Active prosthetic knee joint standing locking and load-sharing integrated structure

Abstract

The present invention relates to an active prosthetic knee joint standing locking and load-sharing integrated structure, comprising an upper end connecting component and a lower end connecting component, wherein the structure of the upper end connecting component comprises an upper end connecting block, a locking member movably matched with the upper end connecting block, and the structure of the lower end connecting component comprises a hollow sleeve, in which a reduction drive component and a joint shaft connected to the reduction drive component are arranged, end caps are respectively connected to the two ends of the hollow sleeve, the end caps are connected to the joint shaft through a bearing member, the joint shaft and the hollow sleeve are coaxially arranged, and the two ends of the joint shaft are respectively connected to the upper end connecting block through side connecting members, the lower part of the hollow sleeve is connected to a prosthetic leg, a gap is formed between the hollow sleeve and the upper end connecting block, the upper end connecting component and the lower end connecting component are relatively rotated by the reduction drive component to realize swinging, the locking member contacts the hollow sleeve to generate friction to realize locking during the standing phase, and is separated from the hollow sleeve during the swinging phase. The present invention optimizes the structural design and improves its comprehensive performance.

Description

Technical Field

[0001] The invention relates to the technical field of active prostheses, in particular to an active prosthesis knee joint standing locking and load sharing integrated structure. Background Art

[0002] Active prostheses are different from passive prostheses that cannot provide active torque. They can provide auxiliary torque for the wearer's movements and provide a more comfortable user experience. The movement process of a person wearing a prosthesis can be divided into two stages: the swing phase and the stance phase. The swing phase is the stage of a person's movement, with the left and right legs swinging alternately, and the stance phase is the stationary stage of a person, with both legs supporting the ground.

[0003] In the prior art, the motor-driven active prosthetic knee joint usually adopts a four-bar linkage structure, and the linear motor is arranged on the trunk of the prosthetic calf. Although it can simulate walking gait well, it has the disadvantages of poor structural compactness and lightness, lack of locking function, and greater impact of the linear motor on the wearer. At the same time, hydraulic drive also has problems such as portability and structural compactness. In addition, the prosthesis is directly installed on the human body, and the weight and size of the prosthesis will directly affect the comfort of wearing. The load-bearing capacity of the prosthetic knee joint structure is often in a contradictory relationship with the volume and mass of the knee joint. Therefore, there is still a lack of active prosthetic solutions with good comprehensive performance. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an active prosthetic knee joint standing locking and load-sharing integrated structure, which optimizes the structural design and improves the overall performance.

[0005] The technical solution adopted by the present invention is as follows:

[0006] An active prosthetic knee joint structure comprises an upper connecting component and a lower connecting component, the structure of the upper connecting component comprises an upper connecting block and a locking piece movably matched with the upper connecting block, the structure of the lower connecting component comprises a hollow sleeve, a reduction drive component and a joint shaft transmission-connected to the reduction drive component are arranged in the hollow sleeve, two ends of the hollow sleeve are respectively connected to end covers, the end covers are connected to the joint shaft through a bearing component, the joint shaft and the hollow sleeve are coaxially arranged, the two ends of the joint shaft are respectively connected to the upper connecting block through side connecting pieces, the lower part of the hollow sleeve is connected to the prosthetic leg, a gap is formed between the hollow sleeve and the upper connecting block, when working, the upper connecting component and the lower connecting component are driven by the reduction drive component to rotate relative to each other, in the standing phase, the locking piece contacts with the hollow sleeve to generate friction to achieve locking, and in the swinging phase, the locking piece is disengaged from the hollow sleeve.

[0007] Further technical solutions are:

[0008] The structure of the locking piece includes a locking neck, an upper end of which is formed with an upper positioning portion, and a lower end is connected to a locking block, a cavity for accommodating the locking neck and the locking block is formed in the upper connecting block, a lower limiting portion is provided on the inner wall of the cavity, and a spring is provided in the cavity, one end of the spring is connected to the lower limiting portion, and the other end is connected to the locking neck, for providing a pre-tightening force to disengage the upper limiting portion of the locking neck from the top surface of the upper connecting block and to limit the locking block by the lower limiting portion.

[0009] The structure of the locking member also includes a friction plate, which is connected to the bottom of the locking block. The friction plate is in an arc-shaped plate shape, and its surface matches the contour of the outer wall of the hollow sleeve.

[0010] The side connecting member is symmetrically arranged with the upper connecting block as the center, the upper side of the side connecting member is fixedly connected to the upper connecting block, and the lower side is sleeved on the joint shaft and connected through a key to realize transmission connection.

[0011] The joint shaft is a hollow structure.

