Curtiss D-12
The Curtiss D-12 (military also Curtiss V-1150 ) is a water-cooled V-12 aircraft engine from the American manufacturer Curtiss Airplane and Motor Company Incorporated .
history
The cylinder angle is 60 °. Both cylinder banks are cast from a block that is bolted to the upper part of the crankcase . Each cylinder has two intake and two exhaust valves, which are operated by an overhead camshaft per cylinder bank. The camshafts are driven by vertical shafts. The cylinders of both banks are exactly opposite. The pistons are therefore connected to the crankshaft, which has seven bearings, via a main and a secondary connecting rod.
Since the reduction gear of the Curtiss K-12 was constantly causing problems, Arthur Nutt decided to leave it out. In an intermediate step, the K-12 became the Curtiss CD-12. However, the wooden propellers used up to now required a limitation of the possible engine speed and thus a reduction in performance. Sylvanus Albert Reed succeeded in producing a metal propeller that enabled a higher propeller speed, and so the full engine power could be used again. The "D" in the name means direct .
The output of the first prototype was 316 hp, which could be continuously increased in series production. The engine was used in both the Curtiss CR-1 and the Curtiss CR-2 and the Curtiss R6 . In addition to its use in Curtiss racing and fighter aircraft, it was also used in the Boeing PW-9 . The first use took place in 1921 at the Pulitzer Trophy Air Race on Long Island , which could be won by the Curtiss CR-2 . The unit developed 400 hp at 2000 rpm. Curtiss also used the unit for record flights. A CR-2 reached a new world record on October 13, 1922 with 358.836 km / h, still with a special wooden propeller. The compression was increased to 5.8: 1 and the engine developed 450 hp.
For use in the Curtiss R6 , the engine was bored out to 117 mm and so the Curtiss D-12A was created with 460 hp for a short time at 2400 rpm with a compression of 5.3: 1. With a compression of 6: 1, 495 hp were possible with this engine. Further development stages for military use were the variants D-12C (Curtiss V-1150-1) and D-12D (V-1150-3), each with 435 hp continuous output.
In Great Britain the engine was produced under license as Fairey Felix . When it was no longer possible to increase performance with the D-12, Nutt designed the successor Curtiss V-1570 .
Technical data (Curtiss D-12)
- 12 cylinders, liquid-cooled
- Bore: 114.3 mm
- Stroke: 152.4 mm
- Displacement: 18763 cm³ (1145 cu.in.)
- Continuous power: 375 hp
- Compression: 5.3: 1
- Maximum engine speed: 2000 / min
- specific consumption 240 g / PSh
- Length: 1437 mm
- Height: 1003 mm
- Width: 718 mm
- Weight: 304 kg
See also
Web links
- Facts and figures in English