High-torque-density double-rigid-gear harmonic speed reducer joint module

Abstract

The utility model provides a high-torque-density double-rigid-gear harmonic speed reducer joint module, which relates to the technical field of speed reducers, and comprises a front end cover, a rear end cover, a harmonic speed reducer and a motor, the harmonic speed reducer comprises a wave generator, a flexible bearing, a flexible gear, an output end rigid gear, a fixed end rigid gear and a crossed roller bearing, the crossed roller bearing comprises a bearing outer ring, the output end rigid wheel and the fixed end rigid wheel serve as a crossed roller bearing inner ring, and crossed rollers are arranged between the outer walls of the output end rigid wheel and the fixed end rigid wheel and the inner wall of the bearing outer ring; the motor comprises a motor shell, a stator, a rotor and a motor shaft, the wave generator is connected with the motor shaft, the front end cover is connected with the motor shell, and the rotor is connected with the servo driving plate; the output end rigid wheel is connected with the rear end cover, and the side, away from the output end rigid wheel, of the fixed end rigid wheel is connected with a torque sensor which is connected with the bearing outer ring and the motor shell. The motor has the characteristics of small size, light weight, high torque density, high torque feedback precision and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of speed reducers, in particular to a double-rigid-wheel harmonic speed reducer joint module with high torque density. Background Art

[0002] Robot joint modules are the core components of small robots such as collaborative robots and mobile robots. The modular joint modules are composed of reducers and motors to achieve fast and convenient assembly and maintenance of robots. Currently, robot joint modules are increasingly being used in the service robot industry, which places strict requirements on the performance of robot joint modules, such as small size, light weight, high torque density, and high reliability.

[0003] Most robot joint modules in the prior art adopt an integrated design of a single rigid wheel harmonic reducer and a frameless torque motor. The thin-walled flexible ring structure of the flexible wheel of the single rigid wheel harmonic reducer makes the axial length of the entire module too long, making it impossible to obtain the most compact spatial layout, and the flexible wheel has weak anti-buckling deformation ability, which greatly limits the load capacity and impact resistance of the entire module. In addition, the independent cross roller bearings in the single rigid wheel harmonic reducer limit the integration, size and weight of the module, and cannot meet the requirements of miniaturization and lightweight of the module. In addition, most existing modules do not use torque sensors, or only have strain gauges attached to the output flange of the module, resulting in low torque feedback accuracy of the entire module, and the module cannot respond to changing torque information in a timely and accurate manner. Utility Model Content

[0004] The purpose of the utility model is to provide a high torque density double-rigid wheel harmonic reducer joint module, which can meet the use requirements of small module size, light weight, high torque density and high torque feedback accuracy.

[0005] The above technical objectives of the utility model are achieved through the following technical solutions:

[0006] A high torque density double rigid wheel harmonic reducer joint module, comprising a front end cover and a rear end cover, wherein a harmonic reducer and a motor are arranged between the front end cover and the rear end cover;

[0007] The harmonic reducer includes a wave generator, a flexible bearing, a flexible wheel, an output end rigid wheel, a fixed end rigid wheel and a cross roller bearing. The flexible bearing is mounted on the cam of the wave generator. The flexible wheel is annular and straight and is sleeved outside the flexible bearing. The outer teeth of the flexible wheel mesh with the inner teeth of the output end rigid wheel and the fixed end rigid wheel, and one meshes with the same number of teeth and the other meshes with a different number of teeth. The cross roller bearing includes an outer ring of the bearing. The output end rigid wheel and the fixed end rigid wheel are both used as the inner ring of the cross roller bearing, and cross rollers are provided between the outer walls of the output end rigid wheel and the fixed end rigid wheel and the inner wall of the outer ring of the bearing.

[0008] The motor comprises a motor housing, a stator, a rotor and a motor shaft, wherein the stator is fixedly mounted in the motor housing, the rotor is fixedly mounted on the motor shaft, the wave generator is fixedly connected to the motor shaft, the front end cover is connected to the motor housing, and the rotor is connected to a servo drive plate that drives the motor shaft to drive the wave generator to rotate;

[0009] The output end rigid wheel is fixedly connected to the rear end cover, and a torque sensor is connected to the side of the fixed end rigid wheel away from the output end rigid wheel, and the torque sensor is connected to the servo drive board for communication and feedback; the torque sensor includes an inner ring, an outer ring and an elastic strain gauge, and the inner ring is connected to the fixed end rigid wheel, and the outer ring is connected to the outer ring of the bearing and the motor housing, and the elastic strain gauge is arranged between the inner ring and the outer ring.

