Abstract: An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.

Abstract: A power tool includes a slide switch which is configured to provide variable speed control of the rotational velocity of a drive member as well as provide ON/OFF functionality for the tool 10 based on the position of the switch. The slide switch eliminates the need for a separate switch for turning the tool on and off.

Abstract: A robotic work tool system (200) comprising a robotic work tool (100) comprising a lift/collision detection sensor (190), said lift/collision detection sensor (190) comprising a polarity element (191) and at least a first sensing element (192?) and a second sensing element (192?), wherein the polarity element (191) has a first and a second polarity and wherein the first and second sensing elements are configured to each sense a polarity of the first polarity element (191). The robotic work tool (100) is configured to detect a polarity change in the first sensing element (192?) and in the second sensing element (192?) and in response thereto determine that a lift has been detected, or detect a polarity change in the first sensing element (192?) but not in the second sensing element (192?) and in response thereto determine that a collision has been detected.

Abstract: A motor controller comprises: a rotation angle estimation unit for estimating and computing a rotation angle of a motor repeatedly based on the current and voltage of the motor without using a motor rotation angle detector; a speed calculation unit for calculating the period of the signal waveform of the rotation angle that is repeatedly estimated and calculated by the rotation angle estimation unit and for calculating an actual rotational speed of the motor based on the period; a drive signal generating unit for generating a drive signal to drive and control the motor based on at least a deviation between the actual rotational speed and a target rotational speed and the rotation angle; and a switching circuit that is switched based on the drive signal to provide drive power to the motor.

Abstract: A power tool includes a variable speed motor coupled to a drive member. A power circuit electrically connects the variable speed motor to a power source. A variable speed signal generator generates a variable speed control signal indicating an operating speed for the motor. The operating speed is dependent upon a value of a variable speed selection signal generated by a slide switch. The slide switch includes a linear slide potentiometer for generating the variable speed selection signal. An actuator slides along the potentiometer to control the value of the selection signal. The slide switch includes an ON/OFF contact and a lever arm that is movable into and out of contact with the ON/OFF contact. The actuator is configured to prevent the lever arm from contacting the ON/OFF contact when the actuator is in an OFF position in relation to the slide potentiometer thereby opening the power circuit.

Abstract: In order to achieve improvement in speed and torque of a rotating electric machine according to an inexpensive, simple, and highly reliable method, Provided is a rotating electric machine including: a stator; a rotor that is rotatably arranged with an intermediation of an air gap in a rotating shaft direction with respect to the stator; and a primary-side mechanism that rotates concentrically with a shaft center of the rotor. The primary-side mechanism includes: a fixed position rotating pulley that is arranged so as to be immovable in the rotating shaft direction; and a variable position rotating pulley that is arranged so as to be movable in the rotating shaft direction with respect to the fixed position rotating pulley. The variable position rotating pulley rotates and moves in an axial direction integrally with the rotor.

Abstract: An electric rotating machine includes a power transmission mechanism and an armature. The power transmission mechanism is equipped with a first, a second, and a third rotor. The first rotor includes n soft-magnetic members. The second rotor includes k soft-magnetic members. Note that n and k are an integer more than one. The third rotor is made up of magnets whose number of pole pairs is m where m is an integer more than or equal to one. The armature faces the third rotor. The first, second, and third rotors are arranged so as to establish a magnetic coupling among them. The soft-magnetic members of the first and second rotors and the magnets of the third rotor meet a relation of 2m=|k±n|. This arrangement is capable of achieving the transmission of power regardless of electric energization of the armature.

Abstract: The utility model discloses an electric heating device with an output greater than an input, including a stator, a rotor, an input controller and a base, characterized in that: the stator is composed of a permanent magnet and an electromagnet, the permanent magnet is disposed externally to the electromagnet. The rotor is composed of a rotor body and a rotor shaft, the rotor body is wholly or partly formed of ferromagnetic material. An end portion at one end of an electromagnet core faces the rotor body and remains a gap with the rotor body. The end portion may be magnetized with an N pole or an S pole under an action of the external permanent magnet. The input controller is connected with an electromagnetic coil. The utility model not only may achieve an output greater than an input, but also may achieve a 100% “output efficiency”.

