An active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism

Abstract

The present invention provides an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism, which has the following characteristics, including: a frame module; a joint rotation module, which is arranged on the frame module and is used to drive the knee joint to rotate; a gear transmission module, which is arranged on the frame module and is used to drive the joint rotation module; and a hydraulic damping module, which is arranged on the frame module. The hydraulic damping module includes a damping motor, a hydraulic cylinder with a rotary valve at the bottom, a hydraulic rod, a hydraulic rod connecting device, a first incomplete gear and a second incomplete gear. The damping motor drives the second incomplete gear to rotate by driving the first incomplete gear. The second incomplete gear is fixed to the rotary valve by a top screw and is used to control the damping effect of the hydraulic cylinder. A hydraulic rod is connected to the top of the hydraulic cylinder, and a hydraulic rod connecting device is provided on the top of the hydraulic rod. The hydraulic rod is connected to the joint rotation module through the hydraulic rod connecting device, thereby controlling the rotation of the knee joint.

Description

Technical Field

[0001] The present invention relates to the technical field of human rehabilitation assistive devices, and in particular to an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism. Background Art

[0002] With the increasing number of lower limb amputees and the continuous development of microelectronics and control technologies, intelligent lower limb prostheses have gradually become a research hotspot in the field of rehabilitation robotics. As the core component of lower limb prosthetic systems, the design of high-performance knee joint prostheses remains a major technical difficulty in current prosthetic design.

[0003] Currently, existing intelligent prosthetic knee joints can be divided into passive and active types according to the joint drive method. Among them, the passive prosthetic knee joint adjusts the knee joint damping torque according to changes in external conditions to achieve gait adjustment when walking, but because it does not provide active torque, it cannot assist patients in climbing stairs; the active prosthetic knee joint can replace the leg muscles to provide torque, allowing the wearer to better complete walking modes that require active torque, such as climbing stairs, but generally lacks a clutch mechanism. The drive motor and transmission mechanism are always connected to the knee joint rotation axis. The motor needs to frequently reverse in any gait phase, resulting in a short battery life of the knee joint prosthesis.

[0004] In the existing technology, the control of drive and damping size is mainly achieved through hydraulic pumps and damping adjustment valves, and the four-bar linkage is directly controlled by the motor. However, since the four-bar linkage has a multi-axis rotation center, the loss is large during the driving process of the active torque. In addition, the self-locking torque of the stepper motor itself requires a magnetic powder clutch to ensure that the torque does not affect the passive control stage when the stepper motor is powered off. The motor is also placed close to the human body, which is not conducive to human safety. Summary of the Invention

[0005] The present invention is made to solve the above-mentioned problems, and its purpose is to provide an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism.

[0006] The present invention provides an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism, which has the following characteristics, including: a frame module; a joint rotation module, which is arranged on the frame module and is used to drive the knee joint to rotate; a gear transmission module, which is arranged on the frame module and is used to drive the joint rotation module; and a hydraulic damping module, which is arranged on the frame module. The hydraulic damping module includes a damping motor, a hydraulic cylinder with a rotary valve at the bottom, a hydraulic rod, a hydraulic rod connecting device, a first incomplete gear and a second incomplete gear. The damping motor drives the second incomplete gear to rotate by driving the first incomplete gear. The second incomplete gear is fixed to the rotary valve by a top screw and is used to control the damping effect of the hydraulic cylinder. A hydraulic rod is connected to the top of the hydraulic cylinder, and a hydraulic rod connecting device is provided on the top of the hydraulic rod. The hydraulic rod is connected to the joint rotation module through the hydraulic rod connecting device, thereby controlling the rotation of the knee joint.

[0007] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following characteristics: wherein, the hydraulic rod connecting device includes a convex connecting part, a piston rotating shaft, a piston fisheye hole and an L-shaped connecting piece, the protruding part of the convex connecting part is provided with a penetrating fisheye hole, the piston rotating shaft passes through the fisheye hole and is connected to one end of the L-shaped connecting piece, and the other end of the L-shaped connecting piece is fixedly connected to the joint rotation module.

