Wright R-1820
| Wright R-1820 Cyclone | |
|---|---|
 R-1820 Cyclone |
|
| Type: | Radial engine |
| Design country: | |
| Manufacturer: | |
| Commissioning: |
1931 |
| Number of pieces: |
unknown |
The Wright R-1820 Cyclone was an air-cooled 9-cylinder - radial engine of the US manufacturer Curtiss-Wright . The designation R-1820 means radial engine (radial engine) - displacement 1820 cubic inches , which corresponds to almost 30 liters. The turbocharged gasoline engine was a further development of the Wright P-2 presented in 1925 .
Production of the R-1820 began in 1931 and continued into the 1950s. The engine was also manufactured by Lycoming , Pratt & Whitney Canada and, during World War II, by Studebaker . The total number of engines built is unknown. Several series of the R-1820 were produced, most of them with propeller drives . The individual series could be distinguished by appending letters and numbers. The power output rose from an initial 574 hp to a maximum of 1577 hp (with a 100/130 octane fuel). The prerequisite for this increase in performance were advances in forging and manufacturing technology. This made it possible to manufacture cylinders and cylinder heads with a much larger cooling surface. In addition, more resilient materials and design changes helped to withstand the increased loads in continuous operation.
Description (R-1820 C9HC)
The cylinders were turned from stainless steel (nitralloy) forgings. The running surfaces have been nitrided . To increase the cooling surface, aluminum segments in a W shape were attached to these cylinders. Adapted air baffles ensured a good air flow. The cylinder heads forged from aluminum were attached to the cylinders in a screwing / shrinking process. The combustion chamber in the cylinder head was designed hemispherical. It contained two valves, the seats of which consisted of shrunk bronze bushings. Rocker arms and valve springs were under a molded cover. Both valves were hollow to reduce mass, the outlet valves were filled with sodium for better cooling . The bumpers were guided in closed protective tubes.
The forged pistons were made of an aluminum alloy. Each wore three compression rings and three oil control rings . The piston pins were overhung in plain bearings.
The connecting rods were machined castings with an I cross section. The eight secondary connecting rods were hinged to the one-piece main connecting rod. The crank pin bearing of the main connecting rod had a vapor-deposited silver layer. All surfaces were also hardened by nitriding .
The crankshaft, which is triple-mounted in roller bearings, is pressed together from two forged steel pieces to accommodate the undivided main connecting rod. To avoid resonances , it is fitted with vibration dampers and mass balance weights in the front and rear areas .
The crankcase consists of a total of six parts: the front part, the front main part, the rear main part, the front charger housing, the rear charger housing and the charger housing cover. The main parts are made of steel, while the other components are made of a magnesium alloy. The front part houses the propeller thrust bearing and the control of the adjustable propeller , if present, as well as the reduction gear. A torque meter can be installed. In addition to the centrifugal compressor impeller with a diameter of 279 mm, the charger housing also contains its drive and the drives for the attachments. These include the Drehzahlmesserabgriff , the oil pumps - and fuel pump connections and power take-offs for the two magnetos , the alternator and optional for two devices. The starter is also flanged there, as is the Stromberg downdraft carburetor PD12K10 with automatic mixture control, acceleration pump and heating.
The engine is supplied with oil through dry sump lubrication . The pressure pump and a return pump are located together in the charger housing. A second return pump is housed in the front part of the engine. The rolling bearings are lubricated by oil mist. The engine oil circuit is also used to adjust the propeller .
Equipped aircraft (selection)
The engine was installed in a number of aircraft. The most famous of these are likely to have been the Boeing B-17 and the Douglas DC-3 / C-47 .
- Boeing B-17 Flying Fortress
- Brewster F2A Buffalo
- Columbia XJL-1
- Consolidated P2Y
- Curtiss SC Seahawk
- Douglas A-33
- Douglas C-47
- Douglas R4D- 8 Skytrain
- Douglas SBD Dauntless
- Douglas B-18 Bolo
- Lockheed C-60 Lodestar
- Vertol CH-21 Workhorse
- Grumman FF
- Grumman F3F
- Grumman FM-2 Wildcat
- Grumman HU-16 Albatross
- Grumman J2F Duck
- Grumman S2F / S-2 tracker
- Grumman WF / E-1 tracer
- Grumman TF / C-1 Trader
- Martin B-10
- North American P-64
- North American T-28 Trojan
- Northrop YC-125 Raider
- Sikorsky H-34 Choctaw
- ZPG-3W (4 US Navy airships)
The Dornier Do 24 built for the Netherlands and then manufactured there under license had two different engine versions installed.
Production under license in the USSR
The USSR received a manufacturing license. The engines built there based on the SGR-1820-F3 were given the designation Schwezow M-25 . The first engines left production in October 1934 and developed 700 hp. Other versions were the M-25A (71 HP), M-25W (750 HP) and M-25E (750 HP). The Schwezow ASch-62 was an independent further development based on this engine .
The M-25 was used at
Technical data (R-1820-C9HC)
- Cylinder: 9, air-cooled
- Valves: 2 per cylinder, OHV, outlet sodium-cooled
- Bore: 155.6 mm
- Stroke: 174 mm
- Displacement: 29.88 l
- Length: 1200 mm
- Diameter: 1400 mm
- Weight: 605 kg
- Loader: a single-stage mechanical loader on the crankshaft (ratio: 7.134: 1 and 10.04)
- Carburetor: two Stromberg PD12K10
- Lubrication: dry sump lubrication
- Output: 1,350 hp (993 kW) at 2700 rpm take-off power, 1,013 hp (745 kW) at 2600 rpm in 5330 m
- Compression: 6.55: 1
- Propeller reduction ratio: 0.5265: 1 or 0.666: 1
literature
- Jane's all the world's Aircraft Edition 1945; Reprint ISBN 0-00-470831-8
