High-safety and high-precision joint of medical mechanical arm
By adopting a single motor dual reducer structure and a built-in servo motor in the three-axis joint of the medical robot arm, the problems of insufficient joint load capacity, stiffness, safety and control accuracy in the prior art are solved, and a joint structure with high safety, high precision and small volume are achieved.
Patent Information
- Application Number
- CN202421349734.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-06-13
AI Technical Summary
The three-axis joints of existing medical robotic arms have shortcomings in load capacity, stiffness, safety and control accuracy, and are large in size and high in working noise.
The single-motor dual reducer structure is adopted, and the two RV reducers are driven by the servo motor to work simultaneously to achieve large load and high stiffness. At the same time, through the cooperation of the built-in servo motor and multiple sets of brakes and encoders, the joint volume is reduced, noise is reduced, and safety and control accuracy are improved.
A high safety, high precision and small volume joint structure is achieved, which improves the load capacity and stiffness of the medical robotic arm, while reducing noise and maintenance frequency.
Smart Images
Figure CN222627824U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of medical robots, in particular to a high-safety and high-precision joint of a medical robot arm. Background Art
[0002] Radiotherapy is one of the most important means of tumor treatment. Through the coordination of medical electron linear accelerator and treatment bed, the patient's posture is adjusted, and the active tumor target area such as the chest and abdominal cavity is accurately aligned with the radiation to accurately kill cancer cells. During the treatment process, the treatment bed is driven by the robotic arm to rotate, calm and lift to achieve accurate positioning of the patient's tumor target area. In the mechanical arm that relies on the three-axis joint and the five-axis joint to coordinate the pitch to achieve the vertical height adjustment of the treatment bed, the three-axis joint set between the rotating arm and the pitch arm is crucial, and its load capacity, stiffness, safety, control accuracy, etc. have extremely high requirements, and at the same time, the volume and working noise of the three-axis joint should be reduced as much as possible. Utility Model Content
[0003] The purpose of the utility model is to provide a high-safety and high-precision joint for a medical robotic arm, which achieves large load and high rigidity through a single-motor dual-reducer structure, and the single motor and dual-reducer are arranged in parallel, while the servo motor is built-in, which effectively reduces the axial length of the joint, achieves small size, compact structure and low noise, and multiple sets of brakes and encoders cooperate to achieve high safety and closed-loop control, thereby improving the control accuracy of the joint.
[0004] The above technical objectives of the utility model are achieved through the following technical solutions:
[0005] A high-safety and high-precision joint of a medical robot arm comprises an input shaft, two RV reducers and a servo motor, wherein the axis of the input shaft is arranged horizontally, the two RV reducers are symmetrically mounted at both ends of the input shaft and are arranged coaxially with the input shaft, the two ends of the input shaft pass through the middle holes of the two RV reducers and mesh with the planetary gears of the two RV reducers for transmission, the fixed ends of the two RV reducers are far away from each other and connected to the rotating arm, and the output ends are close to each other and connected to the pitch arm; the servo motor is arranged on the outer peripheral side of the two RV reducers and is built into the pitch arm, the output shaft of the servo motor is parallel to the input shaft and a transmission assembly is arranged between the servo motor and the input shaft, and a brake assembly is arranged on the servo motor, the transmission assembly, the input shaft and the input end of the RV reducer far away from the transmission assembly.
