HYBRID PERMANENT MAGNET TYPE ELECTRIC ROTATING MACHINE AND MANUFACTURING METHOD THEREOF

Abstract

A stator is constructed by winding excitation coils around respective main poles. A rotor is constructed by fixing a first rotor unit, which consists of a pair of rotor cores and a magnetic material sandwiched between the rotor cores, and a second rotor unit, which has the same construction as the first rotor unit, to a rotation shaft. The rotor is assembled to the stator to form an assembled body. The magnet material of the first rotor unit is magnetized in the axial direction by a magnetizing flux passing through a half of the assembled body in the axial direction. The magnet material of the second rotor unit is magnetized in the axial direction in an opposite polarity by a magnetizing flux passing through the remaining half of the assembled body in the axial direction.

Description

DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a longitudinal sectional view of a stepping motor to which the manufacturing methods of an HB permanent magnet type electric rotating machine concerning first, second, third, and fourth embodiments of the present invention are applied,

FIG. 2 is a front view of the stepping motor shown in FIG. 1 showing the relationship between a rotor core and a stator core,

FIG. 3 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the first embodiment of the present invention,

FIG. 4 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the second embodiment of the present invention,

FIG. 5 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the third embodiment of the present invention,

FIG. 6 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the fourth embodiment of the present invention,

FIG. 7 is a longitudinal sectional view of a stepping motor to which the manufacturing methods of an HB permanent magnet type electric rotating machine concerning fifth, sixth, seventh, eighth, and ninth embodiments of the present invention are applied,

FIG. 8 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the fifth embodiment of the present invention,

FIG. 9 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the sixth embodiment of the present invention,

FIG. 10 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the seventh embodiment of the present invention,

FIG. 11 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the eighth embodiment of the present invention,

FIG. 12 is a longitudinal sectional view of a magnetizing device used in the manufacturing method of the ninth embodiment of the present invention,

FIG. 13 is a front view of the magnetizing device shown in FIG. 12,

FIG. 14 is a longitudinal sectional view of a conventional hybrid type stepping motor, and

FIG. 15 is a front view of the stepping motor shown in FIG. 14 showing the relationship between a rotor core and a stator core.

Claims

1. A manufacturing method of a hybrid permanent magnet type electric rotating machine comprising: constructing a stator of two-phase/four-pole, three-phase/three-pole, or five-phase/five-pole by winding excitation coils around respective main poles that are radially formed on a polygonal or annular magnetic substance of a stator core, and by forming a plurality of inductors on the tip portion of each of said main poles;constructing a rotor by fixing a first rotor unit, which consists of a pair of rotor cores arranged with deviation of ½ the pitch of small teeth formed around said rotor cores in the circumferential direction and a magnetic material sandwiched between said rotor cores, and a second rotor unit, which has the same construction as said first rotor unit, to a common rotation shaft so that the positions of the small teeth of the adjacent rotor cores of said first and second rotor units are identical;assembling said rotor to said stator with a predetermined air gap therebetween to make an assembled body so that said rotor is free to rotate by means of a first bracket arranged at the outside of said first rotor unit and a second bracket arranged at the outside of said second rotor unit;magnetizing said magnet material of said first rotor unit in the axial direction by a magnetizing flux passing through said first bracket and said first rotor unit in the axial direction, passing through said stator core in a direction perpendicular to the axial direction, and passing through a first magnetizing path that connects the portion including said rotation shaft at the side of said first bracket to the outer circumference of said stator core through a yoke positioned outside said assembled body, whereby the magnetizing flux passes through a half of said assembled body in the axial direction; andmagnetizing said magnet material of said second rotor unit in the axial direction in a polarity opposite to that of said magnet material of said first rotor unit by a magnetizing flux passing through said second bracket and said second rotor unit in the axial direction, passing through said stator core in a direction perpendicular to the axial direction, and passing through a second magnetizing path that connects the portion including said rotation shaft at said side of said second bracket to the outer circumference of said stator core through a yoke positioned outside said assembled body, whereby the magnetizing flux passes through the remaining half of said assembled body in the axial direction.

2. The manufacturing method of a hybrid permanent magnet type electric rotating machine according to claim 1, wherein said magnet material of said first rotor unit and said magnet material of said second rotor unit are magnetized at the same time by means of a magnetizing device that is provided with both of said first and second magnetizing paths.

