Abstract: In a q phase-reluctance type motor including a rotor having 2n rotor protrusions with an arc angle X°, a stator having 2m stator protrusions with an arc angle Y° and m pairs of exciting coils, each of the pairs of exciting coils is disposed around one of the stator protrusions spaced apart at 180° in mechanical angle, and the following conditions are met: q≧5, X°, Y°>360°/(n×q), X°+Y°=180°/n−&agr;°, where &agr;° is a counter torque marginal angle which is larger than 0°.
Abstract: In a preferred embodiment, an actuator, including: a shaft (34); a solenoid (24), having a coil (40) and a core (42), disposed at a first selected position on the shaft, with the core being fixedly attached to the shaft such that energization of the coil will cause the shaft to move axially; and a rotary motor (22), having a stator (30) and a rotor (32), disposed at a selected second position on the shaft, with the shaft passing through the rotor, an external surface of the shaft and an internal surface of the rotor having complementary engaging surfaces such that rotation of the rotor will cause rotation of the shaft and axial motion of the shaft will be isolated from the rotor.
Abstract: An inductance rotating electric machine comprises a primary armature having a core that includes a core winding portion, a coil wound within a slot and a facing core portion. The facing core portion faces a secondary armature at a projection end of the core winding portion. The facing core portion has a core height which is higher than that of the core winding portion.
Abstract: An apparatus and method of determine rotor position for a switched reluctance motor is claimed. A phase voltage and a phase current are measured. An estimated flux voltage value is determined from the measured phase voltage and the phase current. The phase current is again measured when the estimated flux linkage value is approximately equal to a reference flux linkage value. Rotor position is determined based on the reference flux linkage value and the measured phase current value.
Abstract: A gas dynamic pressure bearing apparatus comprises a fixed shaft, a bearing member which is positioned opposite from the fixed shaft and at least a radial gas dynamic pressure bearing portion and a thrust gas dynamic pressure bearing portion which are positioned in a space between the fixed shaft and the bearing member. Dynamic pressure generating means are included for pressurizing gas in the radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion such that dynamic pressure action is generated. The bearing member is rotatably supported in relation to the fixed shaft by means of the pressurizing action such that rotational driving is performed by a predetermined motor. The radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion are structured such that gas is sealed from the space around the motor by a space sealing means and that gas flows from one side to other.
Abstract: A high temperature superconducting rotor for a synchronous machine includes a high temperature superconducting field winding, a field winding support concentrically arranged about the high temperature superconducting field winding, and a thermal reserve concentrically arranged about the field winding support. The thermal reserve includes a thermally conductive material. The material is either electrically conductive, for example, aluminum, or electrically nonconductive, for example, ceramics such as beryllium oxide or alumina. The thermal reserve material includes segmentation in a direction normal to the rotor axis, along the rotor axis, neither, or both. The rotor includes a banding concentrically arranged about the thermal reserve. The banding includes an electrically conductive material, for example, steel, an electrically nonconductive material, for example, Kevlar, or both. The rotor includes an outer layer concentrically arranged about the thermal reserve.
Abstract: An electric motor has a rotor for rotation in a stator and a plurality of permanent magnets arranged on an outer peripheral surface of the rotor. A radially inner side surface of each permanent magnet is a curved to generally be convex in a radially inward direction. The outer peripheral surface of the rotor has curved recess surfaces, each of which contacts the radially inner side curved surface of a corresponding permanent magnet so that magnetic flux between adjacent permanent magnets is considerably prevented from locally concentrating within the rotor.
