of it is arranged in the second sealing groove.

4. The speed reducer according to claim 1, characterized in that, The shape of the radial cross-section of the first annular raceway includes a V shape, the shape of the radial cross-section of the second annular raceway includes a V shape, the shape of the rolling elements includes a cylinder or a cone, and the axes of adjacent rolling elements are perpendicular to each other.

5. The speed reducer according to any one of claims 2 to 4, characterized in that It further includes: A flange assembly, rotatably connected to the input shaft section; A second sealing member, the second sealing member has elasticity, the second sealing member includes a first annular sealing portion, a second annular sealing portion, and an annular connecting portion. The annular connecting portion connects the first annular sealing portion and the second annular sealing portion. Wherein, the first annular sealing portion is sleeved on the outer side surface of the housing and is in interference connection with the outer side surface of the housing, and the second annular sealing portion is sleeved on the outer side surface of the flange assembly and is in interference connection with the outer side surface of the flange assembly.

6. The speed reducer according to claim 5, characterized in that, The second annular sealing portion includes: A sealing outer ring, which is connected to the annular connecting portion and is in interference connection with the outer side surface of the flange assembly; A sealing inner ring, which is arranged at an interval from the sealing outer ring, is connected to the annular connecting portion, and is in interference connection with the outer side surface of the flange assembly.

7. The speed reducer according to claim 5, characterized in that, The interference amount between the first annular sealing portion and the outer side surface of the housing is 0.2 - 0.5 mm; and / or The interference amount between the second annular sealing portion and the outer side surface of the flange assembly is 0.2 - 0.5 mm.

8. The speed reducer according to claim 5, wherein The flange assembly includes: A flange body, which is rotatably connected to the input shaft section; A baffle, which is connected to the flange body. The second annular sealing portion is sleeved on the outer side surface of the baffle and is in interference connection with the outer side surface of the baffle. The baffle is configured to axially limit the first cycloid gear. Among them, the material hardness of the baffle is greater than the material hardness of the flange body.

9. The speed reducer according to claim 5, wherein, It further includes: A first bearing, which is arranged between the output member and the output shaft section. The outer ring of the first bearing is connected to the output member, and the inner ring of the first bearing is connected to the output shaft section. The output member has a first limiting portion, and the first limiting portion is configured to axially limit the end surface of the first bearing away from the second cycloid gear; and / or A second bearing, which is arranged between the flange assembly and the input shaft section. The outer ring of the second bearing is connected to the flange assembly, and the inner ring of the second bearing is connected to the input shaft section. The flange assembly has a second limiting portion, and the second limiting portion is configured to axially limit the end surface of the second bearing away from the first cycloid gear.

10. A robot, characterized in that, It includes: The speed reducer according to any one of claims 1 to 9.

Images