[0008] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following features: a hydraulic cylinder fixing seat is provided at the bottom of the hydraulic cylinder, a fixing piece is provided on the outer side of the hydraulic cylinder fixing seat, and the fixing piece is used to connect the hydraulic cylinder fixing seat and the frame module, and a damping motor fixing seat is provided at the bottom of the damping motor, and the damping motor fixing seat is used to connect the damping motor and the hydraulic cylinder fixing seat.

[0009] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following features: wherein, the joint rotation module includes a small quadrangular pyramid, an upper rotating part, a left rotating part, a right rotating part and a joint rotation shaft with a spline sleeve, and the other end of the L-shaped connecting part is fixedly connected to the right rotating part.

[0010] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following characteristics: the upper part of the upper rotating part is connected to the small quadrangular pyramid, the lower left side of the upper rotating part is connected to the left rotating part, and the right side is connected to the right rotating part, the joint rotation axis is used to drive the left rotating part and the right rotating part to rotate, and the upper rotating part, the left rotating part and the right rotating part are used to drive the knee joint to rotate.

[0011] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following characteristics: wherein, the gear transmission module includes a drive motor, a bevel gear transmission system, a three-stage gear transmission system and a worm gear transmission assembly, and the drive motor drives the bevel gear transmission system or the three-stage gear transmission system to drive the joint rotation axis to rotate.

[0012] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following characteristics: wherein, the three-stage gear transmission system includes a first gear, a second gear, a third gear, a fourth gear and a fifth gear, the first gear is engaged with the second gear for transmission, the second gear is engaged with the third gear for transmission, the third gear and the fourth gear share a third D-shaped shaft to achieve synchronous transmission, the fourth gear is engaged with the fifth gear to transmit torque to the fifth gear, and the fifth gear is equipped with a bearing and cooperates with the joint rotation axis.

[0013] In an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following features: wherein, the bevel gear transmission system includes a first bevel gear, a second bevel gear, a third bevel gear and a fourth bevel gear, the worm transmission assembly includes a worm and a worm wheel, the output shaft of the drive motor is fixed to the first bevel gear through the fifth D-shaped shaft, the first bevel gear and the second bevel gear are meshed for transmission, the second bevel gear and the first gear share the first D-shaped shaft to achieve synchronous rotation, the second gear cooperates with the second D-shaped shaft on the worm to achieve synchronous rotation, the worm and the worm wheel are meshed for transmission, the worm wheel and the third bevel gear share the fourth D-shaped shaft to achieve synchronous rotation, the third bevel gear and the fourth bevel gear are meshed for transmission to transmit torque to the fourth bevel gear, and the fourth bevel gear is equipped with a bearing and cooperates with the joint rotation axis.

[0014] In the active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following characteristics: it also includes a switching module, which is arranged on the frame module and is used to switch the bevel gear transmission system and the three-stage gear transmission system by driving the spline sleeve to slide. It includes a switching motor and a switching module transmission assembly. The switching module transmission assembly is sleeved on the spline sleeve. The switching motor drives the switching module transmission assembly to slide, thereby driving the spline sleeve to slide.

[0015] In an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism provided by the present invention, it can also have the following features: wherein, the switching module transmission assembly includes a motor fixing seat, a switching motor gear, a switching motor rack, a rack slide, and a shift fork. The motor fixing seat is arranged above the switching motor and fixed on the rack module. The switching motor gear is fixed to the motor shaft of the switching motor. The switching motor gear is engaged with the switching motor rack. The switching motor rack and the rack slide are clearance-matched. One end of the shift fork is fixed to the switching motor rack, and the other end is sleeved on the spline sleeve, which is used to drive the spline sleeve to slide on the joint rotation axis, thereby driving the spline sleeve to engage with the gear transmission module.

