CN111329631A

CN111329631A - Myoelectric artificial limb wrist

Info

Publication number: CN111329631A
Application number: CN202010151297.7A
Authority: CN
Inventors: 郭伟超; 李钦
Original assignee: Suzhou Tonghe Jingrun Rehabilitation Technology Co Ltd
Current assignee: Suzhou Tonghe Jingrun Rehabilitation Technology Co Ltd
Priority date: 2020-03-06
Filing date: 2020-03-06
Publication date: 2020-06-26
Anticipated expiration: 2040-03-06
Also published as: CN111329631B

Abstract

The invention discloses a myoelectric prosthetic wrist, which comprises a driving motor, a gear transmission system and a flange; the gear transmission system is configured to drive the flange to rotate forwards, reversely or stop under the driving of the driving motor; the gear transmission system is in three-level gear transmission and is connected with the driving motor through a worm; the flange also comprises a limit stop and a flange wire outlet hole. The myoelectric artificial limb wrist disclosed by the invention has the advantages of simple structure, reliable function and convenience in control; the artificial limb wrist can rotate forwards, reversely and stop in time by matching with a control program, and the artificial limb wrist has an over-rotation prevention function; the optimized structure and size design also avoids the occurrence of wire winding and even wire stranding.

Description

Myoelectric artificial limb wrist

Technical Field

The invention relates to the field of artificial limbs, in particular to a myoelectric artificial limb wrist.

Background

In daily life, there are many patients who have had amputations in their hands due to accidents. The hand loss greatly reduces the working and living abilities of the users, and even special people are needed to take care of the users in severe cases. The existing artificial limb can (partially) simulate the functions of human hands and becomes an important auxiliary means for recovering the work and life of hand amputees.

At present, most of myoelectric artificial limbs commonly used in domestic markets do not have wrists which can be controlled independently; the artificial limb wrist which can be automatically controlled to rotate is firstly controlled abroad, and the selling price is usually hundreds of thousands. In addition, the control line is twisted and broken due to frequent winding in the use of the existing myoelectric wrist. Therefore, the development of the myoelectric artificial limb wrist which can automatically control rotation, is low in price, reliable, stable and reliable has great practical significance and social requirements.

Therefore, those skilled in the art are devoted to designing a myoelectric prosthetic wrist that is autonomously controlled, prevents winding and over-rotation, and is low cost.

Disclosure of Invention

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to design a myoelectric prosthetic wrist which can be autonomously controlled, prevent winding and over-rotation, and has low cost.

In order to achieve the aim, the invention provides a myoelectric prosthetic wrist, which comprises a driving motor, a gear transmission system and a flange; the gear transmission system is configured to drive the flange to rotate forwards, reversely or stop under the driving of the driving motor.

Further, the gear transmission system comprises a primary gear transmission, a secondary gear transmission and a tertiary gear transmission; the output shaft of the driving motor is meshed with the gear of the primary gear transmission, the primary gear transmission is meshed with the secondary gear transmission, and the secondary gear transmission is meshed with the tertiary gear transmission.

Further, a first gear, a second gear, a third gear and a fourth gear are included; an output shaft of the driving motor is meshed with the first gear; the first gear is meshed with the second gear to form primary gear transmission; the second gear is meshed with the third gear to form the secondary gear transmission; the third gear is meshed with the fourth gear to form the three-stage gear transmission; the fourth gear is connected with the flange.

Further, the first gear is a duplicate gear.

Further, the second gear is a duplicate gear.

Further, the third gear is a spur gear.

Further, the fourth gear is a spur gear.

Further, still include the bearing, gear drive system passes through the bearing with flange joint.

Further, still include the base, driving motor installs in the base.

Further, the gear of the gear transmission system is mounted on the base through a bolt.

Further, the drive motor is also configured to be adjustable in speed.

Further, the flange comprises a limit stop; and the limit stop is matched with the stroke groove of the shell to limit the wrist from excessively rotating.

Further, the stroke groove is arc-shaped.

Further, the flange also comprises a flange threading hole; the flange threading aperture is configured for exiting a control cable at hand.

Further, a gap with a certain height is formed between the fourth gear and the driving motor.

Furthermore, the fourth gear is also provided with a countersunk threaded hole.

Further, the base is provided with a base arc-shaped groove matched with the circumferential surface of the driving motor in size.

Further, an output worm of the driving motor is connected with the gear transmission system.

