CN103433916B - The isometrical sphere of two degrees of freedom is pure rolls rotating mechanism in parallel - Google Patents

Abstract

The invention discloses a two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism, which relates to the technical fields of robots, precision instruments and equipment, and mechanical manufacturing. The mechanism is mainly composed of a motion platform, a fixed base and a motion branch chain, which can realize the pure rolling and parallel rotation of the motion platform around the fixed base with two degrees of freedom and equal diameter spherical surface. The motion platform and the fixed base are connected with more than three kinematic branch chains through kinematic pairs, and each kinematic branch chain contains more than two connecting rods; each kinematic branch chain has a symmetrical structure and contains two or more kinematic pairs , forming more than 4 degrees of freedom. The rotating mechanism provided by the invention has a large working space of the moving platform; compact structure; high rigidity; the mechanism does not contain redundant constraints, and there is no mutual internal stress between the moving branch chains; the precision and stability are high; the structure is simple and easy to install. These advantages enable the rotating mechanism to be widely used in the field of high-performance pointing devices.

Description

Two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism

technical field

The invention relates to the technical field of robots, precision instruments and equipment, and machinery manufacturing, and in particular to a two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism.

Background technique

The two-degree-of-freedom rotating mechanism has been widely used in machinery manufacturing, automobile manufacturing, aerospace manufacturing, robotics and other fields, including machine tool spindles, automobile couplings, aviation pointing platforms and other fields. With the development of technology, the load at the end of the mechanism is getting larger and larger, and the traditional two-degree-of-freedom rotating mechanism is difficult to meet the design requirements; and the two-degree-of-freedom parallel rotating mechanism has the characteristics of high rigidity, high precision, strong bearing capacity, and small motion inertia. , has attracted more and more attention and has been widely used. Typically, G.R.Dunlop designed a parallel radar tracker (Canterbury Satellite Tracker) with two rotational degrees of freedom based on the three-degree-of-freedom multi-hinge parallel mechanism patent (US4651589); patent US5893296 and WO99/21070 disclose a four-branched two-freedom degree parallel rotation mechanism, and has been successfully used as devices such as entertainment fountains; patents US7478576 and US7472622 both disclose a two-degree-of-freedom parallel rotation mechanism with three branches. Most of the published mechanisms are parallel mechanisms with redundant constraints. The branch chains of the mechanism have unstable assembly stresses that vary with the attitude of the platform. During high-speed motion, the dynamic performance is not good and the precision stability is poor.

Contents of the invention

The purpose of the present invention is to provide a two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism, which is mainly composed of a moving platform, a fixed base and a moving branch chain, which can realize two-degree-of-freedom movement of the moving platform around the fixed base, etc. Radial spherical pure rolling parallel rotation. There are more than three kinematic branch chains between the motion platform and the fixed base, and each kinematic branch chain contains more than two connecting rods; each kinematic branch chain is a symmetrical structure, including two or more kinematic pairs, forming 4 More than one degree of freedom; the input end of each kinematic branch chain is connected to the fixed base through a kinematic pair, and the output end of each kinematic branch chain is connected to the motion platform through a kinematic pair; the relative position of each kinematic branch chain can be symmetrical about the center In this way, the mechanism is beautiful and the bearing capacity of each motion branch chain is balanced, and the service life is long.

The two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention, each of the kinematic branch chains is symmetrical about the symmetry plane II, and realizes the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation of the motion platform around the fixed base; Isometric spherical surface means: assume that the midpoint of the line connecting point A and point B is point C, with point A and point B as the center of the sphere, AC or BC as the radius to make a sphere, and the common tangent plane of the two spheres is a symmetrical plane II;

The A point is determined by the following relationship: when each kinematic branch chain is coplanar with the kinematic auxiliary axis connected to the kinematic platform, A point is located at the center of the surface formed by each kinematic branch chain and the kinematic auxiliary axis connected to the kinematic platform; When the auxiliary axis of motion connected by the branch chain and the motion platform intersects at a common point, point A is located at the common point;

The B point is determined by the following relationship: when each kinematic branch chain is coplanar with the kinematic auxiliary axis connected to the fixed base, B point is located at the center of the surface formed by each kinematic branch chain and the kinematic auxiliary axis connected to the fixed base; When the kinematic secondary axes connected by each kinematic branch chain and the fixed base intersect at a common point, point B is located at the common point.

The two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism has only two rotational degrees of freedom, but has multiple driving motion branches, which can realize redundant driving to ensure that the input torque is insufficient under high load conditions. In specific implementation, drive motors can be installed on the kinematic pair connected between each motion branch chain and the fixed base. When the load is low, only two of the drive motors are required to work and output torque, and the rest of the drive motors are only for position follow-up; When the load is heavy, all drive motors participate in the work and output torque to ensure that there is enough torque to drive the load to rotate in an instant.

The rotating mechanism provided by the present invention has the following advantages:

(1) The working space of the motion platform is large (generally ±60°, up to ±90°); (2) The structure is compact; (3) The rigidity is large; (4) The mechanism does not contain redundant constraints, and there is no Mutual internal stress, high accuracy and stability; (5) Simple structure, easy to install. These advantages enable the rotating mechanism to be widely used in the field of high-performance pointing devices.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 2 is a schematic diagram of the symmetrical structure of the kinematic branch chain in the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention;

Fig. 3 is a structural schematic diagram of the first embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 4 is a structural schematic diagram of the second embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 5 is a structural schematic diagram of the third embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 6 is a structural schematic diagram of the fourth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 7 is a structural schematic diagram of the fifth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 8 is a structural schematic diagram of the sixth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 9 is a structural schematic diagram of the seventh embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 10 is a structural schematic diagram of the eighth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 11 is a structural schematic diagram of the ninth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 12 is a structural schematic diagram of the tenth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 13 is a structural schematic diagram of the eleventh embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention;

Fig. 14 is a structural schematic diagram of the twelfth embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention;

Fig. 15 is a structural schematic diagram of the thirteenth embodiment of the two-degree-of-freedom equal-diameter spherical pure-rolling parallel rotation mechanism of the present invention;

Fig. 16 is a structural schematic diagram of the fourteenth embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention.

detailed description

The present invention will be further described in detail with reference to the accompanying drawings and embodiments.