[0010] By adopting the above technical solution, the servo drive board controls the rotor to drive the motor shaft to rotate, and the motor shaft drives the wave generator to rotate. The working principle of the harmonic reducer is the same as that in the prior art. When the module is subjected to torque in the rotation direction and bending moment in the axial direction, the elastic strain gauge of the torque sensor undergoes elastic deformation, and the magnitude of the torque applied to the torque sensor can be calculated based on the measured deformation. When the output end rigid wheel is subjected to external torque, the torque is transmitted to the flexible wheel, the flexible bearing and the wave generator, and then the torque is transmitted to the fixed end rigid wheel through the meshing of the flexible wheel and the fixed end rigid wheel. The inner ring of the torque sensor is connected to the fixed end rigid wheel, and the outer ring is connected to the outer ring of the bearing and the motor housing. In this way, the harmonic reducer torque from the fixed end rigid wheel can be detected through the deformation of the elastic strain gauge. Among them, the fixed end rigid wheel is connected to the outer ring of the bearing of the cross roller bearing through the corresponding cross roller, so that the fixed end rigid wheel and the outer ring of the bearing can rotate relative to each other, thereby ensuring that the torque sensor can produce slight deformation.

[0011] In addition, the fixed-end rigid wheel and the corresponding cross rollers and the outer ring of the bearing form a row of cross roller bearings, and the output-end rigid wheel and the corresponding cross rollers and the outer ring of the bearing form another row of cross roller bearings. The two rows of cross roller bearings can not only jointly provide bending moment bearing capacity for the harmonic reducer, but also the row of cross roller bearings corresponding to the fixed-end rigid wheel can also provide bending moment bearing capacity for the torque sensor, so that the torque sensor only deforms in the direction of rotation and will not be interfered by the signal generated by the deformation in the bending moment direction, thereby greatly improving the feedback accuracy of the rotational torque of the torque sensor detection module.

[0012] Furthermore, the bearing outer ring includes a bearing steel body and an aluminum alloy inlay, the bearing steel body is provided with a step ring groove at one end close to the rear end cover, and the aluminum alloy inlay is embedded in the step ring groove; the cross roller is installed on the inner ring of the bearing steel body, and the motor housing and the torque sensor outer ring are both connected to the bearing steel body.

[0013] By adopting the above technical solution, the outer ring of the bearing is composed of a bearing steel body and an aluminum alloy inlay, and the cross rollers, motor housing and torque sensor are all installed and connected to the bearing steel body. In this way, while ensuring the rigidity of the outer ring of the bearing, the weight of the outer ring of the bearing is reduced, that is, the weight of the module is further reduced, thereby improving the torque density of the module.

[0014] Furthermore, the motor shaft is a hollow structure, the rear end cover is connected to a wire tube which is integrally formed therewith and coaxial with the motor shaft, the end of the wire tube close to the rear end cover is an open structure, and the end away from the rear end cover passes through the motor shaft close to the front end cover.

[0015] By adopting the above technical solution, the wire tube facilitates the hollow wiring of the module, and the wire tube and the rear end cover are integrally formed, which is convenient for quick installation and use.

[0016] Furthermore, an output end encoder is installed at one end of the wire tube close to the front end cover, and a motor encoder is installed at one end of the motor shaft close to the front end cover. The output end encoder and the motor encoder are connected for communication feedback with the servo drive board, and the output end encoder is located between the front end cover and the motor encoder.

[0017] By adopting the above technical solution, the motor encoder and the output encoder can respectively obtain the angle information of the module input and output ends to form a closed-loop control. The dual encoders can obtain information more accurately, thereby improving the position control accuracy of the module.

[0018] Furthermore, when the servo drive board is built-in, it is arranged between the front end cover and the motor housing, the output end encoder and the motor encoder are respectively located on both sides of the servo drive board, and the servo drive board is provided with encoder reading heads of the output end encoder and the motor encoder.

