Robot wrist transmission structure and robot

Abstract

The utility model provides a robot wrist transmission structure and a robot, and relates to the technical field of robots. The robot wrist transmission structure comprises a forearm shell and a wrist shell, a first bevel gear is arranged in the forearm shell, and a second bevel gear, a gear shaft and an output gear set are arranged in the wrist shell. The first bevel gear is in transmission connection with the second bevel gear, one end of the gear shaft is fixedly connected with the second bevel gear, and the other end is in transmission connection with the output gear set. The outer side of the second bevel gear is sleeved with a first bearing set and fixedly connected with the inner ring of the first bearing set. The outer side of the first bearing set is sleeved with a steel sleeve, the inner side of the steel sleeve is fixedly connected with the outer ring of the first bearing set, and the outer side of the steel sleeve is fixedly connected with the wrist shell. The robot wrist transmission structure is simple in structure, convenient to assemble and capable of reducing assembling difficulty and further reducing cost.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, and in particular to a robot wrist transmission structure and a robot. Background Technology

[0002] Six-joint robots are multi-joint manipulators widely used in industrial fields. They possess a certain degree of automation and are suitable for work on almost any trajectory or angle. They can replace human labor in completing many complex tasks that are unsuitable for human operation, making them very popular. The wrist component of a six-joint robot is a rotating part that connects the robot arm and the end effector. Located at the end of the robot, it is used to adjust or change the posture of the end effector to achieve precision operations. This requires the wrist component to have multiple independent degrees of freedom.

[0003] Typically, in order to achieve multiple degrees of freedom in the wrist component, multi-stage transmission is required. The accuracy of the wrist component's transmission directly affects the overall accuracy of the six-joint robot. Therefore, the wrist component of a six-joint robot often uses a variety of high-precision parts such as bevel gears, spur gears, and spline sleeves.

[0004] However, using multiple high-precision parts increases assembly difficulty and introduces cost issues. Utility Model Content

[0005] This invention provides a robot wrist transmission structure and a robot, which can simplify the wiring harness installation process and reduce equipment costs.

[0006] One embodiment of this utility model provides a robot wrist transmission structure, including a forearm housing and a wrist housing. The forearm housing contains a first bevel gear, and the wrist housing contains a second bevel gear, a gear shaft, and an output gear set.

[0007] The first bevel gear is drivingly connected to the second bevel gear, one end of the gear shaft is fixedly connected to the second bevel gear, and the other end is drivingly connected to the output gear set; wherein...

[0008] The second bevel gear is fitted with a first bearing assembly on its outer side, and the inner ring of the first bearing assembly is fixedly connected to the second bevel gear.

[0009] A steel sleeve is fitted on the outer side of the first bearing assembly. The inner side of the steel sleeve is fixedly connected to the outer ring of the first bearing assembly, and the outer side of the steel sleeve is fixedly connected to the wrist housing.

[0010] The robot wrist transmission structure provided in this application embodiment, by setting a first bevel gear, a second bevel gear, a gear shaft, and an output gear set, can realize power transmission from the first bevel gear to the output gear set. Furthermore, driving the first bevel gear can drive the output gear set, enabling the end effector connected to the output gear set to move. A first bearing set is provided on the outside of the second bevel gear to provide support, ensuring a stable connection between the second and first bevel gears. A steel sleeve restricts the radial degree of freedom of the second bevel gear, preventing radial wobbling. Additionally, the steel sleeve has a simpler structure and is easier to manufacture than the spline sleeve in related technologies, thus reducing processing costs. In this embodiment, the steel sleeve can be directly cast into the wrist housing, reducing assembly difficulty. Furthermore, the steel sleeve undergoes heat treatment during casting, resulting in higher wear resistance compared to aluminum parts in related technologies.

[0011] Optionally, the steel sleeve is a ring-shaped sleeve structure, and the steel sleeve is cast and connected to the wrist shell.

[0012] By designing the steel sleeve as a ring-shaped structure, the structure of the steel sleeve can be simplified, and it is easier to assemble with the first bearing assembly. This reduces assembly difficulty, lowers the structural cost of the steel sleeve, and improves assembly efficiency. Furthermore, by casting the steel sleeve to the wrist housing, the connection stability between the steel sleeve and the wrist housing can be improved, thereby providing stable support for the second bevel gear and enhancing its stability.

[0013] Optionally, it also includes a first end cap and a resilient element; wherein,

[0014] The first end cap is located at the end of the second bevel gear opposite to the gear shaft, and the elastic element is compressed and disposed between the first end cap and the outer ring of the first bearing assembly.

[0015] This configuration reduces the meshing clearance between the first and second bevel gears, ensuring a stable meshing connection between them and improving the transmission accuracy.

[0016] Optionally, the elastic element is a wave-shaped spring.

[0017] This design simplifies the structure of the elastic element, reduces costs, and makes the installation of the wave spring easier, thus reducing assembly difficulty.

[0018] Optionally, the wrist housing has a hollow structure in the middle that is arranged along the axial direction of the wrist housing, and the hollow structure is used for the six-joint robot to make its wiring.

[0019] This configuration allows the wiring to be routed within the wrist structure, reducing wear on the wiring harness during the movement of the actuator at the end of the wrist structure.

[0020] Optionally, an output flange may also be included; wherein,

[0021] In the axial direction of the output gear set, the second bevel gear is located at one end of the wrist housing, and the output gear set is located at the other end of the wrist housing;

[0022] In the axial direction of the output gear set, the output flange is located at the end of the output gear set opposite to the gear shaft, and the output flange is fixedly connected to the output gear set;

[0023] The output flange includes a through hole in the middle that corresponds to the hollow structure.

