Few-drive multi-layer coupling hybrid mechanism

Abstract

The present invention relates to a type of multi-layer coupled hybrid mechanism with few drives, which includes n(3‑R(SSS(R)))+3‑RSR hybrid mechanism, n(3‑R(RRS(S)))+3‑RSR hybrid mechanism, n(3‑R(RSR(S)))+3‑RRS hybrid mechanism, and n(3‑R(SSR(S)))+3‑RRS hybrid mechanism. The multi-layer coupled hybrid mechanism with few drives includes a modular parallel mechanism capable of multi-layer superposition and a terminal parallel mechanism coupled thereto, wherein the modular parallel mechanism includes a fixed platform, a moving platform and three branches with the same structure, and the closed-loop branch chain contained in the branch can realize the coupling between two adjacent layers of parallel mechanisms, thereby achieving the effect of reducing driving and transmitting motion. The terminal parallel mechanism includes a terminal moving platform and three branches with the same structure, and the branch does not contain a closed-loop branch chain. The present invention has the advantages of compact structure and simple driving.

Description

Technical Field

[0001] The invention belongs to the technical field of parallel mechanisms, and in particular relates to a parallel-parallel mechanism with few drives and multiple layers coupled and a large working space. Background Art

[0002] The serial mechanism has the characteristics of small load-bearing capacity, poor precision, large working space and good flexibility due to its structure. The parallel mechanism complements the serial mechanism in performance and has the characteristics of large load-bearing capacity, high stiffness and precision, and small working space. The hybrid mechanism formed by multiple parallel mechanisms in series has the advantages of both parallel and serial mechanisms and has received extensive attention and research from scholars. However, at present, each layer of parallel mechanism in such mechanisms needs to be installed with driving elements, which makes the hybrid mechanism bulky and complex to drive. Therefore, reducing the driving elements and overall weight through structural design has become a key research direction.

[0003] Patent CN202110116056.3 proposes a redundant parallel mechanism with less drive and more degrees of freedom output and a control method. The invention reduces the driving components and the control difficulty by controlling the motion branch with redundant branches, and has a large load-bearing capacity, but its working space is also relatively reduced. Patent CN202120075105.9 proposes to connect the follower rod and the driving rod of the upper and lower parallel mechanisms with the same structure by a slider mechanism, and quantitatively transmit the output of the upper level to the next level as input, thereby increasing the working space of the mechanism, but the stiffness of the mechanism is relatively low. Patent CN201020569030.1 proposes a hybrid robot for automobile spraying composed of a three-degree-of-freedom parallel mechanism and a four-degree-of-freedom parallel mechanism in series. The invention has a compact structure, high rigidity, and is easy to achieve high-speed movement, but the overall structure of the invention is relatively complex and not easy to be widely used.

[0004] In order to effectively improve the above problems, the present invention proposes a type of low-drive multi-layer coupling hybrid mechanism, which aims to reduce the use of driving elements through structural design, so that the hybrid mechanism has a compact structure, is light and flexible, and is easy to operate, making it more suitable for the needs of actual engineering. Summary of the invention

[0005] In response to the problems existing in the prior art, the present invention provides a type of multi-stage coupled hybrid mechanism with few drives, which realizes the coupling between adjacent layers of parallel mechanisms by constructing closed-loop branches, thereby achieving the purpose of reducing driving elements, making the hybrid mechanism more lightweight and flexible, easy to operate, and easy to realize modularization.

[0006] The technical solution adopted by the present invention is a multi-layer coupled hybrid mechanism with few drives, which includes a 3-R (SSS (R)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RSR type terminal parallel mechanism that is coupled and connected. The 3-R (SSS (R)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform, multiple moving platforms and R (SSS (R)) series branches uniformly distributed along the circumferential direction, wherein the R (SSS (R)) series branches are arranged between the fixed platform and the moving platform and between the two adjacent moving platforms, and each of the R (SSS (R)) series branches includes a first rotation pair, a first connecting rod, a first ball joint, a second connecting rod, a second ball joint, a third ball joint, a third connecting rod and a first compound kinematic pair, wherein the first layer of the 3-R The lower end of the first connecting rod in the (SSS(R)) parallel mechanism is connected to the fixed platform through the first rotating pair, and the upper connecting portion close to the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (SSS(R)) parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third ball joint, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the first connecting rod in the adjacent 3-R (SSS(R)) parallel mechanism and the moving platform through the first compound kinematic pair; the third ball joint in the first layer is composed of three axes intersecting at one point and making independent relative The first compound kinematic pair is composed of two coaxial kinematic pairs; the first connecting rod and the moving platform are shared by the two adjacent layers of 3-R (SSS (R)) parallel mechanisms, and the upper connecting portion near the upper end of the first connecting rod in the last layer of 3-R (SSS (R)) parallel mechanism is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third ball joint, the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the first compound kinematic pair and the moving platform The 3-RSR parallel mechanism is arranged at the end of the multi-layer 3-R (SSS (R)) parallel mechanism, and the 3-RSR parallel mechanism includes RSR series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RSR series branches includes a fourth connecting rod, a fourth ball joint, a fifth connecting rod and a second rotation pair, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the fourth ball joint, and the upper end of the fifth connecting rod is connected to the end moving platform through the second rotation pair, and the multi-layer 3-R (SSS (R)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form a three-degree-of-freedom n (3-R (SSS (R))) + 3-RSR type few-drive multi-layer coupling hybrid mechanism.

