3.3 Gun drive assembly. The Gun Drive Assembly shall comply with all
requirements specified on Drawing (Dwg.) F 189F734, all associated drawings,
and with all requirements specified in applicable specifications and standards.
3.3.1 Performance characteristics.
22.214.171.124 Acceleration. Under no-load condition when the input voltage of
28 + 0.5 Vdc is applied to Pins B and C of the drive motor, the output gear
shall rotate counterclockwise a minimum of 12 revolutions within the first
second when viewed from the output end of the drive assembly.
126.96.36.199 Steady-state operation. With 28 0.5 Vdc and a torque of 68.5
inch-pounds applied, the drive assembly output gear shall rotate counterclock-
wise at the steady state operation of 817 to 876 revolutions per minute (rpm)
when viewed from the output end of the drive assembly. Steady-state operation
shall be reached within one second.
188.8.131.52 Maximum torque. With power applied as specified in 184.108.40.206,
mechanical disconnection from the drive motor, caused by the shearing of pins,
shall not occur when a maximum torque of 800 inch-pounds is applied to the
Environmental characteristics (first article inspection only).
220.127.116.11.1 Temperature altitude, Drive assemblies shall operate while
exposed to conditions specified in Method 504.1 of MIL-STD-81O simulating on
altitude of 20,000 feet (temperature of -25F and barometric pressure 2.12
inches mercury) while energized with line-to-neutral voltage of 124 volts.
The test shall be performed as specified in 18.104.22.168.1.
22.214.171.124.2 Vibration. Drive assemblies shall withstand a vibration of 80
Hz with the motor functioning at 6200 rpm for 400 duty cycles. A duty cycle
shall be defined as time-on for 3 seconds and time-off for 5 seconds. After
each series (5 duty cycles); the motor shall be stopped and cooled to ambient
temperature. Cleaning and lubrication shall be accomplished after each 2
series. The magnitude and direction of vibration shall be resultant of 0.15
inch total excursion parallel to the drive rotor axis and 0.40 inch total
excursion perpendicular to the drive rotor axis. In addition, with the motor
stopped, the drive shall withstand vibration of 80 Hz at 0.40 inch total
excursion in a direction parallel to the drive rotor axis for a period of one
(1) hour. The amplitude of vibration shall be within 10 percent of the
specified values. The test shall be performed as specified in 126.96.36.199.2.
188.8.131.52 Proof test (first article inspection only). Gun drive assemblies
shall operate when assembled to an accepted Universal Turret Subsystem (UTS).
The test shall be performed as specified in 184.108.40.206.