In all embodiments, said R _i represents a rotary joint, P _i represents a moving joint, U _i represents a universal joint joint containing two intersecting rotational axes, C _i represents a cylindrical joint, and Pa _i represents a joint composed of A parallel four bar pair composed of four revolving pairs, S _i represents a spherical pair, and i is a natural number.

The two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism provided by the present invention, as shown in Figure 1, includes a motion platform 1, a fixed base 2, a first motion branch chain 3, a second motion branch chain 4, a third motion branch The chain 5; the motion platform 1 and the fixed base 2 are respectively connected with the two ends of the first motion branch chain 3, the second motion branch chain 4 and the third motion branch chain 5 through the motion pairs. The first kinematic branch chain 3, the second kinematic branch chain 4, the third kinematic branch chain 5 (can also include more kinematic branch chains such as the fourth kinematic branch chain 6) can be kinematic branch chains with the same structure, or only Some kinematic branches have the same structure. The same kinematic branches can also have different structural sizes, as long as certain conditions are met. The fixed base 2 can be installed on the moving end of the machine tool and other equipment or on the actuator, and the moving platform 1 is equipped with a rotating cutter head or a target sensor. In this way, the moving platform 1 can achieve ±60° relative to the fixed base 2, and the maximum The working space can reach ±90°, that is, it can realize applications such as machining or target tracking and detection.

The condition that the kinematic branch chain structure needs to meet is: there is a symmetry plane II in each kinematic branch chain, and the kinematic pairs in the kinematic branch chain are all symmetrical up and down with respect to the symmetry plane II, as shown in Figure 2, the revolving pair R ₃ The intersection point D with the extension line of the axis of R ₂ , the intersection point E of the extension line of the axis of the rotating pair R ₁ and R ₂ , the intersection point F of the extension line of the axis of the rotating pair R ₃ and R ₁ , the three intersection points form a plane isosceles Triangle DEF, wherein: point D is the vertex, waist length DE is equal to waist length DF; the perpendicular bisector passing through point D and point C and taking the base EF as normal is called symmetry plane II. Between the motion platform 1 and the fixed base 2, the symmetry planes II of all the motion branch chains coincide with each other to form a common symmetry plane.

The connection relationship between the motion branch chain and the motion platform 1 or the fixed base 2 can be a rotating pair, a moving pair, a universal joint pair or a cylindrical pair; the same kinematic pair can also be used for connection to simplify the structure, Save manufacturing cost.

The motion branch chain and the motion platform 1 can realize a two-degree-of-freedom equidiameter spherical pure rolling motion around the fixed base 2, as shown in Figure 1, points A and B are the centers of two hemispheres, and point C is The contact point of the two hemispheres; the center of the hemisphere where the motion platform 1 is located is point A, and the radius is the distance L _AC between point A and point C; the center of the hemisphere where the fixed base 2 is located is point B, and the radius is point B The distance from point C is L _BC ; and L _AC =L _BC ; plane II is the common tangent plane passing through point C of the two contacting hemispheres, called symmetry plane II. When the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism provided by the present invention is in motion, the motion platform 1 is as if fixed on the hemisphere A, and the fixed base 2 is as if fixed on the hemisphere B, and the two hemispheres do not slip The pure rolling motion of the two hemispheres is point C, so the pure rolling parallel rotation of the equidiametric spherical surface of the moving platform 1 relative to the fixed base 2 is formed.

The point A of the center of the sphere is determined by the following relationship: when each branch chain is coplanar with the secondary axis or the center of the movement that is connected to the movement platform 1, point A is located at the position of the secondary axis or center of the movement that each branch chain is connected to the movement platform 1 The center of the formed surface; when the secondary kinematic axes of each kinematic branch chain and the kinematic platform 1 intersect at a common point, point A is located at the common point.

The point B of the center of the sphere is determined by the following relationship: when the secondary axis or center of the movement of each branch chain connected to the fixed base 2 is coplanar, point B is located at the secondary axis or axis of movement of each branch chain connected to the fixed base 2 The center of the surface formed by the center; when the kinematic secondary axes connected to each kinematic branch chain and the fixed base 2 intersect at a common point, point B is located at the common point.

