Abstract: A rotation detecting device for vehicle speedometers includes a housing, a magnetic induction device, and a magnetized rotor near the magnetic induction device. The rotor is connected through a coupling to a rotation source. A braking device forms a magnetic circuit between one end surface of the rotor and the housing, and brings the rotor into pressure contact with the housing by a magnetic attraction force generated in the magnetic circuit. Accordingly, a stable and proper braking torque can be applied against rotor vibration, to prevent a false output signal while idling. Furthermore, the amount of wear of a bearing for rotatably supporting a rotating shaft of the rotor can be reduced to improve durability of the rotation detecting device by reducing the braking torque during high-speed rotation of the rotor.
October 11, 1990
Date of Patent:
August 6, 1996
Katsuo Nishitani, Masaki Hirota, Takeshi Ai
Abstract: A dual drive motive system used to control the movement or position of another system or structure in a first and second embodiment has two motors, two frame members and a ring moveably mounted between the frame members by means of suitable bearings. One of the motors provides continuous relative motion between the ring and one of the frame members which may be secured to a foundational structure. The other motor provides relative motion between the ring and the other frame member which may be secured to a turret structure. This motion avoids the transient disturbances of lubricants. In a third embodiment, the system includes two armatures which share a common stator. In operation, the armatures and stator which are concentrically positioned rotate relative to each other and in opposite directions. In a fourth embodiment, the armatures share a common stator and the armatures are coaxially positioned.
Abstract: An electrostatic motor comprising a stator and a rotor, one of which is equipped with a plurality of lands to which a voltage is sequentially applied. The other of the stator and rotor is made of conductive material. Rolling contact is established between the stator and rotor along at least one line of contact. The rolling contact is controlled to repetitive first and second paths along first and second surfaces of the stator and rotor, respectively, in which the lengths of the first and second paths are different. Embodiments include a cylindrical motor, a flexible disk motor and a conical motor.
October 13, 1988
Date of Patent:
August 17, 1993
AT&T Bell Laboratories
Robert W. Jebens, William H. Ninke, William S. N. Trimmer
Abstract: A squirrel-cage rotor includes a rotor core composed of steel sheets. Each steel sheet has in the outer circumference a number of slot-forming punched portions along the outer circumference thereof, each punched portion including a main portion and an additional portion inclined toward one of two sides along the outer circumference of the rotor relative to the position of the main portion, such that each punched portion has an unsymmetrical shape. The units include those formed by laminating the steel sheets having the respective additional portions inclined in the direrction of one side, and those formed by laminating the steel sheets having the respective additional portions inclined toward the other side. Slots are formed so as to be parallel with the rotor axis.
Abstract: A vibration generator comprises a first rotational shaft 21 and second rotational shaft 22, with fixed driving gears 31 and 33, movable driving gears 32 and 34, fixed eccentric weights 51A and 52A, and movable eccentric weights 51B and 52B, and on the outer periphery of the phase adjustment shaft 23 which is arranged in parallel therewith, spiral grooves 61 and 62 are provided at two locations in the rotative directions opposite to each other, and at the same time, on the inner periphery of a pair of phase adjustment gears 35 and 36, pins 63 and 64 are planted to be slidably fitted into the above-mentioned spiral grooves 61 and 62. Then, the phase adjustment shaft 23 is forced by a cylinder 50 in the axial direction.The vibromotive force can be varied arbitrarily and infinitely, even during operation; yet the structure is simple and rational, and is fabricated easily.
Abstract: An electronic device, such as a selective call receiver, includes a housing (302) for the electronic device preferably having a rigid member (304) fixedly integrally attached thereto and extending therefrom, the rigid member constructed to cooperatively connect with a rotatable body (308) and to secure the rotatable body (308) to the housing (302) while allowing the rotatable body (308) to rotate about the rigid member (304), a circuit supporting substrate (301) arranged within the housing (302) coupled thereto, and an alerting device (300) for providing a vibratory alert. The alerting device (300) includes coils (320) on the circuit supporting substrate (301) arranged about the rigid member (304), with each coil (322) capable of being selectively energized.
