A surgical instrument rotation and axial feed decoupled drive mechanism based on double bevel gear independent transmission and a system thereof

Abstract

The application discloses a surgical instrument rotary decoupling driving mechanism based on double bevel gear independent transmission integrated in a replaceable driving module and a system thereof, and belongs to the field of minimally invasive surgical robots. The mechanism is configured with two sets of independent transmission chains which do not interfere with each other for a single driving tube: one is driven by a primary motor through a bevel gear pair to rotate an axially limited inner thread driven bevel gear, and relies on the meshing of the inner thread and an ACME outer thread of a screw rod to convert gear rotation into axial movement of the screw rod, thereby completing a feeding action; the other is driven by a secondary motor through a bevel gear pair to drive a driven bevel gear with a non-circular hole, the hole is matched with a non-circular segment of the screw rod, can transmit rotary torque and allow the screw rod to axially slide, and realizes instrument rotation. The two sets of transmission chains are mechanically separated, and rotation and axial feeding motion are completely decoupled in structure. The mechanism is suitable for proximal driving of a continuous tubular surgical robot, has the advantages of good decoupling effect, simplified structure and replaceable driving module.

Description

Technical Field

[0001] This invention relates to the field of minimally invasive surgical robot technology, specifically to a decoupled drive mechanism for the rotational and axial feed motion of surgical instruments based on independent transmission of double bevel gears, integrated into a replaceable drive module, and is particularly suitable for the proximal drive system of a concentric tube robot (CTR). Background Technology

[0002] The concentric tube surgical robot (CTR) consists of multiple pre-bent, hyperelastic tubes nested concentrically. By applying proximal rotation and axial translation to each tube segment, the segments elastically interact within the body, achieving end-effector pose control in three-dimensional space. Due to their extremely small outer diameter and high flexibility, this type of robot has significant application value in confined spaces such as intracranial surgery and transnasal skull base surgery.

[0003] The CTR proximal drive system requires applying two degrees of freedom independently to each pipe segment: rotation (DOF) and translation (DOF). Existing technologies suffer from the following main shortcomings:

[0004] 1. Mechanical coupling between rotation and axial feed: Some existing solutions (such as US20170095299A1) have mechanical coupling between rotation and feed. The rotation drive component bears the feed reaction force, which affects the control accuracy and the life of the drive component.

[0005] 2. Coaxial arrangement of the transmission chain, resulting in a large axial dimension: In most existing solutions, the rotation and translation drive motors are arranged along the axis of the pipe segment, resulting in a large axial dimension of the module, which is not conducive to the compact stacking of multi-pipe segment drive modules.

[0006] 3. The transmission paths of rotational degree of freedom and axial feed degree of freedom share mechanical components: When rotation and feed move simultaneously, they interfere with each other through shared transmission components, increasing control complexity.

[0007] Therefore, a new type of drive mechanism is needed to achieve rotation and axial feed with two completely independent transmission chains, fundamentally eliminating the mechanical coupling between the two degrees of freedom, while achieving compact modular integration. Summary of the Invention

[0008] The present invention aims to solve the technical problems in the existing CTR proximal drive system, such as mechanical coupling of rotation and axial feed, coaxial transmission chain leading to excessive module size, and mutual interference when two degrees of freedom move simultaneously.

[0009] To address the above problems, the present invention provides the following technical solution:

[0010] A surgical instrument rotation and axial feed decoupling drive mechanism based on independent double bevel gear transmission, integrated into a replaceable drive module, includes:

[0011] This invention provides a decoupled drive mechanism for the rotation and axial feed of surgical instruments based on independent transmission of double bevel gears. This drive mechanism is integrated into a replaceable drive module and is used to independently drive the rotational and axial feed degrees of freedom of a concentric tube in a continuous tubular surgical robot. The replaceable drive module includes a module housing, a concentric tube, a concentric tube stop block, a first driven bevel gear with internal threads, a first screw, a driven bevel gear with a non-circular cross-section through hole, a second screw, and a spring. The module housing is provided with bearing slots to constrain the axial position of each transmission component, so that the relevant transmission components maintain their corresponding rotational degrees of freedom while their axial position is restricted.