[0024] By setting an output flange and connecting it to the output gear set, the robot can be connected to the actuator at the end of the wrist structure via the output flange. This reduces assembly difficulty and improves the robot's aesthetics. A through-hole in the center of the output flange corresponds to the hollow structure of the wrist, facilitating cable routing within the robot.

[0025] Optional, including a first oil seal; wherein,

[0026] The first oil seal is disposed between the wrist housing and the output flange, and the first oil seal is used to seal the wrist housing and the output flange.

[0027] This design creates a seal between the wrist housing and the output flange, preventing grease and other substances from leaking between them.

[0028] Optionally, a second end cap may also be included; wherein,

[0029] In the axial direction of the second bevel gear, the second end cover is located at one end of the wrist housing away from the forearm housing and is fixedly connected to the wrist housing, and part of the structure of the output flange is located inside the second end cover;

[0030] A second oil seal is provided between the second end cover and the output flange, the second oil seal being used to seal the space between the second end cover and the output flange.

[0031] By installing a second end cap and placing it outside the output flange, the connection between the output flange and the output gear set can be concealed within the wrist housing, improving aesthetics and preventing dust accumulation at the connection point. The addition of a second oil seal creates a sealed structure between the wrist housing, the output flange, and the second end cap, preventing lubricant leakage between the second end cap and the output flange.

[0032] Optionally, crossed roller bearings are also included; wherein,

[0033] In the radial direction of the output gear set, the crossed roller bearing is disposed between the output gear set and the wrist housing;

[0034] The outer ring of the crossed roller bearing is sandwiched between the output gear set and the output flange;

[0035] The outer ring of the crossed roller bearing is fixedly connected to the output gear set, and the inner ring of the crossed roller bearing is fixedly connected to the wrist housing.

[0036] By using cross roller bearings, the output gear set and the wrist housing can rotate relative to each other, and the cross roller bearings can also provide better support for the output gear set, improving the stability and accuracy during operation.

[0037] Optionally, a bearing cap may also be included; wherein,

[0038] The bearing cap is disposed at the end of the crossed roller bearing opposite to the gear shaft, and the bearing cap is used to fix the crossed roller bearing.

[0039] This configuration ensures that the output gear set and output flange tightly fix the outer ring of the crossed roller bearing, the bearing cap confines the crossed roller bearing on the wrist housing, and guarantees that the gear shaft and output gear set mesh with each other, thereby improving operational accuracy.

[0040] Optionally, the output gear set is a backlash-free gear set, wherein the backlash-free gear set is used to eliminate the backlash in the circumferential direction of the gear shaft when the gear shaft and the backlash-free gear set mesh.

[0041] By setting the output gear set as a backlash-free gear set, the backlash between the gear shaft and the output gear set in the circumferential direction of the gear shaft can be eliminated, resulting in smoother transmission of the gear teeth, reduced noise and vibration, and improved transmission efficiency and accuracy.

[0042] Optionally, needle roller bearings are also included; wherein,

[0043] The needle roller bearing is sleeved on the outside of the gear shaft;

[0044] The inner ring of the needle roller bearing is fixedly connected to the gear shaft, and the outer ring of the needle roller bearing is fixedly connected to the wrist housing.

[0045] This design provides radial support to the gear shaft, reducing stress in the center and extending its service life. Additionally, it prevents wobbling in the center of the gear shaft, thus improving the transmission accuracy between the second bevel gear and the gear shaft.

[0046] Optionally, it also includes a first elastic retaining ring and a second elastic retaining ring; wherein,

[0047] In the radial direction of the gear shaft, one end of the first elastic retaining ring is fixedly connected to the gear shaft, and the other end abuts against the inner ring of the needle roller bearing. The gear shaft is provided with a first groove that mates with the first elastic retaining ring.

[0048] In the radial direction of the gear shaft, one end of the second elastic retaining ring is fixedly connected to the wrist housing, and the other end abuts against the outer ring of the needle roller bearing. The wrist housing is provided with a second groove that mates with the second elastic retaining ring.

[0049] By setting a first elastic retaining ring, the inner ring of the needle roller bearing can be fixed, preventing it from moving axially relative to the outer ring along the gear shaft, thus improving the stability of the needle roller bearing. By setting a second elastic retaining ring, the outer ring of the needle roller bearing can be fixed, thus preventing it from moving axially relative to the inner ring along the gear shaft, further improving the stability of the needle roller bearing.

[0050] Optionally, a first stop is provided on the outer side of the gear shaft, and the inner ring of the needle roller bearing at the end opposite to the first groove abuts against the first stop.

[0051] The wrist housing is provided with a second stop portion, and the outer ring of the needle roller bearing at the end opposite to the first groove abuts against the second stop portion.

[0052] By setting a first stop and a second stop, the inner and outer rings of the needle roller bearing can be fixed. With the cooperation of the first and second elastic retaining rings, the axial movement of the inner and outer rings of the needle roller bearing on the gear shaft can be prevented, thereby improving the stability of the needle roller bearing.

[0053] Optionally, it also includes a second bearing assembly and an input bearing housing; wherein,

[0054] One end of the input bearing housing is located inside the forearm housing and is rotatably connected to the forearm housing via a bearing structure; the other end of the input bearing housing is fixedly connected to the wrist housing.

[0055] The second bearing assembly is sleeved on the outside of the first bevel gear, and the outer ring of the second bearing assembly is fixedly connected to the input bearing housing, while the inner ring of the second bearing assembly is fixedly connected to the first bevel gear.

[0056] By incorporating a second bearing assembly, the coefficient of friction between the input bearing housing and the first bevel gear can be reduced, thereby decreasing the wear of the first bevel gear. The bearing structure also provides support for the input bearing housing, improving the stability between the input bearing housing and the forearm housing.

