Development of a switchable system for longitudinal and longitudinal-torsional vibration extraction

Harkness, P. and Lucas, M. (2012) Development of a switchable system for longitudinal and longitudinal-torsional vibration extraction. In: 41st Annual Symposium of the Ultrasonic Industry Association, San Francisco, CA, USA, 16-18 Apr 2012,

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High-frequency/low-frequency drilling is an attractive technology for planetary exploration tools, and one which has seen considerable innovation in the techniques used to ensure rotation of the front-end cutting bit. This rotation is essential to prevent tooth imprintation in hard materials, and extracting the rotation from the high-frequency or ultrasonic system has obvious benefits in terms of simplicity and robustness. However, extracting the rotation from an ultrasonic horn raises the possibility of bit-walk if it is used to operate a coring device and the authors therefore propose an ultrasonic horn which uses an excitation applied to a single input surface to yield torsional and longitudinal vibration on two physically separated output surfaces. By engaging with the two output surfaces, longitudinal vibration can be extracted to achieve initial percussive drilling, even where a coring bit is applied, and the torsional output can subsequently be added to prevent tooth imprintation once the coring bit has settled into the site in question. In this manner, the horn provides a mechanism whereby high-frequency/low-frequency drilling technique can be applied to coring operations without the need for an exceptionally robust drill structure capable of resisting bit-walk forces.

Item Type:Conference Proceedings
Glasgow Author(s) Enlighten ID:Lucas, Professor Margaret and Harkness, Professor Patrick
Authors: Harkness, P., and Lucas, M.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Copyright Holders:Copyright © 2012 The Authors
Publisher Policy:Reproduced with the permission of the authors.

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