[0012] The concentric tube stop block is fixed on the outer tube section of the concentric tube and is used to constrain the outer tube section to a fixed position on the module shell, so that the inner tube section of the concentric tube can generate independent axial displacement relative to the outer tube section under the drive of the axial feed transmission chain, thereby realizing relative feeding between the inner and outer tube sections.

[0013] The axial feed transmission chain includes a first drive motor, a first driving bevel gear connected to the output shaft of the first drive motor, and a first driven bevel gear with internal threads that meshes with the first driving bevel gear. The first driven bevel gear with internal threads is supported by bearings and its axial position is constrained by bearing slots on the module housing. The internal thread of the first driven bevel gear with internal threads engages with the external thread of the first screw. When the first drive motor drives the first driving bevel gear to rotate, the first driving bevel gear drives the first driven bevel gear with internal threads to rotate. The first driven bevel gear with internal threads drives the first screw to translate along the axial direction through its internal thread, thereby realizing the axial feed freedom of the corresponding pipe sections of the concentric tube.

[0014] The bearing structure of the internally threaded first driven bevel gear constrains its axial position while preserving its rotational freedom. This allows the internally threaded first driven bevel gear to rotate freely with the first screw when the first screw is driven to rotate by the rotary transmission chain, thereby avoiding interference axial reaction forces in the axial feed transmission chain caused by the rotation of the first screw. Through this structure, the axial feed transmission chain can apply axial drive to the first screw without restricting its rotational movement.

[0015] The rotary transmission chain includes a second drive motor, a second driving bevel gear connected to the output shaft of the second drive motor, and a driven bevel gear with a non-circular cross-section through hole meshing with the second driving bevel gear. The driven bevel gear with the non-circular cross-section through hole is supported by bearings and its axial position is constrained by bearing slots on the module housing. The cross-sectional shape of the through hole of the driven bevel gear with the non-circular cross-section matches the corresponding non-circular cross-sectional shape of the first screw. When the second drive motor drives the second driving bevel gear to rotate, the second driving bevel gear drives the driven bevel gear with the non-circular cross-section through hole to rotate. The driven bevel gear with the non-circular cross-section through hole transmits rotational torque to the first screw through the non-circular cross-sectional shape fit, while allowing the first screw to slide freely axially relative to the driven bevel gear with the non-circular cross-section through hole, thereby realizing the rotational freedom of the corresponding pipe segments of the concentric tube.

[0016] The first screw passes through both a first driven bevel gear with internal threads and a driven bevel gear with a through hole of non-circular cross-section. The first screw has external threads that mate with the internal threads of the first driven bevel gear with internal threads, and a non-circular cross-section that matches the through hole of the driven bevel gear with a through hole of non-circular cross-section. The proximal end of the first screw is connected to a corresponding segment of the concentric tube or, through a propulsion output assembly, to the corresponding segment of the concentric tube, enabling the axial translational movement of the first screw to feed the corresponding segment of the concentric tube. The spring plate is positioned at the corresponding connection or limiting position to provide elastic clamping, limiting, or pre-tightening to the relevant components, thereby improving the stability of the transmission connection.

[0017] The axial feed drive chain and the rotary drive chain are each composed of an independent drive motor, a driving bevel gear, and a driven bevel gear, respectively, and are independent of each other in terms of power input and transmission path. The axial feed drive chain applies axial feed drive to the first screw through the threaded engagement between the internally threaded first driven bevel gear and the first screw, while the rotary drive chain applies rotary drive to the first screw through the non-circular cross-section engagement between the driven bevel gear with a non-circular cross-section through hole and the first screw. Thus, the drive mechanism can achieve mechanical decoupling of the rotational degree of freedom and the axial feed degree of freedom of corresponding pipe segments in the concentric tube.

