GB595710A - Improvements in or relating to apparatus for testing engines - Google Patents

Abstract

595,710. Dynamometers. POWER JETS (RESEARCH & DEVELOPMENT), Ltd., and MANNING, E. March 16, 1944, No. 4904. [Class 106 (ii)] An aircraft engine to be tested is mounted rotationally about a transverse axis in a floating structure. Means may be provided for oscillating the engine motmting about the axis during the test. The aircraft engine 1, which is of jet type or of the type provided with a propeller, is secured in a mounting 2 having hollow trunnions 3 carried in bearings 5 mounted in the apices of triangular frames 6. The frames are supported by floats 7 arranged in liquid containers 8 interconnected by pipes 12 and fitted with graduated manometers 29. The floats may be adjustably loaded. One trunnion is fitted with bevel gear 13 coupled disengageably to a hand wheel 17 for operation to rotate the engine mounting to any desired test position. The other trunnion is fitted with a removable crank-arm 22 coupled adjustably by a link 23 to a crank disc 24 which may be operated by a motor 26 to oscillate the engine during test. When the engine is vertical, Fig. 1, the thrust is indicated by the level in the manometer tubes 29. The exhaust outlet 35 is fitted with deflector vanes 36. When the engine is oscillated by the motor and crank mechanism, the gyrostatic couple of the engine is proportional to the loading on spring balances 34 arranged between one of the frames 6 and lugs 26a on the stator of motor 26, the stator being capable of partial rotation relative to the armature of the motor. With the engine horizontal, Fig. 3, the thrust is measured by a meter or spring balance 31 connected to the frames 6 or bearings 5 by compression members 32 and to the stands 9 for the containers 8 by tension members 33.