Abstract: An electrical traction system notably for automobiles which has (a) at least one recharging supply source; (b) at least one synchronous electrical motor with a stator having a plurality of spatially offset stator windings, a commutating device with choppers for routing a current given by the supply source into the stator winding in order to create a rotating magnetic field, and a rotor; (c) a circuit for charging the supply source including a transformer, which transformer includes the stator windings; and (d) at least one converter for charging an auxiliary battery.
Abstract: Disclosed is an electrostrictive effect element comprising a columnar casing having openings on either end, laminated blocks with a laminated ceramic capacitor structure. The laminated blocks are stacked in the casing and electrically connected to each other and have a sufficient number of electrostrictive material layers formed to prevent mechanically damaged due to stress generated when a voltage is applied. The electrostrictive effect also includes means which is disposed outside the casing and made of a spring or the like for applying a compressive force to said laminated blocks in the lamination direction thereof, and engaging members which are engaged with said laminated blocks for applying a compressive force through said compression means to said laminated blocks.
Abstract: A regenerative braking system in a motor vehicle determines a state of deceleration on the basis of the number of revolutions of a motor and an accelerator signal and performs a regenerative braking according to the state of deceleration. The regenerative braking system includes a revolution sensor for detecting;the number of revolutions of a rotor of a vehicle driving motor and an accelerator opening sensor in a RAM stores discrimination data for discriminating between a regenerative braking mode and a drive mode on the basis of the number of revolutions of the rotor and the accelerator opening and also stores on-off duty ratio data of FETs in the regenerative braking mode and that in the drive mode.
Abstract: An apparatus for sensing the relative rotational position between first and second relatively rotatable members includes a transmitter disk having a planar surface and being mountable to the first member so that the planar surface of the transmitter disk is substantially perpendicular the an axis of rotation of the first and second members. The transmitter disk has a conductive material mounted to the planar surface in a circular pattern with a sinusoidal diameter. A receiving disk having a planar surface and is mountable to the second member so that the planar surface of the transmitter disk is substantially perpendicular the an axis of rotation of the first and second members. The receiving disk has a conductive material mounted thereon and arranged in a circular pattern with a squarewave diameter so as to receive a signal from the transmitter disk and output a signal indicative of the relative rotational position of the first and second members.
Abstract: A drive circuit for driving a piezoelectric element includes a transformer having a primary winding connected to a power source and a secondary winding connected to the piezoelectric element, a primary semiconductor element circuit connected to the primary winding for switching the current through the primary winding, and a secondary semiconductor element circuit connected to the secondary winding for switching the current through the secondary winding. A failure detection unit responsive to the potential at a predetermined point of the drive circuit is provided for detecting a failure in the piezoelectric apparatus and outputting a failure detection signal.
Abstract: There is disclosed a driving device for piezoelectric actuator, in which a voltage is applied to a piezoelectric actuator to generate a mechanical deformation therein, thus actuating a mechanical system. In an aspect, the piezoelectric actuator is at first given a voltage of inverse polarity, for generating a displacement in an opposite direction, and then given a voltage of forward polarity, for generating a displacement in the normal functioning direction, thereby actuating the mechanical system. Displacement and acceleration become larger, as the displacement of the actuator takes place from a position in the inverse direction. In another aspect, the electrical insulation state of the piezoelectric actuator is detected, and, if deteriorated, the destruction of insulation is prevented by an alarm generation and/or inhibition of voltage application. In an embodiment, the insulation state is identified from the ambient humidity of the actuator.
Abstract: A rotor having permanent magnets for a brushless electromotor includes a yoke formed from a plurality of silicon steel sheets laminated together and provided along its outer periphery with even number of, at least four magnetic poles. The magnetic poles are alternately provided substantially at equal distances from a rotational axis with slots to receive the respective permanent magnets such that the sides of the permanent magnets facing a rotary shaft have the same polarity. As a result, a compact and efficient rotor is obtained, and damage to or flying off of the permanent magnets is prevented.
