Bearing specialist NKE Austria has developed a modular bearing system for planetary gears in wind turbine gearboxes. The modular concept is based on single-row cylindrical roller bearings of the company’s RN range, which do not have an outer ring. These bearings are equipped with a one-piece solid brass cage, which is guided by the inner ring. Inspection grooves allow endoscopic inspections of the inner raceways. These single row bearings can be assembled as sets of two, three, or four bearings to conform to a design’s load and parameters. The system is already in use in the 1.5, 2, and 2.5-MW wind turbine gearboxes from a well-known German manufacturer.
The bearings come in ready-to-install matched sets. The tightly toleranced overall height of each individual bearing and their precise matching ensures an even distribution of radial loads. Each bearing set includes the components required to secure the bearings axially in the planetary gears – such as retaining rings and loose rib rings. If required, the overall width of each bearing set can be adapted to the operating conditions and the available space with spacer rings fitted between the individual bearings.