Linear Motion Guides Research Articles

Effect of 2nd Axis Linear Motion Guide on Mechanical Performance of Robot in 2-Axis Cartesian Coordinate Robot

Effect of 2nd Axis Linear Motion Guide on Mechanical Performance of Robot in 2-Axis Cartesian Coordinate Robot

Dynamic analysis of a linear motion guide having rolling elements for precision positioning devices

Linear motion (LM) guides supported by rolling elements can be used to ultra-accurately position precision machines. For accurate positioning, the micro and macro dynamic behavior of the LM guide must be understood, but the research on this subject is rather limited. In this investigation, experiments to reveal the dynamic characteristics of the LM guide were performed and a simplified model to predict the observed dynamics of the LM guide was developed. Several experiments conducted in the present research demonstrated the hysteretic behavior as well as frequency- and force-dependent phenomena of the LM guide. The validity of the proposed modeling method was checked with theoretical and numerical analyses.

Design and manufacture of a three-axis ultra-precision CNC grinding machine

A three-axis CNC grinding machine tool for the ultra-precision mirror surface grinding of advanced materials such as ceramics and other hard and brittle materials has been designed. The grinding machine is composed of the air spindle, a high-damping resin concrete bed, and a three-axis CNC controller with high resolution AC servo motors. For the stiffness calculations of the grinding machine, a new modeling method for linear motion guides and ball screws using the three dimensional finite-element method was introduced. From comparison of the calculated results with the experimental results, it was found that the modeling method gives accurate results in the prediction of the stiffness of machine tools. Based on the results, a prototype three-axis CNC grinding machine was designed and manufactured. To investigate the dynamic properties of the grinding machine, the natural frequencies and damping of the spindle and the headstock were measured experimentally. Also, the mode shape of the machine tool x-table at the first natural frequency was obtained experimentally. From the grinding operation of ceramic materials, it was found that the prototype grinding machine tool produced mirror surfaces on aluminum oxide and titanium carbide, with arithmetic surface roughnesses of less than 50 nm.

Float Characteristics of Squeeze-Film Gas Bearing with Elastic Hinges for Linear Motion Guide.

In this paper we describe the float characteristics of a new type of squeeze-film gas bearing which can be used to realize non-contact linear-motion guide systems which do not require supply of pressurized air. Piezoelectric actuators and elastic hinges are used to induce vibration of the bearing and generate squeeze-film pressure under the bearing. In a theoretical analysis, a simple dynamic model of the bearing structure is presented. The influences of the displacement and vibrational frequency of the piezoelectric atcuators on the float characteristics are investigated theoretically and experimentally. Furthermore, the load capacity at a vibrational frequency of 2400 Hz and the float characteristics at the resonance frequency of the bearing are measured. It was found that the bearing can be used to realize a non-contact linear motion guide and that the dynamic model presented in this paper can be used for accurate prediction of the float characteristics of the bearing.

Float Characteristics of Squeeze-Film Gas Bearings Using Elastic Hinges For Linear Motion Guide.

Float Characteristics of Squeeze-Film Gas Bearings Using Elastic Hinges For Linear Motion Guide.