Abstract: An improved cooling arrangement for a dynamoelectric machine of the type having a plurality of stacked laminations forming a stator core. The stacked laminations have a central bore for passage of a rotor therethrough and a plurality of uniformly spaced winding slots extending radially outward from the bore and terminating at an end at least partially through the laminations. Adjacent ones of the slots define pole pieces extending from the bore into a radially outer portion of the laminations. The improvement comprises a plurality of cooling air passages extending axially through the stacked laminations generally parallel to the central bore with each of the air passages being positioned adjacent the terminating end of a corresponding one of the winding slots. Each air passage has a radially outer shape corresponding generally to a radially outer shape of the winding slots and preferably have a crescent shape when viewed axially.
Abstract: A motor is provided which includes a housing, a stator attached to the cylindrical wall of the housing, a sleeve bearing attached to the inner periphery of the cylindrical wall, a rotor rotatably supported by the sleeve bearing, and a rotor magnet attached to the rotor. A plurality of projecting strips are formed substantially at equal intervals on the inner and/or outer periphery of the cylindrical wall of the housing. The cylindrical wall is formed into a shoulder and a mating recess. The stator has elastic pieces. Because of the operation of the elastic pieces, the stator is elastically retained between the shoulder and the mating recess. Circuitry for protecting the motor is improved.
June 1, 1992
Date of Patent:
November 8, 1994
Nippon Densan Corporation
Koji Harada, Takashi Hirata, Fumihiro Morikawa, Shuji Takahashi
Abstract: An offset gearbox of an aircraft has a sump for a lubricant. A heat exchanger core extends through the sump in contact with the lubricant. A fluid coolant for cooling an accessory such as an electrical power generating unit drivingly connected to the offset gearbox is circulated through the core in thermal communication but not mixed with the lubricant of the offset gearbox for cooling the lubricant. The cooling arrangement for the offset gearbox advantageously does not require a separate or dedicated heat exchanger which reduces system weight and cost. The single pump of the accessory can also be used for circulating the coolant. Increased reliability, independent oil change for maintenance and enhanced attitude performance are attained as gearbox performance does not affect power generating unit performance, and visa versa. An existing aircraft can be modified to include the offset gearbox with a minimum of modification and little additional weight and plumbing.
April 27, 1992
Date of Patent:
October 25, 1994
Jeffrey D. Baldwin, Ellen J. Wagle, Jude C. T. Lai
Abstract: A back-up bearing (50, FIG. 1) is provided for a magnetic journal or thrust bearing by a source of pressurized fluid 52 (such as gas), channels 51 supplying the fluid to the suspension gap 30 between moving bearing armature 25 and stationary armature pole faces 28.sub.1, 29.sub.1, and magnet control means 56 responsive to a decrease in gap width at any point below an acceptable minimum to supply the fluid by way of the channel(s) to the gap to form a hydrostatic bearing between stationary and movable armatures to aid or replace the magnetic bearing support. In a journal bearing, (FIG. 3) in which coil-containing spaces (62) exist between radially extending armature limbs the spaces may be closed by an apertured bridging piece (64) extending between pole faces and fluid supplied via that space to provide both increased hydrostatic bearing area and a way of cooling the coil by a low pressure fluid bleed at all times.
Abstract: The electrically motorized wheel assembly comprises a hollow shaft having a first opening at one end thereof and a second opening, the first opening receiving conductors from outside of the assembly; a stator coaxial with and fixedly attached to the shaft, the stator being provided with a hollow portion and coils; a rotor coaxial with the stator and mounted for rotation about the stator; and converting system for converting an input electrical current to the variable AC electrical current, the converting system including power electronics fixedly mounted within the hollow portion, input terminals for receiving the input electrical current and output terminals for delivering the variable AC electrical current; whereby, to provide the variable AC current to the coils of the stator.
Abstract: A novel spindle motor assembly is disclosed that utilizes a fixed shaft and places the motor rotor components on the outside wall of the spindle hub directly below its disc stack supporting flange. The structure disclosed provides a compact yet powerful motor having a relatively low profile.
