Figure 3-14.Crosshead assembly.
An automatic lubrication system is provided to
ensure that lubricant is automatically provided
between the bonded spacers and bearing pads of the
28-inch pitch diameter and 33-inch pitch diameter
high-speed sheaves of the crosshead and fixed
sheave assembly during arrestment operations
( p e n d a n t e n g i n e s o n l y ) . T h e s h i p ' s
medium-pressure air, reduced to 80 (±5) psi, is
piped to a regulator, which reduceds the air to the
required operating pressure of between 60 and 70
psi. Air is fed through a rubber hose to a pump
mounted on top of a 120-pound drum of lubricant.
Lubricant is pumped from the drum through hoses
to control valves mounted on the engine structure.
These control valves adjust the rate of flow of
lubricant to the high-speed sheaves.
The control valves are operated by plunger
rollers, which are cam-actuated at a set position of
the engine crosshead arrestment stroke. An ounce
of lubricant is pumped to the high-speed sheaves
during the arrestment and the retraction cycles. A
hose reel with a flexible rubber hose is mounted on
the crosshead end of the engine structure, with the
hose connected to metal tubing on the engine
crosshead. As the crosshead moves toward the fixed
sheaves during arrestment, the hose pays out and
spring tension in the hose reel takes up the hose
during retraction. The spring tension on the hose
reel must be 9 pounds (±1/2 pound), with the hose
fully retracted, at all times.