A vacuum pump comprises: a rotor rotatable in a predetermined rotation direction; and a case housing the rotor; and a fixed component arranged facing an inner wall of the case. A clearance is formed between the inner wall of the case and the fixed component, and a groove allowing communication between the clearance and an exhaust path in the case is formed at either the inner wall of the case or the fixed component.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic thrust bearing, wherein the hybrid magnetic thrust bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

The stator includes a stator core, a support electric wire formed by one or more conductive wires, and a drive electric wire formed by one or more conductive wires. The stator core includes an annular shaped back yoke and a plurality of teeth on an inner periphery of the back yoke. The support electric wire is disposed so as to pass through a plurality of slots respectively formed between the teeth, and forms a winding portion that generates an electromagnetic force for supporting the rotor in a non-contact manner by being energized. The drive electric wire is disposed so as to pass through the plurality of slots, and forms a winding portion that generates an electromagnetic force for rotating the rotor by being energized. A cross-sectional area per conductive wire of the support electric wire differs from a cross-sectional area per conductive wire of the drive electric wire.

A motor includes: a first portion that includes a plurality of permanent magnets; and a second portion that includes a plurality of coils, wherein the first portion or the second portion is configured to be rotatable around a rotation axis, wherein the plurality of permanent magnets are circumferentially arranged about the rotation axis, and wherein the plurality of coils are arranged so as to face the plurality of permanent magnets in a direction along the rotation axis, and the motor further includes: a control unit that controls a rotational speed and an attitude of the rotating first portion or the rotating second portion by controlling currents that are applied to the plurality of coils.

A gas turbine propulsion system includes a shroud that defines a fluid flow path. A gas turbine engine in the fluid flow path includes a compressor, a combustor downstream from the compressor, and a turbine downstream from the combustor. An electric generator in the fluid flow path defined by the shroud includes a rotor coaxially aligned with the turbine. A propulsor is upstream from the gas turbine engine, and an electric motor is operably coupled to the propulsor to rotate the propulsor. The propulsor is rotationally isolated from the gas turbine engine so that the propulsor rotates independently from operation of the gas turbine engine.

A system includes an electric generator, a power electronics system, a first heat exchanger, and a second heat exchanger. The electric generator includes a turbine wheel, a rotor, and a stator. The turbine wheel is configured to receive process gas and rotate in response to expansion of the process gas flowing through the electric generator. The rotor is configured to rotate with the turbine wheel. The electric generator is configured to generate electrical power upon rotation of the rotor within the stator. The power electronics system is configured to receive the electrical power from the electric generator and convert the electrical power to specified power characteristics. A heat transfer fluid receives waste heat from the power electronics system through the first heat exchanger. The heat transfer fluid transfers the received waste heat to the process gas through the second heat exchanger.

A blood pump includes a housing having an inlet. A rotor disposed in the housing and configured to rotate substantially about the axis to pump blood from the inlet to the outlet. A stator is disposed within the housing and configured to drive rotation of the rotor about the axis. A bearing mechanism for supporting the rotor inside the housing includes a magnetic bearing configured to magnetically support the rotor inside the housing in a radial direction from the axis. The bearing mechanism includes a sliding bearing configured to physically support the rotor inside the housing in an axial direction along the axis of the housing and allow rotation of the rotor substantially about the axis, the sliding bearing comprising at least one point of contact where the rotor is configured to physically contact a trunnion affixed to the housing.

An interstage seal for a turbine of a gas turbine engine, the interstage seal having a seal carrier with an axial extending seal tooth movable with a stator of the engine, and a rotor with a seal surface that forms the interstage seal with the seal tooth, where a magnetic force produced by two magnets and a gas force produced by a gas pressure acting on the seal carrier forms a balancing force to maintain a close clearance of the seal without the seal tooth contacting the rotor seal surfaces during engine operation. In other embodiments, two pairs of magnets produce first and second magnetic forces that balance the seal in the engine.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic thrust bearing, wherein the hybrid magnetic thrust bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

A gas turbine propulsion system includes a shroud that defines a fluid flow path. A gas turbine engine in the fluid flow path includes a compressor, a combustor downstream from the compressor, and a turbine downstream from the combustor. An electric generator in the fluid flow path includes a rotor coaxially aligned with the turbine. A propulsor is upstream from the gas turbine engine, and an electric motor is operably coupled to the propulsor to rotate the propulsor. The propulsor is rotationally isolated from the gas turbine engine so that the propulsor rotates independently from operation of the gas turbine engine.