A continuously variable transmission (CVT) is a type of transmission that allows an infinitely variable ratio change within a finite range, allowing the engine to continuously operate in an efficient or high performance range. A brief history of CVTs is presented, including the families under which they can be categorized. A new family of CVTs, with the classification of positive engagement, is presented. Three different published embodiments of CVTs of the positive engagement type are presented describing a meshing problem that exists apparently regardless of the embodiment in this family. The problem is called the non-integer tooth problem and its occurrences are detailed in each of the three embodiments. Specific solutions to the problem, as embodied in each case, are presented. The proposed embodiment of a new, positive engagement, continuously variable transmission is described in detail with the derived general kinematic equations of its motion. The kinematic equations for two variant embodiments are also derived. The results of the meshing analysis for this new embodiment are given and the non-integer tooth problem is exposed in three different operating conditions of the CVT. Characteristics of a solution to the non-integer tooth problem are then described, which are applicable to the positive engagement family in general.
College and Department
Ira A. Fulton College of Engineering and Technology; Mechanical Engineering
BYU ScholarsArchive Citation
Andersen, Brian S., "An Investigation of a Positive Engagement, Continuously Variable Transmission" (2007). All Theses and Dissertations. 910.
CVT, transmission, meshing