Daimler-Benz DB 605
| Daimler-Benz DB 605 | |
|---|---|
.jpg) Daimler-Benz DB 605 |
|
| Type: | Twelve-cylinder - V engine |
| Design country: | |
| Manufacturer: | |
| Production time: |
1941-1945 |
| Number of pieces: |
approx. 42,000 |
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The Daimler-Benz DB 605 was a liquid-cooled, twelve-cylinder engine - aircraft engine with 35.7 liters of displacement and direct fuel injection by Daimler-Benz . With over 42,000 units, it was one of the most popular German piston aircraft engines of the Second World War after the Junkers Jumo 211 (68,248 units) . Most of the Messerschmitt Bf 109 fighter aircraft were equipped with this engine.
Technology using the example of DB 605A
The DB 605 A / B was developed from the DB 601 model and, like this, was designed as a V-engine with a 60 ° bank angle and mechanical charging .
By enlarging the bore of the DB-601 engine by 4 mm to 154 mm with the same stroke of 160 mm, the DB-605 engine had 1.8 liters more displacement (35.7 l) and each cylinder therefore almost 3 liters. Because of the supercharger mounted on the left side of the engine, the compression ratio of the two cylinder banks was designed to be of different sizes with the same stroke due to different pistons (left 7.3: 1 - right 7.5: 1) in order to reduce the pressure differences due to the different length of the charge air or air flow Compensate suction line. The drop-forged crankshaft weighed almost 100 kilograms. The starting power was 1475 hp at 2800 min -1 .
A characteristic of the Daimler-Benz engine, like its predecessors since the Daimler-Benz F4A prototype built in 1932, was the installation with "hanging" cylinders ( crankshaft on top, hence also called " A-motor "). The hanging arrangement also made it easier to access cylinder heads ( valve control ) and spark plugs during maintenance.
He had a flywheel starter (Bosch AL-SGC 24 DR 2) that was operated electrically or externally via a hand crank . In addition, the engine was equipped with a single-stage radial loader driven by the crankshaft via a hydraulic clutch . The loader's job was to compensate for the drop in performance due to the falling filling level , which is caused by the falling air pressure at higher altitudes. The full pressure height , i.e. H. the height up to which the loader can deliver the same amount of air as near the ground was 5700 meters; in addition, the engine continuously lost power with increasing altitude. The boost pressure was, according to old Daimler-Benz documents moderate 1.42 bar.
The engine block was made of cast aluminum and contained steel cylinder liners . He had each cylinder bank via a vertical shaft driven overhead cam shaft ( overhead camshaft ), which for each cylinder four valves via rollers drag lever actuated (four valves per cylinder). Each cam operated an exhaust valve and an intake valve in turn. The exhaust valves were sodium cooled . The engine had a contact controlled dual ignition ( Bosch -Zwillings magneto ignition ZM 12 CR 8) having two spark plugs (Bosch DW 250 ET 7) per cylinder. The firing order was 1–8–5–10–3–7–6–11–2–9–4–12–1.
A gasoline direct injection system with a mechanical 12-plunger injection pump (Bosch PZ 12 HP 110/19), which delivered an injection pressure of up to 90 bar, was used to supply fuel. The fuel consumption was between 180 and 400 liters per hour, depending on the performance level. The standard fuel B4 had 87 octane , but C3 fuel with 100 octane could also be used. The engine oil - 36.5 liters - was circulated in a dry sump lubrication system by three oil pumps. The engine speed was above a propeller gears with straight-toothed spur gears relative 1.685: 1 (DB 605 B): 1 (DB 605 A) and 1.875 stocky . At an engine speed of 2800 min −1 this resulted in a propeller speed of 1660 min −1 for the DB 605 A and 1495 min −1 for the DB 605 B.
The variant DB605 B1 was manufactured in Sweden by Volvo Flygmotor under license for the SAAB 21 fighter aircraft . This made it possible to equip some of the cells of the Bf 109G2 manufactured in Spain under license as Hispano Aviación HA-1112 from the beginning of the 1980s to today with almost original engines and to present them to the public in flight. The only airworthy original Bf 109 with DB 605 A, the "Black Six", was damaged in an aircraft accident in 1997 and has only been exhibited in the museum since then.
The DB 610 was developed from the DB 605 . This engine consisted of two DB 605 coupled to one another, which drove a single propeller shaft via a common gearbox. The DB 610 was used almost exclusively in the heavy Heinkel He 177 bomber from version A-3.
Additional equipment
To increase performance, either MW-50 or GM-1 injection systems could be installed.
- MW 50
The MW-50 system was a water- methanol injection system that contributed to cooling the charge air through evaporative cooling and increased the knock resistance of the gasoline-air mixture. By operating with then possible higher boost pressures, the power of the engine could be increased by about 350 HP up to about two kilometers below the normal full pressure level; the increase then steadily decreased up to the full pressure level, as the charger could no longer convey enough air. The DB 605 DC, which was operated with higher boost pressure and higher compression than the DB 605 A and required C3 fuel, achieved a special emergency power of 2000 hp with MW-50 injection, the DB 605 DB with B4 fuel 1800 hp.
