An electric motor system includes a drive shaft, first and second magnetic bearing portions facing each other and supporting the drive shaft, an electric motor to rotate the drive shaft, and a gap detection unit to detect a position of the drive shaft During rotation of the drive shaft, greater external force acts, on average, on the drive shaft in a first direction than in a second direction. The first and second direction extend from the second and first magnetic bearing portions to the first and second magnetic bearing portion. The first and second magnetic bearing portions produce first and second magnetic forces on the drive shaft in the first and second directions. A magnitude of the second magnetic force is greater than a magnitude of the first magnetic force. The gap detection unit is arranged closer to the second magnetic bearing portion than to the first magnetic bearing portion.

An electric motor system includes a drive shaft, first and second magnetic bearing portions facing each other and supporting the drive shaft, an electric motor to rotate the drive shaft, and a gap detection unit to detect a position of the drive shaft During rotation of the drive shaft, greater external force acts, on average, on the drive shaft in a first direction than in a second direction. The first and second direction extend from the second and first magnetic bearing portions to the first and second magnetic bearing portion. The first and second magnetic bearing portions produce first and second magnetic forces on the drive shaft in the first and second directions. A magnitude of the second magnetic force is greater than a magnitude of the first magnetic force. The gap detection unit is arranged closer to the second magnetic bearing portion than to the first magnetic bearing portion.

A bearing device includes a bearing having a first ring and a second ring mounted for relative rotation, and an insulating sleeve mounted on the second ring. The insulating sleeve includes a socket and an electrically insulating liner that contacts the second ring. The second ring has a radial outer surface and a radial inner surface delimiting a radial thickness of the second ring, and the insulating liner is overmolded on the socket and at least on one of the inner and outer surfaces of the second ring of the bearing. Also, the surface of the second ring is configured to retain, in the circumferential direction, the insulating liner relative to the surface by complementarity of shapes with the insulating liner.

A bearing device includes a first ring and a second ring mounted for relative rotation and an insulating sleeve including a socket and an electrically insulating liner. The socket has at least one recess, and the liner has at least one protrusion extending into each of the at least one recess. The liner is overmolded on the second ring and on the socket such to connect the second ring to the socket.

A bearing device includes a first ring and a second ring mounted for relative rotation and an insulating sleeve mounted on the second ring. The insulating sleeve incudes a socket and an electrically insulating liner, the liner contacting the second ring. The socket includes an outer surface and an inner surface opposite the outer surface, and the outer surface and the inner surface delimit a radial thickness of the socket. The insulating liner is overmolded on the second ring of the bearing and on the outer surface and/or the inner surface of the socket. The socket and the insulating liner are shaped such that the insulating liner is prevented from moving circumferentially relative to the socket.

A motor includes a stator and a rotor having a rotor shaft. The motor includes a bearing having an inner ring and an outer ring that are configured to rotate relative to each other. The inner ring is supported by the rotor shaft. The motor also includes a holder that supports the outer ring. The holder is clearance-fitted to a retainer on a stator side. A rotation prevention apparatus configured to prevent the rotation of the holder is positioned between the holder and a stopper member on the stator side.

An insulating device for a bearing mountable within a housing, the bearing having an inner ring and an outer ring with an outer circumferential surface and opposing axial ends and a plurality of rolling elements disposed there between. The insulating device comprises: a first annular part, which is adapted to be in contact to the outer circumferential surface of the outer ring, and a second annular part, which is also adapted to be in contact to the outer circumferential surface of the outer ring. The first and second part form the insulation device which is adapted to contact, in an assembled state of the bearing in the housing, both the outer ring and the housing. The first part is thermally conductive and electrically insulating and the second part is electrically insulating and less thermally conductive than the first part or is not thermally conductive.

A system including: a journal bearing having a carrier, a rotor arranged rotatable about a rotational axis relative to the carrier, and a fluid in a clearance between the rotor and the carrier. A sensor measures a vibration signal of the rotor. A control system is adapted to determine a pressure set point for the fluid in the clearance based on the vibration signal, and to provide control signals generated based on the pressure set point. An active device is adapted to modify the pressure of the fluid in the clearance based on the control signals.

An axial flux motor includes a housing; a drive shaft disposed within the housing; at least one rotor; and at least one stator. The at least one rotor includes a diametrically-magnetized single pole pair magnetic ring having a rotor aperture defined through the center of the magnetic ring, where the drive shaft extends through the rotor aperture and where the at least one rotor is fixed to the drive shaft. The at least one stator includes a number of conductive windings and a stator aperture, where the drive shaft extends through the stator aperture and where the drive shaft is rotatable within the aperture. The at least one stator is configured to generate an axial magnetic field that causes the at least one rotor to rotate, thereby rotating the drive shaft.

A system for an unmanned aerial vehicle can include an altitude control system, which further includes a compressor assembly, a valve assembly, and an electronics assembly. The compressor assembly may include a driveshaft and a bearing assembly configured to rotate the driveshaft. The driveshaft may be formed from a first material and a compressor housing may be formed from a second material. The first and second materials may have different rates of thermal expansion. A dynamic preloading mechanism, such as a flexible plate, may be provided within the compressor assembly to exert a preloading force on the bearing assembly. Throughout the duration of the flight of the unmanned aerial vehicle, the preloading mechanism can continually compensate for differences in rates of thermal expansion between the first and second materials throughout.