Embodiment 1 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in Figure 3, including a motion platform 101, a fixed base 102, a first kinematic branch chain 103, a second kinematic branch chain 104 and a third kinematic branch chain. The motion branch chain 105; the motion platform 101 is provided with three rotating pair connection ends, which respectively form three rotating pairs R ₄ , R ₆ and R ₈ with the three moving branch chains, and the axes of the three rotating pairs intersect at a common point; fixed The base 102 is provided with three revolving pairs connecting ends, respectively forming three revolving pairs R ₁ , R ₅ and R ₇ with the three kinematic branch chains, and the axes of the three revolving pairs intersect at a common point; the first kinematic branch chain 103 It consists of three connecting rods, including four rotating pairs, which are R ₁ , R ₂ , R ₃ and R ₄ in turn. The rotating pairs R ₁ and R ₂ form the lower link, and the rotating pairs R ₂ and R ₃ form the middle link. R ₃ and R ₄ constitute the upper link; R ₁ is connected to the fixed base 102, R ₄ is connected to the motion platform 101, and the rotating pair R ₁ and the rotating pair R ₂ are located on both sides of the middle connecting rod; the second moving support The chain 104 is composed of two connecting rods, including _three kinematic pairs, which are _R5 , S1 and R6 in sequence. _The rotating pair _R5 and the ball _pair S1 form the lower link, and the rotating _pair R6 and the ball _pair S1 form the lower link. _On the upper link, the rotating pair R5 is connected to the fixed base 102, and the rotating pair R6 is connected to the motion platform 101. _The rotating pair _R5 and the rotating _pair R6 are located at the two ends of the ball pair S1 _; the third motion branch chain 105 is composed of Composed of two connecting rods, including three kinematic pairs, which are R ₇ , S ₂ and R ₈ in turn, the rotating pair R ₇ and the ball pair S ₂ form the lower link, and the rotating pair R ₈ and the ball pair S ₂ form the upper link , the revolving pair R ₇ is connected with the fixed base 102, the revolving pair R ₈ is connected with the motion platform 101, and the revolving pair R ₇ and the revolving pair R ₈ are located at the two ends of the ball pair S ₂ ; The intersection point of the axes of the pair R2 and the rotating pair _R3 , the center point of the ball pair S1 in the _second kinematic branch chain 104 and the center point _of the ball pair S2 in the third kinematic branch chain 105 form a plane of symmetry _II ;

Embodiment 2 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. The motion branch chain 205; the motion platform 201 is provided with three rotating pair connection ends, which form three rotating pairs R ₄ , R ₆ and R ₈ with the three moving branch chains respectively, and the axes of the three rotating pairs are coplanar and intersect two by two; The fixed base 202 is provided with three revolving pairs connecting ends, respectively forming three revolving pairs R ₁ , R ₅ and R ₇ with the three kinematic branch chains. The chain 203 is composed of three connecting rods, including four rotating pairs, which are R ₁ , R ₂ , R ₃ and R ₄ in turn. The rotating pairs R ₁ and R ₂ form the lower link, and R ₂ and R ₃ form the middle link. Rods, R ₃ and R ₄ constitute the upper link; R ₁ is connected to the fixed base 202, R ₄ is connected to the motion platform 201; the second motion branch chain 204 is composed of two links, including three motion pairs, which are in turn R ₅ , S ₁ and R ₆ , the rotating pair R ₅ and the spherical pair S ₁ form the lower link, the rotating pair R ₆ and the spherical pair S ₁ form the upper link, the rotating pair R ₅ is connected with the fixed base 202, and the rotating pair R ₆ is connected to the motion platform 201; the third motion branch chain 205 is composed of two connecting rods, including three motion pairs, which are R ₇ , S ₂ and R ₈ in turn, and the rotation pair R ₇ and the ball pair S ₂ constitute the lower connection Rod, rotating pair R ₈ and ball pair S ₂ form the upper link, rotating pair R ₇ is connected with the fixed base 202, and rotating pair R ₈ is connected with the motion platform 201; wherein, the rotating pair R ₂ in the first motion branch chain 203 The intersection with the axis of the rotating pair _R3 , the center point of the ball pair S1 in the _second kinematic branch chain 204 and the center point _of the ball pair S2 in the third kinematic branch chain 205 form a plane of symmetry II;

Embodiment 3 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Motion branch chain 305 and the 4th motion branch chain 306; The motion platform 301 is provided with three rotary pair connection ends, respectively and three motion branch chains (the first motion branch chain 303, the second movement branch chain 304, the 3rd movement branch chain chain 305) to form three revolving pairs R ₂ , R ₄ and R ₆ , the axes of the three revolving pairs are coplanar and intersect two by two; the fixed base 302 is provided with three revolving pair connecting ends, respectively connected to the three kinematic branch chains ( The first kinematic branch chain 303, the second kinematic branch chain 304, and the third kinematic branch chain 305) form three revolving pairs R ₁ , R ₃ and R ₅ , and the axes of the three revolving pairs are co-planar and intersect two by two; the first kinematic The branch chain 303, the second motion branch chain 304 and the third motion branch chain 305 are similar in structure and are all composed of two connecting rods, but the length of the connecting rods in the motion branch chain can be selected in different sizes according to the specific application background; Take the branch chain 303 as an example, which includes three kinematic pairs, which are R ₁ , S ₂ and R ₂ in sequence. The rotating pair R ₁ and the ball pair S ₂ form the lower link, and the rotating pair R ₂ and the ball pair S ₂ form the upper link. , the revolving pair R ₁ is connected with the fixed base 302, and the revolving pair R ₂ is connected with the motion platform 301; the fourth kinematic branch chain 306 is a central branch chain, consisting of only one connecting rod, including two kinematic pairs, U ₁ in turn and S ₁ ; the universal joint pair U ₁ is connected to the fixed base 302, and the center of the universal joint U ₁ is located on the plane formed by the axes of R ₁ , R ₃ and R ₅ , and the ball pair S ₁ is connected to the motion platform 301, And the center of the ball pair S ₁ is located on the plane formed by the axes of R ₂ , R ₄ and R ₆ ; wherein, the center point of the ball pair S ₂ in the first motion branch chain 303, the center point of the ball pair S ₃ in the second motion branch chain 304 The center point and the center point of the ball pair S ₄ in the third motion branch chain 305 form a plane of symmetry II;

