Abstract: In an AC servomotor constructed so that the outer circumference (21b) of a stator core (21) formed by laminating thin steel plates (22) is used as part of a motor housing, bearing mounting bores (25a, 26a) for receiving bearing members (27, 28) to be mounted on a pair of brackets (25, 26) attached to the front and rear ends of the stator core (21) and mounting surfaces (25b, 25c) of the motor are formed with accurate concentricity and squareness with reference to the center bore (21a) and the outer circumference (21b) of the stator core (21) after firmly joining the brackets (25, 26) to the stator core (21). Thus, a rotor (29) is supported with high accuracy in concentricity with the stator core (21) on the brackets (25, 26) and the squareness of the output shaft (29a) to the mounting surfaces (25b, 25c) is established.

Abstract: A rotor for a synchronous motor, having a plurality of first magnetic poles formed by a plurality of permanent magnets respectively and disposed at practically equal circumferential intervals on the outer circumference of a yoke fixed to a rotatable motor shaft, and a second magnetic pole projecting radially from the yoke adjacently to each first magnetic pole and the second magnetic pole wherein the shape of the pole face of each first magnetic poles are in a circular arc and the shape of the pole face of each of second magnetic pole is determined by a given equation so that the magnetic flux distribution established by a pair of the first magnetic pole and the second magnetic pole is substantially equivalent to a sinusoidal magnetic flux distribution in the sweeping effect by the armature coils of each phase of the stator.

Abstract: A permanent-magnet field synchronous motor comprises a rotor body (22) having a cylindrical outer surface. A plurality of permanent magnets (25) attached to the cylindrical outer surface of the rotor body and arranged in the circumferential direction thereof form a field system. Each of the permanent magnets has an outer surface (25b) which extends circumferentially in parallel to the cylindrical outer surface of the rotor body and also has a constant thickness in the whole thereof. The inner surface and the outer surface of each of the permanent magnets has a certain configuration, respectively, each of which is composed of a plurality of straight lines and approximates to a contour line consisting of half-sine curves (S.sub.1, S.sub.2) extending between the circumferential opposite ends of each of the permanent magnets when developed in a plane surface.

Abstract: A synchronous machine comprising a stator (41) having armature windings matching to a .phi. phase power source and S number of slots (42) accommodating the armature windings, and a rotor (31) having a number of field poles (32) identical with the P number of poles of the rotor (31) and magnets (33) for exciting the field pole (32), in which where the number of the slots per pole per phase S/P.phi. is expressed by an irreducible fraction m/n, the length (W) of the portion of the field pole (32) facing to the slots (42) of the stator (41) along the circular direction is selected out of the integer multiple value of 1/n of the slot (42) pitch length (L) in the stator (41), whereby slot ripple is reduced and the lack of uniformity of the velocity at light load operation is decreased when the synchronous machine is used as a servomotor.

Abstract: A permanent magnet rotor assembly has a rotor shaft (11), and a plurality of yokes (12) extended along the axis of the rotor shaft at circumferential intervals around the rotor shaft. Permanent magnets (13) extended along the axis of the rotor shaft are held between two adjacent yokes. A pair of end plates (14, 15) attached to the axially opposite ends of the yokes are formed of a nonmagnetic material. Bosses (14a, 15a) fitting the outer circumference of the rotor shaft are formed in the respective central portions of the end plates. The bosses of the end plates are secured to the outer circumference of the rotor shaft by the compressive force of fastening rings (18, 19) mounted on the bosses by thermal shrinkage insertion.

Abstract: A motor with DC brake having a DC electromagnetic brake (10) arranged on the shaft (14) of the rotor (16) thereof, in which a partial shaft (14b) extending through and outward from the DC electromagnetic brake (10) is formed of a nonmagnetic metal material. A partial shaft (14a) extending through the rotor (16) is formed of a free cutting metal material, and partial shafts (14a) and (14b) are coaxially united to form the integral shaft (14) at a junction (18) by friction welding.

Abstract: A rotor for a synchronous motor, having a plurality of first magnetic poles (19) formed by a plurality of permanent magnets respectively and disposed at practically equal circumferential intervals on the outer circumference of a yoke (18) fixed to a rotatable motor shaft (14), and a second magnetic pole (18a) projecting radially from the yoke (18) adjacently to each first magnetic pole (19) so as to form a pair of a first magnetic pole (19) and the second magnetic pole (18a), wherein the shape of the pole face of each second magnetic pole (18a) is decided so that the magnetic flux distribution established by a pair of the first magnetic pole (19) and the second magnetic pole (18a) is practically equivalent to a sinusoidal magnetic flux distribution in the sweeping effect by the armature coils of each phase of the stator (11).

Abstract: A permanent-magnet field rotor (10) includes a plurality of permanent magnets (18) disposed in a radial fashion, and yokes (19) disposed between each two successive permanent magnets (18) and made of a lot of sheet elements (20). The method of manufacturing the permanent-magnet field rotor comprises the step of stacking a lot of same shaped thin plate members (25) each having a plurality of sectoral york element portions (26) arranged in a radial fashion and link portions (27) each linking the outer circumferential edges of each two successive york element portions (26) to one another so as to define therebetween a permanent magnet receiving slot (29). In the state where permanent magnets (18) are inserted in the slots (29) of the stacked thin plate members (25), respectively, the stacked thin plate members (25) are firmly fixed to each other.

