Linear variable-stiffness series elastic mechanism
By designing a linear variable stiffness series elastic mechanism and using the combination of the elastic shaft and the main body, the problems of complex mechanism design and maintenance difficulty in the existing technology are solved, and the effects of simplified structure, high compliance and precise control are achieved.
Patent Information
- Application Number
- CN202421290910.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-06
- Publication Date
- 2025-01-24
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing rehabilitation robot mechanisms with elastic components and adjustable stiffness are complex in design, requiring precise control systems and sensors, increasing manufacturing costs and maintenance difficulties.
Design a linear variable stiffness series elastic mechanism, through the vertical insertion of multiple elastic shafts and the main body, and the combination of the elastic structure and the balance frame to achieve stiffness adjustment and flexibility.
The straight -line variability series elastic mechanisms with simplified structure, high softness, and precision control can be achieved, making the machine more flexible during the movement, can adapt to changes in the external environment, and reduce the cost of manufacturing and maintenance.
Smart Images
Figure CN222391854U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of fitness and rehabilitation equipment, in particular to a linear variable stiffness series elastic mechanism. Background Art
[0002] Rehabilitation robots are advanced devices that combine robotics and rehabilitation medicine to help rehabilitation patients with sports rehabilitation training and treatment. Using machines to assist the human body in stretching muscles and bones often requires the design of mechanisms with elastic components and adjustable stiffness, which makes the machine more flexible during movement and able to adapt to changes in the external environment. Existing mechanisms with elastic components and adjustable stiffness are usually complex in design and require sophisticated control systems and sensors to achieve stiffness adjustment, which increases manufacturing costs and maintenance difficulties. Utility Model Content
[0003] In order to overcome the deficiencies of the prior art, the purpose of the utility model is to realize a linear variable stiffness series elastic mechanism with simplified structure, high compliance and precise control.
[0004] The purpose of the utility model is achieved by the following technical solutions:
[0005] A linear variable stiffness series elastic mechanism comprises a main body, which also comprises a plurality of elastic shafts. The main body comprises a plurality of mutually parallel balance frames, each of which is provided with a plurality of through holes, and each of the elastic shafts is vertically plugged into at least two of the balance frames through the through holes. The elastic shaft comprises a long rod, an elastic sleeve and an elastic structure, the elastic sleeve is located outside the long rod and is sleeved with the long rod, and the elastic structure is located at the upper and lower ends of the elastic sleeve and contacts the balance frame.
[0006] Preferably, the elastic shaft is further provided with a cotter pin, and the cotter pin is located at the lower end of the long rod and is movably connected to the long rod.
[0007] Preferably, the elastic shaft comprises a first elastic shaft and two second elastic shafts, the two second elastic shafts are symmetrically distributed about the first elastic shaft, and the main body comprises a first balancing frame, a second balancing frame and a third balancing frame.
[0008] Preferably, the first elastic shaft is vertically inserted into the first balancing frame, the second balancing frame and the third balancing frame in sequence from top to bottom through the through hole.
[0009] Preferably, the second elastic shaft is vertically inserted into the first balancing frame and the second balancing frame in sequence from top to bottom through the through hole.
[0010] Preferably, the linear variable-stiffness series elastic mechanism further includes two limit shafts, and the limit shafts are respectively vertically plugged into the second balancing frame and the third balancing frame through the through holes.
[0011] Preferably, a plurality of positioning pins are provided on the limiting shaft, and at least one of the positioning pins is located between the second balancing frame and the third balancing frame, so as to limit the moving distance between the second balancing frame and the third balancing frame.
[0012] Preferably, the elastic structure is a spring.
[0013] Preferably, the linear variable stiffness series elastic mechanism further comprises a support plate, the support plate is in a concave shape, a mounting plate is provided inside the concave shape, and the main body and the mounting plate are connected by welding.
[0014] Preferably, the linear variable-stiffness series elastic mechanism further comprises a binding strap, a connecting hole is provided on the support plate, and the binding strap passes through the connecting hole and is connected to the support plate.
