Instrument joint set and surgical instrument comprising sameTechnical Field
The invention relates to the technical field of surgical robots, in particular to an instrument joint set and a surgical instrument comprising the instrument joint set.
Background
With the progress of technology, surgical robot technology is gradually mature and widely used. Surgical robots generally comprise an operating device and a surgical instrument connected to the operating device, in particular the surgical instrument being connected to a drive of the operating device for performing a surgical operation. The surgical instrument includes a distal instrument at its distal end that can perform surgical procedures in different angular orientations, simulating joint movement to perform the surgical procedure.
As shown in fig. 1 and 2, in order to achieve a wider field of view, a larger operable space and a more flexible degree of freedom of movement of the end effector of the surgical robot, in the prior art, the end effector mostly adopts a parallelogram structure, and the structure can enable two sides of the parallelogram to maintain a nearly parallel space geometry during the movement process. The main characteristics and principle are that the driving end part 2, the connecting part 3 and the driven end part 4 are matched through hinge connection or other connection modes to realize flexible degree of freedom rotation, two driven ropes 5 pass through the three parts in equal length, two ends are fixedly connected with the driving end part 2 and the driven end part 4 through crimping or welding modes respectively, and the two driven ropes 5 are parallel at the initial position and maintain a certain pretightening force. At this time, the two passive ropes 5, the driving end member 2 and the passive end member 4 form a parallelogram structure. One end of the driving rope 6 is fixedly connected with the connecting part 3 (or the driven end part 4), and when the connecting part 3 is driven by the driving rope 6 and rotates relative to the driving end part 2, the driving end part 2 and the driven end part 4 always keep a relatively parallel geometric relationship due to the geometric characteristics of the parallelogram.
However, due to the length variation of the rope between the joints during the movement, the passive end piece 4 and the active end piece 2 are not perfectly parallel in theory, and the angular deviation thereof becomes larger as the driving angle becomes larger, which seriously affects the angular accuracy of the end joint of the surgical robot (i.e., the passive end piece 4).
Therefore, although the prior art mostly adopts a parallel mechanism based on a parallelogram structure (as shown in fig. 3 and 4), it is a practical situation that the passive end piece 4 and the active end piece 2 are not completely parallel, and the angles are offset angles. The reason for this is that, as shown in fig. 5, the passive end joint (corresponding to the passive end part 4) moves upward, and at this time, the active end bare wire segment 521 of the second passive rope 52 becomes longer to a certain size due to being pulled to a certain position, but the elastic deformation amount of the rope is negligible, that is, the length is constant. As can be obtained by theoretical calculation, the shorter dimension of the passive-end exposed line segment 522 is shorter than the longer dimension of the active-end exposed line segment 521, so that the passive-end part 4 cannot move to the parallel position, resulting in an angular deviation with the active-end part 2. In the case where the limit angle (limit angle means the angle formed by the opposite surfaces of the driving end member 2 and the connecting member 3 at the junction when the rotation angle of the connecting member 3 with respect to the driving end member 2 is zero) is a certain design value α, the result of the change of the theoretical deviation angle of the driven end member 4 with the driving angle is as shown in fig. 6 (the negative value represents the deviation direction outward), and as seen from fig. 6, the instrument joint group adopting the parallelogram structure becomes larger gradually as the driving angle becomes larger in the range of 0 to α °, and the increase rate (increase rate means the degree of the deviation angle becomes larger with the driving angle, that is, the degree of the increase of the deviation angle) becomes larger gradually, and as the driving angle continues to be gradually increased to approach the limit angle, the deviation angle is even larger than 15 °. The problem seriously affects the precision of the rotation angle and the flexibility of the movement of the instrument joint set, limits and inconvenience are brought to the visual field and the operation freedom degree of operators in the operation process, the safety and the effectiveness of the surgical instrument are affected, and even the operation efficiency and the success rate are affected.
Disclosure of Invention
The invention aims to overcome the defects of poor angle precision and poor motion flexibility of a tail end joint of a surgical robot in the prior art, and provides an instrument joint set and a surgical instrument comprising the instrument joint set.
