MAN L 12V 17.5 / 18
The MAN diesel engine MAN L 12V 17.5 / 18 was a high-speed diesel engine from MAN for installation in fast railcars of the Deutsche Reichsbahn . In terms of numbers, it was inferior to the two-shaft engine MAN L2x6V 17.5 / 18 ; only one vehicle prior to World War II is known to be fitted with this engine at the factory. As a replacement engine, some of the engine was still built before and after the war. The exact number of engines produced cannot be clearly determined. Like the twin-shaft version , the engine had an output of 309 kW (420 hp), but its dimensions were somewhat different from the twin-shaft engine and the Maybach version , so that it could only be installed in specially manufactured machine bogies.
Structure and components
Basic structure
The engine was a pre-chamber engine and had a welded steel housing with also welded cylinders. The two rows of cylinders, arranged in a V-shape, were offset by a connecting rod bearing width so that the engines had simple connecting rods . This required a different length of the engine, and the cooler for the lubricating oil was shaped differently, so that machine bogies from Maybach-Motorenbau and the L 12V 17.5 / 18 could not be freely exchanged. The pressed-in cylinder liners were made of special gray cast iron . The oil pan in this model was made of cast steel. Production models of the engine built later had a cast crankcase .
The engine's crank drive included a case-hardened crankshaft made of special steel with seven bearings . It was mounted on plain bearings in Thermodur bearings (with a support shell made of steel and cast bronze) . Their axial forces were absorbed by a fitting bearing. The connecting rods had a double-T shape and were drop forged , they also ran on the crankshaft in Thermodur bearings , the piston pin was supported in a single row in lead bronze.
The cylinder heads were screwed onto the crankcase. They each had two inlet and two outlet valves, the cast antechamber with the screwed-in burner made of heat-resistant steel and the injection nozzle . In contrast to those of the two-shaft engine, the valves of the single-shaft engine were operated by the camshaft located in the V of the engine via intermediate levers , bumpers and rocker arms.
The engine's pistons were made of an aluminum-silicon alloy and each had four sealing rings and two oil control rings. The rings were evenly distributed above and below the piston pin. The hollow piston pin was drawn into the piston at 80 ° C (created in an oil bath) and was stuck in the piston at normal temperature. It was secured axially by circlips .
Fuel system and engine control
The engine works with pre-chamber injection . The engine had one for each cylinder side diesel injection pump from Bosch that cuts were to the engine longitudinal axis. A double diaphragm pump delivered the fuel to each injection pump. A regulator was attached to each injection pump. If one of the engine controllers failed, the diesel engine could be controlled by one controller alone. The motor was controlled according to the principle of speed regulation in five stages. The engine was started in the usual way by a starter or the main generator. It was turned off by interrupting the fuel supply by the electromagnetically operated shut-off magnet.
Cooling, lubrication and air system
The engine was water-cooled. With the first motors, the cooling water was recooled in an underfloor ventilation cooler of the Windhoff type with temperature-dependent control. In the later series engines, the recooling was done using a combined heat exchange system .
Like all large diesel engines, the engine had pressure circulation lubrication . The oil supply was 45 kg. It was sucked in from the oil pan by a gear pump and fed to the engine bearings via an oil cooler and oil filter. The engine oil was recooled by an oil cooler built into the machine frame.
The combustion air required for the diesel engine was sucked in through openings on the sides of the vehicle and flexible ducts via oil-wetted filters. The combustion exhaust gases were directed to the exhaust hood on the roof centrally above the engine.
Technical specifications
| Parameter | unit | value | comment |
|---|---|---|---|
| rated capacity | kW | 309 | 420 hp |
| Rated speed | min -1 | 1,400 | |
| Idle speed | min -1 | 700 | |
| Number of cylinders | 12 | ||
| Cylinder diameter | mm | 175 | |
| Piston stroke | mm | 180 | |
| Stroke volume | l | 51.96 | |
| Compression ratio | 18th | ||
| medium work pressure | bar | 5.22 | |
| Injection pressure | bar | 180 | |
| highest ignition pressure | bar | 62 | |
| Fuel consumption | g / PSh | 198 | |
| Oil supply | l | 45 | |
| Cooling water supply | l | 35 | |
| Engine ground | kg | 2,900 | with accessories |
| Motor length | mm | 2,100 | |
| Engine width | mm | 1,118 | |
| Engine height | mm | 1,610 | |
| Material for crankshaft | St 29 | ||
| Material for connecting rod | VCN 15 | ||
| Material for pistons | KS 1275 | ||
| Material for cylinder liner | Special gray cast iron | ||
| Material for motor housing | steel | later cast steel |
Vehicles equipped with the engine for delivery
Only the VT 137 100 was equipped with this engine from the factory. However, in some cases the engine was mentioned as a replacement engine for other prime movers.
Operating experience
Mileage over 100,000 km is specified for the engines. Around 1951 major problems arose when operating with railcars and MAN engines that only made it possible to use a MAN single-shaft engine.
literature
- Heinz R. Kurz: The railcars of the Reichsbahn-Bauarten , EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2
Individual evidence
- ↑ a b Heinz R. Kurz: "The railcars of the Reichsbahn-Bauarten", EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2 , p. 301
- ↑ Heinz R. Kurz: The railcars of the Reichsbahn types . EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2 , p. 311
- ↑ Use of the old VT 33.2 multiple unit at the Deutsche Bundesbahn on the homepage of the Bielefelder Eisenbahnfreunde e. V.
- ↑ Heinz R. Kurz: The railcars of the Reichsbahn types . EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2 , p. 282