CN110538015B

CN110538015B - Mechanical artificial limb arm

Info

Publication number: CN110538015B
Application number: CN201910839634.9A
Authority: CN
Inventors: 田和强; 林喆; 徐倩; 李建永; 郑晨玲; 王坤黎; 张弘斌; 周海萍
Original assignee: Shandong University of Science and Technology
Current assignee: Shandong University of Science and Technology
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2021-07-02
Anticipated expiration: 2039-09-06
Also published as: CN110538015A

Abstract

The invention relates to a mechanical artificial limb arm, which consists of a hand, a wrist, a forearm, an elbow joint, an upper arm and a shoulder joint, wherein the hand consists of a palm part and a finger part, the front end of the wrist is connected with the palm of the hand through a wrist disc, the tail end of the wrist is connected with the forearm through a forearm driving mechanism, one end of the elbow joint is connected with the forearm, the other end of the elbow joint is connected with the upper arm, the upper arm is arranged on a body through the shoulder joint, and the mechanical artificial limb arm is provided with the finger driving mechanism, the wrist driving mechanism, the forearm driving mechanism, the elbow joint driving mechanism and the upper arm driving mechanism; the fingers adopt a link mechanism structure to be reliable, the gripping force is high, the whole arm is designed with multiple degrees of freedom, and the flexible and quick response effect can be integrally realized.

Description

Mechanical artificial limb arm

Technical Field

The invention relates to a mechanical artificial limb arm, in particular to a medical mechanical artificial limb arm.

Background

In recent years, patients with limb disabilities due to natural disasters, war, diseases, human violence, and the like have grown year by year. Among them, patients with disabled upper limbs have the most difficult life, and they are difficult to take self-care after losing the upper limbs. Therefore, the self-care problem of the part of people is particularly urgent to solve.

The single human arm is analyzed in a mechanical fashion and can be represented by a linkage of approximately 27 degrees of freedom. But with approximately 20 degrees of freedom centered on the hand. The design of the hand of the prosthesis is particularly important. The mechanical design of the manipulator is also called mechanical synthesis and mainly comprises type synthesis and size synthesis. In the field of robot research, the mechanical design of a manipulator is an important task, and the mechanical type and the structural size of the manipulator determine the operability of the manipulator and the pose of an end effector.

The mechanical artificial limb on the current market has the defects of low degree of freedom, poor reliability, insufficient gripping force and the like, aiming at the current situation, the invention provides a medical mechanical artificial limb arm, which is more designed by adopting mechanical structures and is designed in detail aiming at some important parts. The requirement of the patients with the disabled upper limbs on the living activities of the patients can be met by imitating the arm movement of the people. The whole arm is designed with multiple degrees of freedom, and the flexible and quick response effect can be integrally realized. In addition, a mechanical structure design is adopted, so that high reliability and stability can be guaranteed.

Disclosure of Invention

Aiming at the defects of low degree of freedom, reliability and insufficient gripping force of the conventional mechanical artificial limb arm, the invention provides the mechanical artificial limb arm which can generate motion with multiple degrees of freedom, and has the advantages of high gripping force, reliable structure and flexible whole.

The utility model provides a mechanical artificial limb arm, comprises hand, wrist, forearm, elbow joint, upper arm and shoulder joint, and the hand comprises palm part and finger part, and the wrist front end passes through the wrist dish to be connected with palm part, and the wrist is terminal to be connected with the forearm through the internal gear, and the one end and the forearm of elbow joint are connected, and the other end is connected with the upper arm, and the upper arm passes through the shoulder joint to be installed on the health, mechanical artificial limb arm is provided with the finger actuating mechanism who is used for driving the crooked extension of finger, is used for driving wrist actuating mechanism about the wrist and luffing, is used for driving the forearm actuating mechanism of hand rotation, is used for driving the forearm around the elbow crooked and the elbow joint actuating mechanism who extends and is used for driving arm front and back and the upper arm of luffing, finger part comprises five fingers, and four fingers except that the thumb all adopt link mechanism to set, the finger link mechanism comprises seven movable joints, five connecting rods and two springs, one end of the first connecting rod is hinged with the palm through the first movable joint, the other end of the first connecting rod is hinged with the middle of the second connecting rod through the sixth movable joint, one end of the fourth connecting rod is connected with an output shaft of the motor and is hinged with the motor through the seventh movable joint, the other end of the fourth connecting rod is hinged with one ends of the fifth connecting rod and the second connecting rod through the second movable joint and the third movable joint respectively, the other end of the fifth connecting rod is hinged with one end of the third connecting rod through the fourth movable joint, and the other end of the second connecting rod is hinged with the middle of the third connecting rod through the fifth movable joint.

