Abstract: This disclosure presents a new type of variable stiffness magnetic spring, which can have a highly linear translational force characteristic. The variable stiffness is achieved through the rotation of a central magnet. Both positive and negative spring constants can be created. Using an analytic-based field analysis modelling technique, the operating principle and linearity characteristics of the adjustable magnetic spring are studied. The use of a magnetic spring with an adjustable negative spring constant could enable an ocean generator to continuously operate in a resonant state, thereby greatly increasing its power generation capability. The described variable stiffness spring could also be useful in other energy harvesting applications, robotic actuator applications, and/or other applications.

Abstract: Various examples of a variable stiffness magnetic spring with a linear stroke length are provided. The stiffness of the magnetic springs is varied through rotation of one or more magnets, and both positive and negative spring constants are achievable. In one example, a variable stiffness magnetic spring includes a first magnetic component and a second magnetic component, wherein the first magnetic component is coaxial with the second magnetic component, the first magnetic component is rotatable about an axis and relative to the second magnetic component to adjust a stiffness of the variable stiffness magnetic spring, and the second magnetic component is translatable along the axis and relative to the first magnetic component. While such variable stiffness magnetic springs exhibit highly linear stroke lengths, such variable stiffness magnetic springs can be positioned in series to achieve an even longer linear stroke length.

Abstract: A semiconductor device includes a source, a drain, and a channel electrically connected to the source and the drain. The channel has a channel length from the drain to the source which is less than or equal to an electron mean free path of the channel material. A first gate has two arms, each extending between the drain and the source (i.e., at least a portion of the distance between the source and the drain). Each arm of the first gate is disposed proximate to a corresponding first and second edge of the channel. Each arm of the first gate has a periodic profile along an inner boundary, wherein the periodic profiles of each arm are offset from each other such that a distance between the arms is constant. A Bloch voltage applied to the first gate will reduce the effective channel with such that Bloch resonance conditions are met.

Abstract: This application relates to translating mechanical energy from a low-speed rotor to a high-speed rotor or vice versa in a magnetic gearbox. More specifically, this application discloses various embodiments of a coaxial magnetic gearbox with flux concentration Halbach rotors. In certain implementations, the device further comprises a circular back iron (or other ferromagnetic material) disposed concentrically along the axis of the cylindrical magnetic gearing device. In such embodiments, this flux concentration back iron (or ferromagnetic pole) improves the torque density and can also help retain the magnets in place.

Abstract: The disclosure presents configurations and analyses of magnetic gears, which may be used in the second stage of a multistage magnetically geared generator for a marine hydrokinetic generator application and/or other applications as described. In order to reduce field harmonics and maximize the torque density, a Halbach rotor topology is utilized. One feature of the disclosed configuration is a unique magnet arrangement that enables inner and outer Halbach rotor magnets to be more easily assembled, even with dimensional tolerance inaccuracies. The disclosed Halbach magnet rotor topology makes use of the internal magnet forces to retain the magnets in position, and the disclosed configuration also helps with the assembly process.

Abstract: This application concerns embodiments of a low cost magnetically geared lead screw (MGLS). In some embodiments, a MGLS system comprises at least an outer cylinder, an inner rotor, and a translator sandwiched between the outer cylinder and the inner rotor. In various embodiments, the MGLS overcomes some of the disadvantages of other systems by skewing magnetic pole pairs on either or both of the outer cylinder or the inner rotor instead of skewing magnetic portions of the translator. By skewing the pole pairs, the translator placed between the outer and inner cylinder is generally not required to contain any magnetic material (such as permanent magnets or magnetic rings, rare earth elements, etc.), which may otherwise cause the translator to become costly and/or heavy, or to exhibit any other number of deficiencies.

Abstract: This disclosure presents a new type of variable stiffness magnetic spring, which can have a highly linear translational force characteristic. The variable stiffness is achieved through the rotation of a central magnet. Both positive and negative spring constants can be created. Using an analytic-based field analysis modelling technique, the operating principle and linearity characteristics of the adjustable magnetic spring are studied. The use of a magnetic spring with an adjustable negative spring constant could enable an ocean generator to continuously operate in a resonant state, thereby greatly increasing its power generation capability. The described variable stiffness spring could also be useful in other energy harvesting applications, robotic actuator applications, and/or other applications.

