Abstract: A motor is constructed such that the amplitude of a current phasor of each of the slots on a stator when three-phase sinusoidal current is applied to each phase of the motor in a permanent magnet synchronous motor and reluctance motor. The number of windings of each phase looped through each of the slots is determined such that a phase of each current phasor of each of the slots is coincident with a phase in terms of electrical degrees in a direction of rotor rotation of each of the slots. A center position of each magnetic pole of a rotor steel plate is shifted to the direction of rotor rotation by slot pitch/NRR, 2×slot pitch/NRR, 3×slot pitch/NRR, . . . , 1-slot pitch against a position divided equally into 360°/NRR, where NRR is the number of poles. The stator and the rotor are relatively skewed by the slot pitch/ NRR.

Abstract: In a switched reluctance motor and control system for such a motor, a rotor comprises four salient poles each having a width of about 50-degrees, and a stator has six salient poles each having a width of about 30-degrees. One Excitation winding is mounted around each stator salient pole and these are connected in series. An excitation drive circuit supplies a dc excitation current to each excitation winding to excite the motor in accordance with an excitation command signal. A torque-current drive circuit renders a current, whose magnitude in accordance with a torque command, to flow into torque windings mounted one round on each of the six stator salient poles successively according to the angle of rotation of the rotor.

Abstract: A synchronous motor comprising permanent magnets (35, 41) with N poles arranged at ends of N magnetic poles of a rotor, permanent magnets (38, 34) with S poles arranged at ends of S magnetic poles of the rotor, magnetic pole portions (40) made of soft magnetic member at middle portion of the N magnetic poles of the rotor, and magnetic pole portions (39) made of soft magnetic member at middle portion of the S magnetic poles of the rotor. The synchronous motor has a structure in which the respective N and S magnetic poles are shifted in the rotor rotation direction relatively by NN/NR of a stator slot pitch, wherein NN and NR are integers equal to or less than the number of poles formed in the rotor.

Abstract: A controller for a reluctance type synchronous motor. When field current control depends solely on a rotor speed, large power consumption and heat generation of a motor may be caused. Also, when a field current is small, torque consumption becomes small, resulting in a prolonged acceleration time. To address the above problems, there is provided a section for generating a field current command SIFC using a field current compensation coefficient SKF having been obtained based on a torque command STC. With this arrangement, a large field current SIFC flows when a torque is needed, and a small field current SIFC flows when torque is not needed. There is also provided a section for generating an armature current command SIAC using armature current command compensation SKA having been obtained based on a field current command SIFC. With this arrangement, variation of a torque constant due to variation of a field current is converted into an armature current command SIAC based on a field current command SIFC.

Abstract: The present invention is designed to realize structure having high rigidity in any direction and to realize a parallel mechanism machining device having good chip removal property. According to the present invention, forked adjustable joints 28 are provided at two positions near the tip end of a movable body 20 and near the rear end thereof, respectively, two first links 36 and two second links 37 are attached to the movable body 20 and the tip ends of these links are extended in X and Y axis directions and coupled to a machine-side fixed platform through adjustable joints, respectively. A link 5 extending in Z axis direction is attached to the rear end of the movable body 20 and a restriction link 6 is attached to the back of the forked adjustable joint 28 near the tip end.

Abstract: A motor with small ripple and capable of high-speed rotation includes six stator poles having widths of about 60 degrees, which is less than 60 degrees when converted to rotor rotational angle. Excitation windings (HA3, HA4, and so forth) wound around the stator poles are connected in series with adjacent excitation winding connected in reverse series. Torque windings (HA1, HA2, and so forth) wound around the stator poles have three phases, where each phase winding comprises a pair on opposite sides with respect to the center of rotor rotation, separated from each other by 180 degrees, and connected in reverse series. In addition, two rotor poles (3) having widths from 60 degrees to 120 degrees when converted to the rotor rotational angle are provided.

