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US 7,067,954 B2Granted
Automotive rotary electric machine
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsMasaru Kuribayashi, Yoshihito Asao
Life of this patent
Estimating the term…
Abstract
First and second permanent magnets are each disposed between circumferentially-adjacent pairs of first and second claw-shaped magnetic pole portions so as to contact a circumferential side surface of the first and second claw-shaped magnetic pole portions. An axial length (L1) of a stator core relative to an axial distance (L2) between facing end surfaces of first and second yoke portions is constructed so as to satisfy an expression L1>L2.
Claims4
An automotive rotary electric machine comprising:
- a rotor having:
- a rotor core having:
- a cylindrical boss portion;
- a first yoke portion disposed so as to extend radially outward from a first axial end of said boss portion;
- a second yoke portion disposed so as to extend radially outward from a second axial end of said boss portion;
- a plurality of first claw-shaped magnetic pole portions each disposed so as to extend toward said second axial end from said first yoke portion, arranged at a predetermined pitch in a circumferential direction, and having a radially-outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides;
- and
- a plurality of second claw-shaped magnetic pole portions each disposed so as to extend toward said first axial end from said second yoke portion, arranged at a predetermined pitch in a circumferential direction, having a radially-outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides, and arranged so as to alternate with said first claw-shaped magnetic pole portions in a circumferential direction;
- and
- a field winding installed on said boss portion,
- said rotor being disposed so as to be rotatable around a shaft inserted through a central axial position of said boss portion;
- a stator having:
- a cylindrical stator core;
- and
- a stator winding installed in said stator core,
- said stator core being disposed so as to surround said rotor core coaxially;
- and
- permanent magnets constituted by first and second permanent magnets disposed between each circumferentially-adjacent pair of said first and second claw-shaped magnetic pole portions so as to contact a circumferential side surface of said first and second claw-shaped magnetic pole portions,
- wherein an axial length (L1) of said stator core relative to an axial distance (L2) between facing end surfaces of said first and second yoke portions is constructed so as to satisfy an expression L1>L2,
- wherein said first and second permanent magnets are each formed so as to have a cross-sectional shape positioned inside a circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions,
- wherein said first and second permanent magnets are each formed so as to have a shape matching a tip portion of said circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions;
- and
- wherein axial positions of a tip portion and a base end portion of said first permanent magnets are aligned with axial positions of a base end portion and a tip portion of said second permanent magnets respectively.
20 more elements
An automotive rotary electric machine comprising:
- a rotor having:
- a rotor core having:
- a cylindrical boss portion;
- a first yoke portion disposed so as to extend radially outward from a first axial end of said boss portion;
- a second yoke portion disposed so as to extend radially outward from a second axial end of said boss portion;
- a plurality of first claw-shaped magnetic pole portions each disposed so as to extend toward said second axial end from said first yoke portion, arranged at a predetermined pitch in a circumferential direction, and having a radially outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides;
- and
- a plurality of second claw-shaped magnetic pole portions each disposed so as to extend toward said first axial end from said second yoke portion, arranged at a predetermined pitch in a circumferential direction,
- having a radially outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential long side, and two oblique sides, and arranged so as to alternate with said first claw-shaped magnetic pole portions in a circumferential direction;
- and
- a field winding installed on said boss portion,
- said rotor being disposed so as to be rotatable around a shaft inserted through a central axial position of said boss portion:
- a stator having:
- a cylindrical stator core;
- and
- a stator winding installed in said stator core,
- said stator core being disposed so as to surround said rotor core coaxially;
- and
- permanent magnets constituted by first and second permanent magnets disposed between each circumferentially adjacent pair of said first and second claw-shaped magnetic pole portions so as to contact a circumferential side surface of said first and second claw-shaped magnetic pole portions,
- wherein an axial length (L1) of said stator core relative to an axial distance (Lg) between facing end surfaces of said first and second yoke portions is constructed so as to satisfy an expression L1>Lg,
- wherein said first and second permanent magnets are each formed so as to have a cross-sectional shape positioned inside a circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions, and
- wherein a portion of each of said first and second permanent magnets facing an inner radial side of a root portion of said contacting first and second claw-shaped magnetic pole portions is cut away and removed.
19 more elements
An automotive rotary electric machine comprising:
- a rotor having:
- a rotor core having:
- a cylindrical boss portion;
- a first yoke portion disposed so as to extend radially outward from a first axial end of said boss portion;
- a second yoke portion disposed so as to extend radially outward from a second axial end of said boss portion;
- a plurality of first claw-shaped magnetic pole portions each disposed so as to extend toward said second axial end from said first yoke portion, arranged at a predetermined pitch in a circumferential direction, and having a radially outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side a base end portion circumferential long side, and two oblique sides;
- and
- a plurality of second claw-shaped magnetic pole portions each disposed so as to extend toward said first axial end from said second yoke portion, arranged at a predetermined pitch in a circumferential direction, having a radially outermost circumferential surface shape formed so as to have a trapezoidal shape constituted by a tip end circumferential short side, a base end portion circumferential long side, and two oblique sides and arranged so as to alternate with said first claw-shaped magnetic pole portions in a circumferential direction;
- and
- a field winding installed on said boss portion,
- said rotor being disposed so as to be rotatable around a shaft inserted through a central axial position of said boss portion;
- a stator having:
- a cylindrical stator core;
- and
- a stator core being disposed so as to surround said rotor core coaxially;
- and
- permanent magnets constituted by first and second permanent magnets disposed between such circumferential adjacent pair of said first and second claw-shaped magnetic pole portions so as to contact a circumferential side surface of said first and second claw-shaped magnetic pole portions,
- wherein an axial length (L1) of said stator core relative to an axial distance (Lg) between facing end surfaces of said first and second yoke portions is constructed so as to satisfy an expression L1>Lg,
- wherein said first and second permanent magnets are constructed such that each has a cross-sectional shape having a shape that is substantially similar to a circumferential side surface shape of said contacting first and second claw-shaped magnetic pole portions;
- and
- a ratio (Sm/Sp) occupied by a surface area (Sm) of said first and second permanent magnets relative to a circumferential side surface surface area (Sp) of said first and second claw-shaped magnetic pole portions satisfies an expression Sm/Sp≦1.0.
18 more elements
Dependencies are inferred from the claim text.