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A Geared Infinitely Variable Transmission for Automotive Applications
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1991 by SAE International in United States
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Epilogics, a young engineering firm in Los Gatos, CA, has developed the first fully-geared, high torque, high efficiency, infinitely variable transmission (IVT) suitable for automotive applications. To prove its torque capacity, Epilogics demonstrated a prototype of its patented transmission concept in a Class VII diesel truck in June, 1989. In addition to being ideally suited as a transmission for motor vehicle drivetrains, the IVT can provide a means to efficiently and flexibly drive engine accessories independently of engine speed. Products have already been designed or built to drive alternators at a constant speed (irrespective of engine/vehicle speed) and to control cooling fan speeds independently of engine/vehicle speed. Outside of automotive applications, experimental designs of automatically adjusting manual sailboat winches and continuously variable bicycle transmissions have been implemented. Under normal operating conditions, the efficiency of the Epilogics transmission exceeds 90% as derived mathematically and corroborated experimentally. The device does not rely on traction to transmit torque and can therefore match the torque capacity of any typical gear drive. The size, weight, and cost of the device closely approximates that of a four-speed manual transmission.