[0007] Furthermore, the first link, the second link, the third link and the first link in the adjacent 3-R (SSS (R)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RSR parallel mechanism together constitute a closed-loop branch chain.

[0008] The technical solution adopted in the second aspect of the present invention is a multi-layer coupled hybrid mechanism with few drives, which includes a 3-R (RRS (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RSR type terminal parallel mechanism that is coupled and connected. The 3-R (RRS (S)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform, multiple moving platforms and R (RRS (S)) series branches uniformly distributed along the circumferential direction, the R (RRS (S)) series branches are arranged between the fixed platform and the moving platform and between the two adjacent moving platforms, and each of the R (RRS (S)) series branches includes a first rotation pair, a first connecting rod, a second rotation pair, a second connecting rod, a third rotation pair, a third connecting rod, a first ball joint and a second compound motion pair, wherein the first The lower end of the first connecting rod in the layer 3-R (RRS (S)) parallel mechanism is connected to the fixed platform through the first rotation pair, and the upper connecting part close to the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the second rotation pair, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (RRS (S)) parallel mechanism through the third rotation pair, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the first ball joint, and the upper end of the third connecting rod is connected to the lower connecting part close to the lower end of the first connecting rod in the adjacent 3-R (RRS (S)) parallel mechanism and the moving platform through the second compound motion pair; the first ball joint in the first layer is composed of three axes intersecting at one point and acting independently. The first connecting rod and the moving platform are shared by the two adjacent layers of 3-R (RRS (S)) parallel mechanisms, and the upper connecting portion near the upper end of the first connecting rod in the last layer of 3-R (RRS (S)) parallel mechanism is connected to the lower end of the second connecting rod through the second rotating pair, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the third rotating pair, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the first ball joint, and the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the second compound kinematic pair and The moving platform is connected; the 3-RSR parallel mechanism is arranged at the end of the multi-layer 3-R (RRS (S)) parallel mechanism, and the 3-RSR parallel mechanism includes RSR series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RSR series branches includes a fourth connecting rod, a second ball joint, a fifth connecting rod and a fourth rotation pair, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the second ball joint, and the upper end of the fifth connecting rod is connected to the end moving platform through the fourth rotation pair, and the multi-layer 3-R (RRS (S)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form a three-degree-of-freedom n (3-R (RRS (S))) + 3-RSR type few-drive multi-layer coupling hybrid mechanism.

[0009] Furthermore, the first link, the second link, the third link and the first link in the adjacent 3-R (RRS (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RSR parallel mechanism together constitute a closed-loop branch chain.

[0010] The technical solution adopted in the third aspect of the present invention is a multi-layer coupled hybrid mechanism with few drives, which includes a 3-R (RSR (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. The 3-R (RSR (S)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform, multiple moving platforms and R (RSR (S)) series branches evenly distributed along the circumferential direction. The R (RSR (S)) series branches are arranged between the fixed platform and the moving platform and between the two adjacent moving platforms. Each of the R (RSR (S)) series branches includes a first rotating pair, a first connecting rod, a second rotating pair, a second connecting rod, a first ball joint, a third connecting rod, a third rotating pair and a third connecting rod. Three compound kinematic pairs, wherein the lower end of the first connecting rod in the first layer 3-R (RSR (S)) parallel mechanism is connected to the fixed platform through the first rotation pair, and the upper connecting portion close to the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the second rotation pair, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (RSR (S)) parallel mechanism through the first ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third rotation pair, the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the first connecting rod in the adjacent 3-R (RSR (S)) parallel mechanism and the moving platform through the third compound kinematic pair, and the third compound The kinematic pair is composed of a revolute pair and a ball joint; the first connecting rod and the moving platform are shared by the two adjacent layers of 3-R (RSR (S)) parallel mechanisms, and the upper connecting portion close to the upper end of the first connecting rod in the last layer of 3-R (RSR (S)) parallel mechanism is connected to the lower end of the second connecting rod through the second revolute pair, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism through the first ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third revolute pair, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism and the moving platform through the third compound kinematic pair; The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (RSR (S)) parallel mechanism, and the 3-RRS parallel mechanism includes RRS series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RRS series branches includes a fourth connecting rod, a fourth rotating pair, a fifth connecting rod and a second ball joint, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the fourth rotating pair, and the upper end of the fifth connecting rod is connected to the end moving platform through the second ball joint, and the multi-layer 3-R (RSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form a three-degree-of-freedom n (3-R (RSR (S))) + 3-RRS type few-drive multi-layer coupled hybrid mechanism.

[0011] Furthermore, the first link, the second link, the third link and the first link in the adjacent 3-R (RSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RRS parallel mechanism together constitute a closed-loop branch chain.

