AIRCRAFT PROPULSION — TAYLOR 



281 



HOBIZOMTAL 

 WATER 

 PASSAGES 



MAIN OUd /f/f 



TO INDUCTION " 



MANIFOLD 



BOOST 



CONTROL 



UNIT 



Isr STACe 



SUPtROlARCei! 



ROTOR 



Pertpective dratving of the n<^ic two- 



Mtage tmo-ipeed tuperckarger of the "°??^'' ^p*p 



RolU-Royce Merlin "61" tngim-. "^"^""^iJe^^" 

 The tain rotort are mounted 



single shaft. Change of tpeed of 



the supercharger drive is effected 



by a hydraulic pump. 



FUU GEAR 



aUTCH & CEAR 



DRIVE 



AAftAl. 

 FUEL PRESSURE 

 KDUQNC VAlVt 



Figure 16. — Two-stage two-speed geared supercharger with intercooler and aftercooler of 

 the Rolls-Royce "Merlin 61" engine of 1942, the first of its kind to be used in service. 

 (Courtesy "Flight" magazine.) 



tion engine to be so equipped was the Pratt and Whitney "Wasp" 

 of 1927, a year later than the "Jaguar." Since 1930 all military 

 and transport engines have been equipped with geared centrifugal 

 superchargers, and in all cases some kind of flexible coupling has been 

 introduced in the gear train to prevent critical torsional vibration. 

 The culmination of the geared centrifugal type is represented by the 

 two-stage, two-speed supercharger of the Rolls-Royce "Merlin" 

 (fig. 16). 



In 1918 the Engineering Division of the Army Air Service con- 

 tracted with the General Electric Company to develop turbo super- 

 chargers of the Rateau type. The man in charge of this development 

 for G.E. was Dr. Sanford A. Moss, who remained in this position 

 for over 20 years. Experimental models applied to the Liberty engine 

 were tested at the top of Pikes Peak in 1918, and in flight at McCook 

 Field in 1919. 



Plate 22, figures 1 and 2, show an installation of this early type of 

 General Electric supercharger in the Liberty-equipped Le Pere air- 

 plane. This equipment held the world's altitude record for the years 