3. The manufacturing method of a hybrid permanent magnet type electric rotating machine according to claim 1, wherein said magnet material of said first rotor unit is magnetized by means of a magnetizing device that is provided with one of said first and second magnetizing paths, and then, said magnet material of said second rotor unit is magnetized after said assembled body is removed from said magnetizing device and is reset thereto in a reversed orientation in the axial direction.

4. A manufacturing method of a hybrid permanent magnet type electric rotating machine comprising: constructing a stator of two-phase/four-pole, three-phase/three-pole, or five-phase/five-pole by winding excitation coils around respective main poles that are radially formed on a polygonal or annular magnetic substance of a stator core, and by forming a plurality of inductors on the tip portion of each of said main poles;constructing a rotor by fixing a first rotor unit, which consists of a pair of rotor cores arranged with deviation of ½ the pitch of small teeth formed around said rotor cores in the circumferential direction and a magnetic material sandwiched between said rotor cores, and a second rotor unit, which has the same construction as said first rotor unit, to a common rotation shaft so that the positions of the small teeth of the adjacent rotor cores of said first and second rotor units are identical;magnetizing said magnet material of said first rotor unit in the axial direction by a magnetizing flux passing through said magnet material of said first rotor unit in the axial direction, and passing through a first magnetizing path that connects a side surface or a portion including an outer circumference of the outside rotor core of said first rotor unit to the outer circumference of the inside rotor core of said first rotor unit through a yoke positioned outside said rotor;magnetizing said magnet material of said second rotor unit in the axial direction in a polarity opposite to that of said magnet material of said first rotor unit by a magnetizing flux passing through said magnet material of said second rotor unit in the axial direction, and passing through a second magnetizing path that connects a side surface or a portion including an outer circumference of the outside rotor core of said second rotor unit to the outer circumference of the inside rotor core of said second rotor unit through a yoke positioned outside said rotor; andassembling said rotor to said stator with a predetermined air gap therebetween so that said rotor is free to rotate by means of a first bracket arranged at the outside of said first rotor unit and a second bracket arranged at the outside of said second rotor unit.

5. The manufacturing method of a hybrid permanent magnet type electric rotating machine according to claim 4, wherein said magnet material of said first rotor unit and said magnet material of said second rotor unit are magnetized at the same time by means of a magnetizing device that is provided with both of said first and second magnetizing paths.

6. The manufacturing method of a hybrid permanent magnet type electric rotating machine according to claim 4, wherein said magnet material of said first rotor unit is magnetized by means of a magnetizing device that is provided with one of said first and second magnetizing paths, and then, said magnet material of said second rotor unit is magnetized after said rotor is removed from said magnetizing device and is reset thereto in a reversed orientation in the axial direction.

7. The manufacturing method of a hybrid permanent magnet type electric rotating machine according to one of claims 1 through 6, wherein an electric conductive member is installed between said first rotor unit and said second rotor unit when said rotor is constructed.

8. A hybrid permanent magnet type electric rotating machine comprising: a stator of two-phase/four-pole, three-phase/three-pole, or five-phase/five-pole, that is constructed by winding excitation coils around respective main poles that are radially formed on a polygonal or annular magnetic substance of a stator core, and by forming a plurality of inductors on the tip portion of each of said main poles; anda rotor that is constructed by fixing a first rotor unit, which consists of a pair of rotor cores arranged with deviation of ½ the pitch of small teeth formed around said rotor cores in the circumferential direction and a magnetic material sandwiched between said rotor cores, a second rotor unit, which has the same construction as said first rotor unit, to a common rotation shaft so that an electric conduction member is sandwiched between said first and second rotor units and so that the positions of the small teeth of the adjacent rotor cores of said first and second rotor units are identical,wherein said rotor is assembled to said stator with a predetermined air gap therebetween so that said rotor is free to rotate by means of a first bracket arranged at the outside of said first rotor unit and a second bracket arranged at the outside of said second rotor unit.

9. The hybrid permanent magnet type electric rotating machine according to claim 8, wherein said electric conductive member is made from copper or aluminum and is formed as a disc-shaped member.