Uniaxial passive-active hybrid drive intelligent prosthetic knee joint structure with energy recovery function

Abstract

The application discloses a single-shaft active and passive mixed driving intelligent artificial knee joint structure with energy recovery function, which comprises a joint rotating module, a gear transmission module, a hydraulic damping module, a rack and a motor. The gear transmission module comprises a primary bevel gear transmission system, a secondary gear transmission system, a synchronous belt wheel transmission assembly and a transmission rack. The motor is fixed on the transmission rack. In the active stage, the motor provides an active driving torque for the knee joint through the gear transmission module and the joint rotating module. In the passive stage, the joint rotating module transmits a passive torque of the knee joint to the motor through the gear transmission module, drives the motor to rotate, so that the motor generates electricity to recover energy, and the hydraulic damping module provides a damping torque to ensure the stability of the knee joint. In various use occasions, the required damping or driving torque can be obtained, the power consumption of the motor can be reduced by recovering the passive torque of the knee joint in the passive stage, and the working endurance of the intelligent artificial limb is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of human rehabilitation assistive devices, and particularly relates to a single-axis active-passive hybrid intelligent prosthetic knee joint structure with energy recovery function. BACKGROUND

[0002] With the increasing number of lower limb amputees and the continuous development of microelectronics, control and other technologies, intelligent lower limb prostheses have gradually become a research hotspot in the field of rehabilitation robots. As the core component of the lower limb prosthesis system, the design of high-performance knee joint prosthesis is still the main technical difficulty in current prosthesis design. The existing intelligent prosthetic knee joints can be divided into passive and active types according to the joint driving mode. The passive type of prosthetic knee joint adjusts the knee joint damping torque to realize gait adjustment according to the change of external conditions when walking, but it cannot assist patients to climb stairs because it does not provide active torque. The active type of prosthetic knee joint can provide torque to replace the leg muscles, making the wearer better complete the walking mode that requires active torque such as climbing stairs, but it has the shortcomings of high energy consumption, large size and weight of the battery, and short endurance time. The current adjustment of the damping in the prosthetic knee joint mainly exists in three ways: magneto-rheological, pneumatic and hydraulic. The magneto-rheological intelligent knee joint adjusts the damping by changing the current to change the magnetic field strength, but the viscosity change of the magneto-rheological fluid is closely related to the magnetic field, and the requirement for the magneto-rheological fluid material is very high, which is not easy to control and not easy to improve the production capacity. Both hydraulic and pneumatic are driven by microprocessors to adjust the opening size of the valve inside the damping cylinder, so as to achieve the purpose of adjusting the damping, but the stability of the support performance of the pneumatic knee joint is unreliable, which is easy to cause safety accidents.

[0003] Chinese invention patents with publication numbers CN105769395A, CN106726028B, CN106539633A and CN107035808A all propose electrically controlled hydraulic damping cylinder structures for intelligent knee prostheses, but all of them are essentially pure damping type and cannot provide active torque when going upstairs or uphill. Chinese invention patent with publication number CN102065799A discloses a semi-driven prosthetic knee joint device, which realizes driving and non-driving modes through a hydraulic pump and a damping adjusting valve, but the hydraulic valve circuit is particularly complex, and the hydraulic pump and the motor make the structure complex and bulky. Chinese invention patents with publication numbers CN109806037A and CN111110409B disclose a main and passive hybrid control type hydraulic four-bar linkage prosthetic knee joint, which also realizes driving and damping size control through a hydraulic pump and a damping adjusting valve, but it directly controls the four-bar linkage mechanism by a motor. Since the four-bar linkage mechanism has multiple rotating centers, it has large loss in the driving process of the active torque, and the self-locking torque of the stepping motor itself needs a magnetic powder clutch to ensure that the torque does not affect the passive control stage when the stepping motor is powered off. The position of the motor is also close to the human body, which is not conducive to the safety of the human body.

