Unpowered lower limb rehabilitation robot

Abstract

The application relates to the field of medical rehabilitation devices, and particularly discloses a non-powered lower limb rehabilitation robot, which comprises a vehicle frame, at least two input power wheels for driving the swing of a patient's leg are arranged on the vehicle frame, a speed changing mechanism is arranged between the adjacent input power wheels, the speed changing mechanism comprises a wheel shaft chain wheel coaxially rotating with the input power wheels, at least two speed changing hub chain wheels in transmission cooperation with the wheel shaft chain wheel, a seven-stage speed changing hub connected between the adjacent speed changing hub chain wheels, a speed changing hub flywheel rotating in cooperation with the seven-stage speed changing hub, and the speed changing hub chain wheel and the speed changing hub flywheel can form a motion separation state when the seven-stage speed changing hub is in the first to sixth gears. The non-powered lower limb rehabilitation robot can effectively reduce the resistance brought to a second person when the non-powered lower limb rehabilitation robot advances, and the reverse transmission mechanism is arranged, the driving force of the patient's own gravity is provided for the patient, and the patient with certain movement ability can independently carry out rehabilitation training without the second person.

Description

Technical Field

[0001] This invention relates to the field of medical rehabilitation equipment, and in particular to an adjustable-speed, unpowered lower limb rehabilitation robot. Background Technology

[0002] Currently, lower limb rehabilitation robots are being used for stroke patients. These include wearable exoskeleton rehabilitation robots driven by motors. The exoskeleton is moved by hip, knee, and ankle motors to assist patients in lower limb rehabilitation training. Since patients with hemiplegia often have difficulty controlling their balance, they often need to use a cane when using such wearable exoskeleton rehabilitation robots. This requires that the patient's upper limb motor function be normal. However, most stroke patients usually have varying degrees of hemiplegia in both the upper and lower limbs. Therefore, these types of lower limb exoskeleton rehabilitation robots are difficult to use for people with the aforementioned conditions.

[0003] Besides lower limb rehabilitation robots, another type of lower limb rehabilitation robot currently used in lower limb rehabilitation training is the unpowered lower limb rehabilitation robot. This robot's support structure includes leg links and intermediate transmission components. It relies on a second person to propel it forward. The torque generated by the power input wheel during movement is transmitted through a chain, causing a transmission cam to rotate counter-clockwise. The cam's profile is specially designed so that the motion transmitted from the cam to the leg links follows the trajectory of normal gait, thus guiding the patient through normal gait rehabilitation training. However, the ratio of the leg link's motion to the power input wheel's rotational speed is fixed in this type of robot. When the patient's lower limbs are completely unable to provide active power, the person assisting with rehabilitation needs to apply even greater force to propel the robot forward. This type of unpowered rehabilitation robot is highly dependent on a second person and cannot provide them with easier propulsion when necessary. It also fails to meet the needs of patients in the later stages of rehabilitation to perform independent rehabilitation training and reduce the burden on the second person.

[0004] The technical problem this application aims to solve is: how to better conduct rehabilitation training for stroke patients while reducing the burden on a second person. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a non-powered lower limb rehabilitation robot that is adjustable in speed, has good rehabilitation effect, and has low dependence on a second person.

[0006] The technical solution adopted in this invention is as follows: a non-powered lower limb rehabilitation robot, including a frame, the frame is provided with at least two input power wheels for driving its movement, a speed change mechanism is provided between the input power wheels, the speed change mechanism includes a wheel axle sprocket that rotates coaxially with the input power wheels, at least two speed change hub sprockets that are driven and cooperate with the wheel axle sprockets, a seven-speed change hub connected between adjacent speed change hub sprockets, a speed change hub flywheel that cooperates with the rotation of the seven-speed change hub, and a right speed change hub sprocket. The speed change hub sprocket and the speed change hub flywheel form a motion separation state when the seven-speed change hub is in gear one to six and the speed ratio between the speed change hub flywheel and the speed change hub sprocket is less than the corresponding gear ratio.

