Automotive rotary electric machine

Patent metadata

Field	Value
Publication number	US-10840752-B2
Application number	US-201715795382-A
Country	US
Kind code	B2
Filing date	Oct 27, 2017
Priority date	May 24, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

First side surfaces 22bb of first magnetic pole portions 22b and second side surfaces 23bb of second magnetic pole portions 23b that face each other in a circumferential direction are configured into parallel flat surfaces, first circumferentially tapered portions 25b are formed on circumferential shoulder portions of the first magnetic pole portions 22b, second circumferentially tapered portions 26b are formed on circumferential shoulder portions of the second magnetic pole portions 23b, and portions of the first and second circumferentially tapered portions 25b and 26b enter a region 24 in which the first side surfaces 22bb and the second side surfaces 23bb that face each other in the circumferential direction overlap when viewed from a direction that is perpendicular to the first side surfaces 22bb and the second side surfaces 23bb.

First claim

What is claimed is:

1. An automotive alternator comprising:
a rotor comprising:
a pole core that is fixed to a rotating shaft that is rotatably supported by a case, said pole core being disposed inside said case; and
a field coil that is mounted to said pole core; and

a stator comprising:
a stator core; and
a stator coil that is mounted to said stator core,

said stator being disposed inside said case so as to be coaxial to said rotor so as to surround said rotor,
wherein:
said pole core comprises a first pole core and a second pole core;
said first pole core comprises:
a disk-shaped first main body portion;
a first yoke that protrudes axially from a central portion of said first main body portion; and
a plurality of first claw-shaped magnetic poles that are disposed on an outer circumferential portion of said first main body portion at a uniform angular pitch in a circumferential direction;

said first claw-shaped magnetic poles each comprise:
a first root portion that protrudes radially outward from said outer circumferential portion of said first main body portion; and
a first magnetic pole portion that protrudes axially from an upper end of said first root portion;

said second pole core comprises:
a disk-shaped second main body portion;
a second yoke that protrudes axially from a central portion of said second main body portion; and
second claw-shaped magnetic poles that are equal in number to said first claw-shaped magnetic poles, said second claw-shaped magnetic poles being disposed on an outer circumferential portion of said second main body portion at a uniform angular pitch in a circumferential direction;

said second claw-shaped magnetic poles each comprise:
a second root portion that protrudes radially outward from said outer circumferential portion of said second main body portion; and
a second magnetic pole portion that protrudes axially from an upper end of said second root portion;

said first pole core and said second pole core are fixed to said rotating shaft in a state in which a protruding end of said first yoke and a protruding end of said second yoke are butted together, and in which said first magnetic pole portions and said second magnetic pole portions are arranged alternately;
a first side surface of said first magnetic pole portions and a second side surface of said second magnetic pole portions that face each other and overlap in an overlapping region in a circumferential direction are configured into parallel flat surfaces;
a circumferentially tapered portion is formed on a circumferential shoulder portion of at least one magnetic pole portion of said first magnetic pole portions and said second magnetic pole portions that face each other in said circumferential direction; and
a portion of said circumferentially tapered portion overlaps with the overlapping region when viewed from a direction that is perpendicular to said first side surface and said second side surface,
wherein said first pole core and said second pole core are configured so as to satisfy 0.05<Hcf/Dro<0.10, and 0.35<Lcf/Lp<0.42, where Lcf is a total sum of axial lengths of said first yoke and said second yoke when butted together, Hcf is a radial length of said first yoke from an outer circumferential surface to a bending boundary between said first root portion and said first magnetic pole portion, Lp is an axial length of said pole core, and Dro is a diameter of said pole core.

2. The automotive rotary electric machine according to claim 1 , wherein said circumferentially tapered portion is formed on a circumferential shoulder portion that is positioned forward in a direction of rotation of said pole core on all magnetic pole portions of a plurality of said first magnetic pole portions and said second magnetic pole portions.

3. The automotive rotary electric machine according to claim 2 , wherein said circumferentially tapered portion is formed on a circumferential shoulder portion that is positioned rearward in said direction of rotation of said pole core on all magnetic pole portions of said plurality of said first magnetic pole portions and said second magnetic pole portions.

4. The automotive rotary electric machine according to claim 2 , wherein said first pole core and said second pole core are identically shaped.

5. The automotive rotary electric machine according to claim 1 , wherein a lower side of said circumferentially tapered portion gradually displaces radially outward in an axially outward direction.

Assignees

• Mitsubishi Electric Corp

Inventors

• Imazawa Yoshiro
• Uesato Yuki

Classifications

• H02K19/22

  having windings each turn of which co-operates alternately with poles of opposite polarity, e.g. heteropolar generators · CPC title

• H02K1/12

  Stationary parts of the magnetic circuit · CPC title

• H02K1/26 Primary

  Rotor cores with slots for windings · CPC title

• H02K1/14

  Stator cores with salient poles · CPC title

• H02K7/10

  Structural association with clutches, brakes, gears, pulleys or mechanical starters · CPC title