The invention solves the technical problems by the following technical scheme:
an instrument joint set comprises a driving end part, a connecting part and a driven end part which are connected in turn in a rotating way, wherein the driving end part, the connecting part and the driven end part all rotate on a plane of at least one projection direction of the instrument joint set;
Each pair of driven ropes comprises two driven ropes, the two driven ropes respectively penetrate through the driving end part, the connecting part and the driven end part along the axial direction, the two ends of each driven rope are respectively fixed on the driving end part and the driven end part, and the two driven ropes are distributed on the two sides of a rotating part among the driving end part, the connecting part and the driven end part;
At least one first hole for the passive rope to pass through in the axial direction is distributed on the driving end part, at least one second hole for the passive rope to pass through in the axial direction is distributed on the passive end part, the vertical distance from the circle center of the first hole to the axis of the driving end part is a first distribution radius, the vertical distance from the circle center of the second hole to the axis of the passive end part is a second distribution radius, and the radius ratio of the first distribution radius to the second distribution radius is more than or less than 1.
In the scheme, the instrument joint set drives the driven end part to rotate relative to the connecting part through the pulling of the two driving ropes and the pulling of the driven rope, and meanwhile, the connecting part rotates relative to the driving end part, so that the driven end part rotates at different angles relative to the driving end part, and the operation is performed. When the radius ratio is smaller than 1, the two passive ropes, the active end part and the passive end part form an inverted trapezoid structure, so that in the rotation process, the passive end part (representing the passive joint) can obtain a larger deviation angle under a smaller driving angle, the movable angle of the passive end part can be increased under a specific limiting environment due to the fact that the angle deviation caused by the length change of the driving ropes or the passive ropes between joints is close to or equal to a target angle, and the angle precision of the tail end joint of the surgical robot is improved.
Preferably, the radius ratio is calculated by the equationDetermining;
Wherein K is the radius ratio, alpha is the initial included angle formed by the opposite surfaces of the driving end part and the connecting part at the connecting position when the rotation angles of the connecting part relative to the driving end part and the driven end part are zero, the initial included angle between the driving end part and the connecting part is equal to the initial included angle between the driven end part and the connecting part, beta1 is the driving angle of the connecting part relative to the driving end part, and delta beta is the deviation angle of the axis of the driven end part relative to the axis of the driving end part when the driven end part is rotated.
In the scheme, the radius ratio K is determined by the instrument joint set through the equation, so that the angle of the passive end part is compensated to or is close to the target angle, and the accuracy of angle compensation is improved. The initial included angle between the driving end part and the connecting part is equal to the initial included angle between the driven end part and the connecting part, the complexity of calculating and determining the K value is reduced by adopting the arrangement, the difference of the two initial angles is not needed to be considered, and the angle deviation is needed to be further supplemented, so that the accuracy of the K value is improved. And selecting a proper deviation angle delta beta according to the target angle, thereby determining a K value, and adjusting the two distribution radiuses according to the K value, so that the actual rotation angle of the passive end part is close to the target angle, and the accuracy of angle compensation is improved.
Preferably, the two ends of the connecting part are provided with a third hole corresponding to the first hole and a fourth hole corresponding to the second hole, the vertical distance from the center of the third hole to the axis of the connecting part is a third distribution radius, the vertical distance from the center of the fourth hole to the axis of the connecting part is a fourth distribution radius,
The third distribution radius is equal to the first distribution radius and/or the fourth distribution radius is equal to the second distribution radius.
In the scheme, when the third distribution radius is equal to the first distribution radius, a first exposed line segment of the passive rope between the connecting part and the driving end part is horizontal, so that the first exposed line segment is conveniently determined according to the first distribution radius and the initial angle alpha, the K value is conveniently calculated, and when the fourth distribution radius is equal to the second distribution radius, a second exposed line segment of the passive rope between the connecting part and the passive end part is horizontal, the second exposed line segment is conveniently determined according to the second distribution radius and the initial angle alpha, the K value is conveniently calculated, and therefore the complexity of an equation for determining the K value is reduced, and the accuracy of angle compensation is improved.
Preferably, each pair of the driving ropes is symmetrically distributed with respect to the rotating part.
In this scheme, every pair of drive rope adopts for the setting of rotation portion symmetric distribution, compares in asymmetric distribution, and the drive angle of connecting part or passive end part is more easily accurate control.
