A flat wire motor double planetary reduction joint module

Abstract

This invention discloses a flat wire motor dual planetary reducer joint module, belonging to the field of joint modules. The technical scope includes a dual-braided integrated electronic control component, a flat wire motor component, and an NW reducer component. These components together form the joint module. The dual-braided integrated electronic control component forms a fully closed-loop control link, regulating the movement position and speed of the joint module to ensure the accuracy and dynamic response of the robot's motion. This invention uses a frameless torque flat wire motor, which has a high slot fill factor and increased torque density, resulting in greater output torque for the same volume. It employs an NW-type dual planetary reducer, achieving a large reduction ratio within a single stage. The compact structure and short axial dimension make it suitable for integrated joints. A dual-encoder scheme, consisting of an encoder and a linear Hall effect sensor, can compensate for reducer backlash and transmission errors in real time, resulting in higher positioning accuracy and more stable control.

Description

Technical Field

[0001] This invention relates to the field of flat wire motor technology for robots, specifically a flat wire motor dual planetary reduction joint module. Background Technology

[0002] As robotics technology develops towards intelligence, lightweighting, and high dynamism, the joint drive unit, as the core execution component of a robot, directly affects the overall motion capability, load capacity, and application range of the robot. Humanoid robots, quadruped robots, and collaborative robots are placing increasingly stringent demands on the miniaturization, lightweighting, high power density, and high torque density of joint modules. Robot joints need to achieve continuous operation capability and short-term burst capability within a limited space, which poses a significant challenge to the overall performance of drive motors and reducers.

[0003] In existing robot joint modules, most use frameless torque motors with round wire windings. The slot fill factor is low, resulting in low torque density and low efficiency. The output torque is limited for the same volume. To increase the torque, the motor size needs to be increased, which is not conducive to the miniaturization of the joint. Meanwhile, the reduction module usually uses a harmonic reducer or a common planetary reducer. Although the harmonic reducer has a large reduction ratio, the flexible wheel is prone to fatigue damage and has a limited lifespan. It also requires extremely high machining accuracy. The common planetary reducer has a relatively small reduction ratio. If the reduction ratio is to be increased, the number of stages needs to be increased, which results in a longer structure and a larger axial dimension, making it unsuitable for compact joints. Most of them use a single encoder, which only detects the position at the motor end and lacks direct feedback at the output end. This limits the control accuracy and cannot compensate for the backlash of the reducer and transmission error. The matching scheme between the Hall sensor and the magnetic ring is not perfect, and the signal acquisition stability is poor.

[0004] Therefore, we propose a flat wire motor double planetary reduction joint module to solve the problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a flat wire motor dual planetary reduction joint module to solve the problems mentioned in the background art, such as low torque density, low efficiency, relatively small reduction ratio of reducer, inability to compensate for reducer backlash and transmission error, imperfect matching scheme of Hall sensor and magnetic ring, and poor signal acquisition stability of existing robot joint modules on the market.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a flat wire motor dual planetary reduction joint module, comprising a dual-braided integrated electronic control component, a flat wire motor component, and an NW reducer component. The dual-braided integrated electronic control component, the flat wire motor component, and the NW reducer component together constitute the joint module. The dual-braided integrated electronic control component is used to form a fully closed-loop control link to regulate the motion position and speed of the joint module, ensuring the accuracy and dynamic response of the robot motion. The flat wire motor component is used to improve the slot fill factor and the driving capability of torque and dynamic response. The NW reducer component converts the high-speed, low-torque output of the flat wire motor component into low-speed, high-torque output to meet the requirements of robot joints in heavy-load and high-precision positioning scenarios.

[0007] Preferably, the dual-encoder integrated electronic control assembly includes a top cover, which is mounted on the upper cover. The top cover passes through the middle of the electronic control board and is connected to a mounting plate. A Hall plate and an encoder are mounted on the mounting plate, and multiple mounting positions for the Hall plate and encoder are provided on the mounting plate.

[0008] Preferably, the flat wire motor assembly includes a stator core, which is installed inside the motor housing. A motor rotor is provided inside the stator core, and a magnetic ring is provided in the motor rotor. An induction magnet is provided in the middle of the motor rotor, and the induction magnet is located at the upper end of the intermediate shaft. A rotary seat is connected to the lower end of the intermediate shaft.

