Maybach MD 650

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MD 650
Production period: 1950s
Manufacturer: Maybach
Working principle: diesel
Motor design: 60 ° -V12
Valve control: OHV
Displacement: 64,513 cm 3
Mixture preparation: Pump nozzle
Engine charging: Maybach AGL 123
Power: 883 kW
Previous model: none
Successor: none
The best known locomotive with an MD 650 engine was the DB class V 200.0
Also equipped with MD 650: the express railcars of the DB class VT 11.5

The Maybach MD 650 engine was a high-speed diesel engine from Maybach-Motorenbau GmbH , which became known through its installation in the DB series V 200.0 . The engine is part of a series of diesel engines in the power classes from 300 to 2200 HP, which was designated as the MD series and was used in numerous diesel locomotives in Europe. The engines of the MD series are emblematic of the replacement of steam locomotives by diesel locomotives with high-speed diesel engines. The series was developed as a further development of the tunnel motors with numerous improvements for running and maintenance and was created according to a modular principle in which each cylinder delivers an output of 100 hp. The engine is now called MTU 12V 538.

history

After the tunnel engines had proven their operational safety in everyday operation, the German Federal Railroad planned to replace steam with diesel locomotives from the 1950s onwards. This was only possible through the provision of corresponding engines in different performance classes. Initially, the engine was used as a 12-cylinder V-engine (angle between the cylinder rows 60 °) with an output of 970 kW based on the GTO 6 for the drive equipment of the DB series V 80 , one year later it was used for the DB series V 200.0 was used, where it achieved the greatest popularity.

Structure and components

The engine block, the disc crankshaft and the bearing of the crank drive are the same in the engine as in the tunnel engines. Changes arise in the design of the pistons , cylinder heads , valves and the replacement of the diesel injection pump with individual injection nozzles .

In order to achieve a higher thermal load on the pistons than on the tunnel engines, they were additionally cooled. This was done in such a way that the cooling oil required for cylinder cooling was pressed into the piston, bypassing the crankshaft, passed through the space between the piston and the piston crown and provided additional cooling on the cylinder liners, especially in the area of ​​the piston rings . Before the oil was added to the cooling circuit again, it was re-cooled in a heat exchanger . The piston head was screwed onto the piston and could be removed from the piston. All piston rings were placed in the removable piston crown. This had the additional advantage that the piston ring could be exchanged without dismantling the crank drive. With this design, there was never any metallic contact between the pistons and the cylinder liners. In addition, the diameter could be increased to 185 mm.

Compared to the tunnel engines, the number of valves has been increased to three inlet and outlet valves. This enabled the valves to be designed with a smaller diameter. They were placed in a ring in the cylinder head and these changed according to the diameter and the valve diameter.

The biggest changes resulted from changing the injection unit . Instead of the diesel injection pump still used in the tunnel engine with its long lines to the cylinder heads, the MD series engines used injection valves for the first time , which were developed in collaboration with the L'Orange company . This enabled the ignition timing to be regulated much more reliably. The usual pressure lines could be avoided. Each injection unit was controlled by a rocker arm located on the camshaft , which also contributed to increasing the reliability of the injection unit.

Further changes concerned the engine control, in which the system of the overhead camshafts previously used was retained and the engine regulation in the form of a centrifugal pendulum controller.

Technical specifications

Technical specifications:

Parameter unit value comment
rated capacity kW 883
Rated speed min -1 1,500
Idle speed min -1 600
Cylinder diameter mm 185
Piston stroke mm 200
Stroke volume cm³ 64,513 entire engine
Compression ratio 15.5: 1
Combustion chamber content cm 3 130 per cylinder
Liter output kW / l 13.7 at nominal power
Control time: inlet valve opens ° VOT 45
Control time: inlet valve closes ° NUT 54
Control time: exhaust valve opens ° vUT 70
Control time: exhaust valve closes ° NOT 40
Number of piston rings 3
Number of oil control rings 2
Injection device 12 pieces of L'Orange
Amount of heat to be dissipated in the cooling water kJ / h 1,966,480
Amount of heat to be dissipated in the lubricating oil kJ / h 418,400
Amount of heat to be dissipated in the piston oil kJ / h Contains lubricating oil in the amount of heat
Main dimensions greatest length mm 2,235
Main dimensions greatest width mm 1,400
Main dimensions total height mm 2.140
Main dimensions height above crankshaft center mm 1,505
Main dimensions depth below the center of the crankshaft mm 635
Oil supply l 120 Minimum 60 l
Engine ground kg 4,600 with accessories, without supplies
Exhaust gas turbocharger Maybach AGL 123
Rated speed exhaust gas turbocharger min -1 13,000
Exhaust gas turbocharger, greatest boost pressure bar 0.78

Vehicles equipped with the engine for delivery

In addition to the series mentioned, the engines of the MD series were used in the diesel locomotives of the V 100 series , the express railcars of the VT 08 series and the VT 11.5 series express railcars . They were also used on numerous Krauss-Maffei export orders . The ML 4000 CC of the Denver and Rio Grande Western Railroad had the engines of the MD 870 series.

