MIL-DTL-17060G(SH)
4.6.4 Lubrication. The effectiveness of the lubricating system with the motor in its normal position shall be
observed during the progress of the other tests, or by special test, as applicable. Oil rings of sleeve bearing motors
shall turn freely and there shall be no foaming of the oil. Lubricants similar to those required for service operation
shall be used. It shall be demonstrated that the motor lubrication is satisfactory, that the specified limitations of the
bearing temperatures have not been exceeded, and that there is no suction of lubricant into the electrical windings
under any operating condition.
4.6.5 Noise.
4.6.5.1 Airborne noise. Airborne noise shall be measured using the instrumentation and procedures of
MIL-STD-740-1 with the exception that noise levels at the measurement positions shall be averaged. Except as
required in 4.6.5.3, motors shall be tested while operating at no-load with rated voltage and frequency applied.
4.6.5.2 Structureborne noise. Except as required in 4.6.5.4, motors with structureborne noise requirements
shall be tested at no-load with rated voltage and frequency in accordance with MIL-STD-740-2 with the exception
that quality testing shall be conducted at the transducer location which produced the maximum response during first
article testing.
4.6.5.3 Airborne noise for VSD motors. VSD motors shall be tested per 4.6.5.1 with the exception that testing
shall be at the maximum specified operating speed as follows:
a. If the maximum operating speed (see 6.2) is greater than the base speed (see 6.6.25.6), testing shall be
performed at the maximum operating speed at no-load with a VSD.
b. If the maximum operating speed is less than or equal to the base speed, testing shall be performed at the
base speed at no-load using a VSD or facility power.
4.6.5.4 Structureborne noise for VSD motors. VSD motors shall be tested per 4.6.5.2 with the exception that
testing shall be performed with a VSD at the volts per hertz point to operate no-load at the following conditions:
a. Testing shall be performed at the specified maximum operating speed (see 6.2). If a maximum operating
speed is not specified, testing shall be done at the base speed (see 6.6.25.6).
b. Structureborne noise shall be sampled across the speed range. If the noise at a speed within the range is
greater than the noise measured in 4.6.5.4(a.), testing shall also be performed at the speed within the speed range
with the greatest noise levels.
4.6.6 Mechanical balance. The mechanical balance of the completely assembled motor and any special
attachments (such as brakes or overspeed switches) shall be measured. Motors shall be tested at no-load, except
motors having a varying speed (but not a definite no-load speed) shall be tested at their highest rated speed. The
method of test shall be as follows:
a. The motor shall be mounted on an elastic mounting so proportioned that the up and down natural frequency
shall be at least as low as one-quarter of the maximum operating speed of the motor. To accomplish this, the elastic
mounting shall be deflected downwards at least by the following amounts due to the weight of the motor. The
deformation of the mounting shall be not more than one-half the original height of the elastic element.
Compression (inch)
r/min
900
1
1,800
¼
1
3,600
/16
1
7,200
/64
b. Prior to assembly, the rotor shall be balanced in a balancing machine with or without bearings. If balanced
with bearings, the inside bearing caps shall be supported on the shaft during balancing. Balancing shall be
accomplished in two planes for both static and dynamic correction.
c.
A vibration indicator shall be used.
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