Compared with the prior art, the invention has the beneficial technical effects that:

1) the driving motor drives the flange to rotate through three-stage gear transmission, so that the output is stable, the control is simple, and the cost is low;

2) a limit stop is arranged and matched with the stroke groove of the shell to prevent the wrist from excessively rotating;

3) the worm is connected with the gear transmission system, and staggered surface driving can be realized; and the gap setting between flange through wires hole, fourth gear and the driving motor can prevent the wire winding better to appear.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a schematic overall structure of a preferred embodiment of the present invention;

FIG. 2 is a schematic view of a drive motor in accordance with a preferred embodiment of the present invention;

FIG. 3 is a schematic view of a first gear in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic view of a second gear in accordance with a preferred embodiment of the present invention;

FIG. 5 is a third gear diagram of a preferred embodiment of the present invention;

FIG. 6 is a fourth gear diagram in accordance with a preferred embodiment of the present invention;

FIG. 7 is a schematic representation of a gear system in accordance with a preferred embodiment of the present invention;

FIG. 8 is a schematic view of a flange configuration in accordance with a preferred embodiment of the present invention;

FIG. 9 is a schematic view of a housing in accordance with a preferred embodiment of the present invention;

FIG. 10 is a schematic view of a fourth gear and flange connection in accordance with a preferred embodiment of the present invention;

FIG. 11 is a schematic view of a base structure in accordance with a preferred embodiment of the present invention;

FIG. 12 is a schematic view of the connection of the base to the gear system in accordance with a preferred embodiment of the present invention;

FIG. 13 is a schematic view of the gap between the fourth gear and the driving motor in accordance with a preferred embodiment of the present invention;

FIG. 14 is a schematic view of a first extreme position of a flange in accordance with a preferred embodiment of the present invention;

FIG. 15 is a second extreme position schematic of a flange of a preferred embodiment of the invention.

Description of reference numerals:

1-a base; 11-a first base threaded hole; 12-arc groove of base 13-outlet hole of base; 14-a second base threaded hole; 151-first positioning hole; 152-a second positioning hole; 153-third positioning hole; 16-worm assembly hole;

2-a first gear; 21-a first duplicate gear; 22-a second first duplicate gear;

3-a second gear; 31-a first second duplicate gear; 32-second duplicate gear two;

4-a third gear; 5-a fourth gear; 51-countersunk threaded holes; 6-a bearing;

7-a housing; 71-housing threaded hole; 72-socket threaded hole; 73-a stroke slot;

8-flange 81-first flange threaded hole; 82-second flange threaded hole; 83-flange threading holes; 84-fourth flange threaded hole; 85-limit stop;

9-driving a motor; 91-circumferential surface of the drive motor; 92-driving motor positioning holes; 93-a worm;

101-a first bolt; 102-a second bolt; 103-third pin.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Fig. 1 is a schematic diagram of the overall structure of a preferred embodiment of the present invention, which includes a base 1, a gear transmission system, a bearing 6, a housing 7, a flange 8 and a driving motor 9. The driving motor 9 drives the gear transmission system, and the gear transmission system drives the flange 8 to realize the forward rotation, the reverse rotation or the stop of the wrist.

Considering the power and the actual volume of the existing motor for the artificial limb, in order to reduce the volume of the artificial limb wrist as much as possible, the driving motor 9 is preferably connected with the gear transmission system on the staggered surface; more preferably, the drive motor 9 is connected to said gear transmission system by means of a worm. As shown in fig. 2, the drive motor 9 of the present embodiment includes a drive motor circumferential surface 91, a drive motor positioning hole 92, and a worm 93. Wherein the worm 93 is connected with the gear transmission system.

The connecting structure of the worm 93 and the gear transmission system can provide a larger gear reduction ratio on a staggered surface, so that the worm 93 and the gear transmission system are perpendicular to each other in axis, the space utilization rate is improved, and the equipment volume is reduced. In addition, the connection structure of the worm 93 and the gear transmission system also has a self-locking function. The "self-locking" function prevents the gear drive system from driving the worm 93 to rotate. Namely, the artificial wrist can only receive the control command of the electromyographic signal, the worm 93 drives the gear transmission system to drive the flange 8 to rotate, so as to prevent the external force from forcing the wrist to rotate and prevent the damage of the driving motor 9 caused by the external force.