[0004] Therefore, the skilled in the art is committed to developing a single-axis main and passive hybrid drive intelligent prosthetic knee joint structure with energy recovery function to overcome the problems existing in the prior art. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is how to provide a main and passive hybrid drive intelligent prosthetic knee joint structure with energy recovery function. In the active stage, the knee joint is provided with more efficient and accurate active torque by the motor and the transmission mechanism. In the passive stage, the joint rotating module converts the passive torque into the driving torque of the motor through the transmission module, converts the kinetic energy into electrical energy and stores it, increases the working endurance of the prosthesis, and at the same time, the voice coil motor controls the hydraulic damper to provide a certain damping torque and flexibility to ensure the bionics of the prosthesis movement.

[0006] To achieve the above object, the application provides a single-axis active and passive mixed drive intelligent prosthetic knee joint structure with energy recovery function, which comprises a joint rotation module, a gear transmission module, a hydraulic damping module, a rack, and a motor.

[0007] Further, the joint rotation module comprises a small quadrangular prism, an upper connecting rod, a rotating shaft, a torque sensor, a posture sensor, a connecting rod shaft, and a connecting rod.

[0008] Further, the first-stage bevel gear transmission system comprises a small bevel gear and a large bevel gear, the second-stage gear transmission system comprises a small gear and a large gear, the synchronous belt wheel transmission assembly comprises a small belt wheel and a large belt wheel, the transmission rack is fixed on both sides of the rack, the output shaft of the motor is fixedly connected with the small bevel gear, the small bevel gear is engaged with the large bevel gear, the large bevel gear is connected with the small gear through a key, the large gear is engaged with the small gear, the shaft end of the large gear is connected with the small belt wheel through a key, the small belt wheel is connected with the large belt wheel through a synchronous belt, and the large belt wheel is fixedly connected with the torque sensor.

[0009] Further, the large gear is provided with a third bearing and a fourth bearing at both ends to realize the stability of transmission.

[0010] Further, the hydraulic damping module comprises a hydraulic cylinder, an adjusting seat, an energy accumulator, a needle valve and a voice coil motor, the hydraulic cylinder is pivotally connected with the lower end of the connecting rod through a piston rod, the adjusting seat is connected with the hydraulic cylinder, the adjusting seat is provided with a flexion oil channel and an extension oil channel, the needle valve is arranged in the flexion oil channel, the energy accumulator is arranged at the upper portion of the adjusting seat, and the voice coil motor drives the needle valve, and the flexion damping of the knee joint is adjusted by controlling the coincidence degree of the needle valve and the flexion oil channel to adjust the flow of the oil channel.

[0011] Further, the hydraulic cylinder comprises a piston rod, a cylinder cover, a cylinder body and a piston, the piston rod is pivotally connected with the lower end of the connecting rod, the cylinder cover is threadedly connected with the upper end of the cylinder body, and the piston is threadedly connected with the lower end of the piston rod and slidably connected in the cylinder body.

[0012] Further, the adjusting seat is provided with a first one-way valve and a second one-way valve, and the flow directions of the hydraulic oil in the flexion oil channel and the extension oil channel are controlled respectively.

[0013] Further, the energy accumulator comprises an energy accumulator piston, an energy accumulator cavity sealing cover and a stopper, the upper portion of the adjusting seat is provided with an energy accumulator cavity, the energy accumulator piston is arranged in the energy accumulator cavity, the energy accumulator cavity sealing cover is used for sealing the energy accumulator cavity, and the stopper is fixedly connected with the adjusting seat.

[0014] Further, the bottom of the needle valve is threadedly connected with a needle valve connecting shaft, the output end of the voice coil motor is fixedly connected with the bottom of the needle valve connecting shaft, the bottom of the voice coil motor is fixedly connected with a motor fixing seat, the motor fixing seat is fixedly connected with the adjusting seat, and the voice coil motor controls the coincidence degree of the needle valve penetrating through a needle guide block and the flexion oil channel in the adjusting seat.

[0015] Further, when the piston moves downward, the hydraulic oil returns to the upper oil cavity of the hydraulic cylinder through the extension oil channel, at this time, the active extension of the knee joint is driven by the motor through the gear transmission module to provide a driving torque for the joint rotation module, and the hydraulic damping module does not provide damping; when the piston moves upward, the hydraulic oil returns to the lower oil cavity through the flexion oil channel, the voice coil motor adjusts the flow of the flexion oil channel by controlling the coincidence degree of the needle valve and the flexion oil channel, and then controls the flexion damping.

