CN106826903B - Utilize the biconvex wheel disc output variable speed joint of steel wire drive - Google Patents

Abstract

The double-cam disc output variable speed joint using steel wire transmission involves a variable speed joint to solve the existing problems of using motor speed regulation to realize exoskeleton joint motion, large motor output torque, low joint motion accuracy and high cost. It includes an input shaft, a support frame, a joint shaft, a lower cam, an upper cam, a No. 1 steel wire rope and a No. 2 steel wire rope; the joint shaft is rotatably mounted on the support frame, and the input shaft is rotatably mounted on the support frame and the joint shaft. The lower cam and the upper cam are arranged on both sides of the input shaft and fixed on the joint shaft respectively, the lower cam and the upper cam form a closed eccentric circle; the No. 1 steel wire rope After being laid on the upper arc-shaped rope groove, it is wound on the input shaft; after the No. 2 steel wire rope is laid on the lower arc-shaped rope groove, it is wound on the input shaft. The invention is used for exoskeleton or humanoid robot joints.

Description

Double cam disc output variable speed joint using steel wire transmission

technical field

The invention relates to a speed-changing joint, in particular to a double-cam output speed-changing joint driven by steel wires used on a robot.

Background technique

For exoskeleton robots, joint motion control is a crucial part. At present, most of the existing joint speed regulation designs are based on controlling the motor speed. This type of motion design has low precision, high requirements on the motor, and a large burden on the motor, which leads to an increase in the size and cost of the motor.

SUMMARY OF THE INVENTION

The present invention aims to solve the existing problems of motor speed regulation to realize exoskeleton joint motion, high motor output torque, low joint motion precision and high cost, and further provides a double-cam disc output speed-changing joint utilizing steel wire transmission.

The technical scheme that the present invention takes for solving the above problems is:

The double-cam disc output variable speed joint utilizing steel wire transmission includes an input shaft, a support frame, a joint shaft, a lower cam, an upper cam, a No. 1 steel wire rope and a No. 2 steel wire rope;

The lower cam and the upper cam have the same structure and are connected as one; the joint shaft is rotatably mounted on the support frame, the input shaft is rotatably mounted on the support frame and the joint shaft, and the axial direction of the input shaft is in line with the joint shaft. The axial direction of the joint shaft is vertical, the lower cam and the upper cam are arranged on both sides of the input shaft and fixed on the joint shaft respectively, the lower cam and the upper cam form a closed An eccentric circle, an upper arc-shaped rope groove is processed on the side of the upper cam, and a lower arc-shaped rope groove is processed on the side of the lower cam;

One end of the No. 1 steel wire rope is fixedly connected to the end of the upper cam adjacent to the joint shaft. The No. 1 steel wire rope is laid on the upper arc-shaped rope groove and then wound on the input shaft. The other end of the No. 2 steel wire rope is fixed on the upper end of the input shaft; one end of the No. 2 steel wire rope is fixedly connected to the end of the lower cam adjacent to the joint shaft, and the No. 2 steel wire rope is laid on the lower circular arc. After the rope groove is wound on the input shaft, the other end of the No. 2 steel wire rope is fixed on the lower end of the input shaft; the rope segments of the No. 1 steel wire rope and the No. 2 steel wire rope on the input shaft are wound in the same direction .

The beneficial effects of the present invention are as follows: 1. Adopting double cams for speed change can reduce the demand on the output torque of the motor and play the role of a two-stage speed reducer. 2. The structure has better dynamic characteristics, can make the transmission ratio change continuously according to requirements, has high real-time performance, can better simulate the movement of joints, and has low cost. When a person walks normally, the rotation angle of the cam is about 0-35°. At this time, there is no requirement for the output of the knee joint of the exoskeleton, but high speed is required; when a person goes up the stairs or from squatting to standing up, the rotation angle of the cam is close to 135°, the larger the angle, the greater the requirement for output, and high speed is not required. Due to the constant output torque of the motor, ordinary transmission mechanisms cannot meet this requirement. The radius of the outer contour of the cam increases with the increase of the rotation angle, and the transmission ratio increases accordingly, so it can provide high speed and small output at small rotation angles, and low speed and large output at large rotation angles. Use ropes and cams for reasonable power distribution, realize motor-driven exoskeleton robots or humanoid robots, and realize the motion of knee joints, limb elbow joints and shoulder joints with degrees of freedom of flexion and extension, which improves energy utilization and transmission efficiency.