Abstract: An exterior rotor switched reluctance machine includes a stator, a rotor adjacent the stator and adjacent a housing, the housing connected to the stator. The stator further includes a back iron, a set of stator poles connected to the back iron and a set of windings disposed between the set of stator poles. The rotor, connected to a shaft and rotatively coupled to the stator, further includes a set of rotor segments. The set of windings includes a set of phases, each phase experiencing a flux linkage that varies with an angular position of the rotor. The apparatus operates as a motor in response to selectively energizing the set of phases with a set of current pulses. The apparatus operates as a generator in response to rotating the shaft.

Abstract: A stepper motor is provided in which a permanent ring magnet is sandwiched in an outer part of the stator winding assembly located far from the gap between rotor and stator teeth, so that magnetic flux in the gap is dominated by the Ampere-turns of energized stator coils and therefore more easily controlled for reduced vibration at low stepping speeds. The rotor need not contain any permanent disk magnet. If one is provided, it can be completely embedded within the rotor and merely supplement the primary flux from the stator to enhance torque. In most cases, where the rotor lacks any permanent magnet, the motor's axial shaft can have a larger diameter and may, together with the rotor, form a linear actuator.

Abstract: A method of activating an electric machine having a stator, and a rotor which rotates about an axis with respect to the stator; the stator having a plurality of stator segments arranged about the axis; the rotor having modules made of magnetizable material and arranged about the axis; and the method including the steps of connecting the rotor to the stator by means of a bearing; and magnetizing the modules of magnetizable material when the rotor is connected to the stator.

Abstract: A magnetic gear arrangement is provided having a magnetically active gear member that generates a first magnetic field, which is modulated by interpoles. The modulated magnetic field generates magnetic poles on a magnetically passive gear member, and these poles form a second magnetic field. The material of the passive gear member is sufficiently magnetically hard that the first and second magnetic fields interact to couple the motion of the active and passive gear members according to a given gear ratio.

Abstract: A switched reluctance motor includes a stator and a rotor, the stator having stator poles supporting a magnetic field focusing device such as a near field plates on each stator pole tip. An example near field plate has a spatially modulated surface reactance configured so as to focus magnetic flux extending from each pole tip within at least one region of increased magnetic field proximate the pole tip.

Abstract: An assembly includes multiple adjoined rotor sections each having multiple poles and multiple void rows therethrough that are radially distributed in each of the poles. The rotor sections are skewed in a circumferential direction. The assembly also has multiple conductive rings that substantially surround one of the void rows. A method of assembly and electric machines and vehicles using the assembly are also disclosed. Aspects reduce torque ripple in electric machines and allow for encoderless/sensorless operation in an electric machine using the rotor assembly. The present invention has been described in terms of specific embodiment(s), and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.

Abstract: Disclosed herein is a switched reluctance motor assembly including: a shaft forming the center of rotation of a motor; a rotor part rotatably coupled to the shaft; a balancing member including the rotor part and formed so as to enclose the shaft; a sensor magnet coupled to a lower end portion of the balancing member in an axial direction; and a printed circuit board having a hall sensor attached thereto so as to face the sensor magnet at a lower portion of the sensor magnet in the axial direction. According to the present invention, the coupling precision of the sensor magnet for sensing the position of the rotor part forming the rotor of the switched reluctance motor assembly may be improved.

Abstract: A step motor used to adjust a headlight's up and down includes a supporting pole, a magnet, a coil and a circuit board. The circuit board has a power input terminal subsequently connected with a voltage regulator IC, a control IC, a transistor and a driver. In addition, the driver is connected with the coil; the control IC is connected with a signal input terminal further connected with a vehicle compute; the power input terminal is connected with a vehicle power source. So when a vehicle is started, power can flow through and regulated by the voltage regulator IC. Then it runs through the control IC to command the driver to drive the negative coil to induce the magnet to rotate clockwise or counterclockwise, enabling the supporting pole to move inward or outward to horizontally balance the headlight.

Abstract: Implementations of actuators and capacitor-based position sensors for monitoring and controlling positioning of the actuators are provided, including implementations of actuators that use flexures to provide support to actuators and pivoting mechanisms to the actuators. Such actuators can be electromagnetically activated actuators that include a magnet stator and a coil rotor mounted on a flexure. A positioning sensor, such as a capacitor sensor, is provided to measure and monitor positioning of the actuator and is coupled to a feedback circuit which uses the measured positioning of the actuator to control the actuator.