Preferably, each pair of the passive ropes is symmetrically distributed with respect to the rotating part. In this scheme, every pair of passive rope adopts for the setting of rotating part symmetric distribution, compares in asymmetric distribution, eliminates the difference of radius ratio on the distribution, is favorable to reducing the angle deviation, improves the accuracy of angle compensation. Preferably, the apparatus joint set is provided with a pair of the driven ropes and a pair of the driving ropes in at least two different projection directions, and the radius ratio of the two projection directions is equal or unequal.
In this scheme, this apparatus joint group is through all setting up a pair of passive rope and a pair of drive rope at two different projection directions, realizes the angle compensation in different projection directions. When the radius ratio in two different projection directions is equal, the angle compensation can be sequentially carried out in the different projection directions, and when the radius ratio in two different projection directions is unequal, the angle compensation in the two directions can be integrated, the adjustment in a larger angle range can be realized, and the degree of freedom of rotation is improved.
Preferably, the two projection directions are perpendicular to each other.
In the scheme, the two projection directions are in a mutually perpendicular relation, so that the rotating parts on the two projection directions are conveniently arranged.
Preferably, the rotating parts comprise at least one first rotating part between the driving end part and the connecting part, and at least one second rotating part between the driven end part and the connecting part;
The two ends of the first rotating part along the axial direction comprise two first rotating shafts in the projection direction, the body of the first rotating part is respectively connected with the driving end part and the connecting part through the two first rotating shafts, and/or the two ends of the second rotating part along the axial direction comprise two second rotating shafts in the projection direction, and the body of the second rotating part is respectively connected with the driven end part and the connecting part through the two second rotating shafts.
In this scheme, can realize the rotation on two different projection directions through a first rotation portion between drive end part and the connecting part, when the quantity of first rotation portion is greater than one, still can realize the rotation on more projection directions between drive end part and the connecting part, realize more nimble degree of freedom of rotation. The passive end part and the connecting part can rotate in two different projection directions through the second rotating part, and when the number of the second rotating parts is greater than one, the passive end part and the connecting part can rotate in more projection directions, so that more flexible rotation freedom is realized.
Preferably, the two first rotation axes in the two projection directions are perpendicular to each other, and the two second rotation axes in the two projection directions are perpendicular to each other.
In this scheme, this apparatus joint group adopts mutually perpendicular relation on the basis of adopting the rotation portion that has two axis of rotation above-mentioned, two first axis of rotation and two second axis of rotation, is convenient for arrange two axis of rotation for the rotation portion is easy to process and manufacture.
A surgical instrument comprising an instrument joint set as described above.
According to the technical scheme, the surgical instrument adjusts the radius ratio of the passive ropes distributed on the driving end part and the passive end part through the instrument joint group, when the radius ratio is larger than 1, the two passive ropes, the driving end part and the passive end part form a positive trapezoid structure, so that in the rotating process, the angle deviation caused by the length change of the driving ropes or the passive ropes between the joints can be compensated to be close to or equal to a target angle, the angle precision of the tail end joint of the surgical robot is improved, when the radius ratio is smaller than 1, the two passive ropes, the driving end part and the passive end part form an inverted trapezoid structure, and in the rotating process, the passive end part (representing the passive joint) can obtain a larger deviation angle under a smaller driving angle, and the movable angle of the passive end part can be increased under a specific limiting environment, namely the moving flexibility of the tail end joint is improved.
The invention has the positive progress effects that the instrument joint group and the surgical instrument comprising the instrument joint group have the advantages that the radius ratio of the passive ropes distributed on the driving end part and the passive end part is regulated, when the radius ratio is larger than 1, the two passive ropes, the driving end part and the passive end part form a positive trapezoid structure, the angle deviation caused by the length change of the driving ropes or the passive ropes between the joints can be compensated in the rotation process, and is close to or equal to a target angle, so that the angle precision of the tail end joint of the surgical robot is improved, when the radius ratio is smaller than 1, the two passive ropes, the driving end part and the passive end part form an inverted trapezoid structure, and in the rotation process, the passive end part (representing the passive joint) can obtain a larger deviation angle under a smaller driving angle, and the movable angle of the passive end part can be increased under a specific limiting environment, namely the movement flexibility of the tail end joint is improved.
Drawings
Fig. 1 is a schematic view of a prior art instrument joint set in a parallelogram configuration and in an initial position.
Fig. 2 is a schematic diagram of a joint set of a prior art device in a parallelogram structure and a structure during rotation.
Fig. 3 is a schematic diagram of a second embodiment of the prior art device joint set in a parallelogram configuration when in an initial position.