The artificial wrist is generally in low-speed motion because various movements at hand require the wrist to be stable and the time required for electromyographic signal transmission and processing. Considering that the output speed of the existing drive motor for the prosthesis is generally high, the gear transmission system has enough speed reduction capability. Meanwhile, the gear transmission system must reduce gear mesh wear as much as possible to prevent cost increase and inconvenience in use due to frequent maintenance or part replacement.

Preferably, as shown in fig. 1, 3-7, the gear transmission system of the present embodiment includes a first gear 2, a second gear 3, a third gear 4 and a fourth gear 5; the worm 93 meshes with the first gear 2; the first gear 2 is meshed with the second gear 3 to form primary gear transmission; the second gear 3 is in transmission engagement with the third gear 4 to form secondary gear transmission; the third gear 4 is meshed with the fourth gear 5 to form three-stage gear transmission; the fourth gear wheel 5 is connected to a flange 8. Test results prove that based on the conventional gear, the driving motor 9 is driven to reduce the speed through the worm 93 and the three-level gear, and the speed reduction ratio can reach 100-1000 at least: 1.

more preferably, the first gear 2 adopts a duplicate gear, so that a wider speed regulation ratio is provided; more preferably, the second gear 3 is a duplicate gear, providing a wider range of speed ratios. Fig. 3 shows a dual gear structure of the first gear 2, which includes a first dual gear 21 and a first dual gear 22. According to the actual requirement of increasing or decreasing the speed reduction ratio, whether the worm 93 is meshed with the first duplicate gear 21 or the second duplicate gear 22 is determined. Fig. 4 shows a dual gear structure of the second gear 3, which includes a first dual gear 31 and a second dual gear 32. According to the actual need of increasing or decreasing the speed reduction ratio, whether the first gear 2 is meshed with the first duplicate gear 31 or the second duplicate gear 32 is determined. In this embodiment, the worm 93 is engaged with the first duplicate gear 21, the first duplicate gear 22 is engaged with the second duplicate gear 31, and the second duplicate gear 32 is engaged with the third gear 4.

More preferably, the third gear 4 adopts a straight gear to improve the mechanical transmission efficiency and reduce the manufacturing cost; more preferably, the fourth gear 5 is a spur gear to improve mechanical transmission efficiency. Alternatively, if the manufacturing cost is neglected, the gear shape of the fourth gear 5 of the third gear 4 may be other shapes such as a helical gear as required.

To prevent over-rotation of the wrist, the flange 8 is preferably also provided with a limit stop 85 as shown in fig. 8. Limit stop 85 may cooperate with travel slot 73 (see fig. 9) of housing 7 to limit excessive rotation of flange 8 by the gear system.

In this embodiment, the fourth gear 5 is connected to the flange 8 via a bearing 6. Alternatively, the fourth gear wheel 5 can also be connected directly to the flange 8. As shown in fig. 6 and 10, the fourth gear 5 is provided with three countersunk threaded holes 51 for positioning and connection, so that the alignment of the relative positions of the flange 8 and the fourth gear 5 during the assembly of the device is facilitated.

Fig. 11 shows a specific structure of a base 1 according to a preferred embodiment of the present invention, which includes a first base threaded hole 11, a base arc-shaped groove 12, a base wire outlet hole 13, a second base threaded hole 14, a first positioning hole 151, a second positioning hole 152, a third positioning hole 153, and a worm assembly hole 16.

The first base threaded holes 11 are uniformly distributed along the periphery of the bottom surface of the base 1 and are used for being matched with the shell threaded holes 71 of the shell 7, so that the shell 7 and the base 1 can be fixed through screws. Alternatively, the housing 7 and the base 1 may be fixed by other structures, such as a slot, or a rotating thread that is engaged between the inner and outer walls.

The bottom arc-shaped groove 12 is used for being matched with the circumferential surface 91 of the driving motor, so that the space utilization rate of the inner structure of the artificial limb wrist is further improved, and the size of the device is reduced. Base 1 still sets up second base screw hole 14, cooperates with driving motor locating hole 92, further improves the firm degree that driving motor 9 installed in base 1, prevents in the use the gear drive system vibration leads to driving motor 9 not hard up, and then influences the transmission effect. Similarly, the base 1 is provided with a first positioning hole 151, a second positioning hole 152, and a third positioning hole 153 for fixing the first gear 2, the second gear 3, and the third tooth 4, respectively. As shown in fig. 12, the first gear 2, the second gear 3, and the third tooth 4 are fixed to the first positioning hole 151, the second positioning hole 152, and the third positioning hole 153 by the first latch 101, the second latch 102, and the third latch 103, respectively. Further, the fourth gear 5 is fixed to a fourth flange screw hole 84 of the flange 8 by screws (see fig. 8 and 10).

