Active node for changing octahedral truss unit into geometric truss

Abstract

The invention discloses an active node for changing an octahedral truss unit into a geometric truss. The active node for changing the octahedral truss unit into the geometric truss is a cylindrical hemisphere combined compact active node, is of an upper and lower middle face symmetrical and angular bisector symmetrical structure and comprises a node central spindle sleeve, a central spindle screw, a spherical bearing and retainer, a screw type acting rod connection lantern ring, a first lug plate type acting rod connection lantern ring, a second lug plate type acting rod connection lantern ring, a first passive rod spherical bearing seat, a second passive rod spherical bearing seat, a needle bearing inner ring, a needle bearing, a needle roller thrust bearing pad, a needle roller thrust bearing and retainer, a deep groove ball bearing, a first semi-spherical nut and a second semi-spherical nut and can be connected with two extensible lengthened active rods and four fixed-length passive rods. Four fixed-length passive rods are subjected to motion decoupling, and the node is small, flexible in motion, large in strength and high in accuracy.

Description

technical field [0001] The invention relates to a variable geometry truss active node, in particular to an octahedral truss unit variable geometry truss active node, which belongs to the technical field of structural mechanism engineering. Background technique [0002] The octahedral truss unit consists of 12 rods and 6 nodes to form a space-definite system, which has neither hyperstatic indetermination nor internal mechanism. Therefore, the octahedral truss unit is an effective basis for constructing large-scale and complex structural systems, spatial extension mechanisms, and control mechanisms. Truss unit. When the sides and edges of an octahedral truss unit are equal in length, it is called a regular octahedral truss unit. The six side edges of the octahedral truss unit are set as active rods. This is the famous Stewart platform. The active rods can be greatly expanded or rapidly responded to be micro-expanded. They are used for tracking mechanisms, vibration reduction ...

AI Technical Summary

Problems solved by technology

[0011] However, these studies have shown that the active joints of the octahedral truss element variable geometry truss have the disadvantages of large nodes, low stiffness, high friction, and low precision.

[0012] The Chinese patent "Octahedral truss element variable geometry truss active node" with application number 201310153044.3 discloses an octahedral truss element variable geometry truss active node, but the node is kinematically coupled with the parts connected to the upper and lower passive rods, resulting in the passive rods of each layer There are irregularities and singularities in the movement, and there are many parts

Images