[0012] The technical solution adopted in the fourth aspect of the present invention is a multi-layer coupled hybrid mechanism with few drives, which includes a 3-R (SSR (S)) type modular parallel mechanism that can be superimposed in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. The 3-R (SSR (S)) type modular parallel mechanism that can be superimposed in multiple layers includes a fixed platform, multiple moving platforms and R (SSR (S)) series branches evenly distributed along the circumferential direction. The R (SSR (S)) series branches are arranged between the fixed platform and the moving platform and between the two adjacent moving platforms. Each of the R (SSR (S)) series branches includes a first rotating pair, a first connecting rod, a first ball joint, a second connecting rod, a second ball joint, a third connecting rod, a second rotating pair and a third connecting rod. Four compound kinematic pairs, wherein the lower end of the first connecting rod in the first layer 3-R (SSR (S)) parallel mechanism is connected to the fixed platform through the first rotation pair, and the upper connecting portion close to the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (SSR (S)) parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the second rotation pair, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the first connecting rod in the adjacent 3-R (SSR (S)) parallel mechanism and the moving platform through the fourth compound kinematic pair; the fourth compound The kinematic pair is composed of a revolute pair and a ball joint; the first connecting rod and the moving platform are shared by the two adjacent layers of 3-R (SSR (S)) parallel mechanisms, and the upper connecting portion near the upper end of the first connecting rod in the last layer of 3-R (SSR (S)) parallel mechanism is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the second revolute pair, and the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the fourth connecting rod in the 3-RRS parallel mechanism and the moving platform through the fourth compound kinematic pair; The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (SSR (S)) parallel mechanism, and the 3-RRS parallel mechanism includes RRS series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RRS series branches includes a fourth connecting rod, a third rotating pair, a fifth connecting rod and a third ball joint, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the third rotating pair, and the upper end of the fifth connecting rod is connected to the end moving platform through the third ball joint, and the multi-layer 3-R (SSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form a three-degree-of-freedom n (3-R (SSR (S))) + 3-RRS type few-drive multi-layer coupled hybrid mechanism.

[0013] Furthermore, the first link, the second link, the third link and the first link in the adjacent 3-R (SSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RRS parallel mechanism together constitute a closed-loop branch chain.

[0014] The characteristics and beneficial effects of the present invention are:

[0015] 1. A type of multi-layer coupled hybrid mechanism with few drives provided by the present invention realizes motion transmission of the multi-layer parallel mechanism by generating coupled motion by constructing a closed-loop branch chain, thereby reducing the use of driving elements. The multi-layer parallel mechanism can realize motion control of the hybrid mechanism only by driving the driving elements in the first layer, making the hybrid mechanism more lightweight and flexible.

[0016] 2. The present invention provides a type of multi-layer coupled hybrid mechanism with few drives, which has a compact structure, good mechanism symmetry, a small number of drives, and is easy to control. It has the advantages of being able to be arranged in multiple layers, being easy to achieve modularization, and further increasing the working space of the mechanism. It is suitable for material handling, packaging and sorting. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a schematic structural diagram of an n(3-R(SSS(R)))+3-RSR type few-drive multi-layer coupling hybrid mechanism according to Embodiment 1 of the present invention;

[0018] Figure 2 1 is a schematic structural diagram of the RRS(S) closed-loop branch chain in the n(3-R(RRS(S)))+3-RSR type few-drive multi-layer coupling hybrid mechanism of Example 2 of the present invention;

[0019] Figure 3 1 is a schematic diagram of the structure of the RSR(S) closed-loop branch chain in the n(3-R(RSR(S)))+3-RRS type few-drive multi-layer coupling hybrid mechanism of Example 3 of the present invention;

[0020] Figure 4 It is a schematic structural diagram of the SSR(S) closed-loop branch in the n(3-R(SSR(S)))+3-RRS type few-drive multi-layer coupling hybrid mechanism of Example 4 of the present invention.

[0021] Main reference numerals:

[0022] Fixed platform M0; moving platform M1; end moving platform M2; connecting rod L, ball joint S, revolute pair R. DETAILED DESCRIPTION

[0023] In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0024] Example 1

[0025] The present invention provides a multi-layer coupled hybrid mechanism with few drivers, such as Figure 1 As shown, it includes two layers of superimposed 3-R (SSS (R)) type modular parallel mechanisms and a coupled 3-RSR type terminal parallel mechanism, two layers of superimposed 3-R (SSS (R)) type modular parallel mechanism fixed platform M0, multiple moving platforms M1 and three R (SSS (R)) series branches with the same structure and uniformly distributed along the circumferential direction arranged between the fixed platform M0 and the moving platform M1 and between two adjacent moving platforms M1, each R (SSS (R)) series branch includes a first rotation pair R1, a first connecting rod L1, a first ball joint S1, a second connecting rod L2, a second ball joint S2, a third ball joint S3, a third connecting rod L3 and a first compound motion pair RR1, wherein the lower end of the first connecting rod L1 in the first layer of 3-R (SSS (R)) parallel mechanism is connected to the fixed platform M0 through the first rotation pair R1, and the fixed platform M0 is A motor is provided, the axis of the output shaft of the motor is colinear with the axis of the first rotation pair R1, and the upper connecting part near the upper end of the first connecting rod L1 is connected to the lower end of the second connecting rod L2 through the first ball joint S1, the upper end of the second connecting rod L2 is connected to the lower end of the first connecting rod L1 in the second layer 3-R (SSS (R)) parallel mechanism through the second ball joint S2, and the upper end of the first connecting rod L1 is connected to the lower end of the third connecting rod L3 through the third ball joint S3, wherein the third ball joint S3 is composed of three rotation pairs R31, R32, and R33 whose axes intersect at one point and make independent relative rotation, the upper end of the third connecting rod L3 is connected to the lower connecting part near the lower end of the first connecting rod L1 in the second layer 3-R (SSS (R)) parallel mechanism and the moving platform M1 through the first compound motion pair RR1, and the first compound motion pair RR1 is composed of two coaxial rotation pairs.

