Rotor of rotary electrical machine

A rotor of a rotary electrical machine, the rotor comprising:

• a rotation shaft;
• a field core attached to the rotation shaft and configured to integrally rotate with the rotation shaft, the field core comprising claw-shaped magnetic poles;
• an insulation bobbin secured to the field core and comprising:
• a winding portion;
• and
• flanges on both sides of the winding portion in an axial direction of the winding portion;
• and
• a field coil wound in a space region defined by the winding portion of the insulation bobbin and the flanges of the winding portion,
• wherein a winding-start receiving groove in which a winding-start lead wire of the field coil is received is formed in an inner surface of one of the flanges, and a holder is disposed on that one flange and located on a radially outer side of the winding-start receiving groove, the holder being formed with a holder groove continuous to the winding-start receiving groove and extending at an angle relative to a radial direction of the insulation bobbin, the winding-start lead wire of the field coil being received in the winding-start receiving groove and the holder groove and held by groove wall surfaces of the holder groove, the holder including parallel radially inner and outer arm extensions between which said lead wire is held, and further defining a detachment preventing section preventing radial separation by said lead wire;
• wherein at least one of the flanges which are respectively provided on both sides of the winding portion in the axial direction comprises a plurality of flanges formed at predetermined intervals in a circumferential direction of the insulation bobbin, and the holder is located in one of the predetermined intervals,
• wherein the holder is at a position corresponding to a valley between the magnetic poles of the field core.