Mekydro transmission
The Mekydro gearbox is a compact hydromechanical gearbox, which is mainly used in heavy diesel locomotives . The gearbox is divided into two parts: the hydraulic part with the flow converter as the dividing line between the engine and the gearbox and the mechanical part with the mechanical gearbox and reversing gear. The shift between the individual gears is implemented using several Maybach deflector claws . Mekydro gears combine the advantages of both types of gears in that they are more efficient than pure fluid gears . The switching process is much shorter than with the fluid transmission. The special feature of the hydraulic part is the sliding turbine wheel of the flow converter.
history
The first motor vehicles to be equipped with Mekydro transmissions as standard are the two DR 10 004 and 005 towing vehicles from 1937, which were equipped with the Mekydro M 21 transmission . In these vehicles, the flow converter was still connected downstream of the mechanical transmission. The outbreak of war prevented a planned larger series.
The transmissions were most widespread in the V 200.0 and V 200.1 diesel locomotives . Initially, locomotives of the V 200.0 series were equipped with purely hydraulic transmissions and the Mekydro Mekydro K184U transmission for comparison. The effort brought very good economic and operational values. The undesirable side effect was loud switching noises from the non-noise-insulated gearboxes located directly under the cab floor. This earned them the nickname Ratschbumm-Getriebe among the locomotive crews who used these locomotives. In terms of maintenance, there were no unfavorable assessments, so that the V 200.1 series locomotives were consistently equipped with Mekydro transmissions. While the V 160 series locomotives were still equipped with fluid transmissions , the DB 218 series was optionally equipped with Mekydro K 252 fluid or Mekydro transmissions .
Mode of action
The mode of action can be seen very well on the basis of the enclosed sketch. As with the fluid transmission, the vehicles are driven by the high drive with the hollow shaft, which drives the impeller of the flow converter. The turbine wheel is connected to the output shaft and drives the following pairs of ratchet wheels and the reversing gear, which are arranged on the output shaft and the adjacent auxiliary shaft. The first three shift gears are provided for shifting the gears, the last pair of gears takes over the function of the reversing gear. The gears are shifted by the two right deflector claws, the left deflector claw shifts the reversing gear. With these gear wheel pairs, it is possible to shift four gears and two directions of travel, whereby shifting takes place automatically as with hydrodynamic transmissions.
Shifting process: once the shifting point of the transmission is reached, a linkage of the Maybach deflector claw is activated via hydraulics, which reverses the selection of the relevant wheels. This can only happen if the power flow of the diesel engine is briefly interrupted. This is achieved by disengaging the turbine wheel on the flow converter. As a result, a turbine wheel with different blades enters the flow, which inhibits the power flow of the motor for a short time. This is enough time to switch all of the deflector claws for the next gear. The turbine wheel moves back into its starting position and the power transmission can continue. The turbine wheel is moved by means of pressure oil. There are various blading of the turbine wheel for upshifting or downshifting.
literature
- Matthias Maier, The V 200 series , EK-Verlag Freiburg, 2005, ISBN 3-88255-208-5
Web links
- digitized magazine with the explanation of the Mekydro gearbox
- Explanation of the Mekydro transmission on an e-book article
Individual evidence
- ^ Heinz R. Kurz "The railcars of the Reichsbahn-Bauarten, EK-Verlag 1988, ISBN 3-88255-803-2 , page 430
- ^ Matthias Maier "The V 200 Series", EK-Verlag, 2005, ISBN 3-88255-208-5 , page 385
- ^ Matthias Maier "The V 200 series", EK-Verlag, 2005, ISBN 3-88255-208-5 , page 193
- ^ Högemann, "Die V 160-Familie", EK-Verlag Freiburg, ISBN 978-3-8446-6012-8
- ^ Glatte "Diesel Locomotive Archive", Transpreß-Verlag Berlin, 1993, ISBN 3-344-70767-1
- ↑ Internet page with a sketch of the Mekydro gearbox, page 210
- ↑ Sketch of the principle of the Maybach repelling claw, page 147
- ↑ Photo of turbine wheels with different blading on page 146