Diesel hydraulic drive
In diesel-hydraulic power transmission , the mechanical energy released by a diesel engine is hydraulically transferred to machinery. The diesel-hydraulic drive is often used in locomotives and ships because a diesel engine cannot be started under load. The hydraulic gear is also a reduction gear , since the speed of the diesel engine is usually above the required speed on the wheel circumference. It is also used to balance the speed between two driven bogies when their wheel diameters no longer match one hundred percent due to wear.
With torque converter
In this type of drive, a fluid transmission based on the Föttinger principle is used as the transmission medium. In the early days of gearboxes, water was often used, but today hydraulic oil is used. A torque converter is always required to start up ; at higher speeds, a fluid coupling or another converter is used depending on the power to be transmitted .
Hydrodynamic transmissions were developed by Voith . The year 1932 is considered to be the date for the first hydrodynamic gearbox. It was used particularly in operating situations where a diesel-electric drive is too expensive, but a diesel-mechanical drive has operational disadvantages, e.g. B. when maneuvering .
After the use of hydrodynamic gears in some shunting locomotives and railcars , this type of drive was only used on the DR V 140 001 before the Second World War , after that the diesel-hydraulic drive became established in German main-line locomotives of the DB series V 200.0 (see also: Mekydro- Transmission ) and is z. B. also used in the 612 series, a tilting technology multiple unit built in large numbers .
The components for a diesel-hydraulic power transmission generally have a lower overall weight than those for a diesel-electric power transmission and are also cheaper. In the case of a direct comparison between vehicles with the same body, the electrical standard railcar and hydraulic standard railcar , the hydraulic variant is a good 1,000 kg lighter. On the other hand, there are some operational disadvantages; the diesel-electric drive has a simpler structure and has the option of clearing the route with emergency battery operation in the event of an operational malfunction. Vehicles with electric power transmission also have operational advantages on steep slopes. Compared to the diesel-mechanical drive , the diesel-hydraulic drive was easier to operate, especially when starting up, in the early days of its development, but has a lower degree of efficiency , which led to the use of the Mekydro transmission ( DB series V 200.1 ) and, more recently, the differential converter transmission ( Stadler Regio-Shuttle RS1 ).
With hydrostatic transmission
Another design of the diesel-hydraulic drive works with a hydrostatic transmission . The power transmission is carried out by the force of an oil pressure . The diesel engine drives a hydraulic pump , which in turn drives a hydraulic motor or hydraulic cylinder . This allows a spatial separation of the hydraulic pump and hydraulic motor. This type of drive is used in loading / unloading pumps in shipping, in crane systems and construction vehicles. The hydrostatic power transmission was ready for series production even before the hydrodynamic power transmission in industry. As early as 1924, locomotives with hydrostatic power transmission were presented at the International Railway Exhibition in Seddin , but these could not gain acceptance after the advent of the hydrodynamic transmission.
Later, hydrostatic transmissions were only used to drive auxiliary drives with low power, such as vehicle components for cooling water fans ( DB series 628 ), construction machinery and agricultural machinery (e.g. combine harvesters ), wherever the spatial separation of hydraulic pump and hydraulic motor was structurally necessary is. The poor efficiency of the drive type must be taken into account.
- Wolfgang Messerschmidt: Locomotive technology in the picture - steam, diesel and electric locomotives . Motorbuchverlag Stuttgart, 1991, ISBN 3-613-01384-3 , pp. 121-125.
- Website about the hydrodynamic drives of the DR 137 155 | SVT Kruckenberg
- Website about hydrostatic drive options
- Website about a hydrostatic boat drive
- Website about drives in railway vehicles with mention of hydrodynamic power transmission
- Website about the Voith Maxima with hydrodynamic power transmission
- Wolfgang Messerschmidt: Locomotive technology in the picture - steam, diesel and electric locomotives . Motorbuchverlag Stuttgart, 1991 ISBN 3-613-01384-3 ; Pp. 121–125, page 122
- Heinz R. Kurz (Ed.): Flying trains. From the “Flying Hamburger” to the “Flying Cologne”. Eisenbahn-Kurier Verlag, Freiburg im Breisgau 1986, ISBN 3-88255-237-9 ; Page 176
- Glatte / Reinhardt Diesel Locomotive Archive , transpress-Verlag Berlin, 1993, ISBN 3-344-70767-1 , page 30
- Heinz Kurz: The railcars of the Reichsbahn types. EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2 , p. 347.
- Heinz R. Kurz: The railcars of the Reichsbahn types . EK-Verlag, Freiburg 1988, ISBN 3-88255-803-2 , p. 292.
- Glatte / Reinhardt Diesel Locomotive Archive , transpress-Verlag Berlin, 1993, ISBN 3-344-70767-1 , description of the V 3602
- Description of the shunting locomotives with hydrostatic drive ( memento of the original from November 23, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.