[0018] At the system level, the present invention also provides a continuous tubular surgical robot drive system. The continuous tubular surgical robot drive system includes multiple replaceable drive modules stacked along a common axis. Each replaceable drive module is equipped with the aforementioned decoupling drive mechanism for the rotation and axial feed of surgical instruments based on independent double bevel gear transmission. Each replaceable drive module drives one segment of the concentric tube. For example, one replaceable drive module drives the corresponding segment via a first screw, a first driven bevel gear with internal threads, and a driven bevel gear with a non-circular cross-section through hole; another replaceable drive module drives another corresponding segment via a second screw and its corresponding transmission assembly. Each module is independent and independently applies rotational and axial feed freedom control to its corresponding segment. The segments of the concentric tube are concentrically nested from the outside to the inside, with the inner segment passing through the hollow channels of all outer modules, thereby achieving independent control of the movement of each segment in the multi-segment continuous tubular surgical robot.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The two drive chains are completely mechanically independent, achieving structural decoupling between rotation and axial feed. Specifically, the bearing with an internally threaded driven bevel gear provides rotational freedom, allowing the feed chain to move freely without axial interference when the rotary chain is in motion; the non-circular cross-section through hole allows axial sliding of the screw, ensuring the rotary chain remains unaffected when the feed chain is in motion. The two degrees of freedom are structurally decoupled at the mechanism level. Both degrees of freedom can be controlled simultaneously and independently without interference, simplifying the control algorithm.

[0021] 2. The axis of the active bevel gear is perpendicular to the axis of the screw, and the drive motor can be arranged laterally inside the module, which greatly shortens the axial dimension of the module along the pipe section direction and is conducive to the compact stacking of multi-pipe section modules.

[0022] 3. The driven bevel gear with internal thread combines the functions of a bevel gear and a nut, reducing the number of parts and improving integration.

[0023] 4. The non-circular cross-section through hole transmits torque while allowing axial sliding, eliminating the need for a separate key connection structure, resulting in a simple structure.

[0024] 5. The replaceable driver module can be quickly installed and removed from the host platform, making it suitable for aseptic operation and rapid maintenance. Attached Figure Description

[0025] Figure 1 : Overall structural view of the replaceable drive module;

[0026] Figure 2 Detailed diagram of the first axial feed transmission chain structure;

[0027] Figure 3 : Schematic diagram of the mechanical independence of the two transmission chains;

[0028] Figure 4 : A schematic diagram of a multi-module stacked application;

[0029] Figure 5 The relationship between the slot limit of the motor-controlled transmission gear and the position of the spring piece.

[0030] Notes: 1. Module housing, 2. Concentric tube, 3. Concentric tube stop block, 4. First driven bevel gear with internal thread, 5. First screw, 6. Driven bevel gear with non-circular cross-section through hole, 7. Second screw, 8. Spring. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0032] Example 1: Single screw double bevel gear decoupling drive mechanism.

[0033] See Figures 1 to 4 This embodiment provides a specific implementation of a decoupled drive mechanism for the rotation and axial feed of surgical instruments based on independent transmission of double bevel gears. This drive mechanism is integrated into a replaceable drive module and is used to apply axial feed and rotational motion to corresponding segments of the concentric tube 2.

[0034] The module housing 1 is composed of two half-shells that are joined and fixed together, providing a mounting reference and structural support for the internal transmission components. The inner wall of the module housing 1 has grooves at the respective mounting positions of the threaded first driven bevel gear 4 and the driven bevel gear 6 with a non-circular cross-section through hole. These grooves constrain the axial position of the outer rings of the corresponding bearings, thereby fixing the axial position of the threaded first driven bevel gear 4 and the non-circular cross-section through hole driven bevel gear 6, while allowing them to rotate freely relative to the module housing 1. A quick-release interface for merging with the host platform is located near the end of the module housing 1, allowing the replaceable drive module to be inserted into or removed from the host platform as a whole.

[0035] The concentric tube stop block 3 is fixed on the outer tube section of the concentric tube 2 to constrain the outer tube section to the fixed position of the module shell 1, so that the inner tube section of the concentric tube 2 can generate independent axial displacement and rotational movement relative to the outer tube section under the action of the corresponding drive mechanism.

