Abstract: An electric motor system includes a drive shaft, a first electric motor, a second electric motor, a first inverter, a second inverter and a control unit. The drive shaft is rotatable around an axis. The first electric motor and the second electric motor rotate the drive shaft. The first inverter supplies power in order to generate a torque to the first electric motor. The second inverter supplies power in order to generate a torque to the second electric motor. The control unit controls the first inverter and the second inverter. The controller is configured to be able to change a ratio between an output torque of the first electric motor and an output torque of the second electric motor.

Abstract: A rotating device and a vacuum pump are provided, having a structure in which a refrigerant or the like does not leak out to an inside and which can sufficiently cool a rotating body, obtain high reliability, and realize cost reduction. The structure is constituted to include: a casing; a rotating body including a rotating shaft disposed rotatably relative to the casing, the rotating body constituted integrally with the rotating shaft; a hollow part formed along a center of the rotating shaft in the rotating body; and a cooling rod which is fixed to the casing and provided in a state of non-contact with the rotating body in the hollow part without having a mechanism for injecting a refrigerant, and which absorbs a radiation heat of the rotating body to cool the rotating body.

Abstract: 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.

Abstract: A rotor includes a rotor core having a plurality of magnetic poles. At least one magnetic pole includes a first magnetic pole having three or more circumferentially arranged magnet holes, and a plurality of permanent magnets housed corresponding magnet holes. A portion of the rotor core between adjacent magnet holes has a radially extending region. A maximum radial dimension of each magnet hole is greater than a minimum radial dimension of a portion of the rotor core between a magnet hole radially outer surface and a rotor core outer peripheral surface. The first magnetic pole has a smaller amount of harmonic components in a radial flux density distribution on the rotor core outer peripheral surface, compared to a magnetic pole having a plurality of magnet holes arranged at equal circumferential intervals and a plurality of permanent magnets having substantially the same magnetic flux and number.

Abstract: An electric motor system includes a drive shaft, a first electric motor, a second electric motor, a first inverter, a second inverter and a control unit. The drive shaft is rotatable around an axis. The first electric motor and the second electric motor rotate the drive shaft. The first inverter supplies power in order to generate a torque to the first electric motor. The second inverter supplies power in order to generate a torque to the second electric motor. The control unit controls the first inverter and the second inverter. The controller is configured to be able to change a ratio between an output torque of the first electric motor and an output torque of the second electric motor.

Abstract: An electric motor system includes a drive shaft that rotationally drives a load, a bearingless motor, a power source unit, and a control unit. The bearingless motor includes a rotor and a stator having armature and support windings. The bearingless motor rotationally drives the drive shaft and supports a radial load of the drive shaft in a contactless manner. The power source unit applies a voltage to the armature and support windings. The control unit controls the power source unit so that a radial support force that is a sum of a radial support force caused by a support current and a radial support force caused by both the support current and an armature current is output, and so that one of an armature voltage across the armature winding and the support current is increased and the other of the armature voltage and the support current is decreased.

Abstract: A drive support unit of a turbo compressor includes at least one bearingless motor. The at least one bearingless motor includes a rotor-stator pair constituted by a rotor and a stator, and is configured to rotationally drive a drive shaft and to support a radial load of the drive shaft in a contactless manner. Accordingly, it is possible to provide a turbo compressor to which a bearingless motor is applied.

Abstract: An electric motor system includes a drive shaft that rotationally drives a load, a bearingless motor, a power source unit, and a control unit. The bearingless motor includes a rotor and a stator having armature and support windings. The bearingless motor rotationally drives the drive shaft and supports a radial load of the drive shaft in a contactless manner. The power source unit applies a voltage to the armature and support windings. The control unit controls the power source unit so that a radial support force that is a sum of a radial support force caused by a support current and a radial support force caused by both the support current and an armature current is output, and so that one of an armature voltage across the armature winding and the support current is increased and the other of the armature voltage and the support current is decreased.

Abstract: An electric motor system includes a drive shaft that rotationally drives a load, a bearingless motor, a power source unit, and a control unit. The bearingless motor includes a rotor and a stator having armature and support windings. The bearingless motor rotationally drives the drive shaft and supports a radial load of the drive shaft in a contactless manner. The power source unit applies a voltage to the armature and support windings. The control unit controls the power source unit so that a radial support force that is a sum of a radial support force caused by a support current and a radial support force caused by both the support current and an armature current is output, and so that one of an armature voltage across the armature winding and the support current is increased and the other of the armature voltage and the support current is decreased.

Abstract: 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.

Abstract: In a single-sided paper phenolic resin copper-clad laminate composed of a phenolic resin impregnated paper base having copper foils laminated on and resists applied on the face side thereof, resists formed of the same material as the resists on the face side are applied also on the reverse side of the phenolic resin impregnated paper base, so that the face side and the reverse side match approximately with each other in thermal expansibility. The single-sided paper phenolic resin copper-clad laminate warps only slightly even when the peak temperature is raised to a degree suitable for lead-free solder in the reflow process for mounting electronic components.

Abstract: In a single-sided paper phenolic resin copper-clad laminate composed of a phenolic resin impregnated paper base having copper foils laminated on and resists applied on the face side thereof, resists formed of the same material as the resists on the face side are applied also on the reverse side of the phenolic resin impregnated paper base, so that the face side and the reverse side match approximately with each other in thermal expansibility. The single-sided paper phenolic resin copper-clad laminate warps only slightly even when the peak temperature is raised to a degree suitable for lead-free solder in the reflow process for mounting electronic components.