Loose wheel set
As Losradsatz or Losradpaar is at rail vehicles , the combination of two individually rotatable wheels designated together with the non-rotatable axle or axle housing.
Technical characteristics
In contrast to rigid wheel sets , the two wheel disks can rotate independently of one another, with no sinusoidal running . On the one hand, this leads to smoother running in the straight, on the other hand, depending on the equivalent conicity, the centering within the track can be lost and the wheels do not adjust themselves radially in the curves. This effect is supported by the moment of inertia of the rotating wheel, so that the wheel flanges start up more frequently without further measures. In order to avoid a too large approach angle in the track curve, the wheel sets are articulated. This can be done by passive systems such as, for example , forces mechanically transmitted from the angle between two car body parts through rods to the wheel bridges, or by active systems. Active systems use electronically controlled actuators to exert forces on the wheel bridges or to connect the idler gear sets in curves to form a rigid axle. Instead of actuators, the drive can also be used to steer loose wheel sets.
Applications
Today, loose wheel sets are mainly used in trams , where the missing axle shaft allows a lower floor. For high-speed traffic, loose wheel sets are interesting because of the greater smoothness in the straight. In addition, due to the lack of an axle shaft, it is relatively easy to build re- tracked undercarriages with loose wheel sets .
The articulated trains and high-speed trains from Talgo use loose wheel sets, with the loose wheels being mounted in an axle portal at one end of the car. In addition to the advantage of the lack of a sinusoidal run in high-speed traffic, the design is ideally suited for the construction of re- gauged undercarriages, because the individual wheels sit on separate stub axles which, together with the bearings, can be made transversely displaceable.
In the 1890s, some forest railway locomotives in the USA with idler wheel set bogies were designed according to a patent submitted by George D. Gilbert. As with automobiles, the wheels were driven by a differential gear and drive shafts running lengthways under the vehicle . It was hoped that this design would provide better arc travel, but underestimated the loss of tractive power when the wheels were spinning, as is known from automobiles with open differential gears.
Switzerland
Around 1935, the SLM built the duplex bogie with four pairs of loose wheels, which was specially built for speed tests. The idler gears had cylindrical running surfaces and were installed in the bogie with an inclination of 1:20. The design of the bogie should prevent the sinusoidal movement.
The BLS Blue Arrows, built in 1938 , had two KERFs mounted in a frame as a central bogie.
In the late 1940s and early 1950s, the SNCF and SBB used multiple units and passenger coaches with pneumatic idler bogies. The bogies came from Carel Fouché & Cie in Paris and used wheels with pneumatic tires developed by Michelin . The SBB procured a test car each in aluminum and steel lightweight construction with five-axle bogies. On both railways, the vehicles with these bogies were in operation for about ten times. After the tire supplies were used up, the cars were given ordinary bogies. The vehicles had to be extremely light for this technology, the axle load was limited to 2.5 tons.
Duplex bogie of the SLM
The two KERF bogies in the middle bogie of the BLS blue arrow
Bogie developed by Carel Fouché & Cie in collaboration with Michelin with pneumatic loose wheel sets for the SBB test cars
Loose wheel chassis
There are the following variants of loose wheel chassis:
- Single wheel single running gear (abg .: EEF ), a loose wheel set with a wheel bridge which is attached to the car body
- Curve-controlled single wheel set chassis (abg .: KERF ), a loose wheel set with a wheel bridge, which is attached to the car body and can be adjusted radially
- Single -wheel double chassis (abbr .: EDF ), two left wheels and two right wheels are each combined into a wheel block, which is connected to a bogie
Vehicles with idler wheels
- Talgo trains. The drive portals are controlled by a linkage depending on the angle between the car bodies
- Cobra tram . The drive portals are controlled by a linkage depending on the angle between the car bodies; in addition, the wheel bridges are adjusted radially by the torque applied by the drive.
- SBB tire cars and SNCF train sur pneus with pneumatic tire chassis
- BLS blue arrows with two KERF as a running bogie
- Duewag single-wheel double chassis system Fredrich. Bogie that has been technically tested up to 500 km / h
- Climax locomotives and, according to the Gilbert patent, forest railroad locomotives were built by the Dunkirk Engineering Company in New York State .
literature
- Torsten Dellmann, Basem Abdelfattah: Comparison of the dynamic properties of wheelset and idler gear pair - a theoretical contribution to an almost forgotten technology . In: ZEV Rail . tape 136 , no. 10 , 2012, p. 380-390 .
- Winfried Reinhardt: Public Transport: Technology - Legal and Business Basics . 1st edition. Vieweg + Teubner, Wiesbaden 2011, ISBN 978-3-8348-1268-1 , pp. 209–210 ( single wheel single chassis in the Google book search).
Individual evidence
- ↑ a b Patent US393896 : Proppeling gear for tram cars. Filed February 10, 1888 , published December 4, 1888 , inventor: George D. Gilbert.
- ^ A b Neil Cooney: British group develops autonomous wheel control system . In: International Railway Journal . tape 60 , no. 2 , February 2020, p. 41-43 .
- ↑ S. Dronka: Rail vehicles with active components. (PDF; 641 kB) (No longer available online.) TU Dresden , archived from the original on October 29, 2013 ; Retrieved May 5, 2013 .
- ^ Ed Vasser: History Of The Climax Locomotive. Climax Development. In: Climax Locomotives. Accessed March 11, 2018 (English).
- ^ R. Guignard: Les voitures des CFF montées sur pneumatiques "Michelin", part 1 . In: Schweizerische Bauzeitung . tape 69 , no. 12 , March 24, 1951, p. 157–162 , doi : 10.5169 / seals-58831 .
- ^ R. Guignard: Les voitures des CFF montées sur pneumatiques "Michelin", part 2 . In: Schweizerische Bauzeitung . tape 69 , no. 14 , March 31, 1951, pp. 171-174 , doi : 10.5169 / seals-58833 .
- ^ R. Guignard: Les voitures des CFF montées sur pneumatiques "Michelin", part 3 . In: Schweizerische Bauzeitung . tape 69 , no. 14 , April 7, 1951, pp. 183-187 , doi : 10.5169 / seals-58836 .
- ↑ Düwag single-wheel double chassis system Frederich. if Product Award , accessed May 5, 2013 .
- ↑ DÜWAG bogie. Retrieved May 5, 2013 .
Web links
- A. Brinkmann, T. Kasprzyk: Innovative "wheel sets" for modern low-floor rail vehicles . In: ZEVrail, Glasers Annalen Heft 131, 2007, pp. 211-223. Presentation on tram wheel sets with examples of idler wheel sets (available online at 37th Rail Vehicle Conference (2007): download the presentations )