Micromachines,
Journal Year:
2024,
Volume and Issue:
15(10), P. 1216 - 1216
Published: Sept. 29, 2024
Hard-brittle
materials
are
widely
used
in
the
optics,
electronics,
and
aviation
industries,
but
their
high
hardness
brittleness
make
it
challenging
for
traditional
processing
methods
to
achieve
efficiency
superior
surface
quality.
This
study
aims
investigate
application
of
ultrasonic
local
resonant
grinding
sapphire
improve
meet
requirements
optical
window
roughness
material.
The
frequency
a
piezoelectric
vibration
system
amplitude
head's
working
face
were
simulated
tested,
respectively.
results
experiments
showed
that
reduced
parameter
(Ra)
14
nm
improved
its
flatness
44.2
nm,
thus
meeting
ultra-precision
sapphire.
Compared
with
conventional
system,
ground
was
by
90.79%,
81.58%,
material
removal
rate
increased
31.35%.
These
experimental
has
better
effects
than
those
improving
quality
increasing
rate.
Industrial Lubrication and Tribology,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 23, 2024
Purpose
This
paper
aims
to
study
the
lubrication
mechanism
of
textured
journal
bearings.
Design/methodology/approach
CFD
models
for
bearings
are
established.
The
effect
texture
coverage
on
pressure
distribution
is
studied
find
proper
distribution.
To
enhance
local
load-carrying
capacity
at
textures,
micro-hydrodynamic
and
microflow
different
depth
ratios
captured.
interaction
between
texture-induced
bearing
film
analyzed
from
perspective.
Findings
performance
one
hand
enhanced
by
generated
textures.
On
other
hand,
main
land
maximum
can
be
interfered
leading
reduction
capacity.
minimize
interference
effect,
textures
suggested
distribute
downstream
minimum
thickness
location.
As
increases,
corresponding
optimum
ratio
rises.
vortices
influence
flow
rate
through
further
affect
ratio,
which
begin
occur,
generates
pressure.
Originality/value
introduced,
capable
generate
without
interfering
with
primary
bearing.
found
considerably
necessity
sub-regional
optimization
in
pointed
out.
provides
fundamental
reference
design
Journal-thrust
coupled
bearing
(JTC
bearings),
unlike
conventional
journal
or
thrust
bearings,
require
consideration
of
both
reducing
friction
coefficient
in
the
part
while
increasing
load-carrying
capacity
during
lubrication
design.
This
study
established
a
thermal-elastohydrodynamic
mixed
model
for
JTC
bearings
considering
flow,
pressure,
and
thermal
continuity
conditions,
validated
through
experiments.
Based
on
this,
influence
texture
parameters
under
real
heavy
load
conditions
was
preliminarily
analyzed.
The
orthogonal
test
design
then
used
to
determine
that
had
greatest
impact
optimization.
Subsequently,
particle
swarm
optimization
(PSO)
algorithm
employed
synchronous
textures
parts.
Micromachines,
Journal Year:
2024,
Volume and Issue:
15(10), P. 1216 - 1216
Published: Sept. 29, 2024
Hard-brittle
materials
are
widely
used
in
the
optics,
electronics,
and
aviation
industries,
but
their
high
hardness
brittleness
make
it
challenging
for
traditional
processing
methods
to
achieve
efficiency
superior
surface
quality.
This
study
aims
investigate
application
of
ultrasonic
local
resonant
grinding
sapphire
improve
meet
requirements
optical
window
roughness
material.
The
frequency
a
piezoelectric
vibration
system
amplitude
head's
working
face
were
simulated
tested,
respectively.
results
experiments
showed
that
reduced
parameter
(Ra)
14
nm
improved
its
flatness
44.2
nm,
thus
meeting
ultra-precision
sapphire.
Compared
with
conventional
system,
ground
was
by
90.79%,
81.58%,
material
removal
rate
increased
31.35%.
These
experimental
has
better
effects
than
those
improving
quality
increasing
rate.