[0016] The present application has the following beneficial effects due to the above technical scheme:

[0017] 1. A single-axis active-passive hybrid drive intelligent prosthetic knee joint structure with energy recovery function is provided. It can provide active torque to the patient when the knee joint needs to provide active torque in situations such as the patient going uphill or climbing stairs. When the patient needs to provide passive torque in scenarios such as the patient going downhill or climbing stairs, the passive torque is converted into the driving torque of the motor through the transmission module, and the kinetic energy is converted into electrical energy and stored to increase the working endurance of the prosthesis. At the same time, the hydraulic damper of the valve controlled by the voice coil motor provides a certain damping torque and flexibility to ensure the bionic movement of the prosthesis.

[0018] 2. The motor transmits the active torque directly to the joint rotation module through the transmission mechanism, so that the driving torque can directly drive the rotation of the knee joint, thereby improving the driving efficiency of the motor.

[0019] 3. The joint rotation module is equipped with posture sensors and torque sensors, which can detect the knee joint torque and position in real time. Combined with the high-precision positioning of the voice coil motor, it can accurately provide real-time torque to the knee joint.

[0020] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0021] Figure 1a This is an overall schematic diagram of a preferred embodiment of the present invention;

[0022] Figure 1b This is a schematic diagram of a preferred embodiment of the present invention from another angle.

[0023] Figure 2 This is a module distribution diagram of a preferred embodiment of the present invention;

[0024] Figure 3 This is an exploded view of a joint rotation module according to a preferred embodiment of the present invention;

[0025] Figure 4 This is an exploded view of a gear transmission module according to a preferred embodiment of the present invention;

[0026] Figure 5 This is an exploded view of a hydraulic damping module according to a preferred embodiment of the present invention;

[0027] Figure 6 This is a cross-sectional view of the extension oil passage of a hydraulic damping module according to a preferred embodiment of the present invention;

[0028] Figure 7 This is a cross-sectional view of the buckling oil passage of a hydraulic damping module according to a preferred embodiment of the present invention.

[0029] 1-joint rotation module, 2-gear transmission module, 3-hydraulic damping module, 4-frame, 5-motor, 6-silica gel lock small four pyramid, 101-small four pyramid table, 102-upper connecting rod, 103-first bearing, 104-rotation shaft, 105-torque sensor, 106-shaft sleeve 106, 107-second bearing, 108-rotation shaft clamp spring, 109-posture sensor fixed block, 110-posture sensor, 111-connecting rod, 112-connecting rod shaft 112, 201-transmission frame, 202-large bevel gear, 203-small bevel gear, 204-large gear, 205-small gear, 206-small pulley, 207-synchronous belt, 208-large pulley, 209-first level transmission shaft, 210-third bearing, 211-fourth bearing, 212-fifth bearing, 213-pressing cover, 214-sixth bearing, 301-piston rod, 302-cylinder cover, 303-piston, 304-cylinder body, 305-adjusting seat, 306-energy storage piston, 307-energy storage cavity sealing cover, 308-stop block, 309-needle valve, 310-needle guide block, 311-needle valve connecting shaft, 312-voice coil motor, 313-motor fixing seat, 314-second check valve, 315-first check valve, 3051-energy storage cavity, 3141-extension oil channel, 3151-flexion oil channel. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present application are described below with reference to the accompanying drawings, so that the technical contents of the present application can be more clearly understood and be convenient for understanding. The present application can be embodied in many different forms, and the protection scope of the present application is not limited to the embodiments described herein.

[0031] In the drawings, the same components are denoted by the same reference numerals, and components having similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present application is not limited to the size and thickness of each component. In order to make the drawing clearer, the thickness of some components is appropriately exaggerated in some places in the drawing.

[0032] The application provides a passive and active hybrid driving intelligent prosthesis knee joint structure with energy recovery function.

[0033] The application provides a single-axis passive and active hybrid driving intelligent prosthesis knee joint structure with energy recovery, which comprises a joint rotating module, a gear transmission module, a hydraulic damping module, a rack, a first bevel gear transmission system, a second gear transmission system, a synchronous belt wheel transmission assembly and a transmission rack.

