| 摘要 |
An assembly in which a rotating shaft (10) is supported by a magnetic bearing (13) has a back-up bearing (18), to support the shaft (10) in the event of failure of the magnetic bearing (13), the back-up bearing (18) comprising a first layer of a dry bearing material (19), and with a surface opposite to a wear-resistant surface portion of a second layer (20). One layer (19,20) is provided on a stationary part (16) of the assembly, such as a housing, and the other layer is provided on the shaft (10). When the coefficient of friction between the first and second layers (19,20) is either relatively low; or relatively high; heat can be dissipated from the back-up bearing (18), respectively, at a low rate; or at a high rate. Heat dissipation may be enhanced by providing fins (26) in good thermal contact with at least one of the two layers (19,20) of the back-up bearing (18); and each such layer (19,20), advantageously, has a high thermal conductivity. |
