Study on a Ultra-precisely Joining Method using a Shrink Fitter

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10650139
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 設計工学・機械要素・トライボロジー
• Research Institution: Niigata University
• Principal Investigator: NITTA Isami Niigata University, Graduate School, Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (30159082)
• Project Period (FY): 1998 – 1999
• Keywords: Machine Element / Fixing Element / Shrink Fitter / Out-of-Roundness / Polygon Mirror / Self-Acting Air bearing / Ultra Precision / スキャナー

Research Abstract

A micro machine is one of the high technology for mechanical engineers to give a contribution in the future. The problem is that there is no sufficient equipment to check shapes and functions of the micro machines. Now we can observed the micro machines by an optical microscope or a scanning electron microscope(SEM). The SEM has an advantage of the depth of focus. However the field of view of the SEM is narrow and the sizes of specimens are limited to its vacuum chamber. If a highly accurate laser scanner is developed, these problems are solved. The challenging thing for the development of the laser scanner is to keep the laser spot within several micrometers over a wide scanning width of 30 mm. To do this, several scanning lenses have to be assembled in the housing with their optical axises highly coincided.
The purpose of this research is to establish the technology to assemble several optical lenses to the housing in super-high accuracy by using a shrink fitter that we have developed.
Last year the deformation of each optical lens fitted by the shrink fitter was calculated by three dimensional finite element method. The limit interference for each optical lens by which the deformation of the lens in the direction of the optical axis did not exceed half wavelength, e/2 was obtained. On the basis of the limit interference, the sizes of both the shrink fitter and housing were determined. The materials of the shrink fitter used at room temperature were polyimide and acryl which we used before. We succeeded in obtaining spot diameter about 6μm over the scanning width of 30mm only at the room temperature. The same experiments have been carried out at current year with the temperature changed between 5℃ and 70℃. This time we used cast-nylon for the materials of the shrink fitters because of its heat resistance property. As a result, the spot diameter of 6μm could be obtained and maintained over the scanning width of 30mm even at the temperature range of 5℃ and 70℃.