Rotating joint, mechanical arm and surgical robot

By setting limit components and angle information detection modules in the rotary joint, the problem of the rotary joint being unable to record angle and direction after power failure is solved, thus improving the safety and service life of the robotic arm.

CN121867951APending Publication Date: 2026-04-17CORNERSTONE TECH (SHENZHEN) LTD
View PDF 0 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
CORNERSTONE TECH (SHENZHEN) LTD
Filing Date
2024-10-15
Publication Date
2026-04-17

AI Technical Summary

Technical Problem

In existing technologies, rotary joints cannot record absolute position information for multiple turns when power is off, and the output end cannot record directional information after being rotated by external force, resulting in excessive twisting of cables and damage to the equipment.

Method used

A limiting component and an angle information detection module are set between the moving component and the stationary component of the rotary joint. The rotation angle of the moving component is limited by the limiting component, and the angle information is detected by the encoder and transmission assembly to ensure that the rotation angle and direction can be accurately recorded after power failure.

Benefits of technology

This solves the problem of difficulty in judging the rotation angle of the rotating joint after power failure, prevents excessive cable twisting, improves the safety and service life of the robotic arm, and reduces the risk of equipment damage.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN121867951A_ABST
    Figure CN121867951A_ABST
Patent Text Reader

Abstract

The invention provides a rotating joint, a mechanical arm and a surgical robot. The rotational joint comprises a fixed part component, a movable part component and an angle information detection module. The movable part component is rotatably connected to the fixed part component around a first axis. The angle information detection module is directly or indirectly arranged between the fixed part component and the movable part component. The angle information detection module is configured to determine angle information of rotation of the movable part component. The angle information detection module is arranged between the movable part component and the fixed part component, so that the rotating angle information of the movable part component can be determined, and the rotating angle of the movable part component relative to the fixed part component can be determined when the movable part component is powered on again after power failure; the problem that the rotating angle of the output end of the rotating joint is difficult to judge in the related technology can be solved.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] This application relates generally to the technical field of medical devices, and more specifically to a rotary joint, a robotic arm, and a surgical robot. Background Technology

[0002] The robotic arm in the related technology includes a rotary joint and an output encoder. The output end of the rotary joint can rotate multiple revolutions relative to the input end. The output encoder cannot record the absolute position information of multiple revolutions when the power is off. Furthermore, if the rotary joint is rotated by an external force when the power is off, there will be a problem of not being able to record the direction information when the power is restored. Summary of the Invention

[0003] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] To at least partially solve the above problems, a first aspect of this application provides a rotary joint applied between two adjacent connecting arms of a robotic arm, the rotary joint comprising:

[0005] Fixed component;

[0006] A movable component, rotatably connected to the fixed component about a first axis; and

[0007] An angle information detection module is disposed between the fixed component and the moving component, and the angle information detection module is configured to determine the angle information of the rotation of the moving component.

[0008] According to the rotary joint of the first aspect of this application, by setting an angle information detection module between the moving part and the fixed part, the angle information of the rotation of the moving part can be determined, thereby determining the angle of rotation of the moving part relative to the fixed part when power is restored after power failure, thus solving the problem in the related art of difficulty in determining the rotation angle of the output end of the rotary joint.

[0009] Optionally, the rotary joint further includes:

[0010] An output shaft is rotatably disposed on the fixed component about its own axis, the output shaft is connected to the moving component, and the axis of the output shaft coincides with the first axis.

[0011] Optionally, the angle information detection module includes:

[0012] An output encoder is arranged corresponding to the output shaft, and the output encoder is used to detect the first angular position information of the output shaft relative to the fixed component.

[0013] A transmission assembly, the input end of which is connected to the output shaft;

[0014] An auxiliary encoder, arranged corresponding to the output end of the transmission assembly, is configured to detect a second angular position information of the rotation of the output end of the transmission assembly; and

[0015] A driver electrically connected to the output encoder and the auxiliary encoder, the driver being configured to determine the angle and direction of rotation of the output shaft based on the first angular position information, the second angular position information, and the transmission ratio of the transmission assembly.

[0016] Optionally, the transmission assembly includes:

[0017] A first rotating member, coaxial with the output shaft and fixed to the output shaft, constitutes the input end of the transmission assembly; and

[0018] A second rotating member is rotatably connected to the fixed member about an axis parallel to the first axis, and the second rotating member is drively connected to the first rotating member.

[0019] The auxiliary encoder is disposed on the second rotating member and is configured to detect a second angular position information of the second rotating member relative to the fixed member.

[0020] Optionally, the transmission assembly includes s second rotating members, each of which is connected in sequence, where s is a positive integer. The first of the s second rotating members is connected to the first rotating member, and the s-th second rotating member is configured as the output end of the transmission assembly. The auxiliary encoder is configured to detect the second angular position information of the s-th second rotating member relative to the fixed component.

[0021] Optionally, during the rotation of the moving component relative to the fixed component, the number of rotations of the s-th second rotating component is less than or equal to one rotation.

[0022] Optionally, the first rotating member is a first gear, and the second rotating member is a second gear, wherein...

[0023] The number of teeth of the first of the s second gears is coprime to the number of teeth of the first gear; and / or

[0024] The number of teeth of any two meshing second gears among the s second gears are coprime.

[0025] Optionally, the transmission component is a planetary gear reducer, which is driven to the output shaft.

[0026] The auxiliary encoder is disposed between the output end of the planetary gear reducer and the stationary component, and the auxiliary encoder is configured to detect a second angular position information of the rotation of the output end of the planetary gear reducer relative to the stationary component.

[0027] Optionally, the auxiliary encoder is a Hall encoder.

[0028] Optionally, the rotary joint includes:

[0029] An electric motor, the electric motor including a rotor;

[0030] An input encoder, comprising an input code disk and an input sensor, wherein the input code disk is fixedly disposed relative to the rotor, and the input sensor is fixedly disposed relative to the stationary component; the input encoder is used to detect an input angle of rotation of the rotor relative to the stationary component; and

[0031] A driver electrically connected to the input sensor, the driver being configured to acquire the rotational speed of the rotor based on the input angle.

[0032] A second aspect of this application provides a robotic arm, the robotic arm comprising:

[0033] First connecting arm;

[0034] Second connecting arm; and

[0035] In the aforementioned rotary joint, the stationary component is connected to the first connecting arm, and the movable component is connected to the second connecting arm.