[0019] By adopting the above technical solution, the servo driver board is built-in and the encoder reading head is installed on the servo driver board. The wiring of the module is the simplest and hollow wiring is convenient. The volume of the entire module can be smaller and the number of connectors is reduced, which can effectively reduce the failure rate and improve the reliability of the module.

[0020] Furthermore, when the servo drive board is externally arranged, it is arranged on a side of the front end cover away from the motor housing, and a reading head mounting plate is provided between the front end cover and the motor housing, and an encoder reading head of the output end encoder and the motor encoder is provided on the reading head mounting plate.

[0021] By adopting the above technical solution, the encoder reading head is installed on the reading head mounting plate, and the servo driver board is external, which can further shorten the length of the module and reduce the volume. The servo driver board generates heat when working, and placing it externally can reduce the heat of the module. In addition, the external servo driver board can also be configured with drivers with different functions according to different user needs, so as to achieve special machine for special purpose and achieve the effect of reducing costs and increasing efficiency.

[0022] Furthermore, a wear-resistant ring is provided between the output end encoder and the front end cover, and a mounting ring groove matching with the wear-resistant ring is provided on the front end cover.

[0023] By adopting the above technical solution, the wear-resistant ring can not only greatly reduce the friction resistance of the output end encoder, but also play a role in sealing against dust, water and oil leakage. In addition, the wire tube of the rear end cover is relatively long, and the harmonic reducer will be slightly deformed when subjected to force. The wear-resistant ring can also support the output end encoder to prevent the displacement of the output end encoder and affect the detection accuracy.

[0024] Furthermore, the output end encoder and the motor encoder are one or more of a magnetic encoder and a photoelectric encoder.

[0025] By adopting the above technical solutions, the photoelectric encoder has the characteristics of high precision, fast response, strong anti-interference ability, stable and reliable performance, etc. The magnetic encoder has excellent impact and vibration resistance, is smaller in size and lower in cost than the photoelectric encoder, and can be selected as the output encoder and motor encoder according to actual use requirements. The selection is flexible and has a wide range of applications.

[0026] Furthermore, deep groove ball bearings are respectively provided between the two ends of the motor housing and the two ends of the motor shaft, and the two deep groove ball bearings are respectively close to the wave generator and the front end cover.

[0027] By adopting the above technical solution, the two deep groove ball bearings jointly support the motor and the harmonic reducer to ensure the motion accuracy and stability of the entire module.

[0028] In summary, the utility model has the following beneficial effects:

[0029] 1. The fixed end rigid wheel, output end rigid wheel and the outer ring of the cross roller bearing of the harmonic reducer in the utility model and the corresponding cross rollers form two rows of cross roller bearings. The fixed end rigid wheel and the output end rigid wheel are respectively used as the inner rings of the two rows of cross roller bearings, and share the same outer ring of the bearing. The integrated design not only greatly improves the bending moment bearing capacity of the module, saves the weight and volume of the two bearing inner rings, making the entire module lighter and smaller, but also makes the axial length of the harmonic reducer only equivalent to the width of a cross roller bearing, greatly shortening the axial length of the harmonic reducer and realizing the ultra-thinness of the module;

[0030] 2. The fixed-end rigid wheel, output-end rigid wheel and cross-roller bearing of the harmonic speed reducer in the utility model are integrated into one design. Under the premise of ensuring the moment bearing capacity of the cross-roller bearing, the inner pitch circle radius of the fixed-end rigid wheel and the output-end rigid wheel is increased, and the outer pitch circle radius of the flexible wheel is increased, and the radius size of the inner and outer rings of the flexible bearing and the steel ball is increased, so that the torsional rigidity of the harmonic speed reducer can be increased by more than 30%, and the torsional density of the entire module can be greatly improved;

[0031] 3. In the utility model, the fixed end rigid wheel, the output end rigid wheel and the outer ring of the bearing constitute a double-row cross roller bearing. Under the premise of ensuring the moment bearing capacity of the cross roller bearing, the diameter and length of the cross roller can be reduced, and the number of cross rollers can be increased. While maintaining compactness, improving rigidity and rotation accuracy, the friction torque between the cross roller and the raceway is reduced, thereby reducing the friction resistance of the module, reducing the starting torque, and improving the motion control accuracy;

