Satake Corporation

Satake Engineering Co., Ltd.

Yukio Onogi

Toshihiko Satake

Satoru Satake

Kenji Inoue

Yukio Hosaka

Masanori Matsuda

Hideo Yamashita

A brushless three-phase synchronous generator includes a stator having primary generating windings and stator excitation windings whose number of poles is odd-number times the number of poles of the primary generating windings. The generator further includes a cylindrical rotor on which a plurality of field windings are wound in a full-pitch concentrated winding form. The plurality of field windings are respectively short-circuited by the corresponding diodes. A plurality of field windings in which voltages of the same phase are induced based on the odd-order spatial higher harmonic magnetic fields are connected in parallel and further connected in parallel to the central field windings which effectively produce primary field magnetic fluxes. A circulating rectifier element is connected in parallel to the central field windings. Improvement in the waveforms of the primary magnetic fields can be achieved and self-excitation in the case where the single-phase loads are connected can be prevented from occurring while magnetic coupling of the rotor field windings to the spatial higher harmonic components of the armature reaction magnetic fields is effectively maintained well.

Brushless three-phase synchronous generator having enhanced rotor field

Multiple-stator induction synchronous motor

On a stator core, there are wound T-connection primary generating windings such that the second and third single-phase windings are respectively arranged at positions electrically orthogonal to the first single-phase winding. The winding number of the first single-phase winding is 31/2 times that of the second single-phase winding or the third single-phase winding. The stator excitation windings are also wound on the stator core, which are connected to the center taps of the primary generating windings through a control rectifier. A plurality of field windings are wound on a rotor core. The field windings are arranged at positions where they are magnetically coupled with both the odd-order spatial higher harmonic components of armature reaction magnetic fields produced by currents flowing in the primary generating windings and the static magnetic fields produced by current flowing in the stator excitation windings. Due to the T-connection primary generating windings, the generator is capable of simultaneously generating not only the three-phase outputs but also the single-phase three-line outputs.

Three-phase brushless self-excited synchronous generator with no rotor

On a stator core, there are wound primary generating windings of four (4) poles with a distributed full-pitch winding structure and stator excitation windings with a concentrated full-pitch winding structure, having the number of poles odd-number times the number of poles of the primary generating windings, that is, twelve (12) poles. The primary windings appropriately produce spatial higher harmonic components of the armature reaction magnetic fields. The excitation windings are connected to the center taps of the primary windings through a control rectifier. On a rotor core, six field windings of four poles. The field windings are arranged at positions where they are magnetically coupled with both static magnetic fields produced by the stator excitation windings and odd-order spatial higher harmonic components of armature reaction magnetic fields produced by the currents in the primary generating windings. The field windings are short-circuited by the diodes, respectively. In the brushless self-excited synchronous generator, the number of slots in each of the rotor and stator can be determined irrespective of the order number of the spatial higher harmonic components of the armature reaction magnetic fields. The generator is simple and rigid in its structure.

An induction synchronous motor includes a unitary rotor having first and second pole type rotor cores, first and second stators, a voltage phase shifting means, and DC magnetic excitation circuits. Both of the rotor cores are mounted on a common rotor axis with a predetermined space between them. The first and second rotor windings are wound on the first and second rotor cores, respectively. A plurality of diodes is each connected in parallel between series-connection nodes of the first and second rotor windings. A plurality of rotor conductors is provided on the peripheries of and extend through the first and second rotor cores. A pair of short-circuit rings short-circuits both ends of the plurality of rotor conductors. The first and second stators surround the first and second salient pole type rotor cores, respectively, and have the same number of poles as the first and second rotor cores. The voltage phase shifting means selectively produces a phase difference of 0.degree. for starting and accelerating operations and 180.degree. for synchronous operation. The DC magnetic excitation circuits face the first and second salient pole type rotor cores, and have a different number of poles from the first and second stators.