[0036] According to the robotic arm of the second aspect of this application, by applying the above-mentioned rotary joint, it is convenient to determine the angle of rotation of the first connecting arm and the second connecting arm relative to each other, thereby helping to prevent the first connecting arm and the second connecting arm from rotating excessively relative to each other, thus protecting the robotic arm and extending its service life.

[0037] A third aspect of this application provides a surgical robot, which includes the aforementioned robotic arm.

[0038] According to the surgical robot of the third aspect of this application, by applying the above-mentioned robotic arm, it is easy to determine the rotation angle at each rotation joint, thereby improving the reliability, safety and service life of the surgical robot. Attached Figure Description

[0039] The following drawings, which illustrate embodiments of this application, are incorporated herein by reference and are used to understand this application. The drawings show embodiments of this application and their descriptions, serving to explain the principles of this application. In the drawings,

[0040] Figure 1 A schematic diagram of a surgical robot according to one embodiment of this application;

[0041] Figure 2 A perspective view of a rotating joint according to one embodiment of this application;

[0042] Figure 3 for Figure 2 A cross-sectional view of the rotary joint shown.

[0043] Figure 4 for Figure 2 A schematic diagram showing the connection between the first fixed flange of the fixed component, the limiting component, and the first moving flange of the moving component;

[0044] Figure 5 for Figure 2 A schematic diagram of the structure of the first moving flange in the middle;

[0045] Figure 6 for Figure 2 A schematic diagram of the structure of the first fixed flange in the middle;

[0046] Figure 7 This is a structural schematic diagram of a limiting member according to one embodiment of this application;

[0047] Figure 8 This is a structural schematic diagram of a limiting member according to another embodiment of this application;

[0048] Figure 9 This is a structural schematic diagram of a limiting member according to another embodiment of this application;

[0049] Figure 10 for Figure 2 A cross-sectional view of the moving component, a portion of the stationary component, and the limiting component in the assembled state;

[0050] Figure 11 for Figure 10 Exploded view of the moving part, a portion of the stationary part, and the limiting part shown;

[0051] Figure 12 for Figure 2 Another cross-sectional view of the rotating joint shown;

[0052] Figure 13This is a schematic diagram of the auxiliary sensing element, first rotating element, and second rotating element of an auxiliary encoder according to one embodiment of this application in an assembled state; and

[0053] Figure 14 This is a perspective view of a harmonic drive reducer according to one embodiment of this application.

[0054] Explanation of reference numerals in the attached figures:

[0055] 10: Surgical robot 11: Control system

[0056] 12: Imaging system 13: Robotic arm system

[0057] 100: Rotation joint 101: Wiring channel

[0058] 110: Fixed component 111: Fixed stop

[0059] 112: First positioning flange; 113: Second positioning flange

[0060] 114: First support; 115: Second support

[0061] 116: Third support; 120: Moving component

[0062] 121: Moving part stop 122: Connecting shaft

[0063] 123: First moving flange; 124: Second moving flange

[0064] 131: Limiting component 131a: First stop part

[0065] 131b: Second stop part; 131c: Ring body

[0066] 132: First rotating component; 133: Second rotating component

[0067] 135: Auxiliary encoder; 135a: Auxiliary code disk

[0068] 135b: Auxiliary sensing element; 136: Sliding bearing

[0069] 137: Driver; 138: Output shaft

[0070] 150: Motor; 151: Housing

[0071] 152: Rotor 153: Stator

[0072] 154: Third rotating support component; 155: Rotor shaft

[0073] 160: Harmonic drive reducer; 161: Rigid wheel

[0074] 162: Flexible wheel; 163: Wave generator

[0075] 164: Receiving cavity; 171: Input encoder

[0076] 171a: Input encoder; 171b: Input sensor

[0077] 172: Fourth rotary support component; 173: Output encoder

[0078] 173a: Output encoder; 173b: Output sensor

[0079] 177: Torque sensor 178: Sealed cavity

[0080] 179: First rotating support component; 181: Sealing plate

[0081] 182: Second rotating support member; 183: Brake assembly

[0082] 183a: First brake component; 183b: Second brake component

[0083] AX1: First axis line; AX2: Second axis line Detailed Implementation

[0084] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0085] To fully understand the embodiments of this application, a detailed structure will be presented in the following description. Obviously, the implementation of the embodiments of this application is not limited to the specific details familiar to those skilled in the art.

[0086] It should be understood that the terminology used herein is intended only to describe particular embodiments and is not intended to limit the scope of this application. The singular forms “a,” “an,” and “the” / “the” are also intended to include the plural forms unless the context clearly indicates otherwise. When the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0087] The ordinal numbers such as "first" and "second" used in this application are merely identifiers and have no other meaning, such as a specific order. Furthermore, for example, the term "first component" does not imply the existence of a "second component," and the term "second component" does not imply the existence of a "first component." It should be noted that the terms "upper," "lower," "front," "rear," "left," "right," "inner," "outer," and similar expressions used in this application are for illustrative purposes only and are not intended to be limiting.

[0088] The terms "distal" and "proximal" used in this application are directional terms commonly used in the field of interventional medical devices. "Distal" refers to the end furthest from the operator during surgery, while "proximal" refers to the end closest to the operator during surgery. In a remotely operated surgical robot system, "operator" refers to the patient-side robot that holds and actuates the surgical instruments.

[0089] The terms “parallel” / “perpendicular” and similar expressions used in this application include absolute parallel / perpendicular relationships and approximately parallel / perpendicular relationships (e.g., relationships that differ from absolute parallel / perpendicular relationships by a range of -5° to +5°), and have equivalent effects.

[0090] The specific embodiments of this application will be described in more detail below with reference to the accompanying drawings, which illustrate representative embodiments of this application and are not intended to limit this application.

[0091] like Figure 1 As shown, this application provides a surgical robot 10 for remotely controlling and performing surgery. The surgical robot 10 may also be referred to as a medical system or medical robot. The surgical robot 10 may include a control system 11, an imaging system 12, and a robotic arm system 13, which can communicate with each other.