The palm part comprises finger actuating mechanism, two bevel gear sets, two palm axles, thumb straight-teeth gear and three finger connecting axles, finger actuating mechanism comprises three motors, first motor and second motor set up respectively in two motor notches at the palm back, the third motor sets up in the positive motor groove of palm, thumb and forefinger are by first motor and second motor drive respectively, the middle finger, ring finger and little finger are connected by third motor drive through three finger connecting axles, first motor and second motor drive palm axle through bevel gear set respectively and rotate, provide power for finger link mechanism, the third motor drives the rotation of thumb axle through thumb straight-teeth gear, realize the thumb motion.

Further, the three motors are Maxon motors.

The fifth connecting rod and the sixth connecting rod are of two-section structures, and a spring is arranged in the middle of each connecting rod.

The wrist comprises a wrist disc, a wrist driving mechanism, a universal joint, a ball joint and a support rod, wherein the wrist driving mechanism comprises two linear motors, one ends of the linear motors are connected with the wrist plate through the universal joint, the other ends of the linear motors are connected with the internal gear, and two ends of the support rod are respectively connected with the wrist plate and the internal gear through the ball joint.

The two linear motors can realize synchronous and asynchronous work.

The forearm comprises forearm ring, forearm board and forearm actuating mechanism, forearm actuating mechanism comprises forearm motor, internal gear, needle roller bearing, is provided with the forearm motor on the forearm board, the forearm board with through the bolt fastening on the forearm ring, forearm motor output shaft spur gear, spur gear and the meshing of internal gear provide a rotary motion for the wrist, is provided with needle roller bearing between internal gear and the forearm ring.

The elbow joint, the upper arm and the shoulder joint are composed of an elbow shaft, an elbow joint driving mechanism, an upper arm plate, an upper arm driving mechanism, two groups of synchronous belt mechanisms and a shoulder plate, the elbow joint driving mechanism is composed of a first bevel gear, a second bevel gear and an elbow motor, the first bevel gear is connected with the elbow shaft through a key, two ends of the elbow shaft are fixed on the upper arm plates on two sides through bearings, the elbow motor drives the second bevel gear to rotate, and power is provided for the rotation of the elbow shaft through the engagement of the first bevel gear and the second bevel gear; the upper arm driving mechanism is composed of a first upper arm motor, a second upper arm motor, a third bevel gear and a fourth bevel gear, the first upper arm motor drives a first synchronous belt mechanism to rotate, a large gear of the first synchronous belt mechanism is fixedly connected to a shoulder plate and is rigidly connected with the shoulder, left and right swinging of an arm is achieved under the action of the first synchronous belt mechanism, the second upper arm motor drives a second synchronous belt mechanism to rotate, the second synchronous belt mechanism drives the third bevel gear to rotate, the third bevel gear is meshed with the fourth bevel gear, the fourth bevel gear is rigidly connected with a body through a shaft and does not move, and the arm is connected with the body through the shoulder plate.

