1、MIL-M-7969C 25 MAY 1965 SUPERSEDING MIL-M-7969B(ASG) 10 APRIL 1958 MILITARY SPECIFICATION MOTORS, ALTERNATING CURRENT, 400-CYCLE, 115/20O-VOLT SYSTEM, AIRCRAFT, GENERAL SPECIFICATION FOR ntents and Agencies of the Department of Defense. This specijcation is mandatory for use by all Depart- 1,SCOPE M
2、IL-I-6181-Interference Control Re- 1.1 Scope-. This specification covers the genera.1 requirements for a.ircraft electric motors and, together with the detail specification or with the military standard (MS) containing equivalent information, as described in 3.5.2, forms the complete specification f
3、or procurement of aircraft electric motors operable from 1151 200-volt1 4OO-cyc1el alternating current systems. 1.2 Classification. Motors shall be of the following classes, as specified (see 6.2): Class A-Class A motors are operable under temperature-altitude conditions of curve II of MS33543. quir
4、ements, Aircraft Equipment MIGL6880-Lubrication of Aircraft, General Specification for MIL-S-7742“Screw Threads, Standard, Optimum Selected Series: General Specification for MIL-A-8625-Anodic Coatings, for Alum- inum and Aluminum Alloys MIL-E-16298“Electric Machines Having Rotating Parts and Associa
5、ted Repair Parts: Packaging of MILD-70327-Drawings, Engineering and Associated Lists Class B-Class B motors are operable under temperature-altitude conditions of curve I of MS33543. MILLTARY STANDARDS .2. APPLICABLE DOCUMENTS MILSTD-130“Identification Marking of US Military Property 2.1 The followin
6、g documents, of the issue in MIGSTD-143“Specifications and Stand- effect on date of invitation for bids or request for ards, Order of Precedence for the Selec- proposal, form a part of this specification to the tion of extent specified herein: MILSTD-195-Marking of Connections SPECIFICATIONS for Ele
7、ctric. Assemblies MILSTD-202-Test Methods for Elec- tronic and Electrical Component Parts QQ-P-416-Plating, Cadmium (Electrode- MILSTD-704-Electric Power, Aircraft, MILITARY MS335404afety Wiring, General Prac- MIL“-3171-Magnesium Alloy, Process tices for for Corrosion Protection of MS33543“Criteria
8、Temperature and Alti- MIL-E-5272-Environmental Testing, tude Range Self Cooled Electric Equip- Aeronautical and Associated Equipment, ment General Specification for MS33568-Drive1 Square Mounting Flange MILG5541-Chemical Films and Chem- with Involute Spline-Pinion ical Film Materials for Aluminum an
9、d MS33569-Drive1 Round Mounting Flange Aluminum Alloys with Involute Spline-Pinion FEDERAL posited) Chracteristics and Utilization of -7 . I- r Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-M-7969C MS33570-DriveJ Square Mounting Flange MS33571-
10、DriveJ Round Mounting Flange MS33B8G-MetalsJ Definition of Dissimilar (Copies of spccifications, standards, drawing8, and pull- licntions requircd by suppliera in connection with specific procurement functions should be obtained from the pro- curing activity or as directed by the contracting officer
11、.) with Round Shaft and Key with Round Shaft and Key 3. REQUIREMENTS 3.1 Preproduction. This specification pro- vicies fos pseproduction testing (see 4.3). 3,2 Data. Unless otherwise specified in the contract or order, no data are required by this spccificntion os any of the documents listed in sect
12、ion 2 (see G,2). 3.3 Materials. Materials used in the man- ufacture of motors shall be of high quality, suit- able for the purpose, and shall conform to npplicnble Government specifications wherever practicable. 3.3.1 Corrosion resistance. Materials shall bo corrosion resistant or be suitably proces
13、sed to resist corrosion. 3,3.2 Dissimilar metals. Unless suitably protected, clissimilar metals as defined in M533586 shall not be used in intimate contact with each other, When protection is used, it shall bo of such type that a low-impedance path is oEered to rjdio frequency currents, 3.4 Selectio
14、n of specifications and stand- ards. Specifications and standards for neces- sary commoclities and services not specified llerein shall be selected in accordance with MIL- STB-143, except as provided in 3.4.1 and 3.4.2. 3.4.1 Standard parts. Standard part.s (MS and AN) shall be used wherever they ar
15、e suitable for the purpose, and shall be identified on the drawing by their part numbers. In the event thcre is no suitable corresponding standard part in eftcct on date of invitation for bids, commer- cial parts may be used, provided they conform to all recluircments of this specification. 3.4.2 Co
16、nmercial parts. Commercial utility parts, such as scwws, bolts, nuts, and cotter pins may be used, provided they possess suitable properties and are replaceable by the 1MS or AN parts without alteration, and provided the cor- responding MS OP AN part numbers are refer- enced in the parts list and, i
17、f practicable, on the contractors drawings. 2 3.5 Design and construction. 3.5.1 Dut3 cycle. The duty cycle shall be as specified in the detail specification. 3.5.2 Detail requirements. The detail re- quirements, as specified in the detail specification or MS, shall include all of the applicable dat