[0026] The first-layer and second-layer 3-R (SSS (R)) parallel mechanisms share the first link L1 and the moving platform M1, and the upper connecting portion near the upper end of the first link L1 in the second-layer 3-R (SSS (R)) parallel mechanism is connected to the lower end of the second link L2 through the first ball joint S1, the upper end of the second link L2 is connected to the lower end of the fourth link L4 in the 3-RSR parallel mechanism through the second ball joint S2, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the third ball joint S3, and the upper end of the third link L3 is connected to the lower connecting portion near the lower end of the fourth link L4 in the 3-RSR parallel mechanism and the moving platform M1 through the first compound kinematic pair RR1. The first link L1, the second link L2, the third link L3 in the first-layer 3-R (SSS (R)) parallel mechanism and the first link L1 in the second-layer 3-R (SSS (R)) parallel mechanism together constitute a closed-loop branch chain; the first link L1, the second link L2, the third link L3 in the second-layer 3-R (SSS (R)) parallel mechanism and the fourth link L4 in the third-layer 3-RSR parallel mechanism together constitute a closed-loop branch chain.

[0027] The 3-RSR parallel mechanism is arranged at the end of the two-layer 3-R (SSS (R)) parallel mechanism, and the 3-RSR parallel mechanism includes three RSR series branches with the same structure and uniformly distributed along the circumferential direction and an end moving platform M2, each RSR series branch includes a fourth connecting rod L4, a fourth ball joint S4, a fifth connecting rod L5 and a second rotation pair R2, and the upper end of the fourth connecting rod L4 is connected to the lower end of the fifth connecting rod L5 through the fourth ball joint S4, and the upper end of the fifth connecting rod L5 is connected to the end moving platform M2 through the second rotation pair R2, and the multi-layer 3-R (SSS (R)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form an n (3-R (SSS (R))) + 3-RSR type few-drive multi-layer coupling hybrid mechanism with two rotational degrees of freedom and one translational degree of freedom.

[0028] Example 2

[0029] The present invention provides a multi-layer coupled hybrid mechanism with few drivers, such as Figure 2As shown, it includes a 3-R (RRS (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RSR type terminal parallel mechanism that is coupled and connected. Referring to Example 1, the 3-R (RRS (S)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform M0, a plurality of moving platforms M1, and three R (RRS (S)) series branches with the same structure and uniformly distributed along the circumferential direction, which are arranged between the fixed platform M0 and the moving platform M1 and between two adjacent moving platforms M1. Each R (RRS (S)) series branch includes a first rotation pair R1, a first connecting rod L1, a second rotation pair R2, a second connecting rod L2, a third rotation pair R3, a third connecting rod L3, a first ball joint S1, and a second compound motion pair RS1, wherein the lower end of the first connecting rod L1 in the first layer of the 3-R (RRS (S)) parallel mechanism is connected to the fixed platform M0 through the first rotation pair R1, and a motor is provided on the fixed platform M0, and the output shaft axis of the motor is connected to the first rotation pair R1. The axes are collinear, and the upper connecting portion near the upper end of the first link L1 is connected to the lower end of the second link L2 through the second revolute pair R2, the upper end of the second link L2 is connected to the lower end of the first link L1 in the adjacent 3-R (RRS (S)) parallel mechanism through the third revolute pair R3, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the first ball joint S1, wherein the first ball joint S1 is composed of three revolute pairs R11, R12, and R12 whose axes intersect at one point and rotate independently relative to each other, the upper end of the third link L3 is connected to the lower connecting portion near the lower end of the first link L1 in the adjacent 3-R (RRS (S)) parallel mechanism and the moving platform M1 through the second compound kinematic pair RS1, wherein the second compound kinematic pair RS1 is composed of a revolute pair R and a ball joint S.