[0006] By adopting the above technical solution, the servo motor drives the input shaft to rotate through the transmission assembly when working. The input shaft drives the two RV reducers to work synchronously under the gear meshing action with the two RV reducer planetary gears, thereby driving the pitch arm to perform pitching action. Using a servo motor to drive two RV reducers to work synchronously can output greater torque, increase the load and stiffness of the joint, and the two RV reducers are driven by the same input shaft, which effectively ensures coaxiality and improves the synchronization accuracy of the two RV reducers. It also enables the joint to have three-stage reduction, increases the reduction ratio range, and makes the transmission safer and more reliable. The servo motor is set on one side of the input shaft and located in the pitch arm, realizing the built-in servo motor. Compared with the coaxial setting, it can not only greatly reduce the axial length of the joint, achieve a small size and compact structure, but also avoid the servo motor from being exposed and making a loud noise. At the same time, it can be wired internally to meet the closed requirements of high-demand application scenarios, reduce interference from environmental factors, and improve safety. The servo motor, transmission assembly, input shaft and the input end of the RV reducer far away from the transmission assembly are all equipped with brake assemblies. As long as one of the multiple sets of brake assemblies can work normally, multiple sets of brake assemblies can realize multi-position brake control from the input end, primary transmission, secondary transmission and output end, which greatly improves the safety of the joint and reduces the frequency of joint maintenance.
[0007] Furthermore, the brake assembly arranged on the servo motor includes a first brake and a first encoder arranged on the side of the servo motor away from its output shaft, the first brake and the first encoder are arranged coaxially with the output shaft of the servo motor, and the first brake is located between the first encoder and the output shaft of the servo motor.
[0008] By adopting the above technical solution, the first encoder detects the movement state of the servo motor in real time. When the detection result feedback shows that the servo motor fails, the communication feedback controls the first brake to brake the servo motor, thereby achieving safety control from the input end.
[0009] Furthermore, the transmission assembly includes a driving gear and a driven gear that mesh with each other, the driving gear is detachably fixedly mounted on one end of the servo motor output shaft and is coaxially arranged therewith, and the driven gear is detachably mounted on the input shaft and is coaxially arranged therewith; the brake assembly arranged on the transmission assembly includes a second brake and a second encoder arranged on the side of the driving gear away from the servo motor, the second brake and the second encoder are coaxially arranged with the driving gear, and the second brake is arranged between the second encoder and the driving gear.
[0010] By adopting the above technical solution, the servo motor drives the driving gear to rotate, and under the meshing action of the driving gear and the driven gear, the input shaft is driven to rotate, so as to drive the two RV reducers to rotate synchronously. The driving gear and the driven gear are respectively detachably fixed on the output shaft and the input shaft of the servo motor. Different driving gears and driven gears can be replaced according to actual use requirements to adjust the first-stage transmission reduction ratio. The second encoder detects the movement state of the driving gear in real time. When the detection result feedback shows that the driving gear rotation fails, the communication feedback controls the second brake to brake the driving gear, and performs safety control from the first-stage transmission.
[0011] Furthermore, the brake assembly on the input shaft includes a third brake and a third encoder arranged at one end of the input shaft, the third brake and the third encoder are coaxially arranged with the input shaft, and the third encoder is located on a side of the third brake away from the input shaft.
[0012] By adopting the above technical solution, the third encoder detects the movement state of the input shaft in real time. When the detection result feedback shows that the input shaft movement fails, the communication feedback controls the third brake to brake the input shaft and perform safety control from the secondary transmission.
[0013] Furthermore, a fourth brake and a fourth encoder are provided at one end of the input shaft away from the third brake. The fourth brake and the fourth encoder are coaxially arranged with the input shaft, and the fourth encoder is located on a side of the fourth brake away from the input shaft.
[0014] By adopting the above technical solution, the fourth encoder detects the motion state of the input shaft in real time. When the detection result feedbacks that the input shaft motion fails, the communication feedback controls the fourth brake to work, brake the input shaft, and perform safety control from the secondary transmission. Brake components are respectively set at both ends of the input shaft to improve the accuracy of monitoring the motion state of the input shaft, ensure the braking effect of the input shaft, and further improve safety.
[0015] Furthermore, the brake assembly at the output end of the RV reducer includes a fifth brake and a fifth encoder coaxially arranged with the input shaft, the fifth brake and the fifth encoder are installed on the output end of the RV reducer, and the fifth encoder is located on the side of the fifth brake close to the transmission assembly.