Description of drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of the present invention;

Fig. 2 is the front view of Fig. 2;

Fig. 3 is the A-A direction view of Fig. 2;

Fig. 4 is the B-B direction view of Fig. 2;

Fig. 5 is the left view of Fig. 2;

Fig. 6 is a right side view of Fig. 2 .

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

Referring to Fig. 1-Fig. 6, the double cam disc output variable speed joint using steel wire transmission includes input shaft 1, support frame 2, joint shaft 3, lower cam 4, upper cam 5, No. 1 wire rope 6 and No. 2 wire rope 7;

The lower cam 4 and the upper cam 5 have the same structure and are connected as one; the joint shaft 3 is rotatably mounted on the support frame 2, and the input shaft 1 is rotatably mounted on the support frame 2 and the joint shaft 3. The axial direction of the input shaft 1 is perpendicular to the axial direction of the joint shaft 3, the lower cam 4 and the upper cam 5 are arranged on both sides of the input shaft 1 and fixed on the joint shaft 3 respectively, The lower cam 4 and the upper cam 5 form a closed eccentric circle, the upper arc-shaped rope groove 5-1 is processed on the side of the upper cam 5, and the lower circle is processed on the side of the lower cam 4 Arc rope groove 4-1;

One end of the No. 1 steel wire rope 6 is affixed to the end of the upper cam 5 adjacent to the joint shaft 3, and the No. 1 steel wire rope 6 is laid on the upper arc-shaped rope groove 5-1 and then wound on the On the input shaft 1, the other end of the No. 1 steel wire rope 6 is fixed on the upper end of the input shaft 1; one end of the No. 2 steel wire rope 7 is affixed to the end of the lower cam 4 adjacent to the joint shaft 3, The No. 2 steel wire rope 7 is laid on the lower arc-shaped rope groove 4-1 and wound on the input shaft 1, and the other end of the No. 2 steel wire rope 7 is fixed on the lower end of the input shaft 1; The rope segments of the No. 1 steel wire rope 6 and the No. 2 steel wire rope 7 on the input shaft 1 are wound in the same direction.

In Fig. 1, the output end of the motor reducer is connected to the input shaft 1 through key transmission to transmit the torque to the input shaft 1. The upper arc-shaped rope groove 5-1 is designed in a continuous arc on the wheel surface, and the lower arc-shaped rope groove 4-1 is designed in a continuous arc on the wheel surface.

As shown in Figure 2, the input shaft 1 rotates counterclockwise (viewed from bottom to top), and the second rope 7 leaves the lower arc-shaped rope groove 4-1 while winding on the lower section of the input shaft 1, and pulls the lower cam 4 to follow The joint shaft 3 rotates clockwise. At the same time, the No. 1 steel wire rope 6 winds on the upper arc-shaped rope groove 5-1 and leaves the upper end of the input shaft 1. During the movement, the upper cam 5 and the lower cam 4 remain relatively stationary. Finally, the double cam structure is driven to rotate clockwise. When the input shaft 1 rotated clockwise, the No. 1 rope 6 was wound on the upper end of the input shaft 1 while leaving on the upper arc-shaped rope groove 5-1, and the upper cam 5 was pulled to rotate counterclockwise with the follower joint shaft 3. Simultaneously, the No. 2 rope 7 is laid on the lower arc-shaped rope groove 4-1 while leaving the lower section of the input shaft 1. During the movement, the upper cam 5 and the lower cam 4 remain relatively stationary, and finally drive the double-cam structure counterclockwise turn. The steel wire rope has good flexibility and high strength, which improves the flexibility and strength of use.