[0032] 4. The torque sensor in the utility model is connected with a double-row cross roller bearing, which can not only accurately measure the torque in the torsion direction of the module, but also offset the signal interference of the torque sensor caused by the bending deformation, thereby providing guarantee for the precision control of the module transmission;

[0033] 5. The outer ring of the bearing in the utility model is composed of a bearing steel body and an aluminum alloy inlay, which not only meets the rigidity of the module, but also further reduces the weight of the module and improves the torsional density of the module;

[0034] 6. The servo drive board in the utility model can be built-in or external, which is convenient for flexible design of the module and can obtain the best drive control effect in different robot application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of a high torque density double rigid wheel harmonic reducer joint module, which is used to reflect the built-in servo drive board;

[0036] Figure 2It is a schematic diagram of the overall structure of a high torque density double-rigid wheel harmonic reducer joint module, which is used to reflect the external servo drive board.

[0037] In the figure, 1, front end cover; 11, mounting ring groove; 2, rear end cover; 21, wire tube; 22, output end encoder; 3, wave generator; 31, flexible bearing; 32, flexible wheel; 33, output end rigid wheel; 34, fixed end rigid wheel; 35, bearing outer ring; 351, bearing steel body; 352, step ring groove; 353, aluminum alloy inlay; 36, cross roller; 4, motor housing; 41, stator; 42, rotor; 43, motor shaft; 44, motor encoder; 5, servo drive board; 6, torque sensor; 7, encoder reading head; 71, reading head mounting plate; 8, wear-resistant ring; 9, deep groove ball bearing. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] A high torque density double-gear harmonic reducer joint module, such as Figure 1 As shown, it includes a front cover 1 and a rear cover 2, and a harmonic reducer and a motor are arranged between the front cover 1 and the rear cover 2. The motor drives the harmonic reducer to work, and the basic structure and basic working principle of the motor and the harmonic reducer are the same as those in the prior art.

[0040] Specifically, Figure 1 As shown, the harmonic reducer includes a wave generator 3, a flexible bearing 31, a flexible wheel 32, an output end rigid wheel 33, a fixed end rigid wheel 34 and a cross roller bearing. The wave generator 3 is an elliptical cam. Two flexible bearings 31 are provided, which are mounted on the cam of the wave generator 3 and correspond to the output end rigid wheel 33 and the fixed end rigid wheel 34 respectively. The flexible wheel 32 is an annular straight cylinder and is sleeved outside the flexible bearing 31. The outer circle of the flexible wheel 32 is processed with external teeth, and the inner circles of the fixed end rigid wheel 34 and the output end rigid wheel 33 are processed with internal teeth. The external teeth of the flexible wheel 32 are meshed with the internal teeth of the output end rigid wheel 33 and the fixed end rigid wheel 34 at the same time. Among them, one of the output end rigid wheel 33 and the fixed end rigid wheel 34 has the same number of internal teeth as the number of external teeth of the flexible wheel 32, and the other has 1-4 more internal teeth than the number of external teeth of the flexible wheel 32, that is, one of the output end rigid wheel 33 and the fixed end rigid wheel 34 and the flexible wheel 32 has the same number of teeth meshing and no relative rotation, and the other has a different number of teeth meshing and maintains differential rotation.

[0041] like Figure 1As shown, in this embodiment, the cross roller bearing includes a bearing outer ring 35, and the output end rigid wheel 33 and the fixed end rigid wheel 34 are both used as the inner ring of the cross roller bearing, that is, the inner teeth of the output end rigid wheel 33 and the fixed end rigid wheel 34 are processed on the inner wall of the inner ring of the cross roller bearing. Cross rollers 36 are arranged between the outer walls of the output end rigid wheel 33 and the fixed end rigid wheel 34 and the inner wall of the bearing outer ring 35. The output end rigid wheel 33 and the corresponding cross rollers 36 and the bearing outer ring 35 form a row of cross roller bearings, and the fixed end rigid wheel 34 and the corresponding cross rollers 36 and the bearing outer ring 35 form a row of cross roller bearings, that is, the harmonic reducer has two rows of cross roller bearings with integrated rigid wheels and bearings.