The invention has the advantages that the invention imitates the arm movement of people, meets the requirements of the upper limb disabled patients on the living activities of the upper limb disabled patients when the upper limb disabled patients are worn, and compared with other artificial limbs, the multi-freedom-degree movement mechanical artificial limb arm can generate multi-freedom-degree movement and can roughly simulate the movement of the arm of a normal person. The structure is reliable due to the pure mechanical structure. At some places that use more like the finger, adopted the connecting rod design, compare in adopting more stay cord design or spring rebound design on the market, link mechanism is more reliable to can realize bigger gripping dynamics. The arm body is made of hard aluminum alloy, so that the arm body is light in weight, high in strength and corrosion resistant; the Maxon motor is controlled, the whole size is small, the occupied space is small, and the wearing is convenient. Low cost and high performance-price ratio. Common parts are adopted, so that the cost is low, and the cost performance is high.

Drawings

FIG. 1 is a schematic overall view of a mechanical prosthetic arm;

FIG. 2 is a schematic hand view;

FIG. 3 is a bottom hand view;

FIG. 4 is a schematic view of a finger link mechanism;

FIG. 5 is a schematic view of the wrist and forearm;

figure 6 schematic representation of elbow, upper arm and shoulder joints.

In the figure, 1 hand, 2 wrist, 3 forearm, 4 elbow joint, 5 upper arm, 6 shoulder joint, 11 first Maxon motor, 12 first bevel gear set, 13 second bevel gear set, 14 first palm shaft, 15 second Maxon motor, 16 thumb spur gear, 17 third Maxon motor, 18 second palm shaft, 19 third finger connecting shaft, 21 wrist disc, 22 first linear motor, 23 second linear motor ii, 24 first universal joint, 25 second universal joint ii, 26 internal gear, 27 needle bearing, 28 ball joint, 29 spur gear,

strut

210, 31 forearm ring, 32 forearm plate, 33 forearm motor, 41 elbow shaft, 42 first bevel gear, 43 gear, 44 elbow motor, 51 upper arm plate, 52 first upper arm motor, 53 second upper arm motor, 54 first synchronous belt mechanism, 55 second synchronous belt mechanism, 56 third synchronous belt mechanism, 61 fourth bevel gear, 62 shoulder plate, the first joint is G1, the second joint is G2, the third joint is G3, the fourth joint is G4, the fifth joint is G5, the sixth joint is G6, the seventh joint is G7, the first link is L1, the second link is L2, the third link is L3, the fourth link is L4, the fifth link is L5, the first spring is S1, the second spring is S2, the M1 motor and the palm of H1.

Detailed Description

The invention provides a mechanical artificial limb arm, and in order to make the purpose, technical scheme and effect of the invention clearer and clearer, the invention is further described in detail below with reference to the accompanying drawings.

A mechanical artificial arm is composed of six parts, namely a hand 1, a wrist 2, a forearm 3, an elbow joint 4, an upper arm 5 and a shoulder joint 6, wherein the position of each part is shown in figure 1.

As shown in fig. 2, the hand is divided into a palm and fingers, the back of the palm is provided with two motor notches for placing a first Maxon motor 11 and a second Maxon motor 15 respectively, the front of the palm is provided with a motor notch for placing a third Maxon motor 17, the first Maxon motor 11 is a driving motor for a middle finger, a ring finger and a little finger, the middle finger, the ring finger and the little finger are connected through a three-finger connecting shaft 19, the bevel gear set 12 is driven to rotate through the rotation of the first Maxon motor 11, the first palm shaft 14 is in key connection with the first bevel gear set 12, the first palm shaft 14 can rotate to provide power for the finger link mechanism, and the fingers can move in a bending and stretching mode. Similarly, the second Maxon motor 15 drives the second palm shaft 18 to rotate through the second bevel gear set 13, and drives the finger link mechanism in the index finger to realize the bending and stretching movement of the index finger.

As shown in figure 3, the thumb adopts a motor gear to carry out transmission, and considering that the thumb has 2 finger joints in the actual use process, the rotation of one finger joint can meet the daily requirement. The thumb straight gear 16 is connected with the thumb shaft through a key, and the third Maxon motor 17 drives the thumb straight gear 16 to realize the motion of the thumb.

