FED-STD-791D
8.
Check automatic load-control set point to see that load set point is on "O."
9.
Start drive motor.
10.
Increase gear speed by turning rpm-adjust control clockwise until the
specified 10,000 100 rpm is obtained.
Turn on power to induction heater plate and slowly adjust plate control until
11.
the radiometer reading determined in step 3 is obtained.
12.
Set automatic load-control set point to 34.5-kPa gage (5-psi) load-oil
pressure.
13.
Check gear speed, and adjust if necessary.
14.
Check gear temperature, and adjust plate control if necessary.
15.
Turn timer switch to "START" position. The ten-minute run now begins.
16.
Maintain the test gear temperature and speed at the predetermined specified
values.
Record all pertinent data about midway of the test run.
17.
At the end of the ten-minute run, the timer will automatically turn the power
18.
off to the drive motor and reduce the load to zero. However, the timer switch
will remain in the "START" position, the rpm-adjust will remain in the
running position, and the load set point will remain at the previously set load
position. Restore these to their respective "OFF" positions.
Turn induction heater plate power off.
19.
Make visual scuff inspection of each tooth of the narrow test gear as follows:
20.
a.
Turn 3-way valve (Figure 4) to bypass the gear machine and return the test
oil to the sump.
Remove corks from inspection holes in the gear-case end cover.
b.
c.
Install microscope or television camera and inspection light.
Focus microscope and adjust grid lines over the contact area of the tooth.
d.
e.
Set indexing-rachet wheel to "No. 1" position.
f.
Estimate the percent scuff of No. 1 tooth as accurately as possible but at least
to the nearest 5%, and record the value (see Figure 7).
g.
Operate the test gear rotating device to give No. 2 tooth, and repeat (f).
Repeat for No. 3 tooth, etc, until all 28 teeth have been examined.
h.
Remove inspection equipment and replace corks in holes.
i.
Lock test gear rotating device in disengaged position.
j.
Turn 3-way valve to running position.
21.
Repeat step 3 of 6.2.2.
22.
Repeat steps 7 through 20 at the next test load of 69 kPa gage (10 psig)
load-oil pressure.
23.
Continue the test at 34.5-kPa gage (5-psi) load-oil pressure increments until
the average scuffed area for all 28 teeth is close to 22.5%. At this juncture,
visually estimate the percent effective tooth width to the nearest 1%, and
record the value.
24.
Further continue the test at 34.5-kPa gage (5-psi) load-oil pressure
increments, until an approximate average scuffed area of 30% or more is
obtained.
25.
Push test-oil heater button to "OFF" position.
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