FIG. 4 is a schematic view of the ideal rotation angle of the prior art instrument joint set in a parallelogram configuration during rotation.
Fig. 5 is a schematic view of actual rotation angle of the instrument joint set in the prior art when the instrument joint set is in a parallelogram structure and rotates.
Fig. 6 is a graph showing the variation of the theoretical deviation angle of the joint set of the prior art instrument with the driving angle.
Fig. 7 is a schematic view of the structure of the joint set of the apparatus in the initial position according to embodiment 1 of the present invention.
Fig. 8 is a schematic view of the structure of the joint set of the apparatus according to embodiment 1 of the present invention when rotated.
Fig. 9 is a schematic three-dimensional structure of the instrument joint set in the initial position according to embodiment 1 of the present invention.
Fig. 10 is a schematic three-dimensional structure of the instrument joint set in one projection direction in embodiment 1 of the present invention.
Reference numerals illustrate:
Instrument joint set 1
Drive end part 2
First hole 21
First radius of distribution R1
Connecting part 3
Third hole 31
Fourth hole 32
Passive end piece 4
Second hole 41
Second radius of distribution R2
Projection direction A, B
Passive rope 5
First passive rope 51
Second passive rope 52
Exposed line segment 521 of drive end
Passive end bare segment 522
First bare line segment l of initial position1
Second bare line segment l of initial position2
First bare line segment l 'during rotation'1
A second bare line segment l 'during rotation'2
Drive rope 6
First drive rope 61
Second drive cord 62
Rotation part 7
First rotating portion 71
First rotating shaft 711
Second rotating portion 72
Second rotation shaft 721
Detailed Description
The invention is further illustrated by means of the following examples, which are not intended to limit the scope of the invention.
Example 1
The present embodiment provides an instrument joint set 1 for a surgical robot, which is mounted at the tip of a surgical instrument, as shown in fig. 7 to 10, the instrument joint set 1 includes a driving end member 2, a connecting member 3, and a driven end member 4 which are rotatably connected in this order, and the driving end member 2, the connecting member 3, and the driven end member 4 are each rotated on a plane of at least one projection direction of the instrument joint set 1.
In each projection direction, the instrument joint set 1 is provided with at least one pair of driven ropes 5 and at least one pair of driving ropes 6, each pair of driven ropes 5 comprises two driven ropes 5, the two driven ropes 5 respectively penetrate through the driving end part 2, the connecting part 3 and the driven end part 4 along the axial direction, two ends of each driven rope 5 are respectively fixed on the driving end part 2 and the driven end part 4, the two driven ropes 5 are distributed on two sides of a rotating part 7 among the driving end part 2, the connecting part 3 and the driven end part 4, each pair of driving ropes 6 comprises two driving ropes 6, the two driving ropes 6 are distributed on two sides of the rotating part 7, and one ends of the two driving ropes 6 are fixed on the connecting part 3 or the driven end part 4.
At least one first hole 21 for the driven rope 5 to pass through in the axial direction is distributed on the driving end part 2, at least one second hole 41 for the driven rope 5 to pass through in the axial direction is distributed on the driven end part 4, the vertical distance from the center of the first hole 21 to the axis of the driving end part 2 is a first distribution radius R1, the vertical distance from the center of the second hole 41 to the axis of the driven end part 4 is a second distribution radius R2, and the radius ratio K of the first distribution radius R1 to the second distribution radius R2 is larger than or smaller than 1.
Specifically, in this embodiment, the passive end part 4 corresponds to an end joint in operation, and the active end part 2, the connection part 3, and the passive end part 4 all rotate on the plane of the instrument joint set 1 in the two projection directions A, B, that is, in the two projection directions A, B, the trapezoidal structure of this embodiment is adopted. The specific form of the trapezoid structure is that the pair of passive ropes 5 comprises a first passive rope 51 positioned at the upper part and a second passive rope 52 positioned at the lower part as shown in fig. 7, two ends of the two passive ropes 5 are respectively fixed on the driving end part 2 and the passive end part 4 by means of crimping or welding, and the two passive ropes 5, the driving end part 2 and the passive end part 4 form a trapezoid structure instead of a parallelogram structure due to the fact that the first distribution radius R1 of the first holes 21 on the driving end part 2 and the second distribution radius R2 of the second holes 41 on the passive end part 4 are different. The positive trapezoid structure is formed when the radius ratio K of the first distribution radius R1 to the second distribution radius R2 is larger than 1, and the inverted trapezoid structure is formed when the radius ratio K of the first distribution radius R1 to the second distribution radius R2 is smaller than 1. In this embodiment, a positive trapezoid structure is adopted, and in other embodiments, if it is desired that the passive end part (representing the passive joint) can obtain a larger deviation angle under the driving of a smaller angle, an inverted trapezoid structure may also be adopted. Furthermore, depending on the requirements of the surgical operation, the three parts of the instrument joint set 1 may also rotate only in the plane of one projection direction or in the planes of multiple projection directions, so as to achieve a greater degree of freedom of rotation. Each projection direction may have the above-described trapezoid structure.