[0030] The first link L1 and the moving platform M1 are shared between two adjacent layers of 3-R (RRS (S)) parallel mechanisms, and the upper connecting portion near the upper end of the first link L1 in the last layer of 3-R (RRS (S)) parallel mechanism is connected to the lower end of the second link L2 through the second rotation pair R2, the upper end of the second link L2 is connected to the lower end of the fourth link L4 in the 3-RSR parallel mechanism through the third rotation pair R3, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the first ball joint S1, and the upper end of the third link L3 is connected to the lower connecting portion near the lower end of the fourth link L4 in the 3-RSR parallel mechanism and the moving platform M1 through the second compound motion pair RS1. Among them, the first link L1, the second link L2, the third link L3 in the first-layer 3-R (RRS (S)) parallel mechanism and the first link L1 in the second-layer 3-R (RRS (S)) parallel mechanism together constitute a closed-loop branch chain; the first link L1, the second link L2, the third link L3 in the second-layer 3-R (RRS (S)) parallel mechanism and the fourth link L4 in the third-layer 3-R (RRS (S)) parallel mechanism together constitute a closed-loop branch chain.

[0031] The 3-RSR parallel mechanism is arranged at the end of the multi-layer 3-R (RRS (S)) parallel mechanism, and the 3-RSR parallel mechanism includes three RSR series branches with the same structure and evenly distributed along the circumferential direction and an end moving platform M2, each RSR series branch includes a fourth connecting rod L4, a second ball joint S2, a fifth connecting rod L5 and a fourth rotation pair, and the upper end of the fourth connecting rod L4 is connected to the lower end of the fifth connecting rod L5 through the second ball joint S2, and the upper end of the fifth connecting rod L5 is connected to the end moving platform M2 through the fourth rotation pair, and the connection relationship of its rods is the same as that of the 3-RSR parallel mechanism in Example 1, and the multi-layer 3-R (RRS (S)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form an n (3-R (RRS (S))) + 3-RSR type few-drive multi-layer coupled hybrid mechanism with three degrees of freedom of two rotations and one movement.

[0032] Example 3

[0033] The present invention provides a multi-layer coupled hybrid mechanism with few drivers, such as Figure 3 As shown, it includes a 3-R (RSR (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. Referring to Example 1, the 3-R (RSR (S)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform M0, a plurality of moving platforms M1, and three R (RSR (S)) series branches with the same structure and uniformly distributed along the circumferential direction, which are arranged between the fixed platform M0 and the moving platform M1 and between two adjacent moving platforms M1. Each R (RSR (S)) series branch includes a first rotation pair R1, a first connecting rod L1, a second rotation pair R2, a second connecting rod L2, a first ball joint S1, a third connecting rod L3, a third rotation pair R3 and a third compound motion pair RS1, wherein the lower end of the first connecting rod L1 in the first layer 3-R (RSR (S)) parallel mechanism is connected to the fixed platform M0, a plurality of moving platforms M1, and three R (RSR (S)) series branches with the same structure and uniformly distributed along the circumferential direction are arranged between the fixed platform M0 and the moving platform M1 and between two adjacent moving platforms M1. The pair R1 is connected to the fixed platform M0, and the upper connecting part on the first link L1 is connected to the lower end of the second link L2 through the second rotation pair R2, the upper end of the second link L2 is connected to the lower end of the first link L1 in the adjacent 3-R (RSR (S)) parallel mechanism through the first ball joint S1, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the third rotation pair R3, the upper end of the third link L3 is connected to the lower connecting part close to the lower end of the first link L1 in the adjacent 3-R (RSR (S)) parallel mechanism and the moving platform M1 through the third compound motion pair RS1, wherein the third compound motion pair RS1 is composed of a ball joint S and a rotation pair R.

[0034] The first link L1 and the moving platform M1 are shared between two adjacent layers of 3-R (RSR (S)) parallel mechanisms, and the upper connecting portion near the upper end of the first link L1 in the last layer of 3-R (RSR (S)) parallel mechanism is connected to the lower end of the second link L2 through the second rotation pair R2, the upper end of the second link L2 is connected to the lower end of the fourth link L4 in the 3-RRS parallel mechanism through the first ball joint S1, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the third rotation pair R3, and the upper end of the third link L3 is connected to the lower connecting portion near the lower end of the fourth link L4 in the 3-RRS parallel mechanism and the moving platform M1 through the third compound motion pair RS1. Among them, the first link L1, the second link L2, the third link L3 in the first-layer 3-R (RSR (S)) parallel mechanism and the first link L1 in the second-layer 3-R (RSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link L1, the second link L2, the third link L3 in the second-layer 3-R (RSR (S)) parallel mechanism and the fourth link L4 in the third-layer 3-R (RSR (S)) parallel mechanism together constitute a closed-loop branch chain.

[0035] The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (RSR (S)) parallel mechanism, referring to the 3-RSR parallel mechanism in Example 1, as shown in FIG. Figure 1 As shown. The 3-RRS parallel mechanism includes three RRS series branches with the same structure and uniformly distributed along the circumferential direction and a terminal moving platform M2, each RRS series branch includes a fourth connecting rod L4, a fourth rotation pair, a fifth connecting rod L5 and a second ball joint S2, and the upper end of the fourth connecting rod L4 is connected to the lower end of the fifth connecting rod L5 through the fourth rotation pair, and the upper end of the fifth connecting rod L5 is connected to the terminal moving platform M2 through the second ball joint S2, and the multi-layer 3-R (RSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form an n (3-R (RSR (S))) + 3-RRS type few-drive multi-layer coupling hybrid mechanism with two rotational and one moving degrees of freedom.