[0057] It should be noted that when the input bearing housing is connected to the wrist housing, one end of the input bearing housing is fixedly connected to the forearm housing, and the other end extends into the wrist housing, which is equivalent to a single cantilever structure with one end fixed. The input bearing housing is fixed at one end in the forearm housing, and the end in the outer housing acts as a cantilever. This structure makes the end of the input bearing housing inside the wrist housing unstable. Therefore, by setting a bearing structure between the forearm housing and the input bearing housing, support can be provided for the input bearing housing, thereby making the input bearing housing more stable.

[0058] Optionally, a third elastic retaining ring may also be included; wherein,

[0059] The bearing structure is sleeved on the outside of the input bearing housing, and the inner ring of the bearing structure is fixedly connected to the input bearing housing, while the outer ring of the bearing structure is fixedly connected to the forearm housing.

[0060] In the axial direction of the bearing structure, the third elastic retaining ring is located at one end of the bearing structure away from the wrist housing, and in the radial direction of the input bearing seat, one end of the third elastic retaining ring is fixedly connected to the input bearing seat, and the other end abuts against the end of the bearing structure away from the wrist housing.

[0061] By setting a third elastic retaining ring, the degree of freedom of the bearing structure in the axial direction of the input bearing housing can be restricted, preventing the bearing structure from moving in the axial direction of the input bearing housing, thereby improving the stability of the bearing structure.

[0062] Optionally, a third oil seal may also be included; among which,

[0063] The third oil seal is disposed between the outer side of the input bearing housing and the forearm housing, and the third oil seal is used to seal the space between the outer side of the input bearing housing and the forearm housing.

[0064] By setting a third oil seal, a sealing structure can be formed between the outer side of the input bearing housing and the forearm housing, preventing grease and other substances from leaking between the outer side of the input bearing housing and the forearm housing.

[0065] Optional features also include a timing belt and a fourth oil seal; among which,

[0066] The timing belt is fixedly connected to the first bevel gear, and the timing belt is used to drive the first bevel gear to rotate.

[0067] The fourth oil seal is disposed between the inner side of the synchronous belt and the inner side of the input bearing housing, and the fourth oil seal is used to seal the inner side of the input bearing housing and the synchronous belt.

[0068] By setting a fourth oil seal, a sealing structure can be formed between the synchronous belt and the input bearing housing, preventing grease and other substances from leaking between the synchronous belt and the input bearing housing.

[0069] In one possible implementation, a synchronous belt and an output flange are also included; wherein,

[0070] The timing belt is fixedly connected to the first bevel gear;

[0071] In the axial direction of the output gear set, the output flange is located at the end of the output gear set opposite to the gear shaft, and the output flange is fixedly connected to the output gear set;

[0072] The synchronous belt drives the first bevel gear to rotate, the rotation of the first bevel gear drives the second bevel gear to rotate, the rotation of the second bevel gear drives the gear shaft to rotate, the rotation of the gear shaft drives the output gear set to rotate, and the rotation of the output gear set drives the output flange to rotate.

[0073] This configuration allows power from the timing belt to be transmitted to the output flange, so that when the output flange is connected to an end effector (e.g., a robot), power can be transmitted to the end effector to enable it to perform different operations.

[0074] The second aspect of this application provides a robot, including any of the robot wrist transmission structures described in the first aspect above.

[0075] The robot provided in this application embodiment, by setting a robot wrist transmission structure of the first aspect, has a simpler structure and lower cost compared to related technologies that require high-precision parts such as spline sleeves. This results in a robot with a simpler structure and lower cost. Furthermore, the hollow structure in the middle of the wrist housing of the robot wrist transmission structure facilitates wiring and reduces wear on the wiring harness during the movement of the actuator at the end of the wrist structure. It also reduces processing costs and makes maintenance easier, thereby lowering maintenance costs.

[0076] The structure of this utility model, as well as its other utility model objectives and beneficial effects, will become more apparent and understandable through the description of the preferred embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0077] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0078] Figure 1 This is a partial structural schematic diagram of a robot wrist transmission structure provided in an embodiment of the present invention;

[0079] Figure 2 This is a partial cross-sectional structural diagram of a robot wrist transmission structure provided in an embodiment of this utility model;

[0080] Figure 3 yes Figure 2 A magnified structural diagram of part A in the diagram;

[0081] Figure 4 yes Figure 2 A schematic diagram of the enlarged structure of part B in the diagram;

[0082] Figure 5 yes Figure 2 A schematic diagram of the enlarged structure of part C in the diagram;

[0083] Figure 6 yes Figure 2 A magnified schematic diagram of part D in the diagram.

[0084] Explanation of reference numerals in the attached figures:

[0085] 10-Forearm housing; 11-First bevel gear; 12-Synchronous belt;

[0086] 13-Second bearing assembly; 14-Input bearing housing; 15-Bearing structure;

[0087] 16-Third elastic retaining ring; 17-Third oil seal; 18-Fourth oil seal;

[0088] 20 - Wrist shell; 21 - Hollow structure; 22 - First end cap;

[0089] 23-Second end cap; 24-Second groove; 25-Second stop;

[0090] 30 - Output flange; 31 - Through hole; 32 - Bearing gland;

[0091] 40 - Second bevel gear; 41 - First bearing assembly; 42 - Steel sleeve;

[0092] 43-Elastic element; 44-Gear shaft; 441-First groove;

[0093] 442 - First stop; 45 - Needle roller bearing; 46 - First elastic retaining ring;

[0094] 47 - Second elastic retaining ring; 60 - Output gear set; 61 - Crossed roller bearing;

[0095] 63 - First oil seal; 64 - Second oil seal. Detailed Implementation

[0096] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0097] The robot wrist transmission structure and the robot provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0098] This utility model embodiment provides a robot wrist transmission structure, such as Figure 1 As shown, the robot's wrist transmission structure includes a forearm housing 10 and a wrist housing 20. Figure 2 As shown, the forearm housing 10 contains a first bevel gear 11, and the wrist housing 20 contains a second bevel gear 40, a gear shaft 44, and an output gear set 60. The first bevel gear 11 is connected to the second bevel gear 40 in a driving connection, one end of the gear shaft 44 is fixedly connected to the second bevel gear 40, and the other end is connected to the output gear set 60 in a driving connection.