Abstract: A novel electric motor rotor structure, particularly desirable for use with brittle rare-earth-magnets, offers improved resistance to rattling and axial shifting. This is achieved by forming the rotor with an annular central yoke connecting to a plurality of pole shoes along the periphery of the rotor and defining a magnet-receiving recess or pocket 160 between each pole shoe and the central yoke. Spaced circumferentially between adjacent magnets 38 are regions 146 of reduced magnetic conductivity, which include relatively thin metallic holding segments, which connect adjacent pole shoes to each other and to the central yoke. During manufacturing, tools are applied to upset or crimp the holding segments, and thereby form spring elements, to hold the magnets in stable positions and resist any tendency of the magnets to rattle or axially shift during motor operation. One obtains the same power level from a smaller, and therefore lighter, motor than was previously possible.

Abstract: Disclosed herein is a multi-phase switched reluctance motor apparatus including: a multi-phase switched reluctance motor; a position sensing sensor provided at one side of the multi-phase switched reluctance motor; and a controller connected to the multi-phase switched reluctance motor and the position sensing sensor and controlling power in a multi-phase excitation scheme according to a detection angle of the position sensing sensor to supply the power to the multi-phase switched reluctance motor. The multi-phase switched reluctance motor may generate a reluctance torque while reducing torque pulsation, noise, and vibration.

Abstract: An integrated starter generator device comprising a housing, a stator and a rotor contained within the housing, the device further comprising control electronics operable to configure the device as either a starter or generator and contained entirely within the housing. The device may include a high current terminal having brass and rubber bonded together. The rubber forms both a sealing and an insulating function.

Abstract: Disclosed herein is a switched reluctance motor including: a rotor part including a rotor core of which a shaft is fixedly coupled to a central portion and a plurality of rotor poles protruding from the rotor core; a stator part including a stator yoke rotatably receiving the rotor part therein and a plurality of stator salient poles protruding from the stator yoke so as to face the rotor poles; and auxiliary rotor poles coupled to outer portions of the rotor poles to rotate integrally with the rotor part.

Abstract: Disclosed herein is a switched reluctance motor in which a position detection part capable of detecting a rotational position of the rotor part is formed in a balancing member coupled to a rotor part and a sensor part is positioned at a position corresponding to that of the position detection part and on a cover surface of an inner side of the motor housing. According to a preferred embodiment of the present invention, the sensor part is positioned in the motor housing, thereby making it possible to protect the sensor part and improve reliability in sensing of a rotational position of the rotor part by the sensor part.

Abstract: Disclosed herein is a switched reluctance motor including: a rotor part including a rotor core having a shaft fixedly coupled to the center thereof and a plurality of rotor poles formed to be protruded from the rotor core; a stator part having the rotor part rotatably received therein and a plurality of stator salient poles formed to be protruded from the stator yoke; a balancing part selectively coupled to an upper portion or a lower portion of the rotor part and having a plurality of sensing grooves formed in an outer peripheral surface thereof; a motor housing provided with an opening part through which the shaft penetrates; and a position detecting unit disposed between the rotor part and the stator part and coupled to an inner portion of the motor housing.

Abstract: A method of activating an electric machine having a stator, and a rotor which rotates about an axis with respect to the stator; the stator having a plurality of stator segments arranged about the axis; the rotor having modules made of magnetizable material and arranged about the axis; and the method including the steps of connecting the rotor to the stator by means of a bearing; and magnetizing the modules of magnetizable material when the rotor is connected to the stator.

Abstract: Cooling apparatus and methods for a fractional-horsepower motor. Motor cooling apparatus includes a heat shoe, a heat diffuser, and a heat pipe coupled therebetween. The heat shoe is configured to partially cover a portion of, and to receive motor thermal energy from, the motor. The heat pipe is coupled to the heat shoe, and is configured to convey the motor thermal energy from the heat shoe. Heat diffuser can be coupled to receive motor thermal energy from the heat pipe. It is configured to diffuse at least a portion of the motor thermal energy into an ambient atmosphere. A thermal sensor is coupled to the motor and configured to sense a motor thermal condition; and a fan can be coupled to the thermal sensor through a controller. The controller is configured to control the speed of the fan relative to the motor thermal condition sensed by the thermal sensor.

Abstract: A stepping motor for a meter to rotate a pointer of a meter, the stepping motor for a meter includes: a rotor part having: a cylindrical magnet; and a rotational shaft, which is hollow and made of a resin, and which is molded on an inner periphery of the cylindrical magnet and is coaxial with the cylindrical magnet; a stator part that contains the rotor part therein and has an excitation coil; a front plate made of a resin, and an end plate made of a resin, wherein a fixing part to fix the cylindrical magnet is molded when molding the rotational shaft, and wherein the cylindrical magnet is fixed by the fixing part so that the cylindrical magnet and the rotational shaft are integrated.

