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Chapter 11 Machine Elements and Basic Mechanisms | Up
Basic Machines - Intro to machines and motion theories | Next
Antifrictional or Roller and Ball Bearings |
Figure 11-1.-Babbitt-lined bearing in which steel shaft revolves.
clamped or screwed around the shaft (fig. 11-1). We also
call it a laminated sleeve bearing.
Under favorable conditions the friction in journal
bearings is remarkably small. However, when the
rubbing speed of a journal bearing is very low or
extremely high, the friction loss may become excessive.
A good example is the railroad car. Railroad cars are
now being fitted with roller bearings to eliminate the
“hot box” troubles associated with journal bearings.
Heavy-duty bearings have oil circulated around and
through them. Some have an additional cooling system
that circulates water around the bearing. Although
revolving the steel shaft against babbitt metal produces
less friction (and less heat and wear) than steel against
Figure 11-3.-Diagrammatic arrangement of a Kingsbury
thrust bearing, showing oil film.
steel, keeping the parts cool is still a problem. The same
care and lubrication needed to prevent a burned out
bearing on your car is needed on all Navy equipment,
only more so. Many lives depend on the continued
operation of Navy equipment.
Thrust Bearings
Thrust bearings are used on rotating shafts, such as
those supporting bevel gears, worm gears, propellers,
and fans. They resist axial thrust or force and limit axial
Figure 11-2.-Kingsbury pivoted-shoe thrust bearing.
11-2
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