[0099] For example, the second bevel gear 40 is located at one end of the wrist housing 20, and the output gear set 60 is located at the other end of the wrist housing 20. The output gear set 60 is used to connect to the end effector so that the robot wrist transmission structure can drive the end effector to perform the operation.

[0100] like Figure 1 As shown, the wrist housing 20 has a hollow structure 21 arranged along the axial direction of the wrist housing 20 in the middle. The hollow structure 21 can be used for robot wiring.

[0101] This configuration allows the wiring to be routed within the wrist structure, reducing wear on the wiring harness during the movement of the actuator at the end of the wrist structure.

[0102] like Figure 3 As shown, a first bearing assembly 41 is fitted on the outer side of the second bevel gear 40, and the second bevel gear 40 is fixedly connected to the inner ring of the first bearing assembly 41. A steel sleeve 42 is fitted on the outer side of the first bearing assembly 41, the inner side of the steel sleeve 42 is fixedly connected to the outer ring of the first bearing assembly 41, and the outer side of the steel sleeve 42 is fixedly connected to the wrist housing 20.

[0103] The robot wrist transmission structure provided in this application embodiment can realize the power transmission from the first bevel gear 11 to the output gear set 60 by setting a first bevel gear 11, a second bevel gear 40, a gear shaft 44 and an output gear set 60. In turn, by driving the first bevel gear 11, the output gear set 60 can be driven so that the end effector connected to the output gear set 60 can move.

[0104] By providing a first bearing assembly 41 on the outside of the second bevel gear 40, the second bevel gear 40 can be supported so that the second bevel gear 40 and the first bevel gear 11 can be stably connected. By providing a steel sleeve 42, the radial freedom of the second bevel gear 40 can be restricted, preventing the second bevel gear 40 from shaking radially.

[0105] Furthermore, the steel sleeve 42 has a simpler structure and is easier to manufacture than the spline sleeve in related technologies, thus reducing processing costs. In this embodiment, the steel sleeve 42 can be directly cast into the wrist housing 20, thereby reducing assembly difficulty. Additionally, the steel sleeve 42 undergoes a heat treatment process during casting, resulting in higher wear resistance compared to aluminum parts in related technologies.

[0106] In one possible implementation, the steel sleeve 42 can be an annular sleeve structure, and the steel sleeve 42 is cast and connected to the wrist housing 20.

[0107] By designing the steel sleeve 42 as a ring-shaped structure, the structure of the steel sleeve 42 can be simplified, and it is easier to assemble with the first bearing assembly 41. This reduces assembly difficulty, lowers the structural cost of the steel sleeve 42, and improves assembly efficiency. By casting the steel sleeve 42 to the wrist housing 20, the connection stability between the steel sleeve 42 and the wrist housing 20 can be improved, thereby providing stable support for the second bevel gear 40 and enhancing its stability.

[0108] Of course, in other implementations, the steel sleeve 42 can also be fixedly connected to the wrist shell 20 through nano-injection molding, welding or other methods.

[0109] It should be noted that, in the embodiments of this application, the steel sleeve 42 and the first bearing assembly 41 can be fixedly connected by means of snap-fit ​​connection, interference fit, etc. In the implementation of this application, the connection method between the steel sleeve 42 and the first bearing assembly 41 is not further limited.

[0110] In this embodiment, the robot wrist transmission structure further includes a first end cap 22 and an elastic element 43. The first end cap 22 is located at the end of the second bevel gear 40 opposite to the gear shaft 44, and the elastic element 43 is compressed and disposed between the first end cap 22 and the outer ring of the first bearing assembly 41.

[0111] This configuration reduces the meshing clearance between the first bevel gear 11 and the second bevel gear 40, ensuring a stable meshing connection between the first bevel gear 11 and the second bevel gear 40, and improving the transmission accuracy between the first bevel gear 11 and the second bevel gear 40.

[0112] For example, the elastic element 43 is a wave-shaped spring. This design simplifies the structure of the elastic element 43, reduces costs, and makes the wave-shaped spring easy to install, thus reducing assembly difficulty.

[0113] Of course, in other embodiments, the elastic element 43 may also be a spring or other structure. In this embodiment, the specific structure of the elastic element 43 is not further limited.

[0114] For example, the second bevel gear 40 and the gear shaft 44 can be fixedly connected by fasteners, which facilitates assembly, reduces assembly difficulty, and lowers the processing cost of parts compared to using a spline sleeve connection, thereby reducing the overall cost of the parts. In addition, the fastener connection has better stability, which can improve the transmission accuracy between the second bevel gear 40 and the gear shaft 44.

[0115] Combination Figure 1 and Figure 4 As shown, the robot wrist transmission structure also includes an output flange 30. In the axial direction of the output gear set 60, the second bevel gear 40 is located at one end of the wrist housing 20, and the output gear set 60 is located at the other end of the wrist housing 20. In the axial direction of the output gear set 60, the output flange 30 is located at the end of the output gear set 60 opposite to the gear shaft 44, and the output flange 30 is fixedly connected to the output gear set 60. The middle portion of the output flange 30 includes a through hole 31 corresponding to the hollow structure 21.