[0009] Preferably, the NW reducer assembly includes a double planetary gear set, which is composed of a large planetary gear and a small planetary gear set. The small gear is fixed to the bottom of the large gear. The small gear of the double planetary gear set is meshed with the inner side of an internal gear ring fixed in the reducer housing. An end cover is installed on the inner side of the reducer housing, and a sun gear bearing is installed at the lower end of the end cover. An output disc is connected to the reducer housing via an output disc bearing. A return bearing is installed at the lower center of the output disc, and a bottom cover is connected to the bottom of the reducer housing.

[0010] Preferably, the outer diameter of the stator core is The stator inner diameter is The length of the iron core is The width of the slot is The air gap of the motor is The maximum output torque value is The number of teeth on the internal gear ring is The number of teeth on the sun gear is The number of teeth of the large and small gears of the double planetary gear (14) are respectively , Its characteristics satisfy: .

[0011] Preferably, the flat wire motor assembly adopts a frameless torque flat wire motor with S motor slots and P motor poles, and its characteristics satisfy: P=S±2, P=S±4, and satisfy GCD(S,P)=m, GCD(S,P)=2m, where m is a multiple of 2.

[0012] Preferably, the dual-encoder integrated electronic control component adopts a dual-encoder scheme consisting of an encoder and a linear Hall effect sensor. The encoder has a magnetic encoder chip at its center, a pair of pole magnets in the middle that work with a magnetic induction chip, and a linear Hall effect sensor on the Hall effect sensor board that is in close contact with a magnetic ring. The number of poles of the magnetic ring is the same as the number of poles of the motor. The magnetic ring and the linear Hall effect sensor work together. The magnets are connected to the output end and work with the magnetic induction chip to sense the input. The magnetic ring is connected to the motor rotor and works with the linear Hall effect sensor to generate the input signal, thus realizing a dual encoder that senses both the input and output ends.

[0013] Preferably, the motor rotor has a reserved gap, which is used to provide the allowable axial movement of the motor rotor. In the middle of the output disk, there is an adjusting washer between the return seat and the output disk bearing to realize the axial movement limit of the motor rotor.

[0014] Preferably, the sun gear is fixed to the motor rotor as a whole, and the motor rotor and the sun gear rotate simultaneously to drive the large gear of the double planetary gear to rotate. The large and small gears of the double planetary gear are both mounted on the output disk for rotating at the same speed. The double planetary gear drives the output disk to revolve. The return seat is fixed to the output disk, the intermediate shaft is fixed on the output disk, and the output disk is located at the bottom of the joint module, serving as a direct connecting part for external transmission.

[0015] Preferably, the output disc is connected to the inner ring of the output disc bearing with an interference fit, the end cover is connected to the outer ring of the output disc bearing with a clearance fit, and the lower end face of the reducer housing presses against the upper end face of the output disc bearing to complete the fixing of the output disc bearing.

[0016] Compared with the prior art, the present invention adopts a frameless torque flat wire motor with high slot fill factor and improved torque density, resulting in greater output torque in the same volume, which is conducive to joint weight reduction. It adopts NW type double planetary reducer to achieve a large reduction ratio in a single stage, with compact structure and short axial dimension, which is suitable for integrated joints. The encoder and linear Hall effect form a dual encoder scheme, which can compensate for reducer backlash and transmission error in real time, resulting in higher positioning accuracy and more stable control. 1. The stator core uses flat wire windings, resulting in high slot fill factor; it features a frameless design and is directly integrated into the housing. The frameless structure eliminates the extra weight of traditional motor housings, and the axial length of the motor assembly is shorter, making it easier to directly interface with the reducer. The magnetic ring, together with the linear Hall effect, provides the input position signal, and the inductive magnet, together with the encoder, provides the output position signal. The combination of the two achieves full closed-loop control, which can compensate for errors such as reducer backlash and gear wear in real time. 2. A large reduction ratio can be achieved through a single-stage transmission without the need for multi-stage series transmission. The axial dimension is shorter than that of harmonic reducers or two-stage planetary reducers. The double planetary gears mesh with the internal gear ring simultaneously, resulting in uniform load distribution. Vibration and noise are lower than those of ordinary planetary reducers. Since the internal gear ring is fixed, the planetary gears directly drive the output disc during revolution, resulting in high transmission efficiency and no flexible gear fatigue problem. Its lifespan is much longer than that of harmonic reducers. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the front cross-sectional structure of the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of the stator core of the present invention; Figure 3 This is a schematic diagram of the motor housing structure of the present invention; Figure 4 This is a schematic diagram of the motor housing and double planetary gear structure of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the double planetary gear and internal gear ring of the present invention; Figure 6 This is a top view schematic diagram of the double planetary gear and internal gear ring of the present invention; Figure 7 This is a schematic diagram of the Hall plate structure of the present invention; Figure 8 This is a schematic diagram of the stator core and motor rotor structure of the present invention; Figure 9 This is a schematic diagram of the lifting plate and Hall plate structure of the present invention; Figure 10 This is a schematic diagram of the output disk bearing and output disk structure of the present invention; Figure 11 This is a schematic diagram showing the effect of current on torque in the present invention and the prior art.

