engleski

Possibilities for the Application of Reversible Planetary Two-Speed Gearboxes

Planetary gear trains (PGTs) present an improvement in relation to conventional gear trains, as several transmission ratios may be achieved by providing links between different elements of the component, and the transmission ratio can be varied under load by means of a brake or friction clutch acting on a PGT component. It is known that ships and boats must be able to perform a crash stop without stalling the engine or damaging the transmission, and rail vehicles have to go in both directions at the same speed while developing the same tractive effort. PGTs for this application must provide two equal transmission ratios, however with the output shaft rotating in different directions. This paper deals with two-carrier, two-speed PGTs having two coupling shafts and four external shafts, designed in a way to be able to change gears under load. A method to quickly determinate the structure and basic parameters of two-speed planetary gear trains that meet the application demands is presented in this paper, followed by an overview of the computer program DVOBRZ purposefully developed for this matter. A numerical example is provided, complete with an overview of the shifting capabilities of the studied PGTs.

marine reduction and reverse gearbox ; mechanical power transmission ; planetary gearbox ; railway vehicle transmission

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