[0015] Compared with the prior art, the linear variable stiffness series elastic mechanism of the utility model has the following advantages:
[0016] The linear variable stiffness series elastic mechanism of the present application realizes driving through the vertical connection between the first elastic shaft and the main body on the one hand, and produces stiffness changes with the external input of the system on the other hand. The second elastic shaft runs through the first balance frame and the second balance frame, which plays the role of fixing the first balance frame and flexibly changing the stiffness of the first balance frame, and can ensure that the entire mechanism changes in a linear form. Such a mechanism makes the machine more flexible during movement and can adapt to changes in the external environment. This variable stiffness mechanism can be used in the fields of power-assisted exoskeletons, human motion simulation, human simulation research, human-machine collaboration, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic diagram of the structure of the linear variable stiffness series elastic mechanism of the present application;
[0018] Figure 2 This is a schematic diagram of the structure of the linear variable stiffness series elastic mechanism of the present application without the limit axis;
[0019] Figure 3 for Figure 2 A structural exploded view of the first elastic shaft and the second elastic shaft;
[0020] Figure 4 This is a schematic diagram of the structure of the linear variable stiffness series elastic mechanism of the present application without the elastic axis;
[0021] Figure 5 It is a schematic diagram of the structure of the strap and the support plate;
[0022] Figure 6 This is a schematic diagram of the practical application of the linear variable stiffness series elastic mechanism of the present application.
[0023] In the figure: 100, main body; 101, first balance frame; 102, second balance frame; 103, third balance frame; 200, elastic shaft; 201, first elastic shaft; 202, second elastic shaft; 21, long rod; 22, elastic sleeve; 23, elastic structure; 24, shaft cover; 25, cotter pin; 300, through hole; 400, limit shaft; 401, positioning pin; 500, strap; 600, support plate; 601, mounting plate. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component through which it is fixed. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0027] Figure 1 to Figure 6 The utility model is a linear variable stiffness series elastic mechanism, comprising a main body 100, an elastic shaft 200, and a through hole 300. The through hole 300 is located on the main body 100, and the elastic shaft 200 is vertically plugged into the main body 100 through the through hole 300. Figure 1 , Figure 2As shown, the main body 100 includes a first balance frame 101, a second balance frame 102 and a third balance frame 103, and the elastic shaft 200 includes a first elastic shaft 201 and a second elastic shaft 202. The first elastic shaft 201 is vertically plugged with the first balance frame 101, the second balance frame 102 and the third balance frame 103 from top to bottom through the through hole 300, and the second elastic shaft 202 is vertically plugged with the first balance frame 101 and the second balance frame 102 from top to bottom through the through hole 300.
[0028] Specifically, the first balance frame 101 , the second balance frame 102 , and the third balance frame 103 are parallel to each other.
[0029] Specifically, the first elastic axis 201 is a long axis and is parallel to the second elastic axis 202. There are multiple second elastic axes 202.
[0030] Specifically, there are two second elastic axes 202 . In a preferred embodiment, the two second elastic axes 202 are symmetrically distributed about the first elastic axis 201 .
[0031] like Figure 3 As shown, the elastic shaft 200 includes a long rod 21, an elastic sleeve 22 and an elastic structure 23, wherein the elastic sleeve 22 is located outside the long rod 21 and sleeved with the long rod 21. The elastic structure 23 is located on the elastic sleeve 22, and the effective number of turns of the elastic structure 23 is adjusted by vertical tension to adjust the variable range of the stiffness of the mechanism.
[0032] In a preferred embodiment, the elastic structure 23 is disposed at the upper and lower ends of the elastic sleeve 22 and contacts the main body 100. In some other embodiments, the entire section of the elastic sleeve 22 is the elastic structure 23. In one embodiment, the elastic structure 23 is a spring.
