Parameter Optimization of Two-Speed Manual Drive with Automatic Speed Change for Stop Valves

A flexible shaft planetary gear drive for valve actuators, providing automatic gear shifting based on load, is proposed. The design features two wheels providing internal engagement having a small difference in the numbers of their teeth, along with a leading carrier, an angular clutch and a flexible element made either in the form of a rod having the same section or a beam of equal resistance. Calculations showed that a flexible rod having the same cross section implies a 40–50 % increased length relative to a rod having the form of a beam of equal resistance; this has significant implications for the mass and dimensional characteristics of the drive.