Transcript Project.ppt

Design of a Micro-Mechanical
Bearing
Solid Surfaces
• The shaft and
bearing cage are
constructed as an
assembly by
EFAB technology
• .15 Ra typical on
horizontal
surfaces.
.1 mm shaft
.01 mm gap
Mechanical Contact
• A first attempt to
describe the contact
is made with
Hertzian analysis.
• The rotor is subject
to torque due to
centrifugal loading
at 4,000 rpm.
• Two design
variations are
analyzed.
Friction
• The two surfaces are Ni-Co alloy
• The two design variations seek to reduce
the contact area
Wear
• The application of the bearing is a safe
and arm device in which an eccentrically
weighted rotor must move less than 90
degrees.
Lubrication
• The gap between the shaft and bearing
cage is lubricated with air.
• CFD will be used to study the shear and
pressure distributions due to the rotation of
the rotor.
• Coatings on the Ni-Co surfaces may be
investigated to reduce friction.
Questions?