Brushless induction synchronous motor with two stators

A synchronous motor includes a unitary rotor, a first stator, a second stator and phase-changing switches. The unitary rotor has a first rotor portion formed by a first permanent magnet and a second rotor portion formed by a second permanent magnet and an induction type rotor and these first and second rotor portions are mounted on a common rotary axle with a predetermined space provided therebetween. The first stator faces the first rotor portion for producing a first rotating magnetic field. The second stator faces the second rotor portion for producing a second rotating magnetic field and is disposed such that, at the starting operation, the attracting action or the repelling action produced between the first rotating magnetic field and the first permanent magnet is canceled by the repelling action or the attracting action produced between the second rotating magnetic field and the permanent magnetic field. The phase-changing switches are associated with either one of the first stator or the second stator and set a phase difference of 0 degree or 180 degrees between the first rotating magnetic field and the second rotating magnetic field. Due to the cancellation action, any starting interference which may otherwise be caused by the permanent magnets is made negligible.

Synchronous motor with two permanent magnet rotor portions

An induction synchronous motor with two rotor cores and two stator cores includes a rotor having two mutually connected first rotor windings (31,31) of a predetermined number of poles and two mutually connected second rotor windings (33,34) connected of a different number of poles with respect to the number of poles of the first rotor windings; and two stators having two stator windings (21,22) of the number of poles identical with the number of poles of the first rotor windings (31,32) and two excitation windings (41,42) of the number of poles identical with the number of poles of the second rotor windings (33,34). The motor further includes a rectifier circuit (35) for rectifying outputs from the second rotor windings (33,34) and supplying the rectified voltages to the first rotor windings (31,32) at a synchronous operation. A phase shifter (SW1) associated with the first stator windings (21,22) produces a phase difference of 180.degree. between a rotating magnetic field around one of the rotor cores and that around the other one of the rotor cores. The motor starts based on a theory of an ordinary induction motor under a phase difference of 0.degree. and can operate as a synchronous motor after the rotating speed has reached its synchronous speed under the phase difference of 180.degree. produced by the phase shifter.

Dual-stator induction synchronous motor

A two-stator induction synchronous motor includes a unitary rotor having a first rotor assembly and a second rotor assembly each of which is formed by a permanent magnet and a rotor core. The first rotor assembly and the second rotor assembly respectively have a first pair of and a second pair of magnetic poles of the permanent magnets disposed in such a relative relation that the former and the latter are displaced by 180.degree. or 0.degree. with each other. The motor also includes a phase shifting means which produces a phase difference of 0.degree. or 180.degree. between a voltage induced in rotor conductive members by a rotating magnetic field generated around the first rotor assembly and a voltage induced in rotor conductive members by a rotating magnetic field generated around the second rotor assembly. The two permanent magnets are disposed in such a relation that the attracting or repelling action of one permanent magnet and the repelling or attracting action of the other permanent magnet cancel each other, so that the starting operation is not interfered with. The starting operation is the same as in an induction motor and the running operation is as in a synchronous motor.

Two-stator induction synchronous motor

An induction motor, including a single rotor formed in one-piece and first and second stators disposed side by side, has a phase changing device for varying the phase difference between the rotational magnetic field generated by the first stator and that generated by the second stator. The phase changing device comprises at least first and second short-circuiting switches for short-circuiting or disconnecting the series-junction nodes of the stator windings. The first switching produces a configuration intermediate to series delta and parallel Y (Wye), and the second completes the transformation from delta to Y. The motor presents three different torque curves suitable for starting operation, intermediate speed operation and normal or steady-state operation by the switching operation of the first- and second-switches.

Induction motor switchable between series delta and parallel wye

An induction motor including a single rotor formed in one-piece and first and second stators disposed side by side has a phase changing device for varying the phase difference between the rotational magnetic field generated by the first stator and that generated by the second stator. The phase changing device comprises a first-connection changing switch for making the interconnection of respective stator windings of the stators the first series delta-connection in which the phase difference is 0.degree. when it is in its closed-state and a second-connection changing switch for making the respective stator windings the second series data-connection in which the phase difference is 120.degree. when it is in its closed-state. When both the first- and second-connection changing switches are closed, the interconnection of the stator windings becomes a parallel Y (or star)-connection in which the phase difference produced is 60.degree.. During the motor operation, at least one of the first-switch and the second-switch is always kept in its closed-state. The motor exhibits three different torque curves suitable for starting operation, an intermediate speed operation and normal or steady-state operation by the switching operation of the first- and second-switches.

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Hiroshima, Japan

Yukio Onogi