August 19, 1991
Date of Patent:
December 29, 1992
Alfred N. Danial, Richard A. Ashley, Joseph C. Benedetto
Abstract: An inner portion of a hold structure for a bearing (26) in an electrical motor, in which the output shaft receives a radial load and a thrust load, is constructed by a layer (24) of a ductile material containing iron as a main component. An inner surface of the layer (24) is machined to enhance the concentricity of the inner surface after aluminum front and rear housings (10, 14) are assembled to a stator (16). An end face (46) of the layer (24) is in tight contact with an end-hold portion (44) integrated with the front housing (10) to form a hold structure for a bearing in such a manner that a burr is not generated at an edge (B) of the end face of the layer (24) when machined.
Abstract: A superconductor-magnet system having high thrust and stability, with a method for increasing the thrust and stability of such a system, comprises a first magnet, a second magnet and a superconductor. The magnets are in motion relative to each other and the superconductor is in motion relative to one and stationary relative to the other magnet. High thrust and stability can be achieved by increasing the magnetic field of the magnet in motion relative to the superconductor. Also disclosed are magnetic thrust and journal bearings utilizing the above system.
May 16, 1991
Date of Patent:
October 27, 1992
University of Houston-University Park
Wei-Kan Chu, Ki-Bui Ma, Chase K. McMichael
Abstract: A recorder motor with an encoder, for forming an image on a record medium in accordance with image information, has the encoder on the outside of the motor case and a plastic dust-proof cover for the encoder mounted on the case. Thus, contamination by dust or ink mist is prevented, and stable and high precision motor rotation is maintained.
Abstract: A bearing for radially and axially holding a rotor with large radial dimensions about a stator has sensors (22-25) for determining tilt angles of the rotor with respect to the stator's X and Y axes, and controllers for generating control currents in control coils (17-20) associated with the stator's X and Y axes. The generated currents depend on the output signal of the sensors and, in combination with permanent magnet rings arranged on rotor, exert moments on the rotor, influencing the tilt angles. The controllers have alternating couplers which disable the connection of the tilt axes generated by gyroscopic effects. The controllers may include proportional-derivitive controllers having a gain which is modified proportionately to the square of the speed of the rotor, and a time constant which changes in inverse proportion to the rotor's speed. The central bearing for the radial movement in the X/Y direction either acts passively as a permanent magnet, or actively, as an electromagnet.
Abstract: An electric motor includes at least a stator core carrying toroidal coils wound thereon, a magnet provided in opposition to the stator core so as to constitute a part of a rotor, and magnetic flux detection elements for detecting changes in magnetic polarity of the magnet so as to control a current flowing in the toroidal coils. The stator is provided with a select number of cut portions at its open end. The number of cut portions is not less than that of the magnetic flux detection elements. The winding positions of the toroidal coils are considered in order to maintain magnetic symmetry, the magnetic flux detection elements being provided in the cut portions.
Abstract: The swing-type actuator includes (a) a housing comprising a pair of yokes opposing each other and a permanent magnet attached to at least one of the yokes for defining a magnetic gap therebetween, (b) a swingable arm having one end to which a hold member encompassing a periphery of a movable coil is fixed, and the other end to which a function member is fixed, such that the movable coil is swingable in the magnetic gap, and (c) a thin non-magnetic plate adhered to at least part of a surface of the movable coil facing the permanent magnet. The hold member is made of a thermoplastic resin and molded integrally with the movable coil and the arm, and the hold member has substantially the same thickness as that of the movable coil.
Abstract: Windingless rotor, variable reluctance, field excited, eletromechanical machines that provide for a family of windingless rotor machines consisting of both line commutated, synchronous machines, and self-commutated or self-synchronous machines, in both rotary and linear format. The basic operational format of this group of machines is a combination of an interdependent working relationship between the geometric parameters of the stator and rotor poles, and specially contoured pole surfaces and tips, all working in a complementary relationship to provide magnetically workable, variable reluctance air gaps that are capable of controlling the alternating magnetic flux waveform to effect a viable and efficient energy conversion process at substantially the fundamental frequency component, which is also the synchronous frequency of operation of the machine.
