Generalized Equations for Sprag One-Way Clutch Analysis and Design

In 1997, Chesney and Kremer wrote a paper entitled Generalized Equations for Roller One-Way Clutch Analysis and Design [1]. The paper explained both the static and dynamic behavior of roller One-Way Clutches (OWC), and described the practical application of esoteric stress equations to the design of roller OWCs. This paper offers a similar analysis of another member of the one-way clutch family, namely Sprag one-way clutches. Sprag one-way clutches are clutches that freewheel in one direction, but transmit torque due to the geometry of the sprag, when the races are rotated in the opposite relative direction. Specifically, the paper discusses the theory of operation, equilibrium equations, system deflections, system stresses, and dynamic behavior of a sprag one-way clutch. The paper derives and explains the fundamental equations in terms of dimensionless units, in order to enable the use of either English or metric units.