[0034] Embodiment

[0035] The embodiment provides a single-axis passive and active hybrid driving intelligent prosthesis knee joint structure with energy recovery function.

[0036] As shown in Figure 1a , Figure 1b , Figure 2 , the single-axis passive and active hybrid driving intelligent prosthesis knee joint structure comprises a joint rotating module 1, a gear transmission module 2, a hydraulic damping module 3, a rack 4, a motor 5 and a silica gel lock small four-pyramid 6.

[0037] The joint rotation module 1 is hinged with the frame through the rotation shaft 104, the gear transmission module 2 is fixedly connected with the frame 4 through screws, the hydraulic damping module 3 is fixedly connected with the frame 4 through screws on both sides, and the silica gel lock small four-pyramid 6 is fixedly connected with the bottom of the frame 4 through threads. The silica gel lock small four-pyramid 6 is a standard part for connecting the prosthetic knee joint and the prosthetic foot.

[0038] Figure 3 It is an exploded view of the joint rotation module 1, which includes a small four-pyramid 101, an upper connecting rod 102, a rotation shaft 104, a torque sensor 105, a connecting rod shaft 112, and a connecting rod 111.

[0039] The small four-pyramid 101 is fixed with the upper connecting rod 102 through screws, the two ends of the rotation shaft 104 are provided with first and second bearings 103 and 107, the inner sides of the first and second bearings 103 and 107 are axially fixed through shaft sleeves 106, the outer side of the first bearing 103 is fixed through an end face by a rotation shaft snap spring 108, the two ends of the rotation shaft 104 are pivoted with the upper connecting rod 102 through the first and second bearings 103 and 107, one side of the torque sensor 105 is fixedly connected with the rotation shaft 104 through screws, the other side of the torque sensor 105 is fixed with a large pulley 208 through screws, torque transmission between the joint rotation module 1 and the gear transmission module 2 is realized, a posture sensor fixing block 109 fixes a posture sensor 110 on the side surface of the upper connecting rod 102 through screws, the two ends of a connecting rod shaft 112 are pivoted with the upper connecting rod 102, and the upper end of a connecting rod 111 is pivoted with the connecting rod shaft 112. The small four-pyramid 101 is a standard part for fixedly connecting the prosthetic knee joint and the thigh stump receiving cavity.

[0040] Figure 4 It is an exploded view of the gear transmission module 2, which includes a transmission frame 201, a small bevel gear 203, a large bevel gear 202, a small gear 205, a large gear 204, a small pulley 206, and a large pulley 208.

[0041] The transmission frame 201 is fixed on both sides of the frame 4 by screws, and the output shaft of the motor 5 is fixed with the small bevel gear 203 by screws; the small bevel gear 203 is driven by meshing with the large bevel gear 202, and the output torque is transmitted to the large bevel gear 202, and the large bevel gear 202 transmits the torque to the pinion 205 through the first transmission shaft 209; the large bevel gear 202 and the pinion 205 are connected with the first transmission shaft 209 by means of a flat key, so as to realize synchronous rotation; the pinion 205 is provided with a third bearing 210 and a sixth bearing 214 at both ends, so as to realize stable transmission; the large gear 204 is meshed with the pinion 205, and the shaft end of the large gear 204 is connected with the small pulley 206 by means of a flat key, so as to realize synchronous rotation; the small pulley 206 is connected with the large pulley 208 through the synchronous belt 207, and the large gear 204 is provided with a fourth bearing 211 and a fifth bearing 212 at both ends, so as to realize stable transmission; the large pulley 208 is connected with the torque sensor 105 by means of screws, and the torque is transmitted to the joint rotation module 1; the third bearing 210 and the fourth bearing 211 are installed on the transmission frame 201, and the fifth bearing 212 and the sixth bearing 214 are installed on the gland 213. The gland 213 is fixed on the transmission frame 201 by means of screws; in the active stage of the knee joint, the motor 5 provides driving torque for the joint rotation module 1 through the transmission module 2, provides active torque for the knee joint movement in the situation of uphill or upstairs and the like, realizes active flexion and extension of the knee joint; in the passive stage of the knee joint, the joint rotation module 1 drives the motor 5 to rotate through the transmission module 2, and at this time the motor 5 acts as a generator, converts the kinetic energy in the passive stage into electric energy, recovers the electric quantity and stores it, so as to improve the endurance of the artificial limb.