[0033] Specifically, the elastic structure 23 on the first elastic shaft 201 successively contacts the lower wall of the first balance frame 101, the upper wall of the second balance frame 102, the lower wall of the second balance frame 102 and the upper wall of the third balance frame 103 from top to bottom. It can serve as a driving shaft and can also produce stiffness changes with external input of the system. It is the main elastic element of the entire system.
[0034] In a preferred implementation, the first elastic shaft 201 is connected vertically to the elastic structure 23 of the vertical plug-in portion of the second balancing frame 102 .
[0035] Specifically, the elastic structure 23 of the second elastic shaft 202 contacts the lower wall of the first balance frame 101 and the upper wall of the second balance frame 102 from top to bottom, thereby fixing the first balance frame 101 and flexibly changing the stiffness of the first balance frame 101. Its existence can ensure that the entire mechanism changes in a linear form.
[0036] The elastic shaft 200 also includes a shaft cover 24 and a split pin 25. The shaft cover 24 is located at the head of the elastic shaft 200 and is integrally formed with the long rod 21 to achieve a fixed connection between the elastic shaft 200 and one end of the main body 100. The split pin 25 is located at the bottom end of the elastic shaft 200 and is movably connected to the long rod 21 to serve as a limit.
[0037] The linear variable stiffness series elastic mechanism also includes a limit shaft 400, which is located between the second balance frame 102 and the third balance frame 103, and is vertically plugged into the second balance frame 102 and the third balance frame 103 through the through hole 300. On the one hand, it is used to connect the second balance frame 102 and the third balance frame 103, and on the other hand, it is used to limit the position of the third balance frame 103.
[0038] like Figure 4 As shown, the limiting shaft 400 includes a positioning pin 401 . A plurality of positioning pins 401 are disposed on the limiting shaft 400 , and at least one positioning pin 401 is located between the second balancing frame 102 and the third balancing frame 103 , so as to limit the moving distance between the second balancing frame 102 and the third balancing frame 103 .
[0039] Specifically, the number of the positioning pins 401 is two.
[0040] The linear variable stiffness series elastic mechanism also includes a strap 500 and a support plate 600. The support plate 600 is provided with a mounting plate 601 and a connecting hole. The mounting plate 601 is located on the inner wall of the support plate 600. The connecting hole passes through both ends of the support plate 600. The main body 100 is fixed inside the support plate 600 by welding with the mounting plate 601, and the strap 500 is connected to the support plate 600 by passing through the connecting hole.
[0041] Specifically, there are multiple straps 500 . In one embodiment, there are three straps 500 .
[0042] Specifically, the number of the support plates 600 and the mounting plates 601 corresponds to the number of the straps 500 , and the number of the support plates 600 and the mounting plates 601 is three.
[0043] In a preferred embodiment, the support plate 600 is in a concave shape, which can better fit the curve of the human skeleton.
[0044] The entire structure of the present application is formed in series to form a complete set of series elastic mechanisms with variable stiffness. The device has three working modes. The first working mode is: when the third balance frame 103 is fixed, the first elastic shaft 201 is pulled, and the mechanism fixed on the first balance frame 101 is buffered once due to the action of the elastic structure 23 at the bottom end of the first elastic shaft 201, and is buffered twice due to the action of the elastic structure 23 at the top end of the second elastic shaft 202 and the middle end of the first elastic shaft 201. At the same time, the mechanism fixed on the second balance frame 102 is also buffered due to the change in stiffness, thereby achieving the effect of variable stiffness;
[0045] The second working mode is: when the second balancing frame 102 is fixed, the first elastic shaft 201 is pulled, and the mechanisms fixed on the first balancing frame 101 and the third balancing frame 103 will become more flexible due to the change of rigidity due to the existence of the elastic structure 23;
[0046] The third working mode is: when the first balancing frame 101 is fixed, the first elastic shaft 201 is pulled, and the mechanism for fixing the second balancing frame 102 and the third balancing frame 103 will also change in stiffness, thereby adjusting the stiffness variable range of the entire system.
