### Projects (1999 - Spring 2008)

Engineering >> Mechanical Engineering

## by Andrew Erhart

Submitted : Spring 2015

Three traces were given and the cubic mean load was asked to be calculated for one of them. The cubic mean load relates to the life of a roller screw, or bearing. A roller screw also goes by planetary roller screw and satellite roller screw. It is a light friction, precise actuator used for turning rotational motion into linear motion or rather linear motion into rotational motion. The cubic mean load of a roller screw varies with the inverse of the load cubed. Thus, given three plots of load versus position, to calculate the mean load, the life value must be cubed then multiplied by x. From there, the values must be summed then divided by the sum of the x values, which equates to the total amount of motion. Finally, the cube root must be taken to ultimately obtain the cubic mean load. Continuing on, with a varying load that equals a cubic mean load of “Fm,” the life of the roller screw is determined.