Coupling rod

Coupling rod (center of picture, black out) between the two driven wheel sets of the steam locomotive S 2/6

Drive of a shunting diesel locomotive with coupling rods in connection with a jackshaft

A coupling rod is a machine element in rail vehicles that can be subjected to tensile or compressive forces. The application covers the following areas:

Drive element

In traction vehicles with a common rod drive of two or more wheel sets , a coupling rod connects the crank pins of the wheels with one another in such a way that the drive force is transmitted to all axles at the same time. Apart from the so-called geared locomotives and locomotives with single-axle drive via steam engines on each drive wheel set, coupling rods were always used in steam locomotives with several driven wheel sets. The wheel sets connected to one another via these were called coupled axle (s).

In the first designs of diesel and electric locomotives with rod drive, the drive machine either acted directly on a drive axle and from there via the coupling rods on the other drive axle (s) (see e.g. Deutz OMZ 122 R ) or else on a jackshaft , from which the driving axles are driven via (driving and) coupling rods (e.g. in the V 36 , V 60 or E 63 series ).

Coupling rods were also used in some railcars (e.g. various VT 137 ).

Connecting element

Coupling rod between a Unimog 406 and a freight wagon

Coupling rod also denotes an auxiliary connection of railway vehicles in cases where the existing couplings cannot be used. The tow bar fulfills a similar function in automobiles or other vehicles , but is only used in the event of an accident . For example, a coupling rod is used in the following cases:

For the connection between auxiliary vehicles or between auxiliary and control vehicles.
As a connection between loaded trolleys or trolleys and between trolleys and other narrow-gauge wagons or locomotives.
When maneuvering individual tenders without a regulating clutch.