Abstract: Electric motor cluster consisting of several stator sections each possessing a minimum of two salient pole projections, wound with power windings, and each section containing a single rotor. Each individual motor is angularly displaced one from the other, while mounted within a common housing, and geared together such that each motor section contributes to the rotation of a common output shaft. Each motor comprises at least one stator and one rotor section, such that each rotor section is associated with a specific stator section. The lateral axis of each rotor section is disposed at an oblique angle with respect to the axis of the shaft for that particular motor.

Abstract: A rotary actuator includes a stator on which a sensor surface is arranged and a rotor configured to rotate about the stator. The rotor forms an actuating surface for the sensor surface. An interval fixing device such as a rotationally fixed sliding disk is arranged between the actuating surface and the sensor surface. A spring is configured to press the sensor surface towards the actuating surface.

Abstract: A apparatus is provided in which, in a state before being assembled to a drive target, one end of a rotating shaft is not supported by a bearing, and in this state, the rotating shaft is pressed to the side of a bracket by coil springs and thus centering of the rotating shaft is maintained. In this way, axial run-out of the rotating shaft before a magnetic motor is assembled to the drive target is inhibited. Thus, damage and deterioration in assembly efficiency as a result of axial run-out of the rotating shaft can be inhibited, such as deterioration in assembly efficiency caused by adhesion between a magnet and coils wound on an armature core, for example.

Abstract: Implementations of actuators that use flexures to provide support to the actuators and pivoting mechanisms to the actuators. Such actuators can be electromagnetically activated actuators that include a magnet stator and a coil rotor mounted on a flexure.

Abstract: A spindle motor for use in a disk drive apparatus includes stationary and rotating portions. The stationary portion includes a shaft including a thrust plate. A sleeve portion includes an axial end surface arranged opposite the thrust plate. A first seal member is arranged opposite the thrust plate on an opposite side with respect to the sleeve portion. The thrust plate preferably includes a plate communicating hole arranged to connect first and second thrust gaps defined, respectively, between the thrust plate and the sleeve portion and between the thrust plate and the first seal member. The sleeve portion preferably includes a sleeve communicating hole arranged to connect the first thrust gap with an opposite axial side thereof. A lubricant is arranged to fill a communicating channel extending from a first to a second capillary seal portion through the plate communicating hole and the sleeve communicating hole.

Abstract: A motor includes a turntable and a rotor holder unified with each other by insert-molding. The turntable includes a protrusion portion protruding radially outward beyond a cylinder portion and a substantially cylindrical covering portion extending downward from an radial inner end of the protrusion portion to cover an outer circumferential surface of the cylinder portion. The rotor holder has a radial outer end portion arranged in the same radial position as an outer circumferential surface of the covering portion or arranged radially inward of the outer circumferential surface of the covering portion. For this reason, a sliding contact area between a mold and the rotor holder is reduced. This helps suppress sliding contact between the mold and the rotor holder during a mold releasing process, consequently suppressing degradation of the mold.

Abstract: A linear actuator, in particular for adjusting the flaps in motor vehicle turbochargers. The linear actuator has an adjusting element that can be linearly displaced by an electric motor. The electric motor is a two-phase transverse flux machine. A rotor is arranged between two opposite single-phase stators, and the rotor is connected in a rotationally fixed manner to a rotatable and linearly stationary rotational element that engages with the linearly movable adjusting element in order to cause a linear movement of the adjusting element when the rotational element is rotated.

Abstract: A variable reluctance machine is disclosed, such as a switched reluctance machine, the machine having a rotor, a stator, a housing, and a magnetic eddy current dampening component disposed between stator and housing. The magnetic eddy current dampening component not only reduces the eddy current's impact on surrounding electronics, it also assists in increasing the efficiency of the switched reluctance machine.

Abstract: The invention relates to a gear motor including a multiple-phase electric motor formed by a stator portion excited by electric coils and by a rotor having N pairs of poles radially magnetised in alternating directions, the stator portion including two angular sectors alpha-1 and alpha-2 with respective radii R1 and R2, comprising wide teeth and narrow teeth radially extending from an annular crown, characterised in that the wide teeth have a width higher than or equal to twice the width of the narrow teeth, in that the notch width is higher than the width of a narrow tooth, in that the angular sector alpha-1 is lower than 220° and includes all the coils, and in that the ratio R1/R2 ranges from 1.2 to 2.