Embodiment 4 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in Figure 6, including a motion platform 401, a fixed base 402, a first motion branch chain 403, a second motion branch chain 404, a third motion Motion branch chain 405 and the 4th motion branch chain 406; The motion platform 401 is provided with three rotary pair connection ends, respectively and three motion branch chains (the first motion branch chain 403, the second motion branch chain 404, the 3rd motion branch chain chain 405) constitutes three revolving pairs R ₂ , R ₄ and R ₆ , and the axes of the three revolving pairs intersect at a common point; the fixed base 402 is provided with three connecting ends of the revolving pairs, respectively connected with the three kinematic branch chains (No. A kinematic branch chain 403, a second kinematic branch chain 404, and a third kinematic branch chain 405) form three revolving pairs R ₁ , R ₃ and R ₅ , and the axes of the three revolving pairs intersect at a common point; the first kinematic branch chain 403, the second kinematic branch chain 404 and the third kinematic branch chain 405 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 403 as an example, it contains three kinematic pairs, which are R ₁ , S ₂ and R ₂ , rotating pair R ₁ and ball pair S ₂ form the lower link, rotating pair R ₂ and spherical pair S ₂ form the upper link, rotating pair R ₁ is connected to the fixed base 402, and rotating pair R ₂ is connected to the motion platform 401 connected, the rotating pair R ₁ and the rotating pair R ₂ are located at the two ends of the ball pair S ₂ ; the fourth kinematic branch chain 406 is the central branch chain, which is composed of only one connecting rod and contains two kinematic pairs, which are U ₁ and S in turn ₁ ; the universal joint pair U ₁ is connected with the fixed base 402, and the center is located at the common intersection of the R ₁ , R ₃ and R ₅ axes, the ball pair S ₁ is connected with the motion platform 401, and the center is located at R ₂ , R ₄ and R ₆ axis public intersection; wherein, the center point of ball pair S ₂ in the first motion branch chain 403, the center point of ball pair S ₃ in the second motion branch chain 404 and the ball pair in the third motion branch chain 405 The central point of S ₄ forms the symmetry plane II;

Embodiment 5 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Motion branch chain 505 and the 4th motion branch chain 506; The motion platform 501 is provided with three cylinder pair connection ends, respectively and three motion branch chains (the first motion branch chain 503, the second movement branch chain 504, the 3rd motion branch chain chain 505) constitutes three cylinder pairs C ₂ , C ₆ and C ₄ , and the axes of the three cylinder pairs intersect at a common point; the fixed base 502 is provided with three connection ends of the cylinder pairs, respectively connected with the three kinematic branch chains (No. A kinematic branch chain 503, a second kinematic branch chain 504, and a third kinematic branch chain 505) constitute three cylinder pairs C ₁ , C ₅ and C ₃ , and the axes of the three cylinder sub-chains intersect at a common point; the first kinematic branch chain 503, the second kinematic branch chain 504 and the third kinematic branch chain 505 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 503 as an example, it contains three kinematic pairs, which are C ₁ , R ₁ and C ₂ , the rotating pair R ₁ and the cylindrical pair C ₁ constitute the lower link, the rotating pair R ₁ and the cylindrical pair C ₂ form the upper connecting rod, the cylindrical pair C ₁ is connected to the fixed base 502, and the cylindrical pair C ₂ is connected to the motion platform 501 Connected, the axes of cylinder pair C ₁ and cylinder pair C ₂ are coplanar and intersect with rotating pair R ₁ at a common point; the fourth kinematic branch chain 506 is a central branch chain, consisting of only one connecting rod, including two ball pairs, S ₁ and S ₂ in sequence; the ball pair S ₁ is connected to the fixed base 502, and the ball pair S ₂ is connected to the motion platform 501; wherein, the axis of the rotating pair R ₁ in the first kinematic branch chain 503, the second kinematic branch chain _The axis of the revolving pair R2 in 504 and the axis of the revolving pair _R3 in the third kinematic branch chain 505 are coplanar and form a plane of symmetry II.

Embodiment 6 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Motion branch chain 605 and the 4th motion branch chain 606; The motion platform 601 is provided with three cylinder pair connection ends, respectively and three motion branch chains (the first motion branch chain 603, the second motion branch chain 604, the 3rd motion branch chain Chain 605) constitutes three cylinder pairs C ₂ , C ₆ and C ₄ , and the axes of the three cylinder pairs intersect at a common point; the fixed base 602 is provided with three connection ends of the cylinder pairs, respectively connected with the three kinematic branch chains (No. A kinematic branch chain 603, a second kinematic branch chain 604, and a third kinematic branch chain 605) constitute three cylinder pairs C ₁ , C ₅ and C ₃ , and the axis lines of the three cylinder sub-chains intersect at a common point; the first kinematic branch chain 603, the second kinematic branch chain 604 and the third kinematic branch chain 605 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 603 as an example, it contains three kinematic pairs, which are C ₁ , S ₃ and C ₂ , the ball pair S ₃ and the cylindrical pair C ₁ constitute the lower link, the ball pair S ₃ and the cylindrical pair C ₂ form the upper link, the cylindrical pair C ₁ is connected to the fixed base 602, and the cylindrical pair C ₂ is connected to the motion platform 601 The axes of the cylinder pair C ₁ and the cylinder pair C ₂ are coplanar and intersect at the center point of the ball pair S ₃ ; the fourth kinematic branch chain 606 is a central branch chain, consisting of only one connecting rod, including two ball pairs, sequentially are S ₁ and S ₂ ; the ball pair S ₁ is connected to the fixed base 602, and the ball pair S ₂ is connected to the motion platform 601; wherein, the center point of the ball pair S ₃ in the first motion branch chain 603, the second motion branch chain _The center point of the ball pair S5 in 604 and the center point of the ball _pair S4 in the third motion branch chain 605 form a plane of symmetry II.