[0036] The first transmission chain is an axial feed transmission chain, which includes a first drive motor, a first driving bevel gear, a first driven bevel gear 4 with internal threads, and a first screw 5. The first drive motor is a brushless DC servo motor and is equipped with an encoder to provide position feedback. The first drive motor is installed inside the module housing 1, and its output shaft axis is arranged intersecting the axis of the first screw 5. The output shaft of the first drive motor is fixedly connected to the first driving bevel gear. The first driving bevel gear meshes with the first driven bevel gear 4 with internal threads to transmit the rotational motion of the first drive motor to the first driven bevel gear 4 with internal threads.

[0037] The internally threaded first driven bevel gear 4 functions as both a bevel gear and a nut. Its outer conical surface meshes with the first driving bevel gear, and its internal thread engages with the external thread of the first screw 5. When the first drive motor drives the first driving bevel gear to rotate, the first driving bevel gear drives the internally threaded first driven bevel gear 4 to rotate. The internally threaded first driven bevel gear 4 converts the rotational motion into the translational motion of the first screw 5 along the axial direction through the threaded pair, thereby realizing the axial feed freedom of the corresponding pipe section of the concentric tube 2.

[0038] A first driven bevel gear 4 with internal threads is mounted inside the module housing 1 via a bearing. The bearing constrains the axial position of the first driven bevel gear 4 while preserving its rotational freedom relative to the module housing 1. Thus, when the first screw 5 is driven by the second transmission chain to rotate about its axis, the first driven bevel gear 4 can rotate synchronously with the first screw 5, rather than forming a rigid block or interfering axial reaction force on the rotation of the first screw 5. This structure allows the first transmission chain to primarily apply axial translational drive to the first screw 5 without restricting its rotational freedom.

[0039] The second transmission chain is a rotary transmission chain, which includes a second drive motor, a second driving bevel gear, a driven bevel gear 6 with a non-circular cross-section through hole, and a first screw 5. The second drive motor is set independently of the first drive motor, and its output shaft axis is arranged intersecting the axis of the first screw 5. The output shaft of the second drive motor is fixedly connected to the second driving bevel gear. The second driving bevel gear meshes with the driven bevel gear 6 with a non-circular cross-section through hole to form a rotary drive path independent of the first transmission chain.

[0040] The driven bevel gear 6 with a non-circular cross-section through hole functions as both a bevel gear and a torque transmission interface. Its outer conical surface meshes with the second driving bevel gear, and its through hole is a non-circular cross-section through hole that mates with the corresponding non-circular cross-section segment of the first screw 5. When the second drive motor drives the second driving bevel gear to rotate, the second driving bevel gear drives the driven bevel gear 6 with the non-circular cross-section through hole to rotate. The driven bevel gear 6 with the non-circular cross-section through hole transmits rotational torque to the first screw 5 through its non-circular cross-section shape, thereby realizing the rotational freedom of the corresponding pipe segment of the concentric tube 2. At the same time, since the driven bevel gear 6 with the non-circular cross-section through hole and the first screw 5 are not fixedly connected in the axial direction, the first screw 5 can slide freely in the axial direction relative to the driven bevel gear 6 with the non-circular cross-section through hole. Therefore, the second transmission chain does not restrict the axial feed freedom of the first screw 5 while transmitting rotational torque.

[0041] The first screw 5 is the only output element in this embodiment that interacts simultaneously with both the first and second transmission chains. The first screw 5 is arranged along the module axis and includes a threaded section, a non-circular cross-section section, and an output section. The threaded section has an external thread that engages with the internal thread of the internally threaded first driven bevel gear 4, converting the rotational motion of the internally threaded first driven bevel gear 4 into the axial translational motion of the first screw 5. The non-circular cross-section section passes through the corresponding through-hole of the driven bevel gear 6 with a non-circular cross-section through-hole, receiving rotational torque while maintaining axial sliding freedom. The output section is located near the proximal end of the first screw 5 and is used to connect to the corresponding pipe section of the concentric tube 2, or to connect to the corresponding pipe section of the concentric tube 2 via a push-out output assembly, thereby transmitting the axial translational motion and rotational motion around the axis of the first screw 5 to the driven pipe section.

