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| MIL-A-516J
3.6.6 Transmission. The auger shall be equipped with an internal torque-
coverter transmission The torque-converter transmission shall have a minimum
of four speeds forward and a minimum of three speeds reverse. Engine and
torque-converter transmission shall be matched for power as a unit. The
torque-converter shall be provided with an oil cooler that shall prevent the
temperature of the oil from exceeding 240" F. Augers equipped with
torque-converter transmission shall be furnished with an oil temperature
indicator and an oil pressure indicator. Indicators shall be located at the
operator's station. Gear reductions for the four forward graduated speeds shall
be such as to rotate the boring bar when it is above ground and rotating freely
over a speed range from a minimum speed of not more than 40 revolutions per
minute (rpm) in first gear to a maximum speed of not less than 120 rpm in
highest gear.
3.6.7 Spoil throwoff. The auger bar speed shall be sufficient to throw spoil
from the auger bits specified in 3.6.4, and deposit the spoil so that spoil will
not fall back into the hole when the auger is digging maximum depth holes in the"
soil specified in 3.6.1 (b).
3.6.8 Bearings. Unless otherwise specified herein, all bearings shall be of
the antifriction type and shall conform to FF-B-185, FF-B-187, Or FF-B-171, as
applicable When specified (see 6.2), the contractor's standard commercial
bearings may be used.
3.6.9 Hydraulic system. When a hydraulic system is used, it shall be
protected against the entrance of dirt or other foreign materials. The
hydraulic system shall be complete with all operating accessories, including a
pump, hydraulic cylinders, valves, reservoir, pressure relief valve, and a full
flow 25-micron oil filter accessible for cleaning. The pump shall supply a
continuous flow of hydraulic fluid, and shall have sufficient capacity to
energize all hydraulically powered components. Hydraulic cylinders shall be of
the double-acting type and shall be equipped with counterbalance or lock-type
check valves. A wiper shall be provided on the cylinders adjacent to the piston
rod seals to prevent dirt and abrasives from damaging the seal or entering the
cylinder. Hydraulic cylinder piston rods shall be hard-chrome plated.
Hydraulic valves shall control retracting speed of all hydraulic cylinders, or
an internal flow restriction or bypass shall be provided at each end of the
cylinders. The reservoir shall be baffled and shall be constructed to withstand
vibrations and shocks. The reservoir shall have sufficient capcity to allow
maximum displacement of all cylinders, and aid heat dissipation. The return
line shall terminate below the minimum oil level of the reservoir. The suction
line shall be above the reservoir bottom and shall `be protected with an
accessible strainer. The reservoir shall be equipped with a removable cover
plate for inspection and cleaning. Provisions shall be made for filling and
draining the reservoir and for checking the quantity of fluid in the reservoir.
The drainplug shall be of the magnetic type. The system shall have a shut off
capability to prevent any excessive loss of oil while breaking lines or changing
the pump.
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