TM 5-3810-307-24-1-2
Table K-4. Lubricants Required
Fuel System
Fuel Tank
No. 2 Diesel, JP-8
Lubrication System
Lubricating Oil Tank
MIL-L-2104 (15W40)
Lubricating Oil Tank (Temperatures below -20.0 F (-29 C))
MIL-L-46167 (0W40)
Grease
Lower Cylinder (Impact Block) Lubrication Fittings (four (4) locations)
MIL-G-10924
Impact Hammer Gibs (four (4) locations)
MIL-G-10924
Hammer Trip Assembly Gibs (four (4) locations)
MIL-G-10924
Spotter Slide (two (2) locations)
MIL-G-10924
Piston and Impact Block Compression Rings
MIL-L-2104
Oiling
Fuel Pump Lubrication Fitting
MIL-L-2105
Oil Pump Lubrication Fitting
MIL-L-2105
Fuel Tank Preservative/Fog Oil Spray
Kleen-Flo Tumbler Industries (Stock #789)
Hydraulic Oil
Remote Throttle
Automatic Transmission Fluid Dexron II/III or equivalent
THEORY OF OPERATION
Impact Hammer - General Operation (Refer To Figure K-6.)
There are five stages of operation for the impact hammer. To start the impact hammer, the hammer
line (main hoist) of the crane is used to lift the hammer trip assembly, which raises the piston to a
predetermined height. The hammer trip assembly then releases the piston, allowing it to free-fall in the
cylinder. After initial start-up, the following sequence occurs:
Purge. The piston falls under the force of gravity and accelerates downward. As the piston
1.
falls, the air and/or gases in the cylinder are expelled through the intake/exhaust ports.
Compression. When the piston reaches the intake/exhaust port, the port is closed,
2.
compressing the air in the lower cylinder.
3.
Combustion. As the piston nears the end of its downstroke a combustion chamber is
created by the ring-shaped nose of the piston and the lower cylinder. The fuel pump,
connected to the combustion chamber, amplifies the gas pressure compressed beneath
the piston and delivers high pressure fuel to the fuel injectors. Just before the piston
strikes the impact block, the fuel pressure overcomes the opening pressure of the fuel
injectors, injecting atomized fuel into the combustion chamber. The fuel ignites (due to
high compression temperatures) and the piston strikes the impact block, transferring its
kinetic energy to the direct drive assembly. The combustion force drives the piston
upward and the impact block further downward.
4.
Exhaust. As the piston rises in the cylinder and passes the intake/exhaust port, the port
is opened, allowing the exhaust gases to escape.
5.
Intake. As the piston continues rising, fresh air is drawn into the lower cylinder via the
intake/exhaust port. Under the force of gravity, the piston decelerates on the upward
stroke until completely stopping at the top of the stroke. The piston then begins to fall,
starting the five-stage cycle again. The fuel pump recharges and the cycle is repeated
until the fuel supply is interrupted.
K-18 Change-1
