In its largest order to date, Danish wind turbine test specialist R&D Test Systems will develop the 30 MW powertrain and gearbox test bench for ZF Wind Power’s future “Test & Prototype Center” at Lommel, Belgium, that will house the world’s most powerful validation test bench for wind turbines.
To increase cost efficiency in wind turbines, the wind industry
has seen a significant rise in power density and an increase in the overall size of geared components. Current designs for multimegawatt turbines demand levelized cost of energy (LCOE) reduction, and the gearbox is a key part of this process. Since fatigue failures nearly always occur at or near the surface, where the stresses are greatest, the surface condition strongly affects the gear life. Consequently, an improved surface condition effectively avoids major redesign or increased material cost due to an increase in part size. Additional finishing methods such as shot peening (SP) and superfinishing (SF) significantly increase the gear load capacity, but these effects have not yet been adequately considered in the current ISO 6336 standard or in any other gear standards. The combination of SP followed by SF will be described here as an “improved gear surface” (IGS).
This study deals with the modeling and consideration of misalignments in planetary gearboxes in the optimization and design process. Procedures for taking into account misalignments in cylindrical gearboxes are standardized and established in industry. Misalignments of central elements like carrier, sun gear or ring gear in planetary gearboxes, cause varying contact positions and variable loads, depending on the angular position of the central elements. This load, which is variable over the circumference, is not taken into account in the standardized procedures, despite its effects on the loads on the gears.