[0116] By setting an output flange 30 and connecting it to the output gear set 60, the robot can be connected to the actuator at the end of the wrist structure via the output flange 30. This reduces assembly difficulty and improves the robot's aesthetics. A through hole 31 in the middle of the output flange 30 corresponds to the hollow structure 21 of the wrist, facilitating cable routing for the robot.

[0117] See also Figure 4 As shown, the robot wrist transmission structure also includes a first oil seal 63, which is disposed between the wrist housing 20 and the output flange 30. The first oil seal 63 is used to seal the space between the wrist housing 20 and the output flange 30.

[0118] This configuration creates a sealed structure between the wrist housing 20 and the output flange 30, preventing grease and other substances from leaking between them.

[0119] In this embodiment, the robot wrist transmission structure further includes a second end cap 23. The second end cap 23 is located at the end of the wrist housing 20 opposite to the forearm housing 10 along the axial direction of the second bevel gear 40, and is fixedly connected to the wrist housing 20. A portion of the output flange 30 is located inside the second end cap 23. A second oil seal 64 is provided between the second end cap 23 and the output flange 30 to seal the space between them.

[0120] By providing a second end cap 23 and positioning it outside the output flange 30, the connection between the output flange 30 and the output gear set 60 can be concealed within the wrist housing 20, improving aesthetics and preventing dust accumulation at the connection point. Furthermore, by providing a second oil seal 64, a sealing structure is formed between the wrist housing 20, the output flange 30, and the second end cap 23, preventing leakage of lubricating grease and other substances between the second end cap 23 and the output flange 30.

[0121] For example, the output gear set 60 can be a backlash-free gear set (not shown in the figure), wherein the backlash-free gear set is used to eliminate the backlash in the circumferential direction of the gear shaft 44 when the gear shaft 44 and the backlash-free gear set mesh.

[0122] By setting the output gear set 60 as a backlash-free gear set, the backlash between the gear shaft 44 and the output gear set 60 in the circumferential direction of the gear shaft 44 can be eliminated, resulting in smoother transmission of the gear teeth, reduced noise and vibration, and improved transmission efficiency and accuracy.

[0123] In one possible implementation, the backlash-free gear set may include two gears, a first gear and a second gear, with identical tooth profile parameters, stacked axially. Both the first gear and the second gear have internal tooth structures, while the gear shaft 44 has an external tooth structure. The gear shaft 44 is meshed with both the first gear and the second gear, meaning that in the axial direction of the gear shaft 44, a tooth of the first gear and a tooth of the second gear simultaneously exist in one tooth backlash of the gear shaft 44.

[0124] The first and second gears are movably positioned circumferentially. An elastic backlash-eliminating structure is provided between the first and second gears, capable of extending and retracting circumferentially. When compressed, the elastic backlash-eliminating structure exhibits restoring force, causing one gear to twist around the axis of the other. This results in the tooth profiles of the second and first gears being misaligned circumferentially. In other words, when the teeth of the first and second gears at the same position change from an overlapping state to a misaligned state, the circumferential dimension occupied by the two teeth increases, effectively widening the backlash-eliminating gear set. Thus, when the backlash-eliminating gear set meshes with the gear shaft 44, the teeth of the first and second gears can fill the entire backlash of the gear shaft 44 circumferentially, eliminating the backlash between the output gear set 60 and the gear shaft 44. This results in smoother transmission between the output gear set 60 and the gear shaft 44, reducing noise and vibration, and improving transmission efficiency and accuracy.

[0125] See also Figure 4 As shown, the robot wrist transmission structure also includes a crossed roller bearing 61. In the radial direction of the output gear set 60, the crossed roller bearing 61 is disposed between the output gear set 60 and the wrist housing 20. The outer ring of the crossed roller bearing 61 is sandwiched between the output gear set 60 and the output flange 30. The outer ring of the crossed roller bearing 61 is fixedly connected to the output gear set 60, and the inner ring of the crossed roller bearing 61 is fixedly connected to the wrist housing 20.

[0126] By setting the cross roller bearing 61, the output gear set 60 and the wrist housing 20 can rotate relative to each other, and the cross roller bearing 61 can also provide better support for the output gear set 60, improving the stability and accuracy during operation.

[0127] Optionally, the robot wrist transmission structure also includes a bearing cover 32, wherein the bearing cover 32 is disposed at the end of the crossed roller bearing 61 away from the gear shaft 44, and the bearing cover 32 is used to fix the crossed roller bearing 61.

[0128] This configuration ensures that the output gear set 60 and the output flange 30 tightly fix the outer ring of the crossed roller bearing 61 in place, the bearing cap 32 confines the crossed roller bearing 61 on the wrist housing 20, and ensures that the gear shaft 44 and the output gear set 60 mesh with each other, thereby improving the operating accuracy.

[0129] like Figure 5 As shown, the robot wrist transmission structure also includes a needle roller bearing 45, wherein the needle roller bearing 45 is sleeved on the outside of the gear shaft 44, the inner ring of the needle roller bearing 45 is fixedly connected to the gear shaft 44, and the outer ring of the needle roller bearing 45 is fixedly connected to the wrist housing 20.

[0130] This design provides radial support to the gear shaft 44, reducing stress in the middle of the gear shaft 44 and thus extending its service life. Additionally, it prevents wobbling in the middle of the gear shaft 44, thereby improving the transmission accuracy between the second bevel gear 40 and the gear shaft 44.