[0042] Figure 5 is an exploded view of the hydraulic damping module 3, and the hydraulic damping module 3 comprises a piston rod 301, a cylinder cover 302, a cylinder body 304, a piston 303, a first one-way valve 315, a second one-way valve 314, an adjusting seat 305, an energy storage piston 306, a stop block 308, a needle valve 309, a needle guide block 310, a needle valve connecting shaft 311, a voice coil motor 312 and a motor fixing seat 313.

[0043] Piston rod 301 and connecting rod 111 lower end pivot, cylinder head 302 and cylinder body 304 upper end thread connection, piston 303 and piston rod 301 lower end thread connection and placed in the cylinder body 304 up and down movement, adjusting seat 305 through the screw and cylinder body 304 connection fixed, adjusting seat 305 is provided with flexion oil channel 3151 and extension oil channel 3141, and in the flexion oil channel 3151 is provided with needle valve 309, by controlling the coincidence degree of needle valve 309 and flexion oil channel 3151 to adjust the flow of oil, realize the flexion of knee joint damping adjustment. Adjusting seat 305 is provided with first check valve 315 and second check valve 314, control flexion oil channel 3151 and extension oil channel 3141 respectively hydraulic oil flow. Adjusting seat 305 upper part is provided with energy storage cavity 3051, energy storage piston 306 is placed in energy storage cavity 3051, energy storage cavity sealing cover 307 is used for sealing energy storage cavity 3051, wherein energy storage cavity 3051 is to adjust the piston 303 in the process of up and down movement of the upper oil chamber due to the entry of piston rod 301 leading to the problem of the upper oil chamber oil discharge volume and the lower oil chamber oil inflow volume is not consistent, when the knee joint extension, piston rod 301 into the cylinder body 304, due to the piston rod 301 self volume caused by the volume of hydraulic oil into the upper oil chamber is less than the volume of hydraulic oil discharged from the lower oil chamber, the difference between the hydraulic oil in the process of pushing the energy storage piston 306 into the energy storage cavity 3051; When the knee joint flexion, piston rod 301 away from the cylinder body 304, the volume of hydraulic oil in the upper oil chamber is less than the volume of hydraulic oil into the lower oil chamber, at this time, the energy storage piston 306 in the energy storage cavity 3051 pushes the hydraulic oil into the lower oil chamber. The degree of coincidence of needle valve 309 and adjusting seat 305 flexion oil channel 3151 through the voice coil motor 312 control needle valve 309 and needle valve guide block 310, and then control the flow of flexion oil channel 3151, so as to adjust the damping of the extension and bending motion of the prosthesis. Stop block 308 is fixed with adjusting seat 305 through screw, needle valve 309 bottom and needle valve connecting shaft 311 thread connection, voice coil motor 312 output end is fixedly connected with the bottom of needle valve connecting shaft 311 through screw, voice coil motor 312 bottom is fixedly connected with motor fixed seat 313 through screw, motor fixed seat 313 is fixedly connected with adjusting seat 305 through screw.

[0044] Figure 6 The hydraulic damping module 3 is the extension of the oil channel, when the piston 303 moves downward, the hydraulic oil returns to the upper oil chamber through the extension oil channel 3141, at this time, the active extension of the knee joint is driven by the motor 5 through the gear transmission module 2 to provide driving torque for the joint rotation module 1, and the hydraulic damping module 3 does not provide damping.

[0045] Figure 7is the cross-sectional view of the flexure oil passage in the hydraulic damping module 3, when the piston 303 moves upward, the hydraulic oil returns to the lower oil chamber through the flexure oil passage 3151, the voice coil motor 312 adjusts the flow of the flexure oil passage 3151 by controlling the degree of coincidence between the needle valve 309 and the flexure oil passage 3151, thereby controlling the flexure damping size.