Embodiment 7 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Motion branch chain 705 and the 4th motion branch chain 706; The motion platform 701 is provided with three mobile pairs connecting ends, respectively and three motion branch chains (the first motion branch chain 703, the second movement branch chain 704, the third movement branch chain Chain 705) constitutes three moving pairs P ₂ , P ₆ and P ₄ , and the axes of the three moving pairs intersect at a common point; the fixed base 702 is provided with three connecting ends of moving pairs, which respectively connect with the three kinematic branch chains (No. A kinematic branch chain 703, a second kinematic branch chain 704, and a third kinematic branch chain 705) constitute three moving pairs P ₁ , P ₅ and P ₃ , and the axes of the three moving pairs intersect at a common point; the first kinematic branch chain 703, the second kinematic branch chain 704 and the third kinematic branch chain 705 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 703 as an example, it includes three kinematic pairs, which are P ₁ , S ₃ and P ₂ , the ball pair S ₃ and the moving pair P ₁ form the lower link, the ball pair S ₃ and the moving pair P ₂ form the upper link, the moving pair P ₁ is connected to the fixed base 702, and the moving pair P ₂ is connected to the motion platform 701 connected, the axes of the moving pair P ₁ and the moving pair P ₂ are coplanar and intersect at the center point of the ball pair S ₃ ; the fourth kinematic branch chain 706 is a central branch chain, consisting of only one connecting rod, including two ball pairs, sequentially are S ₁ and S ₂ ; the ball pair S ₁ is connected to the fixed base 702, and the ball pair S ₂ is connected to the motion platform 701; wherein, the center point of the ball pair S ₃ in the first motion branch chain 703, the second motion branch chain _The center point of the ball pair S5 in 704 and the center point of the ball _pair S4 in the third kinematic branch chain 705 form a plane of symmetry II.

The eighth embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in Figure 10, including a motion platform 801, a fixed base 802, a first motion branch chain 803, a second motion branch chain 804, a third Motion branch chain 805 and the 4th motion branch chain 806; The motion platform 801 is provided with three rotary pair connection ends, respectively and three motion branch chains (the first motion branch chain 803, the second movement branch chain 804, the 3rd movement branch chain chain 805) constitutes three revolving pairs R ₃ , R ₉ and R ₆ , and the axes of the three revolving pairs intersect at a common point; the fixed base 802 is provided with three connecting ends of the revolving pairs, which respectively connect with the three kinematic branch chains (No. A kinematic branch chain 803, a second kinematic branch chain 804, and a third kinematic branch chain 805) constitute three revolving pairs R ₁ , R ₇ and R ₄ , and the axes of the three revolving pairs intersect at a common point; the first kinematic branch chain 803, the second kinematic branch chain 804 and the third kinematic branch chain 805 are similar in structure, and are composed of four connecting rods; taking the first kinematic branch chain 803 as an example, it includes five kinematic pairs, which are R ₁ , P ₁ in turn , R ₂ , P ₂ and R ₃ , the rotating pair R ₁ and the moving pair P ₁ form the lower link, the rotating pair R ₂ and the moving pair P ₁ form the middle link one, and the rotating pair R ₂ and the moving pair P ₂ form the middle link The _second connecting rod, the rotating pair _R3 and the moving pair P2 constitute the upper connecting rod, the rotating _pair R1 is connected with the fixed base 802, the rotating pair _R3 is connected with the motion platform 801, and the moving pair P1 and the moving _pair P2 have _a common axis surface and intersects with the revolving pair R ₂ at a common point; the fourth kinematic branch chain 806 is a central branch chain, consisting of only one connecting rod, including two ball pairs, which are S ₁ and S ₂ in turn; ball pairs S ₁ and The fixed base 802 is connected, and the ball pair S2 is connected with the motion platform 801; wherein, the axis of the revolving pair R ₂ in the first kinematic branch chain 803, the axis of the revolving pair _R8 in the _second kinematic branch chain 804 and the third kinematic branch _The axes of revolving pair R5 in chain 805 are coplanar and form plane II of symmetry.

Embodiment 9 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in Figure 11, including a motion platform 901, a fixed base 902, a first motion branch chain 903, a second motion branch chain 904, a third Motion branch chain 905 and the 4th motion branch chain 906; The motion platform 901 is provided with three cylinder pair connection ends, respectively and three motion branch chains (the first motion branch chain 903, the second movement branch chain 904, the 3rd motion branch chain Chain 905) constitutes three cylinder pairs C ₁ , C ₃ and C ₂ , and the axis lines of the three cylinder pairs intersect at a common point; the fixed base 902 is provided with three moving pair connection ends, which respectively connect with the three kinematic branch chains (No. A kinematic branch chain 903, a second kinematic branch chain 904, and a third kinematic branch chain 905) constitute three moving pairs P ₁ , P ₃ and P ₂ , and the axes of the three moving pairs intersect at a common point; the first kinematic branch chain 903, the second kinematic branch chain 904 and the third kinematic branch chain 905 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 903 as an example, it includes three kinematic pairs, which are P ₁ , S ₃ and C ₁ , the ball pair S ₃ and the moving pair P ₁ form the lower link, the ball pair S ₃ and the cylindrical pair C ₁ form the upper link, the moving pair P ₁ is connected to the fixed base 902, and the cylindrical pair C ₁ is connected to the motion platform 901 connected, the axes of the moving pair P ₁ and the cylindrical pair C ₁ are coplanar and intersect at the center point of the ball pair S ₃ ; the fourth kinematic branch chain 906 is a central branch chain, consisting of only one connecting rod, including two ball pairs, sequentially are S ₁ and S ₂ ; the ball pair S ₁ is connected to the fixed base 902, and the ball pair S ₂ is connected to the motion platform 901; wherein, the center point of the ball pair S ₃ in the first motion branch chain 903, the second motion branch chain _The center point of the ball pair S5 in 904 and the center point of the ball _pair S4 in the third motion branch chain 905 form a plane of symmetry II.