[0007] The transmission mechanism also includes a first camshaft sprocket that cooperates with the right-side transmission hub sprocket, a camshaft sleeved in the first camshaft sprocket, and a first one-way bearing. The two sides of the one-way bearing are respectively connected to the first camshaft sprocket and the camshaft key. A second camshaft sprocket that rotates coaxially with the camshaft is provided on one side of the camshaft. When the rotational speed of the first camshaft sprocket is less than the rotational speed of the second camshaft sprocket, the first camshaft sprocket and the second camshaft sprocket form a motion separation state.

[0008] The camshaft is provided with a reverse transmission mechanism on at least one side. The reverse transmission mechanism includes a transmission cam at both ends of the camshaft. A one-way transmission gear is provided on the outside of the transmission cam and rotates with it. The one-way transmission gear is provided with a reverse transmission rack that meshes with it. The reverse transmission rack is provided with a thigh connecting rod that is hinged to it. When the thigh connecting rod rotates, it transmits torque to the reverse transmission mechanism and then acts on the transmission mechanism to drive the input power wheel to rotate.

[0009] In some embodiments, a wheel axle is provided at the input power wheel shaft center and is keyed thereto. The wheel axle is connected to a differential via a bevel gear disposed outside it, and the wheel axle sprocket is fixed to the differential housing.

[0010] In some implementations, the housing of the seven-speed hub is bolted with the left and right sprockets of the hub, and the flywheel of the hub is connected to the housing of the seven-speed hub via a ratchet and a gear set.

[0011] In some implementations, the seven-speed hub is equipped with a gear and a ratchet. The gear-shifting hub flywheel of the seven-speed hub drives the seven-speed hub housing to rotate at different speeds in the forward direction. The speed ratio between the gear-shifting hub flywheel and the seven-speed hub housing is the speed ratio corresponding to the gear of the seven-speed hub.

[0012] In some embodiments, the transmission mechanism further includes a first camshaft sprocket sleeved outside the camshaft, a first drive chain being provided between the first camshaft sprocket and the right sprocket of the transmission hub, and a second drive chain being provided between the second camshaft sprocket and the flywheel of the transmission hub.

[0013] In some embodiments, a first one-way bearing fixed to the outside of the camshaft is sleeved inside the first camshaft sprocket, a cam end bearing is provided outside the one-way transmission gear, the cam end bearing is sleeved inside the frame, a cam follower is provided between the one-way transmission gear and the transmission cam and is fixed to both, a second one-way bearing fixed to the outside of the camshaft is provided inside the one-way transmission gear, a cam middle bearing is also fixed outside the camshaft, and multiple rack guide bearings that limit their engagement are provided at both ends of the one-way transmission gear.

[0014] In some embodiments, the reverse transmission mechanism further includes a swing member fixed to the thigh link, a pneumatic spring hinged between the swing member and the reverse transmission rack, a calf link rotating with the bottom of the thigh link, a first coupling between the thigh link and the calf link, a pedal rotating with the bottom of the calf link, and a second coupling between the pedal and the calf link.

[0015] In some embodiments, the first coupling is hinged to a first lower leg guide link, the top end of the first lower leg guide link is hinged to a lower leg guide swing member mounted on the top end of the thigh link, the lower leg guide swing member is also provided with a second lower leg guide link that rotates with it and is fixed outside the cam follower, the thigh link is also provided with a thigh guide link that is hinged outside the transmission cam, and guide mounting plates are respectively hinged to the transmission cam and the thigh link.

[0016] In some embodiments, the frame is provided with a handrail for a second person to push, and the bottom of the frame is also provided with an auxiliary wheel for maintaining direction, the lowest point of the auxiliary wheel being in the same horizontal plane as the lowest point of the input power wheel.

[0017] The beneficial effects of the unpowered lower limb rehabilitation robot of the present invention are as follows:

[0018] (1) By setting a seven-speed hub, the ratio of the rotational speed of the input power wheel to the swing speed of the thigh link and the lower leg link can be adjusted. By changing the transmission ratio, the amount of thrust required to push the patient for gait rehabilitation training can be changed. When the unpowered lower limb rehabilitation robot is traveling on an uphill road, the thrust required by the second person is reduced through the speed change mechanism. Therefore, the second person pushing the unpowered rehabilitation robot will become a more effortless process, thereby reducing the thrust required by the second person.

