Variable stiffness driver

Abstract

The invention relates to the related technical field of medical instruments, in particular to a variable stiffness driver which comprises a main driving motor, a right connecting block is fixedly connected to the lower surface of the main driving motor, a lower chassis is fixedly connected to the surface of one side of the right connecting block, and a stiffness adjusting motor is fixedly connected to the lower surface of the lower chassis. According to the variable-rigidity driver, through the arrangement of the adjusting driving mechanism, when the variable-rigidity driver is used, the rigidity of the variable-rigidity driver can be adjusted in different working environments so that different task requirements can be met, the rigidity of the variable-rigidity driver can be adjusted by accurately controlling rotation of the rigidity adjusting motor, and the rigidity of the variable-rigidity driver can be adjusted. Accurate adjustment of the rigidity of the actuator can be achieved, and therefore the performance and adaptability of the actuator are improved while the safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field related to medical devices, and in particular to a variable stiffness driver. Background Art

[0002] In the field of rehabilitation and elderly care, with the increasing aging of the population and the increasing attention people pay to health, the demand for advanced medical devices is growing. Traditional rehabilitation training equipment and elderly care assistive devices often have relatively single functions and cannot meet the diverse rehabilitation treatment and elderly care needs. Variable stiffness actuators are used in assistive devices such as exoskeletons and walkers. They can provide additional strength support for the elderly, helping them to complete these daily activities more easily, improve their self-care ability, and enhance their self-confidence and independence. Therefore, a variable stiffness actuator is particularly needed.

[0003] However, existing rehabilitation training equipment and elderly care assistive devices often have relatively simple functions and cannot flexibly adjust the stiffness according to different usage scenarios and the user's physical condition to provide accurate, safe and comfortable assistance or resistance, thereby effectively improving the rehabilitation treatment effect and the quality of life of the elderly. Summary of the Invention

[0004] The purpose of the present invention is to provide a variable stiffness driver to solve the problem raised in the above background technology that the existing rehabilitation training equipment and elderly care auxiliary equipment often have relatively single functions and cannot flexibly adjust the stiffness according to different usage scenarios and the physical condition of the user to provide accurate, safe and comfortable assistance or resistance, thereby effectively improving the rehabilitation treatment effect and the quality of life of the elderly.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a variable stiffness driver, comprising a main drive motor, a bevel gear fixedly connected to one side surface of the main drive motor, a right connecting block fixedly connected to the lower surface of the main drive motor, a lower chassis fixedly connected to one side surface of the right connecting block, a stiffness adjustment motor fixedly connected to the lower surface of the lower chassis, an adjustment drive mechanism provided on the upper surface of the stiffness adjustment motor, a first shell fixedly connected to the upper surface of the lower chassis, and a second shell fixedly connected to the upper surface of the first shell; The adjusting drive mechanism includes a rotating shaft, a driven gear, a first connecting plate, a ball screw, a linear slide, a linear slider, an input ring, a screw nut, a second connecting plate, a first magnetic ring, an output ring, a first encoder, a spring, a second magnetic ring, a bearing and a second encoder. The upper surface of the stiffness adjusting motor is fixedly connected to the rotating shaft, a side surface of the rotating shaft is fixedly connected to the driven gear, the upper surface of the driven gear is fixedly connected to the first connecting plate, a side surface of the first connecting plate is slidably connected to the linear slide, a side surface of the linear slide is slidably connected to the linear slider, and the linear slider is fixedly connected to the driven gear. An input ring is fixedly connected to one side surface of the block, a screw nut is fixedly connected to one side surface of the input ring, a second connecting disk is fixedly connected to one side surface of the ball screw, a first magnetic ring is fixedly connected to the upper surface of the second connecting disk, an output ring is rotatably connected to the upper surface of the ball screw, a first encoder is fixedly connected to the lower surface of the output ring, a spring is fixedly connected to the outer surface of the output ring, a second magnetic ring is fixedly connected to the upper surface of the output ring, a bearing is fixedly connected to the outer surface of the bearing, and a second encoder is fixedly connected to the outer surface of the bearing.

[0006] Preferably, the driven gear and the upper structure form a rotating structure through the arrangement of an umbrella gear and a main drive motor, and the second connecting plate forms a telescopic structure through the arrangement of a screw nut, a ball screw and a stiffness adjustment motor.