[0092] The control system 11, also known as a doctor's console or control device, includes a display unit for showing surgical instruments or the endoscopic environment, a control mechanism for the doctor's operation, and handrails. The display unit has an observation window for the doctor to observe. The control mechanism is designed to perform various actions corresponding to the movements of surgical instruments or the endoscope. The handrails are for supporting the doctor's arms. In addition, the doctor's console has other conveniently accessible control switches for hand or foot touch or press, enabling various functional operations and facilitating human-machine interaction.

[0093] The imaging system 12 includes a display screen, endoscope controller, system electronics, and image processor. This allows the user to see the patient's internal organs more clearly.

[0094] The robotic arm system 13, also known as the patient-side robotic arm system 13, is positioned next to the patient. Its distal end is equipped with surgical instruments or an endoscope for performing various surgical procedures on the patient. The robotic arm system 13 may include at least one robotic arm. The robotic arm has several connecting arms, with adjacent connecting arms connected by joints and moving relative to each other with specific degrees of freedom, allowing the end effector of the robotic arm to achieve multiple degrees of freedom of movement. A holding arm is mounted at the end effector of the robotic arm, on which surgical instruments are detachably mounted. The holding arm may be called an instrument support frame or an instrument arm. An instrument drive module is provided on the holding arm to drive the end effector of the surgical instruments to perform actions such as insertion, clamping, hooking, cutting, and scraping.

[0095] In some cases, a single robotic arm may include an adjusting arm, a manipulating arm, and a holding arm. Surgical instruments or endoscopes are detachably mounted on the holding arm. During surgery, parts of the main circuitry and wrist mechanism of the surgical instruments are passed through tissues such as the chest and abdominal wall, replacing the human hand in the surgical procedure. Adjacent links in the adjusting arm are pivotally connected via a rotary joint. Furthermore, a rotary joint is also provided between the adjusting arm and the manipulating arm for pivotal connection. Before operating the robotic arm system 13 to perform surgery, the adjusting arm must be operated to bring the holding arm to the designated position, and then the rotary joint of the adjusting arm is locked. During surgery, the manipulating arm is remotely controlled to perform surgical operations, while the locking of the rotary joint of the adjusting arm prevents relative rotation between the links of the adjusting arm during the procedure.

[0096] In one example, the robotic arm system 13 includes a base. A handle is provided on the base. The user can use the handle to assist in moving the base.

[0097] In related technologies, robotic arms include rotary joints. While rotary joints can achieve multiple rotations, they lack limitations on the range of rotation angles. In practical applications, if a power outage occurs when the rotation angle at the output end of the rotary joint exceeds ±180°, although the output end can be moved by external force, it is difficult to determine the rotation angle. Furthermore, excessive rotation at the output end of the rotary joint may cause excessive twisting of the cable, resulting in cable damage and affecting equipment safety.

[0098] To address the aforementioned technical problems, embodiments of this application provide a rotating joint, a robotic arm, and a surgical robot having the robotic arm.

[0099] The following will refer to Figures 1 to 14 The examples shown provide a detailed description of the rotary joint 100, the robotic arm, and the surgical robot 10 according to this application.

[0100] See Figures 2 to 13This application provides a rotary joint 100 for use in a robotic arm. The rotary joint 100 includes a fixed component 110, a movable component 120, a limiting component 131, and an angle information detection module. The movable component 120 is rotatable relative to the fixed component 110 about a first axis AX1. The limiting component 131 is disposed between the movable component 120 and the fixed component 110. The limiting component 131 limits the angle of rotation of the movable component 120 relative to the fixed component 110. The angle information detection module is disposed directly or indirectly between the fixed component 110 and the movable component 120. The angle information detection module is configured to determine the angle information of the rotation of the movable component 120. It should be noted that the angle information here includes both angle and direction.

[0101] According to the rotary joint 100 of this application, by providing a limiting member 131 between the moving member 120 and the fixed member 110, the rotation angle of the moving member 120 relative to the fixed member 110 can be limited, thereby solving the problem of excessive cable twisting and damage caused by excessive rotation of the rotary joint in related technologies. Furthermore, compared to related technologies that do not provide a limiting member 131 between the fixed member 110 and the moving member 120, the rotation angle range of the moving member 120 relative to the fixed member 110 can be increased. Moreover, by providing an angle information detection module between the moving member 120 and the fixed member 110, the rotation angle information of the moving member 120 can be determined, thereby determining the rotation angle of the moving member 120 relative to the fixed member 110 even in a power-off state, thus solving the problem in related technologies where it is difficult to determine the rotation angle of the output end of the rotary joint 100. In multi-joint robotic arms, collisions between connecting arms connected to each joint can also be reduced or avoided, thereby improving safety. In applications where the moving component 120 can rotate more than one revolution relative to the stationary component 110, the angle and direction before and after power failure can be determined using two encoders combined with a reduction gear transmission structure. This allows the encoder to operate without power, determining the rotation direction of the joint during the power failure period after power is restored, thus eliminating the limitation of battery use. Since no battery is needed, battery replacement is unnecessary, reducing replacement costs. For example, a Hall effect rotary encoder can be used.

[0102] See Figures 2 to 12For example, the fixed component 110 includes a fixed stop 111. The movable component 120 includes a movable stop 121. The limiting component 131 is rotatable about a first axis AX1 relative to the fixed component 110 and the movable component 120. The limiting component 131 may include a limiting stop. During the rotation of the movable component 120 relative to the fixed component 110 about the first axis AX1, when the movable stop 121 abuts against the limiting stop, the movable component 120 drives the limiting stop to rotate toward the fixed stop 111 and stops at the fixed stop 111. Through the cooperation of the fixed stop 111, the limiting stop, and the movable stop 121, the maximum rotation angle can be limited during the rotation of the movable component 120 relative to the fixed component 110. Moreover, compared to the fixed component 110 being directly connected to the moving component 120, the maximum angle of rotation of the moving component 120 relative to the fixed component 110 is greater than 360°.

[0103] Continue reading Figures 2 to 12 Furthermore, the limiting member 131 may also include a ring body 131c. The limiting stop may include a first stop 131a and a second stop 131b. The first stop 131a and the second stop 131b are disposed on the ring body 131c. The fixed stop 111 is located within the rotation path of the first stop 131a. The moving stop 121 is located within the rotation path of the second stop 131b. By cooperating with the first stop 131a, the limiting between the fixed member 110 and the limiting member 131 can be achieved. By cooperating with the moving stop 121, the limiting between the moving member 120 and the limiting member 131 can be achieved.