[0012] A keyway is provided on the lock neck for cooperating with the upper end connecting block to lock its circumferential position.

[0013] The structure of the reduction drive assembly includes a motor stator, a motor rotor and a reducer. The motor stator is fixed in a hollow sleeve. The motor rotor is connected to the sleeve through a connecting piece. The sleeve is connected to the joint shaft through a bearing. The sleeve is connected to the input end of the reducer. The output end of the reducer is connected to the joint shaft through an output disk.

[0014] The beneficial effects of the present invention are as follows:

[0015] The present invention realizes the standing locking function by only utilizing the friction between the locking block and the friction plate and the hollow sleeve, thereby preventing the wearer from falling due to accidental bending of the joints and improving safety.

[0016] The present invention solves the contradictory relationship between load-bearing capacity and knee joint mass. By transferring the load-bearing capacity to the prosthetic leg through two groups of paths, the load-bearing capacity is shared, and the strength and stiffness requirements of the hollow sleeve and the joint shaft are effectively reduced under the same load-bearing strength, which can effectively protect the joint shaft, thereby helping to reduce the mass of the joint and making the overall structure lighter.

[0017] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0019] Figure 2 It is a cross-sectional view of an embodiment of the present invention.

[0020] Figure 3 It is an exploded view of an embodiment of the present invention.

[0021] In the figure: 1. lock neck; 2. upper end connecting block; 3. spring; 4. locking block; 5. friction plate; 6. hollow sleeve; 7. side connecting piece; 8. cover plate; 9. left end cover; 10. motor stator; 11. motor stator end sleeve; 12. motor rotor; 13. rotor fixing piece; 14. bearing; 15. elastic retaining ring; 16. positioning sleeve; 17. shaft sleeve; 18. joint shaft; 19. reducer; 20. output disk; 21. right end cover; 22. prosthetic leg connecting piece; 23. prosthetic leg; 101. upper limit part; 201. lower limit part. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described below with reference to the accompanying drawings.

[0023] See also Figure 1 and Figure 2 The active prosthetic knee joint structure of this embodiment includes an upper connecting component and a lower connecting component. The structure of the upper connecting component includes an upper connecting block 2 and a locking member movably matched with the upper connecting block 2. The structure of the lower connecting component includes a hollow sleeve 6. A reduction drive component and a joint shaft 18 connected to the reduction drive component are arranged in the hollow sleeve 6. The two ends of the hollow sleeve 6 are respectively connected with end covers by fasteners, which are a left end cover 9 and a right end cover 21. The two end covers are respectively connected to the joint shaft 18 through bearings 14. The joint shaft 18 is coaxially arranged with the hollow sleeve 6. The two ends of the joint shaft 18 are respectively connected to the upper connecting block 2 through side connecting members 7. The lower part of the hollow sleeve 6 is connected to a prosthetic leg 23. A gap is formed between the hollow sleeve 6 and the upper connecting block 2. When working, the upper connecting component and the lower connecting component are driven by the reduction drive component to rotate relative to each other to achieve swing. The locking member can contact with the hollow sleeve 6 to generate friction to achieve locking during the standing phase, and disengage from the hollow sleeve 6 during the swinging phase.

[0024] See also Figure 2 The structure of the locking member includes a lock neck 1, an upper end of which is formed with an upper limit portion 101, and the lower end is connected to the locking block 4. A cavity for accommodating the lock neck 1 and the locking block 4 is formed in the upper end connecting block 2, and a lower limit portion 201 is provided on the inner wall of the cavity, and a spring 3 is provided in the cavity. One end of the spring 3 is connected to the lower limit portion 201, and the other end is connected to the lock neck 1, which is used to provide a pre-tightening force to disengage the upper limit portion 101 of the lock neck 1 from the top surface of the upper end connecting block 2 and to limit the locking block 4 by the lower limit portion 201.

[0025] The structure of the locking member also includes a friction plate 5 , which is connected to the bottom of the locking block 4 . The friction plate 5 is in an arc-shaped plate shape, and its surface matches the outer wall profile of the hollow sleeve 6 .

[0026] The length of the friction plate 5 along the relative movement direction of the upper and lower end connecting components matches the rotation angle range of the joint shaft 18. The friction plate is a friction wear part and is easy to replace.

[0027] The side connecting member 7 is symmetrically arranged around the upper connecting block 2, the upper side of the side connecting member 7 is fixedly connected to the upper connecting block 2, and the lower side is sleeved on the joint shaft 18 and connected by a key to achieve transmission connection.

[0028] The lock neck 1 is provided with a keyway for cooperating with the upper end connecting block 2 to lock its circumferential position.

