Westinghouse spring drive
The Westinghouse spring drive ( quill drive ) is a torsionally flexible power transmission between the electric traction motors and the drive wheel set of an electric locomotive . The design is named after the Westinghouse company that developed this drive for the New York, New Haven and Hartford Railroad until 1912 as a competitor to General Electric's rubber buffer power transmissions . It is no longer used today because it is technically obsolete.
In contrast to the paw-bearing drive , the traction motor is completely cushioned. This saves the route, but also the drive motor, because it is not exposed to the impacts of the rail joints and allows higher speeds because the wheelset is the only unsprung mass of the drive.
The Westinghouse spring drive is a hollow shaft drive whose torsionally flexible coupling between the drive motor and the wheelset reduces the tendency to skid (spinning of the drive wheels) during the approach. This is particularly important in vehicles with single-phase direct motors , because there a torque component pulsating at twice the mains frequency promotes the skid process.
construction
The wheelset shaft is enclosed by a hollow shaft that is firmly mounted in the housing of the traction motor. This can be designed as a single motor or as a twin motor . The large wheel , which is driven by the pinions of the traction motors, is pressed onto the hollow shaft . The hollow shaft is connected via coil springs with the spokes of the driving wheels , respectively. The claws on the hollow shaft are attached in such a way that when the direction of travel remains the same, the springs are subjected to tension in one wheel and compression in the other.
The drive can only be carried out if the drive wheels have a sufficiently large diameter to accommodate the springs. Overstressing such as skidding can break the springs.
Further developments of the Westinghouse spring drive:
Applications
The following locomotives are with Westinghouse spring drive u. a. equipped:
PRR GG1 - drive with two large wheels on the hollow shaft
Individual evidence
- ^ Hans-Peter Bärtschi: Electric locomotives from Swiss factories . In: Verkehrshaus der Schweiz (Ed.): Coal, electricity and rails . The railroad conquers Switzerland. Verlag NZZ, Zurich 1998, ISBN 3-85823-715-9 .