[0007] Preferably, the main drive motor controls the output torque, speed and position of the actuator, and the main drive motor is connected to the input ring through an umbrella gear.

[0008] Preferably, the input ring and the output ring are connected via a spring, and the rotation of the main drive motor causes the input ring to rotate, thereby transmitting torque to the output ring via the spring.

[0009] Preferably, the stiffness adjustment motor changes the distance between the input ring and the output ring through a ball screw, and when the ball screw rotates inside the screw nut, it drives the input ring and the output ring to perform relative linear displacement.

[0010] Preferably, eight groups of the linear slide rails are symmetrically arranged around the central axis of the first connecting plate, and eight groups of the linear sliding blocks are correspondingly arranged above the linear slide rails.

[0011] Preferably, the outer size of the input ring matches the size of the output ring, and eight groups of springs are fixedly connected to the outer surfaces of the input ring and the output ring, and are symmetrically arranged around the central axis of the rotating shaft.

[0012] Preferably, eight springs are provided and are spring-coupled in parallel, so that the input ring and the output ring can be deflected relative to each other at a certain angle.

[0013] Preferably, sixteen groups of holes are provided on the outer surfaces of the first connecting disk and the input ring, and eight groups of holes are provided on the outer side of the output ring. The second shell is bolted to the input ring and the first shell through the holes provided in the input ring.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This device can adjust its stiffness in different working environments to suit different task requirements. By precisely controlling the rotation of the stiffness adjustment motor, the actuator stiffness can be precisely adjusted, thereby improving the actuator's performance and adaptability while ensuring safety. 2. The device's simple interface and easy operation make it easy for the elderly and those recovering from illness to use it, reducing learning costs and the possibility of misoperation, and enhancing their willingness and ability to use it independently. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the side appearance structure of the present invention; Figure 2 A schematic diagram of the coordination of the internal structures of the present invention; Figure 3 This is a schematic diagram of the lower half operation structure of the adjustment drive mechanism of the present invention; Figure 4 This is a schematic diagram of the upper half of the operating structure of the adjustment drive mechanism of the present invention; Figure 5 It is a schematic diagram of the spring torque calculation structure of the present invention.

[0016] In the figure: 1. Main drive motor; 2. Bevel gear; 3. Right connecting block; 4. Lower chassis; 5. Stiffness adjustment motor; 6. Adjustment drive mechanism; 601. Rotating shaft; 602. Driven gear; 603. First connecting plate; 604. Ball screw; 605. Linear guide rail; 606. Linear slider; 607. Input ring; 608. Screw nut; 609. Second connecting plate; 610. First magnetic ring; 611. Output ring; 612. First encoder; 613. Spring; 614. Second magnetic ring; 615. Bearing; 616. Second encoder; 7. First shell; 8. Second shell. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] See also Figure 1-5The application provides a technical scheme: a variable stiffness driver, comprising a main drive motor 1, the side surface of the main drive motor 1 being fixedly connected with an umbrella-shaped gear 2, the lower surface of the main drive motor 1 being fixedly connected with a right connecting block 3, the side surface of the right connecting block 3 being fixedly connected with a lower chassis 4, the lower surface of the lower chassis 4 being fixedly connected with a stiffness adjustment motor 5, the upper surface of the stiffness adjustment motor 5 being provided with an adjustment driving mechanism 6, the upper surface of the lower chassis 4 being fixedly connected with a layer of shell 7, and the upper surface of the layer of shell 7 being fixedly connected with a second layer of shell 8. The adjustment driving mechanism 6 comprises a rotating shaft 601, a driven gear 602, a first connecting disc 603, a ball screw 604, a linear sliding rail 605, a linear sliding block 606, an input ring 607, a screw nut 608, a second connecting disc 609, a first magnetic ring 610, an output ring 611, a first encoder 612, a spring 613, a second magnetic ring 614, a bearing 615 and a second encoder 616, the upper surface of the stiffness adjustment motor 5 is fixedly connected with the rotating shaft 601, the side surface of the rotating shaft 601 is fixedly connected with the driven gear 602, the upper surface of the driven gear 602 is fixedly connected with the first connecting disc 603, the side surface of the first connecting disc 603 is slidably connected with the linear sliding rail 605, the side surface of the linear sliding rail 605 is slidably connected with the linear sliding block 606, the side surface of the linear sliding block 606 is fixedly connected with the input ring 607, the side surface of the input ring 607 is fixedly connected with the screw nut 608, the side surface of the ball screw 604 is fixedly connected with the second connecting disc 609, the upper surface of the second connecting disc 609 is fixedly connected with the first magnetic ring 610, the upper surface of the ball screw 604 is rotatably connected with the output ring 611, the lower surface of the output ring 611 is fixedly connected with the first encoder 612, the outer side surface of the output ring 611 is fixedly connected with the spring 613, the upper surface of the output ring 611 is fixedly connected with the second magnetic ring 614, the upper surface of the output ring 611 is fixedly connected with the bearing 615, and the outer side surface of the bearing 615 is fixedly connected with the second encoder 616.