[0029] The upper end of the lock neck 1 is used to connect with the thigh receiving cavity (not shown in the figure), and the thigh receiving cavity is connected to the user's thigh residual limb. The upper limit portion 101 of the lock neck 1 and the lower limit portion 201 on the upper end connecting block 2 play a limiting role. After reaching the limited position, the bearing force from the thigh residual limb will be more transmitted through the two side connecting members 7. The side connecting member 7 is sleeved on the joint shaft 18, and the rotational movement of the joint shaft 18 is transmitted to the side connecting member 7 and then to the upper end connecting block 2 and the lock neck 1 by using a key. Since the side connecting members 7 are symmetrically arranged at both ends of the joint shaft 18, the bending moments therein can offset each other. The lock neck 1, the upper end connecting block 2 and the spring 3 together constitute a spring buffer module to improve the buffer bearing performance. The locking block 4 and the friction plate 5 thereon will only contact the hollow sleeve 6 when the wearer is subjected to the pressure in the gravity direction in the standing phase, and the friction force can be generated by the mutual extrusion of the friction plate 5 and the hollow sleeve 6 to achieve the locking function. In the swinging phase, although the spring 3 is also compressed, the pressure does not reach the set critical value, so that the friction plate 5 does not contact the hollow sleeve 6, and free movement is achieved.

[0030] The lower part of the hollow sleeve 6 is connected to the prosthetic leg connecting piece 22 via a fastener, and the hollow sleeve 6 is connected to the prosthetic leg 23 via the prosthetic leg connecting piece 22 .

[0031] Specifically, the radial positioning between the hollow sleeve 6 and the end cover can be achieved through step surface matching.

[0032] The outer side of the left end cover 9 is connected to a cover plate 8, and a space is formed between the end cover and the cover plate 8 for placing a spring member, which can be used to store energy during relative movement between the upper connecting component and the lower connecting component, so as to restore the initial set angle between the upper connecting component and the lower connecting component.

[0033] like Figure 2 and Figure 3As shown, the axial positioning of the motor stator 10 relies on the motor stator end sleeve 11 which is interference fit with the motor stator end sleeve 11, the motor stator end sleeve 11 is tightly fit with the inner wall of the hollow sleeve 6, the motor rotor 12 is assembled with the shaft sleeve 17 through the rotor fixing piece 13 which is interference fit with the motor stator 10 and keeps synchronous rotation, the shaft sleeve 17 is sleeved on the joint shaft 18 and connected through the bearing 14, the shaft sleeve 17 is connected to the reducer 19, the reducer 19 is connected to the output disk 20 through fasteners, the output disk 20 is key-connected with the joint shaft 18, and the output of the motor rotor 12 and the speed after being decelerated by the reducer 19 are output to the joint shaft 18.

[0034] Preferably, the joint shaft 18 is a hollow structure, so as to reduce the moment of inertia and the overall weight of the structure.

[0035] Specifically, a positioning sleeve 16 is provided on the joint shaft 18 , one end of which abuts against the bearing 14 to axially position the sleeve 17 .

[0036] Preferably, the reducer 19 is a harmonic reducer, whose wave generator is installed on the shaft sleeve 17 and reduces speed through gear meshing transmission.

[0037] The working principle of the active prosthetic knee joint structure of this embodiment is as follows:

[0038] The structures involved in force bearing include: lock neck 1, upper end connecting block 2, spring 3, side connecting piece 7, joint axis 18. It has two functions in the standing phase. On the one hand, it bears the weight of the human body distributed on this leg (generally half of the weight of the human body), and on the other hand, it provides a standing locking function to prevent the knee joint from bending accidentally and causing the wearer to fall.

[0039] Among them, the principle of realizing the load-bearing function is: the bearing force is transmitted from the residual thigh of the prosthesis wearer (lock neck side) to the prosthetic leg 23 along two paths in the standing locked state, and the transmission paths include two groups: ① along the lock neck 1, spring 3 and locking block 4 to the hollow sleeve 6, and then to the prosthetic leg 23; ② from the lock neck 1 and the upper connecting block 2 along the side connecting piece 7 to the two ends of the joint shaft 18, and then transmitted to the hollow sleeve 6 through the bearing 14, and then transmitted to the prosthetic leg 23.

[0040] Among them, the realization principle of the standing locking function is: when the wearer stands, the gravity of the torso compresses the lock neck 1, the spring 3 and the upper connecting block 2, and then the locking block 4 and the friction plate 5 press the hollow sleeve 6 to generate friction, thereby realizing the locking function.