[0104] See Figures 2 to 4 , Figures 10 to 12Optionally, to achieve greater mechanical limitation, the rotary joint 100 may include n limiting members 131. The n limiting members 131 are located between the stationary member 110 and the moving member 120 along an axial direction parallel to the first axis AX1. The n limiting members 131 are connected sequentially along the axial direction. The first stop portion 131a of the m-th limiting member 131 is located within the rotation path of the second stop portion 131b of the (m-1)-th limiting member 131. The stationary stop portion 111 is located within the rotation path of the first stop portion 131a of the 1st limiting member 131. The moving stop portion 121 is located within the rotation path of the second stop portion 131b of the n-th limiting member 131. Where 1 < m ≤ n, and m and n are integers. It is understandable that in examples where the rotary joint 100 includes two or more limiting members 131, adjacent limiting members 131 achieve the limiting purpose through the cooperation of the first stop 131a and the second stop 131b. Since the limiting member 131 occupies a certain space in the circumferential direction, the maximum angle that adjacent limiting members 131 can rotate relative to each other is less than 360°.

[0105] See Figure 9 and Figure 11 In some embodiments, the first stop portion 131a and the second stop portion 131b are located at both ends of the limiting member 131 along the axial direction parallel to the first axis AX1. That is, the first stop portion 131a and the second stop portion 131b are located at both ends of the ring body 131c along the axial direction parallel to the first axis AX1. Furthermore, the first stop portion 131a is closer to the stationary member 110 axially than the second stop portion 131b. In this embodiment, the first stop portion 131a and the second stop portion 131b are arranged at least partially offset along the axial direction. The limiting member 131 of this embodiment can be applied when the connection portion between the moving member 120 and the stationary member 110 is arranged offset along the axial direction.

[0106] Optionally, in a plane perpendicular to the first axis AX1, the orthographic projections of the first stop portion 131a and the second stop portion 131b are collinear. In other words, the first stop portion 131a and the second stop portion 131b are aligned in a direction parallel to the first axis AX1. This facilitates reducing the manufacturing difficulty of the limiting member 131 and also makes it easier to determine the rotation angle of the rotating joint 100 more accurately.

[0107] See Figure 7 and Figure 8 In other embodiments, the distance between the first stop portion 131a and the first axis AX1 is not equal to the distance between the second stop portion 131b and the first axis AX1. That is, the first stop portion 131a and the second stop portion 131b are distributed radially. This is applicable to application scenarios where the connection between the moving part member 120 and the stationary part member 110 is arranged radially offset.

[0108] Optionally, the distance between the first stop portion 131a and the first axis AX1 is greater than the distance between the second stop portion 131b and the first axis AX1. The limiting member 131 of this embodiment can be applied when the inner diameter of the end of the fixed member 110 facing the moving member 120 is greater than the inner diameter of the end of the moving member 120 facing the fixed member 110.

[0109] exist Figure 3 , Figure 5 as well as Figure 12 In the example shown, the moving part 120 may include a connecting shaft portion 122 extending axially parallel to the first axis AX1. A limiting member 131 is fitted over the connecting shaft portion 122. It is understood that when the moving part 120 and the stationary part 110 are annular structures, this facilitates wiring at the axial center of the rotating joint 100.

[0110] For example, within the path of rotation about the first axis AX1, the maximum rotation angle of the moving part 120 is denoted as α, the central angle corresponding to the first stop 131a is denoted as β1, the central angle corresponding to the second stop 131b is denoted as β2, the central angle corresponding to the fixed stop 111 is denoted as γ1, and the central angle corresponding to the moving stop 121 is denoted as γ2. Then the maximum rotation angle of the moving part 120 is...

[0111] α=2π*(n+1)-n*(β1+β2)-γ1-γ2, and α≥2π.

[0112] According to this application, by using the above-described calculation formula, the maximum angle of rotation of the moving part 120 relative to the stationary part 110 can be calculated.

[0113] See Figures 2 to 4 ,as well as Figure 12 Optionally, the rotary joint 100 may include a limiting member 131. The stationary stop 111 is located within the rotational path of the first stop 131a of the limiting member 131. The moving stop 121 is located within the rotational path of the second stop 131b of the limiting member 131. It is understood that when the rotary joint 100 has only one limiting member 131, the limiting member 131 is limited in engagement with the stationary stop 111 via the first stop 131a, and with the moving stop 121 via the second stop 131b.

[0114] Accordingly, within the path of rotation about the first axis AX1, the maximum rotation angle of the moving part 120 is denoted as α, the central angle corresponding to the first stop 131a is denoted as β1, the central angle corresponding to the second stop 131b is denoted as β2, the central angle corresponding to the fixed stop 111 is denoted as γ1, and the central angle corresponding to the moving stop 121 is denoted as γ2. Then, when there is only one limiting member 131 in the rotary joint 100, the maximum rotation angle of the moving part 120 is...

[0115] α=4π-(β1+β2+γ1+γ2), and 2π≤α<4π.

[0116] See Figure 3 and Figure 12 Furthermore, the rotating joint 100 may also include an output shaft 138. The output shaft 138 is rotatably disposed on the stationary member 110 about its own axis. The output shaft 138 is connected to the moving member 120. The axis of the output shaft 138 coincides with the first axis AX1. According to this application, by providing the output shaft 138 to connect the moving member 120, power can be transmitted to the moving member 120 so that the moving member 120 rotates relative to the stationary member 110.

[0117] To achieve the recording and detection of the angle and rotation direction of the output shaft 138, the angle information detection module according to this application may include an output encoder 173, a transmission assembly (not shown), an auxiliary encoder 135, and a driver 137. The output encoder 173 is arranged corresponding to the output shaft. The output encoder 173 is used to detect a first angular position information of the output shaft's rotation relative to the stationary component. The input end of the transmission assembly is connected to the output shaft. The auxiliary encoder 135 is arranged corresponding to the output end of the transmission assembly. The auxiliary encoder 135 is configured to detect a second angular position information of the rotation of the output end of the transmission assembly. The driver 137 is electrically connected to the output encoder 173 and the auxiliary encoder 135. The driver 137 is configured to determine the number of rotations and direction of the output shaft based on the first angular position information, the second angular position information, and the transmission ratio of the transmission assembly. Here, based on the first angular position information of the output shaft detected by the output encoder 135, the second angular position information of the output end of the transmission assembly detected by the auxiliary encoder 135, and the transmission ratio of the transmission assembly, the angle and direction of rotation of the output shaft 138 can be determined.