As shown in fig. 4, in the finger link mechanism, one end of a first link L1 is connected to the palm of the hand through a first joint G1, the motor is connected to a fourth link L4 through a seventh joint G7, when the first motor M1 rotates clockwise by a certain angle, the fourth link L4 also rotates clockwise by a certain angle around the motor shaft, the fourth link L4 applies a force perpendicular to the right and lower direction of the fourth link L4 to the second link L2 and the fifth link L5 at the second joint G2 and the third joint G3, the force applied to the second link L2 through the third joint G3 causes the second link L2 to rotate counterclockwise by a certain angle around the sixth joint G8, so that the second link L2 applies an upward force to the third link L3 through the fifth joint G5, and the third link L3 can realize the upward movement of the whole lever; the force exerted on the fifth link L5 by the second joint G2 is opposite to the force exerted on the fourth joint G4 and further on the fifth link L5 by the third link L3 rotating counterclockwise around the fifth joint G5, so that the fifth link L5 is exerted, but since the links are rigid, the fifth link L5 is made into two parts, and the second spring S2 is added in the middle for buffering, so that when the pair of opposite forces exerted on the fifth link L5 is exerted, the second spring S2 on the fifth link L5 is compressed and shortened, and the whole length of the fifth link L5 is shortened; likewise, the first spring S1 of the fourth link L4 also plays the same role. After the fourth connecting rod L4 rotates clockwise for a certain angle, the third joint G3 applies a component force to the fourth connecting rod L4, which is directed to the axis of the motor along the fourth connecting rod L4, because the length and the connection of the first connecting rod L1 and the second connecting rod L2 are fixed, the connecting rod vi L4 needs to be made into two parts, the middle is buffered by the first spring S1, and the length of the fourth connecting rod L4 can be changed like the length of the fifth connecting rod L5. The entire finger can perform an extending action. When the motor rotates anticlockwise for a certain angle, the fingers can realize bending action. The whole finger has 3 degrees of freedom, and 3 phalanges rotate around respective finger joints, and the finger motion is the same as that of a normal person.

As shown in fig. 5, the wrist mechanism is designed to have a structure with 2 degrees of freedom, i.e. horizontal swing and vertical swing, following the wrist structure of a normal person, the wrist portion is provided with two linear motors and two universal joints, one end of each linear motor is connected to the wrist disc 21 through the universal joint, two ends of the supporting rod 210 are respectively connected to the wrist disc 21 and the internal gear 26 through ball joints, and the motions of the linear motors are asynchronous in order to realize the horizontal swing of the wrist. When the wrist swings to the left, the second linear motor 23 does not work, the first linear motor 22 works, the push rod of the first linear motor 22 extends, and the wrist swings to the left by a certain angle under the pushing force of the push rod of the first linear motor 22. As the ram continues to extend, the first linear motor 22 stops when the angle reaches the design maximum. When the first linear motor 22 is operated again, the length of the push rod is shortened, and the wrist is pulled by the push rod, so that the wrist swings to the right. Until the push rod is shortened to the initial state, the first linear motor 22 stops working, the wrist returns to the initial state, and therefore the wrist finishes left-hand swing movement. When the wrist swings to the right, the first linear motor 22 does not work, the second linear motor 23 works, and the wrist mechanism realizes the movement of left swing and right swing as the wrist swings to the left. The up-and-down swing of the wrist mechanism is also determined based on the motion of 2 linear motors. Unlike the side-to-side swing of the wrist mechanism, the up-and-down swing of the wrist mechanism is the result of the synchronous motion of 2 linear motors. When the two linear motors are operated together, the pushrods of the 2 linear motors together exert a force on the wrist in the forward direction, at which point the wrist will produce an angular rotational movement about the ball joint 28, since the length of the strut 210 is not variable. When the rotation angle reaches the designed maximum value, the two linear motors stop working, when the two linear motors work together, the push rods retract to a short length, the wrist rotates reversely under the pulling force of the 2 push rods until the wrist returns to the initial position, and therefore the wrist mechanism finishes upward swinging movement. The downswing motion of the wrist is again the opposite of the upswing motion. The wrist mechanism can realize the movement of the upper pendulum and the lower pendulum.