Embodiment 10 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Motion branch chain 1005 and the 4th motion branch chain 1006; The motion platform 1001 is provided with three cylinder pairs connecting ends, and three motion branch chains (the first motion branch chain 1003, the second motion branch chain 1004, the 3rd motion branch chain respectively) Chain 1005) constitutes three cylinder pairs C ₁ , C ₃ and C ₂ , and the axis lines of the three cylinder pairs intersect at a common point; the fixed base 1002 is provided with three moving pair connection ends, which respectively connect with the three kinematic branch chains (No. A kinematic branch chain 1003, a second kinematic branch chain 1004, and a third kinematic branch chain 1005) constitute three moving pairs P ₁ , P ₃ and P ₂ , and the axes of the three moving pairs intersect at a common point; the first kinematic branch chain 1003, the second kinematic branch chain 1004 and the third kinematic branch chain 1005 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 1003 as an example, it includes three kinematic pairs, which are P ₁ , U ₁ and C ₁ , the universal joint pair U ₁ and the moving pair P ₁ form the lower link, the universal joint pair U ₁ and the cylindrical pair C ₁ form the upper link, the moving pair P ₁ is connected with the fixed base 1002, and the cylindrical pair C ₁ Connected with the motion platform 1001, the axes of the moving pair P ₁ and the cylindrical pair C ₁ are coplanar and intersect at the center point of the universal joint pair U ₁ ; the fourth motion branch chain 1006 is a central branch chain, consisting of only one connecting rod, including Two ball pairs, S ₁ and S ₂ in turn; the ball pair S ₁ is connected to the fixed base 1002, and the ball pair S ₂ is connected to the motion platform 1001; among them, the universal joint pair U ₁ in the first motion branch chain 1003 The center point, the center point of the universal joint pair U ₃ in the second kinematic branch 1004 and the center point of the universal joint U ₂ in the third kinematic branch 1005 form a plane of symmetry II.

The eleventh embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Three kinematic branch chains 1105 and the fourth kinematic branch chain 1106; the motion platform 1101 is provided with three mobile pair connection ends, respectively connected with three kinematic branch chains (the first kinematic branch chain 1103, the second kinematic branch chain 1104, the third kinematic branch chain Branch chain 1105) constitutes three moving pairs P ₂ , P ₆ and P ₄ , and the axis lines of the three moving pairs intersect at a common point; the fixed base 1102 is provided with three moving pair connecting ends, respectively connected with the three moving branch chains ( The first kinematic branch chain 1103, the second kinematic branch chain 1104, and the third kinematic branch chain 1105) constitute three moving pairs P ₁ , P ₅ and P ₃ , and the axes of the three moving pairs intersect at a common point; the first moving branch The chain 1103, the second kinematic branch chain 1104 and the third kinematic branch chain 1105 are similar in structure, and are all composed of four connecting rods; taking the first kinematic branch chain 1103 as an example, it includes five kinematic pairs, which are P ₁ , R ₁ , R ₂ , R ₃ and P ₂ , the rotating pair R ₁ and the moving pair P ₁ form the lower link, the rotating ball pair R ₂ and the rotating pair R ₁ form the middle connecting rod 1, the rotating pair R ₂ and the rotating pair R ₃ It constitutes the second connecting rod, the rotating pair R ₃ and the moving pair P ₂ constitute the upper connecting rod, the axes of the rotating pairs R ₁ , R ₂ and R ₃ intersect at a common point on the R ₂ axis, and the moving pair P ₁ and the fixed base 1102 is connected, the moving _pair P2 is connected with the motion platform 1101, the axes _of the moving _pair P1 and the moving pair P2 are coplanar and intersect at the common point of the axes _of the rotating pairs R1, R2 and _{R3 ;} the fourth kinematic branch chain 1106 is The central branch chain consists of only one connecting rod, including two ball pairs, S ₁ and S ₂ in turn; the ball pair S ₁ is connected to the fixed base 1102, and the ball pair S ₂ is connected to the motion platform 1101; among them, the first The axis of the revolving pair R ₂ in the kinematic branch 1103 , the axis of the revolving pair R ₈ in the second kinematic branch 1104 and the axis of the revolving pair R ₅ in the third kinematic branch 1105 form a plane of symmetry II.

Embodiment 12 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Three kinematic branch chains 1205 and the fourth kinematic branch chain 1206; the kinematic platform 1201 is provided with three universal joint pair connection ends, which are connected with three kinematic branch chains (the first kinematic branch chain 1203, the second kinematic branch chain 1204, the second kinematic branch chain 1204, and the third kinematic branch chain respectively). Three kinematic branch chains 1205) constitute three universal joint pairs U ₂ , U ₆ and U ₄ ; three universal joint pair connection ends are provided on the fixed base 1202, which are respectively connected with the three kinematic branch chains (the first kinematic branch chain 1203, the second kinematic branch chain 1204, and the third kinematic branch chain 1205) constitute three universal joint pairs U ₁ , U ₅ and U ₃ ; the first kinematic branch chain 1203, the second kinematic branch chain 1204 and the third kinematic branch chain The chain 1205 has a similar structure and is composed of two connecting rods; taking the first kinematic branch chain 1203 as an example, it includes three kinematic pairs, which are U ₁ , R ₁ and U ₂ , the revolving pair R ₁ and the universal joint U ₁ constitutes the lower link, the rotating pair R ₁ and the universal joint U ₂ constitute the upper link, the universal joint U ₁ is connected with the fixed base 1202, and the universal joint U ₂ is connected with the motion platform 1201; the fourth motion The branch chain 1206 is a central branch chain, consisting of only _one connecting rod, including _two ball pairs, S1 and S2 in turn _; the ball pair S1 is connected to the fixed base 1202, and the ball pair S2 is connected to the motion platform 1201 _; Among them, the axis of the revolving pair R1 in the _first kinematic branch chain 1203, the axis of the revolving pair _R3 in the _second kinematic branch chain 1204 and the axis of the revolving pair R2 in the third kinematic branch chain 1205 form a symmetry plane II.

