PREPRINT — Paper was presented at the Western Michigan Section of the Society of Automotive Engineers at Muskegon, Michigan on October 20, 1953. Subject to revision. permission to publish this paper, in full or in part, after its presentation and with credit to the author and the Society, may be obtained upon request. The Society is not responsible for statements or opinions advanced in papers or discussions at its meetings. OPERATING ADVANTAGE AND USAGE OF ALLISON TORQMATlC CONVERTERS By J. W. CROOKS Allison Division of General Motors Corporation SOCIETY OF AUTOMOTIVE ENGINEERS, Inc., 29 West 39th Street, New York 18, N.Y. Downloaded from SAE International by University of Leeds, Monday, September 24, 2018Downloaded from SAE International by University of Leeds, Monday, September 24, 2018OPERATING ADVANTAGES AND USAGE OF ALLISON TORQMATIC CONVERTERS The Allison Torqmatic Converter is basically a hydraulic transmission which automatically and infinitely varies torque multiplication as high as 3.6:l depending on load requirements. At loads equal to or less than engine torque, the Torqmatic Converter automatically operates as a fluid coupling which enables trans­ mission of efficient cushioned power throughout the high speed range. Present field interest in converter application to industrial equipment is centered around putting to use the converter's basic proven advantage which is the ability to get more work done at decreased operating expense. Manufacturers of both mass volume and specialty produced equipment generally feel there are three ways to gain these advantages: 1. Use the converter in presently designed equipment to be able to do more work in a specified period of time. 2. Use the converter to get a present equivalent amount of work out of lower cost equipment through design of space saving more lightly stressed drive components and use of lower horsepower engines. 3. Use the converter to provide maximum equipment handling ease by simplifying the operator's work requirements. This can be done in conjunction with either of the first two methods and indirectly re­ sults in increased equipment ability. The major reason why converter equipped machinery can do more work is that, because of the automatic torque multiplying feature, the output horsepower is held closer to the maximum horsepower available throughout the whole working portion of the speed range. There is no sudden drop off of horsepower in the working speed range as speed decreases. There are other contributing factors which tend to decrease time required for equipment with converters to do a specific job such as higher equipment availa­ bility due to fewer required overhauls and reduction of operator skill required. Also, there are other design advantages than those directed toward reducing costs such as easy adaptation of twin engine or tandem engine drive components and ease of load control never before possible in equipment of equivalent cost. The major equipment to which converter application has been made with highly successful results ares Power Cranes and Shovels Locomotives Off-Highway Trucks Tractors Logging Equipment Material Handling Vehicles Oil Field Equipment Other equipment which could prove to benefit by converter application and require its usage more than is generally known to date are: On-Highway Trucks Commuter Carriers Downloaded from SAE International by University of Leeds, Monday, September 24, 2018Downloaded from SAE International by University of Leeds, Monday, September 24, 2018- 2 - Road Rollers Loaders Motor Graders Farm Machinery There are three main reasons why converters have not been more universally accepted to date in industrial equipment of all sizes. These include: 1. Natural public resistance to change. 2. Incomplete understanding of factors affecting converter application. 3. Due to comparatively low volume, the higher first cost has restricted its use to