[0019] (2) Since the power source required for gait rehabilitation training of existing rehabilitation equipment is provided by a second person, while patients in the later stages of rehabilitation have stronger autonomous movement ability, the present invention, through the setting of a reverse transmission mechanism, recovers and utilizes the work done by the patient on the pedals during gait training and converts it into the power to drive the input power wheel forward, further reducing the thrust required by the second person. The reverse transmission mechanism fully follows the principle of gradually completing the rehabilitation training of the patient's lower limb function. As the patient's lower limb movement ability improves, the increased active movement work will reduce the work of the second person in rehabilitation training. Therefore, this lower limb unpowered rehabilitation robot can effectively utilize the work done by the patient at different rehabilitation stages, improve the patient's active participation, and reduce the burden on the second person.

[0020] (3) The present invention can effectively reduce the resistance to the second person when the unpowered lower limb rehabilitation robot moves forward, and the reverse transmission mechanism will use the patient's own gravity to provide driving force for the patient, so that patients with a certain degree of motor ability can carry out rehabilitation training independently without the need for a second person. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the vehicle frame of the present invention;

[0022] Figure 2 This is a partial three-dimensional structural diagram of the vehicle frame of the present invention;

[0023] Figure 3 This is a schematic diagram of the reverse transmission mechanism of the present invention;

[0024] Figure 4 This is a schematic diagram of the three-dimensional structure of the camshaft surface of the present invention;

[0025] Figure 5 This is a schematic cross-sectional view of the camshaft structure of the present invention;

[0026] Figure 6 This is a schematic diagram of the three-dimensional structure of the chain drive of the present invention;

[0027] Figure 7 This is a schematic diagram of the planar structure of the chain drive according to the present invention;

[0028] Figure 8 This is a schematic diagram of the three-dimensional structure of the seven-speed hub of the present invention;

[0029] Figure 9 This is one of the schematic diagrams illustrating the reverse transmission principle of the present invention;

[0030] Figure 10 This is the second schematic diagram of the reverse transmission principle of the present invention;

[0031] Figure 11This is a schematic diagram of the transmission cam acquisition process of the present invention.

[0032] In the diagram: 1. Frame; 2. Auxiliary wheel; 3. Input power wheel; 4. Transmission mechanism; 5. Reverse transmission mechanism; 6. Handrail; 7. Thigh linkage; 8. First lower leg guide linkage; 9. First coupling; 10. Lower leg linkage; 11. Second coupling; 12. Pedal; 13. Swing component; 14. Gas spring; 15. Reverse transmission rack; 16. Rack guide bearing; 17. One-way transmission gear; 18. Transmission cam; 19. Lower leg guide swing component; 20. Second lower leg guide linkage; 21. Thigh guide linkage; 22. Seven-speed hub; 23. Differential; 24. 25. Wheel axle; 26. Camshaft; 27. Guide mounting plate; 28. Cam follower; 29. ​​Cam center bearing; 30. Second camshaft sprocket; 31. First camshaft sprocket; 32. Cam end bearing; 33. First one-way bearing; 34. Second one-way bearing; 35. First drive chain; 36. Shift hub sprocket; 37. Second drive chain; 38. Shift hub flywheel; 39. Third drive chain; 40. Wheel axle sprocket; 41. Shift hub left axle; 42. Shift hub right axle; 43. Shift hub left sprocket; 44. Shift hub right sprocket. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1 This invention provides a technical solution: a non-powered lower limb rehabilitation robot, including a frame 1. The bottom of the frame 1 is provided with two input power wheels 3 and two auxiliary wheels 2. The diameter of the input power wheels 3 is much larger than that of the auxiliary wheels 2, and the auxiliary wheels 2 are rotatable, which makes it easier for a second person to control the direction when pushing. The frame 1 is also provided with a handrail 6 for the second person to push. The handrail 6 is made of rubber or plastic with anti-slip strips to prevent the second person from losing control due to sweaty palms when pushing. A speed change mechanism 4 and a reverse transmission mechanism 5 are provided inside the frame 1.

[0035] Please see Figures 2 to 8 The transmission mechanism 4 includes a differential 23, a first transmission chain 34, a second transmission chain 36, a wheel axle sprocket 39, a transmission hub sprocket 35, a transmission hub left sprocket 42, a transmission hub right sprocket 43, a bai'n 41, a seven-speed transmission hub 22, and a transmission hub flywheel 37.

