Motor core and motor using the same
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorHiroyasu Fujinaka
Life of this patent
Estimating the term…
Abstract
A motor generating cogging torque has one-quarter the cycle of basic cogging torque and an extremely small absolute value. First, in order to reduce the cycle of the cogging torque to one-half the cycle of the basic cogging torque, a basic configuration of the core is determined by setting opening angles of its slots to an appropriate electrical angle ranging from 80° to 95° and from 20° to 35°. Next, to produce the above-mentioned effects, an angular displacement of one-quarter the cycle of the basic cogging torque is provided in the motor. Furthermore, polarizing the core with a skew angle equal to one-half or less the cycle of the basic cogging torque at the same time allows the cogging torque to be reduced effectively while decrease in efficiency is minimized.
Claims10
A core for use in a motor, said motor including N and S magnetic poles for generating a magnetic field to which said core is opposed, said core comprising:
- a plurality of slots formed in said core, said slots have an electrical angle which is one of:
- a) between 80 degrees and 95 degrees;
- and
- b) between 20 degrees and 35 degrees
- a number of said magnetic poles is 2m and a number of said slot is 3n (m and n are integers, m is greater than or equal to 4)
- wherein said core is configured by combining P core shapes each having their respective slots displaced by an angle equal to one-2P-th the cycle of basic cogging torque ((180/n·k)° in mechanical angle, where k is a least common multiple of 2m and 3n).
A core for use in a motor, said motor including N and S magnetic poles for generating a magnetic field to which said core is opposed, said core comprising:
- a plurality of slots formed in said core, said slots have an electrical angle which is one of:
- a) between 80 degrees and 95 degrees;
- and
- b) between 20 degrees and 35 degrees
- wherein a number of magnetic poles is 2m and a number of slots of said core is 3n (m and n are integers),
- wherein said core is configured by combining j core shapes each having their slots displaced by an angle equal to one-2j-th (j is an integer equal to 3 or more) the cycle of basic cogging torque ((180/j·k)° in mechanical angle, where k is a least common multiple of 2m and 3n).
A motor including:
- (a) magnetic field generating means having N and S magnetic poles for generating a magnetic field;
- and
- (b) a core made of magnetic material and opposed to said magnetic field generating means;
- wherein one of said magnetic field generating means and said core rotates with respect to the other,
- wherein a number of said magnetic poles is 2m and a number of slots of said core is 3n (m and n are integers, m≧4),
- a plurality of slots formed in said core, said slots have an electrical angle which is one of:
- a) between 80 degrees and 95 degrees;
- and
- b) between 20 degrees and 35 degrees
- wherein said core is configured by combining P core shapes each having the slots displaced by an angle equal to one-2P-th the cycle of basic cogging torque ((180/n·k)° in mechanical angle, where k is a least common multiple of 2m and 3n).
A motor including:
- (a) magnetic field generating means having N and S magnetic poles for generating a magnetic field;
- and
- (b) a core made of magnetic material and opposed to said magnetic field generating means;
- wherein one of said magnetic field generating means and said core rotates with respect to the other,
- wherein in a case where a number of said magnetic poles is 2m and a number of slots of said core is 3n (m and n are integers),
- a plurality of slots formed in said core, said slots have an electrical angle which is one of:
- a) between 80 degrees and 95 degrees;
- and
- b) between 20 degrees and 35 degrees
- wherein said core is configured by combining j core shapes each having the slots displaced by an angle equal to one-2j-th (j is an integer equal to 3 or more) the cycle of basic cogging torque ((180/j·k)° in mechanical angle, where k is a least common multiple of 2m and 3n).
Dependencies are inferred from the claim text.