Embodiment 13 of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Three kinematic branch chains 1305 and the fourth kinematic branch chain 1306; the motion platform 1301 is provided with three cylinder pairs connecting ends, which are respectively connected with three kinematic branch chains (the first kinematic branch chain 1303, the second kinematic branch chain 1304, the third kinematic branch chain Branch chain 1305) constitutes three cylinder pairs C ₂ , C ₆ and C ₄ , and the axis lines of the three cylinder pairs intersect at a common point; the fixed base 1302 is provided with three cylinder pair connection ends, respectively connected with the three kinematic branch chains ( The first kinematic branch chain 1303, the second kinematic branch chain 1304, and the third kinematic branch chain 1305) constitute three cylinder pairs C ₁ , C ₅ and C ₃ , and the three cylinder auxiliary axes intersect at a common point; the first kinematic branch The chain 1303, the second kinematic branch chain 1304 and the third kinematic branch chain 1305 are similar in structure, and are composed of two connecting rods; taking the first kinematic branch chain 1303 as an example, it contains three kinematic pairs, which are C ₁ , U ₁ and C ₂ , the universal joint pair U ₁ and the cylindrical pair C ₁ constitute the lower link, the universal joint U ₁ and the cylindrical pair C ₂ form the upper link, the cylindrical pair C ₁ is connected with the fixed base 1302, and the cylindrical pair C ₂ is connected with the motion platform 1301, the axes of the cylinder pair C ₁ and the cylinder pair C ₂ are coplanar and intersect at the center point of the universal joint pair U ₁ ; the fourth motion branch chain 1306 is the center branch chain, consisting of only one connecting rod, Contains two ball pairs, S ₁ and S ₂ in sequence; the ball pair S ₁ is connected to the fixed base 1302, and the ball pair S ₂ is connected to the motion platform 1301; among them, the universal joint pair U ₁ in the first motion branch chain 1303 , the center point of the universal joint pair U3 in the _second kinematic branch chain 1304 and the center point of the universal joint pair U2 in the _third kinematic branch chain 1305 form a plane of symmetry II.

The fourteenth embodiment of the two-degree-of-freedom equal-diameter spherical pure rolling parallel rotation mechanism of the present invention is shown in FIG. Three kinematic branch chains 1405 and the fourth kinematic branch chain 1406; the motion platform 1401 is provided with three rotating pair connection ends, which are respectively connected with three kinematic branch chains (the first kinematic branch chain 1403, the second kinematic branch chain 1404, the third kinematic branch chain Branch chain 1405) constitutes three revolving pairs R ₃ , R ₉ and R ₆ , and the axes of the three revolving pairs intersect at a common point; the fixed base 1402 is provided with three revolving pair connection ends, respectively connected with the three kinematic branch chains ( The first kinematic branch chain 1403, the second kinematic branch chain 1404, and the third kinematic branch chain 1405) constitute three revolving pairs R ₁ , R ₇ and R ₄ , and the axes of the three revolving pairs intersect at a common point; the first kinematic branch The chain 1403, the second kinematic branch chain 1404 and the third kinematic branch chain 1405 are similar in structure, and are all composed of four connecting rods; taking the first kinematic branch chain 1403 as an example, it contains five kinematic pairs, which are R ₁ , Pa ₁ , R ₂ , Pa ₂ and R ₃ , the rotation pair R ₁ and the parallel four-bar pair Pa ₁ constitute the lower link, the rotation pair R ₂ and the parallel four-bar pair Pa ₁ constitute the first connecting rod, the rotation pair R ₂ and the parallel The four-bar pair Pa ₂ constitutes the second connecting rod, the revolving pair R ₃ and the parallel four-bar pair Pa ₂ constitute the upper connecting rod, the revolving pair R ₁ is connected with the fixed base 1402, the revolving pair R ₃ is connected with the motion platform 1401, and the parallel four The axes of the rod pair Pa ₁ and the parallel quadruple pair Pa ₂ are coplanar and intersect with the rotating pair R ₂ at a common point; the fourth kinematic branch chain 1406 is a central branch chain, consisting of only one connecting rod, including two ball pairs, S ₁ and S ₂ in sequence; the ball pair S ₁ is connected to the fixed base 1402, and the ball pair S ₂ is connected to the motion platform 1401; among them, the axis of the rotating pair R ₂ in the first kinematic branch chain 1403, the second kinematic branch chain _The axis of the revolving pair _R8 in 1404 and the axis of the revolving pair R5 in the third kinematic branch chain 1405 form a plane of symmetry II.

The fourth kinematic branch chain of the above-mentioned embodiment three and embodiment four may also adopt a central kinematic branch chain whose two ends are ball pairs S;

The fourth kinematic branch chain of the above-mentioned embodiment five, embodiment six, embodiment seven, embodiment eight, embodiment nine, embodiment ten, embodiment eleven, embodiment twelve, embodiment thirteen and embodiment fourteen It is also possible to use a central motion branch chain with a ball pair S at one end and a universal joint pair U at the other end;

The kinematic branch chains in Embodiment 6, Embodiment 9 and Embodiment 13 contain redundant degrees of freedom, which is beneficial to the installation and assembly of parallel mechanisms;

Similar kinematic branch chains in the above embodiments may have different connecting rod sizes, as long as the connecting rod size in the same kinematic branch chain is symmetrical about the symmetry plane;

In the above embodiments, each kinematic branch chain has a symmetry plane, and the symmetry planes of the kinematic branch chains in each embodiment coincide with each other.