18、a shown in 6.5. 3.5.3 MountingJlange. The mounting flange, when required, and clearance for mounting studs shall be in accordance with the applicable MS or detail specification. Fhnges in accordance with MS335G8, MS335G9, MS33570, or M533571 are preferred in the applicable motor sizes, 3.5.4 Couplin
19、g spline. The coupling spline, or drive shaft, shall be jn accordance with the applicable MS or detail specification. Splines or drive shafts in accordance with MS33568, MS33569, RIS33570, os M533571 are preferred in the applicable motor sizes, 3.5.5 Lubrication. When lubrication of the motors is pe
20、rmitted by the MS or detail specifi- cation, it shall be in accordance with MILE G880. 3,5.6 Electrical connectio?zs. Unless other- wise shown on the applicable MS or detail speci- fication, external termination of the motor wiring shall be in accordance with MILSTD-195. The motor mounting provision
21、s shall not be used to complete the motor electrical circuits in lieu of a lead. Positive connections which depend upon insulation in compression shall not be used. 3.5.7 Rotor. Motors shall be so construct- ed that the rotor is readily removed without t.he use of special tools. 3.5.8 Electric power
22、. When furnished with category C ac power in accordance with MIL- STD-704, m specified on the detail specification or MS, each motor shall conform to the require- ment,s of MILSTD-704 and shall meet all other requirements of this specification and the detail specification or MS. 3.5.9 Protection. Wh
23、en used, all ventilating openings in the housing shall be of such size as not to permit passage of a 5/1Ginch-diameter rod. 3.5.10 Lifo of motor. The motor shall be so designed that when operating under any of t.he temperature or altitude conditions specified in 3.5.18, the useful life of t.he motor
24、 shall be not, less than 1,000 hours. 3.5.11 Rotation. The direction of rotation Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-of the motor output shaft shall be in accordance with MILSTD-195. 3.5.12 Thermal protection. When specified by the applic
25、able motor drawing or detail speci- fication, a protective means shall be supplied. One of the following methods and types of pro- tection is to be specified: (a) Thermal protection method. (1) Method I: Protection shall be pro- vided by a nonautomatic reset means to prevent smoke or toxic fumes fro
26、m being generated by a motor under locked rotor or operating conditions. The protective device must be man- ually resetable or replaceable after partial disassembly of the motor. (2) Method II: Protection shall be pro- vided to permit a motor to develop maximum output or locked rotor torque to the p
27、oint of failure without being a fire hazard. The protective system must not be automat- ically reset and both motor and protector system are considered expended after one operation. (3) Method III: Protection shall be provided to permit average rated torque capability under all operable environmenta
28、l, power, and load con- ditions, and attain a substantial portion of the rated life of the motor under overload conditions which cause cycling of the thermal protec- tive device. The motor and protec- tor shall provide a minimum of 25 hours of intermittent or continuous locked rotor protection at ra
29、ted volt- age and frequency. (b) Thermal protection type. (1) Direct acting: A protector within or on the motor enclosure shall inter- rupt the motor power supply and shall be of sufficient ra.ting to inter- rupt the maximum locked rotor cur- rent and perform in accordance with the appropriate part
30、of 3.5.12(a), as specified. The protector must be rated to provide a minimum of 5,000 interruptions of the maximum cur- rent, or 25 hours of intermittent or continuous locked rotor protection at . rated voltage and frequency. (2) .Indirect acting: A protector shall be provided with a minimum inducti
31、ve contact rating of 2 amp. at 28V dc to operate relays and signal devices. The protector .must perform in ac- cordance with the appropriate part of 3.5.12(a) specified, and must have a minimum life of 5,000 operations. 3.5.13 Fluid resistance. When specified by the applicable MS or detail specifica
32、tion, the motor shall be designed and constructed to oper- ate under conditions of fluid leakage upon the motor as specified in 4.6.20, 3.5.14 Explosion-proof (aeronautical), When specified by the applicable MS or detail specifica- tion, the motor and thermal protector (if speci- fied) shall be expl
33、osion-proof, as specified in 4.6.21. 3.5.15 Interference. Conducted and radi- ated radio frequency noise shall not exceed the limita specified in MIL-1-6181. 3.5.16 Emergency two-phase operation. When required by the applicable MS or detail specfi- cation, a grounded neutral, threephase, Y- connecte