Abstract: An electromagnetic vibrating motor requires certain criteria to perform its functions. Such criteria include: achieving high amplitudes from the driven motor when compared with the relatively restricted active gap of a simple electromagnet, the amplitude of the driven member should be unaffected by weight variations or changes in resiliently constraining forces, it should have a stationary member for suspending the system without imparting substantial vibrations to the vicinity, and it should be easily connected to driven member of the system. The present invention includes three masses. The first mass is a driven mass, the second mass is an electromagnetic member and the third mass is a magnetic member. These masses are connected together through springs in order to perform its necessary functions while meeting the required criteria.
Abstract: A generator includes a permanent magnet rotor formed in a hollow rotating member rotatably mounted in a casing. A Randell rotor mounted adjacent to the permanent magnet rotor is rotated with the permanent magnet rotor. An armature coil is mounted in association with the permanent magnet rotor and the Randell (claw-tooth) rotor. A first bearing at one end of the casing supports one end of the hollow rotating member. A protruding retainer mounted on the other end of the casing carries a Randell field coil, and a second bearing is mounted on the retainer for supporting a hollow section of the hollow rotating member. The hollow rotating member is supported by the first bearing and a second bearing provided in the hollow section. The generator may be suitably applied to aerospace equipment, unmanned flying objects or to unmanned marine cruising objects.
Abstract: The rotor of a canned motor for a centrifugal pump is cooled by a heat-exchanger installed in the rotor chamber and receives liquid from the plenum chamber of the pump or from another source. Liquid entering the rotor chamber can leak therefrom by way of a flow-restricting outlet (at 10). The outlet permits gases to escape from the rotor chamber when the motor is started, but limits the leakage of liquid from the rotor chamber. Leaking liquid is admitted into the suction chamber of the pump.
Abstract: A linear-motion driving device includes a movable shaft, a gas bearing for supporting the movable shaft, a housing for supporting the gas bearing, and a motor having a voice coil for displacing the movable shaft. The bearing housing is disposed inside the voice coil.
Abstract: A non-contact self-adjusting magnetic guidance device for stabilizing the trajectory of a vehicle suspended in a magnetic field includes a guidance device extending along the guideway which determines the direction of movement of the vehicle. A magnetic unit has permanent magnets, of which has a longitudinal axis. The magnets, each of which is magnetized along its longitudinal axis, are coupled to an undercarriage of the vehicle and are disposed along a horizontal axis of the vehicle, and create opposite magnetic forces that align the trajectory of the vehicle during movement. A regulating mechanism monitors the magnitude of a vertical magnetic force exerted on the magnetic unit, and the regulating mechanism automatically reduces the difference between the vertical magnetic forces to zero.
Abstract: A method of controlling the electromagnets of a magnetic bearing comprises the steps of (1) deriving from a first sensor a first signal representative of the absolute position of a shaft supported in the bearing, (2) limiting the first signal to a first control range which defines a range of shaft displacement, from any desired position smaller than the full range of possible displacements within which the restoring force is related to the displacement sensed, (3) deriving a second signal substantially independent of the first signal and also representative of the absolute position, (4) processing the second signal to derive therefrom a third signal representing the rate of change of the absolute position over the full range of possible shaft displacements, (5) combining the first and third signals to produce a control signal, and (6) applying the control signal to control the electromagnets so as to restore the shaft to the desired position in the bearing.
Abstract: A servo-actuator has a motor driven input pinion engaging a driven gear clutched to an output pinion. The driven gear has an internally notched hub and the output pinion has a central core with a tapered pin slidable therein. Spherical cams are slidably received in a cross hole and are moved outward to lock the output pinions to the hub when a solenoid is energized, to move the tapered pin into contact with the cam members. The angle of the notch and the pin taper are chosen to effect a positive de-energization force on the pin for facilitating disengagement.