[0018] In the diagram: 1. Top cover; 2. Electrical control board; 3. Lifting plate; 4. Hall plate; 5. Encoder; 6. Top cover; 7. Stator core; 8. Magnetic ring; 9. Motor rotor; 10. Induction magnet; 11. Intermediate shaft; 12. Sun gear; 13. Motor housing; 14. Double planetary gear; 15. Internal gear ring; 16. End cover; 17. Sun gear bearing; 18. Reducer housing; 19. Output disc bearing; 20. Output disc; 21. Return seat; 22. Bottom cover. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: Please refer to Figures 1-11 In existing robot joint modules, frameless torque motors with round wire windings are mostly used. The slot fill factor is low, resulting in low torque density and low efficiency. The output torque is limited for the same volume. To increase the torque, the motor size needs to be increased, which is not conducive to the miniaturization of the joint. At the same time, the reduction module usually uses harmonic reducers or ordinary planetary reducers. Although the harmonic reducer has a large reduction ratio, the flexible wheel is prone to fatigue damage and has a limited lifespan. It also requires extremely high machining accuracy. Ordinary planetary reducers have a relatively small reduction ratio. To increase the reduction ratio, the number of stages needs to be increased, resulting in a longer structure and a large axial dimension, which is not suitable for compact joints. Single encoders are mostly used, which only detect the position at the motor end and lack direct feedback at the output end. The control accuracy is limited and cannot compensate for reducer backlash and transmission error. The matching scheme of Hall sensor and magnetic ring is not perfect, and the signal acquisition stability is poor. In order to solve this technical problem, the following technical contents are disclosed in this embodiment. A flat wire motor dual planetary reduction joint module includes a dual-braid integrated electronic control component, a flat wire motor component, and an NW reducer component. The dual-braid integrated electronic control component, the flat wire motor component, and the NW reducer component together form the joint module. The dual-braid integrated electronic control component is used to form a fully closed-loop control link to regulate the motion position and speed of the joint module, ensuring the accuracy and dynamic response of the robot motion. The flat wire motor component is used to improve the slot fill factor and the driving capability of torque and dynamic response. The NW reducer component converts the high-speed, low-torque output of the flat wire motor component into low-speed, high-torque to meet the requirements of robot joints in heavy-load and high-precision positioning scenarios.

[0021] The dual-branch integrated electronic control assembly includes a top cover 1, which is mounted on an upper cover 6. The top cover 1 passes through the middle of the electronic control board 2 and is connected to a mounting plate 3. A Hall plate 4 and an encoder 5 are mounted on the mounting plate 3. Multiple mounting positions for the Hall plates 4 and encoders 5 are provided on the mounting plate 3. The flat wire motor assembly includes a stator core 7, which is installed inside the motor housing 13. A motor rotor 9 is located inside the stator core 7, and a magnetic ring 8 is located within the motor rotor 9. An induction magnet 10 is located in the middle of the motor rotor 9, and the induction magnet 10 is located at the upper end of an intermediate shaft 11. A sun gear 12 is keyed to the intermediate shaft 11. The lower end is connected to a rotary seat 21. The NW reducer assembly includes a double planetary gear 14, which is composed of a large gear and a small gear. The small gear is fixed to the bottom of the large gear. The small gear of the double planetary gear 14 is meshed with the inner side of the internal gear ring 15 fixed in the reducer housing 18. An end cover 16 is installed on the inner side of the reducer housing 18, and a sun gear bearing 17 is installed at the lower end of the end cover 16. An output disc 20 is connected to the reducer housing 18 through an output disc bearing 19. A return seat 21 is installed at the lower center of the output disc 20, and a bottom cover 22 is connected to the bottom of the reducer housing 18. The outer diameter of the stator core 7 is... The stator inner diameter is The length of the iron core is The width of the slot is The air gap of the motor is The maximum output torque value is The number of teeth on the internal gear ring 15 is The number of teeth on the sun gear 12 is The number of teeth on the double planetary gear 14 large gear and small gear are respectively , Its characteristics satisfy: The flat wire motor assembly adopts a frameless torque flat wire motor with S slots and P poles. Its characteristics satisfy: P=S±2, P=S±4, and satisfy GCDS, P=m, GCDS, P=2m, where m is a multiple of 2. The dual-encoder integrated electronic control assembly adopts an encoder 5 and a linear Hall effect sensor to form a dual encoder scheme. The center of the encoder 5 is a magnetic encoder chip, and the middle pair of pole magnets cooperate with the magnetic induction chip. The linear Hall effect sensor on the Hall plate 4 is close to the magnetic ring 8. The number of poles of the magnetic ring 8 is the same as the number of poles of the motor. The magnetic ring 8 is used in conjunction with the linear Hall effect sensor. The magnet is connected to the output end and cooperates with the magnetic induction chip to generate an output signal. The magnetic ring 8 is connected to the motor rotor 9 and cooperates with the linear Hall effect sensor to generate an input signal, realizing a dual encoder with sensing at both the input and output ends.

