Electric Engine‐Testing Plant: The Type of Equipment Used in a Modern Electrical Aero‐Engine Test Laboratory Available to Purchase

IN Figure 1 is shown an example of a purely electrical dynamometer, which uses two electrical carcases in tandem; its range of power and speed being suitable for dealing with medium‐sized aero‐engines and the more powerful automobile and lorry engines. Its speed range is from 500 to 3000 r.p.m. and its maximum continuous absorption 240 b.h.p. The two carcases are yoked together by steel members, and the two shafts are also coupled together by a flexible coupling. Both carcases are mounted on anti‐friction trunnion bearings, so as to permit the utilisation of the principle of torque reaction for the measurement of load. An interesting feature is that by a simple arrangement of levers the steelyard which measures the load caters for forces in either sense, so that it indicates torques arising either from the absorption of the engine power output, or from the use of electrical power to motor the engine.