[0016] Functions and effects of the invention

[0017] According to the active-passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism involved in the present invention, the present invention can change the knee joint prosthesis from an active type to a passive type, and is equipped with a hydraulic damper to improve the stability of the knee joint when the patient needs to provide a passive torque such as walking on flat ground and going down stairs, so that the flexion and extension of the knee joint rotating parts are smoother, thereby better adapting to road conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a front perspective view of an adjustment mechanism in an embodiment of the present invention;

[0019] Figure 2 is a rear perspective view of an adjustment mechanism in an embodiment of the present invention;

[0020] Figure 3 is an exploded view of the adjustment mechanism in an embodiment of the present invention;

[0021] Figure 4 is an exploded view of a joint rotation module according to an embodiment of the present invention;

[0022] Figure 5 is a rear perspective view of a gear transmission module according to an embodiment of the present invention;

[0023] Figure 6 is a front perspective view of a gear transmission module in an embodiment of the present invention;

[0024] Figure 7 is a schematic structural diagram of the fifth gear in the gear transmission module in an embodiment of the present invention;

[0025] Figure 8 2 is a schematic structural diagram of the fourth bevel gear in the gear transmission module in an embodiment of the present invention;

[0026] Figure 9 2 is a schematic structural diagram of a gear transmission module in a disconnected state according to an embodiment of the present invention;

[0027] Figure 10 2 is a schematic diagram of a structure in which a gear transmission module is connected to a high transmission ratio in an embodiment of the present invention;

[0028] Figure 11 2. It is a schematic diagram of the structure of the gear transmission module connected to a low transmission ratio in an embodiment of the present invention;

[0029] Figure 12 is a schematic structural diagram of a switching module in an embodiment of the present invention;

[0030] Figure 13 is an exploded diagram of a switching module in an embodiment of the present invention; and

[0031] Figure 14 Schematic diagram of the structure of the hydraulic damping module in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0033] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and drawings specifically illustrate an active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism of the present invention.

[0034] Figure 1 It is a front perspective view of the adjustment mechanism in the embodiment of the present invention. Figure 2 It is a rear perspective view of the adjustment mechanism in the embodiment of the present invention. Figure 3 Exploded view of the adjustment mechanism in an embodiment of the present invention.

[0035] like Figure 1-3 As shown, the transmission ratio adaptive adjustment mechanism 100 for a lightweight knee joint prosthesis in this embodiment includes a frame module 10 , a joint rotation module 20 , a gear transmission module 40 , a switching module 30 and a hydraulic damping module 70 .

[0036] The rack module 10 is used to fix the joint rotation module 20, the gear transmission module 40, the switching module 30 and the hydraulic damping module 70. The bottom of the rack module 10 is connected to a calf tube connector 11 for connecting the calf tube prosthesis below (not shown in the figure).

[0037] Figure 4 1 is an exploded view of the joint rotation module in an embodiment of the present invention.

[0038] like Figure 4 As shown, the joint rotation module 20 is used to drive the knee joint to rotate, including a small quadrangular platform 21, an upper rotating part 22, a left rotating part 23, a right rotating part 24 and a joint rotating shaft 25 with a spline sleeve 26. The rotating part is used to drive the knee joint to rotate.

[0039] The small square prism 21 is arranged above the upper rotating part 22 and is fixed to the upper rotating part 22 by screws. The upper part of the upper rotating part 22 is connected to the small square prism 21, and the lower part of the upper rotating part 22 is fixed to the left rotating part 23 and the right rotating part 24 by positioning blocks and screws. Specifically, the left side of the upper rotating part 22 is connected to the left rotating part 23, and the right side is connected to the right rotating part 24. The joint rotating shaft 25 with the spline sleeve 26 cooperates with the D-shaped holes of the left rotating part 23 and the right rotating part 24. The joint rotating shaft 25 is used to drive the left rotating part 23 and the right rotating part 24 to rotate.