[0036] The reverse transmission mechanism 5 includes a thigh link 7, a first lower leg guide link 8, a first coupling 9, a lower leg link 10, a second coupling 11, a pedal 12, a swinging component 13, a gas spring 14, a reverse transmission rack 15, a rack guide bearing 16, a one-way transmission gear 17, a transmission cam 18, a lower leg guide swinging component 19, a second lower leg guide link 20, a thigh guide link 21, a camshaft 25, a guide mounting plate 26, a cam follower 27, a cam center bearing 28, a second camshaft sprocket 29, a first camshaft sprocket 30, a cam end bearing 31, a first one-way bearing 32, and a second one-way bearing 33.

[0037] Among them, a wheel axle 24 is keyed between the two input power wheels 3. The wheel axle 24 is connected to a differential 23 via a bevel gear. A wheel axle sprocket 39 is fixedly connected to the housing of the differential 23. The wheel axle sprocket 39 is connected to the left sprocket 42 of the shift hub sprocket 35 via a third drive chain 38 connected to its exterior. The seven-speed hub 22 is fixedly installed on both sides of its sides to the left sprocket 42 and the right sprocket 43 of the shift hub via bolts. The right sprocket 43 of the shift hub is connected to the first camshaft sprocket 30 outside the camshaft 25 via the shift hub sprocket 35 connected to its exterior. The left and right sides of the camshaft 25 are keyed with... Two transmission cams 18 are connected to the second lower leg guide link 20 and the thigh guide link 21 via cam follower 27 fixed on them. The thigh guide link 21 is rotatably connected to the thigh link 7 via a bearing. The second lower leg guide link 20 is rotatably connected to the lower leg guide swing member 19 via a bearing. The lower leg guide swing member 19 is rotatably connected to the first lower leg guide link 8 via a bearing. The thigh link 7 is rotatably connected to the lower leg link 10 via a first coupling 9. The first lower leg guide link 8 is rotatably connected to the lower leg link 10 via a first coupling 9. The lower leg link 10 is rotatably connected to the pedal 12 via a second coupling 11.

[0038] The following are methods for patients to undergo normal gait rehabilitation training in their lower limbs:

[0039] The second person pushes the handlebar 6, causing the frame 1 to move forward. The input drive wheel 3 generates counter-clockwise torque through friction with the ground. This torque is transmitted from the input drive wheel 3 to the differential 23 via the wheel axle 24. The differential 23 then transmits the counter-clockwise torque to the seventh-speed hub 22 via the third drive chain 38. The seventh-speed hub 22 transmits the counter-clockwise torque to the second camshaft sprocket 29 via the second drive chain 36. The second camshaft sprocket 29 drives the camshaft 25 to rotate counter-clockwise, causing the drive cams 18 at both ends to rotate counter-clockwise. Cam 18 has cam grooves on its left and right sides, and cam follower 27 is fixed in the cam grooves. Cam follower 27 is connected to the second lower leg guide link 20 and the thigh guide link 21. The swing of the second lower leg guide link 20 causes the lower leg guide swing member 19, the first lower leg guide link 8, the first coupling 9 and the lower leg link 10 to swing. The thigh guide link 21 causes the thigh link 7 to swing. Thus, the thigh link 7 and the lower leg link 10 simulate the normal human gait while swinging, thereby driving the patient's lower limbs to perform gait simulation walking training.

[0040] The gas spring 14 is hinged to the thigh link 7 via the swing member 13. The gas spring 14 is also hinged to one side of the reverse transmission rack 15 via a pin. Four rack guide bearings 16 are provided on the outside of the reverse transmission rack 15 to cooperate with the rolling restriction of the reverse transmission rack 15. The reverse transmission rack 15 is meshed with the one-way transmission gear 17. The one-way transmission gear 17 is fixedly installed with the second one-way bearing 33.

