The Schaeffler Group is inventing a new paired FAG bearings solution for wind turbine rotor shafts. With the new approach, Schaeffler said it is addressing the key limitations of the current solution, which is a pair of spherical roller bearings.
Schaeffler's solution is to deploy two different bearings to support the rotor shaft. Rather than sphericals for both, a different design is deployed for each function -- shaft location and axial motion control.
The locating bearing unit employs a pair of tapered roller bearings, which can be set up with very tight clearance to allow only minimal axial motion. Tight clearances reduce displacement, cut vibration, and even out the load distribution across the bearings, for a longer service life. With that design, even high axial forces and low speeds do not produce lateral sliding against the races.
In the second position on the shaft, the TRBs are teamed with a double cylindrical roller bearing. The CRBs can also run minimal internal clearance; the load distribution is more uniform because of the dual TRBs. And the bearing housing itself no longer has to handle axial length compensation, which is now limited to within the bearing's rolling elements.
The final installation issue is compensating for angular misalignment of the two bearing blocks relative to the shaft itself. In this TRB / CRB installation, angular misalignments are handled by building the TRBs and CRBs with spherical outers, coated to reduce sticktion and improve corrosion resistance.
Product Model | Inside Diameter | Outside Diameter | Thickness |
6001 NSK | 12 | 28 | 8 |
6040ZZS NSK | 200 | 310 | 51 |