Materials Flashcards
(200 cards)
load or force passing through the axis of rotation
radial load
the number of revolutions or hours at a given constant speed that 90 percent of an apparently identical group of bearings will complete or exceed before the first evidence of fatigue develops
rated life
the radial load that a ball bearing can withstand for one million revolutions of the inner ring
basic dynamic load
rating
constant stationary radial load which, if applied to a bearing with rotating inner ring and
stationary outer ring, would give the same life as that which the bearing will attain under the
actual conditions of load and rotation
equivalent dynamic
load
the maximum radial load, which corresponds to a calculated contact stress at the center of
the most heavily, loaded rolling element/raceway contact
basic static load
rating
static radial load, if applied, which produces a maximum contact stress equal in magnitude to the maximum contact stress in the actual condition of loading
equivalent static load
a mechanical device designed specifically to hold, join, or maintain equilibrium of single or multiple components
fastener
an externally threaded fastener designed for insertion through holes in assembled parts, and
normally tightened or released by torquing a nut
bolt
a block or sleeve having an internal thread designed to assemble with the external thread on a bolt, screw, stud or other threaded part
nut
the designation used for the purpose of general identification
nominal size
the distance from the intersection of the largest diameter of the head with the bearing surface to the extreme end of the fastener, measured parallel to the axis of the fastener
length of fastener
thread which winds in a clockwise and receding direction from the starting end, when viewed from that end
right hand thread
a thread which winds in a counterclockwise and receding direction from the starting end,
when viewed from that end
left hand thread
the specified load which the fastener must withstand without any indication of permanent deformation after the load is released
proof load
the distance (in millimeters), measured parallel to the thread axis, between corresponding
points on adjacent thread forms in the same axial plane on the same side of the axis
pitch
for a straight thread, this is the diameter of the imaginary cylinder bounding the crest of an external thread or the root of an internal thread
major diamater
for a straight thread, this diameter is the imaginary cylinder bounding the root of an external thread or the crest of an internal thread
minor diameter
for a straight thread, this is the diameter of the imaginary cylinder whose surface passes
through the thread profiles in such a way to make the widths of the thread ridge and the
thread groove equal
pitch diameter
used to join lengths of shafting, which must often be sectionalized for practicability and economy in manufacture and shipping or for purposes of ready installation
couplings
couplings which permits the disengagement of the coupled shafts during rotation
clutches
used for the transmission of power from a shaft to hub or vice versa.
splines
designed to reduce coupling shack by slipping during the engagement period. They also
serve as safety devices by slipping when the torque exceeds their maximum rating.
friction clutch
produces its torque by virtue of the centrifugal force of weights pressing against the driving
or frictionally driven member.
centrifugal clutch
consists of a frustum of a cone, so fitted to a shaft by means of a feather key that it can be
pushed into an opposite engaging surface rigidly attached to the other shaft
conical friction clutch