[0036] Example 4

[0037] The present invention provides a multi-layer coupled hybrid mechanism with few drivers, such as Figure 4As shown, it includes a 3-R (SSR (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. Referring to Example 1, the 3-R (SSR (S)) type modular parallel mechanism that can be stacked in multiple layers includes a fixed platform M0, multiple moving platforms M1, and three R (SSR (S)) series branches with the same structure and uniformly distributed along the circumferential direction, which are arranged between the fixed platform M0 and the moving platform M1 and between two adjacent moving platforms M1. Each R (SSR (S)) series branch includes a first rotation pair R1, a first connecting rod L1, a first ball joint S1, a second connecting rod L2, a second ball joint S2, a third connecting rod L3, a second rotation pair R2 and a fourth compound motion pair RS1, wherein the lower end of the first connecting rod L1 in the first layer 3-R (SSR (S)) parallel mechanism is connected through the first rotation pair R1 is connected to the fixed platform M0, and the upper connecting part near the upper end of the first link L1 is connected to the lower end of the second link L2 through the first ball joint S1, the upper end of the second link L2 is connected to the lower end of the first link L1 in the adjacent 3-R (SSR (S)) parallel mechanism through the second ball joint S2, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the second rotation pair R2, the upper end of the third link L3 is connected to the lower connecting part near the lower end of the first link L1 in the adjacent 3-R (SSR (S)) parallel mechanism and the moving platform M1 through the fourth compound motion pair RS1, wherein the fourth compound motion pair RS1 is composed of a rotation pair R and a ball joint S.

[0038] The first link L1 and the moving platform M1 are shared between two adjacent layers of 3-R (SSR (S)) parallel mechanisms, and the upper connecting portion near the upper end of the first link L1 in the last layer of 3-R (SSR (S)) parallel mechanism is connected to the lower end of the second link L2 through the first ball joint S1, the upper end of the second link L2 is connected to the lower end of the fourth link L4 in the 3-RRS parallel mechanism through the second ball joint S2, and the upper end of the first link L1 is connected to the lower end of the third link L3 through the second rotation pair R2, and the upper end of the third link L3 is connected to the lower connecting portion near the lower end of the fourth link L4 in the 3-RRS parallel mechanism and the moving platform M1 through the fourth compound motion pair RS1. Among them, the first link L1, the second link L2, the third link L3 in the first-layer 3-R (SSR (S)) parallel mechanism and the first link L1 in the second-layer 3-R (SSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link L1, the second link L2, the third link L3 in the second-layer 3-R (SSR (S)) parallel mechanism and the fourth link L4 in the third-layer 3-R (SSR (S)) parallel mechanism together constitute a closed-loop branch chain.

[0039] The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (SSR (S)) parallel mechanism, referring to the 3-RSR parallel mechanism in Example 1, as shown in FIG. Figure 1As shown. The 3-RRS parallel mechanism includes three RRS series branches with the same structure and uniformly distributed along the circumferential direction and a terminal moving platform M2, each RRS series branch includes a fourth connecting rod L4, a third rotation pair R3, a fifth connecting rod L5 and a third ball joint S3, and the upper end of the fourth connecting rod L4 is connected to the lower end of the fifth connecting rod L5 through the third rotation pair R3, and the upper end of the fifth connecting rod L5 is connected to the terminal moving platform M2 through the third ball joint S3, and the multi-layer 3-R (SSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form a n (3-R (SSR (S))) + 3-RRS type few-drive multi-layer coupling hybrid mechanism with two rotation and one movement degrees of freedom.

[0040] The invention provides a type of multi-layer coupled hybrid mechanism with few drives. The closed-loop branch chain is constructed to realize coupled motion between two adjacent layers of parallel mechanisms, and the motion of the upper layer is transmitted to the mechanism of the lower layer. According to this method, the same coupling relationship is added between the multi-layer hybrid mechanisms, so that the motion between the mechanisms is transmitted layer by layer, further increasing the working space of the mechanism and reducing the use of driving units. The multi-layer hybrid mechanism can realize the motion control of the hybrid mechanism only by driving the rotating pair in the first layer. The hybrid mechanism can be stacked in multiple layers, which is easy to realize modularization, and has the advantages of compact structure, good mechanism symmetry, small number of drives, light and flexible structure, and easy control.