[0118] See also Figure 3 and Figure 12For example, the output encoder 173 includes an output code disk 173a and an output sensor 173b. The output code disk 173a is fixedly disposed relative to the output shaft 138. The output sensor 173b is fixedly disposed relative to the positioning member 110. The output encoder 173 is used to detect a first angular position information of the rotation of the output shaft 138 relative to the positioning member 110. A driver 137 is electrically connected to the output encoder 173. The driver 137 is configured to obtain the position of the output shaft 138 in the circumferential direction based on the first angular position information. It can be understood that the output encoder 173 may also be an encoder capable of directly detecting information such as angular velocity, angular displacement, and phase angle.

[0119] Optionally, the output encoder 173 is a Hall encoder. The output sensing element 173b and the output code disk 173a are two parts of this Hall encoder that can rotate relative to each other. The output sensing element 173b can be referred to as the output encoder head, and the output code disk 173a can be referred to as the output magnetic ring. The Hall encoder here is, for example, a rotary encoder utilizing the Hall sensing principle.

[0120] See Figure 12 and Figure 13 In some embodiments, the transmission assembly may include a first rotating member 132 and a second rotating member 133. The first rotating member 132 is coaxial with the output shaft 138 and is fixed to the output shaft 138. The first rotating member 132 constitutes the input end of the transmission assembly. The second rotating member 133 is rotatably connected to the stationary member 110 about an axis parallel to the first axis AX1. The second rotating member 133 is drively connected to the first rotating member 132. An auxiliary encoder 135 is disposed between the stationary member 110 and the second rotating member 133, which serves as the output end of the transmission assembly. The auxiliary encoder 135 is configured to detect a second angular position information of the rotation of the second rotating member 133 relative to the stationary member 110. A driver 137 is electrically connected to the auxiliary encoder 135. The driver 137 is configured to obtain the number of revolutions and direction of rotation of the output shaft 138 based on the first angular position information, the second angular position information, and the transmission ratio of the first rotating member 132 and the second rotating member 133. Here, the auxiliary encoder 135 is used to directly detect the second angular position information of the second rotating component 133, and then combined with the transmission ratio of the first rotating component 132 and the second rotating component 133, so as to indirectly determine the angle and direction of rotation of the output shaft 138.

[0121] Optionally, the transmission ratio between the first rotating member 132 and the second rotating member 133 is greater than 1. That is, the angular velocity of the second rotating member 133 is less than the angular velocity of the first rotating member 132. Therefore, in the same amount of time, the first rotating member 132 rotates more times or by more angles than the second rotating member 133. It can be understood that by detecting the position of the second rotating member 133, on the one hand, the rotation direction of the output shaft 138 can be obtained, and on the other hand, it can accommodate the detection requirements for the number of rotations of the output shaft 138 that can rotate more than one revolution. At the same time, it helps to reduce the requirements for selecting the auxiliary encoder 135, thereby reducing costs.

[0122] For example, the angle information detection module may include *s* second rotating members 133, where *s* is a positive integer. The second rotating members 133 are connected sequentially. The first second rotating member 133 of the *s* second rotating members 133 is drive-connected to the first rotating member 132. The first second rotating member 133 is rotatably mounted on the fixed member 110 about an axis parallel to the first axis AX1. The *s*th second rotating member 133 is rotatably mounted on the fixed member 110 about a second axis AX2 parallel to the first axis AX1. The *s*th second rotating member 133 constitutes the output end of the aforementioned transmission assembly. An auxiliary encoder 135 is disposed on the *s*th second rotating member 133. The auxiliary encoder 135 is configured to detect second angular position information of the rotation of the *s*th second rotating member 133 relative to the fixed member 110. The driver 137 is configured to obtain the angle and direction of rotation of the output shaft 138 based on the first angular position information, the second angular position information, and the transmission ratio between the first rotating member 132 and the *s*th second rotating member 133. The s-th second rotating element 133 can be understood as the last transmission element on the transmission path from the output shaft 138 to each of the second rotating elements 133. By detecting the rotation position of the s-th second rotating element 133 through the auxiliary encoder 135, the rotation direction of the output shaft 138 can be obtained, and the requirements for detecting the number of rotations of the output shaft 138 that can rotate more times can be met.

[0123] Optionally, during the rotation of the moving component 120 relative to the stationary component 110, the s-th second rotating member 133 rotates less than or equal to one revolution. Therefore, during the design phase, by setting an appropriate number of second rotating members 133, the number of revolutions of the last second rotating member 133 on the transmission path can be less than or equal to one revolution. If the number of revolutions of the last second rotating member 133 on the transmission path is at most greater than one revolution, it becomes inconvenient to determine the rotation direction of the output shaft 138 when the power is off, and it is also inconvenient to accurately calculate the number of revolutions or the rotation angle of the output shaft 138.

[0124] For example, the auxiliary encoder 135 is an absolute position encoder. When the auxiliary encoder 135 is an absolute position encoder, the rotation direction of the output shaft 138 and the rotation angle of the output shaft 138 can be determined more accurately.

[0125] For example, the auxiliary encoder 135 includes an auxiliary code disk 135a and an auxiliary sensing element 135b. The auxiliary code disk 135a is fixedly disposed relative to the last second rotating member 133 located on the transmission path, so as to rotate with the second rotating member 133. For example, the auxiliary code disk 135a is coaxial with and fixedly arranged with the last second rotating member 133 on the transmission path. The auxiliary sensing element 135b is fixedly disposed relative to the stationary member 110 to sense the angular information of the auxiliary code disk 135a. The auxiliary code disk 135a and the auxiliary sensing element 135b are two parts of the Hall encoder that can rotate relative to each other. The auxiliary sensing element 135b may be referred to as a reading head, and the auxiliary code disk 135a may be referred to as an input magnetic ring.

