coal trade bulletin - Clpdigital.org

18 THE COAL TRADE BULLETIN.
forms. A self-contained gravity system for the
main working parts, a force feed system for cylinders
and valves, and compression grease cups on
valve motion, make a combination that insures
perfect lubrication at all speeds, eliminates dripping
or splashing of oil on outside parts and requires
no drip pans. Attendance is reduced to
the minimum. That compactness and accessibility
can be brought together in the same unit
has been demonstrated in this machine. Notwithstanding
its enclosed and neat appearance, all
working parts are easy to inspect, adjust or remove.
Sectional Elevation. "WJ-3" Compressor,
A single crank pin takes the place of the two
eccentrics customarily used for driving the valve
motion in duplex machines. No supporting brackets
or intermediate rocker arms are required.
A balanced disc on the end of the crank shaft
carries a crank pin on which the connecting rods
are hung for the valve motion of both cylinders.
It is unnecessary to point out the obvious simplicity
and the many advantages of this arrangement
as compared with the usual two eccentrics
and eccentric straps with their high rubbing speeds
and inconvenience of adjustment.
The massive foundations necessary to absorb
the unbalanced vibrations in other types are not
required for the perfectly balanced Angle-Compound
compressor, and it may be successfully
operated in buildings where vibration is objectionable,
or on unstable or filled ground, where vibration
would have a tendency to cause unequal settlement
and thow the compressor out of alignment.
The heavy counterweight peimitted by this design
practically absorbs within the shaft itself all
of the heavy inertia loads which would otherwise
have to be carried by the crank shaft bearings,
and leaves these important
elements of
the compressor free to
perform their proper
WATER OUTLET
function of carrying
M AIR OUTLET
the load due to the
air pressure on the
pistons and to support
the weight of the moving
parts, thereby
greatly reducing
power losses due to
friction, trouble with
heated bearings, etc.
In addition to the
elimination of inertia
loads from the bearings,
a further benefit
is gained by a more
uniform distribution
of the working pressures
around the circumference
of the
crank shaft boxes. In
the horizontal type of
machine, the wear due
to the influence of piston
load is all on the
sides of the boxes,
while with the Angle-
Compound type the
piston load produces
wear in both horizontal
and vertical direc­
tions, with the result that the boxes require less
adjustment, the wear is distributed over a greater
surface, and both the shaft and boxes retain a
more nearly cylindrical shape throughout their
life, resulting in unusual freedom fiom pounding.
In the ordinary duplex design, the stresses due
to piston load are applied to the ends of a crank
shaft supported in bearings several feet apart,
and as the piston loads during certain parts of
the revolution act in opposite directions, a twisting
effect or couple is set up in a horizontal plane
which must be resisted by the machine frame,