Rotary fast tool servo component design
Name
43165986-MIT.pdf
Description
Full printable version
Size
11.7 MB
Format
Adobe PDF
Checksum (MD5)
091f46ea46ad34611263deb6ea6ffdec
Author(s)
Chargin, David Anthony, 1974-
Advisor(s)
David L. Trumper.
Date Issued
1999
Publisher
Massachusetts Institute of Technology
Abstract
This thesis covers the design and implementation of the components of a novel rotary fast tool servo (RFTS). The RFTS enables diamond turning of rotationally asymmetric optics, with an emphasis on eyeglass lenses. These components include the rotary arm which supports the cutting tool, a high resolution angular sensor for position feedback, and a labyrinth seal system to protect the rotary axis hearings. The design of the tool arm meets several conflicting challenges, including maintaining low rotational inertia and high stiffness while providing an integrated tool height adjustment mechanism. A new, novel "double-diaphragm" actuator is developed, which provides sub-micrometer level tool height adjustment. This actuator enables the tool arm to he constructed with little additional material, meeting the low inertia goals without compromising stiffness. The high resolution angular feedback hack sensor selected for the machine is a diffractive laser design. It was successfully interfaced into the machine, both mechanically and electrically, to provide ~ 10 nanometer resolution in cutting tool location. This was essential in enabling the RFTS to turn lenses with micrometer accuracy. Finally, a new possibility of developing rotational damping with a labyrinth hearing seal is explored. Rotational damping is created by exploiting the shear forces developed between a viscous fluid and a labyrinth with a fine gap size. This provides excellent sealing as well as rotational damping.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.
Includes bibliographical references (p. 185-188).
Subjects
Mechanical Engineering
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
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