[0016] By adopting the above technical solution, the fifth encoder detects the movement state of the RV reducer output end in real time. When the detection result feedback shows that there is a failure in the movement of the RV reducer output end, the communication feedback controls the fifth brake to brake the RV reducer output end and perform safety control from the output end.
[0017] Furthermore, the first brake, the second brake, the third brake, the fourth brake and the fifth brake are all electromagnetic brakes and are respectively connected to voltage sensors, the first encoder, the second encoder, the third encoder, the fourth encoder and the fifth encoder are all communication feedback connected, and a closed-loop control is formed between the first encoder and the fifth encoder.
[0018] By adopting the above technical solution, the first brake, the second brake, the third brake, the fourth brake and the fifth brake are all electromagnetic brakes, and the voltage sensor is used to monitor the voltage of the corresponding brake to determine whether each brake is working normally, to understand the working condition of each brake, and to promptly repair multiple brake failures. Among them, the first encoder, the second encoder, the third encoder, the fourth encoder and the fifth encoder are all connected by communication feedback, and a closed-loop control is formed between the first encoder and the fifth encoder to determine the multi-stage transmission situation, realize the closed-loop control between the input end and the output end, and improve the control accuracy of the joint.
[0019] Furthermore, raised reinforcing step rings are provided on both sides of the driving gear, the reinforcing step rings are coaxially arranged with the driving gear, and the second brake is installed on the reinforcing step ring on the side away from the servo motor.
[0020] By adopting the above technical solution, reinforcing step rings are arranged on both sides of the driving gear to enhance the rigidity of the gear, improve the service life of the driving gear, ensure the primary transmission efficiency, and facilitate the installation of the second brake and the second encoder. The structure is simple and the effect is obvious.
[0021] Furthermore, mounting bearings are installed between both sides of the driven gear and the input shaft, first support bearings are installed between both ends of the input shaft and the fixed ends of the two RV reducers, and the two first support bearings are located between the third brake and the fourth brake, and second support bearings are installed between the input shaft and the output ends of the two RV reducers.
[0022] By adopting the above technical solution, the installation bearing ensures the installation and transmission accuracy between the driven gear and the input shaft, the first support bearing and the second support bearing ensure the installation and transmission accuracy between the input shaft and the two RV reducers, ensure the ability to transmit torque, reduce wear, and increase service life. The structure is simple and the effect is obvious.
[0023] Furthermore, the input shaft is provided with an increasing diameter shaft located between the driven gear and the RV reduction gear away from the driving gear. The increasing diameter shaft is coaxially arranged with the input shaft and formed integrally. A third support bearing is provided between the outer wall of one end of the increasing diameter shaft away from the driven gear and the pitch arm.
[0024] By adopting the above technical solution, the increasing diameter shaft coaxially arranged and integrally formed with the input shaft enables the input shaft as a whole to have different diameter sections, which not only ensures that the central hole diameter of the RV reducer does not need to be changed when the input shaft is connected to the two RV reducers, and obtains a small volume of the RV reducer, i.e., the joint, but also ensures the overall strength of the input shaft, improves its torque transmission capacity and service life. Among them, the third support bearing further realizes the support positioning of the input shaft, ensuring the working stability and torque transmission effect of the input shaft.
[0025] In summary, the utility model has the following beneficial effects:
[0026] 1. The utility model joint is provided with an input shaft, two RV reducers and a servo motor. A servo motor is used to drive two RV reducers to work synchronously, which can output a larger torque and improve the load and stiffness of the joint. The two RV reducers are driven by the same input shaft, which effectively ensures the coaxiality and improves the synchronization accuracy of the two RV reducers. Moreover, the servo motor and the input shaft are driven by a transmission assembly, so that the joint has three-stage reduction, the reduction ratio range is increased, and the transmission is safer and more reliable.
