Generators and Motors for Gas-Electric Motorcoach Drive 280067
ELECTRIC transmission is being applied to motorcoaches because of certain advantages which it has over mechanical transmission, such as increased acceleration, easier driving, smoother operation, and greater freedom in the arrangement of the units.
The paper relates principally to the performance characteristics and design features of some of the motors and generators used for this purpose. The speed-torque and electrical characteristics of the generators and motors are described, both separately and as related to the engine performance and the speed and tractive effort requirements of the vehicle. The efficiency is compared with that of the mechanical transmission, and methods of electric braking are described.
Important mechanical requirements for the motors and generators are discussed, and methods of mounting for both the single and double-motor types of drive are illustrated. Advantages of the electric transmission as compared with the mechanical transmission are listed, and it is pointed out that the gas-electric type of drive may play an important part in the present tendency toward a vehicle arrangement in which the engine is placed elsewhere than at the front.
This paper was presented at meetings of the Pennsylvania, Detroit and Chicago Sections, and the oral and written discussion at all three meetings is appended. It includes the views of the representatives of other manufacturers of electrical equipment, of engine builders, and of builders and operators of motorcoaches. Similar transmissions for taxicabs and private passenger-cars are discussed, and data are given on the relative cost, durability, availability and general desirability of electric and mechanical transmissions, with reasons for the views expressed.
Opinion seems to be general that the electric transmission is economically desirable for city use, where stops are frequent, while those who expressed themselves regarding interurban routes considered the additional cost and weight unwarranted for service on them.