Rotational electric machine

Patent metadata

Field	Value
Publication number	US-11050331-B2
Application number	US-201916392101-A
Country	US
Kind code	B2
Filing date	Apr 23, 2019
Priority date	Apr 27, 2018
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A brushless winding field rotational electric machine includes: a stator, held to a case, including an alternating-current coil configured to generate a rotation magnetic field by alternating current; a field core, held to the case, including a field coil to be excited by direct current; and a rotor on an outer periphery of a rotation member and rotatably held about a rotational axis relative to the stator and field coil. The field coil includes a plurality of coil winding layers stacked in a radial direction of the rotational axis. A cross-sectional area along an axial direction of the rotational axis, of a coil winding layer closest to the rotational axis in the radial direction of the rotational axis is smaller than a cross-sectional area along the axial direction of the rotational axis, of a coil winding layer farthest from the rotational axis in the radial direction of the rotational axis.

First claim

The invention claimed is:

1. A brushless winding field rotational electric machine positioned between a rotation member and a case enclosing the rotation member comprising:
a stator, which is held to the case, including an alternating-current coil configured to generate a rotation magnetic field by alternating current;
a field core, which is held to the case, including a field coil to be excited by direct current; and
a rotor disposed on an outer periphery of the rotation member and rotatably held about a rotational axis thereof relative to the stator and
the field coil, wherein the field coil includes a plurality of coil winding layers stacked in a radial direction of the rotational axis,
a cross-sectional area along an axial direction of the rotational axis, of a coil winding layer closest to the rotational axis in the radial direction among the plurality of coil winding layers is smaller than a cross-sectional area along the axial direction, of a coil winding layer farthest from the rotational axis in the radial direction,
a cross-sectional area of the plurality of coil winding layers along the radial direction of the coil winding layer closest to the rotor in the axis direction is smaller than a cross-sectional area of the plurality of coil winding layers along the radial direction of the coil winding layer farthest from the rotor in the axis direction,
a magnetic path includes a first magnetic path and a second magnetic path,
the first magnetic path extends in the axial direction of the rotational axis in the field core so that magnetic flux flows from the rotor toward the field core,
the second magnetic path extends in the axial direction of the rotational axis in the field core and disposed with a gap from the first magnetic path in the radial direction so that magnetic flux flows from the field core toward the rotor, and
the field coil is disposed from a first end portion of the gap closer to the rotor to a second end portion farther from the rotor in the axial direction.

2. The rotational electric machine according to claim 1 , wherein
wire winding starts at one end of a coil winding layer closest to the rotational axis among the plurality of coil winding layers in the axial direction of the rotational axis, and ends at one end of a coil winding layer farthest from the rotational axis among the plurality of coil winding layers in the axial direction of the rotational axis.

3. A brushless winding field rotational electric machine positioned between a rotation member and a case enclosing the rotation member comprising:
a stator, which is held to the case, including an alternating-current coil configured to generate a rotation magnetic field by alternating current;
a field core, which is held to the case, including a field coil to be excited by direct current; and
a rotor disposed on an outer periphery of the rotation member and rotatably held about a rotational axis relative to the stator and
the field coil, wherein the field coil includes a plurality of coil winding layers stacked in a radial direction of the rotational axis,
the plurality of coil winding layers include: a first coil winding layer; and a second coil winding layer adjacent to the first coil winding layer in the radial direction of the rotational axis and having a dimension different from a dimension of the first coil winding layer in an axial direction of the rotational axis,
the field coil further includes a first surface facing the rotor in the axial direction and a second surface opposed to the first surface in the axial direction, the first surface being smaller than the second surface,
a magnetic path includes a first magnetic path and a second magnetic path,
the first magnetic path extends in the axial direction of the rotational axis in the field core so that magnetic flux flows from the rotor toward the field core,
the second magnetic path extends in the axial direction of the rotational axis in the field core and disposed with a gap from the first magnetic path in the radial direction of the rotational axis so that magnetic flux flows from the field core toward the rotor, and
the field coil is disposed completely within the field core from a first end portion of the gap closer to the rotor to a second end portion farther from the rotor in the axial direction of the rotational axis.

4. The rotational electric machine according to claim 3 , wherein
wire winding starts at one end of a coil winding layer closest to the rotational axis among the plurality of coil winding layers in the axial direction of the rotational axis, and ends at one end of a coil winding layer farthest from the rotational axis among the plurality of coil winding layers in the axial direction of the rotational axis.

Assignees

• Exedy Corp

Inventors

• Katsura Hitoshi
• Kitamura Taichi
• Uemura Kimitaka

Classifications

• H02K19/26

  characterised by the arrangement of exciting windings · CPC title

• H02K19/12 Primary

  characterised by the arrangement of exciting windings, e.g. for self-excitation, compounding or pole-changing · CPC title

• H02K19/24

  with variable-reluctance soft-iron rotors without winding · CPC title

• F02N11/04

  the motors being associated with current generators · CPC title

• H02K3/28 Primary

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title