[0027] 2. In the utility model, the servo motor is arranged on one side of the input shaft and located inside the pitch arm, so that the servo motor is built-in. Compared with the coaxial arrangement, it can not only greatly reduce the axial length of the joint, achieve a small volume and compact structure, but also avoid the servo motor being exposed and making a lot of noise. At the same time, the wiring can be routed internally, meeting the closed requirements of high-demand application scenarios, reducing interference from environmental factors, and improving safety;
[0028] 3. In the utility model, brake assemblies including brakes and encoders are provided on the servo motor, transmission assembly, input shaft and the input end of the RV reducer far away from the transmission assembly. Multiple sets of brake assemblies can realize multi-position brake control from the input end, primary transmission, secondary transmission and output end. As long as one set can work normally, the safety of the joint is greatly improved, the frequency of joint maintenance is reduced, and the input and output ends form a closed-loop control, which effectively improves the control accuracy of the joint. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a schematic diagram of the overall structure of a high-safety and high-precision joint of a medical robotic arm;
[0030] Figure 2 It is a cross-sectional view of a high-safety and high-precision joint of a medical robotic arm;
[0031] Figure 3 This is a schematic diagram of multiple brake components in a high-safety and high-precision joint of a medical robotic arm.
[0032] In the figure, 1. input shaft; 11. increasing diameter shaft; 12. third brake; 13. third encoder; 14. fourth brake; 15. fourth encoder; 2. RV reducer; 21. fifth brake; 22. fifth encoder; 3. servo motor; 31. first brake; 32. first encoder; 4. driving gear; 41. second brake; 42. second encoder; 43. enhanced step ring; 5. driven gear; 51. mounting bearing; 6. voltage sensor; 7. first support bearing; 8. second support bearing; 9. third support bearing. DETAILED DESCRIPTION
[0033] 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.
[0034] A high-safety and high-precision joint for a medical robotic arm, such as Figure 1 and Figure 2 As shown, it includes an input shaft 1, two RV reducers 2 and a servo motor 3. The axis of the input shaft 1 is horizontally arranged, and the two RV reducers 2 are symmetrically installed at both ends of the input shaft 1 and are coaxially arranged with the input shaft 1. The two ends of the input shaft 1 pass through the middle holes of the two RV reducers 2, and are meshed with the planetary gears of the two RV reducers 2 through gears. The fixed ends of the two RV reducers 2 are far away from each other and connected to the rotating arm (not shown in the figure), and the output ends are close to each other and connected to the pitch arm (not shown in the figure).
[0035] like Figure 1 and Figure 2 As shown, the servo motor 3 is arranged on the outer peripheral side of the two RV reducers 2 and is built into the pitch arm. The output shaft of the servo motor 3 is parallel to the input shaft 1 and a transmission assembly is arranged between the servo motor 3 and the input shaft 1. In this embodiment, the transmission assembly includes a driving gear 4 and a driven gear 5 that mesh with each other. The driving gear 4 is detachably fixedly mounted on one end of the output shaft of the servo motor 3 and is coaxially arranged therewith, and the driven gear 5 is detachably mounted on the input shaft 1 and is coaxially arranged therewith.
[0036] like Figure 1 and Figure 2As shown, when the servo motor 3 is working, it drives the driving gear 4 to rotate synchronously, and drives the input shaft 1 to rotate under the meshing action of the driving gear 4 and the driven gear 5. Under the meshing action of the gears of the two RV reducers 2 planetary gears, the input shaft 1 drives the two RV reducers 2 to work synchronously, thereby driving the pitch arm to perform a pitching action. Using a servo motor 3 to drive two RV reducers 2 to work synchronously can achieve a greater output torque, improve the load and stiffness of the joint, and the two RV reducers 2 are driven by the same input shaft 1, which effectively ensures the coaxiality, improves the synchronization accuracy of the two RV reductions, and makes the joint have three-stage reduction, increases the reduction ratio range, and makes the transmission safer and more reliable. The servo motor 3 is set on one side of the input shaft 1 and is located in the pitch arm, so that the servo motor 3 is built-in. Compared with the coaxial setting, it can not only greatly reduce the axial length of the joint, achieve a small volume and compact structure, but also avoid the servo motor 3 from being exposed and making a loud noise. At the same time, it can be wired internally to meet the closed requirements of high-demand application scenarios, reduce environmental factors, and improve safety.
