A three-branched six-degree-of-freedom parallel mechanism with arc-shaped moving pairs

Abstract

The invention relates to a three-branched-chain six-degree-of-freedom parallel connection mechanism provided with an arc-shaped movement pair. The three-branched-chain six-degree-of-freedom parallel connection mechanism comprises a fixed platform, a movable platform and three branched chains in the same structure; and the three branched chains are arranged between the movable platform and the fixed platform, and are uniformly arranged on the fixed platform in the circumferential direction by taking the movable platform as the center. The three-branched-chain six-degree-of-freedom parallel connection mechanism is characterized in that each branched-chain comprises a supporting frame, a rear section arc-shaped link rod, a middle section arc-shaped link rod and a front section arc-shaped link rod; the lower parts of the supporting frames are fixedly arranged on the fixed platform; the first driving motors are arranged at the upper parts of the supporting frames; an output shaft of one first driving motor is fixedly connected with one end of one rear section arc-shaped link rod correspondingly; second driving motors are arranged at the other ends of the rear section arc-shaped link rods; an output shaft of one second driving motor is fixedly connected with one end of one middle section arc-shaped link rod correspondingly; arc-shaped cavities are formed in the other ends of the middle section arc-shaped link rods; and one end of one front section arc-shaped link rod is inserted into one arc-shaped cavity of one middle section arc-shaped link rod correspondingly.

Description

technical field [0001] The invention relates to the technical field of industrial robots, in particular to a three-branched six-degree-of-freedom parallel mechanism with arc-shaped moving pairs. Background technique [0002] Parallel Mechanism (PM for short) can be defined as a closed-loop mechanism in which the moving platform and the fixed platform are connected by at least two independent kinematic chains. The mechanism has two or more degrees of freedom and is driven in parallel. . It has the following characteristics: (1) No cumulative error and high precision; (2) The driving device can be placed on or close to the fixed platform, so that the moving part is light in weight, high in speed and good in dynamic response; (3) Compact structure, high rigidity, large bearing capacity; (4) The completely symmetrical parallel mechanism has good isotropy; (5) The working space is small, and it is widely used in space equipment, active shock absorbers, and surgical instruments ...

AI Technical Summary

Problems solved by technology

[0004] The branch chains of the existing six-degree-of-freedom parallel robots are mostly SPS, UPS, and RUS structures. For example, the Chinese patent No. ZL201410388991.5 discloses a three-branch six-degree-of-freedom robot drive mechanism, which includes three structures For the same branch chain, each branch chain is connected by two connecting rods through a pin shaft connection. The two connecting rods are linear connecting rods, and the slider is driven by the screw to drive the first connecting rod to rotate. The disadvantage is that the form of the branch chain is too complicated, the accuracy of symmetrical installation is too high, and the load carried by the first connecting rod is relatively large

The patent application with the application number 201610879835.8 discloses a three-degree-of-freedom robot. The branch chain of the robot drives the drive connecting rod to rotate through the motor, and then drives the rotating telescopic mechanism to rotate. The rotating telescopic mechanism has a semicircular structure, and the driving connecting rod is Linear type, its disadvantage is that when working, the working space is small, and interference between the rotating and telescopic mechanisms is easy to occur

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