[0042] In this embodiment, the axial length of the non-circular cross-section segment of the first screw 5 is not less than the sum of the maximum axial stroke of the first screw 5 and the axial thickness of the driven bevel gear 6 with the non-circular cross-section through hole, to ensure that the first screw 5 can maintain an effective torque transmission relationship with the driven bevel gear 6 with the non-circular cross-section through hole throughout its entire stroke range. The threaded segment and the non-circular cross-section segment are distributed in different regions along the axis of the first screw 5, corresponding to the first transmission chain and the second transmission chain respectively, thereby reducing structural interference between them.

[0043] like Figure 3As shown, the first transmission chain and the second transmission chain can be represented by M1 and M2, respectively. The power transmission path of the first transmission chain M1 is: first drive motor, first driving bevel gear, first driven bevel gear 4 with internal thread, threaded section of first screw 5, ultimately resulting in the axial movement of the first screw 5. The power transmission path of the second transmission chain M2 is: second drive motor, second driving bevel gear, driven bevel gear 6 with non-circular cross-section through hole, non-circular cross-section section of first screw 5, ultimately resulting in the rotation of the first screw 5 around its axis. Except for the first screw 5 itself serving as a common output element, the first transmission chain M1 and the second transmission chain M2 do not share drive motors, driving bevel gears, or driven bevel gears; they are independent in terms of power input and transmission path.

[0044] Based on the above structure, when the first transmission chain M1 applies axial translational drive to the first screw 5, the first screw 5 can slide axially relative to the driven bevel gear 6 with a non-circular cross-section through hole. Therefore, the axial feed motion will not force the gear assembly in the second transmission chain M2 to move axially. When the second transmission chain M2 applies rotational drive to the first screw 5, the first driven bevel gear 4 with internal thread can rotate with the first screw 5. Therefore, the rotational motion will not generate an interfering axial reaction force in the first transmission chain M1. Thus, the axial translation and rotation around the axis of the first screw 5 can be independently controlled by two drive motors, and can be executed simultaneously or separately as needed, thereby achieving mechanical decoupling of the rotational degree of freedom and axial feed degree of freedom of the corresponding pipe segment of the concentric tube 2.

[0045] The spring piece 8 is used to form an elastic limiting element or a mechanical zero-point holding mechanism. In one specific structure, each driving bevel gear has at least one return groove on its gear body, and the module housing 1 is provided with a spring piece 8 corresponding to the return groove. The spring piece 8 is made of elastic material, with one end fixed to the module housing 1 and the other end forming an elastically deformable latch.

[0046] When the drive motor is not engaged with the drive bevel gear, the latch of the spring plate 8 springs up under its own elastic force and engages in the return groove of the drive bevel gear, constraining the drive bevel gear to a predetermined mechanical zero angle position. In this state, the drive bevel gear cannot rotate freely, thus ensuring that the replaceable drive module maintains a consistent initial angle state during power failure or disassembly / reassembly.

[0047] When the drive motor engages with the driving bevel gear, the coupling module at the end of the drive motor output shaft inserts axially into the return groove, occupying the space originally occupied by the spring clip 8, causing the spring clip 8 to disengage from the return groove, thereby releasing the zero-point lock of the driving bevel gear. Simultaneously, the coupling module and the return groove establish a torque transmission connection through form fit to drive the driving bevel gear to rotate. When the drive motor disengages, the coupling module disengages from the return groove, and the spring clip 8 automatically springs back under its own elastic force and re-engages into the return groove, thereby relocking the driving bevel gear to the mechanical zero-point position. The return groove functions as both a zero-point locking interface and a torque transmission interface, thus eliminating the need for a separate drive connection structure.

