First Heavy Load Bearing for Industrial Application with Shaft Loads up to 10 kN

We report on design, construction and testing of a heavy load HTS bearing for a 4 MVA HTS generator. According to the requirement profile of Siemens the bearing was designed for a shaft weight of 1000 kg. To meet these specifications, Nexans has designed and manufactured a HTS bearing fully encapsulated in a stainless steal cryostat with an operation temperature of −240 °C. The working elements of the bearing are single-domain YBCO monoliths fabricated by a top-seeded-melt-growth process, optimized for large batches with 64 pieces per batch. The monoliths exhibit trapped magnetic fields up to 1.4 T and self-field critical current densities at 77 K up to 1.3 × 105 Acm−2. The stator of the bearing comprises 270 such monoliths, which were arranged in nine rings. The levitation properties of the complete system, comprising the HTS stator and a permanent magnet rotor, were recently successfully tested. The system is the largest bearing manufactured worldwide and one of the first to be tested for industrial applications.