Map / envelope based design process of the planetary roller screw

Electro-Mechanical linear actuators have received recent attention for the aircraft control surface systems to eliminate hydraulic systems from aircraft. This approach is intended to improve reliability, safety, efficiency, and maintainability. For linear actuators, one of the most important components is the planetary roller screws (PRSs). The planetary roller screw (also called the satellite roller screw) is a mechanical transmission device, which converts rotational motion to linear motion or vice versa. The mechanism of planetary screw is similar in principle to the conventional ball screw mechanism (BSM). PRS has been receiving attention in lots research and industry, however, it is hard to produce high-quality PRS transmissions, because it is difficult to determine the PRS parameter relationship among all its components and hard to build visual maps for rapid design. The main objective of this research is to provide the parametric relationship between components to build design maps. Developing a visual design process for PRSs is the primary goal. In order to understand contact geometry and relative motions in the PRS, an exact PRSs structure is presented, as well as its parameter analysis. Then the parameters are tested to identify how the parameters affect the PRSs requirements such as load distribution, stiffness, dynamic load capacity, and force density as key measures for the visual design process. One of the key impacts of this research is the utilization of design procedures to build sets of 3-D design maps. These maps and design procedures are helpful to manage parameters to quickly build optimal PRSs dimensions for designers. Each measure has its own parameters. Some of these parameters are fixed constants and others can be set by designer. As variables, the parameters are classified into two types. Ones are primary parameters that have large impact on the mapping and design process and others are secondary parameters that have minor impact. Any set of parameters is given in accordance with each set of 3-D maps and they can be adjusted to generate new visual 3-D maps by designer. Then the designer can reviews the 3-D mapping results, he or she can then quickly decide the effect of first design decision and adjust updated parameter choices to get new maps. This helps the designer to optimize dimensions of PRSs and determine the best solution for application requirements by this design process. Overall, the whole design process accelerates quickly reaching the design goal for the designer