[0042] like Figure 1 As shown, this not only greatly improves the bending moment bearing capacity of the module, saves the weight and volume of the two inner rings of the bearings, making the entire module lighter and smaller, but also makes the axial length of the harmonic reducer only equivalent to the width of a cross roller bearing, greatly shortening the axial length of the harmonic reducer and realizing the ultra-thinness of the module. In addition, under the premise of ensuring the bending moment bearing capacity of the cross roller bearing, not only can the inner tooth pitch circle radius of the fixed end rigid wheel 34 and the output end rigid wheel 33 be increased, but also the outer tooth pitch circle radius of the flexible wheel 32 can be increased, and the radius size of the inner and outer rings of the flexible bearing 31 and the steel ball can be increased, so that the torsional rigidity of the harmonic reducer can be increased by more than 30%, and the torsional density of the entire module can be greatly improved. It is also possible to reduce the diameter and length of the cross roller 36 and increase the number of the cross roller 36. While maintaining compactness, improving rigidity and rotation accuracy, the friction torque of the cross roller 36 and the raceway is reduced, thereby reducing the friction resistance of the module, reducing the starting torque, and improving the motion control accuracy.

[0043] Among them, Figure 1 As shown, the bearing outer ring 35 includes a bearing steel body 351 and an aluminum alloy inlay 353. A step ring groove 352 is provided at one end of the bearing steel body 351 close to the rear end cover 2. The aluminum alloy inlay 353 is embedded in the step ring groove 352. The cross roller 36 is installed on the inner ring of the bearing steel body 351. The motor housing 4 and the outer ring of the torque sensor 6 are both connected to the bearing steel body 351. In other words, the bearing outer ring 35 is composed of steel and aluminum alloy, so that the rigidity of the bearing outer ring 35 is ensured while reducing the weight of the bearing outer ring 35, that is, further reducing the weight of the module, thereby improving the torque density of the module.

[0044] like Figure 1As shown, in this embodiment, the motor includes a motor housing 4, a stator 41, a rotor 42 and a motor shaft 43, the stator 41 is fixedly installed in the motor housing 4, the rotor 42 is fixedly installed on the motor shaft 43, the wave generator 3 is fixedly connected to the motor shaft 43, the front cover 1 is connected to the motor housing 4, the rotor 42 is connected to a servo drive board 5, and the servo drive board 5 controls the rotor 42 to work, so that it drives the motor shaft 43 to drive the servo drive board 5 of the wave generator 3 to rotate. Among them, deep groove ball bearings 9 are respectively provided between the two ends of the motor housing 4 and the two ends of the motor shaft 43, and the two deep groove ball bearings 9 are respectively close to the wave generator 3 and the front cover 1. The two deep groove ball bearings 9 are used to jointly support the motor and the harmonic reducer to ensure the motion accuracy and stability of the module.

[0045] like Figure 1 As shown, the output end rigid wheel 33 is fixedly connected to the rear end cover 2, and the fixed end rigid wheel 34 is connected to a torque sensor 6 on the side away from the output end rigid wheel 33, and the torque sensor 6 is connected to the bearing outer ring 35 and the motor housing 4 at the same time, and the torque sensor 6 is connected to the servo drive board 5 for communication feedback. Specifically, the torque sensor 6 includes an inner ring, an outer ring and an elastic strain gauge, and the inner ring is connected to the fixed end rigid wheel 34, the outer ring is connected to the bearing outer ring 35 and the motor housing 4, and the elastic strain gauge is arranged between the inner ring and the outer ring.

[0046] like Figure 1 As shown, when the module is subjected to torque in the rotation direction and bending moment in the axial direction, the elastic strain gauge of the torque sensor 6 undergoes elastic deformation, and the magnitude of the torque applied to the torque sensor 6 can be calculated based on the measured deformation. When the output end rigid wheel 33 is subjected to external torque, the torque is transmitted to the flexible wheel 32, the flexible bearing 31 and the wave generator 3, and then the torque is transmitted to the fixed end rigid wheel 34 through the meshing of the flexible wheel 32 and the fixed end rigid wheel 34. The inner ring of the torque sensor 6 is connected to the fixed end rigid wheel 34, and the outer ring is connected to the bearing outer ring 35 and the motor housing 4, so that the harmonic reducer torque from the fixed end rigid wheel 34 can be detected through the deformation of the elastic strain gauge.