[0041] Please see Figure 9 and Figure 10When the patient can independently press down pedal 12, it signifies that the patient's recovery has entered a stage where they are gradually able to work independently. After pedal 12 is pressed down, the lower leg connecting rod 10 experiences a clockwise force, which drives the second lower leg guide connecting rod 20 to apply pressure F1 to the transmission cam 18 via the cam follower 27. This pressure F1 acts on the surface of the transmission cam 18, which is equivalent to applying a counterclockwise torque τ to the transmission cam 18, thereby causing the transmission cam 18 to rotate counterclockwise. At this moment, the pneumatic spring 14 is in an uncompressed state, so the reverse transmission rack 15 does not apply pressure to the one-way transmission gear 17. The power source for the transmission cam 18 is entirely provided by F1. As the gait progresses, the thigh link 7 swings counterclockwise. Because the distance between the hinge point of the air spring 14 and the thigh link 7 and the origin of rotation of the thigh link 7 is relatively long, the thigh link 7 compresses the air spring 14, causing the reverse transmission rack 15 to generate tangential pressure F2 on the one-way transmission gear 17, while reducing F1. Due to the action of the second one-way bearing 33, the reverse transmission rack 15 can only generate counterclockwise torque on the one-way transmission gear 17. The one-way transmission gear 17 then transmits this torque to the transmission cam 18. Furthermore, since F2 is a tangential force, its conversion rate of counterclockwise torque to the transmission cam 18 is higher, thereby generating a larger torque τ'.

[0042] Please see Figures 4 to 5 The inner ring of the bearing 31 at the end of the cam is fitted with the camshaft 25 by a hole-shaft fit. The one-way transmission gear 17 is embedded with the second one-way bearing 33. The first camshaft sprocket 30 is embedded with the first one-way bearing 32. The second camshaft sprocket 29 is keyed to the camshaft 25. Therefore, due to the action of the first one-way bearing 32 and the second one-way bearing 33, the camshaft 25 is only subjected to the torsional force of the first camshaft sprocket 30 and the one-way transmission gear 17 in the ω direction. That is, the first camshaft sprocket 30 and the one-way transmission gear 17 can only drive the camshaft 25 to rotate in the ω direction.

[0043] Please see Figures 6 to 8 Since the camshaft 25, the second camshaft sprocket 29, and the first one-way bearing 32 rotate coaxially, their angular velocities are the same, let their angular velocities be ω1; since the right shaft 41 of the shift hub and the shift hub flywheel 37 rotate coaxially, their angular velocities are the same, let their angular velocities be ω2; since the left shaft 40 of the shift hub and the shift hub sprocket 35 rotate coaxially, their angular velocities are the same, let their angular velocities be ω3; let the angular velocity of the first camshaft sprocket 30 be ω4; since the wheel axle 24 and the wheel axle sprocket 39 rotate coaxially, their angular velocities are the same, let their angular velocities be ω5.

[0044] The first one-way bearing 32 is fixedly installed with the camshaft 25. Under certain conditions, i.e., ω4<ω1, that is, when the seven-speed hub 22 is in first to sixth gear, the first camshaft sprocket 30 and the camshaft 25 are in a state of motion separation. That is, the rotation of the first camshaft sprocket 30 cannot drive the camshaft 25 to rotate. Similarly, since the seven-speed hub 22 is equipped with a driving ratchet and a driven ratchet, let the gear ratio of the seven-speed hub 22 be n. When ω3 / ω2>n, that is, when the seven-speed hub 22 is in first to sixth gear, the outer shell of the hub 22 and the hub flywheel 37 are in a state of motion separation. That is, the rotation of the left sprocket 42 of the hub cannot drive the right sprocket 43 of the hub to rotate.

[0045] Please refer to Table 1. The gear ratios of the seven-speed hub 22 from first to seventh gear are 0.632, 0.741, 0.843, 1.145, 1.335, and 1.545, respectively. When the patient drives the camshaft 25 through the reverse transmission mechanism 5... Figure 8 When the patient's drivetrain provides the direction of rotation, and the second person does not provide thrust, the rotational speed relationship is as follows:

[0046] ω2=ω1*13 / 18->ω3=ω2*n->ω5=ω3*29 / 36;

[0047] ω4=ω3*29 / 29

[0048] By determining whether ω4 < ω1, it is possible to determine whether the first camshaft sprocket 30 is separated from the camshaft 25, thus avoiding the situation where the first camshaft sprocket 30 and the right shaft 41 of the shift hub are simultaneously coupled with the left shaft 40 of the shift hub, which could lead to the first transmission chain 34 and the second transmission chain 36 jamming.