[0131] For example, the robot wrist transmission structure also includes a first elastic retaining ring 46 and a second elastic retaining ring 47. In the radial direction of the gear shaft 44, one end of the first elastic retaining ring 46 is fixedly connected to the gear shaft 44, and the other end abuts against the inner ring of the needle roller bearing 45. The gear shaft 44 is provided with a first groove 441 that cooperates with the first elastic retaining ring 46. In the radial direction of the gear shaft 44, one end of the second elastic retaining ring 47 is fixedly connected to the wrist housing 20, and the other end abuts against the outer ring of the needle roller bearing 45. The wrist housing 20 is provided with a second groove 24 that cooperates with the second elastic retaining ring 47.

[0132] By providing a first elastic retaining ring 46, the inner ring of the needle roller bearing 45 can be fixed, preventing it from moving relative to the outer ring along the axial direction of the gear shaft 44, thus improving the stability of the needle roller bearing 45. By providing a second elastic retaining ring 47, the outer ring of the needle roller bearing 45 can be fixed, thus preventing it from moving relative to the inner ring along the axial direction of the gear shaft 44, further improving the stability of the needle roller bearing 45.

[0133] See also Figure 5 As shown, a first stop 442 is provided on the outer side of the gear shaft 44, and the inner ring of the needle roller bearing 45 at the end opposite to the first groove 441 abuts against the first stop 442. A second stop 25 is provided on the wrist housing 20, and the outer ring of the needle roller bearing 45 at the end opposite to the first groove 441 abuts against the second stop 25.

[0134] By setting the first stop 442 and the second stop 25, the inner and outer rings of the needle roller bearing 45 can be fixed. With the cooperation of the first elastic retaining ring 46 and the second elastic retaining ring 47, the inner and outer rings of the needle roller bearing 45 can be prevented from moving axially on the gear shaft 44, thereby improving the stability of the needle roller bearing 45.

[0135] like Figure 6 As shown, the robot wrist transmission structure also includes a second bearing assembly 13 and an input bearing housing 14. One end of the input bearing housing 14 is located inside the forearm housing 10 and is rotatably connected to the forearm housing 10 via a bearing structure 15. The other end of the input bearing housing 14 is fixedly connected to the wrist housing 20. The second bearing assembly 13 is sleeved on the outside of the first bevel gear 11, and the outer ring of the second bearing assembly 13 is fixedly connected to the input bearing housing 14, while the inner ring of the second bearing assembly 13 is fixedly connected to the first bevel gear 11.

[0136] By setting the second bearing assembly 13, the coefficient of friction between the input bearing housing 14 and the first bevel gear 11 can be reduced, thereby reducing the wear of the first bevel gear 11. By setting the bearing structure 15, support can be provided for the input bearing housing 14, improving the stability between the input bearing housing 14 and the forearm housing 10.

[0137] It should be noted that when the input bearing housing 14 is connected to the wrist housing 20, one end of the input bearing housing 14 is fixedly connected to the forearm housing 10, and the other end extends into the wrist housing 20, which is equivalent to a single cantilever structure with one end fixed. Since the end of the input bearing housing 14 located in the forearm housing 10 is fixed, and the end located in the outer housing is equivalent to a cantilever, this structure makes the end of the input bearing housing 14 located inside the wrist housing 20 unstable. Therefore, by setting a bearing structure 15 between the forearm housing 10 and the input bearing housing 14, support can be provided for the input bearing housing 14, thereby making the input bearing housing 14 more stable.

[0138] For example, the robot wrist transmission structure further includes a third elastic retaining ring 16, wherein the bearing structure 15 is sleeved on the outside of the input bearing housing 14, and the inner ring of the bearing structure 15 is fixedly connected to the input bearing housing 14, and the outer ring of the bearing structure 15 is fixedly connected to the forearm housing 10. In the axial direction of the bearing structure 15, the third elastic retaining ring 16 is located at the end of the bearing structure 15 away from the wrist housing 20, and in the radial direction of the input bearing housing 14, one end of the third elastic retaining ring 16 is fixedly connected to the input bearing housing 14, and the other end abuts against the end of the bearing structure 15 away from the wrist housing 20.

[0139] By setting a third elastic retaining ring 16, the degree of freedom of the bearing structure 15 in the axial direction of the input bearing housing 14 can be restricted, preventing the bearing structure 15 from moving in the axial direction of the input bearing housing 14, thereby improving the stability of the bearing structure 15.

[0140] In some embodiments, the bearing structure 15 may be an angular contact bearing. In this application embodiment, the specific type of bearing structure 15 is not further limited.

[0141] It should be noted that both the first elastic retaining ring 46 and the second elastic retaining ring 47 have a certain degree of elasticity, which can alleviate the impact force on the needle roller bearing 45, thus providing a certain degree of protection for the needle roller bearing. The third elastic retaining ring 16 also has a certain degree of elasticity, which can alleviate the impact force on the bearing structure 15, thus providing a certain degree of protection for the bearing structure 15.

[0142] See also Figure 6 As shown, the robot wrist transmission structure also includes a third oil seal 17. The third oil seal 17 is disposed between the outer side of the input bearing housing 14 and the forearm housing 10, and is used to seal the space between the outer side of the input bearing housing 14 and the forearm housing 10.

[0143] By setting a third oil seal 17, a sealing structure can be formed between the outer side of the input bearing housing 14 and the forearm housing 10 to prevent grease and other substances from leaking from the outer side of the input bearing housing 14 and the forearm housing 10.

[0144] For example, the robot wrist transmission structure also includes a timing belt 12 and a fourth oil seal 18, wherein the timing belt 12 is fixedly connected to the first bevel gear 11 and is used to drive the first bevel gear 11 to rotate. The fourth oil seal 18 is disposed between the timing belt 12 and the inner side of the input bearing housing 14, and is used to seal the inner side of the input bearing housing 14 and the timing belt 12.