[0047] like Figure 1 As shown, the fixed end rigid wheel 34 is connected to the outer ring 35 of the cross roller bearing through the corresponding cross roller 36, so that the fixed end rigid wheel 34 and the outer ring 35 can rotate relative to each other, thereby ensuring that the torque sensor 6 can produce slight deformation. In addition, the torque sensor 6 is connected to the double-row cross roller bearing, which can not only accurately measure the torque in the torsion direction of the module, but also offset the signal interference caused by the bending deformation to the torque sensor 6, thereby providing guarantee for the precision control of the module transmission.

[0048] like Figure 1As shown, in the present embodiment, the motor shaft 43 is a hollow structure, and the rear end cover 2 is connected to a wire tube 21 which is integrally formed therewith and coaxial with the motor shaft 43. The end of the wire tube 21 close to the rear end cover 2 is an open structure, and the end away from the rear end cover 2 passes through the motor shaft 43 close to the front end cover 1. The setting of the wire tube 21 facilitates the hollow threading of the entire module.

[0049] like Figure 1 As shown, an output end encoder 22 is installed at one end of the wire tube 21 close to the front end cover 1, and a motor encoder 44 is installed at one end of the motor shaft 43 close to the front end cover 1. The motor encoder 44 and the output end encoder 22 can respectively obtain the angle information of the input end and the output end of the module to form a closed-loop control. The dual encoders obtain information more accurately, thereby improving the position control accuracy of the module. Specifically, the output end encoder 22 and the motor encoder 44 are connected to the servo drive board 5 for communication feedback, and the output end encoder 22 is located between the front end cover 1 and the motor encoder 44. Among them, the output end encoder 22 and the motor encoder 44 are one or more of a magnetic encoder or a photoelectric encoder, which can be flexibly selected according to actual use requirements.

[0050] In addition, if Figure 1 As shown, a wear-resistant ring 8 is provided between the output end encoder 22 and the front end cover 1, and a mounting ring groove 11 cooperating with the wear-resistant ring 8 is provided on the front end cover 1. The wear-resistant ring 8 can not only greatly reduce the friction resistance of the output end encoder 22, but also play a sealing role of dustproof, waterproof and oil leakage prevention. It can also support the output end encoder 22 when the harmonic reducer is slightly deformed by force, so as to avoid displacement of the output end encoder 22 and affect the detection accuracy.

[0051] In this embodiment, if Figure 1 As shown, the servo drive board 5 can be built-in between the front cover 1 and the motor housing 4. In this case, the output end encoder 22 and the motor encoder 44 are respectively located on both sides of the servo drive board 5, and the servo drive board 5 is provided with an encoder reading head 7 of the output end encoder 22 and the motor encoder 44. When the servo drive board 5 is built-in, the wiring of the module is most concise, and hollow wiring is convenient. The volume of the entire module can be smaller, and the number of connectors is reduced, which can effectively reduce the failure rate and improve the reliability of the module.

[0052] Of course, in other embodiments, such as Figure 2As shown, the servo drive board 5 can be externally mounted on the side of the front end cover 1 away from the motor housing 4. In this case, a reading head mounting plate 71 is provided between the front end cover 1 and the motor housing 4, and an encoder reading head 7 of the output end encoder 22 and the motor encoder 44 is provided on the reading head mounting plate 71. The servo drive board 5 is externally mounted to further shorten the length of the module and reduce the volume. The servo drive board 5 generates heat when working, and its external placement can reduce the heat generation of the module. Drivers with different functions can also be configured according to different user needs to achieve dedicated use of a dedicated machine and achieve the effect of reducing costs and increasing efficiency.