The forearm has only 1 degree of freedom, which is the rotational movement of the forearm around the direction of the forearm, in order to change the state of the palm. As shown in fig. 5, the forearm mechanism 3 mainly includes a forearm ring 31, a forearm plate 32, a forearm motor 33, an internal gear 26, a spur gear 29, and a needle bearing 27. A forearm motor 33 is placed on the forearm plate 32, the forearm plate 32 is fixed on a forearm ring 31 through bolts, the tail end of the forearm motor 33 is connected with a spur gear 29, a needle bearing 27 is arranged between an internal gear 26 and the forearm ring 31, the front end of the internal gear 26 is connected with two linear motors and a support rod 210, and one rotation motion is provided for the wrist through the meshing of the spur gear 29 and the internal gear 26.

The elbow joint has only 1 degree of freedom, namely the bending and stretching of the forearm around the elbow, the purpose of the degree of freedom of the elbow joint is to enable the palm to approach or be far away from the human body, and the design of the elbow joint is still realized by adopting motor gear transmission. As shown in fig. 6, the shaft joint 4 includes an elbow shaft 41, a first bevel gear 42, a second bevel gear 43, and an elbow motor 44. The elbow motor 44 drives the second bevel gear 43 to rotate, the first bevel gear 42 is connected to the elbow shaft 41 through a key, two ends of the elbow shaft 41 are fixed to the upper arm plate 51 through bearings, the front arm plate 32 is connected to the elbow shaft 41 through the key, and when the elbow motor 44 works, a rotating power is provided for the elbow shaft 41 through the meshing of the first bevel gear 42 and the second bevel gear 43, so that the whole elbow joint is driven to rotate below the elbow joint, and the bending action of the elbow joint is achieved.

The upper arm 5 includes an upper arm plate 51, a first upper arm motor 52, a second upper arm motor 53, a first timing belt mechanism 54, a second timing belt mechanism 55, and a third bevel gear 56. When the second upper arm motor 53 works, the second synchronous belt mechanism 55 is driven to move, the second synchronous belt mechanism 55 drives the third bevel gear 56 to rotate, the third bevel gear 56 is meshed with the fourth bevel gear 61, the fourth bevel gear 61 is rigidly connected with the body through a shaft and does not move in a phase manner, and when the third bevel gear 56 rotates, the whole upper arm structure rotates through the bearing on the shoulder due to the fact that the fourth bevel gear 61 is not moved, namely, the arm swings back and forth. When the first upper arm motor 52 works, the motor rotates the first synchronous belt pulley mechanism 54, the large belt pulley of the first synchronous belt pulley mechanism 54 is fixedly connected to the shoulder plate 62 and rigidly connected with the shoulder into a whole, and under the action of the first synchronous belt pulley mechanism 54, the first upper arm motor 52 and the whole arm generate movement, namely the left-right swinging of the arm. The entire robotic prosthetic arm is attached to the body by a shoulder plate 62.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.