[0049] If the patient does not provide force when a second person applies pushing force, then Figure 8 The second person's power transmission chain is in the actual direction of rotation. At this time, the speed relationship is:

[0050] ω3=ω5*36 / 29->ω4=ω3*29 / 29->ω1=ω4-;

[0051] ω2 = ω1 * 13 / 18;

[0052] By determining ω3 / ω2>n, it is determined whether the left shaft 40 of the shift hub is disengaged from the right shaft 41 of the shift hub, thus avoiding the situation where the first camshaft sprocket 30 is coupled with the camshaft 25 and the left shaft 40 of the shift hub is coupled with the right shaft 41 of the shift hub, which would cause the first drive chain 34 and the second drive chain 36 to jam.

[0053] Table 1

[0054] 0.632 1.000 0.722 0.456 0.456 0.368 yes 1.385 yes 0.741 2.000 1.444 1.070 1.070 0.862 yes 1.385 yes 0.843 3.000 2.167 1.827 1.827 1.471 yes 1.385 yes 0.989 4.000 2.889 2.857 2.857 2.302 yes 1.385 yes 1.145 5.000 3.611 4.135 4.135 3.331 yes 1.385 yes 1.335 6.000 4.333 5.785 5.785 4.660 yes 1.385 yes 1.545 7.000 5.065 7.811 7.811 6.292 no 1.385 no

[0055] As shown in the table above, when the seven-speed hub 22 is in gears one through six, the unpowered lower limb rehabilitation robot supports both the patient providing power through the reverse transmission mechanism 5 and a second person providing thrust, thereby assisting the patient in performing normal gait rehabilitation training. Furthermore, by adjusting the gears of the seven-speed hub 22, the patient can control the amount of thrust according to their own recovery progress, making the patient's rehabilitation training results more obvious.

[0056] Please see Figure 11 The transmission cam 18 can drive the thigh link 7 and the lower leg link 10 to simulate the trajectory of a normal human gait. Figure 11 A method for obtaining the profile of transmission cam 18 is provided:

[0057] The periodic data of the hip and knee joints in normal human gait are obtained through the OpenSim platform. Then, the mechanism simulation model of thigh link 7, lower leg link 10 and transmission cam 18 is made through CERO or SolidWorks. Finally, the motion data of the hip and knee joints are input into the mechanism model to simulate the joints. At the same time, the original model without cams is rotated for one cycle, and the hub trajectory of cam follower 27 relative to transmission cam 18 is recorded. Thus, the transmission cam 18 model with the trajectory of normal human gait is obtained.

[0058] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A non-powered lower limb rehabilitation robot, comprising a frame (1), said frame (1) having at least two input power wheels (3) for driving its movement, characterized in that, A speed change mechanism (4) is provided between the input power wheels (3). The speed change mechanism (4) includes a wheel axle sprocket (39) that rotates coaxially with the input power wheels (3), at least two speed change hub sprockets (35) that are driven by the wheel axle sprockets (39), a seven-speed hub (22) connected between adjacent speed change hub sprockets (35), a speed change hub flywheel (37) that rotates with the seven-speed hub (22), and a right speed change hub sprocket (35). The speed change hub sprocket (35) and the speed change hub flywheel (37) form a motion separation state when the seven-speed hub (22) is in gear 1 to 6 and the speed change ratio between the speed change hub flywheel (37) and the speed change hub sprocket (35) is less than the corresponding gear ratio. The transmission mechanism (4) also includes a first camshaft sprocket (30) that is driven and cooperates with the right-side transmission hub sprocket (35), a camshaft (25) sleeved in the first camshaft sprocket (30), and a first one-way bearing (32). The two sides of the first one-way bearing (32) are keyed to the first camshaft sprocket (30) and the camshaft (25) respectively. A second camshaft sprocket (29) is provided on one side of the camshaft (25) and rotates coaxially with it. When the rotational speed of the first camshaft sprocket (30) is less than the rotational speed of the second camshaft sprocket (29), the first camshaft sprocket (30) and the second camshaft sprocket (29) form a motion separation state. The camshaft (25) is provided with a reverse transmission mechanism (5) on at least one side. The reverse transmission mechanism (5) includes a transmission cam (18) at both ends of the camshaft (25). The transmission cam (18) is provided with a one-way transmission gear (17) that rotates with it. The one-way transmission gear (17) is provided with a reverse transmission rack (15) that meshes with it. The reverse transmission rack (15) is provided with a thigh link (7) that is hinged to it. When the thigh link (7) rotates, it transmits torque to the reverse transmission mechanism (5) and then acts on the transmission mechanism (4) and drives the input power wheel (3) to rotate.