Abstract: A permanent magnet motor is provided comprising a plurality of individual permanent magnets 7 threaded inside of a rotor, an N pole magnetic circuit commonly connected to N poles of the plurality of individual permanent magnets 7, an S pole magnetic circuit commonly connected to S poles of the plurality of individual permanent magnets 7, a plurality of N pole magnetic poles 5 positioned on the rotor surface, the N pole magnetic poles 5 being a part of the N pole magnetic circuit, and a plurality of S pole magnetic poles 6 positioned alternately with the N pole magnetic poles 5 in the rotational direction of the rotor, the S pole magnetic poles 6 being a part of the S pole magnetic circuit, wherein the change rate of the rotation of flux linked to the stator winding is increased to output a large torque.

Abstract: A reluctance motor is provided that reduces leaking magnetic flux. To generate magnetic flux between adjacent magnetic poles in a rotor 2, permanent magnets 4 are disposed in approximate centers of split magnetic paths near a borderline area between two magnetic poles in an internal portion of the rotor. Further, each of slots 8 in a stator 1 is wound with a coil of a corresponding phase such that the vector phase and amplitude expressed by the products of the number of coil turns and the amount of passing current, namely, ampere-turns, become almost identical for each of the slots. By reducing leaking magnetic flux according to this arrangement, generated torque can be increased. As the rotor mechanical strength is enhanced, the rotor can be safely driven at a higher speed. A practical motor is obtained that simultaneously achieves improved motor characteristics and reduced torque ripples.

Abstract: In a switched reluctance motor and control system for such a motor, a rotor comprises four salient poles each having a width of about 50-degrees, and a stator has six salient poles each having a width of about 30-degrees. One Excitation winding is mounted around each stator salient pole and these are connected in series. An excitation drive circuit supplies a dc excitation current to each excitation winding to excite the motor in accordance with an excitation command signal. A torque-current drive circuit renders a current, whose magnitude in accordance with a torque command, to flow into torque windings mounted one round on each of the six stator salient poles successively according to the angle of rotation of the rotor.

Abstract: The object of the present invention is to increase thrust generation of a linear motor, and to achieve miniaturization and the low price of a linear motor by improving a magnetic circuit. In order to achieve the object, the present invention provides a linear motor including a magnetic yoke for the north pole 8 which is commonly connected to the magnetic pole N of permanent magnets 4, a magnetic yoke for the south pole 9 which is commonly connected to the pole S of permanent magnets 4, a magnetic north pole 5 forming a part of magnetic yoke for the north pole 8 and being mounted on the surface of a slider 3, a magnetic south pole 6 forming a part of magnetic yoke for the south pole 9 and being mounted on the surface of a slider 3 so as to be alternately located in a traverse direction of the slider 3 with the magnetic north pole 5.

Abstract: The object of the present invention is to increase torque generation of a motor, to minimize a motor size, and to reduce a motor cost by improving a magnetic circuit of a rotor. In order to achieve the object and make effective use of the power of each permanent magnet within the entire motor, the present invention provides a motor comprising magnetic circuits for the pole N 5 commonly connected to the north pole of permanent magnets 7, magnetic circuits for the pole S 6 commonly connected to the south pole of permanent magnets 7. Also, the motor further comprises magnetic poles N in the shape of protruding poles of the north pole and the magnetic poles S in the shape of protruding poles of the south pole. The magnetic poles N, forming a part of the magnetic circuits for the pole N, are placed on a part around the perimeter of the rotor, and the number R of the magnetic poles N is different from the number m of stator poles.

Abstract: In an armature current limit value calculator section, limitation is applied to a pre-limitation torque command ST in correspondence with a presently detected speed SPD, to calculate a torque command STC. Meanwhile, in a field current calculator section 12, a pre-correction field current command value SF is decreased in correspondence with the detected speed SPD when the speed is large. In addition, a coefficient K.tau. which increases when the torque command is large is calculated on the basis of the pre-limitation torque command ST at this time. Further, a field current command is calculated from an equation SFC=K.tau.*SF. A current command calculator section 3 prepares a current command on the basis of the torque command STC and the field current command SFC supplied, and drives an electric motor 5 via a current control section 4.

Abstract: A reluctance type synchronous motor comprises: a stator with a plurality of slots placed at an even pitch angle wherein stored inside each slot is a stator winding for creating stator magnetic poles with a predetermined phase alternating current being supplied thereto. A rotor sustained by a shaft and changing magnetic reluctance in its circumferential direction by inclusion inside of a plurality of magnetic isolating portions creates desired magnetic poles. At least one of the central angles between magnetic poles created at the rotor is shifted from the other central angles so that torque ripples during rotation can be reduced.