3 and 4, in order to improve transmission efficiency and facilitate use, the input shaft 1 is a stepped shaft, and one end of the small-diameter section of the input shaft 1 is rotatably mounted on the joint shaft 3, and the input shaft The other end of the small-diameter section of 1 is rotatably mounted on the support frame 2 . Such setting is convenient to use and simple in structure.

2, the support frame 2 includes a horizontal plate 2-1 and two vertical plates 2-2, a vertical plate 2-2 is respectively installed on both sides of the horizontal plate 2-1, and the two vertical plates 2 - 2 is set directly opposite, the input shaft 1 is arranged vertically to the horizontal plate 2-1 and is rotatably mounted on the horizontal plate 2-1, and the joint axis 3 is perpendicular to the two vertical plates 2-2 Set and rotatably installed on the two vertical plates 2-2, the lower cam 4 and the upper cam 5 are both arranged on the horizontal plate 2-1 and the two vertical plates 2-2. inside the groove. With such arrangement, the support frame 2 with grooves has a simple structure, is convenient and reliable to use, and can meet actual use requirements.

Referring to Fig. 1 , Fig. 5 and Fig. 6, the double-cam disc output speed change joint utilizing steel wire transmission also includes a U-shaped connecting piece 8, and the lower cam 4 and the upper cam 5 are connected as a whole through the U-shaped connecting piece 8. Such arrangement has simple structure and is easy to use. The lower cam 4 and the upper cam 5 are fixed together as a large part, which is convenient for fixing the rods at both ends of the joint, and simultaneously ensures that the lower cam 4 and the upper cam 5 rotate synchronously.

1 and 4, the side of the upper cam 5 is provided with an upper arc-shaped boss 5-2, and the upper arc-shaped boss 5-2 forms an arc with the side of the upper cam 5. shaped rope groove 5-1, there is a transition fillet between the upper arc-shaped boss 5-2 and the upper cam 5; the side of the lower cam 4 is provided with a lower arc-shaped boss 4-2 , the lower arc-shaped boss 4-2 forms an arc-shaped rope groove 4-1 with the side of the lower cam 4, and there is a gap between the lower arc-shaped boss 4-2 and the lower cam 4. Transition rounded corners.

working principle

As illustrated in Figure 6, when the input shaft 1 with radius r rotates at a constant speed of _ω1 , the rotation speed of the lower cam 4 (or upper cam 5) with the radius of curvature of the arc-shaped rope groove R(θ) is _ω2 . Then the linear velocity on the outer contour of the motor input shaft 1 and the arc-shaped rope groove is equal: rω ₁ = R(θ)ω ₂ , transmission ratio: It is only necessary to reasonably design the curvature radius R(θ) of the arc-shaped rope groove of the upper cam 5 or the lower cam 4, and when the motor constant speed ω ₁ is input, the required variable speed joint output ω ₂ can be obtained.

When the input shaft 1 rotates at a constant speed of w ₁ in the clockwise direction (viewed from the bottom up), the No. 1 steel wire rope 6 is tensioned, and the line speed Wherein, d is the diameter of the input shaft 1 , and α is the angle between the No. 1 steel wire rope 6 and the center line of the input shaft 1 . No. 1 steel wire rope 6 is producing pulling force to make upper cam 5 rotate, and the rotating speed of upper cam 5 As the curvature radius of gyration ρ changes, w ₂ will change accordingly; similarly, when the input shaft 1 rotates in the opposite direction, the No. 2 steel wire rope 7 is tensioned, driving the lower cam 4 to rotate. Therefore, by designing the cam shape, that is, the size of the curvature radius ρ at each position, the desired speed change law can be obtained.