In this embodiment, the two passive ropes 5 are kept with a certain preload in the initial position (the initial position is also called zero position, i.e. the rotation angle of the connecting part 3 relative to the driving end part 2 and the passive end part 4 is zero). The pair of driving ropes 6 includes a first driving rope 61 located at the upper side and a second driving rope 62 located at the lower side (the same as the driving rope 6 in the related art shown in fig. 1), two driving ropes 6 are distributed at both sides of the driving part 7, one ends of the two driving ropes 6 are fixed to the connection part 3 by crimping or welding, etc., and the other ends of the two driving ropes 6 are connected to a driving device (not shown) of the surgical robot. In other embodiments, the end of the drive rope 6 for fixed connection with the connecting element 3 can also be fixed to the passive end element 4.
The instrument joint set 1 of the surgical robot drives the driven end part 4 to rotate relative to the connecting part 3 through the pulling of the two driving ropes 6 and the pulling of the driven rope 5, and simultaneously the connecting part 3 rotates relative to the driving end part 2, so that the driven end part 4 rotates at different angles relative to the driving end part 2, and surgical operation is performed. By using different distribution radii, the radius ratio K is made larger or smaller than 1. When the radius ratio is larger than 1, the two passive ropes 5, the driving end part 2 and the passive end part 4 form a positive trapezoid, namely R1 is larger than R2, and the positive trapezoid structure can compensate the angle deviation caused by the length change of the driving rope 6 or the passive rope 5 between joints in the rotating process, so that the angle deviation is close to or equal to a target angle, and the angle precision of the tail end joint of the surgical robot is improved. When the radius ratio is smaller than 1, the two passive ropes 5, the driving end part 2 and the passive end part 4 form an inverted trapezoid structure, namely R1 is smaller than R2, and the inverted trapezoid structure can enable the passive end part (representing a passive joint) to obtain a larger deviation angle under a smaller driving angle in the rotating process, so that the connecting part 3 can be beneficial to increasing the moving angle of the passive end part 4 under a specific limiting environment (namely, the connecting part 3 can only rotate within a small angle range under certain specific limiting environments), namely, the moving flexibility of the terminal joint is improved.
In this embodiment, the radius ratio K is determined by the equationAnd (5) determining.
Wherein K is a radius ratio, alpha is an initial included angle formed by opposite surfaces of the driving end part 2 and the connecting part 3 at the joint when the rotation angles of the connecting part 3 relative to the driving end part 2 and the driven end part 4 are zero, the initial included angle between the driving end part 2 and the connecting part 3 is equal to the initial included angle between the driven end part 4 and the connecting part 3, beta 1 is a driving angle of the connecting part 3 relative to the driving end part 2, and delta beta is a deviation angle of the axis of the driven end part 4 relative to the axis of the driving end part 2 when the driven end part 4 is rotated.
The principle of the equation is that K is the ratio of the first distribution radius R1 to the second distribution radius R2, namely K=R1/R2, and when the instrument joint set is in the zero position, the joint rotation hard limit angle is alpha (the hard limit angle is the initial included angle), becauseTherefore:
Same reason
The total length l0 of the segment of the nude leakage at the joint is:
When the connecting part 3 of the instrument joint set 1 is driven to form an angle beta1 with the driving end part 2, the changed connecting part can be obtained
Since the length of the second passive rope 52 is unchanged before and after rotation, i.e. the length l0 of the line segment of the bare joint is unchanged, the following is adopted:
l′2＝l0-l′1;
The geometrical relationship after rotation is obtained:
Therefore:
The rotation angle β2 =α - γ of the passive end piece 4 with respect to the connecting piece 3 is obtained from the geometric relationship after rotation, and γ is the angle formed by the opposite surfaces of the passive end piece 4 and the connecting piece 3 at the joint when the passive end piece 4 is rotated. The final passive end piece 4 is offset by an angle delta beta = beta2-β1 relative to the active end piece 2,
The relation between the final available deviation angle delta beta and the part hard limit angle (namely initial angle) alpha, the parameter K and the driving angle beta1 is as follows:
based on this equation of Δβ, the above equation of K value can be obtained by conversion.