[0041] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A few-drive multi-layer coupling hybrid mechanism, characterized in that: It includes a 3-R (SSS (R)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RSR type terminal parallel mechanism that is coupled and connected. A 3-R (SSS (R)) type modular parallel mechanism capable of being stacked in multiple layers comprises a fixed platform, a plurality of moving platforms and R (SSS (R)) series branches uniformly distributed along the circumferential direction, wherein the R (SSS (R)) series branches are arranged between the fixed platform and the moving platform and between two adjacent moving platforms, wherein each of the R (SSS (R)) series branches comprises a first rotation pair, a first connecting rod, a first ball joint, a second connecting rod, a second ball joint, a third ball joint, a third connecting rod and a first compound kinematic pair, wherein the lower end of the first connecting rod in the first layer of the 3-R (SSS (R)) parallel mechanism is connected to the fixed platform through the first rotation pair, and the upper connecting rod near the upper end of the first connecting rod is connected to the fixed platform through the first rotation pair. The connecting portion is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (SSS (R)) parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third ball joint, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the first connecting rod in the adjacent 3-R (SSS (R)) parallel mechanism and the moving platform through the first compound kinematic pair; the third ball joint in the first layer is composed of a rotating pair in which three axes intersect at one point and rotate independently relative to each other, and the first compound kinematic pair is composed of two coaxial rotating pairs; The first connecting rod and the moving platform are shared between the two adjacent layers of 3-R (SSS (R)) parallel mechanisms, and the upper connecting portion near the upper end of the first connecting rod in the last layer of 3-R (SSS (R)) parallel mechanism is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third ball joint, and the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the fourth connecting rod in the 3-RSR parallel mechanism and the moving platform through the first compound kinematic pair; The 3-RSR parallel mechanism is arranged at the end of the multi-layer 3-R (SSS (R)) parallel mechanism, and the 3-RSR parallel mechanism includes RSR series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RSR series branches includes a fourth connecting rod, a fourth ball joint, a fifth connecting rod and a second rotation pair, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the fourth ball joint, and the upper end of the fifth connecting rod is connected to the end moving platform through the second rotation pair, and the multi-layer 3-R (SSS (R)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form a three-degree-of-freedom n (3-R (SSS (R))) + 3-RSR type few-drive multi-layer coupled hybrid mechanism.

2. The low-drive multi-layer coupling hybrid mechanism according to claim 1, characterized in that: The first link, the second link, the third link and the first link in the adjacent 3-R (SSS (R)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RSR parallel mechanism together constitute a closed-loop branch chain.

3. A few-drive multi-layer coupling hybrid mechanism, characterized in that: It includes a 3-R (RRS (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RSR type terminal parallel mechanism that is coupled and connected. A 3-R (RRS (S)) type modular parallel mechanism capable of being stacked in multiple layers comprises a fixed platform, a plurality of moving platforms and R (RRS (S)) series branches uniformly distributed along the circumferential direction, wherein the R (RRS (S)) series branches are arranged between the fixed platform and the moving platform and between two adjacent moving platforms, wherein each of the R (RRS (S)) series branches comprises a first rotation pair, a first connecting rod, a second rotation pair, a second connecting rod, a third rotation pair, a third connecting rod, a first ball joint and a second compound kinematic pair, wherein the lower end of the first connecting rod in the first layer of the 3-R (RRS (S)) parallel mechanism is connected to the fixed platform through the first rotation pair, and the upper connecting rod near the upper end of the first connecting rod is connected to the fixed platform through the first rotation pair. The upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (RRS (S)) parallel mechanism through the second rotating pair, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the first ball joint, and the upper end of the third connecting rod is connected to the lower connecting part of the adjacent 3-R (RRS (S)) parallel mechanism near the lower end of the first connecting rod and the moving platform through the second compound kinematic pair; the first ball joint in the first layer is composed of a rotating pair with three axes intersecting at one point and performing independent relative rotation, and the second compound kinematic pair is composed of a rotating pair and a ball joint; The first connecting rod and the moving platform are shared between the two adjacent layers of 3-R (RRS (S)) parallel mechanisms, and the upper connecting portion close to the upper end of the first connecting rod in the last layer of 3-R (RRS (S)) parallel mechanism is connected to the lower end of the second connecting rod through the second rotation pair, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RSR parallel mechanism through the third rotation pair, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the first ball joint, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the fourth connecting rod in the 3-RSR parallel mechanism and the moving platform through the second compound kinematic pair; The 3-RSR parallel mechanism is arranged at the end of the multi-layer 3-R (RRS (S)) parallel mechanism, and the 3-RSR parallel mechanism includes RSR series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RSR series branches includes a fourth connecting rod, a second ball joint, a fifth connecting rod and a fourth rotation pair, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the second ball joint, and the upper end of the fifth connecting rod is connected to the end moving platform through the fourth rotation pair, and the multi-layer 3-R (RRS (S)) parallel mechanism is coupled with the 3-RSR parallel mechanism to form a three-degree-of-freedom n (3-R (RRS (S))) + 3-RSR type few-drive multi-layer coupling hybrid mechanism.

4. The low-drive multi-layer coupling hybrid mechanism according to claim 3, characterized in that: The first link, the second link, the third link and the first link in the adjacent 3-R (RRS (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RSR parallel mechanism together constitute a closed-loop branch chain.