[0037] like Figure 1 and Figure 2 As shown, in order to further improve the rigidity, a raised reinforcing step ring 43 is provided on both sides of the driving gear 4, and the reinforcing step ring 43 is coaxially arranged with the driving gear 4. The reinforcing step ring 43 is used to enhance the rigidity of the gear, improve the service life of the driving gear 4, and ensure the primary transmission efficiency. Among them, an increasing diameter shaft 11 is provided outside the input shaft 1 and is located between the driven gear 5 and the RV reduction gear far away from the driving gear 4. The increasing diameter shaft 11 is coaxially arranged with the input shaft 1 and is integrally formed. While facilitating the installation and connection of the input shaft 1 and the RV reducer 2, the overall strength of the input shaft 1 is improved, thereby improving the torque transmission capacity.
[0038] In addition, if Figure 1 and Figure 2 As shown, mounting bearings 51 are installed between both sides of the driven gear 5 and the input shaft 1, first support bearings 7 are installed between both ends of the input shaft 1 and the fixed ends of the two RV reducers 2, second support bearings 8 are installed between the input shaft 1 and the output ends of the two RV reducers 2, and a third support bearing 9 is provided between the outer wall of the end of the diameter-increasing shaft 11 away from the driven gear 5 and the pitch arm. Under the action of the mounting bearings 51, the first support bearings 7, the second support bearings 8 and the third support bearings 9, the overall stability of the joint is effectively improved.
[0039] like Figure 2As shown, in order to ensure the safety of joint operation and the control accuracy, a brake assembly including a brake and an encoder is provided on the servo motor 3, the transmission assembly, the input shaft 1, and the input end of the RV reducer 2 away from the transmission assembly. Specifically, the brake assembly provided on the servo motor 3 includes a first brake 31 and a first encoder 32 provided on the side of the servo motor 3 away from its output shaft, the brake assembly provided on the transmission assembly includes a second brake 41 and a second encoder 42 provided on the side of the driving gear 4 away from the servo motor 3, the brake assembly on the input shaft 1 includes a third brake 12 and a fourth brake 14 respectively provided at both ends of the input shaft 1, and the third brake 12 and the fourth brake 14 are provided with a third encoder 13 and a fourth encoder 15 corresponding thereto on the side away from each other, and the brake assembly at the output end of the RV reducer 2 includes a fifth brake 21 and a fifth encoder 22 provided coaxially with the input shaft 1. Of course, in other embodiments, the number and combination of the five sets of brake assemblies can be freely selected to meet the use requirements.
[0040] Among them, Figure 2 and Figure 3 As shown, the first brake 31 and the first encoder 32 are connected in communication feedback control and are coaxially arranged with the output shaft of the servo motor 3, and the first brake 31 is located between the first encoder 32 and the output shaft of the servo motor 3. The second brake 41 and the second encoder 42 are connected in communication feedback control and are coaxially arranged with the driving gear 4, and the second brake 41 is arranged between the second encoder 42 and the driving gear 4. The third brake 12, the third encoder 13, the fourth brake 14 and the fourth encoder 15 are coaxially arranged with the input shaft 1, and the third brake 12 is connected in communication feedback control with the third encoder 13, and the fourth brake 14 is connected in communication feedback control with the fourth encoder 15. The fifth brake 21 and the fifth encoder 22 are connected in communication feedback control and are installed on the output end of the RV reducer 2, and the fifth encoder 22 is located on the side of the fifth brake 21 close to the transmission component.
