A controller for a rotary machine includes a processor and a memory coupled to the processor. The memory is configured to store operating modes of the controller. The operating modes include a normal operating mode and a fault tolerant operating mode. The controller is configured to receive a signal from at least one sensor and determine an operating state of the rotary machine based on the signal. The controller is also configured to switch the operating modes based on the determined operating state of the rotary machine and regulate at least one electromagnetic bearing and at least one flow control device. The controller is further configured to adjust at least one of the at least one electromagnetic bearing and the at least one flow control device in the fault tolerant operating mode.

A centrifugal pump for conveying a fluid, includes a pump housing, a rotor configured to convey the fluid disposed within the housing; and a stator which, together with the rotor, forms an electromagnetic rotary drive configured to rotate the rotor about an axial direction. The stator is a bearing and drive stator with which the rotor capable of being magnetically driven without contact and magnetically levitated without contact with respect to the stator. The rotor is passively magnetically levitated in the axial direction, and actively magnetically levitated in a radial plane perpendicular to the axial direction. The pump housing includes comprising a bottom and a cover, and the rotor is arranged in the pump housing between the bottom and the cover with respect to the axial direction. An indentation is disposed in the bottom or in the cover, the indentation being configured to generate a local turbulence.

A turbomachine is made by first providing a stepped shaft having a large-diameter cylindrical portion, an intermediate-diameter cylindrical portion, and a small-diameter cylindrical portion all centered on a common axis. A separately manufactured a one-piece and annular first impeller wheel is then permanently mounted on the large-diameter portion with a back face of the first wheel facing axially toward the intermediate-diameter portion and carrying a rotor bearing half of an axial magnetic bearing. A rotor ring of a radial bearing is then detachably mounted on the intermediate-diameter portion of the shaft, and finally a one-piece and annular second impeller wheel is detachably mounted on the small-diameter portion of the shaft with a back face of the second wheel facing axially toward the first wheel and carrying a rotor bearing half of another axial magnetic bearing.

A cryogenic expansion turbine system (10) includes a turbo-expander (12) configured to receive and expand a cryogenic gas feed stream (24). A rotary shaft (16) operatively connects the turbo-expander and a resistance device, such as a compressor (14) or brake. A bearing housing (18) has a bearing cooling fluid inlet port and a bearing cooling fluid outlet port. Electro-magnetic bearings (22) are positioned within the bearing housing and rotatably support the rotary shaft. A bearing cooling circuit (72) directs a stream of bearing cooling fluid (62) into the bearing housing via the bearing cooling fluid inlet port so that the electro-magnetic bearings are cooled and resulting warmed bearing cooling fluid (68) exits the bearing housing via the cooling fluid outlet port.

A turbine engine is provided that includes a compressor section, a combustor section, a turbine section, a flowpath, a first rotating structure, a second rotating structure and a bearing system. The flowpath extends through the compressor section, the combustor section and the turbine section from an inlet to an exhaust. The combustor section includes a combustor. The first rotating structure includes a first compressor rotor within the compressor section and a first turbine rotor within the turbine section. The second rotating structure includes a second turbine rotor within the turbine section. The first turbine rotor is between the combustor and the second turbine rotor along the flowpath. The bearing system rotatably supports the first rotating structure. The bearing system includes an active magnetic bearing and a foil bearing.