Modern Electrical Equipment for Industrial Diesel-Electric Locomotives

Modern electrical equipment for industrial Diesel-electric locomotives is widely different in many respects from that used five or six years ago. New and improved high-temperature insulating materials and modern synthetic varnishes have been developed and are used extensively today. Also new and improved methods of using these and the older materials have been developed. These, together with new design constants, have made possible a reduction in weight per horsepower transmitted with an improvement in the quality of the product. The Diesel engine and generator are close-coupled and mounted as a unit, thus assuring proper alignment and, at the same time, reducing the space required for mounting on the locomotive. A new and improved method of generator excitation has been developed which assures positive control of the engine speed and power. This provides a very flexible transmission of power from the prime mover to the rail. The modern traction motor has a cylindrical instead of a rectangular frame. It is a multipole instead of the conventional fourpole design. It is mounted integral with a double-reduction gear unit which is completely enclosed in an oiltight gear case. All bearings on the motor armature shaft and in the gear case are antifriction except those on the axle, which are sleeve bearings. All bearings in the gear unit are oil-lubricated with the same oil that lubricates the gearing. Both the high and low speed pinions are straddle-mounted to insure proper alignment of the gearing at all times.