| Tweet |
Custom Search
|
|
|
||
 TM 55-1905-220-14-10
5-4. MAIN PROPULSION ENGINE/MARINE GEAR - REMOVAL AND RUN-IN
MAINTENANCE INSTRUCTIONS (Continued).
LOCATION
ITEM
ACTION
REMARKS
RUN IN (Cont)
(2) Dynamometer
(a)
The function of the dynamometer is to absorb and measure the engine output. Its
basic components are a frame, engine mounts, the absorption unit, a heat exchanger,
and a torque loading and measuring device.
(b)
The engine is connected through a universal coupling to the absorption unit. The load
on the engine may be varied from zero to maximum by decreasing or increasing the
resistance in the unit. The amount of power absorbed in a water brake type
dynamometer as an example, is governed by the volume of fluid within the working
system. The fluid offers resistance to a rotating motion. By controlling the volume of
water in the absorption unit, the load may be increased or decreased' as required.
(c)
The power absorbed is generally measured in torque (lb-ft) on-a suitable scale. This
value for a given engine speed will show the brake horsepower developed in the
engine by the following formula:
BHP = (T X RPM) / 5250
Where:
BHP = brake horsepower
T = torque in lb-ft
RPM = revolutions per minute
(d)
Some dynamometers indicate direct brake horsepower readings. Therefore, the use of
the formula is not required when using these units.
(e)
During the actual operation, all data taken should be recorded immediately on an
Engine Test Report (see sample).
(3) Instrumentation.
(a)
Certain instrumentation is necessary so that data required to complete the Engine Test
Report may be obtained. The following list contains both the minimum amount of
instruments and the proper location of the fittings on the engine so that the readings
represent a true evaluation of engine conditions.
1
Oil pressure gage installed in one of the engine main oil galleries.
5-27
|
||
|
||
