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.

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.

The present disclosure provides flywheel systems for generating and/or storing energy, and methods of using same.

A system for storing electrical energy generated by an external energy source that includes a ring for storing kinetic energy of rotation, an assembly a control system, and at least two motors/generators. The assembly includes a plurality of independent supports, each releasably attachable to a levitation electromagnet such that pole faces of the levitation electromagnet oppose a top protruding surface of a levitation rail of the ring and each releasably attachable to a centering electromagnet such that pole faces of the centering electromagnet oppose a surface of the centering rail of the ring. The control system supplies current to each levitation electromagnet to generate vertical forces to levitate and vertically stabilize the ring and to each centering electromagnet to generate radial forces to center and horizontally stabilize the ring. At least two of motor/generators electromagnetically engage a reaction rail of the ring and impose a reversible torque on the ring to enable bi-directional transfer of electrical energy from the energy source to the ring in the form of kinetic energy of rotation of the ring, and subsequent recovery of electrical energy from the kinetic energy of rotation of the ring.

A flywheel system includes a fixture including a bottom support, a rotor characterized by a gravitational load and configured to rotate above the bottom support about a rotation axis, and a bottom magnetic levitation bearing. The bottom magnetic levitation bearing includes (a) a ring of first magnets mechanically coupled with a bottom end of the rotor, (b) a ring of second magnets mechanically coupled to the bottom support, beneath the ring of first magnets, the second magnets repelling the first magnets to magnetically support at least a portion of the gravitational load above the bottom support, (c) a ring of third magnets mechanically coupled with the bottom end, and (d) a ring of fourth magnets mechanically coupled to the bottom support radially outwards from the ring of third magnets, the fourth magnets repelling the third magnets to at least reduce radial decentering of the rotor relative to the fixture.

A motor includes a bearing having a rolling member disposed between an inner ring and an outer ring, a spring connected to the outer ring, and a pusher connected to the spring and configured to move to a first position spaced apart from the inner ring by the spring. The pusher is further configured to move to a second position at which friction with the inner ring is caused by a pressure of air. The inner ring is spaced apart from the rotating shaft by a gap between the inner ring and the rotating shaft when the pusher is at the second position.

A motor that ensures efficient supply of a lubricating oil to a mechanical seal and a bearing to reduce temperature rise in driving of a motor is provided. The motor includes a mechanical seal through which a rotary shaft of a rotor is inserted. The mechanical seal includes a seal ring and a mating ring. The seal ring has a sealing surface. The mating ring is secured to the rotary shaft. The mating ring has a sealing surface that contacts the sealing surface of the seal ring. The mating ring has a through hole on an outer edge side of the mating ring with respect to the sealing surface of the mating ring. The lubricating oil flows through the through hole to the bearing side.

A motor includes a rotor used in conjunction with a stator to produce a magnetic field in the air gap having p pole pairs, wherein a single cross section of the rotor taken orthogonal to an axis of rotation comprises iron having a structure forming p teeth. The stator has at least one stator winding configured to form p pole pairs to produce a first magnetic field to rotate the rotor about the axis of rotation and configured to produce a second magnetic field of either one pole pair or p1 pole pairs to create forces radial to the axis of rotation. The at least one stator winding has two sets of terminals, a first set of terminals for carrying current that produces the first magnetic field in the air gap having p pole pairs to rotate the rotor about the axis of rotation and a second set of terminals for carrying current that produces the second magnetic field in the air gap having either one pole pair or p1 pole pairs to create the forces radial to the axis of rotation. The second set of terminals experience no motional-electromotive force when the rotor is centered on the axis of rotation.

Provided is a propeller for a submersible, comprising a housing (1) having a cylindrical structure with two open ends, a stator sleeve (2) having a cylindrical structure with one open end, the stator sleeve suspended in an internal cavity of the housing (1), a motor stator (3) fixed inside the stator sleeve (2), a rotor sleeve (4) having a cylindrical structure with one open end and disposed on the stator sleeve (2), a motor rotor (5) fixed to an inner wall of the rotor sleeve (4), and a propeller (6) fixed to an outer wall of the rotor sleeve (4). The propeller (6) of the underwater propeller is directly fixed to the rotor sleeve (4) so that the structure of the motor is compact, and the rotational shaft transmission is not required so that the length of the propeller is shortened and the volume is reduced.

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