Operating experience

Since the everyday heavy train service with the frequent load changes in constantly changing uphill and downhill sections places different demands on the prime movers than the railcar operation, technical problems were not absent in everyday operation. These were primarily caused by structural problems and, to a lesser extent, by design errors.

In Maybach engines , oil leaks and cooling water problems were cited as sources of error. The main problems were to be found in the structure of the selection of engines for the locomotives. The industry had offered the engines with too high a nominal power, which was determined on the test bench. American locomotives with their slow-running engines were only offered with an output that was 25 to 30% below the nominal output determined in the test bench. It should be understood that the engines were exposed to significantly lower loads and ran more reliably, with the different engine speeds only being considered secondary. The DR series V 75 as a shunting locomotive, the ČSD series T 478.1 in the performance class between the V 100 and V 200.0 and the NOHAB with only one drive system were considered very reliable; Their internal combustion engines were manufactured to American standards, while German locomotives were happy to have the second drive system as a fault reserve . The other climatic conditions between the test bench and the harsh everyday operation should not be underestimated. In addition, the type range of diesel locomotives in the USA was only considered of secondary importance, so that there were enough reserve machines for different train loads in the USA, while in Germany the locomotives were clearly overwhelmed at peak loads. Engine damage in the V 200.0 with MD 650 occurred after an average of 94,000 km. This value was clearly undercut on journeys in which the diesel engine was operated at full load for a long time . These are values ​​that have been clearly surpassed by US diesel locomotives. This was the reason why the ML 4000 CC was unsuccessful in the USA . It was not until the development of the DB class 218 in 1967 that American experience was fully applied in Germany. These locomotives should get by with one drive motor for peak loads.

Variants of the engine design and further developments

In addition to the MD 650, engines of this type series were known as 16-cylinder V-engines with an output of 1680 kW in the pre-production locomotives of the V 160 series with the designation MD 870.

Other engine types in this series were

  • the four-cylinder in-line engine with the designation MD 215 and an output of 220 kW,
  • the six-cylinder in-line engine with the designation MD 320 with an output of 367 kW,
  • the six-cylinder in-line engine with the designation MD 325 and an output of 440 kW,
  • the eight-cylinder V-engine with the designation MD 430 and an output of 485 kW,
  • the eight-cylinder V-engine with the designation MD 435 and an output of 587 kW and
  • the twelve-cylinder V-engine with the designation MD 645 and an output of 661 kW.

The engine group was further developed by the engine group TB 10, TB 11, known from its use in the DB class 218 .

literature

  • Harry Niemann: Karl Maybach, his engines and automobiles . Motorbuchverlag, Stuttgart 2004, ISBN 3-613-02457-8 .
  • Maybach Motorenbau GmbH: Diesel engines of the MD tunnel design . Maybach-Motorenwerke, Friedrichshafen 1955.
  • Mathias Maier: The V 200 series . EK-Verlag, Freiburg 2005, ISBN 3-88255-208-5 .

Web links

Individual evidence

  1. ^ Photo of the MD 650 on the MTU report
  2. ↑ Internet page about the MD 650 motor
  3. ^ Harry Niemann: Karl Maybach, his engines and automobiles . Motorbuchverlag, Stuttgart 2004, ISBN 3-613-02457-8 , type series page 186.
  4. ↑ Maybach Motorenbau GmbH: Diesel engines of the MD tunnel type . Maybach-Motorenbau GmbH, page 7.
  5. ↑ Maybach Motorenbau GmbH: Diesel engines of the MD tunnel type . Maybach-Motorenbau GmbH, page 9.
  6. ↑ Maybach Motorenbau GmbH: Diesel engines of the MD tunnel type . Maybach-Motorenbau GmbH, page 10.
  7. ^ Mathias Maier: The V 200 series . EK-Verlag, Freiburg 2005, ISBN 3-88255-208-5 , page 28.
  8. ↑ a b c Completely different . Eisenbahn-Kurier 11/2014, EK-Verlag, Freiburg, page 65.
  9. ↑ Completely different . Eisenbahn-Kurier 11/2014, EK-Verlag, Freiburg, page 66
  10. ↑ Completely different . Eisenbahn-Kurier 11/2014, EK-Verlag, Freiburg, page 67.
  11. ↑ Completely different . Eisenbahn-Kurier 11/2014, EK-Verlag, Freiburg, page 61.
  12. ^ Harry Niemann: Karl Maybach, his engines and automobiles . Motorbuchverlag Stuttgart 2004, ISBN 3-613-02457-8 , type series page 186.