Abstract: A motor control device that can control the rotational direction of a rotor with polarity in an initial position detection. The motor control device includes first metering voltage signal generating system for sequentially creating 2N-phase signals to an N-phase motor, current metering system for measuring stator winding current, and first rotational position arithmetic system for detecting an absolute rotational position corresponding to an electrical angle of 180.degree. based on the measured current.

Abstract: An angular contact bearing (100) has a plurality of first and second rolling elements (1,2) interposed between a rotating shaft (3) and a fixed part (4). An outer ring (5) is secured to the fixed part (4). Formed on the inner periphery of the outer ring (5) is a first rolling contact surface (1a) which is in contact with the first rolling elements (1) on the fixed part side at a predetermined angle. An inner ring (8) is secured to the rotating shaft (3) by nuts (9). Formed on the outer periphery of the inner ring (8) is a second rolling contact surface (1b) which is in contact with the first rolling elements (1) on the rotating shaft side at a predetermined angle. Formed on its inner periphery is a third rolling contact surface (2a) which is in contact with the second rolling elements (2) on the fixed part side at a predetermined angle. An Angular member (6) is secured to the outer ring (5). The Angular member (6) has a fourth rolling contact surface (2b) formed on its inner periphery.

Abstract: In a reluctance type synchronous motor, a rotor has magnetic poles which have a low magnetic reluctance in an axial direction of the magnetic poles, and have a high magnetic reluctance toward a circumference of the rotor. The magnetic poles have less components orthogonal to axes thereof, so that armature reaction will be reduced.

Abstract: An electric motor generates a large torque despite its small size, causes small torque ripples, and is able to perform field-weakening control when the number of revolutions is large. The electric motor comprises a stator having m portions where large magnetic resistance and small magnetic resistance exist in the radial direction around the entire circumference, and a rotor having n portions where large magnetic resistance and small magnetic resistance exist in the radial direction around the entire circumference. The value .vertline.m-n.vertline. is an integer less than 3, m and n are large numbers. The stator is provided with two-pole, multi-phase stator windings. The structure such that the salient poles of the stator and rotor are shifted slightly from each other enables the motor to generate large torque and cause only small torque ripples.

Abstract: A position detecting apparatus utilizing optical interferometry changes the wavelength of a light beam from the light source. The variation in the wavelength causes an increment and decrement Cx, Co in the number of waves in the measurement and reference lengths Lx, Lo. The position data calculating section calculates the measurement length Lx on the basis of the detected increment and decrement Cx, Co and the reference length Lo according to an equation, Lx=Lo(Cx/Co). The position detecting apparatus can easily detect an absolute position of an object to be detected.

Abstract: A motor controller includes a power source VG for driving a motor 1, a power source VRG for regenerating energy generated in the motor 1, and a power converter for transferring energy from the power source VRG to the power source VG. Windings of the motor are connected, at their opposite ends, to the power source VG and collectors of transistors TR1 to TR3, respectively. Diodes D1 to D3 are connected to nodes of the windings and the transistors TR1-TR3 such that magnetic energy generated in the motor 1 is supplied to the power source VRG. This configuration enables the motor controller to have a reduced number of transistors for driving the windings, and the power sources to be effectively utilized. Further, the motor controller can use a discharge circuit of small power consumption type, which can reduce heat generated in the motor controller.

Abstract: An electric motor control system compensates torque ripples to control the rotation of an electric motor more accurately. Compensated current amplitudes corresponding to the torques, speeds and rotational positions in the electric motor are stored in a memory 61. Address setting unit 91 prepares a read address AD.sub.1 in the memory 61 from the torque command T, speed information VL and rotational motor position P. The prepared read address AD.sub.1 is then used to read a torque error compensation data MD.sub.1 from the memory 61. An adder 12 adds the torque error compensation data MD.sub.1 thus prepared to the torque command T to determine current amplitudes AM in the electric motor. Three-phase current setting unit 10 sets three-phase AC current commands CU, CV and CW based on the current amplitudes AM and rotational motor position P. Thus, the rotation of the electric motor can be accurately controlled.