Abstract: A stator 3 is provided with a plurality of magnetic poles 3a on the outer circumference thereof, and is configured from a plurality of layers of plate-shaped members. A rotor 4 is rotatably disposed around the stator. The inner circumferential face of the rotor is provided with a magnet 5. The outer circumferential ends of the magnetic poles of the stator are provided with an extended portion that is bent such that at least one plate-shaped member, including an outermost layer, of the plurality of plate-shaped members is substantially parallel to the magnet. When the inner diameter of a bent portion of a plate-shaped member that is the closest to the magnet of the at least one plate-shaped member constituting the extended portion is taken as R1i, and the thickness of the closest plate-shaped member is taken as T1, R1i<T1 is satisfied. Accordingly, it is possible to improve the driving efficiency of an outer rotor-type motor.

Abstract: A speed-variable single phase induction motor. By a plurality of stators disposed with an interval therebetween and a plurality of magnetic rotors corresponding to the respective stators, the motor implements a high efficiency and a speed-variable performance such as a brushless direct current (BLDC) motor with a low cost without using an expensive inverter driving apparatus.

Abstract: A subsea pump drive employs a permanent magnet (PM) motor to drive a subsea pump. The PM motor rotor in one embodiment is canned with a non-magnetic material such as inconel that can provide a desired level of corrosion protection. The PM motor provides a subsea pump drive that is smaller and more efficient, having a high power factor than a subsea pump drive utilizing a conventional induction motor. The PM motor subsea pump drive eliminates the necessity for a topside storage tank and associated fluid transfer lines when the motor rotor is cooled with processed fluid.

Abstract: The present invention comprehends a gerotor or gear pump driven by a permanent magnet motor which exhibits cogging torque, i.e., resistance to rotation when de-energized caused by interaction between permanent magnets in the rotor and teeth on the stator. Such interaction causes the rotor to come to rest in one of many defined rotational positions and resist rotation when electrical power to the motor has been terminated. The permanent magnet motor is coupled, preferably directly, to a gerotor pump having meshing rotors or a gear pump having meshing gears. When the motor is de-energized, the pump rotors or gears come to rest and their rotation is resisted by the cogging torque of the motor. The invention finds particular application in automotive transmissions and systems with parallel pumps.

Abstract: The invention disclosed is a magnet engine, more specifically an engine that derives its power from the power contained in a magnet (22) and employs a cam or barrel drive mechanism (28) to translate the power in the magnet (22) into useful power output. The magnet engine is comprised generally of one or more in-line reciprocating magnet (22) and piston (20) component pairs arranged circularly around and parallel to a central axis, one or more variable magnetic field conductors (23) positioned generally between and generally equidistant from each of the magnet (22) and piston (20) components, in a magnet (22) and piston (20) component pair, that effect a reciprocating motion in the magnet (22) and piston (20) components, and one or more cam drives (28), positioned concentric to the magnet (22) and piston (20) component pairs, that are employed to translate the reciprocating motion of the magnet (22) and piston (20) component pairs into rotary motion.

Abstract: The electric motor device is provided. The electric motor device includes: a first drive member that has a plurality of permanent magnets; a second drive member that has a plurality of electromagnetic coils; and a clearance controller that shifts at least either one of the first drive member and the second drive member, thereby changing a size of a clearance formed between the first drive member and the second drive member.

Abstract: To enable control the number of revolutions of a wheel with a new structure different from an induction motor and adjust the maximum torque rapidly and accurately. A linear drive travel system includes a metal wheel 20 having a drum rotor and a stator 30 arranged inside the metal wheel 20. The stator 30 includes a plurality of rows of electromagnets 32 arranged in the direction of rotation axis, each row being formed of a plurality of electromagnets 32 arranged along the circumference around a rotary shaft 40. A drum rotor includes a plurality of arc-shaped rotor cores 23 arranged along the circumference around the rotary shaft 40. Control means (control system 80) performs control by allowing electromagnets 32 in some rows to be a magnetization coil of the rotor core and by allowing the electromagnets 32 in other rows to be a rotation coil of the drum motor.