[0019] Further, the driven gear 602 and the upper structure constitute a rotating structure through the umbrella gear 2 and the main drive motor 1, the second connecting disc 609 constitutes an extension structure through the screw nut 608, the ball screw 604 and the stiffness adjusting motor 5, and through the driven gear 602 and the second connecting disc 609, in use, the driven gear and the upper structure constitute a rotating structure with the main drive motor through the umbrella gear, efficient power transmission is realized, the torque transmission is smooth and continuous due to the meshing characteristics of the umbrella gear, and in the application of rehabilitation or elderly care equipment, stable motion output is ensured. For example, when driving the joint for rehabilitation training, natural motion is simulated, uniform assistance or resistance is provided for the patient, precise muscle exercise and action specification are helpful, and the rehabilitation effect is improved; in the walking aid equipment for the elderly, continuous and stable power is ensured, different walking speeds of the old people are responded to, use safety and comfort are enhanced, the second connecting disc constitutes an extension structure through the screw nut, the ball screw and the stiffness adjusting motor, precise change of the spring pre-tightening force is realized, and flexible stiffness adjustment is achieved, and in each stage of the rehabilitation process, the stiffness value is accurately designed according to the muscle strength and joint activity of the patient.

[0020] Further, the main drive motor 1 controls the output torque, speed and position of the actuator, the main drive motor 1 is connected with the input ring 607 through the umbrella gear 2, through the main drive motor 1, the umbrella gear 2 and the input ring 607, in use, the main drive motor is connected with the input ring through the umbrella gear, and a stable transmission path is built. The meshing characteristics of the umbrella gear ensure that the motor output torque is transmitted smoothly and continuously to the input ring, and power interruption or fluctuation is avoided. For rehabilitation equipment, such as an upper limb rehabilitation training instrument, stable assistance is provided for joint activity, the patient is helped to accurately repeat the training action, and muscle strength and coordination are strengthened; in the walking aid for the elderly, stable power ensures that the pace of the old people is stable, reduces the risk of falling, improves the safety and comfort of walking, and ensures that the equipment can reliably operate under various working conditions.

[0021] Further, the input ring 607 is connected with the output ring 611 through the spring 613, the rotation of the main drive motor 1 causes the rotation of the input ring 607, and then the torque is transmitted to the output ring 611 through the spring 613, through the input ring 607 and the output ring 611, in use, the input ring 607 and the output ring 611 can be relatively deflected by a certain angle, and the pre-tightening force of the spring 613 determines the stiffness and output torque of the system.

[0022] Furthermore, the stiffness adjustment motor 5 changes the distance between the input ring 607 and the output ring 611 via the ball screw 604. When the ball screw 604 rotates inside the screw nut 608, it drives the input ring 607 and the output ring 611 to perform relative linear displacement. Through the configuration of the stiffness adjustment motor 5, the ball screw 604, the input ring 607, and the output ring 611, when in use, the stiffness adjustment motor changes the distance between the two rings via the ball screw to achieve stiffness adjustment. The ball screw accurately converts the motor's rotational motion into linear displacement, ensuring that the spacing between the input and output rings is accurately and linearly adjusted. Rehabilitation training is based on the patient's progress in the rehabilitation stage, starting with small displacement and reduced stiffness assistance when muscle strength is weak, and gradually increasing displacement and increasing stiffness to strengthen training during recovery, accurately adapting to the needs of the entire rehabilitation process.

