Helicopter Gear Lubricating Problems

Since the gearing in question is high speed, reference to a previous section, which deals with problems in lubricating high speed gears, may indicate similar problems. Also an investigation by peck et al.^39 is an aid in this regard. Under high speed conditions, good results were obtained by lubricating with a “jet hitting the center of the gear tooth on the outgoing side of the tooth mesh”. Also baffles were used to prevent swirling of the oil with resulting heating. Likewise, baffles were necessary to direct oil to the suction lines “without being picked up by high velocity airflow's and whirled around”. The characteristics of suitable oil for lubrication of highly loaded helicopter transmission, turbo-prop reduction gears, variable pitch propeller gearing etc., are similar to those required in aircraft turbine oils. Therefore, if lubricating problems occur, they will be similar in both instances.