The worm mounting hole 16 is used for mounting a worm 93 for fixing a driving motor.

After the artificial wrist is assembled, the artificial wrist is assembled with the hand through the first flange threaded hole 81 and the second flange threaded hole 82 as shown in fig. 8, and is assembled with the socket through the socket positioning hole 72 on the side surface of the shell 7 for use.

It should also be noted that the present invention further optimizes the construction and size of the gear system in addition to the interleaved drive configuration of the worm 93 with the gear system. As shown in fig. 13, the structure and size of the gear transmission system are optimized so that there is enough clearance between the fourth gear 5 and the driving motor 9 for the control wire at hand to pass through the base wire outlet hole 13 and the flange wire through hole 83 shown in fig. 8, so that the control wire does not contact with the gear transmission system or other parts, and the occurrence of wire winding and even wire twisting is avoided. The optimized structure of the gear transmission system means that the planes of the gears of the first gear 2, the second gear 3 and the third gear 4 are in stepped rise; the axes of the first gear 2, the second gear 3 and the third gear 4 approximately form a straight line, and a connecting line of the axes of the third gear 4 and the fourth gear 5 forms a V-shaped structure. Preferably, the "V" shape is an "L" shape.

The working process of the myoelectric prosthetic wrist provided by the invention is further described with the embodiment.

The continuous myoelectric signal received by the myoelectric artificial wrist controls the worm 93 of the driving motor 9 to rotate, and drives the first duplicate gear 21 meshed with the worm to rotate; further, the first duplicate gear 22, the second gear 3, the third gear 4, and the fourth gear 5 rotate in sequence; the fourth gear 5 drives the flange 8 to rotate through a fixing screw.

When the flange 8 is rotated to the first extreme position as in fig. 14, the travel slot 73 of the housing 7 blocks the limit stop 85; and triggering a reverse rotation instruction, wherein the driving motor 9 starts to reversely rotate to drive the gear transmission system to reversely rotate, and finally, the flange 8 is reversely rotated. When the flange is rotated in the reverse direction to the second extreme position as in fig. 15, the other end of the travel slot 73 blocks the limit stop 85; the reversal command triggers the reversal of the flange 8. The circulation is carried out in this way, and the anti-over-rotation function of the wrist is realized.

If the flange 8 does not move to the first limit position or the second limit position when the electromyographic signals stop, the driving motor 9 stops outputting; further, the flange 8 stops rotating, and the stop is achieved in time.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A myoelectric artificial limb wrist is characterized by comprising a driving motor, a gear transmission system and a flange; the gear transmission system is configured to drive the flange to rotate forwards, reversely or stop under the driving of the driving motor.

2. The myoelectric prosthetic wrist of claim 1, wherein the gear drive system comprises a primary gear drive, a secondary gear drive and a tertiary gear drive; the output shaft of the driving motor is meshed with the gear of the primary gear transmission, the primary gear transmission is meshed with the secondary gear transmission, and the secondary gear transmission is meshed with the tertiary gear transmission.

3. The myoelectric prosthetic wrist of claim 2, comprising a first gear, a second gear, a third gear and a fourth gear; an output shaft of the driving motor is meshed with the first gear; the first gear is meshed with the second gear to form primary gear transmission; the second gear is meshed with the third gear to form the secondary gear transmission; the third gear is meshed with the fourth gear to form the three-stage gear transmission; the fourth gear is connected with the flange.

4. The myoelectric prosthetic wrist of claim 3, wherein the first gear is a duplicate gear.

5. The myoelectric prosthetic wrist of claim 3, wherein the second gear is a duplicate gear.

6. The myoelectric prosthetic wrist of claim 3, wherein the third gear is a spur gear.

7. The myoelectric prosthetic wrist of claim 3, wherein the fourth gear is a spur gear.

8. The myoelectric prosthetic wrist of claim 1, further comprising a base, the drive motor being mounted to the base.

9. An electromyographic prosthetic wrist according to claim 8, wherein a gear of the gear transmission system is mounted to the base by a latch.

10. The myoelectric prosthetic wrist of claim 1, wherein the drive motor is further configured to be adjustable in speed.