Abstract: An actuator, with two independent degrees of freedom, rotates a stage about an axis and moves the stage along the axis, the range of motion defining a cylinder or cylindrical section. The stage is mounted on a hollow cylindrical plunger fitting in an annular well. A bearing allows the plunger to move axially and rotationally, in the preferred embodiment the bearing is an air bearing. The plunger has an array of permanent magnets on its external cylindrical face opposite coils in the well. Equal numbers of oppositely-polarized permanent magnets are arranged in a regular cylindrical pattern at 50% packing density forming rings and columns of like-polarity magnets, the rings of one polarity alternating with rings of opposite polarity and the columns of one polarity alternating with columns of opposite polarity. A set of Z-axis coils (for axial movement) curve around the plunger and are shaped to allow a current in them to produce an axial force with respect to the rings of magnets. A set of .phi.
Abstract: A brushless permanent magnet machine that includes a combination of a fractional stator slot/rotor pole and a winding configuration to reduce cogging during operation of the machine. The stator has a series of teeth (preferably eighteen) which are surrounded by a series of coils. The coils are wound around the teeth and connected to a three-phase power supply in a manner that reduces cogging. The rotor has a series of slots (preferably sixteen). In the first embodiment, the coils are wound around every tooth, and the teeth are divided into sections of three, wherein each section of three teeth is connected to one phase of the power supply. In this embodiment, the fractional stator slot/rotor pole ratio is 18/16. In a second embodiment, the coils are wound around every other tooth, which provides for more space for winding the coils. In this embodiment, the fractional stator slot/rotor pole ratio is 9/16.
Abstract: The invention relates to an apparatus for the contact-free journalling of a rotor by rotary field machine stators. The rotary field machine stators are magnetically coupled, on the one hand, via the rotor of ferromagnetic material and, on the other hand, via a flux conduction ring of a ferromagnetic material and/or a housing of a ferromagnetic material. The radial magnetic bearing forces in the rotary field machine stators are produced in that means are present in the arrangement which produce magnetic unipolar fluxes flowing through the rotary field machine stators. Two-pole control fluxes are superimposed on the unipolar fluxes in the rotary field machine stators, and the control fluxes are controlled by the currents in two-pole rotary field windings. The position of the rotor is measured by position sensors. A control apparatus calculates the required phase currents as a result of the position signals and feeds the rotary field windings in such a manner that the rotor is held in suspension.
Abstract: The invention is based on an electrically operated motor, having a shaft with a magnet rotor body, the RPM of the shaft can be picked up by a Hall sensor disposed on a circuit board. The circuit board is embodied with soldered pins or contact shoes and is integrated into a component of the motor, and that contacts, supply and signal lines for the circuit board are injected and/or plugged into the component of the motor.
Abstract: An alternator for vehicle includes a stator and a rotor. The stator is composed of a stator core which is a lamination of steel-sheets and stator winding. The rotor is composed of a pole core, a pair of cooling-fans disposed on opposite axial ends of the pole core and a field coil. The pole core is composed of a cylindrical center core, a pair of disk yokes extending from the center core and claw-pole-pieces extending from the disk yokes to longitudinally cover the field coil. In such a generator, a ratio Y/X of a circumferential distance Y between the adjacent claw-pole-pieces to a circumferential width X of the tooth edges and a ratio r1/R1 of the inside diameter r1 of a cylindrical space where the claw-pole-pieces are disposed to the outside diameter R1 of the same are in specific ranges.
Abstract: A compliant clamp (20) for a power generator and associated methods are provided (see FIG. 5). The clamp (20) preferably includes an end plate (18) mounted to an end of a generator stator core (10) and a core attaching member (15) connected to the generator stator core (10) and positioned to connect the generator stator core (10) to a frame (12). The core attaching member (15) preferably has at least an end portion (22) extending outwardly from the end plate (18). At least one spring member (25) is preferably mounted to the end portion (22) of the core attaching member (15) for springingly biasing the end plate (18) inwardly toward the generator core (10).
Abstract: A rotor position transducer for an electronically commutated electric motor has a vane mounted to rotate with the rotor and a pair of sensors, according to one embodiment. One sensor has an output coincident with positions of zero torque. The other sensor produces signals slightly in advance. Overlapping portions of the signals denote regions of different levels of torque. The second sensor output can also be used in high-speed, single-pulse control of the motor. Method embodiments and other apparatus embodiments are also disclosed.