Claims

1. The utility model provides a mechanical artificial limb arm, the arm comprises hand, wrist, forearm, elbow joint, upper arm and shoulder joint, and the hand comprises palm part and finger part, and the wrist front end is connected with palm part through wrist dish, and the wrist is terminal to be connected with the forearm through the internal gear, and elbow joint's one end is connected with the forearm, and the other end is connected with the upper arm, and the upper arm passes through the shoulder joint to be installed on the health, its characterized in that: the mechanical artificial limb arm is provided with a finger driving mechanism for driving fingers to bend and extend, a wrist driving mechanism for driving the wrist to swing left and right and up and down, a forearm driving mechanism for driving the hand to rotate, an elbow joint driving mechanism for driving the forearm to bend and extend around an elbow and an upper arm driving mechanism for driving the arm to swing front and back and left and right, wherein the finger part comprises five fingers, four fingers except the thumb are all arranged by adopting a connecting rod mechanism, each finger has three degrees of freedom, the connecting rod mechanism comprises seven movable joints, five connecting rods and two springs, one end of a first connecting rod is hinged with a palm through the first movable joint, the other end of the first connecting rod is hinged with the middle part of a second connecting rod through the sixth movable joint, one end of a fourth connecting rod is connected with a motor output shaft and is hinged with the motor through the seventh movable joint, and the other end of the fourth connecting rod is hinged with one ends of the fifth connecting rod, the other end of the fifth connecting rod is hinged with one end of the third connecting rod through a fourth movable joint, and the other end of the second connecting rod is hinged with the middle part of the third connecting rod through a fifth movable joint; the elbow joint, the upper arm and the shoulder joint comprise an elbow shaft, an elbow joint driving mechanism, an upper arm plate, an upper arm driving mechanism, two groups of synchronous belt mechanisms and a shoulder plate, the elbow joint has a degree of freedom, the elbow joint driving mechanism consists of a first bevel gear, a second bevel gear and an elbow motor, the first bevel gear is connected with the elbow shaft through a key, two ends of the elbow shaft are fixed on the upper arm plates on two sides through bearings, the elbow motor drives the second bevel gear to rotate, and power is provided for the rotation of the elbow shaft through the meshing of the first bevel gear and the second bevel gear; the upper arm driving mechanism is composed of a first upper arm motor, a second upper arm motor, a third bevel gear and a fourth bevel gear, the first upper arm motor drives a first synchronous belt mechanism to rotate, a large gear of the first synchronous belt mechanism is fixedly connected to a shoulder plate and is rigidly connected with the shoulder, left and right swinging of an arm is achieved under the action of the first synchronous belt mechanism, the second upper arm motor drives a second synchronous belt mechanism to rotate, the second synchronous belt mechanism drives the third bevel gear to rotate, the third bevel gear is meshed with the fourth bevel gear, the fourth bevel gear is rigidly connected with a body through a shaft and does not move, and the arm is connected with the body through the shoulder plate.

2. A robotic prosthetic arm according to claim 1, wherein: the palm part includes finger actuating mechanism, two bevel gear groups, two palm axles, thumb straight-teeth gear and three finger connecting axles, finger actuating mechanism is three motors, first motor and second motor set up respectively in two motor notches at the palm back, the third motor sets up in the positive motor groove of palm, thumb and forefinger are by third motor and second motor drive respectively, the middle finger, ring finger and little finger are connected by first motor drive through three finger connecting axles, first motor and second motor drive the palm axle through bevel gear group respectively and rotate, provide power for finger link mechanism, the third motor drives the rotation of thumb axle through thumb straight-teeth gear, realize the thumb motion.

3. A robotic prosthetic arm as claimed in claim 2, wherein each of the three motors is a Maxon motor.

4. A robotic prosthetic arm as claimed in claim 1, wherein the fifth and fourth links are of two-piece construction with a spring disposed intermediate the links.

5. A robotic prosthetic arm as claimed in claim 1, wherein the wrist has two degrees of freedom, comprising a wrist plate, a wrist drive mechanism, a universal joint, a ball joint and a strut, the wrist drive mechanism being two linear motors, one end of the linear motor being connected to the wrist plate via the universal joint and the other end being connected to the internal gear, the two ends of the strut being connected to the wrist plate and the internal gear via the ball joint respectively.

6. A robotic prosthetic arm according to claim 5, wherein the two linear motors are operable synchronously and asynchronously.

7. A robotic prosthetic arm as claimed in claim 1, wherein the forearm has a degree of freedom and comprises a forearm ring, a forearm plate and a forearm drive mechanism, the forearm drive mechanism comprising a forearm motor, an internal gear and a needle bearing, the forearm plate having a forearm motor mounted thereon, the forearm plate being secured to the forearm ring by a bolt, the forearm motor having an output shaft connected to a spur gear, the engagement of the spur gear with the internal gear providing a rotational movement to the wrist, the needle bearing being disposed between the internal gear and the forearm ring.