2. The unpowered lower limb rehabilitation robot according to claim 1, characterized in that, The input power wheel (3) has a wheel axle (24) connected to it by a key at its shaft center. The wheel axle (24) is connected to a differential (23) through a bevel gear set outside it. The wheel axle sprocket (39) is fixed to the housing of the differential (23).

3. The unpowered lower limb rehabilitation robot according to claim 1, characterized in that, The outer shell of the seven-speed hub (22) is connected to the left sprocket (42) and the right sprocket (43) of the hub by bolts. A third transmission chain (38) is provided between the left sprocket (42) of the hub and the wheel axle sprocket (39).

4. The unpowered lower limb rehabilitation robot according to claim 3, characterized in that, The seven-speed hub (22) is equipped with a gear set and a ratchet. The gear hub flywheel (37) of the seven-speed hub (22) drives the outer shell of the seven-speed hub (22) to rotate at different speeds in the forward direction. The speed ratio between the gear hub flywheel (37) and the outer shell of the seven-speed hub (22) is the speed ratio corresponding to the gear of the seven-speed hub. The gear hub flywheel (42) and the outer shell of the seven-speed hub (22) are connected by a ratchet and a gear set.

5. The unpowered lower limb rehabilitation robot according to claim 3, characterized in that, The transmission mechanism (4) further includes a first camshaft sprocket (30) sleeved outside the camshaft (25), a first transmission chain (34) is provided between the first camshaft sprocket (30) and the right sprocket (43) of the transmission hub, and a second transmission chain (36) is provided between the second camshaft sprocket (29) and the flywheel (37) of the transmission hub.

6. The unpowered lower limb rehabilitation robot according to claim 1, characterized in that, The first camshaft sprocket (30) is fitted with a first one-way bearing (32) fixed to the outside of the camshaft (25). The one-way transmission gear (17) is provided with a cam end bearing (31). The cam end bearing (31) is fitted inside the frame (1). The one-way transmission gear (17) and the transmission cam (18) are provided with a cam follower (27) fixed to both of them. The one-way transmission gear (17) is provided with a second one-way bearing (33) fixed to the outside of the camshaft (25). The camshaft (25) is also fixed with a cam middle bearing (28). The two ends of the one-way transmission gear (17) are respectively provided with multiple rack guide bearings (16) that are matched with its positioning.

7. The unpowered lower limb rehabilitation robot according to claim 6, characterized in that, The reverse transmission mechanism (5) further includes a swing member (13) fixed on the thigh link (7). A pneumatic spring (14) is hinged between the swing member (13) and the reverse transmission rack (15). The bottom of the thigh link (7) is provided with a calf link (10) that rotates with it. A first coupling (9) is provided between the thigh link (7) and the calf link (10). The bottom of the calf link (10) is provided with a pedal (12) that rotates with it. A second coupling (11) is provided between the pedal (12) and the calf link (10).

8. The unpowered lower limb rehabilitation robot according to claim 7, characterized in that, The first coupling (9) is hinged to a first lower leg guide link (8), and the top end of the first lower leg guide link (8) is hinged to a lower leg guide swing member (19) installed at the top end of the thigh link (7). The lower leg guide swing member (19) is also provided with a second lower leg guide link (20) that rotates with it and is fixed outside the cam follower (27). The thigh link (7) is also provided with a thigh guide link (21) that is hinged outside the transmission cam (18). The transmission cam (18) and the thigh link (7) are respectively hinged to a guide mounting plate (26).

9. The unpowered lower limb rehabilitation robot according to claim 1, characterized in that, The frame (1) is provided with a handrail (6) for a second person to push, and the bottom of the frame (1) is also provided with an auxiliary wheel (2) for maintaining direction. The lowest point of the auxiliary wheel (2) and the lowest point of the input power wheel (3) are located in the same horizontal plane.

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