July 17, 1998
Date of Patent:
July 18, 2000
Switched Reluctance Drives Limited
Peter Richard Mayes, James Christopher Rudd Smart
Abstract: An object of the present invention is to provide a bearingless rotary machine which is capable of stably controlling the levitated position of a rotor of an induction motor even if the rotor comprises a squirrel-cage type rotor that is simple in structure and can easily be manufactured.A bearingless rotary machine has a rotor having secondary current paths and a stator spaced from the rotor by a gap. The stator has two kinds of windings for imparting a rotating and a levitating and supporting force to the rotor. The rotary machine has a magnetic field command calculator, magnetic flux distribution detecting means and correcting means for adjusting the detected control magnetic flux distribution to coincide with the magnetic field distribution command.
November 25, 1998
Date of Patent:
June 20, 2000
Tadashi Satoh, Masaru Ohsawa, Satoshi Mori
Abstract: A vacuum pump a the magnetic bearing assembly includes the magnetic bearing assembly with rotor position sensors and backup bearings being placed inside the rotatable shaft of the vacuum pump. The sensor placements are independent of the bearing position, so that the respective radial sensors can be at the same axial position as the respective radial bearings, which provides sensors co-location and a space saving within a turbopump housing, in particular, in its axial direction, while sensors and mechanical backup bearings are placed in a better protected area with respect to pumped corrosive gases.
Abstract: A spindle motor includes a hydrodynamic gas radial bearing in which an inner ring, which is a radial shaft member, fixed to a bracket, and an outer ring, which is a radial bearing member, fixed to a housing are opposed to each other in a radial direction of the housing; and a hydrodynamic gas thrust bearing having a thrust bearing surface, which is a thrust shaft member, located on an upper surface of the inner ring and a thrust plate, which is a thrust bearing member, fixed to the housing are opposed to each other in the axial direction of the housing, wherein opposing surfaces of the thrust bearing surface and the thrust plate of the hydrodynamic gas thrust bearing are located within a bearing-functional-dimension region L of the hydrodynamic gas radial bearing.
Abstract: It is an object of this invention to provide an alternator for a vehicle in which all electric conductors forming bridge portions are sufficiently exposed to cooling winds so that the cooling performance is remarkably improved. It is another object of this invention to provide an alternator for a vehicle which is excellent in cooling performance, insulating characteristic, and heat resisting property. An alternator for a vehicle includes a stator. The stator includes an iron core 22, an electric conductor 21, and an insulator 23. The electric conductor 21 forms a winding on the iron core 22. The insulator 23 provides electric insulation between the electric conductor 21 and the iron core 22. The stator is supported by a housing. The dimension of openings of slots in the iron core 22 is smaller than the distance between inner side surfaces of the slots. The electric conductor 21 has accommodated portions accommodated in the slots, and bridge portions connecting the accommodated portions.
Abstract: The present invention provides a motor and a stator structure of the motor and an assembly method of the stator structure and a method of installing the motor. The stator structure of the motor contains a stator substrate having a double-layer structure of a printed circuit board and a magnetic plate jointed together at a plurality of calking sections, wherein a centroid is determined with respect to the plurality of calking sections on the printed circuit board, and a vacant area having no electric parts provided is determined nearby the centroid on the printed circuit board to allow the vacant area to be supported by a retainer of a calking jig.
Abstract: A motor comprises a stator core having plural teeth and slots provided among the teeth, a winding applied on the teeth by a turn, and a rotor incorporating plural permanent magnets. The rotor is rotated and driven by utilizing reluctance torque in addition to magnetic torque. Since the winding is not crossed, the size of the coil end is reduced.
February 2, 1998
Date of Patent:
April 11, 2000
Matsushita Electric Industrial Co., Ltd.