[0041] like Figure 2 and Figure 3 As shown, the first encoder 32 detects the motion state of the servo motor 3 in real time, the second encoder 42 detects the motion state of the driving gear 4 in real time, the third encoder 13 and the fourth encoder 15 detect the motion state of the input shaft 1 in real time, and the fifth encoder 22 detects the motion state of the output end of the RV reducer 2 in real time. When one of the detection results feedback shows that a motion fault occurs, the communication control feedback controls the corresponding first brake 31, the second brake 41, the third brake 12, the fourth brake 14, and the fifth brake 21 to brake the corresponding servo motor 3, the driving gear 4, the input shaft 1, and the output end of the RV reducer 2. In this way, multiple groups of brake components can realize multi-position brake control from the input end, the primary transmission, the secondary transmission, and the output end. As long as one group can work normally, it can greatly improve the safety of the joint and reduce the frequency of joint maintenance.
[0042] In this embodiment, if Figure 2 and Figure 3 As shown, the first brake 31, the second brake 41, the third brake 12, the fourth brake 14 and the fifth brake 21 are all electromagnetic brakes, and are respectively connected to a voltage sensor 6, through which the voltage of the corresponding brake is detected to determine whether the corresponding brake is working normally. In addition, the first encoder 32, the second encoder 42, the third encoder 13, the fourth encoder 15 and the fifth encoder 22 are all connected by communication feedback, and a closed-loop control is formed between the first encoder 32 and the fifth encoder 22, so as to determine the multi-stage transmission situation, realize the closed-loop control between the input end and the output end, and improve the control accuracy of the joint.
[0043] Working principle and usage of the utility model:
[0044] When the servo motor 3 is working, it drives the driving gear 4 to rotate synchronously, and drives the input shaft 1 to rotate under the meshing action of the driving gear 4 and the driven gear 5. Under the meshing action with the gears of the two RV reducers 2 planetary gears, the input shaft 1 drives the two RV reducers 2 to work synchronously, thereby driving the pitch arm to perform a pitching action. The first encoder 32 detects the motion state of the servo motor 3 in real time, the second encoder 42 detects the motion state of the driving gear 4 in real time, the third encoder 13 and the fourth encoder 15 detect the motion state of the input shaft 1 in real time, and the fifth encoder 22 detects the motion state of the output end of the RV reducer 2 in real time.
[0045] When the detection result feedback of one of the first encoder 32, the second encoder 42, the third encoder 13, the fourth encoder 15 and the fifth encoder 22 shows that there is a fault in the joint movement, the communication control feedback controls the corresponding first brake 31, the second brake 41, the third brake 12, the fourth brake 14, and the fifth brake 21 to brake the corresponding servo motor 3, the driving gear 4, the input shaft 1, and the output end of the RV reducer 2. Among them, as long as one set of brake components can brake normally, it will be sufficient, which greatly improves the safety of the joints and reduces the frequency of joint maintenance.
[0046] 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-safety and high-precision joint for a medical robot arm, characterized by: The invention comprises an input shaft (1), two RV reducers (2) and a servo motor (3), wherein the axis of the input shaft (1) is arranged horizontally, the two RV reducers (2) are symmetrically mounted at both ends of the input shaft (1) and are arranged coaxially with the input shaft (1), the two ends of the input shaft (1) pass through the holes of the two RV reducers (2) and mesh with the planetary gears of the two RV reducers (2) for transmission, the fixed ends of the two RV reducers (2) are separated from each other and connected to the rotating arm, and the output ends are separated from each other and connected to the pitching arm; the servo motor (3) is arranged on the outer peripheral side of the two RV reducers (2) and is built into the pitching arm, the output shaft of the servo motor (3) is parallel to the input shaft (1) and a transmission assembly is arranged between the servo motor (3) and the input shaft (1), and the servo motor (3), the transmission assembly, the input shaft (1) and the input end of the RV reducer (2) separated from the transmission assembly are all provided with a brake assembly.