Abstract: A semiconductor device includes a source, a drain, and a channel electrically connected to the source and the drain. The channel has a channel length from the drain to the source which is less than or equal to an electron mean free path of the channel material. A first gate has two arms, each extending between the drain and the source (i.e., at least a portion of the distance between the source and the drain). Each arm of the first gate is disposed proximate to a corresponding first and second edge of the channel. Each arm of the first gate has a periodic profile along an inner boundary, wherein the periodic profiles of each arm are offset from each other such that a distance between the arms is constant. A Bloch voltage applied to the first gate will reduce the effective channel with such that Bloch resonance conditions are met.

Abstract: This application relates to translating mechanical energy from a low-speed rotor to a high-speed rotor or vice versa in a magnetic gearbox. More specifically, this application discloses various embodiments of a coaxial magnetic gearbox with flux concentration Halbach rotors. In certain implementations, the device further comprises a circular back iron (or other ferromagnetic material) disposed concentrically along the axis of the cylindrical magnetic gearing device. In such embodiments, this flux concentration back iron (or ferromagnetic pole) improves the torque density and can also help retain the magnets in place.

Abstract: The present invention relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like. The present invention also relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like that incorporates an outer stator assembly that converts a variable input to a constant output. The present invention further relates generally to an axially aligned flux focusing magnetic gear assembly using ferrite magnets or the like. The improved flux focusing magnetic gear assemblies of the present invention find applicability in traction, wind, and ocean power generation, among other applications.

Abstract: The present invention relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like. The present invention also relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like that incorporates an outer stator assembly that converts a variable input to a constant output. The present invention further relates generally to an axially aligned flux focusing magnetic gear assembly using ferrite magnets or the like. The improved flux focusing magnetic gear assemblies of the present invention find applicability in traction, wind, and ocean power generation, among other applications.

Abstract: The present invention relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like. The present invention also relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like that incorporates an outer stator assembly that converts a variable input to a constant output. The present invention further relates generally to an axially aligned flux focusing magnetic gear assembly using ferrite magnets or the like. The improved flux focusing magnetic gear assemblies of the present invention find applicability in traction, wind, and ocean power generation, among other applications.

Abstract: The present invention relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like. The present invention also relates generally to a flux focusing magnetic gear assembly using ferrite magnets or the like that incorporates an outer stator assembly that converts a variable input to a constant output. The present invention further relates generally to an axially aligned flux focusing magnetic gear assembly using ferrite magnets or the like. The improved flux focusing magnetic gear assemblies of the present invention find applicability in traction, wind, and ocean power generation, among other applications.

Abstract: A permanent magnetic machine includes a stator body having a first end, a second end, and a plurality of generally radial slots formed therein for accepting a set of windings having a first set of end-turns at the first end and a second set of end-turns at the second end. The stator body has a plurality of channels adjacent to the slots and extending from the first end of the stator body to the second end of the stator body, wherein the channels are configured to allow the flow of a cooling fluid therethrough. A plurality of nozzles in fluid communication with the plurality of channels are configured to spray the cooling fluid onto the first and second set of end turns.

Abstract: An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor having a plurality of equal-sized (e.g., rectilinear) segmented ferrite magnets arranged in one or more layers. The magnets are inserted within rotor slots that are larger than the magnets themselves, such that one or more air gaps are formed adjacent to the magnets in each layer.

Abstract: An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor having a plurality of ferrite magnets arranged in one or more layers, wherein at least one of the layers includes rare earth magnets (e.g., NdFeB magnets) adjacent to the ferrite magnets to prevent or reduce demagnetization.

Abstract: A permanent magnetic machine includes a stator body having a first end, a second end, and a plurality of generally radial slots formed therein for accepting a set of windings having a first set of end-turns at the first end and a second set of end-turns at the second end. The stator body has a plurality of channels adjacent to the slots and extending from the first end of the stator body to the second end of the stator body, wherein the channels are configured to allow the flow of a cooling fluid therethrough. A plurality of nozzles in fluid communication with the plurality of channels are configured to spray the cooling fluid onto the first and second set of end turns.

Abstract: An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor having a plurality of ferrite magnets arranged in one or more layers, wherein at least one of the layers includes rare earth magnets (e.g., NdFeB magnets) adjacent to the ferrite magnets to prevent or reduce demagnetization.

Abstract: An internal permanent magnet machine (“IPM machine”) of the type used, for example, with traction motors and hybrid electric vehicles, includes a rotor having a plurality of equal-sized (e.g., rectilinear) segmented ferrite magnets arranged in one or more layers. The magnets are inserted within rotor slots that are larger than the magnets themselves, such that one or more air gaps are formed adjacent to the magnets in each layer.