In other embodiments, the initial angle (e.g., α1) between the driving end member 2 and the connecting member 3, the initial angle (e.g., α2) between the driven end member 4 and the connecting member 3 may be slightly different from each other, but the angles α1 and α2 may not be completely equal, but the two initial angles are not equal as in the present embodiment, which is advantageous in reducing the complexity of the equation, and in easily calculating the K value close to the target angle. In other embodiments, the K value may be obtained without using the above equation, and the magnitude of the K value may be reasonably obtained by gradually adjusting the magnitudes of the first distribution radius R1 and the second distribution radius R2, but unlike the embodiment in which the instrument joint set 1 determines the radius ratio K by using the above equation, the angle of the passive end part 4 is compensated to or more close to the target angle, and the accuracy of angle compensation is improved. The initial included angle between the driving end part 2 and the connecting part 3 is equal to the initial included angle between the driven end part 4 and the connecting part 3, and by adopting the arrangement, the complexity of calculating and determining the K value is reduced, and the difference of the two initial angles is not needed to be considered, so that the angle deviation is needed to be further supplemented, and the accuracy of the K value is improved. And selecting a proper deviation angle delta beta according to the target angle, thereby determining a K value, and adjusting the two distribution radiuses according to the K value, so that the actual rotation angle of the passive end part 4 is close to the target angle, and the accuracy of angle compensation is improved.
Wherein, the range of the driving angle beta1 is 0-30 degrees, and the K value is determined by the driving angle in the range of the angle, so that the theoretical angle deviation can be reduced, and the accuracy of angle compensation is further improved.
Wherein, the two ends of the connecting part 3 are provided with a third hole 31 relative to the first hole 21 and a fourth hole 32 relative to the second hole 41, the vertical distance from the center of the third hole 31 to the axis of the connecting part 3 is a third distribution radius, and the vertical distance from the center of the fourth hole 32 to the axis of the connecting part 3 is a fourth distribution radius. The third distribution radius is equal to the first distribution radius R1 and the fourth distribution radius is equal to the second distribution radius R2.
When the third distribution radius is equal to the first distribution radius R1, a first exposed line segment l1 of the driven rope 5 between the connecting part 3 and the driving end part 2 is horizontal, so that the first exposed line segment l1 is conveniently calculated according to the first distribution radius R1 and the initial angle alpha, and when the fourth distribution radius is equal to the second distribution radius R2, a second exposed line segment l2 of the driven rope 5 between the connecting part 3 and the driven end part 4 is horizontal, so that the second exposed line segment l2 is conveniently calculated according to the second distribution radius R2 and the initial angle alpha, thereby reducing the complexity of an equation for determining the K value and improving the accuracy of angle compensation.
In other embodiments, the third distribution radius is not equal to the first distribution radius R1, and the fourth distribution radius is not equal to the second distribution radius R2, that is, the first exposed line segment l1 and the second exposed line segment l2 are not horizontal, when calculating l1 and l2, the values of l1 and l2 need to be compensated by conversion or other calculation methods instead of the above equation for calculating l1 and l2, but such a method is not convenient for calculating the K value and is not beneficial to the accuracy of angle compensation. Therefore, the third distribution radius is equal to the first distribution radius R1, the fourth distribution radius is equal to the second distribution radius R2, and the K value is convenient to calculate, so that the complexity of an equation for determining the K value is reduced, and the accuracy of angle compensation is improved.
Wherein each pair of driving ropes 6 and/or each pair of driven ropes 5 is symmetrically distributed with respect to the rotating part 7. Each pair of driving ropes 6 and/or each pair of driven ropes 5 are symmetrically distributed relative to the rotating part 7, and compared with asymmetric distribution, the difference of radius ratio in distribution is eliminated, so that the angle deviation is reduced, and the accuracy of angle compensation is improved.
