TM-9-2350-256-10
RECOVERY VEHICLE, FULL TRACKED: MEDIUM, M88A1
OPERATOR'S MANUAL
OCTOBER 2014
TM-9-2350-256-10 - Page 43 of 796
THEORY OF OPERATION
POWERPACK
•
Engine (Figure 1, Item 1)
— an air-cooled, 12-cylinder, 90-degree, V-type, 4-cycle, turbocharged diesel.
The engine develops 780 maximum horsepower at 2,400 rpm and delivers that power to the transmission
(Figure 1, Item 3).
•
Transmission and Output Reduction Drives
— the cross-drive transmission is a combined
transmission center section (Figure 1, Item 3) with steering unit and two output reduction drives
(Figure 1, Item 2). The transmission provides power to the drive sprockets at an output torque that varies
automatically according to the drive-load conditions when not in lockup. There are three forward speeds,
one reverse, and one neutral. Steering is possible in all drive ranges and neutral. Steering in neutral
causes the vehicle to pivot in place, the tracks turning in opposite directions.
Figure 1.
Powerpack.
CHARGING/STARTING SYSTEM AND VEHICLE BATTERIES
•
Engine Generator
— an air-cooled, 28-V, dc-rated, 300-Ampere (A), field-regulated unit. It is mounted on
the right side of the engine near the flywheel end and is gear driven by the engine. An integral blower, an
air intake duct, and an outer boot and duct provide a means of cooling the generator. The electrically
operated blower draws air from the crew compartment, forces it through the generator, and exhausts it
upward through an outlet near the right camshaft gear housing.
•
Generator Voltage Regulators
— there are two solid-state generator voltage regulators that maintain
generator output voltage at a constant 28±0.7 Vdc. One controls the generator voltage output of the
engine and the other the generator voltage output of the Auxiliary Power Unit (APU). The voltage
regulators are mounted at the left rear of the engine compartment.
•
Starter Assembly
— the 24-V waterproof starter assembly is mounted on the lower left side of the
engine, toward the rear. It is a heavy-duty, solenoid-operated, enclosed shift-lever-type engine starter.
TM 9-2350-256-10
0003
0003-1
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