Design and application of compliant quasi-kinematic couplings

Better precision at lower costs is a major force in design and manufacturing. However, this is becoming increasingly difficult to achieve as the demands of many location applications are surpassing the practical performance limit (~ five microns) of low-cost couplings. The absence of a means to meet these requirement has motivated the development of the Quasi-Kinematic Coupling (QKC). This thesis covers the theoretical and practical considerations needed to model and design QKCs. In a QKC, one component is equipped with three spherical protrusions while the other contains three corresponding conical grooves. Whereas Kinematic Couplings rely on six points of contact, the six arcs of contact between the mated protrusions and grooves of QKCs result in a weakly over-constrained coupling, thus the name Quasi-Kinematic. QKCs are capable of sub-micron repeatability, permit sealing contact as needed in casting, and can be economically mass produced. The design and application of a QKC is demonstrated via a case study on the location of two engine components. Integration of the QKC has improved coupling precision from 5 to 0.7 microns. In addition, this QKC uses 60% fewer precision features, 60% fewer pieces, costs 40% less per engine, and allows feature placement tolerances which are twice as wide as those of the previous dowel-pin-type coupling.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2000

Author dc:creator

• Culpepper, Martin L. (Martin Luther)

Advisor dc:contributor.advisor

• Alexander H. Slocum.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/9260

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/9260