The supply of the water-methanol mixture of 70 liters (for example in the DB 605 D of the Bf 109 K-4) was sufficient for 26 minutes of flight with special emergency services. However, the machine was not allowed to run continuously at this highest power level for more than ten minutes, otherwise there was a risk of engine damage. The MW substance was pressed from the storage container into the spray nozzle on the charging shaft by the charging pressure tapped (0.7 bar) and fed to the cylinders with the charging air. When the MW production ended, the pilot had to immediately reduce the throttle lever to climb and combat power. However, if the emergency or take-off speed of 2800 min −1 was required in special cases above 8.5 km flight altitude , the MW support had to be switched off and the power lever pushed forward over the lock. The additional MW could be taken up to an altitude of 8.5 km; above an altitude of 8.5 km, the additional MW could no longer result in an increase in output, but rather MW material was used unnecessarily.
- GM-1
GM-1 could be used from about two kilometers above full pressure altitude. The plant used liquid nitrogen oxide (laughing gas). The oxygen released during the reaction to compensate for the lower oxygen pressure in the atmosphere at a height of several kilometers made it possible to gain up to 400 hp.
With the further development of the DB 605, its full pressure height also increased. This made performance increases above full pressure almost superfluous for use by hunters. Therefore, from 1944, the MW-50 injection became standard equipment in the Bf 109 G-14, Bf 109 G-10 and Bf 109 K-4 fighters .
These additional units were only intended for short-term use in order to achieve maximum performance (called special emergency performance) and increased stress and wear . In the war, however, this only played a minor role.
Problems
Both the introduction of the DB 605 A and the DB 605 D had problems with reliability. The newly developed DB 605 A / was due to frequent engine fires in the fall of 1942, the use of the start and emergency power of 1475 hp at 1.42 ata 2800 min -1 prohibited. The throttle position for start and emergency power was mechanically blocked. The climb and combat performance of 1310 hp at 1.3 ata / 2600 min −1 was temporarily the maximum performance . After running through various series of tests, a break in the lubrication due to the formation of bubbles in the oil was found. After improvements such as a larger oil tank and oil cooler as well as an oil slinger (to eliminate bubbles in the oil), the power limitation set for almost the entire year 1943 was lifted in autumn 1943 and the start and emergency power was released again.
The DB 605 D often had burst engines and piston seizures due to the declining quality of the B4 aircraft fuel and operation at high boost pressures. Changing the ignition timing to 5 degrees later solved the problem and, surprisingly, also reduced the problems with the spark plugs getting too hot.
Versions
DB 605 A
5.8 km full pressure height
- DB 605 A: Standard version with 1475 hp take-off power in 0 m, maximum 1550 hp emergency power in 2.1 km
- DB 605 AM: like 605 A, but with MW-50 system up to 1800 HP special emergency power in 0 m
DB 605 B
- DB 605 B: Version of the 605 A for twin-engine aircraft such as the Bf 110 and Me 210 , reduced propeller speed
- DB 605 BM: like 605 B, but with MW-50 system up to 1800 HP special emergency power
DB 605 AS
Elevation engine with 7.8 km full pressure altitude
- DB 605 AS: a DB 605 A with the large loader of the DB 603 , 1435 hp take-off power in 0 m
- DB 605 ASM: like 605 AS, but with MW-50 system up to 1800 HP special emergency power in 0 m
- DB 605 ASB: improved 605 ASM version for B4 fuel with MW-50, up to 1800 PS special emergency power in 0 m
- DB 605 ASC: improved 605 ASM version for C3 fuel with MW-50, up to 2000 HP special emergency power in 0 m
DB 605 D
7.6 km full pressure height
- DB 605 D-2: with the large loader of the DB 603, 1435 hp take-off power in 0 m
- DB 605 DM: A 605 D-2 with MW-50 system as standard equipment, up to 1700 HP special emergency power
- DB 605 DB: improved 605 DM version for B4 fuel with MW-50, initially 1850, later 1800 hp special emergency power
- DB 605 DC: improved 605 DM version for C3 fuel with MW-50, up to 2000 HP special emergency power
DB 610
two coupled DB 605 acting on a propeller shaft
- DB 610 A: right-hand rotation as port engine
- DB 610 B: Left-hand rotation as a starboard engine
The complex engine was used in the Heinkel He 177 heavy bomber and in the Messerschmitt Me 261 V3 test aircraft.
Technical specifications
- DB 605 AM
- Twelve-cylinder V-engine with hanging cylinders
- Bore : 154 mm
- Stroke : 160 mm
- Displacement: 35.7 liters
- Length 2158 mm
- Width 710 mm
- Height 1037 mm
- Dry matter: 756 kg
- Continuous output 1080 hp
- Special emergency power: 1800 HP with MW50
- Gasoline direct injection from Bosch, dual ignition
- Cooling: liquid ( glycol- water mixture as coolant )
- Lubrication: dry sump lubrication with one pressure and two suction pumps (one per cylinder head )
- Loader: a radial compressor on the left , continuously driven by a barometrically controlled hydraulic clutch. Full pressure height 5700m
Prototypes
- DB 605 BS: proposed version of the DB 605 AS for twin-engine aircraft with reduced propeller speed, not built
- DB 605 D: projected first version of the 605 D, full pressure altitude increased to 6.5 km, take-off power at 1.5 ata and 2800 rpm, 1550 hp in 0 m with C3 fuel
- DB 605 L: Elevator engine for 9.8 km full pressure altitude, DB 605 D-2 with two-stage charger, only prototypes / pre-series production, take-off power 1700 HP in 0 m with C3 fuel
See also
Web links
Individual evidence
- ↑ Dick, Patterson, Perkins, Simsa: Classic Fighter Aircraft. HEEL Verlag, 2000, p. 129, ISBN 3-89365-847-5 .
- ↑ Daimler Benz DB610. (No longer available online.) RAF Museum Cosford, archived from the original on April 3, 2012 ; accessed on January 3, 2012 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
