I forgot to mention it: the pulsator is fully functional on these planes. Most rotary engine equipped airplanes did noot possess a tachometer but the pilot could calculate the rpm by watching the pulsator which was also used as an indicator of regular lubrication: the formula number of seconds/ 50 pulses gave a number directly proportional to rev count.
The Pulsometer is connected to the oil supply line via a junction in the pipeline and in the event of the glass bulb breaking, can be turned off by way of the stop cock in the fitting below it.
There is an air space in the glass bulb above the static level of oil.
The oil pump is driven off the engine resulting in pressure pulses in the oil system.
These pressure pulses propagate through the system and make their way up through the oil in the lower part of the glass bulb or sight glass as it is called, and show themselves like a gentle burble or ripple of oil on the oil surface, thus indicating that the oil is flowing.
The oil level in the glass bulb is determined by the equalization of pressures in the system, so as the oil pressure varies in pulses, so too does the pulse in the glass bulb.
The oil pulses are quite minor and difficult to detect, barely moving the meniscus of the oil'no bubble, rather just a 1/16'' bump in the level every few seconds.
Engine rpm can be ascertained by counting the oil pulses.
For example if it took 68 seconds for 50 pulses on a 110 HP Le Rhone rotary engine, the rpm would be 1226.
The pulsator was also used as an indicator of regular lubrication, independently of the tachometer:
For instance the manual of the 110 hp LeRhone indicates: 71 pulse/s=1173 rpm; 69 pulses/s =1208 rpm; 68 pulses/s= 1226 rpm for a
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Topic: Orient is Red - Krarsnyi Vostok - Part 1 v1.0 Ansaldo A1, Sikorsky S12, S12bis, S16-3 S16ser Moscam MB & MB bis (Read 13192 times)