[0023] Furthermore, eight groups of linear slide rails 605 are symmetrically arranged around the central axis of the first connecting disk 603, and eight groups of linear sliders 606 are correspondingly arranged above the linear slide rails 605. Through the arrangement of the linear slide rails 605 and the linear sliders 606, when in use, the symmetrical arrangement of the eight groups of linear slide rails 605 and the linear sliders 606 enables the input ring 607 to have multiple support points and guide structures during movement. When the stiffness adjustment motor 5 drives the input ring 607 to move through the ball screw 604, this symmetrical distribution can effectively prevent the input ring 607 from tilting, shaking, and other unstable conditions.

[0024] Furthermore, the outer dimensions of input ring 607 match those of output ring 611. Eight groups of springs 613 are fixedly connected to the outer surfaces of input ring 607 and output ring 611, and are symmetrically arranged about the central axis of rotating shaft 601. This arrangement of springs 613 ensures that, during use, the eight groups of springs 613 are symmetrically arranged about the central axis of rotating shaft 601, further enhancing the uniformity of force transmission. In three-dimensional space, the symmetrically distributed springs enable balanced force transmission in all directions.

[0025] Furthermore, eight springs 613 are provided, and the parallel springs 613 are coupled, so that the input ring 607 and the output ring 611 can be deflected relative to each other at a certain angle. Through the setting of the input ring 607, the output ring 611 and the springs 613, when in use, the parallel coupled springs 613 allow the input ring 607 and the output ring 611 to be deflected relative to each other at a certain angle, which enables the device to better adapt to the multi-angle movement of the human joints.

[0026] Furthermore, sixteen groups of holes are provided on the outer surfaces of the first connecting disk 603 and the input ring 607, and eight groups of holes are provided on the outer side of the output ring 611. The second-layer shell 8 is bolted to the input ring 607 and the first-layer shell 7 through the holes provided by the input ring 607. Through the arrangement of the first connecting disk 603, the input ring 607 and the output ring 611, when in use, the arrangement of sixteen groups of holes on the outer surfaces of the first connecting disk 603 and the input ring 607 and eight groups of holes on the outer side of the output ring 611 provides a clear and appropriate number of fixed points for connection. During the production and assembly process, workers can use bolts to connect the components accurately and efficiently based on these holes, which can speed up the assembly speed, reduce assembly time and labor costs, and make the production and manufacturing process of the entire variable stiffness driver smoother.

[0027] Working principle: Movement process: The output torque of the main drive motor 1 is transmitted to the driven gear 602 through the umbrella gear 2. The position of the driven gear 602 is fixed. The driven gear 602 and the first magnetic ring 610 are rigidly connected through eight linear sliders 606. The input ring 607 is rigidly fixed to the lead screw nut 608. The input ring 607 is connected to the linear slider 606. The rigidity adjustment motor 5 drives the lead screw nut 608 to rotate so that the input ring 607 moves on the linear slider 606. The position of the output ring 611 is fixed. When the input ring 607 moves, the distance between the two rings changes, thereby changing the preload force of the spring 613. The first encoder 612 is fixedly connected to the output ring 611 for measuring the deflection angle between the magnetic ring and the output ring 611. The second encoder 616 is fixed on the first shell 7 or the second shell 8 of the device for measuring the output The deflection angle of the output ring 611 and the displacement of the input ring 607 along the axial direction are controlled by the stiffness adjustment motor 5 through the ball screw 604 rigidly connected to the stiffness adjustment motor 5. Therefore, the deflection angle of the ball screw 604 is related to the rotation of the stiffness adjustment motor 5. The working mechanism of the device involves the projection and transmission of the spring 613 force in three-dimensional space. In the initial position, the projection of the spring 613 force on the output ring 611 is initially along the radial direction of the ring, that is, position P, which means that the output torque is zero initially. With the passive movement of the output ring 611, the spring 613 force will generate torque around the z-axis. The magnitude of the output torque is related to the deflection angle θ, the distance h between the two rings and the stiffness ks of the spring 613. The change of h changes the preload of the spring 613, thereby adjusting the output stiffness. The projection of the spring force on the output ring 611 is along the radial direction of the ring and does not generate output torque.