Claims (1)

1. the isometrical sphere of two degrees of freedom is pure rolls rotating mechanism in parallel, it is characterized in that: described mechanism is made up of motion platform, fixed pedestal and movement branched chain, described motion platform is connected more than three movement branched chain with between fixed pedestal by kinematic pair, described each movement branched chain is symmetrical about plane of symmetry II, realizes motion platform and does around fixed pedestal that the isometrical sphere of two degrees of freedom is pure rolls in parallel rotation; Described isometrical sphere refers to: suppose that the mid point of the line of A point and B point is C point, respectively with A point and B point for the centre of sphere, AC or BC is that radius makees ball, and the public tangent plane of two balls is plane of symmetry II;

Described A point is determined by following relation: when the kinematic pair axis co-planar that each movement branched chain is connected with motion platform, and A point is positioned at the center, face that kinematic pair axis that each movement branched chain is connected with motion platform is formed; When the kinematic pair axis that each movement branched chain is connected with motion platform meets at a common point, A point is positioned at this common point place;

Described B point is determined by following relation: when the kinematic pair axis co-planar that each movement branched chain is connected with fixed pedestal, and B point is positioned at the center, face that kinematic pair axis that each movement branched chain is connected with fixed pedestal is formed; When the kinematic pair axis that each movement branched chain is connected with fixed pedestal meets at a common point, B point is positioned at this common point place;

Described each movement branched chain comprises two or more connecting rod, comprises more than three kinematic pairs, forms more than 4 frees degree;

Described mechanism also comprises a center side chain, and described center side chain is be connected to connecting rod between A point and B point by kinematic pair, and described kinematic pair is that ball is secondary or universal joint is secondary;

The connection kinematic pair of each movement branched chain and fixed pedestal installs drive motors;

Kinematic pair between described movement branched chain and motion platform or fixed pedestal is more than one in the secondary or cylindrical pair of revolute pair, moving sets, universal joint;

Symmetrical structure centered by between described more than three movement branched chain;

Described more than three movement branched chain are combined by more than one following movement branched chain, are specially:

The first, movement branched chain is made up of three connecting rods, includes four revolute pairs, is followed successively by R ₁, R ₂, R ₃and R ₄, revolute pair R ₁and R ₂form lower link, revolute pair R ₂and R ₃connecting rod in formation, R ₃and R ₄connecting rod in formation;

The second, movement branched chain is made up of two connecting rods, comprises three kinematic pairs, is followed successively by R ₁, S ₁and R ₂, revolute pair R ₁with ball secondary S ₁form lower link, revolute pair R ₂with ball secondary S ₁connecting rod in formation;

The third, movement branched chain is made up of two connecting rods, includes three kinematic pairs, is followed successively by C ₁, R ₁and C ₂, revolute pair R ₁with cylindrical pair C ₁form lower link, revolute pair R ₁with cylindrical pair C ₂connecting rod in formation;

4th kind, movement branched chain is made up of two connecting rods, includes three kinematic pairs, is followed successively by C ₁, S ₁and C ₂, ball secondary S ₁with cylindrical pair C ₁form lower link, ball secondary S ₁with cylindrical pair C ₂connecting rod in formation;

5th kind, movement branched chain is made up of two connecting rods, includes three kinematic pairs, is followed successively by P ₁, S ₁and P ₂, ball secondary S ₁with moving sets P ₁form lower link, ball secondary S ₁with moving sets P ₂connecting rod in formation;

6th kind, movement branched chain is made up of four connecting rods, includes five kinematic pairs, is followed successively by R ₁, P ₁, R ₂, P ₂and R ₃, revolute pair R ₁with moving sets P ₁form lower link, revolute pair R ₂with moving sets P ₁connecting rod one in formation, revolute pair R ₂with moving sets P ₂connecting rod two in formation, revolute pair R ₃with moving sets P ₂connecting rod in formation;

7th kind, movement branched chain is made up of four connecting rods, includes five kinematic pairs, is followed successively by P ₁, R ₁, R ₂, R ₃and P ₂, revolute pair R ₁with moving sets P ₁form lower link, roating sphere secondary R ₂with revolute pair R ₁connecting rod one in formation, revolute pair R ₂with revolute pair R ₃connecting rod two in formation, revolute pair R ₃with moving sets P ₂connecting rod in formation;

8th kind, the movement branched chain forming mechanism is made up of two connecting rods, includes three kinematic pairs, is followed successively by U ₁, R ₁and U ₂, revolute pair R ₁with universal joint secondary U ₁form lower link, revolute pair R ₁with universal joint secondary U ₂connecting rod in formation;

9th kind, movement branched chain is made up of two connecting rods, includes three kinematic pairs, is followed successively by C ₁, U ₁and C ₂, universal joint secondary U ₁with cylindrical pair C ₁form lower link, universal joint secondary U ₁with cylindrical pair C ₂connecting rod in formation;

Tenth kind, movement branched chain is made up of four connecting rods, includes five kinematic pairs, is followed successively by R ₁, Pa ₁, R ₂, Pa ₂and R ₃, revolute pair R ₁with parallel four-bar secondary Pa ₁form lower link, revolute pair R ₂with parallel four-bar secondary Pa ₁connecting rod one in formation, revolute pair R ₂with parallel four-bar secondary Pa ₂connecting rod two in formation, revolute pair R ₃with parallel four-bar secondary Pa ₂connecting rod in formation;

Described R _irepresent a revolute pair, P _irepresent a moving sets, U _irepresent that a universal joint containing two crossing pivot centers is secondary, C _irepresent a cylindrical pair, Pa _irepresent that a parallel four-bar be made up of four revolute pairs is secondary, S _irepresent a ball pair, i is natural number.