Abstract: The present invention realates to an ultrasonic transducer providing a plurality of arranged vibrators as the piezoelectric materials. The present invention easily provide the shading to the polarization in the elevation direction of the piezoelectric materials in order to narrow the beam transmitted from the transducer. For this purpose, a structure of the present invention provides for the polarization (V.sub.1, V.sub.2, V.sub.3) of piezoelectric material of arranged vibrators to be gradually reduced in mass like a staircase from the center of the arranged vibrators to both end portions in the direction orthogonally crossing the arrangment direction of a plurality of arranged vibrators.
Abstract: A switch is used to disable electrical generation by causing a short circuit in a rotating main generator field of a brushless, synchronous generator to protect against transients voltage spikes during start-up. The switch is located inside of a hollow rotor shaft of the generator. In one embodiment the switch is activated by a solenoid assembly. In a second embodiment, the switch is activated by a alternate or redundant method by oil flow through the rotor shaft.
Abstract: A one-piece, plastic, integrally formed deflector for a motor includes a generally annularly shaped shroud portion, an axially offset generally annularly shaped mounting ring portion, and four generally axially extending webs interconnecting them. The deflector may be conveniently mounted to an end bracket with a screw placed through a mounting hole in the mounting ring located at each web such that as the end bracket is assembled to the motor, the shroud portion closely fits nearly adjacent the rotating rotor blades and the inside of the motor shell to restrict the flow of ventilating air through the motor and prevent its re-circulation past the blades.
Abstract: A spindle motor having a housing, a hub member rotatable relative to the housing, a bearing disposed between the housing and the hub member, a rotor magnet mounted on the hub member, and a stator disposed in a facing relationship with the rotor magnet. The hub member includes a supporting wall portion, which cooperates with the stator to constitute an air seal structure. A magnetic fluid seal is provided at a position outward of the bearing, and includes a conductive plate for grounding static electricity. The bearing is comprised of a radial ball bearing, which includes certain improvement.
Abstract: The present invention provides an improved field assembly of an electric motor which is free from broken wires or short circuits when being incorporated in a power-driven tool. The field assembly of the invention includes a metallic core formed of a stack of annular laminations around a cavity and having an upper end and a lower end, and a terminal plate composed of an insulating material and mounted on the upper end of the core. The terminal plate includes a plurality of first terminal supporting structures each disposed in the vicinity of a first or starting end of a coil winding for supporting and retaining an end of a coil wire extending from the coil winding; and a plurality of second terminal supporting structures each disposed in the vicinity of a second or terminal end of the coil winding for supporting and retaining an end of the coil wire.
Abstract: A superconducting bearing device includes a permanent magnet on a rotor, with a superconductor placed opposite the magnet. Flux trapped in the superconductor during cooling helps to stabilize the rotor. More specifically, the permanent magnet is mounted on the rotor so that, as the rotor rotates, its rotation does not alter the magnetic flux distribution around the axis of rotation of the rotor. The superconductor permits penetration of the magnetic flux from the magnet, being space from the magnet by a distance that permits a predetermined quantity of the magnetic flux to penetrate it, while not permitting rotation of the rotor to alter the distribution of the penetrating magnetic flux.
Abstract: A molded rotor assembly (20) including at least one molded fan (28), a method for making the same, and a vehicle alternator (160) using the molded rotor assembly (20) are disclosed. The rotor assembly (20) includes first and second pole pieces (24,26) aligned along a longitudinal axis (40) defining a region (122) between the pole pieces (24,26). Each pole piece (24,26) has an outboard axial face (69,71). At least one molded fan (28) is integrally molded to one of the axial outboard faces (69) of a pole piece (24). Preferably, a molded insert (22) is molded in the region (122) between the pole pieces (24,26) and is integral with the molded fan (28) to secure the molded fan (28) to the pole piece (24). Alternatively, anchoring recesses (241,245) are formed in an outboard face of a pole piece (224) with a molded fan (228) having anchoring portions (249,251) secured within the recesses (241,245) to retain the fan (228) to the outboard axial face.
November 23, 1992
Date of Patent:
July 12, 1994
Ford Motor Company
Steven J. Yockey, Gregory A. Ritchie, Joseph E. Saval, Eric D. Bramson