[0022] The external controller sends motion commands to the control board 2. The linear Hall effect sensor and encoder 5 on the hoisting plate 3 detect the position of the magnetic ring 8 on the motor rotor 9 and the position of the output induction magnet 10, respectively, forming a double closed-loop feedback. According to the commands and feedback signals, the control board 2 drives the flat wire winding in the stator core 7 to be energized, generating a rotating magnetic field. The motor rotor 9 rotates synchronously with the magnetic ring 8. The motor rotor 9 is fixed to the sun gear 12. The sun gear 12 rotates with the motor rotor 9, driving the large gear on the double planetary gear 14. The small gear of the double planetary gear 14 meshes with the fixed internal gear ring 15. Since the internal gear ring 15 is fixed, the double planetary gear 14 revolves while rotating on its own axis, driving the output disk 20 to rotate, achieving a large reduction ratio output. The output disk 20 is directly connected to the external load as the bottom of the module, outputting the power after reduction and torque increase. At the same time, the intermediate shaft 11 passes through the sun gear 12 and is fixed to the output disk 20 through the bottom cover 22 to ensure structural stability.

[0023] The motor rotor 9 has a reserved clearance, which is used to provide the allowable axial movement of the motor rotor 9. In the middle of the output disk 20, there is an adjusting washer between the return seat 21 and the output disk bearing 19 to realize the axial movement limit of the motor rotor 9.

[0024] A controllable axial movement clearance is reserved between the motor rotor 9 and the output disk 20, and the clearance is precisely limited by adjusting the washers. This prevents jamming during thermal expansion, absorbs machining and assembly tolerances, protects the stable clearance between the magnetic ring 8 and the Hall sensor, maintains full tooth width meshing of the gears, buffers axial impact to protect the bearings, and supports on-site replacement of washers for clearance adjustment. This significantly improves the reliability, assembly efficiency and service life of the module.

[0025] The sun gear 12 is fixed to the motor rotor 9 as a whole. The motor rotor 9 and the sun gear 12 rotate simultaneously to drive the large gear of the double planetary gear 14 to rotate. The large and small gears of the double planetary gear 14 are both mounted on the output disk 20 for rotating at the same speed. The double planetary gear 14 drives the output disk 20 to revolve. The return seat 21 is fixed to the output disk 20. The intermediate shaft 11 is fixed on the output disk 20. The output disk 20 is located at the bottom of the joint module and serves as a direct connector for external transmission. The output disk 20 is connected to the inner ring of the output disk bearing 19 with an interference fit. The end cover 16 is connected to the outer ring of the output disk bearing 19 with a clearance fit. The lower end face of the reducer housing 18 presses against the upper end face of the output disk bearing 19 to complete the fixing of the output disk bearing 19.

[0026] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0027] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flat wire motor double planetary reduction joint module, comprising a double-braided integrated electronic control assembly, a flat wire motor assembly, and an NW reducer assembly, characterized in that: The dual-braided integrated electronic control component, the flat wire motor component, and the NW reducer component together form the joint module. The dual-braided integrated electronic control component is used to form a fully closed-loop control link to regulate the movement position and speed of the joint module, ensuring the accuracy and dynamic response of the robot's movement. The flat wire motor component is used to improve the slot fill factor and the driving capability of torque and dynamic response. The NW reducer component converts the high-speed, low-torque output of the flat wire motor component into low-speed, high-torque output to meet the requirements of the robot joint in heavy-load and high-precision positioning scenarios.

2. The flat wire motor double planetary reduction joint module according to claim 1, characterized in that: The flat wire motor assembly includes a stator core (7), which is installed inside the motor housing (13). A motor rotor (9) is provided on the inner side of the stator core (7), and a magnetic ring (8) is provided in the motor rotor (9). An induction magnet (10) is provided in the middle of the motor rotor (9), and the induction magnet (10) is located at the upper end of the intermediate shaft (11). A sun gear (12) is keyed to the intermediate shaft (11), and a rotary seat (21) is connected to the lower end of the intermediate shaft (11).