[0053] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A high torque density double rigid wheel harmonic reducer joint module, characterized in that: It comprises a front end cover (1) and a rear end cover (2), wherein a harmonic reducer and a motor are arranged between the front end cover (1) and the rear end cover (2); The harmonic reducer comprises a wave generator (3), a flexible bearing (31), a flexible wheel (32), an output end rigid wheel (33), a fixed end rigid wheel (34) and a cross roller bearing, wherein the flexible bearing (31) is mounted on a cam of the wave generator (3), the flexible wheel (32) is in the shape of an annular straight cylinder and is sleeved outside the flexible bearing (31), the outer teeth of the flexible wheel (32) mesh with the inner teeth of the output end rigid wheel (33) and the fixed end rigid wheel (34), and one meshes with the same number of teeth and the other meshes with a different number of teeth; the cross roller bearing comprises a bearing outer ring (35), the output end rigid wheel (33) and the fixed end rigid wheel (34) are both used as inner rings of the cross roller bearing, and cross rollers (36) are provided between the outer walls of the output end rigid wheel (33) and the fixed end rigid wheel (34) and the inner wall of the bearing outer ring (35); The motor comprises a motor housing (4), a stator (41), a rotor (42) and a motor shaft (43); the stator (41) is fixedly mounted in the motor housing (4); the rotor (42) is fixedly mounted on the motor shaft (43); the wave generator (3) is fixedly connected to the motor shaft (43); the front end cover (1) is connected to the motor housing (4); and the rotor (42) is connected to a servo drive plate (5) which drives the motor shaft (43) to drive the wave generator (3) to rotate; The output end rigid wheel (33) is fixedly connected to the rear end cover (2); a torque sensor (6) is connected to the side of the fixed end rigid wheel (34) away from the output end rigid wheel (33); the torque sensor (6) is connected to the servo drive board (5) for communication feedback; the torque sensor (6) comprises an inner ring, an outer ring and an elastic strain gauge, wherein the inner ring is connected to the fixed end rigid wheel (34), the outer ring is connected to the bearing outer ring (35) and the motor housing (4), and the elastic strain gauge is arranged between the inner ring and the outer ring.

2. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 1, characterized in that: The bearing outer ring (35) comprises a bearing steel body (351) and an aluminum alloy inlay (353); a step ring groove (352) is provided at one end of the bearing steel body (351) close to the rear end cover (2); the aluminum alloy inlay (353) is embedded in the step ring groove (352); the cross roller (36) is installed on the inner ring of the bearing steel body (351); and the outer rings of the motor housing (4) and the torque sensor (6) are both connected to the bearing steel body (351).

3. A high torque density dual-rigid-wheel harmonic reducer joint module according to claim 1 or 2, characterized in that: The motor shaft (43) is a hollow structure, and the rear end cover (2) is connected to a wire tube (21) which is integrally formed therewith and coaxial with the motor shaft (43); the end of the wire tube (21) close to the rear end cover (2) is an open structure, and the end away from the rear end cover (2) passes through the motor shaft (43) and is close to the front end cover (1).

4. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 3, characterized in that: An output end encoder (22) is installed at one end of the wire tube (21) close to the front end cover (1), and a motor encoder (44) is installed at one end of the motor shaft (43) close to the front end cover (1). The output end encoder (22) and the motor encoder (44) are connected to the servo drive board (5) for communication feedback, and the output end encoder (22) is located between the front end cover (1) and the motor encoder (44).

5. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 4, characterized in that: When the servo drive board (5) is built in, it is arranged between the front end cover (1) and the motor housing (4); the output end encoder (22) and the motor encoder (44) are respectively located on both sides of the servo drive board (5); and the servo drive board (5) is provided with encoder reading heads (7) of the output end encoder (22) and the motor encoder (44).

6. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 4, characterized in that: When the servo drive board (5) is externally arranged, it is arranged on a side of the front end cover (1) away from the motor housing (4); a reading head mounting plate (71) is arranged between the front end cover (1) and the motor housing (4); and an encoder reading head (7) of an output end encoder (22) and a motor encoder (44) is arranged on the reading head mounting plate (71).

7. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 4, characterized in that: A wear-resistant ring (8) is provided between the output end encoder (22) and the front end cover (1), and a mounting ring groove (11) matching with the wear-resistant ring (8) is provided on the front end cover (1).

8. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 4, characterized in that: The output end encoder (22) and the motor encoder (44) are one or more of a magnetic encoder and a photoelectric encoder.

9. The high torque density dual-rigid-wheel harmonic reducer joint module according to claim 1, characterized in that: Deep groove ball bearings (9) are respectively provided between the two ends of the motor housing (4) and the two ends of the motor shaft (43), and the two deep groove ball bearings (9) are respectively close to the wave generator (3) and the front end cover (1).

Images