[0048] During the installation or replacement of the replaceable drive module, the operator can observe whether all the spring clips 8 on the module are in the pop-up and locked state, and verify that all the active bevel gears inside the module have returned to the mechanical zero position without power. This function ensures that the initial angles of each transmission chain are consistent after each module installation, providing a mechanical reference for the software position initialization of the drive motor, thereby improving the reliability of kinematic calculations for the continuous tubular surgical robot and the safety of surgical operations.

[0049] Example 2: Multi-module stacked driving concentric tube system

[0050] See Figure 4 As shown, this embodiment describes an application scenario in which multiple drive mechanisms described in Embodiment 1 are stacked along a common axis in the form of replaceable drive modules for driving multiple segments of a continuous tubular surgical robot.

[0051] Multiple replaceable drive modules are stacked sequentially along a common axis. Each replaceable drive module is equipped with a double bevel gear decoupling drive mechanism that is the same as or similar to that in Embodiment 1, and is respectively driven by one segment of the concentric tube 2. The screw in each module is connected to the proximal end of the corresponding segment, or is connected to the proximal end of the corresponding segment through a corresponding propulsion output component, thereby independently transmitting the axial translational and rotational motion of the screw in each module to the corresponding segment.

[0052] In the multi-module stacked structure, the power chain configurations of the outer and inner pipe segments are identical. That is, for each driven pipe segment, an axial feed transmission chain and a rotary transmission chain can be used to achieve the axial feed degree of freedom and rotational degree of freedom of that pipe segment, respectively. For example, one replaceable drive module can drive one pipe segment of the concentric tube 2 via a first screw 5, a first driven bevel gear 4 with internal threads, and a driven bevel gear 6 with a non-circular cross-section through hole; another replaceable drive module can drive another pipe segment of the concentric tube 2 via a second screw 7 and its corresponding first driven bevel gear 4 with internal threads and a driven bevel gear 6 with a non-circular cross-section through hole. The drive motors, driving bevel gears, driven bevel gears, and screws of each module are arranged correspondingly to each other, and the modules do not share transmission components, thus ensuring that the power transmission between different pipe segments is independent.

[0053] The continuous tubular surgical robot comprises multiple concentrically nested pre-bent or bendable tubular components. Each tubular component is driven by a corresponding replaceable drive module and can independently rotate around an axis and translate axially. The tubular segments are nested sequentially from the outside in, with the innermost segment passing through the hollow channels of all outer modules. The number of stacked modules can be flexibly configured according to the number of segments in the concentric tube 2; in one embodiment, the number of stacked modules is two to four. Through this multi-module stacking structure, the continuous tubular surgical robot can achieve independent motion control of multiple tubular segments and change the end-effector configuration through relative rotation and relative feed between different segments.

Claims

1. A surgical instrument rotation and axial feed decoupling drive mechanism based on independent double bevel gear transmission, integrated within a replaceable drive module, comprising a module housing (1), a rotation drive assembly, and an axial feed drive assembly, characterized in that: The drive mechanism includes a mechanically independent first transmission chain and a second transmission chain; the first transmission chain includes a first drive motor, a first driving bevel gear connected to the output shaft of the first drive motor, and a first driven bevel gear (4) with internal threads meshing with the first driving bevel gear; the first driven bevel gear (4) with internal threads is supported by a bearing, and the outer ring of the bearing is axially limited by a slot on the module housing (1) to fix the axial position of the first driven bevel gear (4) with internal threads and allow the first driven bevel gear (4) with internal threads to rotate freely; the internal thread of the first driven bevel gear (4) with internal threads engages with the external thread of the first screw (5) to convert the rotation of the first driven bevel gear (4) with internal threads into the axial translation of the first screw (5); when the first screw (5) is driven to rotate by the second transmission chain, the first driven bevel gear (4) with internal threads can rotate freely synchronously with the first screw (5), thereby avoiding the first screw (5) from rotating in the first transmission chain. An interfering axial reaction force is generated in the middle; the second transmission chain includes a second drive motor, a second active bevel gear connected to the output shaft of the second drive motor, and a driven bevel gear (6) with a non-circular cross-section through hole meshing with the second active bevel gear; the driven bevel gear (6) with a non-circular cross-section through hole is supported by a bearing and its axial position is constrained by a slot on the module housing (1); the cross-sectional shape of the through hole of the driven bevel gear (6) with a non-circular cross-section is consistent with the cross-sectional shape of the corresponding section of the first screw (5) so as to allow the first screw (5) to slide freely axially while transmitting rotational torque to the first screw (5); the first screw (5) passes through the first driven bevel gear (4) with internal thread and the driven bevel gear (6) with a non-circular cross-section through hole at the same time; the push output assembly is connected to the first screw (5) for outputting the axial translation and rotational motion of the first screw (5) to the driven surgical instrument; the first transmission chain and the second transmission chain do not share transmission elements except for the first screw (5) itself.

2. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, The axis of the first active bevel gear and the axis of the second active bevel gear are both perpendicular to the axis of the first screw (5), and the first drive motor and the second drive motor are arranged laterally in the replaceable drive module.

3. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, The through hole of the driven bevel gear (6) with a non-circular cross-section has a non-circular cross-section structure that matches the corresponding section of the first screw (5).

4. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, The outer rings of the bearings of the first driven bevel gear (4) with internal thread and the driven bevel gear (6) with non-circular cross-section through hole are embedded in the corresponding slots of the module housing (1). The slots restrict the displacement of the corresponding bearing outer rings in two axial directions, thereby fixing the axial positions of the first driven bevel gear (4) with internal thread and the driven bevel gear (6) with non-circular cross-section through hole.

5. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, Each of the first and second active bevel gears has at least one return groove on its gear body; the module housing (1) has an elastic limiting member at a corresponding position, which elastically engages in the return groove of the corresponding active bevel gear in its natural state, constraining the first and second active bevel gears to a predetermined mechanical zero angle position; the output shaft of the drive motor has a coupling module that matches the shape of the return groove at its end, when the drive motor engages with the first and second active bevel gears, the coupling module inserts into the return groove, and at the same time presses the elastic limiting member out of the return groove, unlocking the first and second active bevel gears and establishing a torque transmission connection; when the drive motor exits, the coupling module disengages from the return groove, the elastic limiting member automatically springs back and relocks the first and second active bevel gears to the mechanical zero position.

6. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 5, characterized in that, When the replaceable drive module is separated from the host platform, the elastic limiting member applies a return constraint to the first and second drive bevel gears in the module. By observing whether the elastic limiting member is fully engaged, the operator can verify that the first and second drive bevel gears in the module are at the mechanical zero point position without power, thereby providing a mechanical reference for the position initialization of the drive motor.

7. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, The module housing (1) is provided with a quick-release interface that works with the host platform, and the drive mechanism as a whole can be detachably connected to the host platform.

8. The surgical instrument rotation and axial feed decoupling drive mechanism based on double bevel gear independent transmission according to claim 1, characterized in that, The propulsion output assembly includes a propulsion frame and a tube clamp disposed on the propulsion frame. The tube clamp is used to clamp the proximal end of the concentric tube (2) and transmit the axial translational and rotational motion of the first screw (5) to the concentric tube (2).

9. A decoupled drive system for the rotation and axial feed of surgical instruments based on independent double bevel gear transmission, characterized in that, The invention includes a surgical instrument rotation and axial feed decoupling drive mechanism based on independent transmission of double bevel gears as described in any one of claims 1 to 8, wherein replaceable drive modules of the multiple drive mechanisms are stacked along a common axis; one of the drive mechanisms drives one segment of the concentric tube (2) through a first screw (5), and another drive mechanism drives another segment of the concentric tube (2) through a second screw (7), and each drive mechanism independently controls the rotational degree of freedom and axial feed degree of freedom of the corresponding segment.

10. A surgical instrument rotation and axial feed decoupling drive system based on independent double bevel gear transmission according to claim 9, characterized in that, The concentric tube (2) includes multiple concentric nested pre-bent or bendable tubular components. Each tubular component is connected to a corresponding drive mechanism through a propulsion output component and can rotate and translate axially independently.

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