摘要:
A permanent-magnet electric rotating machine (1) with a concentrated winding stator, comprising: a stator (2) having a plurality of stator magnetic poles (51-62) formed so as to extend radially from an annular yoke portion (40) of a stator iron core (4), and windings (5) mounted on the stator magnetic poles; and a rotor (3) having a permanent magnet (21) with a plurality of magnetic poles and rotatably held so as to face the stator through an air gap. Each of the stator magnetic poles (51-62) has a straight shape having a width which is made constant over a whole length, small grooves (42a,42b) are formed in each of the stator magnetic poles in symmetrical positions on opposite sides and near a top end portion of the stator magnetic pole, a bottom portion of each slot portion defined by adjacent ones of the stator magnetic poles and the yoke is formed triangularly. Each of the stator windings (5) is constituted so that a winding having a predetermined number of turns and winding being formed so as to be fittable to each of the stator magnetic poles is mounted on the stator magnetic pole through an insulator (6), and wedges (13) are fitted to the small grooves (42) formed in the stator magnetic poles.
摘要:
An absolute encoder wherein tracks (3-1, 3-2) are arranged side-by-side on a magnetic drum (1) in the axial direction thereof, and absolute patterns of circulatory random sequence codes are divided and recorded on the tracks (3-1, 3-2), respectively. An additional track (3-3) for generating sinewaves of two phases in synchronism with the reading of the absolute patterns is provided on the magnetic drum (1), so that an output can be obained by combining a coarse value of an absolute position obtained from the tracks (3-1, 3-2) and a fine value of an absolute position obtained from the additional track (3-3). The absolute patterns are detected from the two tracks (3-1, 3-2) recorded on the magnetic drum (1) by magnetic resistive elements (MR) connected with each other to form circuits each having a three-terminal. Terminals of the magnetic resistive elements (MR) are connected through a common line with an electric power source in order to prevent the lines from being crossed.
摘要:
A motor has a stator (4) and a rotor (3), the stator (4) having cores (9A) and drive coils (1) which generate magnetic fields for rotating the rotor (3). The stator (4) also has a yoke (9B,9C) surrounding the rotor (3) and the rotor (3) is positioned such that it is closer to one part (9B) of the outer periphery of the yoke than another part (9B) of the yoke. Such a motor is particularly suitable for use in a disk drive unit as a spindle motor (2) for rotating the disk (1). Then an actuator (12) for moving a head (11) may be located adjacent the part (9B) of the outer periphery of the yoke (9b,9C) which is closest to the rotor. This permits the head (11) to approach closely the axis of rotation of the disk (1) without the spindle motor (2) interfering with the movement of the head (11). The continuous yoke (9B,9C) prevents magnetic flux leakage from the spindle motor interfering with the actuator (12). The actuator (12) may itself have a yoke (9D) integral with the yoke (9B,9C) of the spindle motor (2), and/or other components in common.
摘要:
A multi-polar rotary machine comprising a stator; and a cylindrical outer rotor (10) arranged concentrically with the stator (6) and with an air gap therebetween. The stator (6) has two splitted stator elements (4, 5) and a ring shaped permanent magnet (3) held between the stator elements (4, 5) and magnetized so as to form N and S poles in the axial direction of the stator (6). A plurality of small stator teeth A and A ¯ and B ¯ and B separated in the axial direction of the stator (6) from each other, respectively, are formed on the outer peripheral surface of the splitted stator elements (4, 5). Stator windings (12, 13) for A phase and B phase are wound around the stator elements (4, 5), respectively. The rotor (10) has a plurality of small rotor teeth similar in number to the small stator teeth. The small stator teeth A, A ¯ , B ¯ and B are circumferentially shifted from said small rotor teeth by a 1/4 pitch of the small stator teeth, respectively. Each of the stator (6) and rotor (10) is formed of pressed powder consisting of soft magnetic material, and of resin and / or inorganic material. A ratio of a thickness of the small stator teeth A ¯ in the axial direction of the stator (6) to a thickness of the small stator teeth A in the axial direction of the stator (6) or a ratio of a thickness of the small stator teeth B ¯ in the axial direction of the stator to a thickness of the small stator teeth B in the axial direction of the stator (6) is set to a value smaller than 1 so as to equalize substantially in mean permeance both small stator teeth A and A ¯ or B ¯ and B to each other.
摘要:
A multi-polar rotary machine comprising a stator; and a cylindrical outer rotor (10) arranged concentrically with the stator (6) and with an air gap therebetween. The stator (6) has two splitted stator elements (4, 5) and a ring shaped permanent magnet (3) held between the stator elements (4, 5) and magnetized so as to form N and S poles in the axial direction of the stator (6). A plurality of small stator teeth A and A ¯ and B ¯ and B separated in the axial direction of the stator (6) from each other, respectively, are formed on the outer peripheral surface of the splitted stator elements (4, 5). Stator windings (12, 13) for A phase and B phase are wound around the stator elements (4, 5), respectively. The rotor (10) has a plurality of small rotor teeth similar in number to the small stator teeth. The small stator teeth A, A ¯ , B ¯ and B are circumferentially shifted from said small rotor teeth by a 1/4 pitch of the small stator teeth, respectively. Each of the stator (6) and rotor (10) is formed of pressed powder consisting of soft magnetic material, and of resin and / or inorganic material. A ratio of a thickness of the small stator teeth A ¯ in the axial direction of the stator (6) to a thickness of the small stator teeth A in the axial direction of the stator (6) or a ratio of a thickness of the small stator teeth B ¯ in the axial direction of the stator to a thickness of the small stator teeth B in the axial direction of the stator (6) is set to a value smaller than 1 so as to equalize substantially in mean permeance both small stator teeth A and A ¯ or B ¯ and B to each other.
摘要:
A motor has a stator (4) and a rotor (3), the stator (4) having cores (9A) and drive coils (1) which generate magnetic fields for rotating the rotor (3). The stator (4) also has a yoke (9B,9C) surrounding the rotor (3) and the rotor (3) is positioned such that it is closer to one part (9B) of the outer periphery of the yoke than another part (9B) of the yoke. Such a motor is particularly suitable for use in a disk drive unit as a spindle motor (2) for rotating the disk (1). Then an actuator (12) for moving a head (11) may be located adjacent the part (9B) of the outer periphery of the yoke (9b,9C) which is closest to the rotor. This permits the head (11) to approach closely the axis of rotation of the disk (1) without the spindle motor (2) interfering with the movement of the head (11). The continuous yoke (9B,9C) prevents magnetic flux leakage from the spindle motor interfering with the actuator (12). The actuator (12) may itself have a yoke (9D) integral with the yoke (9B,9C) of the spindle motor (2), and/or other components in common.