5. A multi-layer coupled hybrid mechanism with few drives, characterized in that: It includes a 3-R (RSR (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. The 3-R (RSR (S)) type modular parallel mechanism capable of being stacked in multiple layers comprises a fixed platform, a plurality of movable platforms and R (RSR (S)) series branches uniformly distributed along the circumferential direction, wherein the R (RSR (S)) series branches are arranged between the fixed platform and the movable platform and between the two adjacent movable platforms, and each of the R (RSR (S)) series branches comprises a first rotation pair, a first connecting rod, a second rotation pair, a second connecting rod, a first ball joint, a third connecting rod, a third rotation pair and a third compound motion pair, wherein the lower end of the first connecting rod in the first layer of the 3-R (RSR (S)) parallel mechanism is connected to the fixed platform through the first rotation pair. The upper connecting portion near the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the second revolute pair, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (RSR (S)) parallel mechanism through the first ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third revolute pair, the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the first connecting rod in the adjacent 3-R (RSR (S)) parallel mechanism and the moving platform through the third compound kinematic pair, and the third compound kinematic pair is composed of a revolute pair and a ball joint; The first connecting rod and the moving platform are shared between the two adjacent layers of 3-R (RSR (S)) parallel mechanisms, and the upper connecting portion close to the upper end of the first connecting rod in the last layer of 3-R (RSR (S)) parallel mechanism is connected to the lower end of the second connecting rod through the second rotation pair, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism through the first ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the third rotation pair, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism and the moving platform through the third compound kinematic pair; The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (RSR (S)) parallel mechanism, and the 3-RRS parallel mechanism includes RRS series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RRS series branches includes a fourth connecting rod, a fourth rotation pair, a fifth connecting rod and a second ball joint, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the fourth rotation pair, and the upper end of the fifth connecting rod is connected to the end moving platform through the second ball joint, and the multi-layer 3-R (RSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form a three-degree-of-freedom n (3-R (RSR (S))) + 3-RRS type few-drive multi-layer coupling hybrid mechanism.

6. The low-drive multi-layer coupling hybrid mechanism according to claim 5, characterized in that: The first link, the second link, the third link and the first link in the adjacent 3-R (RSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RRS parallel mechanism together constitute a closed-loop branch chain.

7. A few-drive multi-layer coupling hybrid mechanism, characterized in that: It includes a 3-R (SSR (S)) type modular parallel mechanism that can be stacked in multiple layers and a 3-RRS type terminal parallel mechanism that is coupled and connected. The 3-R (SSR (S)) type modular parallel mechanism capable of being stacked in multiple layers comprises a fixed platform, a plurality of moving platforms and R (SSR (S)) series branches uniformly distributed along the circumferential direction, wherein the R (SSR (S)) series branches are arranged between the fixed platform and the moving platform and between two adjacent moving platforms, and each of the R (SSR (S)) series branches comprises a first rotation pair, a first connecting rod, a first ball joint, a second connecting rod, a second ball joint, a third connecting rod, a second rotation pair and a fourth compound motion pair, wherein the lower end of the first connecting rod in the first layer of the 3-R (SSR (S)) parallel mechanism is connected to the fixed platform through the first rotation pair. The upper connecting portion near the upper end of the first connecting rod is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the first connecting rod in the adjacent 3-R (SSR (S)) parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the second rotation pair, and the upper end of the third connecting rod is connected to the lower connecting portion near the lower end of the first connecting rod in the adjacent 3-R (SSR (S)) parallel mechanism and the moving platform through the fourth compound kinematic pair; the fourth compound kinematic pair is composed of a rotation pair and a ball joint; The first connecting rod and the moving platform are shared between the two adjacent layers of 3-R (SSR (S)) parallel mechanisms, and the upper connecting portion close to the upper end of the first connecting rod in the last layer of 3-R (SSR (S)) parallel mechanism is connected to the lower end of the second connecting rod through the first ball joint, the upper end of the second connecting rod is connected to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism through the second ball joint, and the upper end of the first connecting rod is connected to the lower end of the third connecting rod through the second rotation pair, and the upper end of the third connecting rod is connected to the lower connecting portion close to the lower end of the fourth connecting rod in the 3-RRS parallel mechanism and the moving platform through the fourth compound kinematic pair; The 3-RRS parallel mechanism is arranged at the end of the multi-layer 3-R (SSR (S)) parallel mechanism, and the 3-RRS parallel mechanism includes RRS series branches and an end moving platform uniformly distributed along the circumferential direction, each of the RRS series branches includes a fourth connecting rod, a third rotating pair, a fifth connecting rod and a third ball joint, and the upper end of the fourth connecting rod is connected to the lower end of the fifth connecting rod through the third rotating pair, and the upper end of the fifth connecting rod is connected to the end moving platform through the third ball joint, and the multi-layer 3-R (SSR (S)) parallel mechanism is coupled with the 3-RRS parallel mechanism to form a three-degree-of-freedom n (3-R (SSR (S))) + 3-RRS type few-drive multi-layer coupling hybrid mechanism.

8. The low-drive multi-layer coupling hybrid mechanism according to claim 7, characterized in that: The first link, the second link, the third link and the first link in the adjacent 3-R (SSR (S)) parallel mechanism together constitute a closed-loop branch chain; the first link, the second link, the third link and the fourth link in the adjacent 3-RRS parallel mechanism together constitute a closed-loop branch chain.

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