Abstract: There is disclosed a system for controlling a plurality of motors including a spindle motor of a machine tool to rotate synchronously at command speeds. The system comprises a numerical control unit for generating as positional commands trains of distributed pulses having frequencies corresponding to commanded speeds of rotation respectively for the motors, positional control feedback circuits respectively for the motors for producing speed command outputs from the trains of distributed pulses and detected signals indicative of positions of the motors, and speed control feedback circuits respectively for the motors for controlling the speed of the motors based on the speed command outputs and detected signals indicative of speeds of rotation of the motors.

Abstract: A synchronous rotary machine comprising a stacked stator iron core (21) made of a number of thin plates stacked in the axial direction. The stator iron core forms a part of the outer shell of the synchronous rotary machine. A winding (23) is wound around the stator iron core. A pair of brackets (24, 25) are attached to the opposite ends of the stator iron core. A rotor assembly (29) is rotatably supported on the brackets through bearings mounted to the brackets, respectively. The brackets and stator iron core are tightened in the axial direction thereof and firmly fixed to each other. At least two rods (31) having the same length are provided on the stator iron core. Each of the rods extends through the stator iron core in the axial direction. When the stator iron core is contracted to a predetermined length, the opposite end surfaces thereof abut against the brackets, respectively, and limit the distance between the brackets.

Abstract: A pulse coder comprises a rotating member (1) on which first and second magnetic patterns (221, 222; 221', 222') are formed and a fixed member (3) on which first and second magnetoresistance patterns (MR5, MR6) are formed. When the first and second magnetic patterns of the rotating member directly face the first and second magnetoresistance patterns, respectively, of the fixed member, the first and second magnetoresistance patterns have a minimum resistance value and a maximum resistance value, respectively. The first and second magnetic patterns are constructed by alternately and irregularly arranging strong magnetic field generating areas and weak magnetic field generating areas.

Abstract: A rotor structure comprising a shaft and a magnetic pole assembly comprising radially disposed permanent magnets and yokes. The magnetic pole assembly is supported by the shaft through end plates. The end plate has a recess to receive the end of the magnetic pole assembly. The magnetic pole assembly can be fit into the end plates.

Abstract: Through holes (11, 12, 13 . . . ) are made at predetermined locations of a stator core (1). Reinforcing bars are inserted thereinto while fixed to the stator core by welding (81, 82, 83 . . . ). The stator core is supported between a front bracket (31) and a rear bracket (32) from both sides. Front side tap bolts (91, 92, 93 . . . ) and rear side tap bolts (61, 62, 63 . . . ) are engaged through the front bracket and the rear bracket with internal threads of both ends of the reinforcing bars, thereby fixing in place the stator core, front bracket, and rear bracket. By the foregoing structure, it is possible to improve the heat radiation action of a stator core, and also achieve a compacter motor.

Abstract: In a photoelectric converter-type pulse encoder comprising a light-entrance portion (13, 13'), a rotating slit plate (12) on which a lattice plate receiving light from the light-entrance portion (13, 13') is formed, a fixed slit plate (11) on which a lattice plate arranged to face the lattice plate of the rotating slit plate is formed, and a light-receiving portion (14, 14') arranged below the fixed slit plate, light is emitted from a light-emitting circuit to the light-entrance portion (13, 13') through the light fibers (17), and the light received by the light-receiving portion (14, 14') is introduced into a light-receiving circuit through the light fibers (17), thereby adjustment of the amount of light is made easier, the pulse generation in response to the rotating speed is ensured, and the rotating speed is detected with a high precision.

Abstract: In a non-contacting, speed-detecting device of a DC generator type; comprising a cylindrical permanent magnet rotator 1 having N and S poles distributing alternatingly in the circumferential direction, a stator 2 facing said rotator 1 in which stator output windings 4 are wound, a permanent magnet 3 for location rotating coaxially with the rotator 1, and magnetic induction switches 5 positioned close to the circumference of the magnet 3; switching the flat portions of the multi-phase trapezoid AC signals generated in the output windings by switches 5 in response to the rotating position of the magnet 3 for location; and obtaining a DC voltage proportional to the speed; the S pole regions and the N pole regions of the magnet 3 for location are formed continuously so that the magnetic field is inverted steeply from one polarity to another polarity, and the ratio of the width of the S pole regions and the width of the N pole regions is selected to be a value other than one, whereby only the flat portions of the

Abstract: A tachometer generator comprising a generator section for producing rectangular polyphase alternating voltages having a peak value which is proportional to the speed of the rotor, and a commutator section including contactless change-over switches for successively transferring the alternating voltages from the generator section, and sensors for producing switching signals which actuate the change-over switches in accordance with the rotational position of the rotor of the generator section. In the commutator section the sensors are equivalent in number to the change-over switches and comprise Hall devices arrayed about a rotary shaft which is coupled to the generator section. The alternating voltages which are obtained successively from the coils of the generator section as the rotary shaft rotates, are transferred in order by the change-over switches to produce a speed signal, in analog form; which is proportional to the rotating speed of the rotor.

Abstract: A positioning control system which has a servo system provided with a position feedback system for detected positional information and a velocity feedback system for detected velocity information of a motor and in which the motor is driven by the servo system in accordance with commanded positional information to position a movable machine part of a numerical-controlled machine. The disparity between the detected velocity of the movable machine part and the detected motor velocity is fed back to the control input side of the motor, thereby suppressing vibration of the movable machine part at the moment of completion of the positioning operation.

Abstract: The time for positioning of a machine under numerical control is determined so that the positioning is finished at the moment when the amplitude of vibration of the machine is reduced to zero. In the thus predetermined time at least accelerating control and decelerating control are conducted to achieve control for positioning the machine at a commanded position.