34、d motor aha11 operate with one of the input power lines removed under one or more of the following conditions, as specified in the applicable MS or detail specification: (a) Motor shall be capable of delivering specified reduced horsepower output continuously. (b) Motor shall be capable of deliverin
35、g specified minimum stalled torque. (c) Motor shall be capable of delivering a specified minimum running torque. (d) Motor shall be capable of delivering a specified horsepower output for a speci- fied number of operational cycles prior to failure. ,. (e) Other. 3.5.17 Brakes. When required by the M
36、S or detail specification, the motor shall be equipped with a brake. Stopping revolutions and inertia load shall be as specified by the MS or detail specification. 3.5.18 Operating conditions. The motor shall provide mechanical energy in aircraft under any of the following operating conditions or na
37、tural combination of conditions: (a) Altitude-temperature: Altitude-tem- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-7 MIL-M-7969C perature range in accordance with MS33543, curve I (Class B) or curve II (Clm A), as specified on the applicable MS
38、 or detail specification. The pres- sure may remain constant, or may vary at a rate as high as 1.5 inches Hg./sec. (b) Humidity: Relative humidity ranging up to 100 percent, including conditions wherein condens the motor shall start at no load and run satisfactorily during the test. The motor shall
39、then be rotated 180 degrees about an axis perpendicular to the axis of the centri- fuge arm, and the test repeated. The motor shall be mounted on the centrifuge in four addi- tional positions such that the accelerating force is applied in both directions through each of the remaining axes of the mot
40、or, For each position of the motor, the centrifuge shall be operated at a speed that will produce an acceleration of log. The acceleration of log in each test shall be stabilized and maintained for not less than 1 minute, After completion of this test the motor shall pass the test specified in 4.6.3
41、. 4.6.11 Shock. The motor shall be mounted using its own mounting provisions and subjected to a shock test in accordance with Procedure V of MILE-5272, except that the test specified for “Equipment crash-safety” shall not be re- quired. The shock testing machine shall be in accordance with MILSTD-20
42、2, or other approved equipment. Following this test, the motor shall pass the test specified in 4.6.3. 4.6.12 Vibration. The motor shall be sub- jected to vibration test in accordance with Pro- cedure XII of MIL-E-5272. During the entire test, the motor shall be operated at no load. Ihc MIL-M-7969C
43、“on” time for intermittent-duty motors shall be in accordance with the rated duty cycle. Fol- lowing this test, the motor shall pass the test specified in 4.6.3. Continuous-duty motors shall start and operate at no load during this test. 4.6.13 Life. The motors sha.11 be so instru- mented that the b
44、earing, stator winding, and other hot spot or critical temperature readings can be checked or recorded. The motor shall be operated for 1,000 hours at rated input volt- age, rated frequency, and rated output torque at its specified duty cycle with the exception of the simulated altitude-temperature
45、runs. Re- versible, intermittent-duty motors shall be alternately operated in each direction at the rated duty cycle. Following this test, the motor shall pass the load test specified in 4.6.3. No maintenance of any kind shall be allowed during this test. Simulated altitude-temperature runs shall be
46、 conducted as follows: i (a) Sea level altitude shall be utilized, (b) Temperature data obtained during the altitude chamber runs shall be dupli- cated by varying any or all of the fol- lowing : (1) Input voltage (2) rnput frequency (3) Loading (4) Modification of air flow through or over the unit (
47、5) Any other condition required to accomplish the desired result. 4.6.13.1 Class B motors shall be operated as specified in table I. 4.6.13.2 Class A motors shall be operat.ed a.s specified in table II, 4.6.14 Humidity. The motor shall be sub- jected to humidity test Procedure I of MILE- 5272. Immed
48、iately following this test, the motor shall pass the t.est specified in 4.6.3 at room temperature. 4.6.15 Salt spray. The motor shall be sub- jected to a 50-hour salt spray test in accordance with Procedure I of MILE-5272. During this test, the motor shall be operated as follows: (a) Continuous-duty
49、 motors shall be oper- ated at no load with voltage or fre- quency adjusted to give approximately rated speed for 10 periods of 15 minutes duration with a minimum nonoperating Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I I I -. . . . i: . . , . . . . . . . . . . . r“.-l . I , , ._ . I . -. -.- “_. i . / . -, . .“. . , . - . . . I .I . “.“. F;-gq . .( _.“.“ +zj:Ld “I . . . . I . . . . ! . . - .L . 4 . .“. “. .“.,. , I . .-, 4 “
