From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Production tests for a motor and reduction gear, detailing the light test procedure.
| Identifier | ExFiles\Box 49\5\ Scan207 | |
| Date | 28th August 1919 | |
| U.S.A. 28.8.19. X.1627 - PRODUCTION TESTS OF R.R. MOTOR & X.3082 - REDUCTION GEAR. ---------------------------- TEST 1. LIGHT TEST. The motor and gear shall be run light for a period of half an hour on a battery of three accumulator cells in series. Towards the end of the run the current taken must not exceed 17.5 amperes. This ensures - (a) That the mechanical friction of the motor is within reasonable limits - also(b) That the magnetic circuit of the motor is sufficiently good. The geared down speed will be in the neighbourhood of 600 r.p.m. and the motor speed in the neighbourhood of 3600 r.p.m. but the speed need not be observed on this test. Current in excess of 17.5 amperes implies either or both of the following - (a) Mechanical friction of motor is too great and the chief probability is that the gears require easing. (b) Provided the motor is alright as regards (a) excessive current means that the magnetic circuit of the motor is bad. This might occur as the result of too large an air gap, or of excentricity of the armature. This latter has a double effect on the current. - Firstly because the total flux may be reduced. Secondly because the flux may be twisted round so that the brushes are no longer in exact neutral | ||