Infinitely variable epicyclic transmissions

Abstract

An infinite variable transmission with input shaft (52), planetary carrier (28), planetary pulleys (36) and planetary gears (32) with planetary axles (30) equiangularly disposed on the carrier (28). Variable pitch pulley (41) adjust a serpentine belt (38) which adjust the rotation of the planetary gears (32) to adjust the output shaft (20).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of the filing of U.S. Provisional Patent Application Ser. No. 60 / 095,596, entitled “Continuously Variable Transmission”, filed on Aug. 6, 1998, and the specification thereof is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention is generally concerned with power transmissions, particularly continuously variable transmissions, and more specifically transmissions for use in rotational machines requiring continuous, infinitely adjustable output speed and output torque while maintaining nearly constant rotational speed of the input prime mover.[0004]2. Background Art[0005]A continuously variable transmission suitable for automotive applications has been sought for nearly a century. It has even longer been recognized that pedal-driven vehicles would operate most efficiently if the propulsive ground wheel rotational speed were varied such that the inp...

AI Technical Summary

Benefits of technology

[0020]Several embodiments of the invention are described in this application. These are all capable of continuously varying the output speed and torque through forward, neutral, and reverse while the input shaft remains constant in rotational speed and direction. Each of the devices share: 1) the highly desirable features of compactness of both width and diameter; 2) use of efficient epicyclic gear components to achieve the infinitely variable gear-ratio feature; 3) integral features allowing the direct, independent speed control of the planetary elements driven from the input shaft; 4) coaxially aligned input and output shafts; and 5) a relatively small number of components for inexpensive, reliable manufacture.

[0022]The second means relies nether on belts nor chains for speed control, employing instead a set of tapered split races, coaxially aligned with the input and output shafts, that provide traction and position control to rollers mounted on swing arms coaxially aligned with each of the planetary gears and attached to the planetary carrier. Control means are provided to move the split tapered races relative to each other in axial extent which, by means of mating rollers and planetary moon gears meshed with each planetary, controls the speed of the planetary gears. The design allows for very high torques to be transferred to the output shaft throughout a wide range of speed variation by virtue of the addition of more swing arms and planetary elements providing for multiple points of engagement between rollers and races, as well as the positioning of the arms so that self locking between the rollers and races occurs as the output torque increases.

Problems solved by technology

The chain drive permits significantly higher torque applications than the endless belt version, but is not continuously adjustable (rather is incrementally adjustable to integer values of the chain pitch).

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