[0040] Figure 5 It is a rear perspective view of the gear transmission module in an embodiment of the present invention. Figure 6 It is a front view and a perspective view of a gear transmission module in an embodiment of the present invention. Figure 7 Schematic diagram of the structure of the fifth gear in the gear transmission module in an embodiment of the present invention. Figure 8 Schematic diagram of the structure of the fourth bevel gear in the gear transmission module in an embodiment of the present invention. Figure 9 1 is a schematic structural diagram of a gear transmission module in a disconnected state in an embodiment of the present invention. Figure 10 It is a structural diagram of a gear transmission module connected to a high transmission ratio in an embodiment of the present invention. Figure 11 It is a structural diagram of a gear transmission module connected to a low transmission ratio in an embodiment of the present invention.

[0041] like Figure 5-11 As shown, the gear transmission module 40 is used to drive the joint rotation module 20, including a drive motor 41, a bevel gear transmission system 59, a three-stage gear transmission system 60 and a worm gear transmission assembly. The drive motor 41 drives the bevel gear transmission system 59 or the three-stage gear transmission system 60, thereby driving the joint rotation axis 25 to rotate.

[0042] The three-stage gear transmission system 60 includes a first gear 42, a second gear 43, a third gear 44, a fourth gear 45 and a fifth gear 46. The first gear 42 is engaged with the second gear 43 for transmission, the second gear 43 is engaged with the third gear 44 for transmission, the third gear 44 and the fourth gear 45 share a third D-shaped shaft 53 to achieve synchronous transmission, the fourth gear 45 is engaged with the fifth gear 46 to transmit torque to the fifth gear 46, and the fifth gear 46 is equipped with a bearing 57 and cooperates with the joint rotation shaft 25.

[0043] The bevel gear transmission system 59 includes a first bevel gear 47, a second bevel gear 48, a third bevel gear 49 and a fourth bevel gear 50. The worm 58 transmission assembly includes a worm 58 and a worm wheel 56. The output shaft of the drive motor 41 is fixed to the first bevel gear 47 by screws and the fifth D-shaped shaft 55. The first bevel gear 47 is meshed with the second bevel gear 48 for transmission. The second bevel gear 48 and the first gear 42 share the first D-shaped shaft 51 to form a shaft-hole fit to achieve synchronous rotation. The second gear 43 cooperates with the second D-shaped shaft 52 on the worm 58 to achieve synchronous rotation. The worm 58 is meshed with the worm wheel 56 for transmission. The worm wheel 56 and the third bevel gear 49 share the fourth D-shaped shaft 54 ​​to form a shaft-hole fit to achieve synchronous rotation. The third bevel gear 49 is meshed with the fourth bevel gear 50 for transmission, transmitting the torque to the fourth bevel gear 50. The fourth bevel gear 50 is equipped with a bearing 57 and cooperates with the joint rotation shaft 25.

[0044] The torque of the fourth bevel gear 50 and the fifth gear 46 is not directly transmitted to the joint shaft. The fourth bevel gear 50 and the fifth gear 46 both have meshing teeth that can engage with the spline sleeve 26. The torque obtained by the joint shaft depends on the torque of the fourth bevel gear 50 or the fifth gear 46 that the spline sleeve 26 selects to engage.

[0045] Figure 12 It is a structural diagram of a switching module in an embodiment of the present invention. Figure 13 is an exploded diagram of a switching module in an embodiment of the present invention.

[0046] like Figure 12-13 As shown, the switching module 30 is used to switch the bevel gear transmission system 59 and the three-stage gear transmission system 60 by driving the spline sleeve 26 to slide, and includes a switching motor 31 and a switching module 30 transmission assembly. The switching module 30 transmission assembly is sleeved on the spline sleeve 26. The switching motor 31 drives the switching module 30 transmission assembly to slide, thereby driving the spline sleeve 26 to slide.

[0047] The teeth at both ends of the spline sleeve 26 are chamfered, and the contact ends of the fourth bevel gear 50 and the fifth gear 46 with the spline sleeve 26 are provided with chamfers that match the spline sleeve 26 to ensure consistent meshing directions.