[0046] The preferred embodiments of the present application have been described in detail above. It should be understood that modifications and variations can be made by those of ordinary skill in the art without departing from the spirit and scope of the application. Therefore, it is intended that the application be defined by the scope of the claims and their equivalents.

Claims

1. A single-axis active-passive hybrid intelligent prosthetic knee joint structure with energy recovery function, characterized in that, The knee joint rehabilitation device comprises a joint rotation module, a gear transmission module, a hydraulic damping module, a frame and a motor. In the passive stage of the knee joint, the joint rotation module transmits the passive torque of the knee joint to the motor through the gear transmission module, drives the motor to rotate, thereby realizing the energy recovery of the motor, and the hydraulic damping module provides damping torque to ensure the stability of the knee joint. The joint rotation module comprises a small quadrangular prism, an upper connecting rod, a rotating shaft, a torque sensor, a posture sensor, a connecting rod shaft and a connecting rod. The first-stage bevel gear transmission system comprises a small bevel gear and a large bevel gear, the second-stage gear transmission system comprises a small gear and a large gear, the synchronous belt wheel transmission assembly comprises a small belt wheel and a large belt wheel, the transmission frame is fixed on both sides of the frame, the output shaft of the motor is fixedly connected with the small bevel gear, the small bevel gear is engaged with the large bevel gear, the large bevel gear is connected with the small gear through a key, the large gear is engaged with the small gear, the shaft end of the large gear is connected with the small belt wheel through a key, the small belt wheel is connected with the large belt wheel through a synchronous belt, and the large belt wheel is fixedly connected with the torque sensor. The hydraulic damping module comprises a hydraulic cylinder, an adjusting seat, an energy accumulator, a needle valve and a voice coil motor.

2. The single-axis passive-active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function according to claim 1, characterized in that, The large gear is provided with third and fourth bearings at both ends to realize the stability of transmission. 3.The single-axis passive-active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function of claim 1, wherein, The hydraulic cylinder comprises a piston rod, a cylinder cover, a cylinder body, and a piston, the piston rod is pivotally connected with the lower end of the connecting rod, the cylinder cover is threadedly connected with the upper end of the cylinder body, and the piston is threadedly connected with the lower end of the piston rod and slidably connected in the cylinder body.

4. The single-axis passive / active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function according to claim 3, characterized in that, The adjusting seat is provided with a first one-way valve and a second one-way valve, which respectively control the flow direction of hydraulic oil in the flexion oil passage and the extension oil passage.

5. The single-axis passive / active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function according to claim 4, characterized in that, The energy accumulator comprises an energy accumulator piston, an energy accumulator cavity sealing cover, and a stopper, the upper part of the adjusting seat is provided with an energy accumulator cavity, the energy accumulator piston is arranged in the energy accumulator cavity, the energy accumulator cavity sealing cover is used for sealing the energy accumulator cavity, and the stopper is fixedly connected with the adjusting seat.

6. The single-axis passive / active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function according to claim 5, characterized in that, The needle valve bottom is threadedly connected with a needle valve connecting shaft, the output end of the voice coil motor is fixedly connected with the bottom of the needle valve connecting shaft, the bottom of the voice coil motor is fixedly connected with a motor fixing seat, the motor fixing seat is fixedly connected with the adjusting seat, and the voice coil motor controls the coincidence degree of the needle valve passing through the needle guide block and the flexion oil passage in the adjusting seat.

7. The single-axis passive / active hybrid drivable intelligent prosthetic knee joint structure with energy recovery function according to claim 6, characterized in that, When the piston moves downward, hydraulic oil returns to the upper oil cavity of the hydraulic cylinder through the extension oil passage, at this time, the active extension of the knee joint is driven by the motor through the gear transmission module to provide a driving torque for the joint rotation module, and the hydraulic damping module does not provide damping; when the piston moves upward, hydraulic oil returns to the lower oil cavity through the flexion oil passage, the voice coil motor adjusts the flow of the flexion oil passage by controlling the coincidence degree of the needle valve and the flexion oil passage, thereby controlling the flexion damping size.

Images