Abstract: A motor is disclosed comprising: at least one stator comprising a magnetic core and at least one magnetic winding, having a cylindrical internal cavity; at least one cylindrical rotor inside said stator, comprising magnetically conductive materials; said rotor having an outer diameter significantly smaller than the inner diameter of said stator, being eccentrically mounted with respect to said stator and able to move within, said fixed member; wherein magnetic normal force is induced in said stator periodically, whereby said rotor is periodically moved by magnetic force with respect to said stator, whereby rotary motion is produced; said motor further having: an output shaft concentric with said stator; transmission means for absorbing oscillation and transmitting rotation; wherein said induced magnetic normal force rotates around the circumference of said stator, such that a contact patch between said rotor and said stator rotates around the inner circumference of said stator; whereby said rotor oscillates a

Abstract: A permanent magnet (PM) machine has a reconfigurable fault condition mechanism disposed solely within a stator core portion, wherein the mechanism is automatically reconfigurable to reduce fault currents associated with the PM machine during a fault condition. The reconfigurable fault condition mechanism is automatically reconfigurable to also reduce internal heat associated with the PM machine during a fault condition. A method of reconfiguring the fault condition mechanism upon detection of a fault condition includes the steps of 1) selecting the reconfigurable fault condition mechanism from a) a plurality of rotatable magnetically anisotropic cylinders disposed within stator core slots, b) a plurality of ferrofluid-fillable cavities associated with stator core slots, and c) a sliding shield within the stator core; and 2) reconfiguring the fault condition mechanism to automatically reduce fault currents associated with the PM machine upon detection of a fault condition.

Abstract: A motor drive system 10-1 for a railway vehicle is capable of reducing the weight of wiring, electromagnetic noise, and manufacturing cost. The motor drive system includes an inverter 11. The inverter is configured to control a motor 13-1 and is divided into at least two separate inverter units that are arranged integrally with the motor.

Abstract: The present invention provides a heat-pipe generator. The blade is assembled into the heat pipe, a magnetic rotor is arranged around the blade, and generating coils are assembled externally onto the heat pipe opposite to the magnetic rotor. When the working liquid within the heat pipe is evaporated into vapor to drive the blade and the magnetic rotor, the generating coil outside of the heat pipe will yield inductive power, thus maintaining a vacuum state in the heat pipe for heat conduction. The magnetic rotor and generating coils may generate power accordingly.

Abstract: A magnetic motor which includes an elongated, horizontally disposed frame having a drive shaft rotatably mounted therein with the drive shaft being supported at its opposite ends by titanium bearing blocks. Opposing first and second slide panels having bar magnets at the inner surfaces thereof are movably mounted on the frame and are movable towards the drive shaft which has magnets mounted thereon in a helical fashion. As the slide panels with the magnets thereon are moved towards the drive shaft, the magnets on the slide panels will cause the magnets on the drive shaft to be repelled thereby causing the rotation of the drive shaft. Movement of the slide panels is controlled by actuators.

Abstract: The objects of the present invention is to provide a stepping motors capable of rotating with not only high speed but also less undesired vibration and noises, and moreover enabling a simpler, smaller manufacturing equipment thereof to be constructed.

Abstract: A yarn processing system which includes a yarn feeding device and an accessory device associated with the yarn feeding device. The accessory device has a device which is driven using a signal representing the rotational speed of a component of the yarn feeding device. The signal is generated by an electronic sensor galvanically separated from the control system and the drive mechanism of the yarn feeding device. The sensor also is structurally independent from the yarn feeding device. The sensor is located at or close to the yarn feeding device at a mounting location where a part of a rotating magnetic field is detected by the sensor at the mounting location. The part of the magnetic field originating from inside of the yarn feeding device is not used for the operation of the yarn feeding device at the mounting location of the sensor.

Abstract: A turbomolecular pump device having a DC brushless motor provided with a simplified rpm detection mechanism is provided. A pickup coil for detecting a magnetic flux produced by a permanent magnet of the DC brushless motor is built in the motor. Namely, a small size, low cost, simple and strong pickup coil is disposed in a space between the permanent magnet (rotor) of the DC brushless motor and the motor drive coil (stator coil). The magnetic flux produced by the permanent magnet in the pickup coil is detected. This is converted into an rpm signal of the DC brushless motor by a sequence controlling circuit. It is supervised whether or not the overspeed is performed. Then, when the overspeed is detected, an interruption command is fed to the power source breaker so that the supply of the power is forcibly interrupted to thereby stop the DC brushless motor.