[0041] Among them, the distribution principle of load-bearing and locking forces is as follows: Figure 2As shown, the stiffness selection of the spring 3 is determined by the pressure and the stroke length between the hollow sleeve 6 and the upper end connecting block 2. The reasonable stiffness selection of the spring 3 will ensure that the locking block 4 and the friction plate 5 are always separated from the hollow sleeve 6 during the movement phase of the prosthetic leg. Only when the pressure reaches the design value will they contact and generate friction to achieve locking. When bearing, part of the pressure will press the locking block 4 through the spring 3 and then act on the hollow sleeve 6, and further act on the ground through the prosthetic leg 23.

[0042] The method of using the active prosthetic knee joint structure of this embodiment is as follows:

[0043] When in use, the thigh socket is worn on the user's thigh residual limb, the angle and direction are adjusted, and the power supply of the prosthesis is turned on. During the marching process, that is, when the legs are in the swinging phase, the legs swing alternately and periodically. A single leg has several stages in one cycle, including heel-to-ground, single-foot full-foot support, toe-off and swinging. During the movement, the sensor installed on the prosthesis detects and analyzes the movement mode and the current stage, and controls the motor output to correspond to the required rotation speed, direction and torque, which are transmitted to the joint axis after being decelerated by the reducer. The final output is the rotation of the knee joint axis and the movement of the prosthesis thigh side driven by it. In the standing phase, that is, when the wearer is in a standing state with both legs vertical, the prosthesis leg will bear the gravity of the human body like a healthy leg, and transmit the pressure to the prosthesis leg and then to the ground along the above two groups of paths. At this time, due to the pressure, the lock neck 1 will squeeze the locking block 4 and the spring 3 in the direction of the joint axis 18, thereby causing the locking block 4 and the friction plate 5 to squeeze and generate friction with the hollow sleeve 6 to achieve the locking function.

[0044] Those skilled in the art can understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An active prosthetic knee joint structure, characterized in that: The invention comprises an upper connecting component and a lower connecting component, wherein the structure of the upper connecting component comprises an upper connecting block (2) and a locking member movably matched with the upper connecting block (2), and the structure of the lower connecting component comprises a hollow sleeve (6), a reduction drive component and a joint shaft (18) drivingly connected to the reduction drive component are arranged in the hollow sleeve (6), and end covers are respectively connected to both ends of the hollow sleeve (6), and the end covers are connected to the joint shaft (18) via a bearing member, and the joint shaft (18) and the hollow sleeve are connected to each other. (6) are coaxially arranged, the two ends of the joint shaft (18) are respectively connected to the upper end connection block (2) through the side connection pieces (7), the lower part of the hollow sleeve (6) is connected to the prosthetic leg (23), a gap is formed between the hollow sleeve (6) and the upper end connection block (2), and during operation, the upper end connection component and the lower end connection component are driven by the reduction drive component to rotate relative to each other, and in the standing phase, the locking piece and the hollow sleeve (6) are in contact to generate friction to achieve locking, and in the swinging phase, the locking piece and the hollow sleeve (6) are separated; The structure of the locking member comprises a locking neck (1), an upper end of which is formed with an upper limit portion (101), and a lower end of which is connected to a locking block (4); a cavity for accommodating the locking neck (1) and the locking block (4) is formed in the upper end connecting block (2); a lower limit portion (201) is provided on the inner wall of the cavity, and a spring (3) is provided in the cavity; one end of the spring (3) is connected to the lower limit portion (201), and the other end is connected to the locking neck (1), and is used to provide a pre-tightening force to disengage the upper limit portion (101) of the locking neck (1) from the top surface of the upper end connecting block (2) and to limit the locking block (4) by the lower limit portion (201); The structure of the locking member further comprises a friction plate (5) which is connected to the bottom of the locking block (4); the friction plate (5) is in the form of an arc-shaped plate, and its surface matches the outer wall profile of the hollow sleeve (6); The side connecting member (7) is symmetrically arranged with the upper connecting block (2) as the center, the upper side of the side connecting member (7) is fixedly connected to the upper connecting block (2), and the lower side is sleeved on the joint shaft (18) and connected via a key to achieve transmission connection; The joint shaft (18) is a hollow structure.

2. The active prosthetic knee joint structure according to claim 1, characterized in that: A keyway is provided on the lock neck (1) for cooperating with the upper end connection block (2) to lock its circumferential position.

3. The active prosthetic knee joint structure according to claim 1, characterized in that: The structure of the reduction drive assembly comprises a motor stator (10), a motor rotor (12) and a reducer (19); the motor stator (10) is fixedly arranged in a hollow sleeve (6); the motor rotor (12) is connected to a shaft sleeve (17) via a connecting piece; the shaft sleeve (17) is connected to a joint shaft (18) via a bearing piece; the shaft sleeve (17) is connected to an input end of the reducer (19); and the output end of the reducer (19) is connected to the joint shaft (18) via an output disk (20).

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