[0145] By setting a fourth oil seal 18, a sealing structure can be formed between the synchronous belt 12 and the input bearing housing 14 to prevent grease and other substances from leaking between the synchronous belt 12 and the input bearing housing 14.

[0146] For example, the timing belt 12 and the first bevel gear 11 can be fixedly connected by fasteners, which can reduce assembly difficulty and thus reduce costs.

[0147] It should be noted that the timing belt 12 is used to drive the first bevel gear 11. The forearm housing 10 is also provided with a drive structure for driving the input bearing seat 14, so that the input bearing seat 14 drives the wrist housing 20 to rotate. In this embodiment of the application, the drive structure for driving the input bearing seat 14 is not further limited.

[0148] The power transmission path of the robot wrist transmission structure in this embodiment can be as follows: the synchronous belt 12 drives the first bevel gear 11 to rotate, achieving primary transmission. The rotation of the first bevel gear 11 drives the second bevel gear 40 to rotate, achieving secondary transmission. The rotation of the second bevel gear 40 drives the gear shaft 44 to rotate, and the rotation of the gear shaft 44 drives the output gear set 60 to rotate, achieving tertiary transmission. The rotation of the output gear set 60 drives the output flange 30 to rotate, ultimately transmitting power to the output flange 30. Thus, when the output flange 30 is connected to an end effector (e.g., a robotic arm), power can be transmitted to the end effector, enabling it to perform different operations.

[0149] It should be noted that the robot wrist transmission structure provided in this application embodiment can be applied to six-joint robots, five-joint robots, four-joint robots or other robots. In this application embodiment, the application structure of the robot wrist transmission structure is not further limited.

[0150] This application also provides a robot, including the robot wrist transmission structure of any of the above embodiments. The robot may include, but is not limited to, a six-joint robot, a five-joint robot, a four-joint robot, or other types of robots.

[0151] The robot provided in this application embodiment, by setting the robot wrist transmission structure 100 in the above embodiment, has a simpler structure and lower cost compared to related technologies that require high-precision parts such as spline sleeves. This is because the robot wrist transmission structure 100 in the above embodiment has a first bearing assembly 41 on the outside of the second bevel gear 40, and a steel sleeve 42 is fitted on the outside of the first bearing assembly 41. This results in a simpler and lower-cost robot structure. Furthermore, the hollow structure in the middle of the wrist housing of the robot wrist transmission structure 100 facilitates robot wiring and reduces wear on the wiring harness during the movement of the actuator at the end of the wrist structure. It also reduces processing costs and makes maintenance more convenient, thereby reducing maintenance costs.

[0152] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0153] In the description of this utility model, it should be understood that the terms "comprising" and "having" as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0154] Unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A robot wrist transmission structure, characterized in that, It includes a forearm housing (10) and a wrist housing (20). The forearm housing (10) is provided with a first bevel gear (11), and the wrist housing (20) is provided with a second bevel gear (40), a gear shaft (44), and an output gear set (60). The first bevel gear (11) is connected to the second bevel gear (40) in a transmission connection; One end of the gear shaft (44) is fixedly connected to the second bevel gear (40), and the other end is connected to the output gear set (60) for transmission; wherein, The second bevel gear (40) is fitted with a first bearing assembly (41) on its outer side, and the inner ring of the first bearing assembly (41) is fixedly connected to the second bevel gear (40). A steel sleeve (42) is fitted on the outer side of the first bearing assembly (41). The inner side of the steel sleeve (42) is fixedly connected to the outer ring of the first bearing assembly (41), and the outer side of the steel sleeve (42) is fixedly connected to the wrist housing (20).

2. The robot wrist transmission structure according to claim 1, characterized in that, The steel sleeve (42) has a ring-shaped sleeve structure; The steel sleeve (42) is cast and connected to the wrist housing (20).

3. The robot wrist transmission structure according to claim 2, characterized in that, It also includes a first end cap (22) and an elastic element (43); wherein, The first end cap (22) is located at the end of the second bevel gear (40) away from the gear shaft (44), and the elastic element (43) is compressed between the first end cap (22) and the outer ring of the first bearing assembly (41).

4. The robot wrist transmission structure according to claim 3, characterized in that, The elastic element (43) is a wave-shaped spring sheet.

5. The robot wrist transmission structure according to any one of claims 1-4, characterized in that, The wrist housing (20) has a hollow structure (21) arranged along the axial direction of the wrist housing (20) in the middle, and the hollow structure (21) is used for robot wiring.

6. The robot wrist transmission structure according to claim 5, characterized in that, It also includes an output flange (30); among which, In the axial direction of the output gear set (60), the second bevel gear (40) is located at one end of the wrist housing (20), and the output gear set (60) is located at the other end of the wrist housing (20); In the axial direction of the output gear set (60), the output flange (30) is located at one end of the output gear set (60) away from the gear shaft (44), and the output flange (30) is fixedly connected to the output gear set (60); The middle part of the output flange (30) includes a through hole (31) corresponding to the hollow structure (21).

7. The robot wrist transmission structure according to claim 6, characterized in that, Including the first oil seal (63); among which, The first oil seal (63) is disposed between the wrist housing (20) and the output flange (30), and the first oil seal (63) is used to seal between the wrist housing (20) and the output flange (30).

8. The robot wrist transmission structure according to claim 6 or 7, characterized in that, It also includes a second end cap (23); among which, In the axial direction of the second bevel gear (40), the second end cover (23) is located at one end of the wrist housing (20) away from the forearm housing (10) and is fixedly connected to the wrist housing (20), and part of the structure of the output flange (30) is located inside the second end cover (23); A second oil seal (64) is provided between the second end cap (23) and the output flange (30), the second oil seal (64) being used to seal between the second end cap (23) and the output flange (30).

