Earticle

This study is to investigate the cause of the malfunction of the ground tracked combat vehicle rotating roller and set future direction of improvement. The integrity of the initially used plate and rotating roller was evaluated. As evaluation methods, mechanical property test, radiographic test and size checking test were performed. PA66, PA12, PET, and POM were selected among polymer materials and tested for water absorption rates. Through mechanical property test and radiographic test, the materials used initially were identified to be sound. In the evaluation of the selected four polymer materials, it was confirmed that the PET was excellent in the mechanical properties and the water absorption rate. PET is excellent in mechanical properties and water absorption.

This study is intended to analyze the effect of thin ink-film thickness around rotating printing roll on the printing quality in the gravure printing process which is used for making electronics circuit like a RFID tag with a conductive ink. The present work numerically estimates the film thickness around rotating roller partially immersed in ink, for which the volume of fluid (VOF) method was adopted to figure out the film formation process around rotating roller. Parameter studies were performed to compare the effect of ink viscosity, surface tension, roller rotating speed, immersed angle on the film thickness. The result indicates that the film thickness has a strong dependency on the fluid viscosity, while the surface tension has negligible effect.

Cam mechanism is one of the common devices used in many automatic machinery. Specially cylindrical cam generates three dimensional motions. Thus, the shape design procedures must have high accuracy. This paper proposes the shape design procedure for a cylindrical cam and follower mechanism using a relative velocity method. The relative velocity method and the coordinate transformation are used to find a contact point between the cam and the follower. Also, the full shape of the cylindrical cam can be generated by using the geometric relationships and the contact constraints. As a result, this paper presents an example for the shape design of the cylindrical cam in order to prove the accuracy of the design procedures.