Design of flexure hinges in an H-drive precision stage with a large span

Author(s):  
Shaokai Wang ◽  
Jinxin Hu ◽  
Changqi Li ◽  
Jiubin Tan
Author(s):  
K-B Choi ◽  
C S Han

This paper presents an optimal design of a compliant mechanism with circular notch flexure hinges as well as a performance evaluation of a two-axes ultra-precision stage using the compliant mechanism. The compliant mechanism consists of two double-symmetric four-link mechanisms for two translational motions. As the circular notch flexure hinge can produce rotation as well as axial translation via its deformation, the double symmetric four-link mechanism can translate along one direction in a small range. In the optimal design, a composite global design index based on Min-Max principle is applied for the design of the compliant mechanism with circular notch flexure hinges owing to its simplicity and compactness. The designed compliant mechanism, piezoelectric elements for actuation, and capacitance-type displacement sensors for position measurement are assembled into an ultra-precision stage. The experimental results show that the stage implemented by the compliant mechanism will be applicable to two-axes ultra-precision positioning systems such as the fine positioning table of coarse-fine positioning systems, ultra-precision machining centres, wafer stages, and scanners for atomic force microscopy (AFM).


The article deals with the issues of glass use in the enclosing structures of large-span coverings, which have such advantages as ensuring the penetration of natural light, tightness, minimum labor costs for repair and maintenance. Design shortcomings: the high cost, the need for protection of the internal volume against the penetrating sun rays in the warm season (hothouse effect); arrangement of devices for operation of a roof. The key technical properties and characteristics of glass panels and pane-glass sets, constructive decisions, including interface to the main bearing structures of a large-span covering are given. Peculiarities of their design with due regard for ventilation and smoke removal, a drainage of condensate, ways of fight against frosting and snow drifts on the roof are reflected. Features of the account of loadings, the basic approaches to their calculation are considered. Various design solutions for the spatial metal trussed systems with the original nodal connections are presented. Information on modern solutions of translucent roofs using glass for large-span coverings is given.


2020 ◽  
Vol 140 (4) ◽  
pp. 272-280
Author(s):  
Wataru Ohnishi ◽  
Hiroshi Fujimoto ◽  
Koichi Sakata

1988 ◽  
Vol 16 (4) ◽  
pp. 200-207
Author(s):  
O. B. Tretyakov

Abstract A process is suggested for improving the rubber-cord composite in a radial tire through precision stage-by-stage molding of its parts. This starts by casting an inner elastomeric envelope of the carcass from a liquid oligomer mix. The full molding technology uses acoustic and resonance effects to optimize the degree of order of the structure and of rubber uniformity. The resultant precision tires should have a higher degree of order of both macro- and microstructure than do present commercial tires. Reduced stress concentration in locations that have high failure rates in commercial tires are considered. A new theory, CSSOT, is used for optimizing tires from results of stress-strain cycles.


Author(s):  
Philipp Gräser ◽  
Sebastian Linß ◽  
Felix Harfensteller ◽  
Mario Torres ◽  
Lena Zentner ◽  
...  

2021 ◽  
Vol 11 (10) ◽  
pp. 4576
Author(s):  
Jian Shi ◽  
Desen Kong

Based on plastic limit analysis, the deformation and fracture mechanism of the floor in the large-span chambers of deep mines are discussed and a similarity model test is carried out to verify the reliability of the theoretical analysis. The results show that the local shear failure first appears below the loading area and develops to the middle part of the test model with the increase in load; when the local shear failure develops to form a continuous sliding surface, continuous plastic flow deformation occurs; the distribution of the plastic zone and the deformation mode obtained from the similarity model test are basically consistent with the Hill-like deformation mode derived from plastic limit analysis. A control technology with anti-slide piles is proposed in order to deal with floor heave in large-span chambers on the basis of previous work. An approach for determining the supporting parameters of anti-slide piles is deduced. To deal with the floor heave in the −1100 level gangue winch room of the Huafeng Coal Mine, a comprehensive reinforcement scheme with anti-slide piles composed of discarded rails and anti-floating anchors is introduced for the floor heave control of the chambers. Site monitoring results show that the scheme not only effectively restrains the development of floor heave, but also ensures the long-term stability of the chamber floor.


2012 ◽  
Vol 06 ◽  
pp. 172-177
Author(s):  
Nam-Su Kwak ◽  
Jae-Yeol Kim

In this study, piezoelectric actuator, Flexure guide, Power transmission element and control method and considered for Nano-positioning system apparatus. The main objectives of this thesis were to develop the 3-axis Ultra-precision stages which enable the 3-axis control by the manipulation of the piezoelectric actuator and to enhance the precision of the Ultra-Precision CNC lathe which is responsible for the ductile mode machining of the hardened-brittle material where the machining is based on the single crystal diamond. Ultra-precision CNC lathe is used for machining and motion error of the machine are compensated by using 3-axis Ultra-precision stage. Through the simulation and experiments on ultra-precision positioning, stability and priority on Nano-positioning system with 3-axis ultra-precision stage and control algorithm are secured by using NI Labview. And after applying the system, is to analyze the surface morphology of the mold steel (SKD61)


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