The present invention has been disclosed above with preferred implementation examples, but it is not intended to limit the present invention. Any skilled person who is familiar with the profession can use the structure and technical content disclosed above to make some The changes or modifications are equivalent implementation cases with equivalent changes, but any simple modifications, equivalent changes and modifications made to the above implementation cases according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still The scope of the technical solutions of the present invention.

Claims (5)

1. utilizing the biconvex wheel disc output variable speed joint of steel wire drive, it is characterised in that: it includes input shaft (1), support frame (2), joint shaft (3), lower cam (4), overhead cam (5), No.1 wirerope (6) and No. two wirerope (7)；

The lower cam (4) is identical with the overhead cam (5) structure and is connected as one；The joint shaft (3) is rotatably installed in On support frame (2), the input shaft (1) is rotatably installed on support frame (2) and joint shaft (3), the axial direction of the input shaft (1) Axially vertical with the joint shaft (3), the lower cam (4) and the overhead cam (5) are arranged in the two of the input shaft (1) Side is simultaneously packed on the joint shaft (3) respectively, and the lower cam (4) and the overhead cam (5) constitute a closed bias It is round, it is machined with arc-shaped rope groove (5-1) on the side of the overhead cam (5), is machined with down on the side of the lower cam (4) Arc-shaped rope groove (4-1)；

One end of the No.1 wirerope (6) and the one end of neighbouring joint shaft (3) of the overhead cam (5) are affixed, described No.1 wirerope (6) is wrapped on the input shaft (1) after being laid on the upper arc-shaped rope groove (5-1), the No.1 steel wire The other end of rope (6) is fixed on the upper end of the input shaft (1)；One end and the lower cam (4) of No. two wirerope (7) Neighbouring the joint shaft (3) one end it is affixed, No. two wirerope (7) be laid on it is described under after arc-shaped rope groove (4-1) It is wrapped on the input shaft (1), the other end of No. two wirerope (7) is fixed on the lower end of the input shaft (1)；It is described The rope section of No.1 wirerope (6) and No. two wirerope (7) on input shaft (1) is equidirectional winding.

2. the biconvex wheel disc output variable speed joint according to claim 1 using steel wire drive, it is characterised in that: described defeated Entering axis (1) is multi-diameter shaft, and one end of the reduced diameter section of the input shaft (1) is rotatably installed on the joint shaft (3), described defeated The other end for entering the reduced diameter section of axis (1) is rotatably installed on support frame as described above (2).

3. the biconvex wheel disc output variable speed joint according to claim 1 or 2 using steel wire drive, it is characterised in that: institute Stating support frame (2) includes level board (2-1) and two vertical plates (2-2), and the two sides of the level board (2-1) are respectively equipped with one and stand Plate (2-2), two vertical plate (2-2) face settings, the input shaft (1) and the level board (2-1) are vertically arranged and turn Dynamic to be mounted on the level board (2-1), the joint shaft (3) is vertically arranged and is rotatablely installed with two vertical plates (2-2) On two vertical plates (2-2), the lower cam (4) and the overhead cam (5) are arranged in the level board (2-1) and two In the groove that a vertical plate (2-2) surrounds.

4. the biconvex wheel disc output variable speed joint according to claim 3 using steel wire drive, it is characterised in that: the benefit It further include U-shaped connector (8) with the biconvex wheel disc output variable speed joint of steel wire drive, the lower cam (4) and overhead cam (5) are logical U-shaped connector (8) is crossed to be connected as one.

5. the biconvex wheel disc output variable speed joint according to claim 3 using steel wire drive, it is characterised in that: on described It is provided on the side of cam (5) arc cam (5-2), the upper arc cam (5-2) and the overhead cam (5) Side is formed arc-shaped rope groove (5-1), has knuckle between the upper arc cam (5-2) and the overhead cam (5)； Be provided with lower arc cam (4-2) on the side of the lower cam (4), the lower arc cam (4-2) with it is described under it is convex The side of wheel (4) is formed arc-shaped rope groove (4-1), is had between the lower arc cam (4-2) and the lower cam (4) Cross fillet.