2. A high-safety and high-precision joint for a medical robot arm according to claim 1, characterized in that: The brake assembly arranged on the servo motor (3) comprises a first brake (31) and a first encoder (32) arranged on a side of the servo motor (3) away from its output shaft, the first brake (31) and the first encoder (32) being arranged coaxially with the output shaft of the servo motor (3), and the first brake (31) being located between the first encoder (32) and the output shaft of the servo motor (3).
3. The high-safety and high-precision joint of a medical robot arm according to claim 2, characterized in that: The transmission assembly comprises a driving gear (4) and a driven gear (5) meshing with each other, the driving gear (4) being detachably fixedly mounted on one end of an output shaft of a servo motor (3) and being coaxially arranged therewith, and the driven gear (5) being detachably mounted on an input shaft (1) and being coaxially arranged therewith; the brake assembly arranged on the transmission assembly comprises a second brake (41) and a second encoder (42) arranged on a side of the driving gear (4) away from the servo motor (3), the second brake (41) and the second encoder (42) being coaxially arranged with the driving gear (4), and the second brake (41) being arranged between the second encoder (42) and the driving gear (4).
4. The high-safety and high-precision joint of a medical robot arm according to claim 3, characterized in that: The brake assembly on the input shaft (1) comprises a third brake (12) and a third encoder (13) arranged at one end of the input shaft (1); the third brake (12) and the third encoder (13) are arranged coaxially with the input shaft (1), and the third encoder (13) is located on a side of the third brake (12) away from the input shaft (1).
5. The high-safety and high-precision joint of a medical robot arm according to claim 4, characterized in that: A fourth brake (14) and a fourth encoder (15) are also provided at one end of the input shaft (1) away from the third brake (12); the fourth brake (14) and the fourth encoder (15) are coaxially arranged with the input shaft (1), and the fourth encoder (15) is located on the side of the fourth brake (14) away from the input shaft (1).
6. A high-safety and high-precision joint for a medical robot arm according to claim 5, characterized in that: The brake assembly at the output end of the RV reducer (2) comprises a fifth brake (21) and a fifth encoder (22) which are coaxially arranged with the input shaft (1); the fifth brake (21) and the fifth encoder (22) are installed on the output end of the RV reducer (2), and the fifth encoder (22) is located on the side of the fifth brake (21) close to the transmission assembly.
7. A high-safety and high-precision joint for a medical robot arm according to claim 6, characterized in that: The first brake (31), the second brake (41), the third brake (12), the fourth brake (14) and the fifth brake (21) are all electromagnetic brakes and are respectively connected to a voltage sensor (6); the first encoder (32), the second encoder (42), the third encoder (13), the fourth encoder (15) and the fifth encoder (22) are all connected in a communication feedback manner, and a closed-loop control is formed between the first encoder (32) and the fifth encoder (22).
8. The high-safety and high-precision joint of a medical robot arm according to claim 3, characterized in that: The driving gear (4) is provided with raised reinforcing step rings (43) on both sides. The reinforcing step rings (43) are coaxially arranged with the driving gear (4). The second brake (41) is mounted on the reinforcing step ring (43) on the side away from the servo motor (3).
9. The high-safety and high-precision joint of a medical robot arm according to claim 5, characterized in that: Mounting bearings (51) are installed between the two sides of the driven gear (5) and the input shaft (1), first support bearings (7) are installed between the two ends of the input shaft (1) and the fixed ends of the two RV reducers (2), and the two first support bearings (7) are located between the third brake (12) and the fourth brake (14), and second support bearings (8) are installed between the input shaft (1) and the output ends of the two RV reducers (2).
10. The high-safety and high-precision joint of a medical robot arm according to claim 3, characterized in that: The input shaft (1) is provided with an increasing diameter shaft (11) located between the driven gear (5) and the RV reduction gear away from the driving gear (4); the increasing diameter shaft (11) is coaxially arranged with the input shaft (1) and is integrally formed; a third support bearing (9) is provided between the outer wall of one end of the increasing diameter shaft (11) away from the driven gear (5) and the pitch arm.