3. The flat wire motor double planetary reduction joint module according to claim 2, characterized in that: The NW reducer assembly includes a double planetary gear (14), which is composed of a large gear and a small gear. The small gear is fixed to the bottom of the large gear. The small gear of the double planetary gear (14) is meshed with the inner side of the internal gear ring (15) fixed in the reducer housing (18). An end cover (16) is installed on the inner side of the reducer housing (18), and a sun gear bearing (17) is installed at the lower end of the end cover (16). An output disc (20) is connected to the reducer housing (18) through an output disc bearing (19). A return seat (21) is installed at the lower middle part of the output disc (20), and a bottom cover (22) is connected to the bottom of the reducer housing (18).

4. A flat wire motor double planetary reduction joint module according to claim 3, characterized in that: The outer diameter of the stator core (7) is The stator inner diameter is The length of the iron core is The width of the slot is The air gap of the motor is The maximum output torque value is The number of teeth on the internal gear ring (15) is The number of teeth on the sun gear (12) is The number of teeth of the large and small gears of the double planetary gear (14) are respectively , ; Its characteristics satisfy: 1 * g ∗ D 1 / D i 1 2 ∗ l e f / s l o t 1 ∗ 1 + Z b ∗ Z g / Z f * Z a < T 2 < 3 ∗ g ∗ D 1 / D i 1 2 ∗ l e f / s l o t 1 ∗ 1 + Z b * Z g / Z f * Z a .

5. A flat wire motor double planetary reduction joint module according to claim 4, characterized in that: The flat wire motor assembly adopts a frameless torque flat wire motor with S motor slots and P motor poles. Its characteristics satisfy: P=S±2, P=S±4, and satisfy GCD(S,P)=m, GCD(S,P)=2m, where m is a multiple of 2.

6. A flat wire motor double planetary reduction joint module according to claim 5, characterized in that: The dual-encoder integrated electronic control assembly includes a top cover (1), and the top cover (1) is installed on the upper cover (6). The top cover (1) passes through the middle of the electronic control board (2) and is connected to a lifting plate (3). A Hall plate (4) and an encoder (5) are installed on the lifting plate (3). Multiple mounting positions for Hall plates (4) and encoders (5) are provided on the lifting plate (3).

7. A flat wire motor double planetary reduction joint module according to claim 6, characterized in that: The dual-encoder integrated electronic control component adopts an encoder (5) and a linear Hall to form a dual encoder scheme. The center of the encoder (5) is a magnetic encoder chip, and the middle pair of pole magnets and magnetic induction chip work together. The linear Hall on the Hall plate (4) is close to the magnetic ring (8). The number of poles of the magnetic ring (8) is the same as the number of poles of the motor. The magnetic ring (8) works with the linear Hall. The magnet is connected to the output end and works with the magnetic induction chip to generate input. The magnetic ring (8) is connected to the motor rotor (9) and works with the linear Hall to generate input signal, realizing a dual encoder that senses both the input end and the output end.

8. A flat wire motor double planetary reduction joint module according to claim 7, characterized in that: The motor rotor (9) has a reserved gap, which is used to provide the allowable axial movement of the motor rotor (9). In the middle of the output disk (20), there is an adjusting washer between the return seat (21) and the output disk bearing (19) to realize the axial movement limit of the motor rotor (9).

9. A flat wire motor double planetary reduction joint module according to claim 8, characterized in that: The sun gear (12) is fixed to the motor rotor (9) as a whole. The motor rotor (9) and the sun gear (12) rotate simultaneously to drive the large gear of the double planetary gear (14) to rotate. The large and small gears of the double planetary gear (14) are both mounted on the output disk (20) for rotating at the same speed. The double planetary gear (14) drives the output disk (20) to revolve. The return seat (21) is fixed to the output disk (20). The intermediate shaft (11) is fixed on the output disk (20). The output disk (20) is located at the bottom of the joint module and serves as a direct connecting part for external transmission.

10. A flat wire motor double planetary reduction joint module according to claim 9, characterized in that: The output disc (20) is connected to the inner ring of the output disc bearing (19) by an interference fit, and the end cover (16) is connected to the outer ring of the output disc bearing (19) by a clearance fit. The lower end face of the reducer housing (18) presses against the upper end face of the output disc bearing (19) to complete the fixing of the output disc bearing (19).

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