Beugniot lever
The Beugniot lever is a mechanical component in some locomotives that is used to improve cornering. It was named after its inventor, Édouard Beugniot .
In around 1860, as chief engineer at André Koechlin & Cie in Mulhouse, Alsace, Beugniot developed a system in which the four wheel sets in the vehicle frame can each be laterally displaced, but the two front wheel sets are coupled in opposite directions by a two-armed lever. In the middle of the two rear wheelset axles, too, such a Beugniot lever engages in a form-fitting manner on the side, which is mounted in its middle around a vertical axis of rotation in order to keep these displacements counter-balanced. The vehicle is centered laterally along the two pivot axes, the distance between them forming the guide length of the vehicle.
The four wheelsets are shifted in such a way that all wheelset centers are close to the track center by lateral managers of the track driving shoulder on the wheel flanges.
Because their axes remain parallel and at the same distance from each other , rod drive via coupling rods is possible, but the coupling pins on the wheels must be designed to be correspondingly long in order to allow different lateral movements of the individual wheel sets with respect to the coupling rods.
The managers of the track on the vehicle are distributed more evenly on all axles via the levers, which reduces the wear on the wheel flanges. The transverse mobility of the wheelsets eliminates the need for wheel flange and back weakening, which is otherwise common in locomotives with rigid frames for the purpose of restraint-free running in switches, curves and narrow track curves. The guide length of the locomotive is determined by the distance between the two fixed pivot points.
Wheelsets, in pairs on bogies , cling to curved tracks much better because they can also twist, but not completely because they remain parallel in pairs, for example in the direction of the track radius at the location of the bogie axis. On vehicles with a very long wheelbase, the ability to rotate due to bogies is a great advantage; on short, the advantage disappears so much that the structurally simpler solution of lever-coupled axle displacement is sometimes preferred.
In Germany, Beugniot levers were mainly used in the middle of the 20th century. The best-known examples of this are probably the MaK rod locomotives and the BR 105 and 106 of the DR, but these levers were also used in steam locomotives such as the DB class 82 .
See also
swell
Operating and maintenance instructions for the MaK series 600 D , 650 D and 1200 D
Web links
Keyword: Beugniot - explanation with principle sketch (below on the linked page)