Accession Number : ADA303695

Title :   Bell Helicopter Advanced Rotorcraft Transmission (ART) Program.

Descriptive Note : Final contractors rept.,

Corporate Author : BELL HELICOPTER CO FORT WORTH TX ELECTRONICS DEPT

Personal Author(s) : Henry, Zachary S.

PDF Url : ADA303695

Report Date : JUN 1995

Pagination or Media Count : 223

Abstract : Future rotorcraft transmissions require key emerging material and component technologies using advanced and innovative design practices in order to meet the requirements for a reduced weight to power ratio, a decreased noise level, and a substantially increased reliability. The specific goals for the future rotorcraft transmission when compared with a current state-of-the-art transmission (SOAT) are: (1) a 25% weight reduction, (2) a 10 dB reduction in the transmitted noise level, and (3) a system reliability of 5000 hours mean-time-between-removal (MTBR) for the transmission. This report summarizes the work conducted by Bell Helicopter Textron, Inc. to achieve these goals under the Advanced Rotorcraft Transmission (ART) program from 1988 to 1995. The reference aircraft selected by BHTI for the ART program was the Tactical Tiltrotor which is a 17,000 lb gross weight aircraft. A tradeoff study was conducted comparing the ART with a Selected SOAT. The results showed the ART to be 29% lighter and up to 13 dB quieter with a calculated MTBR in excess of 5000 hours. The results of the following high risk component and material tests are also presented: (1) sequential meshing high contact ratio planetary with cantilevered support posts, (2) thin dense chrome plated M5O NiL double row spherical roller planetary bearings, (3) reduced kinematic error and increased bending strength spiral bevel gears, (4) high temperature WE43 magnesium housing evaluation and coupon corrosion tests, (5) flexure fatigue tests of precision forged coupons simulating precision forged gear teeth, and (6) flexure fatigue tests of plasma carburized coupons simulating plasma carburized gear teeth. (AN)

Descriptors :   *HELICOPTERS, *TRANSMISSION GEARS, KINEMATICS, STRESS STRAIN RELATIONS, MAGNESIUM, LOAD DISTRIBUTION, OPTIMIZATION, CORROSION, LIFE EXPECTANCY(SERVICE LIFE), FATIGUE LIFE, STRESS ANALYSIS, STATE OF THE ART, FINITE ELEMENT ANALYSIS, STATIC LOADS, STRESS TESTING, COST ESTIMATES, COMPOSITE STRUCTURES, HELICOPTER ROTORS, STRENGTH(MECHANICS), STEEL, RELIABILITY, FLEXURAL STRENGTH, ROLLER BEARINGS, NOISE REDUCTION, TRADE OFF ANALYSIS, DESIGN CRITERIA, FAILURE(MECHANICS), WEIGHT REDUCTION, THERMAL STRESSES, LUBRICANTS, TORQUE, FATIGUE TESTS(MECHANICS), BENDING STRESS, AIRCRAFT NOISE, NOTCH TOUGHNESS, GEAR TEETH, TRANSMISSIONS(MECHANICAL), DRIVE SHAFTS, OIL FILTERS.

Subject Categories : Helicopters
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE