Theoretical Reviews on how to Improve the Degree of Efficiency on Power Screws
Proceedings of the 16th International Research/Expert Conference „Trends in the Development of Machinery and Associated Technology” TMT 2012, page 511-514. Dubai, United Arab Emirates, (2012)Abstract
A frequently repeated machine element in almost every mechanical design, regardless of the field of use, is the power screw (leadscrew). It`s main purpose is to transform rotary motion into linear, and vice versa, whereat the last mentioned option is rarely used since self-locking of the power screw is no longer provided. Every machine element has different advantages and disadvantages but all come together in one unique technical parameter which is valid for every machine, the degree of efficiency. Irrespective of many advantages power screws have, it`s wider use in other applications is restricted due to it`s low degree of efficiency. This paper should give some theoretical proposals on how to increase the degree of efficiency on power screws. Authors present several ways to increase the degree of efficiency by starting to increase the pitch, changing the thread geometry (profile), assuming a lower coefficient of drag, using multi-start screws and finally giving a suggestion which includes a combination of some mentioned solutions. It is important to emphasize that all mentioned suggestions are solutions through out the design of power screws, not considering tribological phenomenons like coefficient of drag or used material.