Wherein two driving ropes 6 are arranged inside the two driven ropes 5. In other embodiments, two driving ropes 6 may be disposed outside the two driven ropes 5, and both the two driving ropes may be disposed in a manner that the connection part 3 and the driven end part 4 are rotated relative to the driving end part 2 by traction of the two driving ropes 6.
In this embodiment, the instrument joint set 1 is provided with a pair of passive ropes 5 and a pair of driving ropes 6 in two different projection directions A, B, and the radius ratio K in the two projection directions A, B is equal or unequal. The instrument joint set 1 realizes angle compensation in different projection directions by arranging a pair of driven ropes 5 and a pair of driving ropes 6 in two different projection directions. When the radius ratio in two different projection directions is equal, the angle compensation can be sequentially carried out in the different projection directions, and when the radius ratio in two different projection directions is unequal, the angle compensation in the two directions can be integrated, the adjustment in a larger angle range can be realized, and the degree of freedom of rotation is improved.
Wherein, the two projection directions are mutually perpendicular. The two projection directions are in mutually perpendicular relation, so that the rotating parts 7 in the two projection directions are conveniently arranged.
As shown in fig. 9 and 10, the rotating part 7 includes at least one first rotating part 71 between the driving end member 2 and the connecting member 3, and at least one second rotating part 72 between the driven end member 4 and the connecting member 3, both ends of the first rotating part 71 in the axial direction include two first rotating shafts 711 in the projection direction, the body of the first rotating part 71 is respectively connected to the driving end member 2 and the connecting member 3 through the two first rotating shafts 711, both ends of the second rotating part 72 in the axial direction include two second rotating shafts 721 in the projection direction, and the body of the second rotating part 72 is respectively connected to the driven end member 4 and the connecting member 3 through the two second rotating shafts 721.
The drive end part 2 and the connecting part 3 can rotate in two different projection directions through one first rotating part 71, and when the number of the first rotating parts 71 is larger than one, the drive end part 2 and the connecting part 3 can rotate in more projection directions, so that more flexible rotation degrees of freedom are realized. The passive end part 4 and the connecting part 3 can rotate in two different projection directions through the second rotating part 72, and when the number of the second rotating parts 72 is larger than one, the passive end part 4 and the connecting part 3 can rotate in more projection directions, so that more flexible rotation freedom is realized.
In such a structure, the two first rotation shafts 711 are perpendicular to each other in the two projection directions a and B, and the two second rotation shafts 721 are also perpendicular to each other in the two projection directions a and B, so that the two rotation shafts are easily arranged in such a perpendicular relationship, and the rotation parts are also easily manufactured.
In other embodiments, if the two projection directions a and B are not perpendicular to each other, the two first rotation axes 711 and the two second rotation axes 721 may not be perpendicular to each other, but may adopt other angles according to the rotation requirement. Or when there are a plurality of first rotating parts or a plurality of second rotating parts, the two or more first rotating shafts 711 can realize more angular rotation, and the two or more second rotating shafts 721 can also realize more angular rotation, thereby improving the degree of freedom of rotation. Or other rotation modes can be adopted to realize the rotation among all parts, for example, a ball bearing is adopted to realize the rotation mode of any angle, so that the rotation freedom degree is further improved.
Example 2
The embodiment provides a surgical instrument which is used in a surgical robot. The surgical instrument comprises an instrument joint set 1 as in example 1. According to the surgical instrument, the radius ratio of the driven ropes 5 on the driving end part 2 and the driven end part 4 is regulated through the instrument joint set 1, when the radius ratio is larger than 1, the two driven ropes 5, the driving end part 2 and the driven end part 4 form a positive trapezoid structure, so that in the rotation process, the angle deviation caused by the length change of the driving ropes 6 or the driven ropes 5 between joints can be compensated to be close to or equal to a target angle, the angle precision of the tail end joint of the surgical robot is improved, and when the radius ratio is smaller than 1, the two driven ropes 5, the driving end part 2 and the driven end part 4 form an inverted trapezoid structure, and in the rotation process, the driven end part 4 (representing the driven joint) can obtain a larger deviation angle under a smaller driving angle, and the movable angle of the driven end part can be increased under a specific limiting environment, namely the movable angle of the tail end joint is increased.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.