[0048] The transmission assembly of the switching module 30 includes a motor fixing seat 32, a switching motor gear 33, a switching motor rack 34, a rack slide 36, and a shift fork 35. The motor fixing seat 32 is arranged above the switching motor 31 and fixed on the rack module 10. The switching motor gear 33 is fixed to the motor shaft of the switching motor 31. The switching motor gear 33 is engaged with the switching motor rack 34. The switching motor rack 34 is clearance-matched with the rack slide 36. One end of the shift fork 35 is fixed to the switching motor rack 34 by a screw, and the other end is sleeved on the spline sleeve 26 to drive the spline sleeve 26 to slide on the joint rotation shaft 25.

[0049] The switching motor 31 drives the switching motor gear 33 to rotate, and the motor gear engages with the switching motor rack 34, so that the switching motor rack 34 and the shift fork 35 move linearly on the slide rail, and finally drives the spline sleeve 26 to engage with the left and right fourth bevel gears 50 or the fifth gear 46, thereby realizing the switching of the motion mode.

[0050] Figure 14 Schematic diagram of the structure of the hydraulic damping module in an embodiment of the present invention.

[0051] like Figure 14 As shown, the hydraulic damping module 70 includes a damping motor 72, a damping motor fixing seat 73, a hydraulic cylinder 71 with a rotary valve (not shown in the figure) at the bottom, a hydraulic rod 81, a hydraulic rod connecting device 78, a first incomplete gear 74, a second incomplete gear 75, a hydraulic cylinder fixing seat 77 and a fixing part 76.

[0052] The first incomplete gear 74 is meshed with the gear portion of the second incomplete gear 75. The damping motor 72 drives the first incomplete gear 74 to rotate the second incomplete gear 75. The second incomplete gear 75 is fixed to the rotary valve (not shown in the figure) through a top screw (not shown in the figure), thereby achieving the damping effect of controlling the hydraulic cylinder 71. A hydraulic rod 81 is connected to the top of the hydraulic cylinder 71, and a hydraulic rod connecting device 78 is provided on the top of the hydraulic rod 81. The hydraulic rod 81 is connected to the joint rotation module 20 through the hydraulic rod connecting device 78, thereby controlling the rotation of the knee joint.

[0053] A hydraulic cylinder fixing seat 77 is provided at the bottom of the hydraulic cylinder 71, and a fixing piece 76 is provided on the outside of the hydraulic cylinder fixing seat 77. The fixing piece 76 is used to connect the hydraulic cylinder fixing seat 77 and the rack module 10. A damping motor fixing seat 73 is provided at the bottom of the damping motor 72. The damping motor fixing seat 73 is used to connect the damping motor 72 and the hydraulic cylinder fixing seat 77.

[0054] The hydraulic rod connecting device 78 includes a convex connecting part 80, a piston rotating shaft 79, a piston fisheye hole 84 and an L-shaped connecting part 82. One end of the L-shaped connecting part 82 is provided with a first hole 83, and the other end is fixedly connected to the right rotating part 24 by bolts. The right rotating part 24 extends outward from a circular plate 27 with a second hole 28. The position of the second hole 28 corresponds to the first hole 83. The protruding part of the convex connecting part 80 is provided with a penetrating piston fisheye hole 84. The piston rotating shaft 79 passes through the fisheye hole and is connected to the first hole 83 and the second hole respectively, thereby connecting the hydraulic damping module 70 to the joint rotation module 20.

[0055] Active stage of the knee joint: The driving motor 41 transmits the torque to the fourth bevel gear 50 and meshes with the fifth gear 46 through the gear transmission module 40, and the switching motor 31 transmits the torque to the joint rotation module 20 through the switching module 30, providing suitable active torque for the knee joint movement in situations where active torque is required, such as crossing obstacles or climbing stairs, to achieve flexion and extension of the knee joint.

[0056] Passive stage of the knee joint: the switching motor 31 places the spline sleeve 26 in the middle position, so that the knee joint shaft is disconnected from the gear transmission module 40 and the drive motor 41, thereby enhancing the reverse driving ability of the knee joint and being able to adapt well to the needs of walking on flat ground.