[0126] Continue reading Figure 12 and Figure 13 Optionally, the first rotating member 132 is a first gear, and the second rotating member 133 is a second gear. The number of teeth of the first second gear among the s second gears is coprime to the number of teeth of the first gear. The number of teeth of any two meshing second gears among the s second gears is coprime to the number of teeth. Here, by setting the number of teeth of the meshing gears to be coprime to the number of teeth, wear between gears is reduced / avoided. The second gear acts as an idler gear, transmitting information such as the phase angle of the output shaft 138 of the rotating joint 100 to the auxiliary encoder 135, thereby realizing the recording of the rotation direction and rotation angle data of the rotating joint 100 through the output encoder 173 and the auxiliary encoder 135.

[0127] Alternatively, the second rotating member 133 can be mounted on the stationary member 110 via a sliding bearing 136. Compared to using a rolling bearing, the sliding bearing requires less space while still allowing the second rotating member 133 to rotate relative to the stationary member 110.

[0128] In some other embodiments not shown, the transmission assembly may be a planetary gear reducer. The input end of the planetary gear reducer is drively connected to the output shaft 138. The input end of the planetary gear reducer constitutes the input end of the transmission assembly. An auxiliary encoder 135 is disposed between the output end of the planetary gear reducer and the stationary member 110. The output end of the planetary gear reducer constitutes the output end of the transmission assembly. The auxiliary encoder 135 is configured to detect a second angular position information of the rotation of the output end of the planetary gear reducer relative to the stationary member 110. A driver 137 is electrically connected to the auxiliary encoder 135. The driver 137 is configured to obtain the number of revolutions and direction of rotation of the output shaft 138 based on the first angular position information, the second angular position information, and the gear ratio of the planetary gear reducer.

[0129] It is understood that, in other examples not shown, the transmission components may be replaced by other reduction transmission components besides planetary gear reducers.

[0130] Optionally, the auxiliary encoder 135 described above is a Hall encoder. Here, the Hall encoder is, for example, a rotary encoder utilizing the Hall sensing principle.

[0131] See Figure 3 and Figure 12 In addition, the rotating joint 100 may also include a motor 150. The motor 150 may include a housing 151, a rotor 152, and a stator 153. The housing 151 is fixed to the stator member 110. The rotor 152 is driven to the output shaft 138 to actuate the output shaft 138. The motor 150 here may be, for example, a frameless motor 150. The rotor 152 of the motor 150 is driven to the output shaft 138, thereby providing power to rotate the output shaft 138. The stator 153 is fitted outside the rotor 152 and located inside the housing 151.

[0132] Continue reading Figure 3 and Figure 12For example, the rotating joint 100 may include an input encoder 171. The input encoder 171 includes an input code disk 171a and an input sensor 171b. The input code disk 171a is fixed relative to the rotor 152. The input sensor 171b is fixed relative to the stationary member 110. The input encoder 171 is used to detect the input angle of rotation of the rotor 152 relative to the stationary member 110. A driver 137 is electrically connected to the input sensor 171b. The driver 137 is configured to obtain the rotational speed of the rotor 152 based on the input angle. Here, by setting the input encoder 171 to detect the input angle of the rotor 152, the driver 137 can calculate the rotational speed of the rotor 152 based on the input angle, so as to more accurately control the rotational angle of the rotor 152. It can be understood that the input encoder 171 may also be an encoder capable of directly detecting information such as angular velocity and angular displacement.

[0133] Optionally, the input encoder 171 is another Hall encoder. The input sensor 171b and the input code disk 171a are two parts of this other Hall encoder that can rotate relative to each other. The input sensor 171b can be referred to as the input reading head, and the input code disk 171a can be referred to as the input magnetic ring. This other Hall encoder is, for example, a rotary encoder utilizing the Hall sensing principle.

[0134] See also Figure 3 and Figure 12 For example, the rotating joint 100 may include a rotor shaft 155 and a reducer. The rotor shaft 155 is rotatably mounted around a first axis AX1 on the outside of the output shaft 138. A rotor 152 is mounted on the outside of the rotor shaft 155. The input end of the reducer is connected to the rotor shaft 155. The output end of the reducer is connected to the output shaft 138 so that the rotational speed of the output shaft 138 is lower than the rotational speed of the rotor shaft 155. If the rotor shaft 155 is a hollow shaft, wiring can be routed inside the rotor shaft 155. By providing a reducer, the torque of the output shaft 138 can be increased compared to directly connecting the rotor shaft 155 to the output shaft 138.

[0135] See Figure 3 , Figure 12 and Figure 14Optionally, the reducer is a harmonic drive reducer 160. The harmonic drive reducer 160 may include a rigid wheel 161, a flexible wheel 162, and a wave generator 163. The rigid wheel 161 is fixed relative to the stationary member 110. The flexible wheel 162 is connected to the output shaft 138. The flexible wheel 162 is configured as the output end of the harmonic drive reducer 160. The wave generator 163 is connected to the rotor shaft 155. The wave generator 163 is configured as the input end of the harmonic drive reducer 160. The harmonic drive reducer 160 has advantages such as a relatively simple structure and ease of obtaining a large transmission ratio. By selecting the harmonic drive reducer 160, at least a larger torque can be obtained on the output shaft 138.

[0136] See Figure 3 and Figure 12 Furthermore, the rotating joint 100 may include a third rotating support 154 and a fourth rotating support 172. The third rotating support 154 is connected between the rotor shaft 155 and the housing 151. The fourth rotating support 172 is connected between the rotor shaft 155 and the first bracket 114. Here, the first bracket 114 is part of the positioning component 110 and is used to mount the input encoder 171. The third rotating support 154 and the fourth rotating support 172 may be bearings such as deep groove ball bearings. The third rotating support 154 and the fourth rotating support 172 each cooperate with the rotor shaft 155 to support the rotor shaft 155 so that the rotor shaft 155 can move smoothly.

[0137] Continue reading Figure 3 and Figure 12 For example, the rotary joint 100 may include a torque sensor 177 and a driver 137. The torque sensor 177 is located between the output shaft 138 and the moving part 120. The torque sensor 177 is connected to both the output shaft 138 and the moving part 120. The driver 137 is electrically connected to the torque sensor 177 to acquire torque information between the output shaft 138 and the moving part 120. The torque information acquired by the torque sensor 177 is transmitted to the driver 137 via a cable, enabling closed-loop control of the torque of the rotary joint 100. The driver 137 can more precisely control the operation of the motor 150 based on the torque information.