[0028] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A variable stiffness driver, comprising a main drive motor (1), characterized in that: A side surface of the main drive motor (1) is fixedly connected to a bevel gear (2), a lower surface of the main drive motor (1) is fixedly connected to a right connecting block (3), a side surface of the right connecting block (3) is fixedly connected to a lower chassis (4), a lower surface of the lower chassis (4) is fixedly connected to a stiffness adjustment motor (5), an upper surface of the stiffness adjustment motor (5) is provided with an adjustment drive mechanism (6), an upper surface of the lower chassis (4) is fixedly connected to a first shell (7), and an upper surface of the first shell (7) is fixedly connected to a second shell (8); The adjustment drive mechanism (6) comprises a rotating shaft (601), a driven gear (602), a first connecting plate (603), a ball screw (604), a linear slide (605), a linear slider (606), an input ring (607), a screw nut (608), a second connecting plate (609), a first magnetic ring (610), an output ring (611), a first encoder (612), a spring (613), a second magnetic ring (614), a bearing (615) and a second encoder (616). The upper surface of the stiffness adjustment motor (5) is fixedly connected to the rotating shaft (601), a side surface of the rotating shaft (601) is fixedly connected to the driven gear (602), the upper surface of the driven gear (602) is fixedly connected to the first connecting plate (603), a side surface of the first connecting plate (603) is slidably connected to the linear slide (605), and a side surface of the linear slide (605) is slidably connected to the rotating shaft (601). A linear slider (606) is provided, wherein one side surface of the linear slider (606) is fixedly connected to an input ring (607), one side surface of the input ring (607) is fixedly connected to a lead screw nut (608), one side surface of the ball screw (604) is fixedly connected to a second connecting disk (609), the upper surface of the second connecting disk (609) is fixedly connected to a first magnetic ring (610), the upper surface of the ball screw (604) is rotatably connected to an output ring (611), the lower surface of the output ring (611) is fixedly connected to a first encoder (612), the outer surface of the output ring (611) is fixedly connected to a spring (613), the upper surface of the output ring (611) is fixedly connected to a second magnetic ring (614), the upper surface of the output ring (611) is fixedly connected to a bearing (615), and the outer surface of the bearing (615) is fixedly connected to a second encoder (616).

2. The variable stiffness actuator according to claim 1, characterized in that: The driven gear (602) and the upper structure form a rotating structure by means of the umbrella gear (2) and the main drive motor (1), and the second connecting plate (609) forms a telescopic structure by means of the screw nut (608), the ball screw (604) and the stiffness adjustment motor (5).

3. The variable stiffness actuator according to claim 1, characterized in that: The main drive motor (1) controls the output torque, rotation speed and position of the actuator, and the main drive motor (1) is connected to the input ring (607) via the umbrella gear (2).

4. The variable stiffness actuator according to claim 1, characterized in that: The input ring (607) and the output ring (611) are connected via a spring (613), and the rotation of the main drive motor (1) causes the input ring (607) to rotate, thereby transmitting torque to the output ring (611) via the spring (613).

5. The variable stiffness actuator according to claim 1, characterized in that: The stiffness adjustment motor (5) changes the distance between the input ring (607) and the output ring (611) via the ball screw (604); when the ball screw (604) rotates inside the screw nut (608), it drives the input ring (607) and the output ring (611) to perform relative linear displacement.

6. The variable stiffness actuator according to claim 1, characterized in that: The linear slide rails (605) are symmetrically arranged in eight groups around the central axis of the first connecting plate (603), and the linear sliders (606) are correspondingly arranged in eight groups above the linear slide rails (605).

7. The variable stiffness actuator according to claim 1, characterized in that: The outer dimensions of the input ring (607) match those of the output ring (611), and eight groups of springs (613) are fixedly connected to the outer surfaces of the input ring (607) and the output ring (611), and are symmetrically arranged about the central axis of the rotating shaft (601).

8. The variable stiffness actuator according to claim 1, characterized in that: Eight springs (613) are provided, and the parallel springs (613) are coupled, so that the input ring (607) and the output ring (611) can be relatively deflected at a certain angle.

9. The variable stiffness actuator according to claim 1, characterized in that: Sixteen groups of holes are provided on the outer surfaces of the first connecting disk (603) and the input ring (607), and eight groups of holes are provided on the outer side of the output ring (611). The second layer of the outer shell (8) is bolted to the input ring (607) and the first layer of the outer shell (7) via the holes provided in the input ring (607).

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