[0047] If the mechanism is used in an upper limb exoskeleton, it can be used in the upper arm design of the upper limb exoskeleton. The series elastic mechanism allows the upper arm to have a buffer range when doing large movements to avoid muscle strain. Figure 5 As shown, the design for the lower limb exoskeleton thigh, the strap 500 is connected to the support plate 600 through the connection hole of the support plate 600. The series elastic mechanism allows the thigh to be effectively buffered when doing squatting exercises, avoiding damage to the knee. The linear variable stiffness series elastic mechanism of the present application realizes driving on the one hand through the vertical plugging of the first elastic shaft 201 and the main body 100, and on the other hand, the stiffness changes with the external input of the system, and the second elastic shaft 202 runs through the first balance frame 101 and the second balance frame 102, which plays the role of fixing the first balance frame 101 and flexibly changing the stiffness of the first balance frame 101, and can ensure that the entire mechanism changes in a linear form. Such a mechanism makes the machine more flexible during movement and can adapt to changes in the external environment. This variable stiffness mechanism can be used in the fields of power-assisted exoskeletons, human motion simulation, human simulation research, human-machine collaboration, etc.
[0048] The above embodiments only express several implementation methods of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the utility model, several modifications and improvements can be made, which are equivalent modifications and improvements made to the above embodiments based on the essential technology of the utility model, and all of them belong to the protection scope of the utility model.
Claims
1. A linear variable stiffness series elastic mechanism, comprising a main body, characterized in that: The linear variable stiffness series elastic mechanism also includes a plurality of elastic shafts, the main body includes a plurality of parallel balancing frames, each of the balancing frames is provided with a plurality of through holes, each of the elastic shaft is vertically plugged into at least two of the balancing frames through the through holes, the elastic shaft includes a long rod, an elastic sleeve and an elastic structure, the elastic sleeve is located outside the long rod and is sleeved with the long rod, and the elastic structure is located at the upper and lower ends of the elastic sleeve and is in conflict with the balancing frame.
2. The linear variable stiffness series elastic mechanism according to claim 1, characterized in that: The elastic shaft is also provided with a cotter pin, and the cotter pin is located at the lower end of the long rod and is movably connected to the long rod.
3. The linear variable stiffness series elastic mechanism according to claim 1, characterized in that: The elastic shaft comprises a first elastic shaft and two second elastic shafts, the two second elastic shafts are symmetrically distributed about the first elastic shaft, and the main body comprises a first balancing frame, a second balancing frame and a third balancing frame.
4. The linear variable stiffness series elastic mechanism according to claim 3, characterized in that: The first elastic shaft is vertically inserted into the first balancing frame, the second balancing frame and the third balancing frame in sequence from top to bottom through the through hole.
5. The linear variable stiffness series elastic mechanism according to claim 3, characterized in that: The second elastic shaft passes through the through hole and is vertically inserted into the first balancing frame and the second balancing frame in sequence from top to bottom.
6. The linear variable stiffness series elastic mechanism according to claim 3, characterized in that: The linear variable stiffness series elastic mechanism further includes two limiting shafts, and the limiting shafts are respectively vertically plugged into the second balancing frame and the third balancing frame through the through holes.
7. The linear variable stiffness series elastic mechanism according to claim 6, characterized in that: A plurality of positioning pins are disposed on the limiting shaft, and at least one of the positioning pins is located between the second balancing frame and the third balancing frame, so as to limit the moving distance between the second balancing frame and the third balancing frame.
8. The linear variable stiffness series elastic mechanism according to claim 1, characterized in that: The elastic structure is a spring.
9. The linear variable stiffness series elastic mechanism according to claim 1, characterized in that: The linear variable stiffness series elastic mechanism also includes a support plate, which is in a concave shape. A mounting plate is provided inside the concave shape, and the main body is connected to the mounting plate by welding.
10. The linear variable stiffness series elastic mechanism according to claim 9, characterized in that: The linear variable stiffness series elastic mechanism also includes a binding strap, and a connecting hole is provided on the support plate. The binding strap passes through the connecting hole and is connected to the support plate.