[0138] See also Figure 3 and Figure 12Optionally, the torque sensor 177 is sleeved on the outside of the output shaft 138. A positioning member 110 is sleeved on the outside of the torque sensor 177. The positioning member 110 is supported on the torque sensor 177 by a first rotating support member 179, such as a bearing. A rigid wheel 161 is fixed inside the positioning member 110. The rigid wheel 161 and the torque sensor 177 are axially spaced parallel to the first axis AX1. The harmonic drive reducer 160, the torque sensor 177, and the positioning member 110 enclose a receiving cavity 164 suitable for containing grease or lubricating oil. The rotating joint 100 may also include a sealing plate 181. The sealing plate 181 is connected to the end of the torque sensor 177 near the rigid wheel 161. The sealing plate 181 prevents grease in the receiving cavity 164 from leaking through the gap between the torque sensor 177 and the first rotating support member 179. This improves the sealing performance of the reducer's lubricating oil while meeting the reducer's lubrication requirements. When the output shaft 138 is a hollow shaft, it is beneficial to wire inside the output shaft 138.

[0139] Alternatively, the first rotating support 179 may be a crossed roller bearing.

[0140] exist Figure 12 and Figure 13 In the example shown, the stationary component 110 includes a first stationary flange 112 and a second stationary flange 113. The first stationary flange 112 can be connected to the end of the second stationary flange 113 by fasteners such as screws. The first stationary flange 112 and the second stationary flange 113 are connected to the outer ring of the crossed roller bearing and limit the crossed roller bearing in the axial direction. The moving component 120 includes a first moving flange 123 and a second moving flange 124. The torque sensor 177 is connected to the first moving flange 123 via the second moving flange 124 by fasteners such as screws. The inner ring of the crossed roller bearing is sleeved on the outside of the second moving flange 124 and the torque sensor 177. The second moving flange 124 and the torque sensor 177 each limit the inner ring of the crossed roller bearing at both ends in the axial direction. The first moving flange 123 has a connecting shaft portion 122, and the connecting shaft portion 122 is fitted with a limiting member 131. The limiting member 131 engages with the fixed stop 111 on the first fixed flange 112 during rotation via the first stop 131a. The limiting member 131 also engages with the moving stop 121 on the first moving flange 123 during rotation via the second stop 131b.

[0141] See also Figure 3 and Figure 12 Optionally, the torque sensor 177 has an opening (not shown) at its axial end. The sealing plate 181 is connected to the opening. This saves the axial space occupied by the sealing plate 181 and improves the structural compactness of the rotating joint 100.

[0142] See also Figure 3 and Figure 12 Optionally, a sealing cavity 178 is formed between the torque sensor 177 and the sealing plate 181. The rotating joint 100 may include a first resilient seal (not shown). The first resilient seal is connected to the sealing cavity 178. By providing the first resilient seal, the sealing performance of the sealing cavity 178 can be improved.

[0143] For example, the first elastic seal is an elastomer such as an O-ring made of soft rubber or other soft materials.

[0144] See also Figure 3 and Figure 12 Exemplarily, the rotating joint 100 may include a second rotating support 182 and a second resilient seal (not shown). The second rotating support 182 is supported between the output shaft 138 and the wave generator 163. The second rotating support 182 is a bearing. The second resilient seal is connected between the second rotating support 182 and the wave generator 163 to seal the gap between the second rotating support 182 and the wave generator 163. By providing the second resilient seal, the sealing performance of the harmonic drive reducer 160 can be further improved.

[0145] For example, the second elastic seal is an elastomer such as an O-ring made of soft rubber or other soft materials.

[0146] See also Figure 3 and Figure 12 Furthermore, the rotating joint 100 may also include a brake assembly 183. The brake assembly 183 may include a first brake element 183a and a second brake element 183b. The first brake element 183a is fixed relative to the rotor 152. The second brake element 183b is fixed relative to the stationary member 110. The brake assembly 183 may be configured such that the first brake element 183a and the second brake element 183b engage in a de-energized state to prevent the rotor 152 from rotating. By providing the brake assembly 183, the rotor 152 can be prevented from rotating in a de-energized state, thereby reducing or preventing the rotating joint 100 from being rotated by external forces in a de-energized state. The brake assembly 183 can also serve to safely hold the rotating joint 100 when power is off.

[0147] Optionally, brake assembly 183 is a dry friction pad brake. It is understood that brake assembly 183 may also be a brake other than a dry friction pad brake.

[0148] See also Figure 3 and Figure 12For example, the positioning member 110 may further include a second bracket 115 and a third bracket 116. The second bracket 115 is connected to the end of the first bracket 114 away from the first positioning flange 112. The second bracket 115 is used to mount the output sensing element 173b of the output encoder 173 and the auxiliary sensing element 135b of the auxiliary encoder 135. The second bracket 115 may be configured as a shell-like structure with an internal space. The third bracket 116 is located inside the second bracket 115 and fixed to the second bracket 115. The aforementioned auxiliary encoder 135 may also be located inside the second bracket 115. The third bracket 116 is used to mount the aforementioned second rotating member 133.

[0149] See also Figure 3 and Figure 12 For example, the moving part 120 is arranged at one axial end of the output shaft 138 and is configured as an annular member. The output shaft 138 is a hollow shaft. The output encoder 173 is located at the other axial end of the output shaft 138 and has a through hole corresponding to the hollow portion of the output shaft 138. The driver 137 is, for example, a drive circuit board. The driver 137 is located on the side of the output encoder 173 away from the output shaft 138. The driver 137 has a through hole corresponding to the hollow portion of the output shaft 138. Thus, the moving part 120, the output shaft 138, the output encoder 173, and the driver 137 form a wiring channel 101 for laying cables, etc.

[0150] The rotary joint 100 of this application can achieve the purpose of recording the absolute position of the rotary joint 100, especially the rotary joint 100 that can rotate more than one revolution. It realizes the absolute value encoder function of multi-turn absolute position recording of mechanical rotary joint 100 by calculating the data encoded by the output encoder 173 and the auxiliary encoder 135. Moreover, this application can improve the range of motion of rotary joint 100 during use, and at the same time reduce or avoid interference such as collisions between joints, thereby improving the safety of rotary joint 100.