9. The robot wrist transmission structure according to claim 6 or 7, characterized in that, It also includes crossed roller bearings (61); wherein, In the radial direction of the output gear set (60), the crossed roller bearing (61) is disposed between the output gear set (60) and the wrist housing (20); The outer ring of the crossed roller bearing (61) is sandwiched between the output gear set (60) and the output flange (30); The outer ring of the cross roller bearing (61) is fixedly connected to the output gear set (60), and the inner ring of the cross roller bearing (61) is fixedly connected to the wrist housing (20).

10. The robot wrist transmission structure according to claim 9, characterized in that, It also includes a bearing cap (32); wherein, The bearing cap (32) is disposed at one end of the crossed roller bearing (61) away from the gear shaft (44), and the bearing cap (32) is used to fix the crossed roller bearing (61).

11. The robot wrist transmission structure according to any one of claims 1-4, characterized in that, The output gear set (60) is a backlash-free gear set; wherein, The backlash-eliminating gear set is used to eliminate the backlash in the circumferential direction of the gear shaft (44) when the gear shaft (44) and the backlash-eliminating gear set are meshed.

12. The robot wrist transmission structure according to any one of claims 1-4, characterized in that, It also includes needle roller bearings (45); among which, The needle roller bearing (45) is sleeved on the outside of the gear shaft (44); The inner ring of the needle roller bearing (45) is fixedly connected to the gear shaft (44), and the outer ring of the needle roller bearing (45) is fixedly connected to the wrist housing (20).

13. The robot wrist transmission structure according to claim 12, characterized in that, It also includes a first elastic retaining ring (46) and a second elastic retaining ring (47); wherein, In the radial direction of the gear shaft (44), one end of the first elastic retaining ring (46) is fixedly connected to the gear shaft (44), and the other end abuts against the inner ring of the needle roller bearing (45). The gear shaft (44) is provided with a first groove (441) that cooperates with the first elastic retaining ring (46). In the radial direction of the gear shaft (44), one end of the second elastic retaining ring (47) is fixedly connected to the wrist housing (20), and the other end abuts against the outer ring of the needle roller bearing (45). The wrist housing (20) is provided with a second groove (24) that cooperates with the second elastic retaining ring (47).

14. The robot wrist transmission structure according to claim 13, characterized in that, The gear shaft (44) has a first stop (442) on its outer side, and the inner ring of the needle roller bearing (45) at one end away from the first groove (441) abuts against the first stop (442). The wrist housing (20) is provided with a second stop (25), and the outer ring of the needle roller bearing (45) at one end away from the first groove (441) abuts against the second stop (25).

15. The robot wrist transmission structure according to claim 13 or 14, characterized in that, It also includes a second bearing assembly (13) and an input bearing housing (14); wherein, One end of the input bearing seat (14) is located inside the forearm housing (10) and is rotatably connected to the forearm housing (10) through the bearing structure (15). The other end of the input bearing seat (14) is fixedly connected to the wrist housing (20). The second bearing assembly (13) is sleeved on the outside of the first bevel gear (11), and the outer ring of the second bearing assembly (13) is fixedly connected to the input bearing seat (14), and the inner ring of the second bearing assembly (13) is fixedly connected to the first bevel gear (11).

16. The robot wrist transmission structure according to claim 15, characterized in that, It also includes a third elastic retaining ring (16); wherein, The bearing structure (15) is sleeved on the outside of the input bearing seat (14), and the inner ring of the bearing structure (15) is fixedly connected to the input bearing seat (14), and the outer ring of the bearing structure (15) is fixedly connected to the forearm housing (10). In the axial direction of the bearing structure (15), the third elastic retaining ring (16) is located at one end of the bearing structure (15) away from the wrist housing (20), and in the radial direction of the input bearing seat (14), one end of the third elastic retaining ring (16) is fixedly connected to the input bearing seat (14), and the other end abuts against the end of the bearing structure (15) away from the wrist housing (20).

17. The robot wrist transmission structure according to claim 15, characterized in that, It also includes a third oil seal (17); among which, The third oil seal (17) is disposed between the outer side of the input bearing housing (14) and the forearm housing (10), and the third oil seal (17) is used to seal the outer side of the input bearing housing (14) and the forearm housing (10).

18. The robot wrist transmission structure according to claim 15, characterized in that, It also includes a timing belt (12) and a fourth oil seal (18); among which, The timing belt (12) is fixedly connected to the first bevel gear (11), and the timing belt (12) is used to drive the first bevel gear (11) to rotate; The fourth oil seal (18) is disposed between the inner side of the synchronous belt (12) and the inner side of the input bearing housing (14), and the fourth oil seal (18) is used to seal the inner side of the input bearing housing (14) and the synchronous belt (12).

19. The robot wrist transmission structure according to any one of claims 1-4, characterized in that, It also includes a timing belt (12) and an output flange (30); among which, The synchronous belt (12) is fixedly connected to the first bevel gear (11); In the axial direction of the output gear set (60), the output flange (30) is located at one end of the output gear set (60) away from the gear shaft (44), and the output flange (30) is fixedly connected to the output gear set (60); The synchronous belt (12) is used to drive the first bevel gear (11) to rotate. The rotation of the first bevel gear (11) drives the second bevel gear (40) to rotate. The rotation of the second bevel gear (40) drives the gear shaft (44) to rotate. The rotation of the gear shaft (44) drives the output gear set (60) to rotate. The rotation of the output gear set (60) drives the output flange (30) to rotate.

20. A robot, characterized in that, The robot wrist transmission structure includes any one of the claims 1-19 above.

Images