[0057] The prosthesis has two internal transmission ratios: a high-ratio path with a worm gear assembly and a low-ratio path with a three-stage gear transmission. The two transmission paths diverge at the second gear 43. The DJI M3508 motor has a maximum continuous output torque of 2.8 N·m and a maximum speed of 469 rpm at this torque.

[0058] High transmission ratio path: The worm 58 has 2 teeth, the worm wheel 56 has 27 teeth, the module is 2, the transmission ratio is 13.5, and the transmission ratio is 36.5. It can provide a torque of 106.4 N·M for the knee joint, and the rotation speed of the joint shaft is 74° per second, which meets the torque and speed requirements of most knee amputees for alternating stair climbing.

[0059] Low transmission ratio path: The transmission ratio is 6, which can provide 16.8N·M of torque to the knee joint. The joint axis can reach the joint limit within 0.2S, meeting the obstacle crossing needs of amputees when walking on flat ground.

[0060] like Figure 10-12 As shown, there are three working states of the transmission ratio adaptive adjustment mechanism 100.

[0061] in, Figure 10 Indicates the working state of the knee joint in the passive phase. Figure 11Indicates the working state of the knee joint in the active phase when the high transmission ratio path is connected. Figure 12 Indicates the working state of the knee joint in the active phase when the low transmission ratio path is connected.

[0062] Functions and Effects of the Embodiments

[0063] According to the active-passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism involved in the present invention, the present invention can change the knee joint prosthesis from an active type to a passive type, and is equipped with a hydraulic damper to improve the stability of the knee joint when the patient needs to provide a passive torque such as walking on flat ground and going down stairs, so that the flexion and extension of the knee joint rotating parts are smoother, thereby better adapting to road conditions.

[0064] By setting up the switching module, a reasonable active torque can be provided to the knee joint when the patient crosses obstacles or climbs stairs, etc., and the joint rotation axis can be disconnected from the drive motor when the patient needs the knee joint to provide passive torque, such as walking on flat ground or going down stairs. At the same time, the switching mechanism in the variable transmission ratio mechanism can act as a clutch, and the drive motor does not need to be constantly reversed during the gait cycle of walking on flat ground. It only needs to deal with situations where the knee joint needs to provide active torque, greatly improving the endurance of the knee joint prosthesis.

[0065] The present invention sets two transmission ratios and uses a worm gear assembly on the transmission path with a high transmission ratio. The worm gear assembly is characterized by a compact mechanical structure and provides a larger transmission ratio. It can adapt well to the narrow space inside the knee joint prosthesis. When combined with other reduction gears, it can amplify the motor torque to the required range.

[0066] Those skilled in the art will appreciate that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism, characterized in that: include: Rack modules; A joint rotation module is provided on the frame module and is used to drive the knee joint to rotate. The joint rotation module includes a small quadrangular platform, an upper rotating part, a left rotating part, a right rotating part, and a joint rotation shaft with a spline sleeve; A gear transmission module is provided on the frame module and is used to drive the joint rotation module. The gear transmission module includes a drive motor, a bevel gear transmission system, a three-stage gear transmission system, and a worm gear transmission assembly. The drive motor drives the bevel gear transmission system or the three-stage gear transmission system to drive the joint rotation axis to rotate; A hydraulic damping module is provided on the frame module, comprising a damping motor, a hydraulic cylinder with a rotary valve provided at the bottom, a hydraulic rod, a hydraulic rod connecting device, a first incomplete gear, and a second incomplete gear. The damping motor drives the first incomplete gear to rotate the second incomplete gear. The second incomplete gear is fixed to the rotary valve via a jackscrew and is used to control the damping effect of the hydraulic cylinder. A hydraulic rod is connected to the top of the hydraulic cylinder, and the hydraulic rod connecting device is provided on the top of the hydraulic rod. The hydraulic rod is connected to the joint rotation module via the hydraulic rod connecting device to control the rotation of the knee joint. as well as A switching module is arranged on the rack module, and is used to switch the bevel gear transmission system and the three-stage gear transmission system by driving the spline sleeve to slide. It includes a switching motor and a switching module transmission assembly. The switching module transmission assembly is sleeved on the spline sleeve. The switching motor drives the switching module transmission assembly to slide, thereby driving the spline sleeve to slide, thereby realizing selective engagement of the spline sleeve with the bevel gear transmission system or the three-stage gear transmission system, or disconnecting the gear transmission module drive motor, thereby enhancing the reverse drive ability of the knee joint.

2. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 1, characterized in that: in, The hydraulic rod connecting device includes a convex connecting part, a piston rotating shaft, a piston fisheye hole and an L-shaped connecting piece. The protruding part of the convex connecting part is provided with a penetrating fisheye hole. The piston rotating shaft passes through the fisheye hole and is connected to one end of the L-shaped connecting piece. The other end of the L-shaped connecting piece is fixedly connected to the right rotating piece.

3. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 1, characterized in that: in, A hydraulic cylinder fixing seat is provided at the bottom of the hydraulic cylinder, and a fixing piece is provided on the outside of the hydraulic cylinder fixing seat. The fixing piece is used to connect the hydraulic cylinder fixing seat and the rack module. A damping motor fixing seat is provided at the bottom of the damping motor. The damping motor fixing seat is used to connect the damping motor and the hydraulic cylinder fixing seat.

4. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 1, characterized in that: in, The upper part of the upper rotating part is connected to the small quadrangular pyramid, the lower left side of the upper rotating part is connected to the left rotating part, and the right side is connected to the right rotating part. The joint rotating shaft is used to drive the left rotating part and the right rotating part to rotate, and the upper rotating part, the left rotating part and the right rotating part are used to drive the knee joint to rotate.

5. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 1, characterized in that: in, The three-stage gear transmission system includes a first gear, a second gear, a third gear, a fourth gear and a fifth gear. The first gear is engaged with the second gear for transmission, the second gear is engaged with the third gear for transmission, the third gear and the fourth gear share a third D-shaped shaft to achieve synchronous transmission, the fourth gear is engaged with the fifth gear to transmit torque to the fifth gear, and the fifth gear is equipped with a bearing and cooperates with the joint rotation shaft.

6. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 5, characterized in that: in, The bevel gear transmission system includes a first bevel gear, a second bevel gear, a third bevel gear and a fourth bevel gear. The worm transmission assembly includes a worm and a worm wheel. The output shaft of the drive motor is fixed to the first bevel gear through a fifth D-shaped shaft. The first bevel gear is meshed with the second bevel gear for transmission. The second bevel gear and the first gear share the first D-shaped shaft to achieve synchronous rotation. The second gear cooperates with the second D-shaped shaft on the worm to achieve synchronous rotation. The worm is meshed with the worm wheel for transmission. The worm wheel and the third bevel gear share the fourth D-shaped shaft to achieve synchronous rotation. The third bevel gear is meshed with the fourth bevel gear for transmission to transmit torque to the fourth bevel gear. The fourth bevel gear is equipped with a bearing and cooperates with the joint rotation shaft.

7. The active and passive intelligent prosthetic knee joint based on a variable transmission ratio mechanism according to claim 1, characterized in that: in, The switching module transmission assembly includes a motor fixing seat, a switching motor gear, a switching motor rack, a rack slide, and a shift fork. The motor fixing seat is arranged above the switching motor and fixed on the rack module. The switching motor gear is fixed to the motor shaft of the switching motor. The switching motor gear is engaged with the switching motor rack. The switching motor rack is clearance-matched with the rack slide. One end of the shift fork is fixed to the switching motor rack, and the other end is sleeved on the spline sleeve for driving the spline sleeve to slide on the joint rotation shaft, thereby driving the spline sleeve to engage with the gear transmission module.

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