[0151] After the joint exceeds its ±180° range of motion, the joint is suddenly de-energized. During the power outage, it is driven in the opposite direction by an external force. After the joint is powered back on, the position information of the joint can be determined based on the reading of the output encoder 173. Combined with the reading of the auxiliary encoder 135, the direction of motion of the joint before the power outage can be determined. The driver 137 is configured to obtain the direction of the joint's motion under external force and the angular displacement of the motion during the power outage based on the data detected by the output encoder 173 and the auxiliary encoder 135. When Hall encoders are used in the output encoder 173 and the auxiliary encoder 135, the rotary joint 100 of this application can achieve multi-turn absolute position recording without battery constraints, thus saving energy and reducing costs.

[0152] The rotary joint 100 of this application, by setting a limiting member 131, can improve the range of motion during use while limiting the rotation range of the joint to protect the cables running through the hollow wiring. Specifically, if the joint exceeds its ±180° range of motion, the joint is suddenly de-energized. During the power outage, it is driven in the opposite direction by an external force, limiting the joint from multiple rotations in the same direction and preventing the cables inside the joint from breaking due to excessive twisting. In other cases, when the control system 11 malfunctions, the mechanical limiting between the limiting member 131 and the stationary member 110, the limiting member 131 and the moving member 120, and the limiting member 131 itself can limit the range of motion of the rotary joint 100, thus stopping its rotation. This improves the range of motion and safety of the joint during use. Furthermore, by setting an angle information detection module, the position and direction of motion before the power outage can be determined after the rotary joint 100 is re-energized, and the direction and angle of rotation of the rotary joint 100 under external force during the power outage can also be determined.

[0153] Embodiments of this application provide a robotic arm. The robotic arm may include a first connecting arm, a second connecting arm, and the aforementioned rotary joint 100. A stationary component 110 is connected to the first connecting arm. A movable component 120 is connected to the second connecting arm.

[0154] According to the embodiments of this application, the robotic arm, by applying the aforementioned rotary joint 100, can limit the angle of rotation of the first connecting arm and the second connecting arm relative to each other, thereby facilitating cable protection. In a power-off state, it is convenient to determine the angle of rotation of the first connecting arm and the second connecting arm relative to each other, enabling the encoder to record positions in multiple rotations even when power is off. This means that after power is restored, the position of the motor can be accurately identified, thus protecting the robotic arm and extending its service life.

[0155] This application provides a surgical robot 10. The surgical robot 10 may include the robotic arm described above.

[0156] The surgical robot 10 according to the embodiments of this application can improve the reliability and service life of the surgical robot 10 by applying the above-described robotic arm.

[0157] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application. Terms such as “setup” appearing herein can refer to either a component being directly attached to another component or a component being attached to another component via an intermediary. A feature described in one embodiment herein may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.

[0158] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. A rotary joint, applied between two adjacent connecting arms of a robotic arm, characterized in that, The rotary joint includes: Fixed component; A movable component, rotatably connected to the fixed component about a first axis; and An angle information detection module is disposed between the fixed component and the moving component, and the angle information detection module is configured to determine the angle information of the rotation of the moving component.

2. The rotary joint according to claim 1, characterized in that, The rotary joint also includes: An output shaft is rotatably disposed on the fixed component about its own axis, the output shaft is connected to the moving component, and the axis of the output shaft coincides with the first axis.

3. The rotary joint according to claim 2, characterized in that, The angle information detection module includes: An output encoder is arranged corresponding to the output shaft, and the output encoder is used to detect the first angular position information of the output shaft relative to the fixed component. A transmission assembly, the input end of which is connected to the output shaft; An auxiliary encoder, arranged corresponding to the output end of the transmission assembly, is configured to detect a second angular position information of the rotation of the output end of the transmission assembly; and A driver electrically connected to the output encoder and the auxiliary encoder, the driver being configured to determine the angle and direction of rotation of the output shaft based on the first angular position information, the second angular position information, and the transmission ratio of the transmission assembly.

4. The rotary joint according to claim 3, characterized in that, The transmission assembly includes: A first rotating member, coaxial with the output shaft and fixed to the output shaft, constitutes the input end of the transmission assembly; and A second rotating member is rotatably connected to the fixed member about an axis parallel to the first axis, and the second rotating member is drively connected to the first rotating member. The auxiliary encoder is disposed on the second rotating member and is configured to detect a second angular position information of the second rotating member relative to the fixed member.

5. The rotary joint according to claim 4, characterized in that, The transmission assembly includes s second rotating members, which are connected sequentially, where s is a positive integer. The first second rotating member of the s second rotating members is connected to the first rotating member. The s-th second rotating member is configured as the output end of the transmission assembly. The auxiliary encoder is configured to detect the second angular position information of the s-th second rotating member relative to the fixed component.

6. The rotary joint according to claim 5, characterized in that, During the rotation of the moving component relative to the stationary component, the number of rotations of the s-th second rotating component is less than or equal to one revolution.

7. The rotary joint according to claim 5, characterized in that, The first rotating component is a first gear, and the second rotating component is a second gear, wherein... The number of teeth of the first of the s second gears is coprime to the number of teeth of the first gear; and / or The number of teeth of any two meshing second gears among the s second gears are coprime.

8. The rotary joint according to claim 3, characterized in that, The transmission component is a planetary gear reducer, which is connected to the output shaft. The auxiliary encoder is disposed between the output end of the planetary gear reducer and the stationary component, and the auxiliary encoder is configured to detect a second angular position information of the rotation of the output end of the planetary gear reducer relative to the stationary component.

9. The rotary joint according to claim 3, characterized in that, The auxiliary encoder is a Hall encoder.

10. The rotary joint according to claim 2, characterized in that, The rotary joint includes: An electric motor, the electric motor including a rotor; An input encoder, comprising an input code disk and an input sensor, wherein the input code disk is fixedly disposed relative to the rotor, and the input sensor is fixedly disposed relative to the stationary component; the input encoder is used to detect an input angle of rotation of the rotor relative to the stationary component; and A driver electrically connected to the input sensor, the driver being configured to acquire the rotational speed of the rotor based on the input angle.

11. A robot arm, characterized in that The robotic arm includes: First connecting arm; Second connecting arm; and In the rotary joint according to any one of claims 1 to 10, the stationary component is connected to the first connecting arm, and the movable component is connected to the second connecting arm.

12. A surgical robot, characterized by The surgical robot includes the robotic arm according to claim 11.